Polarizing film and method for manufacturing same

Abstract

The present invention pertains to a polarizing film provided with a cured product layer on at least one surface of a polarizer, the cured product layer being a cured product layer of a curable resin composition containing a specific boron-containing compound and boric acid. The mass ratio of the specific boron-containing compound to the boric acid in the curable resin composition is preferably 1: 0.1 to 1: 30.0. Preferably, the content of the compound represented by general formula (1) in the curable resin composition is 0.05-5% by mass, and the content of boric acid is 0.1-2% by mass. The polarizer is preferably a polarizer containing 10-22 mass% of boric acid. It is preferable that A: B = 1: 0.001-1: 0.1 when A mass% is the ratio of boric acid contained in the polarizer and B mass% is the ratio of boric acid contained in the curable resin composition.

Description

Technical Field

[0001] The present invention relates to a polarizing film having a cured layer on at least one side of a polarizer, particularly a polarizing film having a transparent protective film laminated on at least one side of the polarizer via an adhesive layer, and a method for producing the same. The polarizing film can be used alone or as an optical film laminated with the polarizing film to form an image display device such as a liquid crystal display (LCD), an organic EL display, a CRT, or a PDP. Background Art

[0002] Liquid crystal display devices are rapidly expanding their market share in applications such as watches, mobile phones, PDAs, laptop computers, computer monitors, DVD players, and TVs. Liquid crystal displays visualize the polarization state of liquid crystals when they are switched on and off, and their display principle utilizes polarizers. In particular, applications such as TVs are increasingly demanding high brightness, high contrast, and wide viewing angles, and polarizing films are also increasingly demanding high transmittance, high polarization degree, and high color reproducibility.

[0003] As polarizers, the most widely used are iodine-based polarizers, which have a structure in which iodine is adsorbed on polyvinyl alcohol (hereinafter also referred to as "PVA") and then stretched, due to their high transmittance and high polarization degree. Generally speaking, polarizing films are polarizing films in which transparent protective films are laminated to both sides of the polarizer using a so-called aqueous adhesive made by dissolving a polyvinyl alcohol-based material in water (see Patent Document 1 below). As the transparent protective film, triacetyl cellulose, which has high moisture permeability, is used. When using the above-mentioned aqueous adhesive (so-called wet lamination), a drying process is required after laminating the polarizer and the transparent protective film.

[0004] On the other hand, proposals have been made to use active energy ray-curable adhesives as an alternative to the aforementioned aqueous adhesives. When using active energy ray-curable adhesives to manufacture polarizing films, since a drying step is not required, the productivity of the polarizing film can be improved. For example, the present inventors have proposed a free radical polymerization-type active energy ray-curable adhesive using an N-substituted amide monomer as a curable component (Patent Document 2 below).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-296427

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-052000 Summary of the Invention

[0009] Problems solved by the invention

[0010] Adhesive layers formed using the active energy ray-curable adhesive described in Patent Document 2 are capable of withstanding water resistance tests, such as those evaluating discoloration and peeling after immersion in 60°C warm water for 6 hours. However, in recent years, in addition to the gradual shift to more stringent conditions in water resistance tests, there has also been an increasing demand for maintaining the humidification reliability of polarization characteristics of polarizing films. Therefore, the reality is that previously reported adhesives for polarizing films, including the active energy ray-curable adhesive described in Patent Document 2, have room for further improvement, particularly in terms of humidification reliability of polarization characteristics.

[0011] The present invention has been developed in view of the above-mentioned actual situation, and an object of the present invention is to provide a polarizing film having excellent humidification reliability of polarization characteristics and a method for producing the same.

[0012] Furthermore, an object of the present invention is to provide an optical film using the polarizing film, and to provide an image display device using the polarizing film or the optical film.

[0013] Solutions to the problem

[0014] The present inventors have conducted intensive studies to solve the above problems and have found that the above objects can be achieved by allowing a specific boron-containing compound and boric acid to coexist in a cured product layer provided on at least one surface of a polarizer, thereby completing the present invention.

[0015] That is, the present invention relates to a polarizing film (1) comprising a cured layer on at least one side of a polarizer, wherein the cured layer is a cured layer of a curable resin composition containing a compound represented by the following general formula (1) and boric acid.

[0016] [Chemical Formula 1]

[0017]

[0018] (wherein, X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, R 1 and R 2 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group or a heterocyclic group.)

[0019] In the above polarizing film (1), preferably, it is a polarizing film (2), wherein the mass ratio of the compound represented by the general formula (1) to the boric acid in the curable resin composition is 1:0.1 to 1:30.0.

[0020] Among the polarizing films (1) or (2), the polarizing film (3) is preferred, wherein the curable resin composition further contains a compound represented by the following general formula (2).

[0021] [Chemical Formula 2]

[0022]

[0023] (Among them, R 4 is a hydrogen atom or a methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 Optionally forming a cyclic heterocycle.)

[0024] Among any of the above-mentioned polarizing films (1) to (3), the polarizing film (4) is preferred, wherein the content of the compound represented by the general formula (1) in the curable resin composition is 0.05 to 5% by mass, and the content of the boric acid is 0.1 to 2% by mass.

[0025] In any one of the polarizing films (1) to (4), the polarizing film (5) is preferably selected, wherein the polarizer contains 10 to 22% by mass of boric acid.

[0026] Among the above-mentioned polarizing films (1) to (5), preferred is the polarizing film (6), wherein, when the proportion of boric acid contained in the polarizer is set to A% by mass and the proportion of boric acid contained in the curable resin composition is set to B% by mass, A:B = 1:0.001 to 1:0.1.

[0027] Among any of the polarizing films (1) to (6), the polarizing film (7) is preferred, wherein the thickness of the cured layer is 1 μm or more and 2 μm or less.

[0028] Among any of the above polarizing films (1) to (7), the preferred polarizing film is a polarizing film (8) in which a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer, wherein the adhesive layer is the cured layer.

[0029] Among the above-mentioned polarizing films (8), a polarizing film (9) is preferred, wherein the transparent protective film is a triacetyl cellulose resin film.

[0030] Among the above-mentioned polarizing films (8) or (9), the polarizing film (10) is preferably provided with a compatibility layer between the transparent protective film and the adhesive layer.

[0031] The present invention also relates to an optical film (11) in which at least one of the polarizing films (1) to (10) is laminated.

[0032] Furthermore, the present invention relates to an image display device (12) using any one of the polarizing films (1) to (10) or the optical film (11).

[0033] The present invention also relates to a method (13) for producing a polarizing film, wherein a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer, wherein the adhesive layer is a cured layer of a curable resin composition composed of at least a first composition and a second composition.

[0034] The first composition contains at least a compound represented by the following general formula (1) and boric acid.

[0035] [Chemical Formula 3]

[0036]

[0037] (wherein, X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, R 1 and R 2 (represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group which may have a substituent,

[0038] The second composition contains at least a compound represented by the following general formula (2):

[0039] [Chemical Formula 4]

[0040]

[0041] (Among them, R 4 is a hydrogen atom or a methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 optionally forming a cyclic heterocycle),

[0042] The method for manufacturing the polarizing film (13) includes: a first coating step of coating the first composition on the bonding surface of the polarizer; a second coating step of coating the second composition on the bonding surface of the transparent protective film; a bonding step of bonding the polarizer and the transparent protective film; and a bonding step of irradiating active energy rays from the polarizer surface side or the transparent protective film surface side to cure the curable resin composition to obtain the adhesive layer, and bonding the polarizer and the transparent protective film via the obtained adhesive layer.

[0043] Among the above-mentioned method for manufacturing a polarizing film (13), preferred is the method for manufacturing a polarizing film (14), wherein the mass ratio of the compound represented by the general formula (1) in the first composition to the boric acid is 1:0.1 to 1:30.0.

[0044] Among the above-mentioned methods for manufacturing a polarizing film (13) or (14), preferred is the method for manufacturing a polarizing film (15), wherein the content of the compound represented by the general formula (1) in the curable resin composition is 0.05 to 5% by mass, and the content of the boric acid is 0.1 to 2% by mass.

[0045] In any one of the above-mentioned methods for producing a polarizing film (13) to (15), the method for producing a polarizing film (16) is preferably a polarizer containing 10 to 22% by mass of boric acid.

[0046] Among any one of the above-mentioned methods for manufacturing a polarizing film (13) to (16), preferred is the method for manufacturing a polarizing film (17), wherein, when the proportion of boric acid contained in the polarizer is set to A% by mass and the proportion of boric acid contained in the curable resin composition is set to B% by mass, A:B = 1:0.001 to 1:0.1.

[0047] Among any one of the above-mentioned methods for manufacturing a polarizing film (13) to (17), preferred is the method for manufacturing a polarizing film (18), wherein the coating thickness of the first composition after the first coating step before drying is 0.6 to 2.0 μm and the coating thickness after drying is 0.3 to 1.0 μm.

[0048] In any one of the above-mentioned methods for producing a polarizing film (13) to (18), the method for producing a polarizing film (19) is preferred, wherein the thickness of the adhesive layer is 1 μm or more and 2 μm or less.

[0049] Effects of the Invention

[0050] The polarizing film of the present invention has a cured layer on at least one side of the polarizer, and the cured layer is a cured layer of a curable resin composition containing a specific boron-containing compound represented by general formula (1) and boric acid. Therefore, the polarization characteristics have excellent humidification reliability. The reason for this effect is not clear, but it can be inferred as follows.

[0051] The cured product layer provided on at least one side of the polarizer is formed with a curable resin composition as a raw material, and the curable resin composition contains a specific boron-containing compound represented by the general formula (1). The specific boron-containing compound represented by the general formula (1) contains a boronic acid group (or a boronic acid ester group) and a reactive group X, and the boronic acid group (or a boronic acid ester group) can form a covalent bond with a functional group such as a hydroxyl group present on the surface of the polarizer. In addition, the reactive group X can also form a covalent bond by reacting with other curable components contained in the curable resin composition. Therefore, in order to improve the interfacial adhesion between the polarizer and the cured product layer and to suppress the swelling of the polarizer, it is extremely important to improve the reactivity of the specific boron-containing compound represented by the general formula (1). The present inventors conducted in-depth research and found that by allowing the specific boron-containing compound represented by the general formula (1) and boric acid to coexist in the curable resin composition that serves as the raw material of the cured product layer, the boric acid can significantly improve the reactivity of the specific boron-containing compound represented by the general formula (1). That is, by allowing the specific boron-containing compound represented by general formula (1) and boric acid to coexist, the interfacial adhesion between the cured layer and the polarizer is dramatically improved, so even when the polarizing film is exposed to a high-temperature and humidified environment, the swelling of the polarizer can be suppressed, resulting in a significant improvement in the humidification reliability of the polarization characteristics of the polarizing film. In addition, when boric acid is present in the curable resin composition that serves as the raw material of the cured layer, the boric acid can also contribute to the cross-linking reaction in the polarizer. Therefore, even when the polarizing film is exposed to a high-temperature and humidified environment, the swelling of the polarizer can be suppressed by the cross-linking reaction in the polarizer based on boric acid. That is, it can be inferred that the cross-linking reaction in the polarizer caused by boric acid can also significantly improve the humidification reliability of the polarization characteristics of the polarizing film.

[0052] The present invention also relates to a method for producing a polarizing film in which a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer. The adhesive layer is a cured layer of a curable resin composition composed of at least a first composition and a second composition. When the first composition contains a specific boron-containing compound represented by general formula (1) and boric acid, the humidification reliability of the polarization characteristics of the resulting polarizing film is significantly improved. The reason for this effect is not clear, but it can be inferred as follows.

[0053] The specific boron-containing compound represented by the general formula (1) contains a boronic acid group (or a boronic acid ester group) and a reactive group X. The boronic acid group (or a boronic acid ester group) forms a covalent bond with a functional group such as a hydroxyl group present on the surface of the polarizer. The reactive group X can also form a covalent bond by reacting with other curable components contained in the curable resin composition. Therefore, in order to improve the interfacial adhesion between the polarizer and the cured layer and suppress the swelling of the polarizer, it is extremely important to improve the reactivity of the specific boron-containing compound represented by the general formula (1). The present inventors conducted in-depth research and found that by allowing the specific boron-containing compound represented by the general formula (1) and boric acid to coexist in the curable resin composition that becomes the raw material of the cured layer, the boric acid can significantly improve the reactivity of the specific boron-containing compound represented by the general formula (1). That is, by allowing the specific boron-containing compound represented by general formula (1) and boric acid to coexist, the interfacial adhesion between the cured layer and the polarizer is dramatically improved. Therefore, even when the polarizing film is exposed to a high-temperature and humidified environment, the swelling of the polarizer can be suppressed. As a result, the humidity reliability of the polarization characteristics of the polarizing film is significantly improved. In addition, when boric acid is present in the curable resin composition that serves as the raw material of the cured layer, the boric acid contributes to the cross-linking reaction within the polarizer. Therefore, even when the polarizing film is exposed to a high-temperature and humidified environment, the swelling of the polarizer is suppressed by the cross-linking reaction within the polarizer caused by boric acid. In other words, it can be inferred that the cross-linking reaction within the polarizer caused by boric acid also significantly improves the humidity reliability of the polarization characteristics of the polarizing film. In particular, in the method for producing a polarizing film of the present invention, the first composition containing the specific boron-containing compound represented by general formula (1) and boric acid is applied to the bonding surface of the polarizer. Therefore, the specific boron-containing compound represented by general formula (1) and boric acid are present at high concentrations on the surface of the polarizer. Therefore, the specific boron-containing compound represented by general formula (1) reacts rapidly and efficiently with the polarizer, and the crosslinking reaction within the polarizer caused by the boric acid also proceeds rapidly and efficiently. Therefore, the polarizing film manufacturing method of the present invention can produce a polarizing film with significantly improved humidification reliability of polarization characteristics. DETAILED DESCRIPTION

[0054] The polarizing film of the present invention is a polarizing film comprising a cured layer on at least one side of a polarizer. The cured layer is a cured layer of a curable resin composition containing a compound represented by the following general formula (1) and boric acid.

[0055] [Chemical Formula 5]

[0056]

[0057] (wherein, X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, R 1 and R2 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group or a heterocyclic group.)

[0058] Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group having 1 to 20 carbon atoms and optionally having a substituent, a cyclic alkyl group having 3 to 20 carbon atoms and optionally having a substituent, and an alkenyl group having 2 to 20 carbon atoms. Examples of the aryl group include a phenyl group having 6 to 20 carbon atoms and optionally having a substituent, a naphthyl group having 10 to 20 carbon atoms and optionally having a substituent, and examples of the heterocyclic group include a 5-membered ring or a 6-membered ring group containing at least one heteroatom and optionally having a substituent. These groups may also be linked to each other to form a ring. In the general formula (1), R 1 and R 2 , preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom.

[0059] X in the compound represented by general formula (1) is a reactive group, which is a functional group capable of reacting with a curable component constituting the cured layer, particularly the adhesive layer, and examples thereof include hydroxyl, amino, aldehyde, carboxyl, vinyl, (meth)acryloyl, styryl, (meth)acrylamide, vinyl ether, epoxy, oxetane, α,β-unsaturated carbonyl, mercapto, and halogen groups. When the curable resin composition constituting the cured product layer, particularly the adhesive layer, is active energy ray-curable, the reactive group X is preferably at least one reactive group selected from a vinyl group, a (meth)acryloyl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetanyl group, and a mercapto group. When the curable resin composition constituting the cured product layer, particularly the adhesive layer, is free radical polymerizable, the reactive group X is preferably at least one reactive group selected from a (meth)acryloyl group, a styryl group, and a (meth)acrylamide group. When the compound represented by general formula (1) has a (meth)acrylamide group, the reactivity is high, and the copolymerization rate with the curable component in the cured product layer, particularly the adhesive layer, is increased, which is more preferable. In addition, the (meth)acrylamide group has high polarity and excellent adhesion, and therefore is also preferred from the perspective of effectively achieving the effects of the present invention. When the curable resin composition constituting the cured product layer, particularly the adhesive layer, is cationically polymerizable, the reactive group X preferably has at least one functional group selected from the group consisting of a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, a vinyl ether group, an epoxy group, an oxetanyl group, and a mercapto group. In particular, when the reactive group X has an epoxy group, it is preferred because the resulting cured product layer, particularly the adhesive layer, has excellent adhesion to the adherend. In particular, when the reactive group X has a vinyl ether group, it is preferred because the curable resin composition has excellent curability.

[0060] Preferred specific examples of the compound represented by the general formula (1) include the following compounds (1a) to (1d). 3 is a hydrogen atom or a methyl group.

[0061] [Chemical Formula 6]

[0062]

[0063] Examples of the compound represented by the general formula (1) include, in addition to the compounds exemplified above, esters of (meth)acrylates and boric acid, such as esters of hydroxyethyl acrylamide and boric acid, esters of hydroxymethyl acrylamide and boric acid, esters of hydroxyethyl acrylate and boric acid, and esters of hydroxybutyl acrylate and boric acid.

[0064] The polarizing film of the present invention has a cured layer, in particular an adhesive layer, on at least one side of the polarizer. The cured layer, in particular the adhesive layer, is formed using a curable resin composition as a raw material. The curable resin composition may be composed of only a single composition or may be composed of two or more compositions, for example, a first composition and a second composition. In the case where the curable resin composition is composed of only a single composition, in order to form a cured layer, in particular an adhesive layer, the curable resin composition may be applied to the bonding surface of the polarizer or to other adherends, such as the bonding surface of a transparent protective film. In the case where the curable resin composition is composed of two or more compositions, such as a first composition and a second composition, the first composition may be applied to the bonding surface of the polarizer and the second composition may be applied to other adherends, such as the bonding surface of a transparent protective film. In this case, it is preferred that the compound represented by the general formula (1) and boric acid are compounded in the first composition. It should be noted that a curable component, water or other solvents may also be compounded in the first composition containing the compound represented by the general formula (1) and boric acid. However, when a solvent such as water is added, it is necessary to remove the water or other solvent from the first composition applied to the bonding surface of the polarizer by providing a drying step after the first composition is applied to the bonding surface of the polarizer. Therefore, in the present invention, the amount of solvent added to the curable resin composition is calculated excluding the water or other solvent.

[0065] From the perspective of improving the humidification reliability of the polarization characteristics of the polarizing film, the amount of the compound represented by the general formula (1) in the curable resin composition constituting the cured layer, particularly the adhesive layer, is preferably 0.05 to 5% by mass, more preferably 1.0 to 3.0% by mass. Similarly, the amount of boric acid in the curable resin composition is preferably 0.1 to 2% by mass, more preferably 0.2 to 1.0% by mass.

[0066] In addition, from the perspective of improving the humidification reliability of the polarization characteristics of the polarizing film, the mass ratio of the compound represented by the general formula (1) in the curable resin composition constituting the cured layer, especially the adhesive layer, to boric acid is preferably 1:0.10~1:30.0, and from the perspective of the end discoloration inhibition effect, it is more preferably 1:0.15~1:5.

[0067] In addition to the compound represented by the general formula (1) and boric acid, the curable resin composition may further contain a curable component and other components. The curable resin composition used in the present invention is preferably an active energy ray curable resin composition. Active energy ray curable resin compositions can be divided into free radical polymerization curable resin compositions and cationic polymerization curable resin compositions. In the present invention, active energy rays with a wavelength range of 10 nm or more and less than 380 nm are referred to as ultraviolet rays, and active energy rays with a wavelength range of 380 nm to 800 nm are referred to as visible light.

[0068] Examples of the curable component constituting the radical polymerization curable resin composition include compounds represented by the following general formula (2):

[0069] [Chemical Formula 7]

[0070]

[0071] (Where R 4 Hydrogen atom or methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 The number of carbon atoms in the alkyl group, hydroxyalkyl group, and / or alkoxyalkyl group is not particularly limited, and examples thereof include 1 to 4. 5 and R 6 Examples of the cyclic heterocycle that may be formed include N-acryloylmorpholine.

[0072] Specific examples of the compound represented by general formula (2) include: N-alkyl (meth)acrylamide derivatives such as N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, and N-hexyl (meth)acrylamide; N-hydroxyalkyl (meth)acrylamide derivatives such as N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, and N-hydroxymethyl-N-propane (meth)acrylamide; and N-alkoxy (meth)acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide. Examples of cyclic ether group-containing (meth)acrylamide derivatives include heterocyclic (meth)acrylamide derivatives in which the nitrogen atom of the (meth)acrylamide group forms a heterocyclic ring, such as N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine. Among these, N-hydroxyethylacrylamide and N-acryloylmorpholine are preferably used due to their excellent reactivity, ability to produce a cured product having a high elastic modulus, and excellent adhesion to polarizers.

[0073] When the curable resin composition is composed of two compositions, for example, a first composition and a second composition, the compound represented by general formula (2) may be incorporated only into the second composition or into both the first composition and the second composition.

[0074] From the viewpoint of improving the adhesion and water resistance between the polarizer and the adhesive layer, particularly improving the adhesion and water resistance when the polarizer and the transparent protective film are bonded via the adhesive layer, the content of the compound represented by the general formula (2) in the curable resin composition is preferably 20 to 80% by mass, more preferably 40 to 70% by mass.

[0075] Furthermore, the curable composition used in the present invention may contain, in addition to the compound represented by general formula (2), other monofunctional radical polymerizable compounds as curable components. Examples of the monofunctional radical polymerizable compounds include various (meth)acrylic acid derivatives having a (meth)acryloyloxy group. Specific examples include alkyl (meth)acrylates (having 1 to 20 carbon atoms) such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, 2-methyl-2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, tert-pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, hexadecyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, and n-octadecyl (meth)acrylate.

[0076] Examples of the (meth)acrylic acid derivatives include cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate and cyclopentyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; polycyclic (meth)acrylates such as 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth)acrylate, 5-norbornen-2-ylmethyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; and (meth)acrylates containing an alkoxy group or a phenoxy group such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxyethyl (meth)acrylate, and alkylphenoxypolyethylene glycol (meth)acrylate. Among these, dicyclopentenyloxyethyl acrylate and phenoxyethyl acrylate are preferred because they have excellent adhesion to various protective films.

[0077] Examples of the (meth)acrylic acid derivatives include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; hydroxyl-containing (meth)acrylates such as [4-(hydroxymethyl)cyclohexyl]methyl acrylate, cyclohexanedimethanol mono(meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate; epoxy-containing (meth)acrylates such as glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether; and 2,2,2-trifluoroethyl (meth)acrylate and (meth)acrylate. Halogen-containing (meth)acrylates such as 2,2,2-trifluoroethyl ethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate; alkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate; oxetanyl (meth)acrylates such as 3-oxetanylmethyl (meth)acrylate, 3-methyloxetanylmethyl (meth)acrylate, 3-ethyloxetanylmethyl (meth)acrylate, 3-butyloxetanylmethyl (meth)acrylate, and 3-hexyloxetanylmethyl (meth)acrylate; (meth)acrylates having a heterocyclic ring such as tetrahydrofurfuryl (meth)acrylate and butyrolactone (meth)acrylate, hydroxypivalic acid neopentyl glycol (meth)acrylate adduct, and p-phenylphenol (meth)acrylate. Among these, 2-hydroxy-3-phenoxypropyl acrylate is preferred because of its excellent adhesion to various protective films.

[0078] Examples of the monofunctional radical polymerizable compound include carboxyl group-containing monomers such as (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

[0079] In addition, as monofunctional free radical polymerizable compounds, for example, lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinyl monomers having nitrogen-containing heterocycles such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine; etc.

[0080] In addition, as a monofunctional free radical polymerizable compound, a free radical polymerizable compound having an active methylene group can be used. A free radical polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth)acryloyl group at the end or in the molecule and having an active methylene group. Examples of the active methylene group include acetoacetyl, alkoxymalonyl, and cyanoacetyl. The active methylene group is preferably an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include acetoacetoxyalkyl (meth)acrylates such as 2-acetoacetoxyethyl (meth)acrylate, 2-acetoacetoxypropyl (meth)acrylate, and 2-acetoacetoxy-1-methylethyl (meth)acrylate; 2-ethoxymalonyloxyethyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2-propionylacetoxybutyl)acrylamide, N-(4-acetoacetoxymethylbenzyl)acrylamide, and N-(2-acetoacetylaminoethyl)acrylamide. The radically polymerizable compound having an active methylene group is preferably an acetoacetoxyalkyl (meth)acrylate.

[0081] Furthermore, a difunctional or higher-functional polyfunctional radical polymerizable compound may be blended as a curable component constituting the radical polymerization curable resin composition. Examples of the polyfunctional radical polymerizable compound include N,N'-methylenebis(meth)acrylamide as a polyfunctional (meth)acrylamide derivative, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, dimethacrylate. Ester compounds of (meth)acrylic acid and polyols such as alkylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and EO-modified diglycerol tetra(meth)acrylate; and 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene. Specific examples include ARONIX M-220 (manufactured by Toagosei Co., Ltd.), LIGHT ACRYLATE 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), LIGHT ACRYLATE DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), LIGHT ACRYLATE DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer Co., Ltd.), and CD-536 (manufactured by Sartomer Co., Ltd.). In addition, as needed, examples include various epoxy (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, and various (meth)acrylate monomers. It should be noted that polyfunctional (meth)acrylamide derivatives are preferably included in the curable resin composition because they not only have a fast polymerization rate and excellent productivity, but also have excellent crosslinking properties when the resin composition is converted into a cured product.

[0082] From the perspective of balancing adhesion to polarizers and various transparent protective films and optical durability under harsh environments, the radical polymerizable compound is preferably a combination of a monofunctional radical polymerizable compound and a polyfunctional radical polymerizable compound. The amount of the monofunctional radical polymerizable compound in the curable resin composition is preferably 30 to 90% by mass, more preferably 50 to 80% by mass. The amount of the polyfunctional radical polymerizable compound in the curable resin composition is preferably 10 to 70% by mass, more preferably 20 to 50% by mass.

[0083] <Form of Radical Polymerization Curable Resin Composition>

[0084] The resin composition used in the present invention can be used as an active energy ray-curable resin composition when a curable component is used as an active energy ray-curable component. When the active energy ray is an electron beam or the like, the active energy ray-curable resin composition does not necessarily contain a photopolymerization initiator. However, when the active energy ray is ultraviolet light or visible light, it preferably contains a photopolymerization initiator.

[0085] The photopolymerization initiator can be appropriately selected according to the active energy ray. When curing by ultraviolet light or visible light, a photopolymerization initiator that decomposes by ultraviolet light or visible light can be used. Examples of the above-mentioned photopolymerization initiator include: benzophenone compounds such as benzil, benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone; aromatic ketone compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α′-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenylketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one; benzoin methyl ether, Benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisole methyl ether; aromatic ketal compounds such as benzil dimethyl ketal; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)oxime; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone; camphorquinone; haloketones; acylphosphine oxides; acylphosphonates, etc.

[0086] The amount of the photopolymerization initiator is preferably 0.5 to 5 parts by mass, more preferably 1 to 4 parts by mass, based on 100 parts by mass of the total amount of the active energy ray-curable resin composition.

[0087] When using an active energy ray-curable resin composition of a visible light-curable type, it is particularly preferred to use a photopolymerization initiator that is highly sensitive to light of 380 nm or longer.

[0088] As the photopolymerization initiator, it is preferred to use a compound represented by the following general formula (3) alone or to use the compound represented by the general formula (3) in combination with a photopolymerization initiator having high sensitivity to light of 380 nm or longer, as described later.

[0089] [Chemical Formula 8]

[0090]

[0091] (Where R 7 and R 8 Represents -H, -CH2CH3, -iPr or Cl, R 7 and R 8When the compound represented by the general formula (3) is used, the adhesiveness is excellent compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (3), R 7 and R 8 The compound represented by the general formula (3) in the active energy ray-curable resin composition is preferably contained in an amount of 0.1 to 4% by mass, more preferably 0.5 to 3% by mass, based on 100% by mass of the total amount of the curable resin in the composition.

[0092] In addition, a polymerization initiation aid is preferably added as needed. Examples of the polymerization initiation aid include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and isoamyl 4-dimethylaminobenzoate, with ethyl 4-dimethylaminobenzoate being particularly preferred. When a polymerization initiation aid is used, the amount added is preferably 0.1 to 3 parts by mass, more preferably 0.3 to 1 part by mass, based on 100 parts by mass of the total amount of the active energy ray-curable resin composition.

[0093] In addition, known photopolymerization initiators can be used in combination as needed. The optical functional layer and substrate film with UV absorption ability do not transmit light below 380nm. Therefore, as a photopolymerization initiator, a photopolymerization initiator with high sensitivity to light above 380nm is preferably used. Specifically, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, etc. can be mentioned.

[0094] In the present invention, the curable resin composition preferably contains an acrylic oligomer formed by polymerizing a (meth)acrylic acid monomer. The inclusion of an acrylic oligomer in the curable resin composition can reduce curing shrinkage when the composition is irradiated with active energy rays and cured, thereby reducing the interfacial stress between the adhesive layer and adherends such as the optically functional layer and the substrate film. As a result, a decrease in the adhesion between the adhesive layer and the adherend can be suppressed.

[0095] Considering workability and uniformity during coating, the active energy ray-curable resin composition preferably has a low viscosity. Therefore, the acrylic oligomer obtained by polymerizing (meth)acrylic monomers is preferably also low in viscosity. The acrylic oligomer, which has a low viscosity and can prevent shrinkage of the adhesive layer upon cure, preferably has a weight-average molecular weight (Mw) of 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. On the other hand, to fully suppress shrinkage of the cured product layer (adhesive layer), the acrylic oligomer preferably has a weight-average molecular weight (Mw) of 500 or more, more preferably 1,000 or more, and particularly preferably 1,500 or more.Specific examples of the (meth)acrylic monomer constituting the acrylic oligomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, 2-methyl-2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, t-pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, and t-butyl (meth)acrylate. Alkyl (meth)acrylates (having 1 to 20 carbon atoms) such as cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, and n-octadecyl (meth)acrylate, as well as cycloalkyl (meth)acrylates (such as cyclohexyl (meth)acrylate and cyclopentyl (meth)acrylate), aralkyl (meth)acrylates (such as benzyl (meth)acrylate), polycyclic (meth)acrylates (such as 2-isobornyl (meth)acrylate and 2-norbornyl (meth)acrylate), methyl (meth)acrylate, 5-norbornen-2-ylmethyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, etc.), hydroxyl-containing (meth)acrylates (e.g., hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropylmethylbutyl (meth)acrylate, etc.), alkoxy- or phenoxy-containing (meth)acrylates (2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, Examples of the acrylic oligomer (E) include ethyl carbitol (meth)acrylate, phenoxyethyl (meth)acrylate, etc.), epoxy-containing (meth)acrylates (e.g., glycidyl (meth)acrylate, etc.), halogen-containing (meth)acrylates (e.g., 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethyl ethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, etc.), and alkylaminoalkyl (meth)acrylates (e.g., dimethylaminoethyl (meth)acrylate). These (meth)acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer (E) include "ARUFON" manufactured by Toagosei Co., Ltd., "ACTFLOW" manufactured by Soken Chemical Co., Ltd., and "JONCRYL" manufactured by BASF Japan.

[0096] The content of the acrylic oligomer in the curable resin composition is preferably 3 to 40% by mass, more preferably 5 to 20% by mass.

[0097] The curable resin composition used in the present invention may also contain a silane coupling agent. Specific examples of the silane coupling agent include active energy ray-curable compounds such as vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-phenylyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0098] Preferred are 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0099] Specific examples of non-active energy ray-curable silane coupling agents other than those mentioned above include 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, and imidazole silane.

[0100] The curable resin composition used in the present invention may be a cationically polymerizable curable resin composition. Cationic polymerizable compounds used in cationically polymerizable curable resin compositions can be classified into monofunctional cationically polymerizable compounds having one cationically polymerizable functional group in the molecule, and polyfunctional cationically polymerizable compounds having two or more cationically polymerizable functional groups in the molecule. The liquid viscosity of monofunctional cationically polymerizable compounds is relatively low, so by including them in a cationically polymerizable curable resin composition, the liquid viscosity can be reduced. In addition, monofunctional cationically polymerizable compounds often have functional groups that exhibit various functions, and by including them in a cationically polymerizable curable resin composition, the cationically polymerizable curable resin composition and / or the cured product of the cationically polymerizable curable resin composition can exhibit various functions. Polyfunctional cationically polymerizable compounds are preferably included in a cationically polymerizable curable resin composition because they can cause the cured product of the cationically polymerizable curable resin composition to undergo three-dimensional crosslinking. Regarding the ratio of the monofunctional cationically polymerizable compound to the polyfunctional cationically polymerizable compound, it is preferred to mix the polyfunctional cationically polymerizable compound in an amount ranging from 10 parts by mass to 1000 parts by mass of the monofunctional cationically polymerizable compound. Examples of cationically polymerizable functional groups include epoxy groups, oxetanyl groups, and vinyl ether groups. Examples of compounds having epoxy groups include aliphatic epoxy compounds, alicyclic epoxy compounds, and aromatic epoxy compounds. Due to their excellent curability and adhesive properties, it is particularly preferred to include alicyclic epoxy compounds in the cationically polymerizable resin composition of the present invention. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, caprolactone-modified products, trimethylcaprolactone-modified products, and valerolactone-modified products of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. Specific examples include CELLOXIDE 2021, CELLOXIDE 2021A, CELLOXIDE 2021P, CELLOXIDE 2081, CELLOXIDE 2083, and CELLOXIDE 2085 (all manufactured by Daicel Chemical Industries, Ltd.), Cyracure UVR-6105, Cyracure UVR-6107, Cyracure 30, and R-6110 (all manufactured by Dow Chemical Japan Ltd.). A compound containing an oxetane group is preferred because it has the effect of improving the curability of the cationically polymerizable resin composition and reducing the liquid viscosity of the composition.Examples of the compound having an oxetane group include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetane)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetane)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and novolac oxetane. Commercially available products include ARON OXETANE OXT-101, ARON OXETANE OXT-121, ARON OXETANE OXT-211, ARON OXETANE OXT-221, and ARON OXETANE OXT-212 (all manufactured by Toagosei Co., Ltd.). Compounds having a vinyl ether group are preferably present because they have the effects of improving the curability of the cationically polymerizable resin composition and reducing the liquid viscosity of the composition. Examples of the compound having a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, tricyclodecane vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, and pentaerythritol tetravinyl ether.

[0101] The cationic polymerization curable resin composition contains at least one compound selected from the compounds having epoxy groups, compounds having oxetane groups, and compounds having vinyl ether groups as curable components. All of these are substances that are cured by cationic polymerization, and therefore can be combined with a photocationic polymerization initiator. The photocationic polymerization initiator generates cationic species or Lewis acids by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, thereby initiating the polymerization reaction of epoxy groups and oxetane groups. As the photocationic polymerization initiator, a photoacid generator described later can be appropriately used. In addition, when using a cationic polymerization resin composition with visible light curability, it is particularly preferred to use a photocationic polymerization initiator that is highly sensitive to light above 380nm. However, the photocationic polymerization initiator is a compound that generally exhibits maximum absorption in a wavelength region near 300nm or shorter than 300nm. Therefore, by combining a photosensitizer that exhibits maximum absorption in a wavelength region longer than the wavelength, specifically, light of a wavelength longer than 380nm, it is possible to sense light of a wavelength near the wavelength and promote the generation of cationic species or acids from the photocationic polymerization initiator. As photosensitizer, for example, anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreduction pigments, etc., can also be used by mixing two or more of them. In particular, anthracene compounds have excellent photosensitizing effects, and are therefore preferred. Specifically, Anthracure UVS-1331 and Anthracure UVS-1221 (Kawasaki Chemicals Co., Ltd.) can be mentioned. The content of the photosensitizer is preferably 0.1% to 5% by mass, more preferably 0.5% to 3% by mass.

[0102] In the present invention, the active energy ray-curable resin composition may also contain a photoacid generator. When the active energy ray-curable resin composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be significantly improved compared to when the active energy ray-curable resin composition does not contain a photoacid generator. The photoacid generator can be represented by the following general formula (3).

[0103] General formula (4)

[0104] [Chemical Formula 9]

[0105]

[0106] (Among them, L ＋ Indicates any In addition, X - Indicates selection from PF66 - 、SbF6 - 、AsF6 - 、SbCl6 - 、BiCl5- 、SnCl6 - 、ClO4 - , dithiocarbamate anion, SCN - The counter anion in .)

[0107] Next, the counter anion X in the general formula (4) - Provide explanation.

[0108] For the counter anion X in the general formula (4) - , in principle there is no particular limitation, but non-nucleophilic anions are preferred. Counter anion X - In the case of a non-nucleophilic anion, since it is not easy to cause nucleophilic reactions of coexisting cations in the molecule or various materials used in combination, the stability of the photoacid generator represented by the general formula (4) itself and the composition using the same can be improved over time. The non-nucleophilic anion mentioned here refers to an anion with a low ability to cause nucleophilic reactions. Examples of such anions include: PF6 - 、SbF6 - 、AsF6 - 、SbCl6 - 、BiCl5 - 、SnCl6 - 、ClO4 - 、B(C6H5)4 - , dithiocarbamate anion, SCN - wait.

[0109] Specific examples include "CYRACURE UVI-6992", "CYRACURE UVI-6974" (above, manufactured by Dow Chemical Japan Limited), "Adekaoptomer SP150", "Adekaoptomer SP152", "Adekaoptomer SP170", "Adekaoptomer SP172" (above, manufactured by ADEKA Co., Ltd.), "Omnicat 250" (manufactured by IGM Resins BV), "CI-5102", "CI-2855" (above, manufactured by Nippon Soda Co., Ltd.), "San-Aid SI-60L", "San-Aid SI-80L", "San-Aid SI-100L", "San-Aid SI-110L", "San-Aid Preferred specific examples of the photoacid generator of the present invention include SI-180L (manufactured by Sanshin Chemical Co., Ltd.), IK-1, CPI-100P, CPI-101A, CPI-110P, CPI-200K, CPI-210S, CPI-310B, CPI-410B, and CPI-410S (manufactured by San-Apro Ltd.), and WPI-069, WPI-113, WPI-116, WPI-041, WPI-044, WPI-054, and WPI-055. WPAG-281, WPAG-567, and WPAG-596 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0110] The polarizing film of the present invention comprises a cured layer on at least one side of a polarizer, and preferably a transparent protective film laminated on at least one side of a polarizer via an adhesive layer, wherein the adhesive layer is a cured layer.

[0111] From the viewpoint of improving the humidification reliability of the polarization characteristics of the polarizing film, the thickness of the cured product layer (adhesive layer) is preferably 1 μm or more and 2 μm or less.

[0112] In the case where the polarizing film of the present invention is a polarizing film in which a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer, it is preferable to include a compatibility layer between the transparent protective film and the adhesive layer to form a compatibility layer. The method for confirming the formation of the compatibility layer will be described later.

[0113] In the present invention, the polarizer is not particularly limited, and various polarizers can be used. Examples of the polarizer include films obtained by uniaxially stretching a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified ethylene-vinyl acetate copolymer film, after adsorbing iodine thereon. The thickness of the polarizer is, for example, 3 to 20 μm.

[0114] However, it should be noted that in the present invention, to improve humidification reliability in harsh environments with high temperature and high humidity, a thin polarizer with a thickness of 3 μm or more and 15 μm or less is preferably used as the polarizer. In particular, a thickness of 12 μm or less is preferred, more preferably 10 μm or less, and particularly preferably 8 μm or less is preferred. Such a thin polarizer has minimal thickness variation, excellent visual recognition, and minimal dimensional change, resulting in excellent durability against thermal shock.

[0115] Polarizers made by dyeing a polyvinyl alcohol film with iodine and then uniaxially stretching it can be made, for example, by immersing the polyvinyl alcohol in an aqueous solution of iodine for dyeing and stretching it to 3 to 7 times its original length. Alternatively, the film can be immersed in an aqueous solution of potassium iodide, optionally containing boric acid, zinc sulfate, zinc chloride, or the like. Furthermore, the film can be rinsed by immersing it in water before dyeing, as needed. Rinsing the polyvinyl alcohol film not only cleans stains and anti-blocking agents from the film's surface but also prevents uneven dyeing by causing the film to swell. Stretching can be performed after dyeing with iodine, while dyeing, or after dyeing with iodine. Stretching can also be performed in an aqueous solution of boric acid, potassium iodide, or the like, or in a water bath.

[0116] From the perspectives of tensile stability and humidification reliability, the polarizer preferably contains boric acid. Furthermore, from the perspective of suppressing the occurrence of through-cracks, the boric acid content in the polarizer is preferably 22% by mass or less, more preferably 20% by mass or less, relative to the total amount of the polarizer. From the perspectives of tensile stability and humidification reliability, the boric acid content is preferably 10% by mass or more, more preferably 12% by mass or more, relative to the total amount of the polarizer.

[0117] From the viewpoint of improving the humidification reliability of the polarization characteristics of the polarizing film, in the polarizing film of the present invention, when the proportion of the boric acid content in the polarizer is set to A% by mass and the proportion of the boric acid content in the curable resin composition is set to B% by mass, preferably A:B = 1:0.001~1:0.1, and more preferably A:B = 1:0.01~1:0.05.

[0118] Representative thin polarizers include those described in Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014 / 077599, International Publication No. 2014 / 077636, and the like, or those obtained by the production methods described in these documents.

[0119] As the thin polarizer, in a production method comprising a step of stretching a laminate and a step of dyeing, a thin polarizer obtained by a production method comprising a step of stretching in a boric acid aqueous solution, such as described in Japanese Patent Nos. 4751486, 4751481, and 4815544, is preferred because it can be stretched to a high ratio and thus improve polarization performance. Particularly preferred is a thin polarizer obtained by a production method comprising a step of supplementary stretching in an air atmosphere before stretching in a boric acid aqueous solution, such as described in Japanese Patent Nos. 4751481 and 4815544. These thin polarizing films can be obtained by a production method comprising a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as a PVA-based resin) layer and a stretching resin substrate in a laminate and a step of dyeing. According to this production method, even if the PVA-based resin layer is thin, it can be stretched without causing problems such as breakage due to stretching because it is supported by the stretchable resin substrate.

[0120] As the material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. can be used. Specific examples of such thermoplastic resins include: cellulose resins such as cellulose triacetate resin films, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The transparent protective film may contain one or more arbitrary appropriate additives. As additives, for example, ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, etc. The content of the above-mentioned thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, further preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, there is a concern that the high transparency inherent in the thermoplastic resin may not be fully exhibited.

[0121] In addition, as a material for forming the transparent protective film, a material having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is preferred, and a material having a moisture permeability of 150 g / m 2 / 24h or less, more preferably 140g / m 2 / 24h or less, more preferably a material with a moisture permeability of 120g / m 2 / Materials under 24h.

[0122] A functional layer such as a hard coating layer, an anti-reflection layer, an anti-blocking layer, a diffusion layer, or an anti-glare layer may be provided on the side of the transparent protective film that is not bonded to the polarizer. It should be noted that the functional layers such as the hard coating layer, the anti-reflection layer, the anti-blocking layer, the diffusion layer, and the anti-glare layer may be provided as layers separate from the transparent protective film in addition to being provided to protect the transparent protective film itself.

[0123] The thickness of the transparent protective film can be appropriately determined. Generally, from the perspectives of strength, workability such as handling, and thinness, it is about 1 to 500 μm, preferably 1 to 300 μm, more preferably 5 to 200 μm, further preferably 10 to 200 μm, and even more preferably 20 to 80 μm.

[0124] As the transparent protective film, a retardation film having a front retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used. The front retardation is typically controlled within the range of 40 to 200 nm, and the thickness direction retardation is typically controlled within the range of 80 to 300 nm. When a retardation film is used as a transparent protective film, it also functions as a transparent protective film, thereby enabling thinning.

[0125] Examples of retardation films include birefringent films made by uniaxially or biaxially stretching a polymer material, oriented films of liquid crystal polymers, and retardation films made by supporting an oriented layer of a liquid crystal polymer with a film. The thickness of the retardation film is not particularly limited, but is typically around 20 to 150 μm.

[0126] As the retardation film, a reverse wavelength dispersion type retardation film that satisfies the following formulas (1) to (3) can be used:

[0127] 0.70<Re

[450] / Re

[550] <0.97···(1)

[0128] 1.5×10 -3 <Δn<6×10 -3 ···(2)

[0129] 1.13<NZ<1.50···(3)

[0130] (Wherein, Re

[450] and Re

[550] are the in-plane phase difference values ​​of the phase difference film measured at 23°C using light of wavelengths of 450 nm and 550 nm, respectively; Δn is the in-plane birefringence, which is nx-ny when the refractive indices in the slow axis direction and the fast axis direction of the phase difference film are set to nx and ny, respectively; NZ is the ratio of nx-nz to nx-ny when nz is set to the refractive index in the thickness direction of the phase difference film, wherein nx-nz is the birefringence in the thickness direction and nx-ny is the in-plane birefringence).

[0131] The polarizing film of the present invention may also be provided with a phase difference layer. The phase difference layer may be a single layer or a multilayer layer, and the phase difference layer may also serve as a protective layer for the polarizer.

[0132] In the formation of the phase difference layer, a liquid crystal compound is preferably used, and a solution containing the liquid crystal compound can be applied using, for example, a wire rod, a slit coater, a comma coater, a gravure coater, a slit die, etc. At this time, the liquid crystal solution after coating can be dried naturally or heated and dried. It should be noted that the liquid crystal solution is preferably applied at a concentration lower than the isotropic phase-liquid crystal phase transition concentration, i.e., in the isotropic phase state. In this case, it can be stably oriented by methods such as friction treatment and photo-orientation.

[0133] When the polarizing film of the present invention is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer via an adhesive layer, it can be preferably produced by the following production method.

[0134] In a method for producing a polarizing film in which a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer, the adhesive layer is a cured layer of a curable resin composition composed of at least a first composition and a second composition, the first composition containing at least a compound represented by the following general formula (1) and boric acid.

[0135] [Chemical Formula 10]

[0136]

[0137] (wherein, X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, R 1 and R 2 (represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group which may have a substituent,

[0138] The second composition contains at least a compound represented by the following general formula (2),

[0139] [Chemical Formula 11]

[0140]

[0141] (Among them, R 4 is a hydrogen atom or a methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 optionally forming a cyclic heterocycle),

[0142] The method for producing a polarizing film includes: a first coating step of coating a first composition on the bonding surface of a polarizer; a second coating step of coating a second composition on the bonding surface of a transparent protective film; a bonding step of bonding the polarizer and the transparent protective film; and a bonding step of bonding the polarizer and the transparent protective film via the adhesive layer obtained by curing the curable resin composition by irradiating the polarizer surface or the transparent protective film surface with active energy rays. Each step is described below.

[0143] In the above-mentioned manufacturing method, the curable resin composition is composed of a first composition and a second composition. However, it should be noted that the polarizing film of the present invention can also be composed of a cured layer of a single curable resin composition as the adhesive layer. The above-mentioned first composition contains at least a compound represented by general formula (1) and boric acid. If necessary, the first composition may also contain a curable component such as a compound represented by general formula (2).

[0144] The first composition may contain a solvent and an additive. As the solvent, a solvent that can stabilize the compound represented by the general formula (1) and dissolve or disperse it is preferred. Such a solvent can be an organic solvent, water, or a mixed solvent thereof. As the above-mentioned solvent, for example, it can be selected from the following: esters such as ethyl acetate, butyl acetate, and 2-hydroxyethyl acetate; ketones such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, methyl n-propyl ketone, and acetylacetone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monoethyl ether; glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate; and the like. Examples of additives include binder resins, surfactants, plasticizers, tackifiers, low molecular weight polymers, polymerizable monomers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, titanium coupling agents, inorganic or organic fillers, metal powders, particles, and foils. The binder resin may be transparent, and examples thereof include polymers such as acrylic resins, styrene resins, polyvinyl alcohol resins, urethane resins, polyester resins, polypropylene resins, polyethylene resins, epoxy resins, and polycarbonate resins.

[0145] In the above-mentioned production method, the curable resin composition is composed of a first composition and a second composition. However, when the first composition contains a solvent such as water, the amount of the compound represented by the general formula (1) in the curable resin composition comprising the first composition is preferably 0.05 to 5% by mass, more preferably 1.0 to 3.0% by mass, excluding the amount thereof. Similarly, the amount of boric acid in the curable resin composition is preferably 0.1 to 2% by mass, more preferably 0.2 to 1.0% by mass.

[0146] From the viewpoint of improving the humidification reliability of the polarization characteristics of the manufactured polarizing film, the polarizer used in the above-mentioned manufacturing method is preferably a polarizer containing 10 to 22% by mass of boric acid. Furthermore, when the proportion of boric acid in the polarizer is set to A% by mass and the proportion of boric acid in the curable resin composition is set to B% by mass, it is preferably A:B = 1:0.001 to 1:0.1, and more preferably A:B = 1:0.01 to 1:0.05.

[0147] The second composition contains at least the compound represented by the above-mentioned general formula (2). If necessary, the second composition may contain the compound represented by the general formula (1) and / or boric acid.

[0148] In the above-mentioned method for manufacturing a polarizing film, the first composition is applied to the bonding surface of the polarizer in the first coating process, and the second composition is applied to the transparent protective film in the second coating process. As a method for applying a single curable resin composition, or applying the first composition and the second composition, it can be appropriately selected according to the viscosity and target thickness of the composition. For example, a reverse coater, a gravure coater (direct, reverse, or offset), a rod-type reverse coater, a roller coater, a die coater, a wire rod coater, and a rod coater can be mentioned. The viscosity of the single curable resin composition, or the first composition and the second composition is preferably 3 to 100 mPa·s, more preferably 5 to 50 mPa·s, and most preferably 10 to 30 mPa·s. When the viscosity of the composition is high, the surface smoothness after coating is insufficient, and a poor appearance will occur, which is not preferred. Therefore, each composition can be heated or cooled and then coated after adjusting the viscosity to a preferred range. In addition, when the first composition contains water such as a solvent, a drying step may be provided after the first coating step.

[0149] From the perspective of improving the humidification reliability of the polarization characteristics of the polarizing film, the thickness before drying after the first coating step is preferably 0.6 to 2.0 μm, and the thickness after drying is preferably 0.3 to 1.0 μm. The coating thickness in the second coating step can be appropriately adjusted to achieve the desired adhesive layer thickness.

[0150] It should be noted that the polarizer and / or transparent protective film may also be subjected to a surface modification treatment before the coating process. Surface modification treatment of the polarizer is particularly preferred. Examples of surface modification treatments include corona treatment, plasma treatment, and ITRO treatment, with corona treatment being particularly preferred. Corona treatment generates reactive functional groups such as carbonyl and amino groups on the polarizer surface, thereby improving adhesion to the adhesive layer. Furthermore, ashing can be used to remove foreign matter from the surface or reduce surface irregularities, thereby producing a polarizing film with excellent appearance characteristics.

[0151] The polarizer and the transparent protective film are bonded together using a roll laminator or the like through the curable resin composition (first composition + second composition) applied as described above (bonding step).

[0152] After laminating the polarizer and the transparent protective film, the curable resin composition is cured by irradiation with active energy rays (electron beam, ultraviolet light, visible light, etc.) to form an adhesive layer. The irradiation direction of the active energy rays (electron beam, ultraviolet light, visible light, etc.) can be any appropriate direction.

[0153] The irradiation conditions under the electron beam irradiation condition can be any appropriate conditions as long as they are conditions that can at least cure the curable resin composition. For example, the acceleration voltage of the electron beam irradiation is preferably 5kV~300kV, more preferably 10kV~250kV. When the acceleration voltage is less than 5kV, there is a hidden danger that the electron beam cannot reach the adhesive, resulting in insufficient curing. If the acceleration voltage is greater than 300kV, there is a hidden danger that the penetration force through the sample is too strong, causing damage to the polarizer and the transparent protective film. As for the irradiation dose, it is 5~100kGy, more preferably 10~75kGy. When the irradiation dose is less than 5kGy, the adhesive is not sufficiently cured. If it is greater than 100kGy, the optical functional layer and the base film will be damaged, resulting in a reduction in mechanical strength and yellowing, and the given optical properties cannot be obtained.

[0154] Electron beam irradiation is typically performed in an inert gas atmosphere, but can also be performed in the atmosphere with a small amount of oxygen introduced, if necessary. While this depends on the materials of the polarizer and transparent protective film, by appropriately introducing oxygen, oxygen barriers are created on the optically functional layer and substrate film surface that are initially irradiated with the electron beam, preventing damage to the polarizer and transparent protective film and allowing efficient electron beam irradiation of only the adhesive.

[0155] In the case of manufacturing the polarizing film of the present invention, as the active energy ray, it is preferred to use active energy rays containing visible light in the wavelength range of 380nm to 450nm, especially active energy rays with the largest irradiation amount of visible light in the wavelength range of 380nm to 450nm. When ultraviolet rays, visible light, and a transparent protective film with ultraviolet absorption ability (ultraviolet non-transmissive transparent protective film) are used, light with a wavelength shorter than about 380nm is absorbed. Therefore, light with a wavelength shorter than 380nm does not reach the curable resin composition and does not contribute to its polymerization reaction. In addition, light with a wavelength shorter than 380nm absorbed by the polarizer or transparent protective film is converted into heat, and the polarizer or transparent protective film itself generates heat, which becomes a cause of defects such as curling / wrinkling of the polarizing film. Therefore, in the present invention, when using ultraviolet light or visible light, it is preferred to use a device that does not emit light with a wavelength shorter than 380 nm as the active energy ray generating device. More specifically, the ratio of the cumulative illuminance in the wavelength range of 380-440 nm to the cumulative illuminance in the wavelength range of 250-370 nm is preferably 100:0-100:50, more preferably 100:0-100:40. When manufacturing the polarizing film of the present invention, the active energy ray is preferably a gallium-encapsulated metal halide lamp or an LED light source emitting light in the wavelength range of 380-440 nm. Alternatively, a light source containing ultraviolet light and visible light, such as a low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser, or sunlight, can be used. Ultraviolet light with a wavelength shorter than 380 nm can also be blocked using a bandpass filter. In order to improve the bonding performance of the adhesive layer between the polarizer and the transparent protective film and prevent curling of the polarizing film, it is preferred to use: active energy rays obtained by using a metal halide lamp encapsulated with gallium and a bandpass filter that can block light with a wavelength shorter than 380nm, or active energy rays with a wavelength of 405nm obtained by using an LED light source.

[0156] When producing the polarizing film of the present invention on a continuous production line, the line speed varies depending on the curing time of the curable resin composition, but is preferably 1 to 500 m / min, more preferably 5 to 300 m / min, and even more preferably 10 to 100 m / min. If the line speed is too slow, productivity may be insufficient, or damage to the polarizer or transparent protective film may be excessive, making it impossible to produce a polarizing film that can withstand durability tests, etc. If the line speed is too high, the curable resin composition may not cure sufficiently, and the desired adhesion may not be achieved.

[0157] The polarizing film or the optical film laminated with at least one polarizing film may also be provided with an adhesive layer for bonding to other components such as a liquid crystal cell. The adhesive forming the adhesive layer is not particularly limited; for example, an adhesive having a base polymer such as an acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyether, fluorine-based polymer, or rubber-based polymer can be appropriately selected. In particular, acrylic adhesives are preferably used, as they exhibit excellent optical transparency, appropriate adhesive properties such as wettability, cohesiveness, and adhesion, and excellent weather resistance and heat resistance.

[0158] The adhesive layer can be provided on one or both sides of the polarizing film or optical film as a laminate of layers having different compositions or types. Furthermore, when provided on both sides, adhesive layers having different compositions, types, thicknesses, etc. can be formed on the front and back sides of the polarizing film or optical film. The thickness of the adhesive layer can be appropriately determined depending on the intended use, adhesive strength, etc., and is generally 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

[0159] For the exposed surface of the adhesive layer, a diaphragm may be temporarily bonded to cover it for the purpose of preventing contamination until it is actually used. This prevents contact with the adhesive layer under conventional handling conditions. As a diaphragm, in addition to the above-mentioned thickness conditions, a diaphragm may be used, which is obtained by coating a suitable thin layer such as a plastic film, a rubber sheet, paper, a cloth, a non-woven fabric, a net, a foam sheet, a metal foil, or a laminate thereof with a suitable release agent such as silicone, long-chain alkyl, fluorine, or molybdenum sulfide as needed.

[0160] The polarizing film and optical film of the present invention can be preferably used to form various devices such as liquid crystal displays. Liquid crystal displays can be formed using conventional methods. Specifically, a liquid crystal display is typically formed by appropriately assembling a liquid crystal cell with a polarizing film or optical film, and optionally, components such as a lighting system, and incorporating a drive circuit. In the present invention, there are no particular limitations other than using the polarizing film or optical film of the present invention, and conventional methods can be used. Liquid crystal cells of any type, such as TN, STN, or π, can be used.

[0161] A suitable liquid crystal display device such as a liquid crystal display device in which an optical laminate is arranged on one side or both sides of a liquid crystal cell, a liquid crystal display device in which a backlight or a reflector is used in a lighting system, etc. can be formed. In this case, the optical laminate of the present invention can be arranged on one side or both sides of the liquid crystal cell. When optical laminates are arranged on both sides, they can be the same or different. Furthermore, when forming the liquid crystal display device, suitable components such as a diffusion plate, an anti-glare layer, an anti-reflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, etc., can be arranged at an appropriate position.

[0162] Example

[0163] Examples of the present invention will be described below, but the embodiments of the present invention are not limited to these.

[0164] <Polarizer>

[0165] A stretched laminate comprising a 9μm-thick PVA layer formed on an amorphous PET substrate was subjected to auxiliary stretching in an atmosphere at a stretching temperature of 130°C to produce a stretched laminate. The stretched laminate was then dyed to produce a colored laminate. The colored laminate was further stretched in a boric acid aqueous solution at a stretching temperature of 65°C to produce an optical film laminate comprising a 5μm-thick PVA layer integrally stretched with the amorphous PET substrate to a total stretch ratio of 5.94. This two-step stretching process resulted in a high-order orientation of the PVA molecules in the PVA layer formed on the amorphous PET substrate, resulting in an optical film laminate comprising a 5.5μm-thick PVA layer constituting a thin polarizer in which iodine adsorbed by the dye was highly oriented in one direction as a polyiodide ion complex. Polarizers with varying boric acid contents were produced by varying the boric acid concentration in the water bath during the stretching in the boric acid aqueous solution.

[0166] <Transparent protective film>

[0167] Transparent protective film 1: Cellulose triacetate resin film (trade name "TJ25", manufactured by Fujifilm Corporation)

[0168] <Active Energy Rays>

[0169] As active energy rays, visible light (gallium-encapsulated metal halide lamp) was used. Irradiation device: Light HAMMER 10 manufactured by FusionUV Systems, Inc., valve: V valve, peak illuminance: 1600 mW / cm 2 , cumulative exposure 1000 / mJ / cm 2(Wavelength: 380-440 nm) The illuminance of visible light was measured using the Sola-Check system manufactured by Solatell.

[0170] (Preparation of Curable Resin Composition)

[0171] The first and second compositions constituting the curable resin compositions of Examples 1-2 and Comparative Examples 1-3 were prepared according to the formulations shown in Table 1. The numerical values ​​in the table represent weight percentages when the total amount of each composition is set to 100% by mass. It should be noted that the water incorporated into the first composition is removed during the drying step after the first coating step, so the composition of the curable resin composition (the total of the first and second compositions) was calculated omitting water.

[0172] The materials constituting the curable resin composition are shown below.

[0173] (Curing component)

[0174] N-Acryloylmorpholine (compound represented by general formula (2)): trade name "ACMO", manufactured by Kojin Co., Ltd.

[0175] 1,9-Nonanediol diacrylate: Trade name "LIGHT ACRYLATE 1.9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.

[0176] Phenoxydiethylene glycol acrylate: Trade name "LIGHT ACRYLATE P2H-A", manufactured by Kyoeisha Chemical Co., Ltd.

[0177] (Acrylic oligomer)

[0178] Acrylic oligomer obtained by polymerizing a (meth)acrylic monomer: Trade name "ARUFON UP-1190", manufactured by Toagosei Co., Ltd.

[0179] (Initiator)

[0180] 2-Methyl-4'-methylthio-2-morpholinopropiophenone: Trade name "Omnirad 907", manufactured by IGM Resins B.V.

[0181] Diethylthioxanthone: trade name "KAYACURE DETX-S (referred to as "DETX-S" in Table 1)", manufactured by Nippon Kayaku Co., Ltd.

[0182] (Leveling agent)

[0183] ·Product name "BYK-UV3505", manufactured by BYK

[0184] (Compound represented by general formula (1))

[0185] 3-Methacrylamidophenylboronic acid: Trade name "MAPBA", manufactured by Junsei Chemical Co., Ltd.

[0186] (boric acid)

[0187] (Surface Conditioner)

[0188] · Trade name "EXP.4200", manufactured by Nissin Chemical Industry Co., Ltd.

[0189] (Manufacturing of Polarizing Film)

[0190] Example 1

[0191] Using an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, gravure roller line count: 1000 lines / inch, rotation speed 140% / relative to line speed), the second composition was applied to the bonding surface of the transparent protective film 1 with a coating thickness of 1.0 μm (second coating step). The first composition was applied to the thin polarizer side of the optical film laminate with a coating thickness of 0.8 to 1.2 μm before drying (first coating step). Next, the water contained in the first composition was removed using a blower (drying step). The coating thickness after drying was 0.4 to 0.6 μm. Next, the transparent protective film 1 and the optical film laminate with a thin polarizer were bonded together from the coating side using a roller (bonding step). The thin polarizer and the transparent protective film are then bonded together using an active energy ray irradiation device, which irradiates the laminated transparent protective film with the aforementioned visible light. This cures the curable resin composition composed of the first and second compositions to form an adhesive layer. The adhesive layer then serves to bond the thin polarizer and the transparent protective film together. The amorphous PET substrate of the optical film laminate is then peeled off.

[0192] Example 2, Comparative Examples 1-3

[0193] A polarizing film was produced in the same manner as in Example 1 except that the contents and presence of the compound represented by general formula (1) and boric acid in the first composition used in Example 1, and the boric acid content of the polarizer were changed to those shown in Table 1.

[0194] <Humidification Reliability Evaluation of Polarization Characteristics of Polarizing Films>

[0195] A polarizing film (sample for evaluation of humidity durability test) was prepared by bonding the polarizing film to one surface of 0.7 mm thick alkali-free glass via an adhesive layer (20 μm in thickness).

[0196] The resulting polarizing film was exposed to a 60°C, 95% humidity environment for 240 hours. The polarization degree before and after exposure was measured using a spectrophotometer with an integrating sphere (JASCO Corporation V7100). The change in polarization degree, ΔPz (%), was calculated as |(polarization degree before exposure (%)) - (polarization degree after exposure (%))|. A smaller change in polarization degree, ΔPz (%), indicates greater humidity reliability of the polarization characteristics in a harsh humidified environment.

[0197] <Evaluation of End Discoloration of Polarization Characteristics of Polarizing Film>

[0198] As described above, for the same sample as the one with humidity reliability, the discoloration length of the four sides (from the start of discoloration to the sample end) was measured using an electron microscope. The smaller the value, the better the end discoloration resistance in a severe humidity environment.

[0199] <Measurement of Thickness of Compatible Layer in Adhesive Layer of Polarizing Film>

[0200] The cross section of the polarizing plate was observed with a SEM (SU8200 manufactured by HITACHI HIGH-TECH CORPORATION) and the length was measured.

[0201]

Claims

1. A polarizing film comprising a cured product layer on at least one side of a polarizer, The cured product layer is a cured product layer of a curable resin composition containing a compound represented by the following general formula (1) and boric acid, ， In the general formula (1), X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, and R 1 and R 2 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group or a heterocyclic group.

2. The polarizing film according to claim 1, wherein The mass ratio of the compound represented by the general formula (1) to the boric acid in the curable resin composition is 1:0.1 to 1:30.

0.

3. The polarizing film according to claim 1, wherein The curable resin composition further contains a compound represented by the following general formula (2): ， In the general formula (2), R 4 is a hydrogen atom or a methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 Optionally, a cyclic heterocycle is formed.

4. The polarizing film according to claim 1, wherein The content of the compound represented by the general formula (1) in the curable resin composition is 0.05 to 5% by mass, and the content of the boric acid is 0.1 to 2% by mass.

5. The polarizing film according to claim 1, wherein The polarizer contains 10 to 22% by mass of boric acid. The polarizing film according to claim 1 , wherein: When the ratio of boric acid contained in the polarizer is A% by mass and the ratio of boric acid contained in the curable resin composition is B% by mass, A:B=1:0.001 to 1:0.

1.

7. The polarizing film according to claim 1, wherein The thickness of the cured product layer is 1 μm or more and 2 μm or less.

8. The polarizing film according to claim 1, wherein a transparent protective film is laminated on at least one side of a polarizer via an adhesive layer. in, The adhesive layer is the cured product layer.

9. The polarizing film according to claim 8, wherein The transparent protective film is a cellulose triacetate resin film.

10. The polarizing film according to claim 8, wherein A compatibilizing layer is provided between the transparent protective film and the adhesive layer. An optical film comprising at least one layer of the polarizing film according to claim 1. 12 . An image display device using the polarizing film according to claim 1 or the optical film according to claim 11 .

13. A method for producing a polarizing film, comprising laminating a transparent protective film on at least one side of a polarizer via an adhesive layer, wherein: The adhesive layer is a cured product layer of a curable resin composition composed of at least a first composition and a second composition. The first composition contains at least a compound represented by the following general formula (1) and boric acid. ， In the general formula (1), X is a reactive group, Y is an optionally branched alkylene group having 1 to 12 carbon atoms, or an optionally substituted phenylene group, and R 1 and R 2 Each independently represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group or a heterocyclic group, The second composition contains at least a compound represented by the following general formula (2): ， In the general formula (2), R 4 is a hydrogen atom or a methyl group, R 5 and R 6 are independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R 5 and R 6 optionally forming a cyclic heterocycle, The method for manufacturing the polarizing film includes: A first coating step of coating a first composition on the bonding surface of the polarizer; a second coating step of coating a second composition on the bonding surface of the transparent protective film; a laminating step of laminating the polarizer and the transparent protective film; and a bonding step of irradiating the polarizer surface or the transparent protective film surface with active energy rays to cure the curable resin composition to obtain the adhesive layer, and bonding the polarizer and the transparent protective film via the obtained adhesive layer.

14. The method for manufacturing a polarizing film according to claim 13, wherein: The mass ratio of the compound represented by the general formula (1) to the boric acid in the first composition is 1:0.1 to 1:30.

0.

15. The method for manufacturing a polarizing film according to claim 13, wherein: The content of the compound represented by the general formula (1) in the curable resin composition is 0.05 to 5% by mass, and the content of the boric acid is 0.1 to 2% by mass.

16. The method for manufacturing a polarizing film according to claim 13, wherein: The polarizer contains 10 to 22% by mass of boric acid.

17. The method for manufacturing a polarizing film according to claim 13, wherein: When the ratio of boric acid contained in the polarizer is A% by mass and the ratio of boric acid contained in the curable resin composition is B% by mass, A:B=1:0.001 to 1:0.

1.

18. The method for manufacturing a polarizing film according to claim 13, wherein: The coating thickness of the first composition after the first coating step is 0.6 to 2.0 μm before drying and 0.3 to 1.0 μm after drying.

19. The method for manufacturing a polarizing film according to claim 13, wherein: The thickness of the adhesive layer is 1 μm or more and 2 μm or less.

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