KR20210046587A - Polarizer, polarizing film, optical film, and image display device - Google Patents

Abstract

As a polarizer having a durability improvement layer on at least one surface, the durability improvement layer comprises a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A). A polarizer containing at least a copolymer. The cyclic skeleton of the compound (A) is preferably a heterocyclic skeleton, and preferably a lactone skeleton. Furthermore, it is preferable that the compound (A) is γ-butyrolactone (meth)acrylate.

Description

Polarizer, polarizing film, optical film, and image display device

The present invention relates to a polarizer having a durability improving layer on at least one surface. Further, the present invention relates to a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer. The said polarizing film can form image display devices, such as a liquid crystal display device (LCD), an organic EL display device, CRT, and PDP, as this alone or as an optical film laminated therewith.

In watches, mobile phones, PDAs, notebook PCs, PC monitors, DVD players, and TVs, liquid crystal displays are rapidly expanding the market. A liquid crystal display device visualizes a polarization state by switching of a liquid crystal, and from the display principle, a polarizer is used. In particular, in applications such as TVs, more and more high luminance, high contrast, and wide viewing angle are required, and even more and more high transmittance, high polarization, and high color reproducibility are required for a polarizing film.

As a polarizer, since it has high transmittance and high polarization, for example, iodine is adsorbed to polyvinyl alcohol (hereinafter, also simply referred to as "PVA"), and an iodine polarizer having a stretched structure is most commonly used. In general, a polarizing film is a so-called water-based adhesive in which a polyvinyl alcohol-based material is dissolved in water, and a transparent protective film is bonded on both sides of a polarizer is used (Patent Document 1 below). As the transparent protective film, triacetyl cellulose or the like having high moisture permeability is used. In the case of using the water-based adhesive (so-called wet lamination), after bonding the polarizer and the transparent protective film, a drying step is required.

On the other hand, instead of the water-based adhesive, an active energy ray-curable adhesive has been proposed. When manufacturing a polarizing film using an active energy ray-curable adhesive, since a drying process is not required, productivity of a polarizing film can be improved. For example, a radical polymerization type active energy ray-curable adhesive using an N-substituted amide-based monomer as a curable component has been proposed (Patent Document 2 below). The adhesive layer formed using the active energy ray-curable adhesive described in Patent Document 2 can be sufficiently cleared, for example, with respect to a water resistance test for evaluating the presence or absence of color loss and peeling after immersion in 60°C hot water for 6 hours. However, in recent years, it is possible to clear a more severe water resistance test for evaluating the presence or absence of peeling when the adhesive for a polarizing film is subjected to peeling of an end claw after, for example, immersion in water (saturation). There is a demand for an additional degree of improvement in water resistance.

In the following Patent Document 3, a technique of forming a resin layer on the surface of the polarizer for the purpose of suppressing the deterioration of the polarizer is reported, but under severe humidification conditions, in order to sufficiently suppress the deterioration of the polarizer, there is additional room. It turned out.

Japanese Laid-Open Patent Publication No. 2001-296427 Japanese Unexamined Patent Publication No. 2012-052000 Japanese Unexamined Patent Publication No. 2000-199819

The present invention has been developed in view of the above circumstances, and an object of the present invention is to provide a polarizer and a polarizing film in which deterioration of optical properties is suppressed even under a humidified environment.

Furthermore, it aims at providing an optical film using the said polarizing film, and providing an image display device using the said polarizing film or an optical film.

The inventors of the present invention have repeatedly studied intensively in order to solve the above problems, and as a result, by forming a durability enhancing layer containing a copolymer of a specific compound on at least one surface of the polarizer, even in a humidified environment, a polarizer, and furthermore, such a polarizer It found out that deterioration of the optical properties of the polarizing film provided with can be suppressed, and came to solve this invention.

That is, the present invention is a polarizer having a durability improving layer on at least one surface, wherein the durability enhancing layer is copolymerized with a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and the compound (A) It relates to a polarizer characterized by containing at least a copolymer of a possible compound (B).

In the polarizer, the durability enhancing layer contains at least a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) copolymerizable with the compound (A). It is preferred that it is formed by the composition.

In the polarizer, the compound (B) is represented by the following general formula (1):

[Formula 1]

It is preferable that it is a compound represented by (however, X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group, or a heterocyclic group) .

In the polarizer, it is preferable that the cyclic skeleton of the compound (A) is a heterocyclic skeleton.

In the polarizer, it is preferable that the cyclic skeleton of the compound (A) is a lactone skeleton (cyclic lactone skeleton).

In the polarizer, it is preferable that the compound (A) is γ-butyrolactone (meth)acrylate.

In the polarizer, it is preferable that the curable composition further contains a polymerization initiator.

In the polarizer, it is preferable that the durability improvement layer is formed of a cured product layer of the curable composition.

Moreover, the present invention relates to a polarizing film provided with the polarizer according to any one of the above.

In the polarizing film, it is preferable that a transparent protective film is laminated on at least one surface of the polarizer, and the transparent protective film is laminated on a side of the durability improvement layer provided by the polarizer.

In the polarizing film, it is preferable that an adhesive layer is further provided between the durability improving layer and the transparent protective film.

Further, the present invention relates to an optical film in which at least one of the above-described polarizing films is laminated, or to an image display device in which the above-described polarizing film or the above-described optical film is used.

Further, the present invention relates to a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A).

In the copolymer, the compound (B) is represented by the following general formula (1):

[Formula 2]

It is preferable that it is a compound represented by (however, X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group, or a heterocyclic group) .

In the copolymer, it is preferable that the cyclic skeleton of the compound (A) is a heterocyclic skeleton.

In the above copolymer, it is preferable that the cyclic skeleton of the compound (A) is a lactone skeleton (cyclic lactone skeleton).

In the copolymer, it is preferable that the compound (A) is γ-butyrolactone (meth)acrylate.

Further, the present invention relates to a curable composition containing at least the copolymer described in any of the above, and such curable composition preferably contains a polymerization initiator in addition to the copolymer.

As described above, in general, as a polarizer, an iodine polarizer having a structure in which iodine is adsorbed and stretched to PVA is used. In the present invention, the polarizer has a durability improving layer on at least one surface thereof, and the durability improving layer is copolymerized with a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and the compound (A). It contains at least a copolymer of the possible compound (B). For this reason, deterioration of the optical properties of the polarizer can be suppressed even under a humidified environment. The reason why such an effect is obtained is not clear, but since the polarizer has a durability improving layer containing the compound (A) on at least one surface, it is possible to stabilize the iodine complex present on the surface of the polarizer even under a humidified environment. It seems to be one of the reasons. Further, in the present invention, since at least a part of the compound (A) is copolymerized with the compound (B), the compound (A) is easily fixed in the vicinity of the polarizer. As a result, the stabilizing effect of the iodine complex present on the surface of the polarizer is enhanced even under a humidified environment.

Particularly in the present invention, when the compound (B) is a compound represented by the general formula (1), in the copolymer of the compound (A) and the compound (B) contained in the durability improving layer, the boric acid of the compound (B) The group and/or the boric acid ester group reacts with a functional group such as a hydroxyl group that the polarizer has, and the compound (A) is more likely to be fixed in the vicinity of the polarizer. As a result, the adhesion between the polarizer and the durability improving layer is further improved, and deterioration of the optical properties of the polarizer in a humidified environment can be further suppressed.

In addition, in the polarizing film in which a transparent protective film is laminated on at least one surface of the polarizer according to the present invention, for example, when an adhesive layer is interposed between the polarizer and the transparent protective film, the optical properties of the polarizing film even in a humidified environment Deterioration can be suppressed. The reason for obtaining such an effect is not clear, but the durability improvement layer can suppress the hydrolysis of covalent bonds or hydrogen bonds formed between functional groups such as hydroxyl groups present on the surface of the polarizer and functional groups of the adhesive layer. It is considered as one of the reasons that the iodine complex present on the surface of the polarizer can be stabilized.

In addition, the polarizing film according to the present invention does not need to form a transparent protective film on the durability improvement layer as long as it includes a polarizer in which the specific durability improvement layer is formed on at least one surface. In such a polarizing film, while the durability improving layer suppresses deterioration of the optical properties of the polarizer in a humidified environment, the durability improving layer also exhibits a protective function in place of the transparent protective film.

A copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, a compound (B) capable of copolymerizing with the compound (A), and a curable composition containing at least the copolymer include, for example, a polarizer By applying it to the surface, the durability improving layer can be formed. As described above, in the polarizer provided with such a durability improvement layer, deterioration of the optical properties of the polarizer is suppressed even under a humidified environment. Accordingly, such a copolymer and a curable composition containing at least the copolymer can be particularly preferably used for a polarizer and a polarizing film including at least the polarizer.

The present invention relates to a polarizer comprising a durability improving layer on at least one surface. Hereinafter, each configuration will be described.

<Durability improvement layer>

The durability improving layer contains at least a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A). Such a durability improving layer is, for example, in a curable composition containing at least a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A). Can be formed by

The compound (A) contains at least one or more carbon-carbon double bonds such as a vinyl group and a (meth)acryloyl group, and further has a cyclic skeleton. Although the cyclic skeleton may be composed of only carbon atoms, it is preferably a heterocyclic skeleton having a carbon atom and a hetero atom.

The hetero atom of the heterocyclic skeleton includes a nitrogen atom, an oxygen atom, and a sulfur atom, and specific examples of the heterocyclic skeleton include ethyleneimine, azacyclobutane, pyrrolidine, pyrrole, imidazole, pyrazole, Nitrogen atom-containing heterocyclic skeletons such as oxazole, piperidine, pyridine, morpholine, hexamethyleneimine, and azatopyrroline; Contains oxygen atoms such as ethylene oxide, α-acetolactone, propylene oxide, β-propiolactone, tetrahydrofuran, furan, γ-butyrolactone, tetrahydropyran, dioxane, σ-valerolactone and hexamethylene oxide Heterocyclic skeleton; And sulfur atom-containing heterocyclic skeletons such as ethylene sulfide, trimethylene sulfide, tetrahydrothiophene, thiophene, thiazole, tetrahydrothiopyranthiazine, and hexamethylene sulfide. From the viewpoint of suppressing deterioration of the optical properties of the durability enhancing layer provided by the polarizer, among the heterocyclic skeletons, lactone skeletons such as α-acetolactone, β-propiolactone, γ-butyrolactone and σ-valerolactone (cyclic type Lactone skeleton) is preferred, and γ-butyrolactone is preferred.

As the compound (A), a compound containing at least one or more carbon-carbon double bonds such as a vinyl group and a (meth)acryloyl group, and having the above-described cyclic skeleton can be used. In the present invention, in particular, as the compound (A), (meth)acryloylmorpholine, α-acetolactone (meth)acrylate, β-propiolactone (meth)acrylate, and γ-butyrolactone (meth)acrylic Rate and ?-valerolactone (meth)acrylate and the like are preferred.

If the content of the compound (A) is too small in the durability improving layer, deterioration of the optical properties of the polarizer may not be sufficiently suppressed in a humidified environment. Therefore, in the durability improving layer, the content of the compound (A) is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 95 parts by mass or more.

The compound (B) is a compound that can be copolymerized with the compound (A), for example, a compound containing at least one carbon-carbon double bond such as a vinyl group or a (meth)acryloyl group in the same manner as the compound (A). If it is, it can be used without particular limitation.

As the compound (B), in particular, the following general formula

(One) :

[Formula 3]

When a compound represented by (wherein X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group, or a heterocyclic group) is used , The boric acid group and/or the boric acid ester group which the compound (B) has reacts with a functional group such as a hydroxyl group which the polarizer has, and also reacts with the compound (A). Thereby, the adhesion between the polarizer and the durability improving layer is further improved, and deterioration of the optical properties of the polarizer in a humidified environment can be further suppressed.

Examples of the aliphatic hydrocarbon group include a linear or branched alkyl group which may have a substituent having 1 to 20 carbon atoms, a cyclic alkyl group which may have a substituent having 3 to 20 carbon atoms, and an alkenyl group having 2 to 20 carbon atoms, and aryl Examples of the group include a phenyl group which may have a substituent having 6 to 20 carbon atoms, a naphthyl group which may have a substituent having 10 to 20 carbon atoms, and the like, and the heterocyclic group includes, for example, at least one hetero atom, 5-membered ring or 6-membered ring group which may have a substituent is mentioned. These may be linked to each other to form a ring. In General Formula (1), R ¹ and R ² are preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and most preferably a hydrogen atom.

X in the compound (B) represented by the general formula (1) is a functional group containing a reactive group. Examples of the reactive group contained in X include a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, a vinyl group, a (meth)acryl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetane group. , α,β-unsaturated carbonyl group, mercapto group, halogen group, and the like. However, in order to improve the adhesion between the polarizer and the durability enhancing layer by reacting with the carbon-carbon double bond of the monomer (A), the reactive groups contained in X include vinyl group, (meth)acrylic group, styryl group, (meth) ) It is preferably at least one reactive group selected from the group consisting of an acrylamide group, a vinyl ether group, an epoxy group, an oxetane group and a mercapto group, and consisting of a (meth)acryl group, a styryl group, and a (meth)acrylamide group. It is preferably at least one reactive group selected from the group.

As a preferable specific example of the compound (B) represented by general formula (1), the following general formula (1')

[Formula 4]

The compound represented by (however, Y is an organic group, and X, R ¹ and R ² are the same as above) can be mentioned. More preferably, the following compounds (1a) to (1d) are mentioned.

[Formula 5]

In the present invention, the compound (B) represented by the general formula (1) may be one in which a reactive group and a boron atom are directly bonded to each other, but as shown in the above specific example, the compound (B) represented by the general formula (1), It is preferable that a reactive group and a boron atom are bonded through an organic group, that is, a compound (B) represented by the general formula (1'). When the compound (B) represented by the general formula (1) is, for example, bonded with a reactive group via an oxygen atom bonded to a boron atom, the optical properties of the polarizer tend to deteriorate. On the other hand, when the compound (B) represented by the general formula (1) does not have a boron-oxygen bond, but has a boron-carbon bond and contains a reactive group by bonding a boron atom and an organic group (general formula In the case of (1')), it is preferable because deterioration of the optical properties of the polarizer can be suppressed. The organic group specifically refers to an organic group having 1 to 20 carbon atoms which may have a substituent, and more specifically, for example, a linear or branched alkylene group or a carbon number that may have a substituent having 1 to 20 carbon atoms The cyclic alkylene group which may have a 3-20 substituent, the phenylene group which may have a C6-C20 substituent, the naphthylene group which may have a C10-20 substituent, etc. are mentioned.

As the compound (B) represented by the general formula (1), in addition to the compounds exemplified above, esters of hydroxyethylacrylamide and boric acid, esters of methylolacrylamide and boric acid, esters of hydroxyethyl acrylate and boric acid, and hydrides The ester of (meth)acrylate and boric acid, such as ester of oxybutyl acrylate and boric acid, can be illustrated.

If the content of the compound (B) in the durability improvement layer is too small, the effect of fixing the compound (A) in the vicinity of the polarizer is reduced, and deterioration of the optical properties of the polarizer in a humidified environment may not be sufficiently suppressed. . Therefore, in the durability improving layer, the content of the compound (B) is preferably 0.5 parts by mass or more, more preferably 3.0 parts by mass or more, and still more preferably 10 parts by mass or more.

The method of copolymerizing the compound (A) and the compound (B) includes, for example, radical polymerization in a solution containing the compound (A) and the compound (B). When performing radical polymerization, as an initiator, a thermal polymerization initiator known to those skilled in the art, for example, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvalero Nitrile), 2,2'-azobis(2-methylbutyronitrile), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-methylpropionamidine) 2 hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] 2 hydrochloride, benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxide, 2,2'-azobis(2-methylpropionic acid)dimethyl, dicumyl peroxide, etc. can be used. Further, as the solvent, a solvent known to those skilled in the art, such as an organic solvent, water, or a mixed solvent thereof, can be used. Examples of the solvent include 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; It can be selected from glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate.

The copolymer of the compound (A) and the compound (B) may be a random copolymer or a block copolymer. The copolymerization ratio of the compound (A) and the compound (B) is, in terms of the effect of suppressing deterioration of the optical properties of the polarizer, of the finally obtained durability improving layer, in terms of mass ratio, (Compound (A)): (Compound (B)) It is preferable that it is 60:40 to 99.5:0.5, and it is more preferable that it is 80:20 to 99:1.

As a method of forming a durability improving layer using a curable composition containing at least a copolymer of a compound (A) and a compound (B), for example, on at least one surface of a polarizer, a coating method described later, or the like, is used. A coating layer made of a curable composition containing such a copolymer may be formed and dried as necessary to form a durability improving layer.

The curable composition serving as a raw material for forming the durability improving layer may be composed of only a copolymer of the compound (A) and the compound (B), but may contain a polymerization initiator, a solvent, and an additive in addition to this.

When the curable composition contains a polymerization initiator in addition to the copolymer of the compound (A) and the compound (B), and the durability improvement layer is formed by the cured product layer of the curable composition, the copolymer and the polymer are in the vicinity of the polarizer By being fixed to, the durability improvement of a polarizer further increases. As a result, it is preferable because deterioration of the optical characteristic of a polarizer can be suppressed suitably. Regarding the method of forming the durability enhancing layer by the cured product layer, for example, a curable composition containing at least a copolymer and a polymerization initiator is applied to a polarizer, and the curable composition is cured by irradiating an active energy ray to be described later. The method of forming the cargo layer (durability improvement layer) is mentioned. The usable active energy rays will be described later.

In this invention, it is preferable to use a photoinitiator as a polymerization initiator. The photoinitiator is appropriately selected by an active energy ray. In the case of curing by ultraviolet or visible light, a photopolymerization initiator of ultraviolet or visible light cleavage is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α -Aromatic ketone compounds, such as hydroxycyclohexylphenyl ketone; Methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane Acetophenone compounds such as -1; Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisoin methyl ether; Aromatic ketal compounds such as benzyl dimethyl ketal; Aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; Photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; Thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl thioxanthone, 2,4-dichloro thioxanthone, 2,4-diethyl thioxanthone Thioxanthone compounds such as santon, 2,4-diisopropyl thioxanthone, and dodecyl thioxanthone; Campaquinone; Halogenated ketones; Acylphosphine oxide; Acylphosphonate, etc. are mentioned.

As the photoinitiator, a compound represented by the following general formula (3);

[Formula 6]

(In the formula, R ⁶ and R ⁷ represent -H, -CH ₂ CH ₃ , -iPr or Cl, and R ₆ and R ₇ may be the same or different) or the general formula (3) It is preferable to use together the compound represented by and the photoinitiator which is highly sensitive to light of 380 nm or more mentioned later. When the compound represented by the general formula (3) is used, it is superior in adhesiveness compared to the case where a photoinitiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (3), diethylthioxanthone in which ^{R 6} and R ⁷ are -CH ₂ CH _{3 is particularly preferable.} The composition ratio of the compound represented by the general formula (3) in the curable composition is preferably 0.5 to 4.0 mass%, more preferably 1.0 to 2.5 mass% with respect to the copolymer of compound (A) and compound (B). Do.

Moreover, it is preferable to add a polymerization initiation aid as needed. Examples of the polymerization initiation aid include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Somatomeal and the like, and ethyl 4-dimethylaminobenzoate is particularly preferred. In the case of using a polymerization initiation aid, the amount added is usually 0 to 5% by mass, preferably 0 to 4% by mass, most preferably, based on the total amount of the copolymer of compound (A) and compound (B). It is 0-3 mass %.

Moreover, a known photoinitiator can be used together as needed. Since the transparent protective film having UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photoinitiator with high sensitivity to light of 380 nm or more as the photoinitiator. Specifically, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-buta Non-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2,4,6-trimethylbenzoyl -Diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro Ro-3-(1H-pyrrol-1-yl)-phenyl) titanium and the like.

In particular, as a photoinitiator, in addition to the photoinitiator of the general formula (3), a compound further represented by the following general formula (4);

[Formula 7]

(In the formula, R ⁸ , R ⁹ and R ¹⁰ represent -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ⁸ , R ⁹ and R ¹⁰ may be the same or different) It is desirable to do it. As the compound represented by the general formula (4), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: IRGACURE907 manufacturer: BASF), which is also a commercial product, is preferably used. I can. In addition, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name: IRGACURE369 manufacturer: BASF), 2-(dimethylamino)-2-[(4-methylphenyl )Methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (brand name: IRGACURE379, manufacturer: BASF) is preferable because of its high sensitivity. The composition ratio of the compound represented by the general formula (4) in the curable composition is preferably 0.5 to 4.0% by mass, more preferably 1.0 to 2.5% by mass, based on the copolymer of the compound (A) and the compound (B). Do.

As the solvent which the curable composition may contain, it is preferable that the copolymer of the compound (A) and the compound (B), and further, a polymerization initiator, and the like can be stabilized, dissolved or dispersed. Such a solvent may be the same solvent that can be used when the compound (A) and compound (B) are copolymerized, for example, a solution obtained by copolymerizing the compound (A) and the compound (B) using the solvent of the above example. Is used as it is, and if necessary, a polymerization initiator or an additive may be added and used as a curable composition.

Examples of additives that the curable composition may contain include 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, particulates, thin materials, and the like.

As for the method of forming the durability improvement layer on the polarizer using the curable composition, a method of directly immersing the polarizer in the treatment bath of the curable composition or a known coating method are appropriately used. Specific examples of the coating method include, but are not limited to, a roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, an air knife coat, and a curtain coat method.

When the curable composition contains a polymerization initiator, by curing the curable composition on at least one surface of the polarizer to form a cured product layer, a durability improvement layer may be formed, or an uncured curable composition may be formed on at least one surface of the polarizer. The resulting durability improving layer may be formed, and after lamination with the transparent protective film, the curable composition is cured to form a durability improving layer composed of a cured product layer.

<polarizer>

The polarizer is not particularly limited, and various types of polarizers can be used. As a polarizer, for example, a dichroic material such as iodine or a dichroic dye is added to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene/vinyl acetate copolymer-based partial saponification film. Polyene-based oriented films, such as a thing which was adsorbed and uniaxially stretched, a polyvinyl alcohol dehydration treatment product, and a polyvinyl chloride dehydrochloric acid treatment product, etc. are mentioned. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is generally 1 to 30 µm.

A polarizer obtained by uniaxially stretching a polyvinyl alcohol-based film by dyeing it with iodine can be produced by, for example, dyeing by immersing polyvinyl alcohol in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, it may be immersed in an aqueous solution such as boric acid or potassium iodide. Further, if necessary, before dyeing, the polyvinyl alcohol-based film may be immersed in water and washed with water. By washing the polyvinyl alcohol-based film with water, it is possible to wash the surface of the polyvinyl alcohol-based film with an anti-contamination or blocking agent, and by swelling the polyvinyl alcohol-based film, there is also an effect of preventing unevenness such as staining of dyeing. Stretching may be performed after dyeing with iodine, stretching may be performed while dyeing, or may be dyed with iodine after stretching. It can be stretched in an aqueous solution such as boric acid or potassium iodide or in a water bath.

By the way, in mobile applications such as mobile phones, from the viewpoint of design and compactness, the demand for thin polarizers having a thickness of 10 μm or less is increasing, but when the thickness of the polarizer becomes thin, there is a tendency that the deterioration of optical properties, especially in a humidified environment, becomes remarkable. have. However, even if the polarizer according to the present invention is a thin polarizer having a thickness of 10 µm or less, since the optical enhancement layer is provided on at least one surface thereof, deterioration of optical properties is suppressed even in a humidified environment. It is preferable that the thickness of a polarizer is 1-7 micrometers speaking from a viewpoint of thinning. It is preferable that such a thin polarizer has little thickness unevenness, is excellent in visibility, and has little dimensional change, and furthermore, the thickness as a polarizing film is also thinned.

As a thin polarizer, representatively, Japanese Laid-Open Patent Publication No. 51-069644 or Japanese Laid-Open Patent Publication No. 2000-338329, a pamphlet of WO2010/100917, a specification of PCT/JP2010/001460, or Japanese Patent Application No. 2010-269002 The thin polarizing film described in the specification and Japanese Patent Application No. 2010-263692 can be mentioned. These thin polarizing films can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as a PVA-based resin) layer and a resin substrate for stretching in the state of a laminate and a step of dyeing. In this manufacturing method, even if the PVA-based resin layer is thin, it becomes possible to extend without problems such as fracture due to stretching by being supported by the resin substrate for stretching.

As the thin polarizing film, among the manufacturing methods including the step of stretching and dyeing in the state of a laminate, it can be stretched at a high magnification and thus the polarization performance can be improved. WO2010/100917 pamphlet, PCT/JP2010 It is preferably obtained by a manufacturing method including a step of stretching in an aqueous boric acid solution as described in the specification of /001460 or the specification of Japanese Patent Application 2010-269002 or specification of Japanese Patent Application 2010-263692, and in particular, Japanese Patent Application 2010-269002 It is preferably obtained by a manufacturing method including a step of auxiliary aerial stretching prior to stretching in an aqueous boric acid solution described in the specification of No. 2010-263692 or Japanese Patent Application No. 2010-263692.

Before forming the said durability improvement layer, you may perform the surface modification treatment of a polarizer. Examples of the surface modification treatment include treatments such as corona treatment, plasma treatment, and yeast treatment, and it is particularly preferable that it is corona treatment. By performing the corona treatment, reactive functional groups such as a carbonyl group and an amino group are generated on the surface of the polarizer, and the adhesion with the durability improving layer is improved. Further, foreign matters on the surface are removed by the ashing effect, or irregularities on the surface are reduced, so that a polarizing film excellent in appearance characteristics can be manufactured.

The polarizing film according to the present invention includes a polarizer provided on at least one surface of a durability improving layer formed of a curable composition containing a compound (A) having a carbon-carbon double bond and a cyclic skeleton. In addition, the polarizing film according to the present invention may have a transparent protective film laminated on at least one surface of the polarizer. The polarizer and the transparent protective film may be laminated through the durability improvement layer, and the durability improvement layer and the transparent protective film provided by the polarizer may be further laminated through an adhesive layer. Below, the adhesive layer is demonstrated.

<Adhesive layer>

It is preferable that the thickness of the adhesive layer is 0.01 to 3.0 µm. When the thickness of the adhesive layer is too thin, it is not preferable because the cohesive force of the adhesive layer is insufficient and the peeling force is lowered. When the thickness of the adhesive layer is too thick, peeling when stress is applied to the end face of the polarizing film is liable to occur, and peeling failure due to impact occurs, which is not preferable. The thickness of the adhesive layer is more preferably 0.1 to 2.5 µm, most preferably 0.5 to 1.5 µm.

The adhesive layer is formed by curing the adhesive composition. As a form of curing the adhesive composition, it can be broadly divided into thermal curing and active energy ray curing. Examples of the thermosetting resin include polyvinyl alcohol resin, epoxy resin, unsaturated polyester, urethane resin, acrylic resin, urea resin, melamine resin, phenol resin, and the like, and a curing agent is used in combination as necessary. As a thermosetting resin, a polyvinyl alcohol resin and an epoxy resin can be used more preferably. As an active energy ray-curable resin, it is classified according to an active energy ray, and can be broadly classified into electron beam curing property, ultraviolet curing property, and visible ray curing property. In addition, as a form of curing, it can be classified into a radical polymerization curable adhesive composition and a cation polymerization resin composition. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are indicated as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are indicated as visible rays.

In production of the polarizing film according to the present invention, it is preferable that it is active energy ray-curable as described above. Moreover, it is especially preferable that it is visible light curability using visible light of 380 nm to 450 nm.

Examples of the curable component contained in the radical polymerization curable adhesive composition include a radical polymerizable compound used in the radical polymerization curable adhesive composition. Examples of the radically polymerizable compound include compounds having a radically polymerizable functional group of a carbon-carbon double bond such as a (meth)acryloyl group and a vinyl group. These curable components can be used either as a monofunctional radical polymerizable compound or a bifunctional or more polyfunctional radical polymerizable compound. Moreover, these radically polymerizable compounds can be used individually by 1 type or in combination of 2 or more types. As these radical polymerizable compounds, a compound having a (meth)acryloyl group is preferable, for example. In addition, in this invention, (meth)acryloyl means an acryloyl group and/or a methacryloyl group, and "(meth)" has the same meaning as follows.

As a monofunctional radical polymerizable compound, for example, the following general formula (2):

[Formula 8]

Compound represented by (however, R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or a cyclic ether group, and R ⁴ and R ⁵ are a ring You may form a heterocyclic ring). Although the number of carbon atoms in the alkyl portion of the alkyl group, hydroxyalkyl group, and/or alkoxyalkyl group is not particularly limited, for example, 1 to 4 carbon atoms are exemplified. Moreover, ^{as the cyclic heterocycle which R 4} and R ⁵ may form, N-acryloylmorpholine etc. are mentioned, for example.

Specific examples of the compound represented by the general formula (2) include, for example, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-alkyl group-containing (meth)acrylamide derivatives such as N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, and N-hexyl (meth)acrylamide; N-hydroxyalkyl group-containing (meth)acrylamide derivatives such as N-methylol (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, and N-methylol-N-propane (meth)acrylamide; And N-alkoxy group-containing (meth)acrylamide derivatives such as N-methoxymethylacrylamide and N-ethoxymethylacrylamide. Further, examples of the cyclic ether group-containing (meth)acrylamide derivative include a heterocycle-containing (meth)acrylamide derivative in which the nitrogen atom of the (meth)acrylamide group forms a heterocycle. For example, N -Acryloylmorpholine, N-acryloyl piperidine, N-methacryloyl piperidine, N-acryloylpyrrolidine, and the like. Among these, N-hydroxyethylacrylamide and N-acryloylmorpholine can be preferably used from the viewpoint of excellent reactivity, the ability to obtain a cured product having a high modulus of elasticity, and excellent adhesion to a polarizer. .

From the viewpoint of improving adhesion and water resistance when bonding a polarizer and a transparent protective film via an adhesive layer, in the adhesive composition, the content of the compound described in General Formula (2) is preferably 0.01 to 80% by mass, It is more preferable that it is 5 to 40 mass %.

Moreover, the adhesive composition used in this invention may contain another monofunctional radically polymerizable compound as a curable component in addition to the compound represented by general formula (2). Examples of the monofunctional radical polymerizable compound include various (meth)acrylic acid derivatives having a (meth)acryloyloxy group. Specifically, for example, 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, s-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, cetyl (meth)acrylate, n-octyl (meth)acrylic (Meth)acrylic acid (carbon number 1-20) alkyl esters such as acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, and n-octadecyl (meth)acrylate Can be mentioned.

Further, examples of the (meth)acrylic acid derivative include cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate and cyclopentyl (meth)acrylate; Aralkyl (meth)acrylates such as benzyl (meth)acrylate; 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth)acrylate, 5-norbornen-2-yl-methyl (meth)acrylate, 3-methyl-2-norbornylmethyl Polycyclic (meth)acrylates such as (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethylcarbitol ( Alkoxy groups, such as meth)acrylate, phenoxyethyl (meth)acrylate, and alkylphenoxy polyethylene glycol (meth)acrylate, or (meth)acrylate containing a phenoxy group, etc. are mentioned. Among these, dicyclopentenyloxyethyl acrylate and phenoxyethyl acrylate are preferable from the viewpoint of excellent adhesion to various protective films.

In addition, as the (meth)acrylic acid derivative, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl ( Meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12 -Hydroxyalkyl (meth)acrylates such as hydroxylauryl (meth)acrylate, [4-(hydroxymethyl)cyclohexyl]methylacrylate, cyclohexanedimethanol mono(meth)acrylate, 2- Hydroxyl group-containing (meth)acrylates such as hydroxy-3-phenoxypropyl (meth)acrylate; Epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether; 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-trifluoroethylethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth) Halogen-containing (meth)acrylates such as acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate; Alkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate; 3-oxetanylmethyl(meth)acrylate, 3-methyl-oxetanylmethyl(meth)acrylate, 3-ethyl-oxetanylmethyl(meth)acrylate, 3-butyl-oxetanylmethyl(meth) ) Oxetane group-containing (meth)acrylates such as acrylate and 3-hexyl-oxetanylmethyl (meth)acrylate; Heterocyclic (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate, butyrolactone (meth)acrylate, hydroxypivalate neopentyl glycol (meth)acrylic acid adduct, p-phenylphenol ( And meth)acrylate. Among these, 2-hydroxy-3-phenoxypropyl acrylate is preferable because it is excellent in adhesion to various protective films.

Further, 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.

Further, examples of the monofunctional radical polymerizable compound include lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; Vinyl-based monomers having nitrogen-containing heterocycles such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine.

In the adhesive composition used in the present invention, among monofunctional radical polymerizable compounds, if a hydroxyl group-containing (meth)acrylate, a carboxyl group-containing (meth)acrylate, a phosphoric acid group-containing (meth)acrylate, etc. are contained. , The adhesion to various substrates is improved. The content of the hydroxyl group-containing (meth)acrylate is preferably 1% by mass to 30% by mass with respect to the resin composition. When the content is too large, the water absorption rate of the cured product becomes high, and water resistance may deteriorate. The content of the carboxyl group-containing (meth)acrylate is preferably 1% by mass to 20% by mass with respect to the resin composition. When the content is too large, it is not preferable because the optical durability of the polarizing film is lowered. Examples of the phosphoric acid group-containing (meth)acrylate include 2-(meth)acryloyloxyethyl acid phosphate, and the content is preferably 0.1% by mass to 10% by mass based on the resin composition. When the content is too large, it is not preferable because the optical durability of the polarizing film is lowered.

Moreover, as a monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. The radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth)acryl group at the terminal or in the molecule and further having an active methylene group. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, or a cyanoacetyl group. It is preferable that the active methylene group is an acetoacetyl group. Specific examples of the radical polymerizable compound having an active methylene group include, for example, 2-acetoacetoxyethyl (meth)acrylate, 2-acetoacetoxypropyl (meth)acrylate, and 2-acetoacetoxy-1-methyl. Acetoacetoxyalkyl (meth)acrylate such as ethyl (meth)acrylate; 2-Ethoxymalonyloxyethyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2-propionylacetoxy Butyl)acrylamide, N-(4-acetoacetoxymethylbenzyl)acrylamide, N-(2-acetoacetylaminoethyl)acrylamide, and the like. It is preferable that the radically polymerizable compound having an active methylene group is acetoacetoxyalkyl (meth)acrylate.

In addition, as a polyfunctional radical polymerizable compound having a bifunctional or higher function, for example, N,N'-methylenebis(meth)acrylamide, a polyfunctional (meth)acrylamide derivative, tripropylene glycol di(meth)acrylate, Tetraethylene glycol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 1,9-nonandioldi(meth)acrylate, 1,10-decanediol diacrylate, 2-ethyl- 2-butylpropanediol 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 di Glycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate, dioxane glycol di (Meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaeryth Ester product of (meth)acrylic acid and polyhydric alcohol, such as litolehexa(meth)acrylate and EO-modified diglycerintetra(meth)acrylate, 9,9-bis[4-(2-(meth)acryloyloxye) Oxy)phenyl]fluorene. Specific examples include Aronix M-220 (manufactured by Toa Synthetic Corporation), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), and light acrylate DCP. -A (manufactured by Kyoeisha Chemical), SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer), and the like are preferable. Moreover, as needed, various epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, various (meth)acrylate-type monomers, etc. are mentioned. In addition, since the polyfunctional (meth)acrylamide derivative has a high polymerization rate and excellent productivity, and excellent crosslinkability when a resin composition is used as a cured product, it is preferable to contain it in the adhesive composition.

As for the radical polymerizable compound, it is preferable to use a monofunctional radical polymerizable compound and a polyfunctional radical polymerizable compound together from the viewpoint of making both adhesiveness with a polarizer and various transparent protective films, and optical durability in harsh environments. Usually, it is preferable to use it together in the ratio of 3 to 80 mass% of a monofunctional radical polymerizable compound and 20 to 97 mass% of a polyfunctional radical polymerizable compound with respect to 100 mass% of a radical polymerizable compound.

The adhesive composition used in the present invention can be used as an active energy ray-curable adhesive composition when a curable component is used as an active energy ray-curable component. When the active energy ray-curable adhesive composition uses an electron beam or the like for an active energy ray, the active energy ray-curable adhesive composition does not need to contain a photopolymerization initiator, but ultraviolet or visible light is used for the active energy ray. In the case of doing so, it is preferable to contain a photoinitiator. As the photoinitiator, the same ones used for forming the durability improving layer can be used.

In the active energy ray-curable adhesive composition, when a radically polymerizable compound having an active methylene group is used as the radically polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen extraction function. According to such a configuration, even if it is in a high-humidity environment or immediately after being taken out from water (non-dried state), the adhesiveness of the adhesive layer of the polarizing film is remarkably improved. Although this reason is not clear, the following causes can be considered. In short, the radical polymerizable compound having an active methylene group is introduced into the main chain and/or side chain of the base polymer in the adhesive layer while being polymerized together with other radical polymerizable compounds constituting the adhesive layer to form an adhesive layer. In such a polymerization process, when a radical polymerization initiator having a hydrogen drawing action is present, a base polymer constituting the adhesive layer is formed, while hydrogen is extracted from the radically polymerizable compound having an active methylene group, and a radical is generated in the methylene group. . Then, the methylene group in which the radical has been generated and the hydroxyl group of a polarizer such as PVA reacts to form a covalent bond between the adhesive layer and the polarizer. As a result, even in a non-dried state, it is estimated that the adhesiveness of the adhesive layer which the polarizing film has is remarkably improved.

In the present invention, examples of the radical polymerization initiator having a hydrogen drawing action include a thioxanthone radical polymerization initiator, a benzophenone radical polymerization initiator, and the like. It is preferable that the said radical polymerization initiator is a thioxanthone type radical polymerization initiator. As a thioxanthone type radical polymerization initiator, the compound represented by the said general formula (3) is mentioned, for example. As a specific example of the compound represented by general formula (3), thioxanthone, dimethyl thioxanthone, diethyl thioxanthone, isopropyl thioxanthone, chloro thioxanthone, etc. are mentioned, for example. Among the compounds represented by the general formula (3), diethylthioxanthone in which ^{R 6} and R ⁷ are -CH ₂ CH _{3 is particularly preferable.}

In the case where the active energy ray-curable adhesive composition contains a radical polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen drawing action, the active methylene It is preferable to contain 1 to 50 mass% of a radical polymerizable compound having a group and 0.1 to 10 mass% of a radical polymerization initiator with respect to the total amount of the adhesive composition.

As described above, in the present invention, a radical is generated in the methylene group of a radically polymerizable compound having an active methylene group in the presence of a radical polymerization initiator having a hydrogen extraction function, and the hydroxyl group of such a methylene group and a polarizer such as PVA is reacted. Thus, a covalent bond is formed. Therefore, in order to generate a radical in the methylene group of the radically polymerizable compound having an active methylene group and sufficiently form such a covalent bond, when the total amount of the curable component is 100% by mass, the radically polymerizable compound having an active methylene group is 1 It is preferable to contain -50 mass%, and it is more preferable to contain 3-30 mass%. In order to sufficiently improve water resistance and improve adhesion in a non-dried state, the radical polymerizable compound having an active methylene group is preferably 1% by mass or more. On the other hand, when it exceeds 50 mass %, hardening defect of an adhesive layer may arise. Moreover, it is preferable to contain 0.1-10 mass% with respect to the total amount of the adhesive composition, and it is more preferable to contain the radical polymerization initiator with hydrogen drawing action, and further 0.3-9 mass%. In order to sufficiently advance the hydrogen drawing reaction, it is preferable to use 0.1 mass% or more of a radical polymerization initiator. On the other hand, when it exceeds 10 mass %, it may not completely melt|dissolve in a composition.

The cation polymerizable compound used in the cation polymerization curable adhesive composition includes a monofunctional cation polymerizable compound having one cation polymerizable functional group in the molecule, and two or more cation polymerizable functional groups in the molecule. It is classified as a functional cation polymerizable compound. Since the monofunctional cation polymerizable compound has a relatively low liquid viscosity, the liquid viscosity of the resin composition can be reduced by including it in the resin composition. Moreover, the monofunctional cation-polymerizable compound often has a functional group that expresses various functions, and by incorporating it in the resin composition, various functions can be expressed in the resin composition and/or the cured product of the resin composition. Since the polyfunctional cation polymerizable compound can three-dimensionally crosslink the cured product of the resin composition, it is preferable to contain it in the resin composition. The ratio of the monofunctional cation polymerizable compound and the polyfunctional cation polymerizable compound is in the range of 10 parts by mass to 1000 parts by mass of the polyfunctional cation polymerizable compound with respect to 100 parts by mass of the monofunctional cation polymerizable compound. It is desirable to do it. Examples of the cation-polymerizable functional group include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the compound having an epoxy group include an aliphatic epoxy compound, an alicyclic epoxy compound, and an aromatic epoxy compound, and as the cation polymerization curable adhesive composition of the present invention, an alicyclic epoxy compound is used in terms of excellent curability and adhesiveness. It is particularly preferred to contain. As an alicyclic epoxy compound, caprolactone modification of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate Water, a modified product of trimethylcaprolactone, or a modified product of valerolactone. Specifically, Celoxide 2021, Celoxide 2021A, Celoxide 2021P, Celoxide 2081, Celoxide 2083, Celoxide 2085 (above, di Cell Chemical Industries (manufactured by Co., Ltd.), Cyracure UVR-6105, Cyracure UVR-6107, Cyracure 30, R-6110 (above, manufactured by Dow Chemical Japan Co., Ltd.), and the like. The compound having a nil group is preferably contained because it has an effect of improving the curability of the cation polymerization curable adhesive composition of the present invention or reducing the liquid viscosity of the composition. -Ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, di[ (3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxetane, etc. are mentioned, Aaron oxetane OXT-101, Aaron oxetane OXT-121, Aaron oxetane OXT-211, Aaron oxetane OXT-221, Aaron oxetane OXT-212 (above, manufactured by Toa Synthetic Corporation), etc. are commercially available. Since there is an effect of improving the curability of the cation polymerization curable adhesive composition or lowering the liquid viscosity of the composition, it is preferable to contain the compound having a vinyl ether group, such as 2-hydroxyethyl vinyl ether or diethylene glycol. Monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanoldivinyl ether, cyclohexanedimethanol monovinyl ether, tricyclodecane vinyl ether, cyclohexyl Vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, pentaerythritol type tetravinyl ether Le, etc. are mentioned.

The cation polymerization curable adhesive composition contains at least one compound selected from compounds having an epoxy group, a compound having an oxetanyl group, and a compound having a vinyl ether group as described above as a curable component, all of which are cured by cation polymerization. Therefore, a photocationic polymerization initiator is blended. This photocationic polymerization initiator generates cation species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of an epoxy group or an oxetanyl group. As the photocationic polymerization initiator, a photoacid generator described later is preferably used. In addition, when using the adhesive composition used in the present invention with visible light curing properties, it is particularly preferable to use a photocationic polymerization initiator that is highly sensitive to light of 380 nm or more, but the photocationic polymerization initiator is generally 300 nm. Since it is a compound that exhibits maximum absorption in the vicinity or in a shorter wavelength range, light having a wavelength in the vicinity thereof is mixed with a light sensitizer that exhibits maximum absorption in light of a wavelength range longer than that, specifically, a wavelength longer than 380 nm. In response to the photocationic polymerization initiator, the generation of cation species or acids can be promoted. Examples of photosensitizers include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducing dyes, etc. , You may mix and use 2 or more types. In particular, since an anthracene compound is excellent in a photosensitizing effect, it is preferable, and specifically, an anthracure UVS-1331 and an anthracene UVS-1221 (manufactured by Kawasaki Chemical Co., Ltd.) are mentioned. It is preferable that it is 0.1 mass%-5 mass %, and, as for content of a photosensitizer, it is more preferable that it is 0.5 mass%-3 mass %.

It is preferable that the adhesive composition used in the present invention contains the following components in addition to the above components.

The active energy ray-curable adhesive composition used in the present invention may contain an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer in addition to the curable component related to the radical polymerizable compound. By containing a component in the active energy ray-curable adhesive composition, curing shrinkage when irradiating and curing the active energy ray to the composition is reduced, thereby reducing the interfacial stress between the adhesive and adherends such as polarizers and transparent protective films. have. As a result, it is possible to suppress a decrease in adhesion between the adhesive layer and the adherend. In order to sufficiently suppress cure shrinkage of the cured product layer (adhesive layer), the content of the acrylic oligomer is preferably 20% by mass or less, and more preferably 15% by mass or less with respect to the total amount of the adhesive composition. When the content of the acrylic oligomer in the adhesive composition is too large, the decrease in the reaction rate when the composition is irradiated with an active energy ray may be severe, resulting in poor curing. On the other hand, it is preferable to contain 3 mass% or more of acrylic oligomers with respect to the total amount of the adhesive composition, and it is more preferable to contain 5 mass% or more.

When the active energy ray-curable adhesive composition considers workability and uniformity at the time of application, it is preferable that it has a low viscosity, and therefore it is preferable that the acrylic oligomer obtained by polymerizing a (meth)acrylic monomer is also of a low viscosity. As an acrylic oligomer having a low viscosity and capable of preventing curing shrinkage of the adhesive layer, the weight average molecular weight (Mw) is preferably 15000 or less, more preferably 10000 or less, and particularly preferably 5000 or less. On the other hand, in order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the weight average molecular weight (Mw) of the acrylic oligomer is preferably 500 or more, more preferably 1000 or more, and particularly preferably 1500 or more. As the (meth)acrylic monomer constituting the acrylic oligomer, specifically, for example, 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, S-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, cetyl ( (Meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl (meth) acrylate, N-octadecyl (meth) acrylate, etc. Meth)acrylic acid (C1-C20) alkyl esters, for example, cycloalkyl (meth)acrylate (for example, cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, etc.) (Meth)acrylate (e.g., benzyl (meth)acrylate, etc.), polycyclic (meth)acrylate (e.g., 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth) )Acrylate, 5-norbornen-2-yl-methyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, etc.), hydroxyl group-containing (meth)acrylic acid esters ( For example, hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropylmethyl-butyl (meth)methacrylate, etc.), containing an alkoxy group or a phenoxy group (Meth)acrylic acid esters (2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth) Acrylate, ethylcarbitol (meth)acrylate, phenoxyethyl (meth)acrylate, etc.), epoxy group-containing (meth)acrylic acid esters (for example, glycidyl (meth)acrylate, etc.), halogen-containing ( Meth)acrylic acid esters (e.g., 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2-t Lifluoroethylethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylic Rate, etc.), alkylaminoalkyl (meth)acrylate (for example, dimethylaminoethyl (meth)acrylate, etc.), etc. are mentioned. These (meth)acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer include "ARUFON" manufactured by Toa Synthetic Corporation, "Actflow" manufactured by Soken Chemical Corporation, and "JONCRYL" manufactured by BASF Japan.

The active energy ray-curable adhesive composition may contain a photoacid generator. When the active energy ray-curable adhesive composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared to the case where the photoacid generator is not contained. The photoacid generator can be represented by the following general formula (5).

General Formula (5)

[Formula 9]

(Where, L ⁺ is representative of any of the onium cation addition, X ^{-. _{Is, PF 6 -, SbF 6 -}} , AsF 6 -, SbCl 6 -, BiCl 5 -, SnCl 6 -, ClO 4 -, dt It represents a counter anion selected from the group consisting of ocarbamate anions and SCN-.)

Next, the counter anion X ^- in General Formula (5) will be described.

^{The counter anion X −} in the general formula (5) is not particularly limited in principle, but a non-nucleophilic anion is preferable. When the counter anion X ^- is a non-nucleophilic anion, the cation coexisting in the molecule or the nucleophilic reaction in various materials used in combination does not occur well. As a result, the photoacid generator itself represented by the general formula (4) or It is possible to improve the stability over time of the composition using it. The non-nucleophilic anion here refers to an anion having a low ability to cause a nucleophilic reaction. In this anion, such as it is, PF ₆ ^-, and the like _{^{-, SbF 6 -, AsF 6}} -, SbCl 6 -, BiCl 5 -, SnCl 6 -, ClO 4 -, dithiocarbamate anion, SCN .

Specifically, "Syracure UVI-6992", "Syracure UVI-6974" (above, manufactured by Dow Chemical Japan Co., Ltd.), "Adeka Optomer SP150", "Adeka Optomer SP152", "Ah Deca Optomer SP170", "Adeka Optomer SP172" (above, manufactured by ADEKA Co., Ltd.), "IRGACURE250" (manufactured by Chiba Specialty Chemicals), "CI-5102", "CI-2855" (above, manufactured by Nippon Soda Corporation) ), ``San-Aid SI-60L'', ``San-Aid SI-80L'', ``San-Aid SI-100L'', ``San-Aid SI-110L'', ``San-Aid SI-180L'' (above, manufactured by Sanshin Chemical), `` CPI-100P", "CPI-100A" (above, manufactured by San Apro Co., Ltd.), "WPI-069", "WPI-113", "WPI-116", "WPI-041", "WPI-044", " WPI-054", "WPI-055", "WPAG-281", "WPAG-567", and "WPAG-596" (above, manufactured by Wako Pure Pharmaceutical Co., Ltd.) can be cited as preferred specific examples of the photoacid generator of the present invention. have.

The content of the photoacid generator is 10% by mass or less, preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and particularly 0.1 to 3% by mass with respect to the total amount of the adhesive composition. desirable.

In the active energy ray-curable adhesive composition, in the active energy ray-curable adhesive composition, a photoacid generator and a compound containing either an alkoxy group or an epoxy group can be used in combination.

When a compound having one or more epoxy groups in the molecule or a polymer (epoxy resin) having two or more epoxy groups in the molecule is used, a compound having two or more functional groups having reactivity with an epoxy group may be used in combination. Here, the functional group having reactivity with the epoxy group includes, for example, a carboxyl group, a phenolic hydroxyl group, a mercapto group, and a primary or secondary aromatic amino group. It is particularly preferable to have two or more of these functional groups in one molecule in consideration of three-dimensional curability.

Examples of the polymer having one or more epoxy groups in the molecule include epoxy resins, bisphenol A type epoxy resins derived from bisphenol A and epichlorhydrin, bisphenol A bisphenol derived from bisphenol F and epichlorhydrin. F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, diphenyl ether type Epoxy resin, hydroquinone type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, polyfunctional epoxy resin such as trifunctional epoxy resin or tetrafunctional epoxy resin, glycidyl ester type epoxy There are resins, glycidylamine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, aliphatic chain type epoxy resins, and the like, and these epoxy resins may be halogenated or hydrogenated. Commercially available epoxy resin products include, for example, JER coats 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000, manufactured by Japan Epoxy Resin Co., Ltd., and Epicron manufactured by DIC Corporation. 830, EXA835LV, HP4032D, HP820, ADEKA Co., Ltd. EP4100 series, EP4000 series, EPU series, Daicel Chemical Co., Ltd. Celoxide series (2021, 2021P, 2083, 2085, 3000, etc.), Eporide series, EHPE series, YD series, YDF series, YDCN series, YDB series, phenoxy resin (polyhydroxypolyether synthesized from bisphenols and epichlorohydrin, and has epoxy groups at both ends; YP series, etc.), manufactured by Shinnittetsu Chemical Co., Ltd., Nagase The Denacol series manufactured by Chemtex Co., Ltd., and the Epolite series manufactured by Kyoeisha Chemical Co., Ltd. can be mentioned, but are not limited thereto. These epoxy resins may be used in combination of two or more.

As the compound having an alkoxyl group in the molecule, a known compound can be used without particular limitation as long as it has one or more alkoxyl groups in the molecule. As such a compound, a melamine compound, an amino resin, a silane coupling agent, etc. are mentioned as a representative.

The compounding amount of the compound containing either an alkoxy group or an epoxy group is usually 30% by mass or less with respect to the total amount of the adhesive composition, and when the content of the compound in the composition is too large, the adhesiveness decreases, and resistance to the drop test The impact property may deteriorate. The content of the compound in the composition is more preferably 20% by mass or less. On the other hand, from the viewpoint of water resistance, it is preferable to contain 2 mass% or more of the compound in the composition, and it is more preferable to contain 5 mass% or more.

In the case where the adhesive composition used in the present invention is active energy ray curable, it is preferable to use an active energy ray curable compound as the silane coupling agent, but the same water resistance can be imparted even if it is not active energy ray curable.

As a specific example of the silane coupling agent, the organosilicon compound illustrated above can be used.

The blending amount of the silane coupling agent is preferably in the range of 0.01 to 20% by mass, preferably 0.05 to 15% by mass, and more preferably 0.1 to 10% by mass with respect to the total amount of the adhesive composition. This is because, in the case of the blending amount exceeding 20% by mass, the storage stability of the adhesive composition deteriorates, and in the case of less than 0.1% by mass, the effect of the adhesion water resistance is not sufficiently exhibited.

When the adhesive composition used in the present invention contains a compound having a vinyl ether group, it is preferable because the adhesion water resistance between the polarizer and the adhesive layer is improved. The reason why such an effect is obtained is not clear, but it is presumed that one of the reasons is that the adhesive strength between the polarizer and the adhesive layer increases by interacting with the polarizer with the vinyl ether group of the compound. In order to further increase the adhesion water resistance between the polarizer and the adhesive layer, the compound is preferably a radical polymerizable compound having a vinyl ether group. Moreover, it is preferable to contain the content of a compound from 0.1 to 19 mass% with respect to the total amount of the adhesive composition.

The adhesive composition used in the present invention can contain a compound that causes keto-enol tautomerism. For example, in an adhesive composition containing a crosslinking agent or an adhesive composition that can be used by blending a crosslinking agent, an aspect containing the compound causing the keto-enol tautomerism can be preferably employed. Thereby, the effect of suppressing excessive viscosity increase, gelation, and generation of microgels of the adhesive composition after compounding of the organometallic compound, and extending the pot life of the composition can be realized.

As the compound causing the keto-enol tautomerism, various β-dicarbonyl compounds can be used. As a specific example, acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane Β-diketones such as -3,5-dione; Acetoacetate esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, and tert-butyl acetoacetate; Propionyl acetate, such as propionyl methyl acetate, propionyl ethyl acetate, propionyl isopropyl acetate, and tert-butyl propionyl acetate; Isobutyryl acetate, such as isobutyryl methyl acetate, isobutyryl ethyl acetate, isobutyl isopropyl acetate, and tert-butyl isobutyryl acetate; Malonic acid esters such as methyl malonate and ethyl malonate; And the like. Among them, preferred compounds include acetylacetone and acetoacetic acid esters. The compounds causing such keto-enol tautomerism may be used alone or in combination of two or more.

The amount of the compound causing keto-enol tautomerism is, for example, 0.05 parts by mass to 10 parts by mass, preferably 0.2 parts by mass to 3 parts by mass (e.g., 0.3 parts by mass to 2 parts by mass) based on 1 part by mass of the organometallic compound. Mass parts). If the amount of the compound is less than 0.05 parts by mass per 1 part by mass of the organometallic compound, the sufficient effect of use may not be exhibited well. On the other hand, when the used amount of the compound exceeds 10 parts by mass based on 1 part by mass of the organometallic compound, it may interact excessively with the organometallic compound, resulting in poorly expressing the desired water resistance.

Further, in the adhesive composition used in the present invention, various additives can be blended as other optional components within a range that does not impair the object and effect of the present invention. Examples of such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, Polymers or oligomers such as fluorine-based oligomers, silicone-based oligomers, and polysulfide-based oligomers; Polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; Polymerization initiation aid; Leveling agent; Wettability improving agent; Surfactants ; Plasticizer; Ultraviolet absorber; Inorganic filler; Pigment; Dyes, etc. are mentioned.

The additive is usually 0 to 10% by mass, preferably 0 to 5% by mass, and most preferably 0 to 3% by mass with respect to the total amount of the adhesive composition.

The viscosity of the adhesive composition used in the present invention is preferably 100 cp or less at 25°C from the viewpoint of coatability. On the other hand, when the adhesive composition of the present invention exceeds 100 cp at 25°C, the temperature of the adhesive composition is controlled at the time of coating, and it can be adjusted to 100 cp or less for use. A more preferable range of the viscosity is 1 to 80 cp, most preferably 10 to 50 cp. Viscosity can be measured using an E-type viscometer TVE22LT manufactured by Toki Industries, Inc.

In addition, from the viewpoint of safety, the adhesive composition used in the present invention preferably uses a material having low skin irritation as the curable component. Skin irritation can be judged by an index called P. I. I. P. I. I is widely used as indicating the degree of skin disorder, and is measured by the Draise method. The measured value is displayed in the range of 0 to 8, and the smaller the value is, the lower the stimulus is determined, but since the error of the measured value is large, it is preferable to grasp it as a reference value. P. I. I is preferably 4 or less, more preferably 3 or less, most preferably 2 or less

<polarizing film>

The polarizing film according to the present invention includes a polarizer provided on at least one surface of a durability improving layer formed of a curable composition containing a compound (A) having a carbon-carbon double bond and a cyclic skeleton. In addition, the polarizing film according to the present invention may have a transparent protective film laminated on at least one surface of the polarizer. Further, preferably, an adhesive layer is further provided between the durability improving layer and the transparent protective film. Hereinafter, a polarizing film further provided with an adhesive layer between the durability improving layer and the transparent protective film will be described as an example.

The polarizing film according to the present invention is, for example, the following manufacturing method;

The first application step of forming a durability improving layer by applying a curable composition containing at least a copolymer of compound (A) and compound (B) to the bonding surface of the polarizer, and applying the adhesive composition to the bonding surface of the transparent protective film An adhesive layer obtained by curing the adhesive composition by irradiating an active energy ray from the second application step, the bonding step of bonding the durability enhancing layer formation surface of the polarizer and the adhesive composition application surface of the transparent protective film, and the polarizer surface side or the transparent protective film side It can be produced by a method for producing a polarizing film including an adhesion step of adhering a polarizer and a transparent protective film via a polarizer.

Not only a polarizer but also a transparent protective film may be subjected to a surface modification treatment. Examples of the surface modification treatment include treatments such as corona treatment, plasma treatment, and yeast treatment, and it is particularly preferable that it is corona treatment.

As a method of applying the adhesive composition to the transparent protective film, it is appropriately selected depending on the viscosity of the adhesive composition and the desired thickness, and, for example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll A coater, a die coater, a bar coater, a rod coater, etc. are mentioned. The viscosity of the adhesive composition used in the present invention 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 adhesive composition is high, the surface smoothness after application is insufficient, resulting in poor appearance, which is not preferable. The adhesive composition used in the present invention can be applied by heating or cooling the composition to adjust the viscosity to a preferable range.

The polarizer and the transparent protective film are bonded through the adhesive composition applied as described above. The bonding of the polarizer and the transparent protective film can be performed by a roll laminator or the like.

The adhesive composition used in the present invention is preferably used as an active energy ray-curable adhesive composition. In an active energy ray curable adhesive composition, it can be used in an electron beam curing property, an ultraviolet curing property, and a visible ray curing property. The aspect of the adhesive composition is preferably a visible light-curable adhesive composition from the viewpoint of productivity.

In the active energy ray-curable adhesive composition, after bonding the polarizer and the transparent protective film, an active energy ray (electron ray, ultraviolet ray, visible ray, etc.) is irradiated to cure the active energy ray-curable adhesive composition to form an adhesive layer. The irradiation direction of an active energy ray (electron ray, ultraviolet ray, visible ray, etc.) can be irradiated from any suitable direction. Preferably, it irradiates from the transparent protective film side. When irradiated from the polarizer side, there is a fear that the polarizer is deteriorated by active energy rays (electron rays, ultraviolet rays, visible rays, etc.).

In the electron beam curability, the irradiation condition of the electron beam can be any suitable condition as long as it is a condition capable of curing the active energy ray-curable adhesive composition. For example, in electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, there is a risk that the electron beam does not reach the adhesive, resulting in insufficient curing. If the acceleration voltage exceeds 300 kV, the penetration force passing through the sample is too strong, causing damage to the transparent protective film or polarizer. There is. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive becomes insufficient in curing, and when it exceeds 100 kGy, damage is given to the transparent protective film or polarizer, resulting in a decrease in mechanical strength or yellowing, and predetermined optical properties cannot be obtained.

The electron beam irradiation is usually irradiated in an inert gas, but if necessary, it may be carried out in the atmosphere or under the condition of introducing a little oxygen. Depending on the material of the transparent protective film, it is possible to prevent damage to the transparent protective film by forcibly generating oxygen inhibition on the surface of the transparent protective film to which the electron beam first touches by appropriately introducing oxygen, so that only the adhesive is efficiently irradiated with electron beams. I can make it.

In the manufacturing method of the polarizing film according to the present invention, as the active energy ray, the active energy ray containing the visible light in the wavelength range of 380 nm to 450 nm, in particular, the active energy ray in which the irradiation amount of visible light in the wavelength range of 380 nm to 450 nm is the greatest. It is preferable to use. When using a transparent protective film (ultraviolet non-transmissive transparent protective film) imparted with ultraviolet curing properties and visible ray curing properties, light having a wavelength shorter than 380 nm is absorbed, so that light having a wavelength shorter than 380 nm is active energy. It does not reach the line-curable adhesive composition and does not contribute to the polymerization reaction. Further, light having a wavelength shorter than that of 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, causing defects such as curls and wrinkles of the polarizing film. Therefore, in the case of adopting ultraviolet curing property and visible ray curing property in the present invention, it is preferable to use a device that does not emit light with a wavelength shorter than 380 nm as an active energy ray generating device, and more specifically, a wavelength range of 380 It is preferable that it is 100:0-100:50, and it is more preferable that it is 100:0-100:40 ratio of the integrated illuminance of -440 nm and the integrated illuminance of the wavelength range 250-370 nm. As the active energy ray according to the present invention, a gallium-enclosed metal halide lamp and an LED light source emitting light in a wavelength range of 380 to 440 nm are preferable. Alternatively, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, incandescent lamps, xenon lamps, halogen lamps, carbon arc lamps, metal halide lamps, fluorescent lamps, tungsten lamps, gallium lamps, excimer lasers, ultraviolet rays and visible rays such as sunlight A light source including a may be used, and a band pass filter may be used to block ultraviolet rays having a wavelength shorter than 380 nm. In order to prevent curling of the polarizing film while improving the adhesion performance of the adhesive layer between the polarizer and the transparent protective film, a gallium-encapsulated metal halide lamp is used, and a band pass filter capable of blocking light with a wavelength shorter than 380 nm is interposed. It is preferable to use the obtained active energy ray or an active energy ray with a wavelength of 405 nm obtained using an LED light source.

In the ultraviolet curing property or visible ray curing property, heating the active energy ray-curable adhesive composition (heating before irradiation) before irradiation with ultraviolet or visible ray is preferable, and in that case, heating to 40° C. or higher is preferable, and 50° C. It is more preferable to warm above. In addition, heating the active energy ray-curable adhesive composition after irradiation with ultraviolet or visible light (heating after irradiation) is also preferable, and in that case, heating to 40°C or higher is preferable, and heating to 50°C or higher is more preferable. .

The active energy ray-curable adhesive composition used in the present invention can be particularly preferably used when forming an adhesive layer for bonding a polarizer and a transparent protective film having a light transmittance of less than 5% at a wavelength of 365 nm to form an adhesive layer. Here, the active energy ray-curable adhesive composition according to the present invention contains the photopolymerization initiator of the above-described general formula (3), so that ultraviolet rays are irradiated over the transparent protective film having UV absorption ability to cure the adhesive layer. have. Therefore, also in the polarizing film which laminated|stacked the transparent protective film which has UV absorption ability on both surfaces of a polarizer, the adhesive layer can be hardened. However, naturally, also in the polarizing film which laminated|stacked the transparent protective film which does not have UV absorbing ability, the adhesive layer can be hardened. In addition, the transparent protective film which has UV absorbing ability means the transparent protective film with the transmittance|permeability to light of 380 nm less than 10%.

As a method of imparting the UV absorbing ability to the transparent protective film, a method of including an ultraviolet absorber in the transparent protective film, or a method of laminating a surface treatment layer containing an ultraviolet absorber on the surface of the transparent protective film may be mentioned.

Specific examples of the ultraviolet absorber include, for example, conventionally known oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salt compounds, and triazine compounds. Compounds, etc. are mentioned.

After bonding the polarizer and the transparent protective film, an active energy ray (electron ray, ultraviolet ray, visible ray, etc.) is irradiated to cure the active energy ray-curable adhesive composition to form an adhesive layer. The irradiation direction of an active energy ray (electron ray, ultraviolet ray, visible ray, etc.) can be irradiated from any suitable direction. Preferably, it irradiates from the transparent protective film side. When irradiated from the polarizer side, there is a fear that the polarizer is deteriorated by active energy rays (electron rays, ultraviolet rays, visible rays, etc.).

In the case of manufacturing the polarizing film according to the present invention in a continuous line, the line speed varies depending on the curing time of the adhesive composition, but is preferably 1 to 500 m/min, more preferably 5 to 300 m/min, further preferably It is preferably 10 to 100 m/min. When the line speed is too small, productivity is insufficient, or damage to the transparent protective film is too large, and a polarizing film capable of withstanding a durability test or the like cannot be manufactured. When the line speed is too large, curing of the adhesive composition is insufficient, and the target adhesiveness may not be obtained.

In addition, in the polarizing film of the present invention, preferably, a polarizer and a transparent protective film are bonded via an adhesive layer formed by the cured product layer of the active energy ray-curable adhesive composition, but between the transparent protective film and the adhesive layer , It is possible to form a second easy-to-adhesion layer. The second easy-to-adhesion layer can be formed of various resins having, for example, a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone system, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. I can. These polymer resins can be used alone or in combination of two or more. Moreover, you may add another additive to formation of a 2nd easily bonding layer. Specifically, stabilizers such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat-resistant stabilizer may be used.

The 2nd easily bonding layer is usually formed in advance on a transparent protective film, and the 2nd easily bonding layer side of the said transparent protective film and a polarizer are bonded together by an adhesive layer. The formation of the second easy-adhesion layer is performed by coating and drying the forming material of the second easy-adhesion layer on a transparent protective film by a known technique. The material for forming the second easy-to-adhesion layer is a solution diluted to an appropriate concentration in consideration of the thickness after drying, smoothness of coating, and the like, and is usually adjusted. The thickness of the second easily bonding layer after drying is 0.01 to 5 µm, more preferably 0.02 to 2 µm, and still more preferably 0.05 to 1 µm. In addition, although a plurality of layers of the second easily bonding layer can be formed, even in this case, it is preferable that the total thickness of the second easily bonding layer is within the above range.

<Transparent protective film>

As a transparent protective film, it is preferable that it is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, and the like. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, polystyrene or acrylonitrile-styrene copolymer Styrene polymers, such as (AS resin), polycarbonate polymers, etc. are mentioned. In addition, polyethylene, polypropylene, polyolefin having a cyclo-based or norbornene structure, polyolefin-based polymer such as ethylene-propylene copolymer, vinyl chloride-based polymer, amide-based polymer such as nylon or aromatic polyamide, imide-based polymer, alcohol Pone polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, Epoxy polymers, blends of the polymers, etc. are also exemplified as examples of polymers forming the transparent protective film. One or more types of arbitrary suitable additives may be contained in the transparent protective film. Examples of the additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, releasing agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by mass, more preferably 50 to 99% by mass, still more preferably 60 to 98% by mass, particularly preferably 70 to 97% by mass. . When the content of the thermoplastic resin in the transparent protective film is 50% by mass or less, there is a fear that the high transparency inherent in the thermoplastic resin may not be sufficiently expressed.

In addition, as a transparent protective film, a polymer film described in JP 2001-343529 A (WO01/37007), for example, (A) a thermoplastic resin having a substituted and/or unsubstituted imide group in the side chain, And a resin composition containing a thermoplastic resin having a substituted and/or unsubstituted phenyl and nitrile group in the side chain. As a specific example, a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer is exemplified. As the film, a film made of a mixed extrusion product of a resin composition or the like can be used. Since these films have a small retardation and a small photoelastic coefficient, problems such as unevenness due to deformation of the polarizing film can be solved, and since the moisture permeability is small, the humidification durability is excellent.

In the polarizing film, it is preferable that the moisture permeability of the transparent protective film is 150 g/m 2 /24 h or less. According to such a configuration, moisture in the air does not easily enter the polarizing film, and a change in the moisture content of the polarizing film itself can be suppressed. As a result, curling and dimensional change of the polarizing film caused by the storage environment can be suppressed.

As the transparent protective film formed on one side or both sides of the polarizer, it is preferable to have excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc., and more preferably 150 g/m 2 /24 h or less of moisture permeability. It is particularly preferably 120 g/m 2 /24 h or less, and more preferably 5 to 70 g/m 2 /24 h or less. The moisture permeability can be calculated|required by the method described in an Example.

Examples of the material for forming the transparent protective film satisfying the low moisture permeability include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; Polycarbonate resin; Arylate resin; Amide resins such as nylon and aromatic polyamide; Polyolefin-based polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer, cyclic olefin-based resins having a cyclo-based or norbornene structure, (meth)acrylic-based resins, or mixtures thereof may be used. Among the above resins, polycarbonate resins, cyclic polyolefin resins, and (meth)acrylic resins are preferable, and cyclic polyolefin resins and (meth)acrylic resins are particularly preferable.

The thickness of the transparent protective film can be appropriately determined, but in general, 5 to 100 µm is preferable in terms of workability such as strength and handling properties, and thin layer properties. In particular, 10 to 60 µm is preferable, and 13 to 40 µm is more preferable.

As a method of bonding a polarizer and a protective film, it can implement with a roll laminator. The method of laminating a protective film on both sides of a polarizer is selected from a method of bonding a polarizer and one protective film, and then further bonding another protective film, and a method of bonding a polarizer and two protective films at the same time. It is preferable that the curled air bubbles generated at the time of bonding can be significantly reduced by employing the former method, that is, a method of bonding a polarizer and one protective film, and then further bonding another protective film.

<optical film>

The polarizing film of this invention can be used as an optical film laminated with another optical layer at the time of practical use. The optical layer is not particularly limited, but for example, a retardation film (including a wavelength plate such as 1/2 or 1/4), a visual compensation film, a luminance enhancing film, a liquid crystal display such as a reflective plate or a transflective plate What becomes an optical layer which may be used for formation of an apparatus etc. is mentioned. These optical layers can be used as a base film for a base film with an easy-to-adhesion layer in the present invention, and have reactive functional groups such as hydroxyl groups, carbonyl groups, and amino groups by performing a surface modification treatment if necessary. Therefore, on at least one surface of the retardation film containing at least a reactive functional group on the surface, an easily adhesion-treated retardation film comprising a compound represented by the general formula (1), in particular, a compound represented by the general formula (1). The retardation film or the like with the easy-adhesion layer on which the easy-adhesion layer is formed is preferable because the adhesion between the retardation film and the adhesive layer is improved, and as a result, the adhesion is particularly improved.

As the retardation film, one having a front retardation of 40 nm or more and/or a retardation in the thickness direction of 80 nm or more may be used. The front retardation is usually controlled in the range of 40 to 200 nm, and the thickness direction retardation is usually controlled in the range of 80 to 300 nm.

Examples of the retardation film include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, and a film supporting the alignment layer of a liquid crystal polymer. The thickness of the retardation film is also not particularly limited, but is generally about 20 to 150 µm.

As a retardation film, the following formulas (1) to (3):

0.70 <Re[450]/Re[550] <0.97… (One)

1.5 × 10 ^-3 <Δn <6 × 10 ^-3 … (2)

1.13 <NZ <1.50… (3)

(Wherein, Re[450] and Re[550] are the in-plane retardation values of the retardation film measured with light having a wavelength of 450 nm and 550 nm at 23° C., and Δn is the slow axis direction of the retardation film. , In-plane birefringence is nx-ny when the refractive indexes in the fast axis direction are nx and ny, respectively, and NZ is nx-nz, which is the thickness direction birefringence, and in-plane birefringence when nz is the refractive index in the thickness direction of the retardation film. It is a ratio of phosphorus nx-ny), and a reverse wavelength dispersion type retardation film may be used.

An adhesive layer for bonding to other members such as a liquid crystal cell may be formed on the above-described polarizing film or the optical film in which at least one layer of the polarizing film is laminated. The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is not particularly limited, but for example, an acrylic polymer, a silicone polymer, polyester, polyurethane, polyamide, polyether, a fluorine-based or rubber-based polymer can be appropriately selected and used as a base polymer. have. In particular, those having excellent optical transparency, appropriate wettability, cohesiveness and adhesive properties, such as an acrylic pressure-sensitive adhesive, and excellent weather resistance and heat resistance, can be preferably used.

The adhesive layer may be formed on one side or both sides of a polarizing film or an optical film as an overlapping layer of different compositions or types. Moreover, in the case of forming on both sides, it is also possible to use an adhesive layer such as a different composition, type, or thickness on the front and back of a polarizing film or an optical film. The thickness of the adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 µm, preferably 1 to 200 µm, and particularly preferably 1 to 100 µm.

With respect to the exposed surface of the adhesive layer, a separator is temporarily attached and covered for the purpose of preventing contamination or the like until it is provided for practical use. Thereby, it is possible to prevent contact with the adhesive layer in the usual handling state. As the separator, except for the above-described thickness conditions, for example, suitable thin-leaf bodies such as plastic films, rubber sheets, paper, fabrics, nonwoven fabrics, nets, foam sheets and metal foils, and laminates thereof, as required. It is possible to use suitable ones conforming to the prior art, such as those coated with a suitable release agent such as silicone-based or long-chain alkyl-based, fluorine-based or molybdenum sulfide.

<Image display device>

The polarizing film or optical film of the present invention can be preferably used for formation of various devices such as a liquid crystal display device. The formation of a liquid crystal display device can be carried out according to the prior art. That is, a liquid crystal display device is generally formed by properly assembling a liquid crystal cell, a polarizing film or an optical film, and constituent parts such as a lighting system as required, and attaching a driving circuit. However, in the present invention, according to the present invention, There is no limitation in particular except for using a polarizing film or an optical film, and it may follow conventionally. Also for the liquid crystal cell, for example, any type such as TN type, STN type, or π type can be used.

An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing film or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflector in an illumination system can be formed. In that case, the polarizing film or optical film according to the present invention can be installed on one side or both sides of a liquid crystal cell. When forming a polarizing film or an optical film on both sides, they may be the same thing or different things may be sufficient. In addition, when forming a liquid crystal display device, for example, one layer or two or more layers of appropriate parts 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, and a backlight are placed in an appropriate position. Can be placed.

Example

Examples of the present invention are described below, but the embodiments of the present invention are not limited thereto.

<polarizer>

First, a laminate in which a 9 μm-thick PVA layer was formed on an amorphous PET substrate was formed by air-assisted stretching at a stretching temperature of 130°C to produce a stretched laminate, and then, the stretched laminate was dyed. An optical film laminate comprising a 5 μm-thick PVA layer integrally stretched with an amorphous PET substrate so that the colored laminate is stretched in water with boric acid at a stretching temperature of 65 degrees so that the total draw ratio is 5.94 times. Was created. By such two-stage stretching, the PVA molecules of the PVA layer formed on the amorphous PET substrate are oriented at a high degree, and iodine adsorbed by dyeing constitutes a thin polarizer oriented at a high order in one direction as a polyiodine ion complex. An optical film laminate including a 5 µm PVA layer was obtained.

<Transparent protective film>

100 parts by mass of the imidized MS resin described in Preparation Example 1 of JP 2010-284840 A and 0.62 parts by mass of a triazine-based ultraviolet absorber (manufactured by Adeka Corporation, trade name: T-712) were mixed at 220°C with a twin-screw kneader, A resin pellet was prepared. The obtained resin pellets were dried at 100.5 kPa and 100°C for 12 hours, extruded from a T-die at a die temperature of 270°C with a single screw extruder to form a film (thickness: 160 μm). Further, the film was stretched in an atmosphere of 150° C. in the conveying direction (thickness 80 μm), and then an adhesive agent containing an aqueous urethane resin was applied, and then stretched in an atmosphere of 150° C. in the direction orthogonal to the conveying direction of the film. Thus, a transparent protective film having a thickness of 40 µm (moisture permeability 58 g/m 2 /24 h) was obtained.

<Active energy ray>

As an active energy ray, visible light (gallium-enclosed metal halide lamp) Irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc. Valve: V valve peak illuminance: 1600 mW/㎠, accumulated irradiation dose 1000/mJ/㎠ (wavelength 380 to 440 Nm) was used. In addition, the illuminance of visible light was measured using the Sola-Check system manufactured by Solatell.

(Preparation of a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A))

Ethyl acetate was put into a nitrogen-substituted container, and in the presence of 0.4 parts by mass of 2,2'-azobisisobutyronitrile, 90 mass of γ-butyrolactone acrylate (compound (A)) at 60 to 80°C while stirring Curable composition 1 containing copolymer 1 of γ-butyrolactone acrylate and 4-vinylphenylboronic acid by solution polymerization of 10 parts by mass of parts and 4-vinylphenylboronic acid (compound (B)) (polymerization rate 99.2% , Solid content 30.0 mass%) was prepared. Moreover, curable compositions 2-4 containing copolymers 2-4 were produced under the same conditions as those of copolymer 1, except that the copolymer component and the solvent to be used were changed to those described in Table 1. In Table 1;

"ΓBL" refers to "gamma butyrolactone", "FA513AS" refers to "dicyclopentanyl acrylate (manufactured by Hitachi Chemical Co., Ltd.), and "ACMO" refers to "acroylmorpholine (manufactured by KJ Chemicals Corporation).

(Adjustment of adhesive composition)

1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemicals) 3 parts by mass of IRGACURE 907 (polymerization initiator, manufactured by BASF), KAYACURE DETX-S (polymerization initiator, manufactured by Nippon Explosives) 3 The adhesive composition containing mass% was adjusted.

(Preparation of a polarizing film)

Example 1

A polarizer having a durability improving layer on one surface by applying the curable composition 1 to the PVA surface of an optical film laminate comprising a PVA layer having a thickness of 5 μm constituting a thin polarizer and air-dried at 60° C. for 2 minutes Was prepared. Next, on the bonding surface of the transparent protective film, using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires: 1000 pieces/inch, rotation speed 140%/line speed), the adhesive The composition was applied so as to have a thickness of 0.7 µm, and a transparent protective film was attached from the side of the durability improving layer of the polarizer using a roll machine. Thereafter, from the side of the bonded transparent protective film, the visible light was irradiated with an active energy ray irradiation device, and the polarizer and the transparent protective film were bonded by curing the adhesive composition, followed by hot air drying at 70° C. for 3 minutes, and the polarizer By peeling and removing the amorphous PET substrate laminated on the other side of the polarizer, a polarizing film having a transparent protective film on one side of the polarizer was obtained. The line speed of bonding was performed at 25 m/min.

(Adjustment of composition for easy adhesion)

Containing 5.1 parts by mass of acryloylmorpholine, 0.2 parts by mass of Orphine EXP4200 (manufactured by Nisshin Chemical) and 87.9 parts by mass of pure water, based on 6.9 parts by mass of the isopropyl alcohol solution of 4-vinylphenylboronic acid adjusted to 15% by mass. The composition for easy adhesion was adjusted.

<Polarizer with an easy-to-adhesive layer>

Using a wire bar (manufactured by Daiichi Ewha Corporation, No.2), the easily-adhering composition was applied to the PVA side of the optical film laminate including the PVA layer having a thickness of 5 μm of the polarizer, and 2 at 60°C. The solvent was removed by air drying for a minute to prepare a polarizer with an easy-to-adhesive layer.

Example 2

An MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure rolls: 1000 pieces/inch, rotation speed 140%/line speed) is used on the side of the easily bonding layer of the polarizer to which the easily bonding layer is attached. Then, the curable composition was applied to a thickness of 0.7 µm to form a durability improving layer. Next, using a roll machine, a polyester film (dia foil S-100 38 micrometers Mitsubishi Chemical company make) was pasted from the durability improvement layer side of the said polarizer. Thereafter, from the side of the bonded polyester film, the visible light was irradiated with an active energy ray irradiation device to cure the curable composition constituting the durability improving layer. Subsequently, by peeling the polyester film, a polarizing film made of a polarizer provided with a durability improving layer on one surface was obtained.

Comparative Example 1

MCD coater (manufactured by Fuji Machinery Co., Ltd.) (Cell shape: honeycomb, gravure roll player: 1000 pieces/inch, rotation speed 140%) on the bonding surface of the transparent protective film and the bonding surface of the polarizer with the easily bonding layer attached /Line speed), the adhesive composition was applied so as to have a thickness of 0.7 µm, and the adhesive composition coated surfaces of the polarizer and the transparent protective film were bonded together using a roll machine. Thereafter, from the side of the attached transparent protective film, the visible light was irradiated with an active energy ray irradiation device to cure the adhesive composition constituting the adhesive layer, followed by hot air drying at 70° C. for 3 minutes, and the other side of the polarizer A polarizing film having a transparent protective film on one side of the polarizer was obtained by peeling and removing the amorphous PET substrate laminated on the substrate. The line speed of bonding was performed at 25 m/min.

Comparative Example 2

In place of the curable composition, a polarizing film composed of a polarizer provided with an adhesive layer on one surface was obtained by the same method as in Example 2 except that the adhesive composition was applied.

Examples 3 to 5

In place of the curable composition 1 containing the copolymer 1, a polarizing film was obtained by the same method as in Example 1, except that the curable compositions 2 to 4 containing the copolymers 2 to 4 were used.

The following evaluation was performed about the polarizing film obtained by the said Example and the comparative example. Table 2 shows the evaluation results.

(Humidification durability test)

The transmittance and the degree of polarization of the prepared polarizing film were measured using a spectral transmittance meter with an integrating sphere (Dot-3c of Murakami Color Research Institute). In addition, the polarization degree P is the transmittance (parallel transmittance: Tp) when two identical polarizing films are superimposed so that their transmission axes are parallel to each other (parallel transmittance: Tp), and the transmittance (orthogonal transmittance: It is obtained by applying Tc) to the following equation.

Polarization P (%) = {(Tp-Tc)/(Tp + Tc)}1/2 × 100

Each transmittance is represented by a Y value obtained by correcting the visibility by a 2nd degree field of view (C light source) of JIS Z8701 with 100% of the complete polarization obtained by passing through a Glen Taylor prism polarizer. Corona treatment was performed on the polarizer surface of this polarizing film, an acrylic pressure-sensitive adhesive having a thickness of 20 μm was bonded, and the other side of the acrylic pressure-sensitive adhesive was bonded to an alkali-free glass, and the polarization degree P and transmittance of the polarization degree P based on the definition described above and the transmittance were bonded to each other. The initial value was measured. Subsequently, this polarizing film with glass was put in an environment of 60°C 95% RH for 48 hours, and the degree of polarization of the polarizing film with glass after time was measured. The value obtained by subtracting the initial degree of polarization P from the degree of polarization P after the passage of time was taken as the change of the degree of polarization. The smaller the absolute value of the change in the degree of polarization, the better the humidification durability.

Claims (20)

As a polarizer having a durability improvement layer on at least one surface,
A polarizer, wherein the durability improving layer contains at least a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A). The method of claim 1,
The durability enhancing layer is formed of a curable composition containing at least a copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) copolymerizable with the compound (A) Polarizer. The method according to claim 1 or 2,
The compound (B) is represented by the following general formula (1):

A polarizer which is a compound represented by (wherein X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group). The method according to any one of claims 1 to 3,
A polarizer in which the cyclic skeleton of the compound (A) is a heterocyclic skeleton. The method according to any one of claims 1 to 4,
A polarizer in which the cyclic skeleton of the compound (A) is a lactone skeleton. The method according to any one of claims 1 to 5,
The polarizer in which the compound (A) is γ-butyrolactone (meth)acrylate. The method according to any one of claims 1 to 6,
A polarizer in which the curable composition further contains a polymerization initiator. The method according to any one of claims 2 to 7,
A polarizer in which the durability improvement layer is formed by a cured product layer of the curable composition. A polarizing film comprising the polarizer according to any one of claims 1 to 8. The method of claim 9,
A transparent protective film is laminated on at least one surface of the polarizer,
A polarizing film in which the transparent protective film is laminated on the side of the durability improvement layer provided by the polarizer. The method of claim 10,
A polarizing film further comprising an adhesive layer between the durability improving layer and the transparent protective film. At least one polarizing film according to any one of claims 9 to 11 is laminated. An image display device, wherein the polarizing film according to any one of claims 9 to 11 or the optical film according to claim 12 is used. A copolymer of a compound (A) having a carbon-carbon double bond and a cyclic skeleton, and a compound (B) capable of copolymerizing with the compound (A). The method of claim 14,
The compound (B) is represented by the following general formula (1):

A copolymer which is a compound represented by (wherein X is a functional group containing a reactive group, and R ¹ and R ² each independently represent a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group). The method of claim 14 or 15,
A copolymer in which the cyclic skeleton of the compound (A) is a heterocyclic skeleton. The method according to any one of claims 14 to 16,
A copolymer in which the cyclic skeleton of the compound (A) is a lactone skeleton. The method according to any one of claims 14 to 17,
The copolymer in which the compound (A) is γ-butyrolactone (meth)acrylate. A curable composition containing at least the copolymer according to any one of claims 14 to 18. The method of claim 19,
In addition to the copolymer, a curable composition containing a polymerization initiator.