WO2021024741A1 - Layered article and peeling method - Google Patents

Layered article and peeling method Download PDF

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Publication number
WO2021024741A1
WO2021024741A1 PCT/JP2020/027651 JP2020027651W WO2021024741A1 WO 2021024741 A1 WO2021024741 A1 WO 2021024741A1 JP 2020027651 W JP2020027651 W JP 2020027651W WO 2021024741 A1 WO2021024741 A1 WO 2021024741A1
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WIPO (PCT)
Prior art keywords
layer
sensitive adhesive
pressure
water
base material
Prior art date
Application number
PCT/JP2020/027651
Other languages
French (fr)
Japanese (ja)
Inventor
陽介 清水
尚史 小坂
量子 浅井
聖彦 渡邊
陽介 中西
Original Assignee
日東電工株式会社
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Publication of WO2021024741A1 publication Critical patent/WO2021024741A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/16—Layered products comprising a layer of synthetic resin specially treated, e.g. irradiated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/06—Interconnection of layers permitting easy separation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/29—Laminated material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • the present invention relates to a laminate and a peeling method.
  • an adhesive also referred to as a pressure-sensitive adhesive; the same applies hereinafter
  • the pressure-sensitive adhesive is widely used in various fields in the form of a pressure-sensitive adhesive sheet with a support having a pressure-sensitive adhesive layer on the support or in the form of a support-less pressure-sensitive adhesive sheet without a support. It's being used.
  • Adhesives are required to have various properties depending on the application. Among these characteristics, there are some that are difficult to achieve at a high level, for example, when trying to improve one characteristic, the other characteristic tends to decrease. As an example of such characteristics that are difficult to achieve at the same time, there are adhesive force to the adherend and reworkability.
  • the above-mentioned rework is, for example, when the adhesive sheet is not attached to the adherend due to failure (positional deviation, wrinkles, bubbles, foreign matter, etc.), or after the adhesive sheet is attached to the adherend. When a defect is found, the adhesive sheet is peeled off from the adherend and reattached.
  • the adhesive optical film is provided from a substrate with an optical film in which an adhesive optical film (specifically, an adhesive polarizing plate) is attached to the surface of a substrate (adhesive body) such as a glass substrate.
  • an adhesive optical film specifically, an adhesive polarizing plate
  • a method of peeling a method of peeling the adhesive optical film from the substrate in a state where a liquid is present at the peeling interface between the pressure-sensitive adhesive layer of the adhesive optical film and the substrate is disclosed. Note that Patent Document 1 does not study a method of peeling the pressure-sensitive adhesive attached to an optical film (specifically, a polarizing plate) from the optical film.
  • the method of using the pressure-sensitive adhesive includes a mode in which it is used in a form of being laminated on a base material. It is desirable that the pressure-sensitive adhesive layer and the base material of this embodiment have both reworkability for reattachment and adhesion during use, as in the case of an adherend. Further, in some usage modes, the pressure-sensitive adhesive layer and the base material may be peeled off from the base material after the laminate of the pressure-sensitive adhesive layer and the base material has achieved its intended use. However, depending on the base material and the type of pressure-sensitive adhesive, the pressure-sensitive adhesive may not be smoothly peeled off from the base material layer even if an aqueous liquid such as water is used.
  • the present invention has been created in view of the above circumstances, and is a laminate having a base material layer and an adhesive layer, in which the base material layer and the pressure-sensitive adhesive layer are in good contact with each other, and water or the like is used.
  • An object of the present invention is to provide a laminate capable of easily peeling a pressure-sensitive adhesive layer from a base material layer by using an aqueous liquid.
  • Another object of the present invention is to provide a method for peeling the pressure-sensitive adhesive layer from the base material layer.
  • a laminate having a base material layer and a pressure-sensitive adhesive layer detachably laminated on the base material layer is provided.
  • the pressure-sensitive adhesive layer includes a layer A that constitutes a surface on the base material layer side.
  • a hydrophilic layer is formed on the surface of the base material layer on the pressure-sensitive adhesive layer side.
  • the hydrophilic layer is an inorganic material-containing layer.
  • the peel strength N0 of the pressure-sensitive adhesive layer with respect to the base material layer is 2.0 N / 10 mm or more. Then, the laminate supplies 20 ⁇ L of distilled water between the base material layer and the pressure-sensitive adhesive layer, and after allowing the distilled water to enter one end of the interface between the pressure-sensitive adhesive layer and the base material layer.
  • Method 1 According to 180 ° peeling adhesive strength to the test plate, specifically, at a test temperature of 23 ° C, a tensile speed of 300 mm / min and a peeling angle using a tensile tester. It is calculated by the following formula: (1- (N2 / N0)) ⁇ 100; from the water peeling force N2 [N / 10 mm] measured under the condition of 180 degrees and the peeling strength N0 [N / 10 mm]. The rate of decrease in water peeling power is 40% or more.
  • the pressure-sensitive adhesive layer of the laminate adheres to the base material layer with a peeling strength of a predetermined value or more, while a specific hydrophilic layer is present on the surface of the base material layer on the pressure-sensitive adhesive layer side.
  • the pressure-sensitive adhesive layer can be easily peeled off by applying an aqueous liquid such as water to the surface of the base material layer and allowing it to enter the interface between the surface of the base material layer and the surface of the pressure-sensitive adhesive layer.
  • the peel strength N0 is 3.0 N / 10 mm or more. According to this configuration, the pressure-sensitive adhesive layer of the laminated body can be more stably adhered to the base material layer. In addition, the laminate can be more strongly adhered to the adherend.
  • the laminate according to some preferred embodiments has a post-water immersion peel strength N1 [N / 10 mm], which is measured after the laminate is immersed in water for 30 minutes and then pulled out of the water to wipe off the adhering water. From the peeling strength N0 [N / 10 mm], the rate of decrease in peeling force after immersion in water calculated by the following formula: (1- (N1 / N0)) ⁇ 100; is 30% or less.
  • a laminate containing an adhesive that satisfies the above-mentioned rate of decrease in peeling force after immersion in water (30% or less) is excellent in water resistance reliability.
  • the A layer is a layer formed from a photocurable or solvent type pressure-sensitive adhesive composition.
  • the effect of the technique disclosed herein is preferably exhibited.
  • the photocurable or solvent-type pressure-sensitive adhesive tends to exhibit excellent optical characteristics as compared with the water-dispersed type.
  • the A layer contains a water affinity. According to the layer A containing a water-affinitive agent, it is easy to obtain a pressure-sensitive adhesive that preferably has both peeling strength in a normal state (normal state) and water-peeling property, and a pressure-sensitive adhesive in which the rate of decrease in peeling power after immersion in water is suppressed Easy to obtain.
  • the inorganic material is an inorganic oxide.
  • an inorganic oxide as the hydrophilic layer material on the surface of the base material layer on the pressure-sensitive adhesive layer side, the water contact angle of the surface is effectively reduced, and excellent water peelability can be easily obtained.
  • Silicon oxide is used as a particularly preferable inorganic oxide.
  • the thickness of the hydrophilic layer is less than 5000 nm.
  • the substrate layer is an optical member.
  • the laminate disclosed herein can be preferably used in the form of an optical member with an adhesive suitable for optical applications.
  • the above-mentioned optical laminate optical member with an adhesive
  • the repair work is easy, and after achieving the purpose of use as a laminated body, the two can be easily separated by utilizing the water releasability.
  • the water-based method follows the movement of the peeling front. It includes a water peeling step of peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the liquid into the interface.
  • the peeling front refers to a portion where the pressure-sensitive adhesive layer begins to separate from the base material layer when the pressure-sensitive adhesive layer is peeled off from the base material layer.
  • the pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side.
  • the surface of the base material layer on the pressure-sensitive adhesive layer side is subjected to a hydrophilic treatment.
  • the hydrophilization treatment is the formation of a hydrophilic layer on the pressure-sensitive adhesive layer side surface of the substrate layer.
  • the hydrophilic layer is an inorganic material-containing layer.
  • the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side is preferably composed of a pressure-sensitive adhesive containing a water-affinitive agent.
  • FIG. 1 is a cross-sectional view schematically showing the structure of the laminated body.
  • FIG. 2 is a cross-sectional view schematically showing the structure of another laminated body.
  • the "acrylic polymer” refers to a polymer derived from a monomer component containing an acrylic monomer in an amount of 50% by weight or more.
  • the acrylic monomer refers to a monomer derived from a monomer having at least one (meth) acryloyl group in one molecule.
  • (meth) acryloyl means a comprehensively referring to acryloyl and methacryloyl.
  • (meth) acrylate” means acrylate and methacrylate
  • “(meth) acrylic” means acrylic and methacrylic, respectively.
  • the acrylic polymer can be an acrylic polymer.
  • the acrylic polymer may be, for example, an acrylic polymer contained as a base polymer (main constituent polymer) in a water-dispersible type or solvent type pressure-sensitive adhesive.
  • the "monomer component constituting the acrylic polymer” in the present specification can be paraphrased as the "monomer component constituting the acrylic polymer”.
  • the content of the additive component represented by the relative amount of the "monomer component constituting the polymer” and the “monomer component constituting the acrylic polymer” is relative to the "acrylic polymer". It shall be possible to paraphrase it as a quantity.
  • the laminated body 1 is configured as a single-sided adhesive pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer 10 and a base material layer 20 laminated on one surface 10A of the pressure-sensitive adhesive layer 10.
  • the base material layer 20 has a laminated structure of a main layer 22 and a hydrophilic layer 24, and specifically includes a main layer 22 and a hydrophilic layer 24 forming a surface 20B on the pressure-sensitive adhesive layer 10 side. ..
  • the pressure-sensitive adhesive layer 10 is releasably adhered to the pressure-sensitive adhesive layer-side surface 20B of the base material layer 20.
  • the pressure-sensitive adhesive layer 10 is laminated in direct contact with the hydrophilic layer 24 of the base material layer 20. Further, in the example shown in FIG. 1, the pressure-sensitive adhesive layer 10 has a single-layer structure. That is, the entire pressure-sensitive adhesive layer 10 is composed of the layer A constituting one surface (surface on the base material layer side) 10A of the pressure-sensitive adhesive layer 10. In the laminated body 1 before use (before sticking to the adherend), for example, as shown in FIG. 1, the other surface (adhesive surface) 10B of the pressure-sensitive adhesive layer 10 has a peelable surface (at least the pressure-sensitive adhesive layer side). It may be in the form of a laminate 50 with a release liner, which is protected by a release liner 30 which is a release surface).
  • the back surface 20A of the base material layer 20 (the surface opposite to the pressure-sensitive adhesive layer side surface 20B. It may also be the back surface of the laminate 1) is a peeling surface, and the adhesive surface 10B hits the back surface 20A.
  • the adhesive surface 10B may be protected by being wound or laminated so as to be in contact with each other.
  • FIG. 2 shows another configuration example of the laminated body disclosed here.
  • the laminated body 2 is configured as a single-sided adhesive pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer 110 and a base material layer 20 laminated on one surface (base material layer side surface) 110A of the pressure-sensitive adhesive layer 110.
  • the base material layer 20 has a laminated structure of a main layer 22 and a hydrophilic layer 24, and specifically includes a main layer 22 and a hydrophilic layer 24 forming a surface 20B on the pressure-sensitive adhesive layer 10 side. ..
  • the pressure-sensitive adhesive layer 110 has a two-layer structure including an A layer 112 constituting one surface (base material layer side surface) 110A and a B layer 114 laminated on the back surface side of the A layer 112.
  • the A layer 112 of the pressure-sensitive adhesive layer 110 is releasably adhered to the pressure-sensitive adhesive layer side surface 20B of the base material layer 20. Specifically, the A layer 112 is laminated in a state of being in direct contact with the hydrophilic layer 24 of the base material layer 20.
  • the laminated body 2 before use is a laminated body with a release liner in which the other surface (adhesive surface) 110B is protected by a release liner (not shown), similarly to the laminate 1 shown in FIG. It can be the form of the body.
  • the back surface 20A of the base material layer 20 (which may also be the back surface of the laminated body 2) is a peeling surface, and the adhesive surface is wound or laminated so that the adhesive surface 110B abuts on the back surface 20A. 110B may be in a protected form.
  • the release liner is not particularly limited, and for example, a release liner in which the surface of a liner base material such as a resin film or paper is peeled off, a fluoropolymer (polytetrafluoroethylene, etc.), a polyolefin resin (polyethylene, polypropylene, etc.), etc. ), A release liner made of a low-adhesive material or the like can be used.
  • a silicone-based or long-chain alkyl-based peeling agent can be used for the peeling treatment.
  • the peeled resin film can be preferably used as the peel liner.
  • the peel strength N0 of the pressure-sensitive adhesive layer with respect to the base material layer is 2.0 N / 10 mm or more.
  • the peel strength N0 is a peel strength measured under the conditions of a temperature of 23 ° C., a tensile speed of 300 mm / min, and a peeling angle of 180 degrees. In other words, it can be said that the pressure-sensitive adhesive layer is adhered to the base material layer with a peel strength N0 of a predetermined value or more.
  • the pressure-sensitive adhesive layer of the laminated body is stably adhered to the base material layer, and it is possible to prevent the occurrence of a problem that the pressure-sensitive adhesive layer is unintentionally peeled off from the base material layer during use.
  • the laminate having the above peel strength can show good adhesiveness to the adherend.
  • the peel strength N0 may be, for example, 2.5N / 10mm or more, and may be 3.0N, from the viewpoint of adhesion between the pressure-sensitive adhesive layer and the base material layer and adhesion to the adherend.
  • the peel strength N0 may be, for example, 6.0 N / 10 mm or more, 7.0 N / 10 mm or more, 8.0 N / 10 mm or more, 9.0 N / 10 mm or more. It may be 10.0 N / 10 mm or more, or 11.0 N / 10 mm or more.
  • the upper limit of the peel strength N0 is not particularly limited, and may be, for example, 30 N / 10 mm or less.
  • the peel strength N0 may be 20 N / 10 mm or less, or 15 N / 10 mm or less (for example, 12 N / 10 mm or less). In some embodiments, the peel strength N0 may be less than 10N / 10mm or less than 8N / 10mm. The peel strength N0 is specifically measured by the method described in Examples described later.
  • Water peeling force N2 The laminate disclosed here supplies 20 ⁇ L of distilled water between the base material layer and the pressure-sensitive adhesive layer, and allows the distilled water to enter one end of the interface between the pressure-sensitive adhesive layer and the base material layer.
  • Method 1 180 ° peeling adhesive force to the test plate, specifically, a tensile speed of 300 mm / min using a tensile tester at a test temperature of 23 ° C.
  • the water peeling force N2 [N / 10 mm] measured under the condition of a peeling angle of 180 degrees may be limited to a predetermined value or less.
  • the pressure-sensitive adhesive layer can be easily formed by applying an aqueous liquid such as water to the surface of the base material layer and allowing it to enter the interface between the surface of the base material layer and the surface of the pressure-sensitive adhesive layer. Can be peeled off.
  • the water peeling force N2 may be, for example, 10 N / 10 mm or less, 3.5 N / 10 mm or less, 2.5 N / 10 mm or less, or 1.6 N / 10 mm or less. , 1.2N / 10mm or less, or 1.0N / 10mm or less. According to the laminate having a low water peeling force N2, it is possible to reduce the load applied to the base material layer when the pressure-sensitive adhesive layer is peeled off.
  • the laminate is also preferably carried out in an embodiment in which the water peeling force N2 is 0.75 N / 10 mm or less, 0.50 N / 10 mm or less, 0.25 N / 10 mm or less, or 0.15 N / 10 mm or less. obtain.
  • the lower limit of the water peeling force N2 is not particularly limited, and may be substantially 0N / 10mm or more than 0N / 10mm.
  • the pressure-sensitive adhesive layer can be peeled off from the base material layer without leaving the pressure-sensitive adhesive on the base material layer in the measurement of the water peeling force N2. That is, it is preferable that the pressure-sensitive adhesive layer is excellent in non-adhesive residue property when peeling from the base material layer.
  • the presence or absence of the adhesive remaining on the base material layer can be grasped, for example, by visually observing the base material layer after the pressure-sensitive adhesive layer is peeled off.
  • the water peeling force N2 is specifically measured by the method described in Examples described later.
  • the laminate disclosed here has a water peeling force reduction rate of 40% or more.
  • the pressure-sensitive adhesive layer can be easily peeled off from the base material layer by using an aqueous liquid such as water in the laminate showing the rate of decrease in water peeling power.
  • an aqueous liquid such as water in the laminate showing the rate of decrease in water peeling power.
  • a small amount of an aqueous liquid is supplied between the base material layer and the pressure-sensitive adhesive layer of the laminate, and the aqueous liquid is allowed to enter the interface between the base material layer and the pressure-sensitive adhesive layer from one end of the laminate to cause peeling.
  • the peel strength of the pressure-sensitive adhesive layer from the base material layer can be significantly reduced. Utilizing this property, it is possible to achieve both high adhesion during normal use and good peelability.
  • the rate of decrease in water peeling power may be, for example, 50% or more, 65% or more, 75% or more, 85% or more, 90% or more, 95% or more. It may be 97% or more.
  • the rate of decrease in water peeling force is 100% or less in principle, and typically less than 100%.
  • the rate of decrease in water peeling force is realized by forming a hydrophilic layer, selecting a hydrophilic layer constituent material, an adhesive type, a composition, and the like.
  • the ratio (N2 / N0) of the water peeling force N2 [N / 10 mm] to the peeling strength N0 [N / 10 mm] may be, for example, 1 / 2.5 or less, 1/5 or less, or 1/10 or less. It may be. When the ratio (N2 / N0) is smaller, it means that the water peeling force N2 is more significantly reduced with respect to the peeling strength N0.
  • the laminate disclosed herein can be preferably carried out in an embodiment in which the ratio (N2 / N0) is 1/15 or less, 1/25 or less, or 1/35 or less.
  • the lower limit of the ratio (N2 / N0) is not particularly limited, and may be, for example, 1/200 or more, 1/150 or more, or 1/100 or more.
  • the laminate disclosed herein can be easily peeled off using an aqueous liquid such as water as described above, and the laminate is immersed in water for 30 minutes and then pulled out of the water to wipe off the adhering water.
  • This equation means the following equation: N1 ⁇ 0.7N0 ;.
  • a laminate containing an adhesive that satisfies the above-mentioned rate of decrease in peeling force after immersion in water (30% or less) is excellent in water resistance reliability.
  • the rate of decrease in peeling force after immersion in water is preferably, for example, 20% or less, more preferably 10% or less, and may be 7% or less.
  • the lower limit of the peeling force reduction rate after immersion in water is typically 0% or more.
  • the difference between the water peeling power reduction rate [%] and the water peeling power reduction rate [%] is, for example, 45% or more, 55% or more, 70% or more, or 80% or more, or It can be preferably carried out in an embodiment of 90% or more.
  • the peel strength N1 after water immersion for calculating the rate of decrease in peeling force after water immersion is measured by the method described in Examples described later.
  • the haze value of the laminate is approximately 10% or less, and may be approximately 5% or less (for example, approximately 3% or less).
  • the haze value is preferably 1.0% or less.
  • Such a highly transparent laminate is suitable for optical applications where high light transmission is required.
  • the haze value of the laminate may be less than 1.0%, less than 0.7%, or 0.5% or less (for example, 0 to 0.5%).
  • the range of haze values for the laminate can also be applied to the haze values of the pressure-sensitive adhesive layer and the substrate layer in the techniques disclosed herein.
  • the "haze value” refers to the ratio of diffuse transmitted light to total transmitted light when the measurement target is irradiated with visible light. Also called cloudy value.
  • the haze value can be measured using a haze meter (for example, "MR-100" manufactured by Murakami Color Technology Laboratory). The haze value can be adjusted by selecting, for example, the composition and thickness of the pressure-sensitive adhesive layer, the base material layer material, and the thickness.
  • the pressure-sensitive adhesive constituting the layer A arranged on the surface side of the pressure-sensitive adhesive layer on the base material layer side is preferably water-insoluble.
  • the water-insoluble layer A it is easy to obtain a laminate having a high peeling strength N1 after immersion in water and a low rate of decrease in peeling force after immersion in water.
  • the fact that the A layer is water-insoluble is also preferable from the viewpoint of preventing the phenomenon that the adhesive remains on the base material layer in peeling using an aqueous liquid such as water.
  • the layer A is water-insoluble can be advantageous from the viewpoint of preventing a phenomenon in which the transparency of the laminate is lowered due to immersion in water or moisture in the environment. This can be an advantageous feature in an optical laminate in which the substrate layer is an optical member.
  • the pressure-sensitive adhesive constituting the A layer is preferably non-water-swellable.
  • the non-water-swellable layer A it is easy to obtain a laminated body having a high peeling strength N1 after immersion in water and a low rate of decrease in peeling force after immersion in water. Further, in peeling using an aqueous liquid such as water, a small amount of aqueous liquid can be effectively used to exhibit good peelability.
  • the A layer is non-water swellable from the viewpoint of preventing the phenomenon that the adhesive remains on the base material layer in the peeling using the aqueous liquid.
  • the fact that the layer A is non-water swelling may be advantageous from the viewpoint of preventing the phenomenon that the transparency of the laminated body is lowered due to water immersion or moisture in the environment.
  • This can be an advantageous feature in an optical laminate in which the substrate layer is an optical member.
  • the fact that the pressure-sensitive adhesive is water-insoluble means that the gel fraction measured by the following method is 75% or more.
  • the gel fraction of layer A may be, for example, 80% or more, 90% or more, 95% or more, or 98% or more.
  • the gel fraction of the A layer is 100% or less in principle.
  • the degree of swelling of the layer A may be, for example, 1.7 or less, 1.5 or less, or 1.2 or less.
  • the degree of swelling of the layer A is, for example, 1.0 or more, and typically more than 1.0.
  • the gel fraction of the B layer is not particularly limited in the laminated body having the structure in which the pressure-sensitive adhesive layer includes the A layer and the B layer arranged on the back side of the A layer.
  • the gel fraction of layer B is preferably equal to or greater than the gel fraction of layer A and may be higher than the gel fraction of layer A.
  • the gel fraction of the B layer may be, for example, 90% or more, 95% or more, 98% or more, or 99% or more.
  • the gel fraction of the B layer is 100% or less in principle.
  • the gel fraction of the entire pressure-sensitive adhesive layer may be, for example, 85% or more, 90% or more, 95% or more, 98% or more, or 99% or more.
  • the gel fraction of the entire pressure-sensitive adhesive layer means the gel fraction of the A layer.
  • the degree of swelling of the B layer is not particularly limited in the laminated body having the structure in which the adhesive layer includes the A layer and the B layer arranged on the back side of the A layer.
  • the degree of swelling of the layer B is preferably equal to or less than the degree of swelling of the layer A, and may be lower than the degree of swelling of the layer A.
  • the degree of swelling of the B layer may be, for example, 1.5 or less, 1.3 or less, or 1.1 or less.
  • the degree of swelling of the B layer is, for example, 1.0 or more, and typically more than 1.0.
  • the degree of swelling of the entire pressure-sensitive adhesive layer may be, for example, 1.6 or less, 1.4 or less, 1.2 or less, or 1.1 or less.
  • the degree of swelling of the entire pressure-sensitive adhesive layer means the degree of swelling of the A layer.
  • the gel fraction and swelling degree of the pressure-sensitive adhesive with respect to water are general methods for those skilled in the art at the time of filing the application, such as composition of monomer components, weight average molecular weight of polymers, use of cross-linking agents and polyfunctional monomers. Can be adjusted by appropriately adopting.
  • the base material layer constituting the laminate disclosed here has a hydrophilic layer formed on the surface on the pressure-sensitive adhesive layer side.
  • the base material layer has a hydrophilic layer as a layer (outermost layer of the base material layer) constituting the surface on the pressure-sensitive adhesive layer side.
  • the hydrophilic layer is defined as a layer having a hydrophilic surface.
  • the surface of the hydrophilic layer before laminating the pressure-sensitive adhesive layer also the surface on the pressure-sensitive adhesive layer side of the base material layer; the same shall apply hereinafter unless otherwise specified).
  • the surface may have hydrophilicity such that the contact angle with respect to distilled water (hereinafter, also referred to as “water contact angle”) is, for example, 60 degrees or less, preferably 50 degrees or less.
  • the water contact angle on the surface of the hydrophilic layer may be, for example, 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less.
  • the water contact angle on the surface of the hydrophilic layer becomes small, water tends to get wet and spread along the surface, and the water detachability of the pressure-sensitive adhesive layer from the base material layer tends to be improved. This is preferable from the viewpoint of removing the pressure-sensitive adhesive layer from the base material layer and improving the reworkability.
  • the water contact angle of the surface of the hydrophilic layer is preferably less than 25 degrees, may be less than 20 degrees, may be 15 degrees or less, or may be less than 10 degrees.
  • the lower limit of the water contact angle is 0 degrees in principle. In some embodiments, the water contact angle may be greater than 0 degrees, greater than 1 degree, greater than 3 degrees, or greater than or equal to 5 degrees. According to the technique disclosed herein, better water releasability can be achieved by selecting the hydrophilic layer material and the pressure-sensitive adhesive type. Therefore, in some embodiments, the water contact angle on the surface of the hydrophilic layer is 8 degrees or more. It may be 12 degrees or more, 16 degrees or more, or 20 degrees or more (for example, 24 degrees or more).
  • the water contact angle on the surface of the hydrophilic layer can be set by selecting the material constituting the hydrophilic layer, the thickness of the hydrophilic layer, additional surface treatment, and the like. The water contact angle of the surface of the hydrophilic layer (the surface of the base material layer on the pressure-sensitive adhesive layer side) can be measured by the method described in Examples described later.
  • the technique disclosed herein is to form a hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side to reduce the water contact angle of the surface on the pressure-sensitive adhesive layer side and obtain improved water peelability. obtain. Therefore, the water contact angle WCA1 on the surface of the hydrophilic layer is typically smaller than the water contact angle WCA2 on the surface of the main layer of the base material layer (a single base material layer without the hydrophilic layer) described later.
  • the WCA1 is preferably less than 70%, more preferably less than 50%, even more preferably less than 30%, and particularly preferably less than 20% of the WCA2.
  • the surface of the hydrophilic layer is formed smoothly.
  • the arithmetic mean roughness Ra of the surface of the hydrophilic layer is less than 10 ⁇ m. According to the surface of the hydrophilic layer in which the unevenness is suppressed in this way, it is easy to realize the desired water peelability.
  • the arithmetic mean roughness Ra is preferably less than 5 ⁇ m, more preferably less than 3 ⁇ m (specifically, less than 1.0 ⁇ m). Further, from the viewpoint of maintaining the water releasability for a long period of time, it is preferable that the arithmetic average roughness Ra of the hydrophilic surface is even smaller.
  • the arithmetic mean roughness Ra is preferably less than 100 nm, more preferably less than 10 nm, still more preferably less than 3 nm (specifically less than 1.0 nm).
  • the surface smoothness of the hydrophilic layer can be adjusted by selecting the hydrophilic layer material, forming conditions, the thickness, and the like.
  • the arithmetic mean roughness is defined as a general surface roughness measuring device (for example, a non-contact three-dimensional surface shape measuring device manufactured by Veeco, model "Wyko NT-3300", or manufactured by Hitachi High Technologies America. It can be measured using an atomic force microscope, model "AFM5500M").
  • Inorganic material is used as the material of the hydrophilic layer. Since the hydrophilic layer contains an inorganic material, good water releasability can be easily obtained.
  • the inorganic material a material capable of forming a hydrophilic surface from simple substances of transition metal elements and metalloid elements, various metal materials including alloys, and inorganic compounds such as inorganic oxides is used. The above-mentioned inorganic materials may be used alone or in combination of two or more.
  • Preferable examples of the inorganic material are oxides such as titanium oxide, zinc oxide, magnesium oxide, aluminum oxide, silicon oxide, cerium oxide, chromium oxide, zirconium oxide, manganese oxide, zinc oxide, iron oxide, tin oxide and niobium oxide.
  • the hydrophilic layer may or may not contain various organic materials including an organic polymer compound that can be used as a coating agent or a binder.
  • the amount of the inorganic material (for example, an inorganic oxide such as silicon oxide) in the hydrophilic layer can be an appropriate amount to obtain the desired hydrophilic surface, and is not limited to a specific range.
  • the content ratio of the inorganic material in the hydrophilic layer can be about 30% by weight or more, about 50% by weight or more (for example, more than 50% by weight) is appropriate, and even if it is about 70% by weight or more. Good.
  • the content of the inorganic material in the hydrophilic layer is approximately 90-100% by weight (eg, approximately 95% by weight or more).
  • an inorganic oxide such as silicon oxide (typically silicon oxide represented by SiO X or silicon dioxide represented by SiO 2 ) is used as the inorganic material.
  • the proportion of the inorganic oxide (typically silicon oxide) in the inorganic material can be an appropriate amount to obtain the desired hydrophilic surface and is not limited to a specific range, for example, about 30 weight by weight. % Or more, about 50% by weight or more (for example, more than 50% by weight) is suitable, and may be about 70% by weight or more. In some preferred embodiments, the proportion of the inorganic oxide (typically silicon oxide) in the inorganic material is approximately 90-100% by weight (eg, approximately 95% by weight or more).
  • the method for forming the hydrophilic layer is not particularly limited, and it can be formed by an appropriate method according to the target thickness and the like.
  • an inorganic material formed in layers by using a known film forming method such as a vacuum vapor deposition method, a sputtering method, or a plating method can be used as a hydrophilic layer.
  • various vapor deposition methods can be used.
  • PVD physical vapor deposition
  • CVD chemical vapor deposition method of the above
  • the coating layer containing an inorganic polymer such as polysiloxane can be formed by appropriately selecting a known coating agent capable of obtaining a surface showing a desired water contact angle and using it by a conventional method.
  • the thickness of the hydrophilic layer is not particularly limited. From the viewpoint of not impairing the function of the base material layer main body (main layer of the base material layer), the thickness of the hydrophilic layer is specifically about 5 ⁇ m or less (for example, less than 5000 nm), and is about 2 ⁇ m or less (for example, 2000 nm). Less than). In some preferred embodiments, the thickness of the hydrophilic layer is less than 1000 nm, more preferably less than 500 nm, even more preferably less than 100 nm, particularly preferably less than 50 nm, and may be about 30 nm or less, about 20 nm or less. However, it may be about 15 nm or less (for example, less than 10 nm).
  • the water peelability can be improved without impairing the function of the base material layer.
  • the thin hydrophilic layer is also advantageous from the viewpoint of optical characteristics.
  • the thickness of the hydrophilic layer is preferably 1 nm or more (for example, 3 nm or more), and may be about 5 nm or more, and may be about 10 nm or more (for example, from the viewpoint of improving the hydrophilicity of the surface and improving the water detachability). 15 nm or more) may be used.
  • the thickness can be measured by the method described in Examples described later.
  • the main layer of the base material layer disclosed herein (also referred to as “base material main layer” or, for convenience, simply referred to as “base material layer”; the same shall apply hereinafter unless otherwise specified) is particularly limited. However, it can be appropriately selected according to the purpose of use, the mode of use, and the like.
  • the technique disclosed herein is to form a hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side to reduce the water contact angle of the surface on the pressure-sensitive adhesive layer side and obtain improved water peelability. obtain. Therefore, the water contact angle on the surface of the base material layer alone (main layer) without the hydrophilic layer is typically larger than the water contact angle on the surface of the hydrophilic layer.
  • the water contact angle of the surface of the base material main layer is, for example, higher than 10 degrees and can be more than 30 degrees or more than 50 degrees.
  • the water contact angle on the surface of the main base layer may be 60 degrees or more, 70 degrees or more, or 80 degrees or more (for example, 85 degrees or more) from the viewpoint of better exerting the effect of forming the hydrophilic layer. ..
  • the upper limit of the water contact angle on the surface of the base material main layer is not particularly limited, and may be, for example, less than 115 degrees, less than 105 degrees, or less than 95 degrees.
  • the base material main layer disclosed herein may have a surface on the hydrophilic layer side having a water contact angle in the above range. Further, the water contact angle on the back surface of the base material layer may be the same as the range of the water contact angle of the base material main layer.
  • the water contact angle on the surface of the main base layer can be measured by the method described in Examples described later.
  • Non-limiting examples of the material of the base material main layer are various resin films such as polyolefin film, polyester film and polyvinyl chloride film; foam sheet made of foam such as polyurethane foam, polyethylene foam and polychloroprene foam; Woven and non-woven fabrics of various fibrous substances (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or by blending; Japanese paper, high-quality paper , Craft paper, crepe paper and other papers; aluminum foil, copper foil, stainless steel (SUS) and other metal foils; and the like. It may be a layered body having a structure in which these are combined.
  • resin films such as polyolefin film, polyester film and polyvinyl chloride film
  • foam sheet made of foam such as polyurethane foam, polyethylene foam and polychloroprene foam
  • Woven and non-woven fabrics of various fibrous substances naturally fibers such as hemp and cotton, synthetic fibers such
  • the base material main layer having such a composite structure for example, a laminated base material (multilayer structure base material) having a structure in which a metal foil and the above resin film are laminated, or a resin sheet reinforced with an inorganic fiber such as glass cloth. And so on.
  • a laminated base material multilayer structure base material
  • a resin sheet reinforced with an inorganic fiber such as glass cloth.
  • the base film may be a porous film such as a foam film or a non-woven fabric sheet, or may be a non-porous film, and the porous layer and the non-porous layer are laminated. It may be a film having the same structure.
  • a film containing an independently shape-maintainable (self-supporting or independent) resin film as a base film can be preferably used as the base film.
  • the term "resin film” means a resin film (of voidless) having a non-porous structure and typically containing substantially no bubbles. Therefore, the resin film is a concept that is distinguished from a foam film and a non-woven fabric.
  • the resin film may have a single-layer structure or a multi-layer structure having two or more layers (for example, a three-layer structure).
  • polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefins such as polypropylene and ethylene-propylene copolymers; and aliphatic ring structures such as norbornene structure.
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • polyolefins such as polypropylene and ethylene-propylene copolymers
  • aliphatic ring structures such as norbornene structure.
  • Polycycloolefin derived from monomer Polyimide (PA) such as nylon 6, nylon 66, partially aromatic polyamide; Polyimide (PI) such as transparent polyimide (CPI), Polyamidoimide (PAI); Polyether ether ketone (PEEK) Polyestersulfone (PES); Polyphenylene sulfide (PPS); Polycarbonate (PC); Polyurethane (PU); Ethylene-vinyl acetate copolymer (EVA); Polyvinyl alcohol (PVA); Polystyrene; ABS resin; Polyvinyl chloride; Vinylidene chloride; Fluorine resin such as polytetrafluoroethylene (PTFE); Acrylic resin such as polymethylmethacrylate; Cellulous polymer such as diacetyl cellulose and triacetyl cellulose (TAC); Vinyl butyral polymer; Arilate polymer; Polyoxy Methylene-based polymer; A resin such as an epoxy-based polymer can be used.
  • PA polyimide
  • the surface of the base material main layer disclosed herein may be composed of the above resin material.
  • the resin film that can be used as the base material main layer may be formed by using a resin material containing one kind of the above-mentioned resin alone, or is formed by using a resin material in which two or more kinds are blended. It may be a plastic.
  • the resin film is a composite resin film in which a resin layer containing one or more kinds of resin materials and a resin layer containing one or more kinds of resin materials of the same type or different types from the resin layer are laminated. There may be.
  • the resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).
  • the resin material constituting the resin film include polyester resin, PPS resin, polyolefin resin, and polyimide resin.
  • the polyester-based resin refers to a resin containing polyester in a proportion of more than 50% by weight.
  • the PPS resin is a resin containing PPS in a proportion exceeding 50% by weight
  • the polyolefin resin is a resin containing a polyolefin in a proportion exceeding 50% by weight
  • the polyimide resin is a polyimide resin.
  • polyester-based resin a polyester-based resin containing a polyester obtained by polycondensing a dicarboxylic acid and a diol as a main component is typically used.
  • the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate and the like.
  • polyolefin resin one kind of polyolefin can be used alone, or two or more kinds of polyolefins can be used in combination.
  • the polyolefin can be, for example, a homopolymer of an ⁇ -olefin, a copolymer of two or more kinds of ⁇ -olefins, a copolymer of one kind or two or more kinds of ⁇ -olefins and another vinyl monomer, or the like.
  • Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR), and ethylene-propylene-.
  • Examples thereof include butene copolymers, ethylene-butene copolymers, ethylene-vinyl alcohol copolymers and ethylene-ethyl acrylate copolymers. Both low density (LD) polyolefin and high density (HD) polyolefin can be used.
  • polyolefin resin films include unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, medium density polyethylene (MDPE).
  • Examples thereof include a film, a high-density polyethylene (HDPE) film, a polyethylene (PE) film in which two or more types of polyethylene (PE) are blended, and a PP / PE blend film in which polypropylene (PP) and polyethylene (PE) are blended.
  • HDPE high-density polyethylene
  • PE polyethylene
  • the resin film that can be preferably used as the base material main layer include PET film, PEN film, PPS film, PEEK film, CPI film, CPP film, OPP film, and TAC film.
  • Preferred examples from the viewpoint of strength include PET film, PEN film, PPS film, PEEK film, and CPI film.
  • Preferred examples include PET film, CPI film, and TAC film from the viewpoint of availability, dimensional stability, optical characteristics, and the like.
  • additives such as light stabilizers, antioxidants, antistatic agents, colorants (dye, pigment, etc.), fillers, slip agents, antiblocking agents, etc. shall be added to the resin film, if necessary. Can be done.
  • the blending amount of the additive is not particularly limited, and can be appropriately set according to the intended use and the like.
  • the manufacturing method of the resin film is not particularly limited.
  • conventionally known general resin film molding methods such as extrusion molding, inflation molding, T-die casting molding, and calender roll molding can be appropriately adopted.
  • the base material main layer may be substantially composed of such a resin film.
  • the base material main layer may include an auxiliary layer in addition to the resin film.
  • the auxiliary layer are surfaces such as an optical property adjusting layer (for example, a coloring layer and an antireflection layer), a printing layer or a laminating layer for imparting a desired appearance, an antistatic layer, an undercoat layer, and a peeling layer.
  • a processing layer can be mentioned.
  • the base material main layer disclosed here is an acrylic-based, polyester-based, alkyd-based, melamine-based, urethane-based, acid-epoxy cross-linked system, or a composite system thereof (for example, acrylic) on the resin film, metal foil, or the like. It may be coated with a paint such as melamine-based or alkyd-melamine-based, or plated with zinc plating or the like.
  • the base material main layer is a polarizing film, a wavelength film, a retardation film, an optical compensation film, a brightness improving film, a light guide film, a reflective film, an antireflection film, which can be used as an optical member.
  • the above-mentioned "plate” and “film” shall include a plate-like, a film-like, a sheet-like form, respectively, and for example, the "polarizing film” shall include a “polarizing plate”, a “polarizing sheet” and the like. ..
  • the base material layer using the above material as the base material main layer can be used as the above-mentioned various optical members and functional films in the form of having a hydrophilic layer.
  • a polarizing film (polarizing film layer) is used as the base material main layer.
  • the polarizing film may include a polarizing element and a transparent protective film arranged on at least one surface (preferably both sides) of the polarizing element.
  • the polarizer is not particularly limited, and for example, one in which a dichroic substance such as iodine or a dichroic dye is adsorbed on a hydrophilic polymer film and uniaxially stretched is used.
  • the hydrophilic polymer film include a PVA-based film, a partially formalized PVA-based film, and an ethylene-vinyl acetate copolymer-based partially saponified film.
  • polarizer a polyene-based alignment film such as a dehydrated product of PVA or a dehydrochlorinated product of polyvinyl chloride can also be used.
  • a PVA-based film and a polarizer made of a dichroic substance such as iodine are preferable.
  • thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc.
  • thermoplastic resins include cellulose resins such as TAC, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, and cycloolefin-based resins.
  • resins typically norbornene-based resins
  • polyarylate resins polystyrene resins
  • PVA resins and mixtures of two or more of these.
  • the polarizing film has, for example, a configuration in which the polarizing film is sandwiched between two triacetyl cellulose (TAC) films.
  • TAC triacetyl cellulose
  • a transparent protective film made of a thermoplastic resin such as TAC is placed on one surface of the polarizer, and a cycloolefin resin (typically a norbornene resin) is placed on the other surface.
  • a configuration in which a transparent protective film made of (meth) acrylic resin is arranged can be adopted.
  • a transparent protective film made of a thermoplastic resin such as TAC is arranged on one surface of the polarizer, and the transparent protective film is prepared as a (meth) acrylic or urethane-based film on the other surface.
  • Thermosetting resins such as acrylic urethane-based, epoxy-based, and silicone-based resins or ultraviolet curable resins can be used.
  • These transparent protective films can be laminated on the polarizer via an adhesive such as PVA.
  • the transparent protective film may contain one or more of any suitable additives, depending on the intended purpose.
  • a surface treatment layer may be provided on the back surface of the polarizing film.
  • the surface treatment layer can be provided on the above-mentioned transparent protective film used for the polarizing film, or can be separately provided on the polarizing film as a separate body from the transparent protective film.
  • a preferable example of the surface treatment layer is a hard coat layer.
  • a thermoplastic resin or a material that is cured by heat or radiation can be used as the material for forming the hard coat layer.
  • the material used include radiation-curable resins such as thermosetting resins, ultraviolet curable resins, and electron beam curable resins. Of these, an ultraviolet curable resin is preferable.
  • the ultraviolet curable resin is excellent in processability because the cured resin layer can be efficiently formed by the curing treatment by ultraviolet irradiation.
  • the curable resin one or more kinds such as polyester type, acrylic type, urethane type, amide type, silicone type, epoxy type and melamine type can be used, and these may contain monomers, oligomers, polymers and the like. It can be in the form of inclusion.
  • a radiation-curable resin typically an ultraviolet-curable resin
  • the surface treatment layer include an antiglare treatment layer and an antireflection layer for the purpose of improving visibility.
  • An antiglare treatment layer or an antireflection layer may be provided on the hard coat layer.
  • the antireflection layer may have a multi-layer structure including a plurality of layers.
  • Other examples of the surface treatment layer include a sticking prevention layer and the like.
  • the thickness of the polarizing film (when composed of a plurality of layers, the total thickness thereof) is not particularly limited, and is, for example, approximately 1 ⁇ m or more. Therefore, about 10 ⁇ m or more or about 20 ⁇ m or more is suitable.
  • the thickness of the polarizing film is preferably about 30 ⁇ m or more, more preferably about 50 ⁇ m or more, and further preferably about 70 ⁇ m or more from the viewpoint of protection and the like.
  • the upper limit of the polarizing film is not particularly limited, and is, for example, about 1 mm or less, and about 500 ⁇ m or less or about 300 ⁇ m or less is appropriate. From the viewpoint of optical characteristics and thinning, the thickness is preferably about 150 ⁇ m or less, more preferably about 120 ⁇ m or less, still more preferably about 100 ⁇ m or less.
  • the base material main layer disclosed here typically does not include a glass layer such as an alkaline glass plate or non-alkali glass.
  • a glass layer such as an alkaline glass plate or non-alkali glass.
  • the effect of improving water peelability by providing the hydrophilic layer can be preferably exhibited.
  • the thickness of the base material main layer (when having a plurality of layers other than the hydrophilic layer, the total thickness of the layers other than the hydrophilic layer) is preferably 50% or more of the total thickness of the base material layer, and is preferable. Is 70% or more, more preferably 90% or more, and may be 97% or more (for example, 99% or more).
  • the total thickness of the base material layer is not particularly limited and can be selected according to the purpose of use and the mode of use of the laminate.
  • the total thickness of the base material layer may be, for example, about 1000 ⁇ m or less, may be about 500 ⁇ m or less, and from the viewpoint of weight reduction and thinning, about 300 ⁇ m or less is suitable, preferably about 150 ⁇ m or less, and more preferably about 150 ⁇ m or less. It may be 120 ⁇ m or less, 100 ⁇ m or less, or 70 ⁇ m or less. As the total thickness of the base material layer becomes smaller, the flexibility of the laminate and the followability to the surface shape of the adherend tend to improve.
  • the total thickness of the base material layer may be, for example, 2 ⁇ m or more, and may be 5 ⁇ m or more or 10 ⁇ m or more.
  • the total thickness of the substrate layer is preferably about 20 ⁇ m or more, preferably about 30 ⁇ m or more, more preferably about 50 ⁇ m or more, still more preferably about 70 ⁇ m or more.
  • the surface of the base material layer on the pressure-sensitive adhesive layer side may be further subjected to a hydrophilic treatment such as a corona treatment or a plasma treatment in order to further enhance the hydrophilicity.
  • a hydrophilic treatment such as a corona treatment or a plasma treatment in order to further enhance the hydrophilicity.
  • the apparatus and treatment conditions used for the corona treatment and the plasma treatment can be set so as to obtain a surface showing a desired water contact angle based on a conventionally known technique.
  • the surface of the base material layer on the pressure-sensitive adhesive layer side may be subjected to conventionally known surface treatments such as ultraviolet irradiation treatment, acid treatment, and alkali treatment, if necessary.
  • Such a surface treatment may be a treatment for improving the adhesion between the base material layer and the pressure-sensitive adhesive layer, in other words, the anchoring property of the pressure-sensitive adhesive layer on the base material layer.
  • the surface of the base material main layer (for example, the surface on the hydrophilic layer side) may be subjected to surface treatments such as the above-mentioned various surface treatments, application of an undercoating agent (primer), and antistatic treatment.
  • the composition of the primer is not particularly limited and can be appropriately selected from known ones.
  • the thickness of the undercoat layer is not particularly limited, but for example, about 0.01 ⁇ m to 1 ⁇ m is suitable, and about 0.1 ⁇ m to 1 ⁇ m is preferable.
  • the surface of the base material layer opposite to the pressure-sensitive adhesive layer side (hereinafter, also referred to as the back surface) is conventionally known to have a peeling treatment, an adhesive or adhesive improving treatment, an antistatic treatment, or the like, if necessary.
  • Surface treatment may be applied. For example, by surface-treating the back surface of the base material layer with a release treatment agent, the unwinding force of the laminated body in the form of being wound in a roll shape can be reduced.
  • a silicone-based stripping agent a long-chain alkyl-based stripping agent, an olefin-based stripping agent, a fluorine-based stripping agent, a fatty acid amide-based stripping agent, molybdenum sulfide, silica powder, or the like can be used. ..
  • the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side is, for example, an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive (natural rubber type, synthetic rubber type). , These mixed systems, etc.), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, fluorine adhesives, etc. It may be a pressure-sensitive adhesive layer composed of two or more types of pressure-sensitive adhesives.
  • the acrylic pressure-sensitive adhesive refers to a pressure-sensitive adhesive containing an acrylic polymer as a main component. The same meaning applies to rubber-based adhesives and other adhesives.
  • an acrylic pressure-sensitive adhesive may be preferably used as the constituent material of the A layer in some embodiments.
  • the acrylic pressure-sensitive adhesive is composed of, for example, a monomer component containing more than 50% by weight of a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 20 carbon atoms at the ester terminal. Those containing an acrylic polymer are preferable.
  • a (meth) acrylic acid alkyl ester having an alkyl group having an number of carbon atoms of X or more and Y or less at the ester terminal may be referred to as "(meth) acrylic acid CXY alkyl ester".
  • the ratio of the (meth) acrylic acid C 1-20 alkyl ester in the total monomer component may be, for example, 55% by weight or more, 60% by weight or more, or 70% by weight or more. It may be.
  • the proportion of (meth) acrylic acid C 1-20 alkyl ester in the monomer component may be, for example, 99.9% by weight or less, 99.5% by weight or less, or 99% by weight or less. Good.
  • Non-limiting specific examples of (meth) acrylic acid C 1-20 alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, ( N-butyl acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth) ) Decyl acrylate, Isodecy
  • At least (meth) acrylic acid C 4-20 alkyl ester it is preferable to use at least (meth) acrylic acid C 4-18 alkyl ester.
  • an acrylic pressure-sensitive adhesive containing one or both of n-butyl (BA) acrylate and 2-ethylhexyl acrylate (2EHA) as the monomer component is preferable, and an acrylic pressure-sensitive adhesive containing at least 2 EHA is particularly preferable.
  • (meth) acrylic acid C 4-20 alkyl esters that may be preferably used include isononyl acrylate, n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), isostearyl acrylate (ISTA). ) Etc. can be mentioned.
  • the monomer component constituting the acrylic polymer may contain (meth) acrylic acid C 4-18 alkyl ester in a proportion of 40% by weight or more.
  • (meth) acrylic acid C 4-18 alkyl ester in a proportion of 40% by weight or more.
  • an acrylic polymer having high lipophilicity tends to be formed.
  • an adhesive layer having a low rate of decrease in peeling force after immersion in water is likely to be formed.
  • the ratio of the (meth) acrylic acid C 4-18 alkyl ester to the monomer component may be, for example, 60% by weight or more, 70% by weight or more, 75% by weight or more, or 80% by weight or more. It may be a monomer component containing (meth) acrylic acid C 6-18 alkyl ester at a ratio equal to or higher than any of the above lower limit values. Further, from the viewpoint of enhancing the cohesiveness of the pressure-sensitive adhesive layer (A layer) and preventing cohesive failure, the ratio of (meth) acrylic acid C 4-18 alkyl ester to the monomer component is 99.5% by weight or less. It may be 99% by weight or less, 98% by weight or less, or 97% by weight or less.
  • the ratio of the (meth) acrylic acid C 4-18 alkyl ester to the monomer component is 95% by weight or less, for example, 90% by weight. % Or less is appropriate.
  • the proportion of (meth) acrylic acid C 4-18 alkyl ester in the monomer component may be 85% by weight or less, or 75% by weight or less. It may be a monomer component containing (meth) acrylic acid C 6-18 alkyl ester at a ratio equal to or less than any of the above-mentioned upper limit values.
  • the monomer component constituting the acrylic polymer contains a (meth) acrylic acid alkyl ester and, if necessary, another monomer (copolymerizable monomer) copolymerizable with the (meth) acrylic acid alkyl ester. May be good.
  • a monomer having a polar group for example, a carboxy group, a hydroxyl group, a nitrogen atom-containing ring, etc.
  • Monomers having polar groups can be useful for introducing cross-linking points into acrylic polymers and increasing the cohesive force of adhesives.
  • the copolymerizable monomer may be used alone or in combination of two or more.
  • Non-limiting specific examples of the copolymerizable monomer include the following.
  • Carboxylic group-containing monomer For example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like.
  • Acid anhydride group-containing monomer For example, maleic anhydride, itaconic anhydride.
  • Hydroxyl group-containing monomers for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic.
  • Monomer containing sulfonic acid group or phosphoric acid group For example, styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfo Propyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, 2-hydroxyethylacryloyl phosphate, etc.
  • styrene sulfonic acid allyl sulfonic acid, sodium vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfo Propyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, 2-hydroxyethy
  • Epoxide group-containing monomer For example, an epoxy group-containing acrylate such as glycidyl (meth) acrylate or -2-ethylglycidyl ether (meth) acrylate, allyl glycidyl ether, glycidyl ether (meth) acrylate and the like.
  • Cyanide-containing monomer For example, acrylonitrile, methacrylonitrile, etc.
  • Isocyanate group-containing monomer For example, 2-isocyanate ethyl (meth) acrylate and the like.
  • Amide group-containing monomers (meth) acrylamide; for example, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) N, N-dialkyl (meth) acrylamide, such as acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide; N-ethyl (meth) N-alkyl (meth) acrylamide such as acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, Nn-butyl (meth) acrylamide; N-vinylcarboxylic acid amide such as N-vinylacetamide Classes; monomers having a hydroxyl group and an amide group, for example
  • Amino group-containing monomer For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
  • Monomers having an epoxy group for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, allyl glycidyl ether.
  • N-vinyl-2-pyrrolidone N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N- Vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloyl piperidine, N- (meth) acryloylpyrrolidin, N-vinylmorpholin, N-vinyl-3 -Morholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxadin-2-one, N-vinyl-3,5-morpholindione, N-vinylpyrazole, N-vinylisoxazole, N-vinyl Thiazol
  • Monomers having a succinimide skeleton for example, N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyhexamethylene succinimide and the like.
  • Maleimides For example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like.
  • Itaconimides For example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-lauryl. Itaconimide, etc.
  • Aminoalkyl (meth) acrylates For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t (meth) acrylate. -Butylaminoethyl.
  • Alkoxy group-containing monomers for example, 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, (meth) acrylic acid.
  • Alkoxyalkyls (meth) acrylate such as butoxyethyl, ethoxypropyl (meth) acrylate;
  • Alkoxyalkylene glycol (meth) acrylate such as methoxyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, etc.
  • kind for example, 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, (meth) acrylic acid.
  • Alkoxysilyl group-containing monomers For example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxy. Propylmethyldiethoxysilane.
  • Vinyl esters For example, vinyl acetate, vinyl propionate and the like.
  • Vinyl ethers For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether.
  • Aromatic vinyl compounds for example, styrene, ⁇ -methylstyrene, vinyltoluene and the like.
  • Olefins For example, ethylene, butadiene, isoprene, isobutylene and the like.
  • acrylic acid ester having an aromatic hydrocarbon group For example, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate and the like.
  • heterocyclic-containing (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate, halogen atom-containing (meth) acrylates such as vinyl chloride and fluorine atom-containing (meth) acrylates, and silicon atom-containing silicone (meth) acrylates.
  • the amount used is not particularly limited, but it is appropriate to use 0.01% by weight or more of the total monomer component. From the viewpoint of better exerting the effect of using the copolymerizable monomer, the amount of the copolymerizable monomer used may be 0.1% by weight or more of the total monomer component, or 0.5% by weight or more. Further, from the viewpoint of facilitating the balance of the adhesive properties, the amount of the copolymerizable monomer used is preferably 50% by weight or less of the total monomer component, and preferably 40% by weight or less.
  • the monomer component constituting the acrylic polymer may include a monomer having a nitrogen atom.
  • a monomer having a nitrogen atom By using a monomer having a nitrogen atom, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photocuring can be preferably improved.
  • a preferred example of a monomer having a nitrogen atom is a monomer having a nitrogen atom-containing ring.
  • the monomer having a nitrogen atom-containing ring those exemplified above can be used, and for example, the general formula (1):
  • the N-vinyl cyclic amide represented by is used.
  • R 1 is a divalent organic group, specifically ⁇ (CH 2 ) n ⁇ .
  • n is an integer of 2 to 7 (preferably 2, 3 or 4). Of these, N-vinyl-2-pyrrolidone can be preferably adopted.
  • Other preferred examples of monomers having a nitrogen atom include (meth) acrylamide.
  • the amount of the monomer having a nitrogen atom is not particularly limited, and may be, for example, 1% by weight or more of the total monomer component, or 3% by weight or more. Further, it can be 5% by weight or more or 7% by weight or more. In some embodiments, the amount of the monomer having a nitrogen atom used may be 10% by weight or more, 15% by weight or more, or 20% by weight of the total monomer component from the viewpoint of improving the adhesive strength. It may be the above.
  • the amount of the monomer having a nitrogen atom to be used is appropriately set to, for example, 40% by weight or less of the total monomer component, 35% by weight or less, 30% by weight or less, or 25% by weight or less. May be good. In some other aspects, the amount of the monomer having a nitrogen atom used may be, for example, 20% by weight or less of the total monomer component, or 15% by weight or less.
  • the monomer component preferably contains a carboxy group-containing monomer.
  • the carboxy group-containing monomer include acrylic acid (AA) and methacrylic acid (MAA).
  • AA and MAA may be used in combination.
  • their weight ratio (AA / MAA) is not particularly limited, and can be, for example, in the range of about 0.1 to 10.
  • the weight ratio (AA / MAA) may be, for example, approximately 0.3 or greater, and may be approximately 0.5 or greater. Further, the weight ratio (AA / MAA) may be, for example, about 4 or less, or about 3 or less.
  • an aqueous liquid such as water can be quickly blended into the surface of the A layer. This can help reduce the water peeling force N2.
  • the amount of the carboxy group-containing monomer used may be, for example, 0.05% by weight or more, 0.1% by weight or more, 0.3% by weight or more, or 0.5% by weight or more of the total monomer component. However, it may be 0.8% by weight or more.
  • the proportion of the carboxy group-containing monomer may be, for example, 15% by weight or less, 10% by weight or less, 5% by weight or less, 4.5% by weight or less, and 3.5% by weight or less. However, it may be 3.0% by weight or less, or 2.5% by weight or less.
  • the amount of the carboxy group-containing monomer used is not too large from the viewpoint of suppressing the diffusion of water into the bulk of the A layer and suppressing the decrease in the peel strength N1 after immersion in water. Further, the fact that the amount of the carboxy group-containing monomer used is not too large can be advantageous from the viewpoint of preventing the event that the water used for measuring the water peeling force N2 is absorbed by the layer A and the water is insufficient during the peeling. ..
  • the monomer component may include a hydroxyl group-containing monomer.
  • the hydroxyl group-containing monomer By using the hydroxyl group-containing monomer, the cohesive force and the cross-linking density of the pressure-sensitive adhesive can be adjusted, and the peel strength N0 can be improved.
  • the amount used is not particularly limited, and may be, for example, 0.01% by weight or more, 0.1% by weight or more, or 0.5% by weight or more of the entire monomer component. It may be 1% by weight or more, 5% by weight or more, or 10% by weight or more.
  • the amount of the hydroxyl group-containing monomer used is, for example, 40% by weight or less of the total monomer component in some embodiments. It may be 10% by weight or less, 5% by weight or less, or 3% by weight or less.
  • the laminate disclosed herein can be preferably implemented even in an embodiment in which a hydroxyl group-containing monomer is substantially not used as a monomer component of the pressure-sensitive adhesive layer (A layer).
  • the monomer component may include an alkoxysilyl group-containing monomer.
  • the alkoxysilyl group-containing monomer is typically an ethylenically unsaturated monomer having at least one (preferably two or more, for example two or three) alkoxysilyl groups in one molecule. Specific examples are as described above.
  • the above-mentioned alkoxysilyl group-containing monomer may be used alone or in combination of two or more.
  • a crosslinked structure by a silanol group condensation reaction silanol group condensation reaction (silanol condensation) can be introduced into the pressure-sensitive adhesive layer (A layer).
  • the alkoxysilyl group-containing monomer can also be grasped as a silane coupling agent described later.
  • the ratio of the alkoxysilyl group-containing monomer to the entire monomer component can be, for example, 0.005% by weight or more, and 0.01% by weight or more. Is appropriate. Further, the proportion of the alkoxysilyl group-containing monomer may be, for example, 0.5% by weight or less, 0.1% by weight or less, or 0.05% by weight or less from the viewpoint of improving the adhesion to the adherend. It may be.
  • the monomer component of the acrylic polymer is limited to a total ratio of alkoxyalkyl (meth) acrylate and alkoxypolyalkylene glycol (meth) acrylate of less than 20% by weight from the viewpoint of suppressing gelation. Has been done.
  • the total proportion of the alkoxyalkyl (meth) acrylate and the alkoxypolyalkylene glycol (meth) acrylate is more preferably less than 10% by weight, still more preferably less than 3% by weight, particularly preferably less than 1% by weight, and some
  • the monomer component is substantially free of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol (meth) acrylates (content 0-0.3% by weight).
  • the monomer component of the acrylic polymer disclosed herein may or may not contain an alkoxy group-containing monomer in a proportion of less than 20% by weight.
  • the amount of the alkoxy group-containing monomer in the monomer component is preferably less than 10% by weight, more preferably less than 3% by weight, still more preferably less than 1% by weight, and in a particularly preferable embodiment, the monomer component contains an alkoxy group. Substantially free of monomers (content 0-0.3% by weight).
  • the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer is set in an appropriate range.
  • the "hydrophilic monomer” in the present specification contains a carboxy group-containing monomer, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer, a monomer having a nitrogen atom (typically, an amide group such as (meth) acrylamide).
  • Monomer monomer having a nitrogen atom-containing ring such as N-vinyl-2-pyrrolidone
  • alkoxy group-containing monomer typically, alkoxyalkyl (meth) acrylate and alkoxypolyalkylene glycol (meth) acrylate.
  • the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer is preferably 40% by weight or less (for example, 35% by weight or less), preferably 32% by weight or less, for example, 30% by weight. It may be less than or equal to 28% by weight or less.
  • the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer may be 1% by weight or more, 10% by weight or more, or 20% by weight or more. There may be.
  • the monomer component constituting the acrylic polymer may contain an alicyclic hydrocarbon group-containing (meth) acrylate.
  • an alicyclic hydrocarbon group-containing (meth) acrylate those exemplified above can be used, and for example, cyclohexyl acrylate and isobornyl acrylate can be preferably adopted.
  • the amount used is not particularly limited, and may be, for example, 1% by weight or more, 3% by weight or more, or 5% by weight or more of the total monomer component.
  • the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used may be 10% by weight or more, or 15% by weight or more, of the total monomer components.
  • the upper limit of the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used is appropriately about 40% by weight or less, for example, 30% by weight or less, and 25% by weight or less (for example, 15% by weight). % Or less, and even 10% by weight or less).
  • the composition of the monomer component is such that the glass transition temperature (hereinafter, also referred to as “glass transition temperature of the polymer”) determined by the Fox formula based on the composition of the monomer component is ⁇ 75 ° C. or higher and ⁇ 10 ° C. or lower. Can be set to.
  • the glass transition temperature (Tg) of the above polymer eg, acrylic polymer, typically acrylic polymer
  • the glass transition temperature (Tg) of the above polymer is preferably ⁇ 20 ° C. or lower, preferably ⁇ 30 ° C. or lower. It is preferably ⁇ 40 ° C. or lower, more preferably ⁇ 50 ° C. or lower, and may be ⁇ 55 ° C. or lower, for example.
  • the adhesion of the A layer to the base material layer and the adhesiveness to the adherend tend to be generally improved.
  • the layer A having high adhesion to the base material layer it is easy to suppress water infiltration into the interface between the base material layer and the layer A when the pressure-sensitive adhesive layer is not intended to be peeled off. This can be advantageous from the viewpoint of improving the peeling strength N1 after immersion in water and reducing the rate of decrease in peeling force after immersion in water.
  • the Tg of the polymer may be, for example, ⁇ 70 ° C. or higher, or ⁇ 65 ° C. or higher, from the viewpoint of facilitating the increase in peel strength N0. In some other aspects, the Tg may be, for example, ⁇ 60 ° C. or higher, ⁇ 50 ° C. or higher, ⁇ 45 ° C. or higher, or ⁇ 40 ° C. or higher.
  • Tg is the glass transition temperature (unit: K) of the copolymer
  • Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on the weight)
  • Tgi is the monomer i.
  • the glass transition temperature of the homopolymer used for calculating Tg the value described in the publicly known material shall be used.
  • the monomers listed below the following values are used as the glass transition temperature of the homopolymer of the monomer.
  • a homopolymer solution having a solid content concentration of 33% by weight.
  • this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm.
  • This test sample is punched into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear strain at a frequency of 1 Hz using a viscoelasticity tester (ARES, manufactured by Leometrics) in a temperature range of ⁇ 70 to 150 ° C.
  • the viscoelasticity is measured in a shear mode at a heating rate of 5 ° C./min, and the peak top temperature of tan ⁇ is defined as Tg of the homopolymer.
  • the polymer (for example, an acrylic polymer, typically an acrylic polymer) contained in the pressure-sensitive adhesive layer (A layer) disclosed herein is not particularly limited, but has an SP value of 23.0 (). MJ / m 3 ) It is preferably 1/2 or less.
  • the pressure-sensitive adhesive containing a polymer having such an SP value preferably realizes a pressure-sensitive adhesive having excellent water-removability while having sufficient adhesive strength by containing, for example, a water-affinitive agent described later. Can be.
  • the SP value is more preferably 21.0 (MJ / m 3 ) 1/2 or less (for example, 20.0 (MJ / m 3 ) 1/2 or less).
  • the lower limit of the SP value is not particularly limited, and for example, it is appropriate that it is approximately 10.0 (MJ / m 3 ) 1/2 or more, and approximately 15.0 (MJ / m 3 ) 1/2 or more. Yes, preferably 18.0 (MJ / m 3 ) 1/2 or more.
  • the polymer having the above SP value can be obtained by appropriately determining the monomer composition based on the common general technical knowledge of those skilled in the art.
  • the pressure-sensitive adhesive layer (layer A) contains a monomer component having the above-mentioned composition in the form of a polymer, a non-polymerized product (that is, a form in which a polymerizable functional group is unreacted), or a mixture thereof. It can be formed using a composition (hereinafter, also referred to as "adhesive composition A").
  • the pressure-sensitive adhesive composition A includes a water-dispersed pressure-sensitive adhesive composition in which a pressure-sensitive adhesive (adhesive component) is dispersed in water, a solvent-type pressure-sensitive adhesive composition in which a pressure-sensitive adhesive is contained in an organic solvent, ultraviolet rays, radiation, and the like.
  • An active energy ray-curable pressure-sensitive adhesive composition prepared to be cured by the active energy rays of the above to form a pressure-sensitive adhesive, which is coated in a heat-melted state and forms a pressure-sensitive adhesive when cooled to around room temperature. It can be in various forms such as an agent composition.
  • thermal polymerization initiator or photopolymerization initiator can be used depending on the polymerization method, polymerization mode, and the like.
  • a polymerization initiator may be used alone or in combination of two or more.
  • the thermal polymerization initiator is not particularly limited, but is, for example, an azo-based polymerization initiator, a peroxide-based initiator, a redox-based initiator by a combination of a peroxide and a reducing agent, and a substituted ethane-based initiator.
  • Etc. can be used. More specifically, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (2-amidinopropane) dihydrochloride.
  • 2,2'-Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2,2' -Azobis [N- (2-carboxyethyl) -2-methylpropionamidine]
  • Azo-based initiators such as hydrate; persulfates such as potassium persulfate and ammonium persulfate; benzoyl peroxide, t-butyl hydroperoxide ,
  • Peroxide-based initiators such as hydrogen peroxide; for example, substituted ethane-based initiators such as phenyl-substituted ethane; for example, redox such as a combination of persulfate and sodium hydrogen sulfite, a combination of peroxide and sodium ascorbate, etc.
  • System initiators; and the like are exemplified, but not limited thereto.
  • the photopolymerization initiator is not particularly limited, but for example, a ketal-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, a benzoin ether-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, ⁇ - Ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, thioxanthone-based light
  • a polymerization initiator or the like can be used.
  • the amount of such a thermal polymerization initiator or photopolymerization initiator used can be a normal amount according to the polymerization method, polymerization mode, etc., and is not particularly limited.
  • about 0.001 to 5 parts by weight of the polymerization initiator typically about 0.01 to 2 parts by weight, for example, about 0.01 to 1 part by weight
  • chain transfer agents which can also be grasped as a molecular weight adjusting agent or a degree of polymerization adjusting agent
  • chain transfer agent mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, and thioglycolic acid
  • a chain transfer agent containing no sulfur atom non-sulfur chain transfer agent
  • non-sulfur chain transfer agent examples include anilins such as N, N-dimethylaniline and N, N-diethylaniline; terpenoids such as ⁇ -pinene and turpinolene; ⁇ -methylstyrene and ⁇ -methylstyrene dimer.
  • the chain transfer agent may be used alone or in combination of two or more. When a chain transfer agent is used, the amount used can be, for example, about 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer component.
  • the techniques disclosed herein may also be preferably practiced in aspects that do not use chain transfer agents.
  • the molecular weight of the polymer (for example, acrylic polymer, typically acrylic polymer) obtained by appropriately adopting the above various polymerization methods is not particularly limited and can be set in an appropriate range according to the required performance and the like. .. Viewpoint weight average molecular weight of the polymer (Mw) of suitably be at about 10 ⁇ 10 4 or more, for example may be at about 15 ⁇ 10 4 or more, to achieve both good balance and cohesive force and adhesive force Therefore, it is preferably more than 30 ⁇ 10 4 .
  • the above-mentioned polymer according to some aspects is preferably 40 ⁇ 10 4 or more (typically about 50 ⁇ 10 4 or more, for example, about 55 ⁇ 10) from the viewpoint of obtaining good adhesion reliability even in a high temperature environment.
  • Mw 4 or more).
  • the upper limit of Mw of the polymer may be about 500 ⁇ 10 4 or less (e.g., about 0.99 ⁇ 10 4 or less).
  • the Mw may be of about 75 ⁇ 10 4 or less.
  • Mw refers to a standard polystyrene-equivalent value obtained by gel permeation chromatography (GPC).
  • GPC gel permeation chromatography
  • the model name "HLC-8320GPC" columnumn: TSKgelGMH-H (S), manufactured by Tosoh Corporation
  • the laminate according to some aspects has a layer A formed from the water-dispersible pressure-sensitive adhesive composition.
  • a typical example of the water-dispersible pressure-sensitive adhesive composition is an emulsion-type pressure-sensitive adhesive composition.
  • Emulsion-type pressure-sensitive adhesive compositions typically contain a polymer of monomeric components and, optionally, additives.
  • Emulsion polymerization of monomer components is usually performed in the presence of an emulsifier.
  • the emulsifier for emulsion polymerization is not particularly limited, and known anionic emulsifiers, nonionic emulsifiers and the like can be used.
  • the emulsifier may be used alone or in combination of two or more.
  • anionic emulsifiers include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, polyoxy. Examples thereof include sodium ethylenealkylphenyl ether sulfate and sodium polyoxyethylene alkyl sulfosuccinate.
  • Non-limiting examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyoxypropylene block polymers and the like.
  • An emulsifier having a reactive functional group may be used.
  • the reactive emulsifier include a radically polymerizable emulsifier having a structure in which a radically polymerizable functional group such as a propenyl group or an allyl ether group is introduced into the above-mentioned anionic emulsifier or nonionic emulsifier.
  • the amount of the emulsifier used in the emulsion polymerization may be, for example, 0.2 parts by weight or more, 0.5 parts by weight or more, or 1.0 part by weight or more with respect to 100 parts by weight of the monomer component. It may be 5 parts by weight or more. Further, from the viewpoint of improving the peel strength N1 after immersion in water, reducing the rate of decrease in peeling force after immersion in water, or improving the transparency of the pressure-sensitive adhesive layer (layer A), the amount of the emulsifier used is determined in some embodiments. It is suitable to be 10 parts by weight or less with respect to 100 parts by weight of the component, preferably 5 parts by weight or less, and may be 3 parts by weight or less.
  • the emulsifier used for emulsion polymerization here can also function as an aqueous affinity agent for layer A.
  • a polymerization reaction solution in the form of an emulsion in which a polymer of monomer components is dispersed in water can be obtained.
  • the water-dispersible pressure-sensitive adhesive composition used for forming the A layer can be preferably produced by using the above-mentioned polymerization reaction solution.
  • the laminate may have a layer A formed from a solvent-based pressure-sensitive adhesive composition.
  • the solvent-based pressure-sensitive adhesive composition typically contains a solution polymerization of the monomer components and an additive used as needed.
  • the effect of the technique disclosed herein (the effect of improving water peelability by forming a hydrophilic layer on the base material layer) can be effectively exerted on the solvent-type pressure-sensitive adhesive layer (layer A).
  • the use of a solvent-based pressure-sensitive adhesive is also advantageous in terms of optical properties.
  • the solvent (polymerization solvent) used for solution polymerization can be appropriately selected from conventionally known organic solvents.
  • aromatic compounds such as toluene (typically aromatic hydrocarbons); esters such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane; 1,2- Select from halogenated alkanes such as dichloroethane; lower alcohols such as isopropyl alcohol (for example, monovalent alcohols having 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc. Any one solvent or a mixed solvent of two or more can be used.
  • a polymerization reaction solution in which a polymer of a monomer component is dissolved in a polymerization solvent can be obtained.
  • the solvent-type pressure-sensitive adhesive composition used for forming the A layer can be preferably produced by using the above-mentioned polymerization reaction solution.
  • the laminate may have a layer A formed from an active energy ray-curable pressure-sensitive adhesive composition.
  • active energy ray refers to an energy ray having energy that can cause a chemical reaction such as a polymerization reaction, a cross-linking reaction, or decomposition of an initiator.
  • active energy rays include light such as ultraviolet rays, visible rays, and infrared rays, and radiation such as ⁇ rays, ⁇ rays, ⁇ rays, electron rays, neutron rays, and X-rays.
  • a photocurable pressure-sensitive adhesive composition is mentioned as a preferable example of the active energy ray-curable pressure-sensitive adhesive composition.
  • the photocurable pressure-sensitive adhesive composition has an advantage that even a thick pressure-sensitive adhesive layer can be easily formed. Of these, an ultraviolet curable pressure-sensitive adhesive composition is preferable. Further, the effect of the technique disclosed herein (effect of improving water peelability by forming a hydrophilic layer on the base material layer) can be effectively exerted on the photocurable pressure-sensitive adhesive layer (layer A).
  • the use of a photocurable pressure-sensitive adhesive is also advantageous in terms of optical properties.
  • the photocurable pressure-sensitive adhesive composition typically contains at least a portion of the monomer components of the composition (which may be part of the type of monomer or part of the amount). Included in the form of a polymer.
  • the polymerization method for forming the above-mentioned polymer is not particularly limited, and various conventionally known polymerization methods can be appropriately adopted. For example, thermal polymerization such as solution polymerization, emulsion polymerization, bulk polymerization (typically performed in the presence of a thermal polymerization initiator); photopolymerization performed by irradiating light such as ultraviolet rays (typically).
  • photopolymerization It is carried out in the presence of a photopolymerization initiator.); Radiation polymerization carried out by irradiating radiation such as ⁇ -ray and ⁇ -ray; and the like can be appropriately adopted. Of these, photopolymerization is preferable.
  • the photocurable pressure-sensitive adhesive composition contains a partial polymer of monomer components.
  • a partial polymer is typically a mixture of a polymer derived from a monomer component and an unreacted monomer, and preferably exhibits a syrup-like (viscous liquid) form.
  • the partial polymer having such properties may be referred to as "monomer syrup” or simply "syrup".
  • the polymerization method for partially polymerizing the monomer component is not particularly limited, and various polymerization methods as described above can be appropriately selected and used. From the viewpoint of efficiency and convenience, the photopolymerization method can be preferably adopted. According to photopolymerization, the polymerization conversion rate (monomer conversion) of the monomer component can be easily controlled by the polymerization conditions such as the irradiation amount of light (light amount).
  • the polymerization conversion rate of the monomer mixture in the above partial polymer is not particularly limited.
  • the polymerization conversion rate can be, for example, about 70% by weight or less, and preferably about 60% by weight or less. From the viewpoint of ease of preparation and coatability of the pressure-sensitive adhesive composition containing the partial polymer, the polymerization conversion rate is preferably about 50% by weight or less, and is about 40% by weight or less (for example, about 35% by weight). The following) is preferable.
  • the lower limit of the polymerization conversion rate is not particularly limited, but is typically about 1% by weight or more, and it is appropriate to set it to about 5% by weight or more.
  • the pressure-sensitive adhesive composition containing a partial polymer of the monomer component for example, a monomer mixture containing the entire amount of the monomer component used for preparing the pressure-sensitive adhesive composition is partially polymerized by an appropriate polymerization method (for example, a photopolymerization method).
  • an appropriate polymerization method for example, a photopolymerization method.
  • the pressure-sensitive adhesive composition containing a partial polymer of the monomer component is a partial polymer or a complete polymer of a monomer mixture containing a part of the monomer components used in the preparation of the pressure-sensitive adhesive composition, and the remaining monomer. It may be a mixture with a component or a partial polymer thereof.
  • "complete polymer" means that the polymerization conversion rate is more than 95% by weight.
  • the pressure-sensitive adhesive composition containing the partial polymer may contain other components (for example, a photopolymerization initiator, a polyfunctional monomer, a cross-linking agent, a water affinity agent, etc.) used as necessary.
  • the method of blending such other components is not particularly limited, and for example, it may be contained in the monomer mixture in advance, or may be added to the partial polymer.
  • a cross-linking agent may be used for the pressure-sensitive adhesive layer (layer A), if necessary.
  • the pressure-sensitive adhesive composition A for forming the pressure-sensitive adhesive layer (layer A) may contain a cross-linking agent, if necessary.
  • the cross-linking agent is typically contained in the pressure-sensitive adhesive layer (layer A) in the form after the cross-linking reaction.
  • the pressure-sensitive adhesive layer (layer A) formed from the pressure-sensitive adhesive composition A containing a cross-linking agent typically contains a polymer cross-linked by the cross-linking agent (for example, an acrylic polymer).
  • the pressure-sensitive adhesive layer (layer A) can be a pressure-sensitive adhesive layer (layer A) containing an acrylic polymer crosslinked by a cross-linking agent.
  • the cross-linking agent By using the cross-linking agent, the cohesive force of the pressure-sensitive adhesive layer (A layer) can be appropriately adjusted, and for example, the cohesive force of the pressure-sensitive adhesive layer (A layer) before photo-curing can be appropriately adjusted.
  • the photoreactive compound described later and the cross-linking agent are used in combination, characteristics such as adhesion durability and peel strength of the pressure-sensitive adhesive layer after photocuring can be appropriately adjusted.
  • the type of the cross-linking agent is not particularly limited, and is selected from the conventionally known cross-linking agents so that the cross-linking agent exhibits an appropriate cross-linking function in the pressure-sensitive adhesive layer, for example, depending on the composition of the pressure-sensitive adhesive composition. be able to.
  • the cross-linking agent that can be used include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, carbodiimide-based cross-linking agents, melamine-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, and metals.
  • Examples thereof include a chelate-based cross-linking agent, a metal salt-based cross-linking agent, a hydrazine-based cross-linking agent, and an amine-based cross-linking agent. These can be used alone or in combination of two or more. In the water-dispersible pressure-sensitive adhesive composition, it is preferable to use a cross-linking agent that can be dissolved or dispersed in water.
  • a polyfunctional isocyanate compound having two or more functions can be used.
  • aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris (p-isocyanatophenyl) thiophosphate, diphenylmethane diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate. Isocyanate; etc.
  • Coronate HL isocyanurate of hexamethylene diisocyanate (manufactured by Toso Co., Ltd., trade name” Coronate HX "), trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals Co., Ltd., trade name" Takenate D-110N “), etc.
  • Isocyanate adducts and the like can be exemplified.
  • an isocyanate-based cross-linking agent that can be dissolved or dispersed in water.
  • a water-soluble, water-dispersible or self-emulsifying isocyanate-based cross-linking agent can be preferably adopted.
  • a so-called blocked isocyanate type isocyanate-based cross-linking agent in which the isocyanate group is blocked can be preferably used.
  • epoxy-based cross-linking agent one having two or more epoxy groups in one molecule can be used without particular limitation.
  • An epoxy-based cross-linking agent having 3 to 5 epoxy groups in one molecule is preferable.
  • Specific examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, and 1,6-hexane. Examples thereof include diol diglycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerol polyglycidyl ether.
  • epoxy cross-linking agents include Mitsubishi Gas Chemical Company's product names “TETRAD-X” and “TETRAD-C”, DIC's product name “Epicron CR-5L”, and Nagase ChemteX's products. Examples thereof include the name “Denacol EX-512” and the product name "TEPIC-G” manufactured by Nissan Chemical Industries, Ltd.
  • oxazoline-based cross-linking agent those having one or more oxazoline groups in one molecule can be used without particular limitation.
  • aziridine-based cross-linking agent include trimethylolpropane tris [3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1- (2-methyl) aziridinyl propionate)], and the like. Be done.
  • carbodiimide-based cross-linking agent a low molecular weight compound or a high molecular weight compound having two or more carbodiimide groups can be used.
  • Peroxide may be used as the cross-linking agent in some embodiments.
  • Peroxides include di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, and t-butylperoxyneodecanoate.
  • examples of the peroxide having particularly excellent cross-linking reaction efficiency include di (4-t-butylcyclohexyl) peroxydicarbonate, dilauroyl peroxide, and dibenzoyl peroxide.
  • a peroxide is used as the polymerization initiator, the peroxide remaining without being used in the polymerization reaction can be used in the crosslinking reaction.
  • the residual amount of peroxide may be quantified, and if the ratio of peroxide is less than a predetermined amount, the peroxide may be added so as to be a predetermined amount, if necessary.
  • the amount of peroxide can be quantified by the method described in Japanese Patent No. 4971517.
  • the amount used when a cross-linking agent is used is not particularly limited. From the viewpoint of realizing a pressure-sensitive adhesive that exhibits a well-balanced adhesive property such as adhesive strength and cohesive power, the amount of the cross-linking agent used is 100, which is a monomer component (for example, a monomer component of an acrylic polymer) contained in the pressure-sensitive adhesive composition A. It is appropriate that the amount is about 5 parts by weight or less with respect to the parts by weight, and it may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or less than 1 part by weight. ..
  • the amount of the cross-linking agent (for example, isocyanate-based cross-linking agent) used with respect to 100 parts by weight of the monomer component is 0, for example, from the viewpoint of facilitating the effect of using the photoreactive compound in combination. It may be .50 parts by weight or less, 0.40 parts by weight or less, 0.30 parts by weight or less, or 0.20 parts by weight or less.
  • the lower limit of the amount of the cross-linking agent used is not particularly limited, and may be more than 0 parts by weight with respect to 100 parts by weight of the monomer component.
  • the amount of the cross-linking agent used may be, for example, 0.001 part by weight or more, 0.01 parts by weight or more, and 0.05 parts by weight, based on 100 parts by weight of the monomer component. It may be 10 parts by weight or more, and may be 0.10 parts by weight or more.
  • a cross-linking catalyst may be used to allow the cross-linking reaction to proceed more effectively.
  • the cross-linking catalyst include metal-based cross-linking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric nasem, butyl tin oxide, and dioctyl tin dilaurate. Of these, tin-based cross-linking catalysts such as dioctyl tin dilaurate are preferable.
  • the amount of the cross-linking catalyst used is not particularly limited.
  • the amount of the cross-linking catalyst used is, for example, about 0.0001 parts by weight or more and about 0.001 parts by weight or more with respect to 100 parts by weight of the monomer component (for example, the monomer component of the acrylic polymer) contained in the pressure-sensitive adhesive composition A. It can be about 0.005 parts by weight or more, about 1 part by weight or less, about 0.1 parts by weight or less, about 0.05 parts by weight or less, and the like.
  • the pressure-sensitive adhesive composition A used for forming the pressure-sensitive adhesive layer (layer A) can contain a compound that causes keto-enol tautomerism as a cross-linking retarder.
  • a compound that causes keto-enol tvariability can be preferably used in the pressure-sensitive adhesive composition A containing an isocyanate-based cross-linking agent or the pressure-sensitive adhesive composition A that can be used by blending an isocyanate-based cross-linking agent.
  • a compound that causes keto-enol tvariability can be preferably used.
  • Various ⁇ -dicarbonyl compounds can be used as the compound that causes keto-enol telecommunication.
  • ⁇ -diketones such as acetylacetone and 2,4-hexanedione
  • acetoacetate esters such as methyl acetoacetate and ethyl acetoacetate
  • propionyl acetates such as ethyl propionyl acetate
  • isobutyryl such as ethyl isobutylyl acetate.
  • Acetic acid esters; malonic acid esters such as methyl malonate and ethyl malonate; and the like.
  • acetylacetone and acetoacetic ester are preferable compounds.
  • the compounds that cause keto-enol tautomerism can be used alone or in combination of two or more.
  • the amount of the compound that causes keto-enol remutability is, for example, 0.1 part by weight or more and 20 parts by weight with respect to 100 parts by weight of the monomer component (for example, the monomer component of the acrylic polymer) contained in the pressure-sensitive adhesive composition A. It may be 5 parts by weight or less, and may be 0.5 parts by weight or more and 15 parts by weight or less, for example, 1 part by weight or more and 10 parts by weight or less, and 1 part by weight or more and 5 parts by weight or less. Good.
  • the technology disclosed herein is a form in which the pressure-sensitive adhesive layer is a photo-curable pressure-sensitive adhesive layer (photo-curable pressure-sensitive adhesive layer), and a photo-curable pressure-sensitive adhesive layer (photo-curable pressure-sensitive adhesive layer). In any of the forms, it can be carried out in a manner that satisfies a predetermined peeling strength characteristic and a water peeling force reduction rate characteristic.
  • the pressure-sensitive adhesive composition A for forming the pressure-sensitive adhesive layer (layer A) may contain a photoreactive compound. In some embodiments, the pressure-sensitive adhesive layer (layer A) may contain a photoreactive compound.
  • the photoreactive compound a compound having two or more ethylenically unsaturated groups in the molecule is used.
  • the photoreactive compound according to some preferred embodiments has two or more ethylenically unsaturated groups and an oxyalkylene structural unit in the molecule.
  • the photoreactive compound contained in the pressure-sensitive adhesive layer (layer A) is formed by laminating the pressure-sensitive adhesive layer (layer A) on the base material layer and then reacting the ethylenically unsaturated group with light (for example, ultraviolet rays) irradiation or the like. , A crosslinked structure having moderate flexibility can be formed.
  • the photoreactive compound may be present in a reacted state within the pressure-sensitive adhesive layer (layer A).
  • the photoreactive compound may be present in the pressure-sensitive adhesive layer (layer A) in a free state (which may be unreacted), as described below.
  • the photoreactive compound may be used alone or in combination of two or more.
  • ethylenically unsaturated group examples include, but are not limited to, an acryloyl group, a methacryloyl group, a vinyl group and an allyl group.
  • the two or more ethylene unsaturated groups that the photoreactive compound has in the molecule may be the same group or two or more different groups.
  • Preferred ethylenically unsaturated groups from the viewpoint of photoreactivity include acryloyl group and methacryloyl group. Of these, the acryloyl group is preferable.
  • the oxyalkylene structural unit refers to a structural unit represented by the general formula (U1): -AO- ;, and is typically represented by the general formula (U2): -C m H 2 m O- ;.
  • a in the general formula (U1) is typically an alkylene group having 2 or more carbon atoms, preferably an alkylene group having 2 to 4 carbon atoms.
  • M in the above formula (U2) is an integer of 2 or more, preferably an integer of 2 to 4, and more preferably an integer of 2 to 3.
  • Preferable examples of AO units include oxyethylene units and oxypropylene units. Such AO units can be formed, for example, by modification (addition reaction) with an alkylene oxide or an alkylene glycol.
  • the photoreactive compound may be a compound containing a repeating structure in which two or more AO units represented by the general formula (U1) are continuous, that is, a structure represented by the general formula:-(AO) n- ;. ..
  • n in the above equation is an integer of 2 or more, for example, an integer of 2 to 10, preferably an integer of 2 to 5, and more preferably an integer of 2 to 3.
  • the photoreactive compound may be a compound that does not contain a repeating structure in which two or more AO units are continuous (it may be a compound that discontinuously contains two or more AO units). According to such a photoreactive compound, a pressure-sensitive adhesive layer (layer A) having a good balance between cohesiveness and crosslinking flexibility can be efficiently formed.
  • the photoreactive compound contains at least one, preferably two or more (for example, about 2 to 4) AOs between one ethylenically unsaturated group and any one of the other ethylenically unsaturated groups. It is more preferable to have a molecular structure in which units are arranged. The two or more AO units may or may not be adjacent to each other to form a ⁇ (AO) n ⁇ structure. In some embodiments, the photoreactive compound preferably has a molecular structure in which AO units are arranged adjacent to at least a portion of the ethylenically unsaturated groups contained in the photoreactive compound. ..
  • AO units placed adjacent to an ethylenically unsaturated group can effectively contribute to the softening of the crosslinked structure formed by the reaction of the ethylenically unsaturated group.
  • ethylenically unsaturated groups eg, a (meth) acryloyl group
  • AO units placed adjacent to an ethylenically unsaturated group
  • ethylenically unsaturated group eg, a (meth) acryloyl group
  • AO unit Adjacently arranged photoreactive compounds may be preferably employed.
  • the photoreactive compound a compound having 2 to 10 ethylenically unsaturated groups in the molecule is preferable, a compound having 2 to 8 ethylenically unsaturated groups in the molecule is more preferable, and 2 in the molecule is preferable. Compounds having up to 6 ethylenically unsaturated groups are more preferred.
  • the photoreactive compound can be a compound having 3 or more (typically 3-8, eg 3-6) ethylenically unsaturated groups in the molecule.
  • the pressure-sensitive adhesive layer (layer A) adheres to the base material layer after curing.
  • Durability can be efficiently improved (eg, even with a relatively small amount of photoreactive compound). This can be advantageous from the viewpoint of processability, handleability, and the like of the laminate disclosed herein.
  • the photoreactive compound can be a compound having two ethylenically unsaturated groups in the molecule. Thereby, a pressure-sensitive adhesive showing higher peel strength can be realized.
  • the photoreactive compound comprises a compound having 3 or more (typically 3-8, eg 3-6) ethylenically unsaturated groups in the molecule and 2 in the molecule.
  • a compound having an ethylenically unsaturated group is used in combination.
  • Examples of the photoreactive compound having three or more ethylenically unsaturated groups in the molecule include ethoxylated pentaerythritol trimethylolpropane (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, and ethoxylated dipentaerythritol penta (meth).
  • Examples of the photoreactive compound having two ethylenically unsaturated groups in the molecule include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, and EO-modified bisphenol F. Examples thereof include, but are not limited to, di (meth) acrylate, PO-modified bisphenol A di (meth) acrylate, and PO-modified bisphenol F di (meth) acrylate.
  • the molecular weight of the photoreactive compound is not particularly limited and can be selected so as to preferably exert the desired effect.
  • a compound having a molecular weight of about 2500 or less can be used as the photoreactive compound.
  • the molecular weight of the photoreactive compound may be, for example, 2000 or less, 1500 or less, or 1000 or less.
  • the molecular weight of the photoreactive compound is typically 200 or more.
  • the molecular weight of the photoreactive compound may be, for example, 230 or more, 300 or more, 350 or more, 450 or more, or 500 or more.
  • the molecular weight of the photoreactive compound can be obtained, for example, by the GPC method as a weight average molecular weight (Mw) in terms of standard polystyrene.
  • Mw weight average molecular weight
  • the molecular weight calculated from the manufacturer's nominal value or the molecular structure may be adopted.
  • the amount of the photoreactive compound contained in the pressure-sensitive adhesive layer (layer A) is not particularly limited, and can be appropriately set according to the desired performance.
  • the content of the photoreactive compound in the pressure-sensitive adhesive composition A or the pressure-sensitive adhesive layer (layer A) is a polymer (typically an acrylic polymerization) contained in the pressure-sensitive adhesive layer (layer A).
  • a polymer typically an acrylic polymerization
  • the monomer component of a product for example, it may be 0.5 parts by weight or more, 1 part by weight or more is suitable, 2 parts by weight or more, or 3 parts by weight or more. It may be 4 parts by weight or more.
  • the content of the photoreactive compound with respect to 100 parts by weight of the monomer component can be, for example, 30 parts by weight or less, and from the viewpoint of processability and the like, it is appropriate to be less than 20 parts by weight, and 15 parts by weight. It is preferably less than a portion. From the viewpoint of avoiding a decrease in peel strength due to excessive cross-linking, in some embodiments, the content of the photoreactive compound with respect to 100 parts by weight of the monomer component may be, for example, less than 10 parts by weight, and 8.0 parts by weight. It may be less than 6.0 parts by weight.
  • the photoreactive compound exists in the pressure-sensitive adhesive composition A before the formation of the pressure-sensitive adhesive layer (layer A) and the photo-curable pressure-sensitive adhesive layer (layer A) in a free form, and the pressure-sensitive adhesive after photo-curing.
  • the layer (A layer) is preferably chemically bonded to other components (for example, an acrylic polymer) in the pressure-sensitive adhesive layer.
  • the chemical bond is, for example, a functional group F1 other than the ethylenically unsaturated group that the photoreactive compound has in the molecule, and a functional group that the other component has in the molecule and can react with the functional group F1. It can be formed by reaction with the functional group F2.
  • the above reaction can be suitably proceeded by, for example, allowing a photoreaction catalyst described later to exist in the pressure-sensitive adhesive layer (layer A) and performing a photocuring treatment.
  • a pressure-sensitive adhesive layer (layer A) can be suitably formed by using a pressure-sensitive adhesive composition A containing a photoreactive compound in a free form.
  • the "free form” means that the photoreactive compound is not chemically bonded to the pressure-sensitive adhesive layer (layer A) or other components (for example, an acrylic polymer) contained in the pressure-sensitive adhesive composition A.
  • the pressure-sensitive adhesive composition A containing the photoreactive compound in a free form can be advantageous from the viewpoint of ease of preparation and suppression of gelation.
  • the pressure-sensitive adhesive composition A and the photocurable pressure-sensitive adhesive layer (layer A) have one or more other ethylenically unsaturated groups in the molecule and do not correspond to a photoreactive compound. May contain a photoreactive compound of.
  • Examples of other photoreactive compounds are compounds having two or more ethylenically unsaturated groups in the molecule and no AO building units; having two or more ethylenically unsaturated groups in the molecule.
  • Compounds having a molecular weight of more than 250 and having no AO unit; etc. are included.
  • Specific examples of compounds corresponding to other photoreactive compounds include pentaerythritol trimethylolpropane (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and dipentaerythritol penta (meth) acrylate.
  • the content of the pressure-sensitive adhesive composition A and the other photoreactive compounds in the pressure-sensitive adhesive layer (layer A) is not particularly limited.
  • the content of the pressure-sensitive adhesive composition A and the other photoreactive compounds in the pressure-sensitive adhesive layer (layer A) is a polymer (typically acrylic) contained in the pressure-sensitive adhesive layer (layer A).
  • it may be 0.01 part by weight or more, 0.1 part by weight or more is suitable, and 1 part by weight or more may be used with respect to 100 parts by weight of the monomer component of the system polymer (for example, acrylic polymer).
  • the content of the other photoreactive compound with respect to 100 parts by weight of the monomer component can be, for example, 10 parts by weight or less, preferably less than 5 parts by weight, and less than 3 parts by weight. Is preferable.
  • the content of the other photoreactive compound in the pressure-sensitive adhesive composition A and the pressure-sensitive adhesive layer (layer A) is determined by weight, for example.
  • the content of the photoreactive compound may be 0.9 times or less, preferably 0.5 times or less, 0.2 times or less, or 0.1 times or less.
  • the technique disclosed herein can be carried out in a form in which the pressure-sensitive adhesive composition A and the pressure-sensitive adhesive layer (layer A) substantially do not contain other photoreactive compounds.
  • substantially free of other photoreactive compounds means that other photoreactive compounds are not used at least intentionally, for example, in the material used for preparing the pressure-sensitive adhesive composition A. It is permissible to unintentionally mix a small amount of a compound corresponding to other photoreactive compounds as an impurity or a subcomponent of the above.
  • the other photoreactive compounds are present in the pressure-sensitive adhesive composition A before the formation of the pressure-sensitive adhesive layer (layer A) and the photo-curable pressure-sensitive adhesive layer (layer A) in a free form, and are present in a free form after photo-curing.
  • the pressure-sensitive adhesive layer (A layer) is chemically bonded to other components (for example, an acrylic polymer) in the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive composition A and the photocurable pressure-sensitive adhesive layer (layer A) disclosed herein are provided with a photoreaction catalyst (photoreaction initiator), if necessary, for the purpose of improving or imparting photocurability. It can be contained.
  • a photoreaction catalyst include a ketal-based photochemical reaction initiator, an acetophenone-based photochemical reaction initiator, a benzoin ether-based photochemical reaction initiator, an acylphosphine oxide-based photochemical reaction initiator, an ⁇ -ketol-based photochemical reaction initiator, and an aromatic.
  • a sulfonyl chloride photochemical initiator, a photoactive oxime photochemical initiator, a benzoin photochemical initiator, a benzyl photochemical initiator, a benzophenone photochemical initiator, a thioxanthone photochemical initiator, and the like can be used. ..
  • the photoreaction catalyst one type can be used alone or two or more types can be used in combination as appropriate.
  • ketal-based photoreaction initiator examples include 2,2-dimethoxy-1,2-diphenylethane-1-one and the like.
  • acetophenone-based photoreaction initiator examples include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- (2-hydroxyethoxy) -phenyl]. -2-Hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, methoxyacetophenone and the like are included.
  • benzoin ether-based photoreaction initiator examples include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether and benzoin isobutyl ether, and substituted benzoin ethers such as anisole methyl ether.
  • acylphosphine oxide-based photoreaction initiators include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxy.
  • phenylphosphine oxide 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like.
  • Specific examples of the ⁇ -ketol-based photoreaction initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and the like. Is done.
  • aromatic sulfonyl chloride-based photoreaction initiator include 2-naphthalene sulfonyl chloride and the like.
  • the photoactive oxime-based photoreaction initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime and the like.
  • Specific examples of the benzoin-based photoreaction initiator include benzoin and the like.
  • Specific examples of the benzyl-based photoreaction initiator include benzyl and the like.
  • Specific examples of the benzophenone-based photoreaction initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, ⁇ -hydroxycyclohexylphenylketone and the like.
  • thioxanthone-based photoreaction initiator examples include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and isopropylthioxanthone. , 2,4-Diisopropylthioxanthone, dodecylthioxanthone and the like.
  • the content of the photoreaction catalyst in the pressure-sensitive adhesive layer (layer A) is not particularly limited, and can be set so that the desired effect is appropriately exhibited.
  • the content of the photoreaction catalyst is, for example, approximately 0.005 parts by weight or more with respect to 100 parts by weight of the monomer component of the polymer (typically an acrylic polymer) contained in the pressure-sensitive adhesive layer. It is appropriate that the amount is 0.01 parts by weight or more, preferably 0.05 parts by weight or more, 0.10 parts by weight or more, or 0.15 parts by weight or more. It may be 0.20 parts by weight or more.
  • the content of the photochemical catalyst with respect to 100 parts by weight of the monomer component is preferably 5 parts by weight or less, preferably 2 parts by weight or less, and may be 1 part by weight or less, 0.7. It may be 5 parts by weight or less, or 0.5 parts by weight or less.
  • the fact that the content of the photoreaction catalyst is not too high can be advantageous from the viewpoint of improving the storage stability (for example, stability against photodegradation) of the laminate.
  • the pressure-sensitive adhesive layer (layer A) containing the photoreaction catalyst can typically be formed by using the pressure-sensitive adhesive composition A (for example, a solvent-type pressure-sensitive adhesive composition) containing the photoreaction catalyst.
  • the pressure-sensitive adhesive composition containing the photoreaction catalyst can be prepared, for example, by mixing the other components used in the composition with the photoreaction catalyst.
  • the residue (unreacted product) of the photopolymerization initiator used in the above may be used as a part or all of the photoreaction catalyst contained in the pressure-sensitive adhesive layer (layer A).
  • the pressure-sensitive adhesive layer (layer A) disclosed herein uses a pressure-sensitive adhesive composition prepared by newly adding the above-mentioned amount of photoreaction catalyst to other constituent components. Can be preferably formed.
  • the pressure-sensitive adhesive composition A that can be used for the pressure-sensitive adhesive layer (layer A) in the technique disclosed herein can contain a water-affinitive agent, if desired.
  • a water-affinitive agent in the pressure-sensitive adhesive layer (layer A)
  • the peeling force can be effectively reduced by utilizing an aqueous liquid such as water.
  • the water-affinitive agent has a hydrophilic region, so that the pressure-sensitive adhesive layer (layer A) (for example, the pressure-sensitive adhesive layer formed from the solvent-type pressure-sensitive adhesive composition).
  • water-affinitive agent one that is liquid at room temperature (about 25 ° C.) can be preferably used from the viewpoint of ease of preparation of the pressure-sensitive adhesive composition.
  • the water affinity agent may be used alone or in combination of two or more.
  • At least one compound A selected from a surfactant and a compound having a polyoxyalkylene skeleton can be used.
  • the compound having a surfactant and a polyoxyalkylene skeleton one or more of known surfactants and compounds having a polyoxyalkylene skeleton can be used without particular limitation. Needless to say, among the above-mentioned surfactants, there are compounds having a polyoxyalkylene skeleton, and vice versa.
  • nonionic surfactants As the surfactant that can be used as compound A, known nonionic surfactants, anionic surfactants, cationic surfactants and the like can be used. Of these, nonionic surfactants are preferable.
  • the surfactant may be used alone or in combination of two or more.
  • nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, and poly.
  • Polyoxyethylene alkylphenyl ether such as oxyethylene nonylphenyl ether; sorbitan fatty acid ester such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate; polyoxyethylene sorbitan monolaurate, polyoxyethylene Polyoxyethylene sorbitan such as sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate Examples thereof include fatty acid ester; polyoxyethylene glyceryl ether fatty acid ester; polyoxyelene-polyoxypropylene block copolymer; and the like. These nonionic surfactants can be used alone or in combination of two or more.
  • anionic surfactants include alkylbenzene sulfonates such as nonylbenzene sulfonate, dodecylbenzene sulfonate (eg sodium dodecylbenzene sulfonate); lauryl sulfate (eg sodium lauryl sulfate, ammonium lauryl sulfate), etc.
  • Alkyl sulfate such as octadecyl sulfate; fatty acid salt; polyoxyethylene alkyl ether sulfate such as polyoxyethylene octadecyl ether sulfate, polyoxyethylene lauryl ether sulfate (for example, sodium polyoxyethylene alkyl ether sulfate), polyoxy Polyoxyethylene alkyl phenyl ether sulfate such as ethylene lauryl phenyl ether sulfate (for example, sodium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, etc.), polyoxyethylene styrene phenyl ether sulfate, etc.
  • Polyoxyethylene alkyl ether phosphate ester salt; sulfosuccinate such as lauryl sulfosuccinate, polyoxyethylene lauryl sulfosuccinate (eg, sodium polyoxyethylene alkyl sulfosuccinate); polyoxyethylene alkyl ether acetate; etc. Can be mentioned.
  • the salt may be, for example, a metal salt such as a sodium salt, a potassium salt, a calcium salt or a magnesium salt (preferably a monovalent metal salt), an ammonium salt, an amine salt or the like. Can be.
  • the anionic surfactant may be used alone or in combination of two or more.
  • an anionic surfactant having at least one of a -POH group, a -COH group and a -SOH group may be preferably used.
  • a surfactant having a -POH group is preferable.
  • a preferred example of a surfactant having a -POH group is a polyoxyethylene alkyl ether phosphate ester.
  • the number of carbon atoms of the alkyl group in the polyoxyethylene alkyl ether phosphoric acid ester may be, for example, 6 to 20, 8 to 20, 10 to 20, 12 to 20, and 14 to 20.
  • cationic surfactants examples include polyether amines such as polyoxyethylene laurylamine and polyoxyethylene stearylamine.
  • the cationic surfactant may be used alone or in combination of two or more.
  • Examples of the compound having a polyoxyalkylene skeleton that can be used as compound A include polyalkylene glycols such as polyethylene glycol (PEG) and polypropylene glycol (PPG); polyethers containing polyoxyethylene units, and polyoxypropylene units. Compounds containing polyethers, oxyethylene units and oxypropylene units (the sequences of these units may be random or block-like); derivatives thereof; and the like can be used. Further, among the above-mentioned surfactants, compounds having a polyoxyalkylene skeleton can also be used. These can be used alone or in combination of two or more. Among them, it is preferable to use a compound containing a polyoxyethylene skeleton (also referred to as a polyoxyethylene segment), and PEG is more preferable.
  • PEG polyethylene glycol
  • PPG polypropylene glycol
  • the molecular weight (chemical formula amount) of the compound having a polyoxyalkylene skeleton is not particularly limited, and it is suitable that it is, for example, less than 1000, and is about 600 or less (for example, from the viewpoint of adhesive composition preparability). It is preferably 500 or less).
  • the lower limit of the molecular weight of the compound having a polyoxyalkylene skeleton is not particularly limited, and a compound having a molecular weight of about 100 or more (for example, about 200 or more, further about 300 or more) is preferably used.
  • water-affinitive agents include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylic acid.
  • the water-soluble polymer may be used alone or in combination of two or more.
  • the water affinity agent one kind or two or more kinds of compound A may be used, or one kind or two or more kinds of water-soluble polymers may be used, and these may be used in combination. You may.
  • the HLB of the water-affinitive agent is not particularly limited, for example, 3 or more, about 6 or more is appropriate, and 8 or more (for example, 9 or more) can be used.
  • the water affinity has an HLB of 10 or greater.
  • the HLB is more preferably 11 or more, still more preferably 12 or more, and particularly preferably 13 or more (for example, 14 or more).
  • a water affinity agent typically a surfactant
  • the upper limit of the HLB is 20 or less, for example, 18 or less, 16 or less, or 15 or less.
  • the HLB in the present specification is a Hydrophilic-Lipophile Balance by Griffin, which is a value indicating the degree of affinity of the surfactant with water or oil, and the ratio of hydrophilicity to lipophilicity is between 0 and 20. It is expressed by the numerical value of.
  • the definition of HLB is W. C. Griffin: J. Soc. Cosmetic Chemists, 1,311 (1949), Koshimitsu Takahashi, Yoshiro Namba, Motoo Koike, Masao Kobayashi, "Surfactant Handbook", 3rd edition, published by Engineering Books, November 25, 1972, p179- As described in 182 and the like.
  • the water-affinitive agent having the above-mentioned HLB can be selected based on the common general technical knowledge of those skilled in the art by referring to the above-mentioned references as necessary.
  • water-affinitive agent is contained in the A layer in a free form.
  • the water-affinitive agent one that is liquid at room temperature (about 25 ° C.) is preferably used from the viewpoint of preparation of the pressure-sensitive adhesive composition.
  • the A layer containing the water-affinitive agent is typically formed from the pressure-sensitive adhesive composition A containing the water-affinitive agent.
  • the pressure-sensitive adhesive composition A may be any of the above-mentioned water-dispersible pressure-sensitive adhesive composition, solvent-type pressure-sensitive adhesive composition, active energy ray-curable pressure-sensitive adhesive composition, hot-melt type pressure-sensitive adhesive composition, and the like.
  • the A layer containing the water-affinitive agent can be a pressure-sensitive adhesive layer formed from a photocurable or solvent-type pressure-sensitive adhesive composition A. In such a layer A, the effect of adding a water affinity agent can be preferably exhibited.
  • the layer A may have photocurability.
  • the content of the water affinity agent in the layer A is not particularly limited, and can be set so that the effect of using the water affinity agent is appropriately exhibited.
  • the content of the aqueous affinity agent may be, for example, 0.001 part by weight or more per 100 parts by weight of the monomer component constituting the polymer (for example, acrylic polymer) contained in the layer A. It is suitable that the amount is 0.01 parts by weight or more, 0.03 parts by weight or more, 0.07 parts by weight or more, or 0.1 parts by weight or more.
  • the content of the aqueous affinity agent may be, for example, 0.2 parts by weight or more with respect to 100 parts by weight of the monomer component, and 0.5 parts by weight or more from the viewpoint of obtaining a higher effect. It may be 1.0 part by weight or more, or 1.5 parts by weight or more. Further, from the viewpoint of suppressing excessive water diffusion of the A layer into the bulk, in some embodiments, the amount of the water affinity agent used may be, for example, 20 parts by weight or less with respect to 100 parts by weight of the monomer component. It is suitable to be 10 parts by weight or less, preferably 5 parts by weight or less, and may be 3 parts by weight or less.
  • the content of the water-affinitive agent is not too large from the viewpoint of improving the peel strength N1 after immersion in water, reducing the rate of decrease in peeling force after immersion in water, or improving the transparency of the pressure-sensitive adhesive layer (layer A).
  • the content of the water affinity with respect to 100 parts by weight of the monomer component may be less than 2 parts by weight, less than 1 part by weight, less than 0.7 parts by weight, or 0.3 parts by weight. It may be less than 0.2 parts by weight.
  • a water affinity agent having an HLB of 10 or more tends to exhibit good water desorption even when used in a small amount.
  • the pressure-sensitive adhesive layer (layer A) disclosed herein contains an acrylic oligomer from the viewpoints of improving cohesive force, improving adhesion to the base material layer, and improving adhesion to the adherend. Can be done.
  • the pressure-sensitive adhesive layer (layer A) containing the acrylic oligomer can be formed by using the pressure-sensitive adhesive composition A containing the acrylic oligomer.
  • the acrylic oligomer those having a higher Tg than the Tg of the above-mentioned acrylic polymer (for example, acrylic polymer) can be preferably adopted.
  • the Tg of the acrylic oligomer is not particularly limited, and may be, for example, about 20 ° C. or higher and 300 ° C. or lower.
  • the Tg may be, for example, about 30 ° C. or higher, about 40 ° C. or higher, about 60 ° C. or higher, about 80 ° C. or higher, or about 100 ° C. or higher.
  • the Tg of the acrylic oligomer may be, for example, about 250 ° C. or lower, about 200 ° C. or lower, about 180 ° C. or lower, or about 150 ° C. It may be as follows.
  • the Tg of the acrylic oligomer is a value calculated based on the Fox formula, like the Tg of the acrylic polymer described above.
  • the Mw of the acrylic oligomer is not particularly limited, and for example, it may be about 1000 or more, it is appropriate that it is about 1500 or more, it may be about 2000 or more, or it may be about 3000 or more. Further, the Mw of the acrylic oligomer may be, for example, less than about 30,000, preferably less than about 10,000, less than about 7,000, or less than about 5,000. When Mw is within the above range, the cohesiveness of the pressure-sensitive adhesive layer (layer A) and the effect of improving the adhesiveness are likely to be suitably exhibited.
  • the Mw of the acrylic oligomer can be measured by GPC and obtained as a standard polystyrene-equivalent value.
  • the monomer components constituting the acrylic oligomer include the above-mentioned various (meth) acrylic acid C 1-20 alkyl esters; the above-mentioned various alicyclic hydrocarbon group-containing (meth) acrylates; and the above-mentioned various aromatic hydrocarbons.
  • examples thereof include (meth) acrylate monomers containing a hydrogen group; (meth) acrylate obtained from a terpene compound derivative alcohol; and the like. These can be used alone or in combination of two or more.
  • Acrylic oligomers are alkyl (meth) acrylates in which alkyl groups such as isobutyl (meth) acrylate and t-butyl (meth) acrylate have a branched structure; alicyclic hydrocarbon group-containing (meth) acrylate and aromatic hydrocarbons. It is preferable to contain an acrylic monomer having a relatively bulky structure as a monomer unit, such as a group-containing (meth) acrylate; from the viewpoint of improving adhesiveness. Further, when ultraviolet rays are used when synthesizing an acrylic oligomer or when producing an adhesive layer (layer A), a monomer having a saturated hydrocarbon group at the ester terminal is less likely to cause polymerization inhibition.
  • an alkyl (meth) acrylate in which the alkyl group has a branched structure or a saturated alicyclic hydrocarbon group-containing (meth) acrylate can be preferably used.
  • the ratio of the (meth) acrylate monomer to all the monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight or more, and more preferably 70% by weight or more (for example, 80% by weight). And more, 90% by weight or more).
  • the acrylic oligomer has a monomer composition consisting substantially of only one or more (meth) acrylate monomers.
  • the monomer component contains an alicyclic hydrocarbon group-containing (meth) acrylate and a (meth) acrylic acid C 1-20 alkyl ester, their weight ratios are not particularly limited.
  • the weight ratio of the alicyclic hydrocarbon group-containing (meth) acrylate / (meth) acrylic acid C 1-20 alkyl ester is, for example, 10/90 or higher, 20/80 or higher, or 30/70 or higher. It can also be 90/10 or less, 80/20 or less, or 70/30 or less.
  • a functional group-containing monomer As the constituent monomer component of the acrylic oligomer, in addition to the above (meth) acrylate monomer, a functional group-containing monomer can be used if necessary.
  • the functional group-containing monomer include a monomer having a nitrogen atom-containing heterocycle such as N-vinyl-2-pyrrolidone and N-acryloylmorpholin; an amino group-containing monomer such as N, N-dimethylaminoethyl (meth) acrylate; N, Examples thereof include an amide group-containing monomer such as N-diethyl (meth) acrylamide; a carboxy group-containing monomer such as AA and MAA; and a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate.
  • these functional group-containing monomers may be used alone or in combination of two or more.
  • the ratio of the functional group-containing monomer to all the monomer components constituting the acrylic oligomer can be, for example, 1% by weight or more, 2% by weight or more, or 3% by weight or more, and also. For example, it can be 15% by weight or less, 10% by weight or less, or 7% by weight or less.
  • the acrylic oligomer may be one in which a functional group-containing monomer is not used.
  • Suitable acrylic oligomers include, for example, dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), and the like.
  • DCPMA dicyclopentanyl methacrylate
  • CHMA cyclohexyl methacrylate
  • IBXMA isobornyl methacrylate
  • IBXA isobornyl acrylate
  • DCPA dicyclopentanyl acrylate
  • ADAM 1-adamantyl methacrylate
  • ADA 1-adamantyl methacrylate
  • ADA 1-adamantyl acrylate
  • MMA methyl methacrylate
  • a polymer of CHMA and isobutyl methacrylate IBMA
  • a polymer of CHMA and IBXMA a polymer of CHMA and acryloylmorpholin (ACMO)
  • a polymer of CHMA and diethylacrylamide DEA
  • Examples thereof include a copolymer of CHMA and AA.
  • Acrylic oligomers can be formed by polymerizing their constituent monomer components.
  • the polymerization method and the polymerization mode are not particularly limited, and various conventionally known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be adopted in an appropriate manner.
  • the types of polymerization initiators for example, azo-based polymerization initiators
  • the types of polymerization initiators that can be used as needed are generally as illustrated for the synthesis of acrylic polymers, and the amount of the polymerization initiator and the chain transfer agent arbitrarily used. Since the amount of (for example, mercaptans) is appropriately set based on common general knowledge so as to have a desired molecular weight, detailed description thereof will be omitted.
  • the content thereof is the monomer of the polymer (typically an acrylic polymer) contained in the pressure-sensitive adhesive layer (A).
  • the content of the acrylic-based oligomer with respect to 100 parts by weight of the above-mentioned monomer component is less than 50 parts by weight. It is preferably less than 30 parts by weight, more preferably 25 parts by weight or less, for example, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less.
  • the pressure-sensitive adhesive layer (layer A) may contain a pressure-imparting resin.
  • the tackifier resin include petroleum-based tackifier resins, terpene-based tackifier resins, phenol-based tackifier resins, ketone-based tackifier resins, and the like, including rosin-based tackifier resins and rosin derivative tackifier resins. .. These can be used alone or in combination of two or more.
  • rosin-based tackifier resin examples include rosins such as gum rosin, wood rosin, and tall oil rosin, stabilized rosins (for example, stabilized rosins obtained by disproportionating or hydrogenating the above rosins), and polymerized rosins (for example).
  • the multimer of the above rosin, typically a dimer), modified rosin (for example, unsaturated acid-modified rosin modified with an unsaturated acid such as maleic acid, fumaric acid, (meth) acrylic acid, etc.) Can be mentioned.
  • rosin derivative tackifier resin examples include esters of the rosin-based tackifier resin (for example, rosin esters such as stabilized rosin ester and polymerized rosin ester), and phenol-modified products of the rosin-based resin (phenol-modified rosin). ) And its esterified product (phenol-modified rosin ester) and the like.
  • the petroleum-based tackifier resin examples include aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, alicyclic petroleum resins, and hydrides thereof.
  • Examples of the terpene-based tackifier resin include ⁇ -pinene resin, ⁇ -pinene resin, aromatic-modified terpene resin, and terpene phenol resin.
  • Examples of the ketone-based tackifier resin include ketone-based resins obtained by condensing ketones (for example, aliphatic ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; alicyclic ketones such as cyclohexanone and methylcyclohexanone) and formaldehyde. ; Etc. can be mentioned.
  • tackifier resin one or more selected from a rosin-based tackifier resin, a rosin derivative tackifier resin, and a terpene phenol resin can be preferably used.
  • a rosin derivative tackifier resin is preferable, and preferred examples thereof include rosin esters such as stabilized rosin ester and polymerized rosin ester.
  • the water-dispersible pressure-sensitive adhesive composition it is preferable to use the water-dispersion type pressure-sensitive adhesive resin in which the above-mentioned pressure-imparting resin is dispersed in an aqueous solvent.
  • a pressure-sensitive adhesive composition containing these components in a desired ratio can be easily prepared.
  • a resin that does not substantially contain at least an aromatic hydrocarbon solvent can be preferably used from the viewpoint of consideration for environmental hygiene and the like. It is more preferable to use an aqueous dispersion type tackifier resin which does not substantially contain an aromatic hydrocarbon solvent or other organic solvent.
  • Examples of commercially available water-dispersible tackifier resins containing rosin esters include the trade names "Super Ester E-720", “Super Ester E-730-55”, and “Super Ester E-” manufactured by Arakawa Chemicals Co., Ltd. Examples thereof include “865NT” and the like, and product names "Hariester SK-90D”, “Hariester SK-70D”, “Hariester SK-70E”, “Neotol 115E” and the like manufactured by Harima Chemicals.
  • terpene phenol resin which may be in the form of water-dispersed terpene phenol resin
  • the softening point of the tackifying resin is not particularly limited. From the viewpoint of suppressing a decrease in the cohesive force of the pressure-sensitive adhesive layer (layer A), a pressure-sensitive adhesive resin having a softening point of 80 ° C. or higher can be preferably used.
  • the softening point of the tackifier resin may be 90 ° C. or higher, 100 ° C. or higher, 110 ° C. or higher, or 120 ° C. or higher.
  • a tackifier resin having a softening point of 130 ° C. or higher or 140 ° C. or higher may be used.
  • a tackifier resin having a softening point of 200 ° C. or lower or 180 ° C. or lower can be preferably used.
  • a nominal value described in a document, a catalog, or the like can be adopted.
  • the softening point of the tackifier resin can be measured based on the softening point test method (ring ball method) specified in JIS K5902 or JIS K2207.
  • the amount of the tackifier resin used is preferably 1 part by weight or more with respect to 100 parts by weight of the monomer component constituting the polymer contained in the layer A from the viewpoint of preferably exerting the effect of use. It may be 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, or 25 parts by weight or more. Further, from the viewpoint of achieving both adhesion to the base material layer and the adherend and cohesiveness in a well-balanced manner, the amount of the tackifier resin used for 100 parts by weight of the monomer component may be, for example, 70 parts by weight or less, and 50 parts by weight. It may be 40 parts or less, or 40 parts by weight or less. Alternatively, the layer A may be substantially free of the tackifier resin.
  • the pressure-sensitive adhesive layer (layer A) can contain a silane coupling agent.
  • a silane coupling agent According to the layer A containing a silane coupling agent, a laminate having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized.
  • the silane coupling agent may be used alone or in combination of two or more.
  • silane coupling agent examples include silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; (meth) acrylic group-containing silane coupling agent such as acetoacetyl group-containing trimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; 3-isocyanatepropyltriethoxysilane Examples thereof include
  • the amount of the silane coupling agent used can be set so as to obtain the desired effect of use, and is not particularly limited.
  • the amount of the silane coupling agent used may be, for example, 0.001 part by weight or more with respect to 100 parts by weight of the monomer component constituting the polymer contained in the layer A, and has a higher effect. From the viewpoint of obtaining, it may be 0.005 parts by weight or more, 0.01 parts by weight or more, or 0.015 parts by weight or more.
  • the amount of the silane coupling agent used is, for example, 3 parts by weight or less with respect to 100 parts by weight of the monomer component constituting the A layer. It may be 1 part by weight or less, or 0.5 part by weight or less.
  • the alkoxysilyl group-containing monomer may be used as part or all of the silane coupling agent contained in the layer A.
  • the pressure-sensitive adhesive composition A used for forming the A layer may contain an acid or a base (ammonia water or the like) used for the purpose of pH adjustment or the like, if necessary.
  • Other optional components that may be contained in the composition include viscosity modifiers (eg, thickeners), leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, anti-aging agents.
  • viscosity modifiers eg, thickeners
  • leveling agents eg, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, anti-aging agents.
  • the pressure-sensitive adhesive layer of the laminated body disclosed here is a layer B arranged on the back surface side of the layer A in addition to the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side. Can be further included.
  • the bulk property for example, water resistance, cohesiveness, heat resistance
  • the pressure-sensitive adhesive layer is provided by the B layer while imparting better water peelability to the A layer. Etc.
  • Etc. can be adjusted. Therefore, according to the pressure-sensitive adhesive layer having the structure including the A layer and the B layer, it is easy to obtain a laminated body having good water peelability and excellent water resistance reliability.
  • a laminate having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized.
  • an adhesive layer having both strong adhesiveness and good water peelability at a high level can be preferably realized.
  • the B layer may be arranged in direct contact with the back surface of the A layer, or may be arranged between the back surface of the A layer and the back surface of the A layer via another layer.
  • the other layer (hereinafter, also referred to as an intermediate layer) is typically a non-adhesive layer, for example, a resin film, a foam sheet, a woven fabric, or a woven material that can be used for the above-mentioned base material layer. Cloth, paper, metal foil, etc. can be used. From the viewpoint of the flexibility of the laminated body and the followability to the surface shape of the adherend, in some embodiments, the A layer and the B layer are directly in contact with each other (that is, without an intermediate layer).
  • a pressure-sensitive adhesive layer can be preferably adopted.
  • the B layer is known as, for example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyether-based pressure-sensitive adhesive, a polyamide-based pressure-sensitive adhesive, a fluorine-based pressure-sensitive adhesive, and the like. It may be a pressure-sensitive adhesive layer composed of one type or two or more types of pressure-sensitive adhesives selected from various pressure-sensitive adhesives. From the viewpoint of transparency, weather resistance, and the like, an acrylic pressure-sensitive adhesive may be preferably used as the constituent material of the B layer in some embodiments.
  • the acrylic pressure-sensitive adhesive constituting the B layer can be selected from those exemplified as the acrylic pressure-sensitive adhesive that can be used for the A layer, for example, so as to exhibit desired characteristics in combination with the A layer.
  • the B layer may have a single-layer structure composed of one layer, or may have a multi-layer structure including two or more layers having different compositions.
  • the monomer component constituting the polymer (for example, an acrylic polymer) contained in the B layer is an alkyl C 1-20 (meth) acrylate in a proportion of 40% by weight or more of the total monomer component. May include esters.
  • the ratio of the C 1-20 (meth) acrylic acid alkyl ester to the total monomer component of the B layer may be, for example, 98% by weight or less, and even if it is 95% by weight or less from the viewpoint of improving the cohesiveness of the B layer. It may be 85% by weight or less, 70% by weight or less, or 60% by weight or less.
  • the monomer component constituting the B layer may contain a copolymerizable monomer together with the (meth) acrylic acid alkyl ester.
  • the copolymerizable monomer can be appropriately selected from those exemplified as the copolymerizable monomer that can be used for the A layer.
  • the amount of the copolymerizable monomer used may be, for example, 5% by weight or more, 15% by weight or more, 30% by weight or more, or 40% by weight or more of the total monomer components constituting the B layer.
  • the proportion of the carboxy group-containing monomer in the monomer components constituting the B layer may be, for example, 2% by weight or less, 1% by weight or less, or 0.5% by weight or less. It is not necessary to substantially use the carboxy group-containing monomer as the monomer component constituting the B layer.
  • the fact that the carboxy group-containing monomer is not substantially used means that the carboxy group-containing monomer is not used at least intentionally.
  • a pressure-sensitive adhesive layer having a B layer having such a composition is preferable because it tends to have high water resistance and reliability.
  • the gel fraction of the B layer is higher than the gel fraction of the A layer, and the swelling degree of the B layer is lower than the swelling degree of the A layer.
  • examples include a pressure-sensitive adhesive layer that satisfies one or both. According to such a configuration, it is easy to obtain an adhesive layer having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in peeling force in water.
  • the layer B may be a layer formed from a photocurable pressure-sensitive adhesive composition or a solvent-type pressure-sensitive adhesive composition.
  • a pressure-sensitive adhesive layer having good water resistance and reliability can be easily obtained.
  • a combination of a layer A formed from a water-dispersible pressure-sensitive adhesive composition and a layer B formed from a photocurable pressure-sensitive adhesive composition, or a layer A and a solvent formed from a water-dispersible pressure-sensitive adhesive composition In combination with the B layer formed from the mold pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized.
  • the B layer which does not substantially contain a water affinity agent can be preferably adopted.
  • the pressure-sensitive adhesive layer may be a cured layer of the pressure-sensitive adhesive composition. That is, the pressure-sensitive adhesive layer can be formed by applying (for example, coating) the pressure-sensitive adhesive composition to an appropriate surface and then appropriately performing a curing treatment. When performing two or more types of curing treatments (drying, cross-linking, polymerization, etc.), these can be performed simultaneously or in multiple steps.
  • a pressure-sensitive adhesive composition using a partial polymer (acrylic polymer syrup) of a monomer component a final copolymerization reaction is typically performed as the above-mentioned curing treatment. That is, the partial polymer is subjected to a further copolymerization reaction to form a complete polymer.
  • a photocurable pressure-sensitive adhesive composition For example, in the case of a photocurable pressure-sensitive adhesive composition, light irradiation is performed. If necessary, a hardening treatment such as crosslinking or drying may be carried out. For example, when it is necessary to dry with a photocurable pressure-sensitive adhesive composition, it is preferable to perform photocuring after drying. In the pressure-sensitive adhesive composition using a complete polymer, typically, as the curing treatment, treatments such as drying (heat drying) and cross-linking are carried out as necessary.
  • the pressure-sensitive adhesive layer having a multi-layer structure of two or more layers can be produced by laminating the pressure-sensitive adhesive layers formed in advance. Alternatively, the pressure-sensitive adhesive composition may be applied onto the first pressure-sensitive adhesive layer formed in advance, and the pressure-sensitive adhesive composition may be cured to form a second pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive composition can be applied using, for example, a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater.
  • a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater.
  • a direct method of directly applying the pressure-sensitive adhesive composition to the base material layer to form the pressure-sensitive adhesive layer may be used, and the pressure-sensitive adhesive formed on the peeling surface may be used.
  • a transfer method of transferring the agent layer to the base material layer may be used.
  • the thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, about 3 ⁇ m to 1000 ⁇ m. From the viewpoint of making the pressure-sensitive adhesive layer adhere to the base material layer or the adherend to enhance water resistance reliability, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 5 ⁇ m or more, or 10 ⁇ m or more. It may be 20 ⁇ m or more, 30 ⁇ m or more, 50 ⁇ m or more, 50 ⁇ m or more, 70 ⁇ m or more, 100 ⁇ m or more, or 120 ⁇ m or more.
  • the thickness of the pressure-sensitive adhesive layer may be, for example, 500 ⁇ m or less, 300 ⁇ m or less, or 200 ⁇ m or less. , 170 ⁇ m or less.
  • the technique disclosed herein can also be preferably applied to a laminate having a pressure-sensitive adhesive layer thickness of 130 ⁇ m or less, 90 ⁇ m or less, 60 ⁇ m or less, or 40 ⁇ m or less.
  • the pressure-sensitive adhesive layer consists of layer A.
  • the pressure-sensitive adhesive layer may have a single-layer structure of only the A layer, which does not include the B layer.
  • excellent water exfoliation property is realized by forming a hydrophilic layer on the surface of the base material layer, so that the purpose is to achieve both water exfoliation property and other properties (for example, water resistance reliability).
  • the pressure-sensitive adhesive layer does not need to have a multi-layer structure. That is, the desired characteristics can be realized without relying on the B layer. This is advantageous from the viewpoint of the production efficiency of the pressure-sensitive adhesive layer.
  • the thickness of the pressure-sensitive adhesive layer means the thickness of the A layer.
  • the thickness of the pressure-sensitive adhesive layer is, for example, more than 50 ⁇ m
  • a configuration in which the pressure-sensitive adhesive layer includes an A layer and a B layer can be preferably adopted. According to the pressure-sensitive adhesive layer having such a structure, even if the pressure-sensitive adhesive layer is thickened, it is easy to obtain a pressure-sensitive adhesive layer having both water peelability and water resistance reliability at a high level.
  • the thickness of the A layer may be, for example, 1 ⁇ m or more, 2 ⁇ m or more, 4 ⁇ m or more, 5 ⁇ m or more, or 10 ⁇ m or more. It may be 15 ⁇ m or more.
  • the thickness of the layer A may be, for example, 50 ⁇ m or less, 45 ⁇ m or less, 35 ⁇ m or less, or 25 ⁇ m or less.
  • the fact that the thickness of the A layer is not too large means that the water resistance of the pressure-sensitive adhesive layer is reliable. Is preferable from the viewpoint of improving the transparency of the pressure-sensitive adhesive layer and improving the transparency of the pressure-sensitive adhesive layer.
  • the thickness of the B layer may be, for example, 5 ⁇ m or more, or 10 ⁇ m or more. From the viewpoint of better exerting the effect of providing the B layer on the back surface side of the A layer, in some embodiments, the thickness of the B layer may be, for example, 20 ⁇ m or more, 30 ⁇ m or more, or 50 ⁇ m or more. It may be 70 ⁇ m or more, or 100 ⁇ m or more.
  • the thickness of the A layer in the total thickness of the pressure-sensitive adhesive layer may be, for example, 90% or less, preferably 70% or less, and is preferably 50. It may be% or less, 30% or less, 20% or less, and 15% or less. Further, from the viewpoint of ease of formation of the A layer and water peelability, in some embodiments, the thickness of the A layer in the total thickness of the pressure-sensitive adhesive layer may be, for example, 3% or more, and 5% or more. However, it may be 7% or more, or 10% or more.
  • a method of peeling the pressure-sensitive adhesive layer from the base material layer of a laminate having a base material layer and a pressure-sensitive adhesive layer in the state where the aqueous liquid is present at the interface between the base material layer and the pressure-sensitive adhesive layer in the peeling front of the pressure-sensitive adhesive layer from the base material layer, the water-based material follows the movement of the peeling front. It includes a water peeling step of peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the liquid into the interface. Further, the pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side. Further, the surface of the base material layer on the pressure-sensitive adhesive layer side is hydrophilized. According to the water peeling step, the pressure-sensitive adhesive layer can be peeled from the base material layer by effectively utilizing the aqueous liquid.
  • the hydrophilic treatment applied to the surface of the base material layer is not particularly limited, and various surface treatments capable of reducing the water contact angle can be adopted. Preferable examples include the formation of the above-mentioned hydrophilic layer. Since the details of the formation of the hydrophilic layer are as described above, the repeated description will be omitted.
  • the hydrophilization treatment typically does not include corona treatment or plasma treatment.
  • aqueous liquid water or a mixed solvent containing water as a main component and containing a small amount of additives as necessary can be used.
  • a lower alcohol for example, ethyl alcohol
  • a lower ketone for example, acetone
  • a known surfactant or the like can be used.
  • an aqueous liquid containing substantially no additive may be preferably used in some embodiments.
  • water is particularly preferable to use water as the aqueous liquid.
  • the water is not particularly limited, and for example, distilled water, ion-exchanged water, tap water, or the like can be used in consideration of the purity and availability required according to the application.
  • the stripping method supplies an aqueous liquid onto the substrate layer near the outer edge of the pressure-sensitive adhesive layer attached to the substrate layer, similar to, for example, when measuring the water peeling force N2.
  • the aqueous liquid is allowed to enter the interface between the pressure-sensitive adhesive layer and the base material layer from the outer edge of the pressure-sensitive adhesive layer, it is supplied onto the base material layer without supplying new water (that is, before the start of peeling). It can be preferably carried out in an embodiment in which the peeling of the pressure-sensitive adhesive layer is promoted (using only the aqueous liquid).
  • the water entering the interface between the pressure-sensitive adhesive layer and the base material layer is depleted in the middle of the water peeling step following the movement of the peeling front, it is intermittent after the start of the water peeling step.
  • additional water may be continuously supplied.
  • a mode in which water is additionally supplied after the start of the water peeling step is preferably adopted. obtain.
  • the amount of the aqueous liquid supplied before the start of peeling is not particularly limited as long as the amount of the aqueous liquid can be introduced into the interface between the pressure-sensitive adhesive layer and the base material layer from outside the sticking range of the pressure-sensitive adhesive layer.
  • the amount of the aqueous liquid may be, for example, 5 ⁇ L or more, 10 ⁇ L or more is appropriate, and 20 ⁇ L or more may be used. Further, there is no particular limitation on the upper limit of the amount of the aqueous liquid. In some embodiments, from the viewpoint of improving workability, the amount of the aqueous liquid may be, for example, 10 mL or less, 5 mL or less, 1 mL or less, 0.5 mL or less, 0.1 mL or less.
  • It may be 0.05 mL or less.
  • the operation of allowing the aqueous liquid to enter the interface between the pressure-sensitive adhesive layer and the base material layer from the outer edge of the pressure-sensitive adhesive layer at the start of peeling is, for example, a jig such as a cutter knife or a needle at the interface on the outer edge of the pressure-sensitive adhesive layer. Insert the tip of the adhesive layer, scratch the outer edge of the adhesive layer with a hook or nail, and lift it. Attach a strong adhesive tape or suction cup to the back surface near the outer edge of the laminate to lift the edge of the adhesive layer. , Etc. can be performed.
  • the pressure-sensitive adhesive layer to be peeled off by the above-mentioned peeling method is preferably, for example, any of the pressure-sensitive adhesive layers disclosed herein.
  • the peeling method is suitable as a peeling method for the pressure-sensitive adhesive layer from the base material layer in any of the laminates disclosed herein.
  • the water peeling step according to some aspects can be preferably carried out in a mode in which the peeling front is moved at a speed of 10 mm / min or more.
  • Moving the peeling front at a speed of 10 mm / min or more corresponds to peeling the pressure-sensitive adhesive layer at a tensile speed of 20 mm / min or more, for example, under the condition of a peeling angle of 180 degrees.
  • the speed at which the peeling front is moved may be, for example, 50 mm / min or more, 150 mm / min or more, 300 mm / min or more, or 500 mm / min or more.
  • the peeling method disclosed herein by peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the aqueous liquid into the interface, even at such a relatively high peeling speed. Good water releasability can be exhibited.
  • the upper limit of the speed at which the peeling front is moved is not particularly limited. The speed at which the peeling front is moved can be, for example, 1000 mm / min or less.
  • the peeling method disclosed herein is carried out, for example, in such a manner that the peeling area of the pressure-sensitive adhesive layer per 10 ⁇ L of the volume of the aqueous liquid (for example, water) used in the method is, for example, 50 cm 2 or more, preferably 100 cm 2 or more. can do.
  • the aqueous liquid for example, water
  • the laminate disclosed herein can be easily peeled off from the base material layer using an aqueous liquid such as water, so that it has good reworkability and high water resistance reliability, for example, various portable devices. It can be used for fixing, joining, molding, decorating, protecting, supporting, etc. of a member (portable device), an automobile, a home appliance, or the like.
  • the material constituting at least the surface of the above member is, for example, glass such as an alkaline glass plate or non-alkali glass; a metal material such as a resin film, stainless steel (SUS), or aluminum; an acrylic resin, an ABS resin, a polycarbonate resin, or a polystyrene resin. , Resin material such as transparent polyimide resin; etc.
  • the laminate disclosed herein is a coated surface with a paint such as acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (for example, acrylic melamine, alkyd melamine).
  • a paint such as acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (for example, acrylic melamine, alkyd melamine).
  • a paint such as acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (for example, acrylic melamine, alkyd melamine).
  • a plated surface such as a zinc-plated steel plate.
  • the water contact angle on the surface of the adherend to which the laminate is attached is not particularly limited.
  • the adherend surface may be a surface exhibiting hydrophilicity such that the water contact angle is, for example, 60 degrees or less, preferably 50 degrees or less.
  • the water contact angle of the surface may be, for example, 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less.
  • the laminate disclosed here has, for example, a surface made of a material (for example, glass such as an alkaline glass plate or non-alkali glass) having a water contact angle of about 30 degrees or less (for example, 15 degrees or less, further 10 degrees or less). It can be preferably used for fixing the members to be held.
  • the lower limit of the water contact angle on the surface of the adherend is 0 degrees in principle.
  • the water contact angle on the surface of the adherend may be greater than 0 degrees, greater than 1 degree, greater than 3 degrees, or greater than or equal to 5 degrees.
  • the water contact angle of the adherend surface may be greater than 30 degrees, greater than 50 degrees, greater than 60 degrees (eg, greater than 70 degrees). ..
  • the laminate disclosed herein can be used for various materials having different water contact angles. The water contact angle on the surface of the adherend is measured by the same method as described in Examples described later.
  • the laminate disclosed herein includes, for example, a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), a display device such as electronic paper (image display device), an input device such as a touch panel, and the like.
  • a liquid crystal display device an organic EL (electroluminescence) display device, a PDP (plasma display panel), a display device such as electronic paper (image display device), an input device such as a touch panel, and the like.
  • Optical equipment particularly preferably used when an expensive member such as a foldable display device or an in-vehicle display device is included.
  • the mode in which the optical members are bonded using the laminate disclosed here is not particularly limited, and for example, (1) the base material layer of the laminate disclosed here is the optical member, and the pressure-sensitive adhesive layer is used.
  • the laminate in which the base material layer includes an optical member can also be grasped as an adhesive optical member (for example, an adhesive optical film).
  • an adhesive optical member for example, an adhesive optical film
  • the laminate disclosed here is the pressure-sensitive adhesive layer disclosed here on at least one side of the functional film. It can also be grasped as a "adhesive type functional film" having.
  • the peel strength of the pressure-sensitive adhesive layer from the base material layer under the conditions of a speed of 300 mm / min and a peeling angle of 180 degrees is measured. The measurement is performed three times, and the value obtained by converting the average value into a value per 10 mm width (unit: N / 10 mm) is defined as a peel strength N0 [N / 10 mm]. The peel strength is measured so that the test piece attached to the adherend is peeled from the bottom to the top.
  • the tensile tester an equivalent product of the universal tensile compression tester may be used.
  • the test piece taken out from the autoclave is irradiated with light through the base material layer in an environment of 23 ° C. and 50% RH, and then the peel strength is measured. ..
  • the light irradiation conditions (wavelength, irradiation intensity, irradiation time, etc.) are appropriately set according to the composition and thickness of the pressure-sensitive adhesive layer. Specifically, for the laminates of Examples 1-1 to 1-30 described later, after the autoclave treatment, an integrated light amount of 3000 mJ / cm 2 is used from the base material layer side using a high-pressure mercury lamp (300 mW / cm 2 ).
  • the photocurable pressure-sensitive adhesive layer is cured by irradiating with ultraviolet rays.
  • Examples 2-1 to 2-24 light irradiation after the autoclave treatment is not performed.
  • the non-adhesive layer is arranged on the back surface of the pressure-sensitive adhesive layer, the backing with a PET film is unnecessary.
  • the measurement conditions for the peel strength after the supply of distilled water shall be in accordance with JIS Z0237: 2009 10.4.1 Method 1: 180 ° peeling adhesive strength to the test plate. Specifically, the test temperature is 23 ° C., a tensile tester is used, and the tensile speed is 300 mm / min and the peeling angle is 180 degrees.
  • the peel strength and the water peeling force are measured continuously for each test piece, but the peeling strength and the water peeling force are measured by different test pieces. May be good. For example, when it is difficult to prepare a test piece having a sufficient length for performing continuous measurement, a mode in which measurement is performed using different test pieces can be adopted.
  • a cutter knife is inserted into the interface between the base material layer and the pressure-sensitive adhesive layer to peel off one end of the pressure-sensitive adhesive layer in the longitudinal direction from the base material layer, and distilled water is supplied thereto to measure the peeling strength.
  • a test piece is prepared by cutting the laminate into a rectangular shape having a width of 10 mm and a length of 120 mm. This test piece is put into an autoclave and treated for 15 minutes under the conditions of a pressure of 5 atm and a temperature of 50 ° C. The evaluation sample taken out from the autoclave is kept in an environment of 23 ° C. and 50% RH for 1 day, and then immersed in water at room temperature (23 ° C. to 25 ° C.) for 30 minutes. Ion-exchanged water or distilled water is used as the water. In water, the test piece is held horizontally with the adhesive layer side facing up.
  • the distance (immersion depth) from the upper surface of the test piece to the water surface is 10 mm or more (for example, about 10 mm to 100 mm).
  • the test piece is pulled up from the water, the water adhering to the test piece is gently wiped off, and then a cutter knife is inserted into the interface between the pressure-sensitive adhesive layer and the base material layer to insert a cutter knife into one end of the pressure-sensitive adhesive layer in the longitudinal direction.
  • a cutter knife is inserted into the interface between the pressure-sensitive adhesive layer and the base material layer to insert a cutter knife into one end of the pressure-sensitive adhesive layer in the longitudinal direction.
  • the test temperature was set to 23 ° C.
  • the peel strength of the pressure-sensitive adhesive layer from the base material layer is measured under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 degrees using a tensile tester.
  • the measured value is the peel strength N1 [N / 10 mm] after immersion in water.
  • the time from pulling up the test piece from water to measuring the peel strength shall be within 10 minutes.
  • the measurement conditions for the peel strength after immersion in water are the same as the measurement conditions for the peel strength N0 except for the immersion in water.
  • the laminate containing the photocurable pressure-sensitive adhesive layer was based on the sample taken out from the autoclave at 23 ° C. and 50% RH. Light irradiation is performed through the material layer, and then water immersion is performed to measure the peel strength.
  • the light irradiation conditions (wavelength, irradiation intensity, irradiation time, etc.) may be appropriately set according to the composition and thickness of the pressure-sensitive adhesive layer.
  • tensile tester a universal tensile compression tester (device name "tensile compression tester, TCM-1kNB” manufactured by Minebea) or an equivalent product thereof can be used.
  • TCM-1kNB tensile compression tester
  • the peel strength is measured so that the test piece attached to the adherend is peeled from the bottom to the top.
  • an appropriate backing material can be attached to the back surface of the laminated body (the surface opposite to the surface of the A layer) to reinforce the test piece.
  • the backing material for example, a PET film having a thickness of about 25 ⁇ m can be used.
  • the film thickness of silicon oxide is measured by the X-ray reflectivity method, and the X-ray reflectivity is measured with a powder X-ray diffractometer (manufactured by Rigaku Co., Ltd., device name "RINT-2000") under the following measurement conditions. , Calculated by analyzing the acquired measurement data with analysis software ("GXRR3" manufactured by Rigaku Corporation).
  • the analysis conditions were as follows, and a two-layer model of a polymer film substrate and a silicon oxide film with a density of 2.3 g / cm 3 was adopted, and the film thickness and surface roughness of the silicon oxide film and the surface roughness of the substrate film were adopted.
  • the water contact angle on the surface of the hydrophilic layer of the base material is measured as follows. That is, in a measurement atmosphere of 23 ° C. and 50% RH, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., trade name "DMo-501 type", control box “DMC-2", control / analysis software "FAMAS (version)” Measurement is performed by the sessile drop method using 5.0.30) ”). The amount of distilled water dropped is 2 ⁇ L, and the contact angle is calculated by the ⁇ / 2 method from the image 5 seconds after dropping (implemented at N5).
  • Preparation of base layer material> (Preparation Examples A1 to A5) Oxidized from a Si metal target manufactured by Mitsui Kinzoku Co., Ltd. on a PET film base material A (PET-A; manufactured by Mitsubishi Chemical Co., Ltd., trade name "LC-N50JBN", thickness 50 ⁇ m) by RF (Radio-Frequency) magnetron sputtering. A silicon film was formed. Argon and oxygen were used as the sputtering gas, and the oxygen / argon ratio was 5.3 vol%. By adjusting the film formation time under the above conditions, silicon oxide films having different film thicknesses were formed, and base material layer materials A1 to A5 corresponding to Preparation Examples A1 to A5 were obtained.
  • PET film base material B PET-B; manufactured by Mitsubishi Chemical Co., Ltd., trade name "Diafoil O300E", thickness 125 ⁇ m
  • a silicon film was formed. By adjusting the film formation time under the above conditions, silicon oxide films having different film thicknesses were formed, and base material layer materials A6 to A8 corresponding to Preparation Examples A6 to A8 were obtained.
  • Preparation Examples A12 to A14 On the TAC film in the same manner as in Preparation Examples A9 to A11 except that a triacetyl cellulose (TAC) film (manufactured by Fuji Film Co., Ltd., trade name "TD80UL", thickness 80 ⁇ m, refractive index 1.49) was used as a base material. A silicon oxide film was formed. By adjusting the number of reaction steps, silicon oxide films having different thicknesses were formed on the surface of the base material, and base material layer materials A12 to A14 corresponding to Preparation Examples A12 to A14 were obtained.
  • TAC triacetyl cellulose
  • a silicon oxide film on the CPI film is basically the same as in Preparation Examples A9 to A10 except that a transparent polyimide (CPI) film (manufactured by KOLON INDUSTIES INC., Product name "C_80", thickness 80 ⁇ m) is used as a base material.
  • CPI transparent polyimide
  • C_80 thickness 80 ⁇ m
  • Preparation Examples A19 to A21 A silicon oxide film was formed on the polarizing plate in the same manner as in Preparation Examples A16 to A18 except that a polarizing plate (manufactured by Nitto Denko Corporation, trade name “REGQ-HC3”, thickness 92 ⁇ m) was used as a base material. By adjusting the number of reaction steps, silicon oxide films having different film thicknesses were formed on the surface of the base material, and base material layer materials A19 to A21 corresponding to Preparation Examples A19 to A21 were obtained.
  • a polarizing plate manufactured by Nitto Denko Corporation, trade name “REGQ-HC3”, thickness 92 ⁇ m
  • Dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-DPH") 1.0 as a photoreactive compound per 100 parts of the monomer component used to prepare the solution in the above-mentioned solution.
  • nonionic surfactant A polyoxyethylene sorbitan monolaurate, HLB13.3, trade name: Leodor TW-L106, manufactured by Kao
  • HLB13.3 polyoxyethylene sorbitan monolaurate, HLB13.3, trade name: Leodor TW-L106, manufactured by Kao
  • acrylic oligomer one synthesized by the following method was used.
  • Synthesis of acrylic oligomers 100 parts of toluene, 60 parts of dicyclopentanyl methacrylate (DCPMA) (trade name: FA-513M, manufactured by Hitachi Kasei Kogyo Co., Ltd.), 40 parts of methyl methacrylate (MMA), and 3.5 parts of ⁇ -thioglycerol as a chain transfer agent. was put into a four-necked flask. Then, after stirring at 70 ° C. under a nitrogen atmosphere for 1 hour, 0.2 part of AIBN was added as a thermal polymerization initiator, and the mixture was reacted at 70 ° C.
  • DCPMA dicyclopentanyl methacrylate
  • MMA methyl methacrylate
  • ⁇ -thioglycerol 3.5 parts
  • reaction solution was put into a temperature atmosphere of 130 ° C., and toluene, the chain transfer agent, and the unreacted monomer were dried and removed to obtain a solid acrylic oligomer.
  • the Tg of this acrylic oligomer was 144 ° C. and the Mw was 4300.
  • a 38 ⁇ m-thick release film (Mitsubishi Resin Co., Ltd., MRF # 38) with one side of the polyester film as a peeling surface and a 38 ⁇ m thick release film (Mitsubishi Resin Co., Ltd.) with one side of the polyester film having a peeling surface.
  • MRF # 38 The solvent-based pressure-sensitive adhesive composition B1 prepared above was applied to the peeling surface of one of the release films (MRF # 38) and dried at 60 ° C. for 3 minutes and then at 120 ° C. for 3 minutes to obtain light having a thickness of 150 ⁇ m.
  • a curable pressure-sensitive adhesive layer was formed.
  • the release surface of the other release film (MRE # 38) was attached to this pressure-sensitive adhesive layer to protect it. In this way, the pressure-sensitive adhesive layer B1 whose surface was protected by the two release films was obtained.
  • the monomer emulsion was placed in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and the mixture was stirred at room temperature for 1 hour or more while introducing nitrogen gas.
  • the temperature of the system was raised to 60 ° C., and 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057) was used as a polymerization initiator.
  • 0.1 part was added and reacted at 60 ° C. for 6 hours to obtain an aqueous dispersion of an acrylic polymer.
  • a 38 ⁇ m-thick release film (Mitsubishi Resin Co., Ltd., MRF # 38) with one side of the polyester film as a peeling surface and a 38 ⁇ m thick release film (Mitsubishi Resin Co., Ltd.) with one side of the polyester film having a peeling surface.
  • the pressure-sensitive adhesive composition B2 was applied to the peel-off surface of one of the release films (MRF # 38) and dried at 120 ° C. for 3 minutes to form a pressure-sensitive adhesive layer B2 having a thickness of 20 ⁇ m.
  • the release surface of the other release film (MRE # 38) was attached to this pressure-sensitive adhesive layer to protect it. In this way, the pressure-sensitive adhesive layer B2 whose surface was protected by the two release films was obtained.
  • Example 1-1 to Example 1-21 The release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 ⁇ m was attached to the exposed pressure-sensitive adhesive surface for lining. This is cut into a size of 20 mm in width and 100 mm in length, and then the release liner covering the other surface of the photocurable adhesive layer B1 is peeled off in an environment of 23 ° C. and 50% RH to expose the adhesive surface. A 2 kg rubber roller was reciprocated once on each of the hydrophilic layer forming surfaces of the base material layer materials A1 to A21 and pressure-bonded to laminate the photocurable pressure-sensitive adhesive layer and the base material layer. A laminate according to ⁇ 1-21 was obtained. A PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
  • PET film base material A PET film base material A
  • PET film base material B PET film base material B
  • TAC film manufactured by Fuji Film Co., Ltd., product name “TD80UL”, thickness 80 ⁇ m, refractive index 1.49
  • CPI film manufactured by KOLON INDUSTRIES INC., Product name “C_80”, thickness 80 ⁇ m
  • polarizing plate thickness 125 ⁇ m
  • the base material is applied to a table-type surface corona treatment device (manufactured by KASUGA, device name "AGF-012”), output setting 3 (display 0.17 kW), table speed scale 20. It was carried out by passing it once under the condition of (equivalent to a speed of 3 m / min). Further, the release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 ⁇ m was attached to the exposed pressure-sensitive adhesive surface for lining. This was cut into a size of 20 mm in width and 100 mm in length.
  • the release liner covering the other surface of the photocurable adhesive layer B1 was peeled off, and the exposed adhesive surface was peeled off.
  • the photocurable pressure-sensitive adhesive layer and the base material layer were laminated by reciprocating and crimping a 2 kg rubber roller once to the corona-treated surface of the base material layer material, and in Examples 1-22 to 1-26. Such a laminate was obtained.
  • a PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
  • Example 1-27 to Example 1-30> The release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 ⁇ m was attached to the exposed pressure-sensitive adhesive surface for lining. This was cut into a size of 20 mm in width and 100 mm in length, and then the release liner covering the other surface of the photocurable adhesive layer B1 was peeled off in an environment of 23 ° C. and 50% RH to expose the adhesive surface.
  • PET film base material A PET-A; manufactured by Mitsubishi Chemical Co., Ltd., trade name "LC-N50JBN", thickness 50 ⁇ m
  • PET film base material B PET-B; manufactured by Mitsubishi Chemical Co., Ltd., trade name "Diafoil O300E” , 125 ⁇ m in thickness
  • CPI film manufactured by KOLON INDUSTRIES INC., Product name “C_80”, thickness 80 ⁇ m
  • polarizing plate manufactured by Nitto Denko Co., Ltd., product name “REGQ-HC3”, thickness 92 ⁇ m
  • the photocurable pressure-sensitive adhesive layer and the base material layer were laminated by reciprocating and crimping a 2 kg rubber roller once to obtain the laminates according to Examples 1-27 to 1-30.
  • a PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
  • Example 2-1 to Example 2-24> As the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer B2 was used instead of the photo-curable pressure-sensitive adhesive layer B1, except that the pressure-sensitive adhesive layer B2 was used in the same manner as in Examples 1-1 to 1-21, 1-27 to 1-28, 1-30. A laminate according to the example was obtained.
  • Examples 2-1 to 2-24 using the emulsion type pressure-sensitive adhesive the laminate of Examples 2-1 to 2-21 in which the hydrophilic layer is provided on the surface of the base material layer does not have the hydrophilic layer. It had excellent water releasability as compared with -22 to 2-24. Further, in Examples 2-1 to 2-21, the pressure-sensitive adhesive layer and the base material layer were adhered with sufficient peel strength.

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  • Adhesives Or Adhesive Processes (AREA)

Abstract

Provided is a layered article in which an adhesive layer can easily be peeled from a substrate layer using water or another water-based liquid while the substrate layer and the adhesive layer are bonded together in an excellent manner. A layered article having a substrate layer and an adhesive layer that is peelably layered on the substrate layer is provided. The adhesive layer is provided with a layer A that constitutes a substrate-layer-side surface. A hydrophilic layer is formed on the adhesive-layer-side surface of the substrate layer. The hydrophilic layer is an inorganic-material-containing layer. The peel strength N0 of the adhesive layer with respect to the substrate layer is 2.0 N/10 mm or greater. The layered article is such that the water peel force reduction rate, which is calculated from the water peel force N2 [N/10 mm] measured under prescribed conditions and the peel strength N0 [N/10 mm] using the expression (1 - (N2/N0)) × 100, is 40% or higher.

Description

積層体および剥離方法Laminate and peeling method
　本発明は、積層体および剥離方法に関する。
　本出願は、２０１９年８月２日に出願された日本国特許出願２０１９－１４３２６５号に基づく優先権を主張しており、その出願の全内容は本明細書中に参照として組み入れられている。 The present invention relates to a laminate and a peeling method.
This application claims priority under Japanese Patent Application No. 2019-143265 filed on August 2, 2019, the entire contents of which are incorporated herein by reference.
　一般に、粘着剤（感圧接着剤ともいう。以下同じ。）は、室温付近の温度域において柔らかい固体（粘弾性体）の状態を呈し、圧力により簡単に被着体に接着する性質を有する。このような性質を活かして、粘着剤は、支持体上に粘着剤層を有する支持体付き粘着シートの形態で、あるいは支持体を有しない支持体レス粘着シートの形態で、様々な分野において広く利用されている。 Generally, an adhesive (also referred to as a pressure-sensitive adhesive; the same applies hereinafter) exhibits a soft solid state (viscoelastic body) in a temperature range near room temperature, and has a property of easily adhering to an adherend by pressure. Taking advantage of these properties, the pressure-sensitive adhesive is widely used in various fields in the form of a pressure-sensitive adhesive sheet with a support having a pressure-sensitive adhesive layer on the support or in the form of a support-less pressure-sensitive adhesive sheet without a support. It's being used.
日本国特許出願公開２００５－１４８６３８号公報Japanese Patent Application Publication No. 2005-148638
　粘着剤には用途に応じて様々な特性が求められる。それらの特性のなかには、一方の特性を改善しようとすると他方の特性が低下する傾向にある等、高レベルで両立させることが困難なものがある。このように両立が難しい関係にある特性の一例として、被着体に対する接着力とリワーク性とが挙げられる。上記リワークとは、例えば粘着シートを被着体に貼り付ける際に貼り損ね（位置ズレ、シワや気泡の発生、異物の噛み込み等）が生じた場合や、粘着シートの貼付け後に被着体に不具合が見つかった場合に、被着体から粘着シートを剥がして貼り直すことをいう。特許文献１には、ガラス基板等の基板（被着体）の表面に粘着型光学フィルム（具体的には粘着型偏光板）が貼り付けられている光学フィルム付き基板から該粘着型光学フィルムを剥離する方法として、上記粘着型光学フィルムの粘着剤層と上記基板との剥離界面に液体が存在する状態で上記基板から上記粘着型光学フィルムを剥離する方法が開示されている。なお、特許文献１では、光学フィルム（具体的には偏光板）に貼り付けられた粘着剤の光学フィルムからの剥離方法については検討されていない。 Adhesives are required to have various properties depending on the application. Among these characteristics, there are some that are difficult to achieve at a high level, for example, when trying to improve one characteristic, the other characteristic tends to decrease. As an example of such characteristics that are difficult to achieve at the same time, there are adhesive force to the adherend and reworkability. The above-mentioned rework is, for example, when the adhesive sheet is not attached to the adherend due to failure (positional deviation, wrinkles, bubbles, foreign matter, etc.), or after the adhesive sheet is attached to the adherend. When a defect is found, the adhesive sheet is peeled off from the adherend and reattached. In Patent Document 1, the adhesive optical film is provided from a substrate with an optical film in which an adhesive optical film (specifically, an adhesive polarizing plate) is attached to the surface of a substrate (adhesive body) such as a glass substrate. As a method of peeling, a method of peeling the adhesive optical film from the substrate in a state where a liquid is present at the peeling interface between the pressure-sensitive adhesive layer of the adhesive optical film and the substrate is disclosed. Note that Patent Document 1 does not study a method of peeling the pressure-sensitive adhesive attached to an optical film (specifically, a polarizing plate) from the optical film.
　ところで、粘着剤の使用方法には、基材に積層される形態で使用される態様が含まれる。この態様の粘着剤層および基材は、被着体の場合と同様、貼り直しのためのリワーク性と、使用時の密着性とを両立することが望ましい。また、いくつかの使用態様では、上記のような粘着剤層と基材との積層体は、その使用目的を達成した後、粘着剤層が基材から剥離され得る。しかし、基材材料や粘着剤の種類によっては、水等の水性液体を利用しても、粘着剤を基材層からスムーズに剥離できない場合がある。本発明者らの検討の結果、水性液体を利用した剥離性（以下、便宜上「水剥離性」ともいう。）を高めるために上記基材の粘着剤層側表面にコロナ処理等の処理を施したものは一定の水剥離性向上効果が得られることが明らかとなったが、その効果は、まだ粘着剤や基材材料の種類に依存することがあり、また、上記効果を長期にわたって維持することは難しく、これら基材からの水剥離性には改善の余地がある。 By the way, the method of using the pressure-sensitive adhesive includes a mode in which it is used in a form of being laminated on a base material. It is desirable that the pressure-sensitive adhesive layer and the base material of this embodiment have both reworkability for reattachment and adhesion during use, as in the case of an adherend. Further, in some usage modes, the pressure-sensitive adhesive layer and the base material may be peeled off from the base material after the laminate of the pressure-sensitive adhesive layer and the base material has achieved its intended use. However, depending on the base material and the type of pressure-sensitive adhesive, the pressure-sensitive adhesive may not be smoothly peeled off from the base material layer even if an aqueous liquid such as water is used. As a result of the studies by the present inventors, in order to improve the peelability using an aqueous liquid (hereinafter, also referred to as "water peelability" for convenience), the surface of the base material on the pressure-sensitive adhesive layer side is treated with a corona treatment or the like. It has been clarified that a certain effect of improving water peelability can be obtained, but the effect may still depend on the type of adhesive or base material, and the above effect is maintained for a long period of time. This is difficult, and there is room for improvement in the water releasability from these substrates.
　本発明は、上記の事情に鑑みて創出されたものであり、基材層と粘着剤層と有する積層体であって、基材層と粘着剤層とが良好に密着しつつ、水等の水性液体を利用して基材層から粘着剤層を容易に剥離できる積層体を提供することを目的とする。本発明の他の目的は、基材層から粘着剤層を剥離する方法を提供することである。 The present invention has been created in view of the above circumstances, and is a laminate having a base material layer and an adhesive layer, in which the base material layer and the pressure-sensitive adhesive layer are in good contact with each other, and water or the like is used. An object of the present invention is to provide a laminate capable of easily peeling a pressure-sensitive adhesive layer from a base material layer by using an aqueous liquid. Another object of the present invention is to provide a method for peeling the pressure-sensitive adhesive layer from the base material layer.
　この明細書によると、基材層と、該基材層に剥離可能に積層された粘着剤層と、を有する積層体が提供される。前記粘着剤層は、基材層側表面を構成するＡ層を備える。また、前記基材層の粘着剤層側表面には親水層が形成されている。前記親水層は無機材料含有層である。また、前記基材層に対する前記粘着剤層の剥離強度Ｎ０は２．０Ｎ／１０ｍｍ以上である。そして、積層体は、前記基材層と前記粘着剤層とのあいだに２０μＬの蒸留水を供給し、該蒸留水を該粘着剤層と該基材層との界面の一端に進入させた後、ＪＩＳ　Ｚ０２３７：２００９の１０．４．１　方法１：試験板に対する１８０°引きはがし粘着力に従い、具体的には、試験温度２３℃にて引張試験機を用いて引張速度３００ｍｍ／分、剥離角度１８０度の条件で測定される水剥離力Ｎ２［Ｎ／１０ｍｍ］と、前記剥離強度Ｎ０［Ｎ／１０ｍｍ］とから、次式：（１－（Ｎ２／Ｎ０））×１００；により算出される水剥離力低下率が４０％以上である。
　上記の構成によると、積層体の粘着剤層は、所定値以上の剥離強度で基材層に接着する一方、上記基材層の粘着剤層側表面には特定の親水層が存在するので、水等の水性液体を基材層表面に付与し、基材層表面と粘着剤層表面の界面に進入させることで、粘着剤層を容易に剥離することができる。 According to this specification, a laminate having a base material layer and a pressure-sensitive adhesive layer detachably laminated on the base material layer is provided. The pressure-sensitive adhesive layer includes a layer A that constitutes a surface on the base material layer side. Further, a hydrophilic layer is formed on the surface of the base material layer on the pressure-sensitive adhesive layer side. The hydrophilic layer is an inorganic material-containing layer. Further, the peel strength N0 of the pressure-sensitive adhesive layer with respect to the base material layer is 2.0 N / 10 mm or more. Then, the laminate supplies 20 μL of distilled water between the base material layer and the pressure-sensitive adhesive layer, and after allowing the distilled water to enter one end of the interface between the pressure-sensitive adhesive layer and the base material layer. , JIS Z0237: 2009 10.4.1 Method 1: According to 180 ° peeling adhesive strength to the test plate, specifically, at a test temperature of 23 ° C, a tensile speed of 300 mm / min and a peeling angle using a tensile tester. It is calculated by the following formula: (1- (N2 / N0)) × 100; from the water peeling force N2 [N / 10 mm] measured under the condition of 180 degrees and the peeling strength N0 [N / 10 mm]. The rate of decrease in water peeling power is 40% or more.
According to the above configuration, the pressure-sensitive adhesive layer of the laminate adheres to the base material layer with a peeling strength of a predetermined value or more, while a specific hydrophilic layer is present on the surface of the base material layer on the pressure-sensitive adhesive layer side. The pressure-sensitive adhesive layer can be easily peeled off by applying an aqueous liquid such as water to the surface of the base material layer and allowing it to enter the interface between the surface of the base material layer and the surface of the pressure-sensitive adhesive layer.
　いくつかの好ましい態様に係る積層体において、前記剥離強度Ｎ０は３．０Ｎ／１０ｍｍ以上である。この構成によると、積層体の粘着剤層は、基材層に対してより安定して接着したものとなり得る。また、積層体は被着体により強く接着することができる。 In the laminated body according to some preferred embodiments, the peel strength N0 is 3.0 N / 10 mm or more. According to this configuration, the pressure-sensitive adhesive layer of the laminated body can be more stably adhered to the base material layer. In addition, the laminate can be more strongly adhered to the adherend.
　いくつかの好ましい態様に係る積層体は、前記積層体を水に３０分間浸漬し、次いで水から引き上げて付着水を拭き取った後に測定される水浸漬後剥離強度Ｎ１［Ｎ／１０ｍｍ］と、前記剥離強度Ｎ０［Ｎ／１０ｍｍ］とから、次式：（１－（Ｎ１／Ｎ０））×１００；により算出される水浸漬後剥離力低下率が３０％以下である。上記の水浸漬後剥離力低下率（３０％以下）を満足する粘着剤を含む積層体は、耐水信頼性に優れる。 The laminate according to some preferred embodiments has a post-water immersion peel strength N1 [N / 10 mm], which is measured after the laminate is immersed in water for 30 minutes and then pulled out of the water to wipe off the adhering water. From the peeling strength N0 [N / 10 mm], the rate of decrease in peeling force after immersion in water calculated by the following formula: (1- (N1 / N0)) × 100; is 30% or less. A laminate containing an adhesive that satisfies the above-mentioned rate of decrease in peeling force after immersion in water (30% or less) is excellent in water resistance reliability.
　いくつかの好ましい態様では、前記Ａ層は、光硬化型または溶剤型の粘着剤組成物から形成された層である。光硬化型または溶剤型の粘着剤組成物から形成されたＡ層を備える構成において、ここに開示される技術による効果（親水層形成による水剥離性改善効果）は好ましく発揮される。また、ここに開示される積層体を光学用途に用いる場合、光硬化型または溶剤型の粘着剤は、水分散型と比べて優れた光学特性を発揮しやすい。 In some preferred embodiments, the A layer is a layer formed from a photocurable or solvent type pressure-sensitive adhesive composition. In the configuration including the A layer formed from the photocurable or solvent-type pressure-sensitive adhesive composition, the effect of the technique disclosed herein (the effect of improving water peelability by forming the hydrophilic layer) is preferably exhibited. Further, when the laminate disclosed herein is used for optical purposes, the photocurable or solvent-type pressure-sensitive adhesive tends to exhibit excellent optical characteristics as compared with the water-dispersed type.
　いくつかの好ましい態様では、前記Ａ層は水親和剤を含む。水親和剤を含むＡ層によると、通常状態（常態）の剥離強度と水剥離性とを好適に両立する粘着剤が得られやすく、さらに水浸漬後剥離力低下率が抑制された粘着剤が得られやすい。 In some preferred embodiments, the A layer contains a water affinity. According to the layer A containing a water-affinitive agent, it is easy to obtain a pressure-sensitive adhesive that preferably has both peeling strength in a normal state (normal state) and water-peeling property, and a pressure-sensitive adhesive in which the rate of decrease in peeling power after immersion in water is suppressed Easy to obtain.
　いくつかの好ましい態様では、前記無機材料は無機酸化物である。基材層の粘着剤層側表面の親水層材料として無機酸化物を用いることにより、当該表面の水接触角が効果的に低下し、優れた水剥離性が得られやすい。特に好ましい無機酸化物として酸化ケイ素が用いられる。 In some preferred embodiments, the inorganic material is an inorganic oxide. By using an inorganic oxide as the hydrophilic layer material on the surface of the base material layer on the pressure-sensitive adhesive layer side, the water contact angle of the surface is effectively reduced, and excellent water peelability can be easily obtained. Silicon oxide is used as a particularly preferable inorganic oxide.
　いくつかの態様では、前記親水層の厚さは５０００ｎｍ未満である。このような薄厚の親水層とすることで、基材層の機能を損なうことなく水剥離性を向上することができる。 In some embodiments, the thickness of the hydrophilic layer is less than 5000 nm. By forming such a thin hydrophilic layer, the water releasability can be improved without impairing the function of the base material layer.
　いくつかの好ましい態様では、前記基材層は光学部材である。ここに開示される積層体は、光学用途に適した粘着剤付き光学部材の形態で好ましく利用され得る。上記光学用積層体（粘着剤付き光学部材）は、その構成要素としての基材層と粘着剤層とが信頼性よく接着したものでありながら、水剥離を利用したリワーク性に優れるので、貼り直し作業がしやすく、また積層体としての使用目的を達成した後には、上記水剥離性を利用して、両者を容易に分離することができる。 In some preferred embodiments, the substrate layer is an optical member. The laminate disclosed herein can be preferably used in the form of an optical member with an adhesive suitable for optical applications. The above-mentioned optical laminate (optical member with an adhesive) has a base material layer and an adhesive layer as its constituent elements bonded with high reliability, but has excellent reworkability using water peeling, so that it can be attached. The repair work is easy, and after achieving the purpose of use as a laminated body, the two can be easily separated by utilizing the water releasability.
　また、この明細書によると、基材層と粘着剤層とを有する積層体の該基材層から該粘着剤層を剥離する方法が提供される。この方法は、前記基材層からの前記粘着剤層の剥離前線において前記基材層と前記粘着剤層との界面に水性液体が存在する状態で、前記剥離前線の移動に追随して前記水性液体の前記界面への進入を進行させつつ前記基材層から前記粘着剤層を剥離する水剥離工程を含む。ここで剥離前線とは、基材層からの粘着剤層の剥離を進行させる際に、上記基材層から上記粘着剤層が離れ始める箇所を指す。また、前記粘着剤層は、基材層側表面を構成するＡ層を備える。さらに、前記基材層の粘着剤層側表面には親水化処理が施されている。上記水剥離工程によると、基材層の粘着剤層側表面に親水化処理が施されているので、上記水性液体を有効に利用して基材層から粘着剤層を剥離することができる。いくつかの好ましい態様では、前記親水化処理は、前記基材層の粘着剤層側表面への親水層の形成である。特に好ましい態様において、前記親水層は無機材料含有層である。いくつかの態様において、上記粘着剤層のうち少なくとも基材層側の表面を構成するＡ層は、水親和剤を含む粘着剤により構成されていることが好ましい。 Further, according to this specification, there is provided a method of peeling the pressure-sensitive adhesive layer from the base material layer of a laminate having a base material layer and a pressure-sensitive adhesive layer. In this method, in a state where an aqueous liquid is present at the interface between the base material layer and the pressure-sensitive adhesive layer in the peeling front of the pressure-sensitive adhesive layer from the base material layer, the water-based method follows the movement of the peeling front. It includes a water peeling step of peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the liquid into the interface. Here, the peeling front refers to a portion where the pressure-sensitive adhesive layer begins to separate from the base material layer when the pressure-sensitive adhesive layer is peeled off from the base material layer. Further, the pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side. Further, the surface of the base material layer on the pressure-sensitive adhesive layer side is subjected to a hydrophilic treatment. According to the water peeling step, since the surface of the base material layer on the pressure-sensitive adhesive layer side is hydrophilized, the pressure-sensitive adhesive layer can be peeled off from the base material layer by effectively utilizing the aqueous liquid. In some preferred embodiments, the hydrophilization treatment is the formation of a hydrophilic layer on the pressure-sensitive adhesive layer side surface of the substrate layer. In a particularly preferred embodiment, the hydrophilic layer is an inorganic material-containing layer. In some embodiments, the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side is preferably composed of a pressure-sensitive adhesive containing a water-affinitive agent.
図１は、積層体の構成を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing the structure of the laminated body. 図２は、他の積層体の構成を模式的に示す断面図である。FIG. 2 is a cross-sectional view schematically showing the structure of another laminated body.
　以下、本発明の好適な実施形態を説明する。なお、本明細書において特に言及している事項以外の事柄であって本発明の実施に必要な事柄は、本明細書に記載された発明の実施についての教示と出願時の技術常識とに基づいて当業者に理解され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。また、以下の図面において、同じ作用を奏する部材・部位には同じ符号を付して説明することがあり、重複する説明は省略または簡略化することがある。また、図面に記載の実施形態は、本発明を明瞭に説明するために模式化されており、実際に提供される製品のサイズや縮尺を必ずしも正確に表したものではない。 Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for the implementation of the present invention are based on the teachings regarding the implementation of the invention described in the present specification and the common general knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art. Further, in the following drawings, members / parts having the same action may be described with the same reference numerals, and duplicate description may be omitted or simplified. In addition, the embodiments described in the drawings are schematicized for clearly explaining the present invention, and do not necessarily accurately represent the size and scale of the actually provided product.
　この明細書において「アクリル系重合物」とは、アクリル系モノマーを５０重量％より多く含むモノマー成分に由来する重合物をいう。上記アクリル系モノマーとは、１分子中に少なくとも１つの（メタ）アクリロイル基を有するモノマーに由来するモノマーのことをいう。また、この明細書において「（メタ）アクリロイル」とは、アクリロイルおよびメタクリロイルを包括的に指す意味である。同様に、「（メタ）アクリレート」とはアクリレートおよびメタクリレートを、「（メタ）アクリル」とはアクリルおよびメタクリルを、それぞれ包括的に指す意味である。上記アクリル系重合物は、アクリル系ポリマーであり得る。上記アクリル系重合物は、例えば、水分散型や溶剤型の粘着剤において、ベースポリマー（主構成ポリマー）として含有されるアクリル系ポリマーであり得る。この場合、本明細書における「アクリル系重合物を構成するモノマー成分」は、「アクリル系ポリマーを構成するモノマー成分」に言い換えることができる。また、本明細書において、「重合物を構成するモノマー成分」や「アクリル系重合物を構成するモノマー成分」との相対量で表わされる添加成分の含有量は、「アクリル系ポリマー」との相対量と言い換えることができるものとする。 In this specification, the "acrylic polymer" refers to a polymer derived from a monomer component containing an acrylic monomer in an amount of 50% by weight or more. The acrylic monomer refers to a monomer derived from a monomer having at least one (meth) acryloyl group in one molecule. Moreover, in this specification, "(meth) acryloyl" means a comprehensively referring to acryloyl and methacryloyl. Similarly, "(meth) acrylate" means acrylate and methacrylate, and "(meth) acrylic" means acrylic and methacrylic, respectively. The acrylic polymer can be an acrylic polymer. The acrylic polymer may be, for example, an acrylic polymer contained as a base polymer (main constituent polymer) in a water-dispersible type or solvent type pressure-sensitive adhesive. In this case, the "monomer component constituting the acrylic polymer" in the present specification can be paraphrased as the "monomer component constituting the acrylic polymer". Further, in the present specification, the content of the additive component represented by the relative amount of the "monomer component constituting the polymer" and the "monomer component constituting the acrylic polymer" is relative to the "acrylic polymer". It shall be possible to paraphrase it as a quantity.
　＜積層体の構成例＞
　ここに開示される積層体の一構成例を図１に示す。この積層体１は、粘着剤層１０と、粘着剤層１０の一方の表面１０Ａに積層された基材層２０と、を含む片面接着性の粘着シートとして構成されている。基材層２０は、主層２２と親水層２４との積層構造を有しており、具体的には、主層２２と、粘着剤層１０側の表面２０Ｂを構成する親水層２４とを備える。粘着剤層１０は、基材層２０の粘着剤層側表面２０Ｂに剥離可能に密着している。粘着剤層１０は、基材層２０の親水層２４と直接接触した状態で積層されている。また、図１に示す例では、粘着剤層１０は単層構造である。すなわち、粘着剤層１０の一方の表面（基材層側表面）１０Ａを構成するＡ層によって粘着剤層１０の全体が構成されている。使用前（被着体への貼付け前）の積層体１は、例えば図１に示すように、粘着剤層１０の他方の表面（粘着面）１０Ｂが、少なくとも該粘着剤層側が剥離性表面（剥離面）となっている剥離ライナー３０で保護された、剥離ライナー付き積層体５０の形態であり得る。あるいは、基材層２０の背面２０Ａ（粘着剤層側表面２０Ｂとは反対側の表面。積層体１の背面でもあり得る。）が剥離面となっており、上記背面２０Ａに粘着面１０Ｂが当接するように巻回または積層されることで粘着面１０Ｂが保護された形態であってもよい。 <Structure example of laminated body>
An example of the configuration of the laminated body disclosed herein is shown in FIG. The laminated body 1 is configured as a single-sided adhesive pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer 10 and a base material layer 20 laminated on one surface 10A of the pressure-sensitive adhesive layer 10. The base material layer 20 has a laminated structure of a main layer 22 and a hydrophilic layer 24, and specifically includes a main layer 22 and a hydrophilic layer 24 forming a surface 20B on the pressure-sensitive adhesive layer 10 side. .. The pressure-sensitive adhesive layer 10 is releasably adhered to the pressure-sensitive adhesive layer-side surface 20B of the base material layer 20. The pressure-sensitive adhesive layer 10 is laminated in direct contact with the hydrophilic layer 24 of the base material layer 20. Further, in the example shown in FIG. 1, the pressure-sensitive adhesive layer 10 has a single-layer structure. That is, the entire pressure-sensitive adhesive layer 10 is composed of the layer A constituting one surface (surface on the base material layer side) 10A of the pressure-sensitive adhesive layer 10. In the laminated body 1 before use (before sticking to the adherend), for example, as shown in FIG. 1, the other surface (adhesive surface) 10B of the pressure-sensitive adhesive layer 10 has a peelable surface (at least the pressure-sensitive adhesive layer side). It may be in the form of a laminate 50 with a release liner, which is protected by a release liner 30 which is a release surface). Alternatively, the back surface 20A of the base material layer 20 (the surface opposite to the pressure-sensitive adhesive layer side surface 20B. It may also be the back surface of the laminate 1) is a peeling surface, and the adhesive surface 10B hits the back surface 20A. The adhesive surface 10B may be protected by being wound or laminated so as to be in contact with each other.
　ここに開示される積層体の他の一構成例を図２に示す。この積層体２は、粘着剤層１１０と、粘着剤層１１０の一方の表面（基材層側表面）１１０Ａに積層された基材層２０と、を含む片面接着性の粘着シートとして構成されている。基材層２０は、主層２２と親水層２４との積層構造を有しており、具体的には、主層２２と、粘着剤層１０側の表面２０Ｂを構成する親水層２４とを備える。粘着剤層１１０は、一方の表面（基材層側表面）１１０Ａを構成するＡ層１１２と、Ａ層１１２の背面側に積層配置されたＢ層１１４と、からなる２層構造を有する。粘着剤層１１０のＡ層１１２は、基材層２０の粘着剤層側表面２０Ｂに剥離可能に密着している。具体的には、Ａ層１１２は、基材層２０の親水層２４と直接接触した状態で積層されている。使用前（被着体への貼付け前）の積層体２は、図１に示す積層体１と同様に、他方の表面（粘着面）１１０Ｂが図示しない剥離ライナーで保護された、剥離ライナー付き積層体の形態であり得る。あるいは、基材層２０の背面２０Ａ（積層体２の背面でもあり得る。）が剥離面となっており、当該背面２０Ａに粘着面１１０Ｂが当接するように巻回または積層されることで粘着面１１０Ｂが保護された形態であってもよい。 FIG. 2 shows another configuration example of the laminated body disclosed here. The laminated body 2 is configured as a single-sided adhesive pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer 110 and a base material layer 20 laminated on one surface (base material layer side surface) 110A of the pressure-sensitive adhesive layer 110. There is. The base material layer 20 has a laminated structure of a main layer 22 and a hydrophilic layer 24, and specifically includes a main layer 22 and a hydrophilic layer 24 forming a surface 20B on the pressure-sensitive adhesive layer 10 side. .. The pressure-sensitive adhesive layer 110 has a two-layer structure including an A layer 112 constituting one surface (base material layer side surface) 110A and a B layer 114 laminated on the back surface side of the A layer 112. The A layer 112 of the pressure-sensitive adhesive layer 110 is releasably adhered to the pressure-sensitive adhesive layer side surface 20B of the base material layer 20. Specifically, the A layer 112 is laminated in a state of being in direct contact with the hydrophilic layer 24 of the base material layer 20. The laminated body 2 before use (before being attached to the adherend) is a laminated body with a release liner in which the other surface (adhesive surface) 110B is protected by a release liner (not shown), similarly to the laminate 1 shown in FIG. It can be the form of the body. Alternatively, the back surface 20A of the base material layer 20 (which may also be the back surface of the laminated body 2) is a peeling surface, and the adhesive surface is wound or laminated so that the adhesive surface 110B abuts on the back surface 20A. 110B may be in a protected form.
　剥離ライナーとしては、特に限定されず、例えば樹脂フィルムや紙等のライナー基材の表面が剥離処理された剥離ライナーや、フッ素系ポリマー（ポリテトラフルオロエチレン等）やポリオレフィン系樹脂（ポリエチレン、ポリプロピレン等）の低接着性材料からなる剥離ライナー等を用いることができる。上記剥離処理には、例えば、シリコーン系、長鎖アルキル系等の剥離処理剤が用いられ得る。いくつかの態様において、剥離処理された樹脂フィルムを剥離ライナーとして好ましく採用し得る。 The release liner is not particularly limited, and for example, a release liner in which the surface of a liner base material such as a resin film or paper is peeled off, a fluoropolymer (polytetrafluoroethylene, etc.), a polyolefin resin (polyethylene, polypropylene, etc.), etc. ), A release liner made of a low-adhesive material or the like can be used. For the peeling treatment, for example, a silicone-based or long-chain alkyl-based peeling agent can be used. In some embodiments, the peeled resin film can be preferably used as the peel liner.
　＜積層体の特性＞
　（剥離強度Ｎ０）
　ここに開示される積層体において、基材層に対する粘着剤層の剥離強度Ｎ０は２．０Ｎ／１０ｍｍ以上である。ここで剥離強度Ｎ０は、温度２３℃、引張速度３００ｍｍ／分、剥離角度１８０度の条件で測定される剥離強度である。換言すると、粘着剤層は、基材層に対して所定値以上の剥離強度Ｎ０で接着しているということもできる。これにより、積層体の粘着剤層は、基材層に安定して接着したものとなり、使用中に、意図せずに粘着剤層が基材層から剥がれるような不具合の発生が防止される。上記剥離強度を有する積層体は被着体に対しても、良好な接着性を示し得る。いくつかの態様において、上記剥離強度Ｎ０は、粘着剤層と基材層との密着性および被着体への接着性の観点から、例えば２．５Ｎ／１０ｍｍ以上であってよく、３．０Ｎ／１０ｍｍ以上でもよく、３．５Ｎ／１０ｍｍ以上でもよく、４．０Ｎ／１０ｍｍ以上でもよく、４．５Ｎ／１０ｍｍ以上でもよく、５．０Ｎ／１０ｍｍ以上でもよい。他のいくつかの態様において、上記剥離強度Ｎ０は、例えば６．０Ｎ／１０ｍｍ以上であってよく、７．０Ｎ／１０ｍｍ以上でもよく、８．０Ｎ／１０ｍｍ以上でもよく、９．０Ｎ／１０ｍｍ以上でもよく、１０．０Ｎ／１０ｍｍ以上でもよく、１１．０Ｎ／１０ｍｍ以上でもよい。上記剥離強度Ｎ０の上限は特に限定されず、例えば３０Ｎ／１０ｍｍ以下であり得る。上記剥離強度Ｎ０は、２０Ｎ／１０ｍｍ以下でもよく、１５Ｎ／１０ｍｍ以下（例えば１２Ｎ／１０ｍｍ以下）でもよい。いくつかの態様では、上記剥離強度Ｎ０は、１０Ｎ／１０ｍｍ未満でもよく、８Ｎ／１０ｍｍ未満でもよい。上記剥離強度Ｎ０は、具体的には後述の実施例に記載の方法で測定される。 <Characteristics of laminated body>
(Peeling strength N0)
In the laminate disclosed here, the peel strength N0 of the pressure-sensitive adhesive layer with respect to the base material layer is 2.0 N / 10 mm or more. Here, the peel strength N0 is a peel strength measured under the conditions of a temperature of 23 ° C., a tensile speed of 300 mm / min, and a peeling angle of 180 degrees. In other words, it can be said that the pressure-sensitive adhesive layer is adhered to the base material layer with a peel strength N0 of a predetermined value or more. As a result, the pressure-sensitive adhesive layer of the laminated body is stably adhered to the base material layer, and it is possible to prevent the occurrence of a problem that the pressure-sensitive adhesive layer is unintentionally peeled off from the base material layer during use. The laminate having the above peel strength can show good adhesiveness to the adherend. In some embodiments, the peel strength N0 may be, for example, 2.5N / 10mm or more, and may be 3.0N, from the viewpoint of adhesion between the pressure-sensitive adhesive layer and the base material layer and adhesion to the adherend. It may be / 10 mm or more, 3.5 N / 10 mm or more, 4.0 N / 10 mm or more, 4.5 N / 10 mm or more, 5.0 N / 10 mm or more. In some other embodiments, the peel strength N0 may be, for example, 6.0 N / 10 mm or more, 7.0 N / 10 mm or more, 8.0 N / 10 mm or more, 9.0 N / 10 mm or more. It may be 10.0 N / 10 mm or more, or 11.0 N / 10 mm or more. The upper limit of the peel strength N0 is not particularly limited, and may be, for example, 30 N / 10 mm or less. The peel strength N0 may be 20 N / 10 mm or less, or 15 N / 10 mm or less (for example, 12 N / 10 mm or less). In some embodiments, the peel strength N0 may be less than 10N / 10mm or less than 8N / 10mm. The peel strength N0 is specifically measured by the method described in Examples described later.
　（水剥離力Ｎ２）
　ここに開示される積層体は、その基材層と粘着剤層とのあいだに２０μＬの蒸留水を供給し、該蒸留水を前記粘着剤層と前記基材層との界面の一端に進入させた後、ＪＩＳ　Ｚ０２３７：２００９の１０．４．１　方法１：試験板に対する１８０°引きはがし粘着力に従い、具体的には、試験温度２３℃にて引張試験機を用いて引張速度３００ｍｍ／分、剥離角度１８０度の条件で測定される水剥離力Ｎ２［Ｎ／１０ｍｍ］が、所定値以下に制限されたものであり得る。水剥離力Ｎ２が制限された積層体によると、水等の水性液体を基材層表面に付与し、基材層表面と粘着剤層表面の界面に進入させることで、粘着剤層を容易に剥離することができる。水剥離力Ｎ２は、剥離強度Ｎ０の６０％以下であることが好ましい（Ｎ２≦０．６Ｎ０）。すなわち、水剥離力Ｎ２［Ｎ／１０ｍｍ］は、後述の式：水剥離力低下率［％］＝（１－（Ｎ２／Ｎ０））×１００；において、水剥離力低下率４０％以上であること、すなわち（１－（Ｎ２／Ｎ０））×１００≧４０［％］；を満足することが好ましい。この式は、次式：Ｎ２≦０．６Ｎ０；を意味する。特に限定するものではないが、水剥離力Ｎ２は、例えば１０Ｎ／１０ｍｍ以下であってよく、３．５Ｎ／１０ｍｍ以下でもよく、２．５Ｎ／１０ｍｍ以下でもよく、１．６Ｎ／１０ｍｍ以下でもよく、１．２Ｎ／１０ｍｍ以下でもよく、１．０Ｎ／１０ｍｍ以下でもよい。水剥離力Ｎ２が低い積層体によると、粘着剤層を剥離する際に基材層に与える負荷を軽減することができる。このことは、例えば、基材層が光学部材である態様において、光学部材から粘着剤層を剥離するときに、光学部材表面に剥離の影響を生じさせない点で特に有意義である。上記積層体は、例えば、水剥離力Ｎ２が０．７５Ｎ／１０ｍｍ以下、または０．５０Ｎ／１０ｍｍ以下、または０．２５Ｎ／１０ｍｍ以下、または０．１５Ｎ／１０ｍｍ以下である態様でも好適に実施され得る。水剥離力Ｎ２の下限は特に制限されず、実質的に０Ｎ／１０ｍｍでもよく、０Ｎ／１０ｍｍ超でもよい。
　なお、リワーク性等の観点から、水剥離力Ｎ２の測定において、基材層上に粘着剤を残留させることなく該基材層から粘着剤層を剥離できることが好ましい。すなわち、基材層からの粘着剤層の剥離において、非糊残り性に優れることが好ましい。基材層上への粘着剤の残留の有無は、例えば、粘着剤層剥離後の基材層を目視で観察することにより把握することができる。
　上記水剥離力Ｎ２は、具体的には後述の実施例に記載の方法で測定される。 (Water peeling force N2)
The laminate disclosed here supplies 20 μL of distilled water between the base material layer and the pressure-sensitive adhesive layer, and allows the distilled water to enter one end of the interface between the pressure-sensitive adhesive layer and the base material layer. After that, according to JIS Z0237: 2009 10.4.1 Method 1: 180 ° peeling adhesive force to the test plate, specifically, a tensile speed of 300 mm / min using a tensile tester at a test temperature of 23 ° C. The water peeling force N2 [N / 10 mm] measured under the condition of a peeling angle of 180 degrees may be limited to a predetermined value or less. According to the laminate in which the water peeling force N2 is limited, the pressure-sensitive adhesive layer can be easily formed by applying an aqueous liquid such as water to the surface of the base material layer and allowing it to enter the interface between the surface of the base material layer and the surface of the pressure-sensitive adhesive layer. Can be peeled off. The water peeling force N2 is preferably 60% or less of the peeling strength N0 (N2 ≦ 0.6N0). That is, the water peeling force N2 [N / 10 mm] is 40% or more in the formula: water peeling force reduction rate [%] = (1- (N2 / N0)) × 100; described later. That is, it is preferable to satisfy (1- (N2 / N0)) × 100 ≧ 40 [%] ;. This formula means the following formula: N2 ≦ 0.6N0 ;. Although not particularly limited, the water peeling force N2 may be, for example, 10 N / 10 mm or less, 3.5 N / 10 mm or less, 2.5 N / 10 mm or less, or 1.6 N / 10 mm or less. , 1.2N / 10mm or less, or 1.0N / 10mm or less. According to the laminate having a low water peeling force N2, it is possible to reduce the load applied to the base material layer when the pressure-sensitive adhesive layer is peeled off. This is particularly significant in that, for example, in the embodiment in which the base material layer is an optical member, when the pressure-sensitive adhesive layer is peeled from the optical member, the peeling effect does not occur on the surface of the optical member. The laminate is also preferably carried out in an embodiment in which the water peeling force N2 is 0.75 N / 10 mm or less, 0.50 N / 10 mm or less, 0.25 N / 10 mm or less, or 0.15 N / 10 mm or less. obtain. The lower limit of the water peeling force N2 is not particularly limited, and may be substantially 0N / 10mm or more than 0N / 10mm.
From the viewpoint of reworkability and the like, it is preferable that the pressure-sensitive adhesive layer can be peeled off from the base material layer without leaving the pressure-sensitive adhesive on the base material layer in the measurement of the water peeling force N2. That is, it is preferable that the pressure-sensitive adhesive layer is excellent in non-adhesive residue property when peeling from the base material layer. The presence or absence of the adhesive remaining on the base material layer can be grasped, for example, by visually observing the base material layer after the pressure-sensitive adhesive layer is peeled off.
The water peeling force N2 is specifically measured by the method described in Examples described later.
　（水剥離力低下率）
　ここに開示される積層体は、水剥離力低下率が４０％以上である。上記水剥離力低下率を示す積層体は、水等の水性液体を用いることで基材層から粘着剤層を容易に剥離することができる。例えば、積層体の基材層と粘着剤層とのあいだに少量の水性液体を供給し、該水性液体を積層体の一端から基材層と粘着剤層との界面に進入させることで剥離のきっかけをつくることにより、上記基材層からの粘着剤層の剥離強度を大幅に低下させることができる。この性質を利用して、通常使用時における高い密着性と、良好な剥離性とを両立することができる。いくつかの態様において、水剥離力低下率は、例えば５０％以上であってよく、６５％以上でもよく、７５％以上でもよく、８５％以上でもよく、９０％以上でもよく、９５％以上でもよく、９７％以上でもよい。水剥離力低下率は、原理上１００％以下であり、典型的には１００％未満である。
　水剥離力低下率は、式：
　　　水剥離力低下率［％］＝（１－（Ｎ２／Ｎ０））×１００
；から求めることができる。ここに開示される技術において、上記水剥離力低下率は、親水層の形成、親水層構成材料、粘着剤種や組成等の選定によって実現される。 (Rate of decrease in water peeling power)
The laminate disclosed here has a water peeling force reduction rate of 40% or more. The pressure-sensitive adhesive layer can be easily peeled off from the base material layer by using an aqueous liquid such as water in the laminate showing the rate of decrease in water peeling power. For example, a small amount of an aqueous liquid is supplied between the base material layer and the pressure-sensitive adhesive layer of the laminate, and the aqueous liquid is allowed to enter the interface between the base material layer and the pressure-sensitive adhesive layer from one end of the laminate to cause peeling. By creating a trigger, the peel strength of the pressure-sensitive adhesive layer from the base material layer can be significantly reduced. Utilizing this property, it is possible to achieve both high adhesion during normal use and good peelability. In some embodiments, the rate of decrease in water peeling power may be, for example, 50% or more, 65% or more, 75% or more, 85% or more, 90% or more, 95% or more. It may be 97% or more. The rate of decrease in water peeling force is 100% or less in principle, and typically less than 100%.
The rate of decrease in water peeling power is calculated by the formula:
Water peeling power reduction rate [%] = (1- (N2 / N0)) x 100
Can be obtained from. In the technique disclosed herein, the rate of decrease in water peeling force is realized by forming a hydrophilic layer, selecting a hydrophilic layer constituent material, an adhesive type, a composition, and the like.
　剥離強度Ｎ０［Ｎ／１０ｍｍ］に対する水剥離力Ｎ２［Ｎ／１０ｍｍ］の比（Ｎ２／Ｎ０）は、例えば１／２．５以下であってよく、１／５以下でもよく、１／１０以下でもよい。上記比（Ｎ２／Ｎ０）がより小さいことは、剥離強度Ｎ０に対して水剥離力Ｎ２がより顕著に低下することを意味する。ここに開示される積層体は、比（Ｎ２／Ｎ０）が１／１５以下、１／２５以下または１／３５以下である態様で好ましく実施され得る。比（Ｎ２／Ｎ０）の下限は特に制限されず、例えば１／２００以上であってよく、１／１５０以上でもよく、１／１００以上でもよい。 The ratio (N2 / N0) of the water peeling force N2 [N / 10 mm] to the peeling strength N0 [N / 10 mm] may be, for example, 1 / 2.5 or less, 1/5 or less, or 1/10 or less. It may be. When the ratio (N2 / N0) is smaller, it means that the water peeling force N2 is more significantly reduced with respect to the peeling strength N0. The laminate disclosed herein can be preferably carried out in an embodiment in which the ratio (N2 / N0) is 1/15 or less, 1/25 or less, or 1/35 or less. The lower limit of the ratio (N2 / N0) is not particularly limited, and may be, for example, 1/200 or more, 1/150 or more, or 1/100 or more.
　（水浸漬後剥離力低下率）
　ここに開示される積層体は、上記のように水等の水性液体を用いて容易に剥離することができ、かつ、積層体を水に３０分間浸漬し、次いで水から引き上げて付着水を拭き取った後に剥離強度Ｎ０の測定条件と同じ条件で測定される水浸漬後剥離強度Ｎ１［Ｎ／１０ｍｍ］が、式：
　　　水浸漬後剥離力低下率［％］＝（１－（Ｎ１／Ｎ０））×１００
；において、水浸漬後剥離力低下率３０％以下を満足することが好ましい。すなわち、式：
　　　（１－（Ｎ１／Ｎ０））×１００≦３０［％］
；を満足することが好ましい。この式は、次式：Ｎ１≧０．７Ｎ０；を意味する。上記の水浸漬後剥離力低下率（３０％以下）を満足する粘着剤を含む積層体は、耐水信頼性に優れる。より高い耐水信頼性を得る観点から、水浸漬後剥離力低下率は、例えば２０％以下であることが好ましく、１０％以下であることがより好ましく、７％以下でもよい。水浸漬後剥離力低下率の下限は、典型的には０％以上である。上記積層体は、水剥離力低下率［％］と水浸漬後剥離力低下率［％］との差が、例えば４５％以上、または５５％以上、または７０％以上、または８０％以上、または９０％以上である態様で好ましく実施され得る。なお、上記水浸漬後剥離力低下率を算出するための水浸漬後剥離強度Ｎ１は、後述の実施例に記載の方法で測定される。 (Rate of decrease in peeling force after immersion in water)
The laminate disclosed herein can be easily peeled off using an aqueous liquid such as water as described above, and the laminate is immersed in water for 30 minutes and then pulled out of the water to wipe off the adhering water. After soaking in water, the peel strength N1 [N / 10 mm] measured under the same conditions as the measurement condition of the peel strength N0 is as follows.
Rate of decrease in peeling force after immersion in water [%] = (1- (N1 / N0)) × 100
It is preferable to satisfy the peeling force reduction rate of 30% or less after immersion in water. That is, the formula:
(1- (N1 / N0)) × 100 ≦ 30 [%]
It is preferable to satisfy. This equation means the following equation: N1 ≧ 0.7N0 ;. A laminate containing an adhesive that satisfies the above-mentioned rate of decrease in peeling force after immersion in water (30% or less) is excellent in water resistance reliability. From the viewpoint of obtaining higher water resistance reliability, the rate of decrease in peeling force after immersion in water is preferably, for example, 20% or less, more preferably 10% or less, and may be 7% or less. The lower limit of the peeling force reduction rate after immersion in water is typically 0% or more. In the above laminated body, the difference between the water peeling power reduction rate [%] and the water peeling power reduction rate [%] is, for example, 45% or more, 55% or more, 70% or more, or 80% or more, or It can be preferably carried out in an embodiment of 90% or more. The peel strength N1 after water immersion for calculating the rate of decrease in peeling force after water immersion is measured by the method described in Examples described later.
　いくつかの態様において、積層体のヘイズ値は凡そ１０％以下であることが適当であり、凡そ５％以下（例えば凡そ３％以下）であり得る。上記ヘイズ値は１．０％以下であることが好ましい。このように透明性の高い積層体は、高い光透過性が求められる光学用途に好適である。積層体のヘイズ値は、１．０％未満であってよく、０．７％未満であってもよく、０．５％以下（例えば０～０．５％）であってもよい。積層体に関する上記ヘイズ値の範囲は、ここに開示される技術における粘着剤層および基材層のヘイズ値にも適用され得る。 In some embodiments, it is appropriate that the haze value of the laminate is approximately 10% or less, and may be approximately 5% or less (for example, approximately 3% or less). The haze value is preferably 1.0% or less. Such a highly transparent laminate is suitable for optical applications where high light transmission is required. The haze value of the laminate may be less than 1.0%, less than 0.7%, or 0.5% or less (for example, 0 to 0.5%). The range of haze values for the laminate can also be applied to the haze values of the pressure-sensitive adhesive layer and the substrate layer in the techniques disclosed herein.
　ここで「ヘイズ値」とは、測定対象に可視光を照射したときの全透過光に対する拡散透過光の割合をいう。くもり価ともいう。ヘイズ値は、以下の式で表わすことができる。
　　　Ｔｈ［％］＝Ｔｄ／Ｔｔ×１００
　上記式において、Ｔｈはヘイズ値［％］であり、Ｔｄは散乱光透過率、Ｔｔは全光透過率である。
　ヘイズ値は、ヘイズメーター（たとえば、村上色彩技術研究所製の「ＭＲ－１００」）を用いて測定することができる。ヘイズ値は、例えば、粘着剤層の組成や厚さ等、基材層材料や厚さ等の選択によって調節することができる。 Here, the "haze value" refers to the ratio of diffuse transmitted light to total transmitted light when the measurement target is irradiated with visible light. Also called cloudy value. The haze value can be expressed by the following equation.
Th [%] = Td / Tt × 100
In the above formula, Th is a haze value [%], Td is a scattered light transmittance, and Tt is a total light transmittance.
The haze value can be measured using a haze meter (for example, "MR-100" manufactured by Murakami Color Technology Laboratory). The haze value can be adjusted by selecting, for example, the composition and thickness of the pressure-sensitive adhesive layer, the base material layer material, and the thickness.
　上記積層体において、粘着剤層の基材層側表面側に配置されるＡ層を構成する粘着剤は、非水溶性であることが好ましい。非水溶性のＡ層によると、水浸漬後剥離強度Ｎ１が高く、水浸漬後剥離力低下率の低い積層体が得られやすい。Ａ層が非水溶性であることは、水等の水性液体を用いる剥離において基材層上に粘着剤が残留する現象を防止する観点からも好ましい。また、Ａ層が非水溶性であることは、水浸漬や環境中の湿気によって積層体の透明性が低下する現象を防止する観点からも有利となり得る。このことは、基材層が光学部材である光学用積層体において有利な特徴となり得る。 In the above laminated body, the pressure-sensitive adhesive constituting the layer A arranged on the surface side of the pressure-sensitive adhesive layer on the base material layer side is preferably water-insoluble. According to the water-insoluble layer A, it is easy to obtain a laminate having a high peeling strength N1 after immersion in water and a low rate of decrease in peeling force after immersion in water. The fact that the A layer is water-insoluble is also preferable from the viewpoint of preventing the phenomenon that the adhesive remains on the base material layer in peeling using an aqueous liquid such as water. Further, the fact that the layer A is water-insoluble can be advantageous from the viewpoint of preventing a phenomenon in which the transparency of the laminate is lowered due to immersion in water or moisture in the environment. This can be an advantageous feature in an optical laminate in which the substrate layer is an optical member.
　Ａ層を構成する粘着剤は、非水膨潤性であることが好ましい。非水膨潤性のＡ層によると、水浸漬後剥離強度Ｎ１が高く、水浸漬後剥離力低下率の低い積層体が得られやすい。また、水等の水性液体を用いる剥離において、少量の水性液体を有効に利用して良好な剥離性を発揮することができる。Ａ層が非水膨潤性であることは、水性液体を用いる剥離において基材層上に粘着剤が残留する現象を防止する観点からも好ましい。また、Ａ層が非水膨潤性であることは、水浸漬や環境中の湿気によって積層体の透明性が低下する現象を防止する観点からも有利となり得る。このことは、基材層が光学部材である光学用積層体において有利な特徴となり得る。 The pressure-sensitive adhesive constituting the A layer is preferably non-water-swellable. According to the non-water-swellable layer A, it is easy to obtain a laminated body having a high peeling strength N1 after immersion in water and a low rate of decrease in peeling force after immersion in water. Further, in peeling using an aqueous liquid such as water, a small amount of aqueous liquid can be effectively used to exhibit good peelability. It is preferable that the A layer is non-water swellable from the viewpoint of preventing the phenomenon that the adhesive remains on the base material layer in the peeling using the aqueous liquid. Further, the fact that the layer A is non-water swelling may be advantageous from the viewpoint of preventing the phenomenon that the transparency of the laminated body is lowered due to water immersion or moisture in the environment. This can be an advantageous feature in an optical laminate in which the substrate layer is an optical member.
　ここで、本明細書において、粘着剤が非水溶性であるとは、以下の方法で測定されるゲル分率が７５％以上であることをいう。また、粘着剤が非水膨潤性であるとは、以下の方法で測定される膨潤度が２以下であることをいう。
　すなわち、測定対象の粘着剤を０．５ｇ程度秤量し、その重さをＷ１とする。この粘着剤を室温（約２３℃）において蒸留水５００ｍｌ中に４８時間浸漬した後、ナイロンメッシュで濾過し、水を含んだ粘着剤の重さＷ２を測定する。その後、粘着剤を１３０℃で５時間乾燥させて、不揮発分の重さＷ３を測定する。ゲル分率および膨潤度は、以下の式により算出される。
　　ゲル分率［％］＝（Ｗ３／Ｗ１）×１００
　　膨潤度＝Ｗ２／Ｗ１ Here, in the present specification, the fact that the pressure-sensitive adhesive is water-insoluble means that the gel fraction measured by the following method is 75% or more. Further, the non-water swelling property of the pressure-sensitive adhesive means that the degree of swelling measured by the following method is 2 or less.
That is, about 0.5 g of the pressure-sensitive adhesive to be measured is weighed, and the weight thereof is defined as W1. After immersing this pressure-sensitive adhesive in 500 ml of distilled water at room temperature (about 23 ° C.) for 48 hours, the pressure-sensitive adhesive is filtered through a nylon mesh, and the weight W2 of the pressure-sensitive adhesive containing water is measured. Then, the pressure-sensitive adhesive is dried at 130 ° C. for 5 hours, and the weight W3 of the non-volatile component is measured. The gel fraction and swelling degree are calculated by the following formulas.
Gel fraction [%] = (W3 / W1) x 100
Swelling degree = W2 / W1
　いくつかの態様において、Ａ層のゲル分率は、例えば８０％以上であってよく、９０％以上でもよく、９５％以上でもよく、９８％以上でもよい。Ａ層のゲル分率は、原理上１００％以下である。また、いくつかの態様において、Ａ層の膨潤度は、例えば１．７以下であってよく、１．５以下でもよく、１．２以下でもよい。Ａ層の膨潤度は、例えば１．０以上であり、典型的には１．０超である。 In some embodiments, the gel fraction of layer A may be, for example, 80% or more, 90% or more, 95% or more, or 98% or more. The gel fraction of the A layer is 100% or less in principle. Further, in some embodiments, the degree of swelling of the layer A may be, for example, 1.7 or less, 1.5 or less, or 1.2 or less. The degree of swelling of the layer A is, for example, 1.0 or more, and typically more than 1.0.
　粘着剤層がＡ層と該Ａ層の背面側に配置されたＢ層とを含む構成の積層体において、Ｂ層のゲル分率は特に限定されない。いくつかの態様において、Ｂ層のゲル分率は、Ａ層のゲル分率と同等以上であることが好ましく、Ａ層のゲル分率より高くてもよい。Ｂ層のゲル分率は、例えば９０％以上であってよく、９５％以上でもよく、９８％以上でもよく、９９％以上でもよい。Ｂ層のゲル分率は、原理上１００％以下である。また、粘着剤層全体のゲル分率は、例えば８５％以上であってよく、９０％以上でもよく、９５％以上でもよく、９８％以上でもよく、９９％以上でもよい。なお、Ａ層のみからなる粘着剤層では、該粘着剤層全体のゲル分率とはＡ層のゲル分率を意味する。 The gel fraction of the B layer is not particularly limited in the laminated body having the structure in which the pressure-sensitive adhesive layer includes the A layer and the B layer arranged on the back side of the A layer. In some embodiments, the gel fraction of layer B is preferably equal to or greater than the gel fraction of layer A and may be higher than the gel fraction of layer A. The gel fraction of the B layer may be, for example, 90% or more, 95% or more, 98% or more, or 99% or more. The gel fraction of the B layer is 100% or less in principle. Further, the gel fraction of the entire pressure-sensitive adhesive layer may be, for example, 85% or more, 90% or more, 95% or more, 98% or more, or 99% or more. In the pressure-sensitive adhesive layer consisting of only the A layer, the gel fraction of the entire pressure-sensitive adhesive layer means the gel fraction of the A layer.
　粘着剤層がＡ層と該Ａ層の背面側に配置されたＢ層とを含む構成の積層体において、Ｂ層の膨潤度は特に限定されない。いくつかの態様において、Ｂ層の膨潤度は、Ａ層の膨潤度と同等以下であることが好ましく、Ａ層の膨潤度より低くてもよい。Ｂ層の膨潤度は、例えば１．５以下であってよく、１．３以下でもよく、１．１以下でもよい。Ｂ層の膨潤度は、例えば１．０以上であり、典型的には１．０超である。また、粘着剤層全体の膨潤度は、例えば１．６以下であってよく、１．４以下でもよく、１．２以下でもよく、１．１以下でもよい。なお、Ａ層のみからなる粘着剤層では、該粘着剤層全体の膨潤度とはＡ層の膨潤度を意味する。 The degree of swelling of the B layer is not particularly limited in the laminated body having the structure in which the adhesive layer includes the A layer and the B layer arranged on the back side of the A layer. In some embodiments, the degree of swelling of the layer B is preferably equal to or less than the degree of swelling of the layer A, and may be lower than the degree of swelling of the layer A. The degree of swelling of the B layer may be, for example, 1.5 or less, 1.3 or less, or 1.1 or less. The degree of swelling of the B layer is, for example, 1.0 or more, and typically more than 1.0. Further, the degree of swelling of the entire pressure-sensitive adhesive layer may be, for example, 1.6 or less, 1.4 or less, 1.2 or less, or 1.1 or less. In the pressure-sensitive adhesive layer consisting of only the A layer, the degree of swelling of the entire pressure-sensitive adhesive layer means the degree of swelling of the A layer.
　なお、粘着剤の水に対するゲル分率や膨潤度は、例えばモノマー成分の組成、重合物の重量平均分子量、架橋剤や多官能モノマーの使用等の、本願出願時の当業者にとって一般的な手法を適宜採用することにより調節することができる。 The gel fraction and swelling degree of the pressure-sensitive adhesive with respect to water are general methods for those skilled in the art at the time of filing the application, such as composition of monomer components, weight average molecular weight of polymers, use of cross-linking agents and polyfunctional monomers. Can be adjusted by appropriately adopting.
　＜基材層＞
　（親水層）
　ここに開示される積層体を構成する基材層は、粘着剤層側表面に親水層が形成されている。換言すると、基材層は、粘着剤層側の表面を構成する層（基材層の最外層）として親水層を有する。ここで親水層は、親水性表面を有する層と定義され、例えば、粘着剤層積層前の親水層表面（基材層の粘着剤層側表面でもある。特に断りのないかぎり以下同じ。）は、蒸留水に対する接触角（以下「水接触角」ともいう。）が、例えば６０度以下、好ましくは５０度以下となる程度の親水性を示す表面であり得る。基材層の粘着剤層側表面に親水層を設けることにより、基材材料や、そこに積層される粘着剤の種類等にかかわらず、良好な水剥離性が得られる。 <Base layer>
(Hydrophilic layer)
The base material layer constituting the laminate disclosed here has a hydrophilic layer formed on the surface on the pressure-sensitive adhesive layer side. In other words, the base material layer has a hydrophilic layer as a layer (outermost layer of the base material layer) constituting the surface on the pressure-sensitive adhesive layer side. Here, the hydrophilic layer is defined as a layer having a hydrophilic surface. For example, the surface of the hydrophilic layer before laminating the pressure-sensitive adhesive layer (also the surface on the pressure-sensitive adhesive layer side of the base material layer; the same shall apply hereinafter unless otherwise specified). The surface may have hydrophilicity such that the contact angle with respect to distilled water (hereinafter, also referred to as “water contact angle”) is, for example, 60 degrees or less, preferably 50 degrees or less. By providing the hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side, good water releasability can be obtained regardless of the base material and the type of the pressure-sensitive adhesive laminated therein.
　いくつかの態様において、上記親水層表面の水接触角は、例えば４５度以下であってよく、４０度以下でもよく、３５度以下でもよく、３０度以下でもよい。上記親水層表面の水接触角が小さくなると、該表面に沿って水が濡れ広がりやすくなり、基材層からの粘着剤層の水剥離性が向上する傾向にある。このことは、粘着剤層の基材層からの除去性や、リワーク性向上の観点から好ましい。いくつかの好ましい態様において、上記親水層表面の水接触角は２５度未満が適当であり、２０度未満であってもよく、１５度以下でもよく、１０度未満でもよい。水接触角の下限は、原理上０度である。いくつかの態様において、上記水接触角は、０度超でもよく、１度以上でもよく、３度以上でもよく、５度以上でもよい。ここに開示される技術によると、親水層材料や粘着剤種の選定により、より優れた水剥離性を実現し得るので、いくつかの態様では、上記親水層表面の水接触角は８度以上であってもよく、１２度以上でもよく、１６度以上でもよく、２０度以上（例えば２４度以上）でもよい。親水層表面の水接触角は、親水層を構成する材料の選択や親水層の厚さ、追加の表面処理等によって設定することができる。親水層表面（基材層の粘着剤層側表面）の水接触角は、後述の実施例に記載の方法で測定することができる。 In some embodiments, the water contact angle on the surface of the hydrophilic layer may be, for example, 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less. When the water contact angle on the surface of the hydrophilic layer becomes small, water tends to get wet and spread along the surface, and the water detachability of the pressure-sensitive adhesive layer from the base material layer tends to be improved. This is preferable from the viewpoint of removing the pressure-sensitive adhesive layer from the base material layer and improving the reworkability. In some preferred embodiments, the water contact angle of the surface of the hydrophilic layer is preferably less than 25 degrees, may be less than 20 degrees, may be 15 degrees or less, or may be less than 10 degrees. The lower limit of the water contact angle is 0 degrees in principle. In some embodiments, the water contact angle may be greater than 0 degrees, greater than 1 degree, greater than 3 degrees, or greater than or equal to 5 degrees. According to the technique disclosed herein, better water releasability can be achieved by selecting the hydrophilic layer material and the pressure-sensitive adhesive type. Therefore, in some embodiments, the water contact angle on the surface of the hydrophilic layer is 8 degrees or more. It may be 12 degrees or more, 16 degrees or more, or 20 degrees or more (for example, 24 degrees or more). The water contact angle on the surface of the hydrophilic layer can be set by selecting the material constituting the hydrophilic layer, the thickness of the hydrophilic layer, additional surface treatment, and the like. The water contact angle of the surface of the hydrophilic layer (the surface of the base material layer on the pressure-sensitive adhesive layer side) can be measured by the method described in Examples described later.
　ここに開示される技術は、基材層の粘着剤層側表面に親水層を形成して、当該粘着剤層側表面の水接触角を低下し、改善された水剥離性を得るものであり得る。したがって、親水層表面の水接触角ＷＣＡ１は、典型的には、後述する基材層の主層（親水層のない基材層単体）の表面の水接触角ＷＣＡ２よりも小さい。上記ＷＣＡ１は、上記ＷＣＡ２の７０％未満であることが好ましく、５０％未満がより好ましく、３０％未満がさらに好ましく、２０％未満が特に好ましい。 The technique disclosed herein is to form a hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side to reduce the water contact angle of the surface on the pressure-sensitive adhesive layer side and obtain improved water peelability. obtain. Therefore, the water contact angle WCA1 on the surface of the hydrophilic layer is typically smaller than the water contact angle WCA2 on the surface of the main layer of the base material layer (a single base material layer without the hydrophilic layer) described later. The WCA1 is preferably less than 70%, more preferably less than 50%, even more preferably less than 30%, and particularly preferably less than 20% of the WCA2.
　また、水剥離性の観点から、親水層表面は平滑に形成されていることが好ましい。例えば、上記親水層表面の算術平均粗さＲａは１０μｍ未満である。このように凹凸の抑制された親水層表面によると、所望の水剥離性を実現しやすい。上記算術平均粗さＲａは、好ましくは５μｍ未満であり、より好ましくは３μｍ未満（具体的には１．０μｍ未満）である。また、水剥離性を長期間維持するという観点からは、上記親水性表面の上記算術平均粗さＲａはさらに小さいことが好ましい。例えば、上記算術平均粗さＲａは、好ましくは１００ｎｍ未満であり、より好ましくは１０ｎｍ未満、さらに好ましくは３ｎｍ未満（具体的には１．０ｎｍ未満）である。親水層の表面平滑性は、親水層材料の選定や形成条件、厚み等によって調節することができる。なお、本明細書において算術平均粗さは、一般的な表面粗さ測定装置（例えば、Ｖｅｅｃｏ社製の非接触３次元表面形状測定装置、型式「Ｗｙｋｏ　ＮＴ－３３００」や日立ハイテクノロジーズ社製の原子間力顕微鏡、型式「ＡＦＭ５５００Ｍ」）を用いて測定することができる。 Further, from the viewpoint of water peelability, it is preferable that the surface of the hydrophilic layer is formed smoothly. For example, the arithmetic mean roughness Ra of the surface of the hydrophilic layer is less than 10 μm. According to the surface of the hydrophilic layer in which the unevenness is suppressed in this way, it is easy to realize the desired water peelability. The arithmetic mean roughness Ra is preferably less than 5 μm, more preferably less than 3 μm (specifically, less than 1.0 μm). Further, from the viewpoint of maintaining the water releasability for a long period of time, it is preferable that the arithmetic average roughness Ra of the hydrophilic surface is even smaller. For example, the arithmetic mean roughness Ra is preferably less than 100 nm, more preferably less than 10 nm, still more preferably less than 3 nm (specifically less than 1.0 nm). The surface smoothness of the hydrophilic layer can be adjusted by selecting the hydrophilic layer material, forming conditions, the thickness, and the like. In the present specification, the arithmetic mean roughness is defined as a general surface roughness measuring device (for example, a non-contact three-dimensional surface shape measuring device manufactured by Veeco, model "Wyko NT-3300", or manufactured by Hitachi High Technologies America. It can be measured using an atomic force microscope, model "AFM5500M").
　親水層の材質としては、無機材料が用いられる。親水層が無機材料を含むことで、良好な水剥離性が得られやすい。無機材料としては、遷移金属元素や半金属元素の単体、合金を含む各種の金属材料や、無機酸化物等の無機化合物のなかから親水性表面を形成し得る材料が用いられる。上記無機材料は１種を単独でまたは２種以上を組み合わせて用いることができる。無機材料の好適例としては、酸化チタン、酸化亜鉛、酸化マグネシウム、酸化アルミニウム、酸化ケイ素、酸化セリウム、酸化クロム、酸化ジルコニウム、酸化マンガン、酸化亜鉛、酸化鉄、酸化錫、酸化ニオブ等の酸化物（無機酸化物、典型的には金属酸化物）が挙げられる。なかでも、好ましい無機材料として酸化ケイ素等の無機酸化物が用いられる。親水層は、無機材料に加えて、コーティング剤やバインダとして利用され得る有機高分子化合物を含む各種有機材料を含んでもよく、含まなくてもよい。 Inorganic material is used as the material of the hydrophilic layer. Since the hydrophilic layer contains an inorganic material, good water releasability can be easily obtained. As the inorganic material, a material capable of forming a hydrophilic surface from simple substances of transition metal elements and metalloid elements, various metal materials including alloys, and inorganic compounds such as inorganic oxides is used. The above-mentioned inorganic materials may be used alone or in combination of two or more. Preferable examples of the inorganic material are oxides such as titanium oxide, zinc oxide, magnesium oxide, aluminum oxide, silicon oxide, cerium oxide, chromium oxide, zirconium oxide, manganese oxide, zinc oxide, iron oxide, tin oxide and niobium oxide. (Inorganic oxide, typically metal oxide). Among them, an inorganic oxide such as silicon oxide is used as a preferable inorganic material. In addition to the inorganic material, the hydrophilic layer may or may not contain various organic materials including an organic polymer compound that can be used as a coating agent or a binder.
　親水層中の無機材料（例えば酸化ケイ素等の無機酸化物）の量は、目的とする親水性表面が得られる適当量とすることができ、特定の範囲に限定されない。例えば、親水層中の無機材料の含有割合は、凡そ３０重量％以上とすることができ、凡そ５０重量％以上（例えば５０重量％超）が適当であり、凡そ７０重量％以上であってもよい。いくつかの好ましい態様では、親水層中の無機材料の含有割合は、凡そ９０～１００重量％（例えば凡そ９５重量％以上）である。 The amount of the inorganic material (for example, an inorganic oxide such as silicon oxide) in the hydrophilic layer can be an appropriate amount to obtain the desired hydrophilic surface, and is not limited to a specific range. For example, the content ratio of the inorganic material in the hydrophilic layer can be about 30% by weight or more, about 50% by weight or more (for example, more than 50% by weight) is appropriate, and even if it is about 70% by weight or more. Good. In some preferred embodiments, the content of the inorganic material in the hydrophilic layer is approximately 90-100% by weight (eg, approximately 95% by weight or more).
　いくつかの好ましい態様において、上記無機材料として、酸化ケイ素（典型的にはＳｉＯXで表わされる酸化ケイ素や、ＳｉＯ2で表わされる二酸化ケイ素）等の無機酸化物が用いられる。上記無機材料に占める無機酸化物（典型的には酸化ケイ素）の割合は、目的とする親水性表面が得られる適当量とすることができ、特定の範囲に限定されず、例えば、凡そ３０重量％以上とすることができ、凡そ５０重量％以上（例えば５０重量％超）が適当であり、凡そ７０重量％以上であってもよい。いくつかの好ましい態様では、上記無機材料中の無機酸化物（典型的には酸化ケイ素）の割合は、凡そ９０～１００重量％（例えば凡そ９５重量％以上）である。 In some preferred embodiments, as the inorganic material, an inorganic oxide such as silicon oxide (typically silicon oxide represented by SiO X or silicon dioxide represented by SiO 2 ) is used. The proportion of the inorganic oxide (typically silicon oxide) in the inorganic material can be an appropriate amount to obtain the desired hydrophilic surface and is not limited to a specific range, for example, about 30 weight by weight. % Or more, about 50% by weight or more (for example, more than 50% by weight) is suitable, and may be about 70% by weight or more. In some preferred embodiments, the proportion of the inorganic oxide (typically silicon oxide) in the inorganic material is approximately 90-100% by weight (eg, approximately 95% by weight or more).
　上記親水層の形成方法は特に限定されず、目的とする厚さ等に応じて適当な方法で形成され得る。例えば、真空蒸着法やスパッタリング法、あるいは、めっき法等の公知の成膜方法を利用して層状に形成した無機材料を親水層として利用することができる。無機材料として、無機化合物を用いる場合には、各種の蒸着法を用いることができ、例えば、真空蒸着法、スパッタリング法、イオンプレーティング法等の物理蒸着法（ＰＶＤ）や、原子層堆積層等の化学蒸着法（ＣＶＤ）等を採用することができる。ポリシロキサン等の無機ポリマーを含むコーティング層の形成は、公知のコーティング剤から所望の水接触角を示す表面が得られるものを適宜選択し、常法により使用して行うことができる。 The method for forming the hydrophilic layer is not particularly limited, and it can be formed by an appropriate method according to the target thickness and the like. For example, an inorganic material formed in layers by using a known film forming method such as a vacuum vapor deposition method, a sputtering method, or a plating method can be used as a hydrophilic layer. When an inorganic compound is used as the inorganic material, various vapor deposition methods can be used. For example, physical vapor deposition (PVD) such as vacuum vapor deposition, sputtering, ion plating, atomic layer deposition, etc. The chemical vapor deposition method (CVD) of the above can be adopted. The coating layer containing an inorganic polymer such as polysiloxane can be formed by appropriately selecting a known coating agent capable of obtaining a surface showing a desired water contact angle and using it by a conventional method.
　親水層の厚さは特に限定されない。基材層本体（基材層の主層）の機能を損なわない観点から、親水層の厚さは、具体的には凡そ５μｍ以下（例えば５０００ｎｍ未満）が適当であり、凡そ２μｍ以下（例えば２０００ｎｍ未満）であってもよい。いくつかの好ましい態様では、親水層の厚さは１０００ｎｍ未満であり、より好ましくは５００ｎｍ未満、さらに好ましくは１００ｎｍ未満、特に好ましくは５０ｎｍ未満であり、凡そ３０ｎｍ以下であってもよく、凡そ２０ｎｍ以下でもよく、凡そ１５ｎｍ以下（例えば１０ｎｍ未満）でもよい。このような薄厚の親水層とすることで、基材層の機能を損なうことなく、水剥離性を向上することができる。薄厚の親水層とすることは、光学特性の観点からも有利である。また、親水層の厚さは１ｎｍ以上（例えば３ｎｍ以上）が適当であり、表面の親水性を高めて水剥離性を向上する観点から、凡そ５ｎｍ以上であってもよく、凡そ１０ｎｍ以上（例えば１５ｎｍ以上）でもよい。薄厚（例えばナノオーダー）の親水層については、後述の実施例に記載の方法で厚さを測定することができる。 The thickness of the hydrophilic layer is not particularly limited. From the viewpoint of not impairing the function of the base material layer main body (main layer of the base material layer), the thickness of the hydrophilic layer is specifically about 5 μm or less (for example, less than 5000 nm), and is about 2 μm or less (for example, 2000 nm). Less than). In some preferred embodiments, the thickness of the hydrophilic layer is less than 1000 nm, more preferably less than 500 nm, even more preferably less than 100 nm, particularly preferably less than 50 nm, and may be about 30 nm or less, about 20 nm or less. However, it may be about 15 nm or less (for example, less than 10 nm). By forming such a thin hydrophilic layer, the water peelability can be improved without impairing the function of the base material layer. The thin hydrophilic layer is also advantageous from the viewpoint of optical characteristics. Further, the thickness of the hydrophilic layer is preferably 1 nm or more (for example, 3 nm or more), and may be about 5 nm or more, and may be about 10 nm or more (for example, from the viewpoint of improving the hydrophilicity of the surface and improving the water detachability). 15 nm or more) may be used. For a thin (for example, nano-order) hydrophilic layer, the thickness can be measured by the method described in Examples described later.
　（基材主層）
　ここに開示される基材層の主層（「基材主層」ともいう。あるいは便宜上、単に「基材層」ということがある。特に断りがないかぎり以下同じ。）としては、特に限定されず、使用目的や使用態様等に応じて適宜選択することができる。ここに開示される技術は、基材層の粘着剤層側表面に親水層を形成して、当該粘着剤層側表面の水接触角を低下し、改善された水剥離性を得るものであり得る。したがって、親水層のない基材層単体（主層）の表面の水接触角は、典型的には、親水層表面の水接触角よりも大きい。基材主層表面の水接触角は、例えば１０度よりも高く、３０度超または５０度超であり得る。基材主層表面の水接触角は、親水層形成の効果をよりよく発揮する観点から、６０度以上であってもよく、７０度以上でもよく、８０度以上（例えば８５度以上）でもよい。基材主層表面の水接触角の上限は特に限定されず、例えば１１５度未満であり、１０５度未満であってもよく、９５度未満であり得る。ここに開示される基材主層は、その親水層側表面が上記範囲の水接触角を有するものであり得る。また、基材層背面の水接触角は、上記基材主層の水接触角の範囲と同じ範囲をとり得る。基材主層表面の水接触角は、後述の実施例に記載の方法で測定することができる。 (Main base layer)
The main layer of the base material layer disclosed herein (also referred to as "base material main layer" or, for convenience, simply referred to as "base material layer"; the same shall apply hereinafter unless otherwise specified) is particularly limited. However, it can be appropriately selected according to the purpose of use, the mode of use, and the like. The technique disclosed herein is to form a hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side to reduce the water contact angle of the surface on the pressure-sensitive adhesive layer side and obtain improved water peelability. obtain. Therefore, the water contact angle on the surface of the base material layer alone (main layer) without the hydrophilic layer is typically larger than the water contact angle on the surface of the hydrophilic layer. The water contact angle of the surface of the base material main layer is, for example, higher than 10 degrees and can be more than 30 degrees or more than 50 degrees. The water contact angle on the surface of the main base layer may be 60 degrees or more, 70 degrees or more, or 80 degrees or more (for example, 85 degrees or more) from the viewpoint of better exerting the effect of forming the hydrophilic layer. .. The upper limit of the water contact angle on the surface of the base material main layer is not particularly limited, and may be, for example, less than 115 degrees, less than 105 degrees, or less than 95 degrees. The base material main layer disclosed herein may have a surface on the hydrophilic layer side having a water contact angle in the above range. Further, the water contact angle on the back surface of the base material layer may be the same as the range of the water contact angle of the base material main layer. The water contact angle on the surface of the main base layer can be measured by the method described in Examples described later.
　基材主層の材質の非限定的な例としては、ポリオレフィンフィルム、ポリエステルフィルム、ポリ塩化ビニルフィルム等の各種樹脂フィルム；ポリウレタンフォーム、ポリエチレンフォーム、ポリクロロプレンフォーム等の発泡体からなる発泡体シート；各種の繊維状物質（麻、綿等の天然繊維、ポリエステル、ビニロン等の合成繊維、アセテート等の半合成繊維、等であり得る。）の単独または混紡等による織布および不織布；和紙、上質紙、クラフト紙、クレープ紙等の紙類；アルミニウム箔、銅箔、ステンレス鋼（ＳＵＳ）等の金属箔；等が挙げられる。これらを複合した構成の層状体であってもよい。このような複合構造の基材主層の例として、例えば、金属箔と上記樹脂フィルムとが積層した構造の積層基材（多層構造基材）、ガラスクロス等の無機繊維で強化された樹脂シート等が挙げられる。 Non-limiting examples of the material of the base material main layer are various resin films such as polyolefin film, polyester film and polyvinyl chloride film; foam sheet made of foam such as polyurethane foam, polyethylene foam and polychloroprene foam; Woven and non-woven fabrics of various fibrous substances (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or by blending; Japanese paper, high-quality paper , Craft paper, crepe paper and other papers; aluminum foil, copper foil, stainless steel (SUS) and other metal foils; and the like. It may be a layered body having a structure in which these are combined. As an example of the base material main layer having such a composite structure, for example, a laminated base material (multilayer structure base material) having a structure in which a metal foil and the above resin film are laminated, or a resin sheet reinforced with an inorganic fiber such as glass cloth. And so on.
　基材主層の材料としては、各種のフィルム（以下、基材フィルムともいう。）を好ましく用いることができる。上記基材フィルムは、発泡体フィルムや不織布シート等のように多孔質のフィルムであってもよく、非多孔質のフィルムであってもよく、多孔質の層と非多孔質の層とが積層した構造のフィルムであってもよい。いくつかの態様において、上記基材フィルムとしては、独立して形状維持可能な（自立型の、あるいは非依存性の）樹脂フィルムをベースフィルムとして含むものを好ましく用いることができる。ここで「樹脂フィルム」とは、非多孔質の構造であって、典型的には実質的に気泡を含まない（ボイドレスの）樹脂フィルムを意味する。したがって、上記樹脂フィルムは、発泡体フィルムや不織布とは区別される概念である。上記樹脂フィルムは、単層構造であってもよく、二層以上の多層構造（例えば三層構造）であってもよい。 As the material of the base material main layer, various films (hereinafter, also referred to as base film) can be preferably used. The base film may be a porous film such as a foam film or a non-woven fabric sheet, or may be a non-porous film, and the porous layer and the non-porous layer are laminated. It may be a film having the same structure. In some embodiments, as the base film, a film containing an independently shape-maintainable (self-supporting or independent) resin film as a base film can be preferably used. As used herein, the term "resin film" means a resin film (of voidless) having a non-porous structure and typically containing substantially no bubbles. Therefore, the resin film is a concept that is distinguished from a foam film and a non-woven fabric. The resin film may have a single-layer structure or a multi-layer structure having two or more layers (for example, a three-layer structure).
　樹脂フィルムを構成する樹脂材料としては、例えば、ポリエチレンテレフタレート（ＰＥＴ）やポリブチレンテレフタレート（ＰＢＴ）等のポリエステル；ポリプロピレンやエチレン－プロピレン共重合体等のポリオレフィン；ノルボルネン構造等の脂肪族環構造を有するモノマーに由来するポリシクロオレフィン；ナイロン６、ナイロン６６、部分芳香族ポリアミド等のポリアミド（ＰＡ）；透明ポリイミド（ＣＰＩ）等のポリイミド（ＰＩ）、ポリアミドイミド（ＰＡＩ）；ポリエーテルエーテルケトン（ＰＥＥＫ）；ポリエーテルスルホン（ＰＥＳ）；ポリフェニレンサルファイド（ＰＰＳ）；ポリカーボネート（ＰＣ）；ポリウレタン（ＰＵ）；エチレン－酢酸ビニル共重合体（ＥＶＡ）；ポリビニルアルコール（ＰＶＡ）；ポリスチレン；ＡＢＳ樹脂；ポリ塩化ビニル；ポリ塩化ビニリデン；ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素樹脂；ポリメチルメタクリレート等のアクリル樹脂；ジアセチルセルロースやトリアセチルセルロース（ＴＡＣ）等のセルロース系ポリマー；ビニルブチラール系ポリマー；アリレート系ポリマー；ポリオキシメチレン系ポリマー；エポキシ系ポリマー等の樹脂を用いることができる。ここに開示される基材主層は、その表面が上記樹脂材料から構成されたものであり得る。基材主層として用いられ得る樹脂フィルムは、上記樹脂の１種を単独で含む樹脂材料を用いて形成されたものであってもよく、２種以上がブレンドされた樹脂材料を用いて形成されたものであってもよい。上記樹脂フィルムは、１種または２種以上の樹脂材料を含む樹脂層と、当該樹脂層と同種または異種の１種または２種以上の樹脂材料を含む樹脂層とが積層された複合樹脂フィルムであってもよい。上記樹脂フィルムは、無延伸であってもよく、延伸（例えば一軸延伸または二軸延伸）されたものであってもよい。 Examples of the resin material constituting the resin film include polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefins such as polypropylene and ethylene-propylene copolymers; and aliphatic ring structures such as norbornene structure. Polycycloolefin derived from monomer; Polyimide (PA) such as nylon 6, nylon 66, partially aromatic polyamide; Polyimide (PI) such as transparent polyimide (CPI), Polyamidoimide (PAI); Polyether ether ketone (PEEK) Polyestersulfone (PES); Polyphenylene sulfide (PPS); Polycarbonate (PC); Polyurethane (PU); Ethylene-vinyl acetate copolymer (EVA); Polyvinyl alcohol (PVA); Polystyrene; ABS resin; Polyvinyl chloride; Vinylidene chloride; Fluorine resin such as polytetrafluoroethylene (PTFE); Acrylic resin such as polymethylmethacrylate; Cellulous polymer such as diacetyl cellulose and triacetyl cellulose (TAC); Vinyl butyral polymer; Arilate polymer; Polyoxy Methylene-based polymer; A resin such as an epoxy-based polymer can be used. The surface of the base material main layer disclosed herein may be composed of the above resin material. The resin film that can be used as the base material main layer may be formed by using a resin material containing one kind of the above-mentioned resin alone, or is formed by using a resin material in which two or more kinds are blended. It may be a plastic. The resin film is a composite resin film in which a resin layer containing one or more kinds of resin materials and a resin layer containing one or more kinds of resin materials of the same type or different types from the resin layer are laminated. There may be. The resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).
　樹脂フィルムを構成する樹脂材料の好適例として、ポリエステル系樹脂、ＰＰＳ樹脂、ポリオレフィン系樹脂、ポリイミド樹脂が挙げられる。ここで、ポリエステル系樹脂とは、ポリエステルを５０重量％を超える割合で含有する樹脂のことをいう。同様に、ＰＰＳ樹脂とはＰＰＳを５０重量％を超える割合で含有する樹脂のことをいい、ポリオレフィン系樹脂とはポリオレフィンを５０重量％を超える割合で含有する樹脂のことをいい、ポリイミド樹脂とはポリイミドを５０重量％を超える割合で含有する樹脂のことをいう。 Preferable examples of the resin material constituting the resin film include polyester resin, PPS resin, polyolefin resin, and polyimide resin. Here, the polyester-based resin refers to a resin containing polyester in a proportion of more than 50% by weight. Similarly, the PPS resin is a resin containing PPS in a proportion exceeding 50% by weight, the polyolefin resin is a resin containing a polyolefin in a proportion exceeding 50% by weight, and the polyimide resin is a polyimide resin. A resin containing polyimide in a proportion of more than 50% by weight.
　ポリエステル系樹脂としては、典型的には、ジカルボン酸とジオールを重縮合して得られるポリエステルを主成分として含むポリエステル系樹脂が用いられる。ポリエステル系樹脂の具体例としては、ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリブチレンナフタレート等が挙げられる。 As the polyester-based resin, a polyester-based resin containing a polyester obtained by polycondensing a dicarboxylic acid and a diol as a main component is typically used. Specific examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate and the like.
　ポリオレフィン樹脂としては、１種のポリオレフィンを単独で、または２種以上のポリオレフィンを組み合わせて用いることができる。該ポリオレフィンは、例えばα－オレフィンのホモポリマー、２種以上のα－オレフィンの共重合体、１種または２種以上のα－オレフィンと他のビニルモノマーとの共重合体等であり得る。具体例としては、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、ポリ－１－ブテン、ポリ－４－メチル－１－ペンテン、エチレンプロピレンゴム（ＥＰＲ）等のエチレン－プロピレン共重合体、エチレン－プロピレン－ブテン共重合体、エチレン－ブテン共重合体、エチレン－ビニルアルコール共重合体、エチレン－エチルアクリレート共重合体等が挙げられる。低密度（ＬＤ）ポリオレフィンおよび高密度（ＨＤ）ポリオレフィンのいずれも使用可能である。ポリオレフィン樹脂フィルムの例としては、無延伸ポリプロピレン（ＣＰＰ）フィルム、二軸延伸ポリプロピレン（ＯＰＰ）フィルム、低密度ポリエチレン（ＬＤＰＥ）フィルム、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）フィルム、中密度ポリエチレン（ＭＤＰＥ）フィルム、高密度ポリエチレン（ＨＤＰＥ）フィルム、２種以上のポリエチレン（ＰＥ）をブレンドしたポリエチレン（ＰＥ）フィルム、ポリプロピレン（ＰＰ）とポリエチレン（ＰＥ）をブレンドしたＰＰ／ＰＥブレンドフィルム等が挙げられる。 As the polyolefin resin, one kind of polyolefin can be used alone, or two or more kinds of polyolefins can be used in combination. The polyolefin can be, for example, a homopolymer of an α-olefin, a copolymer of two or more kinds of α-olefins, a copolymer of one kind or two or more kinds of α-olefins and another vinyl monomer, or the like. Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR), and ethylene-propylene-. Examples thereof include butene copolymers, ethylene-butene copolymers, ethylene-vinyl alcohol copolymers and ethylene-ethyl acrylate copolymers. Both low density (LD) polyolefin and high density (HD) polyolefin can be used. Examples of polyolefin resin films include unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, medium density polyethylene (MDPE). Examples thereof include a film, a high-density polyethylene (HDPE) film, a polyethylene (PE) film in which two or more types of polyethylene (PE) are blended, and a PP / PE blend film in which polypropylene (PP) and polyethylene (PE) are blended.
　基材主層として好ましく利用し得る樹脂フィルムの具体例として、ＰＥＴフィルム、ＰＥＮフィルム、ＰＰＳフィルム、ＰＥＥＫフィルム、ＣＰＩフィルム、ＣＰＰフィルム、ＯＰＰフィルム、ＴＡＣフィルムが挙げられる。強度の点から好ましい例として、ＰＥＴフィルム、ＰＥＮフィルム、ＰＰＳフィルム、ＰＥＥＫフィルム、ＣＰＩフィルムが挙げられる。入手容易性、寸法安定性、光学特性等の観点から好ましい例としてＰＥＴフィルム、ＣＰＩフィルム、ＴＡＣフィルムが挙げられる。 Specific examples of the resin film that can be preferably used as the base material main layer include PET film, PEN film, PPS film, PEEK film, CPI film, CPP film, OPP film, and TAC film. Preferred examples from the viewpoint of strength include PET film, PEN film, PPS film, PEEK film, and CPI film. Preferred examples include PET film, CPI film, and TAC film from the viewpoint of availability, dimensional stability, optical characteristics, and the like.
　樹脂フィルムには、光安定剤、酸化防止剤、帯電防止剤、着色剤（染料、顔料等）、充填材、スリップ剤、アンチブロッキング剤等の公知の添加剤を、必要に応じて配合することができる。添加剤の配合量は特に限定されず、用途等に応じて適宜設定することができる。 Known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dye, pigment, etc.), fillers, slip agents, antiblocking agents, etc. shall be added to the resin film, if necessary. Can be done. The blending amount of the additive is not particularly limited, and can be appropriately set according to the intended use and the like.
　樹脂フィルムの製造方法は特に限定されない。例えば、押出成形、インフレーション成形、Ｔダイキャスト成形、カレンダーロール成形等の、従来公知の一般的な樹脂フィルム成形方法を適宜採用することができる。 The manufacturing method of the resin film is not particularly limited. For example, conventionally known general resin film molding methods such as extrusion molding, inflation molding, T-die casting molding, and calender roll molding can be appropriately adopted.
　上記基材主層は、このような樹脂フィルムから実質的に構成されたものであり得る。あるいは、上記基材主層は、上記樹脂フィルムの他に、補助的な層を含むものであってもよい。上記補助的な層の例としては、光学特性調整層（例えば着色層、反射防止層）、所望の外観を付与するための印刷層やラミネート層、帯電防止層、下塗り層、剥離層等の表面処理層が挙げられる。 The base material main layer may be substantially composed of such a resin film. Alternatively, the base material main layer may include an auxiliary layer in addition to the resin film. Examples of the auxiliary layer are surfaces such as an optical property adjusting layer (for example, a coloring layer and an antireflection layer), a printing layer or a laminating layer for imparting a desired appearance, an antistatic layer, an undercoat layer, and a peeling layer. A processing layer can be mentioned.
　また、ここに開示される基材主層は、上記樹脂フィルムや金属箔等に、アクリル系、ポリエステル系、アルキド系、メラミン系、ウレタン系、酸エポキシ架橋系、あるいはこれらの複合系（例えばアクリルメラミン系、アルキドメラミン系）等の塗料が塗布されたものや、亜鉛めっき等のめっきが施されたものであってもよい。 Further, the base material main layer disclosed here is an acrylic-based, polyester-based, alkyd-based, melamine-based, urethane-based, acid-epoxy cross-linked system, or a composite system thereof (for example, acrylic) on the resin film, metal foil, or the like. It may be coated with a paint such as melamine-based or alkyd-melamine-based, or plated with zinc plating or the like.
　他のいくつかの好ましい態様に係る基材主層は、光学部材として用いられ得る偏光フィルム、波長フィルム、位相差フィルム、光学補償フィルム、輝度向上フィルム、導光フィルム、反射フィルム、反射防止フィルム、ハードコート（ＨＣ）フィルム、衝撃吸収フィルム、防汚フィルム、フォトクロミックフィルム、調光フィルム、透明導電フィルム（ＩＴＯフィルム）、意匠フィルム、装飾フィルム、表面保護フィルム、プリズム、レンズ、カラーフィルター、透明基板や、さらにはこれらが積層されている部材（これらを総称して「機能性フィルム」と称する場合がある。）等のいずれかであり得る。なお、上記の「板」および「フィルム」は、それぞれ板状、フィルム状、シート状等の形態を含むものとし、例えば、「偏光フィルム」は、「偏光板」、「偏光シート」等を含むものとする。上記材料を基材主層に用いた基材層は、親水層を有する形態で、上述の各種光学部材、機能性フィルムとして用いられ得る。 The base material main layer according to some other preferred embodiments is a polarizing film, a wavelength film, a retardation film, an optical compensation film, a brightness improving film, a light guide film, a reflective film, an antireflection film, which can be used as an optical member. Hard coat (HC) film, shock absorbing film, antifouling film, photochromic film, dimming film, transparent conductive film (ITO film), design film, decorative film, surface protection film, prism, lens, color filter, transparent substrate, etc. Further, it may be any of a member in which these are laminated (these may be collectively referred to as a "functional film") or the like. The above-mentioned "plate" and "film" shall include a plate-like, a film-like, a sheet-like form, respectively, and for example, the "polarizing film" shall include a "polarizing plate", a "polarizing sheet" and the like. .. The base material layer using the above material as the base material main layer can be used as the above-mentioned various optical members and functional films in the form of having a hydrophilic layer.
　いくつかの好ましい態様では、基材主層として偏光フィルム（偏光フィルム層）が用いられる。偏光フィルムは、偏光子と、該偏光子の少なくとも一方の面（好ましくは両面）に配置された透明保護フィルムとを備えるものであり得る。偏光子としては、特に限定されず、例えば、親水性高分子フィルムに、ヨウ素や二色性染料の二色性物質を吸着させて一軸延伸したものが用いられる。親水性高分子フィルムとしては、ＰＶＡ系フィルム、部分ホルマール化ＰＶＡ系フィルム、エチレン・酢酸ビニル共重合体系部分ケン化フィルム等が挙げられる。偏光子として、ＰＶＡの脱水処理物やポリ塩化ビニルの脱塩酸処理物等のポリエン系配向フィルム等を用いることもできる。なかでも、ＰＶＡ系フィルムとヨウ素等の二色性物質からなる偏光子が好ましい。 In some preferred embodiments, a polarizing film (polarizing film layer) is used as the base material main layer. The polarizing film may include a polarizing element and a transparent protective film arranged on at least one surface (preferably both sides) of the polarizing element. The polarizer is not particularly limited, and for example, one in which a dichroic substance such as iodine or a dichroic dye is adsorbed on a hydrophilic polymer film and uniaxially stretched is used. Examples of the hydrophilic polymer film include a PVA-based film, a partially formalized PVA-based film, and an ethylene-vinyl acetate copolymer-based partially saponified film. As the polarizer, a polyene-based alignment film such as a dehydrated product of PVA or a dehydrochlorinated product of polyvinyl chloride can also be used. Of these, a PVA-based film and a polarizer made of a dichroic substance such as iodine are preferable.
　透明保護フィルムを構成する材料としては、例えば、透明性、機械的強度、熱安定性、水分遮断性、等方性等に優れる熱可塑性樹脂が好ましく用いられる。このような熱可塑性樹脂の具体例としては、ＴＡＣ等のセルロース樹脂、ポリエステル樹脂、ポリエーテルスルホン樹脂、ポリスルホン樹脂、ポリカーボネート樹脂、ポリアミド樹脂、ポリイミド樹脂、ポリオレフィン樹脂、（メタ）アクリル樹脂、シクロオレフィン系樹脂（典型的にはノルボルネン系樹脂）、ポリアリレート樹脂、ポリスチレン樹脂、ＰＶＡ樹脂、および、これらの２種以上の混合物等が挙げられる。いくつかの態様では、偏光フィルムは、例えば、偏光フィルムが２枚のトリアセチルセルロース（ＴＡＣ）フィルムで挟まれた構成を有する。他のいくつかの好ましい態様では、偏光子の一方の面に、例えばＴＡＣ等の熱可塑性樹脂からなる透明保護フィルムを配置し、他方の面に、シクロオレフィン系樹脂（典型的にはノルボルネン系樹脂）や、あるいは（メタ）アクリル樹脂からなる透明保護フィルムを配置する構成が採用され得る。さらに他の好ましい態様では、偏光子の一方の面に、例えばＴＡＣ等の熱可塑性樹脂からなる透明保護フィルムを配置し、他方の面に、透明保護フィルムとして、（メタ）アクリル系、ウレタン系、アクリルウレタン系、エポキシ系、シリコーン系等の熱硬化性樹脂または紫外線硬化型樹脂を用いることができる。これら透明保護フィルムは、ＰＶＡ系等の接着剤を介して偏光子に積層され得る。透明保護フィルムには、目的に応じて、任意の適切な添加剤が１種類以上含まれ得る。 As a material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc. is preferably used. Specific examples of such thermoplastic resins include cellulose resins such as TAC, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, and cycloolefin-based resins. Examples thereof include resins (typically norbornene-based resins), polyarylate resins, polystyrene resins, PVA resins, and mixtures of two or more of these. In some embodiments, the polarizing film has, for example, a configuration in which the polarizing film is sandwiched between two triacetyl cellulose (TAC) films. In some other preferred embodiments, a transparent protective film made of a thermoplastic resin such as TAC is placed on one surface of the polarizer, and a cycloolefin resin (typically a norbornene resin) is placed on the other surface. ) Or, a configuration in which a transparent protective film made of (meth) acrylic resin is arranged can be adopted. In still another preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC is arranged on one surface of the polarizer, and the transparent protective film is prepared as a (meth) acrylic or urethane-based film on the other surface. Thermosetting resins such as acrylic urethane-based, epoxy-based, and silicone-based resins or ultraviolet curable resins can be used. These transparent protective films can be laminated on the polarizer via an adhesive such as PVA. The transparent protective film may contain one or more of any suitable additives, depending on the intended purpose.
　また、偏光フィルムの背面には表面処理層を設けてもよい。表面処理層は、偏光フィルムに用いられる上述の透明保護フィルムに設けることができる他、別途、透明保護フィルムとは別体のものとして、偏光フィルム上に設けることもできる。 Further, a surface treatment layer may be provided on the back surface of the polarizing film. The surface treatment layer can be provided on the above-mentioned transparent protective film used for the polarizing film, or can be separately provided on the polarizing film as a separate body from the transparent protective film.
　表面処理層の好適例としては、ハードコート層が挙げられる。ハードコート層の形成材料としては、例えば、熱可塑性樹脂、熱または放射線により硬化する材料を用いることができる。用いられる材料としては、熱硬化型樹脂や紫外線硬化型樹脂、電子線硬化型樹脂等の放射線硬化性樹脂が挙げられる。なかでも、紫外線硬化型樹脂が好適である。紫外線硬化型樹脂は、紫外線照射による硬化処理により、効率よく硬化樹脂層を形成し得るので、加工性に優れる。硬化型樹脂としては、ポリエステル系、アクリル系、ウレタン系、アミド系、シリコーン系、エポキシ系、メラミン系等の１種または２種以上を用いることができ、これらは、モノマー、オリゴマー、ポリマー等を含む形態であり得る。熱（基材損傷の原因となり得る。）を必要とせず、加工速度に優れることから、放射線硬化型樹脂（典型的には紫外線硬化型樹脂）が特に好ましい。 A preferable example of the surface treatment layer is a hard coat layer. As the material for forming the hard coat layer, for example, a thermoplastic resin or a material that is cured by heat or radiation can be used. Examples of the material used include radiation-curable resins such as thermosetting resins, ultraviolet curable resins, and electron beam curable resins. Of these, an ultraviolet curable resin is preferable. The ultraviolet curable resin is excellent in processability because the cured resin layer can be efficiently formed by the curing treatment by ultraviolet irradiation. As the curable resin, one or more kinds such as polyester type, acrylic type, urethane type, amide type, silicone type, epoxy type and melamine type can be used, and these may contain monomers, oligomers, polymers and the like. It can be in the form of inclusion. A radiation-curable resin (typically an ultraviolet-curable resin) is particularly preferable because it does not require heat (which can cause damage to the base material) and is excellent in processing speed.
　表面処理層の他の例としては、視認性の向上を目的とした防眩処理層や反射防止層が挙げられる。上記ハードコート層上に、防眩処理層や反射防止層を設けてもよい。反射防止層は、複数の層からなる多層構造を有するものであり得る。表面処理層のその他の例としては、スティッキング防止層等が挙げられる。ここに開示される偏光フィルムが表面処理層を備える態様で実施される場合、表面処理層に導電剤を含有させて導電性を付与することができる。 Other examples of the surface treatment layer include an antiglare treatment layer and an antireflection layer for the purpose of improving visibility. An antiglare treatment layer or an antireflection layer may be provided on the hard coat layer. The antireflection layer may have a multi-layer structure including a plurality of layers. Other examples of the surface treatment layer include a sticking prevention layer and the like. When the polarizing film disclosed herein is carried out in a manner including a surface treatment layer, the surface treatment layer can be provided with a conductive agent to impart conductivity.
　基材主層が、ひいては基材層が偏光フィルムである態様において、偏光フィルムの厚さ（複数の層から構成される場合は、それらの総厚）は、特に限定されず、例えば凡そ１μｍ以上であり、凡そ１０μｍ以上または凡そ２０μｍ以上が適当である。例えば、透明保護フィルムを設ける場合、保護性等の観点から、偏光フィルムの厚さは、好ましくは凡そ３０μｍ以上、より好ましくは凡そ５０μｍ以上、さらに好ましくは凡そ７０μｍ以上である。偏光フィルムの上限は特に制限されず、例えば凡そ１ｍｍ以下であり、凡そ５００μｍ以下または凡そ３００μｍ以下が適当である。光学特性や薄厚化の観点から、上記厚さは、好ましくは凡そ１５０μｍ以下、より好ましくは凡そ１２０μｍ以下、さらに好ましくは凡そ１００μｍ以下である。 In the embodiment in which the base material main layer is, by extension, the base material layer is a polarizing film, the thickness of the polarizing film (when composed of a plurality of layers, the total thickness thereof) is not particularly limited, and is, for example, approximately 1 μm or more. Therefore, about 10 μm or more or about 20 μm or more is suitable. For example, when a transparent protective film is provided, the thickness of the polarizing film is preferably about 30 μm or more, more preferably about 50 μm or more, and further preferably about 70 μm or more from the viewpoint of protection and the like. The upper limit of the polarizing film is not particularly limited, and is, for example, about 1 mm or less, and about 500 μm or less or about 300 μm or less is appropriate. From the viewpoint of optical characteristics and thinning, the thickness is preferably about 150 μm or less, more preferably about 120 μm or less, still more preferably about 100 μm or less.
　特に限定されるものではないが、ここに開示される基材主層は、典型的には、アルカリガラス板や無アルカリガラス等のガラス層を含まない。そのような基材主層材料を用いる態様において、親水層を設けることによる水剥離性向上効果は好ましく発揮され得る。 Although not particularly limited, the base material main layer disclosed here typically does not include a glass layer such as an alkaline glass plate or non-alkali glass. In an embodiment using such a base material main layer material, the effect of improving water peelability by providing the hydrophilic layer can be preferably exhibited.
　基材主層の厚さ（親水層以外に複数の層を有する場合は、親水層以外の層の総厚）は、基材層の総厚の５０％以上とすることが適当であり、好ましくは７０％以上、より好ましくは９０％以上であり、９７％以上（例えば９９％以上）であってもよい。 The thickness of the base material main layer (when having a plurality of layers other than the hydrophilic layer, the total thickness of the layers other than the hydrophilic layer) is preferably 50% or more of the total thickness of the base material layer, and is preferable. Is 70% or more, more preferably 90% or more, and may be 97% or more (for example, 99% or more).
　基材層の総厚は、特に限定されず、積層体の使用目的や使用態様等に応じて選択し得る。基材層の総厚は、例えば凡そ１０００μｍ以下であってよく、凡そ５００μｍ以下でもよく、軽量化や薄厚化の観点から、凡そ３００μｍ以下が適当であり、好ましくは凡そ１５０μｍ以下、より好ましくは凡そ１２０μｍ以下であり、１００μｍ以下であってもよく、７０μｍ以下でもよい。基材層の総厚が小さくなると、積層体の柔軟性や被着体の表面形状への追従性が向上する傾向にある。また、取扱い性や加工性等の観点から、基材層の総厚は、例えば２μｍ以上であってよく、５μｍ超または１０μｍ超でもよい。いくつかの態様において、基材層の総厚は凡そ２０μｍ以上が適当であり、好ましくは凡そ３０μｍ以上、より好ましくは凡そ５０μｍ以上、さらに好ましくは凡そ７０μｍ以上である。 The total thickness of the base material layer is not particularly limited and can be selected according to the purpose of use and the mode of use of the laminate. The total thickness of the base material layer may be, for example, about 1000 μm or less, may be about 500 μm or less, and from the viewpoint of weight reduction and thinning, about 300 μm or less is suitable, preferably about 150 μm or less, and more preferably about 150 μm or less. It may be 120 μm or less, 100 μm or less, or 70 μm or less. As the total thickness of the base material layer becomes smaller, the flexibility of the laminate and the followability to the surface shape of the adherend tend to improve. Further, from the viewpoint of handleability, processability and the like, the total thickness of the base material layer may be, for example, 2 μm or more, and may be 5 μm or more or 10 μm or more. In some embodiments, the total thickness of the substrate layer is preferably about 20 μm or more, preferably about 30 μm or more, more preferably about 50 μm or more, still more preferably about 70 μm or more.
　基材層の粘着剤層側表面（したがって親水層の表面）には、親水性をさらに高めるため、例えば、コロナ処理やプラズマ処理等の親水化処理がさらに施されていてもよい。コロナ処理やプラズマ処理に使用する装置や処理条件は、従来公知の技術に基づいて、所望の水接触角を示す表面が得られるように設定することができる。また、基材層のうち粘着剤層側表面には、必要に応じて、紫外線照射処理、酸処理、アルカリ処理等の、従来公知の表面処理が施されていてもよい。このような表面処理は、基材層と粘着剤層との密着性、言い換えると粘着剤層の基材層への投錨性を向上させるための処理であり得る。また、基材主層の表面（例えば親水層側表面）には、上記の各種表面処理や、下塗り剤（プライマー）の塗布、帯電防止処理等の表面処理が施されていてもよい。プライマーの組成は特に限定されず、公知のものから適宜選択することができる。下塗り層の厚さは特に制限されないが、例えば０．０１μｍ～１μｍ程度が適当であり、０．１μｍ～１μｍ程度が好ましい。 The surface of the base material layer on the pressure-sensitive adhesive layer side (hence, the surface of the hydrophilic layer) may be further subjected to a hydrophilic treatment such as a corona treatment or a plasma treatment in order to further enhance the hydrophilicity. The apparatus and treatment conditions used for the corona treatment and the plasma treatment can be set so as to obtain a surface showing a desired water contact angle based on a conventionally known technique. Further, the surface of the base material layer on the pressure-sensitive adhesive layer side may be subjected to conventionally known surface treatments such as ultraviolet irradiation treatment, acid treatment, and alkali treatment, if necessary. Such a surface treatment may be a treatment for improving the adhesion between the base material layer and the pressure-sensitive adhesive layer, in other words, the anchoring property of the pressure-sensitive adhesive layer on the base material layer. Further, the surface of the base material main layer (for example, the surface on the hydrophilic layer side) may be subjected to surface treatments such as the above-mentioned various surface treatments, application of an undercoating agent (primer), and antistatic treatment. The composition of the primer is not particularly limited and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, but for example, about 0.01 μm to 1 μm is suitable, and about 0.1 μm to 1 μm is preferable.
　基材層のうち粘着剤層側とは反対側の面（以下、背面ともいう。）には、必要に応じて、剥離処理、接着性または粘着性向上処理、帯電防止処理等の、従来公知の表面処理が施されていてもよい。例えば、基材層の背面を剥離処理剤で表面処理することにより、ロール状に巻回された形態の積層体の巻戻し力を軽くすることができる。剥離処理剤としては、シリコーン系剥離処理剤、長鎖アルキル系剥離処理剤、オレフィン系剥離処理剤、フッ素系剥離処理剤、脂肪酸アミド系剥離処理剤、硫化モリブデン、シリカ粉等を用いることができる。 The surface of the base material layer opposite to the pressure-sensitive adhesive layer side (hereinafter, also referred to as the back surface) is conventionally known to have a peeling treatment, an adhesive or adhesive improving treatment, an antistatic treatment, or the like, if necessary. Surface treatment may be applied. For example, by surface-treating the back surface of the base material layer with a release treatment agent, the unwinding force of the laminated body in the form of being wound in a roll shape can be reduced. As the stripping agent, a silicone-based stripping agent, a long-chain alkyl-based stripping agent, an olefin-based stripping agent, a fluorine-based stripping agent, a fatty acid amide-based stripping agent, molybdenum sulfide, silica powder, or the like can be used. ..
　＜粘着剤層＞
（１）Ａ層
　ここに開示される積層体において、粘着剤層の少なくとも基材層側表面を構成するＡ層は、例えば、アクリル系粘着剤、ゴム系粘着剤（天然ゴム系、合成ゴム系、これらの混合系等）、シリコーン系粘着剤、ポリエステル系粘着剤、ウレタン系粘着剤、ポリエーテル系粘着剤、ポリアミド系粘着剤、フッ素系粘着剤等の各種粘着剤から選択される１種または２種以上の粘着剤を含んで構成された粘着剤層であり得る。ここで、アクリル系粘着剤とは、アクリル系重合物を主成分とする粘着剤をいう。ゴム系粘着剤その他の粘着剤についても同様の意味である。 <Adhesive layer>
(1) Layer A In the laminate disclosed here, the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side is, for example, an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive (natural rubber type, synthetic rubber type). , These mixed systems, etc.), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, fluorine adhesives, etc. It may be a pressure-sensitive adhesive layer composed of two or more types of pressure-sensitive adhesives. Here, the acrylic pressure-sensitive adhesive refers to a pressure-sensitive adhesive containing an acrylic polymer as a main component. The same meaning applies to rubber-based adhesives and other adhesives.
　（アクリル系粘着剤）
　透明性や耐候性等の観点から、いくつかの態様において、Ａ層の構成材料としてアクリル系粘着剤を好ましく採用し得る。 (Acrylic adhesive)
From the viewpoint of transparency, weather resistance, and the like, an acrylic pressure-sensitive adhesive may be preferably used as the constituent material of the A layer in some embodiments.
　アクリル系粘着剤としては、例えば、エステル末端に炭素原子数１以上２０以下の直鎖または分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステルを５０重量％より多く含むモノマー成分から構成されたアクリル系重合物を含むものが好ましい。以下、炭素原子数がＸ以上Ｙ以下のアルキル基をエステル末端に有する（メタ）アクリル酸アルキルエステルを「（メタ）アクリル酸ＣＸ－Ｙアルキルエステル」と表記することがある。特性のバランスをとりやすいことから、モノマー成分全体のうち（メタ）アクリル酸Ｃ１－２０アルキルエステルの割合は、例えば５５重量％以上であってよく、６０重量％以上でもよく、７０重量％以上でもよい。同様の理由から、モノマー成分のうち（メタ）アクリル酸Ｃ１－２０アルキルエステルの割合は、例えば９９．９重量％以下であってよく、９９．５重量％以下でもよく、９９重量％以下でもよい。 The acrylic pressure-sensitive adhesive is composed of, for example, a monomer component containing more than 50% by weight of a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 20 carbon atoms at the ester terminal. Those containing an acrylic polymer are preferable. Hereinafter, a (meth) acrylic acid alkyl ester having an alkyl group having an number of carbon atoms of X or more and Y or less at the ester terminal may be referred to as "(meth) acrylic acid CXY alkyl ester". Since it is easy to balance the characteristics, the ratio of the (meth) acrylic acid C 1-20 alkyl ester in the total monomer component may be, for example, 55% by weight or more, 60% by weight or more, or 70% by weight or more. It may be. For the same reason, the proportion of (meth) acrylic acid C 1-20 alkyl ester in the monomer component may be, for example, 99.9% by weight or less, 99.5% by weight or less, or 99% by weight or less. Good.
　（メタ）アクリル酸Ｃ１－２０アルキルエステルの非限定的な具体例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ペンチル、（メタ）アクリル酸イソペンチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸ヘプチル、（メタ）アクリル酸オクチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸イソノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸イソデシル、（メタ）アクリル酸ウンデシル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸トリデシル、（メタ）アクリル酸テトラデシル、（メタ）アクリル酸ペンタデシル、（メタ）アクリル酸ヘキサデシル、（メタ）アクリル酸ヘプタデシル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸イソステアリル、（メタ）アクリル酸ノナデシル、（メタ）アクリル酸エイコシル等が挙げられる。 Non-limiting specific examples of (meth) acrylic acid C 1-20 alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, ( N-butyl acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth) ) Decyl acrylate, Isodecyl (meth) acrylate, Undecyl (meth) acrylate, Dodecyl (meth) acrylate, Tridecyl (meth) acrylate, Tetradecyl (meth) acrylate, Pentadecyl (meth) acrylate, (meth) Examples thereof include hexadecyl acrylate, heptadecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, nonadecil (meth) acrylate, and eicocil (meth) acrylate.
　これらのうち、少なくとも（メタ）アクリル酸Ｃ４－２０アルキルエステルを用いることが好ましく、少なくとも（メタ）アクリル酸Ｃ４－１８アルキルエステルを用いることがより好ましい。例えば、上記モノマー成分としてアクリル酸ｎ－ブチル（ＢＡ）およびアクリル酸２－エチルヘキシル（２ＥＨＡ）の一方または両方を含むアクリル系粘着剤が好ましく、少なくとも２ＥＨＡを含むアクリル系粘着剤が特に好ましい。好ましく用いられ得る（メタ）アクリル酸Ｃ４－２０アルキルエステルの他の例としては、アクリル酸イソノニル、メタクリル酸ｎ－ブチル（ＢＭＡ）、メタクリル酸２－エチルヘキシル（２ＥＨＭＡ）、アクリル酸イソステアリル（ＩＳＴＡ）等が挙げられる。 Of these, it is preferable to use at least (meth) acrylic acid C 4-20 alkyl ester, and it is more preferable to use at least (meth) acrylic acid C 4-18 alkyl ester. For example, an acrylic pressure-sensitive adhesive containing one or both of n-butyl (BA) acrylate and 2-ethylhexyl acrylate (2EHA) as the monomer component is preferable, and an acrylic pressure-sensitive adhesive containing at least 2 EHA is particularly preferable. Other examples of (meth) acrylic acid C 4-20 alkyl esters that may be preferably used include isononyl acrylate, n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), isostearyl acrylate (ISTA). ) Etc. can be mentioned.
　いくつかの態様において、アクリル系重合物を構成するモノマー成分は、（メタ）アクリル酸Ｃ４－１８アルキルエステルを４０重量％以上の割合で含み得る。このようにエステル末端に炭素原子数４以上のアルキル基を有する（メタ）アクリル酸アルキルエステルを比較的多く含むモノマー成分によると、親油性の高いアクリル系重合物が形成される傾向にある。親油性の高いアクリル系重合物によると、水浸漬後剥離力低下率の低い粘着剤層が形成されやすい。モノマー成分に占める（メタ）アクリル酸Ｃ４－１８アルキルエステルの割合は、例えば６０重量％以上であってよく、７０重量％以上でもよく、７５重量％以上でもよく、８０重量％以上でもよい。上述したいずれかの下限値以上の割合で（メタ）アクリル酸Ｃ６－１８アルキルエステルを含むモノマー成分であってもよい。
　また、粘着剤層（Ａ層）の凝集性を高めて凝集破壊を防止する観点から、モノマー成分に占める（メタ）アクリル酸Ｃ４－１８アルキルエステルの割合は、９９．５重量％以下とすることが適当であり、９９重量％以下でもよく、９８重量％以下でもよく、９７重量％以下でもよい。粘着剤層（Ａ層）の凝集性向上の観点から、いくつかの態様では、上記モノマー成分に占める（メタ）アクリル酸Ｃ４－１８アルキルエステルの割合は９５重量％以下であり、例えば９０重量％以下が適当である。他のいくつかの態様では、モノマー成分に占める（メタ）アクリル酸Ｃ４－１８アルキルエステルの割合は、８５重量％以下でもよく、７５重量％以下でもよい。上述したいずれかの上限値以下の割合で（メタ）アクリル酸Ｃ６－１８アルキルエステルを含むモノマー成分であってもよい。 In some embodiments, the monomer component constituting the acrylic polymer may contain (meth) acrylic acid C 4-18 alkyl ester in a proportion of 40% by weight or more. As described above, according to the monomer component containing a relatively large amount of (meth) acrylic acid alkyl ester having an alkyl group having 4 or more carbon atoms at the ester terminal, an acrylic polymer having high lipophilicity tends to be formed. According to the acrylic polymer having high lipophilicity, an adhesive layer having a low rate of decrease in peeling force after immersion in water is likely to be formed. The ratio of the (meth) acrylic acid C 4-18 alkyl ester to the monomer component may be, for example, 60% by weight or more, 70% by weight or more, 75% by weight or more, or 80% by weight or more. It may be a monomer component containing (meth) acrylic acid C 6-18 alkyl ester at a ratio equal to or higher than any of the above lower limit values.
Further, from the viewpoint of enhancing the cohesiveness of the pressure-sensitive adhesive layer (A layer) and preventing cohesive failure, the ratio of (meth) acrylic acid C 4-18 alkyl ester to the monomer component is 99.5% by weight or less. It may be 99% by weight or less, 98% by weight or less, or 97% by weight or less. From the viewpoint of improving the cohesiveness of the pressure-sensitive adhesive layer (A layer), in some embodiments, the ratio of the (meth) acrylic acid C 4-18 alkyl ester to the monomer component is 95% by weight or less, for example, 90% by weight. % Or less is appropriate. In some other embodiments, the proportion of (meth) acrylic acid C 4-18 alkyl ester in the monomer component may be 85% by weight or less, or 75% by weight or less. It may be a monomer component containing (meth) acrylic acid C 6-18 alkyl ester at a ratio equal to or less than any of the above-mentioned upper limit values.
　アクリル系重合物を構成するモノマー成分は、（メタ）アクリル酸アルキルエステルとともに、必要に応じて、（メタ）アクリル酸アルキルエステルと共重合可能な他のモノマー（共重合性モノマー）を含んでいてもよい。共重合性モノマーとしては、極性基（例えば、カルボキシ基、水酸基、窒素原子含有環等）を有するモノマーを好適に使用することができる。極性基を有するモノマーは、アクリル系重合物に架橋点を導入したり、粘着剤の凝集力を高めたりするために役立ち得る。共重合性モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 The monomer component constituting the acrylic polymer contains a (meth) acrylic acid alkyl ester and, if necessary, another monomer (copolymerizable monomer) copolymerizable with the (meth) acrylic acid alkyl ester. May be good. As the copolymerizable monomer, a monomer having a polar group (for example, a carboxy group, a hydroxyl group, a nitrogen atom-containing ring, etc.) can be preferably used. Monomers having polar groups can be useful for introducing cross-linking points into acrylic polymers and increasing the cohesive force of adhesives. The copolymerizable monomer may be used alone or in combination of two or more.
　共重合性モノマーの非限定的な具体例としては、以下のものが挙げられる。
　カルボキシ基含有モノマー：例えば、アクリル酸、メタクリル酸、カルボキシエチルアクリレート、カルボキシペンチルアクリレート、イタコン酸、マレイン酸、フマル酸、クロトン酸、イソクロトン酸等。
　酸無水物基含有モノマー：例えば、無水マレイン酸、無水イタコン酸。
　水酸基含有モノマー：例えば、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸２－ヒドロキシブチル、（メタ）アクリル酸３－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１０－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル、（４－ヒドロキシメチルシクロへキシル）メチル（メタ）アクリレート等の（メタ）アクリル酸ヒドロキシアルキル等。
　スルホン酸基またはリン酸基を含有するモノマー：例えば、スチレンスルホン酸、アリルスルホン酸、ビニルスルホン酸ナトリウム、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸、スルホプロピル（メタ）アクリレート、（メタ）アクリロイルオキシナフタレンスルホン酸、２－ヒドロキシエチルアクリロイルホスフェート等。
　エポキシ基含有モノマー：例えば、（メタ）アクリル酸グリシジルや（メタ）アクリル酸－２－エチルグリシジルエーテル等のエポキシ基含有アクリレート、アリルグリシジルエーテル、（メタ）アクリル酸グリシジルエーテル等。
　シアノ基含有モノマー：例えば、アクリロニトリル、メタクリロニトリル等。
　イソシアネート基含有モノマー：例えば、２－イソシアナートエチル（メタ）アクリレート等。
　アミド基含有モノマー：例えば、（メタ）アクリルアミド；Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジプロピル（メタ）アクリルアミド、Ｎ，Ｎ－ジイソプロピル（メタ）アクリルアミド、Ｎ，Ｎ－ジ（ｎ－ブチル）（メタ）アクリルアミド、Ｎ，Ｎ－ジ（ｔ－ブチル）（メタ）アクリルアミド等の、Ｎ，Ｎ－ジアルキル（メタ）アクリルアミド；Ｎ－エチル（メタ）アクリルアミド、Ｎ－イソプロピル（メタ）アクリルアミド、Ｎ－ブチル（メタ）アクリルアミド、Ｎ－ｎ－ブチル（メタ）アクリルアミド等の、Ｎ－アルキル（メタ）アクリルアミド；Ｎ－ビニルアセトアミド等のＮ－ビニルカルボン酸アミド類；水酸基とアミド基とを有するモノマー、例えば、Ｎ－（２－ヒドロキシエチル）（メタ）アクリルアミド、Ｎ－（２－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（１－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（３－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（２－ヒドロキシブチル）（メタ）アクリルアミド、Ｎ－（３－ヒドロキシブチル）（メタ）アクリルアミド、Ｎ－（４－ヒドロキシブチル）（メタ）アクリルアミド等の、Ｎ－ヒドロキシアルキル（メタ）アクリルアミド；アルコキシ基とアミド基とを有するモノマー、例えば、Ｎ－メトキシメチル（メタ）アクリルアミド、Ｎ－メトキシエチル（メタ）アクリルアミド、Ｎ－ブトキシメチル（メタ）アクリルアミド等の、Ｎ－アルコキシアルキル（メタ）アクリルアミド；その他、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリルアミド、Ｎ－（メタ）アクリロイルモルホリン等。
　アミノ基含有モノマー：例えばアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、ｔ－ブチルアミノエチル（メタ）アクリレート。
　エポキシ基を有するモノマー：例えばグリシジル（メタ）アクリレート、メチルグリシジル（メタ）アクリレート、アリルグリシジルエーテル。
　窒素原子含有環を有するモノマー：例えば、Ｎ－ビニル－２－ピロリドン、Ｎ－メチルビニルピロリドン、Ｎ－ビニルピリジン、Ｎ－ビニルピペリドン、Ｎ－ビニルピリミジン、Ｎ－ビニルピペラジン、Ｎ－ビニルピラジン、Ｎ－ビニルピロール、Ｎ－ビニルイミダゾール、Ｎ－ビニルオキサゾール、Ｎ－（メタ）アクリロイル－２－ピロリドン、Ｎ－（メタ）アクリロイルピペリジン、Ｎ－（メタ）アクリロイルピロリジン、Ｎ－ビニルモルホリン、Ｎ－ビニル－３－モルホリノン、Ｎ－ビニル－２－カプロラクタム、Ｎ－ビニル－１，３－オキサジン－２－オン、Ｎ－ビニル－３，５－モルホリンジオン、Ｎ－ビニルピラゾール、Ｎ－ビニルイソオキサゾール、Ｎ－ビニルチアゾール、Ｎ－ビニルイソチアゾール、Ｎ－ビニルピリダジン等（例えば、Ｎ－ビニル－２－カプロラクタム等のラクタム類）。
　スクシンイミド骨格を有するモノマー：例えば、Ｎ－（メタ）アクリロイルオキシメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－６－オキシヘキサメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－８－オキシヘキサメチレンスクシンイミド等。
　マレイミド類：例えば、Ｎ－シクロヘキシルマレイミド、Ｎ－イソプロピルマレイミド、Ｎ－ラウリルマレイミド、Ｎ－フェニルマレイミド等。
　イタコンイミド類：例えば、Ｎ－メチルイタコンイミド、Ｎ－エチルイタコンイミド、Ｎ－ブチルイタコンイミド、Ｎ－オクチルイタコンイミド、Ｎ－２－エチルへキシルイタコンイミド、Ｎ－シクロへキシルイタコンイミド、Ｎ－ラウリルイタコンイミド等。
　（メタ）アクリル酸アミノアルキル類：例えば、（メタ）アクリル酸アミノエチル、（メタ）アクリル酸Ｎ，Ｎ－ジメチルアミノエチル、（メタ）アクリル酸Ｎ，Ｎ－ジエチルアミノエチル、（メタ）アクリル酸ｔ－ブチルアミノエチル。
　アルコキシ基含有モノマー：例えば、（メタ）アクリル酸２－メトキシエチル、（メタ）アクリル酸３－メトキシプロピル、（メタ）アクリル酸２－エトキシエチル、（メタ）アクリル酸プロポキシエチル、（メタ）アクリル酸ブトキシエチル、（メタ）アクリル酸エトキシプロピル等の、（メタ）アクリル酸アルコキシアルキル類；（メタ）アクリル酸メトキシエチレングリコール、（メタ）アクリル酸メトキシポリプロピレングリコール等の、（メタ）アクリル酸アルコキシアルキレングリコール類。
　アルコキシシリル基含有モノマー：例えば３－（メタ）アクリロキシプロピルトリメトキシシラン、３－（メタ）アクリロキシプロピルトリエトキシシラン、３－（メタ）アクリロキシプロピルメチルジメトキシシラン、３－（メタ）アクリロキシプロピルメチルジエトキシシラン。
　ビニルエステル類：例えば、酢酸ビニル、プロピオン酸ビニル等。
　ビニルエーテル類：例えば、メチルビニルエーテルやエチルビニルエーテル等のビニルアルキルエーテル。
　芳香族ビニル化合物：例えば、スチレン、α－メチルスチレン、ビニルトルエン等。
　オレフィン類：例えば、エチレン、ブタジエン、イソプレン、イソブチレン等。
　脂環式炭化水素基を有する（メタ）アクリル酸エステル：例えば、シクロペンチル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、アダマンチル（メタ）アクリレート等。
　芳香族炭化水素基を有する（メタ）アクリル酸エステル：例えば、フェニル（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、ベンジル（メタ）アクリレート等。
　その他、（メタ）アクリル酸テトラヒドロフルフリル等の複素環含有（メタ）アクリレート、塩化ビニルやフッ素原子含有（メタ）アクリレート等のハロゲン原子含有（メタ）アクリレート、シリコーン（メタ）アクリレート等のケイ素原子含有（メタ）アクリレート、テルペン化合物誘導体アルコールから得られる（メタ）アクリル酸エステル等。 Non-limiting specific examples of the copolymerizable monomer include the following.
Carboxylic group-containing monomer: For example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like.
Acid anhydride group-containing monomer: For example, maleic anhydride, itaconic anhydride.
Hydroxyl group-containing monomers: for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic. 4-Hydroxybutyl acid, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxy) Hydroxyalkyl (meth) acrylates such as methylcyclohexyl) methyl (meth) acrylate.
Monomer containing sulfonic acid group or phosphoric acid group: For example, styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfo Propyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, 2-hydroxyethylacryloyl phosphate, etc.
Epoxide group-containing monomer: For example, an epoxy group-containing acrylate such as glycidyl (meth) acrylate or -2-ethylglycidyl ether (meth) acrylate, allyl glycidyl ether, glycidyl ether (meth) acrylate and the like.
Cyanide-containing monomer: For example, acrylonitrile, methacrylonitrile, etc.
Isocyanate group-containing monomer: For example, 2-isocyanate ethyl (meth) acrylate and the like.
Amide group-containing monomers: (meth) acrylamide; for example, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) N, N-dialkyl (meth) acrylamide, such as acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide; N-ethyl (meth) N-alkyl (meth) acrylamide such as acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, Nn-butyl (meth) acrylamide; N-vinylcarboxylic acid amide such as N-vinylacetamide Classes; monomers having a hydroxyl group and an amide group, for example, N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (1-hydroxypropyl) (meth). Acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (4-hydroxybutyl) ( N-Hydroxyalkyl (meth) acrylamide, such as meta) acrylamide; monomers with an alkoxy group and an amide group, such as N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl ( N-alkoxyalkyl (meth) acrylamide such as meta) acrylamide; In addition, N, N-dimethylaminopropyl (meth) acrylamide, N- (meth) acryloylmorpholine and the like.
Amino group-containing monomer: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
Monomers having an epoxy group: for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, allyl glycidyl ether.
Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N- Vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloyl piperidine, N- (meth) acryloylpyrrolidin, N-vinylmorpholin, N-vinyl-3 -Morholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxadin-2-one, N-vinyl-3,5-morpholindione, N-vinylpyrazole, N-vinylisoxazole, N-vinyl Thiazol, N-vinylisothiazole, N-vinylpyridazine and the like (eg, lactams such as N-vinyl-2-caprolactam).
Monomers having a succinimide skeleton: for example, N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyhexamethylene succinimide and the like.
Maleimides: For example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like.
Itaconimides: For example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-lauryl. Itaconimide, etc.
Aminoalkyl (meth) acrylates: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t (meth) acrylate. -Butylaminoethyl.
Alkoxy group-containing monomers: for example, 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, (meth) acrylic acid. Alkoxyalkyls (meth) acrylate, such as butoxyethyl, ethoxypropyl (meth) acrylate; Alkoxyalkylene glycol (meth) acrylate, such as methoxyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, etc. Kind.
Alkoxysilyl group-containing monomers: For example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxy. Propylmethyldiethoxysilane.
Vinyl esters: For example, vinyl acetate, vinyl propionate and the like.
Vinyl ethers: For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether.
Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyltoluene and the like.
Olefins: For example, ethylene, butadiene, isoprene, isobutylene and the like.
(Meta) acrylic acid ester having an alicyclic hydrocarbon group: For example, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate and the like. ..
(Meta) acrylic acid ester having an aromatic hydrocarbon group: For example, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate and the like.
In addition, heterocyclic-containing (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate, halogen atom-containing (meth) acrylates such as vinyl chloride and fluorine atom-containing (meth) acrylates, and silicon atom-containing silicone (meth) acrylates. (Meta) acrylate, (meth) acrylic acid ester obtained from terpene compound derivative alcohol, etc.
　このような共重合性モノマーを使用する場合、その使用量は特に限定されないが、モノマー成分全体の０．０１重量％以上とすることが適当である。共重合性モノマーの使用効果をよりよく発揮する観点から、共重合性モノマーの使用量をモノマー成分全体の０．１重量％以上としてもよく、０．５重量％以上としてもよい。また、粘着特性のバランスをとりやすくする観点から、共重合性モノマーの使用量は、モノマー成分全体の５０重量％以下とすることが適当であり、４０重量％以下とすることが好ましい。 When such a copolymerizable monomer is used, the amount used is not particularly limited, but it is appropriate to use 0.01% by weight or more of the total monomer component. From the viewpoint of better exerting the effect of using the copolymerizable monomer, the amount of the copolymerizable monomer used may be 0.1% by weight or more of the total monomer component, or 0.5% by weight or more. Further, from the viewpoint of facilitating the balance of the adhesive properties, the amount of the copolymerizable monomer used is preferably 50% by weight or less of the total monomer component, and preferably 40% by weight or less.
　いくつかの態様において、アクリル系重合物を構成するモノマー成分は、窒素原子を有するモノマーを含み得る。窒素原子を有するモノマーの使用により、粘着剤の凝集力を高め、光硬化後の剥離強度を好ましく向上させ得る。窒素原子を有するモノマーの一好適例として、窒素原子含有環を有するモノマーが挙げられる。窒素原子含有環を有するモノマーとしては上記で例示したもの等を用いることができ、例えば、一般式（１）：
Figure JPOXMLDOC01-appb-C000001
 で表わされるＮ－ビニル環状アミドを用いることができる。ここで、一般式（１）中、Ｒ1は２価の有機基であり、具体的には－（ＣＨ2）ｎ－である。ｎは２～７（好ましくは２，３または４）の整数である。なかでも、Ｎ－ビニル－２－ピロリドンを好ましく採用し得る。窒素原子を有するモノマーの他の好適例としては、（メタ）アクリルアミドが挙げられる。 In some embodiments, the monomer component constituting the acrylic polymer may include a monomer having a nitrogen atom. By using a monomer having a nitrogen atom, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photocuring can be preferably improved. A preferred example of a monomer having a nitrogen atom is a monomer having a nitrogen atom-containing ring. As the monomer having a nitrogen atom-containing ring, those exemplified above can be used, and for example, the general formula (1):
Figure JPOXMLDOC01-appb-C000001
 The N-vinyl cyclic amide represented by is used. Here, in the general formula (1), R 1 is a divalent organic group, specifically − (CH 2 ) n −. n is an integer of 2 to 7 (preferably 2, 3 or 4). Of these, N-vinyl-2-pyrrolidone can be preferably adopted. Other preferred examples of monomers having a nitrogen atom include (meth) acrylamide.
　窒素原子を有するモノマー（好ましくは窒素原子含有環を有するモノマー）の使用量は特に制限されず、例えばモノマー成分全体の１重量％以上であってもよく、３重量％以上であってもよく、さらには５重量％以上または７重量％以上とすることができる。いくつかの態様では、窒素原子を有するモノマーの使用量は、接着力向上の観点から、モノマー成分全体の１０重量％以上であってもよく、１５重量％以上であってもよく、２０重量％以上であってもよい。また、窒素原子を有するモノマーの使用量は、モノマー成分全体の例えば４０重量％以下とすることが適当であり、３５重量％以下としてもよく、３０重量％以下としてもよく、２５重量％以下としてもよい。他のいくつかの態様では、窒素原子を有するモノマーの使用量は、モノマー成分全体の例えば２０重量％以下としてもよく、１５重量％以下としてもよい。 The amount of the monomer having a nitrogen atom (preferably the monomer having a nitrogen atom-containing ring) is not particularly limited, and may be, for example, 1% by weight or more of the total monomer component, or 3% by weight or more. Further, it can be 5% by weight or more or 7% by weight or more. In some embodiments, the amount of the monomer having a nitrogen atom used may be 10% by weight or more, 15% by weight or more, or 20% by weight of the total monomer component from the viewpoint of improving the adhesive strength. It may be the above. Further, the amount of the monomer having a nitrogen atom to be used is appropriately set to, for example, 40% by weight or less of the total monomer component, 35% by weight or less, 30% by weight or less, or 25% by weight or less. May be good. In some other aspects, the amount of the monomer having a nitrogen atom used may be, for example, 20% by weight or less of the total monomer component, or 15% by weight or less.
　いくつかの態様において、モノマー成分は、カルボキシ基含有モノマーを含むことが好ましい。カルボキシ基含有モノマーの好適例として、アクリル酸（ＡＡ）およびメタクリル酸（ＭＡＡ）が挙げられる。ＡＡとＭＡＡとを併用してもよい。ＡＡとＭＡＡとを併用する場合、それらの重量比（ＡＡ／ＭＡＡ）は特に限定されず、例えば凡そ０．１～１０の範囲とすることができる。いくつかの態様において、上記重量比（ＡＡ／ＭＡＡ）は、例えば凡そ０．３以上であってよく、凡そ０．５以上でもよい。また、上記重量比（ＡＡ／ＭＡＡ）は、例えば凡そ４以下であってよく、凡そ３以下でもよい。 In some embodiments, the monomer component preferably contains a carboxy group-containing monomer. Preferable examples of the carboxy group-containing monomer include acrylic acid (AA) and methacrylic acid (MAA). AA and MAA may be used in combination. When AA and MAA are used in combination, their weight ratio (AA / MAA) is not particularly limited, and can be, for example, in the range of about 0.1 to 10. In some embodiments, the weight ratio (AA / MAA) may be, for example, approximately 0.3 or greater, and may be approximately 0.5 or greater. Further, the weight ratio (AA / MAA) may be, for example, about 4 or less, or about 3 or less.
　カルボキシ基含有モノマーの使用により、Ａ層の表面に水等の水性液体を素早く馴染ませることができる。このことは水剥離力Ｎ２の低下に役立ち得る。カルボキシ基含有モノマーの使用量は、例えば、モノマー成分全体の０．０５重量％以上であってよく、０．１重量％以上でもよく、０．３重量％以上でもよく、０．５重量％以上でもよく、０．８重量％以上でもよい。また、上記カルボキシ基含有モノマーの割合は、例えば１５重量％以下であってよく、１０重量％以下でもよく、５重量％以下でもよく、４．５重量％以下でもよく、３．５重量％以下でもよく、３．０重量％以下でもよく、２．５重量％以下でもよい。カルボキシ基含有モノマーの使用量が多過ぎないことは、Ａ層のバルクへの水の拡散を抑制し、水浸漬後剥離強度Ｎ１の低下を抑制する観点から好ましい。また、カルボキシ基含有モノマーの使用量が多過ぎないことは、水剥離力Ｎ２の測定に使用する水がＡ層に吸収されて剥離途中で水が不足する事象を防止する観点からも有利となり得る。 By using a carboxy group-containing monomer, an aqueous liquid such as water can be quickly blended into the surface of the A layer. This can help reduce the water peeling force N2. The amount of the carboxy group-containing monomer used may be, for example, 0.05% by weight or more, 0.1% by weight or more, 0.3% by weight or more, or 0.5% by weight or more of the total monomer component. However, it may be 0.8% by weight or more. The proportion of the carboxy group-containing monomer may be, for example, 15% by weight or less, 10% by weight or less, 5% by weight or less, 4.5% by weight or less, and 3.5% by weight or less. However, it may be 3.0% by weight or less, or 2.5% by weight or less. It is preferable that the amount of the carboxy group-containing monomer used is not too large from the viewpoint of suppressing the diffusion of water into the bulk of the A layer and suppressing the decrease in the peel strength N1 after immersion in water. Further, the fact that the amount of the carboxy group-containing monomer used is not too large can be advantageous from the viewpoint of preventing the event that the water used for measuring the water peeling force N2 is absorbed by the layer A and the water is insufficient during the peeling. ..
　いくつかの態様において、モノマー成分は、水酸基含有モノマーを含み得る。水酸基含有モノマーの使用により、粘着剤の凝集力や架橋密度を調整し、剥離強度Ｎ０を向上させ得る。水酸基含有モノマーを使用する場合における使用量は特に制限されず、例えばモノマー成分全体の０．０１重量％以上であってよく、０．１重量％以上でもよく、０．５重量％以上でもよく、１重量％以上でもよく、５重量％以上または１０重量％以上でもよい。また、Ａ層のバルクへの過度の水拡散を抑制する観点から、いくつかの態様において、水酸基含有モノマーの使用量は、モノマー成分全体の例えば４０重量％以下とすることが適当であり、３０重量％以下としてもよく、２０重量％以下としてもよく、１０重量％以下、５重量％以下または３重量％以下としてもよい。ここに開示される積層体は、粘着剤層（Ａ層）のモノマー成分として水酸基含有モノマーを実質的に使用しない態様でも好適に実施され得る。 In some embodiments, the monomer component may include a hydroxyl group-containing monomer. By using the hydroxyl group-containing monomer, the cohesive force and the cross-linking density of the pressure-sensitive adhesive can be adjusted, and the peel strength N0 can be improved. When a hydroxyl group-containing monomer is used, the amount used is not particularly limited, and may be, for example, 0.01% by weight or more, 0.1% by weight or more, or 0.5% by weight or more of the entire monomer component. It may be 1% by weight or more, 5% by weight or more, or 10% by weight or more. Further, from the viewpoint of suppressing excessive water diffusion of the A layer into the bulk, it is appropriate that the amount of the hydroxyl group-containing monomer used is, for example, 40% by weight or less of the total monomer component in some embodiments. It may be 10% by weight or less, 5% by weight or less, or 3% by weight or less. The laminate disclosed herein can be preferably implemented even in an embodiment in which a hydroxyl group-containing monomer is substantially not used as a monomer component of the pressure-sensitive adhesive layer (A layer).
　いくつかの態様において、モノマー成分は、アルコキシシリル基含有モノマーを含み得る。アルコキシシリル基含有モノマーは、典型的には、一分子内に少なくとも１つ（好ましくは２つ以上、例えば２つまたは３つ）のアルコキシシリル基を有するエチレン性不飽和単量体であり、その具体例は上述のとおりである。上記アルコキシシリル基含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。アルコキシシリル基含有モノマーの使用により、粘着剤層（Ａ層）にシラノール基の縮合反応（シラノール縮合）による架橋構造を導入することができる。なお、アルコキシシリル基含有モノマーは、後述するシランカップリング剤としても把握され得る。 In some embodiments, the monomer component may include an alkoxysilyl group-containing monomer. The alkoxysilyl group-containing monomer is typically an ethylenically unsaturated monomer having at least one (preferably two or more, for example two or three) alkoxysilyl groups in one molecule. Specific examples are as described above. The above-mentioned alkoxysilyl group-containing monomer may be used alone or in combination of two or more. By using the alkoxysilyl group-containing monomer, a crosslinked structure by a silanol group condensation reaction (silanol condensation) can be introduced into the pressure-sensitive adhesive layer (A layer). The alkoxysilyl group-containing monomer can also be grasped as a silane coupling agent described later.
　モノマー成分がアルコキシシリル基含有モノマーを含む態様において、該モノマー成分全体に占めるアルコキシシリル基含有モノマーの割合は、例えば０．００５重量％以上とすることができ、０．０１重量％以上とすることが適当である。また、上記アルコキシシリル基含有モノマーの割合は、被着体に対する密着性向上の観点から、例えば０．５重量％以下であってよく、０．１重量％以下でもよく、０．０５重量％以下でもよい。 In the embodiment in which the monomer component contains an alkoxysilyl group-containing monomer, the ratio of the alkoxysilyl group-containing monomer to the entire monomer component can be, for example, 0.005% by weight or more, and 0.01% by weight or more. Is appropriate. Further, the proportion of the alkoxysilyl group-containing monomer may be, for example, 0.5% by weight or less, 0.1% by weight or less, or 0.05% by weight or less from the viewpoint of improving the adhesion to the adherend. It may be.
　また、いくつかの好ましい態様に係るアクリル系重合物のモノマー成分は、ゲル化抑制の観点から、アルコキシアルキル（メタ）アクリレートおよびアルコキシポリアルキレングリコール（メタ）アクリレートの合計割合が２０重量％未満に制限されている。上記アルコキシアルキル（メタ）アクリレートおよびアルコキシポリアルキレングリコール（メタ）アクリレートの合計割合は、より好ましくは１０重量％未満、さらに好ましくは３重量％未満、特に好ましくは１重量％未満であり、いくつかの態様では、上記モノマー成分はアルコキシアルキル（メタ）アクリレートおよびアルコキシポリアルキレングリコール（メタ）アクリレートを実質的に含まない（含有量０～０．３重量％）。
　同様に、ここに開示されるアクリル系重合物のモノマー成分は、アルコキシ基含有モノマーを２０重量％未満の割合で含むか、含まないものであり得る。上記モノマー成分に占めるアルコキシ基含有モノマーの量は、好ましくは１０重量％未満、より好ましくは３重量％未満、さらに好ましくは１重量％未満であり、特に好ましい態様では、上記モノマー成分はアルコキシ基含有モノマーを実質的に含まない（含有量０～０．３重量％）。 Further, the monomer component of the acrylic polymer according to some preferred embodiments is limited to a total ratio of alkoxyalkyl (meth) acrylate and alkoxypolyalkylene glycol (meth) acrylate of less than 20% by weight from the viewpoint of suppressing gelation. Has been done. The total proportion of the alkoxyalkyl (meth) acrylate and the alkoxypolyalkylene glycol (meth) acrylate is more preferably less than 10% by weight, still more preferably less than 3% by weight, particularly preferably less than 1% by weight, and some In aspects, the monomer component is substantially free of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol (meth) acrylates (content 0-0.3% by weight).
Similarly, the monomer component of the acrylic polymer disclosed herein may or may not contain an alkoxy group-containing monomer in a proportion of less than 20% by weight. The amount of the alkoxy group-containing monomer in the monomer component is preferably less than 10% by weight, more preferably less than 3% by weight, still more preferably less than 1% by weight, and in a particularly preferable embodiment, the monomer component contains an alkoxy group. Substantially free of monomers (content 0-0.3% by weight).
　また、いくつかの好ましい態様において、アクリル系重合物のモノマー成分は、親水性モノマーの割合が適切な範囲に設定されている。これにより、水剥離性が好ましく発揮される。ここで、本明細書における「親水性モノマー」は、カルボキシ基含有モノマー、酸無水物基含有モノマー、水酸基含有モノマー、窒素原子を有するモノマー（典型的には、（メタ）アクリルアミド等のアミド基含有モノマー、Ｎ－ビニル－２－ピロリドン等の窒素原子含有環を有するモノマー）およびアルコキシ基含有モノマー（典型的には、アルコキシアルキル（メタ）アクリレートおよびアルコキシポリアルキレングリコール（メタ）アクリレート）をいうものとする。この態様において、アクリル系重合物のモノマー成分のうち上記親水性モノマーの割合は４０重量％以下（例えば３５重量％以下）が適当であり、３２重量％以下であることが好ましく、例えば３０重量％以下であってもよく、２８重量％以下であってもよい。特に限定されるものではないが、アクリル系重合物のモノマー成分のうち上記親水性モノマーの割合は１重量％以上であってもよく、１０重量％以上であってもよく、２０重量％以上であってもよい。 Further, in some preferable embodiments, the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer is set in an appropriate range. As a result, water peelability is preferably exhibited. Here, the "hydrophilic monomer" in the present specification contains a carboxy group-containing monomer, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer, a monomer having a nitrogen atom (typically, an amide group such as (meth) acrylamide). Monomer, monomer having a nitrogen atom-containing ring such as N-vinyl-2-pyrrolidone) and alkoxy group-containing monomer (typically, alkoxyalkyl (meth) acrylate and alkoxypolyalkylene glycol (meth) acrylate). To do. In this embodiment, the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer is preferably 40% by weight or less (for example, 35% by weight or less), preferably 32% by weight or less, for example, 30% by weight. It may be less than or equal to 28% by weight or less. Although not particularly limited, the proportion of the hydrophilic monomer in the monomer component of the acrylic polymer may be 1% by weight or more, 10% by weight or more, or 20% by weight or more. There may be.
　いくつかの態様において、アクリル系重合物を構成するモノマー成分は、脂環式炭化水素基含有（メタ）アクリレートを含み得る。これにより、粘着剤の凝集力を高め、光硬化後の剥離強度を向上させることができる。脂環式炭化水素基含有（メタ）アクリレートとしては上記で例示したもの等を用いることができ、例えばシクロヘキシルアクリレートやイソボルニルアクリレートを好ましく採用し得る。脂環式炭化水素基含有（メタ）アクリレートを使用する場合における使用量は特に制限されず、例えばモノマー成分全体の１重量％以上、３重量％以上または５重量％以上とすることができる。いくつかの態様では、脂環式炭化水素基含有（メタ）アクリレートの使用量は、モノマー成分全体の１０重量％以上であってもよく、１５重量％以上であってもよい。脂環式炭化水素基含有（メタ）アクリレートの使用量の上限は、凡そ４０重量％以下とすることが適当であり、例えば３０重量％以下であってもよく、２５重量％以下（例えば１５重量％以下、さらには１０重量％以下）であってもよい。 In some embodiments, the monomer component constituting the acrylic polymer may contain an alicyclic hydrocarbon group-containing (meth) acrylate. As a result, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photocuring can be improved. As the alicyclic hydrocarbon group-containing (meth) acrylate, those exemplified above can be used, and for example, cyclohexyl acrylate and isobornyl acrylate can be preferably adopted. When the alicyclic hydrocarbon group-containing (meth) acrylate is used, the amount used is not particularly limited, and may be, for example, 1% by weight or more, 3% by weight or more, or 5% by weight or more of the total monomer component. In some embodiments, the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used may be 10% by weight or more, or 15% by weight or more, of the total monomer components. The upper limit of the amount of the alicyclic hydrocarbon group-containing (meth) acrylate used is appropriately about 40% by weight or less, for example, 30% by weight or less, and 25% by weight or less (for example, 15% by weight). % Or less, and even 10% by weight or less).
　モノマー成分の組成は、該モノマー成分の組成に基づいてＦｏｘの式により求められるガラス転移温度（以下、「重合物のガラス転移温度」ともいう。）が－７５℃以上－１０℃以下となるように設定され得る。いくつかの態様において、上記重合物（例えばアクリル系重合物、典型的にはアクリル系ポリマー）のガラス転移温度（Ｔｇ）は、－２０℃以下であることが適当であり、－３０℃以下であることが好ましく、－４０℃以下であることがより好ましく、－５０℃以下であることがさらに好ましく、例えば－５５℃以下であってもよい。上記重合物のＴｇが低くなると、Ａ層の基材層に対する密着性や被着体に対する接着性は概して向上する傾向にある。基材層への密着性の高いＡ層によると、粘着剤層の剥離を意図しない局面において基材層とＡ層との界面への水浸入を抑制しやすい。このことは、水浸漬後剥離強度Ｎ１の向上や、水浸漬後剥離力低下率の低減の観点から有利となり得る。また、重合物のＴｇは、剥離強度Ｎ０を高めやすくする観点から、例えば－７０℃以上であってよく、－６５℃以上でもよい。他のいくつかの態様では、上記Ｔｇは、例えば－６０℃以上であってよく、－５０℃以上でもよく、－４５℃以上または－４０℃以上でもよい。 The composition of the monomer component is such that the glass transition temperature (hereinafter, also referred to as “glass transition temperature of the polymer”) determined by the Fox formula based on the composition of the monomer component is −75 ° C. or higher and −10 ° C. or lower. Can be set to. In some embodiments, the glass transition temperature (Tg) of the above polymer (eg, acrylic polymer, typically acrylic polymer) is preferably −20 ° C. or lower, preferably −30 ° C. or lower. It is preferably −40 ° C. or lower, more preferably −50 ° C. or lower, and may be −55 ° C. or lower, for example. When the Tg of the polymer is low, the adhesion of the A layer to the base material layer and the adhesiveness to the adherend tend to be generally improved. According to the layer A having high adhesion to the base material layer, it is easy to suppress water infiltration into the interface between the base material layer and the layer A when the pressure-sensitive adhesive layer is not intended to be peeled off. This can be advantageous from the viewpoint of improving the peeling strength N1 after immersion in water and reducing the rate of decrease in peeling force after immersion in water. Further, the Tg of the polymer may be, for example, −70 ° C. or higher, or −65 ° C. or higher, from the viewpoint of facilitating the increase in peel strength N0. In some other aspects, the Tg may be, for example, −60 ° C. or higher, −50 ° C. or higher, −45 ° C. or higher, or −40 ° C. or higher.
　ここで、上記Ｆｏｘの式とは、以下に示すように、共重合体のＴｇと、該共重合体を構成するモノマーのそれぞれを単独重合したホモポリマーのガラス転移温度Ｔｇｉとの関係式である。
　　　１／Ｔｇ＝Σ（Ｗｉ／Ｔｇｉ）
　なお、上記Ｆｏｘの式において、Ｔｇは共重合体のガラス転移温度（単位：Ｋ）、Ｗｉは該共重合体におけるモノマーｉの重量分率（重量基準の共重合割合）、Ｔｇｉはモノマーｉのホモポリマーのガラス転移温度（単位：Ｋ）を表す。 Here, the Fox formula is a relational formula between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer in which each of the monomers constituting the copolymer is homopolymerized, as shown below. ..
1 / Tg = Σ (Wi / Tgi)
In the Fox formula, Tg is the glass transition temperature (unit: K) of the copolymer, Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on the weight), and Tgi is the monomer i. Represents the glass transition temperature (unit: K) of the homopolymer.
　Ｔｇの算出に使用するホモポリマーのガラス転移温度としては、公知資料に記載の値を用いるものとする。例えば、以下に挙げるモノマーについては、該モノマーのホモポリマーのガラス転移温度として、以下の値を使用する。
　　２－エチルヘキシルアクリレート　　－７０℃
　　ｎ－ブチルアクリレート　　　　　　－５５℃
　　イソステアリルアクリレート　　　　－１８℃
　　メチルメタクリレート　　　　　　　１０５℃
　　メチルアクリレート　　　　　　　　　　８℃
　　シクロヘキシルアクリレート　　　　　１５℃
　　Ｎ－ビニル－２－ピロリドン　　　　　５４℃
　　２－ヒドロキシエチルアクリレート　－１５℃
　　４－ヒドロキシブチルアクリレート　－４０℃
　　ジシクロペンタニルメタクリレート　１７５℃
　　イソボルニルアクリレート　　　　　　９４℃
　　アクリル酸　　　　　　　　　　　　１０６℃
　　メタクリル酸　　　　　　　　　　　２２８℃ As the glass transition temperature of the homopolymer used for calculating Tg, the value described in the publicly known material shall be used. For example, for the monomers listed below, the following values are used as the glass transition temperature of the homopolymer of the monomer.
2-Ethylhexyl acrylate-70 ° C
n-Butyl acrylate-55 ° C
Isostearyl acrylate -18 ° C
Methyl methacrylate 105 ° C
Methyl acrylate 8 ℃
Cyclohexyl acrylate 15 ° C
N-Vinyl-2-pyrrolidone 54 ° C
2-Hydroxyethyl acrylate -15 ° C
4-Hydroxybutyl acrylate-40 ° C
Dicyclopentanyl methacrylate 175 ° C
Isobornyl acrylate 94 ° C
Acrylic acid 106 ℃
Methacrylic acid 228 ° C
　上記で例示した以外のモノマーのホモポリマーのガラス転移温度については、「Polymer Handbook」（第３版、John Wiley & Sons, Inc., 1989）に記載の数値を用いるものとする。本文献に複数種類の値が記載されている場合は、最も高い値を採用する。 For the glass transition temperature of homopolymers of monomers other than those exemplified above, the values described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. When multiple types of values are described in this document, the highest value is adopted.
　上記Polymer Handbookにもホモポリマーのガラス転移温度が記載されていないモノマーについては、以下の測定方法により得られる値を用いるものとする（日本国特許出願公開２００７－５１２７１号公報参照）。具体的には、温度計、攪拌機、窒素導入管および還流冷却管を備えた反応器に、モノマー１００重量部、アゾビスイソブチロニトリル０．２重量部および重合溶媒として酢酸エチル２００重量部を投入し、窒素ガスを流通させながら１時間攪拌する。このようにして重合系内の酸素を除去した後、６３℃に昇温し１０時間反応させる。次いで、室温まで冷却し、固形分濃度３３重量％のホモポリマー溶液を得る。次いで、このホモポリマー溶液を剥離ライナー上に流延塗布し、乾燥して厚さ約２ｍｍの試験サンプル（シート状のホモポリマー）を作製する。この試験サンプルを直径７．９ｍｍの円盤状に打ち抜き、パラレルプレートで挟み込み、粘弾性試験機（ＡＲＥＳ、レオメトリックス社製）を用いて周波数１Ｈｚのせん断歪みを与えながら、温度領域－７０～１５０℃、５℃／分の昇温速度でせん断モードにより粘弾性を測定し、ｔａｎδのピークトップ温度をホモポリマーのＴｇとする。 For monomers for which the glass transition temperature of homopolymer is not described in the above Polymer Handbook, the value obtained by the following measurement method shall be used (see Japanese Patent Application Publication No. 2007-51271). Specifically, in a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube and a reflux condenser, 100 parts by weight of a monomer, 0.2 parts by weight of azobisisobutyronitrile and 200 parts by weight of ethyl acetate as a polymerization solvent The mixture is charged and stirred for 1 hour while flowing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature is raised to 63 ° C. and the reaction is carried out for 10 hours. Then, the mixture is cooled to room temperature to obtain a homopolymer solution having a solid content concentration of 33% by weight. Next, this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm. This test sample is punched into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear strain at a frequency of 1 Hz using a viscoelasticity tester (ARES, manufactured by Leometrics) in a temperature range of −70 to 150 ° C. The viscoelasticity is measured in a shear mode at a heating rate of 5 ° C./min, and the peak top temperature of tan δ is defined as Tg of the homopolymer.
　ここに開示される粘着剤層（Ａ層）に含まれる重合物（例えばアクリル系重合物、典型的にはアクリル系ポリマー）は、特に限定されるものではないが、ＳＰ値が２３．０（ＭＪ／ｍ3）1/2以下であることが好ましい。そのようなＳＰ値を有する重合物を含む粘着剤は、例えば後述の水親和剤を含ませることによって、十分な接着強度を有しつつ、優れた水剥離性を有する粘着剤を好ましく実現するものとなり得る。上記ＳＰ値は、より好ましくは２１．０（ＭＪ／ｍ3）1/2以下（例えば２０．０（ＭＪ／ｍ3）1/2以下）である。上記ＳＰ値の下限は特に限定されず、例えば凡そ１０．０（ＭＪ／ｍ3）1/2以上であり、また凡そ１５．０（ＭＪ／ｍ3）1/2以上であることが適当であり、好ましくは１８．０（ＭＪ／ｍ3）1/2以上である。 The polymer (for example, an acrylic polymer, typically an acrylic polymer) contained in the pressure-sensitive adhesive layer (A layer) disclosed herein is not particularly limited, but has an SP value of 23.0 (). MJ / m 3 ) It is preferably 1/2 or less. The pressure-sensitive adhesive containing a polymer having such an SP value preferably realizes a pressure-sensitive adhesive having excellent water-removability while having sufficient adhesive strength by containing, for example, a water-affinitive agent described later. Can be. The SP value is more preferably 21.0 (MJ / m 3 ) 1/2 or less (for example, 20.0 (MJ / m 3 ) 1/2 or less). The lower limit of the SP value is not particularly limited, and for example, it is appropriate that it is approximately 10.0 (MJ / m 3 ) 1/2 or more, and approximately 15.0 (MJ / m 3 ) 1/2 or more. Yes, preferably 18.0 (MJ / m 3 ) 1/2 or more.
　なお、上記重合物のＳＰ値は、Fedorsの算出法［「ポリマー・エンジニアリング・アンド・サイエンス（POLYMER ENG. & SCI．）」，第１４巻，第２号（1974），第１４８～１５４ページ参照］すなわち、式：
　　　ＳＰ値δ＝（Σ△ｅ／Σ△ｖ）１／２
（上式中、Δｅは、２５℃における各原子または原子団の蒸発エネルギー△ｅであり、Δｖは、同温度における各原子または原子団のモル容積である。）；
に従って計算することができる。上記ＳＰ値を有する重合物は、当業者の技術常識に基づき、適切にモノマー組成を決定することにより得ることができる。 For the SP value of the above polymer, refer to the Federal calculation method ["Polymer Engineering and Science (POLYMER ENG. &SCI.)", Vol. 14, No. 2 (1974), pp. 148-154. ] That is, the formula:
SP value δ = (Σ △ e / Σ △ v) 1/2
(In the above equation, Δe is the evaporation energy Δe of each atom or atomic group at 25 ° C., and Δv is the molar volume of each atom or atomic group at the same temperature.);
Can be calculated according to. The polymer having the above SP value can be obtained by appropriately determining the monomer composition based on the common general technical knowledge of those skilled in the art.
　粘着剤層（Ａ層）は、上述のような組成のモノマー成分を、重合物、未重合物（すなわち、重合性官能基が未反応である形態）、あるいはこれらの混合物の形態で含む粘着剤組成物（以下「粘着剤組成物Ａ」ともいう。）を用いて形成され得る。上記粘着剤組成物Ａは、粘着剤（粘着成分）が水に分散した形態の水分散型粘着剤組成物、有機溶媒中に粘着剤を含む形態の溶剤型粘着剤組成物、紫外線や放射線等の活性エネルギー線により硬化して粘着剤を形成するように調製された活性エネルギー線硬化型粘着剤組成物、加熱溶融状態で塗工され、室温付近まで冷えると粘着剤を形成するホットメルト型粘着剤組成物、等の種々の形態であり得る。 The pressure-sensitive adhesive layer (layer A) contains a monomer component having the above-mentioned composition in the form of a polymer, a non-polymerized product (that is, a form in which a polymerizable functional group is unreacted), or a mixture thereof. It can be formed using a composition (hereinafter, also referred to as "adhesive composition A"). The pressure-sensitive adhesive composition A includes a water-dispersed pressure-sensitive adhesive composition in which a pressure-sensitive adhesive (adhesive component) is dispersed in water, a solvent-type pressure-sensitive adhesive composition in which a pressure-sensitive adhesive is contained in an organic solvent, ultraviolet rays, radiation, and the like. An active energy ray-curable pressure-sensitive adhesive composition prepared to be cured by the active energy rays of the above to form a pressure-sensitive adhesive, which is coated in a heat-melted state and forms a pressure-sensitive adhesive when cooled to around room temperature. It can be in various forms such as an agent composition.
　重合にあたっては、重合方法や重合態様等に応じて、公知または慣用の熱重合開始剤や光重合開始剤を使用し得る。このような重合開始剤は、１種を単独でまたは２種以上を適宜組み合わせて用いることができる。 In the polymerization, a known or commonly used thermal polymerization initiator or photopolymerization initiator can be used depending on the polymerization method, polymerization mode, and the like. Such a polymerization initiator may be used alone or in combination of two or more.
　熱重合開始剤としては、特に限定されるものではないが、例えばアゾ系重合開始剤、過酸化物系開始剤、過酸化物と還元剤との組合せによるレドックス系開始剤、置換エタン系開始剤等を使用することができる。より具体的には、例えば２，２’－アゾビスイソブチロニトリル、２，２’－アゾビス（２－メチルプロピオンアミジン）二硫酸塩、２，２’－アゾビス（２－アミジノプロパン）ジヒドロクロライド、２，２’－アゾビス［２－（５－メチル－２－イミダゾリン－２－イル）プロパン］ジヒドロクロライド、２，２’－アゾビス（Ｎ，Ｎ’－ジメチレンイソブチルアミジン）、２，２’－アゾビス［Ｎ－（２－カルボキシエチル）－２－メチルプロピオンアミジン］ハイドレート等のアゾ系開始剤；例えば過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩；ベンゾイルパーオキサイド、ｔ－ブチルハイドロパーオキサイド、過酸化水素等の過酸化物系開始剤；例えばフェニル置換エタン等の置換エタン系開始剤；例えば過硫酸塩と亜硫酸水素ナトリウムとの組合せ、過酸化物とアスコルビン酸ナトリウムとの組合せ等のレドックス系開始剤；等が例示されるが、これらに限定されない。なお、熱重合は、例えば２０～１００℃（典型的には４０～８０℃）程度の温度で好ましく実施され得る。 The thermal polymerization initiator is not particularly limited, but is, for example, an azo-based polymerization initiator, a peroxide-based initiator, a redox-based initiator by a combination of a peroxide and a reducing agent, and a substituted ethane-based initiator. Etc. can be used. More specifically, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (2-amidinopropane) dihydrochloride. , 2,2'-Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2,2' -Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] Azo-based initiators such as hydrate; persulfates such as potassium persulfate and ammonium persulfate; benzoyl peroxide, t-butyl hydroperoxide , Peroxide-based initiators such as hydrogen peroxide; for example, substituted ethane-based initiators such as phenyl-substituted ethane; for example, redox such as a combination of persulfate and sodium hydrogen sulfite, a combination of peroxide and sodium ascorbate, etc. System initiators; and the like are exemplified, but not limited thereto. The thermal polymerization can be preferably carried out at a temperature of, for example, about 20 to 100 ° C. (typically 40 to 80 ° C.).
　光重合開始剤としては、特に限定されるものではないが、例えばケタール系光重合開始剤、アセトフェノン系光重合開始剤、ベンゾインエーテル系光重合開始剤、アシルホスフィンオキサイド系光重合開始剤、α－ケトール系光重合開始剤、芳香族スルホニルクロリド系光重合開始剤、光活性オキシム系光重合開始剤、ベンゾイン系光重合開始剤、ベンジル系光重合開始剤、ベンゾフェノン系光重合開始剤、チオキサントン系光重合開始剤等を用いることができる。 The photopolymerization initiator is not particularly limited, but for example, a ketal-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, a benzoin ether-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, α- Ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, thioxanthone-based light A polymerization initiator or the like can be used.
　このような熱重合開始剤または光重合開始剤の使用量は、重合方法や重合態様等に応じた通常の使用量とすることができ、特に限定されない。例えば、重合対象のモノマー１００重量部に対して重合開始剤凡そ０．００１～５重量部（典型的には凡そ０．０１～２重量部、例えば凡そ０．０１～１重量部）を用いることができる。 The amount of such a thermal polymerization initiator or photopolymerization initiator used can be a normal amount according to the polymerization method, polymerization mode, etc., and is not particularly limited. For example, about 0.001 to 5 parts by weight of the polymerization initiator (typically about 0.01 to 2 parts by weight, for example, about 0.01 to 1 part by weight) is used with respect to 100 parts by weight of the monomer to be polymerized. Can be done.
　上記重合には、必要に応じて、従来公知の各種の連鎖移動剤（分子量調節剤あるいは重合度調節剤としても把握され得る。）を使用することができる。連鎖移動剤としては、ｎ－ドデシルメルカプタン、ｔ－ドデシルメルカプタン、チオグリコール酸等のメルカプタン類を用いることができる。あるいは、硫黄原子を含まない連鎖移動剤（非硫黄系連鎖移動剤）を用いてもよい。非硫黄系連鎖移動剤の具体例としては、Ｎ，Ｎ－ジメチルアニリン、Ｎ，Ｎ－ジエチルアニリン等のアニリン類；α－ピネン、ターピノーレン等のテルペノイド類；α－メチルスチレン、α―メチルスチレンダイマー等のスチレン類；ジベンジリデンアセトン、シンナミルアルコール、シンナミルアルデヒド等のベンジリデニル基を有する化合物；ヒドロキノン、ナフトヒドロキノン等のヒドロキノン類；ベンゾキノン、ナフトキノン等のキノン類；２，３－ジメチル－２－ブテン、１，５－シクロオクタジエン等のオレフィン類；フェノール、ベンジルアルコール、アリルアルコール等のアルコール類；ジフェニルベンゼン、トリフェニルベンゼン等のベンジル水素類；等が挙げられる。
　連鎖移動剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。連鎖移動剤を使用する場合、その使用量は、モノマー成分１００重量部に対して、例えば凡そ０．０１～１重量部程度とすることができる。ここに開示される技術は、連鎖移動剤を使用しない態様でも好ましく実施され得る。 For the above-mentioned polymerization, various conventionally known chain transfer agents (which can also be grasped as a molecular weight adjusting agent or a degree of polymerization adjusting agent) can be used, if necessary. As the chain transfer agent, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, and thioglycolic acid can be used. Alternatively, a chain transfer agent containing no sulfur atom (non-sulfur chain transfer agent) may be used. Specific examples of the non-sulfur chain transfer agent include anilins such as N, N-dimethylaniline and N, N-diethylaniline; terpenoids such as α-pinene and turpinolene; α-methylstyrene and α-methylstyrene dimer. Such as styrenes; compounds having a benzylidenyl group such as dibenzylidene acetone, cinnamyl alcohol, cinnamyl aldehyde; hydroquinones such as hydroquinone and naphthohydroquinone; quinones such as benzoquinone and naphthoquinone; 2,3-dimethyl-2-butene , 1,5-Cyclooctadiene and the like; alcohols such as phenol, benzyl alcohol and allyl alcohol; benzyl hydrogens such as diphenylbenzene and triphenylbenzene; and the like.
The chain transfer agent may be used alone or in combination of two or more. When a chain transfer agent is used, the amount used can be, for example, about 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer component. The techniques disclosed herein may also be preferably practiced in aspects that do not use chain transfer agents.
　上記の各種重合法を適宜採用して得られる重合物（例えばアクリル系重合物、典型的にはアクリル系ポリマー）の分子量は特に制限されず、要求性能等に合わせて適当な範囲に設定し得る。上記重合物の重量平均分子量（Ｍｗ）は、凡そ１０×１０４以上であることが適当であり、例えば凡そ１５×１０４以上であってよく、凝集力と接着力とをバランスよく両立する観点から、３０×１０４超であることが好ましい。いくつかの態様に係る上記重合物は、高温環境下においても良好な接着信頼性を得る観点から、好ましくは４０×１０４以上（典型的には凡そ５０×１０４以上、例えば凡そ５５×１０４以上）のＭｗを有する。上記重合物のＭｗの上限は、凡そ５００×１０４以下（例えば凡そ１５０×１０４以下）であり得る。上記Ｍｗは凡そ７５×１０４以下であってもよい。ここでＭｗとは、ゲルパーミエーションクロマトグラフィ（ＧＰＣ）により得られた標準ポリスチレン換算の値をいう。ＧＰＣ装置としては、例えば機種名「ＨＬＣ－８３２０ＧＰＣ」（カラム：ＴＳＫｇｅｌＧＭＨ－Ｈ（Ｓ）、東ソー社製）を使用すればよい。後述の実施例においても同様である。 The molecular weight of the polymer (for example, acrylic polymer, typically acrylic polymer) obtained by appropriately adopting the above various polymerization methods is not particularly limited and can be set in an appropriate range according to the required performance and the like. .. Viewpoint weight average molecular weight of the polymer (Mw) of suitably be at about 10 × 10 4 or more, for example may be at about 15 × 10 4 or more, to achieve both good balance and cohesive force and adhesive force Therefore, it is preferably more than 30 × 10 4 . The above-mentioned polymer according to some aspects is preferably 40 × 10 4 or more (typically about 50 × 10 4 or more, for example, about 55 × 10) from the viewpoint of obtaining good adhesion reliability even in a high temperature environment. It has Mw of 4 or more). The upper limit of Mw of the polymer may be about 500 × 10 4 or less (e.g., about 0.99 × 10 4 or less). The Mw may be of about 75 × 10 4 or less. Here, Mw refers to a standard polystyrene-equivalent value obtained by gel permeation chromatography (GPC). As the GPC apparatus, for example, the model name "HLC-8320GPC" (column: TSKgelGMH-H (S), manufactured by Tosoh Corporation) may be used. The same applies to the examples described later.
　いくつかの態様に係る積層体は、水分散型粘着剤組成物から形成されたＡ層を有する。水分散型粘着剤組成物の代表例として、エマルション型粘着剤組成物が挙げられる。エマルション型粘着剤組成物は、典型的には、モノマー成分の重合物と、必要に応じて用いられる添加剤とを含有する。 The laminate according to some aspects has a layer A formed from the water-dispersible pressure-sensitive adhesive composition. A typical example of the water-dispersible pressure-sensitive adhesive composition is an emulsion-type pressure-sensitive adhesive composition. Emulsion-type pressure-sensitive adhesive compositions typically contain a polymer of monomeric components and, optionally, additives.
　モノマー成分のエマルション重合は、通常、乳化剤の存在下で行われる。エマルション重合用の乳化剤としては、特に制限されず、公知のアニオン性乳化剤、ノニオン性乳化剤等を用いることができる。乳化剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 Emulsion polymerization of monomer components is usually performed in the presence of an emulsifier. The emulsifier for emulsion polymerization is not particularly limited, and known anionic emulsifiers, nonionic emulsifiers and the like can be used. The emulsifier may be used alone or in combination of two or more.
　アニオン性乳化剤の非限定的な例としては、ラウリル硫酸ナトリウム、ラウリル硫酸アンモニウム、ドデシルベンゼンスルホン酸ナトリウム、ポリオキシエチレンラウリル硫酸ナトリウム、ポリオキシエチレンアルキルエーテル硫酸ナトリウム、ポリオキシエチレンアルキルフェニルエーテル硫酸アンモニウム、ポリオキシエチレンアルキルフェニルエーテル硫酸ナトリウム、ポリオキシエチレンアルキルスルホコハク酸ナトリウム等が挙げられる。ノニオン性乳化剤の非限定的な例としては、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレン脂肪酸エステル、ポリオキシエチレンポリオキシプロピレンブロックポリマー等が挙げられる。反応性官能基を有する乳化剤（反応性乳化剤）を用いてもよい。反応性乳化剤の例としては、上述したアニオン性乳化剤またはノニオン性乳化剤に、プロペニル基やアリルエーテル基等のラジカル重合性官能基が導入された構造のラジカル重合性乳化剤が挙げられる。 Non-limiting examples of anionic emulsifiers include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, polyoxy. Examples thereof include sodium ethylenealkylphenyl ether sulfate and sodium polyoxyethylene alkyl sulfosuccinate. Non-limiting examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyoxypropylene block polymers and the like. An emulsifier having a reactive functional group (reactive emulsifier) may be used. Examples of the reactive emulsifier include a radically polymerizable emulsifier having a structure in which a radically polymerizable functional group such as a propenyl group or an allyl ether group is introduced into the above-mentioned anionic emulsifier or nonionic emulsifier.
　エマルション重合における乳化剤の使用量は、モノマー成分１００重量部に対して、例えば０．２重量部以上であってよく、０．５重量部以上でもよく、１．０重量部以上でもよく、１．５重量部以上でもよい。また、水浸漬後剥離強度Ｎ１の向上や水浸漬後剥離力低下率の低減、あるいは粘着剤層（Ａ層）の透明性向上の観点から、いくつかの態様において、乳化剤の使用量は、モノマー成分１００重量部に対して１０重量部以下とすることが適当であり、５重量部以下とすることが好ましく、３重量部以下としてもよい。なお、ここでエマルション重合に使用する乳化剤は、Ａ層の水親和剤としても機能し得る。 The amount of the emulsifier used in the emulsion polymerization may be, for example, 0.2 parts by weight or more, 0.5 parts by weight or more, or 1.0 part by weight or more with respect to 100 parts by weight of the monomer component. It may be 5 parts by weight or more. Further, from the viewpoint of improving the peel strength N1 after immersion in water, reducing the rate of decrease in peeling force after immersion in water, or improving the transparency of the pressure-sensitive adhesive layer (layer A), the amount of the emulsifier used is determined in some embodiments. It is suitable to be 10 parts by weight or less with respect to 100 parts by weight of the component, preferably 5 parts by weight or less, and may be 3 parts by weight or less. The emulsifier used for emulsion polymerization here can also function as an aqueous affinity agent for layer A.
　エマルション重合によると、モノマー成分の重合物が水に分散したエマルション形態の重合反応液が得られる。Ａ層の形成に用いる水分散型粘着剤組成物は、上記重合反応液を用いて好ましく製造され得る。 According to emulsion polymerization, a polymerization reaction solution in the form of an emulsion in which a polymer of monomer components is dispersed in water can be obtained. The water-dispersible pressure-sensitive adhesive composition used for forming the A layer can be preferably produced by using the above-mentioned polymerization reaction solution.
　いくつかの好ましい態様において、積層体は、溶剤型粘着剤組成物から形成されたＡ層を有し得る。溶剤型粘着剤組成物は、典型的には、モノマー成分の溶液重合物と、必要に応じて用いられる添加剤とを含有する。ここに開示される技術による効果（基材層に親水層を形成することによる水剥離性向上効果）は、溶剤型粘着剤層（Ａ層）に対して効果的に発揮され得る。また、溶剤型粘着剤の使用は光学特性の点でも有利である。溶液重合に用いる溶媒（重合溶媒）は、従来公知の有機溶媒から適宜選択することができる。例えば、トルエン等の芳香族化合物類（典型的には芳香族炭化水素類）；酢酸エチルや酢酸ブチル等のエステル類；ヘキサンやシクロヘキサン等の脂肪族または脂環式炭化水素類；１，２－ジクロロエタン等のハロゲン化アルカン類；イソプロピルアルコール等の低級アルコール類（例えば、炭素原子数１～４の一価アルコール類）；ｔｅｒｔ－ブチルメチルエーテル等のエーテル類；メチルエチルケトン等のケトン類；等から選択されるいずれか１種の溶媒、または２種以上の混合溶媒を用いることができる。溶液重合によると、モノマー成分の重合物が重合溶媒に溶解した形態の重合反応液が得られる。Ａ層の形成に用いる溶剤型粘着剤組成物は、上記重合反応液を用いて好ましく製造され得る。 In some preferred embodiments, the laminate may have a layer A formed from a solvent-based pressure-sensitive adhesive composition. The solvent-based pressure-sensitive adhesive composition typically contains a solution polymerization of the monomer components and an additive used as needed. The effect of the technique disclosed herein (the effect of improving water peelability by forming a hydrophilic layer on the base material layer) can be effectively exerted on the solvent-type pressure-sensitive adhesive layer (layer A). The use of a solvent-based pressure-sensitive adhesive is also advantageous in terms of optical properties. The solvent (polymerization solvent) used for solution polymerization can be appropriately selected from conventionally known organic solvents. For example, aromatic compounds such as toluene (typically aromatic hydrocarbons); esters such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane; 1,2- Select from halogenated alkanes such as dichloroethane; lower alcohols such as isopropyl alcohol (for example, monovalent alcohols having 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc. Any one solvent or a mixed solvent of two or more can be used. By solution polymerization, a polymerization reaction solution in which a polymer of a monomer component is dissolved in a polymerization solvent can be obtained. The solvent-type pressure-sensitive adhesive composition used for forming the A layer can be preferably produced by using the above-mentioned polymerization reaction solution.
　いくつかの好ましい態様において、積層体は、活性エネルギー線硬化型粘着剤組成物から形成されたＡ層を有し得る。ここで、本明細書において「活性エネルギー線」とは、重合反応、架橋反応、開始剤の分解等の化学反応を引き起こし得るエネルギーをもったエネルギー線を指す。ここでいう活性エネルギー線の例には、紫外線、可視光線、赤外線のような光や、α線、β線、γ線、電子線、中性子線、Ｘ線のような放射線等が含まれる。活性エネルギー線硬化型粘着剤組成物の一好適例として、光硬化型粘着剤組成物が挙げられる。光硬化型の粘着剤組成物は、厚手の粘着剤層であっても容易に形成し得るという利点を有する。なかでも紫外線硬化型粘着剤組成物が好ましい。また、ここに開示される技術による効果（基材層に親水層を形成することによる水剥離性向上効果）は、光硬化型粘着剤層（Ａ層）に対して効果的に発揮され得る。また、光硬化型粘着剤の使用は光学特性の点でも有利である。 In some preferred embodiments, the laminate may have a layer A formed from an active energy ray-curable pressure-sensitive adhesive composition. Here, the term "active energy ray" as used herein refers to an energy ray having energy that can cause a chemical reaction such as a polymerization reaction, a cross-linking reaction, or decomposition of an initiator. Examples of active energy rays referred to here include light such as ultraviolet rays, visible rays, and infrared rays, and radiation such as α rays, β rays, γ rays, electron rays, neutron rays, and X-rays. A photocurable pressure-sensitive adhesive composition is mentioned as a preferable example of the active energy ray-curable pressure-sensitive adhesive composition. The photocurable pressure-sensitive adhesive composition has an advantage that even a thick pressure-sensitive adhesive layer can be easily formed. Of these, an ultraviolet curable pressure-sensitive adhesive composition is preferable. Further, the effect of the technique disclosed herein (effect of improving water peelability by forming a hydrophilic layer on the base material layer) can be effectively exerted on the photocurable pressure-sensitive adhesive layer (layer A). The use of a photocurable pressure-sensitive adhesive is also advantageous in terms of optical properties.
　光硬化型粘着剤組成物は、典型的には、該組成物のモノマー成分のうち少なくとも一部（モノマーの種類の一部であってもよく、分量の一部であってもよい。）を重合物の形態で含む。上記重合物を形成する際の重合方法は特に限定されず、従来公知の各種重合方法を適宜採用することができる。例えば、溶液重合、エマルション重合、塊状重合等の熱重合（典型的には、熱重合開始剤の存在下で行われる。）；紫外線等の光を照射して行う光重合（典型的には、光重合開始剤の存在下で行われる。）；β線、γ線等の放射線を照射して行う放射線重合；等を適宜採用することができる。なかでも光重合が好ましい。 The photocurable pressure-sensitive adhesive composition typically contains at least a portion of the monomer components of the composition (which may be part of the type of monomer or part of the amount). Included in the form of a polymer. The polymerization method for forming the above-mentioned polymer is not particularly limited, and various conventionally known polymerization methods can be appropriately adopted. For example, thermal polymerization such as solution polymerization, emulsion polymerization, bulk polymerization (typically performed in the presence of a thermal polymerization initiator); photopolymerization performed by irradiating light such as ultraviolet rays (typically). It is carried out in the presence of a photopolymerization initiator.); Radiation polymerization carried out by irradiating radiation such as β-ray and γ-ray; and the like can be appropriately adopted. Of these, photopolymerization is preferable.
　いくつかの好ましい態様に係る光硬化型粘着剤組成物は、モノマー成分の部分重合物を含む。このような部分重合物は、典型的にはモノマー成分に由来する重合物と未反応のモノマーとの混合物であって、好ましくはシロップ状（粘性のある液状）を呈する。以下、かかる性状の部分重合物を「モノマーシロップ」または単に「シロップ」ということがある。モノマー成分を部分重合させる際の重合方法は特に制限されず、上述のような各種重合方法を適宜選択して用いることができる。効率や簡便性の観点から、光重合法を好ましく採用し得る。光重合によると、光の照射量（光量）等の重合条件によって、モノマー成分の重合転化率（モノマーコンバーション）を容易に制御することができる。 The photocurable pressure-sensitive adhesive composition according to some preferred embodiments contains a partial polymer of monomer components. Such a partial polymer is typically a mixture of a polymer derived from a monomer component and an unreacted monomer, and preferably exhibits a syrup-like (viscous liquid) form. Hereinafter, the partial polymer having such properties may be referred to as "monomer syrup" or simply "syrup". The polymerization method for partially polymerizing the monomer component is not particularly limited, and various polymerization methods as described above can be appropriately selected and used. From the viewpoint of efficiency and convenience, the photopolymerization method can be preferably adopted. According to photopolymerization, the polymerization conversion rate (monomer conversion) of the monomer component can be easily controlled by the polymerization conditions such as the irradiation amount of light (light amount).
　上記部分重合物におけるモノマー混合物の重合転化率は、特に限定されない。上記重合転化率は、例えば凡そ７０重量％以下とすることができ、凡そ６０重量％以下とすることが好ましい。上記部分重合物を含む粘着剤組成物の調製容易性や塗工性等の観点から、上記重合転化率は、凡そ５０重量％以下が適当であり、凡そ４０重量％以下（例えば凡そ３５重量％以下）が好ましい。重合転化率の下限は特に制限されないが、典型的には凡そ１重量％以上であり、凡そ５重量％以上とすることが適当である。 The polymerization conversion rate of the monomer mixture in the above partial polymer is not particularly limited. The polymerization conversion rate can be, for example, about 70% by weight or less, and preferably about 60% by weight or less. From the viewpoint of ease of preparation and coatability of the pressure-sensitive adhesive composition containing the partial polymer, the polymerization conversion rate is preferably about 50% by weight or less, and is about 40% by weight or less (for example, about 35% by weight). The following) is preferable. The lower limit of the polymerization conversion rate is not particularly limited, but is typically about 1% by weight or more, and it is appropriate to set it to about 5% by weight or more.
　モノマー成分の部分重合物を含む粘着剤組成物は、例えば、該粘着剤組成物の調製に用いられるモノマー成分の全量を含むモノマー混合物を適当な重合方法（例えば光重合法）により部分重合させることにより得ることができる。また、モノマー成分の部分重合物を含む粘着剤組成物は、該粘着剤組成物の調製に用いられるモノマー成分のうちの一部を含むモノマー混合物の部分重合物または完全重合物と、残りのモノマー成分またはその部分重合物との混合物であってもよい。なお、本明細書において「完全重合物」とは、重合転化率が９５重量％超であることをいう。 For the pressure-sensitive adhesive composition containing a partial polymer of the monomer component, for example, a monomer mixture containing the entire amount of the monomer component used for preparing the pressure-sensitive adhesive composition is partially polymerized by an appropriate polymerization method (for example, a photopolymerization method). Can be obtained by Further, the pressure-sensitive adhesive composition containing a partial polymer of the monomer component is a partial polymer or a complete polymer of a monomer mixture containing a part of the monomer components used in the preparation of the pressure-sensitive adhesive composition, and the remaining monomer. It may be a mixture with a component or a partial polymer thereof. In addition, in this specification, "complete polymer" means that the polymerization conversion rate is more than 95% by weight.
　上記部分重合物を含む粘着剤組成物には、必要に応じて用いられる他の成分（例えば、光重合開始剤、多官能モノマー、架橋剤、水親和剤等）が配合され得る。そのような他の成分を配合する方法は特に限定されず、例えば上記モノマー混合物にあらかじめ含有させてもよく、上記部分重合物に添加してもよい。 The pressure-sensitive adhesive composition containing the partial polymer may contain other components (for example, a photopolymerization initiator, a polyfunctional monomer, a cross-linking agent, a water affinity agent, etc.) used as necessary. The method of blending such other components is not particularly limited, and for example, it may be contained in the monomer mixture in advance, or may be added to the partial polymer.
　（架橋剤）
　粘着剤層（Ａ層）には、必要に応じて架橋剤が用いられ得る。換言すれば、粘着剤層（Ａ層）を形成するための粘着剤組成物Ａは、必要に応じて架橋剤を含有し得る。架橋剤は、典型的には架橋反応後の形態で粘着剤層（Ａ層）に含まれている。架橋剤を含む粘着剤組成物Ａから形成された粘着剤層（Ａ層）は、典型的には、架橋剤によって架橋された重合物（例えばアクリル系重合物）を含む。例えば、粘着剤層（Ａ層）は、架橋剤によって架橋されたアクリル系ポリマーを含む粘着剤層（Ａ層）であり得る。架橋剤の使用により、粘着剤層（Ａ層）の凝集力を適切に調節することができ、例えば光硬化前の粘着剤層（Ａ層）の凝集力等を適切に調節することができる。また、後述の光反応性化合物と架橋剤とを組み合わせて用いる態様においては、光硬化後の粘着剤層の密着耐久性や剥離強度等の特性を適切に調節することができる。 (Crosslinking agent)
A cross-linking agent may be used for the pressure-sensitive adhesive layer (layer A), if necessary. In other words, the pressure-sensitive adhesive composition A for forming the pressure-sensitive adhesive layer (layer A) may contain a cross-linking agent, if necessary. The cross-linking agent is typically contained in the pressure-sensitive adhesive layer (layer A) in the form after the cross-linking reaction. The pressure-sensitive adhesive layer (layer A) formed from the pressure-sensitive adhesive composition A containing a cross-linking agent typically contains a polymer cross-linked by the cross-linking agent (for example, an acrylic polymer). For example, the pressure-sensitive adhesive layer (layer A) can be a pressure-sensitive adhesive layer (layer A) containing an acrylic polymer crosslinked by a cross-linking agent. By using the cross-linking agent, the cohesive force of the pressure-sensitive adhesive layer (A layer) can be appropriately adjusted, and for example, the cohesive force of the pressure-sensitive adhesive layer (A layer) before photo-curing can be appropriately adjusted. Further, in the embodiment in which the photoreactive compound described later and the cross-linking agent are used in combination, characteristics such as adhesion durability and peel strength of the pressure-sensitive adhesive layer after photocuring can be appropriately adjusted.
　架橋剤の種類は特に制限されず、従来公知の架橋剤のなかから、例えば粘着剤組成物の組成に応じて、該架橋剤が粘着剤層内で適切な架橋機能を発揮するように選択することができる。用いられ得る架橋剤としては、イソシアネート系架橋剤、エポキシ系架橋剤、オキサゾリン系架橋剤、アジリジン系架橋剤、カルボジイミド系架橋剤、メラミン系架橋剤、尿素系架橋剤、金属アルコキシド系架橋剤、金属キレート系架橋剤、金属塩系架橋剤、ヒドラジン系架橋剤、アミン系架橋剤等を例示することができる。これらは１種を単独でまたは２種以上を組み合わせて用いることができる。水分散型粘着剤組成物においては、水に溶解または分散可能な架橋剤の使用が好ましい。 The type of the cross-linking agent is not particularly limited, and is selected from the conventionally known cross-linking agents so that the cross-linking agent exhibits an appropriate cross-linking function in the pressure-sensitive adhesive layer, for example, depending on the composition of the pressure-sensitive adhesive composition. be able to. Examples of the cross-linking agent that can be used include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, carbodiimide-based cross-linking agents, melamine-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, and metals. Examples thereof include a chelate-based cross-linking agent, a metal salt-based cross-linking agent, a hydrazine-based cross-linking agent, and an amine-based cross-linking agent. These can be used alone or in combination of two or more. In the water-dispersible pressure-sensitive adhesive composition, it is preferable to use a cross-linking agent that can be dissolved or dispersed in water.
　イソシアネート系架橋剤としては、２官能以上の多官能イソシアネート化合物を用いることができる。例えば、トリレンジイソシアネート、キシレンジイソシアネート、ポリメチレンポリフェニルジイソシアネート、トリス（ｐ－イソシアナトフェニル）チオホスフェート、ジフェニルメタンジイソシアネート等の芳香族イソシアネート；イソホロンジイソシアネート等の脂環族イソシアネート；ヘキサメチレンジイソシアネート等の脂肪族イソシアネート；等が挙げられる。市販品としては、トリメチロールプロパン／トリレンジイソシアネート３量体付加物（東ソー社製、商品名「コロネートＬ」）、トリメチロールプロパン／ヘキサメチレンジイソシアネート３量体付加物（東ソー社製、商品名「コロネートＨＬ」）、ヘキサメチレンジイソシアネートのイソシアヌレート体（東ソー社製、商品名「コロネートＨＸ」）、トリメチロールプロパン／キシリレンジイソシアネート付加物（三井化学社製、商品名「タケネートＤ－１１０Ｎ」）等のイソシアネート付加物等を例示することができる。水分散型の粘着剤組成物においては、水に溶解または分散可能なイソシアネート系架橋剤の使用が好ましい。例えば、水溶性、水分散性または自己乳化型のイソシアネート系架橋剤を好ましく採用し得る。イソシアネート基がブロックされた、いわゆるブロックドイソシアネート型のイソシアネート系架橋剤を好ましく使用し得る。 As the isocyanate-based cross-linking agent, a polyfunctional isocyanate compound having two or more functions can be used. For example, aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris (p-isocyanatophenyl) thiophosphate, diphenylmethane diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate. Isocyanate; etc. Commercially available products include trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Toso Co., Ltd., trade name "Coronate L") and trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Toso Co., Ltd., trade name "Coronate L"). Coronate HL "), isocyanurate of hexamethylene diisocyanate (manufactured by Toso Co., Ltd., trade name" Coronate HX "), trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals Co., Ltd., trade name" Takenate D-110N "), etc. Isocyanate adducts and the like can be exemplified. In the water-dispersible pressure-sensitive adhesive composition, it is preferable to use an isocyanate-based cross-linking agent that can be dissolved or dispersed in water. For example, a water-soluble, water-dispersible or self-emulsifying isocyanate-based cross-linking agent can be preferably adopted. A so-called blocked isocyanate type isocyanate-based cross-linking agent in which the isocyanate group is blocked can be preferably used.
　エポキシ系架橋剤としては、１分子中に２個以上のエポキシ基を有するものを特に制限なく用いることができる。１分子中に３～５個のエポキシ基を有するエポキシ系架橋剤が好ましい。エポキシ系架橋剤の具体例としては、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラグリシジル－ｍ－キシレンジアミン、１，３－ビス（Ｎ，Ｎ－ジグリシジルアミノメチル）シクロヘキサン、１，６－ヘキサンジオールジグリシジルエーテル、ポリエチレングリコールジグリシジルエーテル、ポリグリセロールポリグリシジルエーテル等が挙げられる。エポキシ系架橋剤の市販品としては、三菱ガス化学社製の商品名「ＴＥＴＲＡＤ－Ｘ」、「ＴＥＴＲＡＤ－Ｃ」、ＤＩＣ社製の商品名「エピクロンＣＲ－５Ｌ」、ナガセケムテックス社製の商品名「デナコールＥＸ－５１２」、日産化学工業社製の商品名「ＴＥＰＩＣ－Ｇ」等が挙げられる。 As the epoxy-based cross-linking agent, one having two or more epoxy groups in one molecule can be used without particular limitation. An epoxy-based cross-linking agent having 3 to 5 epoxy groups in one molecule is preferable. Specific examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, and 1,6-hexane. Examples thereof include diol diglycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerol polyglycidyl ether. Commercially available epoxy cross-linking agents include Mitsubishi Gas Chemical Company's product names "TETRAD-X" and "TETRAD-C", DIC's product name "Epicron CR-5L", and Nagase ChemteX's products. Examples thereof include the name "Denacol EX-512" and the product name "TEPIC-G" manufactured by Nissan Chemical Industries, Ltd.
　オキサゾリン系架橋剤としては、１分子内に１個以上のオキサゾリン基を有するものを特に制限なく使用することができる。
　アジリジン系架橋剤の例としては、トリメチロールプロパントリス［３－（１－アジリジニル）プロピオネート］、トリメチロールプロパントリス［３－（１－（２－メチル）アジリジニルプロピオネート）］等が挙げられる。
　カルボジイミド系架橋剤としては、カルボジイミド基を２個以上有する低分子化合物または高分子化合物を用いることができる。 As the oxazoline-based cross-linking agent, those having one or more oxazoline groups in one molecule can be used without particular limitation.
Examples of the aziridine-based cross-linking agent include trimethylolpropane tris [3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1- (2-methyl) aziridinyl propionate)], and the like. Be done.
As the carbodiimide-based cross-linking agent, a low molecular weight compound or a high molecular weight compound having two or more carbodiimide groups can be used.
　いくつかの態様において、架橋剤として過酸化物を用いてもよい。過酸化物としては、ジ（２－エチルヘキシル）パーオキシジカーボネート、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート、ジ－ｓｅｃ－ブチルパーオキシジカーボネート、ｔ－ブチルパーオキシネオデカノエート、ｔ－へキシルパーオキシピバレート、ｔ－ブチルパーオキシピバレート、ジラウロイルパーオキシド、ジ－ｎ－オクタノイルパーオキシド、１，１，３，３－テトラメチルブチルパーオキシイソブチレート、ジベンゾイルパーオキシド等が挙げられる。これらのなかでも、特に架橋反応効率に優れる過酸化物として、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカルボネート、ジラウロイルパーオキシド、ジベンゾイルパーオキシド等が挙げられる。なお、上記重合開始剤として過酸化物を使用した場合には、重合反応に使用されずに残存した過酸化物を架橋反応に使用することも可能である。その場合は過酸化物の残存量を定量して、過酸化物の割合が所定量に満たない場合には、必要に応じて、所定量になるように過酸化物を添加するとよい。過酸化物の定量は、日本国特許第４９７１５１７号公報に記載の方法により行うことができる。 Peroxide may be used as the cross-linking agent in some embodiments. Peroxides include di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, and t-butylperoxyneodecanoate. , T-hexyl peroxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxyisobutyrate, di Examples thereof include benzoyl peroxide. Among these, examples of the peroxide having particularly excellent cross-linking reaction efficiency include di (4-t-butylcyclohexyl) peroxydicarbonate, dilauroyl peroxide, and dibenzoyl peroxide. When a peroxide is used as the polymerization initiator, the peroxide remaining without being used in the polymerization reaction can be used in the crosslinking reaction. In that case, the residual amount of peroxide may be quantified, and if the ratio of peroxide is less than a predetermined amount, the peroxide may be added so as to be a predetermined amount, if necessary. The amount of peroxide can be quantified by the method described in Japanese Patent No. 4971517.
　架橋剤を使用する場合における使用量（２種以上の架橋剤を使用する場合にはそれらの合計量）は、特に限定されない。接着力や凝集力等の粘着特性をバランスよく発揮する粘着剤を実現する観点から、架橋剤の使用量は、粘着剤組成物Ａに含まれるモノマー成分（例えばアクリル系重合物のモノマー成分）１００重量部に対して、凡そ５重量部以下とすることが適当であり、３重量部以下としてもよく、２重量部以下としてもよく、１重量部以下としてもよく、１重量部未満としてもよい。光反応性化合物との組合せ使用による効果を好適に発揮しやすくする観点から、いくつかの態様において、上記モノマー成分１００重量部に対する架橋剤（例えば、イソシアネート系架橋剤）の使用量は、例えば０．５０重量部以下であってよく、０．４０重量部以下でもよく、０．３０重量部以下でもよく、０．２０重量部以下でもよい。架橋剤の使用量の下限は特に限定されず、上記モノマー成分１００重量部に対して０重量部より多い量であればよい。いくつかの態様において、架橋剤の使用量は、上記モノマー成分１００重量部に対して、例えば０．００１重量部以上とすることができ、０．０１重量部以上としてもよく、０．０５重量部以上としてもよく、０．１０重量部以上としてもよい。 The amount used when a cross-linking agent is used (when two or more kinds of cross-linking agents are used, the total amount thereof) is not particularly limited. From the viewpoint of realizing a pressure-sensitive adhesive that exhibits a well-balanced adhesive property such as adhesive strength and cohesive power, the amount of the cross-linking agent used is 100, which is a monomer component (for example, a monomer component of an acrylic polymer) contained in the pressure-sensitive adhesive composition A. It is appropriate that the amount is about 5 parts by weight or less with respect to the parts by weight, and it may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or less than 1 part by weight. .. In some embodiments, the amount of the cross-linking agent (for example, isocyanate-based cross-linking agent) used with respect to 100 parts by weight of the monomer component is 0, for example, from the viewpoint of facilitating the effect of using the photoreactive compound in combination. It may be .50 parts by weight or less, 0.40 parts by weight or less, 0.30 parts by weight or less, or 0.20 parts by weight or less. The lower limit of the amount of the cross-linking agent used is not particularly limited, and may be more than 0 parts by weight with respect to 100 parts by weight of the monomer component. In some embodiments, the amount of the cross-linking agent used may be, for example, 0.001 part by weight or more, 0.01 parts by weight or more, and 0.05 parts by weight, based on 100 parts by weight of the monomer component. It may be 10 parts by weight or more, and may be 0.10 parts by weight or more.
　架橋反応をより効果的に進行させるために、架橋触媒を用いてもよい。架橋触媒としては、テトラ－ｎ－ブチルチタネート、テトライソプロピルチタネート、ナーセム第二鉄、ブチルスズオキシド、ジオクチルスズジラウレート等の金属系架橋触媒等が例示される。なかでも、ジオクチルスズジラウレート等のスズ系架橋触媒が好ましい。架橋触媒の使用量は特に制限されない。架橋触媒の使用量は、粘着剤組成物Ａに含まれるモノマー成分（例えばアクリル系重合物のモノマー成分）１００重量部に対して、例えば凡そ０．０００１重量部以上、凡そ０．００１重量部以上、凡そ０．００５重量以上等とすることができ、また、凡そ１重量部以下、凡そ０．１重量部以下、凡そ０．０５重量部以下等とすることができる。 A cross-linking catalyst may be used to allow the cross-linking reaction to proceed more effectively. Examples of the cross-linking catalyst include metal-based cross-linking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric nasem, butyl tin oxide, and dioctyl tin dilaurate. Of these, tin-based cross-linking catalysts such as dioctyl tin dilaurate are preferable. The amount of the cross-linking catalyst used is not particularly limited. The amount of the cross-linking catalyst used is, for example, about 0.0001 parts by weight or more and about 0.001 parts by weight or more with respect to 100 parts by weight of the monomer component (for example, the monomer component of the acrylic polymer) contained in the pressure-sensitive adhesive composition A. It can be about 0.005 parts by weight or more, about 1 part by weight or less, about 0.1 parts by weight or less, about 0.05 parts by weight or less, and the like.
　粘着剤層（Ａ層）の形成に用いられる粘着剤組成物Ａには、所望により、架橋遅延剤として、ケト－エノール互変異性を生じる化合物を含有させることができる。例えば、イソシアネート系架橋剤を含む粘着剤組成物Ａまたはイソシアネート系架橋剤を配合して使用され得る粘着剤組成物Ａにおいて、ケト－エノール互変異性を生じる化合物を好ましく使用し得る。これにより、粘着剤組成物のポットライフを延長する効果が発揮され得る。
　ケト－エノール互変異性を生じる化合物としては、各種のβ－ジカルボニル化合物を用いることができる。具体例としては、アセチルアセトン、２，４－ヘキサンジオン等のβ－ジケトン類；アセト酢酸メチル、アセト酢酸エチル等のアセト酢酸エステル類；プロピオニル酢酸エチル等のプロピオニル酢酸エステル類；イソブチリル酢酸エチル等のイソブチリル酢酸エステル類；マロン酸メチル、マロン酸エチル等のマロン酸エステル類；等が挙げられる。なかでも好適な化合物として、アセチルアセトンおよびアセト酢酸エステル類が挙げられる。ケト－エノール互変異性を生じる化合物は、１種を単独でまたは２種以上を組み合わせて用いることができる。
　ケト－エノール互変異性を生じる化合物の使用量は、粘着剤組成物Ａに含まれるモノマー成分（例えばアクリル系重合物のモノマー成分）１００重量部に対して、例えば０．１重量部以上２０重量部以下であってよく、０．５重量部以上１５重量部以下とすることが適当であり、例えば１重量部以上１０重量部以下とすることができ、１重量部以上５重量部以下としてもよい。 If desired, the pressure-sensitive adhesive composition A used for forming the pressure-sensitive adhesive layer (layer A) can contain a compound that causes keto-enol tautomerism as a cross-linking retarder. For example, in the pressure-sensitive adhesive composition A containing an isocyanate-based cross-linking agent or the pressure-sensitive adhesive composition A that can be used by blending an isocyanate-based cross-linking agent, a compound that causes keto-enol tvariability can be preferably used. As a result, the effect of extending the pot life of the pressure-sensitive adhesive composition can be exhibited.
Various β-dicarbonyl compounds can be used as the compound that causes keto-enol telecommunication. Specific examples include β-diketones such as acetylacetone and 2,4-hexanedione; acetoacetate esters such as methyl acetoacetate and ethyl acetoacetate; propionyl acetates such as ethyl propionyl acetate; isobutyryl such as ethyl isobutylyl acetate. Acetic acid esters; malonic acid esters such as methyl malonate and ethyl malonate; and the like. Among them, acetylacetone and acetoacetic ester are preferable compounds. The compounds that cause keto-enol tautomerism can be used alone or in combination of two or more.
The amount of the compound that causes keto-enol remutability is, for example, 0.1 part by weight or more and 20 parts by weight with respect to 100 parts by weight of the monomer component (for example, the monomer component of the acrylic polymer) contained in the pressure-sensitive adhesive composition A. It may be 5 parts by weight or less, and may be 0.5 parts by weight or more and 15 parts by weight or less, for example, 1 part by weight or more and 10 parts by weight or less, and 1 part by weight or more and 5 parts by weight or less. Good.
　（光反応性化合物）
　ここに開示される技術は、粘着剤層が光硬化性粘着剤層（光硬化可能な状態の粘着剤層）である形態、光硬化型粘着剤層（光硬化後の粘着剤層）である形態のいずれの形態でも、所定の剥離強度特性や水剥離力低下率特性を満足する態様で実施され得る。このような態様において、粘着剤層（Ａ層）を形成するための粘着剤組成物Ａは、光反応性化合物を含有し得る。いくつかの態様では、粘着剤層（Ａ層）は光反応性化合物を含有し得る。光反応性化合物としては、２個以上のエチレン性不飽和基を分子内に有する化合物が用いられる。また、いくつかの好ましい態様に係る光反応性化合物は、２個以上のエチレン性不飽和基と、オキシアルキレン構造単位と、を分子内に有する。粘着剤層（Ａ層）に含まれる光反応性化合物は、粘着剤層（Ａ層）を基材層に積層した後に光（例えば紫外線）照射等により上記エチレン性不飽和基を反応させることで、適度な柔軟性を有する架橋構造を形成し得る。したがって、いくつかの態様において、光反応性化合物は、粘着剤層（Ａ層）内において反応した状態で存在し得る。他のいくつかの態様では、光反応性化合物は、粘着剤層（Ａ層）内において、後述するように遊離の状態（未反応であり得る。）で存在し得る。これにより、粘着剤層（Ａ層）の基材層に対する剥離強度（投錨性）の低下を抑制しつつ、耐久性を効果的に向上させることができる。光反応性化合物は、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Photoreactive compound)
The technology disclosed herein is a form in which the pressure-sensitive adhesive layer is a photo-curable pressure-sensitive adhesive layer (photo-curable pressure-sensitive adhesive layer), and a photo-curable pressure-sensitive adhesive layer (photo-curable pressure-sensitive adhesive layer). In any of the forms, it can be carried out in a manner that satisfies a predetermined peeling strength characteristic and a water peeling force reduction rate characteristic. In such an embodiment, the pressure-sensitive adhesive composition A for forming the pressure-sensitive adhesive layer (layer A) may contain a photoreactive compound. In some embodiments, the pressure-sensitive adhesive layer (layer A) may contain a photoreactive compound. As the photoreactive compound, a compound having two or more ethylenically unsaturated groups in the molecule is used. In addition, the photoreactive compound according to some preferred embodiments has two or more ethylenically unsaturated groups and an oxyalkylene structural unit in the molecule. The photoreactive compound contained in the pressure-sensitive adhesive layer (layer A) is formed by laminating the pressure-sensitive adhesive layer (layer A) on the base material layer and then reacting the ethylenically unsaturated group with light (for example, ultraviolet rays) irradiation or the like. , A crosslinked structure having moderate flexibility can be formed. Therefore, in some embodiments, the photoreactive compound may be present in a reacted state within the pressure-sensitive adhesive layer (layer A). In some other aspects, the photoreactive compound may be present in the pressure-sensitive adhesive layer (layer A) in a free state (which may be unreacted), as described below. As a result, the durability of the pressure-sensitive adhesive layer (layer A) can be effectively improved while suppressing a decrease in peel strength (anchorability) with respect to the base material layer. The photoreactive compound may be used alone or in combination of two or more.
　上記エチレン性不飽和基の例には、アクリロイル基、メタクリロイル基、ビニル基およびアリル基が含まれるが、これらに限定されない。光反応性化合物が分子内に有する２個以上のエチレン不飽和基は、互いに同一の基であってもよく、２種以上の異なる基であってもよい。光反応性の観点から好ましいエチレン性不飽和基として、アクリロイル基およびメタクリロイル基が挙げられる。なかでもアクリロイル基が好ましい。 Examples of the ethylenically unsaturated group include, but are not limited to, an acryloyl group, a methacryloyl group, a vinyl group and an allyl group. The two or more ethylene unsaturated groups that the photoreactive compound has in the molecule may be the same group or two or more different groups. Preferred ethylenically unsaturated groups from the viewpoint of photoreactivity include acryloyl group and methacryloyl group. Of these, the acryloyl group is preferable.
　上記オキシアルキレン構造単位（ＡＯ単位）とは、一般式（Ｕ１）：－ＡＯ－；で表される構造単位をいい、典型的には一般式（Ｕ２）：－ＣｍＨ２ｍＯ－；で表される構造単位をいう。ここで、上記一般式（Ｕ１）中のＡは、典型的には炭素原子数２以上のアルキレン基であり、好ましくは炭素原子数２～４のアルキレン基である。上記式（Ｕ２）中のｍは、２以上の整数であり、好ましくは２～４の整数、より好ましくは２～３の整数である。ＡＯ単位の好適例として、オキシエチレン単位およびオキシプロピレン単位が挙げられる。このようなＡＯ単位は、例えば、アルキレンオキサイドまたはアルキレングリコールによる変性（付加反応）により形成され得る。 The oxyalkylene structural unit (AO unit) refers to a structural unit represented by the general formula (U1): -AO- ;, and is typically represented by the general formula (U2): -C m H 2 m O- ;. The structural unit represented. Here, A in the general formula (U1) is typically an alkylene group having 2 or more carbon atoms, preferably an alkylene group having 2 to 4 carbon atoms. M in the above formula (U2) is an integer of 2 or more, preferably an integer of 2 to 4, and more preferably an integer of 2 to 3. Preferable examples of AO units include oxyethylene units and oxypropylene units. Such AO units can be formed, for example, by modification (addition reaction) with an alkylene oxide or an alkylene glycol.
　光反応性化合物は、上記一般式（Ｕ１）で表されるＡＯ単位が２以上連続する繰返し構造、すなわち一般式：－（ＡＯ）ｎ－；で表される構造を含む化合物であってもよい。ここで、上記式中のｎは２以上の整数であり、例えば２～１０の整数、好ましくは２～５の整数、より好ましくは２～３の整数である。あるいは、光反応性化合物は、ＡＯ単位が２以上連続する繰返し構造を含まない化合物（２以上のＡＯ単位を不連続に含む化合物であり得る。）であってもよい。このような光反応性化合物によると、凝集性と架橋の柔軟性とのバランスのよい粘着剤層（Ａ層）が効率よく形成され得る。 The photoreactive compound may be a compound containing a repeating structure in which two or more AO units represented by the general formula (U1) are continuous, that is, a structure represented by the general formula:-(AO) n- ;. .. Here, n in the above equation is an integer of 2 or more, for example, an integer of 2 to 10, preferably an integer of 2 to 5, and more preferably an integer of 2 to 3. Alternatively, the photoreactive compound may be a compound that does not contain a repeating structure in which two or more AO units are continuous (it may be a compound that discontinuously contains two or more AO units). According to such a photoreactive compound, a pressure-sensitive adhesive layer (layer A) having a good balance between cohesiveness and crosslinking flexibility can be efficiently formed.
　光反応性化合物は、一のエチレン性不飽和基と他のいずれか一のエチレン性不飽和基との間に、少なくとも１個、好ましくは２個以上（例えば２個～４個程度）のＡＯ単位が配置された分子構造を有していることがより好ましい。上記２個以上のＡＯ単位は、隣接して－（ＡＯ）ｎ－構造を形成していてもよく、隣接していなくてもよい。
　いくつかの態様において、光反応性化合物としては、該光反応性化合物に含まれるエチレン性不飽和基の少なくとも一部に隣接してＡＯ単位が配置された分子構造を有していることが好ましい。エチレン性不飽和基（例えば、（メタ）アクリロイル基）に隣接して配置されたＡＯ単位は、該エチレン性不飽和基の反応により形成される架橋構造の柔軟化に効果的に貢献し得ると考えられる。いくつかの態様において、分子内に含まれるエチレン性不飽和基のうち、５０個数％以上、より好ましくは７５個数％以上、例えば実質的に１００個数％のエチレン性不飽和基に、ＡＯ単位が隣接して配置されている光反応性化合物を好ましく採用し得る。 The photoreactive compound contains at least one, preferably two or more (for example, about 2 to 4) AOs between one ethylenically unsaturated group and any one of the other ethylenically unsaturated groups. It is more preferable to have a molecular structure in which units are arranged. The two or more AO units may or may not be adjacent to each other to form a − (AO) n − structure.
In some embodiments, the photoreactive compound preferably has a molecular structure in which AO units are arranged adjacent to at least a portion of the ethylenically unsaturated groups contained in the photoreactive compound. .. AO units placed adjacent to an ethylenically unsaturated group (eg, a (meth) acryloyl group) can effectively contribute to the softening of the crosslinked structure formed by the reaction of the ethylenically unsaturated group. Conceivable. In some embodiments, among the ethylenically unsaturated groups contained in the molecule, 50% or more, more preferably 75% or more, for example, substantially 100% of the ethylenically unsaturated groups have an AO unit. Adjacently arranged photoreactive compounds may be preferably employed.
　光反応性化合物としては、分子内に２～１０個のエチレン性不飽和基を有する化合物が好ましく、分子内に２～８個のエチレン性不飽和基を有する化合物がより好ましく、分子内に２～６個のエチレン性不飽和基を有する化合物がさらに好ましい。いくつかの態様において、光反応性化合物として、分子内に３個以上（典型的には３～８個、例えば３～６個）のエチレン性不飽和基を有する化合物を用いることができる。分子内に３個以上のエチレン性不飽和基を有する光反応性化合物を粘着剤層（Ａ層）に含有させることにより、該粘着剤層（Ａ層）の硬化後における基材層への密着の耐久性を効率よく（例えば、比較的少量の光反応性化合物によっても十分に）向上させ得る。このことは、ここに開示される積層体の加工性や取扱い性等の観点から有利となり得る。他のいくつかの態様において、光反応性化合物として、分子内に２個のエチレン性不飽和基を有する化合物を用いることができる。これにより、より高い剥離強度を示す粘着剤が実現され得る。いくつかの好ましい態様では、光反応性化合物として、分子内に３個以上（典型的には３～８個、例えば３～６個）のエチレン性不飽和基を有する化合物と、分子内に２個のエチレン性不飽和基を有する化合物とが併用される。 As the photoreactive compound, a compound having 2 to 10 ethylenically unsaturated groups in the molecule is preferable, a compound having 2 to 8 ethylenically unsaturated groups in the molecule is more preferable, and 2 in the molecule is preferable. Compounds having up to 6 ethylenically unsaturated groups are more preferred. In some embodiments, the photoreactive compound can be a compound having 3 or more (typically 3-8, eg 3-6) ethylenically unsaturated groups in the molecule. By incorporating a photoreactive compound having three or more ethylenically unsaturated groups in the molecule into the pressure-sensitive adhesive layer (layer A), the pressure-sensitive adhesive layer (layer A) adheres to the base material layer after curing. Durability can be efficiently improved (eg, even with a relatively small amount of photoreactive compound). This can be advantageous from the viewpoint of processability, handleability, and the like of the laminate disclosed herein. In some other embodiments, the photoreactive compound can be a compound having two ethylenically unsaturated groups in the molecule. Thereby, a pressure-sensitive adhesive showing higher peel strength can be realized. In some preferred embodiments, the photoreactive compound comprises a compound having 3 or more (typically 3-8, eg 3-6) ethylenically unsaturated groups in the molecule and 2 in the molecule. A compound having an ethylenically unsaturated group is used in combination.
　分子内に３個以上のエチレン性不飽和基を有する光反応性化合物としては、例えばエトキシ化ペンタエリスリトールトリ（メタ）アクリレート、エトキシ化ペンタエリスリトールテトラ（メタ）アクリレート、エトキシ化ジペンタエリスリトールペンタ（メタ）アクリレート、エトキシ化ジペンタエリスリトールヘキサ（メタ）アクリレート、トリメチロールプロパントリオキシエチル（メタ）アクリレートやトリメチロールプロパンポリオキシエチル（メタ）アクリレート等のエチレンオキサイド（ＥＯ）変性トリメチロールプロパントリ（メタ）アクリレート、トリメチロールプロパントリオキシプロピル（メタ）アクリレートやトリメチロールプロパンポリオキシプロピル（メタ）アクリレート等のプロピレンオキサイド（ＰＯ）変性トリメチロールプロパントリ（メタ）アクリレート、等が挙げられるが、これらに限定されない。分子内に２個のエチレン性不飽和基を有する光反応性化合物としては、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ＥＯ変性ビスフェノールＡジ（メタ）アクリレート、ＥＯ変性ビスフェノールＦジ（メタ）アクリレート、ＰＯ変性ビスフェノールＡジ（メタ）アクリレート、ＰＯ変性ビスフェノールＦジ（メタ）アクリレート、等が挙げられるが、これらに限定されない。 Examples of the photoreactive compound having three or more ethylenically unsaturated groups in the molecule include ethoxylated pentaerythritol trimethylolpropane (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, and ethoxylated dipentaerythritol penta (meth). ) Acrylate, Dipentaerythritol hexa (meth) acrylate, trimethylolpropane Trioxyethyl (meth) acrylate, trimethylolpropane polyoxyethyl (meth) acrylate, and other ethylene oxide (EO) -modified trimethylolpropane tri (meth) Examples thereof include, but are not limited to, acrylate, propylene oxide (PO) -modified trimethylolpropane tri (meth) acrylate such as trimethylolpropane trioxypropyl (meth) acrylate and trimethylolpropane polyoxypropyl (meth) acrylate. .. Examples of the photoreactive compound having two ethylenically unsaturated groups in the molecule include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, and EO-modified bisphenol F. Examples thereof include, but are not limited to, di (meth) acrylate, PO-modified bisphenol A di (meth) acrylate, and PO-modified bisphenol F di (meth) acrylate.
　光反応性化合物の分子量は、特に限定されず、所望の効果が好適に発揮されるように選択し得る。例えば、光反応性化合物としては、分子量が凡そ２５００以下であるものを用いることができる。粘着剤組成物Ａの調製容易性等の観点から、いくつかの態様において、光反応性化合物の分子量は、例えば２０００以下であってよく、１５００以下でもよく、１０００以下でもよい。光反応性化合物の分子量は、典型的には２００以上である。加工性や取扱い性等の観点から、いくつかの態様において、光反応性化合物の分子量は、例えば２３０以上であってよく、３００以上でもよく、３５０以上でもよく、４５０以上でもよく、５００以上でもよく、５５０以上でもよい。
　なお、上記光反応性化合物の分子量は、例えばＧＰＣ法により標準ポリスチレン換算の重量平均分子量（Ｍｗ）として得ることができる。あるいは、光反応性化合物の分子量として、メーカー公称値または分子構造から算出される分子量を採用してもよい。 The molecular weight of the photoreactive compound is not particularly limited and can be selected so as to preferably exert the desired effect. For example, as the photoreactive compound, a compound having a molecular weight of about 2500 or less can be used. From the viewpoint of ease of preparation of the pressure-sensitive adhesive composition A and the like, in some embodiments, the molecular weight of the photoreactive compound may be, for example, 2000 or less, 1500 or less, or 1000 or less. The molecular weight of the photoreactive compound is typically 200 or more. From the viewpoint of processability, handleability, etc., in some embodiments, the molecular weight of the photoreactive compound may be, for example, 230 or more, 300 or more, 350 or more, 450 or more, or 500 or more. It may be 550 or more.
The molecular weight of the photoreactive compound can be obtained, for example, by the GPC method as a weight average molecular weight (Mw) in terms of standard polystyrene. Alternatively, as the molecular weight of the photoreactive compound, the molecular weight calculated from the manufacturer's nominal value or the molecular structure may be adopted.
　粘着剤層（Ａ層）に含まれる光反応性化合物の量は特に限定されず、目的とする性能に応じて適切に設定することができる。いくつかの態様において、粘着剤組成物Ａや粘着剤層（Ａ層）における光反応性化合物の含有量は、該粘着剤層（Ａ層）に含まれる重合物（典型的にはアクリル系重合物、例えばアクリル系ポリマー）のモノマー成分１００重量部に対して、例えば０．５重量部以上であってよく、１重量部以上が適当であり、２重量部以上でもよく、３重量部以上でもよく、４重量部以上でもよい。光反応性化合物の含有量の増大により、光硬化後における粘着剤層（Ａ層）の基材層への密着耐久性は向上する傾向にある。また、上記モノマー成分１００重量部に対する光反応性化合物の含有量は、例えば３０重量部以下とすることができ、加工性等の観点から、２０重量部未満とすることが適当であり、１５重量部未満とすることが好ましい。過度の架橋による剥離強度の低下を避ける観点から、いくつかの態様において、上記モノマー成分１００重量部に対する光反応性化合物の含有量は、例えば１０重量部未満であってよく、８．０重量部未満でもよく、６．０重量部未満でもよい。 The amount of the photoreactive compound contained in the pressure-sensitive adhesive layer (layer A) is not particularly limited, and can be appropriately set according to the desired performance. In some embodiments, the content of the photoreactive compound in the pressure-sensitive adhesive composition A or the pressure-sensitive adhesive layer (layer A) is a polymer (typically an acrylic polymerization) contained in the pressure-sensitive adhesive layer (layer A). For 100 parts by weight of the monomer component of a product (for example, an acrylic polymer), for example, it may be 0.5 parts by weight or more, 1 part by weight or more is suitable, 2 parts by weight or more, or 3 parts by weight or more. It may be 4 parts by weight or more. As the content of the photoreactive compound increases, the adhesion durability of the pressure-sensitive adhesive layer (layer A) to the base material layer after photocuring tends to improve. Further, the content of the photoreactive compound with respect to 100 parts by weight of the monomer component can be, for example, 30 parts by weight or less, and from the viewpoint of processability and the like, it is appropriate to be less than 20 parts by weight, and 15 parts by weight. It is preferably less than a portion. From the viewpoint of avoiding a decrease in peel strength due to excessive cross-linking, in some embodiments, the content of the photoreactive compound with respect to 100 parts by weight of the monomer component may be, for example, less than 10 parts by weight, and 8.0 parts by weight. It may be less than 6.0 parts by weight.
　光反応性化合物は、粘着剤層（Ａ層）形成前の粘着剤組成物Ａおよび光硬化性粘着剤層（Ａ層）内においては遊離の形態で存在しており、光硬化後の粘着剤層（Ａ層）においては、粘着剤層中の他の成分（例えばアクリル系ポリマー）と化学結合していることが好ましい。上記化学結合は、例えば、光反応性化合物が分子内に有するエチレン性不飽和基以外の官能基Ｆ１と、上記他の成分が分子内に有する官能基であって上記官能基Ｆ１と反応可能な官能基Ｆ２との反応により形成され得る。上記反応は、例えば後述の光反応触媒を粘着剤層（Ａ層）内に存在させて、光硬化処理を行うことにより好適に進行させ得る。このような粘着剤層（Ａ層）は、光反応性化合物を遊離の形態で含む粘着剤組成物Ａを用いて好適に形成することができる。ここで「遊離の形態」とは、光反応性化合物が、粘着剤層（Ａ層）または粘着剤組成物Ａに含まれる他の成分（例えば、アクリル系ポリマー）と化学結合していないことをいう。光反応性化合物を遊離の形態で含む粘着剤組成物Ａは、調製容易性やゲル化抑制の観点から有利となり得る。 The photoreactive compound exists in the pressure-sensitive adhesive composition A before the formation of the pressure-sensitive adhesive layer (layer A) and the photo-curable pressure-sensitive adhesive layer (layer A) in a free form, and the pressure-sensitive adhesive after photo-curing. The layer (A layer) is preferably chemically bonded to other components (for example, an acrylic polymer) in the pressure-sensitive adhesive layer. The chemical bond is, for example, a functional group F1 other than the ethylenically unsaturated group that the photoreactive compound has in the molecule, and a functional group that the other component has in the molecule and can react with the functional group F1. It can be formed by reaction with the functional group F2. The above reaction can be suitably proceeded by, for example, allowing a photoreaction catalyst described later to exist in the pressure-sensitive adhesive layer (layer A) and performing a photocuring treatment. Such a pressure-sensitive adhesive layer (layer A) can be suitably formed by using a pressure-sensitive adhesive composition A containing a photoreactive compound in a free form. Here, the "free form" means that the photoreactive compound is not chemically bonded to the pressure-sensitive adhesive layer (layer A) or other components (for example, an acrylic polymer) contained in the pressure-sensitive adhesive composition A. Say. The pressure-sensitive adhesive composition A containing the photoreactive compound in a free form can be advantageous from the viewpoint of ease of preparation and suppression of gelation.
　粘着剤組成物Ａおよび光硬化性粘着剤層（Ａ層）は、分子内に２個以上のエチレン性不飽和基を有し、かつ光反応性化合物に該当しない１種または２種以上のその他の光反応性化合物を含んでいてもよい。その他の光反応性化合物の例には、分子内に２個以上のエチレン性不飽和基を有し、かつＡＯ造単位を有しない化合物；分子内に２個以上のエチレン性不飽和基を有し、該エチレン性不飽和基１個当たりの分子量が２５０より大きく、かつＡＯ単位を有する化合物；分子内に２個以上のエチレン性不飽和基を有し、該エチレン性不飽和基１個当たりの分子量が２５０より大きく、かつＡＯ単位を有しない化合物；等が含まれる。その他の光反応性化合物に該当する化合物の具体例としては、ペンタエリスリトールトリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ジトリメチロールプロパンテトラ（メタ）アクリレート、トリメチロールエタントリ（メタ）アクリレート、テトラメチロールメタントリ（メタ）アクリレート、トリス（２－ヒドロキシエチル）イソシアヌレートジ（メタ）アクリレート、トリス（２－ヒドロキシエチル）イソシアヌレートトリ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ヒドロキシピバリン酸ネオペンチルグリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、アリル（メタ）アクリレート、ビニル（メタ）アクリレート、ジビニルベンゼン、ハイドロキノンジ（メタ）アクリレート、レゾルシンジ（メタ）アクリレート、トリシクロデカンジメタノールジ（メタ）アクリレート、等が含まれるが、これらに限定されない。粘着剤組成物Ａや粘着剤層（Ａ層）におけるその他の光反応性化合物の含有量は、特に限定されない。いくつかの態様において、粘着剤組成物Ａや粘着剤層（Ａ層）におけるその他の光反応性化合物の含有量は、該粘着剤層（Ａ層）に含まれる重合物（典型的にはアクリル系重合物、例えばアクリル系ポリマー）のモノマー成分１００重量部に対して、例えば０．０１重量部以上であってよく、０．１重量部以上が適当であり、１重量部以上でもよい。また、上記モノマー成分１００重量部に対するその他の光反応性化合物の含有量は、例えば１０重量部以下とすることができ、５重量部未満とすることが適当であり、３重量部未満とすることが好ましい。上記光反応性化合物とその他の光反応性化合物とを併用する態様では、粘着剤組成物Ａや粘着剤層（Ａ層）におけるその他の光反応性化合物の含有量は、重量基準で、例えば、光反応性化合物の含有量の０．９倍以下であってよく、０．５倍以下とすることが適当であり、０．２倍以下でもよく、０．１倍以下でもよい。ここに開示される技術は、粘着剤組成物Ａや粘着剤層（Ａ層）がその他の光反応性化合物を実質的に含有しない形態で実施され得る。ここで、その他の光反応性化合物を実質的に含有しないとは、少なくとも意図的にはその他の光反応性化合物を使用しないことを意味し、例えば粘着剤組成物Ａの調製に用いられる材料中の不純物または副成分としてその他の光反応性化合物に該当する化合物が非意図的に少量混入することは許容され得る。その他の光反応性化合物は、粘着剤層（Ａ層）形成前の粘着剤組成物Ａおよび光硬化性粘着剤層（Ａ層）内においては遊離の形態で存在しており、光硬化後の粘着剤層（Ａ層）においては、粘着剤層中の他の成分（例えばアクリル系ポリマー）と化学結合していることが好ましい。 The pressure-sensitive adhesive composition A and the photocurable pressure-sensitive adhesive layer (layer A) have one or more other ethylenically unsaturated groups in the molecule and do not correspond to a photoreactive compound. May contain a photoreactive compound of. Examples of other photoreactive compounds are compounds having two or more ethylenically unsaturated groups in the molecule and no AO building units; having two or more ethylenically unsaturated groups in the molecule. A compound having an AO unit having a molecular weight of more than 250 per ethylenically unsaturated group; having two or more ethylenically unsaturated groups in the molecule and per one ethylenically unsaturated group. Compounds having a molecular weight of more than 250 and having no AO unit; etc. are included. Specific examples of compounds corresponding to other photoreactive compounds include pentaerythritol trimethylolpropane (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and dipentaerythritol penta (meth) acrylate. Dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane tetra (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tris (2-hydroxy) Ethyl) isocyanurate di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, pentaerythritol di ( Includes meth) acrylates, allyl (meth) acrylates, vinyl (meth) acrylates, divinylbenzene, hydroquinone di (meth) acrylates, resorcindi (meth) acrylates, tricyclodecanedimethanol di (meth) acrylates, etc. Not limited to. The content of the pressure-sensitive adhesive composition A and the other photoreactive compounds in the pressure-sensitive adhesive layer (layer A) is not particularly limited. In some embodiments, the content of the pressure-sensitive adhesive composition A and the other photoreactive compounds in the pressure-sensitive adhesive layer (layer A) is a polymer (typically acrylic) contained in the pressure-sensitive adhesive layer (layer A). For example, it may be 0.01 part by weight or more, 0.1 part by weight or more is suitable, and 1 part by weight or more may be used with respect to 100 parts by weight of the monomer component of the system polymer (for example, acrylic polymer). Further, the content of the other photoreactive compound with respect to 100 parts by weight of the monomer component can be, for example, 10 parts by weight or less, preferably less than 5 parts by weight, and less than 3 parts by weight. Is preferable. In the embodiment in which the photoreactive compound and the other photoreactive compound are used in combination, the content of the other photoreactive compound in the pressure-sensitive adhesive composition A and the pressure-sensitive adhesive layer (layer A) is determined by weight, for example. The content of the photoreactive compound may be 0.9 times or less, preferably 0.5 times or less, 0.2 times or less, or 0.1 times or less. The technique disclosed herein can be carried out in a form in which the pressure-sensitive adhesive composition A and the pressure-sensitive adhesive layer (layer A) substantially do not contain other photoreactive compounds. Here, substantially free of other photoreactive compounds means that other photoreactive compounds are not used at least intentionally, for example, in the material used for preparing the pressure-sensitive adhesive composition A. It is permissible to unintentionally mix a small amount of a compound corresponding to other photoreactive compounds as an impurity or a subcomponent of the above. The other photoreactive compounds are present in the pressure-sensitive adhesive composition A before the formation of the pressure-sensitive adhesive layer (layer A) and the photo-curable pressure-sensitive adhesive layer (layer A) in a free form, and are present in a free form after photo-curing. In the pressure-sensitive adhesive layer (layer A), it is preferable that the pressure-sensitive adhesive layer (A layer) is chemically bonded to other components (for example, an acrylic polymer) in the pressure-sensitive adhesive layer.
　（光反応触媒）
　ここに開示される粘着剤組成物Ａおよび光硬化性粘着剤層（Ａ層）には、光硬化性の向上または付与等を目的として、必要に応じて光反応触媒（光反応開始剤）を含有させることができる。光反応触媒としては、例えば、ケタール系光反応開始剤、アセトフェノン系光反応開始剤、ベンゾインエーテル系光反応開始剤、アシルホスフィンオキサイド系光反応開始剤、α－ケトール系光反応開始剤、芳香族スルホニルクロリド系光反応開始剤、光活性オキシム系光反応開始剤、ベンゾイン系光反応開始剤、ベンジル系光反応開始剤、ベンゾフェノン系光反応開始剤、チオキサントン系光反応開始剤等を用いることができる。光反応触媒は、１種を単独でまたは２種以上を適宜組み合わせて用いることができる。 (Photoreaction catalyst)
The pressure-sensitive adhesive composition A and the photocurable pressure-sensitive adhesive layer (layer A) disclosed herein are provided with a photoreaction catalyst (photoreaction initiator), if necessary, for the purpose of improving or imparting photocurability. It can be contained. Examples of the photoreaction catalyst include a ketal-based photochemical reaction initiator, an acetophenone-based photochemical reaction initiator, a benzoin ether-based photochemical reaction initiator, an acylphosphine oxide-based photochemical reaction initiator, an α-ketol-based photochemical reaction initiator, and an aromatic. A sulfonyl chloride photochemical initiator, a photoactive oxime photochemical initiator, a benzoin photochemical initiator, a benzyl photochemical initiator, a benzophenone photochemical initiator, a thioxanthone photochemical initiator, and the like can be used. .. As the photoreaction catalyst, one type can be used alone or two or more types can be used in combination as appropriate.
　ケタール系光反応開始剤の具体例には、２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン等が含まれる。
　アセトフェノン系光反応開始剤の具体例には、１－ヒドロキシシクロヘキシル－フェニル－ケトン、４－フェノキシジクロロアセトフェノン、４－ｔ－ブチル－ジクロロアセトフェノン、１－［４－(２－ヒドロキシエトキシ)－フェニル］－２－ヒドロキシ－２－メチル－１－プロパン－１－オン、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、メトキシアセトフェノン等が含まれる。
　ベンゾインエーテル系光反応開始剤の具体例には、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインプロピルエーテル、ベンゾインイソプロピルエーテル、ベンゾインイソブチルエーテル等のベンゾインエーテルおよびアニソールメチルエーテル等の置換ベンゾインエーテルが含まれる。
　アシルホスフィンオキサイド系光反応開始剤の具体例には、ビス（２，４，６－トリメチルベンゾイル）フェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２，４－ジ－ｎ－ブトキシフェニルホスフィンオキシド、２，４，６－トリメチルベンゾイルジフェニルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－２，４，４－トリメチルペンチルホスフィンオキシド等が含まれる。
　α－ケトール系光反応開始剤の具体例には、２－メチル－２－ヒドロキシプロピオフェノン、１－［４－（２－ヒドロキシエチル）フェニル］－２－メチルプロパン－１－オン等が含まれる。芳香族スルホニルクロリド系光反応開始剤の具体例には、２－ナフタレンスルホニルクロライド等が含まれる。光活性オキシム系光反応開始剤の具体例には、１－フェニル－１，１－プロパンジオン－２－（ｏ－エトキシカルボニル）－オキシム等が含まれる。ベンゾイン系光反応開始剤の具体例にはベンゾイン等が含まれる。ベンジル系光反応開始剤の具体例にはベンジル等が含まれる。
　ベンゾフェノン系光反応開始剤の具体例には、ベンゾフェノン、ベンゾイル安息香酸、３，３’－ジメチル－４－メトキシベンゾフェノン、ポリビニルベンゾフェノン、α－ヒドロキシシクロヘキシルフェニルケトン等が含まれる。
　チオキサントン系光反応開始剤の具体例には、チオキサントン、２－クロロチオキサントン、２－メチルチオキサントン、２，４－ジメチルチオキサントン、イソプロピルチオキサントン、２，４－ジクロロチオキサントン、２，４－ジエチルチオキサントン、イソプロピルチオキサントン、２，４－ジイソプロピルチオキサントン、ドデシルチオキサントン等が含まれる。 Specific examples of the ketal-based photoreaction initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one and the like.
Specific examples of the acetophenone-based photoreaction initiator include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- (2-hydroxyethoxy) -phenyl]. -2-Hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, methoxyacetophenone and the like are included.
Specific examples of the benzoin ether-based photoreaction initiator include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether and benzoin isobutyl ether, and substituted benzoin ethers such as anisole methyl ether.
Specific examples of acylphosphine oxide-based photoreaction initiators include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxy. Includes phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like.
Specific examples of the α-ketol-based photoreaction initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and the like. Is done. Specific examples of the aromatic sulfonyl chloride-based photoreaction initiator include 2-naphthalene sulfonyl chloride and the like. Specific examples of the photoactive oxime-based photoreaction initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime and the like. Specific examples of the benzoin-based photoreaction initiator include benzoin and the like. Specific examples of the benzyl-based photoreaction initiator include benzyl and the like.
Specific examples of the benzophenone-based photoreaction initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenylketone and the like.
Specific examples of the thioxanthone-based photoreaction initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and isopropylthioxanthone. , 2,4-Diisopropylthioxanthone, dodecylthioxanthone and the like.
　粘着剤層（Ａ層）における光反応触媒の含有量は、特に限定されず、所望の効果が適切に発揮されるように設定することができる。いくつかの態様において、光反応触媒の含有量は、粘着剤層に含まれる重合物（典型的にはアクリル系重合物）のモノマー成分１００重量部に対して、例えば凡そ０．００５重量部以上とすることができ、０．０１重量部以上とすることが適当であり、０．０５重量部以上とすることが好ましく、０．１０重量部以上としてもよく、０．１５重量部以上としてもよく、０．２０重量部以上としてもよい。光反応触媒の含有量の増大により、粘着剤層（Ａ層）の光硬化性が向上する。また、上記モノマー成分１００重量部に対する光反応触媒の含有量は、５重量部以下とすることが適当であり、２重量部以下とすることが好ましく、１重量部以下としてもよく、０．７重量部以下としてもよく、０．５重量部以下としてもよい。光反応触媒の含有量が多すぎないことは、積層体の保存安定性（例えば、光劣化に対する安定性）向上の観点から有利となり得る。 The content of the photoreaction catalyst in the pressure-sensitive adhesive layer (layer A) is not particularly limited, and can be set so that the desired effect is appropriately exhibited. In some embodiments, the content of the photoreaction catalyst is, for example, approximately 0.005 parts by weight or more with respect to 100 parts by weight of the monomer component of the polymer (typically an acrylic polymer) contained in the pressure-sensitive adhesive layer. It is appropriate that the amount is 0.01 parts by weight or more, preferably 0.05 parts by weight or more, 0.10 parts by weight or more, or 0.15 parts by weight or more. It may be 0.20 parts by weight or more. By increasing the content of the photoreaction catalyst, the photocurability of the pressure-sensitive adhesive layer (layer A) is improved. The content of the photochemical catalyst with respect to 100 parts by weight of the monomer component is preferably 5 parts by weight or less, preferably 2 parts by weight or less, and may be 1 part by weight or less, 0.7. It may be 5 parts by weight or less, or 0.5 parts by weight or less. The fact that the content of the photoreaction catalyst is not too high can be advantageous from the viewpoint of improving the storage stability (for example, stability against photodegradation) of the laminate.
　光反応触媒を含む粘着剤層（Ａ層）は、典型的には、該光反応触媒を含む粘着剤組成物Ａ（例えば、溶剤型粘着剤組成物）を用いて形成することができる。光反応触媒を含む粘着剤組成物は、例えば、該組成物に使用される他の成分と光反応触媒とを混合して調製することができる。また、光重合開始剤の存在下で合成（光重合）された重合物（典型的にはアクリル系重合物）を使用して粘着剤組成物を調製する場合は、上記重合物を合成する際に用いられた光重合開始剤の残留物（未反応物）を、粘着剤層（Ａ層）に含まれる光反応触媒の一部または全部として利用してもよい。必要に応じて用いられるアクリル系オリゴマーとして光重合開始剤の存在下で合成されたものを使用する場合も同様である。製造管理の容易性の観点から、ここに開示される粘着剤層（Ａ層）は、他の構成成分に、上述した量の光反応触媒を新たに加えて調製された粘着剤組成物を用いて好ましく形成され得る。 The pressure-sensitive adhesive layer (layer A) containing the photoreaction catalyst can typically be formed by using the pressure-sensitive adhesive composition A (for example, a solvent-type pressure-sensitive adhesive composition) containing the photoreaction catalyst. The pressure-sensitive adhesive composition containing the photoreaction catalyst can be prepared, for example, by mixing the other components used in the composition with the photoreaction catalyst. When preparing a pressure-sensitive adhesive composition using a polymer (typically an acrylic polymer) synthesized (photopolymerized) in the presence of a photopolymerization initiator, when synthesizing the above-mentioned polymer. The residue (unreacted product) of the photopolymerization initiator used in the above may be used as a part or all of the photoreaction catalyst contained in the pressure-sensitive adhesive layer (layer A). The same applies to the case where an acrylic oligomer synthesized as necessary in the presence of a photopolymerization initiator is used. From the viewpoint of ease of production control, the pressure-sensitive adhesive layer (layer A) disclosed herein uses a pressure-sensitive adhesive composition prepared by newly adding the above-mentioned amount of photoreaction catalyst to other constituent components. Can be preferably formed.
　（水親和剤）
　ここに開示される技術における粘着剤層（Ａ層）に用いられ得る粘着剤組成物Ａには、所望により、水親和剤を含有させることができる。粘着剤層（Ａ層）に水親和剤を含有させることにより、水等の水性液体を利用して剥離力を効果的に低下させることができる。その理由は、特に限定解釈されるものではないが、一般に水親和剤は親水性領域を有することにより粘着剤層（Ａ層）（例えば、溶剤型粘着剤組成物から形成された粘着剤層）の表面に偏在しやすく、それによって該粘着剤層（Ａ層）表面の水親和性を効率よく高める作用が発揮され、該粘着剤層（Ａ層）が水と接触したときに剥離力を効果的に低下させるものと考えられる。 (Water affinity)
The pressure-sensitive adhesive composition A that can be used for the pressure-sensitive adhesive layer (layer A) in the technique disclosed herein can contain a water-affinitive agent, if desired. By incorporating a water-affinitive agent in the pressure-sensitive adhesive layer (layer A), the peeling force can be effectively reduced by utilizing an aqueous liquid such as water. The reason is not particularly limited, but in general, the water-affinitive agent has a hydrophilic region, so that the pressure-sensitive adhesive layer (layer A) (for example, the pressure-sensitive adhesive layer formed from the solvent-type pressure-sensitive adhesive composition). It is easy to be unevenly distributed on the surface of the adhesive layer (A layer), thereby exerting an effect of efficiently increasing the water affinity of the surface of the adhesive layer (A layer), and exerting a peeling force when the adhesive layer (A layer) comes into contact with water. It is thought that it will be lowered.
　水親和剤としては、粘着剤組成物の調製容易性等の点から、常温（約２５℃）において液状であるものが好ましく用いられ得る。水親和剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 As the water-affinitive agent, one that is liquid at room temperature (about 25 ° C.) can be preferably used from the viewpoint of ease of preparation of the pressure-sensitive adhesive composition. The water affinity agent may be used alone or in combination of two or more.
　いくつかの態様において、水親和剤としては、界面活性剤およびポリオキシアルキレン骨格を有する化合物から選択される少なくとも１種の化合物Ａを用いることができる。界面活性剤およびポリオキシアルキレン骨格を有する化合物としては、公知の界面活性剤、ポリオキシアルキレン骨格を有する化合物の１種または２種以上を特に制限なく用いることができる。なお、上記界面活性剤のなかには、ポリオキシアルキレン骨格を有する化合物が存在し、逆もまた然りであることは言うまでもない。 In some embodiments, as the water-affinitive agent, at least one compound A selected from a surfactant and a compound having a polyoxyalkylene skeleton can be used. As the compound having a surfactant and a polyoxyalkylene skeleton, one or more of known surfactants and compounds having a polyoxyalkylene skeleton can be used without particular limitation. Needless to say, among the above-mentioned surfactants, there are compounds having a polyoxyalkylene skeleton, and vice versa.
　化合物Ａとして用いられ得る界面活性剤としては、公知の非イオン性界面活性剤、アニオン性界面活性剤、カチオン性界面活性剤等を用いることができる。なかでも、非イオン性界面活性剤が好ましい。界面活性剤は１種を単独でまたは２種以上を組み合わせて用いることができる。 As the surfactant that can be used as compound A, known nonionic surfactants, anionic surfactants, cationic surfactants and the like can be used. Of these, nonionic surfactants are preferable. The surfactant may be used alone or in combination of two or more.
　非イオン性界面活性剤の例としては、ポリオキシエチレンラウリルエーテル、ポリオキシエチレンセチルエーテル、ポリオキシエチレンステアリルエーテル、ポリオキシエチレンオレイルエーテル等のポリオキシエチレンアルキルエーテル；ポリオキシエチレンオクチルフェニルエーテル、ポリオキシエチレンノニルフェニルエーテル等のポリオキシエチレンアルキルフェニルエーテル；ソルビタンモノラウレート、ソルビタンモノパルミテート、ソルビタンモノステアレート、ソルビタンモノオレエート等のソルビタン脂肪酸エステル；ポリオキシエチレンソルビタンモノラウレート、ポリオキシエチレンソルビタンモノパルミテート、ポリオキシエチレンソルビタンモノステアレート、ポリオキシエチレンソルビタントリステアレート、ポリオキシエチレンソルビタントリイソステアレート、ポリオキシエチレンソルビタンモノオレエート、ポリオキシエチレンソルビタントリオレエート等のポリオキシエチレンソルビタン脂肪酸エステル；ポリオキシエチレングリセリルエーテル脂肪酸エステル；ポリオキシエレン－ポリオキシプロピレンブロックコポリマー；等が挙げられる。これらの非イオン性界面活性剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, and poly. Polyoxyethylene alkylphenyl ether such as oxyethylene nonylphenyl ether; sorbitan fatty acid ester such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate; polyoxyethylene sorbitan monolaurate, polyoxyethylene Polyoxyethylene sorbitan such as sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate Examples thereof include fatty acid ester; polyoxyethylene glyceryl ether fatty acid ester; polyoxyelene-polyoxypropylene block copolymer; and the like. These nonionic surfactants can be used alone or in combination of two or more.
　アニオン性界面活性剤の例としては、ノニルベンゼンスルホン酸塩、ドデシルベンゼンスルホン酸塩（例えばドデシルベンゼンスルホン酸ナトリウム）等の、アルキルベンゼンスルホン酸塩；ラウリル硫酸塩（例えばラウリル硫酸ナトリウム、ラウリル硫酸アンモニウム）、オクタデシル硫酸塩等のアルキル硫酸塩；脂肪酸塩；ポリオキシエチレンオクタデシルエーテル硫酸塩、ポリオキシエチレンラウリルエーテル硫酸塩等のポリオキシエチレンアルキルエーテル硫酸塩（例えば、ポリオキシエチレンアルキルエーテル硫酸ナトリウム）、ポリオキシエチレンラウリルフェニルエーテル硫酸塩等のポリオキシエチレンアルキルフェニルエーテル硫酸塩（例えば、ポリオキシエチレンアルキルフェニルエーテル硫酸アンモニウム、ポリオキシエチレンアルキルフェニルエーテル硫酸ナトリウム等）、ポリオキシエチレンスチレン化フェニルエーテル硫酸塩等の、ポリエーテル硫酸塩；ポリオキシエチレンステアリルエーテルリン酸エステル、ポリオキシエチレンラウリルエーテルリン酸エステル等の、ポリオキシエチレンアルキルエーテルリン酸エステル；上記ポリオキシエチレンアルキルエーテルリン酸エステルのナトリウム塩、カリウム塩等のポリオキシエチレンアルキルエーテルリン酸エステル塩；ラウリルスルホコハク酸塩、ポリオキシエチレンラウリルスルホコハク酸塩（例えば、ポリオキシエチレンアルキルスルホコハク酸ナトリウム）等の、スルホコハク酸塩；ポリオキシエチレンアルキルエーテル酢酸塩；等が挙げられる。アニオン性界面活性剤が塩を形成している場合、該塩は、例えばナトリウム塩、カリウム塩、カルシウム塩、マグネシウム塩等の金属塩（好ましくは一価金属の塩）、アンモニウム塩、アミン塩等であり得る。アニオン性界面活性剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of anionic surfactants include alkylbenzene sulfonates such as nonylbenzene sulfonate, dodecylbenzene sulfonate (eg sodium dodecylbenzene sulfonate); lauryl sulfate (eg sodium lauryl sulfate, ammonium lauryl sulfate), etc. Alkyl sulfate such as octadecyl sulfate; fatty acid salt; polyoxyethylene alkyl ether sulfate such as polyoxyethylene octadecyl ether sulfate, polyoxyethylene lauryl ether sulfate (for example, sodium polyoxyethylene alkyl ether sulfate), polyoxy Polyoxyethylene alkyl phenyl ether sulfate such as ethylene lauryl phenyl ether sulfate (for example, sodium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, etc.), polyoxyethylene styrene phenyl ether sulfate, etc. Polyether sulfate; polyoxyethylene alkyl ether phosphate such as polyoxyethylene stearyl ether phosphate and polyoxyethylene lauryl ether phosphate; sodium salt and potassium salt of the above polyoxyethylene alkyl ether phosphate and the like. Polyoxyethylene alkyl ether phosphate ester salt; sulfosuccinate such as lauryl sulfosuccinate, polyoxyethylene lauryl sulfosuccinate (eg, sodium polyoxyethylene alkyl sulfosuccinate); polyoxyethylene alkyl ether acetate; etc. Can be mentioned. When the anionic surfactant forms a salt, the salt may be, for example, a metal salt such as a sodium salt, a potassium salt, a calcium salt or a magnesium salt (preferably a monovalent metal salt), an ammonium salt, an amine salt or the like. Can be. The anionic surfactant may be used alone or in combination of two or more.
　いくつかの態様において、例えば、－ＰＯＨ基、－ＣＯＨ基および－ＳＯＨ基の少なくとも一つを有するアニオン性界面活性剤を好ましく使用し得る。なかでも－ＰＯＨ基を有する界面活性剤が好ましい。このような界面活性剤は、典型的にはリン酸エステル構造を含んでおり、例えばリン酸のモノエステル（ＲＯＰ（＝Ｏ）（ＯＨ）２；ここでＲは１価の有機基）、ジエステル（（ＲＯ）２Ｐ（＝Ｏ）ＯＨ；ここでＲは、同一のまたは異なる１価の有機基）、モノエステルおよびジエステルの両方を含む混合物等であり得る。－ＰＯＨ基を有する界面活性剤の好適例として、ポリオキシエチレンアルキルエーテルリン酸エステルが挙げられる。ポリオキシエチレンアルキルエーテルリン酸エステルにおけるアルキル基の炭素原子数は、例えば６～２０であってよく、８～２０でもよく、１０～２０でもよく、１２～２０でもよく、１４～２０でもよい。 In some embodiments, for example, an anionic surfactant having at least one of a -POH group, a -COH group and a -SOH group may be preferably used. Of these, a surfactant having a -POH group is preferable. Such surfactants typically contain a phosphoric acid ester structure, such as a phosphoric acid monoester (ROP (= O) (OH) 2 ; where R is a monovalent organic group), a diester. ((RO) 2 P (= O) OH; where R is the same or different monovalent organic group), a mixture containing both monoesters and diesters, and the like. A preferred example of a surfactant having a -POH group is a polyoxyethylene alkyl ether phosphate ester. The number of carbon atoms of the alkyl group in the polyoxyethylene alkyl ether phosphoric acid ester may be, for example, 6 to 20, 8 to 20, 10 to 20, 12 to 20, and 14 to 20.
　カチオン性界面活性剤の例としては、ポリオキシエチレンラウリルアミン、ポリオキシエチレンステアリルアミン等のポリエーテルアミンが挙げられる。カチオン性界面活性剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of cationic surfactants include polyether amines such as polyoxyethylene laurylamine and polyoxyethylene stearylamine. The cationic surfactant may be used alone or in combination of two or more.
　化合物Ａとして用いられ得るポリオキシアルキレン骨格を有する化合物としては、例えば、ポリエチレングリコール（ＰＥＧ）、ポリプロピレングリコール（ＰＰＧ）等のポリアルキレングリコール；ポリオキシエチレン単位を含むポリエーテル、ポリオキシプロピレン単位を含むポリエーテル、オキシエチレン単位とオキシプロピレン単位とを含む化合物（これら単位の配列は、ランダムであってもよく、ブロック状であってもよい。）；これらの誘導体；等を用いることができる。また、上述の界面活性剤のうちポリオキシアルキレン骨格を有する化合物を用いることもできる。これらは１種を単独でまたは２種以上を組み合わせて用いることができる。なかでも、ポリオキシエチレン骨格（ポリオキシエチレンセグメントともいう。）を含む化合物を用いることが好ましく、ＰＥＧがより好ましい。 Examples of the compound having a polyoxyalkylene skeleton that can be used as compound A include polyalkylene glycols such as polyethylene glycol (PEG) and polypropylene glycol (PPG); polyethers containing polyoxyethylene units, and polyoxypropylene units. Compounds containing polyethers, oxyethylene units and oxypropylene units (the sequences of these units may be random or block-like); derivatives thereof; and the like can be used. Further, among the above-mentioned surfactants, compounds having a polyoxyalkylene skeleton can also be used. These can be used alone or in combination of two or more. Among them, it is preferable to use a compound containing a polyoxyethylene skeleton (also referred to as a polyoxyethylene segment), and PEG is more preferable.
　ポリオキシアルキレン骨格を有する化合物（例えばポリエチレングリコール）の分子量（化学式量）は特に限定されず、例えば１０００未満であることが適当であり、粘着剤組成物調製性の点から、凡そ６００以下（例えば５００以下）であることが好ましい。ポリオキシアルキレン骨格を有する化合物（例えばポリエチレングリコール）の分子量の下限は特に限定されず、分子量が凡そ１００以上（例えば凡そ２００以上、さらには凡そ３００以上）のものが好ましく用いられる。 The molecular weight (chemical formula amount) of the compound having a polyoxyalkylene skeleton (for example, polyethylene glycol) is not particularly limited, and it is suitable that it is, for example, less than 1000, and is about 600 or less (for example, from the viewpoint of adhesive composition preparability). It is preferably 500 or less). The lower limit of the molecular weight of the compound having a polyoxyalkylene skeleton (for example, polyethylene glycol) is not particularly limited, and a compound having a molecular weight of about 100 or more (for example, about 200 or more, further about 300 or more) is preferably used.
　水親和剤の他の例として、ポリビニルアルコール、ポリビニルピロリドン、ポリアクリル酸等の水溶性ポリマーが挙げられる。水溶性ポリマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。ここに開示される技術において、水親和剤としては、化合物Ａの１種または２種以上を用いてもよく、水溶性ポリマーの１種または２種以上を用いてもよく、これらを組み合わせて用いてもよい。 Other examples of water-affinitive agents include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylic acid. The water-soluble polymer may be used alone or in combination of two or more. In the technique disclosed herein, as the water affinity agent, one kind or two or more kinds of compound A may be used, or one kind or two or more kinds of water-soluble polymers may be used, and these may be used in combination. You may.
　水親和剤のＨＬＢは特に限定されず、例えば３以上であり、凡そ６以上が適当であり、８以上（例えば９以上）であり得る。いくつかの好ましい態様では、水親和剤のＨＬＢは１０以上である。これによって、水剥離性が好ましく発現する傾向がある。上記ＨＬＢは、より好ましくは１１以上、さらに好ましくは１２以上、特に好ましくは１３以上（例えば１４以上）である。上記範囲のＨＬＢを有する水親和剤（典型的には界面活性剤）をＡ層に含ませることで、水剥離性をより効果的に発現させ得る。上記ＨＬＢの上限は２０以下であり、例えば１８以下であってもよく、１６以下でもよく、１５以下でもよい。 The HLB of the water-affinitive agent is not particularly limited, for example, 3 or more, about 6 or more is appropriate, and 8 or more (for example, 9 or more) can be used. In some preferred embodiments, the water affinity has an HLB of 10 or greater. As a result, water peelability tends to be preferably exhibited. The HLB is more preferably 11 or more, still more preferably 12 or more, and particularly preferably 13 or more (for example, 14 or more). By including a water affinity agent (typically a surfactant) having an HLB in the above range in the A layer, water detachability can be more effectively exhibited. The upper limit of the HLB is 20 or less, for example, 18 or less, 16 or less, or 15 or less.
　なお、本明細書におけるＨＬＢは、GriffinによるHydrophile-Lipophile Balanceであり、界面活性剤の水や油への親和性の程度を表す値であり、親水性と親油性の比を０～２０の間の数値で表したものである。ＨＬＢの定義は、W．C．Griffin：J．Soc．Cosmetic Chemists，1,311（1949）や、高橋越民、難波義郎、小池基生、小林正雄共著、「界面活性剤ハンドブック」、第３版、工学図書社出版、昭和４７年１１月２５日、ｐ１７９～１８２等に記載されるとおりである。上記ＨＬＢを有する水親和剤は、上記参考文献を必要に応じて参酌するなどして、当業者の技術常識に基づき、選定することができる。 The HLB in the present specification is a Hydrophilic-Lipophile Balance by Griffin, which is a value indicating the degree of affinity of the surfactant with water or oil, and the ratio of hydrophilicity to lipophilicity is between 0 and 20. It is expressed by the numerical value of. The definition of HLB is W. C. Griffin: J. Soc. Cosmetic Chemists, 1,311 (1949), Koshimitsu Takahashi, Yoshiro Namba, Motoo Koike, Masao Kobayashi, "Surfactant Handbook", 3rd edition, published by Engineering Books, November 25, 1972, p179- As described in 182 and the like. The water-affinitive agent having the above-mentioned HLB can be selected based on the common general technical knowledge of those skilled in the art by referring to the above-mentioned references as necessary.
　このような水親和剤は、遊離の形態でＡ層に含まれていることが好ましい。水親和剤としては、粘着剤組成物調製性の点から、常温（約２５℃）において液状であるものが好ましく用いられる。 It is preferable that such a water-affinitive agent is contained in the A layer in a free form. As the water-affinitive agent, one that is liquid at room temperature (about 25 ° C.) is preferably used from the viewpoint of preparation of the pressure-sensitive adhesive composition.
　水親和剤を含むＡ層は、典型的には、水親和剤を含む粘着剤組成物Ａから形成される。上記粘着剤組成物Ａは、上述した水分散型粘着剤組成物、溶剤型粘着剤組成物、活性エネルギー線硬化型粘着剤組成物、ホットメルト型粘着剤組成物等のいずれでもよい。いくつかの好ましい態様において、水親和剤を含むＡ層は、光硬化型または溶剤型の粘着剤組成物Ａから形成された粘着剤層であり得る。このようなＡ層において、水親和剤の添加効果が好ましく発揮され得る。Ａ層は、光硬化性を有していてもよい。 The A layer containing the water-affinitive agent is typically formed from the pressure-sensitive adhesive composition A containing the water-affinitive agent. The pressure-sensitive adhesive composition A may be any of the above-mentioned water-dispersible pressure-sensitive adhesive composition, solvent-type pressure-sensitive adhesive composition, active energy ray-curable pressure-sensitive adhesive composition, hot-melt type pressure-sensitive adhesive composition, and the like. In some preferred embodiments, the A layer containing the water-affinitive agent can be a pressure-sensitive adhesive layer formed from a photocurable or solvent-type pressure-sensitive adhesive composition A. In such a layer A, the effect of adding a water affinity agent can be preferably exhibited. The layer A may have photocurability.
　Ａ層における水親和剤の含有量は、特に限定されず、該水親和剤の使用効果が適切に発揮されるように設定することができる。いくつかの態様において、水親和剤の含有量は、Ａ層に含まれる重合物（例えば、アクリル系重合物）を構成するモノマー成分１００重量部あたり、例えば０．００１重量部以上とすることができ、０．０１重量部以上とすることが適当であり、０．０３重量部以上でもよく、０．０７重量部以上でもよく、０．１重量部以上でもよい。いくつかの好ましい態様において、水親和剤の含有量は、モノマー成分１００重量部に対して、例えば０．２重量部以上であってよく、より高い効果を得る観点から０．５重量部以上でもよく、１．０重量部以上でもよく、１．５重量部以上でもよい。また、Ａ層のバルクへの過度の水拡散を抑制する観点から、いくつかの態様において、水親和剤の使用量は、モノマー成分１００重量部に対して、例えば２０重量部以下であってよく、１０重量部以下とすることが適当であり、５重量部以下とすることが好ましく、３重量部以下としてもよい。水親和剤の含有量が多過ぎないことは、水浸漬後剥離強度Ｎ１の向上や水浸漬後剥離力低下率の低減、あるいは粘着剤層（Ａ層）の透明性向上の観点からも好ましい。例えば、いくつかの態様において、モノマー成分１００重量部に対する水親和剤の含有量は、２重量部未満でもよく、１重量部未満でもよく、０．７重量部未満でもよく、０．３重量部未満でもよく、０．２重量部未満でもよい。ＨＬＢが１０以上である水親和剤は、少量の使用によっても良好な水剥離性を発揮する傾向がある。 The content of the water affinity agent in the layer A is not particularly limited, and can be set so that the effect of using the water affinity agent is appropriately exhibited. In some embodiments, the content of the aqueous affinity agent may be, for example, 0.001 part by weight or more per 100 parts by weight of the monomer component constituting the polymer (for example, acrylic polymer) contained in the layer A. It is suitable that the amount is 0.01 parts by weight or more, 0.03 parts by weight or more, 0.07 parts by weight or more, or 0.1 parts by weight or more. In some preferred embodiments, the content of the aqueous affinity agent may be, for example, 0.2 parts by weight or more with respect to 100 parts by weight of the monomer component, and 0.5 parts by weight or more from the viewpoint of obtaining a higher effect. It may be 1.0 part by weight or more, or 1.5 parts by weight or more. Further, from the viewpoint of suppressing excessive water diffusion of the A layer into the bulk, in some embodiments, the amount of the water affinity agent used may be, for example, 20 parts by weight or less with respect to 100 parts by weight of the monomer component. It is suitable to be 10 parts by weight or less, preferably 5 parts by weight or less, and may be 3 parts by weight or less. It is preferable that the content of the water-affinitive agent is not too large from the viewpoint of improving the peel strength N1 after immersion in water, reducing the rate of decrease in peeling force after immersion in water, or improving the transparency of the pressure-sensitive adhesive layer (layer A). For example, in some embodiments, the content of the water affinity with respect to 100 parts by weight of the monomer component may be less than 2 parts by weight, less than 1 part by weight, less than 0.7 parts by weight, or 0.3 parts by weight. It may be less than 0.2 parts by weight. A water affinity agent having an HLB of 10 or more tends to exhibit good water desorption even when used in a small amount.
　（アクリル系オリゴマー）
　ここに開示される粘着剤層（Ａ層）には、凝集力の向上や、基材層との密着性向上や被着体との接着性向上等の観点から、アクリル系オリゴマーを含有させることができる。アクリル系オリゴマーを含む粘着剤層（Ａ層）は、該アクリル系オリゴマーを含む粘着剤組成物Ａを用いて形成することができる。アクリル系オリゴマーとしては、上述したアクリル系重合物（例えばアクリル系ポリマー）のＴｇに対して、より高いＴｇを有するものを好ましく採用し得る。 (Acrylic oligomer)
The pressure-sensitive adhesive layer (layer A) disclosed herein contains an acrylic oligomer from the viewpoints of improving cohesive force, improving adhesion to the base material layer, and improving adhesion to the adherend. Can be done. The pressure-sensitive adhesive layer (layer A) containing the acrylic oligomer can be formed by using the pressure-sensitive adhesive composition A containing the acrylic oligomer. As the acrylic oligomer, those having a higher Tg than the Tg of the above-mentioned acrylic polymer (for example, acrylic polymer) can be preferably adopted.
　上記アクリル系オリゴマーのＴｇは特に限定されず、例えば約２０℃以上３００℃以下であり得る。上記Ｔｇは、例えば約３０℃以上であってよく、約４０℃以上でもよく、約６０℃以上でもよく、約８０℃以上または約１００℃以上でもよい。アクリル系オリゴマーのＴｇが高くなると、凝集力を向上させる効果は概して高くなる傾向にある。また、基材層への投錨性や衝撃吸収性等の観点から、アクリル系オリゴマーのＴｇは、例えば約２５０℃以下であってよく、約２００℃以下でもよく、約１８０℃以下または約１５０℃以下でもよい。なお、アクリル系オリゴマーのＴｇは、上述のアクリル系重合物のＴｇと同じく、Ｆｏｘの式に基づいて計算される値である。 The Tg of the acrylic oligomer is not particularly limited, and may be, for example, about 20 ° C. or higher and 300 ° C. or lower. The Tg may be, for example, about 30 ° C. or higher, about 40 ° C. or higher, about 60 ° C. or higher, about 80 ° C. or higher, or about 100 ° C. or higher. As the Tg of the acrylic oligomer increases, the effect of improving the cohesive force tends to increase in general. Further, from the viewpoint of anchoring property to the base material layer, shock absorption, etc., the Tg of the acrylic oligomer may be, for example, about 250 ° C. or lower, about 200 ° C. or lower, about 180 ° C. or lower, or about 150 ° C. It may be as follows. The Tg of the acrylic oligomer is a value calculated based on the Fox formula, like the Tg of the acrylic polymer described above.
　アクリル系オリゴマーのＭｗは、特に限定されず、例えば凡そ１０００以上であってよく、凡そ１５００以上であることが適当であり、凡そ２０００以上でもよく、凡そ３０００以上でもよい。また、アクリル系オリゴマーのＭｗは、例えば凡そ３００００未満であってよく、凡そ１００００未満であることが適当であり、凡そ７０００未満でもよく、凡そ５０００未満でもよい。Ｍｗが上記範囲内にあると、粘着剤層（Ａ層）の凝集性や、接着性向上効果が好適に発揮されやすい。アクリル系オリゴマーのＭｗは、ＧＰＣにより測定し、標準ポリスチレン換算の値として求めることができる。具体的には、例えば、東ソー社製のＨＰＬＣ８０２０に、カラムとしてＴＳＫｇｅｌＧＭＨ－Ｈ（２０）×２本を用いて、テトラヒドロフラン溶媒で流速約０．５ｍＬ／分の条件にて測定することができる。 The Mw of the acrylic oligomer is not particularly limited, and for example, it may be about 1000 or more, it is appropriate that it is about 1500 or more, it may be about 2000 or more, or it may be about 3000 or more. Further, the Mw of the acrylic oligomer may be, for example, less than about 30,000, preferably less than about 10,000, less than about 7,000, or less than about 5,000. When Mw is within the above range, the cohesiveness of the pressure-sensitive adhesive layer (layer A) and the effect of improving the adhesiveness are likely to be suitably exhibited. The Mw of the acrylic oligomer can be measured by GPC and obtained as a standard polystyrene-equivalent value. Specifically, for example, it can be measured in a tetrahydrofuran solvent at a flow rate of about 0.5 mL / min using TSKgelGMH-H (20) × 2 as a column on HPLC8020 manufactured by Tosoh Corporation.
　アクリル系オリゴマーを構成するモノマー成分としては、上述した各種の（メタ）アクリル酸Ｃ１－２０アルキルエステル；上述した各種の脂環式炭化水素基含有（メタ）アクリレート；上述した各種の芳香族炭化水素基含有（メタ）アクリレート；テルペン化合物誘導体アルコールから得られる（メタ）アクリレート；等の（メタ）アクリレートモノマーを挙げることができる。これらは１種を単独でまたは２種以上を組み合わせて使用することができる。 The monomer components constituting the acrylic oligomer include the above-mentioned various (meth) acrylic acid C 1-20 alkyl esters; the above-mentioned various alicyclic hydrocarbon group-containing (meth) acrylates; and the above-mentioned various aromatic hydrocarbons. Examples thereof include (meth) acrylate monomers containing a hydrogen group; (meth) acrylate obtained from a terpene compound derivative alcohol; and the like. These can be used alone or in combination of two or more.
　アクリル系オリゴマーは、イソブチル（メタ）アクリレートやｔ－ブチル（メタ）アクリレートのようなアルキル基が分岐構造を有するアルキル（メタ）アクリレート；脂環式炭化水素基含有（メタ）アクリレートや芳香族炭化水素基含有（メタ）アクリレート；等に代表される、比較的嵩高い構造を有するアクリル系モノマーをモノマー単位として含んでいることが、接着性向上の観点から好ましい。また、アクリル系オリゴマーの合成の際や粘着剤層（Ａ層）の作製の際に紫外線を採用する場合には、重合阻害を起こしにくいという点で、エステル末端に飽和炭化水素基を有するモノマーが好ましく、例えばアルキル基が分岐構造を有するアルキル（メタ）アクリレートや飽和脂環式炭化水素基含有（メタ）アクリレートを好適に用いることができる。 Acrylic oligomers are alkyl (meth) acrylates in which alkyl groups such as isobutyl (meth) acrylate and t-butyl (meth) acrylate have a branched structure; alicyclic hydrocarbon group-containing (meth) acrylate and aromatic hydrocarbons. It is preferable to contain an acrylic monomer having a relatively bulky structure as a monomer unit, such as a group-containing (meth) acrylate; from the viewpoint of improving adhesiveness. Further, when ultraviolet rays are used when synthesizing an acrylic oligomer or when producing an adhesive layer (layer A), a monomer having a saturated hydrocarbon group at the ester terminal is less likely to cause polymerization inhibition. Preferably, for example, an alkyl (meth) acrylate in which the alkyl group has a branched structure or a saturated alicyclic hydrocarbon group-containing (meth) acrylate can be preferably used.
　アクリル系オリゴマーを構成する全モノマー成分に占める（メタ）アクリレートモノマーの割合は、典型的には５０重量％超であり、好ましくは６０重量％以上、より好ましくは７０重量％以上（例えば８０重量％以上、さらには９０重量％以上）である。いくつかの好ましい態様では、アクリル系オリゴマーは、実質的に１種または２種以上の（メタ）アクリレートモノマーのみからなるモノマー組成を有する。モノマー成分が脂環式炭化水素基含有（メタ）アクリレートと（メタ）アクリル酸Ｃ１－２０アルキルエステルとを含む場合、それらの重量比は特に限定されない。いくつかの態様において、脂環式炭化水素基含有（メタ）アクリレート／（メタ）アクリル酸Ｃ１－２０アルキルエステルの重量比は、例えば１０／９０以上、２０／８０以上または３０／７０以上とすることができ、また、９０／１０以下、８０／２０以下または７０／３０以下とすることができる。 The ratio of the (meth) acrylate monomer to all the monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight or more, and more preferably 70% by weight or more (for example, 80% by weight). And more, 90% by weight or more). In some preferred embodiments, the acrylic oligomer has a monomer composition consisting substantially of only one or more (meth) acrylate monomers. When the monomer component contains an alicyclic hydrocarbon group-containing (meth) acrylate and a (meth) acrylic acid C 1-20 alkyl ester, their weight ratios are not particularly limited. In some embodiments, the weight ratio of the alicyclic hydrocarbon group-containing (meth) acrylate / (meth) acrylic acid C 1-20 alkyl ester is, for example, 10/90 or higher, 20/80 or higher, or 30/70 or higher. It can also be 90/10 or less, 80/20 or less, or 70/30 or less.
　アクリル系オリゴマーの構成モノマー成分としては、上記の（メタ）アクリレートモノマーに加えて、必要に応じて官能基含有モノマーを用いることができる。官能基含有モノマーとしては、Ｎ－ビニル－２－ピロリドン、Ｎ－アクリロイルモルホリン等の窒素原子含有複素環を有するモノマー；Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート等のアミノ基含有モノマー；Ｎ，Ｎ－ジエチル（メタ）アクリルアミド等のアミド基含有モノマー；ＡＡ、ＭＡＡ等のカルボキシ基含有モノマー；２－ヒドロキシエチル（メタ）アクリレート等の水酸基含有モノマー；が挙げられる。これらの官能基含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。官能基含有モノマーを用いる場合、アクリル系オリゴマーを構成する全モノマー成分に占める官能基含有モノマーの割合は、例えば１重量％以上、２重量％以上または３重量％以上とすることができ、また、例えば１５重量％以下、１０重量％以下または７重量％以下とすることができる。アクリル系オリゴマーは、官能基含有モノマーが用いられていないものであってもよい。 As the constituent monomer component of the acrylic oligomer, in addition to the above (meth) acrylate monomer, a functional group-containing monomer can be used if necessary. Examples of the functional group-containing monomer include a monomer having a nitrogen atom-containing heterocycle such as N-vinyl-2-pyrrolidone and N-acryloylmorpholin; an amino group-containing monomer such as N, N-dimethylaminoethyl (meth) acrylate; N, Examples thereof include an amide group-containing monomer such as N-diethyl (meth) acrylamide; a carboxy group-containing monomer such as AA and MAA; and a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate. These functional group-containing monomers may be used alone or in combination of two or more. When a functional group-containing monomer is used, the ratio of the functional group-containing monomer to all the monomer components constituting the acrylic oligomer can be, for example, 1% by weight or more, 2% by weight or more, or 3% by weight or more, and also. For example, it can be 15% by weight or less, 10% by weight or less, or 7% by weight or less. The acrylic oligomer may be one in which a functional group-containing monomer is not used.
　好適なアクリル系オリゴマーとしては、例えば、ジシクロペンタニルメタクリレート（ＤＣＰＭＡ）、シクロヘキシルメタクリレート（ＣＨＭＡ）、イソボルニルメタクリレート（ＩＢＸＭＡ）、イソボルニルアクリレート（ＩＢＸＡ）、ジシクロペンタニルアクリレート（ＤＣＰＡ）、１－アダマンチルメタクリレート（ＡＤＭＡ）、１－アダマンチルアクリレート（ＡＤＡ）の各単独重合体のほか、ＤＣＰＭＡとＭＭＡの共重合体、ＤＣＰＭＡとＩＢＸＭＡとの共重合体、ＡＤＡとメチルメタクリレート（ＭＭＡ）の共重合体、ＣＨＭＡとイソブチルメタクリレート（ＩＢＭＡ）との共重合体、ＣＨＭＡとＩＢＸＭＡとの共重合体、ＣＨＭＡとアクリロイルモルホリン（ＡＣＭＯ）との共重合体、ＣＨＭＡとジエチルアクリルアミド（ＤＥＡＡ）との共重合体、ＣＨＭＡとＡＡとの共重合体等を挙げることができる。 Suitable acrylic oligomers include, for example, dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), and the like. In addition to 1-adamantyl methacrylate (ADAM) and 1-adamantyl acrylate (ADA) homopolymers, DCPMA and MMA copolymers, DCPMA and IBXMA copolymers, and ADA and methyl methacrylate (MMA) copolymer weights. Combined, a polymer of CHMA and isobutyl methacrylate (IBMA), a polymer of CHMA and IBXMA, a polymer of CHMA and acryloylmorpholin (ACMO), a polymer of CHMA and diethylacrylamide (DEAA), Examples thereof include a copolymer of CHMA and AA.
　アクリル系オリゴマーは、その構成モノマー成分を重合することにより形成され得る。重合方法や重合態様は特に限定されず、従来公知の各種重合方法（例えば、溶液重合、エマルション重合、塊状重合、光重合、放射線重合等）を、適宜の態様で採用することができる。必要に応じて使用し得る重合開始剤（例えばアゾ系重合開始剤）の種類は、概ねアクリル系重合物の合成に関して例示したとおりであり、重合開始剤量や、任意に使用される連鎖移動剤（例えばメルカプタン類）の量は、所望の分子量となるよう技術常識に基づいて適切に設定されるので、詳細な説明は省略する。 Acrylic oligomers can be formed by polymerizing their constituent monomer components. The polymerization method and the polymerization mode are not particularly limited, and various conventionally known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be adopted in an appropriate manner. The types of polymerization initiators (for example, azo-based polymerization initiators) that can be used as needed are generally as illustrated for the synthesis of acrylic polymers, and the amount of the polymerization initiator and the chain transfer agent arbitrarily used. Since the amount of (for example, mercaptans) is appropriately set based on common general knowledge so as to have a desired molecular weight, detailed description thereof will be omitted.
　粘着剤層（Ａ層）または粘着剤組成物Ａにアクリル系オリゴマーを含有させる場合、その含有量は、粘着剤層（Ａ）に含まれる重合物（典型的にはアクリル系重合物）のモノマー成分１００重量部に対して、例えば０．０１重量部以上とすることができ、より高い効果を得る観点から０．０５重量部以上としてもよく、０．１重量部以上または０．２重量部以上としてもよい。また、上記重合物（典型的にはアクリル系重合物）との相溶性等の観点から、上記モノマー成分１００重量部に対するアクリル系オリゴマーの含有量は、５０重量部未満とすることが適当であり、好ましくは３０重量部未満、より好ましくは２５重量部以下であり、例えば１０重量部以下であってもよく、５重量部以下または１重量部以下でもよい。 When the pressure-sensitive adhesive layer (layer A) or the pressure-sensitive adhesive composition A contains an acrylic oligomer, the content thereof is the monomer of the polymer (typically an acrylic polymer) contained in the pressure-sensitive adhesive layer (A). For example, it may be 0.01 parts by weight or more with respect to 100 parts by weight of the component, and may be 0.05 parts by weight or more from the viewpoint of obtaining a higher effect, and 0.1 parts by weight or more or 0.2 parts by weight. The above may be applied. Further, from the viewpoint of compatibility with the above-mentioned polymer (typically, acrylic-based polymer), it is appropriate that the content of the acrylic-based oligomer with respect to 100 parts by weight of the above-mentioned monomer component is less than 50 parts by weight. It is preferably less than 30 parts by weight, more preferably 25 parts by weight or less, for example, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less.
　（粘着付与樹脂）
　粘着剤層（Ａ層）には粘着付与樹脂を含有させてもよい。粘着付与樹脂としては、例えば、ロジン系粘着付与樹脂、ロジン誘導体粘着付与樹脂を包含する、石油系粘着付与樹脂、テルペン系粘着付与樹脂、フェノール系粘着付与樹脂、ケトン系粘着付与樹脂等が挙げられる。これらは、１種を単独でまたは２種以上を組み合わせて使用することができる。 (Adhesive-imparting resin)
The pressure-sensitive adhesive layer (layer A) may contain a pressure-imparting resin. Examples of the tackifier resin include petroleum-based tackifier resins, terpene-based tackifier resins, phenol-based tackifier resins, ketone-based tackifier resins, and the like, including rosin-based tackifier resins and rosin derivative tackifier resins. .. These can be used alone or in combination of two or more.
　上記ロジン系粘着付与樹脂としては、例えば、ガムロジン、ウッドロジン、トール油ロジン等のロジンの他、安定化ロジン（例えば、上記ロジンを不均化もしくは水素添加処理した安定化ロジン）、重合ロジン（例えば、上記ロジンの多量体、典型的には二量体）、変性ロジン（例えば、マレイン酸、フマル酸、（メタ）アクリル酸等の不飽和酸により変性された不飽和酸変性ロジン等）等が挙げられる。
　上記ロジン誘導体粘着付与樹脂としては、例えば、上記ロジン系粘着付与樹脂のエステル化物（例えば、安定化ロジンエステルや重合ロジンエステル等のロジンエステル類）、上記ロジン系樹脂のフェノール変性物（フェノール変性ロジン）およびそのエステル化物（フェノール変性ロジンエステル）等が挙げられる。
　上記石油系粘着付与樹脂としては、例えば、脂肪族系石油樹脂、芳香族系石油樹脂、共重合系石油樹脂、脂環族系石油樹脂、これらの水素化物等が挙げられる。
　上記テルペン系粘着付与樹脂としては、例えば、α－ピネン樹脂、β－ピネン樹脂、芳香族変性テルペン系樹脂、テルペンフェノール樹脂等が挙げられる。
　上記ケトン系粘着付与樹脂としては、例えば、ケトン類（例えば、メチルエチルケトン、メチルイソブチルケトン、アセトフェノン等の脂肪族ケトン；シクロヘキサノン、メチルシクロヘキサノン等の脂環式ケトン等）とホルムアルデヒドとの縮合によるケトン系樹脂；等が挙げられる。 Examples of the rosin-based tackifier resin include rosins such as gum rosin, wood rosin, and tall oil rosin, stabilized rosins (for example, stabilized rosins obtained by disproportionating or hydrogenating the above rosins), and polymerized rosins (for example). , The multimer of the above rosin, typically a dimer), modified rosin (for example, unsaturated acid-modified rosin modified with an unsaturated acid such as maleic acid, fumaric acid, (meth) acrylic acid, etc.) Can be mentioned.
Examples of the rosin derivative tackifier resin include esters of the rosin-based tackifier resin (for example, rosin esters such as stabilized rosin ester and polymerized rosin ester), and phenol-modified products of the rosin-based resin (phenol-modified rosin). ) And its esterified product (phenol-modified rosin ester) and the like.
Examples of the petroleum-based tackifier resin include aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, alicyclic petroleum resins, and hydrides thereof.
Examples of the terpene-based tackifier resin include α-pinene resin, β-pinene resin, aromatic-modified terpene resin, and terpene phenol resin.
Examples of the ketone-based tackifier resin include ketone-based resins obtained by condensing ketones (for example, aliphatic ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; alicyclic ketones such as cyclohexanone and methylcyclohexanone) and formaldehyde. ; Etc. can be mentioned.
　いくつかの態様において、粘着付与樹脂としては、ロジン系粘着付与樹脂、ロジン誘導体粘着付与樹脂およびテルペンフェノール樹脂から選択される１種または２種以上を好ましく使用し得る。なかでもロジン誘導体粘着付与樹脂が好ましく、好適例として安定化ロジンエステルおよび重合ロジンエステル等のロジンエステル類が挙げられる。 In some embodiments, as the tackifier resin, one or more selected from a rosin-based tackifier resin, a rosin derivative tackifier resin, and a terpene phenol resin can be preferably used. Of these, a rosin derivative tackifier resin is preferable, and preferred examples thereof include rosin esters such as stabilized rosin ester and polymerized rosin ester.
　水分散型の粘着剤組成物においては、上述のような粘着付与樹脂が水性溶媒に分散した形態の水分散型粘着付与樹脂の使用が好ましい。例えば、アクリル系ポリマーの水分散液と水分散型粘着付与樹脂とを混合することにより、これらの成分を所望の割合で含有する粘着剤組成物を容易に調製することができる。いくつかの態様において、水分散型粘着付与樹脂としては、環境衛生への配慮等の観点から、少なくとも芳香族炭化水素系溶剤を実質的に含有しないものを好ましく用いることができる。芳香族炭化水素系溶剤その他の有機溶剤を実質的に含有しない水分散型粘着付与樹脂の使用がより好ましい。 In the water-dispersible pressure-sensitive adhesive composition, it is preferable to use the water-dispersion type pressure-sensitive adhesive resin in which the above-mentioned pressure-imparting resin is dispersed in an aqueous solvent. For example, by mixing an aqueous dispersion of an acrylic polymer and an aqueous dispersion type tackifier resin, a pressure-sensitive adhesive composition containing these components in a desired ratio can be easily prepared. In some embodiments, as the water-dispersible tackifier resin, a resin that does not substantially contain at least an aromatic hydrocarbon solvent can be preferably used from the viewpoint of consideration for environmental hygiene and the like. It is more preferable to use an aqueous dispersion type tackifier resin which does not substantially contain an aromatic hydrocarbon solvent or other organic solvent.
　ロジンエステル類を含む水分散型粘着付与樹脂の市販品としては、例えば、荒川化学工業社製の商品名「スーパーエステルＥ－７２０」、「スーパーエステルＥ－７３０－５５」、「スーパーエステルＥ－８６５ＮＴ」等や、ハリマ化成社製の商品名「ハリエスターＳＫ－９０Ｄ」、「ハリエスターＳＫ－７０Ｄ」、「ハリエスターＳＫ－７０Ｅ」、「ネオトール１１５Ｅ」等が挙げられる。また、テルペンフェノール樹脂（水分散型テルペンフェノール樹脂の形態であり得る。）の市販品としては、荒川化学工業社製の商品名「タマノルＥ－１００」、「タマノルＥ－２００」、「タマノルＥ－２００ＮＴ」等が挙げられる。 Examples of commercially available water-dispersible tackifier resins containing rosin esters include the trade names "Super Ester E-720", "Super Ester E-730-55", and "Super Ester E-" manufactured by Arakawa Chemicals Co., Ltd. Examples thereof include "865NT" and the like, and product names "Hariester SK-90D", "Hariester SK-70D", "Hariester SK-70E", "Neotol 115E" and the like manufactured by Harima Chemicals. In addition, as commercial products of terpene phenol resin (which may be in the form of water-dispersed terpene phenol resin), trade names "Tamanor E-100", "Tamanor E-200", and "Tamanor E" manufactured by Arakawa Chemical Industries, Ltd. -200NT "and the like.
　粘着付与樹脂の軟化点は特に限定されない。粘着剤層（Ａ層）の凝集力の低下を抑制する観点から、軟化点が８０℃以上の粘着付与樹脂を好ましく使用し得る。粘着付与樹脂の軟化点は、９０℃以上でもよく、１００℃以上でもよく、１１０℃以上でもよく、１２０℃以上でもよい。軟化点１３０℃以上または１４０℃以上の粘着付与樹脂を使用してもよい。また、透明性や基材層に対する密着性、被着体に対する接着性等の観点から、軟化点が２００℃以下または１８０℃以下の粘着付与樹脂を好ましく使用し得る。なお、ここでいう粘着付与樹脂の軟化点としては、文献やカタログ等に記載された公称値を採用することができる。公称値がない場合には、ＪＩＳ　Ｋ５９０２またはＪＩＳ　Ｋ２２０７に規定する軟化点試験方法（環球法）に基づいて粘着付与樹脂の軟化点を測定することができる。 The softening point of the tackifying resin is not particularly limited. From the viewpoint of suppressing a decrease in the cohesive force of the pressure-sensitive adhesive layer (layer A), a pressure-sensitive adhesive resin having a softening point of 80 ° C. or higher can be preferably used. The softening point of the tackifier resin may be 90 ° C. or higher, 100 ° C. or higher, 110 ° C. or higher, or 120 ° C. or higher. A tackifier resin having a softening point of 130 ° C. or higher or 140 ° C. or higher may be used. Further, from the viewpoint of transparency, adhesion to the base material layer, adhesiveness to the adherend, and the like, a tackifier resin having a softening point of 200 ° C. or lower or 180 ° C. or lower can be preferably used. As the softening point of the tackifier resin referred to here, a nominal value described in a document, a catalog, or the like can be adopted. When there is no nominal value, the softening point of the tackifier resin can be measured based on the softening point test method (ring ball method) specified in JIS K5902 or JIS K2207.
　粘着付与樹脂の使用量は、その使用効果を好適に発揮させる観点から、Ａ層に含まれる重合物を構成するモノマー成分１００重量部に対して１重量部以上とすることが適当であり、５重量部以上でもよく、１０重量部以上でもよく、１５重量部以上でもよく、２０重量部以上でもよく、２５重量部以上でもよい。また、基材層や被着体に対する密着性と凝集性とをバランスよく両立する観点から、モノマー成分１００重量部に対する粘着付与樹脂の使用量は、例えば７０重量部以下であってよく、５０重量部以下でもよく、４０重量部以下でもよい。あるいは、粘着付与樹脂を実質的に含有しないＡ層であってもよい。 The amount of the tackifier resin used is preferably 1 part by weight or more with respect to 100 parts by weight of the monomer component constituting the polymer contained in the layer A from the viewpoint of preferably exerting the effect of use. It may be 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, or 25 parts by weight or more. Further, from the viewpoint of achieving both adhesion to the base material layer and the adherend and cohesiveness in a well-balanced manner, the amount of the tackifier resin used for 100 parts by weight of the monomer component may be, for example, 70 parts by weight or less, and 50 parts by weight. It may be 40 parts or less, or 40 parts by weight or less. Alternatively, the layer A may be substantially free of the tackifier resin.
　（シランカップリング剤）
　いくつかの態様において、粘着剤層（Ａ層）にシランカップリング剤を含有させることができる。シランカップリング剤を含むＡ層によると、水浸漬後剥離力低下率が低く、かつ水剥離力低下率の高い積層体が好適に実現され得る。シランカップリング剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Silane coupling agent)
In some embodiments, the pressure-sensitive adhesive layer (layer A) can contain a silane coupling agent. According to the layer A containing a silane coupling agent, a laminate having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized. The silane coupling agent may be used alone or in combination of two or more.
　シランカップリング剤としては、３－グリシドキシプロピルトリメトキシシラン、３－グリシドキシプロピルメチルジメトキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン等のエポキシ構造を有するケイ素化合物；３－アミノプロピルトリメトキシシラン、Ｎ－（２－アミノエチル）３－アミノプロピルトリメトキシシラン、Ｎ－（２－アミノエチル）３－アミノプロピルメチルジメトキシシラン等のアミノ基含有ケイ素化合物；３－クロロプロピルトリメトキシシラン；アセトアセチル基含有トリメトキシシラン、３－アクリロキシプロピルトリメトキシシラン、３－メタクリロキシプロピルトリエトキシシランなどの（メタ）アクリル基含有シランカップリング剤；３－イソシアネートプロピルトリエトキシシランなどのイソシアネート基含有シランカップリング剤などが挙げられる。なかでも好ましい例として、３－グリシドキシプロピルトリメトキシシランおよびアセトアセチル基含有トリメトキシシランが挙げられる。 Examples of the silane coupling agent include silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; (meth) acrylic group-containing silane coupling agent such as acetoacetyl group-containing trimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; 3-isocyanatepropyltriethoxysilane Examples thereof include isocyanate group-containing silane coupling agents such as. Among them, preferred examples include 3-glycidoxypropyltrimethoxysilane and acetoacetyl group-containing trimethoxysilane.
　シランカップリング剤の使用量は、所望の使用効果が得られるように設定することができ、特に限定されない。いくつかの態様において、シランカップリング剤の使用量は、Ａ層に含まれる重合物を構成するモノマー成分１００重量部に対して、例えば０．００１重量部以上であってよく、より高い効果を得る観点から０．００５重量部以上でもよく、０．０１重量部以上でもよく、０．０１５重量部以上でもよい。また、基材層への密着性向上の観点から、いくつかの態様において、シランカップリング剤の使用量は、Ａ層を構成するモノマー成分１００重量部に対して、例えば３重量部以下であってよく、１重量部以下でもよく、０．５重量部以下でもよい。 The amount of the silane coupling agent used can be set so as to obtain the desired effect of use, and is not particularly limited. In some embodiments, the amount of the silane coupling agent used may be, for example, 0.001 part by weight or more with respect to 100 parts by weight of the monomer component constituting the polymer contained in the layer A, and has a higher effect. From the viewpoint of obtaining, it may be 0.005 parts by weight or more, 0.01 parts by weight or more, or 0.015 parts by weight or more. Further, from the viewpoint of improving the adhesion to the base material layer, in some embodiments, the amount of the silane coupling agent used is, for example, 3 parts by weight or less with respect to 100 parts by weight of the monomer component constituting the A layer. It may be 1 part by weight or less, or 0.5 part by weight or less.
　なお、モノマー成分がアルコキシシリル基含有モノマーを含む態様では、Ａ層に含まれるシランカップリング剤の一部または全部として上記アルコキシシリル基含有モノマーを利用してもよい。 In the embodiment in which the monomer component contains an alkoxysilyl group-containing monomer, the alkoxysilyl group-containing monomer may be used as part or all of the silane coupling agent contained in the layer A.
　Ａ層の形成に用いられる粘着剤組成物Ａは、必要に応じて、ｐＨ調整等の目的で使用される酸または塩基（アンモニア水等）を含有するものであり得る。該組成物に含有され得る他の任意成分としては、粘度調整剤（例えば増粘剤）、レベリング剤、可塑剤、充填剤、顔料や染料等の着色剤、安定剤、防腐剤、老化防止剤等の、粘着剤組成物の分野において一般的な各種の添加剤が例示される。このような各種添加剤については、従来公知のものを常法により使用することができ、特に本発明を特徴づけるものではないので、詳細な説明は省略する。 The pressure-sensitive adhesive composition A used for forming the A layer may contain an acid or a base (ammonia water or the like) used for the purpose of pH adjustment or the like, if necessary. Other optional components that may be contained in the composition include viscosity modifiers (eg, thickeners), leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, anti-aging agents. Various additives that are common in the field of pressure-sensitive adhesive compositions such as, etc. are exemplified. As for such various additives, conventionally known ones can be used by a conventional method and do not particularly characterize the present invention, and thus detailed description thereof will be omitted.
（２）Ｂ層
　ここに開示される積層体の粘着剤層は、粘着剤層の少なくとも基材層側の表面を構成するＡ層に加えて、該Ａ層の背面側に配置されたＢ層をさらに含み得る。このようにＡ層とＢ層とを含む構成によると、例えば、Ａ層により良好な水剥離性を付与しつつ、Ｂ層により粘着剤層のバルク特性（例えば、耐水性、凝集性、耐熱性等）を調節することができる。したがって、Ａ層とＢ層とを含む構成の粘着剤層によると、水剥離性が良く、かつ耐水信頼性に優れた積層体が得られやすい。例えば、水浸漬後剥離力低下率が低く、かつ水剥離力低下率の高い積層体が好適に実現され得る。また、例えば、強粘着性と良好な水剥離性とを高レベルで両立する粘着剤層が好適に実現され得る。 (2) Layer B The pressure-sensitive adhesive layer of the laminated body disclosed here is a layer B arranged on the back surface side of the layer A in addition to the layer A constituting at least the surface of the pressure-sensitive adhesive layer on the base material layer side. Can be further included. According to the configuration including the A layer and the B layer as described above, for example, the bulk property (for example, water resistance, cohesiveness, heat resistance) of the pressure-sensitive adhesive layer is provided by the B layer while imparting better water peelability to the A layer. Etc.) can be adjusted. Therefore, according to the pressure-sensitive adhesive layer having the structure including the A layer and the B layer, it is easy to obtain a laminated body having good water peelability and excellent water resistance reliability. For example, a laminate having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized. Further, for example, an adhesive layer having both strong adhesiveness and good water peelability at a high level can be preferably realized.
　Ｂ層は、Ａ層の背面に直接接して配置されていてもよく、Ａ層の背面との間に他の層を介して配置されていてもよい。上記他の層（以下、中間層ともいう。）は、典型的には非粘着性の層であって、例えば、上述の基材層に用いられ得る樹脂フィルムや発泡体シート、織布や織布、紙類、金属箔等を利用し得る。積層体の柔軟性や被着体の表面形状への追従性の観点から、いくつかの態様において、Ａ層とＢ層とが直接接して（すなわち、中間層を介さずに）積層した構成の粘着剤層を好ましく採用し得る。 The B layer may be arranged in direct contact with the back surface of the A layer, or may be arranged between the back surface of the A layer and the back surface of the A layer via another layer. The other layer (hereinafter, also referred to as an intermediate layer) is typically a non-adhesive layer, for example, a resin film, a foam sheet, a woven fabric, or a woven material that can be used for the above-mentioned base material layer. Cloth, paper, metal foil, etc. can be used. From the viewpoint of the flexibility of the laminated body and the followability to the surface shape of the adherend, in some embodiments, the A layer and the B layer are directly in contact with each other (that is, without an intermediate layer). A pressure-sensitive adhesive layer can be preferably adopted.
　Ｂ層は、例えば、アクリル系粘着剤、ゴム系粘着剤、シリコーン系粘着剤、ポリエステル系粘着剤、ウレタン系粘着剤、ポリエーテル系粘着剤、ポリアミド系粘着剤、フッ素系粘着剤等の公知の各種粘着剤から選択される１種または２種以上の粘着剤を含んで構成された粘着剤層であり得る。透明性や耐候性等の観点から、いくつかの態様において、Ｂ層の構成材料としてアクリル系粘着剤を好ましく採用し得る。Ｂ層を構成するアクリル系粘着剤は、例えば、Ａ層に使用し得るアクリル系粘着剤として例示したものから、Ａ層との組合せにおいて所望の特性が発揮されるように選択することができる。Ｂ層は、一層からなる単層構造であってもよく、組成の異なる二以上の層を含む多層構造であってもよい。 The B layer is known as, for example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyether-based pressure-sensitive adhesive, a polyamide-based pressure-sensitive adhesive, a fluorine-based pressure-sensitive adhesive, and the like. It may be a pressure-sensitive adhesive layer composed of one type or two or more types of pressure-sensitive adhesives selected from various pressure-sensitive adhesives. From the viewpoint of transparency, weather resistance, and the like, an acrylic pressure-sensitive adhesive may be preferably used as the constituent material of the B layer in some embodiments. The acrylic pressure-sensitive adhesive constituting the B layer can be selected from those exemplified as the acrylic pressure-sensitive adhesive that can be used for the A layer, for example, so as to exhibit desired characteristics in combination with the A layer. The B layer may have a single-layer structure composed of one layer, or may have a multi-layer structure including two or more layers having different compositions.
　いくつかの態様において、Ｂ層に含まれる重合物（例えば、アクリル系重合物）を構成するモノマー成分は、該モノマー成分全体の４０重量％以上の割合でＣ１－２０（メタ）アクリル酸アルキルエステルを含み得る。Ｂ層のモノマー成分全体に占めるＣ１－２０（メタ）アクリル酸アルキルエステルの割合は、例えば９８重量％以下であってよく、Ｂ層の凝集性向上の観点から９５重量％以下であってもよく、８５重量％以下でもよく、７０重量％以下でもよく、６０重量％以下でもよい。
　Ｂ層を構成するモノマー成分は、（メタ）アクリル酸アルキルエステルとともに、共重合性モノマーを含み得る。共重合性モノマーは、Ａ層に用いられ得る共重合性モノマーとして例示したものから適宜選択することができる。共重合性モノマーの使用量は、Ｂ層を構成するモノマー成分全体の例えば５重量％以上であってよく、１５重量％以上でもよく、３０重量％以上でもよく、４０重量％以上でもよい。 In some embodiments, the monomer component constituting the polymer (for example, an acrylic polymer) contained in the B layer is an alkyl C 1-20 (meth) acrylate in a proportion of 40% by weight or more of the total monomer component. May include esters. The ratio of the C 1-20 (meth) acrylic acid alkyl ester to the total monomer component of the B layer may be, for example, 98% by weight or less, and even if it is 95% by weight or less from the viewpoint of improving the cohesiveness of the B layer. It may be 85% by weight or less, 70% by weight or less, or 60% by weight or less.
The monomer component constituting the B layer may contain a copolymerizable monomer together with the (meth) acrylic acid alkyl ester. The copolymerizable monomer can be appropriately selected from those exemplified as the copolymerizable monomer that can be used for the A layer. The amount of the copolymerizable monomer used may be, for example, 5% by weight or more, 15% by weight or more, 30% by weight or more, or 40% by weight or more of the total monomer components constituting the B layer.
　いくつかの態様において、Ｂ層を構成するモノマー成分に占めるカルボキシ基含有モノマーの割合は、例えば２重量％以下であってよく、１重量％以下でもよく、０．５重量％以下でもよい。Ｂ層を構成するモノマー成分としてカルボキシ基含有モノマーを実質的に使用しなくてもよい。ここで、カルボキシ基含有モノマーを実質的に使用しないとは、少なくとも意図的にはカルボキシ基含有モノマーを使用しないことをいう。このような組成のＢ層を有する粘着剤層は、耐水信頼性の高いものとなりやすいので好ましい。 In some embodiments, the proportion of the carboxy group-containing monomer in the monomer components constituting the B layer may be, for example, 2% by weight or less, 1% by weight or less, or 0.5% by weight or less. It is not necessary to substantially use the carboxy group-containing monomer as the monomer component constituting the B layer. Here, the fact that the carboxy group-containing monomer is not substantially used means that the carboxy group-containing monomer is not used at least intentionally. A pressure-sensitive adhesive layer having a B layer having such a composition is preferable because it tends to have high water resistance and reliability.
　Ａ層とＢ層とを備える粘着剤層の一好適例として、Ｂ層のゲル分率がＡ層のゲル分率より高い、および、Ｂ層の膨潤度がＡ層の膨潤度より低い、の一方または両方を満たす粘着剤層が挙げられる。このような構成によると、水浸漬後剥離力低下率が低く、かつ水剥離力低下率の高い粘着剤層が得られやすい。 As a preferable example of the pressure-sensitive adhesive layer having the A layer and the B layer, the gel fraction of the B layer is higher than the gel fraction of the A layer, and the swelling degree of the B layer is lower than the swelling degree of the A layer. Examples include a pressure-sensitive adhesive layer that satisfies one or both. According to such a configuration, it is easy to obtain an adhesive layer having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in peeling force in water.
　いくつかの態様において、Ｂ層は、光硬化型粘着剤組成物または溶剤型粘着剤組成物から形成された層であり得る。このような組成物から形成されたＢ層によると、耐水信頼性のよい粘着剤層が得られやすい。例えば、水分散型粘着剤組成物から形成されたＡ層と光硬化型粘着剤組成物から形成されたＢ層との組合せ、または、水分散型粘着剤組成物から形成されたＡ層と溶剤型粘着剤組成物から形成されたＢ層との組合せにおいて、水浸漬後剥離力低下率が低く、かつ水剥離力低下率の高い粘着剤層が好適に実現され得る。いくつかの態様において、耐水性向上の観点から、水親和剤を実質的に含有しないＢ層を好ましく採用し得る。 In some embodiments, the layer B may be a layer formed from a photocurable pressure-sensitive adhesive composition or a solvent-type pressure-sensitive adhesive composition. According to the B layer formed from such a composition, a pressure-sensitive adhesive layer having good water resistance and reliability can be easily obtained. For example, a combination of a layer A formed from a water-dispersible pressure-sensitive adhesive composition and a layer B formed from a photocurable pressure-sensitive adhesive composition, or a layer A and a solvent formed from a water-dispersible pressure-sensitive adhesive composition. In combination with the B layer formed from the mold pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer having a low rate of decrease in peeling force after immersion in water and a high rate of decrease in water peeling force can be preferably realized. In some embodiments, from the viewpoint of improving water resistance, the B layer which does not substantially contain a water affinity agent can be preferably adopted.
（３）粘着剤層に関する共通事項
　粘着剤層は、粘着剤組成物の硬化層であり得る。すなわち、該粘着剤層は、粘着剤組成物を適当な表面に付与（例えば塗布）した後、硬化処理を適宜施すことにより形成され得る。２種以上の硬化処理（乾燥、架橋、重合等）を行う場合、これらは、同時に、または多段階にわたって行うことができる。モノマー成分の部分重合物（アクリル系ポリマーシロップ）を用いた粘着剤組成物では、典型的には、上記硬化処理として、最終的な共重合反応が行われる。すなわち、部分重合物をさらなる共重合反応に供して完全重合物を形成する。例えば、光硬化性の粘着剤組成物であれば、光照射が実施される。必要に応じて、架橋、乾燥等の硬化処理が実施されてもよい。例えば、光硬化性粘着剤組成物で乾燥させる必要がある場合は、乾燥後に光硬化を行うとよい。完全重合物を用いた粘着剤組成物では、典型的には、上記硬化処理として、必要に応じて乾燥（加熱乾燥）、架橋等の処理が実施される。二層以上の多層構造の粘着剤層は、あらかじめ形成した粘着剤層を貼り合わせることによって作製することができる。あるいは、あらかじめ形成した第一の粘着剤層の上に粘着剤組成物を塗布し、該粘着剤組成物を硬化させて第二の粘着剤層を形成してもよい。 (3) Common matters concerning the pressure-sensitive adhesive layer The pressure-sensitive adhesive layer may be a cured layer of the pressure-sensitive adhesive composition. That is, the pressure-sensitive adhesive layer can be formed by applying (for example, coating) the pressure-sensitive adhesive composition to an appropriate surface and then appropriately performing a curing treatment. When performing two or more types of curing treatments (drying, cross-linking, polymerization, etc.), these can be performed simultaneously or in multiple steps. In a pressure-sensitive adhesive composition using a partial polymer (acrylic polymer syrup) of a monomer component, a final copolymerization reaction is typically performed as the above-mentioned curing treatment. That is, the partial polymer is subjected to a further copolymerization reaction to form a complete polymer. For example, in the case of a photocurable pressure-sensitive adhesive composition, light irradiation is performed. If necessary, a hardening treatment such as crosslinking or drying may be carried out. For example, when it is necessary to dry with a photocurable pressure-sensitive adhesive composition, it is preferable to perform photocuring after drying. In the pressure-sensitive adhesive composition using a complete polymer, typically, as the curing treatment, treatments such as drying (heat drying) and cross-linking are carried out as necessary. The pressure-sensitive adhesive layer having a multi-layer structure of two or more layers can be produced by laminating the pressure-sensitive adhesive layers formed in advance. Alternatively, the pressure-sensitive adhesive composition may be applied onto the first pressure-sensitive adhesive layer formed in advance, and the pressure-sensitive adhesive composition may be cured to form a second pressure-sensitive adhesive layer.
　粘着剤組成物の塗布は、例えば、グラビアロールコーター、リバースロールコーター、キスロールコーター、ディップロールコーター、バーコーター、ナイフコーター、スプレーコーター等の慣用のコーターを用いて実施することができる。例えば、基材層上に粘着剤層を設ける方法として、該基材層に粘着剤組成物を直接付与して粘着剤層を形成する直接法を用いてもよく、剥離面上に形成した粘着剤層を基材層に転写する転写法を用いてもよい。 The pressure-sensitive adhesive composition can be applied using, for example, a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater. For example, as a method of providing the pressure-sensitive adhesive layer on the base material layer, a direct method of directly applying the pressure-sensitive adhesive composition to the base material layer to form the pressure-sensitive adhesive layer may be used, and the pressure-sensitive adhesive formed on the peeling surface may be used. A transfer method of transferring the agent layer to the base material layer may be used.
　粘着剤層の厚さは特に限定されず、例えば３μｍ～１０００μｍ程度であり得る。粘着剤層を基材層や被着体に密着させて耐水信頼性を高める観点から、いくつかの態様において、粘着剤層の厚さは、例えば５μｍ以上であってよく、１０μｍ以上でもよく、２０μｍ以上でもよく、３０μｍ以上でもよく、５０μｍ以上でもよく、５０μｍ超でもよく、７０μｍ以上でもよく、１００μｍ以上でもよく、１２０μｍ以上でもよい。また、粘着剤層の凝集破壊による糊残りの発生を防止する観点から、いくつかの態様において、粘着剤層の厚さは、例えば５００μｍ以下であってよく、３００μｍ以下でもよく、２００μｍ以下でもよく、１７０μｍ以下でもよい。ここに開示される技術は、粘着剤層の厚さが１３０μｍ以下、９０μｍ以下、６０μｍ以下または４０μｍ以下である積層体にも好ましく適用され得る。 The thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, about 3 μm to 1000 μm. From the viewpoint of making the pressure-sensitive adhesive layer adhere to the base material layer or the adherend to enhance water resistance reliability, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 5 μm or more, or 10 μm or more. It may be 20 μm or more, 30 μm or more, 50 μm or more, 50 μm or more, 70 μm or more, 100 μm or more, or 120 μm or more. Further, from the viewpoint of preventing the generation of adhesive residue due to cohesive failure of the pressure-sensitive adhesive layer, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 500 μm or less, 300 μm or less, or 200 μm or less. , 170 μm or less. The technique disclosed herein can also be preferably applied to a laminate having a pressure-sensitive adhesive layer thickness of 130 μm or less, 90 μm or less, 60 μm or less, or 40 μm or less.
　いくつかの好ましい態様では、粘着剤層はＡ層からなる。換言すると、粘着剤層はＢ層を含まないＡ層のみの単層構造であり得る。ここに開示される技術によると、基材層表面への親水層形成により優れた水剥離性が実現されるので、水剥離性と他の特性（例えば耐水信頼性）との両立を目的として、粘着剤層を多層構造にする必要はない。つまり、Ｂ層に頼ることなく、所望の特性を実現することができる。このことは、粘着剤層の生産効率の観点から有利である。また、粘着剤層がＡ層からなる積層体によると、被着体がガラス材料（例えばアルカリガラス板）などの親水性表面を有するものである場合、基材層からの水剥離性だけでなく、被着体からの水剥離性にも優れたものとなり得る。なお、Ａ層からなる粘着剤層では、粘着剤層の厚さとはＡ層の厚さを意味する。 In some preferred embodiments, the pressure-sensitive adhesive layer consists of layer A. In other words, the pressure-sensitive adhesive layer may have a single-layer structure of only the A layer, which does not include the B layer. According to the technique disclosed herein, excellent water exfoliation property is realized by forming a hydrophilic layer on the surface of the base material layer, so that the purpose is to achieve both water exfoliation property and other properties (for example, water resistance reliability). The pressure-sensitive adhesive layer does not need to have a multi-layer structure. That is, the desired characteristics can be realized without relying on the B layer. This is advantageous from the viewpoint of the production efficiency of the pressure-sensitive adhesive layer. Further, according to the laminate in which the pressure-sensitive adhesive layer is composed of the A layer, when the adherend has a hydrophilic surface such as a glass material (for example, an alkaline glass plate), not only the water releasability from the base material layer but also the water releasability , It can also be excellent in water detachability from the adherend. In the pressure-sensitive adhesive layer composed of the A layer, the thickness of the pressure-sensitive adhesive layer means the thickness of the A layer.
　粘着剤層が厚くなると、概して、水剥離性と耐水信頼性との両立は難しくなる傾向にある。かかる観点から、該粘着剤層の厚さが例えば５０μｍ超である態様において、粘着剤層がＡ層とＢ層とを含む構成を好ましく採用し得る。このような構成の粘着剤層によると、該粘着剤層が厚くなっても、水剥離性と耐水信頼性とを高レベルで両立する粘着剤層が得られやすい。 As the pressure-sensitive adhesive layer becomes thicker, it tends to be difficult to achieve both water peelability and water resistance reliability in general. From this point of view, in an embodiment in which the thickness of the pressure-sensitive adhesive layer is, for example, more than 50 μm, a configuration in which the pressure-sensitive adhesive layer includes an A layer and a B layer can be preferably adopted. According to the pressure-sensitive adhesive layer having such a structure, even if the pressure-sensitive adhesive layer is thickened, it is easy to obtain a pressure-sensitive adhesive layer having both water peelability and water resistance reliability at a high level.
　粘着剤層がＡ層とＢ層とを含む態様において、Ａ層の厚さは、例えば１μｍ以上であってよく、２μｍ以上でもよく、４μｍ以上でもよく、５μｍ以上でもよく、１０μｍ以上でもよく、１５μｍ以上でもよい。また、Ａ層の厚さは、例えば５０μｍ以下であってよく、４５μｍ以下でもよく、３５μｍ以下でもよく、２５μｍ以下でもよい。特に、水分散型粘着剤組成部から形成されたＡ層を備える態様や、Ａ層が水親和剤を含む態様では、Ａ層の厚さが大きすぎないことは、粘着剤層の耐水信頼性の向上、粘着剤層の透明性の向上等の観点から好ましい。 In the embodiment in which the pressure-sensitive adhesive layer includes the A layer and the B layer, the thickness of the A layer may be, for example, 1 μm or more, 2 μm or more, 4 μm or more, 5 μm or more, or 10 μm or more. It may be 15 μm or more. The thickness of the layer A may be, for example, 50 μm or less, 45 μm or less, 35 μm or less, or 25 μm or less. In particular, in a mode in which the A layer formed from the water-dispersible pressure-sensitive adhesive composition portion is provided or in a mode in which the A layer contains a water-affinitive agent, the fact that the thickness of the A layer is not too large means that the water resistance of the pressure-sensitive adhesive layer is reliable. Is preferable from the viewpoint of improving the transparency of the pressure-sensitive adhesive layer and improving the transparency of the pressure-sensitive adhesive layer.
　粘着剤層がＡ層とＢ層とを含む態様において、Ｂ層の厚さは、例えば５μｍ以上であってよく、１０μｍ以上でもよい。Ａ層の背面側にＢ層を設けることによる効果をよりよく発揮する観点から、いくつかの態様において、Ｂ層の厚さは、例えば２０μｍ以上であってよく、３０μｍ以上でもよく、５０μｍ以上でもよく、７０μｍ以上でもよく、１００μｍ以上でもよい。 In the embodiment in which the pressure-sensitive adhesive layer includes the A layer and the B layer, the thickness of the B layer may be, for example, 5 μm or more, or 10 μm or more. From the viewpoint of better exerting the effect of providing the B layer on the back surface side of the A layer, in some embodiments, the thickness of the B layer may be, for example, 20 μm or more, 30 μm or more, or 50 μm or more. It may be 70 μm or more, or 100 μm or more.
　粘着剤層がＡ層とＢ層とを含む態様において、粘着剤層全体の厚さに占めるＡ層の厚さは、例えば９０％以下であってよく、７０％以下であることが好ましく、５０％以下でもよく、３０％以下でもよく、２０％以下でもよく、１５％以下でもよい。また、Ａ層の形成容易性や水剥離性の観点から、いくつかの態様において、粘着剤層全体の厚さに占めるＡ層の厚さは、例えば３％以上であってよく、５％以上でもよく、７％以上でもよく、１０％以上でもよい。 In the embodiment in which the pressure-sensitive adhesive layer includes the A layer and the B layer, the thickness of the A layer in the total thickness of the pressure-sensitive adhesive layer may be, for example, 90% or less, preferably 70% or less, and is preferably 50. It may be% or less, 30% or less, 20% or less, and 15% or less. Further, from the viewpoint of ease of formation of the A layer and water peelability, in some embodiments, the thickness of the A layer in the total thickness of the pressure-sensitive adhesive layer may be, for example, 3% or more, and 5% or more. However, it may be 7% or more, or 10% or more.
　＜剥離方法＞
　この明細書によると、基材層と粘着剤層とを有する積層体の該基材層から該粘着剤層を剥離する方法が提供される。この方法は、上記基材層からの上記粘着剤層の剥離前線において上記基材層と上記粘着剤層との界面に水性液体が存在する状態で、上記剥離前線の移動に追随して上記水性液体の上記界面への進入を進行させつつ上記基材層から上記粘着剤層を剥離する水剥離工程を含む。また、上記粘着剤層は、基材層側表面を構成するＡ層を備える。さらに、上記基材層の粘着剤層側表面には親水化処理が施されている。上記水剥離工程によると、上記水性液体を有効に利用して基材層から粘着剤層を剥離することができる。 <Peeling method>
According to this specification, there is provided a method of peeling the pressure-sensitive adhesive layer from the base material layer of a laminate having a base material layer and a pressure-sensitive adhesive layer. In this method, in the state where the aqueous liquid is present at the interface between the base material layer and the pressure-sensitive adhesive layer in the peeling front of the pressure-sensitive adhesive layer from the base material layer, the water-based material follows the movement of the peeling front. It includes a water peeling step of peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the liquid into the interface. Further, the pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side. Further, the surface of the base material layer on the pressure-sensitive adhesive layer side is hydrophilized. According to the water peeling step, the pressure-sensitive adhesive layer can be peeled from the base material layer by effectively utilizing the aqueous liquid.
　基材層表面に施される親水化処理としては、特に限定されず、水接触角を低下し得る各種の表面処理を採用することができる。好適例としては、上述の親水層の形成が挙げられる。親水層形成の詳細については上記のとおりであるので、繰返しの説明は省略する。なお、上記親水化処理は、典型的には、コロナ処理やプラズマ処理は含まない。 The hydrophilic treatment applied to the surface of the base material layer is not particularly limited, and various surface treatments capable of reducing the water contact angle can be adopted. Preferable examples include the formation of the above-mentioned hydrophilic layer. Since the details of the formation of the hydrophilic layer are as described above, the repeated description will be omitted. The hydrophilization treatment typically does not include corona treatment or plasma treatment.
　水性液体としては、水または水を主成分とする混合溶媒に、必要に応じて少量の添加剤を含有させたものを用いることができる。上記混合溶媒を構成する水以外の溶媒としては、水と均一に混合し得る低級アルコール（例えばエチルアルコール）や低級ケトン（例えばアセトン）等を使用し得る。上記添加剤としては、公知の界面活性剤等を用いることができる。被着体の汚染を避ける観点から、いくつかの態様において、添加剤を実質的に含有しない水性液体を好ましく使用し得る。環境衛生の観点から、水性液体として水を用いることが特に好ましい。水としては、特に制限されず、用途に応じて求められる純度や入手容易性等を考慮して、例えば蒸留水、イオン交換水、水道水等を用いることができる。 As the aqueous liquid, water or a mixed solvent containing water as a main component and containing a small amount of additives as necessary can be used. As the solvent other than water constituting the mixed solvent, a lower alcohol (for example, ethyl alcohol) or a lower ketone (for example, acetone) that can be uniformly mixed with water can be used. As the additive, a known surfactant or the like can be used. From the viewpoint of avoiding contamination of the adherend, an aqueous liquid containing substantially no additive may be preferably used in some embodiments. From the viewpoint of environmental hygiene, it is particularly preferable to use water as the aqueous liquid. The water is not particularly limited, and for example, distilled water, ion-exchanged water, tap water, or the like can be used in consideration of the purity and availability required according to the application.
　いくつかの態様において、上記剥離方法は、例えば水剥離力Ｎ２の測定時と同様に、基材層に貼り付けられた粘着剤層の外縁付近の基材層上に水性液体を供給し、その水性液体を上記粘着剤層の外縁から該粘着剤層と上記基材層との界面に進入させた後、新たな水の供給を行うことなく（すなわち、剥離開始前に基材層上に供給した水性液体のみを利用して）粘着剤層の剥離を進行させる態様で好ましく行うことができる。なお、水剥離工程の途中で、剥離前線の移動に追随して粘着剤層と基材層との界面に進入させる水が途中で枯渇するようであれば、該水剥離工程の開始後に断続的または連続的に水を追加供給してもよい。例えば、基材層が吸水性を有する場合や、剥離後の基材層表面または粘着面に水性液体が残留しやすい場合等において、水剥離工程の開始後に水を追加供給する態様を好ましく採用し得る。 In some embodiments, the stripping method supplies an aqueous liquid onto the substrate layer near the outer edge of the pressure-sensitive adhesive layer attached to the substrate layer, similar to, for example, when measuring the water peeling force N2. After the aqueous liquid is allowed to enter the interface between the pressure-sensitive adhesive layer and the base material layer from the outer edge of the pressure-sensitive adhesive layer, it is supplied onto the base material layer without supplying new water (that is, before the start of peeling). It can be preferably carried out in an embodiment in which the peeling of the pressure-sensitive adhesive layer is promoted (using only the aqueous liquid). If the water entering the interface between the pressure-sensitive adhesive layer and the base material layer is depleted in the middle of the water peeling step following the movement of the peeling front, it is intermittent after the start of the water peeling step. Alternatively, additional water may be continuously supplied. For example, when the base material layer has water absorption, or when the aqueous liquid tends to remain on the surface or adhesive surface of the base material layer after peeling, a mode in which water is additionally supplied after the start of the water peeling step is preferably adopted. obtain.
　剥離開始前に供給する水性液体の量は、粘着剤層の貼付け範囲外から該粘着剤層と基材層との界面に上記水性液体を導入し得る量であればよく、特に限定されない。上記水性液体の量は、例えば５μＬ以上であってよく、１０μＬ以上が適当であり、２０μＬ以上でもよい。また、上記水性液体の量の上限について特に制限はない。いくつかの態様において、作業性向上等の観点から、上記水性液体の量は、例えば１０ｍＬ以下であってよく、５ｍＬ以下でもよく、１ｍＬ以下でもよく、０．５ｍＬ以下でもよく、０．１ｍＬ以下でもよく、０．０５ｍＬ以下でもよい。上記水性液体の量を少なくすることにより、粘着剤層の剥離後に上記水性液体を乾燥や拭き取り等により除去する操作を省略または簡略化し得る。 The amount of the aqueous liquid supplied before the start of peeling is not particularly limited as long as the amount of the aqueous liquid can be introduced into the interface between the pressure-sensitive adhesive layer and the base material layer from outside the sticking range of the pressure-sensitive adhesive layer. The amount of the aqueous liquid may be, for example, 5 μL or more, 10 μL or more is appropriate, and 20 μL or more may be used. Further, there is no particular limitation on the upper limit of the amount of the aqueous liquid. In some embodiments, from the viewpoint of improving workability, the amount of the aqueous liquid may be, for example, 10 mL or less, 5 mL or less, 1 mL or less, 0.5 mL or less, 0.1 mL or less. It may be 0.05 mL or less. By reducing the amount of the aqueous liquid, the operation of removing the aqueous liquid by drying, wiping, or the like after the pressure-sensitive adhesive layer is peeled off can be omitted or simplified.
　剥離開始時に上記粘着剤層の外縁から該粘着剤層と上記基材層との界面に水性液体を進入させる操作は、例えば、粘着剤層の外縁において上記界面にカッターナイフや針等の治具の先端を差し込む、粘着剤層の外縁を鉤や爪等で引掻いて持ち上げる、強粘着性の粘着テープや吸盤等を積層体の外縁付近の背面に付着させて該粘着剤層の端を持ち上げる、等の態様で行うことができる。このように粘着剤層の外縁から上記界面に水性液体を強制的に進入させることにより、基材層と上記粘着剤層との界面に水性液体が存在する状態を効率よく形成することができる。また、水性液体を界面に強制的に進入させる操作を行って剥離のきっかけをつくった後における良好な水剥離性と、かかる操作を行わない場合における高い耐水信頼性とを、好適に両立することができる。 The operation of allowing the aqueous liquid to enter the interface between the pressure-sensitive adhesive layer and the base material layer from the outer edge of the pressure-sensitive adhesive layer at the start of peeling is, for example, a jig such as a cutter knife or a needle at the interface on the outer edge of the pressure-sensitive adhesive layer. Insert the tip of the adhesive layer, scratch the outer edge of the adhesive layer with a hook or nail, and lift it. Attach a strong adhesive tape or suction cup to the back surface near the outer edge of the laminate to lift the edge of the adhesive layer. , Etc. can be performed. By forcibly allowing the aqueous liquid to enter the interface from the outer edge of the pressure-sensitive adhesive layer in this way, it is possible to efficiently form a state in which the aqueous liquid exists at the interface between the base material layer and the pressure-sensitive adhesive layer. In addition, good water peeling property after creating a trigger for peeling by forcibly entering the aqueous liquid into the interface and high water resistance reliability when such operation is not performed are preferably compatible. Can be done.
　上記剥離方法により剥離される粘着剤層は、例えば、ここに開示されるいずれかの粘着剤層であることが好ましい。上記剥離方法は、ここに開示されるいずれかの積層体における基材層からの粘着剤層の剥離方法として好適である。 The pressure-sensitive adhesive layer to be peeled off by the above-mentioned peeling method is preferably, for example, any of the pressure-sensitive adhesive layers disclosed herein. The peeling method is suitable as a peeling method for the pressure-sensitive adhesive layer from the base material layer in any of the laminates disclosed herein.
　いくつかの態様に係る水剥離工程は、上記剥離前線を１０ｍｍ／分以上の速度で移動させる態様で好ましく実施され得る。剥離前線を１０ｍｍ／分以上の速度で移動させることは、例えば剥離角度１８０度の条件においては、粘着剤層を２０ｍｍ／分以上の引張速度で剥離することに相当する。上記剥離前線を移動させる速度は、例えば５０ｍｍ／分以上でもよく、１５０ｍｍ／分以上でもよく、３００ｍｍ／分以上でもよく、５００ｍｍ／分以上でもよい。ここに開示される剥離方法によると、上記水性液体の上記界面への進入を進行させつつ上記基材層から上記粘着剤層を剥離することにより、このように比較的早い剥離速度であっても良好な水剥離性を発揮することができる。剥離前線を移動させる速度の上限は特に制限されない。上記剥離前線を移動させる速度は、例えば１０００ｍｍ／分以下であり得る。 The water peeling step according to some aspects can be preferably carried out in a mode in which the peeling front is moved at a speed of 10 mm / min or more. Moving the peeling front at a speed of 10 mm / min or more corresponds to peeling the pressure-sensitive adhesive layer at a tensile speed of 20 mm / min or more, for example, under the condition of a peeling angle of 180 degrees. The speed at which the peeling front is moved may be, for example, 50 mm / min or more, 150 mm / min or more, 300 mm / min or more, or 500 mm / min or more. According to the peeling method disclosed herein, by peeling the pressure-sensitive adhesive layer from the base material layer while advancing the entry of the aqueous liquid into the interface, even at such a relatively high peeling speed. Good water releasability can be exhibited. The upper limit of the speed at which the peeling front is moved is not particularly limited. The speed at which the peeling front is moved can be, for example, 1000 mm / min or less.
　ここに開示される剥離方法は、例えば、該方法に使用する水性液体（例えば水）の体積１０μＬ当たりの粘着剤層の剥離面積が、例えば５０ｃｍ２以上、好ましくは１００ｃｍ２以上となる態様で実施することができる。 The peeling method disclosed herein is carried out, for example, in such a manner that the peeling area of the pressure-sensitive adhesive layer per 10 μL of the volume of the aqueous liquid (for example, water) used in the method is, for example, 50 cm 2 or more, preferably 100 cm 2 or more. can do.
　＜用途＞
　ここに開示される積層体は、水等の水性液体を用いて基材層から容易に剥離し得ることからリワーク性がよく、かつ耐水信頼性が良いという特長を活かして、例えば各種の携帯機器（ポータブル機器）、自動車、家電製品等を構成する部材に貼り付けられる態様で、該部材の固定、接合、成形、装飾、保護、支持等の用途に用いられ得る。上記部材の少なくとも表面を構成する材質は、例えば、アルカリガラス板や無アルカリガラス等のガラス；樹脂フィルム、ステンレス鋼（ＳＵＳ）、アルミニウム等の金属材料；アクリル樹脂、ＡＢＳ樹脂、ポリカーボネート樹脂、ポリスチレン樹脂、透明ポリイミド樹脂等の樹脂材料；等であり得る。ここに開示される積層体は、アクリル系、ポリエステル系、アルキド系、メラミン系、ウレタン系、酸エポキシ架橋系、あるいはこれらの複合系（例えばアクリルメラミン系、アルキドメラミン系）等の塗料による塗装面や、亜鉛メッキ鋼板等のメッキ面に貼り付けられてもよい。 <Use>
The laminate disclosed herein can be easily peeled off from the base material layer using an aqueous liquid such as water, so that it has good reworkability and high water resistance reliability, for example, various portable devices. It can be used for fixing, joining, molding, decorating, protecting, supporting, etc. of a member (portable device), an automobile, a home appliance, or the like. The material constituting at least the surface of the above member is, for example, glass such as an alkaline glass plate or non-alkali glass; a metal material such as a resin film, stainless steel (SUS), or aluminum; an acrylic resin, an ABS resin, a polycarbonate resin, or a polystyrene resin. , Resin material such as transparent polyimide resin; etc. The laminate disclosed herein is a coated surface with a paint such as acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (for example, acrylic melamine, alkyd melamine). Alternatively, it may be attached to a plated surface such as a zinc-plated steel plate.
　積層体が貼付けられる被着体の表面の水接触角は特に限定されない。いくつかの態様において、被着体表面は、水接触角が、例えば６０度以下、好ましくは５０度以下となる程度の親水性を示す表面であり得る。いくつかの好ましい態様において、上記表面の水接触角は、例えば４５度以下であってよく、４０度以下でもよく、３５度以下でもよく、３０度以下でもよい。上記水接触角が小さくなると、被着体表面に沿って水が濡れ広がりやすくなり、積層体の水剥離性が向上する傾向にある。ここに開示される積層体は、例えば、水接触角が３０度以下（例えば１５度以下、さらには１０度以下）程度の材料（例えばアルカリガラス板や無アルカリガラス等のガラス）からなる表面を有する部材の固定に好ましく利用され得る。上記被着体表面の水接触角の下限は、原理上０度である。いくつかの態様において、上記被着体表面の水接触角は、０度超でもよく、１度以上でもよく、３度以上でもよく、５度以上でもよい。他のいくつかの態様では、被着体表面の水接触角は、３０度超であってもよく、５０度超であってもよく、６０度超（例えば７０度以上）であってもよい。ここに開示される積層体は、水接触角の異なる種々の材料に用いることが可能である。被着体表面の水接触角は、後述の実施例に記載の方法と同様の方法により測定される。 The water contact angle on the surface of the adherend to which the laminate is attached is not particularly limited. In some embodiments, the adherend surface may be a surface exhibiting hydrophilicity such that the water contact angle is, for example, 60 degrees or less, preferably 50 degrees or less. In some preferred embodiments, the water contact angle of the surface may be, for example, 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less. When the water contact angle becomes small, water tends to get wet and spread along the surface of the adherend, and the water detachability of the laminated body tends to be improved. The laminate disclosed here has, for example, a surface made of a material (for example, glass such as an alkaline glass plate or non-alkali glass) having a water contact angle of about 30 degrees or less (for example, 15 degrees or less, further 10 degrees or less). It can be preferably used for fixing the members to be held. The lower limit of the water contact angle on the surface of the adherend is 0 degrees in principle. In some embodiments, the water contact angle on the surface of the adherend may be greater than 0 degrees, greater than 1 degree, greater than 3 degrees, or greater than or equal to 5 degrees. In some other embodiments, the water contact angle of the adherend surface may be greater than 30 degrees, greater than 50 degrees, greater than 60 degrees (eg, greater than 70 degrees). .. The laminate disclosed herein can be used for various materials having different water contact angles. The water contact angle on the surface of the adherend is measured by the same method as described in Examples described later.
　ここに開示される積層体は、例えば、液晶表示装置、有機ＥＬ（エレクトロルミネッセンス）表示装置、ＰＤＰ（プラズマディスプレイパネル）、電子ペーパー等の表示装置（画像表示装置）や、タッチパネル等の入力装置等の機器（光学機器）、特に、フォルダブル表示装置や車載用の表示装置のように高価な部材を含む場合に好ましく用いられる。 The laminate disclosed herein includes, for example, a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), a display device such as electronic paper (image display device), an input device such as a touch panel, and the like. (Optical equipment), particularly preferably used when an expensive member such as a foldable display device or an in-vehicle display device is included.
　ここに開示される積層体を用いて光学部材を貼り合わせる態様としては、特に限定されず、例えば、（１）ここに開示される積層体の基材層が光学部材であり、粘着剤層を介して光学部材同士（したがって被着体は光学部材）を貼り合わせる態様や、（２）ここに開示される積層体の基材層が光学部材であり、粘着剤層を介して光学部材以外の部材（被着体）に貼り合わせる態様であってもよいし、（３）ここに開示される積層体の基材層が光学部材以外の材料であり、積層体（具体的には、その粘着剤層）を光学部材（被着体）に貼り合わせる態様であってもよい。なお、基材層が光学部材を含む形態の積層体は、粘着型光学部材（例えば、粘着型光学フィルム）としても把握され得る。また、ここに開示される積層体の基材層が上述の機能性フィルムを含む場合には、ここに開示される積層体は、機能性フィルムの少なくとも片面側にここに開示される粘着剤層を有する「粘着型機能性フィルム」としても把握され得る。 The mode in which the optical members are bonded using the laminate disclosed here is not particularly limited, and for example, (1) the base material layer of the laminate disclosed here is the optical member, and the pressure-sensitive adhesive layer is used. The mode in which the optical members are bonded to each other (therefore, the adherend is an optical member) via the optical member, and (2) the base material layer of the laminated body disclosed here is the optical member, and other than the optical member via the adhesive layer. It may be attached to a member (adhesive body), or (3) the base material layer of the laminate disclosed here is a material other than the optical member, and the laminate (specifically, its adhesion) The agent layer) may be attached to the optical member (adhesive body). The laminate in which the base material layer includes an optical member can also be grasped as an adhesive optical member (for example, an adhesive optical film). Further, when the base material layer of the laminate disclosed herein includes the above-mentioned functional film, the laminate disclosed here is the pressure-sensitive adhesive layer disclosed here on at least one side of the functional film. It can also be grasped as a "adhesive type functional film" having.
　以下、本発明に関するいくつかの実施例を説明するが、本発明をかかる実施例に示すものに限定することを意図したものではない。なお、以下の説明において「部」および「％」は、特に断りがない限り重量基準である。 Hereinafter, some examples of the present invention will be described, but the present invention is not intended to be limited to those shown in such examples. In the following description, "part" and "%" are based on weight unless otherwise specified.
　＜評価方法＞
　［剥離強度Ｎ０］
　幅２０ｍｍ、長さ１００ｍｍのサイズを有する積層体を試験片として用意する。この積層体の粘着面はＰＥＴフィルムにより裏打ちされている。
　上記試験片をオートクレーブ処理（５０℃、０．５ＭＰａ、１５分）した後、２３℃、５０％ＲＨの環境下において、同環境下において、基材層と粘着剤層との界面にカッターナイフを差し込んで該粘着剤層の長手方向の一端を基材層から剥がし、引張試験機（ミネベア社製、万能引張圧縮試験機、装置名「引張圧縮試験機、ＴＣＭ－１ｋＮＢ」）を用いて、引張速度３００ｍｍ／分、剥離角度１８０度の条件で基材層からの粘着剤層の剥離強度（ただし、下記の水剥離力測定に移行するまで、すなわち剥離界面に蒸留水を供給するまでの間についての剥離強度）を測定する。測定は３回行い、それらの平均値を幅１０ｍｍ当たりの値（単位：Ｎ／１０ｍｍ）に換算した値を剥離強度Ｎ０［Ｎ／１０ｍｍ］とする。なお、剥離強度の測定は、被着体に貼り付けられた試験片の剥離が下から上に進行するように行う。引張試験機としては、上記万能引張圧縮試験機の相当品を用いてもよい。
　光硬化性粘着剤層を含む積層体では、上記オートクレーブから取り出した試験片に対し、２３℃、５０％ＲＨの環境下で基材層を介して光照射を行い、その後に剥離強度を測定する。光照射の条件（波長、照射強度、照射時間等）は、粘着剤層の組成や厚み等に応じて適宜設定される。具体的には、後述の例１－１～１－３０の積層体については、上記オートクレーブ処理後、高圧水銀ランプ（３００ｍＷ／ｃｍ2）を用いて上記基材層側から積算光量３０００ｍＪ／ｃｍ２の紫外線を照射して光硬化性粘着剤層を硬化させる。例２－１～２－２４では、オートクレーブ処理後の光照射は行わない。
　なお、粘着剤層の背面に非粘着性の層が配置されている場合には、ＰＥＴフィルムによる裏打ちは不要である。 <Evaluation method>
[Peeling strength N0]
A laminate having a size of 20 mm in width and 100 mm in length is prepared as a test piece. The adhesive surface of this laminate is lined with a PET film.
After the above test piece is autoclaved (50 ° C., 0.5 MPa, 15 minutes), a cutter knife is placed at the interface between the base material layer and the pressure-sensitive adhesive layer in an environment of 23 ° C. and 50% RH. Insert and peel off one end of the pressure-sensitive adhesive layer in the longitudinal direction from the base material layer, and use a tensile tester (Minebear, universal tensile compression tester, device name "tensile compression tester, TCM-1kNB") to pull. The peel strength of the pressure-sensitive adhesive layer from the base material layer under the conditions of a speed of 300 mm / min and a peeling angle of 180 degrees (however, until the transition to the water peeling force measurement described below, that is, until distilled water is supplied to the peeling interface. Peeling strength) is measured. The measurement is performed three times, and the value obtained by converting the average value into a value per 10 mm width (unit: N / 10 mm) is defined as a peel strength N0 [N / 10 mm]. The peel strength is measured so that the test piece attached to the adherend is peeled from the bottom to the top. As the tensile tester, an equivalent product of the universal tensile compression tester may be used.
In the laminate containing the photocurable pressure-sensitive adhesive layer, the test piece taken out from the autoclave is irradiated with light through the base material layer in an environment of 23 ° C. and 50% RH, and then the peel strength is measured. .. The light irradiation conditions (wavelength, irradiation intensity, irradiation time, etc.) are appropriately set according to the composition and thickness of the pressure-sensitive adhesive layer. Specifically, for the laminates of Examples 1-1 to 1-30 described later, after the autoclave treatment, an integrated light amount of 3000 mJ / cm 2 is used from the base material layer side using a high-pressure mercury lamp (300 mW / cm 2 ). The photocurable pressure-sensitive adhesive layer is cured by irradiating with ultraviolet rays. In Examples 2-1 to 2-24, light irradiation after the autoclave treatment is not performed.
When the non-adhesive layer is arranged on the back surface of the pressure-sensitive adhesive layer, the backing with a PET film is unnecessary.
　［水剥離力Ｎ２］
　上記剥離強度Ｎ０の測定において、基材層からの粘着剤層の剥離強度の測定中に、上記基材層から上記粘着剤層が離れ始める箇所（剥離界面）に２０μＬの蒸留水を供給し、該蒸留水供給後の剥離強度を測定する。測定は、各剥離強度の測定毎に（すなわち３回）行い、それらの平均値を幅１０ｍｍ当たりの値（単位：Ｎ／１０ｍｍ）に換算した値を水剥離力Ｎ２［Ｎ／１０ｍｍ］とする。
　蒸留水供給後の剥離強度の測定条件は、ＪＩＳ　Ｚ０２３７：２００９の１０．４．１　方法１：試験板に対する１８０°引きはがし粘着力に従うものとする。具体的には、試験温度２３℃にて引張試験機を用いて引張速度３００ｍｍ／分、剥離角度１８０度の条件とする。
　なお、ここでは１つの試験片毎に剥離強度の測定と水剥離力の測定とを連続して行うことにしているが、剥離強度の測定と水剥離力の測定とを異なる試験片により行ってもよい。例えば、連続測定を実施するために十分な長さの試験片を用意することが難しい場合等において、異なる試験片を用いて測定を行う態様を採用することができる。その場合、基材層と粘着剤層との界面にカッターナイフを差し込んで該粘着剤層の長手方向の一端を基材層から剥離させ、そこに蒸留水を供給して剥離強度の測定を実施する。 [Water peeling force N2]
In the measurement of the peel strength N0, during the measurement of the peel strength of the pressure-sensitive adhesive layer from the base material layer, 20 μL of distilled water was supplied to a portion (peeling interface) where the pressure-sensitive adhesive layer began to separate from the base material layer. The peel strength after supplying the distilled water is measured. The measurement is performed for each peeling strength measurement (that is, three times), and the value obtained by converting the average value into a value per 10 mm width (unit: N / 10 mm) is defined as a water peeling force N2 [N / 10 mm]. ..
The measurement conditions for the peel strength after the supply of distilled water shall be in accordance with JIS Z0237: 2009 10.4.1 Method 1: 180 ° peeling adhesive strength to the test plate. Specifically, the test temperature is 23 ° C., a tensile tester is used, and the tensile speed is 300 mm / min and the peeling angle is 180 degrees.
Here, the peel strength and the water peeling force are measured continuously for each test piece, but the peeling strength and the water peeling force are measured by different test pieces. May be good. For example, when it is difficult to prepare a test piece having a sufficient length for performing continuous measurement, a mode in which measurement is performed using different test pieces can be adopted. In that case, a cutter knife is inserted into the interface between the base material layer and the pressure-sensitive adhesive layer to peel off one end of the pressure-sensitive adhesive layer in the longitudinal direction from the base material layer, and distilled water is supplied thereto to measure the peeling strength. To do.
　［水浸漬後剥離強度Ｎ１］
　積層体を幅１０ｍｍ、長さ１２０ｍｍの長方形状にカットして試験片を作製する。この試験片を、オートクレーブに投入し、圧力５ａｔｍ、温度５０℃の条件で１５分間処理する。
　オートクレーブから取り出した評価用サンプルを２３℃、５０％ＲＨの環境に１日保持した後、室温（２３℃～２５℃）の水に３０分間浸漬する。水としてはイオン交換水または蒸留水を使用する。水中において試験片は、粘着剤層側が上になる向きで水平に保持する。試験片の上面から水面までの距離（浸漬深さ）は１０ｍｍ以上（例えば１０ｍｍ～１００ｍｍ程度）とする。次いで、試験片を水から引き上げ、該試験片に付着している水を静かに拭き取った後、粘着剤層と基材層との界面にカッターナイフを差し込んで該粘着剤層の長手方向の一端を剥がし、２３℃、５０％ＲＨの環境下において、ＪＩＳ　Ｚ０２３７：２００９の「１０．４．１　方法１：試験板に対する１８０°引きはがし粘着力」に従い、具体的には、試験温度２３℃にて引張試験機を用いて引張速度３００ｍｍ／分、剥離角度１８０度の条件で、基材層からの粘着剤層の剥離強度を測定する。測定値を水浸漬後剥離強度Ｎ１［Ｎ／１０ｍｍ］とする。試験片を水から引き上げてから剥離強度を測定するまでの時間は１０分以内とする。 [Peeling strength N1 after immersion in water]
A test piece is prepared by cutting the laminate into a rectangular shape having a width of 10 mm and a length of 120 mm. This test piece is put into an autoclave and treated for 15 minutes under the conditions of a pressure of 5 atm and a temperature of 50 ° C.
The evaluation sample taken out from the autoclave is kept in an environment of 23 ° C. and 50% RH for 1 day, and then immersed in water at room temperature (23 ° C. to 25 ° C.) for 30 minutes. Ion-exchanged water or distilled water is used as the water. In water, the test piece is held horizontally with the adhesive layer side facing up. The distance (immersion depth) from the upper surface of the test piece to the water surface is 10 mm or more (for example, about 10 mm to 100 mm). Next, the test piece is pulled up from the water, the water adhering to the test piece is gently wiped off, and then a cutter knife is inserted into the interface between the pressure-sensitive adhesive layer and the base material layer to insert a cutter knife into one end of the pressure-sensitive adhesive layer in the longitudinal direction. In an environment of 23 ° C. and 50% RH, according to JIS Z0237: 2009 "10.4.1 Method 1: 180 ° peeling adhesive strength to the test plate", specifically, the test temperature was set to 23 ° C. The peel strength of the pressure-sensitive adhesive layer from the base material layer is measured under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 degrees using a tensile tester. The measured value is the peel strength N1 [N / 10 mm] after immersion in water. The time from pulling up the test piece from water to measuring the peel strength shall be within 10 minutes.
　上記水浸漬後剥離強度の測定条件は、水浸漬を行う他は上記剥離強度Ｎ０の測定条件と同じである。具体的には、上述した水浸漬後剥離強度Ｎ１の測定において、光硬化性の粘着剤層を含む積層体では、上記オートクレーブから取り出したサンプルに対し、２３℃、５０％ＲＨの環境下で基材層を介して光照射を行い、その後に水浸漬を実施し、剥離強度を測定する。光照射の条件（波長、照射強度、照射時間等）は、粘着剤層の組成や厚み等に応じて適宜設定すればよい。また、引張試験機としては、万能引張圧縮試験機（装置名「引張圧縮試験機、ＴＣＭ－１ｋＮＢ」ミネベア社製）またはその相当品を用いることができる。剥離強度の測定は、被着体に貼り付けられた試験片の剥離が下から上に進行するように行う。測定にあたっては、必要に応じて積層体の背面（Ａ層の表面とは反対側の表面）に適当な裏打ち材を貼り付けて試験片を補強することができる。裏打ち材としては、例えば、厚さ２５μｍ程度のＰＥＴフィルムを用いることができる。 The measurement conditions for the peel strength after immersion in water are the same as the measurement conditions for the peel strength N0 except for the immersion in water. Specifically, in the above-mentioned measurement of the peel strength N1 after immersion in water, the laminate containing the photocurable pressure-sensitive adhesive layer was based on the sample taken out from the autoclave at 23 ° C. and 50% RH. Light irradiation is performed through the material layer, and then water immersion is performed to measure the peel strength. The light irradiation conditions (wavelength, irradiation intensity, irradiation time, etc.) may be appropriately set according to the composition and thickness of the pressure-sensitive adhesive layer. Further, as the tensile tester, a universal tensile compression tester (device name "tensile compression tester, TCM-1kNB" manufactured by Minebea) or an equivalent product thereof can be used. The peel strength is measured so that the test piece attached to the adherend is peeled from the bottom to the top. In the measurement, if necessary, an appropriate backing material can be attached to the back surface of the laminated body (the surface opposite to the surface of the A layer) to reinforce the test piece. As the backing material, for example, a PET film having a thickness of about 25 μm can be used.
　［膜厚の測定］
　酸化ケイ素の膜厚は、Ｘ線反射率法を測定原理とし、以下の測定条件にて粉末Ｘ線回折装置（リガク社製、装置名「ＲＩＮＴ－２０００」）にてＸ線反射率を測定し、取得した測定データを解析ソフト（リガク社製、「ＧＸＲＲ３」）で解析することで算出する。解析条件は以下の条件とし、高分子フィルム基材と密度２．３ｇ／ｃｍ3の酸化ケイ素膜の２層モデルを採用し、酸化ケイ素膜の膜厚と表面粗さ、基材フィルムの表面粗さを変数として、最小自乗（二乗）フィッティングを行い、酸化ケイ素層の厚さを解析する。
　（測定条件）
　　光源：　Ｃｕ－Ｋα線（波長：１．５４１８Å）、４０ｋＶ、４０ｍＡ
　　光学系：　平行ビーム光学系
　　発散スリット：　０．０５ｍｍ
　　受光スリット：　０．０５ｍｍ
　　単色化・平行化：　多層ゲーベルミラー使用
　　測定モード：θ／２θスキャンモード
　　測定範囲（２θ）：０．３～１．５°
　（解析条件）
　　解析手法：　最小自乗（二乗）フィッティング
　　解析範囲（２θ）：　２θ＝０．３～１．５° [Measurement of film thickness]
The film thickness of silicon oxide is measured by the X-ray reflectivity method, and the X-ray reflectivity is measured with a powder X-ray diffractometer (manufactured by Rigaku Co., Ltd., device name "RINT-2000") under the following measurement conditions. , Calculated by analyzing the acquired measurement data with analysis software ("GXRR3" manufactured by Rigaku Corporation). The analysis conditions were as follows, and a two-layer model of a polymer film substrate and a silicon oxide film with a density of 2.3 g / cm 3 was adopted, and the film thickness and surface roughness of the silicon oxide film and the surface roughness of the substrate film were adopted. With this as a variable, the minimum square (square) fitting is performed and the thickness of the silicon oxide layer is analyzed.
(Measurement condition)
Light source: Cu-Kα ray (wavelength: 1.5418 Å), 40 kV, 40 mA
Optical system: Parallel beam optical system Divergence slit: 0.05 mm
Light receiving slit: 0.05 mm
Monochromatic / parallelization: Using multi-layer Goebel mirror Measurement mode: θ / 2θ Scan mode Measurement range (2θ): 0.3 to 1.5 °
(Analysis conditions)
Analysis method: Minimum square (square) fitting Analysis range (2θ): 2θ = 0.3 to 1.5 °
　［水接触角の測定］
　基材層材料の親水層表面の水接触角は、次のとおり測定する。すなわち、測定雰囲気２３℃、５０％ＲＨの環境下において、接触角計（協和界面科学社製、商品名「ＤＭｏ－５０１型」、コントロールボックス「ＤＭＣ－２」、制御・解析ソフト「ＦＡＭＡＳ（バージョン５．０．３０）」）を用いて液滴法により測定を行う。蒸留水の滴下量は２μＬとし、滴下５秒後の画像からΘ／２法により接触角を算出する（Ｎ５で実施）。 [Measurement of water contact angle]
The water contact angle on the surface of the hydrophilic layer of the base material is measured as follows. That is, in a measurement atmosphere of 23 ° C. and 50% RH, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., trade name "DMo-501 type", control box "DMC-2", control / analysis software "FAMAS (version)" Measurement is performed by the sessile drop method using 5.0.30) ”). The amount of distilled water dropped is 2 μL, and the contact angle is calculated by the Θ / 2 method from the image 5 seconds after dropping (implemented at N5).
　［水剥離性］
　剥離強度Ｎ０［Ｎ／１０ｍｍ］および水剥離力Ｎ２［Ｎ／１０ｍｍ］を式：
　　　水剥離力低下率［％］＝（１－（Ｎ２／Ｎ０））×１００；
に代入し、水剥離力低下率が４０％以上のものを「○」と評価し、４０％未満のものを「×」と評価する。 [Water peelability]
The formula: peeling strength N0 [N / 10mm] and water peeling force N2 [N / 10mm]:
Water peeling power reduction rate [%] = (1- (N2 / N0)) × 100;
When the rate of decrease in water peeling force is 40% or more, it is evaluated as “◯”, and when it is less than 40%, it is evaluated as “x”.
　＜基材層材料の作製＞
　（調製例Ａ１～Ａ５）
　ＰＥＴフィルム基材Ａ（ＰＥＴ－Ａ；三菱ケミカル社製、商品名「ＬＣ－Ｎ５０ＪＢＮ」、厚み５０μｍ）上に、ＲＦ（Radio-Frequency）マグネトロンスパッタにて、三井金属社製のＳｉメタルターゲットから酸化ケイ素膜を成膜した。スパッタガスにはアルゴンと酸素を用い、酸素／アルゴン比率は５．３ｖｏｌ％とした。上記の条件で成膜時間を調整することで、膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ１～Ａ５にそれぞれ対応する基材層材料Ａ１～Ａ５を得た。 <Preparation of base layer material>
(Preparation Examples A1 to A5)
Oxidized from a Si metal target manufactured by Mitsui Kinzoku Co., Ltd. on a PET film base material A (PET-A; manufactured by Mitsubishi Chemical Co., Ltd., trade name "LC-N50JBN", thickness 50 μm) by RF (Radio-Frequency) magnetron sputtering. A silicon film was formed. Argon and oxygen were used as the sputtering gas, and the oxygen / argon ratio was 5.3 vol%. By adjusting the film formation time under the above conditions, silicon oxide films having different film thicknesses were formed, and base material layer materials A1 to A5 corresponding to Preparation Examples A1 to A5 were obtained.
　（調製例Ａ６～Ａ８）
　基材として、ＰＥＴフィルム基材Ｂ（ＰＥＴ－Ｂ；三菱ケミカル社製、商品名「ダイアホイル　Ｏ３００Ｅ」、厚み１２５μｍ）を用いた他は調製例Ａ３～Ａ５と同様にして、ＰＥＴフィルム上に酸化ケイ素膜を成膜した。上記の条件で成膜時間を調整することで、膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ６～Ａ８にそれぞれ対応する基材層材料Ａ６～Ａ８を得た。 (Preparation Examples A6 to A8)
Oxidation on PET film in the same manner as in Preparation Examples A3 to A5 except that PET film base material B (PET-B; manufactured by Mitsubishi Chemical Co., Ltd., trade name "Diafoil O300E", thickness 125 μm) was used as the base material. A silicon film was formed. By adjusting the film formation time under the above conditions, silicon oxide films having different film thicknesses were formed, and base material layer materials A6 to A8 corresponding to Preparation Examples A6 to A8 were obtained.
　（調製例Ａ９～Ａ１１）
　ＡＬＤ（原子層堆積）装置（Picosun社製、装置名「Ｒ２００」）を用いて、ＰＥＴフィルム基材Ｂ（ＰＥＴ－Ｂ；三菱ケミカル社製、商品名「ダイアホイル　Ｏ３００Ｅ」、厚み１２５μｍ）の表面に酸化ケイ素膜を形成した。酸化ケイ素の前駆体としてはビス（ジエチルアミノ）シラン（日本エア・リキード社製、製品名「ＳＡＭ２４」）を用いた。具体的な反応ステップとしては、まず気化した前駆体をチャンバー内に導入した後、真空排気と窒素ガスパージを行った。続いて、酸素プラズマを導入した後、真空排気と窒素ガスパージを行った。上記の反応ステップを繰り返し、ステップ数を調整することで上記基材の表面に膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ９～Ａ１１にそれぞれ対応する基材層材料Ａ９～Ａ１１を得た。 (Preparation Examples A9 to A11)
Surface of PET film base material B (PET-B; manufactured by Mitsubishi Chemical Corporation, trade name "Diafoil O300E", thickness 125 μm) using an ALD (atomic layer deposition) device (manufactured by Picosun, device name “R200”) A silicon oxide film was formed on the surface. As a precursor of silicon oxide, bis (diethylamino) silane (manufactured by Air Liquide Japan Ltd., product name "SAM24") was used. As a specific reaction step, the vaporized precursor was first introduced into the chamber, and then vacuum exhaust and nitrogen gas purging were performed. Subsequently, after introducing oxygen plasma, vacuum exhaust and nitrogen gas purging were performed. By repeating the above reaction steps and adjusting the number of steps, silicon oxide films having different thicknesses were formed on the surface of the base material, and base material layer materials A9 to A11 corresponding to Preparation Examples A9 to A11 were obtained. ..
　（調製例Ａ１２～Ａ１４）
　基材としてトリアセチルセルロース（ＴＡＣ）フィルム（富士フィルム社製、商品名「ＴＤ８０ＵＬ」、厚み８０μｍ、屈折率１．４９）を用いた他は調製例Ａ９～Ａ１１と同様にして、ＴＡＣフィルム上に酸化ケイ素膜を形成した。反応ステップ数を調整することで基材の表面に膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ１２～Ａ１４にそれぞれ対応する基材層材料Ａ１２～Ａ１４を得た。 (Preparation Examples A12 to A14)
On the TAC film in the same manner as in Preparation Examples A9 to A11 except that a triacetyl cellulose (TAC) film (manufactured by Fuji Film Co., Ltd., trade name "TD80UL", thickness 80 μm, refractive index 1.49) was used as a base material. A silicon oxide film was formed. By adjusting the number of reaction steps, silicon oxide films having different thicknesses were formed on the surface of the base material, and base material layer materials A12 to A14 corresponding to Preparation Examples A12 to A14 were obtained.
　（調製例Ａ１５）
　基材としてのＴＡＣフィルム（富士フィルム社製、商品名「ＴＤ８０ＵＬ」、厚み８０μｍ、屈折率１．４９）の表面に、ワイヤーバー＃５（ｒｄｓ社製）を用いて親水コーティング剤を塗布した後、１２０℃で２分間乾燥させることにより、厚さ０．２μｍ～０．５μｍの親水コーティング層を形成した。上記親水コーティング剤としては、コルコート社製の商品名「コルコート　Ｎ－１０３Ｘ」を使用した。このようにして、親水コーティング層（ポリシロキサン系コーティング層）を有するＴＡＣフィルムＡ１５を得た。 (Preparation Example A15)
After applying a hydrophilic coating agent to the surface of a TAC film (manufactured by Fuji Film Co., Ltd., trade name "TD80UL", thickness 80 μm, refractive index 1.49) as a base material using wire bar # 5 (manufactured by rds). By drying at 120 ° C. for 2 minutes, a hydrophilic coating layer having a thickness of 0.2 μm to 0.5 μm was formed. As the hydrophilic coating agent, the trade name "Colcoat N-103X" manufactured by Colcoat Co., Ltd. was used. In this way, a TAC film A15 having a hydrophilic coating layer (polysiloxane-based coating layer) was obtained.
　（調製例Ａ１６～Ａ１８）
　基材として透明ポリイミド（ＣＰＩ）フィルム（KOLON　INDUSTIES　INC. 製、商品名「Ｃ＿８０」、厚み８０μｍ）を用いた他は調製例Ａ９～Ａ１０と基本的に同様にして、ＣＰＩフィルム上に酸化ケイ素膜を形成した。反応ステップ数を調整することで基材の表面に膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ１６～Ａ１８にそれぞれ対応する基材層材料Ａ１６～Ａ１８を得た。 (Preparation Examples A16 to A18)
A silicon oxide film on the CPI film is basically the same as in Preparation Examples A9 to A10 except that a transparent polyimide (CPI) film (manufactured by KOLON INDUSTIES INC., Product name "C_80", thickness 80 μm) is used as a base material. Was formed. By adjusting the number of reaction steps, silicon oxide films having different film thicknesses were formed on the surface of the base material, and base material layer materials A16 to A18 corresponding to Preparation Examples A16 to A18 were obtained.
　（調製例Ａ１９～Ａ２１）
　基材として偏光板（日東電工社製、商品名「ＲＥＧＱ－ＨＣ３」、厚み９２μｍ）を用いた他は調製例Ａ１６～Ａ１８と同様にして、偏光板上に酸化ケイ素膜を形成した。反応ステップ数を調整することで基材の表面に膜厚の異なる酸化ケイ素膜を形成し、調製例Ａ１９～Ａ２１にそれぞれ対応する基材層材料Ａ１９～Ａ２１を得た。 (Preparation Examples A19 to A21)
A silicon oxide film was formed on the polarizing plate in the same manner as in Preparation Examples A16 to A18 except that a polarizing plate (manufactured by Nitto Denko Corporation, trade name “REGQ-HC3”, thickness 92 μm) was used as a base material. By adjusting the number of reaction steps, silicon oxide films having different film thicknesses were formed on the surface of the base material, and base material layer materials A19 to A21 corresponding to Preparation Examples A19 to A21 were obtained.
　＜粘着剤の作製＞
　（調製例Ｂ１）
　冷却管、窒素導入管、温度計および撹拌装置を備えた反応容器に、モノマー成分としてｎ－ブチルアクリレート（ＢＡ）６４．５部、シクロヘキシルアクリレート（ＣＨＡ）６部、Ｎ－ビニル－２－ピロリドン（ＮＶＰ）１５部、イソステアリルアクリレート（ｉＳＴＡ）５部および４－ヒドロキシブチルアクリレート（４ＨＢＡ）１４．９部、連鎖移動剤としてα－チオグリセロール０．０７部、重合溶媒として酢酸エチル１２２部を仕込み、熱重合開始剤として２，２’－アゾビスイソブチロニトリル（ＡＩＢＮ）０．２部を投入して窒素雰囲気下で溶液重合を行うことにより、Ｍｗが６０万のアクリル系ポリマーを含有する溶液を得た。 <Making adhesive>
(Preparation Example B1)
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 64.5 parts of n-butyl acrylate (BA), 6 parts of cyclohexyl acrylate (CHA) and N-vinyl-2-pyrrolidone (N-vinyl-2-pyrrolidone) as monomer components. 15 parts of NVP), 5 parts of isostearyl acrylate (iSTA) and 14.9 parts of 4-hydroxybutyl acrylate (4HBA), 0.07 part of α-thioglycerol as a chain transfer agent, and 122 parts of ethyl acetate as a polymerization solvent were charged. A solution containing an acrylic polymer having an Mw of 600,000 by adding 0.2 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator and performing solution polymerization in a nitrogen atmosphere. Got
　上記で得られた溶液に、該溶液の調製に使用したモノマー成分１００部あたり、光反応性化合物としてジペンタエリスリトールヘキサアクリレート（新中村化学工業社製、商品名「Ａ－ＤＰＨ」）１．０部およびポリプロピレングリコール#４００ジアクリレート（新中村化学工業社製、商品名「ＡＰＧ－４００」）３．０部、光反応触媒（光反応開始剤）として１－ヒドロキシシクロヘキシル－フェニル－ケトン（ＩＧＭ　Ｒｅｇｉｎｓ社製、商品名：オムニラッド１８４）０．２２部、イソシアネート系架橋剤（トリメチロールプロパン／キシリレンジイソシアネート付加物（三井化学社製、商品名：タケネートＤ－１１０Ｎ、固形分濃度７５％）を固形分基準で０．１６部、架橋促進剤としてジオクチルスズジラウレート（東京ファインケミカル社製、商品名：エンビライザーＯＬ－１）０．０１１部、架橋遅延剤としてアセチルアセトン３．３３部、アクリル系オリゴマー０．４部、および水親和剤として非イオン性界面活性剤Ａ（ポリオキシエチレンソルビタンモノラウレート、ＨＬＢ１３．３、商品名：レオドールＴＷ－Ｌ１０６、花王社製）０．３部を加え、均一に混合して、本調製例に係る溶剤型粘着剤組成物Ｂ１を調製した。 Dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-DPH") 1.0 as a photoreactive compound per 100 parts of the monomer component used to prepare the solution in the above-mentioned solution. Part and 3.0 parts of polypropylene glycol # 400 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "APG-400"), 1-hydroxycyclohexyl-phenyl-ketone (IGM Regins) as a photoreaction catalyst (photoreaction initiator) Made by the company, trade name: Omnirad 184) 0.22 parts, isocyanate-based cross-linking agent (monomer propane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, trade name: Takenate D-110N, solid content concentration 75%) solid 0.16 parts on a minute basis, 0.011 parts of dioctyltin dilaurate (manufactured by Tokyo Fine Chemicals, trade name: Envirizer OL-1) as a cross-linking accelerator, 3.33 parts of acetylacetone as a cross-linking retarder, acrylic oligomer 0. Add 4 parts and 0.3 part of nonionic surfactant A (polyoxyethylene sorbitan monolaurate, HLB13.3, trade name: Leodor TW-L106, manufactured by Kao) as a water affinity, and mix uniformly. Then, the solvent-type pressure-sensitive adhesive composition B1 according to this preparation example was prepared.
　上記アクリル系オリゴマーとしては、以下の方法で合成したものを使用した。
　　［アクリル系オリゴマーの合成］
　トルエン１００部、ジシクロペンタニルメタクリレート（ＤＣＰＭＡ）（商品名：ＦＡ－５１３Ｍ、日立化成工業社製）６０部、メチルメタクリレート（ＭＭＡ）４０部、および連鎖移動剤としてα－チオグリセロール３．５部を４つ口フラスコに投入した。そして、７０℃にて窒素雰囲気下で１時間攪拌した後、熱重合開始剤としてＡＩＢＮ０．２部を投入し、７０℃で２時間反応させ、続いて８０℃で２時間反応させた。その後、反応液を１３０℃の温度雰囲気下に投入し、トルエン、連鎖移動剤、および未反応モノマーを乾燥除去することにより、固形状のアクリル系オリゴマーを得た。このアクリル系オリゴマーのＴｇは１４４℃であり、Ｍｗは４３００であった。 As the acrylic oligomer, one synthesized by the following method was used.
[Synthesis of acrylic oligomers]
100 parts of toluene, 60 parts of dicyclopentanyl methacrylate (DCPMA) (trade name: FA-513M, manufactured by Hitachi Kasei Kogyo Co., Ltd.), 40 parts of methyl methacrylate (MMA), and 3.5 parts of α-thioglycerol as a chain transfer agent. Was put into a four-necked flask. Then, after stirring at 70 ° C. under a nitrogen atmosphere for 1 hour, 0.2 part of AIBN was added as a thermal polymerization initiator, and the mixture was reacted at 70 ° C. for 2 hours and then at 80 ° C. for 2 hours. Then, the reaction solution was put into a temperature atmosphere of 130 ° C., and toluene, the chain transfer agent, and the unreacted monomer were dried and removed to obtain a solid acrylic oligomer. The Tg of this acrylic oligomer was 144 ° C. and the Mw was 4300.
　ポリエステルフィルムの片面が剥離面となっている厚さ３８μｍの剥離フィルム（三菱樹脂社製、ＭＲＦ＃３８）と、ポリエステルフィルムの片面が剥離面となっている厚さ３８μｍの剥離フィルム（三菱樹脂社製、ＭＲＥ＃３８）とを用意した。一方の剥離フィルム（ＭＲＦ＃３８）の剥離面に、上記で調製した溶剤型粘着剤組成物Ｂ１を塗布し、６０℃で３分間、次いで１２０℃で３分間乾燥させて、厚さ１５０μｍの光硬化性粘着剤層を形成した。この粘着剤層に、他方の剥離フィルム（ＭＲＥ＃３８）の剥離面を貼り合わせて保護した。このようにして、２枚の剥離フィルムに表面が保護された粘着剤層Ｂ１を得た。 A 38 μm-thick release film (Mitsubishi Resin Co., Ltd., MRF # 38) with one side of the polyester film as a peeling surface and a 38 μm thick release film (Mitsubishi Resin Co., Ltd.) with one side of the polyester film having a peeling surface. Made by MRE # 38). The solvent-based pressure-sensitive adhesive composition B1 prepared above was applied to the peeling surface of one of the release films (MRF # 38) and dried at 60 ° C. for 3 minutes and then at 120 ° C. for 3 minutes to obtain light having a thickness of 150 μm. A curable pressure-sensitive adhesive layer was formed. The release surface of the other release film (MRE # 38) was attached to this pressure-sensitive adhesive layer to protect it. In this way, the pressure-sensitive adhesive layer B1 whose surface was protected by the two release films was obtained.
　（調製例Ｂ２）
　２－エチルヘキシルアクリレート（２ＥＨＡ）８５部、メチルアクリレート（ＭＡ）１３部、アクリル酸（ＡＡ）１．２部、メタクリル酸（ＭＡＡ）０．８部、３－メタクリロキシプロピルトリメトキシシラン（信越化学工業社製、ＫＢＭ－５０３）０．０２部、連鎖移動剤としてのｔ－ドデシルメルカプタン０．０４８部および乳化剤（花王社製、ラテムルＥ－１１８Ｂ）２．０部を、イオン交換水１００部中で混合して乳化することにより、モノマー混合物の水性エマルション（モノマーエマルション）を調製した。
　冷却管、窒素導入管、温度計および攪拌装置を備えた反応容器に上記モノマーエマルションを入れ、窒素ガスを導入しながら室温にて１時間以上攪拌した。次いで、系を６０℃に昇温し、重合開始剤として２，２’－アゾビス［Ｎ－（２－カルボキシエチル）－２－メチルプロピオンアミジン］ハイドレート（和光純薬工業社製、ＶＡ－０５７）０．１部を投入し、６０℃で６時間反応させて、アクリル系ポリマーの水分散液を得た。系を常温まで冷却した後、上記アクリル系ポリマーの水分散液の固形分１００部あたり、粘着付与樹脂エマルション（荒川化学工業社製、スーパーエステルＥ－８６５ＮＴ、軟化点１６０℃の重合ロジンエステルの水分散液）を固形分で３０部添加した。さらに、ｐＨ調整剤としての１０％アンモニア水および増粘剤としてのポリアクリル酸（不揮発分３６％の水溶液）を使用して、ｐＨを約７．５、粘度を約９Ｐａ・ｓに調整することにより、本調製例に係るエマルション型粘着剤組成物Ｂ２を調製した。 (Preparation Example B2)
2-ethylhexyl acrylate (2EHA) 85 parts, methyl acrylate (MA) 13 parts, acrylic acid (AA) 1.2 parts, methacrylic acid (MAA) 0.8 parts, 3-methacryloxypropyltrimethoxysilane (Shinetsu Chemical Industry) 0.02 part of KBM-503), 0.048 part of t-dodecyl mercaptan as a chain transfer agent, and 2.0 part of emulsifier (Latemuru E-118B, manufactured by Kao) in 100 parts of ion-exchanged water. An aqueous emulsion (monomer emulsion) of the monomer mixture was prepared by mixing and emulsifying.
The monomer emulsion was placed in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and the mixture was stirred at room temperature for 1 hour or more while introducing nitrogen gas. Next, the temperature of the system was raised to 60 ° C., and 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057) was used as a polymerization initiator. ) 0.1 part was added and reacted at 60 ° C. for 6 hours to obtain an aqueous dispersion of an acrylic polymer. After cooling the system to room temperature, water of a pressure-imparting resin emulsion (manufactured by Arakawa Chemical Industries, Ltd., super ester E-865NT, polymerized rosin ester at a softening point of 160 ° C.) per 100 parts of the solid content of the aqueous dispersion of the acrylic polymer. Dispersion solution) was added in 30 parts by solid content. Further, the pH is adjusted to about 7.5 and the viscosity is adjusted to about 9 Pa · s by using 10% aqueous ammonia as a pH adjuster and polyacrylic acid (an aqueous solution having a non-volatile content of 36%) as a thickener. To prepare the emulsion-type pressure-sensitive adhesive composition B2 according to this preparation example.
　ポリエステルフィルムの片面が剥離面となっている厚さ３８μｍの剥離フィルム（三菱樹脂社製、ＭＲＦ＃３８）と、ポリエステルフィルムの片面が剥離面となっている厚さ３８μｍの剥離フィルム（三菱樹脂社製、ＭＲＥ＃３８）とを用意した。一方の剥離フィルム（ＭＲＦ＃３８）の剥離面に粘着剤組成物Ｂ２を塗布し、１２０℃で３分間乾燥させて、厚さ２０μｍの粘着剤層Ｂ２を形成した。この粘着剤層に、他方の剥離フィルム（ＭＲＥ＃３８）の剥離面を貼り合わせて保護した。このようにして、２枚の剥離フィルムに表面が保護された粘着剤層Ｂ２を得た。 A 38 μm-thick release film (Mitsubishi Resin Co., Ltd., MRF # 38) with one side of the polyester film as a peeling surface and a 38 μm thick release film (Mitsubishi Resin Co., Ltd.) with one side of the polyester film having a peeling surface. Made by MRE # 38). The pressure-sensitive adhesive composition B2 was applied to the peel-off surface of one of the release films (MRF # 38) and dried at 120 ° C. for 3 minutes to form a pressure-sensitive adhesive layer B2 having a thickness of 20 μm. The release surface of the other release film (MRE # 38) was attached to this pressure-sensitive adhesive layer to protect it. In this way, the pressure-sensitive adhesive layer B2 whose surface was protected by the two release films was obtained.
　＜例１－１～例１－２１＞
　上記で得た光硬化性粘着剤層Ｂ１の一方の表面を覆う剥離ライナーを剥がし、露出した粘着面に厚さ２５μｍのＰＥＴフィルムを貼り合わせて裏打ちした。これを幅２０ｍｍ、長さ１００ｍｍのサイズにカットし、次いで、２３℃、５０％ＲＨの環境下において、上記光硬化性粘着剤層Ｂ１の他方の表面を覆う剥離ライナーを剥がし、露出した粘着面を、基材層材料Ａ１～Ａ２１の各々の親水層形成面に２ｋｇのゴムローラーを一往復させて圧着することにより、光硬化性粘着剤層と基材層とを積層し、例１－１～１－２１に係る積層体を得た。各例の積層体の粘着面（基材層側表面の反対面）にはＰＥＴフィルム（裏打ちフィルム）が積層されている。 <Example 1-1 to Example 1-21>
The release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 μm was attached to the exposed pressure-sensitive adhesive surface for lining. This is cut into a size of 20 mm in width and 100 mm in length, and then the release liner covering the other surface of the photocurable adhesive layer B1 is peeled off in an environment of 23 ° C. and 50% RH to expose the adhesive surface. A 2 kg rubber roller was reciprocated once on each of the hydrophilic layer forming surfaces of the base material layer materials A1 to A21 and pressure-bonded to laminate the photocurable pressure-sensitive adhesive layer and the base material layer. A laminate according to ~ 1-21 was obtained. A PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
　＜例１－２２～例１－２６＞
　ＰＥＴフィルム基材Ａ（ＰＥＴ－Ａ；三菱ケミカル社製、商品名「ＬＣ－Ｎ５０ＪＢＮ」、厚み５０μｍ）、ＰＥＴフィルム基材Ｂ（ＰＥＴ－Ｂ；三菱ケミカル社製、商品名「ダイアホイル　Ｏ３００Ｅ」、厚み１２５μｍ）、ＴＡＣフィルム（富士フィルム社製、商品名「ＴＤ８０ＵＬ」、厚み８０μｍ、屈折率１．４９）、ＣＰＩフィルム（KOLON　INDUSTRIES　INC.製、商品名「Ｃ＿８０」、厚み８０μｍ）および偏光板（日東電工社製、商品名「ＲＥＧＱ－ＨＣ３」、厚み９２μｍ）の各々の一方の面にコロナ処理を施した。具体的には、コロナ処理は、上記基材層材料をテーブル式表面コロナ処理装置（ＫＡＳＵＧＡ社製、装置名「ＡＧＦ－０１２」）に、出力設定３（表示０．１７ｋＷ）、テーブルスピード目盛り２０（速度３ｍ／ｍｉｎ相当）の条件で１回通すことにより行った。また、上記で得た光硬化性粘着剤層Ｂ１の一方の表面を覆う剥離ライナーを剥がし、露出した粘着面に厚さ２５μｍのＰＥＴフィルムを貼り合わせて裏打ちした。これを幅２０ｍｍ、長さ１００ｍｍのサイズにカットした。次いで、上記コロナ処理直後（コロナ処理後３０分以内に）、２３℃、５０％ＲＨの環境下において、上記光硬化性粘着剤層Ｂ１の他方の表面を覆う剥離ライナーを剥がし、露出した粘着面を、上記基材層材料のコロナ処理面に２ｋｇのゴムローラーを一往復させて圧着することにより、光硬化性粘着剤層と基材層とを積層し、例１－２２～１－２６に係る積層体を得た。各例の積層体の粘着面（基材層側表面の反対面）にはＰＥＴフィルム（裏打ちフィルム）が積層されている。 <Example 1-22 to Example 1-26>
PET film base material A (PET-A; manufactured by Mitsubishi Chemical Co., Ltd., product name "LC-N50JBN", thickness 50 μm), PET film base material B (PET-B; manufactured by Mitsubishi Chemical Co., Ltd., product name "Diafoil O300E", Thickness 125 μm), TAC film (manufactured by Fuji Film Co., Ltd., product name “TD80UL”, thickness 80 μm, refractive index 1.49), CPI film (manufactured by KOLON INDUSTRIES INC., Product name “C_80”, thickness 80 μm) and polarizing plate (thickness 125 μm) One side of each of Nitto Denko Co., Ltd., trade name "REGQ-HC3", thickness 92 μm) was subjected to corona treatment. Specifically, in the corona treatment, the base material is applied to a table-type surface corona treatment device (manufactured by KASUGA, device name "AGF-012"), output setting 3 (display 0.17 kW), table speed scale 20. It was carried out by passing it once under the condition of (equivalent to a speed of 3 m / min). Further, the release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 μm was attached to the exposed pressure-sensitive adhesive surface for lining. This was cut into a size of 20 mm in width and 100 mm in length. Then, immediately after the corona treatment (within 30 minutes after the corona treatment), in an environment of 23 ° C. and 50% RH, the release liner covering the other surface of the photocurable adhesive layer B1 was peeled off, and the exposed adhesive surface was peeled off. The photocurable pressure-sensitive adhesive layer and the base material layer were laminated by reciprocating and crimping a 2 kg rubber roller once to the corona-treated surface of the base material layer material, and in Examples 1-22 to 1-26. Such a laminate was obtained. A PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
　＜例１－２７～例１－３０＞
　上記で得た光硬化性粘着剤層Ｂ１の一方の表面を覆う剥離ライナーを剥がし、露出した粘着面に厚さ２５μｍのＰＥＴフィルムを貼り合わせて裏打ちした。これを幅２０ｍｍ、長さ１００ｍｍのサイズにカットし、次いで、２３℃、５０％ＲＨの環境下において、上記光硬化性粘着剤層Ｂ１の他方の表面を覆う剥離ライナーを剥がし、露出した粘着面を、ＰＥＴフィルム基材Ａ（ＰＥＴ－Ａ；三菱ケミカル社製、商品名「ＬＣ－Ｎ５０ＪＢＮ」、厚み５０μｍ）、ＰＥＴフィルム基材Ｂ（ＰＥＴ－Ｂ；三菱ケミカル社製、商品名「ダイアホイル　Ｏ３００Ｅ」、厚み１２５μｍ）、ＣＰＩフィルム（KOLON　INDUSTRIES　INC. 製、商品名「Ｃ＿８０」、厚み８０μｍ）および偏光板（日東電工社製、商品名「ＲＥＧＱ－ＨＣ３」、厚み９２μｍ）の各々の一方の面に２ｋｇのゴムローラーを一往復させて圧着することにより、光硬化性粘着剤層と基材層とを積層し、例１－２７～１－３０に係る積層体を得た。各例の積層体の粘着面（基材層側表面の反対面）にはＰＥＴフィルム（裏打ちフィルム）が積層されている。 <Example 1-27 to Example 1-30>
The release liner covering one surface of the photocurable pressure-sensitive adhesive layer B1 obtained above was peeled off, and a PET film having a thickness of 25 μm was attached to the exposed pressure-sensitive adhesive surface for lining. This was cut into a size of 20 mm in width and 100 mm in length, and then the release liner covering the other surface of the photocurable adhesive layer B1 was peeled off in an environment of 23 ° C. and 50% RH to expose the adhesive surface. PET film base material A (PET-A; manufactured by Mitsubishi Chemical Co., Ltd., trade name "LC-N50JBN", thickness 50 μm), PET film base material B (PET-B; manufactured by Mitsubishi Chemical Co., Ltd., trade name "Diafoil O300E" , 125 μm in thickness), CPI film (manufactured by KOLON INDUSTRIES INC., Product name “C_80”, thickness 80 μm) and polarizing plate (manufactured by Nitto Denko Co., Ltd., product name “REGQ-HC3”, thickness 92 μm) The photocurable pressure-sensitive adhesive layer and the base material layer were laminated by reciprocating and crimping a 2 kg rubber roller once to obtain the laminates according to Examples 1-27 to 1-30. A PET film (lining film) is laminated on the adhesive surface (opposite surface of the base material layer side surface) of the laminated body of each example.
　＜例２－１～例２－２４＞
　粘着剤層として、光硬化性粘着剤層Ｂ１に代えて粘着剤層Ｂ２を用いた他は例１－１～１－２１、１－２７～１～２８，１－３０と同様にして、各例に係る積層体を得た。 <Example 2-1 to Example 2-24>
As the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer B2 was used instead of the photo-curable pressure-sensitive adhesive layer B1, except that the pressure-sensitive adhesive layer B2 was used in the same manner as in Examples 1-1 to 1-21, 1-27 to 1-28, 1-30. A laminate according to the example was obtained.
　＜性能評価＞
　各例に係る積層体について、剥離強度Ｎ０［Ｎ／１０ｍｍ］および水剥離力Ｎ２［Ｎ／１０ｍｍ］を測定し、また、水剥離性の評価を行った。結果を表１および２に示す。各表には、各例の概要と、基材層における親水層の膜厚［ｎｍ］および粘着剤層積層前における基材層の粘着剤層側表面の水接触角［°］もあわせて示す。また、各例の積層体につき、水浸漬後剥離強度Ｎ１［Ｎ／１０ｍｍ］を測定した。 <Performance evaluation>
The peel strength N0 [N / 10 mm] and the water peeling force N2 [N / 10 mm] were measured for the laminated body according to each example, and the water peelability was evaluated. The results are shown in Tables 1 and 2. Each table also shows an outline of each example, the film thickness [nm] of the hydrophilic layer in the base material layer, and the water contact angle [°] of the surface of the base material layer on the pressure-sensitive adhesive layer side before laminating the pressure-sensitive adhesive layer. .. In addition, the peel strength N1 [N / 10 mm] after immersion in water was measured for the laminated body of each example.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１，２に示されるように、基材層表面に親水層を設けた例１－１～１－２１に係る積層体では、検討したすべての基材材料において、粘着剤層と基材層とが十分な剥離強度で接着しており、かつ水剥離性にも優れていた。これに対して、基材層表面にコロナ処理を施した例１－２２～１－２６に係る積層体は良好な水剥離性を得ることができなかった。コロナ処理を施さなかった例１－２７～１－３０についても同様であった。また、エマルション型粘着剤を使用した例２－１～２－２４についても、基材層表面に親水層を設けた例２－１～２－２１の積層体は、親水層を有しない例２－２２～２－２４と比べて、優れた水剥離性を有していた。また、上記例２－１～２－２１では、粘着剤層と基材層とが十分な剥離強度で接着していた。 As shown in Tables 1 and 2, in the laminates according to Examples 1-1 to 1-21 in which the hydrophilic layer was provided on the surface of the base material layer, the pressure-sensitive adhesive layer and the base material layer were used in all the base material materials examined. Adhesive with sufficient peel strength and excellent water peelability. On the other hand, the laminates according to Examples 1-22 to 1-26 in which the surface of the base material layer was subjected to corona treatment could not obtain good water peelability. The same was true for Examples 1-27 to 1-30 that were not subjected to corona treatment. Further, also in Examples 2-1 to 2-24 using the emulsion type pressure-sensitive adhesive, the laminate of Examples 2-1 to 2-21 in which the hydrophilic layer is provided on the surface of the base material layer does not have the hydrophilic layer. It had excellent water releasability as compared with -22 to 2-24. Further, in Examples 2-1 to 2-21, the pressure-sensitive adhesive layer and the base material layer were adhered with sufficient peel strength.
　以上、本発明の具体例を詳細に説明したが、これらは例示にすぎず、請求の範囲を限定するものではない。請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。 Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.
　　１，２　積層体
　１０　　粘着剤層（Ａ層）
　１０Ａ　一方の表面（基材層側表面）
　１０Ｂ　他方の表面（粘着面）
　２０　　基材層
　２０Ａ　背面
　２０Ｂ　粘着剤層側表面
　２２　　主層
　２４　　親水層
　３０　　剥離ライナー
　５０　　剥離ライナー付き積層体
１１０　　粘着剤層
１１０Ａ　一方の表面（基材層側表面）
１１０Ｂ　他方の表面（粘着面）
１１２　　Ａ層
１１４　　Ｂ層 1, 2, Laminated body 10 Adhesive layer (A layer)
10A One surface (base material layer side surface)
10B The other surface (adhesive surface)
20 Base material layer 20A Back surface 20B Adhesive layer side surface 22 Main layer 24 Hydrophilic layer 30 Peeling liner 50 Laminate with peeling liner 110 Adhesive layer 110A One surface (base material layer side surface)
110B The other surface (adhesive surface)
112 A layer 114 B layer

Claims (12)

  1. 　基材層と、該基材層に剥離可能に積層された粘着剤層と、を有する積層体であって、
    　前記粘着剤層は、基材層側表面を構成するＡ層を備え、
    　前記基材層の粘着剤層側表面には親水層が形成されており、
    　前記親水層は無機材料含有層であり、
    　前記基材層に対する前記粘着剤層の剥離強度Ｎ０は２．０Ｎ／１０ｍｍ以上であり、かつ
    　前記基材層と前記粘着剤層とのあいだに２０μＬの蒸留水を供給し、該蒸留水を該粘着剤層と該基材層との界面の一端に進入させた後、ＪＩＳ　Ｚ０２３７：２００９の１０．４．１　方法１：試験板に対する１８０°引きはがし粘着力に従い、具体的には、試験温度２３℃にて引張試験機を用いて引張速度３００ｍｍ／分、剥離角度１８０度の条件で測定される水剥離力Ｎ２［Ｎ／１０ｍｍ］と、前記剥離強度Ｎ０［Ｎ／１０ｍｍ］とから、次式：（１－（Ｎ２／Ｎ０））×１００；により算出される水剥離力低下率が４０％以上である、積層体。     A laminate having a base material layer and an adhesive layer detachably laminated on the base material layer.
    The pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side.
    A hydrophilic layer is formed on the surface of the base material layer on the pressure-sensitive adhesive layer side.
    The hydrophilic layer is an inorganic material-containing layer and
    The peel strength N0 of the pressure-sensitive adhesive layer with respect to the base material layer is 2.0 N / 10 mm or more, and 20 μL of distilled water is supplied between the base material layer and the pressure-sensitive adhesive layer, and the distilled water is used. After entering one end of the interface between the pressure-sensitive adhesive layer and the base material layer, JIS Z0237: 2009 10.4.1 Method 1: According to the 180 ° peeling adhesive strength to the test plate, specifically, the test temperature. From the water peeling force N2 [N / 10 mm] measured at 23 ° C. using a tensile tester at a tensile speed of 300 mm / min and a peeling angle of 180 degrees, and the peeling strength N0 [N / 10 mm], the following A laminated body having a water peeling force reduction rate of 40% or more calculated by the formula: (1- (N2 / N0)) × 100 ;.
  2. 　前記剥離強度Ｎ０は３．０Ｎ／１０ｍｍ以上である、請求項１に記載の積層体。 The laminate according to claim 1, wherein the peel strength N0 is 3.0 N / 10 mm or more.
  3. 　前記積層体を水に３０分間浸漬し、次いで水から引き上げて付着水を拭き取った後に測定される水浸漬後剥離強度Ｎ１［Ｎ／１０ｍｍ］と、前記剥離強度Ｎ０［Ｎ／１０ｍｍ］とから、次式：（１－（Ｎ１／Ｎ０））×１００；により算出される水浸漬後剥離力低下率が３０％以下である、請求項１または２に記載の積層体。 From the peel strength N1 [N / 10 mm] after immersion in water and the peel strength N0 [N / 10 mm] measured after immersing the laminate in water for 30 minutes and then pulling it out of the water to wipe off the adhering water. The laminate according to claim 1 or 2, wherein the rate of decrease in peeling force after immersion in water calculated by the following formula: (1- (N1 / N0)) × 100; is 30% or less.
  4. 　前記Ａ層は、光硬化型または溶剤型の粘着剤組成物から形成された層である、請求項１～３のいずれか一項に記載の積層体。 The laminate according to any one of claims 1 to 3, wherein the layer A is a layer formed from a photocurable or solvent-type pressure-sensitive adhesive composition.
  5. 　前記Ａ層は水親和剤を含む、請求項１～４のいずれか一項に記載の積層体。 The laminate according to any one of claims 1 to 4, wherein the layer A contains a water affinity agent.
  6. 　前記無機材料は無機酸化物である、請求項１～５のいずれか一項に記載の積層体。 The laminate according to any one of claims 1 to 5, wherein the inorganic material is an inorganic oxide.
  7. 　前記無機酸化物は酸化ケイ素である、請求項６に記載の積層体。 The laminate according to claim 6, wherein the inorganic oxide is silicon oxide.
  8. 　前記親水層の厚さは５０００ｎｍ未満である、請求項１～７のいずれか一項に記載の積層体。 The laminate according to any one of claims 1 to 7, wherein the thickness of the hydrophilic layer is less than 5000 nm.
  9. 　前記基材層は光学部材である、請求項１～８のいずれか一項に記載の積層体。 The laminate according to any one of claims 1 to 8, wherein the base material layer is an optical member.
  10. 　基材層と粘着剤層とを有する積層体の該基材層から該粘着剤層を剥離する方法であって、
    　前記基材層からの前記粘着剤層の剥離前線において前記基材層と前記粘着剤層との界面に水性液体が存在する状態で、前記剥離前線の移動に追随して前記水性液体の前記界面への進入を進行させつつ前記基材層から前記粘着剤層を剥離する水剥離工程を含み、
    　前記粘着剤層は、基材層側表面を構成するＡ層を備え、
    　前記基材層の粘着剤層側表面には親水化処理が施されている、剥離方法。     A method of peeling the pressure-sensitive adhesive layer from the base material layer of a laminate having a base material layer and a pressure-sensitive adhesive layer.
    In the state where the aqueous liquid is present at the interface between the base material layer and the pressure-sensitive adhesive layer in the peeling front of the pressure-sensitive adhesive layer from the base material layer, the interface of the water-based liquid follows the movement of the peeling front. Including a water peeling step of peeling the pressure-sensitive adhesive layer from the base material layer while advancing the invasion into.
    The pressure-sensitive adhesive layer includes a layer A constituting the surface on the base material layer side.
    A peeling method in which the surface of the base material layer on the pressure-sensitive adhesive layer side is hydrophilized.
  11. 　前記親水化処理は、前記基材層の粘着剤層側表面への親水層の形成である、請求項１０に記載の方法。 The method according to claim 10, wherein the hydrophilic treatment is the formation of a hydrophilic layer on the surface of the base material layer on the pressure-sensitive adhesive layer side.
  12. 　前記親水層は無機材料含有層である、請求項１１に記載の方法。 The method according to claim 11, wherein the hydrophilic layer is an inorganic material-containing layer.
PCT/JP2020/027651 2019-08-02 2020-07-16 Layered article and peeling method WO2021024741A1 (en)

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