Laminated film for image display device, surface protective film for image display device, laminate with liquid crystal polarizing film, and image display device

Abstract

To provide a laminate film that can suppress photo-degradation of an optical member and can accommodate the reduced thickness and weight of image displays.SOLUTION: A laminate film for image displays contains a base film and a cured resin layer formed from a curable resin composition. The average value of light transmittance at 300-430 nm is 35% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate film for an image display device, a surface protective film for an image display device, a laminate with a liquid crystal polarizing film, and an image display device. [Background technology]

[0002] BACKGROUND ART In recent years, image display devices such as liquid crystal display devices and organic EL devices have been required to be thinner, lighter, and have higher performance. As one means of improving the performance of image display devices, efforts are being made to suppress light degradation of the various optical components (hereinafter simply referred to as "optical components") that make up the image display device.One known example of this is an adhesive sheet containing an ultraviolet absorber that is placed between a surface protection panel and an image display module.

[0003] For example, Patent Document 1 discloses a film having an acrylic adhesive layer, * The optical pressure-sensitive adhesive sheet is disclosed, which has a transmittance of 0.42 or less and a transmittance of light with a wavelength of 350 nm of 5% or less. Furthermore, Patent Document 2 discloses an ultraviolet-curable acrylic pressure-sensitive adhesive layer that is disposed between a cover glass or cover plastic and a polarizing film in an image display device and has a transmittance of 40% or less at a wavelength of 380 nm and a transmittance of 30% or more at a wavelength of 400 nm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-214722 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-155981 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the transparent pressure-sensitive adhesives for image display devices having a light-absorbing function described in Patent Documents 1 and 2 complement the functions of polarizing plates such as conventional TAC films that have two protective films for protecting polarizers, i.e., protective films containing an ultraviolet absorber. Therefore, in order to respond to further reductions in thickness and weight of image display devices, it is necessary to suppress light degradation of optical components without providing protective films.

[0006] Therefore, an object of the present invention is to provide a laminated film that can suppress photodegradation of optical members and can also accommodate thinner and lighter image display devices. [Means for solving the problem]

[0007] The inventors have discovered that by using a laminated film that combines ultraviolet absorption and surface protection functions as a constituent component of an image display device, it is possible to suppress light degradation of optical components while achieving a thinner and lighter image display device, and have completed the present invention.

[0008] That is, the present invention provides the following [1] to

[29] . [1] A laminate film for an image display device, comprising a substrate film and a cured resin layer formed from a curable resin composition, the laminate film having an average light transmittance of 35% or less in the range of 300 to 430 nm. [2] The laminate film for an image display device according to [1] above, wherein the substrate film contains an ultraviolet absorber. [3] The laminate film for an image display device according to [2] above, wherein the ultraviolet absorber is at least one selected from the group consisting of triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and benzoxazine-based ultraviolet absorbers. [4] The laminate film for an image display device according to any one of the above [1] to [3], wherein the curable resin composition contains a (meth)acrylate and a modifier. [5] The laminate film for an image display device according to any one of the above [1] to [4], wherein the surface on which the cured resin layer is provided has a surface hardness of H or more. [6] The laminate film for an image display device according to any one of the above [1] to [5], which does not develop cracks after a bending test of 200,000 times under the condition of R=2 mm. [7] The laminate film for an image display device according to any one of the above [1] to [6], wherein the base film is a polyester film. [8] The laminate film for an image display device according to the above [7], wherein the polyester film has a three-layer structure. [9] The laminated film for an image display device according to the above [8], wherein the intermediate layer contains the ultraviolet absorber.

[10] The laminate film for an image display device according to any one of the above [1] to [9], wherein the thickness of the cured resin layer is 1 μm or more and 10 μm or less.

[11] The laminate film for an image display device according to any one of the above [1] to

[10] , wherein the thickness of the substrate film is 9 μm or more and 125 μm or less.

[12] The laminate film for an image display device according to any one of the above [1] to

[11] , wherein the thickness ratio of the base film to the cured resin layer is 6 or more.

[13] The laminate film for an image display device according to any one of the above [1] to

[12] , wherein the b value of the laminate film is 6.0 or less.

[14] The laminate film for an image display device according to any one of the above [1] to

[13] , which has a light transmittance of 57% or more at 410 nm.

[0009]

[15] A surface protective film for an image display device, in which the cured resin layer is provided on one surface of the base film, and an adhesive layer is provided on the other surface, in the laminate film for an image display device according to any one of [1] to

[14] above.

[16] The surface protective film for an image display device according to the above

[15] , wherein the adhesive layer contains a (meth)acrylic polymer (A).

[17] The surface protective film for an image display device according to the above

[15] or

[16] , wherein the adhesive layer contains a curable compound (B) and a radical polymerization initiator (C).

[18] The surface protective film for an image display device according to any one of the above

[15] to

[17] , wherein the thickness of the adhesive layer is 10 μm or more and 175 μm or less.

[19] A surface protective film with a release film, which is obtained by laminating the surface protective film for an image display device according to any one of the above

[15] to

[18] and a release film.

[0010]

[20] A laminate with a liquid crystal polarizing film, obtained by laminating the laminate film for an image display device according to any one of the above [1] to

[14] or the surface protective film for an image display device according to any one of the above

[15] to

[18] , and a liquid crystal polarizing film.

[21] The laminate with a liquid crystal polarizing film according to the above

[20] , wherein the liquid crystal polarizing film has an optically anisotropic layer.

[22] The laminate with a liquid crystal polarizing film according to the above

[20] or

[21] , wherein the liquid crystal polarizing film has an optically anisotropic layer and an alignment film.

[23] The laminate with a liquid crystal polarizing film according to the above

[21] or

[22] , wherein the optically anisotropic layer contains a polymerizable liquid crystal compound.

[24] The laminate with a liquid crystal polarizing film according to any one of the above

[21] to

[23] , wherein the optically anisotropic layer contains a polymerizable liquid crystal compound and a dye.

[25] The laminate with a liquid crystal polarizing film according to any one of the above

[20] to

[24] , wherein the thickness (total thickness) of the liquid crystal polarizing film is 1 / 5 or less of the thickness of the base film.

[26] Using a xenon light resistance tester (manufactured by Atlas, equipment name "Ci4000"), illuminance: 0.55 W / m 2 The laminate with a liquid crystal polarizing film according to any one of the above

[20] to

[25] , which shows a change in polarization degree of 4.0% or less at a wavelength of 595 nm after a test under irradiation conditions of (340 nm) for 40 hours.

[0011]

[27] An image display device comprising the laminate film for an image display device according to any one of the above [1] to

[14] or the surface protective film for an image display device according to any one of the above

[15] to

[18] .

[28] An image display device comprising the laminate with a liquid crystal polarizing film according to any one of the above

[20] to

[26] .

[29] An image display device comprising the laminate film for an image display device according to any one of the above [1] to

[14] or the surface protective film for an image display device according to any one of the above

[15] to

[18] , laminated with an anti-reflection film and / or a color filter. [Effects of the Invention]

[0012] The laminate film for an image display device according to the present invention has both an ultraviolet absorbing function and a surface protecting function, and therefore can suppress photodegradation of optical components without sandwiching a polarizer on both sides with protective films containing an ultraviolet absorber, as in the case of conventional TAC films, and can contribute to making image display devices thinner, lighter, and more resistant to photodegradation. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view showing an example of a laminate film for an image display device of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an example of a surface protection film for an image display device of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of a laminate with a liquid crystal polarizing film of the present invention. [Figure 4] 1 is a schematic cross-sectional view showing an example of an image display device of the present invention. [Figure 5] FIG. 10 is a schematic cross-sectional view showing another example of an image display device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, an example of an embodiment of the present invention will be described, but the present invention is not limited to the embodiment described below.

[0015] <Laminated film for image display devices> [Physical Properties] First, the physical properties of the laminate film for an image display device according to the present invention (hereinafter also referred to as "the present laminate film") will be described.

[0016] (UV absorption performance) The present laminated film has an average light transmittance of 35% or less in the range of 300 to 430 nm, preferably 33% or less, and more preferably 31% or less. By satisfying the above requirements, good ultraviolet absorbing performance can be exhibited, and photodegradation of optical components can be suppressed.

[0017] (Surface hardness) The surface hardness of the surface of the present laminate film on which the cured resin layer is provided is preferably H or more from the viewpoint of protecting the surface of the image display device. The surface hardness in the present invention is a pencil hardness determined in accordance with JIS K 5600-5-4:1999 under a load of 750 g using a pencil hardness tester (manufactured by Yasuda Seiki Co., Ltd.).

[0018] (Flexibility) It is preferable that the present laminated film does not crack when subjected to a bending test of 200,000 times under the condition of R=2 mm. More specifically, a bending tester (DLDMLH-FS, manufactured by Yuasa System Equipment Co., Ltd.) is used to perform a bending test 200,000 times at R = 2 mm with the cured resin layer side of the laminated film facing outward, and the presence or absence of cracks in the cured resin layer on the outward surface can be determined by visually checking.

[0019] (shock resistance) In the present laminate film, when impact resistance is to be imparted, the ratio of the thickness of the base film to the thickness of the cured resin layer is preferably at least 6. This ratio is more preferably at least 10, and particularly preferably at least 15. By satisfying this range, impact resistance can be imparted to the base film itself, and bending resistance can also be imparted to the cured resin layer, even though it is a thin film.

[0020] (Color (b value)) The b value of the present laminated film is preferably 6.0 or less, more preferably 5.8 or less, even more preferably 4.0 or less, and even more preferably 2.0 or less.

[0021] As described below, because the liquid crystal polarizing film itself is composed of organic compounds consisting of a polymerizable liquid crystal compound and a dye, there is a concern that the color tone may change over time. If the present laminate film is attached to a liquid crystal polarizing film via an adhesive layer as a cover film for a display in order to suppress this color tone change over time, it is expected that the color of the display screen when viewed from the cover film side (the present laminate film side) will change significantly depending on the color of the laminate film itself. Therefore, when combining a liquid crystal polarizing film with the present laminate film, it is preferable that the color of the laminate film itself be close to colorless and transparent, from the viewpoints of suppressing color tone change over time and suppressing color change on the display screen.

[0022] (Light transmittance at 410 nm) The light transmittance of the present laminated film at 410 nm is preferably 55% or more, more preferably 57% or more, even more preferably 65% ​​or more, and particularly preferably 80% or more. In particular, when the base film constituting the laminated film is a polyester film, if an attempt is made to keep the wavelength in the visible light region of 410 nm or more low, the film itself tends to become yellow and easily discolored, so it is preferable to keep it in the above range. Therefore, in the present invention, it is preferable not to impart to the laminate film a function of cutting light in the wavelength region of 410 nm or more (for example, blue light of 415 to 430 nm, etc.). In the present invention, wavelengths of 410 nm or more are controlled by a liquid crystal polarizing film or a color filter combined with the laminate film, and by dividing the controlled wavelength range between the laminate film and the liquid crystal polarizing film or the color filter, it is possible to control the light transmittance from the ultraviolet region to the visible light region.

[0023] [composition] Next, the configuration of the present laminate film will be described. As shown in Fig. 1, the present laminate film 10 comprises a base film 2 and a cured resin layer 1. Each of the components will be described in detail below.

[0024] 1. Base film The material of the substrate film constituting the present laminate film is not particularly limited as long as it is film-shaped. The material of the substrate film may be, for example, paper, resin, metal, etc. Among these, a resin substrate film is preferred from the viewpoints of mechanical strength and flexibility.

[0025] Examples of resin substrate films include polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as cycloolefin polymer (COP); polyester resin; polystyrene resin; (meth)acrylic resin; polycarbonate resin; polyurethane resin; triacetyl cellulose (TAC) resin; polyvinyl chloride resin; polyether resins such as polyether ketone and polyether sulfone; and resin films formed from polymers such as polyamide resin, polyimide resin, and polyamideimide resin in the form of a film. Furthermore, if it is possible to form a film, a mixture of the above-exemplified materials (polymer blend) or a composite of the structural units (copolymer) may be used.

[0026] Among the films exemplified above, polyester films containing polyester as the main resin are preferred from the viewpoints of heat resistance, flatness, optical properties, strength, etc. The term "main resin" refers to the resin that is contained in the film in the largest proportion, for example, 50% by mass or more, particularly 70% by mass or more, and even more particularly 80% by mass or more (including 100% by mass). The polyester film may be a single layer or a multilayer film (i.e., a laminate film) having two or more layers with different properties. The polyester film may be a non-stretched film (sheet) or a stretched film. Among these, a stretched film stretched uniaxially or biaxially is preferred. Among these, a biaxially stretched film is more preferred from the viewpoint of balance of mechanical properties and flatness. Therefore, a biaxially stretched polyester film is even more preferred.

[0027] When the polyester is a homopolyester, the homopolyester is preferably one obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include isophthalic acid, phthalic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid, with terephthalic acid being preferred. Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol, with ethylene glycol being preferred. Representative examples of homopolyester include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

[0028] On the other hand, when the polyester is a copolymer polyester, it contains a third component as a copolymerization component other than the compound that is the main component of the dicarboxylic acid component constituting the polyester and the compound that is the main component of the diol component. For example, in the case of PET, the third component is a component other than terephthalic acid and ethylene glycol. Specific examples of the dicarboxylic acid and diol of the main component are as described above. Specific examples of the dicarboxylic acid as the third component include the aromatic dicarboxylic acids described above, as well as aliphatic dicarboxylic acids such as adipic acid and sebacic acid. Specific examples of the diol as the third component include the aliphatic glycols described above.

[0029] The copolymer polyester preferably contains terephthalic acid as the dicarboxylic acid, ethylene glycol as the glycol component, and a dicarboxylic acid or glycol other than terephthalic acid and ethylene glycol as the third component. In the case of the copolymer polyester, the copolymer component is preferably 30 mol % or less out of 100 mol % of all dicarboxylic acid components, and the copolymer component is preferably 30 mol % or less out of 100 mol % of all diol components.

[0030] Particles may be blended into the base film for the main purposes of imparting lubricity and preventing scratches during each process. The type of particles is not particularly limited as long as they are particles that can impart lubricity, and examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenolic resin, epoxy resin, and benzoguanamine resin. Furthermore, in the case of polyester films, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester production process can also be used.

[0031] The shape of the particles to be used is not particularly limited, and any of spherical, blocky, rod-like, flat, etc. may be used. Furthermore, there are no particular limitations on the hardness, specific gravity, color, etc. Two or more types of these particles may be used in combination as needed. The average particle size of the particles used is preferably 5 μm or less, more preferably in the range of 0.1 to 3 μm. By setting the average particle size within this range, the film is given an appropriate surface roughness, ensuring good slipperiness and smoothness. Here, the average particle size of the particles can be determined by measuring the diameters of 10 or more particles using a scanning electron microscope (SEM) and taking the average value. In this case, in the case of non-spherical particles, the average value of the longest and shortest diameters can be measured as the diameter of each particle. When particles are blended, it is preferable that the substrate film has a laminated structure and the particles are contained in the surface layer, as described below. In this case, it is more preferable that the substrate film has a multilayer structure having a particle-containing surface layer, a base layer, and another particle-containing surface layer in this order.

[0032] The content of particles in the substrate film is preferably 5% by mass or less, more preferably in the range of 0.0003 to 3% by mass, based on 100% by mass of the substrate film containing the particles. By setting the particle content within this range, it becomes easier to impart slipperiness to the substrate film while ensuring the transparency of the substrate film. However, the substrate film may be substantially free of particles. When the substrate film has a laminated structure, the particle content is the content of particles in 100% by mass of the layer containing the particles. In this specification, "substantially free of particles" means that particles are not intentionally contained, and specifically refers to a particle content (particle mass concentration) of 200 ppm or less, more preferably 150 ppm or less, relative to the member or layer (here, the substrate film). Similar terms used below also have similar meanings. When the substrate film does not substantially contain particles or the content is small, the transparency of the substrate film is high, the film has a good appearance, and the smoothness of the cured resin layer surface is likely to be high. On the other hand, the slipperiness of the laminated film may be insufficient. In such a case, for example, the slipperiness may be improved by blending particles into the cured resin layer, or the slipperiness may be improved by providing a slippery layer containing particles, as described below.

[0033] [Base film thickness] The thickness of the substrate film is preferably 9 to 125 μm, more preferably 12 to 100 μm, and even more preferably 20 to 75 μm. When the thickness of the substrate film is within the above range, it is possible to achieve both a thinner image display device and a surface protection function.

[0034] [Base film composition] The substrate film may be composed of a single layer, or may have a laminated structure having two or more layers. Examples of the laminate structure of the substrate film include a three-type, three-layer structure (B / A / C) composed of a base layer A, a surface layer B, and a surface layer C, and a two-type, three-layer structure (B / A / B) composed of a base layer A and a surface layer B. As described above, the main component resin constituting each of the base layer A, surface layer B, and surface layer C is preferably polyester. That is, it is preferable that the substrate film is a polyester film and that the polyester film has a three-layer structure.

[0035] In the three-layer structure of B / A / C and B / A / B, the surface layer B and the surface layer C may contain the above-mentioned particles to ensure ease of handling. In the above-mentioned three-layer structure of B / A / C and B / A / B, the surface layer B and the surface layer C may contain, as the above-mentioned particles, particles having a narrow particle size distribution and a substantially uniform average particle size (so-called monodispersity).

[0036] The average particle size of the particles in the surface layer B is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm.The average particle size of the particles in the surface layer C is preferably 0.05 to 5 μm, more preferably 0.05 to 3 μm. The average particle size of particles can be determined by measuring the diameters of 10 or more particles using a scanning electron microscope (SEM) and taking the average value. In this case, for non-spherical particles, the average value of the longest and shortest diameters can be measured as the diameter of each particle.

[0037] The particle content in each of the surface layers B and C is preferably 200 ppm or more, more preferably 300 to 10,000 ppm, even more preferably 350 to 9,500 ppm, and even more preferably 400 to 9,000 ppm. In particular, the content of particles in the surface layer B is preferably less than 5000 ppm, and more preferably 300 to 4000 ppm. Moreover, the particle content of the surface layer C is particularly preferably 200 ppm or more and 6000 ppm or less from the viewpoint of handling of the film.

[0038] The base layer A preferably functions as the thickest main layer, and in order to reduce costs, it preferably contains substantially no particles or at least a lower concentration of particles than the surface layer B.

[0039] [UV absorber] The substrate film preferably contains an ultraviolet absorber, which can suppress photodegradation of optical components. When the base film is made of a laminated polyester film, it is preferable that the ultraviolet absorber is contained in at least one layer. From the viewpoint of preventing bleed-out of the ultraviolet absorber, it is more preferable that the ultraviolet absorber be contained in an intermediate layer (layer A in the case of the above-mentioned B / A / C structure or B / A / B structure).

[0040] Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, benzoxazine-based ultraviolet absorbers, etc. These ultraviolet absorbers can be used alone or in combination of two or more.

[0041] Examples of benzophenone-based ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulfonate, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.

[0042] Examples of benzotriazole-based ultraviolet absorbers include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, and 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole. Examples of such benzotriazoles include chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-(2H-benzotriazol-2-yl)phenol, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(2-hydroxyethyl)phenol], and 2-[2-hydroxy-3-(4,5,6,7-tetrahydro-1,3-dioxo-1H-isoindol-2-ylmethyl)-5-methylphenyl]-2H-benzotriazole.

[0043] Examples of triazine-based ultraviolet absorbers include 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-ethoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-propoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-butoxyphenyl)-4,6-diphenyl-1,3,5-triazine, and 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine. ,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-benzyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxy- 3-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine )-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-acryloyloxyethoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxynaphthyl)-1,3,5-triazine, and 2,4,6-tris(2-hydroxynaphthyl)-1,3,5-triazine.

[0044] Examples of salicylic acid-based ultraviolet absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate. Examples of cyanoacrylate ultraviolet absorbers include 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate. Examples of benzoxazine-based ultraviolet absorbers include 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one), 2-methyl-3,1-benzoxazin-4-one, 2-butyl-3,1-benzoxazin-4-one, and 2-phenyl-3,1-benzoxazin-4-one.

[0045] Among these, from the viewpoint of effectively suppressing photodegradation of optical components, at least one selected from the group consisting of benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzoxazine-based ultraviolet absorbers is preferred, and at least one selected from the group consisting of triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and benzoxazine-based ultraviolet absorbers is more preferred.

[0046] From the viewpoint of improving lightfastness reliability, the lower limit of the content of the ultraviolet absorber is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.5% by mass or more, still more preferably 3% by mass or more, and particularly preferably 5% by mass or more, based on 100% by mass of the substrate film containing the ultraviolet absorber. When the substrate film has a laminated structure, the content of the ultraviolet absorber is the amount of the ultraviolet absorber in 100% by mass of the layer containing the ultraviolet absorber. On the other hand, the upper limit of the content of the ultraviolet absorber is preferably 15% by mass or less, more preferably 12% by mass or less, even more preferably 10% by mass or less, still more preferably 8% by mass or less, and particularly preferably 7% by mass or less, from the viewpoint of suppressing bleed-out and improving yellowing resistance. When two or more of the above ultraviolet absorbents are used in combination, the total amount thereof should fall within the above range.

[0047] 2. Cured resin layer The cured resin layer constituting the present laminated film is formed by curing a curable resin composition, and has the function of protecting an optical member, for example. The cured resin layer may be provided on only one side of the substrate film, or on both sides.

[0048] The curable resin composition may contain a photopolymerizable compound and / or a thermally polymerizable compound as a component that becomes a polymer upon polymerization. In the present invention, however, a photocurable resin composition containing a photopolymerizable compound is preferred. Being photocurable eliminates the need for high-temperature heat treatment to cure the curable resin composition, thereby preventing the generation of impurities due to heat treatment, the occurrence of thermal shrinkage, and the like. Examples of polymerizable compounds include monomers having one or more polymerizable functional groups in one molecule.

[0049] [Curable resin composition (α)] The curable resin composition of the present invention is preferably a curable resin composition (α) containing an (HA) (meth)acrylate and an (HB) modifier. In the curable resin composition (α), the (HA) component is typically a photopolymerizable compound, and both the (HA) component and the (HB) component may be photopolymerizable compounds. In the present invention, when the expression "(meth)acrylate" is used, it means one or both of "acrylate" and "methacrylate". When the expression "(meth)acryloyl" is used, it means one or both of "acryloyl" and "methacryloyl". When the expression "(meth)acrylic" is used, it means one or both of "acrylic" and "methacrylic", and the same applies to other similar expressions. The (meth)acryloyl group concentration of the (meth)acryloyl group-containing compound used in the present invention may be expressed as (meth)acryloyl group equivalent (g / eq). The (meth)acryloyl group equivalent is the average molecular weight per (meth)acryloyl group. For example, if a (meth)acrylate compound with a number average molecular weight (Mn) of 10,000 contains 10 (meth)acryloyl groups per molecule, the (meth)acryloyl group equivalent is 10,000 / 10 = 1,000 g / eq. The number average molecular weight (Mn) is a value measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene.

[0050] ((HA)(meth)acrylate) By including (meth)acrylate (HA), the curable resin composition (α) tends to have a favorable effect of improving the flex resistance of the cured resin layer, and also tends to improve scratch resistance and adhesion to the substrate film. Examples of (HA) (meth)acrylates include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris-2-hydroxyethyl isocyanurate tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate. trifunctional or higher polyfunctional (meth)acrylates containing three or more ethylenically unsaturated groups, such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane hexa(meth)acrylate; Modified polyfunctional (meth)acrylate compounds substituted with ethylene; polyfunctional (meth)acrylates having a nitrogen atom-containing heterocyclic structure such as polyfunctional (meth)acrylates having an isocyanurate structure; polyfunctional (meth)acrylates having a dendrimer structure, polyfunctional (meth)acrylates having a hyperbranched resin structure such as polyfunctional (meth)acrylates having a hyperbranched structure; polyisocyanates such as diisocyanates and triisocyanates, or trimers (isocyanurates) thereof, for example, pentaerythritol, Examples include urethane (meth)acrylates to which (meth)acrylates having hydroxyl groups such as thritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate are added, and polyfunctional urethane (meth)acrylates formed from the reaction product of a polyol compound having two or more hydroxyl groups in the molecule, a compound having two or more isocyanate groups in the molecule, and a (meth)acrylate containing at least one hydroxyl group in the molecule. The (meth)acrylate having hydroxyl groups is preferably polyfunctional having two or more ethylenically unsaturated groups.The (HA) (meth)acrylate preferably includes a urethane (meth)acrylate.

[0051] Among the above, from the viewpoints of the scratch resistance and weather resistance of the coating film and the effect of suppressing the bleeding out of the ultraviolet absorber, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, urethane(meth)acrylate which is a reaction product of pentaerythritol tri(meth)acrylate and hexamethylene diisocyanate, and urethane(meth)acrylate which is a reaction product of pentaerythritol tri(meth)acrylate and isophorone diisocyanate are preferred. Preferred are urethane (meth)acrylates, which are reaction products of dipentaerythritol penta(meth)acrylate and hexamethylene diisocyanate, urethane (meth)acrylates, which are reaction products of dipentaerythritol penta(meth)acrylate and isophorone diisocyanate, and polyfunctional urethane (meth)acrylates formed from reaction products of a polyol compound having two or more hydroxyl groups in the molecule, a compound having two or more isocyanate groups in the molecule, and a (meth)acrylate containing at least one hydroxyl group in the molecule. These may be used alone or in combination of two or more.

[0052] Furthermore, among the above, trifunctional to hexafunctional polyfunctional (meth)acrylates or urethane (meth)acrylates obtained by adding a polyfunctional (e.g., trifunctional to pentafunctional) (meth)acrylate having a hydroxyl group to a polyisocyanate are more preferred, and it is also more preferred to use the above polyfunctional (meth)acrylates in combination with urethane (meth)acrylates. Furthermore, it is more preferred that the polyisocyanate used in the urethane (meth)acrylate is a diisocyanate.

[0053] The mass average molecular weight of the (HA) (meth)acrylate is, for example, from 250 to 8000, preferably from 300 to 7000, more preferably from 400 to 5000, and particularly preferably from 500 to 4000. By satisfying the above range, the bleed-out suppression effect of the ultraviolet absorber can be improved. The mass average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene.

[0054] The (meth)acryloyl group equivalent of the (HA) (meth)acrylate may be, for example, 80 g / eq or more and less than 150 g / eq, preferably 85 g / eq or more and less than 135 g / eq, and more preferably 90 g / eq or more and less than 120 g / eq. When the (meth)acryloyl group equivalent of the (A) (meth)acrylate is within the above range, flex resistance can be imparted.

[0055] As described above, the urethane (meth)acrylate used as the component (HA) is a reaction product of a polyisocyanate or isocyanurate with a (meth)acrylate having a hydroxyl group, but it may also be produced by reacting a polyisocyanate or isocyanurate with a mixture of a (meth)acrylate having a hydroxyl group and a (meth)acrylate having no hydroxyl group. In this case, the (meth)acrylate having no hydroxyl group remains as an unreacted product, but it is preferable to incorporate it as is into the curable resin composition (α) and use it as the component (HA).

[0056] ((HB) modifier) The curable resin composition (α) has the advantage that by using the (HA) (meth)acrylate component and the (HB) modifier in combination, it is possible to maintain or improve flex resistance while preventing the occurrence of curling, heat wrinkles, etc., and to improve the film flatness. The (HB) modifier is not particularly limited as long as it does not impair the gist of the present invention, but it is preferable to use at least one selected from a (meth)acrylic polymer and a urethane (meth)acrylate. Here, the (HB) modifier preferably has a larger molecular weight than the (HA) (meth)acrylate, which provides a modifying effect of improving the film flatness.

[0057] The urethane (meth)acrylate used as the (HB) modifier may be used as a component that modifies the curable resin composition (α) containing, for example, a (HA) component that contains a (meth)acrylate, and it is preferable to use a component having a larger molecular weight than the (meth)acrylate as the (HA) component. Therefore, when the curable resin composition (α) contains a urethane (meth)acrylate as the (HB) component, it is preferable that the curable resin composition (α) contains a urethane (meth)acrylate as the (HA) component and a urethane (meth)acrylate as the (HB) component having a mass average molecular weight greater than that of the urethane (meth)acrylate of the (HA) component.

[0058] =(Meth)acrylic polymer= The mass average molecular weight of the (meth)acrylic polymer used as the (HB) component is larger than that of the (A) (meth)acrylate, and is preferably 1,000 or more and 100,000 or less, more preferably 3,000 or more and 70,000 or less, even more preferably 5,000 or more and 30,000 or less, and even more preferably 10,000 or more and 30,000 or less.

[0059] When the mass average molecular weight of the (meth)acrylic polymer is 1,000 or more and 100,000 or less, the flatness of the film can be easily ensured. Furthermore, when the mass average molecular weight of the (meth)acrylic polymer is 1,000 or more, a decrease in the surface hardness of the cured resin layer can be prevented. Furthermore, when the mass average molecular weight of the (meth)acrylic polymer is 70,000 or less, an increase in the viscosity of the coating liquid can be prevented, and a decrease in the smoothness of the cured resin layer can be prevented.

[0060] The (meth)acrylic polymer is a polymer having a (meth)acrylic acid alkyl ester as a main structural unit. Examples of the (meth)acrylic acid alkyl ester include (meth)acrylic acid chain alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate, and (meth)acrylic acid alkyl esters having a cyclic structure such as isobornyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentaenyl (meth)acrylate, and adamantyl (meth)acrylate. These may be used alone or in combination of two or more. Among these, methyl (meth)acrylate is preferred from the viewpoints of the compatibility of the (meth)acrylic polymer with (meth)acrylate and the heat resistance of the cured resin layer. That is, a polymer having methyl (meth)acrylate as a main structural unit is preferred. The (meth)acrylic polymer may also have a radically polymerizable double bond. Incidentally, the term "main structural unit" means that the structural unit is the main component in the (meth)acrylic polymer, and is contained in an amount of, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 85% by mass or more.

[0061] The (meth)acrylic polymer can be copolymerized with (meth)acrylic acid esters other than (meth)acrylic acid alkyl esters, (meth)acrylic acid, or other compounds having a vinyl group, for the purpose of improving the glass transition temperature, mechanical properties, compatibility, etc. Examples of the (meth)acrylic acid esters other than (meth)acrylic acid alkyl esters include hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, alkoxyalkyl (meth)acrylates such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, glycidyl (meth)acrylate, and γ-butyrolactone (meth)acrylate. Examples of the compound having a vinyl group include acrylamide compounds such as dimethylacrylamide, hydroxyethylacrylamide, and dimethylaminopropylacrylamide; styrene compounds such as styrene, α-methylstyrene, and p-methoxystyrene; and maleic anhydride.

[0062] The glass transition temperature (Tg) of the (meth)acrylic polymer is preferably 60° C. or higher, more preferably 80° C. or higher, and even more preferably 90° C. or higher, from the viewpoint of improving the mechanical properties of the cured resin layer. Furthermore, the glass transition temperature (Tg) is preferably 140° C. or lower, more preferably 130° C. or lower, and even more preferably 120° C. or lower, from the viewpoint of improving the processability of a laminate film having the cured resin layer laminated thereon.

[0063] The glass transition temperature (Tg) can be calculated from the type and mass fraction of the monomers forming the (meth)acrylic polymer using the following Fox formula. 1 / Tg=Σ(Wi / Tgi) In the above formula, Tg represents the glass transition temperature (unit: K) of the (meth)acrylic polymer, Wi represents the mass fraction of the monomer units derived from monomer i constituting the (meth)acrylic polymer, and Tgi represents the glass transition temperature (unit: K) of the homopolymer of monomer i. The value of Tgi can be the value described in POLYMERHANDBOOK Volume 1 (WILEY-INTERSCIENCE).

[0064] =Urethane (meth)acrylate= The urethane (meth)acrylate used as the (HB) modifier is obtained by reacting an isocyanate compound with a hydroxyl group-containing (meth)acrylate compound, or by reacting an isocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound. The urethane (meth)acrylate can be used alone or in combination with two or more types. The use of a urethane (meth)acrylate as the (HB) modifier improves scratch resistance.

[0065] Examples of the isocyanate compound include polyisocyanate compounds such as aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates, among which diisocyanate compounds are preferred. Examples of the isocyanate compound include isocyanate compounds having an isocyanurate skeleton obtained by isocyanating a diisocyanate compound. Examples of the aromatic polyisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, pentamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate. Examples of the alicyclic polyisocyanate include hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-bis(isocyanatomethyl)cyclohexane. Among these, aliphatic diisocyanates or alicyclic diisocyanates are preferred because of their excellent yellowing resistance. Also preferred are isocyanate compounds having an isocyanurate skeleton, and from the same viewpoint, isocyanurate compounds having an isocyanurate skeleton obtained by isocyanating aliphatic diisocyanates or alicyclic diisocyanates are also preferred, and among these, isocyanate compounds having an isocyanurate skeleton are more preferred. The isocyanate compounds may be used alone or in combination of two or more.

[0066] Examples of the hydroxyl group-containing (meth)acrylate include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; ethyl (meth)acrylates such as 2-hydroxyethyl acryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate; Examples of the hydroxyl group-containing (meth)acrylate include monofunctional hydroxyl group-containing (meth)acrylates containing one ethylenically unsaturated group; bifunctional hydroxyl group-containing (meth)acrylates containing two ethylenically unsaturated groups, such as glycerin di(meth)acrylate and 2-hydroxy-3-acryloyl-oxypropyl methacrylate; and trifunctional or higher hydroxyl group-containing (meth)acrylates containing three or more ethylenically unsaturated groups, such as pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate. These may be used alone or in combination of two or more. Among these, (meth)acrylate compounds containing three or less ethylenically unsaturated groups are preferred, as they have excellent reactivity and versatility and provide an excellent balance between the scratch resistance and film flatness of the cured coating film. Furthermore, polyfunctional (meth)acrylate compounds containing two or more ethylenically unsaturated groups are more preferred, with pentaerythritol tri(meth)acrylate and / or pentaerythritol tetra(meth)acrylate being particularly preferred.

[0067] The polyol compound may be any compound having two or more hydroxyl groups (excluding the hydroxyl group-containing (meth)acrylates).

[0068] Examples of the polyol-based compound include aliphatic polyols, alicyclic polyols, polyether-based polyols, polyester-based polyols, polycarbonate-based polyols, polyolefin-based polyols, polybutadiene-based polyols, polyisoprene-based polyols, (meth)acrylic-based polyols, and polysiloxane-based polyols.

[0069] Examples of the aliphatic polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, dimethylolpropane, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, 1 Examples of suitable hydroxyl groups include aliphatic alcohols containing two hydroxyl groups such as 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, pentaerythritol diacrylate, 1,9-nonanediol, and 2-methyl-1,8-octanediol; sugar alcohols such as xylitol and sorbitol; and aliphatic alcohols containing three or more hydroxyl groups such as glycerin, trimethylolpropane, and trimethylolethane.

[0070] Examples of the alicyclic polyol include cyclohexanediols such as 1,4-cyclohexanediol and cyclohexyldimethanol, hydrogenated bisphenols such as hydrogenated bisphenol A, and tricyclodecane dimethanol.

[0071] Examples of polyether polyols include alkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polypentamethylene glycol, and polyhexamethylene glycol, and random or block copolymers of these polyalkylene glycols.

[0072] Examples of polyester polyols include condensation polymers of polyhydric alcohols and polycarboxylic acids, ring-opening polymers of cyclic esters (lactones), and reaction products of three components: polyhydric alcohols, polycarboxylic acids, and cyclic esters.

[0073] Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylene diol, 1,3-tetramethylene diol, 2-methyl-1,3-trimethylene diol, 1,5-pentamethylene diol, neopentyl glycol, 1,6-hexamethylene diol, 3-methyl-1,5-pentamethylene diol, 2,4-diethyl-1,5-pentamethylene diol, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (such as 1,4-cyclohexanediol), bisphenols (such as bisphenol A), and sugar alcohols (such as xylitol and sorbitol).

[0074] Examples of the polycarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, and trimellitic acid.

[0075] Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone.

[0076] Examples of the polycarbonate polyol include a reaction product of a polyhydric alcohol with phosgene, and a ring-opening polymer of a cyclic carbonate (such as alkylene carbonate).

[0077] Examples of the polyhydric alcohols used in the polycarbonate-based polyols include the polyhydric alcohols exemplified in the description of the polyester-based polyols, and examples of the alkylene carbonates include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate.

[0078] The polycarbonate polyol may be any compound having a carbonate bond in the molecule and a hydroxyl group at the end, and may have an ester bond in addition to the carbonate bond.

[0079] The polyolefin polyols include those having a homopolymer or copolymer of ethylene, propylene, butene, or the like as a saturated hydrocarbon skeleton and having hydroxyl groups at the molecular terminals.

[0080] The polybutadiene-based polyols include those having a butadiene copolymer as a hydrocarbon skeleton and having hydroxyl groups at the molecular terminals. The polybutadiene polyol may be a hydrogenated polybutadiene polyol in which all or part of the ethylenically unsaturated groups contained in the structure thereof have been hydrogenated.

[0081] The polyisoprene-based polyols include those having an isoprene copolymer as a hydrocarbon skeleton and having hydroxyl groups at the molecular terminals. The polyisoprene-based polyol may be a hydrogenated polyisoprene polyol in which all or part of the ethylenically unsaturated groups contained in the structure thereof have been hydrogenated.

[0082] The (meth)acrylic polyols include those having at least two hydroxyl groups in the molecule of a (meth)acrylic acid ester polymer or copolymer, and examples of such (meth)acrylic acid esters include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. Furthermore, copolymers of a (meth)acrylic acid ester with a hydroxyalkyl (meth)acrylate such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate may also be used.

[0083] Examples of the polysiloxane polyol include dimethylpolysiloxane polyol and methylphenylpolysiloxane polyol.

[0084] The above polyol compounds can be used alone or in combination of two or more.

[0085] In the addition reaction of the above-mentioned isocyanate compound with a hydroxyl group-containing (meth)acrylate compound, or an isocyanate compound, a hydroxyl group-containing (meth)acrylate compound, and a polyol, the reaction is terminated when the residual isocyanate group content in the reaction system reaches 0.5 mass% or less, thereby obtaining a urethane (meth)acrylate.

[0086] When the urethane (meth)acrylate used as the (HB) modifier includes a compound obtained by reacting an isocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound, the urethane (meth)acrylate may be obtained by reacting a reaction product having an isocyanate group obtained by reacting an isocyanate compound with a polyol compound, or a mixture of the reaction product and an isocyanate compound, with a hydroxyl group-containing (meth)acrylate compound. The urethane (meth)acrylate used as an (HB) modifier obtained by such a reaction may be a mixture of one obtained by reacting an isocyanate compound with a hydroxyl group-containing (meth)acrylate compound, and one obtained by reacting an isocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound.

[0087] In the reaction between an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, it is also preferable to use a catalyst to promote the reaction. Examples of such catalysts include organometallic compounds such as dibutyltin dilaurate, dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, zinc bisacetylacetonate, zirconium tris(acetylacetonate)ethylacetoacetate, and zirconium tetraacetylacetonate; metal salts such as tin octenoate, zinc hexanoate, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannic chloride, and potassium acetate; triethylamine, triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, and 1,8-diazabicyclo[5,4,0]undecane. Examples of suitable catalysts include amine catalysts such as decene, N,N,N',N'-tetramethyl-1,3-butanediamine, N-methylmorpholine, and N-ethylmorpholine; bismuth nitrate, bismuth bromide, bismuth iodide, and bismuth sulfide; organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate; and organic acid bismuth salts such as bismuth 2-ethylhexanoate, bismuth naphthenate, bismuth isodecanoate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bisneodecanoate, bismuth disalicylate, and bismuth digallate. Among these, dibutyltin dilaurate and 1,8-diazabicyclo[5.4.0]undecene are particularly suitable. These catalysts may be used alone or in combination.

[0088] In the reaction between an isocyanate compound and a hydroxyl group-containing (meth)acrylate compound, an organic solvent that does not have a functional group that reacts with an isocyanate group, such as an ester such as ethyl acetate or butyl acetate, a ketone such as methyl ethyl ketone or methyl isobutyl ketone, or an aromatic solvent such as toluene or xylene, can be used. In addition, a polymerization inhibitor or the like may be used as appropriate.

[0089] The urethane (meth)acrylate used as the (HB) component is a reaction product of a hydroxyl group-containing (meth)acrylate compound and an isocyanate compound, or a hydroxyl group-containing (meth)acrylate compound, an isocyanate compound, and a polyol compound. Alternatively, the urethane (meth)acrylate may be produced by reacting a mixture of a hydroxyl group-containing (meth)acrylate and a hydroxyl group-free (meth)acrylate with an isocyanate compound. Alternatively, the urethane (meth)acrylate may be produced by reacting a mixture of a hydroxyl group-containing (meth)acrylate and a hydroxyl group-free (meth)acrylate with an isocyanate compound and a polyol compound. In this case, the hydroxyl group-free (meth)acrylate remains unreacted, but it may be incorporated as is into the curable resin composition and used as the (HA) component. Furthermore, in the reaction between the isocyanate compound and the hydroxyl group-containing (meth)acrylate compound described above, part or all of the isocyanate compound may be a reaction product of the isocyanate compound and the polyol compound, as described above.

[0090] The mass average molecular weight of the urethane (meth)acrylate used as the (HB) modifier is larger than that of the (HA) (meth)acrylate, for example, from 3,000 to 100,000, preferably from 5,000 to 70,000, and more preferably from 8,000 to 30,000. By satisfying this range, good film flatness can be ensured by forming a cured resin layer in a laminate structure such as a laminate film.

[0091] The (meth)acryloyl group equivalent of the urethane (meth)acrylate as the (HB) component should be greater than the (meth)acryloyl group equivalent of the urethane (meth)acrylate as the (HA) component. Specific (meth)acryloyl group equivalents of the urethane (meth)acrylate as the (HB) component are, for example, 120 g / eq or more and 250 g / eq or less, preferably 135 g / eq or more and 220 g / eq or less, and more preferably 150 g / eq or more and 200 g / eq or less. When the (meth)acryloyl group equivalent of the urethane (meth)acrylate as the (HB) component is within the above range, good film flatness can be ensured.

[0092] The content ratio (HA / HB) of the (HB) modifier to the (HA) (meth)acrylate in the curable resin composition (α) is preferably 3 / 97 or more and 45 / 55 or less, more preferably 5 / 95 or more and 35 / 65 or less, and even more preferably 10 / 90 or more and 25 / 75 or less, by mass ratio. When the content ratio (HA / HB) is within the above range, it is easy to improve the film flatness.

[0093] In addition, in the curable resin composition (α), the (HA) component and the (HB) component are the main components, and the total amount of the (HA) component and the (HB) component is 50 mass% or more, preferably 70 mass% or more and 99 mass% or less, and more preferably 80 mass% or more and 97 mass% or less, based on the total solid content of the curable resin composition (α).

[0094] ((HC) solvent) The curable resin composition (α) may be diluted with a solvent (HC) to form a coating liquid. The curable resin composition (α) may be applied as a liquid coating liquid to a substrate film, dried, and cured to form a cured resin layer. The components constituting the curable resin composition (α) (such as the components (HA) to (HB)) may be dissolved in a solvent or dispersed in a solvent. When a cured resin layer is formed by drying and curing a coating liquid diluted with a solvent, wrinkles, curling, etc. may occur. However, by combining the components (HA) and (HB), the curable resin composition (α) can prevent wrinkles and curling due to drying and curing of the coating liquid.

[0095] The solvent is preferably an organic solvent. Examples of the organic solvent include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone (MEK), acetone, methyl isobutyl ketone (MIBK), cyclohexanone, and diisobutyl ketone; ether solvents such as diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether (PGM), anisole, and phenetole; ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate, and ethylene glycol diacetate; amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone; cellosolve solvents such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; alcohol solvents such as methanol, ethanol, propanol, isopropanol, and butanol; and halogenated solvents such as dichloromethane and chloroform. These organic solvents may be used alone or in combination of two or more. Among these organic solvents, ester solvents, ether solvents, alcohol solvents and ketone solvents are preferably used.

[0096] The amount of organic solvent used is not particularly limited and is appropriately determined taking into consideration the coatability of the prepared curable resin composition (α), the viscosity and surface tension of the liquid, the compatibility of the solids, etc. The curable resin composition (α) is prepared using the above-mentioned solvent as a coating liquid having a solids concentration of preferably 15 to 80 mass %, more preferably 20 to 70 mass %. Note that the "solids" in the curable resin composition means the components excluding the solvent, which is a volatile component, and includes not only solid components but also semi-solid and viscous liquid substances.

[0097] ((HD) Other ingredients) If necessary, various additives may be appropriately blended into the curable resin composition (α) within the scope of the present invention. Examples of additives that may be used in combination include photoinitiators, light stabilizers, antioxidants, antistatic agents, organic pigments, organic particles, inorganic particles, flame retardants, leveling agents, dispersants, thixotropy-imparting agents (thickeners), and antifoaming agents.

[0098] =Photoinitiator= When the curable resin composition (α) is a photocurable resin composition, it is preferable that the curable resin composition (α) contains a photoinitiator to improve curability. The photoinitiator is a photopolymerization initiator, and known ones can be used. Examples of the photopolymerization initiator include a photoradical generator and a photoacid generator.

[0099] Among the photopolymerization initiators that can be used in the curable resin composition (α), examples of the photoradical generator include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone [e.g., trade name "Omnirad (registered trademark) 651", manufactured by IGM Resins], 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone [e.g., trade name "Omnirad (registered trademark) 184", manufactured by IGM Resins], 2-hydroxy-2-methyl-1-phenylpropan-1-one [e.g., trade name "Omnirad (registered trademark) 1173", manufactured by IGM Resins], and the like. IGM RESINS], 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one [e.g., trade name "Omnirad® 127", IGM RESINS], 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one [e.g., trade name "Omnirad® 2959", IGM RESINS], 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one [e.g., trade name "Omnirad® 907", IGM alkylphenones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide [for example, trade name "Omnirad (registered trademark) TPO", manufactured by IGM RESINS] and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide [for example, trade name "Omnirad (registered trademark) 819", manufactured by IGM RESINS]; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; benzophenone and various derivatives thereof; and formic acid derivatives such as methyl benzoylformate and ethyl benzoylformate.These may be used alone or in combination of two or more.

[0100] Among these photoradical generators, from the viewpoint of the light resistance of the cured product, alkylphenones, phosphine oxides, and formic acid derivatives are preferred, and 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and methyl benzoylformate are particularly preferred. 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one are more preferred.

[0101] Known photoacid generators can be used, but diaryliodonium salts and triarylsulfonium salts are preferred from the viewpoints of curability, acid generation efficiency, etc. Specific examples include anion salts of di(alkyl-substituted)phenyliodonium (specifically, PF6 salts, SbF5 salts, tetrakis(perfluorophenyl)borate salts, etc.). A particularly preferred example of anion salts of (alkyl-substituted)phenyliodonium is PF6 salts of dialkylphenyliodonium (trade name "Omniad (registered trademark) 250", manufactured by IGM RESINS). These photoacid generators may be used alone or in combination of two or more.

[0102] The content of the photoinitiator is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of the total of the compounds having a (meth)acryloyl group in the curable resin composition (α), from the viewpoint of improving curability. On the other hand, from the viewpoint of maintaining the stability of the coating liquid when the curable resin composition (α) is made into a solution and from the viewpoint of the flatness of the cured coating film, the content is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and particularly preferably 5 parts by mass or less.

[0103] The curable resin composition (α) may contain resins other than the above-mentioned components (HA) and (HB) as long as the effects of the present invention are not impaired. However, the cured resin layer is preferably an acrylic resin layer whose main component resin is an acrylic resin. The main component resin means the resin with the largest mass ratio among the resins constituting the cured resin layer, and may account for 50 mass % or more, 75 mass % or more, 90 mass % or more, or 100 mass % of the resins constituting the cured resin layer.

[0104] [Thickness of cured resin layer] The thickness of the cured resin layer is preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and 8 μm or less, even more preferably 1 μm or more and 6 μm or less, and even more preferably 1 μm or more and 4 μm or less. When the thickness of the cured resin layer is equal to or greater than these lower limits, the cured resin layer can adequately protect the substrate film and easily improve weather resistance, etc. Furthermore, when the thickness of the cured resin layer is equal to or less than these upper limits, curling and heat wrinkles of the present laminate film can be prevented and good flatness can be ensured.

[0105] [Method for forming a cured resin layer] The cured resin layer can be obtained by applying a curable resin composition to the surface of a substrate film, drying the composition to form a coating layer, and curing the coating layer. Examples of a method for applying the curable resin composition include air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, kiss roll coating, cast coating, spray coating, curtain coating, calendar coating, and extrusion coating. The drying conditions are not particularly limited, and the drying may be carried out at around room temperature or by heating, for example, at about 25 to 120° C., preferably 50 to 100° C., and more preferably 60 to 90° C. The drying time is not particularly limited as long as the solvent can be sufficiently evaporated, and is, for example, about 10 seconds to 30 minutes, and preferably about 15 seconds to 10 minutes.

[0106] The curing method of the curable resin composition may be appropriately selected depending on the curing mechanism of the curable resin composition, and if the curable resin composition is a thermosetting resin composition, it may be cured by heating, or if it is a photocurable resin composition, it may be cured by irradiating it with energy rays. In the laminated film of the present invention, active energy rays that can be used to cure the curable resin composition include ultraviolet rays, electron beams, X-rays, infrared rays, and visible light. Of these active energy rays, ultraviolet rays and electron beams are preferred from the viewpoints of curability and prevention of resin deterioration. Among these, the curing method of the curable resin composition is preferably curing by energy ray irradiation, from the viewpoints of molding time and productivity, and of preventing thermal shrinkage and thermal degradation of each member due to heating, etc. The energy ray irradiation may be performed from either side, or may be performed from the substrate film side or the opposite side of the substrate film. When the curable resin composition is cured by ultraviolet irradiation in producing the laminated film of the present invention, various ultraviolet irradiation devices can be used, and the light source can be a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, an LED-UV lamp, etc. The ultraviolet irradiation dose (unit: mJ / cm 2 ) is usually 50 to 3,000 mJ / cm 2From the viewpoints of the curability of the curable resin composition and the flexibility of the cured product (cured film), it is preferably 100 to 1,000 mJ / cm 2 From the viewpoint of the flatness of the laminated film, it is more preferably 100 to 500 mJ / cm 2 The range is appropriately determined depending on the reaction rate of the (meth)acryloyl group required in each curing step.

[0107] When the curable resin composition is cured by electron beam irradiation in producing the laminated film of the present invention, various electron beam irradiation devices can be used. The electron beam irradiation dose (Mrad) is usually 0.5 to 20 Mrad, and is preferably in the range of 1 to 15 Mrad from the viewpoints of the curability of the curable resin composition, the flexibility of the cured product, and prevention of damage to the substrate, and is appropriately determined depending on the reaction rate of the (meth)acryloyl group required in each curing step.

[0108] 3. Other layers The present laminate film may include various functional layers such as an easy-adhesion layer and an easy-slip layer in addition to the above-mentioned substrate film and cured resin layer.

[0109] [Easy adhesive layer] When the present laminate film includes an easy-adhesion layer, the easy-adhesion layer is preferably provided on one side of the base film on which the cured resin layer is provided, and the cured resin layer is preferably formed on the surface of the easy-adhesion layer. The adhesive layer is formed from an adhesive layer composition containing a binder resin and a crosslinking agent, and the adhesive layer can be easily bonded to the substrate film.

[0110] Examples of binder resins include polyester resins, acrylic resins, urethane resins, polyvinyl resins such as polyvinyl alcohol, polyalkylene glycols, polyalkyleneimines, methyl cellulose, hydroxycellulose, and starches. Among these, from the viewpoint of improving adhesion to the cured resin layer, polyester resins, acrylic resins, and urethane resins are preferably used, and polyester resins and acrylic resins are more preferred. These binder resins may be used alone or in combination of two or more. In the adhesion layer composition, the content of the binder resin is, for example, 20 to 90% by mass, preferably 30 to 80% by mass, based on the solid content.

[0111] As the crosslinking agent, various known crosslinking agents can be used, for example, oxazoline compounds, melamine compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, etc. The oxazoline compound may be an acrylic polymer having an oxazoline group, etc. Among these, melamine compounds, oxazoline compounds, and epoxy compounds are preferred. These crosslinking agents may be used alone or in combination of two or more. The content of the crosslinking agent in the adhesive layer composition is, for example, 5 to 50 mass %, preferably 10 to 40 mass %, based on the solid content.

[0112] The adhesion layer composition may contain particles for the purpose of improving blocking resistance and slippage. The particles may be any of those described below for the slip layer. However, it is preferable that the adhesion layer composition (i.e., the adhesion layer) does not substantially contain particles. By substantially not containing particles, the smoothness of the cured resin layer surface can be increased. The adhesive layer composition may also contain a component for accelerating crosslinking, such as a crosslinking catalyst, etc. Furthermore, it is also possible to use in combination with an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, etc.

[0113] The adhesive layer composition is generally preferably diluted with water, an organic solvent, or a mixture thereof, and the adhesive layer can be formed by coating the surface of the substrate film with a diluted adhesive layer composition as a coating liquid and drying it. The coating can be performed by a conventionally known method. The thickness of the adhesive layer is usually in the range of 0.003 to 1 μm, preferably 0.005 to 0.6 μm, and more preferably 0.01 to 0.4 μm. By setting the thickness to 0.003 μm or more, sufficient adhesiveness can be ensured. Furthermore, by setting the thickness to 1 μm or less, deterioration of appearance and blocking, etc., can be prevented.

[0114] [Easy layer] When the present laminate film includes a lubrication layer, the lubrication layer is preferably provided on the surface of the substrate film opposite to the surface on which the cured resin layer is provided. The lubrication layer is preferably provided on the surface of the substrate film. By having the lubrication layer, the laminate film has good slip properties. As described above, even if the smoothness of the surface of the laminate film on which the cured resin layer is provided is made high in advance, the provision of the lubrication layer can improve the roll winding properties and handling properties of the laminate film.

[0115] The lubrication layer is formed from a lubrication layer composition containing, for example, a binder resin, a crosslinking agent, and particles. Compounds that can be used for the binder resin and the crosslinking agent are as described above for the binder resin and the crosslinking agent used in the adhesion layer. The content of the binder resin in the lubrication layer composition is, for example, 20 to 90 mass %, preferably 30 to 80 mass %, based on the solid content.The content of the crosslinking agent in the lubrication layer composition is, for example, 5 to 50 mass %, preferably 10 to 40 mass %, based on the solid content.

[0116] Specific examples of particles used in the lubrication layer include silica, alumina, kaolin, calcium carbonate, and organic polymer particles. Among these, silica is preferred from the viewpoint of transparency. The average particle size of the particles is preferably 0.005 to 1.0 μm, more preferably 0.01 to 0.8 μm, and even more preferably 0.01 to 0.6 μm, from the viewpoint of improving lubrication without impairing the surface smoothness of the polyester film. The content of the particles in the lubrication layer composition is, for example, 1 to 20 mass %, preferably 3 to 15 mass %, based on the solid content. The particles used in the lubrication layer may be used alone or in combination of two or more types.

[0117] The lubrication layer composition is generally preferably diluted with water, an organic solvent, or a mixture thereof, and the lubrication layer may be formed by coating the diluted lubrication layer composition as a coating liquid on the surface of the substrate film and drying it. Coating may be performed by a conventionally known method. The thickness of the lubrication layer is usually in the range of 0.003 to 1 μm, preferably 0.005 to 0.6 μm, and more preferably 0.01 to 0.4 μm. By making the thickness 0.003 μm or more, the particles contained in the lubrication layer can be sufficiently held and lubrication can be imparted. Furthermore, by making the thickness 1 μm or less, deterioration of appearance and blocking are less likely to occur.

[0118] A coating can be applied to the surface of the base film as needed, and the above-mentioned easy-adhesion layer and easy-lubrication layer can be formed by coating. The coating can be performed inline, offline, or a combination of both, but is preferably performed inline. Inline coating is preferably performed by applying a coating to the base film in the base film production line. For example, when the base film is a biaxially stretched film, for example, after the longitudinal stretching is completed, a coating liquid for forming at least one of the easy-adhesion layer and the easy-lubrication layer can be applied, and then the coating liquid can be dried, cured, etc. in the subsequent base film production process.

[0119] <Surface protection film for image display devices> An example of a surface protection film for an image display device according to the present invention (hereinafter also referred to as "the present surface protection film") is shown in Fig. 2. The present surface protection film 20 has a cured resin layer 1 provided on one surface of a base film 2, and an adhesive layer 3 provided on the other surface of the base film 2. Furthermore, in the present surface protection film 20, a release film may be further laminated on the surface of the adhesive layer 3. The adhesive layer and the release film will be described in detail below.

[0120] 1. Adhesive layer The pressure-sensitive adhesive layer in the present surface protection film is formed from a pressure-sensitive adhesive composition, which preferably contains a (meth)acrylic polymer (A).

[0121] [(Meth)acrylic polymer (A)] Examples of the (meth)acrylic polymer (A) include a homopolymer of alkyl(meth)acrylate and a copolymer obtained by polymerizing the homopolymer with a monomer component copolymerizable therewith. Examples of the copolymer include a copolymer of an alkyl(meth)acrylate (a1) having 4 to 18 carbon atoms in the side chain as the main component and a monomer component copolymerizable therewith. The above-mentioned main component means a component that has a significant effect on the properties of the (meth)acrylic polymer (A), and the content of the component is usually 30% by mass or more, preferably 35% by mass or more, of the total (meth)acrylic polymer (A). The (meth)acrylic polymer (A) may contain two or more (meth)acrylic polymers having different glass transition temperatures, from the viewpoint of ensuring processability, adhesive strength, stress relaxation property, heat resistance reliability, and wet heat haze resistance.

[0122] Examples of the alkyl(meth)acrylate (a1) having 4 to 18 carbon atoms in the side chain include linear alkyl(meth)acrylates such as n-butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate, heptyl(meth)acrylate, n-octyl(meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acrylate, tridecyl(meth)acrylate, tetradecyl(meth)acrylate, cetyl(meth)acrylate, and stearyl(meth)acrylate; isobutyl(meth)acrylate, sec-butyl(meth)acrylate, t-butyl(meth)acrylate; and isopentyl(meth)acrylate. Examples of suitable acrylates include branched alkyl (meth)acrylates such as butyl (meth)acrylate, neopentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, and isostearyl (meth)acrylate, and alicyclic (meth)acrylates such as cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, 3,5,5-trimethylcyclohexane (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and isobornyl (meth)acrylate. These may be used alone or in combination of two or more.

[0123] From the viewpoint of improving stress relaxation properties and heat resistance reliability when formed into an adhesive layer, the content of the alkyl (meth)acrylate (a1) is preferably 3 mass% or more, more preferably 5 mass% or more, even more preferably 8 mass% or more, particularly preferably 10 mass% or more, and most preferably 12 mass% or more, based on the total components of the (meth)acrylic polymer (A). Furthermore, from the viewpoint of suppressing a decrease in adhesive strength, the content of the alkyl (meth)acrylate (a1) is preferably 90 mass % or less, more preferably 85 mass % or less, even more preferably 80 mass % or less, particularly preferably 75 mass % or less, and most preferably 70 mass % or less, based on the total components of the (meth)acrylic polymer (A). When a plurality of alkyl methacrylates (a1) are contained, the total amount of these falls within the above content range.

[0124] Examples of the monomer component copolymerizable with the alkyl (meth)acrylate (a1) having 4 to 18 carbon atoms in the side chain include a hydroxyl group-containing (meth)acrylate monomer (a2), a (meth)acrylate monomer or vinyl ester-based monomer (a3) ​​having 1 to 3 carbon atoms in the side chain, a functional group-containing ethylenically unsaturated monomer (a4), and other copolymerizable monomers (a5).

[0125] Examples of the hydroxyl group-containing monomer (a2) include hydroxyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth)acrylate; oxyalkylene-modified monomers such as diethylene glycol (meth)acrylate and polyethylene glycol (meth)acrylate; primary hydroxyl group-containing monomers such as 2-acryloyloxyethyl-2-hydroxyethyl phthalate; secondary hydroxyl group-containing monomers such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate; and tertiary hydroxyl group-containing monomers such as 2,2-dimethyl-2-hydroxyethyl (meth)acrylate. These can be used alone or in combination of two or more.

[0126] Among the above hydroxyl group-containing monomers (a2), primary hydroxyl group-containing monomers, particularly 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate, and especially 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred because they have an excellent balance between moist heat resistance and heat resistance.

[0127] From the viewpoint of improving moist heat resistance, the lower limit of the content of the hydroxyl group-containing monomer (a2) is usually 3 mass% or more, preferably 5 mass% or more, more preferably 8 mass% or more, even more preferably 10 mass% or more, and particularly preferably 12 mass% or more, based on the total components of the (meth)acrylic polymer (A). On the other hand, the upper limit of the content of the hydroxyl group-containing monomer (a2) is usually 60% by mass or less, preferably 45% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, and particularly preferably 28% by mass or less, from the viewpoint of suppressing the self-crosslinking reaction of the pressure-sensitive adhesive composition and improving processability and heat resistance reliability. When a plurality of hydroxyl group-containing monomers (a2) are contained, the total amount of these monomers falls within the above content range.

[0128] Examples of the (meth)acrylate monomer or vinyl ester monomer (a3) ​​having 1 to 3 carbon atoms in the side chain include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, vinyl propionate, vinyl acetate, etc. These monomers (a3) ​​may be used alone or in combination of two or more. Of the above-mentioned components (a3), it is preferable to use methyl (meth)acrylate and ethyl (meth)acrylate from the viewpoint of improving cohesive strength when used as an adhesive.

[0129] When the component (a3) ​​is contained, the lower limit of its content is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, based on the total components of the (meth)acrylic polymer (A), from the viewpoint of improving cohesive strength when used as a pressure-sensitive adhesive. Also, when the component (a3) ​​is contained, the upper limit of its content is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total components of the (meth)acrylic polymer (A), from the viewpoint of improving processability. When a plurality of components (a3) ​​are contained, the total amount of these components falls within the above range.

[0130] Examples of the functional group-containing ethylenically unsaturated monomer (a4) include carboxyl group-containing monomers, nitrogen atom-containing functional group-containing monomers, acetoacetyl group-containing monomers, isocyanate group-containing monomers, and glycidyl group-containing monomers. Among these, functional group-containing monomers having a nitrogen atom are preferred in terms of imparting cohesive strength and crosslinking-promoting action, more preferably amino group-containing monomers and amide group-containing monomers, and even more preferably amino group-containing monomers. Examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxylethyl (meth)acrylate, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate.

[0131] Examples of the amino group-containing monomer include primary amino group-containing (meth)acrylates such as aminomethyl (meth)acrylate and aminoethyl (meth)acrylate; secondary amino group-containing (meth)acrylates such as t-butylaminoethyl (meth)acrylate and t-butylaminopropyl (meth)acrylate; and tertiary amino group-containing (meth)acrylates such as ethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, and dimethylaminopropylacrylamide.

[0132] Examples of the amide group-containing monomer include (meth)acrylamide; N-alkyl(meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, Nn-butyl(meth)acrylamide, diacetone(meth)acrylamide, and N,N'-methylenebis(meth)acrylamide; N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-ethylmethylacrylamide, and N,N-diallyl(meth)acrylamide; hydroxyalkyl(meth)acrylamides such as N-hydroxymethyl(meth)acrylamide and N-hydroxyethyl(meth)acrylamide; and alkoxyalkyl(meth)acrylamides such as N-methoxymethyl(meth)acrylamide and N-(n-butoxymethyl)(meth)acrylamide.

[0133] Examples of the acetoacetyl group-containing monomer include 2-(acetoacetoxy)ethyl (meth)acrylate and allyl acetoacetate.

[0134] Examples of the isocyanate group-containing monomer include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof. The isocyanate group may be protected with a blocking agent such as methyl ethyl ketone oxime, 3,5-dimethylpyrazole, 1,2,4-triazole, or diethyl malonate.

[0135] Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate and allyl glycidyl (meth)acrylate.

[0136] These functional group-containing ethylenically unsaturated monomers (a4) may be used alone or in combination of two or more.

[0137] From the viewpoint of improving the heat resistance and light resistance of the pressure-sensitive adhesive composition, the upper limit of the content of the functional group-containing ethylenically unsaturated monomer (a4) is preferably 30 mass % or less, more preferably 20 mass % or less, even more preferably 10 mass % or less, and particularly preferably 5 mass % or less, based on the total components of the (meth)acrylic polymer (A). When a plurality of functional group-containing ethylenically unsaturated monomers (a4) are contained, the total amount of these components falls within the above content range.

[0138] In the present invention, other copolymerizable monomers (a5) can be used as copolymerization components for the acrylic resin, if necessary.

[0139] Examples of the other copolymerizable monomers (a5) include aromatic (meth)acrylic acid ester monomers such as phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenyldiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol-polypropylene glycol (meth)acrylate, and nonylphenol ethylene oxide adduct (meth)acrylate; 4-acryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4'-methoxybenzophenone, 4-acryloyloxyethoxy-4'-methoxybenzophenone, 4-acryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-methacryloyloxybenzophenone, and 4-methacryloyloxybenzophenone. Examples of the vinyl monomers include (meth)acrylic acid ester monomers having a benzophenone structure, such as 4-hydroxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, 4-methacryloyloxyethoxy-4'-bromobenzophenone, and mixtures thereof, as well as vinyl monomers such as acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ethers, vinyl toluene, vinylpyridine, vinylpyrrolidone, dialkyl itaconate esters, dialkyl fumarate esters, allyl alcohol, acrylic chloride, methyl vinyl ketone, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethylallyl vinyl ketone. These may be used alone or in combination of two or more.

[0140] From the viewpoint of improving the heat resistance and light resistance of the pressure-sensitive adhesive composition, the upper limit of the content of the copolymerizable monomer (a5) is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the total components of the (meth)acrylic polymer (A). When a plurality of copolymerizable monomers (a5) are contained, the total amount of these monomers falls within the above content range.

[0141] The (meth)acrylic polymer (A) of the present invention may have a polymerizable carbon-carbon double bond group introduced into its side chain, which can enhance the crosslinking sensitivity of the pressure-sensitive adhesive composition, allowing the pressure-sensitive adhesive composition to be crosslinked by irradiation with lower-energy active energy rays, thereby imparting cohesive strength and heat resistance.

[0142] Examples of a method for introducing a polymerizable carbon double bond group into the side chain of the (meth)acrylic polymer (A) include a method in which a copolymer containing the above-mentioned hydroxyl group-containing (meth)acrylate monomer (a2) or functional group-containing ethylenically unsaturated monomer (a4) is prepared, and then a compound (a6) having a polymerizable carbon double bond group and a functional group reactive with these functional groups is subjected to a condensation or addition reaction while maintaining the activity of the polymerizable carbon double bond group. Combinations of these functional groups include epoxy groups (glycidyl groups) and carboxyl groups, amino groups and carboxyl groups, amino groups and isocyanate groups, epoxy groups (glycidyl groups) and amino groups, hydroxyl groups and epoxy groups, and hydroxyl groups and isocyanate groups. Among these combinations of functional groups, the combination of hydroxyl groups and isocyanate groups is preferred because of the ease of reaction control. Among these, a combination in which the copolymer has a hydroxyl group and the compound has an isocyanate group is preferred. Examples of the isocyanate compound having a polymerizable carbon-carbon double bond group include the above-mentioned 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof.

[0143] From the viewpoint of improving adhesiveness and stress relaxation properties, the amount of the compound (a6) added is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic polymer (A).

[0144] From the viewpoint of obtaining a pressure-sensitive adhesive composition with high cohesive strength, the mass average molecular weight of the (meth)acrylic polymer (A) is preferably 100,000 or more, more preferably 300,000 or more, and even more preferably 500,000 or more. Furthermore, the upper limit of the mass average molecular weight of the (meth)acrylic polymer (A) is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less, from the viewpoint of obtaining a pressure-sensitive adhesive composition having high fluidity and stress relaxation properties.

[0145] [Curable compound (B)] The pressure-sensitive adhesive composition preferably further contains a curable compound (B). The curable compound (B) is a compound that has the property of being cured by heat or light irradiation. In the present pressure-sensitive adhesive composition, the curable compound (B) preferably forms a crosslinked structure with the (meth)acrylic (co)polymer (A).

[0146] The curable compound (B) is preferably a compound having an ethylenically unsaturated group in the molecule from the viewpoint of curing to form a crosslinked structure with the (meth)acrylic (co)polymer (A). In particular, the curable compound (B) is preferably a (meth)acrylate, and more preferably a monofunctional (meth)acrylate. Here, the monofunctional (meth)acrylate refers to a (meth)acrylate having one (meth)acryloyl group, and the polyfunctional (meth)acrylate refers to a (meth)acrylate having two or more (meth)acryloyl groups.

[0147] The curable compound (B) preferably has a glass transition temperature of -40°C or lower, more preferably -45°C or lower, when homopolymerized. When the curable compound (B) has a glass transition temperature within this range, the glass transition temperature of the (meth)acrylic (co)polymer (A) can be set relatively high, thereby providing an adhesive layer that is both flexible and resistant to buckling during bending deformation while maintaining adhesiveness.

[0148] The curable compound (B) is preferably a (meth)acrylate having a glycol skeleton, which can easily lower the glass transition temperature after curing and can easily impart flexibility by adjusting the molecular weight of the skeleton component. Examples of the glycol skeleton include an ethylene glycol skeleton, a propylene glycol skeleton, a diethylene glycol skeleton, a butanediol skeleton, a hexanediol skeleton, a 1,4-cyclohexanedimethanol skeleton, a glycolic acid skeleton, a polyglycol skeleton, etc. Among these, a polyethylene glycol skeleton and / or a polypropylene glycol skeleton is particularly preferred.

[0149] Furthermore, the curable compound (B) is preferably a (meth)acrylate having a mass average molecular weight (Mw) of 5,000 or more, more preferably 7,000 or more, and even more preferably 9,000 or more. If the curable compound (B) is such a (meth)acrylate, the backbone with long linear structures bonded together can result in a curable compound with a low glass transition temperature, which can impart good flexibility to the adhesive layer. In particular, urethane (meth)acrylates having a glycol skeleton with a mass average molecular weight of 5,000 or more, more preferably 7,000 or more, and even more preferably 9,000 or more are preferred. By using such urethane (meth)acrylates, good wettability to the adherend can also be imparted.

[0150] The curable compound (B) is preferably contained in a proportion of more than 15 parts by mass and less than 75 parts by mass per 100 parts by mass of the (meth)acrylic (co)polymer (A). By containing the photocurable compound (B) in such a proportion, it is possible to obtain a pressure-sensitive adhesive layer having a good balance between adhesive strength and flex resistance. From this viewpoint, the curable compound (B) is preferably contained in an amount of more than 15 parts by mass and less than 75 parts by mass relative to 100 parts by mass of the (meth)acrylic (co)polymer (A), and more preferably in an amount of 20 parts by mass or more or 70 parts by mass or less, and even more preferably in an amount of 25 parts by mass or more or 65 parts by mass or less. Two or more types of curable compounds (B) may be used in combination, and when the curable compounds (B) are used in combination, the total amount satisfies the above content.

[0151] [Radical polymerization initiator (C)] The pressure-sensitive adhesive composition preferably further contains a radical polymerization initiator (C). The radical polymerization initiator (C) may be any as long as it is capable of releasing a substance that initiates radical polymerization upon at least one of irradiation with active energy rays such as light and heating. Examples of thermal radical polymerization initiators include organic peroxides such as hydrogen peroxide and perbenzoic acid, and azo compounds such as azobisbutyronitrile.

[0152] Photoradical polymerization initiators are broadly classified into two types based on the radical generation mechanism: cleavage-type photoradical polymerization initiators, which can generate radicals by cleaving and decomposing the single bond of the photoradical polymerization initiator itself, and hydrogen abstraction-type photoradical polymerization initiators, which form an exciplex between the photoexcited initiator and the hydrogen donor in the system and can transfer hydrogen from the hydrogen donor.

[0153] Among these, cleavage-type photoradical polymerization initiators are preferred because they decompose into different compounds when they generate radicals upon irradiation with light, and once excited, they no longer function as a reaction initiator. Therefore, they do not remain as active species in the pressure-sensitive adhesive after the crosslinking reaction is complete, and there is no possibility of causing unexpected photodegradation or the like to the pressure-sensitive adhesive. On the other hand, hydrogen abstraction-type photoradical polymerization initiators not only maintain their function as reaction initiators even after multiple light irradiations, but also do not produce decomposition products, unlike cleavage-type photoradical polymerization initiators, during the radical-generating reaction caused by irradiation with active energy rays such as ultraviolet rays. Therefore, they are less likely to become volatile components after the reaction is completed, and are therefore useful in that they can reduce damage to the adherend.

[0154] When a photoradical polymerization initiator is used, it is preferable that the initiator be one that generates radicals when irradiated with light in a wavelength range of, for example, 380 nm to 700 nm, and serves as the starting point for the crosslinking reaction of the present pressure-sensitive adhesive composition.

[0155] Examples of the cleavage-type photoradical polymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl 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, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), and phenylglyoxyl. Examples of suitable methyl benzoates include methyl benzoate, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1-butanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, and derivatives thereof. Among these, acylphosphine oxide photoinitiators such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide are preferred, from the viewpoint of becoming decomposed products and losing color after the reaction.

[0156] Examples of the hydrogen abstraction type photoradical polymerization initiator include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloyloxybenzophenone, 4-[2-((meth)acryloyloxy)ethoxy]benzophenone, 4-(meth)acryloyloxy-4'-methoxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoylformate, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, and 4-(1,3-acryloyl-1,4,7,10,13-pentaoxotridecyl)benzophenone. Examples of suitable phenol compounds include bis(2-phenyl-2-oxoacetic acid)oxybisethylene, phenylglyoxylic acid methyl ester, a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]ethyl ester, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, camphorquinone, and derivatives thereof. Among these, any one or two selected from the group consisting of 4-methylbenzophenone, phenylglyoxylic acid methyl ester, and a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]ethyl ester are preferred.

[0157] The radical polymerization initiator (C) is not limited to the substances listed above. Any one of the photoradical polymerization initiators listed above or its derivative may be used, or two or more may be used in combination. A thermal radical polymerization initiator and a photoradical polymerization initiator may also be used in combination.

[0158] The content of the radical polymerization initiator (C) is not particularly limited, but from the viewpoint of sufficiently progressing the polymerization reaction and improving the shape stability of the adhesive layer, it is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, and particularly preferably 2 parts by mass or more, per 100 parts by mass of the (meth)acrylic polymer (A). Furthermore, from the viewpoint of ensuring adhesiveness, the upper limit of the content of the radical polymerization initiator (C) is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 6 parts by mass or less, and particularly preferably 4 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic polymer (A). When multiple types of radical polymerization initiators are used, the total amount is set within the above range.

[0159] The pressure-sensitive adhesive composition can be laminated on an optical member such as a liquid crystal polarizing film, a color filter and / or an anti-reflection film, and then exposed to light to be used as a pressure-sensitive adhesive layer. When the pressure-sensitive adhesive composition is active energy ray-curable, the release film is peeled off from the surface protective film, and the pressure-sensitive adhesive layer is laminated with a liquid crystal polarizing film or a color filter and / or an anti-reflection film, or a laminate is formed with a liquid crystal polarizing film and other optical components. Then, the pressure-sensitive adhesive composition is cured by irradiating the composition with light, thereby more firmly adhering the liquid crystal polarizing film, color filter, and / or anti-reflection film, and other optical components, thereby improving the reliability of the laminate. From the viewpoints of suppressing damage to optical components and controlling reactions, ultraviolet light and visible light are preferred as the light source used. The irradiation means is not particularly limited, but it is preferable to irradiate the light from the side opposite to the surface on which the liquid crystal polarizing film or the color filter and / or anti-reflection film is laminated. Furthermore, the irradiation energy, irradiation time, irradiation method, etc. of the active energy ray are not particularly limited as long as they can activate the initiator and polymerize the (meth)acrylate component.

[0160] [Adhesive layer thickness] The thickness of the adhesive layer is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and particularly preferably 40 μm or more, from the viewpoint of protecting the optical member, while the upper limit of the thickness is preferably 175 μm or less, more preferably 120 μm or less, even more preferably 80 μm or less, and particularly preferably 60 μm or less, from the viewpoint of contributing to the thinning of the image display device.

[0161] [Method of manufacturing adhesive layer] Next, an example of a method for producing the adhesive layer will be described.

[0162] The adhesive layer can be produced by mixing predetermined amounts of the (meth)acrylic polymer (A), and, if necessary, the curable compound (B) and the radical initiator (C), and further, if necessary, other components, to prepare an adhesive composition, forming the composition into a sheet, and, if necessary, crosslinking, i.e., polymerizing, the curable compound (B) to harden it.

[0163] When preparing the present pressure-sensitive adhesive composition, the above raw materials may be kneaded using a temperature-controllable kneader (for example, a single-screw extruder, a twin-screw extruder, a planetary mixer, a twin-screw mixer, a pressure kneader, etc.). When mixing various raw materials, the various additives may be blended together with the resin in advance and then supplied to the kneader, or all of the materials may be melt-mixed in advance and then supplied, or a master batch in which only the additives are concentrated in the resin may be prepared and then supplied.

[0164] The pressure-sensitive adhesive composition can be formed into a sheet by any known method, such as wet lamination, dry lamination, extrusion casting using a T-die, extrusion lamination, calendaring, inflation, injection molding, and liquid injection curing. Among these, when producing a sheet, wet lamination, extrusion casting, and extrusion lamination are preferred.

[0165] Furthermore, when the pressure-sensitive adhesive composition contains a radical initiator, it can be cured by irradiating it with heat and / or active energy rays to produce a cured product. In particular, the pressure-sensitive adhesive sheet can be produced by irradiating a molded product, such as a sheet, of the composition with heat and / or active energy rays. Examples of the active energy rays to be irradiated include ionizing radiation such as α-rays, β-rays, γ-rays, neutron rays, and electron beams, as well as ultraviolet rays and visible light rays. Among these, ultraviolet rays and visible light rays are preferred from the viewpoints of suppressing damage to components of the optical device and controlling reactions. Furthermore, the irradiation energy, irradiation time, irradiation method, etc. of the active energy ray are not particularly limited as long as they can activate the initiator and polymerize the (meth)acrylate component.

[0166] A preferred method for forming the adhesive layer includes applying an adhesive composition onto a release film described below, drying the composition, laminating a release film on top of the sheet-like composition, and curing the composition by irradiating it with ultraviolet light.

[0167] In another embodiment of the method for producing the adhesive layer, the adhesive composition may be dissolved in an appropriate solvent and then coated using various coating techniques. When a coating method is used, the adhesive layer can be obtained by heat curing in addition to the above-mentioned active energy ray irradiation curing. In the case of coating, the thickness of the adhesive layer can be adjusted by the coating thickness and the solid content concentration of the coating liquid. Furthermore, the pressure-sensitive adhesive composition can be directly filled between the optical member to be adhered and the present laminate film to form a pressure-sensitive adhesive layer.

[0168] 2.Release film When the present surface protection film has a release film, the material is not particularly limited, and any known release film can be used as appropriate. As the release film, for example, a film such as a polyester film, a polyolefin film, a polycarbonate film, a polystyrene film, an acrylic film, a triacetyl cellulose film, or a fluororesin film that has been subjected to a release treatment by coating with a silicone resin, or release paper, etc. can be appropriately selected and used. The film may have other layers, such as an antistatic layer, a hard coat layer, or an anchor layer, as required.

[0169] The thickness of the release film is not particularly limited, but from the viewpoint of processability and handleability, it is preferably from 12 μm to 250 μm, more preferably from 25 μm to 200 μm, and even more preferably from 38 μm to 188 μm.

[0170] <Laminate with liquid crystal polarizing film> The laminate film and surface protective film of the present invention can be laminated with a liquid crystal polarizing film. When laminating the present laminate film or the present surface protective film with a liquid crystal polarizing film, it is preferable to interpose the above-mentioned adhesive layer, but lamination may also be performed using other known adhesives. Figure 3 shows an example of a laminate in which the surface protective film 20 of the present invention is laminated with a liquid crystal polarizing film 4. In the present invention, the term "polarizing element" refers to an optical component having optical anisotropy, and the term "liquid crystal polarizing film" refers to a laminate including a film formed by applying an optically anisotropic composition containing a liquid crystal compound. Examples of liquid crystal compounds include polymerizable liquid crystal compounds, polymeric liquid crystal compounds, and lyotropic liquid crystal compounds. For example, a cured product obtained by applying an optically anisotropic composition containing a polymerizable liquid crystal compound to a substrate and curing it in an aligned state can be used as a polarizing element. In this case, the substrate may or may not be included. In addition, the liquid crystal polarizing film used as the polarizing element in the present invention is formed by coating, and therefore is classified as a coated polarizing element, and is different from conventional stretched polarizing elements.

[0171] For example, conventional polarizing plates generally have a structure in which a polyvinyl alcohol (PVA) film is sandwiched between protective films such as triacetyl cellulose (TAC) film, and then an adhesive is applied to the film or an adhesive sheet is laminated on top. However, if a liquid crystal polarizing film is used, it has better moisture resistance than conventional polarizing plates, and therefore there is no need to sandwich it between protective films, so the thickness can be made thinner. Furthermore, since the laminate film or surface protection film of the present invention has both ultraviolet absorption function and surface protection function, by laminating it with a liquid crystal polarizing film, it is possible to achieve a thinner and lighter image display device while suppressing photodegradation of the liquid crystal polarizing film.

[0172] A laminate with a liquid crystal polarizing film can be obtained, for example, by a method of forming a liquid crystal polarizing film on a substrate having releasability and then transferring the liquid crystal polarizing film onto the surface of a laminate film or a surface protective film, a method of molding a laminate film or a surface protective film directly onto the liquid crystal polarizing film, or a method of forming a liquid crystal polarizing film on a laminate film or a surface protective film. The laminate with a liquid crystal polarizing film of the present invention has the effect of increasing the light resistance of the polarizing film by the present laminate film or the present surface protective film. Specifically, the light resistance test was carried out using a xenon light resistance tester (manufactured by Atlas Co., Ltd., equipment name "Ci4000") at an illuminance of 0.55 W / m 2 After 40 hours of irradiation of the laminate with the liquid crystal polarizing film of the present invention under irradiation conditions of 340 nm, the change in the degree of polarization at a wavelength of 595 nm (degree of polarization before the test - degree of polarization after the test) can be kept to 4.0% or less, exhibiting excellent light resistance. The change in the degree of polarization is more preferably 3.5% or less, even more preferably 3.0% or less, even more preferably 2.5% or less, particularly preferably 2.0% or less, and can even be kept to 1.0% or less.

[0173] [Liquid crystal polarizing film] As described above, the liquid crystal polarizing film of the present invention is a laminate including a liquid crystal polarizing film formed by applying an optically anisotropic composition containing a polymerizable liquid crystal compound. This liquid crystal polarizing film typically has an optically anisotropic layer obtained by applying an optically anisotropic composition containing a polymerizable liquid crystal compound and the like onto an alignment film formed on a substrate, and polymerizing the polymerizable liquid crystal compound in an aligned state. That is, as shown in FIG. 3, the liquid crystal polarizing film may have an optically anisotropic layer 4a made of an optically anisotropic composition and an alignment film 4b. Alternatively, the liquid crystal polarizing film may have only the optically anisotropic layer 4a without the alignment film 4b.

[0174] Examples of the substrate include glass or a resin sheet mainly composed of one or more resins selected from the group consisting of polyolefin resin, cyclic polyolefin resin, polyester resin, poly(meth)acrylic acid ester resin, cellulose ester resin, polycarbonate resin, and polyimide resin. The substrate may have other layers, such as an antistatic layer, a hard coat layer, an anchor layer, a release layer, an easy-adhesion layer, a protective layer, a bleeding prevention layer, and a flattening layer, as needed.

[0175] The polymerizable liquid crystal compound can be aligned by a method using an alignment regulating force by an alignment film provided on a substrate, an alignment regulating force by an external field such as an electric field or a magnetic field, and / or a shear force during coating. In particular, the method using an alignment film is preferred from the viewpoint of achieving a liquid crystal polarizing film that can align the liquid crystal compound in a highly ordered state and exhibit good optical performance. The alignment film provided on the substrate is a layer having an alignment regulating force for aligning the liquid crystal compound described later in a desired direction. The alignment film preferably has solvent resistance so that the optically anisotropic composition solution is not dissolved when applied, moderate solution affinity so that the optically anisotropic composition solution is not repelled, and heat resistance in the heating treatment during solvent drying and liquid crystal alignment. In order to control the orientation direction, the alignment film may be subjected to an alignment treatment by a known method (such as a rubbing method, a method of forming grooves (fine groove structures) on the surface of the alignment film (photoalignment method) using polarized ultraviolet light or a polarized laser, an alignment method by forming an LB film, or an alignment method by oblique deposition of an inorganic material) as described, for example, on pages 226 to 239 of "Liquid Crystal Handbook" (Maruzen Co., Ltd., published October 30, 2000). In particular, the rubbing method and the photoalignment method are preferred from the viewpoint of easily achieving a high degree of orientation. The thickness of the alignment film is usually 10 nm to 1000 nm, preferably 50 nm to 800 nm. When the thickness is within this range, it is possible to achieve both an alignment control force sufficient to align the liquid crystal compound and a thin film.

[0176] The optically anisotropic composition may be a composition containing, in addition to a polymerizable liquid crystal compound and a photopolymerization initiator, a polymerization initiator, and, if necessary, various additives such as a polymerization inhibitor, a polymerization aid, a polymerizable non-liquid crystal compound, a non-liquid crystal compound, a surfactant, a leveling agent, a coupling agent, a pH adjuster, a dispersant, an antioxidant, an organic or inorganic filler, or a metal oxide, or a solvent, and a cured layer of this composition exhibits the optical function as a polarizing element. When the polarizing element is a liquid crystal polarizing film, the composition preferably contains a dye. The dye is preferably a dichroic dye, and examples of the dichroic dye include iodine and dichroic organic dyes. The dichroic dye used may be one type, or a combination of multiple different dyes. The dichroic organic dye is not particularly limited, but examples thereof include azo dyes, quinone dyes (including naphthoquinone dyes, anthraquinone dyes, etc.), stilbene dyes, cyanine dyes, phthalocyanine dyes, indigo dyes, condensed polycyclic dyes (including perylene dyes, oxazine dyes, acridine dyes, etc.), etc. Among these dyes, azo dyes are preferred because they have a large molecular long-to-short axis ratio and can exhibit good dichroism.

[0177] (Polymerizable liquid crystal compound) A polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable functional group, and has both the properties of a polymerizable monomer and the properties of a liquid crystal. Therefore, when this compound is polymerized and cured in an oriented state, a cured product consisting of a polymer with fixed orientation, i.e., an optically anisotropic material, can be obtained. Therefore, a polarizing film having optical anisotropy can be formed by applying an optically anisotropic composition containing a polymerizable liquid crystal compound to a substrate and curing the composition in an aligned state. The polymerizable liquid crystal compound used may be one type, or a combination of multiple compounds with different structures. The polymerizable liquid crystal compound may be either a low molecular weight liquid crystal compound having a polymerizable functional group or a high molecular weight liquid crystal compound having a polymerizable functional group. Among them, a low molecular weight liquid crystal compound is preferred because a polymerizable liquid crystal compound tends to easily give a cured product exhibiting high alignment. The liquid crystal phase exhibited by the polymerizable liquid crystal compound can be appropriately selected from nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, discotic liquid crystal, etc., but from the viewpoint of ease of production and obtaining a highly ordered orientation state, it is preferable that the polymerizable liquid crystal compound exhibits nematic liquid crystal or smectic liquid crystal. The polymerizable functional group is preferably a photopolymerizable group because it is easy to fix the orientation structure.Specific examples include an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, a vinyl group, a vinyloxy group, an ethynyl group, an ethynyloxy group, a 1,3-butadienyl group, a 1,3-butadienyloxy group, an oxiranyl group, an oxetanyl group, a glycidyl group, a glycidyloxy group, a styryl group, and a styryloxy group.Among these, a (meth)acryloyl group or a (meth)acryloyloxy group is preferred.

[0178] The polymerizable liquid crystal compound is not particularly limited in molecular structure, and any liquid crystal compound having a polymerizable group can be used. For example, the polymerizable liquid crystal compound contained in the composition for forming an anisotropic dye film of the present invention may be a compound represented by the following formula (1) (hereinafter, sometimes referred to as "polymerizable liquid crystal compound (1)").

[0179] Q 1 -R 1 -A 11 -Y 1 -A 12 -(Y 2 -A 13 ) k -R 2 -Q 2 ···(1)

[0180] (In formula (1), -Q 1 represents a hydrogen atom or a polymerizable group; -Q 2 represents a polymerizable group; -R 1 -and-R 2 - each independently represents a chain organic group; -A 11 - and A 13 - each independently represents a partial structure represented by the following formula (2), a divalent organic group, or a single bond: -A 12 - represents a partial structure represented by the following formula (2) or a divalent organic group; -Y 1 - and Y 2 - each independently represents a single bond, -C(=O)O-, -OC(=O)-, -C(=S)O-, -OC(=S)-, -C(=O)S-, -SC(=O)-, -CHCH-, -CH=CH-, -C≡C-, -C(=O)NH-, -NHC(=O)-, -CHO-, -OCH-, -CHS-, or -SCH-; -A 11 -and-A 13 - is a partial structure represented by the following formula (2) or a divalent organic group: k is 1 or 2. If k is 2, two -Y 2 -A 13 - may be the same or different.)

[0181] -Cy-X 2 -C≡CX 1 - (2)

[0182] (In formula (2), -Cy- represents a hydrocarbon ring group or a heterocyclic group; -X 1 - represents -C(=O)O-, -OC(=O)-, -C(=S)O-, -OC(=S)-, -C(=O)S-, -SC(=O)-, -CH2CH2-, -CH=CH-, -C(=O)NH-, -NHC(=O)-, -C2O-, -OCH2-, -CH2S-, or SCH2-; -X 2 - represents a single bond, -C(=O)O-, -OC(=O)-, -C(=S)O-, -OC(=S)-, -C(=O)S-, -SC(=O)-, -CHCH-, -CH=CH-, -C(=O)NH-, -NHC(=O)-, -CHO-, -OCH-, -CHS-, or -SCH-.

[0183] In the above formula (1), -R 1 -and-R 2 The chain organic group represented by - is -(CH2) n -CH2-, -O-(CH2) n -CH2-, -(O) n1 -(CH2CH2O) n2 -(CH2) n3 -, -(O) n1 -(CH2) n2 -(CH2CH2O) n3 - is preferred. In these formulas, n represents an integer of 1 to 24, preferably an integer of 2 to 24, more preferably an integer of 4 to 19, and even more preferably an integer of 5 to 19. In these formulas, n1, n2, and n3 each independently represent an integer, and are appropriately adjusted so that the number of atoms in the main chain of the chain organic group (meaning the longest chain portion in the chain organic group, and when the chain organic group is substituted with a polymerizable group, meaning the longest chain portion excluding the polymerizable group) is preferably 3 to 25, more preferably 5 to 20, and even more preferably 6 to 20.

[0184] In addition, -A 11 When - is a partial structure represented by formula (2), formula (1) may be the following formula (1A) or the following formula (1B). Q1 -R 1 -Cy-X 2 -C≡CX 1 -Y 1 -A 12 -(Y 2 -A 13 ) k -R 2 -Q 2 (1A) Q 1 -R 1 -X 1 -C≡CX 2 -Cy-Y 1 -A 12 -(Y 2 -A 13 ) k -R 2 -Q 2 (1B)

[0185] Also, -A 12 When - is a partial structure represented by formula (2), formula (1) may be the following formula (1C) or the following formula (1D). Q 1 -R 1 -A 11 -Y 1 -Cy-X 2 -C≡CX 1 -(Y 2 -A 13 ) k -R 2 -Q 2 (1C) Q 1 -R 1 -A 11 -Y 1 -X 1 -C≡CX 2 -Cy-(Y 2 -A 13 ) k -R 2 -Q 2 (1D)

[0186] Also, -A 13When - is a partial structure represented by formula (2), formula (1) may be the following formula (1E) or the following formula (1F). Q 1 -R 1 -A 11 -Y 1 -A 12 -(Y 2 -Cy-X 2 -C≡CX 1 ) k -R 2 -Q 2 ···(1E) Q 1 -R 1 -A 11 -Y 1 -A 12 -(Y 2 -X 1 -C≡CX 2 -Cy) k -R 2 -Q 2 ···(1F)

[0187] Similarly, -A 11 -, -A 12 - and -A 13 - When two or more of the partial structures are partial structures represented by formula (2), the orientation of each partial structure represented by formula (2) may be inverted.

[0188] Also, as mentioned above, -A 11 -, -A 12 - and -A 13 - is independently a partial structure represented by formula (2) or a divalent organic group, and -A 11 -and-A 13 - may be a single bond, but -A 11 -and-A 13 -, but neither of them is a single bond.

[0189] As the polymerizable liquid crystal compound (1), a compound represented by the formula (1A), (1B), (1E) or (1F) is preferred because it tends to provide high alignment.

[0190] When the polymerizable liquid crystal compound is photopolymerized, it is preferable that the optically anisotropic composition contains a photopolymerization initiator. Any known photopolymerization initiator can be used.

[0191] The thickness of the cured film of the optically anisotropic composition is preferably 100 nm or more, more preferably 300 nm or more, and even more preferably 1 μm or more, from the viewpoint of ensuring optical functionality. The thickness of the cured film is preferably 50 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less, from the viewpoint of contributing to thinner image display devices. The thickness of the liquid crystal polarizing film, which is a laminate including a film formed by applying the optically anisotropic composition, is preferably 1 / 5 or less, more preferably 1 / 7 or less, of the thickness of the substrate film in the present laminate film or the present surface protective film. When the liquid crystal polarizing film has an optically anisotropic layer and an alignment film, the total thickness of the liquid crystal polarizing film and the thickness of the substrate film satisfy the above ratio.

[0192] On the cured film of the composition, other layers such as an antistatic layer, a hard coat layer, an anchor layer, a release layer, an easy-adhesion layer, a protective layer, a bleeding prevention layer, a flattening layer, etc. may be formed as needed.

[0193] <Image display device> The laminate film and surface protective film according to the present invention can be laminated with other optical components to form an image display device. That is, the image display device includes the present laminate film or the present surface protective film. For example, the image display device includes the above-mentioned laminate with a liquid crystal polarizing film, in which the present laminate film or the present surface protective film is laminated with a liquid crystal polarizing film. Alternatively, the image display device includes the present laminate film or the present surface protective film laminated with an antireflection film and / or a color filter. Specific examples of image display devices include liquid crystal displays, organic EL displays, inorganic EL displays, electronic paper, plasma displays, and microelectromechanical system (MEMS) displays. The present laminate film and surface protective film are preferably used for organic EL devices.

[0194] 4 and 5 show examples of image display devices (organic EL devices) according to the present invention.

[0195] FIG. 4 shows an example of a configuration in which an image display device (organic EL device) 100 includes a liquid crystal polarizing film 4, a retardation film 6, and an organic EL light-emitting layer 7, and the present surface protective film 20 is provided on the viewing side of the liquid crystal polarizing film 4. 4, the surface protection film 20 serves as a cover plastic (front panel), which can prevent the liquid crystal polarizer 4 from being deteriorated by incident light from the outside.

[0196] Figure 5 shows an example of a configuration in which an image display device (organic EL device) 200 includes an anti-reflection layer 8, a color filter-containing layer 9, a retardation film 6, and an organic EL light-emitting layer 7 (a color filter-embedded organic EL device), and the present surface protective film 20 is provided on the viewing side of the anti-reflection layer 8 and the color filter-containing layer 9. The color filter-embedded organic EL device can reduce external light reflection by using the built-in color filter, a black matrix that is provided as needed, and an anti-reflection layer, eliminating the need for the circular polarizer used in conventional organic EL devices, thereby contributing to further thinning and weight reduction of image display devices. Furthermore, in an organic EL device with a built-in color filter, the color filter plays the role of a conventional circular polarizer, eliminating light emission loss due to absorption of light emitted from the organic EL element. This dramatically improves the luminous efficiency of the light-emitting element of the organic EL device, and ultimately the luminous life of the light-emitting element of the organic EL device, thereby contributing to further improving the performance of image display devices. As shown in Figure 5, by placing the present surface protective film 20 on the viewing side of the image display device 200, it is possible to prevent the light-emitting elements constituting the organic EL device from deteriorating due to incident light from outside, particularly ultraviolet radiation of 400 nm or less, and to obtain an image display device 200 with a stable color tone.

[0197] The configuration of the image display device according to the present invention is not limited to that shown in FIGS. For example, when the present laminate film or the present surface protective film is used in an image display device including a liquid crystal polarizing film, the present laminate film or the present surface protective film and the liquid crystal polarizing film may be laminated together with a known pressure-sensitive adhesive. Further, other members may be interposed between the present laminate film and the liquid crystal polarizing film, and between the present surface protective film and the liquid crystal polarizing film. Examples of the "other components" include a reflective sheet, a light guide plate and a light source, a diffusion film, a prism sheet, a retardation plate, a glass substrate, an electrode, an anti-reflection film, a touch sensor, and a composite integrated combination of these components. In addition to the above-mentioned members, other layers such as an antistatic layer, a hard coat layer, an anchor layer, an easy-adhesion layer, a protective layer, a bleeding prevention layer, and a flattening layer may be interposed as needed.

[0198] <Explanation of terms, etc.> In the present invention, the term "film" includes the term "sheet", and the term "sheet" includes the term "film". In the present invention, when it is stated that "X to Y" (X and Y are any numbers), unless otherwise specified, it means "X or more and Y or less", and also means "preferably larger than X" or "preferably smaller than Y". Furthermore, when it is stated that the amount is "X or more" (X is any number), it also means that the amount is "preferably greater than X" unless otherwise specified, and when it is stated that the amount is "Y or less" (Y is any number), it also means that the amount is "preferably smaller than Y" unless otherwise specified. [Example]

[0199] The present invention will now be described in more detail with reference to examples, although the present invention is not limited to the examples described below.

[0200] <Materials for each layer> The materials of the layers constituting the laminated films of Example 1 and Comparative Example 1 and the surface protective films of Example 2 and Comparative Example 2 are as follows.

[0201] (1) Base film [Polyester raw materials] Polyester A The starting materials were 100 parts by mass of dimethyl terephthalate and 60 parts by mass of ethylene glycol. 0.09 parts by mass of magnesium acetate tetrahydrate was used as the catalyst. The reaction was initiated at 150°C and gradually increased to 230°C after 3 hours as methanol was distilled off. After 4 hours, the transesterification reaction was essentially complete. 0.04 parts by mass of ethyl acid phosphate and 0.04 parts by mass of antimony trioxide were added to the reaction mixture, and the polycondensation reaction was carried out for 4 hours and 30 minutes. During the polycondensation reaction, the temperature was gradually increased from 230°C to 280°C, while the pressure was gradually reduced from atmospheric pressure to 0.3 mmHg. The reaction was stopped 4 hours and 30 minutes after the start of the polycondensation reaction, and the polymer was discharged under nitrogen pressure. The resulting polyester A had an intrinsic viscosity of 0.64 dL / g, and 98% by mass of the ester units were ethylene terephthalate, with the remainder being units formed by condensation of diethylene glycol and terephthalic acid.

[0202] Polyester B Polyester A was pre-crystallized at 160°C and then solid-state polymerized at 220°C in a nitrogen atmosphere to obtain Polyester B, which had an intrinsic viscosity of 0.82 dL / g and consisted of 98% by mass of ester units of ethylene terephthalate, with the remainder being units obtained by polymerizing diethylene glycol and terephthalic acid.

[0203] Polyester C Polyester C was obtained in the same manner as Polyester A, except that amorphous silica having an average particle size of 3 μm was added as an ethylene glycol slurry after the transesterification reaction. The polyester C had an intrinsic viscosity of 0.64 dL / g and contained 98% by mass of ester units of ethylene terephthalate, with the remainder being diethylene glycol and terephthalic acid condensation ester units. The silica content was 0.3 parts by mass.

[0204] Polyester D (UV absorber masterbatch polyester) Polyester A was fed into a vented twin-screw extruder, and 2,2'-(1,4-phenylene)bis[4H-3,1-benzoxazin-4-one] (CYTEC CYASORB UV-3638, molecular weight 369, benzoxazine-based) as an ultraviolet absorber was added so as to have a concentration of 10 mass%, melt-kneaded, and formed into chips to produce ultraviolet absorber masterbatch polyester D. The intrinsic viscosity of the resulting polyester D was 0.61 dL / g.

[0205] Polyester E (UV absorber masterbatch polyester) Polyester A was fed to a vented twin-screw extruder, and triazine 1 and benzotriazole 2 were added as ultraviolet absorbers to a concentration of 16% by mass and 5% by mass, respectively, and the mixture was melt-kneaded and formed into chips to obtain an ultraviolet absorber masterbatch polyester. E The obtained polyester was prepared. E The intrinsic viscosity of the polymer was 0.57 dL / g. [ka] [ka]

[0206] Polyester F (UV absorber masterbatch polyester) Polyester A was fed to a vented twin-screw extruder, and triazine 3 and benzotriazole 2 were added as ultraviolet absorbers to a concentration of 16% by mass and 5% by mass, respectively, and the mixture was melt-kneaded and formed into chips to obtain an ultraviolet absorber masterbatch polyester. F The obtained polyester was prepared. F The intrinsic viscosity of the polymer was 0.57 dL / g. [ka]

[0207] Polyester G (UV absorber masterbatch polyester) We used a copolymerized polybutylene terephthalate (UVAPBT, manufactured by Daiwa Chemical Industry Co., Ltd.) containing benzotriazole groups and containing 30% by mass of units derived from 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(2-hydroxyethyl)phenol] (manufactured by Daiwa Chemical Industry Co., Ltd.: DAINSORB T-33). The resulting polyester G had an intrinsic viscosity of 0.68 dL / g.

[0208] The intrinsic viscosity of the polyesters A to G was measured as follows: When particles were blended, 1 g of polyester from which the particles had been removed was precisely weighed, dissolved in 100 ml of a mixed solvent of phenol / tetrachloroethane = 50 / 50 (mass ratio), and measured at 30°C. The average particle size of the amorphous silica contained in Polyester C was determined by observing the powder using a scanning electron microscope (Hitachi, "SU8220"), measuring the size of each particle from the image data obtained, and averaging the size at 10 points. In this case, in the case of non-spherical particles, the average value of the longest and shortest diameters was measured as the diameter of each particle.

[0209] (2) Cured resin layer [Curable resin composition (α-1)] An active energy ray-curable resin composition (α-1) was obtained by uniformly mixing 10 parts by mass of a urethane (meth)acrylate compound (HA-1), 90 parts by mass of a urethane (meth)acrylate compound (HB-1), 5 parts by mass of Omnirad127 manufactured by IGM Resins as a photoinitiator (HD), and 100 parts by mass of methyl ethyl ketone (MEK) as a dilution solvent (HC).

[0210] (HA) (meth)acrylate: urethane (meth)acrylate compound (HA-1) A four-neck flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet was charged with 37.5 g (0.17 mol) of isophorone diisocyanate, 25.5 g of polytetramethylene glycol diol (hydroxyl value 167 mg KOH / g; molecular weight calculated from the hydroxyl value 672; 0.04 mol), 13.4 g of polyester triol (hydroxyl value 262 mg KOH / g; molecular weight calculated from the hydroxyl value 642; 0.02 mol), and 0.02 g of dibutyltin dilaurate as a reaction catalyst, and the mixture was reacted at 80°C. When the residual isocyanate groups reached 11% or less, 23.6 g (0.2 mol) of 2-hydroxyethyl acrylate and 0.04 g of methoxyphenol as a polymerization inhibitor were further added and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.3% or less, yielding a urethane (meth)acrylate compound (HA-1) (ethylenically unsaturated group concentration: 2.0 mmol / g; mass average molecular weight: 3,400).

[0211] (HB) Modifier: Urethane (meth)acrylate compound (HB-1) A four-neck flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet was charged with 29.3 g (0.05 mol) of a hexamethylene diisocyanate trimer having an isocyanurate skeleton (isocyanate group content: 21.0%), 70.7 g (0.15 mol) of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value: 120 mgKOH / g), 0.06 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.02 g of dibutyltin dilaurate as a reaction catalyst. The mixture was reacted at 60 °C. The reaction was terminated when the residual isocyanate group content reached 0.3% or less, yielding a mixture of 70 g of a urethane (meth)acrylate compound (HB-1) (ethylenically unsaturated group concentration: 6.0 mmol / g; mass average molecular weight: 10,500) and 30 g of pentaerythritol tetraacrylate.

[0212] (HC) Solvent: Methyl ethyl ketone (MEK) (HD) Photoinitiator: Omnirad127 manufactured by GM Resins

[0213] (3) Easy adhesion layer [Easy adhesive layer composition] The following compounds were mixed in a ratio of X1:X2:Y1:Y2:Y3=60:10:10:10:10 (mass % of solid content) to prepare an easy-adhesion layer composition.

[0214] Binder resin (X1): A water dispersion of a polyester resin having a condensed polycyclic structure copolymerized with the following composition: Monomer composition: (acid component) 2,6-naphthalenedicarboxylic acid / 5-sodium sulfoisophthalic acid / / (diol component) ethylene glycol / diethylene glycol = 92 / 8 / / 80 / 20 (mol%) (X2): Aqueous dispersion of acrylic resin polymerized with the following composition: Emulsion polymer of ethyl acrylate / n-butyl acrylate / methyl methacrylate / N-methylolacrylamide / acrylic acid = 65 / 21 / 10 / 2 / 2 (mass%) (emulsifier: anionic surfactant)

[0215] Crosslinking agent (Y1): Hexamethoxymethylol melamine (Y2): Water-soluble polyglycerol polyglycidyl ether (Y3): Oxazoline group-containing acrylic polymer (Epocross (registered trademark), oxazoline group amount 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)

[0216] (4)Adhesive layer [Adhesive composition] (Meth)acrylic polymer (A-1): A copolymer of 67% by mass of 2-ethylhexyl acrylate, 5% by mass of methyl acrylate, 10% by mass of ethyl acrylate, 14% by mass of 2-hydroxyethyl acrylate, and 4% by mass of 4-hydroxybutyl acrylate. The mass average molecular weight (Mw) of the acrylic polymer (A-1) measured by GPC was 700,000.

[0217] Curable compound (B-1): Propylene glycol skeleton-containing monofunctional urethane acrylate, PEM-X264 (AGC Corporation), mass average molecular weight (Mw): approximately 10,000, glass transition temperature: -53°C

[0218] Radical initiator (C-1): 4-methylbenzophenone

[0219] Solvent: Ethyl acetate Silane coupling agent: 3-glycidoxypropylmethyldiethoxysilane (Shin-Etsu Silicone, KBM403) Rust inhibitor: 1,2,3-triazole

[0220] <Liquid crystal polarizing film> The liquid crystal polarizing film to be laminated with the surface protective film of Example 5 and Comparative Example 2 was produced from an optically anisotropic composition containing a polymerizable liquid crystal compound prepared by the following method.

[0221] [Preparation of polymerizable liquid crystal compounds] Liquid crystal compound (I-1): Synthesized according to the description of JP 2020-042305 A. The chemical structure of liquid crystal compound (I-1) is shown below in Chemical Formula 1.

[0222] [ka]

[0223] Dye (II-1): Synthesized according to the synthesis method described below.

[0224] [ka]

[0225] Synthesis of (II-1-a): Tetrahydrofuran (100 mL) and sodium hydride (60% purity, 6.7 g, 168.0 mmol) were added to an ice-cooled reactor, and a mixture of diethyl (4-nitrobenzyl)phosphonate (18.0 g, 65.9 mmol), 4-butylbenzaldehyde (9.1 g, 56.1 mmol), and tetrahydrofuran (50 mL) was added dropwise over 10 minutes. The mixture was washed with tetrahydrofuran (30 mL) and then stirred at 50 °C for 0.5 hours. The reaction mixture was poured into water, extracted with ethyl acetate, washed with water and saturated brine, and the solvent was evaporated. The resulting crude product was dissolved in ethyl acetate (20 mL) with heating, added with hexane (50 mL), and cooled. The precipitate was filtered, washed with hexane, and dried under reduced pressure to obtain 15.0 g of (II-1-a).

[0226] Synthesis of (II-1-b): (II-1-a) (15.0 g, 53.3 mmol), tetrahydrofuran (150 mL), and iron powder (13.9 g, 248.9 mmol) were mixed, and ammonium chloride (13.3 g, 248.6 mmol) dissolved in water (30 mL) was added dropwise, followed by stirring at 50 °C for 3 hours. The mixture was filtered through Celite, extracted with ethyl acetate, washed with water and saturated brine, and the solvent was distilled off. The resulting crude product was suspended in hexane, and the precipitate was filtered off, washed with hexane, and dried to obtain 10.9 g of (II-1-b).

[0227] Synthesis of (II-1): (II-1-b) (2.51 g, 10.0 mmol), N-methylpyrrolidone (40 mL), concentrated hydrochloric acid (2.2 mL), and water (20 mL) were mixed and cooled to 3°C. Then, sodium nitrite (789 mg, 11.4 mmol) was added and the mixture was stirred at 15°C for 3.5 hours. 1-Phenylpyrrolidine (1.47 g, 10.0 mmol), methanol (60 mL), and water (30 mL) were mixed, and the pH was adjusted to 3.5 with concentrated hydrochloric acid. While maintaining the pH at 3 to 5 with aqueous sodium hydroxide, the solution containing the diazonium salt was added dropwise, and the mixture was stirred at 15°C for 3 hours. The resulting precipitate was filtered, washed with water, and dried under reduced pressure. The resulting crude product was purified by silica gel column chromatography (hexane / methylene chloride) to obtain 3.06 g of a red solid (II-2).

[0228] Dye (II-2): Synthesized according to the synthesis method described below.

[0229] [ka]

[0230] Synthesis of (II-2): (II-1-b) (1.0 g, 4.0 mmol) and N-methylpyrrolidone (13 mL) were mixed, concentrated hydrochloric acid (1.0 g, 10.0 mmol) was added, and the mixture was cooled in an ice bath. After that, sodium nitrite (0.3 g, 4.4 mmol) dissolved in water (1.3 mL) was added and stirred for 1 hour. The reaction mixture was coupled with 1-phenylpiperidine (0.6 g, 4.0 mmol) dissolved in methanol (25 mL) and water (6.5 mL) at pH = 7. The precipitate was filtered, washed with water, and dried under reduced pressure. The resulting crude product was purified by silica gel column chromatography (hexane / methylene chloride) to give 760 mg of an orange solid (II-2).

[0231] The chemical structures of the liquid crystal compound (I-1) and the dyes (II-1) and (II-2) synthesized above are shown below. 11 H 22 means that 11 methylene chains are bonded in a linear fashion.

[0232] [ka]

[0233] [ka]

[0234] [ka]

[0235] The chemical structures of dyes (II-3) (manufactured by Hayashibara Co., Ltd.) and (II-4) (manufactured by Showa Kako Co., Ltd.) are shown below.

[0236] [ka]

[0237] [ka]

[0238] [Preparation of Optically Anisotropic Composition] To 69.31 parts by mass of cyclopentanone, 28.57 parts by mass of liquid crystal compound (I-1), 0.10 parts by mass of dye (II-1), 0.43 parts by mass of dye (II-2), 0.39 parts by mass of dye (II-3) (manufactured by Hayashibara Co., Ltd.), 0.90 parts by mass of dye (II-4) (manufactured by Showa Kako Co., Ltd.), 0.23 parts by mass of initiator (PI-1) shown in Chemical Formula 9 below, and 0.34 parts by mass of BYK-361N (manufactured by BYK-Chemie) were added, and the mixture was heated and stirred at 80°C, followed by filtration using a syringe equipped with a syringe filter (manufactured by Membrane Solutions, PTFE13045, diameter 0.45 μm) to obtain an optically anisotropic composition.

[0239] [ka]

[0240] [Preparation of liquid crystal polarizing film] The optically anisotropic composition obtained above was spin-coated onto a substrate on which a polyimide alignment film (LX1400, manufactured by Hitachi Chemical DuPont Microsystems, alignment film formed by rubbing) had been formed on glass, and the film was dried by heating at 120°C for 2 minutes, then cooled to the liquid crystal phase and exposed to an exposure dose of 500 mJ / cm. 2 (365 nm standard) to obtain a liquid crystal polarizing film. An overcoat layer was further formed on the liquid crystal polarizing film using an overcoat composition. The curable resin (R-1) contained in the overcoat composition was synthesized by the following method.

[0241] Synthesis of (R-1): Propylene glycol monomethyl ether (157 parts by mass), glycidyl methacrylate (98 parts by mass), methyl methacrylate (1.0 part by mass), ethyl acrylate (1.0 part by mass), 2,2'-azobis(2,4-dimethylvaleronitrile) (1.0 part by mass), and 1.9 parts by mass of 3-mercaptopropyltrimethoxysilane (KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to a flask equipped with a thermometer, a stirrer, and a reflux condenser, and the mixture was allowed to react at 65°C for 3 hours. After that, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.5 parts by mass) was further added and reacted for 3 hours, after which propylene glycol monomethyl ether (138 parts by mass) and p-methoxyphenol (0.45 parts by mass) were added and the mixture was heated to 100°C. Next, acrylic acid (51 parts by mass) and triphenylphosphine (3.1 parts by mass) were added and reacted at 110°C for 6 hours to obtain a (meth)acryloyl copolymer (R-1) with a carbon-carbon double bond content (acryloyl equivalent (amount of acryloyl group introduced)) of 4.6 mmol / g and a mass average molecular weight (Mw) of 17,700.

[0242] An overcoat composition was obtained by mixing and stirring 23.08 parts by mass of a 65% propylene glycol monomethyl ether solution of curable resin (R-1), 0.13 parts by mass of a photopolymerization initiator (PI-2) shown in Chemical Formula 10 below, 0.40 parts by mass of BYK-3550 (manufactured by BYK-Chemie), and 76.39 parts by mass of ethanol. The overcoat composition was formed into a film on a liquid crystal polarizing film by spin coating, and after heating and drying at 50°C for 2 minutes, an exposure dose of 500 mJ / cm was applied. 2 After that, the film was heated at 80° C. for 5 minutes to obtain a liquid crystal polarizing film having an overcoat layer laminated thereon. When the liquid crystal polarizing film having the overcoat layer laminated thereon was held over a commercially available polarizing plate and rotated, it became bright and dark, and it was confirmed that the film exhibited good performance suitable for use as a polarizing film.

[0243] [ka]

[0244] <Example 1: Laminated film> A laminated film of Example 1 consisting of a polyester film containing an ultraviolet absorber / an easy-adhesion layer / a cured resin layer was obtained by the following method.

[0245] (Preparation of polyester film containing ultraviolet absorber) A mixed raw material obtained by blending polyester A and polyester D at a mass ratio of 90:10 was used as the raw material for the intermediate layer, and a mixed raw material obtained by blending polyester B and polyester C at a mass ratio of 86:14 was used as the raw material for the surface layer. Each material was melted in a separate twin-screw extruder and co-extruded through a T-die at a discharge rate ratio of 1:23:1. The molten sheet was quenched on a casting drum to below the glass transition temperature to obtain a three-layer unstretched film. Subsequently, the film was stretched 3.4 times in the longitudinal direction at 83°C using a roll stretching machine. The above-mentioned composition for the easy-adhesion layer was applied to one surface of this film, which was then stretched 4 times in the transverse direction at 125°C using a tenter stretching machine, further heat-set at 234°C, and then quenched to below the glass transition temperature to obtain a 75 μm thick film having an easy-adhesion layer with a thickness (after drying) of 0.1 μm.

[0246] (Formation of cured resin layer) A curable resin composition was applied onto the adhesive layer by bar coating to a thickness (after curing) of 3 μm, dried at 80° C. for 60 seconds, and then irradiated with ultraviolet light (integrated light amount: 400 mJ / cm ). 2 ) to form a cured resin layer.

[0247] <Example 2: Laminated film> A laminated film of Example 2 consisting of a polyester film containing an ultraviolet absorber / an easy-adhesion layer / a cured resin layer was obtained by the following method. (Preparation of polyester film containing ultraviolet absorber) A mixed raw material obtained by blending polyester A and polyester E in a mass ratio of 93:7 was used as the raw material for the intermediate layer, and a mixed raw material obtained by blending polyester B and polyester C in a mass ratio of 86:14 was used as the raw material for the surface layer. Each material was melted in a separate twin-screw extruder and coextruded through a T-die at a discharge rate ratio of 2.5:45:2.5. The molten sheet was quenched on a casting drum to below the glass transition temperature to obtain a three-layer unstretched film. Subsequently, the film was stretched 3.3 times in the longitudinal direction at 86°C using a roll stretching machine. The above-mentioned composition for the easy-adhesion layer was applied to one surface of this film, and then the film was stretched 3.6 times in the transverse direction at 110°C using a tenter stretching machine, further heat-set at 200°C, and then quenched to below the glass transition temperature to obtain a 50 μm-thick film having an easy-adhesion layer with a thickness (after drying) of 0.1 μm.

[0248] (Formation of cured resin layer) A curable resin composition was applied onto the adhesive layer by bar coating to a thickness (after curing) of 3 μm, dried at 80° C. for 60 seconds, and then irradiated with ultraviolet light (integrated light amount: 400 mJ / cm ). 2 ) to form a cured resin layer.

[0249] <Example 3: Laminated film> The same production process as in Example 2 was carried out, except that a mixed raw material obtained by blending polyester A and polyester F in a mass ratio of 90:10 was used as the intermediate layer, to obtain a laminated film consisting of a polyester film containing an ultraviolet absorber, an easy-adhesion layer, and a cured resin layer.

[0250] <Example 4: Laminated film> The same production process as in Example 2 was carried out, except that a mixed raw material obtained by blending polyester A and polyester G in a mass ratio of 85:15 was used as the intermediate layer, to obtain a laminated film consisting of a polyester film containing an ultraviolet absorber, an easy-adhesion layer, and a cured resin layer.

[0251] <Example 5: Surface protection film> Using the adhesive sheet obtained by the method described below, a surface protection film of Example 5 having an adhesive layer on one side of the laminated film of Example 1 was obtained.

[0252] (Preparation of adhesive sheet) A pressure-sensitive adhesive composition was prepared by uniformly mixing 200 parts by mass of a (meth)acrylic polymer (A-1) solution (dilution solvent: ethyl acetate, solids concentration: 50% by mass), 25 parts by mass of a curable compound (B-1), 3 parts by mass of a radical initiator (C-1), 0.3 parts by mass of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicones, KBM-403) as a silane coupling agent, 0.3 parts by mass of 1,2,3-triazole as a rust inhibitor, and 101 parts by mass of ethyl acetate. The pressure-sensitive adhesive composition was spread in a sheet form on a 100 μm thick silicone release-treated release film (Diafoil MRV, manufactured by Mitsubishi Chemical Corporation) so that the thickness after solvent drying would be 50 μm.

[0253] Next, the sheet-shaped pressure-sensitive adhesive composition together with the release film was placed in a dryer heated to 95°C and held there for 10 minutes to volatilize the solvent in the pressure-sensitive adhesive composition. Furthermore, a 75 μm-thick release film (Diafoil MRQ, manufactured by Mitsubishi Chemical Corporation) that had been subjected to silicone release treatment was laminated on the sheet-like resin composition from which the solvent had been dried to form a laminate, and a metal halide lamp irradiation device (Ushio Inc., UVC-0516S1, Lamp UVL-8001M3-N) was used to irradiate the pressure-sensitive adhesive composition through the release film with a cumulative irradiation dose of 1000 mJ / cm at a wavelength of 365 nm. 2 The adhesive sheet had a release film laminated on both sides (adhesive sheet thickness: 50 μm). The adhesive strength of the adhesive sheet was 10 N / cm and the glass transition temperature (Tg) was -38°C.

[0254] The adhesive strength of the adhesive sheet was measured by the following method. One release film was peeled off, and a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd.; product name "Cosmoshine A4300", thickness 100 μm) was roll-pressed onto the backing film using a hand roller. This was cut into 10 mm wide x 100 mm long strips, and the remaining release film was peeled off, revealing an adhesive surface that was then roll-pressed onto a soda-lime glass using a hand roller. The strip was autoclaved (60°C, gauge pressure 0.2 MPa, 20 minutes) for final adhesion, producing a sample for adhesive strength measurement. Using a universal material testing machine (manufactured by INSTRON, model number "5965"), the adhesive sheet was peeled from the glass while pulling the backing film at an angle of 180° at a peeling rate of 300 mm / min, and the tensile strength was measured with a load cell to determine the 180° peel strength (N / cm) of the adhesive sheet to the glass.

[0255] The glass transition temperature (Tg) of the pressure-sensitive adhesive sheet was measured by the following method. The release film was removed from the adhesive sheet with the release film, and multiple layers were laminated to form a 1.0 mm thick laminate. A cylindrical object with a diameter of 8 mm (height of 1.0 mm) was punched out from the resulting adhesive layer laminate, and this was used as a measurement sample. The loss tangent (tan δ) of the above sample was measured using a viscoelasticity measuring device (manufactured by TA Instruments, device name "DHR 1") under the following measurement conditions. From the obtained data, the temperature at which the maximum point of the loss tangent (tanδ) appears is determined as the glass transition temperature. The temperature was taken as Tg.

[0256] (Preparation of surface protection film with release film) One of the release films was peeled off, and the surface of the laminated film obtained in Example 1 on which the cured resin layer was not provided was attached to an adhesive sheet, thereby obtaining a surface protection film with a release film.

[0257] (Preparation of a laminate with a liquid crystal polarizing film) Furthermore, as an evaluation sample, the release film was peeled off from the surface protection film with the release film, and the exposed adhesive layer surface was attached to the overcoat layer surface of the liquid crystal polarizing film to prepare a laminate with the liquid crystal polarizing film.

[0258] <Comparative Example 1: Laminated Film> A laminated film of Comparative Example 1 consisting of a polyester film containing no ultraviolet absorber / an easy-adhesion layer / a cured resin layer was obtained by the following method.

[0259] (Preparation of Polyester Film Containing No UV Absorber) Polyester A was used as the raw material for the intermediate layer, and a mixed raw material obtained by blending polyester B and polyester C in a mass ratio of 86:14 was used as the raw material for the surface layer. Each material was melted in a separate twin-screw extruder and co-extruded through a T-die at a discharge rate ratio of 1:23:1. The molten sheet was quenched on a casting drum to below the glass transition temperature to obtain a three-layer unstretched film. Subsequently, the film was stretched 3.4 times in the longitudinal direction at 83°C using a roll stretching machine. The above-mentioned composition for the easy-adhesion layer was applied to one surface of this film, and then the film was stretched 4 times in the transverse direction at 125°C using a tenter stretching machine, further heat-set at 234°C, and then quenched to below the glass transition temperature to obtain a 75 μm thick film having an easy-adhesion layer with a thickness (after drying) of 0.1 μm.

[0260] A cured resin layer was formed on the obtained film in the same manner as in Example 1, to obtain a laminated film of Comparative Example 1.

[0261] <Comparative Example 2: Surface Protection Film> A surface protection film of Comparative Example 2 having an adhesive layer on one side was obtained in the same manner as in Example 5, except that the laminated film of Comparative Example 1 was used. Furthermore, a laminate with a liquid crystal polarizing film was prepared as an evaluation sample.

[0262] <Reference example: laminated film> A laminated film of Example 1 consisting of a polyester film containing an ultraviolet absorber / an easy-adhesion layer / a cured resin layer was obtained by the following method. The hard coat layer composition 1 was applied to the laminated film using a bar coater to form a coating film. The formed coating film was then heated at 90°C for 1 minute to evaporate the solvent in the coating film, and the ultraviolet irradiation dose was adjusted to 100 mJ / cm2 in terms of cumulative light dose. 2 The coating film was semi-cured (half-cured) by irradiating it with ultraviolet light so that the UV intensity reached 200 mJ / cm. Next, the hard coat layer composition 2 was applied to the surface of the semi-cured coating film of the hard coat layer composition 1 using a bar coater to form a coating film. The formed coating film was heated at 90°C for 1 minute to evaporate the solvent in the coating film, and the UV irradiation dose reached 200 mJ / cm in cumulative light intensity. 2 The coating was fully cured by irradiating it so that the coating was completely cured. As a result, a hard coat layer was formed on the polyester film substrate, which consisted of a first hard coat layer with a thickness of 10 μm and a second hard coat layer with a thickness of 5 μm laminated on the first hard coat layer.

[0263] (Hard Coat Composition 1) Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (product name "M-405", manufactured by Toagosei Co., Ltd.): 25 parts by mass Dipentaerythritol EO-modified hexaacrylate (product name "A-DPH-6E", manufactured by Shin-Nakamura Chemical Co., Ltd.): 25 parts by mass Silica fine particles (average particle diameter 15 nm, MEK-AC-2140Z, manufactured by Nissan Chemical Industries, Ltd.): 50 parts by mass (solid content equivalent) Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan Ltd.): 4 parts by mass Fluorine-based leveling agent (product name "DAC-HP", manufactured by Daikin Corporation): 1 part by mass (solid content equivalent) Methyl ethyl ketone (MEK): 158 parts by weight

[0264] (Hard Coat Composition 2) Urethane acrylate (product name "UV1700B", manufactured by Mitsubishi Chemical Corporation): 25 parts by weight Antifouling agent (product name "BYK-UV3570", manufactured by BYK-Chemie): 1.5 parts by mass (solid content equivalent) Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan Ltd.): 4 parts by mass Methyl ethyl ketone (MEK): 233 parts by weight

[0265] <Evaluation of laminated film> The laminated films of Example 1 and Comparative Example 1 were evaluated for surface hardness, flex resistance, and ultraviolet absorbing performance.

[0266] (1)Surface hardness The pencil hardness of the surface of the cured resin layer of each laminate film was measured using a pencil hardness tester (manufactured by Yasuda Seiki Co., Ltd.) under a load of 750 g in accordance with JIS K 5600-5-4:1999.

[0267] (2) Flexibility Using a bending tester (DLDMLH-FS, manufactured by Yuasa System Equipment Co., Ltd.), each laminated film was subjected to a bending test 200,000 times at R = 2 mm, with the cured resin layer side facing the outer surface. The presence or absence of cracks in the cured resin layer on the outer surface was visually confirmed, and the film was rated as A (good) if no cracks occurred, and B (bad) if cracks occurred.

[0268] (3) UV absorption performance The light transmittance of each laminated film in the wavelength range of 300 to 430 nm was measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Corporation; device name "U-3900H"), and the average value was calculated.

[0269] (4) Light transmittance at each wavelength The light transmittance at each wavelength of each laminated film was measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Corporation; device name "U-3900H").

[0270] (5) Measurement method of b value For each laminated film, the b value of a single film was measured by the transmission method using a spectrophotometer "CM-3700d" manufactured by Konica Minolta Inc. in accordance with JIS Z 8722:2009.

[0271] <Evaluation of surface protection films> The surface protective films of Example 5 and Comparative Example 2 were evaluated for their protective function against the liquid crystal polarizing film.

[0272] [Protection function of LCD polarizing film] The release films were peeled off from the surface protection films with release films (cured resin layer / easy-adhesion layer / polyester film containing UV absorber / adhesive layer / release film) obtained in Example 5 and Comparative Example 2, and the films were roll-pressed onto the liquid crystal polarizing film using a hand roller. Autoclaving (60°C, gauge pressure 0.2 MPa, 20 minutes) was performed for finish bonding, producing samples for measuring the protective function of the liquid crystal polarizing film. The sample was subjected to a xenon light resistance test using a xenon light resistance tester (manufactured by Atlas, equipment name "Ci4000") at an illuminance of 0.55 W / m 2 The test was carried out for 40 hours under irradiation conditions of (340 nm). As the light resistance test results, the change in polarization degree (%) at a wavelength of 595 nm before and after the light resistance test (polarization degree before test - polarization degree after test) is shown in Table 2. The degree of polarization (Pe) was calculated by irradiating linearly polarized measurement light onto the anisotropic dye film, measuring the transmittance for light polarized in the absorption axis direction of the anisotropic dye film and the transmittance for light polarized in the polarization axis direction of the anisotropic dye film using a spectrophotometer equipped with a Glan-Thompson polarizer (manufactured by Otsuka Electronics Co., Ltd., product name "RETS-100"), and then using the following formula: Pe=(Ty-Tz) / (Ty+Tz) (In the formula, Tz is the transmittance of the anisotropic dye film for light polarized along the absorption axis; Ty is the transmittance of the anisotropic dye film for polarized light in the direction of the polarization axis.

[0273] [Table 1]

[0274] [Table 2]

[0275] From the above examples, it was confirmed that the laminate film and surface protection film of the present invention have an average light transmittance of 35% or less in the range of 300 to 430 nm, and therefore there is little change in the degree of polarization even when irradiated with ultraviolet rays, and light degradation of optical components such as liquid crystal polarizing films can be suppressed. [Explanation of symbols]

[0276] 1 Cured resin layer 2. Base film 3 Adhesive layer 4. Liquid crystal polarizing film (polarizing element) 4a Optically anisotropic layer 4b Alignment film 5a, 5b Adhesive layer or adhesive layer 6 Phase difference film 7 Organic EL light-emitting layer 8 Anti-reflection layer 9 Color filter containing layer 10 Laminated film 20 Surface protection film 100 Organic EL Devices 200 Color filter built-in organic EL device

Claims

1. The film includes a substrate film and a cured resin layer formed from a curable resin composition, the substrate film contains an ultraviolet absorber, The thickness of the cured resin layer is 1 μm or more and 4 μm or less, the thickness ratio of the base film to the cured resin layer is 15 or more, The average light transmittance in the range of 300 to 430 nm is 16.2 to 35%, The light transmittance at 410 nm is 57% or more, A laminated film for an image display device, having a b value of 6.0 or less.

2. 2. The laminate film for an image display device according to claim 1, wherein the ultraviolet absorber is at least one selected from the group consisting of triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and benzoxazine-based ultraviolet absorbers.

3. The laminate film for an image display device according to claim 1 or 2, wherein the curable resin composition contains a (meth)acrylate and a modifier.

4. 4. The laminated film for an image display device according to claim 1, wherein the surface on which the cured resin layer is provided has a surface hardness of H or more.

5. 5. The laminate film for an image display device according to claim 1, which does not crack after a bending test of 200,000 times under a condition of R=2 mm.

6. 6. The laminate film for an image display device according to claim 1, wherein the substrate film is a polyester film.

7. 7. The laminate film for an image display device according to claim 6, wherein the polyester film has a three-layer structure.

8. The laminate film for an image display device according to claim 7 , wherein the ultraviolet absorber is contained in an intermediate layer.

9. 9. The laminate film for an image display device according to claim 1, wherein the thickness of the substrate film is 9 μm or more and 125 μm or less.

10. 10. The laminate film for an image display device according to claim 1, wherein the cured resin layer is provided on one surface of the substrate film, and an adhesive layer is provided on the other surface.

11. The surface protective film for an image display device according to claim 10 , wherein the adhesive layer comprises a (meth)acrylic polymer (A).

12. The surface protective film for an image display device according to claim 10 or 11, wherein the adhesive layer comprises a curable compound (B) and a radical polymerization initiator (C).

13. The surface protective film for an image display device according to any one of claims 10 to 12, wherein the adhesive layer has a thickness of 10 µm or more and 175 µm or less.

14. A surface protective film with a release film, which is obtained by laminating the surface protective film for an image display device according to any one of claims 10 to 13 and a release film.

15. A laminate with a liquid crystal polarizing film, which is obtained by laminating the laminate film for an image display device according to any one of claims 1 to 9 or the surface protective film for an image display device according to any one of claims 10 to 13 and a liquid crystal polarizing film.

16. The laminate with a liquid crystal polarizing film according to claim 15 , wherein the liquid crystal polarizing film has an optically anisotropic layer.

17. 17. The laminate with a liquid crystal polarizing film according to claim 15, wherein the liquid crystal polarizing film comprises an optically anisotropic layer and an alignment film.

18. The laminate with a liquid crystal polarizing film according to claim 16 or 17, wherein the optically anisotropic layer contains a polymerizable liquid crystal compound.

19. 19. The laminate with a liquid crystal polarizing film according to claim 16, wherein the optically anisotropic layer contains a polymerizable liquid crystal compound and a dye.

20. 20. The laminate with a liquid crystal polarizing film according to claim 15, wherein the thickness (total thickness) of the liquid crystal polarizing film is 1 / 5 or less of the thickness of the substrate film.

21. Using a xenon light resistance tester (manufactured by Atlas, equipment name "Ci4000"), illuminance: 0.55 W / m ２ 21. The laminate with a liquid crystal polarizing film according to claim 15, wherein after a test is carried out for 40 hours under irradiation conditions of (340 nm), the change in polarization degree at a wavelength of 595 nm is 4.0% or less.

22. An image display device comprising the laminate film for an image display device according to any one of claims 1 to 9 or the surface protective film for an image display device according to any one of claims 10 to 13.

23. An image display device comprising the liquid crystal polarizing film-attached laminate according to any one of claims 15 to 21.

24. An image display device comprising the laminate film for an image display device according to any one of claims 1 to 9 or the surface protective film for an image display device according to any one of claims 10 to 13 laminated with an anti-reflection film and / or a color filter.

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