WO2022163281A1 - Active energy ray curable adhesive sheet, adhesive sheet equipped with mold release film, laminate, production method for laminate, laminated sheet, laminate for image display devices, flexible image display device ,adhesive sheet for flexible displays, and production method for laminate for image display devices - Google Patents

Active energy ray curable adhesive sheet, adhesive sheet equipped with mold release film, laminate, production method for laminate, laminated sheet, laminate for image display devices, flexible image display device ,adhesive sheet for flexible displays, and production method for laminate for image display devices Download PDF

Info

Publication number
WO2022163281A1
WO2022163281A1 PCT/JP2021/048543 JP2021048543W WO2022163281A1 WO 2022163281 A1 WO2022163281 A1 WO 2022163281A1 JP 2021048543 W JP2021048543 W JP 2021048543W WO 2022163281 A1 WO2022163281 A1 WO 2022163281A1
Authority
WO
WIPO (PCT)
Prior art keywords
adhesive sheet
pressure
sensitive adhesive
meth
active energy
Prior art date
Application number
PCT/JP2021/048543
Other languages
French (fr)
Japanese (ja)
Inventor
優那 原田
亮太 山本
公平 広瀬
Original Assignee
三菱ケミカル株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱ケミカル株式会社 filed Critical 三菱ケミカル株式会社
Priority to JP2022578190A priority Critical patent/JPWO2022163281A1/ja
Priority to CN202180091745.1A priority patent/CN116806245A/en
Priority to KR1020237019425A priority patent/KR20230136732A/en
Publication of WO2022163281A1 publication Critical patent/WO2022163281A1/en

Links

Classifications

    • 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
    • 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
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • 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
    • C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
    • 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
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
    • 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]
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • 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
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/20—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself
    • C09J2301/208—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself the adhesive layer being constituted by at least two or more adjacent or superposed adhesive layers, e.g. multilayer adhesive
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/304—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being heat-activatable, i.e. not tacky at temperatures inferior to 30°C
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
    • C09J2301/416—Additional features of adhesives in the form of films or foils characterized by the presence of essential components use of irradiation

Definitions

  • the present invention relates to an adhesive sheet that can be suitably used for an image display device having a curved surface, a bendable flexible image display device, and the like.
  • a pressure-sensitive adhesive sheet that can be suitably used for bonding members for constituting an image display device having a stepped portion on the bonding surface, a pressure-sensitive adhesive sheet with a release film using the pressure-sensitive adhesive sheet, a laminate, and a laminate Laminate sheet, laminate for image display device, flexible image display device, adhesive sheet for flexible display, and method for producing laminate for image display device.
  • Such a display device has a laminated structure in which multiple sheet members such as a cover lens, a circularly polarizing plate, a touch film sensor, and a light-emitting element are bonded together with a transparent adhesive sheet. When applied, it can be regarded as a laminate in which the member and the adhesive sheet are laminated.
  • Patent Document 1 by setting the product value of the creep compliance fluctuation value and the relaxation elastic modulus fluctuation value to a suitable range, it is applied to a repeatedly bending device, and the bending state can be maintained for a long period of time.
  • the pressure-sensitive adhesive for repeatedly bending devices and the pressure-sensitive adhesive that exhibits high resilience such as suppressing deformation of the pressure-sensitive adhesive layer after being released from the bending state in the case of being placed in a curved state and mitigating the effects of being placed in the bending state Sheets and flex laminate members and repeat flex devices are disclosed.
  • the surface of a member constituting the image display device (also referred to as “image display device constituent member”) is made uneven by wiring, printing, pattern development, surface treatment, or the like.
  • the pressure-sensitive adhesive sheet for bonding image display device constituent members having such a stepped portion follows the step while being thin, under the limitation that it cannot be thickened due to the demand for thinning of the image display device. If it is not possible to fill all the corners of the adhesive layer, air bubbles may be generated inside the adhesive layer, so the adhesive sheet is required to have high fluidity. However, it has been difficult to stably exhibit resilience and durability in a wide temperature range with a pressure-sensitive adhesive sheet having high fluidity at the time of lamination.
  • the present invention enables even an image display device component having a stepped portion on the surface to be filled to every corner so as to follow the stepped portion so as not to generate air bubbles, and to display an image.
  • a laminate having a configuration in which a device component and an adhesive sheet are laminated can exhibit excellent resilience and durability even when bending is performed in a high temperature environment, and when bending is performed in a low temperature environment.
  • the present invention proposes an active energy ray-curable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing a meth)acrylic polymer (A) and satisfying the following requirements (1) to (3).
  • (1) It has a thickness of 0.8 mm to 1.5 mm and a strain (creep strain) of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds.
  • (2) After irradiating an active energy ray with a wavelength of 365 nm with an integrated light amount of 2000 to 4000 mJ / cm 2 with a thickness of 0.8 mm to 1.5 mm, a pressure of 1000 Pa at a temperature of 80 ° C. is applied for 180 seconds. creep strain) becomes 10% or more.
  • the present invention also proposes a release film-attached pressure-sensitive adhesive sheet having a structure in which the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention and a release film are laminated.
  • the present invention also provides a method in which a release film and a member for constituting an image display device having a step with a height difference of 2 ⁇ m or more on the surface to be laminated are laminated via the active energy ray-curable adhesive sheet proposed by the present invention.
  • a laminate having a structure of
  • a release film and an image display device constituting member having a step with a height difference of 2 ⁇ m or more on the surface to be laminated are laminated via the active energy ray-curable adhesive sheet proposed by the present invention,
  • a method for producing a laminate is proposed in which the pressure-sensitive adhesive sheet is irradiated with an active energy ray through the release film from the release film side.
  • the present invention also proposes a laminated sheet having a structure in which the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention and another pressure-sensitive adhesive sheet are laminated.
  • the present invention also includes a structure in which two image display device constituent members are laminated via the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention, and at least one of the image display device constituent members is proposes a layered product for an image display device having a step having a height difference of 2 ⁇ m or more on the contact surface with the pressure-sensitive adhesive sheet.
  • the present invention also provides a flexible display pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A),
  • the thickness is 15 ⁇ m or more and 50 ⁇ m or less,
  • a member for constituting an image display device having active energy ray curability and having steps with a height difference of 2 to 10 ⁇ m at intervals of 10 mm or less is laminated under the following bonding conditions, there is no foaming around the steps.
  • a pressure-sensitive adhesive sheet for a flexible display characterized by: (Lamination conditions) a) A pressure-sensitive adhesive sheet having a thickness of 15 to 50 ⁇ m is irradiated with ultraviolet rays so that the integrated amount of light at 365 nm is 2000 to 4000 mJ/cm 2 . b) The pressure-sensitive adhesive sheet is vacuum-bonded to the surface of a substrate having steps with height differences of 2 to 10 ⁇ m at intervals of 10 mm or less under conditions of a press pressure of 0.2 MPa and 30 seconds. c) Perform autoclave treatment under conditions of 70° C., atmospheric pressure of 0.45 MPa, and 20 minutes.
  • the present invention also provides a method for producing a laminate for image display device comprising two image display device constituent members 1 and 2 laminated via an active energy ray-curable adhesive sheet, comprising:
  • a method for producing a laminate for an image display device is proposed, which has the following steps 1 to 3, and is characterized by performing steps 1 and 2 and then performing step 3.
  • Step 1 One surface of the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention is attached to the member 1 for constituting an image display device.
  • Step 2 The active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention is cured by irradiating it with an active energy ray.
  • Step 3 The image display device constituting member 2 is adhered to the other surface of the pressure-sensitive adhesive sheet to form a laminate.
  • the pressure-sensitive adhesive sheet proposed by the present invention fills every corner of the adherend so as to follow the step so as not to generate air bubbles even if there is a step on the sticking surface of the image display device constituent member that is the adherend. can do. Furthermore, the pressure-sensitive adhesive sheet proposed by the present invention exhibits excellent resilience and durability even when a laminate having a configuration in which the pressure-sensitive adhesive sheet and image display device constituent members are laminated is operated to bend in a high-temperature environment. Excellent durability can be exhibited even when a bending operation is performed in a low-temperature environment. Therefore, for example, even when the laminate is folded, curved, or wound up in a high-temperature or low-temperature environment, excellent durability or resilience can be exhibited. From the above points, the pressure-sensitive adhesive sheet proposed by the present invention can be suitably used, for example, as a pressure-sensitive adhesive sheet for flexible displays.
  • a pressure-sensitive adhesive sheet (referred to as "the present pressure-sensitive adhesive sheet") according to an example of the embodiment of the present invention includes a (meth)acrylic polymer (A), particularly a pressure-sensitive adhesive layer (“the present pressure-sensitive adhesive layer ”) is an active energy ray-curable pressure-sensitive adhesive sheet.
  • the present pressure-sensitive adhesive layer in the present pressure-sensitive adhesive sheet contains, for example, a (meth)acrylic polymer (A), particularly the (meth)acrylic polymer (A) as a main component resin, preferably a cross-linking agent (B) and/or a polymerization initiator (C) and, if necessary, a pressure-sensitive adhesive composition (referred to as "the present pressure-sensitive adhesive composition”) containing other components.
  • the "active energy ray-curable adhesive sheet” is a pressure-sensitive adhesive sheet having properties that can be cured by an active energy ray, in other words, an active energy ray-curable adhesive sheet that leaves room for curing by an active energy ray. is the meaning of This pressure-sensitive adhesive sheet may have been cured (also referred to as “temporary curing”) in a state in which there is room for curing by the active energy ray, or may have not been cured at all (referred to as “uncured”). ) and can be cured by active energy rays. If the adhesive sheet is temporarily cured or uncured, the adhesive sheet is cured with active energy rays before or after bonding the adhesive sheet to the adherend ("main curing ), which can result in increased cohesion and improved adhesion.
  • the "main component resin” means the resin having the highest mass ratio among the resins constituting the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition.
  • the content of the main component resin is 70% by mass or more, especially 80% by mass or more, and 90% by mass or more (including 100% by mass) of the resins constituting the present pressure-sensitive adhesive layer or the present pressure-sensitive adhesive composition. may occupy.
  • the pressure-sensitive adhesive sheet preferably has a thickness of 0.8 mm to 1.5 mm and a strain (creep strain) of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds.
  • the fact that the pressure-sensitive adhesive sheet has a creep strain of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds before curing indicates that it is easily deformable in this state. Even if the surface of the member constituting the image display device, which is the adherend, has unevenness, it can be made to follow every corner of the stepped portion, which is preferable.
  • the pressure-sensitive adhesive sheet preferably has a creep strain of 50% or more, more preferably 100% or more, more preferably 105% or more, particularly 110% or more.
  • the creep strain is preferably 10000% or less because the shape can be maintained at room temperature or lower.
  • the creep strain of the present pressure-sensitive adhesive sheet is more preferably 5000% or less, more preferably 2500% or less, further preferably 1000% or less, more preferably 500% or less, particularly 250% or less. % or less is more preferable.
  • the creep strain in the present pressure-sensitive adhesive sheet is a numerical value when the thickness is 0.8 mm to 1.5 mm. It is necessary to avoid fluctuations in measurement results due to the influence of measurement jigs due to insufficient thickness. To this end, it is necessary to measure the present pressure-sensitive adhesive sheet after adjusting it within a certain range of thickness. By adjusting the thickness of the pressure-sensitive adhesive sheet in advance within the above range and then measuring the creep strain, the creep strain of the pressure-sensitive adhesive sheet can be accurately determined without being affected by the measuring jig.
  • the above-mentioned "thickness of 0.8 mm to 1.5 mm” means that if the thickness of the adhesive sheet as a measurement sample is less than this range, the thickness of the measurement sample may be adjusted by stacking several sheets. It means to adjust the depth to this range. The same is true when the thickness of the measurement sample is specified in other tests.
  • the composition and molecular weight of the (meth)acrylic polymer (A) are adjusted, and the type and amount of the cross-linking agent (B) are adjusted. is preferred. However, it is not limited to this means.
  • the pressure-sensitive adhesive sheet had a thickness of 0.8 mm to 1.5 mm, and was irradiated with an active energy ray having a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , and then a pressure of 1000 Pa was applied at a temperature of 80 ° C. for 180 seconds. It is preferable that the time strain (creep strain) is 10% or more.
  • This PSA sheet has a strain (creep strain) of 10% or more when a pressure of 1000 Pa is applied at a temperature of 80° C. for 180 seconds after curing.
  • the creep strain after curing with active energy rays is more preferably 10% or more, more preferably 20% or more, more preferably 30% or more, more preferably 40% or more.
  • the upper limit of the strain (creep strain) after curing is too high, the pressure-sensitive adhesive sheet may protrude from the end face of the laminate in a high-temperature environment and the end face may become sticky, cohesive peeling may occur during folding, It is preferably 500% or less, more preferably 300% or less, even more preferably 100% or less, and 80% or less because there is a risk of impairing the resilience when opened from the state. is particularly preferred, and 60% or less is most preferred.
  • the creep strain of the present pressure-sensitive adhesive sheet after curing with active energy rays is also measured after adjusting the thickness of the present pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. As described above, is based on consideration of the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
  • the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent ( It is preferable to adjust the type and addition amount of B) or to adjust the irradiation dose of the active energy ray.
  • the type and addition amount of B may be adjusted, or the cross-linking agent ( It is preferable to adjust the type and addition amount of B) or to adjust the irradiation dose of the active energy ray.
  • This pressure-sensitive adhesive sheet preferably has a recovery rate of 60% or more after 200% deformation at 25° C., which is represented by the following formula when irradiated with an active energy ray having a wavelength of 365 nm with an accumulated amount of light of 2000 to 4000 mJ/cm 2 .
  • the recovery rate is represented by the following formula.
  • Restoration rate (%) ⁇ (xy)/x ⁇ x 100 (x is the initial strain applied in the shear direction to the adhesive sheet with a thickness of 0.8 mm to 1.5 mm, and y is the residual strain after 600 seconds after the initial strain was applied for 600 seconds and released. A more specific measurement method is described in Examples.)
  • the recovery rate of this adhesive sheet after curing is 60% or more, permanent deformation can be suppressed, and the recovery property when unfolded from the folded state is also good. From this point of view, the recovery rate is preferably 70% or more, more preferably 75% or more, and more preferably 80% or more.
  • the recovery rate of the present pressure-sensitive adhesive sheet is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. It is intended to take into consideration the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
  • the adhesive sheet Before being cured by active energy rays, the adhesive sheet is preferably in an uncrosslinked state or a slightly crosslinked state, that is, in a state where the gel fraction is 0% or more and 20% or less. From the viewpoint of conformability to irregularities on the adherend surface, the gel fraction is more preferably 10% or less, even more preferably 8% or less, and even more preferably 5% or less.
  • the gel fraction after curing with active energy rays is 10% or more, the shape stability of the pressure-sensitive adhesive sheet, and the resilience and durability when folded when formed into a laminate can be imparted.
  • the gel fraction after curing with active energy rays is preferably 10% or more, more preferably 30% or more, and more preferably 40% or more.
  • the gel fraction after active energy ray curing is preferably 85% or less.
  • the gel fraction after curing with active energy rays is more preferably 70% or less, more preferably 60% or less, and even more preferably 55% or less.
  • this pressure-sensitive adhesive sheet is cured by irradiating an active energy ray with a wavelength of 365 nm at an accumulated light amount of 1000 mJ/cm 2 , the gel fraction does not change or increases by less than 0.5% compared to before curing. There may be.
  • the present pressure-sensitive adhesive sheet may have such a low photosensitivity.
  • the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer, may be adjusted, or the type of the cross-linking agent (B) may be adjusted. It is preferable to adjust the addition amount of the active energy ray, and to adjust the intensity of the active energy ray to be irradiated and the integrated amount of light. However, it is not limited to this means.
  • the pressure-sensitive adhesive sheet preferably has the following properties (4). (4) Adhesive strength to the surface of soda lime glass at 23° C. 50% RH, peel angle 180°, peel speed 300 mm / min is 1 N / cm or more.
  • the adhesive strength is 1 N/cm or more, it is preferable because it facilitates positioning and temporary fixation when bonding the image display device constituent members to be described later. From this point of view, the adhesive strength is preferably 1 N/cm or more, more preferably 2 N/cm or more, still more preferably 4 N/cm or more, and particularly preferably 5 N/cm or more. , 10 N/cm or more. Incidentally, the normal upper limit is 40 N/cm.
  • the pressure-sensitive adhesive sheet also preferably has the following properties (5).
  • the adhesive strength is 1 N/cm or more, it is preferable because when a laminated body is formed by laminating together with the image display device constituent members described later, delamination or the like does not occur at the time of bending, and durability is improved.
  • the adhesive strength when irradiated with active energy rays after lamination to soda lime glass is preferably 1 N/cm or more, more preferably 2 N/cm or more, and 3 N/cm or more. It is more preferable that it is 5 N/cm or more. Incidentally, the normal upper limit is 40 N/cm.
  • the pressure-sensitive adhesive sheet further preferably has the following properties (6).
  • (6) After irradiating an active energy ray with a wavelength of 365 nm at an integrated light amount of 2000 to 4000 mJ/cm 2 , when the adhesive sheet is laminated to soda lime glass, peeling at 23 ° C. 50% RH and peeling from the surface of the soda lime glass.
  • Adhesive strength is 1 N/cm or more at an angle of 180° and a peeling speed of 300 mm/min
  • the adhesive strength is 1 N/cm or more, it is preferable because delamination or the like does not occur at the time of bending when a laminate is formed by laminating together with the image display device constituent members described later, and durability is improved.
  • the pressure-sensitive adhesive sheet has an adhesive force of 1 N/cm or more, more preferably 2 N/cm or more, more preferably 3 N/cm or more when the adhesive sheet is laminated to soda lime glass after being cured with an active energy ray. /cm or more, and more preferably 5 N/cm or more.
  • the normal upper limit is 40 N/cm.
  • the pressure-sensitive adhesive sheet preferably has a thickness of 0.8 mm to 1.5 mm, and a loss tangent obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz is 0.8 or more at -30°C. It is more preferably 1 or more, especially 1.2 or more, still more preferably 1.5 or more, and more preferably 2.0 or less, still more preferably 1.8 or less.
  • the loss tangent (tan ⁇ ) of the present adhesive sheet is within the above range, even if the adherend has irregularities on the adherend surface, the adhesive resin can flow and fill the stepped portions by heating, which is preferable.
  • the pressure-sensitive adhesive sheet after curing the active energy ray, that is, after irradiating the active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a shear at a wave number of 1 Hz.
  • the loss tangent obtained by dynamic viscoelasticity measurement in mode is preferably 0.5 or more and 2.3 or less in the range of -30°C or more and -10°C or less.
  • the loss tangent (tan ⁇ ) after curing is within the above range, even if the laminate using the present pressure-sensitive adhesive sheet is folded in a low-temperature environment, peeling or buckling at the interface of image display device constituent members, and image display device constituent members do not occur. It is preferable because it does not cause cracks or the like.
  • the loss tangent (tan ⁇ ) in the range of ⁇ 30° C. or higher and ⁇ 10° C. or lower is preferably 0.5 or higher and 2.3 or lower, especially 0.8 or higher or 2.0 or lower. is more preferable, and among them, 1.1 or more or 1.9 or less is more preferable.
  • the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm, and the maximum loss tangent obtained when dynamic viscoelasticity is measured in a shear mode at a frequency of 1 Hz is ⁇ 20° C. or less. is preferred. It is preferable that the maximum point of the loss tangent is ⁇ 20° C. or less, because the laminate can have durability when folded. From this point of view, the maximum point of the loss tangent is more preferably ⁇ 25° C. or less, more preferably ⁇ 30° C. or less, even more preferably ⁇ 33° C. or less, and particularly preferably ⁇ 35° C. or less. Also, the lower limit is usually -60° C. or higher.
  • the loss tangent before or after curing of the pressure-sensitive adhesive sheet is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. As described above, is based on consideration of the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
  • the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent (B ) is preferably adjusted and the amount of active energy ray irradiation is adjusted.
  • the cross-linking agent (B ) is preferably adjusted and the amount of active energy ray irradiation is adjusted.
  • the adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a storage modulus (G′) of 0.01 to 0.2 MPa obtained by dynamic viscoelasticity measurement in a shear mode at a temperature of 25° C. and a frequency of 1 Hz. It is preferable to have When the storage elastic modulus (G′) of the present pressure-sensitive adhesive sheet is within such a range, even if the adherend surface of the adherend has unevenness, it can be attached so as to follow the unevenness and absorb the unevenness.
  • the storage elastic modulus (G') of the present pressure-sensitive adhesive sheet is preferably 0.01 MPa or more and 0.2 MPa or less at a temperature of 25° C. and a frequency of 1 Hz, especially 0.02 MPa or more or 0.1 MPa or less. and more preferably 0.03 MPa or more or 0.09 MPa or less.
  • the pressure-sensitive adhesive sheet after curing the active energy ray, that is, after irradiating the active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a temperature of 25°C.
  • the storage elastic modulus (G') obtained by dynamic viscoelasticity measurement in shear mode at a frequency of 1 Hz is preferably 0.02 MPa or more and 0.24 MPa or less.
  • the storage elastic modulus (G′) after curing of the pressure-sensitive adhesive sheet is within such a range, when a layered product is formed by laminating it with an image display device item painter member described later, delamination or the like does not occur when bending, and the adhesive sheet is durable. good properties.
  • the storage elastic modulus (G′) after curing of the pressure-sensitive adhesive sheet is preferably 0.02 MPa or more and 0.24 MPa or less at a temperature of 25° C. and a frequency of 1 Hz. It is preferably 0.20 MPa or less, more preferably 0.04 MPa or more or 0.10 MPa or less.
  • the storage elastic modulus (G') of the pressure-sensitive adhesive sheet before or after curing is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above.
  • the reason for this is that the influence of the measuring jig is considered, and the thickness of the pressure-sensitive adhesive sheet is not necessarily within the above range.
  • the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent may be adjusted. It is preferable to adjust the type and amount of addition of (B), and to adjust the dose of active energy rays. However, it is not limited to this means.
  • the pressure-sensitive adhesive composition is a composition containing a (meth)acrylic polymer (A), preferably a cross-linking agent (B) and/or a polymerization initiator (C), and optionally other components. .
  • the pressure-sensitive adhesive composition contains a (meth)acrylic polymer (A), especially as a main component resin. That is, the (meth)acrylic polymer (A) is a resin having the highest mass ratio among the resins constituting the pressure-sensitive adhesive composition. At this time, among the resins constituting the present pressure-sensitive adhesive composition, the mass ratio of the (meth)acrylic polymer (A) is 50% by mass or more, especially 70% by mass or more, especially 80% by mass or more, especially 90% by mass. % or more (including 100% by mass).
  • the (meth)acrylic polymer (A) As the (meth)acrylic polymer (A), the following formula 1 (wherein R 1 represents a hydrogen atom or a methyl group and R 2 represents a linear or branched alkyl having 4 to 18 carbon atoms group or an alicyclic hydrocarbon), and is preferably obtained by polymerizing a polymer component containing 50% by mass or more of the monomer component.
  • the (meth)acrylic polymer (A) is more preferably polymerized to contain 55% by mass or more of the monomer component as a polymerization component, and particularly preferably polymerized to contain 60% by mass or more.
  • (meth)acrylic means acrylic and methacrylic
  • (meth)acryloyl means acryloyl and methacryloyl
  • (meth)acrylate means acrylate and methacrylate, respectively.
  • (co)polymer is meant to include polymers and copolymers.
  • Examples of the monomer represented by Formula 1 include n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl ( meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, unde
  • butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate and lauryl (meth)acrylate is particularly preferable.
  • the (meth)acrylic polymer (A) is preferably a copolymer having "another copolymerizable monomer" other than the monomer component as a copolymerization component.
  • the above-mentioned "other copolymerizable monomer” is preferably contained in the (meth)acrylic polymer (A) in an amount of 1 to 30% by mass, and is contained in a proportion of 2% by mass or more or 25% by mass or less. is more preferred.
  • Examples of the “other copolymerizable monomer” include (a) a carboxyl group-containing monomer (hereinafter also referred to as “copolymerizable monomer a1”), (b) a hydroxyl group-containing monomer (hereinafter also referred to as “copolymerizable monomer a2").
  • Examples of the copolymerizable monomer a1 include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypropyl (meth)acrylate, carboxybutyl (meth)acrylate, ⁇ -carboxypolycaprolactone mono(meth)acrylate, 2- (Meth) acryloyloxyethyl hexahydrophthalate, 2-(meth) acryloyloxypropyl hexahydrophthalate, 2-(meth) acryloyloxyethyl phthalate, 2-(meth) acryloyloxypropyl phthalate, 2-(meth) ) ) acryloyloxyethyl maleate, 2-(meth)acryloyloxypropyl maleate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxypropyl succinate, crotonic acid, fumaric acid, maleic acid, itacon Men
  • Examples of the copolymerizable monomer a2 include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-1-methylethyl acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy Butyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerin mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol polypropylene glycol mono (meth) acrylate, polyethylene glycol Hydroxyalkyl (meth)acrylates such as polybutylene glycol mono(meth)acrylate, polypropylene glycol polybutylene glycol mono(meth)acrylate and hydroxyphenyl(meth)acrylate can be mentioned. These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a3 include aminoalkyl (meth)acrylates such as aminomethyl (meth)acrylate, aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, aminoisopropyl (meth)acrylate, N-alkylamino Examples include N,N-dialkylaminoalkyl (meth)acrylates such as alkyl (meth)acrylates, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate. These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a4 include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate glycidyl ether. . These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a5 include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, Mention may be made of N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, maleic acid amide and maleimide. These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a6 include compounds having a vinyl group in the molecule.
  • Examples of such compounds include functional monomers having functional groups such as alkoxylalkyl groups such as ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxydipropylene glycol acrylate, and methoxypolypropylene glycol acrylate.
  • polyalkylene glycol di(meth)acrylates and vinyl ester monomers such as vinyl acetate, N-vinyl-2-pyrrolidone, vinyl propionate and vinyl laurate, and styrene, chlorostyrene, chloromethylstyrene, ⁇ -methylstyrene and Other aromatic vinyl monomers such as substituted styrene can be exemplified. These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a7 include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, and the like. These may be used alone or in combination of two or more.
  • the macromonomer as the copolymerizable monomer a8 is a macromonomer having a terminal functional group and a high-molecular-weight skeleton component.
  • the "other copolymerizable monomer” is the copolymerizable monomer a8
  • the (meth)acrylic polymer (A) is a copolymer containing a macromonomer-derived structural unit.
  • the skeleton component of the macromonomer is preferably composed of an acrylic acid ester polymer or a vinyl polymer.
  • the (meth)acrylate having a linear or branched alkyl group having 4 to 18 carbon atoms, the copolymerizable monomer a1, the copolymerizable monomer a2, the copolymerizable monomer a6, the copolymerizable Those exemplified by the monomer a7 and the like can be mentioned, and these can be used alone or in combination of two or more.
  • the number average molecular weight of the macromonomer is preferably 1,000 or more, more preferably 1,500 or more, and even more preferably 2,000 or more. The upper limit of the number average molecular weight is usually 20,000.
  • the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 1 to 3 carbon atoms. It is good because it can improve the properties.
  • the number average molecular weight of such a macromonomer is preferably 1,000 to 10,000, particularly preferably 1,500 or more or 5,000 or less, and still more preferably 2,000 or more or 4,000 or less.
  • the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 8 to 18 carbon atoms, the adhesion surface of the adherend becomes more uneven.
  • the number average molecular weight of such a macromonomer is preferably 2,000 to 20,000, particularly preferably 3,000 or more or 15,000 or less, and still more preferably 4,000 or more or 10,000 or less.
  • a macromonomer can be introduced as a branch component of the graft copolymer, and the (meth)acrylic acid ester copolymer can be made into a graft copolymer.
  • a (meth)acrylic polymer (A) comprising a copolymer containing a macromonomer-derived structural unit as a branch component can be used. Therefore, the properties of the main chain and the side chains of the graft copolymer can be changed by selecting the copolymerizable monomer a8 and the other monomers and blending ratio.
  • the copolymerization ratio of the macromonomer in the (meth)acrylic polymer (A) is preferably 30% by mass or less in terms of imparting fluidity during hot-melt, more preferably 2 % by mass or more and 15% by mass or less, more preferably 3% by mass or more and 10% by mass or less, particularly preferably 4% by mass or more and 7% by mass or less.
  • Examples of the copolymerizable monomer a9 include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, nonylphenol EO-modified (meth)acrylate, and the like. These may be used alone or in combination of two or more.
  • Examples of the copolymerizable monomer a10 include (meth)acryl-modified silicone, 2-acryloyloxyethyl acid phosphate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-- Tetrafluoropropyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-tridecafluoro- Examples include fluorine-containing monomers such as n-octyl (meth)acrylate. These may be used alone or in combination of two or more.
  • the glass transition temperature of at least one of the (meth)acrylic acid ester-derived repeating units of the acrylic polymer (A) is preferably -70 to 0°C.
  • the glass transition temperature of the copolymer component means a value calculated by the Fox formula from the glass transition temperature of the polymer obtained from the homopolymer of each component of the copolymer and the composition ratio.
  • the glass transition temperature of at least one of the (meth)acrylic acid ester-derived repeating units of the acrylic polymer (A) is -70. ⁇ 0°C is preferred.
  • (Meth)acrylic acid esters constituting such repeating units include, for example, n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acrylate, 2-ethylhexyl acrylate, 2 -ethylhexyl methacrylate, 2-methylhexyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, isodecyl methacrylate, isostearyl acrylate, isostearyl (meth)acrylate, multi-branched stearyl acrylate, multi-branched stearyl (meth)acrylate, etc. can be mentioned, but are not limited to these.
  • the glass transition temperature of at least one repeating unit derived from the (meth)acrylic acid ester of the acrylic polymer (A) is 20 to 120° C.
  • excellent workability and storage are obtained. It is preferable because stability can be maintained.
  • the glass transition temperature (Tg) is preferably 30° C. to 120° C., especially 40° C. or higher or 110° C. or lower, especially 50° C. or higher, because it affects the hot-melt temperature of the pressure-sensitive adhesive sheet. Alternatively, it is more preferably 100° C. or less. If there is a repeating unit having such a glass transition temperature (Tg), it is possible to maintain excellent workability and storage stability by adjusting the molecular weight, and to adjust it so that it hot melts at 50 ° C. or higher. can.
  • (Meth)acrylic acid esters constituting such repeating units include, for example, methyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl acrylates, isobutyl acrylate, isobutyl methacrylate, isobornyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 1,4-cyclohexanedimethanol monoacrylate, tetrahydrofurfuryl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, etc. can be mentioned.
  • the (meth)acrylic polymer (A) is preferably a block copolymer and/or a graft copolymer from the viewpoint of imparting hot-melt properties to the pressure-sensitive adhesive.
  • a block copolymer or a graft copolymer as the (meth)acrylic polymer (A), a pressure-sensitive adhesive sheet having excellent shape stability and hot-melt properties can be obtained.
  • the block copolymer refers to a copolymer having a plurality of polymer chains containing repeating units derived from (meth)acrylic acid ester, and having a plurality of polymer chains with different chemical structures bonded in a straight chain.
  • some blocks of the block copolymer contain repeating units derived from the macromonomer.
  • graft copolymers are copolymers containing repeating units derived from (meth)acrylic acid ester as a trunk component, and depending on the method of introducing the branch component, they can be comb-shaped polymers, brush-shaped polymers, star polymers, palm-shaped polymers, and so on.
  • a copolymer containing repeating units derived from a macromonomer as a branch component of the graft copolymer is preferred.
  • a graft copolymer containing repeating units derived from a macromonomer is used as the base polymer.
  • block copolymers containing repeating units derived from macromonomers it is common to graft copolymers that the repeating units derived from macromonomers aggregate and phase-separate to exert an effect. It can be expected that a block copolymer containing a can also obtain the same effect as a graft copolymer containing a macromonomer.
  • the (meth)acrylic polymer (A) is a copolymer containing a structural unit derived from a macromonomer as described above, if the copolymerization ratio of the macromonomer is 2% by mass or more, the hot-melt property On the other hand, if it is 30% by mass or less, when it is laminated with the image display device constituent members described later to form a laminate, delamination or the like does not occur during bending, and durability is improved.
  • the copolymerization ratio of the macromonomer in the (meth)acrylic polymer (A) is preferably 2% by mass or more, more preferably 3% by mass or more, and more preferably 4% by mass or more. On the other hand, it is preferably 30% by mass or less, more preferably 15% by mass or less, more preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less.
  • a (meth)acrylic polymer (A) using a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 1 to 3 carbon atoms is used as the macromonomer.
  • the glass transition temperature of the repeating unit derived from the macromonomer is preferably 20 to 150°C, more preferably 40°C or higher or 130°C or lower, and more preferably 60°C or higher or 120°C or lower.
  • the content of the copolymer component having a glass transition temperature within the above range is preferably 3% by mass or more, more preferably 4% by mass or more, relative to the (meth)acrylic polymer (A).
  • it is preferably 10% by mass or less, more preferably 9% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less.
  • the repeating unit derived from the macromonomer that is, the copolymer component having a glass transition temperature of 20 to 150 ° C.
  • the cross-linking agent (B) is a compound or composition that forms a cross-linked structure in the pressure-sensitive adhesive composition, and is a compound having two or more cross-linkable functional groups.
  • the present pressure-sensitive adhesive composition contains the cross-linking agent (B)
  • the present pressure-sensitive adhesive composition forms a cross-linked structure and can impart durability and restorability to the present pressure-sensitive adhesive sheet.
  • crosslinkable functional groups examples include isocyanate groups, epoxy groups, (meth)acryloyl groups, thioisocyanate groups, primary or secondary amino groups, and thiol groups. These may be protected with a suitable protecting group.
  • crosslinkable functional groups contained in the crosslinker include only epoxy groups, only isocyanate groups, only (meth)acryloyl groups, only thioisocyanate groups, only thiol groups, only primary or secondary amino groups, epoxy and (meth)acryloyl groups, and combinations of isocyanate groups and (meth)acryloyl groups.
  • a polyfunctional (meth)acrylate (b) having two or more (meth)acryloyl groups is used as the cross-linking agent (B). is preferred.
  • the content of the polyfunctional (meth)acrylate (b) is preferably 0.5 parts by mass or more, preferably 1 part by mass or more, with respect to 100 parts by mass of the (meth)acrylic polymer (A). Among them, 1.5 parts by mass or more is more preferable. Regarding the upper limit, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, from the viewpoint of maintaining appropriate flexibility and ensuring followability to the adherend when bent. It is more preferably 5 parts by mass or less, more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less.
  • the amount is preferably 5 parts by mass or less, especially from the viewpoint of imparting flexibility to the extent that it can follow the step. 3 parts by mass or less, more preferably 2 parts by mass or less.
  • Polyfunctional (meth)acrylates (b) include, for example, 1,4-butanediol di(meth)acrylate, glycerin di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin glycidyl ether di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecane dimethacrylate, tricyclodecanedimethanol di(meth)acrylate, bisphenol A polyethoxydi(meth)acrylate, bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxy di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ⁇ -
  • the adhesive composition may further contain a monofunctional (meth)acrylate component (D) having one (meth)acryloyl group.
  • a monofunctional (meth)acrylate component By including a monofunctional (meth)acrylate component, the molecular weight between cross-linking points of the cured product can be increased, so that the degree of freedom of movement of the molecular chains is increased, and the components constituting the image display device are bonded via the pressure-sensitive adhesive sheet.
  • the pressure-sensitive adhesive sheet made of the pressure-sensitive adhesive composition can be deformed accordingly.
  • Examples of the monofunctional (meth)acrylate component (D) include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, Acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate Acrylate, dodecyl (meth)acrylate, isododecyl (meth)acrylate, tetradecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate
  • the content ratio by mass of the polyfunctional (meth)acrylate (b) and the monofunctional (meth)acrylate component (D) is the polyfunctional (meth)acrylate (b):
  • Monofunctional (meth)acrylate (D) is preferably 1:0.1 to 1:9, more preferably 1:1 to 1:9, and preferably 1:2 to 1:9. More preferred. Within this range, the amount of the monofunctional (meth)acrylate component is not too large, and there is no concern that the sensitivity to light will decrease and the productivity will decrease.
  • the polymerization initiator (C) imparts active energy ray curability to the present pressure-sensitive adhesive sheet, and may be any compound that generates radicals by means of active energy rays.
  • the polymerization initiator (C) is roughly classified into two groups according to the mechanism of radical generation: a cleavage-type photoinitiator capable of cleaving and decomposing a single bond of the polymerization initiator itself to generate radicals, and an excited initiator. and a hydrogen abstraction type photoinitiator capable of forming an exciplex with a hydrogen donor in the system and transferring hydrogen of the hydrogen donor.
  • the polymerization initiator (C) may be either a cleavage photoinitiator or a hydrogen abstraction photoinitiator, each of which may be used alone or a mixture of both may be used. may be used alone or in combination of two or more.
  • a hydrogen abstraction type photoinitiator is used as the photoinitiator, a hydrogen abstraction reaction also occurs from the acrylic (co)polymer, and not only the active energy ray-curable compound but also the acrylic (co)polymer has a crosslinked structure. It is preferable in terms of being able to form a crosslinked structure with many crosslinked points.
  • cleavage type photoinitiator when used as the polymerization initiator (C), once radicals are generated, it decomposes and deactivates, which is preferable in that there is no risk of unexpected reaction or deterioration after curing.
  • cleavage-type photoinitiators examples include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one. , 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-[4- ⁇ 4-(2-hydroxy-2- Methyl-propionyl)benzyl ⁇ phenyl]-2-methyl-propan-1-one, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), phenylglyoxylic acid methyl, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one , 2-(dimethylamino)-2-[(4-methylpheny
  • Hydrogen abstraction photoinitiators include, for example, benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloyl Oxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoylformate, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, 4-(1,3-acryloyl-1,4,7,10,13-pentaoxo tridecyl)benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone and derivatives thereof, etc. can be mentioned.
  • the content of the polymerization initiator (C) is not particularly limited.
  • “Other components" other than the above contained in the present pressure-sensitive adhesive composition include, for example, silane coupling agents, tackifying resins, plasticizers, antioxidants, light stabilizers, metal deactivators, if necessary.
  • Various additives such as a curing agent, anti-aging agent, hygroscopic agent, polymerization inhibitor, ultraviolet absorber, anticorrosive agent, inorganic particles, sensitizer and pigment can be incorporated as appropriate.
  • the amounts of these additives are typically preferably selected so as not to adversely affect the curing of the adhesive sheet or adversely affect the physical properties of the adhesive sheet.
  • a reaction catalyst such as a tertiary amine compound, a quaternary ammonium compound, a tin laurate compound, or the like may be appropriately contained.
  • silane coupling agent examples include compounds having a hydrolyzable functional group such as an alkoxy group together with an unsaturated group such as a vinyl group, an acryloxy group and a methacryloxy group, an amino group, an epoxy group, and the like. .
  • silane coupling agents include N-( ⁇ -aminoethyl)- ⁇ -aminopropyltrimethoxysilane, N-( ⁇ -aminoethyl)- ⁇ -aminopropylmethyldimethoxysilane, ⁇ -aminopropyl Examples include triethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, ⁇ -methacryloxypropyltrimethoxysilane, and the like. Among them, ⁇ -glycidoxypropyltrimethoxysilane or ⁇ -methacryloxypropyltrimethoxysilane can be preferably used from the viewpoint of good adhesiveness and little discoloration such as yellowing.
  • the silane coupling agents may be used singly or in combination of two or more.
  • silane coupling agent When the silane coupling agent is contained, it is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer, and is preferably 0.2 parts by mass or more or 3 parts by mass or less. More preferred. Coupling agents such as organic titanate compounds can also be effectively used in the same manner as silane coupling agents.
  • the present pressure-sensitive adhesive composition can contain a hydrocarbon tackifier in order to impart stickiness and hot-melt properties to the present pressure-sensitive adhesive sheet.
  • Hydrocarbon tackifiers include terpene resins such as polyterpenes (e.g., ⁇ -pinene-based resins, ⁇ -pinene-based resins, and limonene-based resins) and aromatic-modified polyterpene resins (e.g., phenol-modified polyterpene resins), and coumaran-indene.
  • Resins C5-based hydrocarbon resins, C9-based hydrocarbon resins, C5/C9-based hydrocarbon resins, petroleum-based resins such as dicyclopentadiene-based resins, modified rosins, hydrogenated rosins, polymerized rosins, rosins such as rosin esters can be mentioned.
  • the hydrocarbon tackifier is preferably compatible with the present pressure sensitive adhesive composition.
  • the content of the hydrocarbon tackifier is not particularly limited. It is preferably 0.1 to 20 parts by mass, more preferably 0.5 parts by mass or more or 15 parts by mass or less, based on 100 parts by mass of the (meth)acrylic polymer.
  • silane coupling agents and tackifiers By including these silane coupling agents and tackifiers, it is possible to suitably prepare a pressure-sensitive adhesive composition having excellent adhesive properties.
  • this adhesive sheet in addition to the (meth)acrylic polymer (A), if necessary, a crosslinking agent (B) and / or a polymerization initiator (C), and optionally other components are mixed in predetermined amounts to prepare the present pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition is formed into a sheet, and if necessary, the curable compound is crosslinked or polymerized to be cured, and the present pressure-sensitive adhesive sheet should be made.
  • a crosslinking agent (B) and / or a polymerization initiator (C) e.g., it is not limited to this method.
  • the raw materials are kneaded using a temperature-controllable kneader (e.g., single-screw extruder, twin-screw extruder, planetary mixer, twin-screw mixer, pressure kneader, etc.). Just do it.
  • a temperature-controllable kneader e.g., single-screw extruder, twin-screw extruder, planetary mixer, twin-screw mixer, pressure kneader, etc.
  • various additives such as silane coupling agents and antioxidants may be blended in advance with the resin and then supplied to the kneader, or all the materials may be melted and mixed in advance.
  • a masterbatch in which only the additive is concentrated in the resin in advance may be prepared and supplied.
  • Methods for forming the present pressure-sensitive adhesive composition into a sheet include known methods such as wet lamination, dry lamination, extrusion casting using a T-die, extrusion lamination, calendering, inflation, injection molding, and injection molding.
  • a liquid curing method or the like can be employed.
  • the wet lamination method, the extrusion casting method, and the extrusion lamination method are suitable for producing a sheet.
  • the present pressure-sensitive adhesive composition contains a radical initiator
  • a cured product can be produced by curing by irradiating heat and/or active energy rays.
  • the present pressure-sensitive adhesive sheet can be produced by irradiating heat and/or active energy rays to a molded article, for example, a sheet formed from the present pressure-sensitive adhesive composition.
  • the active energy rays to be irradiated include ⁇ rays, ⁇ rays, ⁇ rays, ionizing radiation such as neutron rays and electron beams, ultraviolet rays, visible rays, and the like. Ultraviolet rays are preferable from the viewpoint of suppression and reaction control.
  • the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as the initiator can be activated to polymerize the (meth)acrylate component.
  • the present pressure-sensitive adhesive composition can be dissolved in an appropriate solvent and various coating techniques can be used.
  • the pressure-sensitive adhesive sheet can also be obtained by thermal curing in addition to the active energy ray irradiation curing described above.
  • the thickness of the adhesive sheet can be adjusted by the coating thickness and the solid content concentration of the coating liquid.
  • the present pressure-sensitive adhesive sheet may have a single-layer structure composed of the present pressure-sensitive adhesive layer, or may have a multi-layer structure of two or more layers provided with the present pressure-sensitive adhesive layer.
  • the composition of the layers other than the layer composed of the pressure-sensitive adhesive composition is arbitrary.
  • the pressure-sensitive adhesive composition forming a layer other than the present pressure-sensitive adhesive layer also It is preferably formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer, and more preferably contains the same (meth)acrylic polymer (A) as that of the present pressure-sensitive adhesive layer. Furthermore, it is more preferable that layers other than the pressure-sensitive adhesive layer also contain a cross-linking agent (B) and/or a polymerization initiator (C).
  • B cross-linking agent
  • C polymerization initiator
  • the pressure-sensitive adhesive sheet has a multi-layer structure of two or more layers, it is preferable that at least the outermost layer, the backmost layer, or both layers correspond to the pressure-sensitive adhesive layer. All the layers may be layers corresponding to the pressure-sensitive adhesive layer.
  • the thickness of the layer corresponding to the pressure-sensitive adhesive layer preferably accounts for 10% or more and 100% or less of the total thickness of the pressure-sensitive adhesive sheet. % or more or 70% or less, more preferably 20% or more or 50% or less.
  • the thickness of the pressure-sensitive adhesive sheet Since the bending stress at the time of bending or bending is proportional to the thickness, if the thickness of the pressure-sensitive adhesive sheet is 50 ⁇ m or less, the stress at the time of bending or bending can be alleviated, and the thickness of the laminate can be reduced. In addition, it can contribute to thinning of the flexible image display device. On the other hand, when the thickness is 15 ⁇ m or more, the handling property is good, and even if there is an uneven portion having a height difference of 2 ⁇ m or more and 10 ⁇ m or less in the constituent member of the image display device, it is possible to follow the step.
  • the thickness of the pressure-sensitive adhesive sheet is preferably 50 ⁇ m or less, more preferably 45 ⁇ m or less, more preferably 40 ⁇ m or less, particularly 35 ⁇ m or less.
  • the lower limit is preferably 15 ⁇ m or more, more preferably 17 ⁇ m or more, and more preferably 20 ⁇ m or more.
  • the pressure-sensitive adhesive sheet is thin as described above, it can be deformed to follow the unevenness on the surface of the member for an image display device and penetrate into the unevenness. Therefore, the surface of the pressure-sensitive adhesive sheet, that is, the surface opposite to the adhesive surface can be made smooth by absorbing the unevenness. At this time, if the height difference of the unevenness is 12% or less of the thickness of the present pressure-sensitive adhesive sheet, it can be absorbed.
  • An example of the present pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet for a flexible display, which has a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A), has a thickness of 15 ⁇ m or more and 50 ⁇ m or less, and exhibits active energy ray curability. and having a difference in height of 2 ⁇ m or more, for example, steps of 2 to 10 ⁇ m at intervals of 10 mm or less.
  • a pressure-sensitive adhesive sheet for a flexible display can be mentioned. (Lamination conditions) a) A pressure-sensitive adhesive sheet having a thickness of 15 to 50 ⁇ m is irradiated with ultraviolet rays so that the integrated amount of light at 365 nm is 2000 to 4000 mJ/cm 2 .
  • the pressure-sensitive adhesive sheet is vacuum-bonded to the surface of a base material having a difference in height of 2 ⁇ m or more, for example, 2 to 10 ⁇ m at intervals of 10 mm or less under the conditions of a press pressure of 0.2 MPa and 30 seconds.
  • This pressure-sensitive adhesive sheet can also be used as a single pressure-sensitive adhesive sheet.
  • the present pressure-sensitive adhesive composition may be directly applied to a member for an image display device to be described later to form a sheet, or the pressure-sensitive adhesive composition may be directly extruded or injected into a mold to obtain the present pressure-sensitive adhesive sheet. can be used.
  • the present pressure-sensitive adhesive sheet can also be used by directly filling the present pressure-sensitive adhesive composition between image display device constituent members.
  • this pressure-sensitive adhesive sheet can be used by being laminated with other pressure-sensitive adhesive sheets.
  • other pressure-sensitive adhesive sheets are more suitable for the flexible image display device if they are more flexible than the present pressure-sensitive adhesive sheet.
  • Such other adhesive sheets have a gel fraction of 70% or more, a thickness of 0.8 mm to 1.5 mm, and a maximum loss tangent obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz.
  • a pressure-sensitive adhesive sheet having a temperature of -25°C or less can be mentioned.
  • the maximum point of the loss tangent is ⁇ 25° C. or less, it is preferable because it can be restored even when it is bent at high and low temperatures.
  • the maximum point of the loss tangent of the other PSA sheet is preferably ⁇ 25° C. or lower, more preferably ⁇ 30° C. or lower, and more preferably ⁇ 35° C. or lower.
  • the pressure-sensitive adhesive sheet can be used as a pressure-sensitive adhesive sheet with a release film (referred to as a "pressure-sensitive adhesive sheet with a release film") comprising the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a release film.
  • a pressure-sensitive adhesive sheet with a release film comprising the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a release film.
  • the present pressure-sensitive adhesive composition can be in the form of a release film-attached pressure-sensitive adhesive sheet formed by molding a single-layer or multilayer sheet on a release film.
  • polyester film examples include polyester film, polyolefin film, polycarbonate film, polystyrene film, acrylic film, triacetylcellulose film, and fluororesin film.
  • polyester films and polyolefin films are particularly preferred.
  • the thickness of the release film is not particularly limited. Among them, for example, from the viewpoint of workability and handleability, the thickness is preferably 25 ⁇ m to 500 ⁇ m, more preferably 38 ⁇ m or more or 250 ⁇ m or less, and more preferably 50 ⁇ m or more or 200 ⁇ m or less.
  • the release film is preferably a polyester-based film, and from the standpoint of releasability, it is preferable that the release film be easily peeled off even after irradiation with active energy rays. From this point of view, when the active energy ray with a wavelength of 365 nm is irradiated with an accumulated light amount of 2000 to 4000 mJ/cm 2 , the peel force for the present adhesive sheet is 0.1 N/cm or less at a peel angle of 180° and a peel speed of 300 mm/min. It is preferable to be
  • a laminate (referred to as "this laminate") according to an example of an embodiment of the present invention includes a release film and a member for constituting an image display device having a step with a height difference of 2 ⁇ m or more on the surface to be laminated, It is a layered product having a configuration in which layers are layered via an adhesive sheet.
  • the release film of the laminate is the same as the release film of the pressure-sensitive adhesive sheet with the release film.
  • a release film and a member for constituting an image display device having a step with a height difference of 2 ⁇ m or more on the laminated surface are laminated via the present adhesive sheet, and the present adhesive is passed through the release film from the release film side.
  • the laminate can be produced by irradiating the sheet with active energy rays.
  • the irradiation dose of the active energy rays is preferably 4000 mJ/cm 2 or less, particularly 3500 mJ/cm 2 or less, further preferably 3200 mJ/cm 2 or less, from the viewpoint of step absorption.
  • it is preferably 2000 mJ/cm 2 or more, more preferably 2500 mJ/cm 2 or more, and even more preferably 2800 mJ/cm 2 or more.
  • a laminate for an image display device according to an example of the embodiment of the present invention (hereinafter sometimes referred to as "this laminate") is provided with an image display device constituent member on at least one side of the above-described present pressure-sensitive adhesive sheet. It is a laminated body.
  • the laminate includes a first image display device constituent member (hereinafter sometimes referred to as “first member”), the present pressure-sensitive adhesive sheet, and a second image display device constituent member (hereinafter sometimes referred to as “second member”). (sometimes referred to as “members”) are preferably laminated in this order. Further, the first member, the second member and the third image display device constituting member (hereinafter sometimes referred to as “third member”) are laminated in this order with the adhesive sheet interposed therebetween. It may also be a laminated body having a different configuration. Two or more members to be laminated may be the same or different.
  • the thickness of the laminate is not particularly limited.
  • the laminate when used in an image display device, the laminate is in the form of a sheet, and if the thickness is 0.02 mm or more, the handleability is good, and the thickness is 1.0 mm or less. If it is, it can contribute to thickness reduction of a laminated body. Therefore, the thickness of the laminate is preferably 0.02 mm or more, more preferably 0.03 mm or more, particularly 0.05 mm or more.
  • the upper limit is preferably 1.0 mm or less, more preferably 0.7 mm or less, particularly 0.5 mm or less.
  • the present laminate can be produced by attaching the present adhesive sheet to the first member, the second member and/or the third member. However, it is not limited to such a manufacturing method.
  • the first member, the second member, and the third member include, for example, A cover lens, a polarizing plate, a retardation film, a barrier film, a touch sensor film, a light emitting element, a PSA and the like can be mentioned.
  • the first member preferably has a touch input function.
  • the second member to the third member may have a touch input function.
  • at least one of the members may have various irregularities formed by wiring, printing, pattern development, surface treatment, embossing, etc. on the contact surface with the pressure-sensitive adhesive sheet.
  • the height difference of the unevenness is preferably 2 ⁇ m or more, for example, 2 ⁇ m or more and 10 ⁇ m or less, more preferably 8 ⁇ m or less, and more preferably 3 ⁇ m or more or 7 ⁇ m or less. is more preferable, and among them, 4 ⁇ m or more or 6 ⁇ m or less is more preferable.
  • At least one of the members for forming an image display device (including the first member, the second member, and the third member) to be laminated is made of urethane resin, cycloolefin resin, triacetylcellulose resin, (meta) It may be a resin sheet or a thin film glass mainly composed of one or more resins selected from the group consisting of acrylate resins, epoxy resins and polyimide resins.
  • the term "main component” refers to a component that accounts for the largest mass ratio among the components constituting the image display device constituent member, and specifically, the image display device constituent member or the member forming the member. It accounts for 50% by mass or more of the pressure-sensitive adhesive composition, more preferably 55% by mass or more, and more preferably 60% by mass or more.
  • This adhesive sheet can be hot-melted after being cured by active energy rays. With such a hot melt, even if the adherend surface of the adherend has unevenness, it can be laminated so as to follow the unevenness and absorb the unevenness, and the surface can be smoothed. . Therefore, when two image display device constituent members are bonded via the present pressure-sensitive adhesive sheet, even if one or both of the image display device constituent members are members that do not transmit light, the unevenness can be absorbed. Two members for forming an image display device can be pasted together.
  • This image display device> Forming a flexible image display device (also referred to as "present image display device") comprising this laminate by incorporating this laminate, for example, by laminating this laminate on another image display device constituent member. can be done.
  • a flexible image display device leaves no trace of bending even after repeated bending, bending, or winding operations, and can be bent, bent, or wound up when the bending, bending, or winding state is released. It is an image display device that can quickly recover to the state before the display and can display an image without distortion.
  • the laminate conforms to and absorbs unevenness having a height difference of 2 ⁇ m or more on the contact surface of the constituent member of the image display device with the adhesive sheet so as not to generate air bubbles.
  • a display device can be manufactured.
  • the present pressure-sensitive adhesive sheet can be placed on the viewing side of an image display panel such as a liquid crystal panel, or can be placed on the side opposite to the viewing side of the image display panel, that is, on the light source side. can.
  • the present laminate can be produced by a method for producing a laminate for an image display device including the following steps 1 to 3 and, if necessary, step 4.
  • Step 1 One surface of the pressure-sensitive adhesive sheet is attached to the member 1 for constituting an image display device.
  • Step 2 The pressure-sensitive adhesive sheet is cured by irradiation with active energy rays.
  • Step 3 The image display device constituting member 2 is adhered to the other surface of the pressure-sensitive adhesive sheet to form a laminate.
  • Step 4 The laminate is heat-treated to hot-melt the pressure-sensitive adhesive sheet.
  • Step 2 may be carried out after Step 1, or Step 1 may be carried out after Step 2. After performing steps 1 and 2, step 3 is performed.
  • Step 1 is a step of bonding one surface of the pressure-sensitive adhesive sheet to the member 1 for constituting an image display device.
  • a lamination method known methods such as roll lamination, press lamination using a parallel plate, and diaphragm lamination can be used.
  • the lamination environment there are an air lamination method in which lamination is performed under normal pressure and a vacuum lamination method in which lamination is performed under reduced pressure. From the viewpoint of preventing air bubbles during lamination, a method of laminating with a parallel plate under a reduced pressure environment is preferable. Moreover, you may adjust bonding temperature suitably.
  • Step 2 is a step of curing the adhesive sheet by irradiating it with active energy rays.
  • active energy rays ultraviolet rays and visible rays are suitable.
  • the light source when irradiating the active energy ray it is possible to use properly according to the wavelength and irradiation amount of the light to be irradiated from, for example, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a halogen lamp, an LED lamp, a fluorescent lamp, etc. can.
  • irradiation time and irradiation means are not particularly limited, for example, in the case of ultraviolet irradiation, it is preferable to irradiate so that the integrated light amount at a wavelength of 365 nm is 2000 mJ/cm 2 or more, particularly 3000 mJ/cm 2 or more.
  • the present pressure-sensitive adhesive sheet is hot-melted. can absorb the step by following the step, and preferably the surface of the laminate can be smoothed.
  • Step 3 is a step of laminating the member 2 for constituting an image display device to the other surface of the pressure-sensitive adhesive sheet that has undergone steps 1 and 2 to form a laminate.
  • the image display device-constituting member 1 and/or the image display device-constituting member 2 may be heated and the image display device-constituting member 2 may be bonded together as needed.
  • the heating at this time is performed, for example, by applying a press plate heated to a predetermined temperature to a laminate for an image display device composed of image display device constituent member 1/adhesive sheet/image display device constituent member 2 from both sides.
  • a method of applying pressure can be mentioned.
  • the heating temperature at this time is preferably 50° C. or higher and 80° C. or lower. That is, the image display device constituent member 1 and/or the image display device constituent member 2 are heated to 50° C. or more and 80° C. or less to hot-melt the adhesive sheet, and the image display device constituent member 2 is bonded. is preferred.
  • the press pressure when pressing with the press plate is preferably 0.01 MPa or more or 0.4 MPa or less, more preferably 0.02 MPa or more or 0.35 MPa or less.
  • Step 4 is a step of heat-treating the laminated body obtained in Step 3 to hot-melt the pressure-sensitive adhesive sheet. This step 4 may be performed as required.
  • the surface of the first member or the second member for example, the surface to be laminated, has a height difference of 2 ⁇ m or more, for example, 2 ⁇ m or more and 10 ⁇ m or less. Even if the adhesive sheet has unevenness having a level difference, the pressure-sensitive adhesive sheet can follow the level difference and absorb the level difference, thereby smoothing the surface.
  • the heating temperature for the heat treatment of the laminate is preferably 40° C. or higher and 90° C. or lower. Above all, the temperature is preferably 50° C. or higher or 80° C. or lower, more preferably 60° C. or higher or 70° C. or lower.
  • an air pressure of 0.2 MPa or more and 0.8 MPa or less may be applied to the laminate for 5 minutes or more. At this time, the atmospheric pressure is preferably 0.2 MPa or more and 0.8 MPa or less, more preferably 0.4 MPa or more or 0.6 MPa or less.
  • the treatment time is preferably 5 minutes or more or 60 minutes or less, more preferably 10 minutes or more or 30 minutes or less.
  • a press pressure of 0.01 MPa or more and 0.4 MPa or less may be applied to the laminate in combination with the heat treatment.
  • the pressing pressure is preferably 0.01 MPa or more or 0.4 MPa or less, more preferably 0.02 MPa or more or 0.35 MPa or less.
  • the treatment time is preferably 5 seconds or more or 10 minutes or less, more preferably 10 seconds or more or 5 minutes or less.
  • the hot-melt treatment is preferably performed within 30 minutes after irradiating the adhesive sheet with active energy rays. The reason for this is that if the hot-melt treatment is performed before the adhesive is completely cured, it becomes easier to follow the unevenness having a level difference of 2 ⁇ m or more. From this point of view, the time from the irradiation of the active energy ray to the hot-melt treatment is preferably within 30 minutes, more preferably within 20 minutes, and even more preferably within 10 minutes.
  • the term “film” includes the “sheet”
  • the term “sheet” includes the “film”.
  • the expression “panel” such as an image display panel, a protective panel, etc. includes a plate, a sheet and a film.
  • (Meth)acrylic polymer (A-1) 6 parts by mass of polymethyl methacrylate macromonomer (Tg 105°C) having a number average molecular weight of 2800, 90 parts by mass of butyl acrylate (Tg -55°C), and acrylic acid ( Tg 106° C.) 4 parts by mass of acrylic graft copolymer (mass average molecular weight: 220,000, Tg ⁇ 45° C.) -
  • the glass transition temperature of each copolymer component in the (meth)acrylic polymer is the literature value of the glass transition temperature obtained from the homopolymer of the component.
  • the macromonomer the literature value of the glass transition temperature obtained from the homopolymer of the component forming the high-molecular-weight skeleton in the macromonomer was used.
  • the glass transition temperature of the acrylic copolymer the theoretical Tg calculated by the Fox calculation formula is described from the glass transition temperature and the composition ratio of each component of the copolymer.
  • ⁇ Crosslinking agent (B)> ⁇ Crosslinking agent (B-1): propoxylated pentaerythritol triacrylate
  • the sheet-shaped pressure-sensitive adhesive composition a release film having a thickness of 75 ⁇ m (PET film manufactured by Mitsubishi Chemical Corporation) that has been subjected to silicone release treatment is laminated to form a laminate, and the release film/ A pressure-sensitive adhesive sheet 1 with a release film composed of pressure-sensitive adhesive sheet 1/release film was obtained.
  • the adhesive sheet 1 was an active energy ray-curable adhesive sheet having an active energy ray-curable adhesive sheet that is cured by irradiation with an active energy ray.
  • Adhesive sheet 2 and adhesive sheet 2 with a release film composed of release film/adhesive sheet 2/release film were produced in the same manner as in Example 1, except that the thickness was changed as shown in Table 1.
  • the adhesive sheet 2 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • Example 3 Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive composition was applied to a release film of 100 ⁇ m (PET film manufactured by Mitsubishi Chemical Corporation, thickness 100 ⁇ m) and a release film of 75 ⁇ m (Mitsubishi Chemical Corporation).
  • PET film that is, sandwiched between two release films, hot-melt molded into a sheet with a thickness of 50 ⁇ m, and release film/adhesive sheet 3/release film-attached adhesive sheet 3 consisting of release film got
  • the adhesive sheet 3 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • Example 4 Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
  • Adhesive sheet 4 and adhesive sheet 4 with a release film composed of release film/adhesive sheet 4/release film were prepared in the same manner as in Example 3.
  • the adhesive sheet 4 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • Example 5 Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
  • Adhesive sheet 5 and adhesive sheet 5 with a release film composed of release film/adhesive sheet 5/release film were prepared in the same manner as in Example 1.
  • the adhesive sheet 5 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • Example 6 Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
  • Adhesive sheet 6 and adhesive sheet 6 with a release film composed of release film/adhesive sheet 6/release film were prepared in the same manner as in Example 3.
  • the adhesive sheet 6 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • Example 7 Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
  • Adhesive sheet 7 and adhesive sheet 7 with a release film composed of release film/adhesive sheet 7/release film were prepared in the same manner as in Example 3.
  • the adhesive sheet 7 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • a release film having a thickness of 75 ⁇ m (PET film manufactured by Mitsubishi Chemical Corporation) subjected to silicone release treatment is laminated to form a laminate, and a metal halide lamp irradiation device is formed.
  • a metal halide lamp irradiation device (Ushio Denki, UVC-0516S1, lamp UVL-8001M3-N) was applied to the pressure-sensitive adhesive composition through the release film so that the cumulative irradiation dose at a wavelength of 365 nm was 3000 mJ/cm 2 . Irradiation was performed to obtain a pressure-sensitive adhesive sheet laminate in which release films were laminated on both front and back sides of a 25 ⁇ m pressure-sensitive adhesive sheet (adhesive sheet 8).
  • the adhesive sheet 8 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing.
  • the pressure-sensitive adhesive composition was applied to a release film of 100 ⁇ m (PET film manufactured by Mitsubishi Chemical Corporation, thickness 100 ⁇ m) and a release film of 75 ⁇ m (Mitsubishi Chemical Corporation).
  • PET film that is, sandwiched between two release films, hot-melt molded into a sheet with a thickness of 25 ⁇ m, and release film/adhesive sheet 9/release film-attached adhesive sheet 9 consisting of release film got
  • the adhesive sheet 9 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
  • ⁇ Creep test> The release film was removed from the release film-attached pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples, and the stacking was repeated with a hand roller so that the thickness was about 0.9 mm.
  • a pressure-sensitive adhesive sheet with a release film was produced by punching into a shape, and this was used as a sample.
  • the release film was removed when installed in a rheometer ("DHR-2" manufactured by TA Instruments), and the measurement jig was a parallel plate with a diameter of 8 mm, temperature: 25 ° C., pressure: 1000 Pa. , the strain (creep strain) (%) after 3600 seconds was measured.
  • the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were examined with an integrated amount of light at 365 nm of 3000 mJ/cm 2 for the pressure-sensitive adhesive sheets 1 to 4 and 6-7, and 4000 mJ/cm 2 for the pressure-sensitive adhesive sheets 5 and 9.
  • the adhesive sheet was irradiated with ultraviolet rays through the release film to cure the adhesive sheet.
  • the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing. did.
  • the adhesive sheets after curing were laminated to a thickness of about 0.9 mm, and a circle with a diameter of 8 mm was punched out and used as a sample.
  • a rheometer (DHR-2" manufactured by TA Instruments) measuring jig: diameter 8 mm parallel plate, temperature: 80 ° C., pressure: 1000 Pa, strain after 180 seconds (creep strain ) (%) was measured.
  • the integrated light quantity at 365 nm was 3000 mJ/cm 2 for adhesive sheets 1 to 4 and 6 to 7, and for adhesive sheets 5 and 9.
  • the adhesive sheet was irradiated with ultraviolet rays through the release film so as to be 4000 mJ/cm 2 to cure the adhesive sheet.
  • the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing. did.
  • the adhesive sheets after curing were laminated so as to have a thickness of about 0.9 mm, and a circle with a diameter of 8 mm was punched out and used as a sample.
  • a rheometer (“DHR-2" manufactured by TA Instruments Co., Ltd., measuring jig: 8 mm diameter parallel plate) was used at a temperature of 25 ° C., and the shear strain as the initial strain (x) was 200%.
  • a shear stress was applied to the sample for 600 seconds. After that, the stress was released and the residual strain (y) was measured after 600 seconds had passed, and the recovery rate was obtained from the following formula.
  • the integrated light quantity at 365 nm was 3000 mJ/cm 2 for adhesive sheets 1 to 4 and 6 to 7, and for adhesive sheets 5 and 9.
  • the adhesive sheet was irradiated with ultraviolet rays through the release film so as to be 4000 mJ/cm 2 to cure the adhesive sheet.
  • the gel fraction after curing with active energy rays was obtained in the same manner as the gel fraction evaluation procedure described above.
  • the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing, so this is measured as the gel fraction after curing. provided.
  • ⁇ Adhesive strength> One of the release films was removed from the pressure-sensitive adhesive sheets with release films prepared in Examples and Comparative Examples, and a polyethylene terephthalate film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., thickness 100 ⁇ m) was applied as a backing film to a hand roller. and roll crimped. This was cut into strips of 10 mm width ⁇ 150 mm length, the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. ° C., gauge pressure of 0.2 MPa, 20 minutes), and finished adhesion was performed to prepare an adhesive force measurement sample. At 23 ° C.
  • the backing film was peeled from the soda lime glass, the tensile strength was measured with a load cell, and the adhesive strength to the soda lime glass. (N/cm) was measured.
  • One of the release films was removed from the pressure-sensitive adhesive sheets with release films prepared in Examples and Comparative Examples, and a polyethylene terephthalate film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., thickness 100 ⁇ m) was applied as a backing film to a hand roller. and roll crimped. This was cut into strips of 10 mm width ⁇ 150 mm length, the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. ° C., gauge pressure of 0.2 MPa, 20 minutes) to finish pasting.
  • the pressure-sensitive adhesive sheets were placed through a backing film so that the integrated amount of light at 365 nm was 3000 mJ/cm 2 for pressure-sensitive adhesive sheets 1 to 4 and 6-7, and 4000 mJ/cm 2 for pressure-sensitive adhesive sheets 5 and 9. was irradiated with ultraviolet rays to cure the adhesive sheet, and an adhesive force measurement sample was produced.
  • the backing film was peeled off from the soda lime glass while being pulled at an angle of 180° at a peeling speed of 300 mm/min, and the tensile strength was measured with a load cell.
  • the 180° peel strength (N/cm) of the sheet against soda lime glass was measured and taken as adhesive strength (curing after lamination).
  • the pressure-sensitive adhesive sheet 8 produced in Comparative Example 1 was not subject to this measurement because the reaction due to light irradiation had sufficiently progressed and there was almost no room for active energy ray curing.
  • the adhesive sheet cured as described above was cut into strips with a width of 10 mm and a length of 150 mm, and the remaining release film was peeled off.
  • This laminate was subjected to an autoclave treatment (60° C., gauge pressure 0.2 MPa, 20 minutes) and then finished and adhered to prepare an adhesive force measurement sample.
  • the backing film was peeled off from the soda lime glass while being pulled at an angle of 180° at a peeling speed of 300 mm/min, and the tensile strength was measured with a load cell.
  • the 180° peel strength (N/cm) of the sheet against soda lime glass was measured and taken as the adhesive strength (curing before lamination).
  • the pressure-sensitive adhesive sheet with a release film prepared in Examples and Comparative Examples was cut into a size of 5 cm ⁇ 5 cm, and the pressure-sensitive adhesive surface exposed by peeling one release film and the step of the evaluation substrate were provided.
  • the side surfaces are opposed to each other, vacuum lamination is performed under the conditions of a press pressure of 0.2 MPa for 30 seconds, and an autoclave treatment is performed under the conditions of 70 ° C. and an air pressure of 0.45 MPa for 20 minutes to prepare a laminate for step absorption evaluation. did.
  • the produced laminate was visually observed and evaluated according to the following evaluation criteria.
  • ⁇ The pressure-sensitive adhesive sheet followed in the vicinity of all steps, and there were no air bubbles.
  • Good Two or less bubbles were generated near the step.
  • x The pressure-sensitive adhesive sheet did not follow the surface at three or more locations near the step, and air bubbles were generated.
  • the pressure-sensitive adhesive surface exposed by peeling off one release film of the pressure-sensitive adhesive sheet cured as described above is opposed to the surface of the side having a step of the evaluation substrate, and the press pressure is 0.2 MPa for 30 seconds.
  • Vacuum lamination was performed under the conditions of 70° C., atmospheric pressure of 0.45 MPa, and autoclave treatment for 20 minutes. The above procedure was performed within 10 minutes after the ultraviolet irradiation treatment to prepare a laminate for evaluation of step absorbability after curing. The produced laminate was visually observed and evaluated according to the same evaluation criteria as the step absorbability evaluation described above.
  • the integrated light quantity at 365 nm was 3000 mJ/cm for the adhesive sheets 1 to 4, 6 to 7 and the laminated sheet of Reference Example 1 for the adhesive sheets with release films prepared in Examples and Comparative Examples. 2.
  • the adhesive sheets 5 and 9 were cured by irradiating the adhesive sheets with ultraviolet rays through the release film so as to obtain 4000 mJ/cm 2 .
  • the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing.
  • each adhesive sheet was removed, and a transparent polyimide film (manufactured by Kolon Co., Ltd., thickness 50 ⁇ m) was rolled on both sides of the adhesive sheet with a hand roll. After that, autoclave treatment was performed under the conditions of 60° C., atmospheric pressure of 0.2 MPa, and 20 minutes to obtain a laminate sample for flexibility evaluation.
  • a transparent polyimide film manufactured by Kolon Co., Ltd., thickness 50 ⁇ m
  • the laminate sheet of Reference Example 1 was evaluated with the side of the adhesive sheet 5 as another adhesive sheet set inside. After being bent 200,000 times in a test environment of ⁇ 20° C. or 60° C. and 90% RH, evaluation was made according to the following evaluation criteria.
  • ⁇ None of delamination, breakage, buckling, and flow occurred at the bent portion.
  • x Any of delamination, breakage, buckling, or flow occurred at the bent portion.
  • the laminate sample was bent at a radius of curvature R of 3 mm, stored at 60° C. and 90% RH for 24 hours, and then evaluated according to the following evaluation criteria.
  • the laminated sheet of Reference Example 1 was tested in a state in which the pressure-sensitive adhesive sheet 5 as another pressure-sensitive adhesive sheet was positioned inside and bent at a radius of curvature R of 3 mm.
  • ⁇ None of delamination, breakage, buckling, and flow occurred at the bent portion.
  • x Any of delamination, rupture, buckling, or flow was observed at the bent portion.
  • Table 1 shows the results obtained by measuring and evaluating the adhesive sheet and laminate.
  • the pressure-sensitive adhesive sheets of Examples 1-7 exhibited good bonding properties in the step absorption test, excellent restorability, and exhibited excellent durability in the bending test when formed into a laminate. Furthermore, the pressure-sensitive adhesive sheets of Examples 1-4 exhibited good lamination properties in the level difference absorption test even when laminated after being cured. The pressure-sensitive adhesive sheet of Reference Example 1 also exhibited excellent step absorbability and excellent bending durability. On the other hand, the pressure-sensitive adhesive sheet produced in Comparative Example 1 used a material that did not have high fluidity, so the strain after 3,600 seconds at 25°C was 50% or less, and the step absorbability was poor. .
  • the pressure-sensitive adhesive sheet prepared in Comparative Example 2 uses a material with low flexibility after curing, so it has poor restorability after 200% deformation at 25 ° C after curing with active energy, and bending durability when used as a laminate. It was inferior in terms of sex.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Adhesive Tapes (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)

Abstract

Proposed as an adhesive sheet which, even in the case of an image display device constituent member having a step part in the surface thereof, can conform to the step and be filled up to the corners, which exhibits excellent resilience and durability even when a laminate obtained by laminating an image display device constituent member and the adhesive sheet is subjected to a bending operation at high temperature, and which exhibits excellent durability even when the laminate is subjected to a bending operation at a low temperature, is an active energy ray curable adhesive sheet that comprises an adhesive agent layer comprising a meth)acrylic polymer (A) and that satisfies the following requirements (1)-(3).　(1) Strain (creep strain) is not less than 50% when thickness is 0.8-1.5 mm and a pressure of 1,000 Pa is applied for 3,600 seconds at 25°C.　(2) Strain (creep strain) is not less than 10% when thickness is 0.8-1.5 mm, irradiation with an active energy ray having a wavelength of 365 nm is performed such that the integrated quantity of light is 2,000-4,000 mJ/cm2, and thereafter a pressure of 1,000 Pa is applied for 180 seconds at 80°C.　(3) Recovery after 200% deformation at 25°C as represented by the formula below is not less than 60% when irradiation with an active energy ray having a wavelength of 365 nm is performed such that the integrated quantity of light is 2,000-4,000 mJ/cm2.　Recovery (%)=\{(x-y)/x\}×100 (where x is the initial strain applied in the shear direction of the adhesive sheet having a thickness of 0.8-1.5 mm, and y is the residual strain 600 seconds after release of the initial strain that has been applied for 600 seconds.)　

Description

活性エネルギー線硬化性粘着シート、離型フィルム付き粘着シート、積層体、積層体の製造方法、積層シート、画像表示装置用積層体、フレキシブル画像表示装置，フレキシブルディスプレイ用粘着シートおよび画像表示装置用積層体の製造方法Active energy ray-curable adhesive sheet, adhesive sheet with release film, laminate, manufacturing method of laminate, laminate sheet, laminate for image display device, flexible image display device, adhesive sheet for flexible display, and laminate for image display device body manufacturing method
　本発明は、曲面からなる画像表示装置や、折り曲げ可能なフレキシブル画像表示装置などに好適に用いることができる粘着シートに関する。特に、貼合面に段差部を有する画像表示装置構成用部材を貼合するのに好適に使用することができる粘着シート、該粘着シートを用いた離型フィルム付き粘着シート、積層体、積層体の製造方法、積層シート、画像表示装置用積層体、フレキシブル画像表示装置，フレキシブルディスプレイ用粘着シートおよび画像表示装置用積層体の製造方法に関する。 The present invention relates to an adhesive sheet that can be suitably used for an image display device having a curved surface, a bendable flexible image display device, and the like. In particular, a pressure-sensitive adhesive sheet that can be suitably used for bonding members for constituting an image display device having a stepped portion on the bonding surface, a pressure-sensitive adhesive sheet with a release film using the pressure-sensitive adhesive sheet, a laminate, and a laminate Laminate sheet, laminate for image display device, flexible image display device, adhesive sheet for flexible display, and method for producing laminate for image display device.
　近年、有機発光ダイオード（ＯＬＥＤ）や量子ドット（ＱＤ）を用いた、湾曲部を含む画像表示装置や、折り曲げや巻き取りが可能なフレキシブル画像表示装置が開発され、広く商用化されつつある。
　このような表示装置では、カバーレンズ、円偏光板、タッチフィルムセンサー、発光素子等の複数のシート部材が、透明な粘着シートで貼り合された積層構造をしており、ある粘着シートに焦点を当てると、部材と粘着シートが積層された積層体とみなすことができる。 In recent years, an image display device including a curved portion using an organic light emitting diode (OLED) or a quantum dot (QD) and a flexible image display device that can be bent or wound have been developed and are being widely commercialized.
Such a display device has a laminated structure in which multiple sheet members such as a cover lens, a circularly polarizing plate, a touch film sensor, and a light-emitting element are bonded together with a transparent adhesive sheet. When applied, it can be regarded as a laminate in which the member and the adhesive sheet are laminated.
　折り曲げや巻き取りが可能なフレキシブル画像表示装置に関しては、折り曲げた時の層間応力に起因する様々な課題が生じている。例えば、折り畳んだ際に層間で剥離する場合があり（；デラミネーション、層間が剥離する現象を「デラミ」と称する）、折り畳んでも剥離しない積層体が求められている。
　また、画面を折り畳んだ状態から開いたときに、速やかに平らな状態に復元する積層体が求められている。
　さらに、折り曲げや巻き取り操作を繰り返すうちに、粘着シートの被着体である部材にストレスがかかることで亀裂が生じ、遂には破断する場合があり、特に低温での繰り返しの折り畳み操作で耐久性のある積層体であることも求められている。 As for flexible image display devices that can be bent and wound up, various problems arise due to interlaminar stress when they are bent. For example, there is a case where the layers are separated when folded (; delamination, a phenomenon in which the layers are separated is called "delamination"), and there is a demand for a laminate that does not separate even when folded.
In addition, there is a demand for a laminate that quickly restores a flat state when the screen is unfolded from a folded state.
Furthermore, during repeated folding and winding operations, stress is applied to the member to which the pressure-sensitive adhesive sheet is adhered, which may cause cracks and eventually breakage. It is also required to be a laminate with
　折り畳み可能なフレキシブル画像表示装置に関しては、例えば特許文献１において、クリープコンプライアンス変動値と緩和弾性率変動値の積値を好適な範囲とすることで、繰り返し屈曲デバイスに適用して、長期間屈曲状態に置かれた場合において屈曲状態から解放した後、粘着剤層の変形を抑制し、屈曲状態に置かれたことによる影響を緩和するような高い復元性を示す、繰り返し屈曲デバイス用粘着剤および粘着シート、ならびに屈曲積層部材および繰り返し屈曲デバイスが開示されている。 Regarding a foldable flexible image display device, for example, in Patent Document 1, by setting the product value of the creep compliance fluctuation value and the relaxation elastic modulus fluctuation value to a suitable range, it is applied to a repeatedly bending device, and the bending state can be maintained for a long period of time. The pressure-sensitive adhesive for repeatedly bending devices and the pressure-sensitive adhesive that exhibits high resilience such as suppressing deformation of the pressure-sensitive adhesive layer after being released from the bending state in the case of being placed in a curved state and mitigating the effects of being placed in the bending state Sheets and flex laminate members and repeat flex devices are disclosed.
特開２０１９－１２３８２６号公報JP 2019-123826 A
　粘着シートのクリープコンプライアンス変動値と緩和弾性率変動値の積値を、特許文献１に開示されるように室温で好適な範囲に制御しても、高温下で折り畳み操作を行うと、屈曲状態に置かれたことによる影響が残って復元性が不十分となったり、低温下で繰り返しの折り畳み操作を行うと、粘着シートの被着体である部材にストレスがかかるため、部材が割れてしまったりする等の不具合が生じることがあった。
　粘着シートを含むデバイスは、デバイスの発熱による高温下での使用や、地域や季節等の環境に応じて高温及び低温下での使用が想定されるため、当該粘着シートには幅広い温度範囲で安定して復元性や耐久性を発現する性質が求められる。 Even if the product of the creep compliance fluctuation value and the relaxation elastic modulus fluctuation value of the pressure-sensitive adhesive sheet is controlled within a suitable range at room temperature as disclosed in Patent Document 1, when the folding operation is performed at a high temperature, the bending state occurs. The effect of being placed remains and the resilience is insufficient, and if the adhesive sheet is repeatedly folded at low temperatures, stress is applied to the member that the adhesive sheet adheres to, causing the member to crack. There were some problems such as
Devices containing adhesive sheets are expected to be used under high temperatures due to heat generated by the devices, or under high and low temperatures depending on the environment such as region and season. It is required to have the property of exhibiting resilience and durability.
　また、画像表示装置を構成する部材（「画像表示装置構成部材」とも称する）の表面は、配線、印刷、パターン現像や表面処理等により凹凸が施されている場合がある。このような段差部を備えた画像表示装置構成部材を貼り合わせるための粘着シートは、画像表示装置の薄肉化の要望により厚くすることができない制限のもと、薄肉でありながら、段差に追従して隅々まで充填させることができないと、粘着剤層内部に気泡が発生したりするため、当該粘着シートには高い流動性が求められる。
　しかしながら、貼り合わせ時に高い流動性をもつ粘着シートでは、幅広い温度範囲で安定して復元性や耐久性を発現することが困難であった。 In some cases, the surface of a member constituting the image display device (also referred to as "image display device constituent member") is made uneven by wiring, printing, pattern development, surface treatment, or the like. The pressure-sensitive adhesive sheet for bonding image display device constituent members having such a stepped portion follows the step while being thin, under the limitation that it cannot be thickened due to the demand for thinning of the image display device. If it is not possible to fill all the corners of the adhesive layer, air bubbles may be generated inside the adhesive layer, so the adhesive sheet is required to have high fluidity.
However, it has been difficult to stably exhibit resilience and durability in a wide temperature range with a pressure-sensitive adhesive sheet having high fluidity at the time of lamination.
　そこで、本発明は、表面に段差部を備えた画像表示装置構成部材であっても、気泡が発生することがないように、段差に追従して隅々まで充填することができるとともに、画像表示装置構成部材と粘着シートが積層されてなる構成を備えた積層体を、高温環境下において屈曲操作した際でも優れた復元性及び耐久性を発現することができ、低温環境下において屈曲操作した際でも優れた耐久性を発現することができる粘着シート、これを用いた画像表示装置用積層体及びその製造方法を提供せんとするものである。 Therefore, the present invention enables even an image display device component having a stepped portion on the surface to be filled to every corner so as to follow the stepped portion so as not to generate air bubbles, and to display an image. A laminate having a configuration in which a device component and an adhesive sheet are laminated can exhibit excellent resilience and durability even when bending is performed in a high temperature environment, and when bending is performed in a low temperature environment. However, it is an object of the present invention to provide a pressure-sensitive adhesive sheet capable of exhibiting excellent durability, a laminate for an image display device using the same, and a method for producing the same.
　本発明は、メタ）アクリル系重合体（Ａ）を含む粘着剤層を備え、下記（１）～（３）の要件を満たす活性エネルギー線硬化性粘着シートを提案する。
　（１）厚さ０．８ｍｍ～１．５ｍｍとし、温度２５℃にて１０００Ｐａの圧力を３６００秒印加した時の歪み（クリープ歪）が５０％以上である。
　（２）厚さ０．８ｍｍ～１．５ｍｍとし、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後に、温度８０℃にて１０００Ｐａの圧力を１８０秒印加した時の歪み（クリープ歪）が１０％以上となる。
　（３）波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の、下記式で表される２５℃２００％変形後の復元率が６０％以上となる。
　復元率（％）＝｛（ｘ－ｙ）／ｘ｝×１００
　（ｘは、厚さ０．８ｍｍ～１．５ｍｍとした粘着シートにせん断方向に印加する初期歪であり、ｙは初期歪を６００秒間印加した後、解放して６００秒経過後の残留歪である。） The present invention proposes an active energy ray-curable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing a meth)acrylic polymer (A) and satisfying the following requirements (1) to (3).
(1) It has a thickness of 0.8 mm to 1.5 mm and a strain (creep strain) of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds.
(2) After irradiating an active energy ray with a wavelength of 365 nm with an integrated light amount of 2000 to 4000 mJ / cm 2 with a thickness of 0.8 mm to 1.5 mm, a pressure of 1000 Pa at a temperature of 80 ° C. is applied for 180 seconds. creep strain) becomes 10% or more.
(3) When irradiated with an active energy ray having a wavelength of 365 nm with an accumulated light amount of 2000 to 4000 mJ/cm 2 , the recovery rate after 200% deformation at 25°C represented by the following formula is 60% or more.
Restoration rate (%) = {(xy)/x} x 100
(x is the initial strain applied in the shear direction to an adhesive sheet with a thickness of 0.8 mm to 1.5 mm, and y is the residual strain after 600 seconds after the initial strain was applied for 600 seconds and released. be.)
　本発明はまた、本発明が提案する上記活性エネルギー線硬化性粘着シートと、離型フィルムとが積層してなる構成を備えた離型フィルム付き粘着シートを提案する。 The present invention also proposes a release film-attached pressure-sensitive adhesive sheet having a structure in which the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention and a release film are laminated.
　本発明はまた、離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とが、本発明が提案する上記活性エネルギー線硬化性粘着シートを介して積層してなる構成を備えた、積層体を提案する。 The present invention also provides a method in which a release film and a member for constituting an image display device having a step with a height difference of 2 μm or more on the surface to be laminated are laminated via the active energy ray-curable adhesive sheet proposed by the present invention. We propose a laminate having a structure of
　本発明はまた、離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とを、本発明が提案する上記活性エネルギー線硬化性粘着シートを介して積層し、前記離型フィルム側から該離型フィルムを通して前記粘着シートに活性エネルギー線照射を行う、積層体の製造方法を提案する。 In the present invention, a release film and an image display device constituting member having a step with a height difference of 2 μm or more on the surface to be laminated are laminated via the active energy ray-curable adhesive sheet proposed by the present invention, A method for producing a laminate is proposed in which the pressure-sensitive adhesive sheet is irradiated with an active energy ray through the release film from the release film side.
　本発明はまた、本発明が提案する上記活性エネルギー線硬化性粘着シートと、他の粘着シートとが積層してなる構成を備えた、積層シートを提案する。 The present invention also proposes a laminated sheet having a structure in which the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention and another pressure-sensitive adhesive sheet are laminated.
　本発明はまた、２つの画像表示装置構成用部材が、本発明が提案する上記活性エネルギー線硬化性粘着シートを介して積層してなる構成を備え、前記画像表示装置構成用部材の少なくとも一方が、前記粘着シートとの接触面に、高低差２μｍ以上の段差を有する画像表示装置用積層体を提案する。 The present invention also includes a structure in which two image display device constituent members are laminated via the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention, and at least one of the image display device constituent members is proposes a layered product for an image display device having a step having a height difference of 2 μm or more on the contact surface with the pressure-sensitive adhesive sheet.
　本発明はまた、（メタ）アクリル系重合体（Ａ）を含む粘着剤層を備えたフレキシブルディスプレイ用粘着シートであって、
　厚さが１５μｍ以上５０μｍ以下であり、
　活性エネルギー線硬化性を有し、高低差が２～１０μｍの段差を１０ｍｍ以下の間隔で有する画像表示装置構成用部材に下記貼合条件で貼り合せたときに、前記段差の周囲に発泡が無いことを特徴とするフレキシブルディスプレイ用粘着シートを提案する。
　（貼合条件）
　ａ）厚み１５～５０μｍの粘着シートに、３６５ｎｍの積算光量が２０００～４０００ｍＪ／ｃｍ２となるよう紫外線を照射する。
　ｂ）高低差２～１０μｍの段差を１０ｍｍ以下の間隔で有する基材の表面に、前記粘着シートを、プレス圧０．２ＭＰａ、３０秒の条件で真空貼合する。
　ｃ）７０℃、気圧０．４５ＭＰａ、２０分の条件でオートクレーブ処理を行う。 The present invention also provides a flexible display pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A),
The thickness is 15 μm or more and 50 μm or less,
When a member for constituting an image display device having active energy ray curability and having steps with a height difference of 2 to 10 μm at intervals of 10 mm or less is laminated under the following bonding conditions, there is no foaming around the steps. We propose a pressure-sensitive adhesive sheet for a flexible display characterized by:
(Lamination conditions)
a) A pressure-sensitive adhesive sheet having a thickness of 15 to 50 μm is irradiated with ultraviolet rays so that the integrated amount of light at 365 nm is 2000 to 4000 mJ/cm 2 .
b) The pressure-sensitive adhesive sheet is vacuum-bonded to the surface of a substrate having steps with height differences of 2 to 10 μm at intervals of 10 mm or less under conditions of a press pressure of 0.2 MPa and 30 seconds.
c) Perform autoclave treatment under conditions of 70° C., atmospheric pressure of 0.45 MPa, and 20 minutes.
　本発明はまた、２つの画像表示装置構成用部材１、２が、活性エネルギー線硬化性粘着シートを介して積層されてなる構成を備えた画像表示装置構成用積層体の製造方法であって、
　以下の工程１～３を有し、工程１および２を行った後、工程３を行うことを特徴とする、画像表示装置用積層体の製造方法を提案する。
　工程１：画像表示装置構成用部材１に、本発明が提案する上記活性エネルギー線硬化性粘着シートの一方の表面を貼合する。
　工程２：活性エネルギー線を照射して、本発明が提案する上記活性エネルギー線硬化性粘着シートを硬化させる。
　工程３：前記粘着シートの他方の表面に画像表示装置構成用部材２を貼合して積層体とする。 The present invention also provides a method for producing a laminate for image display device comprising two image display device constituent members 1 and 2 laminated via an active energy ray-curable adhesive sheet, comprising:
A method for producing a laminate for an image display device is proposed, which has the following steps 1 to 3, and is characterized by performing steps 1 and 2 and then performing step 3.
Step 1: One surface of the active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention is attached to the member 1 for constituting an image display device.
Step 2: The active energy ray-curable pressure-sensitive adhesive sheet proposed by the present invention is cured by irradiating it with an active energy ray.
Step 3: The image display device constituting member 2 is adhered to the other surface of the pressure-sensitive adhesive sheet to form a laminate.
　本発明が提案する粘着シートは、被着体である画像表示装置構成部材の貼着面に段差部があっても、気泡を発生することがないように、段差に追従して隅々まで充填することができる。
　さらに本発明が提案する粘着シートは、当該粘着シートと画像表示装置構成部材とが積層してなる構成を備えた積層体を、高温環境下において屈曲操作しても優れた復元性及び耐久性を発現することができ、低温環境下において屈曲操作しても優れた耐久性を発現することができる。
　よって、例えば当該積層体を、高温及び低温環境下において、折り曲げたり、湾曲させたり、巻き取ったりした際でも、優れた耐久性乃至復元性を発現することができる。
　以上の点から、本発明が提案する粘着シートは、例えばフレキシブルディスプレイ用粘着シートとして好適に利用することができる。 The pressure-sensitive adhesive sheet proposed by the present invention fills every corner of the adherend so as to follow the step so as not to generate air bubbles even if there is a step on the sticking surface of the image display device constituent member that is the adherend. can do.
Furthermore, the pressure-sensitive adhesive sheet proposed by the present invention exhibits excellent resilience and durability even when a laminate having a configuration in which the pressure-sensitive adhesive sheet and image display device constituent members are laminated is operated to bend in a high-temperature environment. Excellent durability can be exhibited even when a bending operation is performed in a low-temperature environment.
Therefore, for example, even when the laminate is folded, curved, or wound up in a high-temperature or low-temperature environment, excellent durability or resilience can be exhibited.
From the above points, the pressure-sensitive adhesive sheet proposed by the present invention can be suitably used, for example, as a pressure-sensitive adhesive sheet for flexible displays.
　次に、実施の形態例に基づいて本発明を説明する。ただし、本発明が次に説明する実施形態に限定されるものではない。 Next, the present invention will be described based on an embodiment. However, the present invention is not limited to the embodiments described below.
　＜本粘着シート＞
　本発明の実施形態の一例に係る粘着シート（「本粘着シート」と称する）は、（メタ）アクリル系重合体（Ａ）を含む、とりわけ主成分樹脂として含む粘着剤層（「本粘着剤層」と称する）を備えた活性エネルギー線硬化性粘着シートである。
　本粘着シートにおける本粘着剤層は、例えば、(メタ)アクリル系重合体（Ａ）を含み、とりわけ主成分樹脂として(メタ)アクリル系重合体（Ａ）を含み、好ましくは架橋剤（Ｂ）及び／又は重合開始剤（Ｃ）、さらに必要に応じてその他成分を含む粘着剤組成物（「本粘着剤組成物」と称する）から形成することができる。 <This adhesive sheet>
A pressure-sensitive adhesive sheet (referred to as "the present pressure-sensitive adhesive sheet") according to an example of the embodiment of the present invention includes a (meth)acrylic polymer (A), particularly a pressure-sensitive adhesive layer ("the present pressure-sensitive adhesive layer ”) is an active energy ray-curable pressure-sensitive adhesive sheet.
The present pressure-sensitive adhesive layer in the present pressure-sensitive adhesive sheet contains, for example, a (meth)acrylic polymer (A), particularly the (meth)acrylic polymer (A) as a main component resin, preferably a cross-linking agent (B) and/or a polymerization initiator (C) and, if necessary, a pressure-sensitive adhesive composition (referred to as "the present pressure-sensitive adhesive composition") containing other components.
　前記「活性エネルギー線硬化性粘着シート」とは、活性エネルギー線によって硬化し得る性質を備えた粘着シート、言い換えれば、活性エネルギー線により硬化する余地が残された活性エネルギー線硬化性を有する粘着シートの意である。
　本粘着シートは、活性エネルギー線によって硬化する余地が残された状態に硬化（「仮硬化」とも称する）されたものであってもよいし、未だ何ら硬化されておらず（「未硬化」と称する）、且つ、活性エネルギー線によって硬化し得るものであってもよい。
　本粘着シートが、仮硬化された又は未硬化のものであれば、当該本粘着シートを被着体へ貼合する前又は貼合した後、本粘着シートを活性エネルギー線により硬化（「本硬化」とも称する）させることができ、その結果、凝集力を高めて接着性を高めることができる。 The "active energy ray-curable adhesive sheet" is a pressure-sensitive adhesive sheet having properties that can be cured by an active energy ray, in other words, an active energy ray-curable adhesive sheet that leaves room for curing by an active energy ray. is the meaning of
This pressure-sensitive adhesive sheet may have been cured (also referred to as “temporary curing”) in a state in which there is room for curing by the active energy ray, or may have not been cured at all (referred to as “uncured”). ) and can be cured by active energy rays.
If the adhesive sheet is temporarily cured or uncured, the adhesive sheet is cured with active energy rays before or after bonding the adhesive sheet to the adherend ("main curing ), which can result in increased cohesion and improved adhesion.
　また、前記「主成分樹脂」とは、本粘着剤層又は本粘着剤組成物を構成する樹脂のうち最も質量割合の高い樹脂を意味する。該主成分樹脂の含有量は、本粘着剤層又は本粘着剤組成物を構成する樹脂のうち、７０質量％以上、中でも８０質量％以上、９０質量％以上（１００質量％を包含する）を占める場合がある。 In addition, the "main component resin" means the resin having the highest mass ratio among the resins constituting the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition. The content of the main component resin is 70% by mass or more, especially 80% by mass or more, and 90% by mass or more (including 100% by mass) of the resins constituting the present pressure-sensitive adhesive layer or the present pressure-sensitive adhesive composition. may occupy.
　＜クリープ特性＞
　本粘着シートは、厚さ０．８ｍｍ～１．５ｍｍとし、温度２５℃にて１０００Ｐａの圧力を３６００秒印加した時の歪み（クリープ歪）が５０％以上であるのが好ましい。
　本粘着シートにおいて、硬化前の状態で、温度２５℃にて１０００Ｐａの圧力を３６００秒印加した時のクリープ歪が５０％以上であるということは、この状態で変形し易いことを示しているから、被着体となる画像表示装置構成部材表面に凹凸を有する場合であっても、段差部の隅々まで追従させることができるから好ましい。
　かかる観点から、本粘着シートは、前記クリープ歪が５０％以上となるのが好ましく、中でも１００％以上、その中でも１０５％以上、特には１１０％以上となるのがさらに好ましい。
　他方、上限については、室温以下において形状を維持できる点から、前記のクリープ歪が１００００％以下であることが好ましい。
　かかる観点から、本粘着シートは、前記クリープ歪は５０００％以下であることがより好ましく、その中でも２５００％以下、さらには１０００％以下となるのがさらに好ましく、その中でも５００％以下、特には２５０％以下がより好ましい。 <Creep characteristics>
The pressure-sensitive adhesive sheet preferably has a thickness of 0.8 mm to 1.5 mm and a strain (creep strain) of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds.
The fact that the pressure-sensitive adhesive sheet has a creep strain of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds before curing indicates that it is easily deformable in this state. Even if the surface of the member constituting the image display device, which is the adherend, has unevenness, it can be made to follow every corner of the stepped portion, which is preferable.
From this point of view, the pressure-sensitive adhesive sheet preferably has a creep strain of 50% or more, more preferably 100% or more, more preferably 105% or more, particularly 110% or more.
On the other hand, as for the upper limit, the creep strain is preferably 10000% or less because the shape can be maintained at room temperature or lower.
From this point of view, the creep strain of the present pressure-sensitive adhesive sheet is more preferably 5000% or less, more preferably 2500% or less, further preferably 1000% or less, more preferably 500% or less, particularly 250% or less. % or less is more preferable.
　上記のとおり、本粘着シートにおける前記クリープ歪は、厚さ０．８ｍｍ～１．５ｍｍとした際の数値であるが、本粘着シートが有するクリープ歪を正確に測定するには、粘着シートの厚さ不足による測定治具の影響を受けて測定結果が変動することを避ける必要があり、そのためには、本粘着シートを一定の厚み範囲に調整した上で測定する必要がある。
　本粘着シートの厚さを上記範囲内に予め調整した上でクリープ歪を測定することにより、測定治具の影響を受けることなく、本粘着シートが有するクリープ歪を正確に把握することができる。 As described above, the creep strain in the present pressure-sensitive adhesive sheet is a numerical value when the thickness is 0.8 mm to 1.5 mm. It is necessary to avoid fluctuations in measurement results due to the influence of measurement jigs due to insufficient thickness. To this end, it is necessary to measure the present pressure-sensitive adhesive sheet after adjusting it within a certain range of thickness.
By adjusting the thickness of the pressure-sensitive adhesive sheet in advance within the above range and then measuring the creep strain, the creep strain of the pressure-sensitive adhesive sheet can be accurately determined without being affected by the measuring jig.
　なお、前記の「厚さ０．８ｍｍ～１．５ｍｍとし」とは、測定サンプルとしての粘着シートの厚さがこの範囲に満たない場合には、何枚か重ねるなどして、測定サンプルの厚さをこの範囲に調整するという意味である。他の試験において、測定サンプルの厚さを規定している場合も同様である。 In addition, the above-mentioned "thickness of 0.8 mm to 1.5 mm" means that if the thickness of the adhesive sheet as a measurement sample is less than this range, the thickness of the measurement sample may be adjusted by stacking several sheets. It means to adjust the depth to this range. The same is true when the thickness of the measurement sample is specified in other tests.
　本粘着シートにおいて、クリープ歪を上記範囲に調整するには、（メタ）アクリル系重合体（Ａ）の組成や分子量を調整したり、架橋剤（Ｂ）の種類や添加量を調整したりするのが好ましい。ただし、この手段に限定するものではない。 In this pressure-sensitive adhesive sheet, in order to adjust the creep strain within the above range, the composition and molecular weight of the (meth)acrylic polymer (A) are adjusted, and the type and amount of the cross-linking agent (B) are adjusted. is preferred. However, it is not limited to this means.
　また、本粘着シートは、厚さ０．８ｍｍ～１．５ｍｍとし、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後に、温度８０℃にて１０００Ｐａの圧力を１８０秒印加した時の歪み（クリープ歪）が１０％以上となることが好ましい。
　本粘着シートは、硬化後において、温度８０℃にて、１０００Ｐａの圧力を１８０秒印加した時の歪み（クリープ歪）が１０％以上であるということは、硬化後であっても加熱状態では、変形し易いことを示しているから、被着体となる画像表示装置構成部材表面に凹凸を有する場合であっても、硬化後に加熱することで、段差部の隅々までさらに追従させることができ、表面が平滑になるまで段差部を吸収することができる。
　かかる観点から、活性エネルギー線硬化後におけるクリープ歪は１０％以上となるのがさらに好ましく、中でも２０％以上、その中でも３０％以上、さらに４０％以上となるのが好ましい。
　他方、硬化後における前記歪み（クリープ歪）の上限値は、それが高過ぎると、高温環境下で粘着シートが積層体の端面からはみ出して端面がべたついたり、折り曲げ時に凝集剥離を起こしたり、折り曲げ状態から開いた時の復元性を損ねたりするおそれがあることから、５００％以下であるのが好ましく、３００％以下であるのがより好ましく、１００％以下であるのがさらに好ましく、８０％以下であるのが特に好ましく、６０％以下であるのが最も好ましい。 Further, the pressure-sensitive adhesive sheet had a thickness of 0.8 mm to 1.5 mm, and was irradiated with an active energy ray having a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , and then a pressure of 1000 Pa was applied at a temperature of 80 ° C. for 180 seconds. It is preferable that the time strain (creep strain) is 10% or more.
This PSA sheet has a strain (creep strain) of 10% or more when a pressure of 1000 Pa is applied at a temperature of 80° C. for 180 seconds after curing. Since it shows that it is easy to deform, even if the surface of the image display device constituting member to be the adherend has unevenness, it can be made to follow even the corners of the stepped portion by heating after curing. , the step can be absorbed until the surface becomes smooth.
From this point of view, the creep strain after curing with active energy rays is more preferably 10% or more, more preferably 20% or more, more preferably 30% or more, more preferably 40% or more.
On the other hand, if the upper limit of the strain (creep strain) after curing is too high, the pressure-sensitive adhesive sheet may protrude from the end face of the laminate in a high-temperature environment and the end face may become sticky, cohesive peeling may occur during folding, It is preferably 500% or less, more preferably 300% or less, even more preferably 100% or less, and 80% or less because there is a risk of impairing the resilience when opened from the state. is particularly preferred, and 60% or less is most preferred.
　なお、上記本粘着シートの活性エネルギー線硬化後のクリープ歪についても、前述と同様に、本粘着シートの厚さを０．８ｍｍ～１．５ｍｍに調整したうえで測定しているが、この理由は、上述のとおり、測定治具による影響を考慮したものであり、本粘着シートの厚みが前記範囲内であることを要する意図ではない。 It should be noted that the creep strain of the present pressure-sensitive adhesive sheet after curing with active energy rays is also measured after adjusting the thickness of the present pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. As described above, is based on consideration of the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
　本粘着シートにおいて、活性エネルギー線硬化後のクリープ歪を上記範囲に調整するには、後述するベースポリマーである（メタ）アクリル系重合体（Ａ）の組成や分子量を調整したり、架橋剤（Ｂ）の種類や添加量を調整したり、活性エネルギー線の照射量を調整するのが好ましい。ただし、この手段に限定するものではない。 In this adhesive sheet, in order to adjust the creep strain after active energy ray curing within the above range, the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent ( It is preferable to adjust the type and addition amount of B) or to adjust the irradiation dose of the active energy ray. However, it is not limited to this means.
　＜復元性＞
　本粘着シートは、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の、下記式で表される２５℃２００％変形後の復元率が６０％以上であるのが好ましい。 <Restorability>
This pressure-sensitive adhesive sheet preferably has a recovery rate of 60% or more after 200% deformation at 25° C., which is represented by the following formula when irradiated with an active energy ray having a wavelength of 365 nm with an accumulated amount of light of 2000 to 4000 mJ/cm 2 .
　当該復元率は、以下の式で表される。
　復元率（％）＝｛（ｘ－ｙ）／ｘ｝×１００
　（ｘは、厚さ０．８ｍｍ～１．５ｍｍとした粘着シートにせん断方向に印加する初期歪みであり、ｙは初期歪を６００秒間印加した後、解放して６００秒経過後の残留歪である。より具体的な測定方法は実施例に記載する。） The recovery rate is represented by the following formula.
Restoration rate (%) = {(xy)/x} x 100
(x is the initial strain applied in the shear direction to the adhesive sheet with a thickness of 0.8 mm to 1.5 mm, and y is the residual strain after 600 seconds after the initial strain was applied for 600 seconds and released. A more specific measurement method is described in Examples.)
　本粘着シートの硬化後における復元率が６０％以上であれば、永久変形を抑えることができ、折り曲げ状態から開いた際の復元性も良好なものとなる。かかる観点から、前記復元率は７０％以上であるのが好ましく、中でも７５％以上、その中でも８０％以上であるのがさらに好ましい。 If the recovery rate of this adhesive sheet after curing is 60% or more, permanent deformation can be suppressed, and the recovery property when unfolded from the folded state is also good. From this point of view, the recovery rate is preferably 70% or more, more preferably 75% or more, and more preferably 80% or more.
　なお、上記本粘着シートの復元率についても、前述と同様に、本粘着シートの厚さを０．８ｍｍ～１．５ｍｍに調整したうえで測定しているが、この理由は、上述のとおり、測定治具による影響を考慮したものであり、本粘着シートの厚みが前記範囲内であることを要する意図ではない。 The recovery rate of the present pressure-sensitive adhesive sheet is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. It is intended to take into consideration the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
　＜ゲル分率＞
　本粘着シートは、活性エネルギー線によって硬化する前は、未架橋状態または少し架橋された状態、すなわち、ゲル分率が０％以上２０％以下の状態であることが好ましい。
　被着面における凹凸への追従性の観点からは、ゲル分率が１０％以下であるのがより好ましく、８％以下であるのがさらに好ましく、５％以下であるのがより好ましい。 <Gel fraction>
Before being cured by active energy rays, the adhesive sheet is preferably in an uncrosslinked state or a slightly crosslinked state, that is, in a state where the gel fraction is 0% or more and 20% or less.
From the viewpoint of conformability to irregularities on the adherend surface, the gel fraction is more preferably 10% or less, even more preferably 8% or less, and even more preferably 5% or less.
　また、本粘着シートは、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射して硬化させると、硬化前に比べてゲル分率が上昇し、該ゲル分率が１０％以上８５％以下となるのが好ましい。
　活性エネルギー線硬化後のゲル分率が１０％以上であることで、粘着シートの形状安定性や、積層体とした時の折り曲げ時の復元性や耐久性を付与することができる。
　かかる観点から活性エネルギー線硬化後のゲル分率は１０％以上であるのが好ましく、中でも３０％以上、その中でも４０％以上であるのがより好ましい。
　他方、活性エネルギー線硬化後におけるゲル分率が８５％以下であることが好ましい。 In addition, when the present pressure-sensitive adhesive sheet is cured by irradiating an active energy ray with a wavelength of 365 nm at an accumulated light amount of 2000 to 4000 mJ/cm 2 , the gel fraction increases compared to before curing, and the gel fraction is 10% or more 85 % or less.
When the gel fraction after curing with active energy rays is 10% or more, the shape stability of the pressure-sensitive adhesive sheet, and the resilience and durability when folded when formed into a laminate can be imparted.
From this point of view, the gel fraction after curing with active energy rays is preferably 10% or more, more preferably 30% or more, and more preferably 40% or more.
On the other hand, the gel fraction after active energy ray curing is preferably 85% or less.
　なお、活性エネルギー線硬化後の本粘着シートを貼合する場合は、活性エネルギー線硬化後のゲル分率が高過ぎなければ、ある程度の柔軟性を有することから、被着体が表面に段差部を備えた画像表示装置構成部材であっても、気泡を発生することなく、段差に追従して隅々まで充填することができる。かかる観点から、活性エネルギー線硬化後におけるゲル分率が７０％以下であるのがより好ましく、中でも６０％以下、その中でも５５％以下であるのがさらに好ましい。 When laminating this adhesive sheet after curing with active energy rays, if the gel fraction after curing with active energy rays is not too high, it will have a certain degree of flexibility. Even in the image display device component having the above, it is possible to fill all the corners following the steps without generating air bubbles. From this point of view, the gel fraction after curing with active energy rays is more preferably 70% or less, more preferably 60% or less, and even more preferably 55% or less.
　また、本粘着シートは、波長３６５ｎｍの活性エネルギー線を積算光量１０００ｍＪ／ｃｍ２照射して硬化させても、硬化前に比べてゲル分率が変わらない若しくは０．５％未満程度上昇するものであってもよい。
　本粘着シートは、このように光感度が鈍いものであってもよい。 In addition, even if this pressure-sensitive adhesive sheet is cured by irradiating an active energy ray with a wavelength of 365 nm at an accumulated light amount of 1000 mJ/cm 2 , the gel fraction does not change or increases by less than 0.5% compared to before curing. There may be.
The present pressure-sensitive adhesive sheet may have such a low photosensitivity.
　本粘着シートにおいて、硬化後のゲル分率を上記範囲に調製するには、ベースポリマーである（メタ）アクリル系重合体（Ａ）の組成や分子量を調整したり、架橋剤（Ｂ）の種類や添加量を調整したり、照射する活性エネルギー線の強度や積算光量を調整するのが好ましい。ただし、この手段に限定するものではない。 In this pressure-sensitive adhesive sheet, in order to adjust the gel fraction after curing within the above range, the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer, may be adjusted, or the type of the cross-linking agent (B) may be adjusted. It is preferable to adjust the addition amount of the active energy ray, and to adjust the intensity of the active energy ray to be irradiated and the integrated amount of light. However, it is not limited to this means.
　＜粘着力＞
　本粘着シートは、下記（４）の特性を有することが好ましい。
　（４）ソーダライムガラス表面に対する、２３℃５０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における粘着力が１Ｎ／ｃｍ以上 <Adhesive strength>
The pressure-sensitive adhesive sheet preferably has the following properties (4).
(4) Adhesive strength to the surface of soda lime glass at 23° C. 50% RH, peel angle 180°, peel speed 300 mm / min is 1 N / cm or more.
　当該粘着力が１Ｎ／ｃｍ以上であれば、後述する画像表示装置構成部材を貼り合わせる際の位置決めや、仮固定が容易となるから、好ましい。
　かかる観点から、当該粘着力は１Ｎ／ｃｍ以上であるのが好ましく、２Ｎ／ｃｍ以上であるのがより好ましく、４Ｎ／ｃｍ以上であるのがさらに好ましく、５Ｎ／ｃｍ以上であるのが特に好ましく、１０Ｎ／ｃｍ以上であるのがより好ましい。なお、通常上限は４０Ｎ／ｃｍである。 If the adhesive strength is 1 N/cm or more, it is preferable because it facilitates positioning and temporary fixation when bonding the image display device constituent members to be described later.
From this point of view, the adhesive strength is preferably 1 N/cm or more, more preferably 2 N/cm or more, still more preferably 4 N/cm or more, and particularly preferably 5 N/cm or more. , 10 N/cm or more. Incidentally, the normal upper limit is 40 N/cm.
　本粘着シートはまた、下記（５）の特性を有することが好ましい。
　（５）粘着シートをソーダライムガラスに貼合した後、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の、２３℃５０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における前記ソーダライムガラス表面に対する粘着力が１Ｎ／ｃｍ以上 The pressure-sensitive adhesive sheet also preferably has the following properties (5).
(5) After laminating the adhesive sheet to soda lime glass, when irradiating an active energy ray with a wavelength of 365 nm at an integrated light amount of 2000 to 4000 mJ / cm 2 , 23 ° C. 50% RH, peeling angle 180 °, peeling speed 300 mm / Adhesion to the soda lime glass surface in minutes is 1 N / cm or more
　当該粘着力が１Ｎ／ｃｍ以上であれば、後述する画像表示装置構成部材と貼り合わせて積層体とした際、折り曲げ時にデラミ等起こさず、耐久性が良好となるため好ましい。
　かかる観点から、ソーダライムガラスに貼り合わせた後、活性エネルギー線照射した時の粘着力は、１Ｎ／ｃｍ以上であるのが好ましく、２Ｎ／ｃｍ以上であるのがより好ましく、３Ｎ／ｃｍ以上であるのがさらに好ましく、５Ｎ／ｃｍ以上であるのがより好ましい。なお、通常上限は４０Ｎ／ｃｍである。 If the adhesive strength is 1 N/cm or more, it is preferable because when a laminated body is formed by laminating together with the image display device constituent members described later, delamination or the like does not occur at the time of bending, and durability is improved.
From this point of view, the adhesive strength when irradiated with active energy rays after lamination to soda lime glass is preferably 1 N/cm or more, more preferably 2 N/cm or more, and 3 N/cm or more. It is more preferable that it is 5 N/cm or more. Incidentally, the normal upper limit is 40 N/cm.
　本粘着シートはさらにまた、下記（６）の特性を有することが好ましい。
　（６）波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後、該粘着シートをソーダライムガラスに貼合した時の、前記ソーダライムガラス表面に対する、２３℃５０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における粘着力が１Ｎ／ｃｍ以上 The pressure-sensitive adhesive sheet further preferably has the following properties (6).
(6) After irradiating an active energy ray with a wavelength of 365 nm at an integrated light amount of 2000 to 4000 mJ/cm 2 , when the adhesive sheet is laminated to soda lime glass, peeling at 23 ° C. 50% RH and peeling from the surface of the soda lime glass. Adhesive strength is 1 N/cm or more at an angle of 180° and a peeling speed of 300 mm/min
　当該粘着力が１Ｎ／ｃｍ以上であれば、後述する画像表示装置構成部材と貼り合わせて積層体とした際、折り曲げ時にデラミ等を起こさず、耐久性が良好となるため好ましい。
　かかる観点から、本粘着シートに活性エネルギー線硬化した後、ソーダライムガラスに貼り合わせた時の粘着力は、１Ｎ／ｃｍ以上であるのが好ましく、２Ｎ／ｃｍ以上であるのがより好ましく、３Ｎ／ｃｍ以上であるのがさらに好ましく、５Ｎ／ｃｍ以上であるのがより好ましい。なお、通常上限は４０Ｎ／ｃｍである。 If the adhesive strength is 1 N/cm or more, it is preferable because delamination or the like does not occur at the time of bending when a laminate is formed by laminating together with the image display device constituent members described later, and durability is improved.
From this point of view, the pressure-sensitive adhesive sheet has an adhesive force of 1 N/cm or more, more preferably 2 N/cm or more, more preferably 3 N/cm or more when the adhesive sheet is laminated to soda lime glass after being cured with an active energy ray. /cm or more, and more preferably 5 N/cm or more. Incidentally, the normal upper limit is 40 N/cm.
　＜損失正接（ｔａｎδ）＞
　本粘着シートは、厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接が、－３０℃において、０．８以上であるのが好ましい。より好ましくは１以上、中でも１．２以上、さらに好ましくは１．５以上であり、また、より好ましくは２．０以下、更に好ましくは１．８以下である。
　本粘着シートの損失正接（ｔａｎδ）が上記範囲にあることで、被着体が被着面に凹凸を有する場合であっても、加熱により段差部に粘着樹脂が流動充填できる点で好ましい。 <Loss tangent (tan δ)>
The pressure-sensitive adhesive sheet preferably has a thickness of 0.8 mm to 1.5 mm, and a loss tangent obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz is 0.8 or more at -30°C. It is more preferably 1 or more, especially 1.2 or more, still more preferably 1.5 or more, and more preferably 2.0 or less, still more preferably 1.8 or less.
When the loss tangent (tan δ) of the present adhesive sheet is within the above range, even if the adherend has irregularities on the adherend surface, the adhesive resin can flow and fill the stepped portions by heating, which is preferable.
　また、本粘着シートは、活性エネルギー線硬化後、すなわち、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後は、厚さ０．８ｍｍ～１．５ｍｍとし、波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接が、－３０℃以上－１０℃以下の範囲において、０．５以上２．３以下であるのが好ましい。
　硬化後の損失正接（ｔａｎδ）が上記範囲にあることで、本粘着シートを用いた積層体を低温環境下で折り曲げても、画像表示装置構成部材界面の剥離や座屈、画像表示装置構成部材の割れ等を起こすことがないため、好ましい。かかる観点から、－３０℃以上－１０℃以下の範囲における当該損失正接（ｔａｎδ）は、０．５以上２．３以下であるのが好ましく、中でも０．８以上或いは２．０以下であるのがさらに好ましく、その中でも１．１以上或いは１．９以下であるのがより好ましい。 In addition, after curing the active energy ray, that is, after irradiating the active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a shear at a wave number of 1 Hz. The loss tangent obtained by dynamic viscoelasticity measurement in mode is preferably 0.5 or more and 2.3 or less in the range of -30°C or more and -10°C or less.
Since the loss tangent (tan δ) after curing is within the above range, even if the laminate using the present pressure-sensitive adhesive sheet is folded in a low-temperature environment, peeling or buckling at the interface of image display device constituent members, and image display device constituent members do not occur. It is preferable because it does not cause cracks or the like. From this point of view, the loss tangent (tan δ) in the range of −30° C. or higher and −10° C. or lower is preferably 0.5 or higher and 2.3 or lower, especially 0.8 or higher or 2.0 or lower. is more preferable, and among them, 1.1 or more or 1.9 or less is more preferable.
　また、本発明において、前記粘着シートを厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定した際に得られる損失正接の極大点は、－２０℃以下であることが好ましい。
　損失正接の極大点が－２０℃以下であることで、積層体とした時の折り曲げ時の耐久性を付与できる点から好ましい。かかる観点から、当該損失正接の極大点は－２５℃以下がより好ましく、－３０℃以下がより好ましく、－３３℃以下がさらに好ましく、－３５℃以下が特に好ましい。また通常、下限は－６０℃以上である。 In the present invention, the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm, and the maximum loss tangent obtained when dynamic viscoelasticity is measured in a shear mode at a frequency of 1 Hz is −20° C. or less. is preferred.
It is preferable that the maximum point of the loss tangent is −20° C. or less, because the laminate can have durability when folded. From this point of view, the maximum point of the loss tangent is more preferably −25° C. or less, more preferably −30° C. or less, even more preferably −33° C. or less, and particularly preferably −35° C. or less. Also, the lower limit is usually -60° C. or higher.
　なお、上記本粘着シートの硬化前又は硬化後における損失正接についても、前述と同様に、本粘着シートの厚さを０．８ｍｍ～１．５ｍｍに調整したうえで測定しているが、この理由は、上述のとおり、測定治具による影響を考慮したものであり、本粘着シートの厚みが前記範囲内であることを要する意図ではない。 The loss tangent before or after curing of the pressure-sensitive adhesive sheet is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. As described above, is based on consideration of the influence of the measuring jig, and is not intended to require the thickness of the pressure-sensitive adhesive sheet to be within the above range.
　本粘着シートの硬化前又は硬化後の損失正接（ｔａｎδ）を調整するには、後述するベースポリマーである（メタ）アクリル系重合体（Ａ）の組成や分子量を調整したり、架橋剤（Ｂ）の種類や添加量を調整したり、活性エネルギー線の照射量を調整するのが好ましい。ただし、この手段に限定するものではない。 In order to adjust the loss tangent (tan δ) before or after curing of the pressure-sensitive adhesive sheet, the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent (B ) is preferably adjusted and the amount of active energy ray irradiation is adjusted. However, it is not limited to this means.
　＜貯蔵弾性率（Ｇ’）＞
　本粘着シートは、厚さ０．８ｍｍ～１．５ｍｍとし、温度２５℃、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる貯蔵弾性率（Ｇ’）が０．０１～０．２ＭＰａであるのが好ましい。
　本粘着シートの前記貯蔵弾性率（Ｇ’）がかかる範囲であることで、被着体の被着面に凹凸を有する場合であっても、該凹凸に追随しかつ凹凸を吸収するように貼合することができるなどの効果を得ることができる。
　かかる観点から、本粘着シートの前記貯蔵弾性率（Ｇ’）は、温度２５℃、周波数１Ｈｚにおいて、０．０１ＭＰａ以上０．２ＭＰａ以下であるのが好ましく、中でも０．０２ＭＰａ以上或いは０．１ＭＰａ以下であるのが好ましく、その中でも０．０３ＭＰａ以上或いは０．０９ＭＰａ以下であることがさらに好ましい。 <Storage modulus (G')>
The adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a storage modulus (G′) of 0.01 to 0.2 MPa obtained by dynamic viscoelasticity measurement in a shear mode at a temperature of 25° C. and a frequency of 1 Hz. It is preferable to have
When the storage elastic modulus (G′) of the present pressure-sensitive adhesive sheet is within such a range, even if the adherend surface of the adherend has unevenness, it can be attached so as to follow the unevenness and absorb the unevenness. It is possible to obtain an effect such as being able to combine
From this point of view, the storage elastic modulus (G') of the present pressure-sensitive adhesive sheet is preferably 0.01 MPa or more and 0.2 MPa or less at a temperature of 25° C. and a frequency of 1 Hz, especially 0.02 MPa or more or 0.1 MPa or less. and more preferably 0.03 MPa or more or 0.09 MPa or less.
　また、本粘着シートは、活性エネルギー線硬化後、すなわち、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後は、厚さ０．８ｍｍ～１．５ｍｍとし、温度２５℃、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる貯蔵弾性率（Ｇ’）が０．０２ＭＰａ以上０．２４ＭＰａ以下であるのが好ましい。
　本粘着シートの硬化後の前記貯蔵弾性率（Ｇ’）がかかる範囲であることで、後述する画像表示装置項絵師部材と貼り合わせて積層体とした際、折り曲げ時にデラミ等を起こさず、耐久性が良好となる。
　かかる観点から、本粘着シートの硬化後の前記貯蔵弾性率（Ｇ’）は、温度２５℃、周波数１Ｈｚにおいて、０．０２ＭＰａ以上０．２４ＭＰａ以下であるのが好ましく、中でも０．０３ＭＰａ以上或いは０．２０ＭＰａ以下であるのが好ましく、その中でも０．０４ＭＰａ以上或いは０．１０ＭＰａ以下であるのがさらに好ましい。 In addition, after curing the active energy ray, that is, after irradiating the active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm and a temperature of 25°C. The storage elastic modulus (G') obtained by dynamic viscoelasticity measurement in shear mode at a frequency of 1 Hz is preferably 0.02 MPa or more and 0.24 MPa or less.
Since the storage elastic modulus (G′) after curing of the pressure-sensitive adhesive sheet is within such a range, when a layered product is formed by laminating it with an image display device item painter member described later, delamination or the like does not occur when bending, and the adhesive sheet is durable. good properties.
From this point of view, the storage elastic modulus (G′) after curing of the pressure-sensitive adhesive sheet is preferably 0.02 MPa or more and 0.24 MPa or less at a temperature of 25° C. and a frequency of 1 Hz. It is preferably 0.20 MPa or less, more preferably 0.04 MPa or more or 0.10 MPa or less.
　なお、上記本粘着シートの硬化前または硬化後における貯蔵弾性率（Ｇ’）についても、前述と同様に、本粘着シートの厚さを０．８ｍｍ～１．５ｍｍに調整したうえで測定しているが、この理由は、上述のとおり、測定治具による影響を考慮したものであり、本粘着シートの厚みが前記範囲内であることを要する意図ではない。 The storage elastic modulus (G') of the pressure-sensitive adhesive sheet before or after curing is also measured after adjusting the thickness of the pressure-sensitive adhesive sheet to 0.8 mm to 1.5 mm in the same manner as described above. However, as described above, the reason for this is that the influence of the measuring jig is considered, and the thickness of the pressure-sensitive adhesive sheet is not necessarily within the above range.
　本粘着シートの硬化前又は硬化後の貯蔵弾性率（Ｇ’）を調整するには、後述するベースポリマーである（メタ）アクリル系重合体（Ａ）の組成や分子量を調整したり、架橋剤（Ｂ）の種類や添加量を調整したり、活性エネルギー線の照射量を調整するのが好ましい。ただし、この手段に限定するものではない。 In order to adjust the storage elastic modulus (G′) before or after curing of the pressure-sensitive adhesive sheet, the composition and molecular weight of the (meth)acrylic polymer (A), which is the base polymer described later, may be adjusted, or the cross-linking agent may be adjusted. It is preferable to adjust the type and amount of addition of (B), and to adjust the dose of active energy rays. However, it is not limited to this means.
　＜本粘着剤組成物＞
　本粘着剤組成物は、(メタ)アクリル系重合体（Ａ）、好ましくは架橋剤（Ｂ）及び／又は重合開始剤（Ｃ）、その他さらに必要に応じてその他の成分を含む組成物である。 <Present adhesive composition>
The pressure-sensitive adhesive composition is a composition containing a (meth)acrylic polymer (A), preferably a cross-linking agent (B) and/or a polymerization initiator (C), and optionally other components. .
　＜(メタ)アクリル系重合体（Ａ）＞
　本粘着剤組成物において、(メタ)アクリル系重合体（Ａ）を含有し、とりわけ主成分樹脂として含有するものである。
　すなわち、(メタ)アクリル系重合体（Ａ）は、本粘着剤組成物を構成する樹脂の中で最も質量割合が高い樹脂である。この際、本粘着剤組成物を構成する樹脂のうち、(メタ)アクリル系重合体（Ａ）の質量割合は５０質量％以上、中でも７０質量％以上、その中でも８０質量％以上、その中でも９０質量％以上（１００質量％を含む）であってもよい。 <(Meth) acrylic polymer (A)>
The pressure-sensitive adhesive composition contains a (meth)acrylic polymer (A), especially as a main component resin.
That is, the (meth)acrylic polymer (A) is a resin having the highest mass ratio among the resins constituting the pressure-sensitive adhesive composition. At this time, among the resins constituting the present pressure-sensitive adhesive composition, the mass ratio of the (meth)acrylic polymer (A) is 50% by mass or more, especially 70% by mass or more, especially 80% by mass or more, especially 90% by mass. % or more (including 100% by mass).
　前記（メタ）アクリル系重合体（Ａ）としては、次の式１（式中、Ｒ１は水素原子又はメチル基を表し、Ｒ２は炭素原子数４～１８の直鎖もしくは分岐状のアルキル基または脂環式炭化水素を表す。）で示される化合物由来の構造単位を含むものであり、当該モノマー成分を５０質量％以上含む重合成分を重合したものが好ましい。 As the (meth)acrylic polymer (A), the following formula 1 (wherein R 1 represents a hydrogen atom or a methyl group and R 2 represents a linear or branched alkyl having 4 to 18 carbon atoms group or an alicyclic hydrocarbon), and is preferably obtained by polymerizing a polymer component containing 50% by mass or more of the monomer component.
　中でも、（メタ）アクリル系重合体（Ａ）は、前記モノマー成分を重合成分として５５質量％以上含み重合したものがさらに好ましく、その中でも６０質量％以上含み重合したものが特に好ましい。 Above all, the (meth)acrylic polymer (A) is more preferably polymerized to contain 55% by mass or more of the monomer component as a polymerization component, and particularly preferably polymerized to contain 60% by mass or more.
　なお、本発明において、「（メタ）アクリル」とは、アクリル及びメタクリルを、「（メタ）アクリロイル」とは、アクリロイル及びメタクリロイルを、「（メタ）アクリレート」とはアクリレート及びメタクリレートをそれぞれ包括する意味であり、「（共）重合体」とは、重合体及び共重合体を包括する意味である。 In the present invention, "(meth)acrylic" means acrylic and methacrylic, "(meth)acryloyl" means acryloyl and methacryloyl, and "(meth)acrylate" means acrylate and methacrylate, respectively. and "(co)polymer" is meant to include polymers and copolymers.
Figure JPOXMLDOC01-appb-I000001
Figure JPOXMLDOC01-appb-I000001
　前記式１で表されるモノマーとしては、例えばｎ－ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ｓｅｃ－ブチル（メタ）アクリレート、ｔ－ブチル（メタ）アクリレート、ペンチル（メタ）アクリレート、イソペンチル（メタ）アクリレート、ネオペンチル（メタ）アクリレート、ヘキシル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、ヘプチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ｎ－オクチル（メタ）アクリート、イソオクチル（メタ）アクリレート、ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、ｔ－ブチルシクロヘキシル（メタ）アクリレート、デシル（メタ）アクリレート、イソデシル（メタ）アクリレート、ウンデシル（メタ）アクリレート、ラウリル（メタ）アクリレート、トリデシル（メタ）アクリレート、テトラデシル（メタ）アクリレート、セチル（メタ）アクリレート、ステアリル（メタ）アクリレート、イソステアリル（メタ）アクリレート、イソボルニル（メタ）アクリレート、３，５，５－トリメチルシクロヘキサン（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、ジシクロペンテニル（メタ）アクリレート等を挙げることができる。これらは１種又は２種以上を組み合わせて使用してもよい。前記の中でも、ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ｎ－オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、ラウリル（メタ）アクリレートの何れか１種以上を含むことが特に好ましい。 Examples of the monomer represented by Formula 1 include n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl ( meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate , tetradecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, isobornyl (meth)acrylate, 3,5,5-trimethylcyclohexane (meth)acrylate, dicyclopentanyl ( meth)acrylate, dicyclopentenyl (meth)acrylate and the like can be mentioned. These may be used singly or in combination of two or more. Among them, one or more of butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate and lauryl (meth)acrylate is particularly preferable.
　前記（メタ）アクリル系重合体（Ａ）は、前記モノマー成分以外の「他の共重合性モノマー」を共重合成分として有する共重合体であるのが好ましい。 The (meth)acrylic polymer (A) is preferably a copolymer having "another copolymerizable monomer" other than the monomer component as a copolymerization component.
　前記「他の共重合性モノマー」は、（メタ）アクリル系重合体（Ａ）中に、１～３０質量％含むことが好ましく、中でも２質量％以上或いは２５質量％以下の割合で含まれることがより好ましい。 The above-mentioned "other copolymerizable monomer" is preferably contained in the (meth)acrylic polymer (A) in an amount of 1 to 30% by mass, and is contained in a proportion of 2% by mass or more or 25% by mass or less. is more preferred.
　当該「他の共重合性モノマー」としては、例えば（ａ）カルボキシル基含有モノマー（以下「共重合性モノマーａ１」とも称する。）、（ｂ）水酸基含有モノマー（以下「共重合性モノマーａ２」とも称する。）、（ｃ）アミノ基含有モノマー（以下「共重合性モノマーａ３」とも称する。）、（ｄ）エポキシ基含有モノマー（以下「共重合性モノマーａ４」とも称する。）、（ｅ）アミド基含有モノマー（以下「共重合性モノマーａ５」とも称する。）、（ｆ）ビニルモノマー（以下「共重合性モノマーａ６」とも称する。）、（ｇ）アルキル基の炭素数が１～３の（メタ）アクリレートモノマー（以下「共重合性モノマーａ７」とも称する。）、（ｈ）マクロモノマー（以下「共重合性モノマーａ８」とも称する。）、（ｉ）芳香族含有モノマー（以下「共重合性モノマーａ９」と称する）や、（ｊ）その他官能基含有モノマー（以下「共重合性モノマーａ１０」）を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the "other copolymerizable monomer" include (a) a carboxyl group-containing monomer (hereinafter also referred to as "copolymerizable monomer a1"), (b) a hydroxyl group-containing monomer (hereinafter also referred to as "copolymerizable monomer a2"). ), (c) amino group-containing monomer (hereinafter also referred to as “copolymerizable monomer a3”), (d) epoxy group-containing monomer (hereinafter also referred to as “copolymerizable monomer a4”), (e) amide Group-containing monomer (hereinafter also referred to as "copolymerizable monomer a5"), (f) vinyl monomer (hereinafter also referred to as "copolymerizable monomer a6"), (g) alkyl group having 1 to 3 carbon atoms ( meth) acrylate monomer (hereinafter also referred to as “copolymerizable monomer a7”), (h) macromonomer (hereinafter also referred to as “copolymerizable monomer a8”), (i) aromatic-containing monomer (hereinafter also referred to as “copolymerizable (hereinafter referred to as "monomer a9") and (j) other functional group-containing monomers (hereinafter referred to as "copolymerizable monomer a10"). These may be used alone or in combination of two or more.
　前記共重合性モノマーａ１としては、例えば（メタ）アクリル酸、カルボキシエチル（メタ）アクリレート、カルボキシプロピル（メタ）アクリレート、カルボキシブチル（メタ）アクリレート、ω－カルボキシポリカプロラクトンモノ（メタ）アクリレート、２－（メタ）アクリロイルオキシエチルヘキサヒドロフタル酸、２－（メタ）アクリロイルオキシプロピルヘキサヒドロフタル酸、２－（メタ）アクリロイルオキシエチルフタル酸、２－（メタ）アクリロイルオキシプロピルフタル酸、２－（メタ）アクリロイルオキシエチルマレイン酸、２－（メタ）アクリロイルオキシプロピルマレイン酸、２－（メタ）アクリロイルオキシエチルコハク酸、２－（メタ）アクリロイルオキシプロピルコハク酸、クロトン酸、フマル酸、マレイン酸、イタコン酸を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a1 include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypropyl (meth)acrylate, carboxybutyl (meth)acrylate, ω-carboxypolycaprolactone mono(meth)acrylate, 2- (Meth) acryloyloxyethyl hexahydrophthalate, 2-(meth) acryloyloxypropyl hexahydrophthalate, 2-(meth) acryloyloxyethyl phthalate, 2-(meth) acryloyloxypropyl phthalate, 2-(meth) ) acryloyloxyethyl maleate, 2-(meth)acryloyloxypropyl maleate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxypropyl succinate, crotonic acid, fumaric acid, maleic acid, itacon Mention may be made of acids. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ２としては、例えば２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシ－１－メチルエチルアクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、グリセリンモノ（メタ）アクリレート、ポリエチレングリコールモノ（メタ）アクリレート、ポリプロピレングリコールモノ(メタ)アクリレート、ポリエチレングリコールポリプロピレングリコールモノ(メタ)アクリレート、ポリエチレングリコールポリブチレングリコールモノ(メタ)アクリレート、ポリプロピレングリコールポリブチレングリコールモノ(メタ)アクリレート、ヒドロキシフェニル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート類を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a2 include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-1-methylethyl acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy Butyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerin mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol polypropylene glycol mono (meth) acrylate, polyethylene glycol Hydroxyalkyl (meth)acrylates such as polybutylene glycol mono(meth)acrylate, polypropylene glycol polybutylene glycol mono(meth)acrylate and hydroxyphenyl(meth)acrylate can be mentioned. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ３としては、例えばアミノメチル（メタ）アクリレート、アミノエチル（メタ）アクリレート、アミノプロピル（メタ）アクリレート、アミノイソプロピル（メタ）アクリレート等のアミノアルキル（メタ）アクリレート、Ｎ－アルキルアミノアルキル（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、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリレート等のＮ，Ｎ－ジアルキルアミノアルキル（メタ）アクリレートを挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a3 include aminoalkyl (meth)acrylates such as aminomethyl (meth)acrylate, aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, aminoisopropyl (meth)acrylate, N-alkylamino Examples include N,N-dialkylaminoalkyl (meth)acrylates such as alkyl (meth)acrylates, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ４としては、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、３，４－エポキシシクロヘキシルメチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレートグリシジルエーテルを挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a4 include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate glycidyl ether. . These may be used alone or in combination of two or more.
　前記共重合性モノマーａ５としては、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－ブチル（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ－メチロールプロパン（メタ）アクリルアミド、Ｎ－メトキシメチル（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、ダイアセトン（メタ）アクリルアミド、マレイン酸アミド、マレイミドを挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a5 include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, Mention may be made of N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, maleic acid amide and maleimide. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ６としては、ビニル基を分子内に有する化合物を挙げることができる。このような化合物としては、例えばエトキシジエチレングリコールアクリレート、メトキシトリエチレングルコールアクリレート、メトキシポリエチレングリコールアクリレート、メトキシジプロピレングルコールアクリレート、メトキシポリプロピレングルコールアクリレート等のアルコキシルアルキル基等の官能基を有する官能性モノマー類並びにポリアルキレングリコールジ（メタ）アクリレート類並びに酢酸ビニル、Ｎ－ビニル－２－ピロリドン、プロピオン酸ビニル及びラウリン酸ビニル等のビニルエステルモノマー並びにスチレン、クロロスチレン、クロロメチルスチレン、α－メチルスチレン及びその他の置換スチレン等の芳香族ビニルモノマーを例示することができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a6 include compounds having a vinyl group in the molecule. Examples of such compounds include functional monomers having functional groups such as alkoxylalkyl groups such as ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxydipropylene glycol acrylate, and methoxypolypropylene glycol acrylate. and polyalkylene glycol di(meth)acrylates and vinyl ester monomers such as vinyl acetate, N-vinyl-2-pyrrolidone, vinyl propionate and vinyl laurate, and styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene and Other aromatic vinyl monomers such as substituted styrene can be exemplified. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ７としては、例えばメチル（メタ）アクリレート、エチル（メタ）アクリレート、ｎ－プロピル（メタ）アクリレート、ｉ－プロピル（メタ）アクリレート等を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a7 include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, and the like. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ８としてのマクロモノマーは、末端の官能基と高分子量骨格成分とを有する高分子単量体である。
　前記「他の共重合性モノマー」が共重合性モノマーａ８である場合、前記（メタ）アクリル系重合体（Ａ）は、マクロモノマー由来の構造単位を含む共重合体である。 The macromonomer as the copolymerizable monomer a8 is a macromonomer having a terminal functional group and a high-molecular-weight skeleton component.
When the "other copolymerizable monomer" is the copolymerizable monomer a8, the (meth)acrylic polymer (A) is a copolymer containing a macromonomer-derived structural unit.
　前記マクロモノマーの骨格成分は、アクリル酸エステル重合体又はビニル系重合体から構成されるのが好ましい。例えば、前記炭素数４～１８の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレート、前記共重合性モノマーａ１、前記の共重合性モノマーａ２、前記共重合性モノマーａ６、前記共重合性モノマーａ７等に例示されるものを挙げることができ、これらは単独で又は２種類以上を組み合わせて使用することができる。
　マクロモノマーの数平均分子量は、好ましくは１０００以上であり、より好ましくは１５００以上であり、さらに好ましくは２０００以上である。なお、数平均分子量の上限は通常２００００である。 The skeleton component of the macromonomer is preferably composed of an acrylic acid ester polymer or a vinyl polymer. For example, the (meth)acrylate having a linear or branched alkyl group having 4 to 18 carbon atoms, the copolymerizable monomer a1, the copolymerizable monomer a2, the copolymerizable monomer a6, the copolymerizable Those exemplified by the monomer a7 and the like can be mentioned, and these can be used alone or in combination of two or more.
The number average molecular weight of the macromonomer is preferably 1,000 or more, more preferably 1,500 or more, and even more preferably 2,000 or more. The upper limit of the number average molecular weight is usually 20,000.
　本樹脂組成物においては、前記マクロモノマーとしては、炭素数１～３の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレートが共重合されたマクロモノマーであることで、加工性や保管安定性を向上させることができるから良好である。
　かかるマクロモノマーの数平均分子量としては、好ましくは１０００～１００００、特に好ましくは１５００以上或いは５０００以下、更に好ましくは２０００以上或いは４０００以下である。
　また、前記マクロモノマーが、炭素数８～１８の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレートが共重合されたマクロモノマーであることで、より被着体の被着面に凹凸がある場合でも、凹凸追従性を良好にすることができるから良好である。
　かかるマクロモノマーの数平均分子量としては、好ましくは２０００～２００００、特に好ましくは３０００以上或いは１５０００以下、更に好ましくは４０００以上或いは１００００以下である。 In the present resin composition, the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 1 to 3 carbon atoms. It is good because it can improve the properties.
The number average molecular weight of such a macromonomer is preferably 1,000 to 10,000, particularly preferably 1,500 or more or 5,000 or less, and still more preferably 2,000 or more or 4,000 or less.
Further, since the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 8 to 18 carbon atoms, the adhesion surface of the adherend becomes more uneven. Even if there is, it is good because it can improve the followability to irregularities.
The number average molecular weight of such a macromonomer is preferably 2,000 to 20,000, particularly preferably 3,000 or more or 15,000 or less, and still more preferably 4,000 or more or 10,000 or less.
　共重合性モノマーａ８を用いることにより、グラフト共重合体の枝成分としてマクロモノマーを導入し、（メタ）アクリル酸エステル共重合体をグラフト共重合体とすることができる。例えば枝成分としてマクロモノマー由来の構造単位を含む共重合体からなる（メタ）アクリル系重合体（Ａ）とすることができる。
　したがって、共重合性モノマーａ８と、それ以外のモノマーの選択や配合比率によって、グラフト共重合体の主鎖と側鎖の特性を変化させることができる。
　特に本樹脂組成物においては、（メタ）アクリル系重合体（Ａ）におけるマクロモノマーの共重合割合が３０質量％以下であることがホットメルト時の流動性付与の点で好ましく、より好ましくは２質量％以上或いは１５質量％以下、さらに好ましくは３質量％以上或いは１０質量％以下、とくに好ましくは４質量％以上或いは７質量％以下である。 By using the copolymerizable monomer a8, a macromonomer can be introduced as a branch component of the graft copolymer, and the (meth)acrylic acid ester copolymer can be made into a graft copolymer. For example, a (meth)acrylic polymer (A) comprising a copolymer containing a macromonomer-derived structural unit as a branch component can be used.
Therefore, the properties of the main chain and the side chains of the graft copolymer can be changed by selecting the copolymerizable monomer a8 and the other monomers and blending ratio.
In particular, in the present resin composition, the copolymerization ratio of the macromonomer in the (meth)acrylic polymer (A) is preferably 30% by mass or less in terms of imparting fluidity during hot-melt, more preferably 2 % by mass or more and 15% by mass or less, more preferably 3% by mass or more and 10% by mass or less, particularly preferably 4% by mass or more and 7% by mass or less.
　前記共重合性モノマーａ９としては、例えばベンジル（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、２－ヒドロキシ－３－フェノキシプロピル（メタ）アクリレート、ノニルフェノールＥＯ変性（メタ）アクリレート等を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a9 include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, nonylphenol EO-modified (meth)acrylate, and the like. These may be used alone or in combination of two or more.
　前記共重合性モノマーａ１０としては、例えば（メタ）アクリル変性シリコーンや、２－アクリロイルオキシエチルアシッドフォスフェート、２，２，２－トリフルオロエチル（メタ）アクリレート、２，２，３，３－-テトラフルオロプロピル（メタ）アクリレート、２，２，３，３－テトラフルオロプロピル（メタ）アクリレート、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチル（メタ）アクリレート、１Ｈ，１Ｈ，２Ｈ，２Ｈ－トリデカフルオロ－ｎ－オクチル（メタ）アクリレート等の含フッ素モノマー等を挙げることができる。これらは１種又は２種以上を組み合わせてもよい。 Examples of the copolymerizable monomer a10 include (meth)acryl-modified silicone, 2-acryloyloxyethyl acid phosphate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-- Tetrafluoropropyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-tridecafluoro- Examples include fluorine-containing monomers such as n-octyl (meth)acrylate. These may be used alone or in combination of two or more.
　アクリル系重合体（Ａ）が有する（メタ）アクリル酸エステル由来の繰り返し単位のうち、少なくとも１つの繰り返し単位のガラス転移温度は－７０～０℃であるのが好ましい。 The glass transition temperature of at least one of the (meth)acrylic acid ester-derived repeating units of the acrylic polymer (A) is preferably -70 to 0°C.
　なお、共重合体成分のガラス転移温度とは、当該共重合体各成分のホモポリマーから得られるポリマーのガラス転移温度と構成比率から、Ｆｏｘの計算式によって算出される値を意味する。
　Ｆｏｘの計算式とは、以下の式により求められる計算値であり、ポリマーハンドブック〔ＰｏｌｙｍｅｒＨａｎｄＢｏｏｋ，Ｊ．Ｂｒａｎｄｒｕｐ，Ｉｎｔｅｒｓｃｉｅｎｃｅ，１９８９〕に記載されている値を用いて求めることができる。
　１／（２７３＋Ｔｇ）＝Σ（Ｗｉ／（２７３＋Ｔｇｉ））
　［式中、Ｗｉはモノマーｉの重量分率、ＴｇｉはモノマーｉのホモポリマーのＴｇ（℃）を示す。］ The glass transition temperature of the copolymer component means a value calculated by the Fox formula from the glass transition temperature of the polymer obtained from the homopolymer of each component of the copolymer and the composition ratio.
The Fox calculation formula is a calculated value obtained by the following formula, which is described in Polymer Handbook [Polymer Handbook, J. Am. Brandrup, Interscience, 1989].
1/(273+Tg)=Σ(Wi/(273+Tgi))
[In the formula, Wi is the weight fraction of the monomer i, and Tgi is the Tg (° C.) of the homopolymer of the monomer i. ]
　上記（メタ）アクリル系重合体（Ａ）を得るに際しては、アクリル系重合体（Ａ）が有する（メタ）アクリル酸エステル由来の繰り返し単位のうち、少なくとも１つの繰り返し単位のガラス転移温度は－７０～０℃であるのが好ましい。 In obtaining the (meth)acrylic polymer (A), the glass transition temperature of at least one of the (meth)acrylic acid ester-derived repeating units of the acrylic polymer (A) is -70. ~0°C is preferred.
　このような繰り返し単位を構成する(メタ)アクリル酸エステルとしては、例えば、ｎ－ブチルアクリレート、ｎ－ヘキシルアクリレート、ｎ－オクチルアクリレート、ｎ－ノニルアクリレート、ｎ－デシルアクリレート、２－エチルヘキシルアクリレート、２－エチルヘキシルメタクリレート、２－メチルヘキシルアクリレート、イソオクチルアクリレート、イソノニルアクリレート、イソデシルアクリレート、イソデシルメタクリレート、イソステアリルアクリレート、イソステアリル（メタ）アクリレート、多分岐ステアリルアクリレート、多分岐ステアリル（メタ）アクリレート等を挙げることができるが、これらに限定されるものではない。 (Meth)acrylic acid esters constituting such repeating units include, for example, n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acrylate, 2-ethylhexyl acrylate, 2 -ethylhexyl methacrylate, 2-methylhexyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, isodecyl methacrylate, isostearyl acrylate, isostearyl (meth)acrylate, multi-branched stearyl acrylate, multi-branched stearyl (meth)acrylate, etc. can be mentioned, but are not limited to these.
　また、アクリル系重合体（Ａ）が有する（メタ）アクリル酸エステル由来の繰り返し単位のうち、少なくとも１つの繰り返し単位のガラス転移温度が２０～１２０℃である場合には、優れた加工性や保管安定性を保持できる為好ましい。具体的には、本粘着シートのホットメルト温度に影響するため、このガラス転移温度（Ｔｇ）は３０℃～１２０℃であるのが好ましく、中でも４０℃以上或いは１１０℃以下、その中でも５０℃以上或いは１００℃以下であるのがさらに好ましい。
　このようなガラス転移温度（Ｔｇ）を有する繰り返し単位があれば、分子量を調整することにより、優れた加工性や保管安定性を保持できると共に、５０℃以上でホットメルトするように調整することができる。 Further, when the glass transition temperature of at least one repeating unit derived from the (meth)acrylic acid ester of the acrylic polymer (A) is 20 to 120° C., excellent workability and storage are obtained. It is preferable because stability can be maintained. Specifically, the glass transition temperature (Tg) is preferably 30° C. to 120° C., especially 40° C. or higher or 110° C. or lower, especially 50° C. or higher, because it affects the hot-melt temperature of the pressure-sensitive adhesive sheet. Alternatively, it is more preferably 100° C. or less.
If there is a repeating unit having such a glass transition temperature (Tg), it is possible to maintain excellent workability and storage stability by adjusting the molecular weight, and to adjust it so that it hot melts at 50 ° C. or higher. can.
　このような繰り返し単位を構成する（メタ）アクリル酸エステルとしては、例えば、メチルアクリレート、エチルメタクリレート、ｎ－プロピルアクリレート、ｎ－プロピルメタクリレート、イソプロピルアクリレート、イソプロピルメタクリレート、ｎ－ブチルメタクリート、t－ブチルアクリレート、イソブチルアクリレート、イソブチルメタクリレート、イソボルニルアクリレート、シクロヘキシルアクリレート、シクロヘキシルメタクリレート、１，４－シクロヘキサンジメタノールモノアクリレート、テトラヒドロフルフリルメタクリレート、ベンジルアクリレート、ベンジルメタクリレート、フェノキシエチルアクリレート、フェノキシエチルメタクリレート、などを挙げることができる。 (Meth)acrylic acid esters constituting such repeating units include, for example, methyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl acrylates, isobutyl acrylate, isobutyl methacrylate, isobornyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 1,4-cyclohexanedimethanol monoacrylate, tetrahydrofurfuryl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, etc. can be mentioned.
　また、アクリル系重合体（Ａ）が有する（メタ）アクリル酸エステル由来の繰り返し単位のガラス転移温度が全て－７０～２０℃であれば、被着体の被着面に凹凸がある場合、凹凸追従性をより優れたものにできる為、好ましい。 Further, if all the repeating units derived from the (meth)acrylic acid ester of the acrylic polymer (A) have a glass transition temperature of −70 to 20° C., when the adherend surface of the adherend has unevenness, It is preferable because the followability can be improved.
　以上の中でも、前記（メタ）アクリル系重合体（Ａ）は、粘着剤にホットメルト性を付与する観点から、ブロック共重合体、及び／又は、グラフト共重合体であることが好ましい。
　（メタ）アクリル系重合体（Ａ）が、ブロック共重合体又はグラフト共重合体であることによって、形状安定性、及び、ホットメルト性に優れた粘着シートとすることができる。 Among them, the (meth)acrylic polymer (A) is preferably a block copolymer and/or a graft copolymer from the viewpoint of imparting hot-melt properties to the pressure-sensitive adhesive.
By using a block copolymer or a graft copolymer as the (meth)acrylic polymer (A), a pressure-sensitive adhesive sheet having excellent shape stability and hot-melt properties can be obtained.
　ここで、ブロック共重合体とは、（メタ）アクリル酸エステル由来の繰り返し単位を含有するポリマー鎖を複数有し、これら化学構造が異なる複数のポリマー鎖が直鎖状に結合した共重合体をいう。
　当該ブロック共重合体の一部のブロックが、マクロモノマー由来の繰り返し単位を含有するものであるのが好ましい。
　他方、グラフト共重合体は、幹成分として（メタ）アクリル酸エステル由来の繰り返し単位を含有する共重合体であり、枝成分の導入方法により、櫛型ポリマー、ブラシ状ポリマー、スターポリマー、ヤシ状ポリマー、ダンベルポリマー等の構造をもつものをいう。
　当該グラフト共重合体の枝成分としてマクロモノマー由来の繰り返し単位を含有する共重合体であるのが好ましい。
　なお、後述する実施例では、ベースポリマーとして、マクロモノマー由来の繰り返し単位を含有するグラフト共重合体を使用している。マクロモノマー由来の繰り返し単位を含有するブロック共重合体であっても、マクロモノマー由来の繰り返し単位が凝集して相分離して効果を発揮することは、グラフト共重合体と共通するため、マクロモノマーを含有するブロック共重合体も、マクロモノマーを含有するグラフト共重合体と同様の効果を得ることができると予想できる。 Here, the block copolymer refers to a copolymer having a plurality of polymer chains containing repeating units derived from (meth)acrylic acid ester, and having a plurality of polymer chains with different chemical structures bonded in a straight chain. Say.
It is preferable that some blocks of the block copolymer contain repeating units derived from the macromonomer.
On the other hand, graft copolymers are copolymers containing repeating units derived from (meth)acrylic acid ester as a trunk component, and depending on the method of introducing the branch component, they can be comb-shaped polymers, brush-shaped polymers, star polymers, palm-shaped polymers, and so on. It refers to those with structures such as polymers and dumbbell polymers.
A copolymer containing repeating units derived from a macromonomer as a branch component of the graft copolymer is preferred.
In Examples described later, a graft copolymer containing repeating units derived from a macromonomer is used as the base polymer. Even in block copolymers containing repeating units derived from macromonomers, it is common to graft copolymers that the repeating units derived from macromonomers aggregate and phase-separate to exert an effect. It can be expected that a block copolymer containing a can also obtain the same effect as a graft copolymer containing a macromonomer.
　前記（メタ）アクリル系重合体（Ａ）は、上記のようにマクロモノマー由来の構造単位を含む共重合体である場合、マクロモノマーの共重合割合が２質量％以上であれば、ホットメルト性を付与することができるから好ましく、他方、３０質量％以下であれば、後述する画像表示装置構成部材と貼り合わせて積層体とした際、折り曲げ時にデラミ等を起こさず、耐久性が良好となるから好ましい。
　かかる観点から、（メタ）アクリル系重合体（Ａ）におけるマクロモノマーの共重合割合は２質量％以上であるのが好ましく、中でも３質量％以上、中でも４質量％以上であるのがさらに好ましい。他方、３０質量％以下であるのが好ましく、中でも１５質量％以下であるのが好ましく、中でも１０質量％以下、その中でも８質量％以下、さらにその中でも７質量％以下であるのがさらに好ましい。 When the (meth)acrylic polymer (A) is a copolymer containing a structural unit derived from a macromonomer as described above, if the copolymerization ratio of the macromonomer is 2% by mass or more, the hot-melt property On the other hand, if it is 30% by mass or less, when it is laminated with the image display device constituent members described later to form a laminate, delamination or the like does not occur during bending, and durability is improved. preferred from
From this point of view, the copolymerization ratio of the macromonomer in the (meth)acrylic polymer (A) is preferably 2% by mass or more, more preferably 3% by mass or more, and more preferably 4% by mass or more. On the other hand, it is preferably 30% by mass or less, more preferably 15% by mass or less, more preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less.
　本発明において、前記マクロモノマーとして、炭素数１～３の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレートが共重合されたマクロモノマーを用いた（メタ）アクリル系重合体（Ａ）を用いる場合、前記マクロモノマー由来の繰り返し単位のガラス転移温度は２０～１５０℃であるのが好ましく、中でも４０℃以上或いは１３０℃以下、その中でも６０℃以上或いは１２０℃以下であるのがさらに好ましい。
　そして、前記（メタ）アクリル系重合体（Ａ）が、ブロック共重合体、及び／又は、グラフト共重合体である場合において、ガラス転移温度が上記範囲にある共重合成分の含有量は、上記と同様の理由から、前記（メタ）アクリル系重合体（Ａ）に対して３質量％以上であるのが好ましく、中でも４質量％以上であるのがさらに好ましい。他方、１０質量％以下であるのが好ましく、中でも９質量％以下、その中でも８質量％以下、さらにその中でも７質量％以下であるのがさらに好ましい。
　なお、後述する実施例で確認しているように、マクロモノマー由来の繰り返し単位、すなわち、ガラス転移温度が２０～１５０℃である共重合体成分は、（メタ）アクリル系重合体（Ａ）に対して３質量％以上であれば、ホットメルト性を付与することができ、４質量％以上であれば、形状を安定させることができることから、この範囲であれば、実施例と同様の効果を得ることができる。 In the present invention, a (meth)acrylic polymer (A) using a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 1 to 3 carbon atoms is used as the macromonomer. When used, the glass transition temperature of the repeating unit derived from the macromonomer is preferably 20 to 150°C, more preferably 40°C or higher or 130°C or lower, and more preferably 60°C or higher or 120°C or lower.
In the case where the (meth)acrylic polymer (A) is a block copolymer and/or a graft copolymer, the content of the copolymer component having a glass transition temperature within the above range is For the same reason as above, the content is preferably 3% by mass or more, more preferably 4% by mass or more, relative to the (meth)acrylic polymer (A). On the other hand, it is preferably 10% by mass or less, more preferably 9% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less.
In addition, as confirmed in Examples described later, the repeating unit derived from the macromonomer, that is, the copolymer component having a glass transition temperature of 20 to 150 ° C. is added to the (meth)acrylic polymer (A). On the other hand, if it is 3% by mass or more, it is possible to impart hot-melt properties, and if it is 4% by mass or more, it is possible to stabilize the shape. Obtainable.
　＜架橋剤（Ｂ）＞
　架橋剤（Ｂ）は、本粘着剤組成物に架橋構造を形成する化合物乃至組成物であり、２以上の架橋性官能基を有する化合物である。
　本粘着剤組成物が、架橋剤（Ｂ）を含むことにより、本粘着剤組成物が架橋構造を形成し、本粘着シートに耐久性や復元性を付与することができる。 <Crosslinking agent (B)>
The cross-linking agent (B) is a compound or composition that forms a cross-linked structure in the pressure-sensitive adhesive composition, and is a compound having two or more cross-linkable functional groups.
When the present pressure-sensitive adhesive composition contains the cross-linking agent (B), the present pressure-sensitive adhesive composition forms a cross-linked structure and can impart durability and restorability to the present pressure-sensitive adhesive sheet.
　前記架橋性官能基としては、例えばイソシアネート基、エポキシ基、（メタ）アクリロイル基、チオイソシアネート基、１級もしくは２級のアミノ基及びチオール基が挙げられる。これらは適当な保護基で保護されていてもよい。 Examples of the crosslinkable functional groups include isocyanate groups, epoxy groups, (meth)acryloyl groups, thioisocyanate groups, primary or secondary amino groups, and thiol groups. These may be protected with a suitable protecting group.
　架橋剤に含まれる架橋性官能基の好ましい組み合わせとしては、エポキシ基のみ、イソシアネート基のみ、（メタ）アクリロイル基のみ、チオイソシアネート基のみ、チオール基のみ、１級もしくは２級のアミノ基のみ、エポキシ基と（メタ）アクリロイル基、イソシアネート基と（メタ）アクリロイル基の組み合わせが挙げられる。
　中でも、本粘着シートが活性エネルギー線を照射されることにより硬化する性質を担保する観点から、架橋剤（Ｂ）として、（メタ）アクリロイル基を２つ以上有する多官能（メタ）アクリレート（ｂ）であるのが好ましい。 Preferred combinations of crosslinkable functional groups contained in the crosslinker include only epoxy groups, only isocyanate groups, only (meth)acryloyl groups, only thioisocyanate groups, only thiol groups, only primary or secondary amino groups, epoxy and (meth)acryloyl groups, and combinations of isocyanate groups and (meth)acryloyl groups.
Among them, from the viewpoint of securing the property that the adhesive sheet is cured by being irradiated with an active energy ray, a polyfunctional (meth)acrylate (b) having two or more (meth)acryloyl groups is used as the cross-linking agent (B). is preferred.
　多官能（メタ）アクリレート（ｂ）の含有質量は、(メタ)アクリル系重合体（Ａ）１００質量部に対して、０．５質量部以上であるのが好ましく、中でも１質量部以上、その中で１．５質量部以上である方がより好ましい。
　上限値に関しては、適度な柔軟性を維持して折り曲げ時の被着体への追従性を担保する観点から、１０質量部以下であるのが好ましく、７質量部以下であるのがより好ましく、５質量部以下であるのがさらに好ましく、さらにその中でも３質量部以下、その中でも２質量部以下である方が特に好ましい。
　特に、硬化後に、段差を有する画像表示装置構成部材等へ貼合する場合において、段差に追従することができる程度な柔軟性を付与する観点からは、５質量部以下であるのが好ましく、中でも３質量部以下、その中でも２質量部以下である方がより好ましい。 The content of the polyfunctional (meth)acrylate (b) is preferably 0.5 parts by mass or more, preferably 1 part by mass or more, with respect to 100 parts by mass of the (meth)acrylic polymer (A). Among them, 1.5 parts by mass or more is more preferable.
Regarding the upper limit, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, from the viewpoint of maintaining appropriate flexibility and ensuring followability to the adherend when bent. It is more preferably 5 parts by mass or less, more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less.
In particular, in the case of bonding to a member constituting an image display device having a step after curing, the amount is preferably 5 parts by mass or less, especially from the viewpoint of imparting flexibility to the extent that it can follow the step. 3 parts by mass or less, more preferably 2 parts by mass or less.
　多官能（メタ）アクリレート（ｂ）としては、例えば１，４－ブタンジオールジ（メタ）アクリレート、グリセリンジ（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、グリセリングリシジルエーテルジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、１，９－ノナンジオールジ（メタ）アクリレート、トリシクロデカンジメタクリレート、トリシクロデカンジメタノールジ（メタ）アクリレート、ビスフェノールＡポリエトキシジ（メタ）アクリレート、ビスフェノールＡポリプロポキシジ（メタ）アクリレート、ビスフェノールＦポリエトキシジ（メタ）アクリレート、エチレングリコールジ（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、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、ε－カプロラクトン変性トリス（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、ペンタエリスリトールトリ（メタ）アクリレート、プロポ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、プロポ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ヘキサ（メタ）アクリレート、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、ポリテトラメチレングリコールジ（メタ）アクリレート、（トリス（アクリロキシエチル）イソシアヌレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、トリペンタエリスリトールヘキサ（メタ）アクリレート、トリペンタエリスリトールペンタ（メタ）アクリレート、ヒドロキシビバリン酸ネオペンチルグリコールジ（メタ）アクリレート、ヒドロキシビバリン酸ネオペングリコールのε－カプロラクトン付加物のジ（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、トリメチロールプロパンポリエトキシトリ（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）アクリレート等の紫外線硬化型の多官能（メタ）アクリル系モノマーの他、ポリエステル（メタ）アクリレート、エポキシ（メタ）アクリレート、ウレタン（メタ）アクリレート、ポリエーテル（メタ）アクリレート等の多官能（メタ）アクリル系オリゴマーを挙げることができる。中でも、プロポキシ化ペンタエリスリトールトリ（メタ）アクリレート、ポリテトラメチレングリコールジ（メタ）アクリレート、が好ましい。これらは１種又は２種以上を組み合わせて使用してもよい。 Polyfunctional (meth)acrylates (b) include, for example, 1,4-butanediol di(meth)acrylate, glycerin di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin glycidyl ether di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecane dimethacrylate, tricyclodecanedimethanol di(meth)acrylate, bisphenol A polyethoxydi(meth)acrylate, bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxy di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ε-caprolactone modified tris (2-hydroxyethyl) isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, Propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate (Meth)acrylate, (tris(acryloxyethyl)isocyanurate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate) , neopentyl glycol di(meth)acrylate hydroxybivalate, di(meth)acrylate of ε-caprolactone adduct of neopentyl hydroxybivalate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxy tri ( In addition to UV-curable polyfunctional (meth)acrylic monomers such as meth)acrylate and ditrimethylolpropane tetra(meth)acrylate, polyester (meth)acrylate, epoxy (meth) ) polyfunctional (meth)acrylic oligomers such as acrylates, urethane (meth)acrylates and polyether (meth)acrylates. Among them, propoxylated pentaerythritol tri(meth)acrylate and polytetramethylene glycol di(meth)acrylate are preferable. These may be used singly or in combination of two or more.
　本粘着剤組成物は、さらに、（メタ）アクリロイル基を１つ有する単官能（メタ）アクリレート成分（Ｄ）を含んでいてもよい。単官能（メタ）アクリレート成分を含むことにより、硬化物の架橋点間分子量を大きくすることができるため、分子鎖の運動自由度が増し、本粘着シートを介して画像表示装置構成部材を貼り合わせた積層体を高温又は低温環境下で折り曲げた際に、本粘着剤組成物からなる本粘着シートはそれに追随して変形することができる。 The adhesive composition may further contain a monofunctional (meth)acrylate component (D) having one (meth)acryloyl group. By including a monofunctional (meth)acrylate component, the molecular weight between cross-linking points of the cured product can be increased, so that the degree of freedom of movement of the molecular chains is increased, and the components constituting the image display device are bonded via the pressure-sensitive adhesive sheet. When the laminated body is folded in a high-temperature or low-temperature environment, the pressure-sensitive adhesive sheet made of the pressure-sensitive adhesive composition can be deformed accordingly.
　単官能（メタ）アクリレート成分（Ｄ）としては、例えばエチル（メタ）アクリレート、プロピル（メタ）アクリレート、イソプロピル（メタ）アクリレート、ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ｔ－ブチル（メタ）アクリレート、アミル（メタ）アクリレート、イソアミル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、デシル（メタ）アクリレート、イソデシル（メタ）アクリレート、ドデシル（メタ）アクリレート、イソドデシル（メタ）アクリレート、テトラデシル（メタ）アクリレート、ステアリル（メタ）アクリレート、イソステアリル（メタ）アクリレート、ベへニル（メタ）アクリレート、シクロプロピル（メタ）アクリレート、シクロブチル（メタ）アクリレート、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、シクロヘプチル（メタ）アクリレート、シクロオクチル（メタ）アクリレート、シクロノニル（メタ）アクリレート、シクロデシル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ノルボルニル（メタ）アクリレート、アダマンチル（メタ）アクリレート、トリシクロデカンジメタノールアクリレート、エトキシ化－ｏ－フェニルフェノールアクリレート、２－ヒドロキシ－ｏ－フェニルフェノールプロピルアクリレート、メトキシポリエチレングリコール（メタ）アクリレート、メトキシポリプロピレングリコール（メタ）アクリレート、ポリエチレングリコール（メタ）アクリレート、ポリプロピレングリコール（メタ）アクリレート、フェノキシエチレングリコール（メタ）アクリレート、フェノキシジエチレングリコール（メタ）アクリレート、フェノキシポリエチレングリコール（メタ）アクリレート、２－ヒドロキシ－ｏ－フェニルフェノールプロピルアクリレート、２－（メタ）アクリロイルオキシエチルコハク酸、２－（メタ）アクリロイルオキシエチルテトラヒドロフタル酸、２－（メタ）アクリロイルオキシエチルヘキサヒドロフタル酸、２－（メタ）アクリロイルオキシプロピルフタル酸、２－（メタ）アクリロイルオキシプロピルヒドロフタル酸、２－（メタ）アクリロイルオキシプロピルヘキサヒドロフタル酸等ベンジル（メタ）アクリレート、ベンジル（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、フェノキシエチレングリコール（メタ）アクリレート、２－ナフチル（メタ）アクリレート、９－アントラセニル（メタ）アクリレート、１－ピレニルメチル（メタ）アクリレート、ベンジル（メタ）アクリレート、トリシクロデカンジメタノールモノアクリレートモノカルボン酸、ジシクロペンタニルアクリレート、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、トリメチロールプロパンモノ（メタ）アクリレート、グリセリンモノ（メタ）アクリレート、ペンタエリスリトールモノ（メタ）アクリレート、ジグリセリンモノ（メタ）アクリレート、ジトリメチロールプロパンモノ（メタ）アクリレート、ジペンタエリスリトールモノ（メタ）アクリレート、エトキシ化トリメチロールプロパンモノ（メタ）アクリレート、プロポキシ化トリメチロールプロパンモノ（メタ）アクリレート、エトキシ化グリセリンモノ（メタ）アクリレート、プロポキシ化グリセリンモノ（メタ）アクリレート、エトキシ化ペンタエリスリトールモノ（メタ）アクリレート、プロポキシ化ペンタエリスリトールモノ（メタ）アクリレート、エトキシ化ジトリメチロールプロパンモノ（メタ）アクリレート、プロポキシ化ジトリメチロールプロパンモノ（メタ）アクリレート、アルキレンオキサイド変性ジグリセリンモノ（メタ）アクリレート及びアルキレンオキサイド変性ジペンタエリスリトールモノ（メタ）アクリレート等の他、単官能ウレタン（メタ）アクリレート、単官能エポキシ（メタ）アクリレート、単官能ポリエステル（メタ）アクリレート等の単官能オリゴマー類を挙げることができる。これらは１種又は２種以上を組み合わせて使用してもよい。 Examples of the monofunctional (meth)acrylate component (D) include ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, Acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate Acrylate, dodecyl (meth)acrylate, isododecyl (meth)acrylate, tetradecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, behenyl (meth)acrylate, cyclopropyl (meth)acrylate, cyclobutyl ( meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, cyclononyl (meth)acrylate, cyclodecyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl ( meth)acrylate, adamantyl (meth)acrylate, tricyclodecanedimethanol acrylate, ethoxylated-o-phenylphenol acrylate, 2-hydroxy-o-phenylphenolpropyl acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate ) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, 2-hydroxy-o-phenylphenolpropyl acrylate , 2-(meth) acryloyloxyethyl succinate, 2-(meth) acryloyloxyethyl tetrahydrophthalate, 2-(meth) acryloyloxyethyl hexahydrophthalate, 2-(meth) acryloyloxypropyl phthalate, 2- (Meth)acryloyloxypropylhydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid, etc. Benzyl (meth)acrylate, benzyl (methyl) t) acrylates, phenoxyethyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, 2-naphthyl (meth) acrylate, 9-anthracenyl (meth) acrylate, 1-pyrenylmethyl (meth) acrylate, benzyl (meth) acrylate, tri Cyclodecane dimethanol monoacrylate monocarboxylic acid, dicyclopentanyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) Acrylate, 4-hydroxybutyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono(meth)acrylate, diglycerin mono(meth)acrylate, ditrimethylolpropane mono(meth)acrylate Acrylates, dipentaerythritol mono(meth)acrylate, ethoxylated trimethylolpropane mono(meth)acrylate, propoxylated trimethylolpropane mono(meth)acrylate, ethoxylated glycerin mono(meth)acrylate, propoxylated glycerin mono(meth)acrylate , ethoxylated pentaerythritol mono (meth) acrylate, propoxylated pentaerythritol mono (meth) acrylate, ethoxylated ditrimethylolpropane mono (meth) acrylate, propoxylated ditrimethylolpropane mono (meth) acrylate, alkylene oxide-modified diglycerin mono ( In addition to meth)acrylates and alkylene oxide-modified dipentaerythritol mono(meth)acrylates, monofunctional oligomers such as monofunctional urethane (meth)acrylates, monofunctional epoxy (meth)acrylates, and monofunctional polyester (meth)acrylates are mentioned. be able to. These may be used singly or in combination of two or more.
　単官能（メタ）アクリレート成分（Ｄ）を含む場合、多官能（メタ）アクリレート（ｂ）と単官能（メタ）アクリレート成分（Ｄ）の含有質量比率は、多官能（メタ）アクリレート（ｂ）：単官能（メタ）アクリレート（Ｄ）＝１：０．１～１：９であるのが好ましく、１：１～１：９であるのがより好ましく、１：２～１：９であるのがさらに好ましい。この範囲にあることで単官能（メタ）アクリレート成分が多すぎず、光に対する感度が落ちて生産性が低下するおそれもない。 When the monofunctional (meth)acrylate component (D) is included, the content ratio by mass of the polyfunctional (meth)acrylate (b) and the monofunctional (meth)acrylate component (D) is the polyfunctional (meth)acrylate (b): Monofunctional (meth)acrylate (D) is preferably 1:0.1 to 1:9, more preferably 1:1 to 1:9, and preferably 1:2 to 1:9. More preferred. Within this range, the amount of the monofunctional (meth)acrylate component is not too large, and there is no concern that the sensitivity to light will decrease and the productivity will decrease.
　＜重合開始剤（Ｃ）＞
　重合開始剤（Ｃ）は、本粘着シートに活性エネルギー線硬化性を付与するものであり、活性エネルギー線によってラジカルを発生する化合物であればよい。
　重合開始剤（Ｃ）は、ラジカル発生機構によって大きく２つに分類され、重合開始剤自身の単結合を開裂分解してラジカルを発生させることができる開裂型光開始剤と、励起した開始剤と系中の水素供与体とが励起錯体を形成し、水素供与体の水素を転移させることができる水素引抜型光開始剤と、に大別される。 <Polymerization initiator (C)>
The polymerization initiator (C) imparts active energy ray curability to the present pressure-sensitive adhesive sheet, and may be any compound that generates radicals by means of active energy rays.
The polymerization initiator (C) is roughly classified into two groups according to the mechanism of radical generation: a cleavage-type photoinitiator capable of cleaving and decomposing a single bond of the polymerization initiator itself to generate radicals, and an excited initiator. and a hydrogen abstraction type photoinitiator capable of forming an exciplex with a hydrogen donor in the system and transferring hydrogen of the hydrogen donor.
　重合開始剤（Ｃ）としては、開裂型光開始剤及び水素引抜型光開始剤のいずれであってもよく、それぞれ単独に使用しても両者を混合して使用してもよく、さらに、各々について１種又は２種以上を併用してもよい。
　光開始剤として水素引抜型光開始剤を用いた場合、アクリル系（共）重合体からも水素引抜反応を起こして、活性エネルギー線硬化性化合物のみならずアクリル系（共）重合体も架橋構造に取り込まれ、架橋点が多い架橋構造を形成することができる点で好ましい。
　また、重合開始剤（Ｃ）として開裂型光開始剤を用いた場合、一度ラジカル発生させると分解して失活することから、硬化後に予期せぬ反応や劣化をおこす恐れがない点で好ましい。 The polymerization initiator (C) may be either a cleavage photoinitiator or a hydrogen abstraction photoinitiator, each of which may be used alone or a mixture of both may be used. may be used alone or in combination of two or more.
When a hydrogen abstraction type photoinitiator is used as the photoinitiator, a hydrogen abstraction reaction also occurs from the acrylic (co)polymer, and not only the active energy ray-curable compound but also the acrylic (co)polymer has a crosslinked structure. It is preferable in terms of being able to form a crosslinked structure with many crosslinked points.
In addition, when a cleavage type photoinitiator is used as the polymerization initiator (C), once radicals are generated, it decomposes and deactivates, which is preferable in that there is no risk of unexpected reaction or deterioration after curing.
　開裂型光開始剤としては、例えば２,２－ジメトキシ－１,２－ジフェニルエタン－１－オン、１－ヒドロキシシクロヘキシルフェニルケトン、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、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－ヒロドキシ－１－［４－｛４－（２－ヒドロキシ－２－メチル－プロピオニル）ベンジル｝フェニル］－２－メチル－プロパン－１－オン、オリゴ（２－ヒドロキシ－２－メチル－１－（４－（１－メチルビニル）フェニル）プロパノン）、フェニルグリオキシリック酸メチル、２－ベンジル－２－ジメチルアミノ－１－（４－モルフォリノフェニル）ブタン－１－オン、２－メチル－１－［４－（メチルチオ）フェニル］－２－モルフォリノプロパン－１－オン、２－（ジメチルアミノ）－２－[（４－メチルフェニル）メチル]－１－[４－（４－モルホリニル）フェニル]－１－ブタノン、ビス（２，４，６－トリメチルベンゾイル）－フェニルフォスフィンオキサイド、２，４，６－トリメチルベンゾイルジフェニルフォスフィンオキサイド、（２，４，６－トリメチルベンゾイル）エトキシフェニルホスフィンオキサイド、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フォスフィンオキサイドや、それらの誘導体などを挙げることができる。 Examples of cleavage-type photoinitiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one. , 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-[4-{4-(2-hydroxy-2- Methyl-propionyl)benzyl}phenyl]-2-methyl-propan-1-one, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), phenylglyoxylic acid methyl, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one , 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, bis(2,4,6-trimethylbenzoyl)-phenyl Phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, bis(2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine Fin oxides and their derivatives can be mentioned.
　水素引抜型光開始剤としては、例えばベンゾフェノン、４－メチル－ベンゾフェノン、２，４，６－トリメチルベンゾフェノン、４－フェニルベンゾフェノン、３，３‘－ジメチル－４－メトキシベンゾフェノン、４－（メタ）アクリロイルオキシベンゾフェノン、２－ベンゾイル安息香酸メチル、ベンゾイル蟻酸メチル、ビス（２－フェニル－２－オキソ酢酸）オキシビスエチレン、４－（１，３－アクリロイル－１，４，７，１０，１３－ペンタオキソトリデシル）ベンゾフェノン、チオキサントン、２－クロロチオキサントン、３－メチルチオキサントン、２，４－ジメチルチオキサントン、２－メチルアントラキノン、２－エチルアントラキノン、２－ｔｅｒｔ－ブチルアントラキノン、２－アミノアントラキノンやその誘導体などを挙げることができる。 Hydrogen abstraction photoinitiators include, for example, benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloyl Oxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoylformate, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, 4-(1,3-acryloyl-1,4,7,10,13-pentaoxo tridecyl)benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone and derivatives thereof, etc. can be mentioned.
　上記重合開始剤（Ｃ）の含有量は特に制限されるものではない。目安としては、（メタ）アクリル系重合体（Ａ）１００質量部に対して０．５質量部以上５質量部以下、中でも１質量部以上或いは４質量部以下、その中でも１．２質量部以上或いは３質量部以下の割合で含有するのが好ましい。 The content of the polymerization initiator (C) is not particularly limited. As a guideline, 0.5 parts by mass or more and 5 parts by mass or less, especially 1 part by mass or more or 4 parts by mass or less, and among them 1.2 parts by mass or more per 100 parts by mass of the (meth)acrylic polymer (A) Alternatively, it is preferably contained in a proportion of 3 parts by mass or less.
　＜その他の成分＞
　本粘着剤組成物に含まれる前記以外の「その他の成分」として、例えば、必要に応じて、シランカップリング剤や、粘着付与樹脂、可塑剤、酸化防止剤、光安定化剤、金属不活性化剤、老化防止剤、吸湿剤、重合禁止剤、紫外線吸収剤、防錆剤、無機粒子、増感剤、顔料などの各種の添加剤を適宜含有させることが可能である。これら添加剤の量は、典型的には、粘着シートの硬化に悪影響を与えないように、又は、粘着シートの物理的特性に悪影響を与えないように選択するのが好ましい。
　また、必要に応じて、三級アミン系化合物、四級アンモニウム系化合物、ラウリル酸スズ化合物などの反応触媒を適宜含有してもよい。 <Other ingredients>
"Other components" other than the above contained in the present pressure-sensitive adhesive composition include, for example, silane coupling agents, tackifying resins, plasticizers, antioxidants, light stabilizers, metal deactivators, if necessary. Various additives such as a curing agent, anti-aging agent, hygroscopic agent, polymerization inhibitor, ultraviolet absorber, anticorrosive agent, inorganic particles, sensitizer and pigment can be incorporated as appropriate. The amounts of these additives are typically preferably selected so as not to adversely affect the curing of the adhesive sheet or adversely affect the physical properties of the adhesive sheet.
Moreover, if necessary, a reaction catalyst such as a tertiary amine compound, a quaternary ammonium compound, a tin laurate compound, or the like may be appropriately contained.
　シランカップリング剤としては、例えばビニル基、アクリロキシ基、メタクリロキシ基のような不飽和基、アミノ基、エポキシ基等とともに、アルコキシ基のような加水分解可能な官能基を有する化合物を挙げることができる。
　シランカップリング剤の具体例としては、例えば、Ｎ－（β－アミノエチル）－γ－アミノプロピルトリメトキシシラン、Ｎ－（β－アミノエチル）－γ－アミノプロピルメチルジメトキシシラン、γ－アミノプロピルトリエトキシシラン、γ－グリシドキシプロピルトリメトキシシラン、γ－メタクリロキシプロピルトリメトキシシラン等を例示することができる。
　中でも、接着性が良好であり、黄変等の変色が少ないこと等の観点から、γ－グリシドキシプロピルトリメトキシシラン又はγ－メタクリロキシプロピルトリメトキシシランを好ましく用いることができる。
　前記シランカップリング剤は、１種のみを単独で又は２種以上を組み合わせて用いることができる。 Examples of the silane coupling agent include compounds having a hydrolyzable functional group such as an alkoxy group together with an unsaturated group such as a vinyl group, an acryloxy group and a methacryloxy group, an amino group, an epoxy group, and the like. .
Specific examples of silane coupling agents include N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyl Examples include triethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like.
Among them, γ-glycidoxypropyltrimethoxysilane or γ-methacryloxypropyltrimethoxysilane can be preferably used from the viewpoint of good adhesiveness and little discoloration such as yellowing.
The silane coupling agents may be used singly or in combination of two or more.
　シランカップリング剤を含有する場合、（メタ）アクリル系重合体１００質量部に対し０．１～５質量部であるのが好ましく、中でも０．２質量部以上或いは３質量部以下であるのがさらに好ましい。
　なお、シランカップリング剤と同様に、有機チタネート化合物等のカップリング剤も有効に活用できる。 When the silane coupling agent is contained, it is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer, and is preferably 0.2 parts by mass or more or 3 parts by mass or less. More preferred.
Coupling agents such as organic titanate compounds can also be effectively used in the same manner as silane coupling agents.
　本粘着剤組成物は、本粘着シートに粘着性やホットメルト性を付与するために、炭化水素粘着付与剤を含むことができる。
　炭化水素粘着付与剤としては、ポリテルペン（例えば、αピネン系樹脂、βピネン系樹脂、及びリモネン系樹脂）、及び芳香族変性ポリテルペン樹脂（例えば、フェノール変性ポリテルペン樹脂）等のテルペン樹脂、クマラン－インデン樹脂、並びにＣ５系炭化水素樹脂、Ｃ９系炭化水素樹脂、Ｃ５／Ｃ９系炭化水素樹脂、及びジシクロペンタジエン系樹脂等の石油系樹脂、変性ロジンや水素化ロジン、重合ロジン、ロジンエステル等ロジン類を挙げることができる。
　炭化水素粘着付与剤は本粘着剤組成物に相溶することが好ましい。 The present pressure-sensitive adhesive composition can contain a hydrocarbon tackifier in order to impart stickiness and hot-melt properties to the present pressure-sensitive adhesive sheet.
Hydrocarbon tackifiers include terpene resins such as polyterpenes (e.g., α-pinene-based resins, β-pinene-based resins, and limonene-based resins) and aromatic-modified polyterpene resins (e.g., phenol-modified polyterpene resins), and coumaran-indene. Resins, C5-based hydrocarbon resins, C9-based hydrocarbon resins, C5/C9-based hydrocarbon resins, petroleum-based resins such as dicyclopentadiene-based resins, modified rosins, hydrogenated rosins, polymerized rosins, rosins such as rosin esters can be mentioned.
The hydrocarbon tackifier is preferably compatible with the present pressure sensitive adhesive composition.
　炭化水素粘着付与剤の含有質量は特に制限されるものではない。（メタ）アクリル系重合体１００質量部に対し０．１～２０質量部であるのが好ましく、中でも０．５質量部以上或いは１５質量部以下であるのがさらに好ましい。 The content of the hydrocarbon tackifier is not particularly limited. It is preferably 0.1 to 20 parts by mass, more preferably 0.5 parts by mass or more or 15 parts by mass or less, based on 100 parts by mass of the (meth)acrylic polymer.
　これらシランカップリング剤や粘着付与剤を含むことにより、優れた粘着特性を有する粘着剤組成物を好適に作製することができる。 By including these silane coupling agents and tackifiers, it is possible to suitably prepare a pressure-sensitive adhesive composition having excellent adhesive properties.
　＜本粘着シートの製造方法＞
　次に、本粘着シートの製造方法について説明する。ただし、以下の説明は、本粘着シートを製造する方法の一例であり、本粘着シートはかかる製造方法により製造されるものに限定されるものではない。 <Manufacturing method of this adhesive sheet>
Next, a method for producing the pressure-sensitive adhesive sheet will be described. However, the following description is an example of the method for producing the present pressure-sensitive adhesive sheet, and the present pressure-sensitive adhesive sheet is not limited to those produced by such a production method.
　本粘着シートの作製においては、(メタ)アクリル系重合体（Ａ）のほか、必要に応じて、架橋剤（Ｂ）および／又は重合開始剤（Ｃ）、さらに必要に応じての他の成分をそれぞれ所定量混合することにより本粘着剤組成物を調製し、当該粘着剤組成物をシート状に成形し、必要に応じて硬化性化合物を架橋すなわち重合反応させて硬化させて、本粘着シートを作製すればよい。ただし、この方法に限定するものではない。 In the preparation of this adhesive sheet, in addition to the (meth)acrylic polymer (A), if necessary, a crosslinking agent (B) and / or a polymerization initiator (C), and optionally other components are mixed in predetermined amounts to prepare the present pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition is formed into a sheet, and if necessary, the curable compound is crosslinked or polymerized to be cured, and the present pressure-sensitive adhesive sheet should be made. However, it is not limited to this method.
　本粘着剤組成物を調製する際、上記原料を、温度調節可能な混練機（例えば、一軸押出機、二軸押出機、プラネタリーミキサー、二軸ミキサー、加圧ニーダー等）を用いて混練すればよい。
　なお、種々の原料を混合する際、シランカップリング剤、酸化防止剤等の各種添加剤は、予め樹脂とともにブレンドしてから混練機に供給してもよいし、予め全ての材料を溶融混合してから供給してもよいし、添加剤のみを予め樹脂に濃縮したマスターバッチを作製し供給してもよい。 When preparing the present pressure-sensitive adhesive composition, the raw materials are kneaded using a temperature-controllable kneader (e.g., single-screw extruder, twin-screw extruder, planetary mixer, twin-screw mixer, pressure kneader, etc.). Just do it.
When mixing various raw materials, various additives such as silane coupling agents and antioxidants may be blended in advance with the resin and then supplied to the kneader, or all the materials may be melted and mixed in advance. Alternatively, a masterbatch in which only the additive is concentrated in the resin in advance may be prepared and supplied.
　本粘着剤組成物をシート状に成形する方法としては、公知の方法、例えばウェットラミネーション法、ドライラミネート法、Ｔダイを用いる押出キャスト法、押出ラミネート法、カレンダー法やインフレーション法、射出成型、注液硬化法等を採用することができる。中でも、シートを製造する場合は、ウェットラミネーション法、押出キャスト法、押出ラミネート法が好適である。 Methods for forming the present pressure-sensitive adhesive composition into a sheet include known methods such as wet lamination, dry lamination, extrusion casting using a T-die, extrusion lamination, calendering, inflation, injection molding, and injection molding. A liquid curing method or the like can be employed. Among them, the wet lamination method, the extrusion casting method, and the extrusion lamination method are suitable for producing a sheet.
　また、本粘着剤組成物がラジカル開始剤を含む場合、熱および／又は活性エネルギー線を照射し硬化させることにより、硬化物を製造することができる。特に、本粘着剤組成物を成形体、例えばシート体に成形したものに、熱および／又は活性エネルギー線を照射することにより、本粘着シートを製造することができる。
　ここで、照射する活性エネルギー線としては、α線、β線、γ線、中性子線、電子線などの電離性放射線、紫外線、可視光線などを挙げることができ、中でも光学装置構成部材へのダメージ抑制や反応制御の観点から紫外線が好適である。
　また、活性エネルギー線の照射エネルギー、照射時間、照射方法などに関しては特に限定されず、開始剤を活性化させて（メタ）アクリレート成分を重合できればよい。 Moreover, when the present pressure-sensitive adhesive composition contains a radical initiator, a cured product can be produced by curing by irradiating heat and/or active energy rays. In particular, the present pressure-sensitive adhesive sheet can be produced by irradiating heat and/or active energy rays to a molded article, for example, a sheet formed from the present pressure-sensitive adhesive composition.
Here, the active energy rays to be irradiated include α rays, β rays, γ rays, ionizing radiation such as neutron rays and electron beams, ultraviolet rays, visible rays, and the like. Ultraviolet rays are preferable from the viewpoint of suppression and reaction control.
Moreover, the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as the initiator can be activated to polymerize the (meth)acrylate component.
　また、本粘着シートの製造方法の別の実施態様として、本粘着剤組成物を適切な溶剤に溶解させ、各種コーティング手法を用いて実施することもできる。
　コーティング手法を用いた場合、上記の活性エネルギー線照射硬化の他、熱硬化させることにより本粘着シートを得ることもできる。 Moreover, as another embodiment of the method for producing the present pressure-sensitive adhesive sheet, the present pressure-sensitive adhesive composition can be dissolved in an appropriate solvent and various coating techniques can be used.
When a coating method is used, the pressure-sensitive adhesive sheet can also be obtained by thermal curing in addition to the active energy ray irradiation curing described above.
　コーティングの場合、粘着シートの厚みは塗工厚みと塗工液の固形分濃度によって調整できる。 In the case of coating, the thickness of the adhesive sheet can be adjusted by the coating thickness and the solid content concentration of the coating liquid.
　（本粘着剤層以外の層）
　本粘着シートは、本粘着剤層からなる単層構成であっても、本粘着剤層を備えた２層以上の複数層構成であってもよい。
　本粘着シートが２層以上の複数層構成である場合、本粘着剤組成物からなる層以外の層の組成は任意である。ただし、例えば中間層や最表層或いは最裏層を本粘着剤層以外の層で形成する場合、層間接着性をより高める観点から、本粘着剤層以外の層を形成する粘着剤組成物も、（メタ）アクリル系重合体を含む粘着剤組成物から形成するのが好ましく、中でも、本粘着剤層と同じ（メタ）アクリル系重合体（Ａ）を含むのがより好ましい。さらには、本粘着剤層以外の層も、架橋剤（Ｂ）および／又は重合開始剤（Ｃ）を含むのがより好ましい。 (Layers other than this adhesive layer)
The present pressure-sensitive adhesive sheet may have a single-layer structure composed of the present pressure-sensitive adhesive layer, or may have a multi-layer structure of two or more layers provided with the present pressure-sensitive adhesive layer.
When the pressure-sensitive adhesive sheet has a multi-layer structure of two or more layers, the composition of the layers other than the layer composed of the pressure-sensitive adhesive composition is arbitrary. However, for example, when the intermediate layer, the outermost layer, or the outermost layer is formed of a layer other than the present pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition forming a layer other than the present pressure-sensitive adhesive layer also It is preferably formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer, and more preferably contains the same (meth)acrylic polymer (A) as that of the present pressure-sensitive adhesive layer. Furthermore, it is more preferable that layers other than the pressure-sensitive adhesive layer also contain a cross-linking agent (B) and/or a polymerization initiator (C).
　本粘着シートが２層以上の複数層構成である場合、少なくとも、最表層、最裏層又はその両層が本粘着剤層に該当する層であるのが好ましい。全ての層が本粘着剤層に該当する層であってもよい。 When the pressure-sensitive adhesive sheet has a multi-layer structure of two or more layers, it is preferable that at least the outermost layer, the backmost layer, or both layers correspond to the pressure-sensitive adhesive layer. All the layers may be layers corresponding to the pressure-sensitive adhesive layer.
　本粘着シートが２層以上の複数層構成である場合、本粘着剤層に該当する層の厚みが、本粘着シート全体の厚みに対して１０％以上１００％以下を占めるのが好ましく、中でも１４％以上或いは７０％以下、その中でも２０％以上或いは５０％以下の割合で占めるのがさらに好ましい。 When the pressure-sensitive adhesive sheet has a multilayer structure of two or more layers, the thickness of the layer corresponding to the pressure-sensitive adhesive layer preferably accounts for 10% or more and 100% or less of the total thickness of the pressure-sensitive adhesive sheet. % or more or 70% or less, more preferably 20% or more or 50% or less.
　（本粘着シートの厚み）
　折り曲げ時や湾曲時の曲げ応力は厚みに比例することから、本粘着シートは、厚みが５０μｍ以下であれば、折り曲げ時や湾曲時の応力を緩和することができ、また、積層体の薄型化、ひいてはフレキシブル画像表示装置の薄膜化に寄与することができる。一方、１５μｍ以上であれば、ハンドリング性が良好であり、画像表示装置構成部材に高低差２μｍ以上１０μｍ以下の段差を有する凹凸部がある場合でも段差に追従することができる。
　よって、本粘着シートの厚みは、５０μｍ以下であるのが好ましく、中でも４５μｍ以下、さらにその中でも４０μｍ以下、特に３５μｍ以下であるのがさらに好ましい。一方、下限に関しては、１５μｍ以上であるのが好ましく、中でも１７μｍ以上、その中でも２０μｍ以上であるのがより好ましい。 (Thickness of this adhesive sheet)
Since the bending stress at the time of bending or bending is proportional to the thickness, if the thickness of the pressure-sensitive adhesive sheet is 50 μm or less, the stress at the time of bending or bending can be alleviated, and the thickness of the laminate can be reduced. In addition, it can contribute to thinning of the flexible image display device. On the other hand, when the thickness is 15 μm or more, the handling property is good, and even if there is an uneven portion having a height difference of 2 μm or more and 10 μm or less in the constituent member of the image display device, it is possible to follow the step.
Therefore, the thickness of the pressure-sensitive adhesive sheet is preferably 50 μm or less, more preferably 45 μm or less, more preferably 40 μm or less, particularly 35 μm or less. On the other hand, the lower limit is preferably 15 μm or more, more preferably 17 μm or more, and more preferably 20 μm or more.
　本粘着シートは、上記のように厚さが薄いにもかかわらず、画像表示装置用部材表面の凹凸に追随して変形して凹凸内部に侵入することができる。よって、その凹凸を吸収して、粘着シート表面すなわち接着面とは反対面を平滑にすることができる。
　この際、凹凸の段差高低差が、本粘着シートの厚さの１２％以下であれば吸収することができる。 Although the pressure-sensitive adhesive sheet is thin as described above, it can be deformed to follow the unevenness on the surface of the member for an image display device and penetrate into the unevenness. Therefore, the surface of the pressure-sensitive adhesive sheet, that is, the surface opposite to the adhesive surface can be made smooth by absorbing the unevenness.
At this time, if the height difference of the unevenness is 12% or less of the thickness of the present pressure-sensitive adhesive sheet, it can be absorbed.
　本粘着シートの一例として、（メタ）アクリル系重合体（Ａ）を含む粘着剤層を備えたフレキシブルディスプレイ用粘着シートであって、厚さが１５μｍ以上５０μｍ以下であり、活性エネルギー線硬化性を有し、高低差が２μｍ以上、例えば２～１０μｍの段差を１０ｍｍ以下の間隔で有する画像表示装置構成用部材に下記貼合条件で貼り合せたときに、前記段差の周囲に発泡が無いことを特徴とするフレキシブルディスプレイ用粘着シートを挙げることができる。
　（貼合条件）
　ａ）厚み１５～５０μｍの粘着シートに、３６５ｎｍの積算光量が２０００～４０００ｍＪ／ｃｍ２となるよう紫外線を照射する。
　ｂ）高低差２μｍ以上、例えば２～１０μｍの段差を１０ｍｍ以下の間隔で有する基材の表面に、前記粘着シートを、プレス圧０．２ＭＰａ、３０秒の条件で真空貼合する。
　ｃ）７０℃、気圧０．４５ＭＰａ、２０分の条件でオートクレーブ処理を行う。 An example of the present pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet for a flexible display, which has a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A), has a thickness of 15 μm or more and 50 μm or less, and exhibits active energy ray curability. and having a difference in height of 2 μm or more, for example, steps of 2 to 10 μm at intervals of 10 mm or less. A pressure-sensitive adhesive sheet for a flexible display can be mentioned.
(Lamination conditions)
a) A pressure-sensitive adhesive sheet having a thickness of 15 to 50 μm is irradiated with ultraviolet rays so that the integrated amount of light at 365 nm is 2000 to 4000 mJ/cm 2 .
b) The pressure-sensitive adhesive sheet is vacuum-bonded to the surface of a base material having a difference in height of 2 μm or more, for example, 2 to 10 μm at intervals of 10 mm or less under the conditions of a press pressure of 0.2 MPa and 30 seconds.
c) Perform autoclave treatment under conditions of 70° C., atmospheric pressure of 0.45 MPa, and 20 minutes.
　＜本粘着シートの使用態様＞
　本粘着シートは、粘着シート単体として用いることも可能である。例えば、後述する画像表示装置用部材に本粘着剤組成物を直接塗布してシート状に形成したり、本粘着剤組成物を直接押出成形したり、型に注入したりして、本粘着シートを使用することができる。更には、画像表示装置構成部材間に本粘着剤組成物を直接充填することによって、本粘着シートを使用することもできる。 <How to use this adhesive sheet>
This pressure-sensitive adhesive sheet can also be used as a single pressure-sensitive adhesive sheet. For example, the present pressure-sensitive adhesive composition may be directly applied to a member for an image display device to be described later to form a sheet, or the pressure-sensitive adhesive composition may be directly extruded or injected into a mold to obtain the present pressure-sensitive adhesive sheet. can be used. Furthermore, the present pressure-sensitive adhesive sheet can also be used by directly filling the present pressure-sensitive adhesive composition between image display device constituent members.
　また、本粘着シートは、他の粘着シートと積層して使用することも可能である。
　例えば、他の粘着シートが、本粘着シートよりも屈曲性に優れたものであれば、フレキシブル画像表示装置により好適である。
　そのような他の粘着シートとして、ゲル分率が７０％以上であり、厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接の極大点が－２５℃以下である粘着シートを挙げることができる。
　この際、当該損失正接の極大点が－２５℃以下であれば、高温及び低温下での折り曲げにおいても復元することができるため好ましい。
　かかる観点から、他の粘着シートの当該損失正接の極大点は－２５℃以下であるのが好ましく、中でも－３０℃以下、その中でも－３５℃以下であるのがさらに好ましい。 In addition, this pressure-sensitive adhesive sheet can be used by being laminated with other pressure-sensitive adhesive sheets.
For example, other pressure-sensitive adhesive sheets are more suitable for the flexible image display device if they are more flexible than the present pressure-sensitive adhesive sheet.
Such other adhesive sheets have a gel fraction of 70% or more, a thickness of 0.8 mm to 1.5 mm, and a maximum loss tangent obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz. A pressure-sensitive adhesive sheet having a temperature of -25°C or less can be mentioned.
In this case, if the maximum point of the loss tangent is −25° C. or less, it is preferable because it can be restored even when it is bent at high and low temperatures.
From this point of view, the maximum point of the loss tangent of the other PSA sheet is preferably −25° C. or lower, more preferably −30° C. or lower, and more preferably −35° C. or lower.
　（本離型フィルム付き粘着シート）
　本粘着シートは、本粘着剤組成物から形成される本粘着剤層と、離型フィルムとを備えた離型フィルム付き粘着シート（「本離型フィルム付き粘着シート」と称する）として使用することも可能である。例えば、本粘着剤組成物を、離型フィルム上に単層又は多層のシート状に成型した離型フィルム付き粘着シートの形態とすることもできる。 (Adhesive sheet with release film)
The pressure-sensitive adhesive sheet can be used as a pressure-sensitive adhesive sheet with a release film (referred to as a "pressure-sensitive adhesive sheet with a release film") comprising the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a release film. is also possible. For example, the present pressure-sensitive adhesive composition can be in the form of a release film-attached pressure-sensitive adhesive sheet formed by molding a single-layer or multilayer sheet on a release film.
　前記離型フィルムの材質としては、例えばポリエステルフィルム、ポリオレフィンフィルム、ポリカーボネートフィルム、ポリスチレンフィルム、アクリルフィルム、トリアセチルセルロースフィルム、フッ素樹脂フィルム等を挙げることができる。これらの中でも、ポリエステルフィルム及びポリオレフィンフィルムが特に好ましい。 Examples of materials for the release film include polyester film, polyolefin film, polycarbonate film, polystyrene film, acrylic film, triacetylcellulose film, and fluororesin film. Among these, polyester films and polyolefin films are particularly preferred.
　離型フィルムの厚みは特に制限されない。中でも、例えば加工性及びハンドリング性の観点からは、２５μｍ～５００μｍであるのが好ましく、その中でも３８μｍ以上或いは２５０μｍ以下、その中でも５０μｍ以上或いは２００μｍ以下であるのがさらに好ましい。 The thickness of the release film is not particularly limited. Among them, for example, from the viewpoint of workability and handleability, the thickness is preferably 25 μm to 500 μm, more preferably 38 μm or more or 250 μm or less, and more preferably 50 μm or more or 200 μm or less.
　本離型フィルム付き粘着シートは、離型フィルムがポリエステル系フィルムであることが好ましく、また、活性エネルギー線を照射した後にも剥離し易いものであるものが離型性の点から好ましい。かかる観点から、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の本粘着シートに対する剥離力が、剥離角１８０°、剥離速度３００ｍｍ／分において、０．１Ｎ／ｃｍ以下となるものであることが好ましい。 In the pressure-sensitive adhesive sheet with a release film, the release film is preferably a polyester-based film, and from the standpoint of releasability, it is preferable that the release film be easily peeled off even after irradiation with active energy rays. From this point of view, when the active energy ray with a wavelength of 365 nm is irradiated with an accumulated light amount of 2000 to 4000 mJ/cm 2 , the peel force for the present adhesive sheet is 0.1 N/cm or less at a peel angle of 180° and a peel speed of 300 mm/min. It is preferable to be
　＜本積層体＞
　本発明の実施形態の一例に係る積層体（「本積層体」と称する）は、離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とが、前記本粘着シートを介して積層してなる構成を備えた積層体である。 <Main laminate>
A laminate (referred to as "this laminate") according to an example of an embodiment of the present invention includes a release film and a member for constituting an image display device having a step with a height difference of 2 μm or more on the surface to be laminated, It is a layered product having a configuration in which layers are layered via an adhesive sheet.
　本積層体の離型フィルムは、上記本離型フィルム付き粘着シートの離型フィルムと同様である。 The release film of the laminate is the same as the release film of the pressure-sensitive adhesive sheet with the release film.
　例えば、離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とを、本粘着シートを介して積層し、前記離型フィルム側から該離型フィルムを通して本粘着シートに活性エネルギー線照射を行うようにして、本積層体を製造することができる。
　この際、活性エネルギー線の照射量は、段差吸収性の点から、４０００ｍＪ／ｃｍ２以下であることが好ましく、特に３５００ｍＪ／ｃｍ２以下、更に３２００ｍＪ／ｃｍ２以下であるのがさらに好ましい。また、十分に硬化させて復元性を向上させる点から、２０００ｍＪ／ｃｍ２以上が好ましく、２５００ｍJ／ｃｍ２以上がより好ましく、２８００ｍＪ／ｃｍ２以上がさらに好ましい。 For example, a release film and a member for constituting an image display device having a step with a height difference of 2 μm or more on the laminated surface are laminated via the present adhesive sheet, and the present adhesive is passed through the release film from the release film side. The laminate can be produced by irradiating the sheet with active energy rays.
At this time, the irradiation dose of the active energy rays is preferably 4000 mJ/cm 2 or less, particularly 3500 mJ/cm 2 or less, further preferably 3200 mJ/cm 2 or less, from the viewpoint of step absorption. In addition, from the viewpoint of sufficient curing to improve restorability, it is preferably 2000 mJ/cm 2 or more, more preferably 2500 mJ/cm 2 or more, and even more preferably 2800 mJ/cm 2 or more.
　＜本画像表示装置用積層体＞
　本発明の実施形態の一例に係る画像表示装置用積層体（以下、「本積層体」と称することがある。）は、上述した本粘着シートの少なくとも片面に、画像表示装置構成用部材を備えた積層体である。 <Laminate for this image display device>
A laminate for an image display device according to an example of the embodiment of the present invention (hereinafter sometimes referred to as "this laminate") is provided with an image display device constituent member on at least one side of the above-described present pressure-sensitive adhesive sheet. It is a laminated body.
　本積層体は、第１の画像表示装置構成用部材（以下「第１の部材」と称することがある）と、本粘着シートと、第２の画像表示装置構成用部材（以下「第２の部材」と称することがある）とが、この順で積層されてなる構成を備えた積層体であるのが好ましい。
　さらに、第１の部材、第２の部材及び第３の画像表示装置構成用部材（以下「第３の部材」と称することがある）とが、それぞれ本粘着シートを介してこの順で積層されてなる構成を備えた積層体であってもよい。積層する２以上の部材は同じでもよいし、異なるものでもよい。 The laminate includes a first image display device constituent member (hereinafter sometimes referred to as "first member"), the present pressure-sensitive adhesive sheet, and a second image display device constituent member (hereinafter sometimes referred to as "second member"). (sometimes referred to as "members") are preferably laminated in this order.
Further, the first member, the second member and the third image display device constituting member (hereinafter sometimes referred to as "third member") are laminated in this order with the adhesive sheet interposed therebetween. It may also be a laminated body having a different configuration. Two or more members to be laminated may be the same or different.
　本積層体の厚みは、特に制限されるものではない。例えば、画像表示装置に使用される場合の一例としては、本積層体はシート状であり、その厚みが０．０２ｍｍ以上であれば、ハンドリング性が良好であり、また、厚みが１．０ｍｍ以下であれば、積層体の薄型化に寄与することができる。
　よって、本積層体の厚みは、０．０２ｍｍ以上であるのが好ましく、中でも０．０３ｍｍ以上、特に０．０５ｍｍ以上であるのがより好ましい。一方、上限に関しては、１．０ｍｍ以下であるのが好ましく、中でも０．７ｍｍ以下、特に０．５ｍｍ以下であるのがさらに好ましい。 The thickness of the laminate is not particularly limited. For example, when used in an image display device, the laminate is in the form of a sheet, and if the thickness is 0.02 mm or more, the handleability is good, and the thickness is 1.0 mm or less. If it is, it can contribute to thickness reduction of a laminated body.
Therefore, the thickness of the laminate is preferably 0.02 mm or more, more preferably 0.03 mm or more, particularly 0.05 mm or more. On the other hand, the upper limit is preferably 1.0 mm or less, more preferably 0.7 mm or less, particularly 0.5 mm or less.
　本粘着シートを、第１の部材、第２の部材及び／又は第３の部材に貼着することにより、本積層体を作製することができる。ただし、このような製造方法に限定するものではない。 The present laminate can be produced by attaching the present adhesive sheet to the first member, the second member and/or the third member. However, it is not limited to such a manufacturing method.
　（画像表示装置構成部材）
　フレキシブル画像表示装置の構成や本粘着シートの位置にも依るが、第１の部材、第２の部材及び第３の部材（これらをまとめて「本部材」と称する場合がある）としては、例えばカバーレンズ、偏光板、位相差フィルム、バリアフィルム、タッチセンサーフィルム、発光素子、ＰＳＡ等を挙げることができる。 (Image display device component)
Depending on the configuration of the flexible image display device and the position of the pressure-sensitive adhesive sheet, the first member, the second member, and the third member (these may be collectively referred to as "this member") include, for example, A cover lens, a polarizing plate, a retardation film, a barrier film, a touch sensor film, a light emitting element, a PSA and the like can be mentioned.
　特に、画像表示の構成を考慮すると、第１の部材は、タッチ入力機能を有することが好ましい。本粘着シートが前述した第２の部材、第３の部材を有する場合、第２の部材乃至第３の部材がタッチ入力機能を有していてもよい。
　また、本部材のうちの少なくとも一つは、本粘着シートとの接触面に、配線、印刷、パターン現像や表面処理、エンボス加工等により種々の凹凸が賦形されていてもよい。部材の表面が凹凸を有する場合、凹凸の段差の高低差は２μｍ以上、例えば２μｍ以上１０μｍ以下であるのが好ましく、中でも８μｍ以下であるのがより好ましく、その中でも３μｍ以上或いは７μｍ以下であるのがより好ましく、その中でも４μｍ以上或いは６μｍ以下であるのがさらに好ましい。 In particular, considering the configuration of image display, the first member preferably has a touch input function. When the adhesive sheet has the second member and the third member described above, the second member to the third member may have a touch input function.
In addition, at least one of the members may have various irregularities formed by wiring, printing, pattern development, surface treatment, embossing, etc. on the contact surface with the pressure-sensitive adhesive sheet. When the surface of the member has unevenness, the height difference of the unevenness is preferably 2 μm or more, for example, 2 μm or more and 10 μm or less, more preferably 8 μm or less, and more preferably 3 μm or more or 7 μm or less. is more preferable, and among them, 4 μm or more or 6 μm or less is more preferable.
　貼り合わせる画像表示装置構成用部材（第１の部材、第２の部材及び第３の部材を包含する）のうちの少なくとも一つは、ウレタン樹脂、シクロオレフィン樹脂、トリアセチルセルロース樹脂、（メタ）アクリレート樹脂、エポキシ樹脂及びポリイミド樹脂からなる群から選択される一種若しくは二種以上の樹脂を主成分とする樹脂シート又は薄膜ガラスであってもよい。
　ここで「主成分」とは、画像表示装置構成用部材を構成する成分のうち最も多い質量比率を占める成分であることをいい、具体的には画像表示装置構成用部材又は該部材を形成する粘着剤組成物の５０質量％以上を占めるものであり、５５質量％以上、中でも６０質量％以上を占めるのがさらに好ましい。 At least one of the members for forming an image display device (including the first member, the second member, and the third member) to be laminated is made of urethane resin, cycloolefin resin, triacetylcellulose resin, (meta) It may be a resin sheet or a thin film glass mainly composed of one or more resins selected from the group consisting of acrylate resins, epoxy resins and polyimide resins.
Here, the term "main component" refers to a component that accounts for the largest mass ratio among the components constituting the image display device constituent member, and specifically, the image display device constituent member or the member forming the member. It accounts for 50% by mass or more of the pressure-sensitive adhesive composition, more preferably 55% by mass or more, and more preferably 60% by mass or more.
　本粘着シートは、活性エネルギー線による硬化後においてホットメルトすることが可能である。かかるホットメルトにより、被着体の被着面に凹凸を有する場合であっても、該凹凸に追随しかつ凹凸を吸収するように貼合することができ、その表面を平滑にすることもできる。そのため、２つの画像表示装置構成用部材を、本粘着シートを介して貼合する際、一方又は両方の画像表示装置構成用部材が光を透過しない部材であっても、該凹凸を吸収しつつ２つの画像表示装置構成用部材を貼合することができる。 This adhesive sheet can be hot-melted after being cured by active energy rays. With such a hot melt, even if the adherend surface of the adherend has unevenness, it can be laminated so as to follow the unevenness and absorb the unevenness, and the surface can be smoothed. . Therefore, when two image display device constituent members are bonded via the present pressure-sensitive adhesive sheet, even if one or both of the image display device constituent members are members that do not transmit light, the unevenness can be absorbed. Two members for forming an image display device can be pasted together.
　＜本画像表示装置＞
　本積層体を組み込むことで、例えば本積層体を他の画像表示装置構成部材に積層することで、本積層体を備えたフレキシブル画像表示装置（「本画像表示装置」とも称する）を形成することができる。
　フレキシブル画像表示装置とは、繰り返し折り曲げや湾曲操作、巻き取り操作をしても曲げ跡を残さず、折り曲げ状態や湾曲状態、巻き取り状態を解放した際には折り曲げや湾曲操作、巻き取り操作をする前の状態まで素早く回復することができ、歪みなく画像を表示できる画像表示装置をいう。特に本積層体は、画像表示装置構成部材の本粘着シートとの接触面に、高低差２μｍ以上の段差を有する凹凸があっても、気泡を発生させないように、段差に追従して段差を吸収することができるばかりか、低温或いは高温における環境下で折り曲げや湾曲、巻き取り操作をしても、積層体のデラミや割れを防止でき、復元性も良好であるので、フレキシブル性にすぐれた画像表示装置を製造できることが特徴の一つである。 <This image display device>
Forming a flexible image display device (also referred to as "present image display device") comprising this laminate by incorporating this laminate, for example, by laminating this laminate on another image display device constituent member. can be done.
A flexible image display device leaves no trace of bending even after repeated bending, bending, or winding operations, and can be bent, bent, or wound up when the bending, bending, or winding state is released. It is an image display device that can quickly recover to the state before the display and can display an image without distortion. In particular, the laminate conforms to and absorbs unevenness having a height difference of 2 μm or more on the contact surface of the constituent member of the image display device with the adhesive sheet so as not to generate air bubbles. In addition, even when bending, curving, or winding operations are performed in a low-temperature or high-temperature environment, delamination and cracking of the laminate can be prevented, and the resilience is good, so images with excellent flexibility can be obtained. One of the features is that a display device can be manufactured.
　本画像表示装置においては、液晶パネルなどの画像表示パネルの視認側に本粘着シートを配置することもできるし、また、画像表示パネルの視認側とは反対側、すなわち光源側に配置することもできる。 In the present image display device, the present pressure-sensitive adhesive sheet can be placed on the viewing side of an image display panel such as a liquid crystal panel, or can be placed on the side opposite to the viewing side of the image display panel, that is, on the light source side. can.
　＜画像表示装置構成用積層体の製造方法＞
　次に、本積層体の製造方法の一例について説明する。ただし、本積層体の製造方法が、次に説明する方法に限定されるものではない。 <Method for producing a laminate for constituting an image display device>
Next, an example of the manufacturing method of this laminated body is demonstrated. However, the manufacturing method of this laminate is not limited to the method described below.
　本積層体は、以下の工程１～３、必要に応じてさらに工程４を有する画像表示装置用積層体の製造方法によって製造することができる。
　工程１：画像表示装置構成用部材１に、本粘着シートの一方の表面を貼合する。
　工程２：活性エネルギー線を照射して本粘着シートを硬化させる。
　工程３：前記粘着シートの他方の表面に画像表示装置構成用部材２を貼合して積層体とする。
　工程４：前記積層体に加熱処理を施して前記粘着シートをホットメルトさせる。 The present laminate can be produced by a method for producing a laminate for an image display device including the following steps 1 to 3 and, if necessary, step 4.
Step 1: One surface of the pressure-sensitive adhesive sheet is attached to the member 1 for constituting an image display device.
Step 2: The pressure-sensitive adhesive sheet is cured by irradiation with active energy rays.
Step 3: The image display device constituting member 2 is adhered to the other surface of the pressure-sensitive adhesive sheet to form a laminate.
Step 4: The laminate is heat-treated to hot-melt the pressure-sensitive adhesive sheet.
　工程１を行った後に工程２を実施してもよいし、工程２を行った後に工程１を行ってもよい。工程１および工程２を行った後に、工程３を行う。 Step 2 may be carried out after Step 1, or Step 1 may be carried out after Step 2. After performing steps 1 and 2, step 3 is performed.
　（工程１）
　工程１は、画像表示装置構成用部材１に、本粘着シートの一方の表面を貼合する工程である。
　貼合方法としては、ロール貼合、平行平板によるプレス貼合、ダイヤフラム貼合等の既知の方式を用いることができる。
　貼合環境としては、常圧で貼り合わせる大気貼合方式と、減圧下で貼り合わせる真空貼合方式がある。貼合時の気泡を防止する観点からは、減圧環境下で平行平板にて貼合する方法が好ましい。また、貼合温度を適宜調整してもよい。 (Step 1)
Step 1 is a step of bonding one surface of the pressure-sensitive adhesive sheet to the member 1 for constituting an image display device.
As a lamination method, known methods such as roll lamination, press lamination using a parallel plate, and diaphragm lamination can be used.
As the lamination environment, there are an air lamination method in which lamination is performed under normal pressure and a vacuum lamination method in which lamination is performed under reduced pressure. From the viewpoint of preventing air bubbles during lamination, a method of laminating with a parallel plate under a reduced pressure environment is preferable. Moreover, you may adjust bonding temperature suitably.
　（工程２）
　工程２は、活性エネルギー線を照射して本粘着シートを硬化させる工程である。
　活性エネルギー線としては、紫外線及び可視光線が好適である。
　活性エネルギー線を照射する際の光源については、例えば高圧水銀ランプ、メタルハライドランプ、キセノンランプ、ハロゲンランプ、ＬＥＤランプ、蛍光ランプなどの中から、照射する光の波長や照射量に応じて使い分けることができる。
　照射時間や照射手段に関しては特に限定されないが、例えば紫外線照射であれば、波長３６５ｎｍにおける積算光量が２０００ｍＪ／ｃｍ２以上、特に３０００ｍＪ／ｃｍ２以上となるように照射するのが好ましい。 (Step 2)
Step 2 is a step of curing the adhesive sheet by irradiating it with active energy rays.
As active energy rays, ultraviolet rays and visible rays are suitable.
As for the light source when irradiating the active energy ray, it is possible to use properly according to the wavelength and irradiation amount of the light to be irradiated from, for example, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a halogen lamp, an LED lamp, a fluorescent lamp, etc. can.
Although irradiation time and irradiation means are not particularly limited, for example, in the case of ultraviolet irradiation, it is preferable to irradiate so that the integrated light amount at a wavelength of 365 nm is 2000 mJ/cm 2 or more, particularly 3000 mJ/cm 2 or more.
　第１の部材又は第２の部材の表面、例えば被積層面に高低差２μｍ以上、例えば２μｍ以上１０μｍ以下の段差を有する凹凸を有する場合は、本粘着シートをホットメルトさせることにより、本粘着シートを当該段差に追従して段差を吸収することができ、好ましくは積層体表面を平滑にすることができる。 When the surface of the first member or the second member, for example, the surface to be laminated has unevenness having a height difference of 2 μm or more, for example, 2 μm or more and 10 μm or less, the present pressure-sensitive adhesive sheet is hot-melted. can absorb the step by following the step, and preferably the surface of the laminate can be smoothed.
　（工程３）
　工程３は、工程１及び工程２を経た本粘着シートの他方の表面に画像表示装置構成用部材２を貼合して積層体とする工程である。
　工程３では、必要に応じて、画像表示装置構成用部材１及び／又は画像表示装置構成用部材２を加熱すると共に、画像表示装置構成用部材２を貼合するようにしてもよい。
　この際の加熱は、例えば、画像表示装置構成用部材１／本粘着シート／画像表示装置構成用部材２からなる画像表示装置用積層体を、両側から、所定温度に加熱されたプレス板で加圧する方法などを挙げることができる。
　また、この際の加熱温度は、温度５０℃以上８０℃以下であるのが好ましい。すなわち、５０℃以上８０℃以下に画像表示装置構成用部材１及び／又は画像表示装置構成用部材２を加熱して前記粘着シートをホットメルトさせながら、画像表示装置構成用部材２を貼合するのが好ましい。
　また、プレス板で加圧する際のプレス圧は、０．０１ＭＰａ以上或いは０．４ＭＰａ以下、その中でも０．０２ＭＰａ以上或いは０．３５ＭＰａ以下であるのがさらに好ましい。 (Step 3)
Step 3 is a step of laminating the member 2 for constituting an image display device to the other surface of the pressure-sensitive adhesive sheet that has undergone steps 1 and 2 to form a laminate.
In the step 3, the image display device-constituting member 1 and/or the image display device-constituting member 2 may be heated and the image display device-constituting member 2 may be bonded together as needed.
The heating at this time is performed, for example, by applying a press plate heated to a predetermined temperature to a laminate for an image display device composed of image display device constituent member 1/adhesive sheet/image display device constituent member 2 from both sides. For example, a method of applying pressure can be mentioned.
Moreover, the heating temperature at this time is preferably 50° C. or higher and 80° C. or lower. That is, the image display device constituent member 1 and/or the image display device constituent member 2 are heated to 50° C. or more and 80° C. or less to hot-melt the adhesive sheet, and the image display device constituent member 2 is bonded. is preferred.
Further, the press pressure when pressing with the press plate is preferably 0.01 MPa or more or 0.4 MPa or less, more preferably 0.02 MPa or more or 0.35 MPa or less.
　（工程４）
　工程４は、工程３で得られた、貼合後の前記積層体に加熱処理を施して前記粘着シートをホットメルトさせる工程である。この工程４は、必要に応じて実施すればよい。
　貼合後の前記積層体に加熱処理を施して前記粘着シートをホットメルトさせることにより、第１の部材又は第２の部材の表面、例えば被積層面に高低差２μｍ以上、例えば２μｍ以上１０μｍ以下の段差を有する凹凸を有する場合であっても、前記粘着シートは当該段差に追従して段差を吸収してその表面を平滑にすることができる。 (Step 4)
Step 4 is a step of heat-treating the laminated body obtained in Step 3 to hot-melt the pressure-sensitive adhesive sheet. This step 4 may be performed as required.
By subjecting the laminate after lamination to heat treatment to hot-melt the pressure-sensitive adhesive sheet, the surface of the first member or the second member, for example, the surface to be laminated, has a height difference of 2 μm or more, for example, 2 μm or more and 10 μm or less. Even if the adhesive sheet has unevenness having a level difference, the pressure-sensitive adhesive sheet can follow the level difference and absorb the level difference, thereby smoothing the surface.
　積層体を加熱処理する際の加熱温度は、温度４０℃以上９０℃以下であるのが好ましい。中でも、上記温度は５０℃以上或いは８０℃以下、その中でも６０℃以上或いは７０℃以下であるのがさらに好ましい。
　また、加熱処理と併せて、０．２ＭＰａ以上０．８ＭＰａ以下の気圧を５分間以上、本積層体に掛けるようにしてもよい。この際の気圧は、０．２ＭＰａ以上０．８ＭＰａ以下であるのが好ましく、その中でも０．４ＭＰａ以上或いは０．６ＭＰａ以下であるのがさらに好ましい。
　上記処理時間は、５分以上或いは６０分以下、その中でも１０分以上或いは３０分以下であるのがさらに好ましい。 The heating temperature for the heat treatment of the laminate is preferably 40° C. or higher and 90° C. or lower. Above all, the temperature is preferably 50° C. or higher or 80° C. or lower, more preferably 60° C. or higher or 70° C. or lower.
In addition to the heat treatment, an air pressure of 0.2 MPa or more and 0.8 MPa or less may be applied to the laminate for 5 minutes or more. At this time, the atmospheric pressure is preferably 0.2 MPa or more and 0.8 MPa or less, more preferably 0.4 MPa or more or 0.6 MPa or less.
The treatment time is preferably 5 minutes or more or 60 minutes or less, more preferably 10 minutes or more or 30 minutes or less.
　工程４では、上記加熱処理と併せて、本積層体に０．０１ＭＰａ以上０．４ＭＰａ以下のプレス圧をかけてもよい。
　上記プレス圧は、０．０１ＭＰａ以上或いは０．４ＭＰａ以下、その中でも０．０２ＭＰａ以上或いは０．３５ＭＰａ以下であるのがさらに好ましい。
　上記処理時間は、５秒以上或いは１０分以下、その中でも１０秒以上或いは５分以下であるのがさらに好ましい。 In step 4, a press pressure of 0.01 MPa or more and 0.4 MPa or less may be applied to the laminate in combination with the heat treatment.
The pressing pressure is preferably 0.01 MPa or more or 0.4 MPa or less, more preferably 0.02 MPa or more or 0.35 MPa or less.
The treatment time is preferably 5 seconds or more or 10 minutes or less, more preferably 10 seconds or more or 5 minutes or less.
　また、工程４を実施する際は、工程１，２，３，４の順に実施するのが好ましい。
　本製造方法は、第１及び第２の部材が活性エネルギー線を透過しない場合に有効である。
　硬化後の本粘着シートをホットメルトさせる場合、本粘着シートに活性エネルギー線を照射した後３０分以内にホットメルト処理するのが好ましい。その理由は完全に硬化する前にホットメルト処理をすることで、２μｍ以上の段差を有する凹凸により一層追従させ易くなるからである。かかる観点から、活性エネルギー線を照射してからホットメルト処理するまでの時間は３０分以内が好ましく、２０分以内がより好ましく、１０分以内がさらに好ましい。 Moreover, when carrying out the step 4, it is preferable to carry out the steps 1, 2, 3 and 4 in this order.
This manufacturing method is effective when the first and second members do not transmit active energy rays.
When hot-melting the adhesive sheet after curing, the hot-melt treatment is preferably performed within 30 minutes after irradiating the adhesive sheet with active energy rays. The reason for this is that if the hot-melt treatment is performed before the adhesive is completely cured, it becomes easier to follow the unevenness having a level difference of 2 μm or more. From this point of view, the time from the irradiation of the active energy ray to the hot-melt treatment is preferably within 30 minutes, more preferably within 20 minutes, and even more preferably within 10 minutes.
　＜語句の説明など＞
　本発明においては、「フィルム」と称する場合でも「シート」を含むものとし、「シート」と称する場合でも「フィルム」を含むものとする。
　また、画像表示パネル、保護パネル等のように「パネル」と表現する場合、板体、シートおよびフィルムを包含するものである。 <Explanation of terms, etc.>
In the present invention, the term "film" includes the "sheet", and the term "sheet" includes the "film".
In addition, the expression "panel" such as an image display panel, a protective panel, etc. includes a plate, a sheet and a film.
　本明細書において、「Ｘ～Ｙ」（Ｘ，Ｙは任意の数字）と記載した場合、特にことわらない限り「Ｘ以上Ｙ以下」の意と共に、「好ましくはＸより大きい」或いは「好ましくはＹより小さい」の意も包含するものである。
　また、「Ｘ以上」（Ｘは任意の数字）と記載した場合、特にことわらない限り「好ましくはＸより大きい」の意を包含し、「Ｙ以下」（Ｙは任意の数字）と記載した場合、特にことわらない限り「好ましくはＹより小さい」の意も包含するものである。 In this specification, when described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably It also includes the meaning of "smaller than Y".
In addition, when described as "X or more" (X is an arbitrary number), it includes the meaning of "preferably greater than X" unless otherwise specified, and is described as "Y or less" (Y is an arbitrary number). If not otherwise specified, it also includes the meaning of "preferably smaller than Y".
　本発明は、以下の実施例により更に説明する。ただし、下記に示す実施例に本発明が限定解釈されるものではない。 The present invention is further illustrated by the following examples. However, the present invention is not limited to the examples shown below.
　先ず、実施例で調製した粘着剤組成物の原料の詳細について説明する。 First, the details of the raw materials of the pressure-sensitive adhesive composition prepared in Examples will be described.
　＜（メタ）アクリル系重合体（Ａ）＞
　・（メタ）アクリル系重合体（Ａ－１）：数平均分子量２８００のポリメタクリル酸メチルマクロモノマー（Ｔｇ１０５℃）６質量部と、ブチルアクリレート（Ｔｇ－５５度）９０質量部と、アクリル酸（Ｔｇ１０６℃）４質量部とが共重合してなるアクリル系グラフト共重合体（質量平均分子量：２２万、Ｔｇ－４５℃）
　・（メタ）アクリル系重合体（Ａ－２）：数平均分子量２８００のポリメタクリル酸メチルマクロモノマー（Ｔｇ１０５℃）１５質量部と、ブチルアクリレート（Ｔｇ－５５℃）８１質量部と、アクリル酸４（１０６℃）質量部とが共重合してなるアクリル系グラフト共重合体（質量平均分子量：１６万、Ｔｇ－３６℃）
　・（メタ）アクリル系重合体（Ａ－３）：２－エチルヘキシルアクリレート（Ｔｇ－７０℃）、メチルアクリレート（Ｔｇ８℃）、エチルアクリレート（Ｔｇ－２０℃）、２－ヒドロキシエチルアクリレート（Ｔｇ－１５℃）及び４－ヒドロキシブチルアクリレート（Ｔｇ－４０℃）が共重合してなるアクリル共重合体（質量平均分子量：約７０万、Ｔｇ－５４℃）
　・（メタ）アクリル系重合体（Ａ－４）：数平均分子量５５００のＳＬＭＡ（ラウリルメタクリレート）マクロモノマー（Ｔｇ－６５℃）１５質量部と、ブチルアクリレート（Ｔｇ－５５℃）８５質量部とがランダム共重合してなるアクリル系グラフト共重合体（質量平均分子量：４１万、Ｔｇ－３８℃）
　・（メタ）アクリル系重合体（Ａ－５）：数平均分子量２８００のポリメタクリル酸メチルマクロモノマー（Ｔｇ１０５℃）９質量部と、ブチルアクリレート（Ｔｇ－５５℃）８７質量部と、アクリル酸４（１０６℃）質量部とが共重合してなるアクリル系グラフト共重合体（質量平均分子量：１６万、Ｔｇ－３６℃）
　・（メタ）アクリル系重合体（Ａ－６）：２－エチルヘキシルアクリレート（Ｔｇ－７０℃）、メチルアクリレート（Ｔｇ８℃）、２－ヒドロキシエチルアクリレート（Ｔｇ－１５℃）が共重合してなるアクリル共重合体（質量平均分子量：約４０万、Ｔｇ－５０℃） <(Meth)acrylic polymer (A)>
- (Meth)acrylic polymer (A-1): 6 parts by mass of polymethyl methacrylate macromonomer (Tg 105°C) having a number average molecular weight of 2800, 90 parts by mass of butyl acrylate (Tg -55°C), and acrylic acid ( Tg 106° C.) 4 parts by mass of acrylic graft copolymer (mass average molecular weight: 220,000, Tg −45° C.)
- (Meth) acrylic polymer (A-2): 15 parts by mass of polymethyl methacrylate macromonomer (Tg 105 ° C.) having a number average molecular weight of 2800, 81 parts by mass of butyl acrylate (Tg -55 ° C.), and 4 parts by mass of acrylic acid (106 ° C.) acrylic graft copolymer (mass average molecular weight: 160,000, Tg -36 ° C.)
- (Meth)acrylic polymer (A-3): 2-ethylhexyl acrylate (Tg-70°C), methyl acrylate (Tg8°C), ethyl acrylate (Tg-20°C), 2-hydroxyethyl acrylate (Tg-15 ° C.) and 4-hydroxybutyl acrylate (Tg-40 ° C.) acrylic copolymer (mass average molecular weight: about 700,000, Tg-54 ° C.)
- (Meth)acrylic polymer (A-4): 15 parts by mass of SLMA (lauryl methacrylate) macromonomer (Tg-65°C) having a number average molecular weight of 5500 and 85 parts by mass of butyl acrylate (Tg-55°C) Acrylic graft copolymer obtained by random copolymerization (mass average molecular weight: 410,000, Tg-38°C)
- (Meth) acrylic polymer (A-5): 9 parts by mass of polymethyl methacrylate macromonomer (Tg 105 ° C.) having a number average molecular weight of 2800, 87 parts by mass of butyl acrylate (Tg -55 ° C.), and 4 parts by mass of acrylic acid (106 ° C.) acrylic graft copolymer (mass average molecular weight: 160,000, Tg -36 ° C.)
(Meth)acrylic polymer (A-6): acrylic obtained by copolymerizing 2-ethylhexyl acrylate (Tg-70°C), methyl acrylate (Tg8°C), and 2-hydroxyethyl acrylate (Tg-15°C) Copolymer (mass average molecular weight: about 400,000, Tg-50°C)
　上記（メタ）アクリル系重合体中の共重合各成分のガラス転移温度は、該成分のホモポリマーから得られるガラス転移温度の文献値である。マクロモノマーについては、マクロモノマー中の高分子量骨格を形成する成分のホモポリマーから得られるガラス転移温度の文献値とした。
　アクリル系共重合体のガラス転移温度は、上記共重合各成分のガラス転移温度と構成比率から、Ｆｏｘの計算式によって算出される理論Ｔｇを記載した。 The glass transition temperature of each copolymer component in the (meth)acrylic polymer is the literature value of the glass transition temperature obtained from the homopolymer of the component. For the macromonomer, the literature value of the glass transition temperature obtained from the homopolymer of the component forming the high-molecular-weight skeleton in the macromonomer was used.
As for the glass transition temperature of the acrylic copolymer, the theoretical Tg calculated by the Fox calculation formula is described from the glass transition temperature and the composition ratio of each component of the copolymer.
　＜架橋剤（Ｂ）＞
　・架橋剤（Ｂ－１）：プロポキシ化ペンタエリスリトールトリアクリレート
　・架橋剤（Ｂ－２）：ポリテトラメチレングリコールジ（メタ）アクリレート <Crosslinking agent (B)>
・Crosslinking agent (B-1): propoxylated pentaerythritol triacrylate ・Crosslinking agent (B-2): polytetramethylene glycol di(meth)acrylate
　＜重合開始剤（Ｃ）＞
　・開始剤（Ｃ－１）：２，４，６－トリメチルベンゾフェノン及び４－メチルベンゾフェノンの混合物（ＩＧＭ社製「Ｅｓａｃｕｒｅ　ＴＺＴ」） <Polymerization initiator (C)>
- Initiator (C-1): a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone ("Esacure TZT" manufactured by IGM)
　＜単官能（メタ）アクリレート（Ｄ）＞
　・単官能（メタ）アクリレート（Ｄ－１）：４－ヒドロキシブチルアクリレート
　・単官能（メタ）アクリレート（Ｄ－２）：プロピレングリコール骨格含有単官能ウレタンアクリレート（ＡＧＣ社製「ＰＥＭ－Ｘ２６４」、質量平均分子量：１万） <Monofunctional (meth)acrylate (D)>
・Monofunctional (meth)acrylate (D-1): 4-hydroxybutyl acrylate ・Monofunctional (meth)acrylate (D-2): propylene glycol skeleton-containing monofunctional urethane acrylate (“PEM-X264” manufactured by AGC, weight Average molecular weight: 10,000)
　＜その他＞
　・シランカップリング剤（Ｅ－１）：ＫＢＭ４０３（信越シリコーン社製）
　・防錆剤（Ｅ－２）：１，２，３－ベンゾトリアゾール <Others>
・ Silane coupling agent (E-1): KBM403 (manufactured by Shin-Etsu Silicone Co., Ltd.)
・Rust inhibitor (E-2): 1,2,3-benzotriazole
　［実施例１］
　（メタ）アクリル系重合体（Ａ－１）１００質量部、架橋剤（Ｂ－１）１．５質量部、開始剤（Ｃ－１）１．５質量部、防錆剤（Ｅ－２）０．５質量部を均一混合し、粘着剤組成物を作製した。
　シリコーン離型処理された厚さ１００μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）上に、前記粘着剤組成物の厚みが２５μｍとなるようにシート状に展開した。 [Example 1]
(Meth) acrylic polymer (A-1) 100 parts by mass, cross-linking agent (B-1) 1.5 parts by mass, initiator (C-1) 1.5 parts by mass, rust inhibitor (E-2) 0.5 parts by mass were uniformly mixed to prepare a pressure-sensitive adhesive composition.
On a 100 μm-thick release film (PET film manufactured by Mitsubishi Chemical Co., Ltd.) subjected to silicone release treatment, the pressure-sensitive adhesive composition was spread in a sheet form to a thickness of 25 μm.
　次に、当該シート状の粘着剤組成物の上に、シリコーン離型処理された厚さ７５μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）を積層して積層体を形成し、離型フィルム／粘着シート１／離型フィルムからなる離型フィルム付き粘着シート１を得た。
　なお、粘着シート１は、活性エネルギー線を照射することにより硬化する活性エネルギー線硬化性を備えた活性エネルギー線硬化性粘着シートであった。 Next, on the sheet-shaped pressure-sensitive adhesive composition, a release film having a thickness of 75 μm (PET film manufactured by Mitsubishi Chemical Corporation) that has been subjected to silicone release treatment is laminated to form a laminate, and the release film/ A pressure-sensitive adhesive sheet 1 with a release film composed of pressure-sensitive adhesive sheet 1/release film was obtained.
In addition, the adhesive sheet 1 was an active energy ray-curable adhesive sheet having an active energy ray-curable adhesive sheet that is cured by irradiation with an active energy ray.
　［実施例２］
　表１に示したように厚みを変更した以外、実施例１と同様に粘着シート２及び離型フィルム／粘着シート２／離型フィルムからなる離型フィルム付き粘着シート２を作製した。
　なお、粘着シート２は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 [Example 2]
Adhesive sheet 2 and adhesive sheet 2 with a release film composed of release film/adhesive sheet 2/release film were produced in the same manner as in Example 1, except that the thickness was changed as shown in Table 1.
The adhesive sheet 2 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［実施例３］
　表１に示したように各成分を準備し、粘着剤層の原料とした。 [Example 3]
Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
　次に、前記粘着剤組成物を、シリコーン離型処理された１００μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム、厚さ１００μｍ）と、シリコーン離型処理された７５μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）、すなわち２枚の離型フィルムの間に挟んで、厚さ５０μｍのシート状にホットメルト成形し、離型フィルム／粘着シート３／離型フィルムからなる離型フィルム付き粘着シート３を得た。
　なお、粘着シート３は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 Next, the pressure-sensitive adhesive composition was applied to a release film of 100 μm (PET film manufactured by Mitsubishi Chemical Corporation, thickness 100 μm) and a release film of 75 μm (Mitsubishi Chemical Corporation). PET film), that is, sandwiched between two release films, hot-melt molded into a sheet with a thickness of 50 μm, and release film/adhesive sheet 3/release film-attached adhesive sheet 3 consisting of release film got
The adhesive sheet 3 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［実施例４］
　表１に示したように各成分を準備し、粘着剤層の原料とした。 [Example 4]
Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
　実施例３と同様に粘着シート４および離型フィルム／粘着シート４／離型フィルムからなる離型フィルム付き粘着シート４を作製した。
　なお、粘着シート４は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 Adhesive sheet 4 and adhesive sheet 4 with a release film composed of release film/adhesive sheet 4/release film were prepared in the same manner as in Example 3.
The adhesive sheet 4 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［実施例５］
　表１に示したように各成分を準備し、粘着剤層の原料とした。
　実施例１と同様に粘着シート５および離型フィルム／粘着シート５／離型フィルムからなる離型フィルム付き粘着シート５を作製した。
　なお、粘着シート５は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 [Example 5]
Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
Adhesive sheet 5 and adhesive sheet 5 with a release film composed of release film/adhesive sheet 5/release film were prepared in the same manner as in Example 1.
The adhesive sheet 5 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［実施例６］
　表１に示したように各成分を準備し、粘着剤層の原料とした。
　実施例３と同様に粘着シート６および離型フィルム／粘着シート６／離型フィルムからなる離型フィルム付き粘着シート６を作製した。
　なお、粘着シート６は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 [Example 6]
Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
Adhesive sheet 6 and adhesive sheet 6 with a release film composed of release film/adhesive sheet 6/release film were prepared in the same manner as in Example 3.
The adhesive sheet 6 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［実施例７］
　表１に示したように各成分を準備し、粘着剤層の原料とした。
　実施例３と同様に粘着シート７および離型フィルム／粘着シート７／離型フィルムからなる離型フィルム付き粘着シート７を作製した。
　なお、粘着シート７は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 [Example 7]
Each component was prepared as shown in Table 1 and used as a raw material for the pressure-sensitive adhesive layer.
Adhesive sheet 7 and adhesive sheet 7 with a release film composed of release film/adhesive sheet 7/release film were prepared in the same manner as in Example 3.
The adhesive sheet 7 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［比較例１］
　（メタ）アクリル系重合体（Ａ－３）１００質量部、単官能（メタ）アクリレート（Ｄ－１）２５量部、開始剤（Ｃ－１）３質量部、シランカップリング剤０．３質量部、防錆剤０．３質量部を配合して粘着剤組成物を作製し、シリコーン処理された厚さ１００μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）上に、前記粘着剤組成物の厚みが２５μｍとなるようにシート状に展開した。 [Comparative Example 1]
(Meth) acrylic polymer (A-3) 100 parts by weight, monofunctional (meth) acrylate (D-1) 25 parts by weight, initiator (C-1) 3 parts by weight, silane coupling agent 0.3 parts by weight part, and 0.3 parts by mass of a rust inhibitor to prepare a pressure-sensitive adhesive composition, and on a silicone-treated release film having a thickness of 100 μm (Mitsubishi Chemical Co., Ltd. PET film), the pressure-sensitive adhesive composition It was developed into a sheet with a thickness of 25 μm.
　次に、当該シート状の粘着剤組成物の上に、シリコーン離型処理された厚さ７５μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）を積層して積層体を形成し、メタルハライドランプ照射装置(ウシオ電気社、ＵＶＣ－０５１６Ｓ１、ランプＵＶＬ－８００１Ｍ３－Ｎ)を用いて、離型フィルムを通して前記粘着剤組成物に対して、波長３６５ｎｍの照射量が積算で３０００ｍＪ／ｃｍ２となるように光照射を行い、２５μｍの粘着シート（粘着シート８）の表裏両側に離型フィルムが積層された粘着シート積層体を得た。
　粘着シート８は光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートである。 Next, on the sheet-like adhesive composition, a release film having a thickness of 75 μm (PET film manufactured by Mitsubishi Chemical Corporation) subjected to silicone release treatment is laminated to form a laminate, and a metal halide lamp irradiation device is formed. (Ushio Denki, UVC-0516S1, lamp UVL-8001M3-N) was applied to the pressure-sensitive adhesive composition through the release film so that the cumulative irradiation dose at a wavelength of 365 nm was 3000 mJ/cm 2 . Irradiation was performed to obtain a pressure-sensitive adhesive sheet laminate in which release films were laminated on both front and back sides of a 25 μm pressure-sensitive adhesive sheet (adhesive sheet 8).
The adhesive sheet 8 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing.
　［比較例２］
　（メタ）アクリル系重合体（Ａ－２）１００質量部、架橋剤（Ｂ－１）２．５質量部、単官能（メタ）アクリレート（Ｄ－１）７．５量部、開始剤（Ｃ－１）１．５質量部、防錆剤０．３質量部を準備し、粘着剤層の原料とした。 [Comparative Example 2]
(Meth) acrylic polymer (A-2) 100 parts by weight, cross-linking agent (B-1) 2.5 parts by weight, monofunctional (meth) acrylate (D-1) 7.5 parts by weight, initiator (C -1) 1.5 parts by mass and 0.3 parts by mass of a rust preventive agent were prepared and used as raw materials for the pressure-sensitive adhesive layer.
　次に、前記粘着剤組成物を、シリコーン離型処理された１００μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム、厚さ１００μｍ）と、シリコーン離型処理された７５μｍの離型フィルム（三菱ケミカル社製ＰＥＴフィルム）、すなわち２枚の離型フィルムの間に挟んで、厚さ２５μｍのシート状にホットメルト成形し、離型フィルム／粘着シート９／離型フィルムからなる離型フィルム付き粘着シート９を得た。
　なお、粘着シート９は、光を照射することにより硬化する活性エネルギー線硬化性を備えた粘着シートであった。 Next, the pressure-sensitive adhesive composition was applied to a release film of 100 μm (PET film manufactured by Mitsubishi Chemical Corporation, thickness 100 μm) and a release film of 75 μm (Mitsubishi Chemical Corporation). PET film), that is, sandwiched between two release films, hot-melt molded into a sheet with a thickness of 25 μm, and release film/adhesive sheet 9/release film-attached adhesive sheet 9 consisting of release film got
The adhesive sheet 9 was an active energy ray-curing adhesive sheet that was cured by irradiation with light.
　［参考例１］
　実施例１で作製した粘着シート１と、他の粘着シートとしての比較例１で作製した粘着シート８をハンドローラーにて積層し、総厚み５０μｍの積層シートを作製した。
　なお、他の粘着シートとしての粘着シート５のゲル分率は７０％であり、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接の極大点が－３７℃であった。 [Reference example 1]
The adhesive sheet 1 produced in Example 1 and the adhesive sheet 8 produced in Comparative Example 1 as another adhesive sheet were laminated with a hand roller to produce a laminated sheet having a total thickness of 50 μm.
The gel fraction of adhesive sheet 5 as another adhesive sheet was 70%, and the maximum point of loss tangent obtained by dynamic viscoelasticity measurement in shear mode at a frequency of 1 Hz was -37°C.
　[粘着シートの評価］
　実施例で得た粘着シートの測定・評価を次のように行った。 [Evaluation of Adhesive Sheet]
The pressure-sensitive adhesive sheets obtained in Examples were measured and evaluated as follows.
　＜クリープ試験＞
　実施例及び比較例で作製した離型フィルム付き粘着シートから離型フィルムを取り除き、ハンドローラーにて積層することを繰り返して、厚さが約０．９ｍｍになるように積層し、直径８ｍｍの円状に打ち抜いた離型フィルム付き粘着シートを作製し、これをサンプルとした。
　上記サンプルについて、レオメータ（ＴＡインスツルメント社製「ＤＨＲ－２」）への設置時に離型フィルムを取り除いて使用し、測定治具：直径８ｍｍパラレルプレート、温度：２５℃、圧力：１０００Ｐａにて、３６００秒後の歪み（クリープ歪）（％）を測定した。 <Creep test>
The release film was removed from the release film-attached pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples, and the stacking was repeated with a hand roller so that the thickness was about 0.9 mm. A pressure-sensitive adhesive sheet with a release film was produced by punching into a shape, and this was used as a sample.
For the above sample, the release film was removed when installed in a rheometer ("DHR-2" manufactured by TA Instruments), and the measurement jig was a parallel plate with a diameter of 8 mm, temperature: 25 ° C., pressure: 1000 Pa. , the strain (creep strain) (%) after 3600 seconds was measured.
　実施例及び比較例で作製した粘着シートを、高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７では３０００ｍＪ／ｃｍ２、粘着シート５、９では４０００ｍＪ／ｃｍ２となるよう、離型フィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、上記の紫外線照射は行わず、測定に供した。 Using a high-pressure mercury lamp, the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were examined with an integrated amount of light at 365 nm of 3000 mJ/cm 2 for the pressure-sensitive adhesive sheets 1 to 4 and 6-7, and 4000 mJ/cm 2 for the pressure-sensitive adhesive sheets 5 and 9. The adhesive sheet was irradiated with ultraviolet rays through the release film to cure the adhesive sheet.
In addition, the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing. did.
　硬化後の粘着シートを用いて厚さ約０．９ｍｍになるように積層し、直径８ｍｍの円状に打ち抜いたものを作製し、これをサンプルとした。
　上記サンプルについて、レオメータ（ＴＡインスツルメント社製「ＤＨＲ－２」）を用いて、測定治具：直径８ｍｍパラレルプレート、温度：８０℃、圧力：１０００Ｐａにて、１８０秒後の歪み（クリープ歪）（％）を測定した。 The adhesive sheets after curing were laminated to a thickness of about 0.9 mm, and a circle with a diameter of 8 mm was punched out and used as a sample.
For the above sample, using a rheometer ("DHR-2" manufactured by TA Instruments), measuring jig: diameter 8 mm parallel plate, temperature: 80 ° C., pressure: 1000 Pa, strain after 180 seconds (creep strain ) (%) was measured.
　＜復元率＞
　実施例及び比較例で作製した離型フィルム付き粘着シートに対して、高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７では３０００ｍＪ／ｃｍ２、粘着シート５、９では４０００ｍＪ／ｃｍ２となるよう、離型フィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、上記の紫外線照射は行わず、測定に供した。 <Restoration rate>
Using a high-pressure mercury lamp, the integrated light quantity at 365 nm was 3000 mJ/cm 2 for adhesive sheets 1 to 4 and 6 to 7, and for adhesive sheets 5 and 9. In , the adhesive sheet was irradiated with ultraviolet rays through the release film so as to be 4000 mJ/cm 2 to cure the adhesive sheet.
In addition, the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing. did.
　硬化後の粘着シートを用いて厚さが約０．９ｍｍになるように積層し、直径８ｍｍの円状に打ち抜いたものを作製し、これをサンプルとした。
　上記サンプルについて、レオメータ（ＴＡインスツルメント社製「ＤＨＲ－２」、測定治具：直径８ｍｍパラレルプレート）を用いて、温度２５℃にて、初期歪（ｘ）としてのせん断歪が２００％となるように、６００秒間サンプルにせん断方向に応力を印加した。その後、応力を解放して６００秒経過後の残留歪（ｙ）を測定し、復元率を下記式より求めた。
　復元率（％）＝｛（ｘ－ｙ）／ｘ｝×１００
　上記式において、ｘは、厚さ約０．９ｍｍになるように積層した粘着シートに、せん断方向に印加する初期歪みであり、ｙは初期歪を６００秒間印加した後、解放して６００秒経過後の残留歪である。 The adhesive sheets after curing were laminated so as to have a thickness of about 0.9 mm, and a circle with a diameter of 8 mm was punched out and used as a sample.
For the above sample, a rheometer ("DHR-2" manufactured by TA Instruments Co., Ltd., measuring jig: 8 mm diameter parallel plate) was used at a temperature of 25 ° C., and the shear strain as the initial strain (x) was 200%. A shear stress was applied to the sample for 600 seconds. After that, the stress was released and the residual strain (y) was measured after 600 seconds had passed, and the recovery rate was obtained from the following formula.
Restoration rate (%) = {(xy)/x} x 100
In the above formula, x is the initial strain applied in the shearing direction to the adhesive sheet laminated to a thickness of about 0.9 mm, and y is the initial strain applied for 600 seconds and then released for 600 seconds. This is the post-residual strain.
　＜損失正接（ｔａｎδ）＞
　実施例及び比較例で作製した粘着シートを、厚さが約０．９ｍｍになるように積層し、直径８ｍｍの円状に打ち抜いたものを作製した。
　上記サンプルについて、粘弾性測定装置（Ｔ．Ａ．Ｉｎｓｔｒｕｍｅｎｔｓ社製，製品名「ＤＨＲ－２」）を用いて、測定治具：直径８ｍｍパラレルプレート、周波数：１Ｈｚ、測定温度：－５０～１５０℃、昇温速度：５℃／分にて動的粘弾性測定を行い、得られたデータから、－３０℃における損失正接（ｔａｎδ）の値を読みとった。 <Loss tangent (tan δ)>
The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were laminated to a thickness of about 0.9 mm, and punched into a circle with a diameter of 8 mm.
For the above sample, using a viscoelasticity measuring device (manufactured by TA Instruments, product name "DHR-2"), measurement jig: 8 mm diameter parallel plate, frequency: 1 Hz, measurement temperature: -50 to 150 ° C. , and the dynamic viscoelasticity measurement was performed at a heating rate of 5°C/min, and the value of the loss tangent (tan δ) at -30°C was read from the obtained data.
　＜ゲル分率＞
　実施例及び比較例で作製した各離型フィルム付き粘着シートから離型フィルムを取り除き、約０．１ｇの粘着シート片を採取した。
　採取した粘着シート片は、あらかじめ袋状にした質量（Ｘ）のＳＵＳメッシュ（＃１５０）に包み、袋の口を閉じてサンプルを作製して、当該サンプルの質量（Ｙ）を測定した。前記サンプルを酢酸エチルに浸漬させた状態で２３℃、２４時間暗所保管したのち、前記サンプルを取り出して７０℃で４．５時間加熱することで酢酸エチルを蒸発させ、乾燥させたサンプルの質量（Ｚ）を測定した。測定したそれぞれの質量を下記式によって、硬化前のゲル分率を算出した。
　ゲル分率（％）＝[（Ｚ－Ｘ）／（Ｙ－Ｘ）]×１００ <Gel fraction>
The release film was removed from each pressure-sensitive adhesive sheet with a release film produced in Examples and Comparative Examples, and about 0.1 g of pressure-sensitive adhesive sheet pieces were collected.
The collected adhesive sheet piece was wrapped in a bag-shaped SUS mesh (#150) having a mass (X), and the mouth of the bag was closed to prepare a sample, and the mass (Y) of the sample was measured. After the sample was immersed in ethyl acetate and stored in the dark at 23°C for 24 hours, the sample was taken out and heated at 70°C for 4.5 hours to evaporate the ethyl acetate. (Z) was measured. The gel fraction before curing was calculated from the measured masses according to the following formula.
Gel fraction (%) = [(Z - X) / (Y - X)] x 100
　実施例及び比較例で作製した離型フィルム付き粘着シートに対して、高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７では３０００ｍＪ／ｃｍ２、粘着シート５、９では４０００ｍＪ／ｃｍ２となるよう、離型フィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。硬化後の粘着シートについて、前記ゲル分率の評価手順と同様にして、活性エネルギー線硬化後のゲル分率を求めた。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、これを硬化後のゲル分率として測定に供した。 Using a high-pressure mercury lamp, the integrated light quantity at 365 nm was 3000 mJ/cm 2 for adhesive sheets 1 to 4 and 6 to 7, and for adhesive sheets 5 and 9. In , the adhesive sheet was irradiated with ultraviolet rays through the release film so as to be 4000 mJ/cm 2 to cure the adhesive sheet. With respect to the adhesive sheet after curing, the gel fraction after curing with active energy rays was obtained in the same manner as the gel fraction evaluation procedure described above.
In addition, the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing, so this is measured as the gel fraction after curing. provided.
　＜粘着力＞
　実施例及び比較例で作製した各離型フィルム付き粘着シートから、一方の離型フィルムを取り除き、裏打ちフィルムとしてポリエチレンテレフタレートフィルム（東洋紡績社製「コスモシャインＡ４３００」、厚さ１００μｍ）をハンドローラーにてロール圧着した。これを、１０ｍｍ幅×１５０ｍｍ長の短冊状に裁断し、残る離型フィルムを剥がして露出した粘着面を、ソーダライムガラスにハンドローラーを用いてロール貼着し、この積層体にオートクレーブ処理（６０℃、ゲージ圧０．２ＭＰａ、２０分）を施して仕上げ貼着し、粘着力測定サンプルを作製した。
　２３℃、４０％ＲＨにて、１８０°をなす角度に剥離速度３００ｍｍ／分にて引っ張りながら、ソーダライムガラスから裏打ちフィルムを剥離し、ロードセルで引張強度を測定して、ソーダライムガラスに対する粘着力（Ｎ／ｃｍ）を測定した。 <Adhesive strength>
One of the release films was removed from the pressure-sensitive adhesive sheets with release films prepared in Examples and Comparative Examples, and a polyethylene terephthalate film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., thickness 100 μm) was applied as a backing film to a hand roller. and roll crimped. This was cut into strips of 10 mm width × 150 mm length, the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. ° C., gauge pressure of 0.2 MPa, 20 minutes), and finished adhesion was performed to prepare an adhesive force measurement sample.
At 23 ° C. and 40% RH, while pulling at an angle of 180 ° at a peeling speed of 300 mm / min, the backing film was peeled from the soda lime glass, the tensile strength was measured with a load cell, and the adhesive strength to the soda lime glass. (N/cm) was measured.
　＜粘着力（貼合後硬化）＞
　実施例及び比較例で作製した各離型フィルム付き粘着シートから、一方の離型フィルムを取り除き、裏打ちフィルムとしてポリエチレンテレフタレートフィルム（東洋紡績社製「コスモシャインＡ４３００」、厚さ１００μｍ）をハンドローラーにてロール圧着した。これを、１０ｍｍ幅×１５０ｍｍ長の短冊状に裁断し、残る離型フィルムを剥がして露出した粘着面を、ソーダライムガラスにハンドローラーを用いてロール貼着し、この積層体にオートクレーブ処理（６０℃、ゲージ圧０．２ＭＰａ、２０分）を施して仕上げ貼着した。その後、高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７では３０００ｍＪ／ｃｍ２、粘着シート５、９では４０００ｍＪ／ｃｍ２となるよう、裏打ちフィルムを介して粘着シートに紫外線を照射して粘着シートを硬化させ、粘着力測定サンプルを作製した。
　２３℃４０％ＲＨにて、１８０°をなす角度に剥離速度３００ｍｍ／分にて引っ張りながら、ソーダライムガラスから裏打ちフィルムを剥離し、ロードセルで引張強度を測定して、活性エネルギー線硬化後における粘着シートのソーダライムガラスに対する１８０°剥離強度（Ｎ／ｃｍ）を測定し、粘着力（貼合後硬化）とした。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、本測定は行わなかった。 <Adhesive strength (curing after bonding)>
One of the release films was removed from the pressure-sensitive adhesive sheets with release films prepared in Examples and Comparative Examples, and a polyethylene terephthalate film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., thickness 100 μm) was applied as a backing film to a hand roller. and roll crimped. This was cut into strips of 10 mm width × 150 mm length, the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. ° C., gauge pressure of 0.2 MPa, 20 minutes) to finish pasting. After that, using a high-pressure mercury lamp, the pressure-sensitive adhesive sheets were placed through a backing film so that the integrated amount of light at 365 nm was 3000 mJ/cm 2 for pressure-sensitive adhesive sheets 1 to 4 and 6-7, and 4000 mJ/cm 2 for pressure-sensitive adhesive sheets 5 and 9. was irradiated with ultraviolet rays to cure the adhesive sheet, and an adhesive force measurement sample was produced.
At 23° C. and 40% RH, the backing film was peeled off from the soda lime glass while being pulled at an angle of 180° at a peeling speed of 300 mm/min, and the tensile strength was measured with a load cell. The 180° peel strength (N/cm) of the sheet against soda lime glass was measured and taken as adhesive strength (curing after lamination).
The pressure-sensitive adhesive sheet 8 produced in Comparative Example 1 was not subject to this measurement because the reaction due to light irradiation had sufficiently progressed and there was almost no room for active energy ray curing.
　＜粘着力（貼合前硬化）＞
　実施例及び比較例で作製した各離型フィルム付き粘着シートから、一方の離型フィルムを取り除き、裏打ちフィルムとしてポリエチレンテレフタレートフィルム（東洋紡績社製「コスモシャインＡ４３００」、厚さ１００μｍ）をハンドローラーにてロール圧着した。高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７では３０００ｍＪ／ｃｍ２、粘着シート５、９では４０００ｍＪ／ｃｍ２となるよう、裏打ちフィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、これを貼合前硬化したシートとして測定に供した。 <Adhesive strength (curing before bonding)>
One of the release films was removed from the pressure-sensitive adhesive sheets with release films prepared in Examples and Comparative Examples, and a polyethylene terephthalate film ("Cosmo Shine A4300" manufactured by Toyobo Co., Ltd., thickness 100 μm) was applied as a backing film to a hand roller. and roll crimped. Using a high-pressure mercury lamp, ultraviolet light was applied to the adhesive sheet through the backing film so that the integrated light intensity at 365 nm was 3000 mJ/cm 2 for adhesive sheets 1 to 4 and 6 to 7, and 4000 mJ/cm 2 for adhesive sheets 5 and 9. was irradiated to cure the adhesive sheet.
In the adhesive sheet 8 produced in Comparative Example 1, the reaction due to light irradiation has progressed sufficiently, and there is almost no room for active energy ray curing. provided.
　前記のように硬化させた粘着シートを、１０ｍｍ幅×１５０ｍｍ長の短冊状に裁断し、残る離型フィルムを剥がして露出した粘着面を、ソーダライムガラスにハンドローラーを用いてロール貼着し、この積層体にオートクレーブ処理（６０℃、ゲージ圧０．２ＭＰａ、２０分）を施して仕上げ貼着し、粘着力測定サンプルを作製した。
　２３℃４０％ＲＨにて、１８０°をなす角度に剥離速度３００ｍｍ／分にて引っ張りながら、ソーダライムガラスから裏打ちフィルムを剥離し、ロードセルで引張強度を測定して、活性エネルギー線硬化後における粘着シートのソーダライムガラスに対する１８０°剥離強度（Ｎ／ｃｍ）を測定し、粘着力（貼合前硬化）とした。 The adhesive sheet cured as described above was cut into strips with a width of 10 mm and a length of 150 mm, and the remaining release film was peeled off. This laminate was subjected to an autoclave treatment (60° C., gauge pressure 0.2 MPa, 20 minutes) and then finished and adhered to prepare an adhesive force measurement sample.
At 23° C. and 40% RH, the backing film was peeled off from the soda lime glass while being pulled at an angle of 180° at a peeling speed of 300 mm/min, and the tensile strength was measured with a load cell. The 180° peel strength (N/cm) of the sheet against soda lime glass was measured and taken as the adhesive strength (curing before lamination).
　＜段差吸収性＞
　５４ｍｍ×８２ｍｍ×厚さ０．５５ｍｍのソーダライムガラス上に、６ｍｍ×１００ｍｍ×厚さ５．４μｍのＰＥＴフィルムを１０ｍｍ間隔で２枚配置し、高低差５．４μｍの段差を有する凸状部を表面に形成してなる評価用基材とした。 <Step absorption>
Two pieces of PET film of 6 mm × 100 mm × thickness 5.4 μm are placed on a soda lime glass of 54 mm × 82 mm × thickness 0.55 mm at intervals of 10 mm, and a convex portion having a height difference of 5.4 μm is formed. It was used as a substrate for evaluation formed on the surface.
　実施例及び比較例で作製した各離型フィルム付き粘着シートを５ｃｍ×５ｃｍの大きさにカットし、一方の離型フィルムを剥離して露出した粘着面と、前記評価用基材の段差を有する側の表面を対向させ、プレス圧０．２ＭＰａ、３０秒の条件で真空貼合し、７０℃、気圧０．４５ＭＰａ、２０分の条件でオートクレーブ処理を行い、段差吸収性評価用積層体を作製した。 The pressure-sensitive adhesive sheet with a release film prepared in Examples and Comparative Examples was cut into a size of 5 cm × 5 cm, and the pressure-sensitive adhesive surface exposed by peeling one release film and the step of the evaluation substrate were provided. The side surfaces are opposed to each other, vacuum lamination is performed under the conditions of a press pressure of 0.2 MPa for 30 seconds, and an autoclave treatment is performed under the conditions of 70 ° C. and an air pressure of 0.45 MPa for 20 minutes to prepare a laminate for step absorption evaluation. did.
　作製した積層体を目視観察し、下記の評価基準で評価した。
　◎：全ての段差近傍で粘着シートが追従し気泡がなかった。
　○：段差近傍で発生する気泡が２ヵ所以下であった。
　×：段差近傍で３ヵ所以上粘着シートが追従せず気泡が発生した。 The produced laminate was visually observed and evaluated according to the following evaluation criteria.
⊚: The pressure-sensitive adhesive sheet followed in the vicinity of all steps, and there were no air bubbles.
Good: Two or less bubbles were generated near the step.
x: The pressure-sensitive adhesive sheet did not follow the surface at three or more locations near the step, and air bubbles were generated.
　＜段差吸収性（硬化後）＞
　実施例１～４で作製した離型フィルム付き粘着シートに対して、高圧水銀ランプを用いて、３６５ｎｍの積算光量が３０００ｍＪ／ｃｍ２となるよう、離型フィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。 <Step absorption (after curing)>
Using a high-pressure mercury lamp, the pressure-sensitive adhesive sheet with a release film prepared in Examples 1 to 4 was irradiated with ultraviolet light through the release film so that the integrated light intensity at 365 nm was 3000 mJ/cm 2 . and cured the adhesive sheet.
　前記のように硬化させた粘着シートの一方の離型フィルムを剥離して露出した粘着面と、前記評価用基材の段差を有する側の表面を対向させ、プレス圧０．２ＭＰａ、３０秒の条件で真空貼合し、７０℃、気圧０．４５ＭＰａ、２０分の条件でオートクレーブ処理を行った。前記の手順を紫外線照射処理後１０分以内に行い、硬化後の段差吸収性評価用積層体を作製した。作製した積層体を目視観察し、上記段差吸収性評価と同じ評価基準で評価した。 The pressure-sensitive adhesive surface exposed by peeling off one release film of the pressure-sensitive adhesive sheet cured as described above is opposed to the surface of the side having a step of the evaluation substrate, and the press pressure is 0.2 MPa for 30 seconds. Vacuum lamination was performed under the conditions of 70° C., atmospheric pressure of 0.45 MPa, and autoclave treatment for 20 minutes. The above procedure was performed within 10 minutes after the ultraviolet irradiation treatment to prepare a laminate for evaluation of step absorbability after curing. The produced laminate was visually observed and evaluated according to the same evaluation criteria as the step absorbability evaluation described above.
　[積層体の評価］
　実施例及び比較例で作製した離型フィルム付き粘着シートに対して、高圧水銀ランプを用いて、３６５ｎｍの積算光量が粘着シート１～４、６～７および参考例１の積層シートでは３０００ｍＪ／ｃｍ２、粘着シート５，９では４０００ｍＪ／ｃｍ２となるよう、離型フィルムを介して粘着シートに紫外線を照射し、粘着シートを硬化させた。
　なお、比較例１で作製した粘着シート８は、光照射による反応が十分進行しており、活性エネルギー線硬化の余地がほとんどない粘着シートであるため、上記の紫外線照射は行わず、屈曲性評価用の積層体サンプルとした。 [Evaluation of laminate]
Using a high-pressure mercury lamp, the integrated light quantity at 365 nm was 3000 mJ/cm for the adhesive sheets 1 to 4, 6 to 7 and the laminated sheet of Reference Example 1 for the adhesive sheets with release films prepared in Examples and Comparative Examples. 2. For the adhesive sheets 5 and 9, the adhesive sheets were cured by irradiating the adhesive sheets with ultraviolet rays through the release film so as to obtain 4000 mJ/cm 2 .
In addition, the adhesive sheet 8 produced in Comparative Example 1 is an adhesive sheet in which the reaction due to light irradiation has progressed sufficiently and there is almost no room for active energy ray curing. A laminate sample for
　各粘着シートの離型フィルムを取り除き、粘着シートの両面に透明ポリイミドフィルム（コーロン社製、厚み５０μｍ）をハンドロールによりロール貼合した。その後６０℃、気圧０．２ＭＰａ、２０分の条件でオートクレーブ処理を行い、屈曲性評価用の積層体サンプルとした。 The release film of each adhesive sheet was removed, and a transparent polyimide film (manufactured by Kolon Co., Ltd., thickness 50 μm) was rolled on both sides of the adhesive sheet with a hand roll. After that, autoclave treatment was performed under the conditions of 60° C., atmospheric pressure of 0.2 MPa, and 20 minutes to obtain a laminate sample for flexibility evaluation.
　＜動的屈曲性＞
　前記積層体サンプルを、恒温恒湿器内耐久システムと面状体無負荷Ｕ字伸縮試験機（ユアサシステム機器(株)製）を用いて、曲率半径Ｒ＝３ｍｍ、６０ｒｐｍ（１Ｈｚ）の設定にて、Ｕ字曲げのサイクル評価を行った。
　なお、参考例１の積層シートについては、他の粘着シートとしての粘着シート５側を内側として評価を行った。
　試験環境－２０℃又は６０℃、９０％ＲＨにおいて２０万回折り曲げ後、下記の評価基準で評価した。 <Dynamic Flexibility>
The laminate sample was set to a curvature radius R = 3 mm and 60 rpm (1 Hz) using a durability system in a constant temperature and humidity chamber and a planar body no-load U-shaped expansion tester (manufactured by Yuasa System Equipment Co., Ltd.). Then, cycle evaluation of U-shaped bending was performed.
The laminate sheet of Reference Example 1 was evaluated with the side of the adhesive sheet 5 as another adhesive sheet set inside.
After being bent 200,000 times in a test environment of −20° C. or 60° C. and 90% RH, evaluation was made according to the following evaluation criteria.
　○：屈曲部のデラミ、破断、座屈、流動のいずれも発生しなかった。
　×：屈曲部のデラミ、破断、座屈、流動の何れかが発生した。 ◯: None of delamination, breakage, buckling, and flow occurred at the bent portion.
x: Any of delamination, breakage, buckling, or flow occurred at the bent portion.
　＜静的屈曲性＞
　前記積層体サンプルを、曲率半径Ｒ＝３ｍｍにて屈曲し、６０℃、９０％ＲＨの条件で２４時間保管後、下記の評価基準で評価した。
　なお、参考例１の積層シートについては、他の粘着シートとしての粘着シート５を内側として曲率半径Ｒ＝３ｍｍにて屈曲した状態で試験を行った。
　○：屈曲部のデラミ、破断、座屈、流動のいずれも発生しなかった。
　×：屈曲部でデラミ・破断・座屈・流動の何れかが見られた。 <Static Flexibility>
The laminate sample was bent at a radius of curvature R of 3 mm, stored at 60° C. and 90% RH for 24 hours, and then evaluated according to the following evaluation criteria.
The laminated sheet of Reference Example 1 was tested in a state in which the pressure-sensitive adhesive sheet 5 as another pressure-sensitive adhesive sheet was positioned inside and bent at a radius of curvature R of 3 mm.
◯: None of delamination, breakage, buckling, and flow occurred at the bent portion.
x: Any of delamination, rupture, buckling, or flow was observed at the bent portion.
　粘着シートおよび積層体の測定、評価によって得られた結果を表１に示す。 Table 1 shows the results obtained by measuring and evaluating the adhesive sheet and laminate.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　実施例１－７の粘着シートは、段差吸収性試験において良好な貼合性を示し、復元性にも優れており、積層体とした際の屈曲性試験においても優れた耐久性を示した。さらに実施例１－４の粘着シートは、硬化させた後に貼合しても、段差吸収性試験において良好な貼合性を示した。
　参考例１の粘着シートも、優れた段差吸収性及び優れた屈曲耐久性を示した。
　一方、比較例１で作製した粘着シートは、高い流動性をもたない材料を使用しているため、２５℃３６００秒後のひずみが５０％以下であり、段差吸収性に劣るものであった。
　比較例２で作製した粘着シートは、硬化後の柔軟性が低い材料を使用しているため、活性エネルギー硬化後において２５℃２００％変形後の復元性に劣り、積層体とした時の屈曲耐久性にも劣るものであった。 The pressure-sensitive adhesive sheets of Examples 1-7 exhibited good bonding properties in the step absorption test, excellent restorability, and exhibited excellent durability in the bending test when formed into a laminate. Furthermore, the pressure-sensitive adhesive sheets of Examples 1-4 exhibited good lamination properties in the level difference absorption test even when laminated after being cured.
The pressure-sensitive adhesive sheet of Reference Example 1 also exhibited excellent step absorbability and excellent bending durability.
On the other hand, the pressure-sensitive adhesive sheet produced in Comparative Example 1 used a material that did not have high fluidity, so the strain after 3,600 seconds at 25°C was 50% or less, and the step absorbability was poor. .
The pressure-sensitive adhesive sheet prepared in Comparative Example 2 uses a material with low flexibility after curing, so it has poor restorability after 200% deformation at 25 ° C after curing with active energy, and bending durability when used as a laminate. It was inferior in terms of sex.

Claims (32)

  1. 　（メタ）アクリル系重合体（Ａ）を含む粘着剤層を備え、下記（１）～（３）の要件を満たす活性エネルギー線硬化性粘着シート。
    　（１）厚さ０．８ｍｍ～１．５ｍｍとし、温度２５℃にて１０００Ｐａの圧力を３６００秒印加した時の歪み（クリープ歪）が５０％以上である。
    　（２）厚さ０．８ｍｍ～１．５ｍｍとし、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後に、温度８０℃にて１０００Ｐａの圧力を１８０秒印加した時の歪み（クリープ歪）が１０％以上となる。
    　（３）波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の、下記式で表される２５℃２００％変形後の復元率が６０％以上となる。
    　復元率（％）＝｛（ｘ－ｙ）／ｘ｝×１００
    　（ｘは、厚さ０．８ｍｍ～１．５ｍｍとした粘着シートにせん断方向に印加する初期歪であり、ｙは初期歪を６００秒間印加した後、解放して６００秒経過後の残留歪である。）     An active energy ray-curable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A) and satisfying the following requirements (1) to (3).
    (1) It has a thickness of 0.8 mm to 1.5 mm and a strain (creep strain) of 50% or more when a pressure of 1000 Pa is applied at a temperature of 25° C. for 3600 seconds.
    (2) After irradiating an active energy ray with a wavelength of 365 nm with an integrated light amount of 2000 to 4000 mJ / cm 2 with a thickness of 0.8 mm to 1.5 mm, a pressure of 1000 Pa at a temperature of 80 ° C. is applied for 180 seconds. creep strain) becomes 10% or more.
    (3) When irradiated with an active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the recovery rate after 200% deformation at 25°C represented by the following formula is 60% or more.
    Restoration rate (%) = {(xy)/x} x 100
    (x is the initial strain applied in the shear direction to an adhesive sheet with a thickness of 0.8 mm to 1.5 mm, and y is the residual strain after 600 seconds after the initial strain was applied for 600 seconds and released. be.)
  2. 　前記（メタ）アクリル系重合体（Ａ）は、ブロック共重合体、及び／又はグラフト共重合体である、請求項１に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to claim 1, wherein the (meth)acrylic polymer (A) is a block copolymer and/or a graft copolymer.
  3. 　前記粘着シートを厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定した際に得られる損失正接の極大点が－２０℃以下である、請求項１又は２に記載の活性エネルギー線硬化性粘着シート。 3. According to claim 1 or 2, wherein the pressure-sensitive adhesive sheet has a thickness of 0.8 mm to 1.5 mm, and the maximum point of the loss tangent obtained when dynamic viscoelasticity is measured in a shear mode at a frequency of 1 Hz is -20 ° C. or less. The active energy ray-curable pressure-sensitive adhesive sheet described.
  4. 　前記（メタ）アクリル系重合体（Ａ）は、マクロモノマー由来の構造単位を含む共重合体である、請求項１～３の何れか一項に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the (meth)acrylic polymer (A) is a copolymer containing structural units derived from a macromonomer.
  5. 　前記マクロモノマーは、炭素数１～３の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレートが共重合されたマクロモノマーである、請求項１～４の何れか一項に記載のエネルギー線硬化性粘着シート。 The energy beam according to any one of claims 1 to 4, wherein the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 1 to 3 carbon atoms. Hardening adhesive sheet.
  6. 　前記マクロモノマーは、炭素数８～１８の直鎖もしくは分岐状のアルキル基を持つ（メタ）アクリレートが共重合されたマクロモノマーである、請求項１～４の何れか一項に記載のエネルギー線硬化性粘着シート。 The energy beam according to any one of claims 1 to 4, wherein the macromonomer is a macromonomer obtained by copolymerizing a (meth)acrylate having a linear or branched alkyl group having 8 to 18 carbon atoms. Hardening adhesive sheet.
  7. 　（メタ）アクリル系重合体（Ａ）は、マクロモノマーの共重合割合が２質量％以上３０質量％以下である請求項４～６の何れか一項に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 4 to 6, wherein the (meth)acrylic polymer (A) has a macromonomer copolymerization ratio of 2% by mass or more and 30% by mass or less.
  8. 　前記粘着剤層は、（メタ）アクリル系重合体（Ａ）、架橋剤（Ｂ）及び／又は重合開始剤（Ｃ）を含む粘着剤組成物から形成された層である、請求項１～７の何れか一項に記載の活性エネルギー線硬化性粘着シート。 Claims 1 to 7, wherein the pressure-sensitive adhesive layer is a layer formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A), a cross-linking agent (B) and/or a polymerization initiator (C). The active energy ray-curable pressure-sensitive adhesive sheet according to any one of .
  9. 　前記架橋剤（Ｂ）は、多官能（メタ）アクリレート（ｂ）である、請求項８に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to claim 8, wherein the cross-linking agent (B) is a polyfunctional (meth)acrylate (b).
  10. 　前記多官能（メタ）アクリレート（ｂ）の含有質量は、前記（メタ）アクリル系重合体（Ａ）１００質量部に対して０．５質量部以上１０質量部以下である、請求項９に記載の活性エネルギー線硬化性粘着シート。 10. The content of the polyfunctional (meth)acrylate (b) is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic polymer (A), according to claim 9 active energy ray-curable adhesive sheet.
  11. 　ゲル分率が０％以上２０％以下である、請求項１～１０の何れか一項に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 10, which has a gel fraction of 0% or more and 20% or less.
  12. 　波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時、照射前に比べてゲル分率が上昇し、該ゲル分率が１０％以上８５％以下となる、請求項１～１１の何れか一項に記載の活性エネルギー線硬化性粘着シート。 Claims 1 to 11, wherein when irradiated with an active energy ray having a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , the gel fraction increases compared to before irradiation, and the gel fraction is 10% or more and 85% or less. The active energy ray-curable pressure-sensitive adhesive sheet according to any one of .
  13. 　厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接が、－３０℃において、０．８以上である、請求項１～１２の何れか一項に記載のエネルギー線硬化性粘着シート。 Any one of claims 1 to 12, wherein the thickness is 0.8 mm to 1.5 mm, and the loss tangent obtained by dynamic viscoelasticity measurement in a shear mode with a frequency of 1 Hz is 0.8 or more at -30 ° C. The energy ray-curable pressure-sensitive adhesive sheet according to Item 1.
  14. 　下記の（４）及び（５）の特性をさらに有することを特徴とする、請求項１～１３の何れか一項に記載の活性エネルギー線硬化性粘着シート。
    　（４）ソーダライムガラス表面に対する、２３℃５０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における粘着力が１Ｎ／ｃｍ以上。
    　（５）粘着シートをソーダライムガラスに貼合した後、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した時の、２３℃５０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における前記ソーダライムガラス表面に対する粘着力が１Ｎ／ｃｍ以上。     The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 13, further comprising the following properties (4) and (5).
    (4) Adhesion to the surface of soda lime glass at 23°C, 50% RH, a peeling angle of 180°, and a peeling speed of 300 mm/min is 1 N/cm or more.
    (5) After laminating the adhesive sheet to soda lime glass, when irradiating an active energy ray with a wavelength of 365 nm at an integrated light amount of 2000 to 4000 mJ / cm 2 , 23 ° C. 50% RH, peeling angle 180 °, peeling speed 300 mm / The adhesive strength to the surface of the soda-lime glass in minutes is 1 N/cm or more.
  15. 　さらに、（６）の特性を有することを特徴とする、請求項１４に記載の活性エネルギー線硬化性粘着シート。
    　（６）波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後、該粘着シートをソーダライムガラスに貼合した時の、前記ソーダライムガラス表面に対する、２３℃４０％ＲＨ、剥離角１８０°、剥離速度３００ｍｍ／分における粘着力が１Ｎ／ｃｍ以上。     15. The active energy ray-curable pressure-sensitive adhesive sheet according to claim 14, further having the property (6).
    (6) After irradiating an active energy ray with a wavelength of 365 nm in an integrated light amount of 2000 to 4000 mJ/cm 2 , when the adhesive sheet is laminated to soda lime glass, peeling at 23 ° C. and 40% RH against the soda lime glass surface. Adhesive strength of 1 N/cm or more at an angle of 180° and a peeling speed of 300 mm/min.
  16. 　厚みが１５μｍ以上５０μｍ以下である、請求項１～１５の何れか一項に記載の活性エネルギー線硬化性粘着シート。 The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 15, which has a thickness of 15 µm or more and 50 µm or less.
  17. 　請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートと、離型フィルムとが積層してなる構成を備えた離型フィルム付き粘着シート。 A pressure-sensitive adhesive sheet with a release film having a configuration in which the active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 16 and a release film are laminated.
  18. 　前記離型フィルムが、ポリエステル系フィルムであり、波長３６５ｎｍの活性エネルギー線を積算光量２０００～４０００ｍＪ／ｃｍ２照射した後の前記活性エネルギー線硬化性粘着シートに対する剥離力が、剥離角１８０°、剥離速度３００ｍｍ／分において０．１Ｎ／ｃｍ以下となる、請求項１７記載の離型フィルム付き粘着シート。 The release film is a polyester-based film, and after irradiation with an active energy ray having a wavelength of 365 nm with an accumulated light amount of 2000 to 4000 mJ/cm 2 , the peeling force against the active energy ray-curable adhesive sheet is a peeling angle of 180 °, peeling. 18. The pressure-sensitive adhesive sheet with a release film according to claim 17, which is 0.1 N/cm or less at a speed of 300 mm/min.
  19. 　離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とが、請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートを介して積層してなる構成を備えた、積層体。 A release film and a member for constituting an image display device having a step with a height difference of 2 μm or more on the surface to be laminated are laminated via the active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 16. A laminate having a structure formed by:
  20. 　離型フィルムと、高低差２μｍ以上の段差を被積層面に有する画像表示装置構成用部材とを、請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートを介して積層し、前記離型フィルム側から該離型フィルムを通して前記粘着シートに活性エネルギー線照射を行う、積層体の製造方法。 A release film and a member for constituting an image display device having a step with a height difference of 2 μm or more on the surface to be laminated are laminated via the active energy ray-curable adhesive sheet according to any one of claims 1 to 16. and irradiating the adhesive sheet with an active energy ray through the release film from the release film side.
  21. 　請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートと、他の粘着シートとが積層してなる構成を備えた、積層シート。 A laminated sheet having a configuration in which the active energy ray-curable adhesive sheet according to any one of claims 1 to 16 and another adhesive sheet are laminated.
  22. 　前記他の粘着シートが、ゲル分率が７０％以上であり、厚さ０．８ｍｍ～１．５ｍｍとし、周波数１Ｈｚの剪断モードで動的粘弾性測定により得られる損失正接の極大点が－２５℃以下である、請求項２１に記載の積層シート。 The other pressure-sensitive adhesive sheet has a gel fraction of 70% or more, a thickness of 0.8 mm to 1.5 mm, and a maximum point of loss tangent obtained by dynamic viscoelasticity measurement in a shear mode at a frequency of 1 Hz is -25. °C or less, the laminated sheet according to claim 21.
  23. 　２つの画像表示装置構成用部材が、請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートを介して積層してなる構成を備え、
    　前記画像表示装置構成用部材の少なくとも一方が、前記粘着シートとの接触面に、高低差２μｍ以上の段差を有する画像表示装置用積層体。     Two image display device constituent members are laminated via the active energy ray-curable adhesive sheet according to any one of claims 1 to 16,
    A layered product for an image display device, wherein at least one of the members constituting the image display device has a step with a height difference of 2 μm or more on the contact surface with the pressure-sensitive adhesive sheet.
  24. 　前記画像表示装置構成用部材の少なくとも一方が、ウレタン樹脂、シクロオレフィン樹脂、トリアセチルセルロース樹脂、（メタ）アクリレート樹脂、エポキシ樹脂及びポリイミド樹脂からなる群から選択される一種若しくは二種以上の樹脂を主成分とする樹脂シート又は薄膜ガラスである、請求項２３に記載の画像表示装置用積層体。 At least one of the image display device constituent members contains one or more resins selected from the group consisting of urethane resins, cycloolefin resins, triacetylcellulose resins, (meth)acrylate resins, epoxy resins and polyimide resins. 24. The laminate for an image display device according to claim 23, which is a resin sheet or thin glass as a main component.
  25. 　請求項２３又は２４に記載の積層体を備えたフレキシブル画像表示装置。 A flexible image display device comprising the laminate according to claim 23 or 24.
  26. 　（メタ）アクリル系重合体（Ａ）を含む粘着剤層を備えたフレキシブルディスプレイ用粘着シートであって、
    　厚さが１５μｍ以上５０μｍ以下であり、
    　活性エネルギー線硬化性を有し、高低差が２～１０μｍの段差を１０ｍｍ以下の間隔で有する画像表示装置構成用部材に下記貼合条件で貼り合せたときに、前記段差の周囲に発泡が無いことを特徴とするフレキシブルディスプレイ用粘着シート。
    　（貼合条件）
    　ａ）厚み１５～５０μｍの粘着シートに、３６５ｎｍの積算光量が２０００～４０００ｍＪ／ｃｍ２となるよう紫外線を照射する。
    　ｂ）高低差２～１０μｍの段差を１０ｍｍ以下の間隔で有する基材の表面に、前記粘着シートを、プレス圧０．２ＭＰａ、３０秒の条件で真空貼合する。
    　ｃ）７０℃、気圧０．４５ＭＰａ、２０分の条件でオートクレーブ処理を行う。     A pressure-sensitive adhesive sheet for a flexible display, comprising a pressure-sensitive adhesive layer containing a (meth)acrylic polymer (A),
    The thickness is 15 μm or more and 50 μm or less,
    When a member for constituting an image display device having active energy ray curability and having steps with a height difference of 2 to 10 μm at intervals of 10 mm or less is laminated under the following bonding conditions, there is no foaming around the steps. An adhesive sheet for a flexible display, characterized by:
    (Lamination conditions)
    a) A pressure-sensitive adhesive sheet having a thickness of 15 to 50 μm is irradiated with ultraviolet rays so that the integrated amount of light at 365 nm is 2000 to 4000 mJ/cm 2 .
    b) The pressure-sensitive adhesive sheet is vacuum-bonded to the surface of a substrate having steps with height differences of 2 to 10 μm at intervals of 10 mm or less under conditions of a press pressure of 0.2 MPa and 30 seconds.
    c) Perform autoclave treatment under conditions of 70° C., atmospheric pressure of 0.45 MPa, and 20 minutes.
  27. 　２つの画像表示装置構成用部材１、２が、活性エネルギー線硬化性粘着シートを介して積層されてなる構成を備えた画像表示装置構成用積層体の製造方法であって、
    　以下の工程１～３を有し、工程１および２を行った後、工程３を行うことを特徴とする、画像表示装置用積層体の製造方法。
    　工程１：画像表示装置構成用部材１に、請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートの一方の表面を貼合する。
    　工程２：活性エネルギー線を照射して、請求項１～１６の何れか一項に記載の活性エネルギー線硬化性粘着シートを硬化させる。
    　工程３：前記粘着シートの他方の表面に画像表示装置構成用部材２を貼合して積層体とする。     A method for producing a laminate for constituting an image display device having a configuration in which two image display device constituting members 1 and 2 are laminated via an active energy ray-curable adhesive sheet, the method comprising:
    A method for producing a laminate for an image display device, comprising the following steps 1 to 3, wherein step 3 is performed after steps 1 and 2 are performed.
    Step 1: One surface of the active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 16 is adhered to the member 1 for constituting an image display device.
    Step 2: The active energy ray-curable pressure-sensitive adhesive sheet according to any one of claims 1 to 16 is cured by irradiation with an active energy ray.
    Step 3: The image display device constituting member 2 is adhered to the other surface of the pressure-sensitive adhesive sheet to form a laminate.
  28. 　前記工程３において、５０℃以上８０℃以下に前記粘着シートを加熱してホットメルトさせながら画像表示装置構成用部材２を貼合して積層体とする、請求項２７に記載の画像表示装置用積層体の製造方法。 28. The image display device according to claim 27, wherein in said step 3, said pressure-sensitive adhesive sheet is heated to 50° C. or more and 80° C. or less to hot-melt it, and said image display device-constituting member 2 is laminated to form a laminate. A method for manufacturing a laminate.
  29. 　前記工程３の後、さらに、前記積層体に加熱処理を施して前記粘着シートをホットメルトさせる工程４を有する、請求項２７又は２８に記載の画像表示装置用積層体の製造方法。 The method for producing a laminate for an image display device according to claim 27 or 28, further comprising a step 4 of heat-treating the laminate to hot-melt the adhesive sheet after the step 3.
  30. 　前記工程４において、前記加熱処理では、前記積層体を温度４０℃以上９０℃以下に加熱すると共に、０．２ＭＰａ以上０．８ＭＰａ以下の気圧を５分間以上加えることを特徴とする、請求項２９に記載の画像表示装置用積層体の製造方法。 30. In said step 4, said heat treatment includes heating said laminate to a temperature of 40° C. or more and 90° C. or less and applying an air pressure of 0.2 MPa or more and 0.8 MPa or less for 5 minutes or more. The method for producing the laminate for an image display device according to 1.
  31. 　前記工程１～４は、工程１，２，３，４の順に実施する、請求項２９又は３０に記載の画像表示装置用積層体の製造方法。 The method for producing a laminate for an image display device according to claim 29 or 30, wherein the steps 1 to 4 are performed in the order of steps 1, 2, 3 and 4.
  32. 　画像表示装置構成用部材１又は画像表示装置構成用部材２の少なくとも一方が、前記粘着シートとの接触面に、高低差２μｍ以上の段差を有することを特徴とする請求項２７～３１の何れか一項に記載の画像表示装置用積層体の製造方法。 32. Any one of claims 27 to 31, wherein at least one of the image display device constituting member 1 and the image display device constituting member 2 has a step with a height difference of 2 μm or more on a contact surface with the adhesive sheet. A method for producing the laminate for an image display device according to item 1.
PCT/JP2021/048543 2021-01-27 2021-12-27 Active energy ray curable adhesive sheet, adhesive sheet equipped with mold release film, laminate, production method for laminate, laminated sheet, laminate for image display devices, flexible image display device ,adhesive sheet for flexible displays, and production method for laminate for image display devices WO2022163281A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2022578190A JPWO2022163281A1 (en) 2021-01-27 2021-12-27
CN202180091745.1A CN116806245A (en) 2021-01-27 2021-12-27 Active energy ray-curable adhesive sheet, adhesive sheet with release film, laminate, method for producing laminate, laminate for image display device, flexible image display device, adhesive sheet for flexible display, and method for producing laminate for image display device
KR1020237019425A KR20230136732A (en) 2021-01-27 2021-12-27 Active energy ray-curable adhesive sheet, adhesive sheet with release film, laminate, manufacturing method of laminate, laminated sheet, laminate for image display device, flexible image display device, adhesive sheet for flexible display, and lamination for image display device Sieve manufacturing method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021-011199 2021-01-27
JP2021011199 2021-01-27

Publications (1)

Publication Number Publication Date
WO2022163281A1 true WO2022163281A1 (en) 2022-08-04

Family

ID=82654571

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/048543 WO2022163281A1 (en) 2021-01-27 2021-12-27 Active energy ray curable adhesive sheet, adhesive sheet equipped with mold release film, laminate, production method for laminate, laminated sheet, laminate for image display devices, flexible image display device ,adhesive sheet for flexible displays, and production method for laminate for image display devices

Country Status (5)

Country Link
JP (1) JPWO2022163281A1 (en)
KR (1) KR20230136732A (en)
CN (1) CN116806245A (en)
TW (1) TW202239915A (en)
WO (1) WO2022163281A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023054218A1 (en) * 2021-09-28 2023-04-06 三菱ケミカル株式会社 Actinic-ray-curable pressure-sensitive adhesive sheet, pressure-sensitive adhesive sheet laminate with release film, laminate for constituting image display device, image display device, and method for producing laminate for constituting image display device
WO2024111438A1 (en) * 2022-11-22 2024-05-30 三菱ケミカル株式会社 Transparent adhesive sheet, release film-provided transparent adhesive sheet, transparent adhesive sheet for member constituting flexible image display device, laminate for image display device, and flexible image display device

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015105296A (en) * 2013-11-29 2015-06-08 三菱樹脂株式会社 Tacky agent resin composition
JP2016222915A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Adhesive sheet and picture display unit using the same
JP2016222914A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Photosetting adhesive sheet, adhesive sheet and image display device
JP2016222916A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Adhesive sheet
JP2017095658A (en) * 2015-11-27 2017-06-01 三星エスディアイ株式会社Samsung SDI Co., Ltd. Adhesive composition, optical member and adhesive sheet
JP2017155213A (en) * 2016-02-29 2017-09-07 三菱ケミカル株式会社 Transparent double-sided adhesive sheet and adhesive sheet laminate
JP2017173479A (en) * 2016-03-23 2017-09-28 三菱ケミカル株式会社 Laminate for image display device configuration, and method for manufacturing image display device
WO2018173896A1 (en) * 2017-03-23 2018-09-27 三菱ケミカル株式会社 Double-sided pressure-sensitive adhesive sheet, laminate comprising component member for image display device, kit for laminate formation, and use of double-sided pressure-sensitive adhesive sheet
JP2019173003A (en) * 2018-03-27 2019-10-10 Dic株式会社 Manufacturing method of laminate containing adhesive sheet

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7081927B2 (en) 2018-01-18 2022-06-07 リンテック株式会社 Adhesives for repetitive bending devices, adhesive sheets, repetitive bending laminated members and repetitive bending devices

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015105296A (en) * 2013-11-29 2015-06-08 三菱樹脂株式会社 Tacky agent resin composition
JP2016222915A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Adhesive sheet and picture display unit using the same
JP2016222914A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Photosetting adhesive sheet, adhesive sheet and image display device
JP2016222916A (en) * 2015-06-02 2016-12-28 三菱樹脂株式会社 Adhesive sheet
JP2017095658A (en) * 2015-11-27 2017-06-01 三星エスディアイ株式会社Samsung SDI Co., Ltd. Adhesive composition, optical member and adhesive sheet
JP2017155213A (en) * 2016-02-29 2017-09-07 三菱ケミカル株式会社 Transparent double-sided adhesive sheet and adhesive sheet laminate
JP2017173479A (en) * 2016-03-23 2017-09-28 三菱ケミカル株式会社 Laminate for image display device configuration, and method for manufacturing image display device
WO2018173896A1 (en) * 2017-03-23 2018-09-27 三菱ケミカル株式会社 Double-sided pressure-sensitive adhesive sheet, laminate comprising component member for image display device, kit for laminate formation, and use of double-sided pressure-sensitive adhesive sheet
JP2019173003A (en) * 2018-03-27 2019-10-10 Dic株式会社 Manufacturing method of laminate containing adhesive sheet

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023054218A1 (en) * 2021-09-28 2023-04-06 三菱ケミカル株式会社 Actinic-ray-curable pressure-sensitive adhesive sheet, pressure-sensitive adhesive sheet laminate with release film, laminate for constituting image display device, image display device, and method for producing laminate for constituting image display device
WO2024111438A1 (en) * 2022-11-22 2024-05-30 三菱ケミカル株式会社 Transparent adhesive sheet, release film-provided transparent adhesive sheet, transparent adhesive sheet for member constituting flexible image display device, laminate for image display device, and flexible image display device

Also Published As

Publication number Publication date
KR20230136732A (en) 2023-09-26
CN116806245A (en) 2023-09-26
JPWO2022163281A1 (en) 2022-08-04
TW202239915A (en) 2022-10-16

Similar Documents

Publication Publication Date Title
JP7491342B2 (en) Double-sided pressure-sensitive adhesive sheet, laminate having components for constituting an image display device, laminate forming kit, and use of the double-sided pressure-sensitive adhesive sheet
JP5552338B2 (en) Adhesive composition, adhesive and adhesive sheet
JP7197255B2 (en) Transparent double-sided adhesive sheet and adhesive sheet laminate
JP6558287B2 (en) Image display device laminate and image display device manufacturing method
JPWO2012032995A1 (en) Manufacturing method of laminated body for constituting image display apparatus, and image display apparatus using this laminated body
WO2022163281A1 (en) Active energy ray curable adhesive sheet, adhesive sheet equipped with mold release film, laminate, production method for laminate, laminated sheet, laminate for image display devices, flexible image display device ,adhesive sheet for flexible displays, and production method for laminate for image display devices
JP2020105525A (en) Photocurable adhesive sheet, adhesive sheet and image display device
JP7282687B2 (en) OPTICAL TRANSPARENT ADHESIVE SHEET, COMPOSITION FOR MANUFACTURING THE SAME AND FLAT DISPLAY DEVICE USING THE SAME
TW201920565A (en) Photocurable pressure-sensitive adhesive sheet, photocurable pressure-sensitive adhesive sheet laminate, production method for photocurable pressure-sensitive adhesive sheet laminate, and production method for image display panel laminate
WO2020122229A1 (en) Adhesive agent resin composition, adhesive agent resin cured article, adhesive sheet, and image display device stack
JP5889365B2 (en) Adhesive composition, adhesive and adhesive sheet
JP2022144651A (en) Adhesive sheet, laminate sheet, flexible image display device and flexible image display device member
JP7415366B2 (en) Photocurable adhesive sheets, adhesive sheet laminates, laminates for image display devices, and image display devices
JP7484104B2 (en) Photocurable adhesive sheet, laminate for image display device, and image display device
JP7278967B2 (en) Optical transparent adhesive sheet
JP7251073B2 (en) Adhesive sheet, adhesive sheet with release sheet, laminate, and method for producing laminate
JP6724956B2 (en) Adhesive sheet, adhesive sheet with release sheet, laminate and method for producing laminate
WO2023120136A1 (en) Adhesive sheet with release film, laminate for flexible image display device, flexible image display device, and adhesive sheet
TWI842162B (en) Light-curing adhesive sheet
JPWO2018105413A1 (en) Adhesive sheet and method for producing the same
WO2023054218A1 (en) Actinic-ray-curable pressure-sensitive adhesive sheet, pressure-sensitive adhesive sheet laminate with release film, laminate for constituting image display device, image display device, and method for producing laminate for constituting image display device
WO2023188926A1 (en) Double-sided adhesive sheet, multilayer body for constituting image display device, and image display device
JP6747475B2 (en) Adhesive sheet, adhesive sheet with release sheet, laminate and method for producing laminate
WO2022158121A1 (en) Adhesive sheet curable by active energy rays, adhesive sheet laminate that includes release film, adhesive sheet, laminate for configuring image display device, and image display device
WO2024111438A1 (en) Transparent adhesive sheet, release film-provided transparent adhesive sheet, transparent adhesive sheet for member constituting flexible image display device, laminate for image display device, and flexible image display device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21923284

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022578190

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 202180091745.1

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21923284

Country of ref document: EP

Kind code of ref document: A1