CN116034019A - Transfer medium laminate, polarizing film, and method for producing same - Google Patents
Transfer medium laminate, polarizing film, and method for producing same Download PDFInfo
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- CN116034019A CN116034019A CN202180055913.1A CN202180055913A CN116034019A CN 116034019 A CN116034019 A CN 116034019A CN 202180055913 A CN202180055913 A CN 202180055913A CN 116034019 A CN116034019 A CN 116034019A
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- layer
- hard coat
- transfer medium
- resin
- polarizing film
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
- B32B7/023—Optical properties
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- 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
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- 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]
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/14—Protective coatings, e.g. hard coatings
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
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- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Laminated Bodies (AREA)
- Polarising Elements (AREA)
Abstract
A transfer medium laminate comprising a hard coat layer and a resin layer (A) provided on one surface of the hard coat layer, wherein the hard coat layer has stretchability and the resin constituting the resin layer has a storage modulus of 1000MPa or less. The resin layer (a) preferably contains an ultraviolet absorber. The hard coat layer is preferably a semi-cured product of a hard coat material, and the resin layer (a) is preferably a layer formed on the surface of the semi-cured product. The invention also provides a polarizing film having the transfer medium laminate, a method for producing the same, and a method for producing a molded body using the polarizing film.
Description
Technical Field
The present invention relates to a transfer medium laminate, a polarizing film, a method for producing a polarizing film, and a method for producing a molded body using a polarizing film.
Background
In display devices such as liquid crystal display devices and organic electroluminescence display devices, films functioning as line polarizers are provided for various purposes. The linear polarizer is often a thin layered material with weak mechanical strength, and is therefore generally used in the state of a polarizing film having a polarizer and a protective film. For the purpose of improving scratch resistance and the like of the surface of the display device, the polarizing film is sometimes further provided with a hard coat layer. The hard coat layer is often formed by applying a liquid hard coat material for forming the hard coat layer on the surface of a molded body to be formed and curing the material. However, a laminate including a hard coat layer may be formed on the surface of a member other than the object to be formed, and transferred to the surface of a molded body (for example, patent documents 1 and 2).
Prior art literature
Patent literature
Patent document 1: japanese patent application laid-open No. 2014-130298;
patent document 2: international publication No. 2019/087806 (corresponding publication: U.S. patent application publication No. 2021/109268).
Disclosure of Invention
Problems to be solved by the invention
Conventionally, the display surface of the display device has only a flat shape, but in recent years, a display device having a curved display surface has been demanded. If the hard coat layer can be transferred to such a curved surface, improvement in manufacturing efficiency can be expected. In particular, if a polarizing film having a hard coat layer can be laminated to provide the polarizing film and the hard coat layer at the same time, further improvement in manufacturing efficiency can be expected.
However, if a film having a hard coat layer is to be bonded to a curved surface, there is a problem that cracks are generated. Further, the polarizing film having the hard coat layer has a problem that curling is easily generated and handling is difficult in a state before lamination.
Accordingly, an object of the present invention is to provide a polarizing film and a material constituting the polarizing film, which have high follow-up property to a curved surface, are easy to attach to the curved surface, and are suppressed in occurrence of curling, a method for producing the same, and a method for producing a molded article using the same.
Solution for solving the problem
The present inventors have studied to solve the above problems, and as a result, have found that the above problems can be solved by constituting a transfer medium laminate as a combination of a hard coat layer and a resin layer having specific physical properties, and have completed the present invention. Namely, the present invention provides the following.
[1] A transfer medium laminate having a hard coat layer and a resin layer (A) provided on one surface of the hard coat layer,
the hard coat layer has a stretchability such that,
the storage modulus of the resin constituting the resin layer is 1000MPa or less.
[2] The transfer medium laminate according to [1], wherein the resin layer (A) has a thickness of 0.1 μm or more and 10 μm or less.
[3] The transfer medium laminate according to [1] or [2], wherein the resin layer (A) contains an ultraviolet absorber.
[4] The transfer medium laminate according to any one of [1] to [3], wherein the hard coat layer is a semi-cured product of a hard coat material, and the resin layer (A) is a layer formed on the surface of the semi-cured product.
[5] The transfer medium laminate according to any one of [1] to [4], wherein a retardation Re in an in-plane direction of the resin layer is 0nm or more and 5nm or less.
[6] The transfer medium laminate according to any one of [1] to [5], wherein the transfer medium laminate further comprises a support provided on a surface of the hard coat layer on the opposite side from the resin layer (A) side.
[7] The transfer medium laminate according to [6], wherein the support has a release layer provided on the surface of the hard coat layer side.
[8] A method for producing a transfer medium laminate according to any one of [1] to [7], comprising:
a step of spreading a hard coating material on the surface of the support;
a step of semi-curing the hard coat material to form a hard coat layer having stretchability; and
and a step of developing a resin on the hard coat layer to form a resin layer (A) having a storage modulus of 1000MPa or less.
[9] A polarizing film, comprising: [1] the transfer medium laminate of any one of [7 ];
a polarizer layer provided on the resin layer (a) side of the transfer medium laminate; and
and an adhesive layer interposed between the transfer medium laminate and the polarizer layer.
[10] A method for manufacturing a polarizing film, the polarizing film comprising: [1] the transfer medium laminate of any one of [7 ];
A polarizer layer provided on the resin layer (a) side of the transfer medium laminate; and
an adhesive layer interposed between the transfer medium laminate and the polarizer layer,
the resin layer (A) contains an ultraviolet absorber,
the method for manufacturing the polarizing film comprises the following steps: a step of bonding the transfer medium laminate and the polarizer layer to each other via an ultraviolet-curable adhesive to form a bonded product; and
and irradiating the adherend with ultraviolet light from the polarizer layer side of the adherend.
[11] A method for producing a molded article with a polarizer layer, the method comprising:
a step (A) of producing a polarizing film by the production method described in [10 ];
a step (B) of bonding the polarizing film to a base member; and
a step (C) of curing (main curing) the hard coat layer in the polarizing film,
the base member used in the step (B) may be a member having a curved surface, or may further include a step (Bx) of bending the base member after the step (B) and before the step (C).
Effects of the invention
According to the present invention, it is possible to provide a polarizing film which is easily bonded to a curved surface and is suppressed in occurrence of curling, and a transfer medium laminate constituting the polarizing film. According to the present invention, there are also provided a method for producing such a polarizing film, and a method for easily producing a molded body using such a polarizing film, which can be used as a constituent element of a display device having a curved display surface.
Detailed Description
Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and can be arbitrarily modified and implemented within the scope not departing from the scope of the claims and the equivalents thereof.
In the following description, "solution", "solvent" includes not only a solution in which a solute is dissolved in a solvent and a medium therein, but also those in which other substances are contained in a liquid-like medium in a broad sense and mediums therein. For example, the term "solution" includes a dispersion in which a solid particulate dispersoid is dispersed in a liquid dispersion medium, and an emulsion in which a liquid particulate discontinuous phase is dispersed in a liquid continuous phase.
In the following description, the expressions "(meth) acrylate", "(meth) acryl", "(meth) acrylic" include a substance related to an acrylic group, a substance related to a methacrylic group, and a mixture thereof. For example, "(meth) acrylate" is a representation that includes acrylates, methacrylates, and mixtures thereof.
In the following description, a "long film" refers to a film having a length of 5 times or more, preferably 10 times or more, the width of the film, and specifically, a film having a length of a degree that can be stored or transported in a roll form. The upper limit of the ratio of the length to the width of the film is not particularly limited, and may be 100000 times or less, for example.
In the following description, unless otherwise indicated, the adhesive includes not only an adhesive in a narrow sense but also an adhesive having a shear storage modulus at 23 ℃ of less than 1MPa (an adhesive capable of being used as a pressure-sensitive adhesive). The adhesive in the narrow sense is an adhesive having a shear storage modulus of 1MPa to 500MPa at 23℃after irradiation with energy rays or after heat treatment.
In the following description, unless otherwise specified, the in-plane retardation Re of a certain film is a value represented by re= (nx-ny) ×d. Here, nx denotes a refractive index in a direction (in-plane direction) giving a maximum refractive index in a direction perpendicular to the thickness direction of the film. ny represents a refractive index in a direction perpendicular to the direction of nx in the in-plane direction of the film. d represents the thickness of the film. Unless otherwise indicated, the measurement wavelength was 550nm.
[1. Transfer Medium laminate and outline of method for producing the same ]
In the present invention, the transfer medium laminate is a laminate including a hard coat layer, and is a laminate for realizing transfer of the hard coat layer by bonding to the surface of a solid molded body. The transfer medium laminate of the present invention has a hard coat layer and a resin layer (a) provided directly or via another layer on one surface of the hard coat layer. The transfer medium laminate of the present invention may further include a support provided on a surface of the hard coat layer opposite to the resin layer (a) side as an optional constituent element.
The transfer medium laminate of the present invention can be produced by any production method, and examples of a preferred production method include the following steps. Hereinafter, this method will be described as a method for producing a transfer medium laminate of the present invention.
Step (1): and a step of spreading the hard coating material on the surface of the support.
Step (2): and a step of semi-curing the hard coat material to form a hard coat layer having stretchability.
Step (3): and a step of developing the resin on the hard coat layer to form a resin layer (A) having a storage modulus of 1000MPa or less.
[2. Support body ]
As the support, any member having a surface suitable for forming a hard coat layer can be used. In the final product (display device, or molded body with polarizer layer constituting the display device, etc.), the support may remain as a part thereof, and in general, the support may be peeled off and removed in the step after the step (3) until the final product is obtained.
The support may be a resin film in general. Examples of the resin constituting the support include resins containing a general-purpose polymer such as polypropylene (PP) and polyethylene terephthalate (PET) as a main component.
When the support and the hard coat layer are peeled off in the step subsequent to the step (3), a film having a surface treated to facilitate the peeling can be preferably used as the support. Specifically, a film having a surface treated with silicone for peeling can be used. Further, the biaxially stretched film may have a surface texture suitable for peeling, and thus such a film is also preferable as a support.
The surface of the support is usually a flat surface, but not limited to this, and a concave-convex structure formed by, for example, shape transfer of an embossing roller may be provided on the surface of the support. By providing the surface of the support with the uneven structure, the uneven structure can be transferred to the hard coat layer, whereby an antiglare function and/or a reflection reducing function can be imparted to the surface of the hard coat layer.
The support may have any layer such as an antistatic layer, an antireflection layer, and a release layer on the surface thereof. The arbitrary layer may be removed together with the support when the support is peeled off, or may remain in the product. In particular, the support has a release layer provided on the surface of the hard coat layer side in addition to the layer having the resin, and thus the support and the hard coat layer can be easily peeled off.
The thickness of the support can be appropriately adjusted to a desired range. Specifically, the thickness of the support is preferably 20 μm or more, more preferably 30 μm or more, and on the other hand, preferably 80 μm or less, more preferably 60 μm or less.
[3. Hard coating ]
The hard coat layer in the transfer medium laminate of the present invention has stretchability. In the present invention, the stretchability of the hard coat layer means that when the hard coat layer is uniaxially stretched as a separate film, the stretching can be performed 1.50 times or more without causing cracks. More specifically, the hard coat layer as an independent film was formed into a rectangular shape having a length of 150mm and a width of 20mm, and was uniaxially stretched to a magnification of 1.50 times or more in the longitudinal direction, and the presence or absence of occurrence of cracks was observed, whereby the presence or absence of stretchability was determined. If no crack is generated at the time when the stretch ratio is 1.50 times, it can be determined that the sheet has stretchability. By having such stretchability, the transfer medium laminate and the polarizing film can have improved following properties with respect to a curved surface.
In the final product, the hard coat layer has a hardness higher than that of the resin layer (a), and can have a function of suppressing the occurrence of damage on the surface of the resin layer (a). The hard coat layer in the final product preferably has a hardness of "HB" or more in the pencil hardness test defined in JIS K5600-5-4. In addition, the hard coat layer at this time preferably has high scratch resistance. Specifically, it is preferable to have scratch resistance of the following degree: the steel wool #0000 was pressed against the hard coat layer under a load of 0.025Mpa to reciprocate 10 times on the surface of the hard coat layer, and no flaw was visually recognized when observation was performed. The hard coat layer may have an antiglare function and/or a reflection reducing function.
The hard coat layer in the transfer medium laminate can be a semi-solid of the hard coat material. In the present invention, the hard coat material means a material capable of forming a hard coat layer by curing. The "semi-cured product" of the hard coat material is a material which is cured as compared with the hard coat material before curing, but which can be brought into a state of a material having higher hardness by further processing (for example, ultraviolet irradiation or the like) after that. On the other hand, a substance having a hardness increased to a level that gives a desired property such as hardness of the final product is referred to as a "primary cured product".
The hard coat layer material may be a material containing a polymerizable substance (H) as a main component and an optional component which may be contained as needed. As the polymerizable material (H), various polymerizable materials capable of imparting a desired hardness to the hard coat layer in the final product can be used.
Specific examples of the polymerizable material (H) include polyfunctional (meth) acrylates.
The weight average molecular weight of the polyfunctional (meth) acrylate is preferably 10000 or more, and more preferably 100000 or less. The weight average molecular weight of each (meth) acryloyl group of the polyfunctional (meth) acrylate is preferably 200 or more, and more preferably 400 or less. By having this molecular weight, synthesis becomes easy, good performance of the hard coat layer can be obtained and handling of the hard coat layer material becomes easy.
The polyfunctional (meth) acrylate is preferably a substance having a structure obtained by reacting a polymer containing a monomer component of an epoxy group-containing (meth) acrylate monomer with an α, β -unsaturated carboxylic acid. By using such a substance as a polyfunctional (meth) acrylate, a hard coat layer having high hardness and excellent scratch resistance can be easily obtained.
The epoxy group-containing (meth) acrylate monomer refers to a compound having one or more epoxy groups and one or more unsaturated double bonds in the molecule. Examples of the epoxy group-containing (meth) acrylate monomer include glycidyl (meth) acrylate, β -methyl glycidyl (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, vinylcyclohexene monooxide (i.e. 1, 2-epoxy-4-vinylcyclohexane), and combinations thereof. Among these, glycidyl (meth) acrylate is preferable from the viewpoint of easiness of obtaining.
The monomer component may contain, in addition to the epoxy group-containing (meth) acrylate monomer, any monomer copolymerizable therewith.
Examples of the optional monomer include (meth) acrylate, styrene, vinyl acetate, (meth) acrylamide, acrylonitrile, a macromer having an unsaturated double bond at either end and not containing an epoxy group and a carboxyl group, and a combination thereof.
Specific examples of the macromer include: macromers AA-6, AB-6, AS-6, and AY-707S (manufactured by Toyama Synthesis Co., ltd.); silaplaine FM-0711 and FM-0721 (manufactured by Ixoma Co., ltd.); placcel FA10L (manufactured by Dairy Chemie Co., ltd.); and Blemmer PME-4000 and PSE-1300 (manufactured by Nikko Co., ltd.).
Examples of the α, β -unsaturated carboxylic acid include α, β -unsaturated monocarboxylic acids such as (meth) acrylic acid, α, β -unsaturated dicarboxylic acids such as (meth) acrylic acid dimer, and combinations thereof. Among these, (meth) acrylic acid is preferable from the viewpoint of imparting a desired hardness to the hard coat layer in the final product.
Examples of the optional components that can be contained in the hard coat material include a polymerization initiator. As the polymerization initiator, various polymerization initiators capable of initiating polymerization of the polymerizable substance (H) by irradiation of active energy rays such as ultraviolet rays can be used. Specific examples of the polymerization initiator include 2, 2-dimethoxy-1, 2-diphenylethan-1-one, 1-cyclohexylphenyl ketone, 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, phenylglyoxylic acid methyl ester, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholinyl) phenyl ] -1-butanone, bis (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide, 4-methylbenzophenone, and the like, 1- [4- (4-benzoylphenylthio) phenyl ] -2-methyl-2- (4-methylphenyl sulphonyl) propan-1-one, 1- [4- (phenylthio) phenyl ] -1, 2-octanedione-2- (O-benzoyloxime), ethanone-1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -1- (O-acetyl oxime), and combinations thereof. As an example of a commercially available polymerization initiator, there may be mentioned IRGACURE184, manufactured by Ciba refining Co., ltd.
The proportion of the polymerization initiator in the hard coat material is preferably 0.1 parts by weight or more, and more preferably 10 parts by weight or less, based on 100 parts by weight of the polymerizable substance (H). By making the ratio of the polymerization initiator within the above range, it is possible to easily impart desired stretchability to the hard coat layer in the transfer medium laminate and the polarizing film, and to impart desired hardness to the hard coat layer in the final product.
The hard coat material may contain fine particles in addition to the above components. The fine particles can adjust various physical properties such as conductivity and refractive index of the hard coat layer. The refractive index of the fine particles is preferably 1.4 or more.
The fine particles may be organic fine particles composed of an organic substance or inorganic fine particles composed of an inorganic substance. The fine particles are preferably inorganic fine particles, and more preferably fine particles of an inorganic oxide. Examples of the inorganic oxide capable of constituting the fine particles include silica, titania (titanium oxide), zirconia (zirconium dioxide), zinc oxide, tin oxide, cerium oxide, antimony pentoxide, titania, indium oxide doped with tin (ITO), tin oxide doped with Antimony (ATO), tin oxide doped with Phosphorus (PTO), indium oxide doped with zinc (IZO), zinc oxide doped with Aluminum (AZO), and tin oxide doped with Fluorine (FTO).
The fine particles are preferably silica fine particles because the fine particles have excellent balance between adhesion to the polymer of the polymerizable substance (H) and transparency, and the refractive index of the hard coat layer can be easily adjusted.
The hard coat material may contain one kind of fine particles alone or two or more kinds of fine particles in combination.
The number average particle diameter of the fine particles is preferably 1nm to 1000nm, more preferably 1nm to 500nm, still more preferably 1nm to 250 nm. The smaller the number average particle diameter of the fine particles, the lower the haze of the hard coating layer and the higher the adhesion between the fine particles and the polymer of the polymerizable substance (H).
The haze (%) can be measured according to JIS K-7136 using, for example, a commercially available haze meter (for example, "NDH2000" manufactured by Nippon Denshoku Co., ltd.).
The content of the fine particles in the composition for forming a hard coat layer is preferably 10 to 80 parts by weight, more preferably 10 to 50 parts by weight, and even more preferably 20 to 40 parts by weight, relative to 100 parts by weight of the polymerizable substance (H). When the content of the fine particles is in the above range, the optical characteristics such as haze value and total light transmittance are excellent.
The total light transmittance (%) can be measured according to JIS K-7361 using, for example, a commercially available haze meter (product of Japanese electric Co., ltd. "NDH 2000").
The hard coat material may contain any component in addition to the above components. Examples thereof include polymerization inhibitors, antioxidants, antistatic agents, light stabilizers, solvents, antifoaming agents, and leveling agents.
In the method for producing a transfer medium laminate of the present invention, the hard coat layer is formed by a process including the above-described process (1) and process (2).
The development of the hard coat material in the step (1) can be performed by applying the hard coat material or a solution containing the hard coat material to the surface of the support to form a coating film of the hard coat material or the solution. In the case of preparing a solution containing a hard coat material, as a solvent used therefor, any liquid capable of dissolving or dispersing the hard coat material therein can be used. Examples of the solvent include various organic solvents. Specific examples thereof include: alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; glycols such as ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diacetone glycol, and the like; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as n-hexane and n-heptane; esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; oximes such as methyl ethyl ketoxime; and combinations of two or more of them. When the hard coat layer is formed using a hard coat layer material solution, the solvent volatilizes as a result of operations such as drying in the forming step, and the solid content remains in the hard coat layer. The proportion of the solid component in the hard coat material solution (i.e., the component remaining in the hard coat layer after the formation of the hard coat layer) can be appropriately adjusted to perform a desired operation, and can be, for example, 5% by weight or more and 40% by weight or less.
The hardening of the hard coat material in the step (2) can be performed by drying the coating film of the hard coat material, irradiation of the coating film of the hard coat material with an active energy ray, or a combination thereof. As the active energy ray, an active energy ray suitable for the polymerization initiator contained in the hard coat material can be selected. From the viewpoint of easiness of the process such as adjustment of the polymerization degree, it is preferable to use an ultraviolet polymerization initiator as the polymerization initiator and ultraviolet rays as the active energy rays. By appropriately adjusting the conditions under which the hard coat material is semi-cured, a hard coat layer having stretchability can be formed.
The surface of the hard coat layer in the semi-cured state formed in the step (2) is preferably in a so-called tack-free state. The surface being non-tacky means having such a degree that the material constituting the hard coat layer does not adhere to the finger when the surface is contacted with the finger. By making the surface non-tacky, the laminate in which the hard coat layer is exposed on the surface can be stored in a state such as a film roll, and thus the degree of freedom in implementation of the manufacturing method can be improved.
The thickness of the hard coat layer can be appropriately adjusted to a desired range. Specifically, the thickness of the hard coat layer is preferably 0.5 μm or more and 20 μm or less, more preferably 0.5 μm or more and 10 μm or less, and still more preferably 0.5 μm or more and 8 μm or less.
[4 resin layer (A) ]
The resin layer (A) is a layer made of a resin having a storage modulus of 1000MPa or less. The storage modulus is preferably 960MPa or less, more preferably 920MPa or less. The lower limit of the storage modulus is not particularly limited, and may be, for example, 200MPa or more. By setting the storage modulus in this range, it is possible to suppress the occurrence of significant curl in the transfer medium laminate and the polarizing film, and to improve the follow-up property to the curved surface.
The storage modulus of the resin constituting the resin layer (a) can be obtained by molding the resin into a measurement film having a thickness of 1mm and measuring the storage modulus at 23 ℃ of the measurement film by a dynamic viscoelasticity measurement device (for example, "ARES" manufactured by TA Instruments Japan inc.).
The resin constituting the resin layer (A) preferably has a low water vapor transmission rate at 40℃and 90% RH measured as a film having a thickness of 100. Mu.m. The water vapor transmission rate is preferably less than 5 g/(m) 2 Day), more preferably 4 g/(m) 2 Day) below. The lower limit of the water vapor permeability is desirably 0 g/(. Times.m 2 Day) may be 0.1 g/(m) 2 Day). By setting the water vapor permeability to the upper limit value or less, the low moisture permeability of the resin layer (a) can be sufficiently excellent, and the water vapor can be suppressed from reaching the polarizer layer, thereby making the polarizing film excellent in reliability. The water vapor permeability can be measured using a commercially available water vapor permeability measuring apparatus, and specifically, can be measured according to the method described in the evaluation item column in examples.
The resin constituting the resin layer (a) generally contains a polymer as a main component. Examples of the polymer include polyesters, acrylic polymers, and polymers having an alicyclic structure.
The resin forming the resin layer (a) preferably contains a polymer having an alicyclic structure.
The polymer having an alicyclic structure is a polymer having an alicyclic structure as a structural unit of the polymer. Polymers having alicyclic structures generally have low water vapor transmission rates. Therefore, by forming the resin layer (a) with a resin containing a polymer having an alicyclic structure, water vapor can be suppressed from reaching the polarizer layer, and the moisture resistance of the polarizing film can be improved.
The resin forming the resin layer (a) may contain one polymer having an alicyclic structure alone or two or more kinds may be contained in combination.
The polymer having an alicyclic structure may have an alicyclic structure in the main chain, may have an alicyclic structure in the side chain, or may have an alicyclic structure in both the main chain and the side chain. Among them, a polymer having an alicyclic structure at least in the main chain is preferable from the viewpoints of mechanical strength and heat resistance.
Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene or cycloalkyne) structure. Among them, from the viewpoints of mechanical strength and heat resistance, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.
The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, still more preferably 30 or less, still more preferably 20 or less, and particularly preferably 15 or less per alicyclic structure. By setting the number of carbon atoms constituting the alicyclic structure within this range, the mechanical strength, heat resistance and moldability of the resin containing the polymer having an alicyclic structure are highly balanced.
In the polymer having an alicyclic structure, the proportion of the structural units having an alicyclic structure can be appropriately selected according to the purpose of use. The proportion of the structural unit having an alicyclic structure in the polymer having an alicyclic structure is preferably 55% by weight or more, more preferably 70% by weight or more, particularly preferably 90% by weight or more, and can be 100% by weight or less. When the proportion of the structural unit having an alicyclic structure in the polymer having an alicyclic structure is within this range, the transparency and heat resistance of the resin containing the polymer having an alicyclic structure become good.
Examples of the polymer having an alicyclic structure include norbornene polymers, monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof, and hydrides of vinyl aromatic hydrocarbon polymers. Among these, one or more kinds selected from the group consisting of norbornene-based polymers and hydrides of vinyl aromatic hydrocarbon polymers are more preferable because of good transparency and moldability.
Examples of the norbornene-based polymer include: a ring-opened polymer of a monomer having a norbornene structure and a hydride thereof; addition polymers of monomers having norbornene structures and hydrides thereof. Examples of the ring-opening polymer of the monomer having a norbornene structure include a ring-opening homopolymer of one monomer having a norbornene structure, a ring-opening copolymer of two or more monomers having a norbornene structure, and a ring-opening copolymer of a monomer having a norbornene structure and an optional monomer copolymerizable therewith. Examples of the addition polymer of the monomer having a norbornene structure include an addition homopolymer of one monomer having a norbornene structure, an addition copolymer of two or more monomers having a norbornene structure, and an addition copolymer of a monomer having a norbornene structure and an optional monomer copolymerizable therewith. Among these, preferred are hydrogenated polymers of ring-opened polymers of monomers having a norbornene structure, hydrogenated copolymers of monomers having a norbornene structure and an alpha-olefin, and hydrogenated copolymers of addition copolymers of monomers having a norbornene structure and an alpha-olefin, more preferred are hydrogenated copolymers of ring-opened copolymers of two or more monomers having a norbornene structure, addition copolymers of monomers having a norbornene structure and an alpha-olefin, and hydrogenated copolymers of monomers having a norbornene structure and an alpha-olefin.
Examples of the monomer having a norbornene structure include bicyclo [2.2.1 ]]Hept-2-ene (commonly known as norbornene), tricyclo [4.3.0.1 ] 2,5 ]Dec-3, 7-diene (commonly known as dicyclopentadiene), 7, 8-benzotricyclo [4.3.0.1 ] 2,5 ]Dec-3-ene (common name: A-bridge tetrahydrofluorene), tetracyclo [4.4.0.1 ] 2,5 .1 7,10 ]Dodec-3-ene (commonly known as tetracyclododecene) and derivatives of these compounds (for example, derivatives having a substituent on the ring) and the like. Examples of the substituent include an alkyl group, an alkylene group, and a polar group. These substituents may be the same or different, and a plurality of substituents may be bonded to form a ring. The monomer having a norbornene structure may be used alone or in combination of two or more kinds in any ratio.
Examples of the polar group include a heteroatom and an atomic group having a heteroatom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Specific examples of the polar group include a carboxyl group, a carbooxycarbonyl group, an epoxy group, a hydroxyl group, an oxo group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, a sulfonic acid group, and the like.
Examples of the monomer capable of ring-opening copolymerization with the monomer having a norbornene structure include: monocyclic olefins such as cyclohexene, cycloheptene and cyclooctene, and derivatives thereof; cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene, and derivatives thereof. The monomer capable of ring-opening copolymerization with the monomer having a norbornene structure may be used alone or in combination of two or more at an arbitrary ratio.
The ring-opened polymer of the monomer having a norbornene structure can be produced by, for example, polymerizing or copolymerizing the monomer in the presence of a ring-opening polymerization catalyst.
Examples of the addition copolymer of a monomer having a norbornene structure and an α -olefin include an α -olefin having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof. Among them, ethylene is preferred. The α -olefin may be used alone or in combination of two or more thereof in any ratio.
The addition polymer of the monomer having a norbornene structure can be produced by, for example, polymerizing or copolymerizing the monomer in the presence of an addition polymerization catalyst.
The hydrogenated product of the ring-opening polymer and the addition polymer can be produced, for example, by hydrogenating preferably 90% or more of the carbon-carbon unsaturated bonds in a solution of the ring-opening polymer and the addition polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium.
The hydride of the vinyl aromatic hydrocarbon polymer means a hydride of a polymer containing a repeating unit [ I ] derived from an aromatic vinyl compound. The repeating unit derived from an aromatic vinyl compound means a repeating unit having a structure obtained by polymerizing an aromatic vinyl compound. However, the hydride and its structural unit are not limited by the method of manufacturing the same.
Examples of the aromatic vinyl compound corresponding to the repeating unit [ I ] include: styrene; styrenes having an alkyl group having 1 to 6 carbon atoms as a substituent such as α -methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2, 4-dimethylstyrene, 2, 4-diisopropylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene; styrenes having a halogen atom as a substituent such as 4-chlorostyrene, dichlorostyrene and 4-monofluorostyrene; styrenes having an alkoxy group having 1 to 6 carbon atoms as a substituent such as 4-methoxystyrene; styrenes having an aryl group as a substituent such as 4-phenylstyrene; vinyl naphthalenes such as 1-vinyl naphthalene and 2-vinyl naphthalene. One kind of these may be used alone, or two or more kinds may be used in combination in any ratio. Among these, from the viewpoint of reducing hygroscopicity, styrene and aromatic vinyl compounds containing no polar group such as styrenes having an alkyl group having 1 to 6 carbon atoms as a substituent are preferable, and from the viewpoint of industrial availability, styrene is particularly preferable.
The hydride of the polymer comprising the repeating unit [ I ] derived from an aromatic vinyl compound is preferably a specific block copolymer hydride [ E ]. The block copolymer hydride [ E ] is a hydride of the block copolymer [ D ]. The block copolymer [ D ] is a polymer block formed from the polymer block [ A ] and the polymer block [ B ], or the polymer block [ A ] and the polymer block [ C ]. The polymer block [ A ] is a polymer block mainly composed of a repeating unit [ I ] derived from an aromatic vinyl compound. The polymer block [ B ] is a polymer block mainly composed of a repeating unit [ I ] derived from an aromatic vinyl compound and a repeating unit [ II ] derived from a chain conjugated diene compound. The polymer block [ C ] is a polymer block mainly composed of a repeating unit [ II ] derived from a chain conjugated diene compound. The term "main component" as used herein means a component in the polymer block at 50% by weight or more. The repeating unit derived from the chain conjugated diene compound means a repeating unit having a structure obtained by polymerizing the chain conjugated diene compound.
Examples of the chain conjugated diene compound corresponding to the repeating unit [ II ] include 1, 3-butadiene, isoprene, 2, 3-dimethyl-1, 3-butadiene, and 1, 3-pentadiene. One kind of these may be used alone, or two or more kinds may be used in combination in any ratio. The chain conjugated diene compound may be linear or branched.
The hydrogenated product of the vinyl aromatic hydrocarbon polymer is obtained by hydrogenating unsaturated bonds of the vinyl aromatic hydrocarbon polymer. Here, the unsaturated bond of the hydrogenated vinyl aromatic hydrocarbon polymer includes any one of carbon-carbon unsaturated bonds of the main chain and side chains of the polymer and carbon-carbon unsaturated bonds of the aromatic ring.
The hydrogenated product can be produced, for example, by hydrogenating the unsaturated bond of the polymer preferably by 90% or more in a solution of the vinyl aromatic hydrocarbon polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium.
The weight average molecular weight Mw of the polymer included in the resin forming the resin layer (a) is preferably 10000 or more, more preferably 15000 or more, particularly preferably 20000 or more, preferably 100000 or less, more preferably 80000 or less, particularly preferably 50000 or less. When the weight average molecular weight is within such a range, the mechanical strength of the resin layer (a) is highly balanced with moldability.
The molecular weight distribution (Mw/Mn) of the polymer contained in the resin forming the resin layer (a) is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 3.5 or less, more preferably 3.0 or less, particularly preferably 2.7 or less. Here, mn represents a number average molecular weight. By setting the molecular weight distribution to the lower limit or more of the above range, the productivity of the polymer can be improved, and the production cost can be suppressed. In addition, by setting the molecular weight distribution to the upper limit value or less, the amount of the low molecular component becomes small. As a result, the resin layer (a) can be prevented from loosening when exposed to high temperature, and the stability of the resin layer (a) can be improved.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) described above can be measured using Gel Permeation Chromatography (GPC). The solvent used for GPC includes cyclohexane, toluene, and tetrahydrofuran. In the case of using GPC, the weight average molecular weight is measured as a relative molecular weight in terms of, for example, polyisoprene or polystyrene.
The resin forming the resin layer (a) preferably contains a plasticizer and/or a softener (plasticizer or softener, or both) in addition to the polymer. By further containing a plasticizer and/or a softener, moldability (e.g., stretchability) of the resin forming the resin layer (a) can be improved.
Examples of the plasticizer and/or softener include compounds having an ester structure and aliphatic hydrocarbon polymers. The resin forming the resin layer (a) preferably contains one or more selected from the group consisting of a compound having an ester structure and an aliphatic hydrocarbon polymer as a plasticizer and/or a softener, and more preferably contains an aliphatic hydrocarbon polymer.
Examples of the compound having an ester structure include: phosphate compounds such as triphenyl phosphate, tricresyl phosphate, and phenyl diphenyl phosphate; aliphatic carboxylic acid esters such as oxalic ester, malonic ester, succinic ester, glutaric ester, adipic ester, pimelic ester, suberic ester, azelaic ester, sebacic ester, and stearic ester; aromatic carboxylic acid ester compounds such as benzoate, phthalate, isophthalate, terephthalate, trimellitate, and pyromellitate.
Examples of aliphatic hydrocarbon polymers include polyisobutylene, hydrogenated polyisoprene, hydrogenated 1, 3-pentadiene petroleum resin, hydrogenated cyclopentadiene petroleum resin, and hydrogenated styrene/indene petroleum resin.
The total amount of the plasticizer and the softener is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, further preferably 20 parts by weight or more, preferably 100 parts by weight or less, more preferably 70 parts by weight or less, further preferably 50 parts by weight or less, relative to 100 parts by weight of the polymer contained in the resin forming the resin layer (a). By setting the total ratio of the plasticizer and the softener in the resin within the above range, the moldability of the resin can be further improved.
The resin forming the resin layer (a) preferably contains an ultraviolet absorber. By including the ultraviolet absorber in the resin, the resin layer (a) including the ultraviolet absorber can be formed. By including the ultraviolet absorber in the resin layer (a), the following effects can be obtained: in the process of producing the polarizing film, it is easy to perform a process of bonding the transfer medium laminate and the polarizer layer via an ultraviolet-curable adhesive while maintaining the stretchability of the hard coat layer. In addition, the effect of reducing degradation of the final product due to irradiation of ultraviolet rays included in external light can be obtained.
Specific examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers. Examples of commercially available ultraviolet absorbers include "Tinuvin326", "Tinuvin329" and "Tinuvin234" (both of which are benzotriazole-based ultraviolet absorbers manufactured by BASF corporation), and "ATASTAB LA-70" (manufactured by ADEKA, a triazine-based ultraviolet absorber, inc.).
The resin forming the resin layer (a) may contain various additives in addition to the above-described components. Examples of the additives include antioxidants and light stabilizers.
The thickness of the resin layer (A) is preferably 0.5 μm or more, more preferably 0.8 μm or more, preferably 9 μm or less, more preferably 8 μm or less. By setting the thickness of the resin layer (a) to the above lower limit value or more, the reliability of the polarizing film in a high-temperature and high-humidity environment can be further improved, and the polarizer layer included in the polarizing film can be more favorably protected. By setting the thickness of the resin layer (a) to the above upper limit or less, the thickness of the polarizing film can be reduced, and the effect of suppressing curling can be improved.
The resin layer (a) is preferably optically isotropic. Here, "optically substantially isotropic" means that the in-plane retardation Re is preferably 0nm to 5nm, more preferably 0nm to 2 nm.
In the method for producing a transfer medium laminate of the present invention, the resin layer (a) is formed by a process including the above-described process (3).
The development of the resin in the step (3) can be performed by applying the resin or a solution containing the resin to the surface of the hard coat layer to form a coating film thereof. In the case of preparing a solution containing a resin, as a solvent used therefor, any liquid capable of dissolving or dispersing the resin therein can be used. Examples of the solvent include various organic solvents. Specific examples thereof include the same solvents as those which can be used in the step (1).
After the step (3), the spread resin or a solution thereof may be subjected to a drying operation or the like as needed, to cure the coating film, thereby forming the resin layer (a).
After the formation of the resin layer (a), the surface of the resin layer (a) may be subjected to a treatment such as corona treatment. By this treatment, the resin layer (a) can exhibit properties such as improved adhesion to an adhesive layer.
By performing the step of forming the resin layer (a) including the step (3), a transfer medium laminate having a layer structure of (support)/(hard coat layer)/(resin layer (a)) can be obtained. Here, by performing the step (3) at the time when the hard coat layer is in a state of a semi-cured product, a transfer medium laminate having a structure in which a resin layer (a) is formed on the surface of the semi-cured product can be obtained. By having this structure, various advantages can be obtained. That is, since the hard coat layer having a low hardness is protected by the resin layer (a) and the support at this time, mechanical damage of the hard coat layer caused by the subsequent operation can be reduced. In addition, by making the hard coat layer a semi-cured product, the following property of the hard coat layer to the curved surface is maintained.
[5. Outline of polarizing film ]
The polarizing film of the present invention has the above-described transfer medium laminate of the present invention, a polarizer layer, and an adhesive layer interposed between the transfer medium laminate and the polarizer layer. The polarizer layer is provided on the resin layer (a) side of the transfer medium laminate (i.e., on the opposite side from the hard coat layer side; on the opposite side from the support in the case of having a support).
The polarizing film has a transfer medium laminate, and as described above, the transfer medium laminate has a layer having stretchability as a hard coat layer, and therefore the hard coat layer in the polarizing film is also a layer having stretchability. In general, a polarizing film having a polarizer layer and a hard coat layer is brittle, and therefore has low follow-up property to a curved surface when it is bonded to the curved surface. Here, the polarizing film of the present invention can be made into a film having high follow-up property to a curved surface by having the above-described structure. Further, the tendency of curl generation of the transfer medium laminate is low, and therefore the tendency of curl generation of the polarizing film is also low. Therefore, the process of attaching the polarizing film to the base member having a curved surface or the like is easy.
[6 polarizer layer ]
As the polarizer layer, a film that transmits one of two linearly polarized light beams intersecting at right angles and absorbs or reflects the other linearly polarized light beam can be used. When a specific example of the polarizer layer is given, the following polarizer layer may be given: a polarizer layer obtained by applying a suitable treatment such as a dyeing treatment with a dichroic substance such as iodine or a dichroic dye, a stretching treatment, or a crosslinking treatment to a film of a polyvinyl alcohol resin containing a polyvinyl alcohol polymer such as polyvinyl alcohol or a partially formalized polyvinyl alcohol in a suitable order and in a suitable manner. The polarizer layer preferably comprises a polyvinyl alcohol resin.
The thickness of the polarizer layer is preferably 1 μm or more, more preferably 2 μm or more, further preferably 4 μm or more, preferably 25 μm or less, further preferably 23 μm or less.
[7. Adhesive layer ]
The adhesive layer is generally a layer that adheres the polarizer layer to the resin layer (a). As an example of the adhesive for forming the adhesive layer, there may be mentioned: an acrylic adhesive; an epoxy adhesive; a polyurethane-based adhesive; a polyester-based binder; a polyvinyl alcohol-based adhesive; a polyolefin-based adhesive; a modified polyolefin-based adhesive; a polyvinyl alkyl ether-based adhesive; rubber-based adhesives, vinyl chloride-vinyl acetate-based adhesives; ethylene-based adhesives such as SEBS (styrene-ethylene-butylene-styrene copolymer) based adhesives and ethylene-styrene copolymers; and acrylic acid ester adhesives such as ethylene-methyl (meth) acrylate copolymer and ethylene-ethyl (meth) acrylate copolymer.
The adhesive is preferably an ultraviolet-curable adhesive. The method for producing a polarizing film described later can be easily performed by using an ultraviolet curable adhesive. As a specific example of the ultraviolet curable adhesive, "ARKLS KRX-7007" (trade name, manufactured by ADEKA) may be mentioned.
The thickness of the adhesive layer is usually more than 0 μm, preferably 0.1 μm or more, more preferably 1 μm or more, preferably 5 μm or less, more preferably 3 μm or less. By making the thickness of the adhesive layer within the above range, the adhesive layer can more strongly adhere the polarizer layer to the resin layer (a), bending recovery of the polarizing film can be improved, and the thickness of the polarizing film can be made thin.
[8. Optional layer ]
The polarizing film may have any layer in addition to the above layers. As an example of an arbitrary layer, an adhesive layer provided on the side opposite to the resin layer (a) side of the polarizer layer is given. The thickness of the adhesive layer is preferably 2 μm or more, more preferably 5 μm or more, preferably 25 μm or less, more preferably 20 μm or less.
[9. Method for producing polarizing film ]
The polarizing film of the present invention can be produced by any production method, and as an example of a preferred production method, a production method using a resin layer containing an ultraviolet absorber as the resin layer (a), using an ultraviolet-curable adhesive as an adhesive for forming the adhesive layer, and including the following steps is given. Hereinafter, this method will be described as a method for producing a polarizing film of the present invention.
Step (4): and a step of bonding the transfer medium laminate to the polarizer layer via an ultraviolet-curable adhesive to form a bonded product.
Step (5): and irradiating the adherend with ultraviolet rays from the polarizer layer side of the adherend.
[9.1 step (4) ]
In step (4), the transfer medium laminate is bonded to the polarizer layer via an ultraviolet-curable adhesive. At the end of the bonding, the adhesive is in a state of not being cured. Therefore, for example, when a laminate having a layer structure of (support)/(hard coat layer)/(resin layer (a)) is used as the transfer medium laminate, the laminate obtained in step (4) has a layer structure of (support)/(hard coat layer)/(resin layer (a))/(layer of adhesive (uncured))/(polarizer layer).
[9.2 step (5) ]
In the step (5), the adherend is irradiated with ultraviolet rays from the polarizer layer side of the adherend. Thus, the irradiated ultraviolet rays pass through the polarizer layer to reach the layer (uncured) of the adhesive, thereby effecting curing of the adhesive to form an adhesive layer. As a result, the polarizing film of the present invention having a layer structure of (support)/(hard coat layer)/(resin layer (a))/(adhesive layer (layer obtained by curing adhesive layer))/(polarizer layer) can be obtained.
Part of the ultraviolet light irradiated in the step (5) can pass through the adhesive layer or the adhesive layer and reach the resin layer (a). If the resin layer (a) is a layer having high ultraviolet transmittance, ultraviolet rays can further pass through the resin layer (a) to reach the hard coat layer. However, in the method for producing a polarizing film of the present invention, since a resin layer containing an ultraviolet absorber is used as the resin layer (a), the amount of ultraviolet rays reaching the hard coat layer can be reduced. Therefore, even when an ultraviolet-curable material is used as the hard coat layer, the polarizing film can be manufactured while maintaining the properties of the hard coat layer, such as the stretchability and the semi-cured state. The degree of curing of the ultraviolet-curable material can be easily adjusted by adjusting the irradiation amount. Therefore, in the manufacturing method of the present invention, all of these advantages can be enjoyed conveniently.
[9.3. Optional procedure ]
The method for producing a polarizing film of the present invention may include any process in addition to the above-described process. For example, a step of forming an arbitrary layer that the polarizing film can have may be included. Specifically, the method may include a step of providing an adhesive layer as an arbitrary layer on a surface of the polarizer layer opposite to the adhesive layer. The adhesive layer is preferably formed by applying an adhesive composition to a suitable release film to form a layer of the adhesive composition and adhering the layer to the surface of the polarizer layer. The step of providing the adhesive layer may be performed at any stage from before the step (4) to after the step (5), and is preferably performed after the step (5) in view of ease of handling. As a result of performing this optional step, a polarizing film with an adhesive layer and a release film having a layer structure of (support)/(hard coat layer)/(resin layer (a))/(adhesive layer (layer formed by curing adhesive layer))/(polarizer layer)/(adhesive layer)/(release film) can be obtained. In the case of using a laminate including a support as a transfer medium laminate, the support may be peeled off at any stage of the method for producing a polarizing film, or may remain without peeling off.
[10. Method for producing molded article with polarizer layer ]
The method for producing a molded body with a polarizer layer of the present invention comprises the following steps.
Step (A): and a step of producing a polarizing film by the above-described method for producing a polarizing film of the present invention.
Step (B): and a step of bonding the polarizing film to the base member.
Step (C): and a step of mainly curing the hard coat layer in the polarizing film.
The molded article produced by the method for producing a molded article with a polarizer layer according to the present invention may include: a base member having a curved surface; a polarizer layer formed on the curved surface; a resin layer (A) which is formed on the polarizer layer and can function as a protective film for protecting the polarizer; and a hard coat layer formed on the resin layer (A). The hard coat layer in such a molded article has sufficient properties such as hardness and scratch resistance as a hard coat layer for protecting the outermost surface of the molded article, and can be formed into a layer that favorably follows the shape of a curved surface.
The base member used in the step (B) may be a component of a display device such as a liquid crystal display device or an organic electroluminescence display device.
As an example, the base member can be a liquid crystal panel of a liquid crystal display device. The liquid crystal panel is a member having a pair of substrates and a plurality of display units provided between the pair of substrates and enclosing a liquid crystal material. A liquid crystal display device generally has a liquid crystal panel and a pair of polarizer layers disposed on the viewing side and the back side thereof. The method for producing a molded body with a polarizer layer according to the present invention can be preferably applied to the production of a liquid crystal display device having a curved display surface, which has a liquid crystal panel as a base member, a polarizer layer on the viewing side thereof, and a hard coat layer protecting the outermost surface on the viewing side of the display device, or the production of a structural member thereof.
As another example, the base member can be a display element of an organic electroluminescent display device. Here, the display element refers to a member including a substrate, a layered first electrode formed on the substrate, a light-emitting layer formed on the first electrode, a second electrode formed on the light-emitting layer, and a sealing layer sealing the electrode and the light-emitting layer. In an organic electroluminescent display device, a member including a polarizer layer may be provided on the viewing side of a display element for the purpose of preventing reflection glare of external light, improving display quality when a display surface is observed through polarized sunglasses, and the like. The method for producing a molded body with a polarizer layer according to the present invention can be preferably applied to the production of an organic electroluminescent display device having a curved display surface, which has a display element as a base member, a polarizer layer on the viewing side thereof, and a hard coat layer protecting the viewing side outermost surface of the display device, or the production of a structural member thereof.
The lamination in the step (B) can be performed by laminating the polarizing film and the base member with an appropriate adhesive. As the adhesive, an adhesive layer as an optional component described above can be used. For example, when a polarizing film having a layer structure of (support)/(hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizer layer)/(adhesive layer)/(release film) is used as the polarizing film, the release film can be released to expose the adhesive layer, and adhesion to the base member can be achieved via the adhesive layer.
In one embodiment of the method for producing a molded article with a polarizer layer of the present invention, the base member used in the step (B) is a member having a curved surface. In another embodiment of the method for producing a molded body with a polarizer layer of the present invention, the method further includes a step (Bx) of bending the base member after the step (B) and before the step (C). Hereinafter, the former manufacturing method is referred to as "manufacturing method 1", and the latter manufacturing method is referred to as "manufacturing method 2".
In the manufacturing method 1, in the step (B), the polarizing film is bonded to the base member having a curved surface. Specifically, a polarizing film is bonded to the curved surface. Since the polarizing film is generally manufactured as a flat film, the polarizing film needs to follow a curved surface when such bonding is performed. In the method for producing a molded body with a polarizer layer of the present invention, since a polarizing film having high follow-up property to a curved surface produced by the above-described method for producing a polarizing film of the present invention is used as a polarizing film, this step can be easily performed. Further, since the polarizing film has a low tendency to curl, lamination can be easily performed.
In the manufacturing method 2, as the step (Bx), the base member is bent after the step (B). The surface of the base member before bending may be a flat surface. Alternatively, the curved surface may be deformed further in the step (Bx) to change the degree of bending. In this way, even when the base member is bent after bonding, the polarizing film needs to follow the curved surface after the step (Bx). In the method for producing a molded body with a polarizer layer of the present invention, a polarizing film having high follow-up property to a curved surface produced by the above-described method for producing a polarizing film of the present invention is used as a polarizing film, and therefore this step can be easily performed. Further, since the polarizing film has a low tendency to curl, the lamination in the step (B) can be easily performed.
In the step (C), the hard coat layer in the polarizing film is mainly cured. By this primary curing step, the hard coat layer becomes a primary cured product, and loses stretchability, while having the hardness and other properties required for the hard coat layer in the final product. This step is performed while maintaining the state in which the polarizing film follows the curved surface. Thus, after such a step, the product, i.e., the molded body with the polarizer layer, is a molded body having a curved surface shape, and the molded body has: a polarizer layer; a resin layer (A) for protecting the polarizer layer; a hard coat layer which has properties such as sufficient hardness and scratch resistance as a hard coat layer protecting the resin layer (a) and protecting the outer surface of the product, and which well follows the shape of a curved surface.
Examples
Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the embodiments described below, and can be arbitrarily modified and implemented within the scope not departing from the scope of the claims and the equivalents thereof.
In the following description, unless otherwise indicated, "%" and "parts" representing amounts are weight basis. The operations described below are performed under normal temperature and normal pressure conditions unless otherwise specified.
[ evaluation method ]
(storage modulus)
The resin to be measured was melted and molded under conditions of a gap of 1mm, 250℃and 30MPa using a hot-melt press, whereby a film for measurement having a thickness of 1mm was obtained.
For this measurement film, the storage modulus at 23℃was measured by a dynamic viscoelasticity measuring device (TA Instruments Japan Inc. manufactured by ARES).
(Water vapor Transmission Rate)
The resin to be measured was thermally melted and molded using a hot-melt press at a gap of 100 μm and 250℃under 30MPa, whereby a film for measurement having a thickness of 100 μm was obtained.
The film for measurement was measured for water vapor permeability by using a water vapor permeability measuring device (MOCON Co., ltd. "PERMATRAN-W") according to JIS K7129B at 40℃and 90% RH.
(crimping Property)
The film to be measured was cut, and a square slice of 10cm×10cm was produced. The sections were allowed to stand at 23℃under 55% RH for 24 hours to wet them. Then, the cut piece was placed on the surface of the horizontal stage with the hard coat layer on the upper side. The heights of the four vertexes of the slice (the distances in the vertical direction from the flat surface to the vertexes of the slice) were measured, the maximum value h1 thereof was obtained, and the curling was evaluated according to the following criteria.
AA (very small curl, very good mountability to panel): h1 is less than or equal to 10mm
A (small curl, good mountability to panel): h1 is more than 10mm and less than or equal to 25mm
B (curl is large, mountability to the panel is poor, yield of the panel is reduced): 25mm < h 1.ltoreq.40 mmC (very large curl, difficult to install on panel): h1 is less than 40mm
(bending test)
The bending test laminates including the aluminum sheet and the other layers obtained in examples and comparative examples were bent by 90 ° with the aluminum sheet inside. From the hard coating side750mJ/cm 2 The laminate is irradiated with ultraviolet rays. After the bending test laminate was left at 85℃for 120 hours under 85%, the state of the bent portion was observed and evaluated according to the following criteria. The curved portion as the observation object is a band-shaped region of 20mm in width centered on a straight line at a position where the plate is curved.
A: no discoloration.
B: discoloration was observed in less than 40% of the area of the bent portion.
C: discoloration was observed in the region of 40% or more of the bent portion.
Example 1
(1-1. Hard coating material solution)
Ethyl acetate as a diluent was added to a solution containing a polymerizable substance (H) for a hard coat material (trade name "LUXYDIR V-6850", manufactured by DIC Co., ltd., solid content ratio: 50% by weight) to obtain a solution (i) having a solid content ratio of 20% by weight. A photopolymerization initiator (trade name "IRGACURE184" manufactured by Ciba corporation) was added in a proportion of 3 parts by weight relative to 100 parts by weight of the solid content of the solution (i), and the mixture was stirred for 10 minutes.
(1-2. Hard coat layer)
A support (trade name "TORAYFAN BO40-2500", manufactured by Toli) was prepared as a biaxially stretched polypropylene film. The hard coat material solution (ii) obtained in (1-1) was applied by gravure printing on one surface of the support and dried (90 ℃ C..times.2 minutes). By this operation, a hard coat layer having a film thickness of 7 μm was formed, and a laminate (i) having a layer structure of (support)/(hard coat layer) was obtained.
(1-3. Resin A1)
Referring to the production example described in JP-A2002-105151, after 25 parts of styrene monomer are polymerized in the first stage, 30 parts of styrene monomer and 25 parts of isoprene monomer are polymerized in the second stage, and then 20 parts of styrene monomer are polymerized in the third stage to obtain a block copolymer [ D1], and the block copolymer [ D1] is hydrogenated to synthesize a block copolymer hydride [ E1]. The Mw of the block copolymer hydride [ E1] was 84500, the Mw/Mn was 1.20, and the hydrogenation ratio of the main chain and the aromatic ring was almost 100%.
In 100 parts of block copolymer hydride [ E1]]In the medium melt-kneading and blending 0.1 part of pentaerythritol tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant](Songnox 1010, product name of Songnox Co., ltd.) and pelletized to obtain a resin A1 for molding. The storage modulus was measured for the resin A1, and found to be 720MPa. As a result of measurement of the water vapor permeability of the resin A1, the water vapor permeability was 4.0 g/(m) 2 ·day)。
(1-4. Transfer Medium laminate)
The resin A1 obtained in (1-3) was dissolved in cyclohexane, and 7 parts by weight of an ultraviolet absorber (trade name "ADEKASTAB LA-70", manufactured by ADEKA, co., ltd.) was added to 100 parts by weight of the resin A1 to obtain a solution (iii) having a solid content of 15% by weight.
The solution (iii) was applied to the hard coat side surface of the laminate (i) obtained in (1-2) by a gravure coater, and dried (90 ℃ C..times.2 minutes). By this operation, a resin layer (a) having a film thickness of 5 μm was formed, and a transfer medium laminate having a layer structure of (support)/(hard coat layer)/(resin layer (a)) was obtained.
Some of the obtained transfer medium laminates were used after the following steps (1-6). The other part is used to determine the in-plane retardation Re. That is, the resin layer (a) was peeled off from the transfer medium laminate, and Re was measured.
(1-5. Polarizer)
As a raw material film, an unstretched polyvinyl alcohol film (vinylon film, average polymerization degree about 2400, saponification degree 99.9 mol%) having a thickness of 20 μm was prepared. The film was swollen while being continuously transported in the longitudinal direction via a guide roller, and then dyed to adsorb iodine. In the swelling treatment, the membrane was immersed in pure water at 30℃for 1 minute. In the dyeing treatment, the film was immersed in a dyeing solution (a dye solution containing iodine and potassium iodide in a molar ratio of 1:23, a dye concentration of 1.2 mmol/L) at 32℃for 2 minutes. Then, after washing the film with a 3% aqueous solution of boric acid at 35℃for 30 seconds, the film was stretched 6 times in an aqueous solution containing 3% of boric acid and 5% of potassium iodide at 57 ℃. Then, after the film was subjected to complementary color treatment at 35℃in an aqueous solution containing 5% of potassium iodide and 1.0% of boric acid, the film was dried at 60℃for 2 minutes, and by this operation, a polarizer Pa1 having a thickness of 23 μm was obtained. The polarizer Pa1 had a thickness of 7. Mu.m. The water content of polarizer Pa1 was measured by an on-line water content measuring device manufactured by Kugaku textile Co., ltd., and found to be 7.5%.
(1-6. Polarizing film)
An on-line corona treatment was performed on the surface of the transfer medium laminate obtained in (1-4) on the resin layer (a) side, and an ultraviolet curable adhesive (trade name "ARKLS KRX-7007", manufactured by ADEKA corporation) was applied by a gravure coater to form an adhesive layer. The polarizer Pa1 obtained in (1-5) and the resin layer (a) are pressed and bonded by pinch rolls through the adhesive layer. Next, the adherend was subjected to 750mJ/cm from the polarizer Pa1 side by an ultraviolet irradiation device 2 The adhesive layer was cured by ultraviolet irradiation to form an adhesive layer having a thickness of 2. Mu.m. By this operation, the polarizing film Pb1 with support having a layer structure of (support)/(hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizer layer Pa 1) was obtained.
Some of the obtained polarizing films Pb1 were used after the following steps (1 to 8). The other portion was used for evaluation of curling and stretching. That is, the support is peeled off from the polarizing film Pb1 with support, and the polarizing film Pc1 having a layer structure of (hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizer layer Pa 1) is obtained. The curling property was evaluated by using the sample as a measurement object. The hard coat layer was peeled off from the polarizing film Pc1 to have a rectangular shape having a length of 150mm and a width of 20mm, and was subjected to free uniaxial stretching in the longitudinal direction, and it was confirmed that the stretching was able to be performed up to 2.00 times without generating cracks.
At this time, the hard coat layer exposed on the surface of the polarizing film Pc1 was touched with a finger to evaluate the tackiness. As a result, even if the hard coat layer is touched with a finger, the material constituting the hard coat layer does not adhere to the finger, and thus is evaluated as tack-free.
(1-7. Adhesive composition)
69 parts by weight of n-butyl acrylate (n-BA), 30 parts by weight of phenoxydiglycol acrylate, 1 part by weight of 4-hydroxybutyl acrylate (4 HBA), 120 parts by weight of ethyl acetate and 0.1 part by weight of Azobisisobutyronitrile (AIBN) were added to a reaction vessel, the air in the reaction vessel was replaced with nitrogen, and after that, the reaction solution was heated to 66℃under stirring in a nitrogen atmosphere to react for 10 hours. After the completion of the reaction, the mixture was diluted with ethyl acetate to obtain an acrylic copolymer solution having a solid content of 20% by weight. The weight average molecular weight (Mw) of the obtained acrylic copolymer was 110 ten thousand as measured by GPC.
To 500 parts by weight (100 parts by weight of solid content) of the obtained copolymer solution were added 0.1 part by weight of an isocyanate-based crosslinking agent (trade name "CORONATE L", manufactured by japan polyurethane co., ltd.) and 0.1 part by weight of a silane coupling agent (trade name "KBM-402", manufactured by messenger polymer co., ltd.) and the mixture was thoroughly mixed to obtain an adhesive composition A1.
(1-8. Polarizing film Complex with adhesive layer and Release film)
As the release film, a PET film (trade name "MRV38", mitsubishi chemical) after the release treatment with silicone was prepared. The adhesive composition A1 obtained in (1-7) was applied to the surface of a release film by using a die coater, and the solvent component was volatilized by drying at 90℃for 3 minutes to form a 20 μm adhesive layer, thereby obtaining a laminate (iv) having a layer structure of (adhesive layer)/(release film).
The surface of the laminate (iv) on the adhesive layer side was bonded to the surface of the polarizer layer Pa1 side of the polarizing film Pb1 with support obtained in (1-6), and a polarizing film composite Pd1 with adhesive layer and release film having a layer structure of (support)/(hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizing layer Pa 1)/(adhesive layer)/(release film) was obtained.
(1-9. Bending test)
The obtained polarizing film complex Pd1 was stored at a temperature of 23 ℃ and a humidity of 55% for 5 days, and cured. Then, the release film was peeled off from the polarizing film composite Pd1 to expose the adhesive layer. The adhesive layer was bonded to an aluminum plate having a thickness of 0.5mm, and the support was peeled off. Thus, a bending test laminate having a layer structure of (hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizer layer Pa 1)/(adhesive layer)/(aluminum plate) was obtained. The bending test laminate was subjected to a bending test.
Example 2
In the production of the transfer medium laminate of (1-4), a transfer medium laminate, a polarizing film and a bending test laminate were obtained and evaluated in the same manner as in example 1, except that the coating thickness of the solution (iii) was changed and the thickness of the resin layer (a) formed was changed to 1 μm.
Example 3
(3-1. Resin A2)
Resin A2 was obtained by mixing 100 parts by weight of a norbornene-based polymer resin (trade name "ZEONOR1430", manufactured by Japanese Rayleigh Weng Zhushi Co., ltd.) with 50 parts by weight of polyisobutylene (trade name "Nisseki Polybutene HV-300", manufactured by JX Nitsshi energy Co., ltd., number average molecular weight 1400) as a plasticizer. As a result of measurement of the water vapor permeability of the resin A2, the ratio was 1 g/(m) 2 ·day)。
(3-2. Transfer Medium laminate, etc.)
In the production of the transfer medium laminate of (1-4), a transfer medium laminate, a polarizing film, and a bending test laminate were obtained and evaluated by the same operations as those of (1-1) to (1-2) and (1-4) to (1-9) of example 1 except that the resin A2 obtained in (3-1) was used instead of the resin A1.
Example 4
Except for the following modifications, transfer medium laminates, polarizing films, and bending test laminates were obtained and evaluated in the same manner as in (1-1) to (1-2) and (1-4) to (1-9) of example 1.
In the production of the transfer medium laminate of (1-4), the resin A2 obtained in (3-1) of example 3 was used instead of the resin A1.
When the transfer medium laminate of (1-4) was produced, the coating thickness of the solution (iii) was changed, and the thickness of the resin layer (a) formed was changed to 1 μm.
Example 5
Except for the following modifications, a transfer medium laminate, a polarizing film and a bending test laminate were obtained and evaluated in the same manner as in example 1.
In forming the hard coat layer of (1-2), the same film as the release-treated PET film used in (1-8) was used as a support instead of the biaxially stretched polypropylene film.
When the transfer medium laminate of (1-4) was produced, the coating thickness of the solution (iii) was changed, and the thickness of the resin layer (a) formed was changed to 1 μm.
Example 6
(6-1. Polarizer)
Polarizer Pa2 was produced by the same operation as in (1-5) of example 1 except that a thicker film was used as the raw material film than that used in (1-5). The polarizer Pa2 had a thickness of 5. Mu.m.
(6-2. Transfer Medium laminate, etc.)
In the production of the polarizing film of (1-6), a transfer medium laminate, a polarizing film and a bending test laminate were obtained and evaluated by the same operations as those of (1-1) to (1-4) and (1-6) to (1-9) of example 1 except that the polarizer Pa2 obtained in (6-1) was used instead of the polarizer Pa 1.
Comparative example 1
(C1-1. Resin layer (CA))
As a film constituting the resin layer (CA), a triacetyl cellulose (TAC) film (FUJITAC T25, manufactured by fuji film, thickness 25 μm) was prepared. The storage modulus and water vapor transmission rate of triacetyl cellulose constituting the film were measured.
(C1-2. Hard coat)
The hard coat material solution (ii) obtained in (1-1) of example 1 was applied by gravure printing on one surface of the resin layer (CA) and dried (90 ℃ C..times.2 minutes). By this operation, a hard coat layer having a film thickness of 7 μm was formed, and a laminate (C-i) having a layer structure of (hard coat layer)/(resin layer (CA)) was obtained.
(C1-3. Polarizing film)
An on-line corona treatment was performed on the resin layer (CA) -side surface of the laminate (C-i) obtained in (C1-2), and an ultraviolet-curable adhesive was applied by a gravure coater (same as that used in example 1The binder is the same) to form a layer of binder. The resin layer (CA) and the polarizer Pa1 obtained in (1-5) of example 1 were pressed and bonded by pinch rolls via the adhesive layer. Next, the adherend was subjected to 750mJ/cm from the polarizer Pa1 side by an ultraviolet irradiation device 2 The adhesive layer was cured by ultraviolet irradiation to form an adhesive layer having a thickness of 2. Mu.m. By this operation, the polarizing film PC having a layer structure of (hard coat layer)/(resin layer (CA))/(adhesive layer)/(polarizer layer Pa 1) was obtained.
Some of the obtained polarizing films PC were used after the following step (C1-4). The other portion was used for evaluation of curling and stretching. As an evaluation of stretchability, the hard coat layer was peeled from the polarizing film PC, and the hard coat layer was rectangular with a length of 150mm and a width of 20mm, and was free uniaxially stretched in the longitudinal direction, and as a result, cracks were generated before the stretching magnification reached 1.50 times, and the subsequent stretching was not performed.
(C1-4. Bending test)
A bending test laminate was obtained and evaluated in the same manner as in (1-7) to (1-9) of example 1 except that the polarizing film PC obtained in (C1-3) was used instead of the polarizing film Pb1 in the production of the polarizing film composite with an adhesive layer and a release film of (1-8). However, since the polarizing film PC does not have a support, the support in (1-9) is not peeled off.
Comparative example 2
(C2-1. Resin layer (CA))
Acrylic resin (Sumipex HT55X, manufactured by sumitomo chemical corporation) was supplied to a hot melt extrusion film former having a T die. The acrylic resin was extruded from the T die and wound around a roll at a drawing speed of 4 m/min, whereby the acrylic resin was molded into a film shape. Thus, a long film (thickness: 40 μm) made of an acrylic resin was obtained. The film was used as a film constituting the resin layer (CA). The storage modulus and the water vapor permeability of the acrylic resin constituting the film were measured.
(C2-2. Polarizer)
Polarizer Pa3 was produced by the same operation as in (1-5) of example 1 except that a thicker film was used as the raw material film than that used in (1-5). The polarizer Pa3 had a thickness of 23. Mu.m.
(C2-3. Laminate, etc.)
Except for the following modifications, a laminate (C-i), a polarizing film and a bending test laminate were obtained and evaluated in the same manner as in (C1-2) to (C1-4) of comparative example 1.
As the resin layer (CA), a resin layer of (C2-1) was used instead of the resin layer of (C1-1).
As the polarizer, the polarizer Pa3 obtained in (C2-2) was used instead of the polarizer Pa1 obtained in example 1.
In the evaluation of the stretchability of the hard coat layer, cracks were generated before the stretch ratio reached 1.50 times, and the subsequent stretching was not performed.
Comparative example 3
(C3-1. Resin layer (CA))
Norbornene-based polymer resin (the same as used in example 3) was supplied to a hot melt extrusion film forming machine having a T die. The resin was extruded from the T die and wound around a roll at a drawing speed of 4 m/min, whereby the resin was molded into a film shape. Thus, a long film (thickness 23 μm) made of norbornene resin was obtained. The film was used as a film constituting the resin layer (CA). The storage modulus and the water vapor permeability of the resin constituting the film were measured.
(C3-2. Laminate, etc.)
A laminate (C-i), a polarizing film and a bending test laminate were obtained and evaluated by the same operations as those of (C1-2) to (C1-4) of comparative example 1 except that (C3-1) was used as the resin layer (CA) instead of (C1-1).
In the evaluation of the stretchability of the hard coat layer, cracks were generated before the stretch ratio reached 1.50 times, and the subsequent stretching was not performed.
The summaries and evaluation results of the examples and comparative examples are shown in tables 1 to 2.
TABLE 1
TABLE 1
Example 1 | Example 2 | Example 3 | Example 4 | |
Resin material | A1 | A1 | A2 | A2 |
Modulus of elasticity | 720 | 720 | 900 | 900 |
Water vapor transmission rate | 4.0 | 4.0 | 1 | 1 |
Thickness of resin layer | 5 | 1 | 5 | 1 |
Resin layer Re | 0 | 0 | 0 | 0 |
Thickness of polarizer | 7 | 7 | 7 | 7 |
Support type | OPP | OPP | OPP | OPP |
Overall thickness of | 41 | 37 | 41 | 37 |
Stretchability of | Has the following components | Has the following components | Has the following components | Has the following components |
Viscosity of the adhesive | Without any means for | Without any means for | Without any means for | Without any means for |
Curl value | 9 | 4 | 10 | 5 |
Curl evaluation | AA | AA | AA | AA |
Bending | AA | AA | A | A |
TABLE 2
TABLE 2
The meanings of abbreviations in the tables are as follows.
Resin material: a material of the resin used for the resin layer (a) or the resin layer (CA). A1: resin A1 prepared in example 1. A2: resin A2 prepared in example 3. TAC: triacetyl cellulose. PMMA: acrylic resin. 1430: norbornene-based polymer resins.
Modulus of elasticity: storage modulus of the resin material. Units: and (5) MPa.
Water vapor transmission rate: water vapor transmission rate of the resin material. Units: g/(m) 2 Day). Measurement value in measurement film having a thickness of 100. Mu.m.
Thickness of resin layer: thickness of the resin layer (a) or the resin layer (CA). Units μm.
Resin layer Re: in-plane retardation Re of the resin layer (a) or the resin layer (CA). In nm.
Thickness of polarizer: units μm.
Type of support: the type of support used. OPP: biaxially stretched polypropylene film. Si-PET: and (3) the PET film subjected to stripping treatment by using organosilicon.
Overall thickness: the total thickness of (hard coat layer)/(resin layer (a))/(adhesive layer)/(polarizer layer)/(adhesive layer), or the total thickness of (hard coat layer)/(resin layer (CA))/(adhesive layer)/(polarizer layer)/(adhesive layer). Units: μm.
Stretchability: as a result of evaluating the stretchability of the hard coat layer when forming the polarizing film. The method comprises the following steps: free uniaxial stretching of the hard coat layer can be performed up to 1.50 times without generating cracks. The method is free of: free uniaxial stretching of the hard coat layer to 1.50 times cannot be performed without generating cracks.
Viscosity: evaluation results of the tackiness of the hard coat layer at the time of forming the polarizing film. The method is free of: even if the hard coat layer is touched with a finger, the material constituting the hard coat layer does not adhere to the finger. The method comprises the following steps: when the hard coat layer is touched with a finger, the material constituting the hard coat layer adheres to the finger.
Crimping: the value of the value h1 in the evaluation of crimping. Units: mm. Cannot be measured: the curl was too strong to measure h1.
Crimping: evaluation result of crimping.
Bending: evaluation results of the bending test.
As is clear from the results of tables 1 to 2, the polarizing film of the present invention obtained using the transfer medium laminate of the present invention has a small tendency to curl and follows the curved shape well when attached to an aluminum plate having a curved surface. Accordingly, the polarizing film of the present invention can be preferably used for producing a molded body with a polarizer layer having a curved surface.
Claims (11)
1. A transfer medium laminate having a hard coat layer and a resin layer (A) provided on one surface of the hard coat layer,
the hard coat layer has a stretchability such that,
the storage modulus of the resin constituting the resin layer is 1000MPa or less.
2. The transfer medium laminate according to claim 1, wherein the thickness of the resin layer (a) is 0.1 μm or more and 10 μm or less.
3. The transfer medium laminate according to claim 1 or 2, wherein the resin layer (a) contains an ultraviolet absorber.
4. The transfer medium laminate according to any one of claims 1 to 3, wherein the hard coat layer is a semi-solid of a hard coat material, and the resin layer (a) is a layer formed on a surface of the semi-solid.
5. The transfer medium laminate according to any one of claims 1 to 4, wherein a retardation Re in an in-plane direction of the resin layer is 0nm or more and 5nm or less.
6. The transfer medium laminate according to any one of claims 1 to 5, further comprising a support provided on a surface of the hard coat layer on the opposite side from the resin layer (a) side.
7. The transfer medium laminate according to claim 6, wherein the support has a release layer provided on a surface of the hard coat layer side.
8. A method for producing the transfer medium laminate according to any one of claims 1 to 7, comprising the steps of:
a step of spreading a hard coating material on the surface of the support;
a step of semi-curing the hard coat material to form a hard coat layer having stretchability; and
and a step of developing a resin on the hard coat layer to form a resin layer (A) having a storage modulus of 1000MPa or less.
9. A polarizing film, comprising:
the transfer medium laminate according to any one of claims 1 to 7;
a polarizer layer provided on the resin layer (a) side of the transfer medium laminate; and
An adhesive layer interposed between the transfer medium laminate and the polarizer layer.
10. A method for manufacturing a polarizing film,
the polarizing film has: the transfer medium laminate according to any one of claims 1 to 7;
a polarizer layer provided on the resin layer (a) side of the transfer medium laminate; and
an adhesive layer interposed between the transfer medium laminate and the polarizer layer,
the resin layer (A) contains an ultraviolet absorber,
the method for manufacturing the polarizing film comprises the following steps: a step of bonding the transfer medium laminate to the polarizer layer via an ultraviolet-curable adhesive to form a bonded product; and
and irradiating the adherend with ultraviolet light from the polarizer layer side of the adherend.
11. A manufacturing method, which is a manufacturing method of a molded body with a polarizer layer, the manufacturing method comprising:
a step (a) of producing a polarizing film by the production method of claim 10;
a step (B) of bonding the polarizing film to a base member; and
a step (C) of mainly curing the hard coat layer in the polarizing film,
the base member used in the step (B) may be a member having a curved surface, or the manufacturing method may further include a step (Bx) of bending the base member after the step (B) and before the step (C).
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