KR20170012321A - Polarizing plate provided with adhesive, and liquid crystal display device - Google Patents

Abstract

A polarizing plate with a pressure-sensitive adhesive, wherein the optical performance of the polarizing layer is suppressed from being lowered even when the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer contains an ionic compound. A pressure-sensitive adhesive layer comprising a polarizer layer, a first protective layer which is a cured product of a curable resin composition containing an active energy ray-curable compound, and a pressure-sensitive adhesive composition containing an ionic compound. The polarizer layer may have a second protective layer on the surface opposite to the first protective layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polarizing plate having a pressure-

The present invention relates to a polarizing plate and a liquid crystal display using the polarizing plate.

The polarizing plate is useful as one of the optical components constituting the liquid crystal display device. The polarizing plate is usually inserted and used in a liquid crystal display device in a state where a transparent resin film is laminated on both surfaces of a polarizer layer as a protective layer. In accordance with a demand for thinning of a thin film, for example, JP-A 10-186133 1) discloses a polarizing plate in which a protective layer is laminated only on one side of a polarizer layer.

In general, the polarizing plate is circulated in a state in which a pressure-sensitive adhesive layer is formed on the outermost layer and a release film is adhered on the pressure-sensitive adhesive layer. Prior to bonding to the liquid crystal cell, the release film is peeled off from the polarizing plate and bonded to the liquid crystal cell through the exposed pressure-sensitive adhesive layer. Such a polarizing plate has a problem that static electricity is generated when the release film is peeled off and bonded to the liquid crystal cell. For example, as described in JP-A-2009-251281 (Patent Document 2) , A method of imparting antistatic ability by mixing an ionic compound has been proposed.

Generally, in the polarizing plate described in Patent Document 1, a pressure-sensitive adhesive layer is laminated on the surface of the polarizer layer on which the protective layer is not laminated (the surface opposite to the surface on which the protective layer is laminated). In the pressure-sensitive adhesive composition for forming the pressure- In the case where an ionic compound is blended, there is a problem that the optical performance of the polarizer is deteriorated due to the influence of the ionic compound, particularly in the anti-wet heat test. With respect to such a problem, Japanese Patent Laid-Open Publication No. 2014-32360 (Patent Document 3), for example, discloses that performance deterioration can be suppressed by selecting the composition of the ionic compound to be blended. However, depending on the composition of the pressure-sensitive adhesive composition, due to the limitation of the ionic compound, there is a problem that compatibility is deteriorated or the adhesive force is lowered, and peeling or lifting of the polarizing plate occurs in the heat resistance test.

Patent Document 1: JP-A-10-186133 Patent Document 2: JP-A-2009-251281 Patent Document 3: JP-A-2014-32360

It is an object of the present invention to suppress the deterioration of the optical performance of the polarizer layer even when the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer contains an ionic compound.

As a result of diligent studies to achieve the above object, the present inventors have found that, between a polarizer layer and a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing an ionic compound, a curable resin containing an active energy ray- It has been found that the deterioration of the polarizer layer in a humid condition can be suppressed by providing a protective layer which is a cured product of the composition.

That is, the present invention provides, from one aspect, a pressure-sensitive adhesive layer comprising a polarizer layer, a first protective layer which is a cured product of a curable resin composition containing an active energy ray-curable compound, and a pressure- To provide a pressure-sensitive adhesive sheet with a pressure-sensitive adhesive.

In the above-mentioned polarizer with a pressure-sensitive adhesive, the polarizer layer may have a second protective layer on the surface opposite to the first protective layer. The second protective layer is preferably a transparent resin film formed of a thermoplastic resin.

It is preferable that the active energy ray-curable compound includes a cationic polymerizable compound. The cationic polymerizable compound is more preferably a compound containing a compound having at least one oxirane ring.

In addition, any of the above-mentioned active energy ray-curable compounds preferably contains a (meth) acrylic compound having at least one (meth) acryloyloxy group.

In the above-mentioned polarizer with a pressure-sensitive adhesive, the first protective layer preferably has a glass transition temperature of 23 ° C or higher, and the first protective layer preferably has a thickness of 0.1 to 10 μm, The water contact angle is preferably 60 DEG or more.

In the polarizing plate with a pressure-sensitive adhesive of the present invention, a liquid crystal cell or the like can be bonded on the pressure-sensitive adhesive layer side. Therefore, it is preferable that a release film on which the releasing treatment has been performed is laminated on the pressure-sensitive adhesive layer until use.

The above-mentioned polarizer with a pressure-sensitive adhesive may be applied to a liquid crystal cell to make a liquid crystal display device. In other words, the present invention provides, in another aspect, a liquid crystal display comprising a liquid crystal cell and a polarizer with a pressure-sensitive adhesive described above. As one of the preferable forms, for example, a polarizing plate with a pressure-sensitive adhesive is bonded to a liquid crystal cell on the pressure-sensitive adhesive layer side.

According to the present invention, even when the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing an ionic compound in which the optical characteristics of the polarizer layer are remarkably deteriorated, the thickness of the protective layer existing between the pressure- It is possible to reduce the thickness and weight of the liquid crystal display device while suppressing deterioration of the optical performance of the polarizer layer.

The polarizing plate of the present invention is laminated in the order of a polarizer layer, a first protective layer which is a cured product of a curable resin composition containing an active energy ray curable compound and a pressure sensitive adhesive layer formed of a pressure sensitive adhesive composition containing an ionic compound. If necessary, the second protective layer is laminated on the surface opposite to the surface on which the first protective layer of the polarizer layer is laminated. Herein, in the present specification, the curable resin composition containing an active energy ray-curable compound is referred to simply as a " curable resin composition " and a cured product of a curable resin composition containing an active energy ray- Cargo ", respectively. Hereinafter, each constituent member will be described.

[Polarizer layer]

The polarizer layer may be one in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol-based resin. In the present invention, the thickness of the polarizer layer is usually 30 占 퐉 or less, preferably 25 占 퐉 or less, more preferably 15 占 퐉 or less, further preferably 10 占 퐉 or less, particularly preferably 7 占 퐉 or less. On the other hand, when a polyvinyl alcohol resin layer having a dichroic dye adsorbed and oriented on the polyvinyl alcohol-based resin layer is used as the polarizer layer, the polyvinyl alcohol resin alone may be stretched, or a solution of a polyvinyl alcohol- And then stretched together with the substrate to remove the substrate. In the case of stretching together with a substrate, it is easy to produce a polarizer layer having a thickness of 7 탆 or less.

Examples of the above-mentioned substrate include a polyethylene terephthalate film, a polycarbonate film, a triacetylcellulose film, a norbornene film, a polyester film, and a polystyrene film.

As the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based resin layer, a saponified polyvinyl acetate-based resin can be used. As the polyvinyl acetate resin, a copolymer of vinyl acetate and other monomers copolymerizable therewith may be mentioned in addition to polyvinyl acetate as a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having an ammonium group, and the like.

The degree of saponification of the polyvinyl alcohol-based resin may be 80 mol% or more, preferably 90 to 99.5 mol%, and more preferably 94 to 99 mol%. When the degree of saponification is less than 80 mol%, the water resistance and the moisture resistance of the resultant polarizing plate are lowered. When the degree of saponification is more than 99.5 mol%, the dyeing speed is slowed, and the productivity is lowered, and a polarizer layer having sufficient polarization performance may not be obtained.

The degree of saponification indicates the unit ratio (mol%) of the ratio of the acetic acid group (acetoxy group: -OCOCH ₃ ) contained in the polyvinyl acetate-based resin as the raw material of the polyvinyl alcohol-based resin to the hydroxyl group by the saponification process, Is defined by the following equation. The saponification degree can be obtained in accordance with JIS K 6726: 1994 "Polyvinyl alcohol test method". The higher the degree of saponification, the higher the proportion of hydroxyl groups, and therefore the ratio of acetic acid groups which inhibit crystallization is low Respectively.

Saponification degree (mol%) = 100 占 (number of hydroxyl groups) / (number of hydroxyl groups + number of acetic acid groups)

The polyvinyl alcohol-based resin may be modified polyvinyl alcohol partially modified, and examples thereof include: olefin modification with ethylene and propylene; Unsaturated carboxylic acid modification with acrylic acid, methacrylic acid and crotonic acid; An alkyl ester of an unsaturated carboxylic acid, an acrylamide, or the like may be used. The modification ratio of the polyvinyl alcohol-based resin is preferably less than 30 mol%, more preferably less than 10%. When the modification is performed in an amount exceeding 30 mol%, the dichroic dye tends to be less likely to be adsorbed, so that a polarizer layer having sufficient polarization performance may not be obtained.

The average degree of polymerization of the polyvinyl alcohol-based resin is preferably about 100 to 10,000, more preferably 1,500 to 8,000, and still more preferably 2,000 to 5,000. The average degree of polymerization of the polyvinyl alcohol resin can also be obtained according to JIS K 6726: 1994 " Polyvinyl alcohol test method ". When the average degree of polymerization is less than 100, it tends to make it difficult to obtain the desired polarizing performance. When the average degree of polymerization exceeds 10000, the solubility in a solvent tends to deteriorate and the formation of the polyvinyl alcohol-based resin layer tends to be difficult.

In the present invention, suitable commercially available products can be used as the polyvinyl alcohol-based resin. (All saponification degree: 98 to 99 mol%) and "PVA624" (saponification degree: 95 to 96 mol%) manufactured by KURARAY CO., LTD. , "PVA 617" (saponification degree: 94.5 to 95.5 mol%); N-300 "and" NH-18 "(both having a degree of saponification of 98 to 99 mol%) and" AH-22 "(having a saponification degree of 97.5 to 98.5 mol%) manufactured by Nippon Kogaku Kagaku Kogyo Co., AH-26 "(saponification degree: 97 to 98.8 mol%); "JC-33" (saponification degree: 99 mol% or more), "JF-17", "JF-17L" and "JF-20" (both having a saponification degree of 98 to 99%) manufactured by Nippon Sakubi- JM-33 "(saponification degree: 93.5 to 95.5 mol%) and" JP-45 "(saponification degree: 86.5 to 89.5 mol%)," JM- ) And the like.

The dichroic dye contained in the polarizer layer (adsorption orientation) may be iodine or a dichroic organic dye. Specific examples of the dichroic organic dyes include red BR, red LR, red R, pink LB, Rubin BL, Bordeaux GS, sky blue LG, lemon yellow, blue BR, blue 2R, navy RY, green LG, violet LB, violet B , Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Kongogred, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Direct First Orange S, and First Black. The dichroic dye may be used alone, or two or more dichroic dyes may be used in combination.

[First protective layer]

The first protective layer laminated on one surface of the polarizer layer is composed of a cured product of the curable resin composition containing the active energy ray curable compound as described above. The active energy ray-curable compound means a compound that can be cured by irradiation with active energy rays (for example, ultraviolet rays, visible rays, electron rays, X-rays, etc.). The active energy ray-curable compound may be a compound containing a cationic polymerizable compound, a compound containing a radical polymerizable compound, or a compound containing both of them.

Examples of the cationic polymerizable compound include compounds having at least one oxirane ring in the molecule (hereinafter, sometimes simply referred to as "oxetane compound") and compounds having at least one epoxy group in the molecule (hereinafter, simply referred to as " Compound "), and the like.

Examples of the radically polymerizable compound include compounds having at least one (meth) acryloyloxy group in the molecule (hereinafter sometimes simply referred to as "(meth) acrylic compound"), at least one (meth) (Hereinafter sometimes referred to as a " (meth) acrylamide-based compound "). The term " (meth) acryloyloxy " means a methacryloyloxy group or an acryloyloxy group, and the term " (meth) acrylamide " Means a methacryloylamide group or an acryloylamide group.

Among them, when the oxetane compound and / or the (meth) acrylic compound is used, the effect of suppressing the optical performance degradation of the polarizer layer becomes remarkable.

The oxetane compound is a compound having at least one oxirane ring (4-membered ring ether) in the molecule, and examples thereof include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [ Ethyl-3-oxetanyl) benzene, 3-ethyl-3- (phenoxymethyl) oxetane, di [ Ethylhexyloxymethyl) oxetane, phenol novolac oxetane, and the like. These oxetane compounds are readily available on the market and include, for example, "Aronoxetane (registered trademark) OXT-101", "Aronoxetane (registered trademark)", OXT-121 "," Aroon Oxetan (registered trademark) OXT-211 "," Aroon Oxetan (registered trademark) OXT-221 "and" Aroon Oxetan (registered trademark) OXT-212 ".

The blending amount of the oxetane compound is not particularly limited, but is usually 90% by weight or less, preferably 20 to 80% by weight, based on the total amount of the cationic polymerizable compound. The curable resin composition may contain an epoxy compound in addition to the above oxetane compound. By adding the epoxy compound, the adhesion between the curable resin composition and the polarizer layer becomes better.

Examples of the epoxy compound include, but are not limited to, aromatic epoxy compounds, glycidyl ethers of polyols having alicyclic rings, aliphatic epoxy compounds, epoxy compounds having alicyclic epoxy compounds, and the like.

The aromatic epoxy compounds include, for example, bisphenol-type epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F and diglycidyl ether of bisphenol S; Novolak type epoxy resins such as phenol novolak epoxy resin, cresol novolak epoxy resin and hydroxybenzaldehyde phenol novolac epoxy resin; Polyfunctional epoxy resins such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, and epoxylated polyvinylphenol.

The glycidyl ether of a polyol having an alicyclic ring is a glycidyl etherified product of a hydrogenated polyhydroxy compound obtained by selectively hydrogenating an aromatic ring in an aromatic polyol under pressure in the presence of a catalyst have. Examples of the aromatic polyol include bisphenol-type compounds such as bisphenol A, bisphenol F and bisphenol S; Novolak type resins such as phenol novolak resins, cresol novolac resins and hydroxybenzaldehyde phenol novolac resins; Polyfunctional compounds such as tetrahydroxydiphenylmethane, tetrahydroxybenzophenone and polyvinylphenol, and the like. Glycidyl ether can be obtained by reacting epichlorohydrin with an alicyclic polyol obtained by hydrogenating an aromatic ring of these aromatic polyols. Of the glycidyl ethers of polyols having alicyclic rings, diglycidyl ethers of hydrogenated bisphenol A are preferred.

The aliphatic epoxy compound may be a polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof. More specifically, diglycidyl ether of 1,4-butanediol; Diglycidyl ether of 1,6-hexanediol; Triglycidyl ether of glycerin; Triglycidyl ether of trimethylolpropane; Diglycidyl ether of polyethylene glycol; Diglycidyl ether of propylene glycol; Diglycidyl ether of neopentyl glycol; And polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide or propylene oxide) to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol or glycerin.

The monofunctional epoxy compound represented by the following formula (I) is also exemplified as an aliphatic epoxy compound. R ¹ is an alkyl group having 1 to 15 carbon atoms. The alkyl group may be linear or branched when the number of carbon atoms is 3 or more. The alkyl group preferably has a relatively long chain, for example, a carbon number of 6 or more, and more preferably a carbon number of 6 to 10. Among them, it is preferably branched alkyl group. As a typical example of the monofunctional epoxy compound represented by the formula (I), 2-ethylhexyl glycidyl ether may be mentioned.

The alicyclic epoxy compound is a compound having at least one epoxy group bonded to an alicyclic ring in the molecule. Here, the "epoxy group bonded to the alicyclic ring" means a bridging oxygen atom -O- in the structure represented by the following formula (II), wherein n is an integer of 2 to 5.

A compound in which one or more hydrogen atoms of (CH ₂ ) _n in the formula (II) are removed from other groups bonded to another chemical structure may be an alicyclic epoxy compound. In addition, one or plural hydrogen atoms of (CH ₂ ) _n forming an alicyclic ring may be appropriately substituted with a straight chain alkyl group such as a methyl group or an ethyl group.

Of the above epoxy compounds, alicyclic epoxy compounds, that is, compounds in which at least one of the epoxy groups is bonded to the alicyclic ring are preferable. Especially, epoxycyclohexane (n = 4 in the formula (II) The epoxy compound having heptane (n = 5 in the above formula (II)) is more preferably used since it has a high modulus of elasticity of the cured product of the curable resin composition and easily obtains a protective layer excellent in adhesion to the polarizer layer. Specific examples of the alicyclic epoxy compound are given below. Here, the compound names are given first, and then the corresponding chemical formulas are shown. The compound names and the corresponding chemical formulas are given the same reference numerals.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-

B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate,

C: Ethylene bis (3,4-epoxycyclohexanecarboxylate),

D: bis (3,4-epoxycyclohexylmethyl) adipate,

E: bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate,

F: diethylene glycol bis (3,4-epoxycyclohexylmethyl ether),

G: ethylene glycol bis (3,4-epoxycyclohexylmethyl ether),

H: 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispyro [5.2.2.5.2.2] heneic acid,

I: 3- (3,4-epoxycyclohexyl) -8,9-epoxy-1,5-dioxaspiro [5.5] undecane,

J: 4-vinylcyclohexene dioxide,

K: limonene dioxide,

L: bis (2,3-epoxycyclopentyl) ether,

M: dicyclopentadiene dioxide.

In the curable resin composition, the epoxy compound may be used alone, or two or more epoxy compounds may be used in combination.

The compounding amount of the epoxy compound is not particularly limited, but is usually 90% by weight or less, preferably 20 to 80% by weight, based on the total amount of the cationic polymerizable compound. In addition, the amount of the cationic polymerizable compound is usually 100% by weight or less, preferably 30 to 90% by weight, based on the total amount of the active energy ray-curable compound.

When the curable resin composition contains a cationic polymerizable compound such as an oxetane compound or an epoxy compound as an active energy ray curable compound, a cadmium ion polymerization initiator is usually incorporated in the curable resin composition. The use of a photocationic polymerization initiator makes it possible to form a protective layer at room temperature, so that it is possible to form a first protective layer on the polarizer layer with good adhesiveness by reducing the need to consider the heat resistance and distortion caused by expansion of the polarizer layer have. Also, since the photocationic polymerization initiator acts catalytically with light, it is excellent in storage stability and workability even when it is mixed with the curable resin composition.

The cationic ionic polymerization initiator generates a cationic species or Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray and electron beam to initiate the polymerization reaction of the cationic polymerizable compound. Any of the types of photocationic polymerization initiators may be used, and specific examples thereof include aromatic diazonium salts; Onium salts such as aromatic iodonium salts and aromatic sulfonium salts; Iron-arene complexes and the like.

Examples of the aromatic diazonium salt include the following compounds.

Benzene diazonium hexafluoroantimonate, benzene diazonium hexafluoroantimonate,

Benzene diazonium hexafluorophosphate,

Benzene diazonium hexafluoroborate and the like.

Examples of the aromatic iodonium salt include the following compounds.

Diphenyl iodonium tetrakis (pentafluorophenyl) borate,

Diphenyl iodonium hexafluorophosphate,

Diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate,

Di (4-nonylphenyl) iodonium hexafluorophosphate, and the like.

Examples of the aromatic sulfonium salt include the following compounds.

Triphenylsulfonium hexafluorophosphate,

Triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate,

Triphenylsulfonium tetrakis (pentafluorophenyl) borate,

4,4'-bis [diphenylsulfonio] diphenylsulfide bis hexafluorophosphate,

4,4'-bis [di (beta -hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluoroantimonate,

4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluorophosphate,

7- (di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate,

7- (di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate,

4-phenylcarbonyl-4'-diphenylsulfone-diphenylsulfide hexafluorophosphate,

4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate,

4- (p-tert-butylphenylcarbonyl) -4'-di (p-toluyl) sulfonio-diphenylsulfide tetrakis (pentafluorophenyl) borate and the like.

Examples of the iron-arene complexes include the following compounds.

Xylene-cyclopentadienyl iron (II) hexafluoroantimonate,

Cumene-cyclopentadienyl iron (II) hexafluorophosphate,

Xylene-cyclopentadienyl iron (II) tris (trifluoromethylsulfonyl) methanide, and the like.

These cationic ion polymerization initiators can be easily obtained from commercial products. For example, "KAYARAD (registered trademark) PCI-220" and "KAYARAD (registered trademark)", which are trade names of Nippon Kayaku Co., UVI-6990 " sold by Dow Chemical Co., Ltd., "UVACURE 1590" sold by Daicel Cytech Co., Ltd., Adeka Optoma CI-5102 "," CIT-1370 "," CIT-1682 ", and" CIP-1682 "sold by Nippon Soda Co., DPI-101 "," DPI-102 "," DPI-103 "," DPI-105 ", and" DPI-2064S "sold by Midori Kagaku Co., MPI-103, MPI-105, BBI-101, BBI-102, BBI-103, BBI-105, TPS-101, TPS- 103 "," TPS-105 "," MDS-103 "," MDS-105 "," DTS-102 "and" DTS-103 "and" PI-2074 "sold by Rhodia.

These photo cationic polymerization initiators may be used alone or in combination of two or more. Among them, the aromatic sulfonium salt has an ultraviolet ray absorbing property even in the wavelength region of 300 nm or more, and thus can give a cured product of the curable resin composition having excellent mechanical strength and good adhesion with the polarizer layer , Are preferably used.

The blending amount of the photocationic polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, based on 100 parts by weight of the total amount of the cationic polymerizable compound including an epoxy compound and an oxetane compound. If the blending amount of the photocationic polymerization initiator is small, the curing becomes insufficient, and the mechanical strength and the adhesion between the first protective layer and the polarizer layer tend to be lowered. On the other hand, if the blending amount of the photocationic polymerization initiator is too large, there is a possibility that the optical performance of the polarizer layer is lowered.

When the curable resin composition contains a radically polymerizable compound as an active energy ray curable compound, the radical polymerizable compound may be, for example, a (meth) acrylic compound or a (meth) acrylamide compound. The (meth) acrylic compound is a compound obtained by reacting two or more kinds of (meth) acrylate monomers having at least one (meth) acryloyloxy group in the molecule or a compound having a functional group, and at least two (meth) (Meth) acrylate oligomer having an acryloyloxy group and the like. These may be used alone, or two or more of them may be used in combination. When two or more (meth) acrylic compounds are used in combination, two or more (meth) acrylate monomers may be used, and two or more (meth) acrylate oligomers may be used. Of course, And (meth) acrylate oligomers may be used in combination. Here, "(meth) acrylate" means methacrylate or acrylate.

Examples of the (meth) acrylate monomer include monofunctional (meth) acrylate monomers having one (meth) acryloyloxy group in the molecule, bifunctional (meth) acryloyloxyalkyl groups having two (meth) acryloyloxy groups in the molecule, (Meth) acrylate monomers having three or more (meth) acryloyloxy groups in the molecule.

Specific examples of monofunctional (meth) acrylate monomers include tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, (Meth) acrylate, ethyl (meth) acrylate, isobutyl (meth) acrylate, isobutyl (meth) acrylate, Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert- (Meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclohexyl (meth) acrylate, ) Acrylate, phenoxyethyl (meth) acrylate, Acrylate, dicyclopentenyloxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, ethylcarbitol (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (Meth) acrylate, and phenoxypolyethylene glycol (meth) acrylate.

As the mono-functional (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer may be used. Examples of the monofunctional (meth) acrylate monomer containing a carboxyl group include 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, carboxyethyl (meth) Methacryloyloxyethyl succinic acid, N- (meth) acryloyloxy-N ', N'-dicarboxymethyl-p-phenylenediamine and 4- (meth) acryloyloxyethyltrimellitic acid. .

As the (meth) acrylamide-based compound, N-substituted (meth) acrylamide may be used. N-substituted (meth) acrylamide is a (meth) acrylamide having a substituent at the N-position. A typical example of the substituent is an alkyl group which may be further substituted, and may form a ring together with the nitrogen atom of the (meth) acrylamide. The ring may have, in addition to the carbon atom and the nitrogen atom of the (meth) acrylamide , And an oxygen atom may be contained as a ring member. A substituent such as alkyl or oxo (= O) may be bonded to the carbon atom constituting the ring. N-substituted (meth) acrylamides can generally be prepared by the reaction of (meth) acrylic acid or its chloride with a primary or secondary amine.

The N-substituted (meth) acrylamide is preferably represented by the following formula (III). Q ¹ represents a hydrogen atom or a methyl group, Q ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Q ³ represents an alkyl group having 1 to 6 carbon atoms, which may have a hydroxyl group or an amino group. Or Q ² and Q ³ become one to form a 5-membered ring or a 6-membered ring, which may have an oxygen atom as a ring member, together with the nitrogen atom to which they are bonded. When Q ² is an alkyl group and Q ³ is an alkyl group which may have a hydroxyl group or an amino group, each alkyl group may be linear or branched if it has 3 or more carbon atoms. And Q ³ is an alkyl group having a hydroxyl group, such as a hydroxyalkyl group. Examples of the alkyl group having Q ³ in the amino group include an aminoalkyl group, an N-alkylaminoalkyl group and an N, N-dialkylaminoalkyl group. When Q ² and Q ³ are taken together to form a 5-membered or 6-membered ring, which may have an oxygen atom as a ring member, together with the nitrogen atom to which they are bonded, (C ₄ H ₈ N-), 2-oxazolidinone-3-yl [C ₂ H ₄ OC (= O) N- , Piperidino (C ₅ H ₁₀ N-), morpholino (C ₂ H ₄ OC ₂ H ₄ N-), and the like.

Specific examples of the N-substituted (meth) acrylamides corresponding to the above formula (III) wherein Q ² is a hydrogen atom and Q ³ is an alkyl group include N-methyl (meth) acrylamide, N- Amide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide and N-hexyl (meth) acrylamide. Similarly, specific examples of N-substituted (meth) acrylamides wherein Q ² and Q ³ together are an alkyl group include N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and the like.

Examples of N-substituted (meth) acrylamides wherein Q ² is a hydrogen atom and Q ³ is an alkyl group having a hydroxyl group include N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) Methacrylamide, N- (2-hydroxypropyl) (meth) acrylamide, and the like. Similarly, specific examples of N-substituted (meth) acrylamides in which Q ² is a hydrogen atom and Q ³ is an alkyl group having an amino group are N- [2- (N, N-dimethylamino) ethyl] (meth) (Meth) acrylamide, N- [3- (N, N-dimethylamino) propyl] -1- (N, N-dimethylamino) ethyl] (meth) acrylamide.

Specific examples of N-substituted (meth) acrylamides in which Q ² and Q ³ in the formula (III) are combined to form a 5-membered ring or a 6-membered ring together with the nitrogen atom to which they are bonded are N- Acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine and the like.

Of the above N-substituted (meth) acrylamides, N-hydroxyalkyl (meth) acrylamides such as N-hydroxymethylacrylamide and N- (2-hydroxyethyl) acrylamide, N, N, N-dialkyl (meth) acrylamides such as acrylamide and N, N-diethylacrylamide are preferred and N- (2-hydroxyethyl) acrylamide or N, N- Do.

In addition, N-alkyl (meth) acrylamides having long chain alkyl such as N-dodecyl (meth) acrylamide, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) N- (alkoxyalkyl) (meth) acrylamides such as (propoxymethyl) acrylamide and N- (butoxymethyl) acrylamide can also be used as N-substituted (meth) acrylamides constituting active energy ray- have.

Examples of the bifunctional (meth) acrylate monomer include alkylene glycol di (meth) acrylate, polyoxyalkylene glycol di (meth) acrylate, halogen substituted alkylene glycol di (meth) acrylate, ) Di (meth) acrylates of di (meth) acrylate, hydrogenated dicyclopentadiene or tricyclodecanedialcohol, di (meth) acrylates of dioxane glycol or dioxanedialanol, alkylene oxide adducts of bisphenol A or bisphenol F Di (meth) acrylate of water, epoxy di (meth) acrylate of bisphenol A or bisphenol F, and the like.

More specific examples of the bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) (Meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylol propane di (meth) acrylate, pentaerythritol di (meth) acrylate, (Meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, dipropylene glycol di ) Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, silicone di (meth) acrylate, (Meth) acryloyloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxy Acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,3-dioxane-2,5-diyl di (meth) acrylate, hydrogenated dicyclopentadienyl di (meth) Acrylate (trade name: dioxane glycol di (meth) acrylate), acetal compound of hydroxypivalaldehyde and trimethylolpropane (chemical name: 2- (2-hydroxy- 1,1-dimethylethyl) Di (meth) acrylate, tris (hydroxyethyl) isocyanurate di (meth) acrylate of bis (hydroxymethyl) -1,3-dioxane].

Examples of the trifunctional or higher polyfunctional (meth) acrylate monomer include glycerin tri (meth) acrylate, trimethylol propane tri (meth) acrylate, ditrimethylol propane tri (meth) acrylate, ditrimethylol propane tetra Acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, (Meth) acrylate of trifunctional or higher aliphatic polyols such as tri (meth) acrylate of trifunctional or higher halogen substituted polyol, tri (meth) acrylate of alkylene oxide adduct of glycerin, trimethyl Tri (meth) acrylates of alkylene oxide adducts of olpropane, 1,1,1-tris [ (Meth) acryloyloxyethoxyethoxy] propane, and tris (hydroxyethyl) isocyanurate tri (meth) acrylates.

On the other hand, (meth) acrylate oligomers include urethane (meth) acrylate oligomers, polyester (meth) acrylate oligomers and epoxy (meth) acrylate oligomers.

Urethane (meth) acrylate oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth) acryloyloxy groups in the molecule. Specifically, the urethane reaction product of a hydroxyl group-containing (meth) acrylate monomer having at least one (meth) acryloyloxy group and at least one hydroxyl group in the molecule and a polyisocyanate, or a reaction product of a polyol with a polyisocyanate (Meth) acrylate monomers each having at least one (meth) acryloyloxy group and at least one hydroxyl group in the molecule, and the like can be used as the urethanization reaction product of the isocyanato group-containing urethane compound.

Examples of the hydroxyl group-containing (meth) acrylate monomers used in the urethanization reaction include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, And the like.

Examples of the polyisocyanate used in the urethanization reaction with such a hydroxyl group-containing (meth) acrylate monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate Diisocyanates such as hydrogenated tolylene diisocyanate and hydrogenated xylylene diisocyanate obtained by hydrogenating an aromatic isocyanate in these diisocyanates, di- or diisocyanates such as triphenylmethane triisocyanate, dibenzylbenzene triisocyanate and the like Triisocyanate and a polyisocyanate obtained by mass-increasing the above-mentioned diisocyanate.

In addition to the aromatic, aliphatic and alicyclic polyols, polyester polyols, polyether polyols and the like can be used as the polyols used for forming the terminal isocyanato group-containing urethane compound by the reaction with the polyisocyanate. Examples of the aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, ditrimethylol Propylene, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, hydrogenated bisphenol A, and the like.

The polyester polyol is obtained by a dehydration condensation reaction between the polyol and the polybasic carboxylic acid or an anhydride thereof. (Anhydrous) succinic acid, adipic acid, (maleic anhydride) maleic acid, (anhydride) itaconic acid, (anhydrous) maleic anhydride, Trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and hexahydro (phthalic) phthalic acid.

The polyether polyol may be a polyoxyalkylene-modified polyol obtained by the reaction of the aforementioned polyols or dihydroxybenzenes with an alkylene oxide in addition to the polyalkylene glycol.

The polyester (meth) acrylate oligomer is a compound having an ester bond in the molecule and at least two (meth) acryloyloxy groups. Specifically, it can be obtained by a dehydration condensation reaction using (meth) acrylic acid, a polybasic carboxylic acid or an anhydride thereof, and a polyol. (Anhydrous) succinic acid, adipic acid, (maleic anhydride) maleic acid, (anhydride) maleic acid, and maleic anhydride may be represented by an example of an anhydride carboxylic acid or its anhydride, (Anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and the like can be given as examples of the acid anhydride, itaconic acid, anhydrous trimellitic acid, (anhydrous) pyromellitic acid, hexahydrophthalic anhydride, Examples of the polyol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, Ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, hydrogenated bisphenol A, and the like.

The epoxy (meth) acrylate oligomer can be obtained by an addition reaction of polyglycidyl ether and (meth) acrylic acid, and has at least two (meth) acryloyloxy groups in the molecule. Examples of the polyglycidyl ether used in the addition reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether, and the like. On the basis of the entire active energy ray-curable compound, the blending amount of the radical polymerizable compound is usually 100% by weight or less, preferably 10 to 70% by weight.

When the curable resin composition contains a radically polymerizable compound as an active energy ray curable compound, it is preferable that a photo radical polymerization initiator is blended. As the photo radical polymerization initiator, any one capable of initiating polymerization of a radically polymerizable compound such as a (meth) acrylic compound by irradiation of active energy rays such as visible light, ultraviolet light, X-ray and electron beam can be used. have. Specific examples of the photoradical polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxypropyl- Acetophenone based initiators such as -1- [4- (methylthio) phenyl-2-morpholinopropane-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; Benzophenone based initiators such as benzophenone, 4-chlorobenzophenone and 4,4'-diaminobenzophenone; Benzoin ether initiators such as benzoin propyl ether and benzoin ethyl ether; Thioxanthone initiators such as 4-isopropylthioxanthone; In addition, there are xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, and the like.

These photo radical polymerization initiators can be easily obtained from commercial products, and examples thereof include "IRGACURE (registered trademark) 184", "IRGACURE (registered trademark) 907", "DAROCURE (Registered trademark) 1173 "and" Lucirin (registered trademark) TPO ".

The compounding amount of the photo radical polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, based on 100 parts by weight of the total amount of the radically polymerizable compound such as a (meth) acrylic compound. If the blending amount of the photo radical polymerization initiator is small, the curing becomes insufficient, and the mechanical strength and adhesion between the protective layer and the polarizer layer tend to decrease. If the blending amount of the photo radical polymerization initiator is too large, the active energy ray-curable compound in the curable resin composition becomes relatively small, and the durability of the obtained optical polarizer may deteriorate.

The curable resin composition may be used in combination with the above-mentioned oxetane compound, oxetane compound or epoxy compound and the above-mentioned (meth) acrylic compound which is a radical polymerization. By using these in combination, the effect of increasing the hardness and mechanical strength of the first protective layer can be expected, and further, the viscosity and the curing speed of the curable resin composition can be further easily adjusted.

(Other components)

The curable resin composition may further contain a photosensitizer, if necessary. By adding the photosensitizer, the reactivity of the cationic polymerization and / or the radical polymerization becomes high, so that the mechanical strength of the protective layer and the adhesion between the protective layer and the polarizer layer can be improved. Examples of the photosensitizer include a carbonyl compound, an organic sulfur compound, a persulfate, a redox compound, an azo and diazo compound, a halogen compound, a photoreducible dye, and the like.

A known polymer additive commonly used in polymers may be added to the curable resin composition. Examples of the polymer additive include, for example, primary antioxidants such as phenol type and amine type, secondary antioxidants of sulfur type, hindered amine type light stabilizers (HALS), ultraviolet absorbers such as benzophenone type, benzotriazole type and benzoate type, .

Fine particles of silica may be added to the above-mentioned curable resin composition. By adding silica fine particles, the hardness and mechanical strength of the obtained protective layer can be further improved. The fine silica particles can be blended in the curable resin composition as a liquid material dispersed in, for example, an organic solvent.

The silica fine particles may have a reactive functional group such as a hydroxyl group, an epoxy group, a (meth) acryloyl group, or a vinyl group on the surface thereof. The particle size of the fine silica particles is usually 100 nm or less, preferably about 5 to 50 nm. When the particle size of the fine particles exceeds 100 nm, there is a tendency that an optically transparent protective layer can not be obtained.

When silica fine particles dispersed in an organic solvent are used, the silica concentration is not particularly limited, and a commercially available product such as about 20 to 40% by weight can be used.

The curable resin composition may contain a solvent as required. The solvent is appropriately selected in consideration of the solubility of the components constituting the curable resin composition. Examples of common solvents include aliphatic hydrocarbons such as n-hexane and cyclohexane; Aromatic hydrocarbons such as toluene and xylene; Alcohols such as methanol, ethanol, propanol, isopropanol and n-butanol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as methyl acetate, ethyl acetate and butyl acetate; Cellosolve such as methylcellosolve, ethylcellosolve and butylcellosolve; And halogenated hydrocarbons such as methylene chloride and chloroform. The blending ratio of the solvent is appropriately determined in view of viscosity adjustment depending on processing purposes such as film forming properties.

Further, the curable resin composition may contain a leveling agent as required. When the curable resin composition is coated on a polarizing film or a substrate, when the wettability on the polarizing film or substrate is insufficient or when the surface property of the cured product of the curable resin composition is poor, these can be improved by adding a leveling agent. As the leveling agent, various compounds such as a silicone type, a fluorine type, a polyether type, an acrylic acid copolymer type and a titanate type can be used. These leveling agents may be used alone or in combination of two or more.

The leveling agent is preferably added in an amount of 0.01 to 1 part by weight, more preferably 0.1 to 0.7 part by weight, and still more preferably 0.2 to 0.5 part by weight, based on 100 parts by weight of the active energy ray-curable compound contained in the curable resin composition to be. If the amount is less than 0.01 part by weight, improvement in wettability and surface properties tends to be insufficient. If the amount is more than 1 part by weight, the adhesion between the polarizing film and the protective layer tends to deteriorate.

The first protective layer, which is a cured product of the curable resin composition containing the active energy ray-curable compound, preferably has a glass transition temperature (Tg) of 23 ° C or higher, more preferably 40 ° C or higher, , And particularly preferably 60 ° C or higher. If the glass transition temperature of the first protective layer is less than 23 占 폚, suppression of deterioration of optical performance of the polarizer layer tends to be insufficient. The glass transition temperature can be measured by differential scanning calorimetry (DSC).

The thickness of the first protective layer is preferably 0.1 to 10 占 퐉, more preferably 1 to 5 占 퐉, and further preferably 1.5 to 3 占 퐉. When the thickness of the first protective layer is less than 0.1 탆, the durability and the deterioration of the optical performance may be insufficient. On the other hand, when the thickness exceeds 10 탆, the effect of reducing the thickness of the polarizing plate may be small.

The first protective layer preferably has a water contact angle of 60 ° or more, more preferably 60 ° to 95 °, and still more preferably 60 ° to 80 °. If the water contact angle of the first protective layer is less than 60 °, the suppression of the deterioration of the optical performance may be insufficient. On the other hand, when the water contact angle exceeds 95 °, the adhesion with the polarizer tends to be insufficient. A method of forming the first protective layer using the curable resin composition will be described later.

[Pressure sensitive adhesive layer]

In the present invention, a pressure-sensitive adhesive layer is formed on the surface of the first protective layer opposite to the polarizer layer. The polarizing plate with a pressure-sensitive adhesive of the present invention can be bonded to, for example, a liquid crystal cell through such a pressure-sensitive adhesive layer. As the pressure-sensitive adhesive (composition) for forming the pressure-sensitive adhesive layer, an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyether or the like may be used as the base polymer. Among them, those which have excellent optical transparency and adhesiveness, maintain appropriate wettability and cohesive force, have weather resistance and heat resistance, and do not cause peeling problems such as lifting and peeling under the conditions of heating and humidification It is preferable to use them selectively. In the acrylic pressure-sensitive adhesive, it is preferable to use a copolymer of an alkyl ester of (meth) acrylic acid having an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group and a butyl group and an acrylic monomer containing a functional group comprising (meth) acrylic acid or (meth) An acrylic copolymer having a weight average molecular weight of 100,000 or more blended so as to have a glass transition temperature of preferably 25 占 폚 or lower, more preferably 0 占 폚 or lower is useful as a base polymer.

The pressure-sensitive adhesive layer can be formed, for example, by dissolving or dispersing the above-mentioned pressure-sensitive adhesive composition including the base polymer in an organic solvent such as toluene or ethyl acetate to prepare a solution of 10 to 40% by weight and forming a pressure- , And a method of forming a pressure-sensitive adhesive layer by transferring it onto a transparent resin film or the like. In addition to the above base polymer, a cross-linking agent is generally added to the pressure-sensitive adhesive. In the case where bonding to the liquid crystal cell is intended, it is also preferable to blend a silane coupling agent. The thickness of the pressure-sensitive adhesive layer is determined depending on the adhesive strength and the like, but is usually in the range of 1 to 50 占 퐉.

In the present invention, a pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing an ionic compound. The ionic compound is composed of a cation component (organic cation or inorganic cation) and an anion component (organic anion or inorganic anion). Hereinafter, examples of the structure of the organic cation with respect to the ionic compound having an organic cation are as follows.

Pyridinium salts:

1-butylpyridinium tetrafluoroborate,

1-butylpyridinium hexafluorophosphate,

1-butyl-3-methylpyridinium tetrafluoroborate,

1-butyl-3-methylpyridinium trifluoromethanesulfonate,

1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide,

1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) imide,

1-butyl-4-methylpyridinium hexafluorophosphate,

1-hexylpyridinium tetrafluoroborate,

1-hexylpyridinium hexafluorophosphate,

1-hexyl-4-methyl-pyridinium bis (fluorosulfonyl) imide,

1-octylpyridinium hexafluorophosphate,

1-butylpyridinium N- (trifluoromethanesulfonyl) trifluoroacetamide,

1-butyl-3-methylpyridinium N- (trifluoromethanesulfonyl) trifluoroacetamide and the like.

Imidazolium salt:

Ethyl-3-methylimidazolium tetrafluoroborate,

1-ethyl-3-methylimidazolium hexafluorophosphate,

Ethyl-3-methylimidazolium acetate,

Ethyl-3-methylimidazolium trifluoroacetate,

1-ethyl-3-methylimidazolium heptafluorobutyrate,

1-ethyl-3-methylimidazolium trifluoromethanesulfonate,

1-ethyl-3-methylimidazolium perfluorobutanesulfonate,

1-ethyl-3-methylimidazolium p-toluenesulfonate,

1-ethyl-3-methylimidazolium dicyanamide,

1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide,

1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl) imide,

1-ethyl-3-methylimidazolium tris (trifluoromethanesulfonyl) methanide,

1-ethyl-3-methylimidazolium N- (trifluoromethanesulfonyl) trifluoroacetamide,

1-butyl-3-methylimidazolium methanesulfonate,

1-butyl-3-methylimidazolium tetrafluoroborate,

1-butyl-3-methylimidazolium hexafluorophosphate,

1-butyl-3-methylimidazolium trifluoroacetate,

1-butyl-3-methylimidazolium heptafluorobutyrate,

1-butyl-3-methylimidazolium trifluoromethanesulfonate,

1-butyl-3-methylimidazolium perfluorobutanesulfonate,

1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide,

1-hexyl-3-methylimidazolium bromide,

1-hexyl-3-methylimidazolium chloride,

1-hexyl-3-methylimidazolium tetrafluoroborate,

1-hexyl-3-methylimidazolium hexafluorophosphate,

1-hexyl-3-methylimidazolium trifluoromethanesulfonate,

1-octyl-3-methylimidazolium tetrafluoroborate,

1-octyl-3-methylimidazolium hexafluorophosphate,

1-hexyl-2,3-dimethylimidazolium tetrafluoroborate,

1,2-dimethyl-3-propylimidazolium bis (trifluoromethanesulfonyl) imide and the like.

Pyrrolidinium salt:

1-butyl-1-methylpyrrolidinium hexafluorophosphate and the like.

Quaternary ammonium salts:

Tetrabutylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate,

Tetrabutylammonium p-toluenesulfonate,

Tetrahexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate,

N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl)

Diallyldimethylammonium tetrafluoroborate,

Diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium trifluoromethanesulfonate,

Diallyldimethylammonium bis (trifluoromethanesulfonyl) imide,

Diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide,

Diallyldimethylammonium N- (trifluoromethanesulfonyl) trifluoroacetamide,

Glycidyl trimethyl ammonium trifluoromethanesulfonate,

Glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide,

Glycidyl trimethyl ammonium bis (pentafluoroethanesulfonyl) imide,

Glycidyltrimethylammonium N- (trifluoromethanesulfonyl) trifluoroacetamide,

N, N-dimethyl-N-ethyl-N-propylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl)

N, N-dimethyl-N-ethyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl)

N, N-dimethyl-N-ethyl-N-nonylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-propyl-N-butylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl)

N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl)

N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N-butyl-N-heptylammonium bis (trifluoromethanesulfonyl)

N, N-dimethyl-N-pentyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dimethyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide,

Trimethylheptylammonium bis (trifluoromethanesulfonyl) imide,

N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide,

N, N-diethyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide,

N, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide,

N, N-diethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide,

Triethylpropylammonium bis (trifluoromethanesulfonyl) imide,

Triethylpentylammonium bis (trifluoromethanesulfonyl) imide,

Triethylheptylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dipropyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dipropyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl)

N, N-dibutyl-N-methyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide,

Trioctylmethylammonium bis (trifluoromethanesulfonyl) imide,

Trioctylmethylammonium hexafluorophosphate,

N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl)

(2-hydroxyethyl) trimethylammonium bis (trifluoromethanesulfonyl) imide,

(2-hydroxyethyl) trimethylammonium dimethylphosphinate and the like.

Examples of ionic compounds having inorganic cations include the following.

Lithium bromide,

Lithium iodide,

Lithium tetrafluoroborate,

Lithium hexafluorophosphate,

Lithium thiocyanate,

Lithium perchlorate,

Lithium trifluoromethanesulfonate,

Lithium bis (trifluoromethanesulfonyl) imide,

Lithium bis (pentafluoroethanesulfonyl) imide,

Lithium tris (trifluoromethanesulfonyl) methanide,

Potassium bis (fluorosulfonyl) imide and the like.

The ionic compounds having organic cations and inorganic cations have counter ions (anions), respectively, as exemplified above. Regarding the anion, an organic anion or an inorganic anion may be used as described above. Specific examples thereof include those described in the ionic compounds exemplified above.

These ionic compounds may be used alone or in combination of two or more.

When the anionic component constituting the ionic compound is hexafluorophosphate, the performance of the polarizer layer tends to be markedly deteriorated in particular. In the polarizing plate with a pressure-sensitive adhesive of the present invention, even when a pressure-sensitive adhesive composition comprising such an ionic compound is employed, the performance of the polarizing layer can be effectively suppressed by the first protective layer.

The pressure-sensitive adhesive may be blended with a filler, pigment, colorant, antioxidant, ultraviolet absorber or the like, which is composed of inorganic powder such as glass fiber, glass bead, resin bead or metal powder, if necessary. Examples of the ultraviolet absorber include a salicylate ester compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex salt compound.

[Second protective layer]

The second protective layer is laminated on the surface of the polarizer layer opposite to the side where the first protective layer is laminated. As the second protective layer, conventionally used materials for forming a protective layer such as a cellulose acetate resin, a cycloolefin resin, a polyolefin resin, an acrylic resin, a polyimide resin, a polycarbonate resin and a polyester resin A thermoplastic resin film made of a suitable material widely used can be used without particular limitation. The second protective layer may be composed of a cured product of a curable resin composition containing an active energy ray-curable compound similarly to the first protective layer. From the viewpoints of mass productivity and adhesion, it is preferable to use a cellulose acetate resin film or a cycloolefin resin film as the second protective layer. Further, from the viewpoint of ease of installation of the surface treatment layer and optical characteristics, it is more preferable to use a cellulose acetate resin film as the second protective layer.

The cellulose acetate-based resin film that can be suitably used as the second protective layer in the present invention is a film made of a cellulose part or a completely acetic acid esterified product, and examples thereof include a triacetyl cellulose film, a diacetyl cellulose film, .

As such cellulose acetate based resin film, suitable commercially available products can be used. Suitable commercially available products include, for example, "Fuji ™ (registered trademark) TD80", "Fuji ™ (registered trademark) TD80UF", "Fuji ™ (registered trademark) TD80UZ", Konica Minolta Opt Quot; KC8UX2M "and" KC8UY "(all of which are trade names).

The cycloolefin-based resin which can be suitably used for the second protective layer is, for example, a thermoplastic resin having a unit of a monomer composed of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer Also referred to as a thermoplastic cycloolefin resin). The cycloolefin resin may be a hydrogenated product of a ring-opening polymer of the above cycloolefin, a ring-opening copolymer using two or more cycloolefins, or an addition polymer with an aromatic compound having a cycloolefin, a chain olefin, a vinyl group or the like . It is also effective that a polar group is introduced.

When the second protective layer is constituted by using a copolymer of cycloolefin and a chain-like olefin and an aromatic compound having a vinyl group, examples of the chain olefin include ethylene and propylene. Examples of the aromatic compound having a vinyl group include styrene, Methyl styrene, and nuclear alkyl-substituted styrene. In such a copolymer, the unit of the monomer composed of cycloolefin may be 50 mol% or less (preferably 15 to 50 mol%). Particularly, when the second protective layer is constituted by using a ternary copolymer of cycloolefin, chain olefin and aromatic compound having a vinyl group, the unit of the monomer comprising cycloolefin can be formed in a relatively small amount as described above have. In such a ternary copolymer, the unit of the monomer composed of the chain olefin is usually 5 to 80 mol%, and the unit of the monomer composed of the aromatic group having the vinyl group is usually 5 to 80 mol%.

The cycloolefin resin is preferably a commercially available product such as "TOPAS (registered trademark)" (manufactured by Topas Advanced Polymers GmbH), "ATON" (manufactured by JSR Corporation), "ZEONOR ZEONEX (registered trademark) "manufactured by Nippon Zeon Co., Ltd.," APEL (registered trademark) "(manufactured by Mitsui Chemicals, Inc.) Can be suitably used. When the cycloolefin resin is formed into a film, known methods such as a solvent casting method and a melt extrusion method are suitably used. Further, it is also possible to use a film-forming material such as "ESCINA (registered trademark)" and "SCA40" (manufactured by Sekisui Chemical Co., Ltd.) or "Zeonoafilm (registered trademark) A commercially available product of a film made of a cycloolefin resin may be used.

The above-mentioned cycloolefin-based resin film may be uniaxially or biaxially-stretched. In this case, the draw ratio is usually 1.1 to 5 times, preferably 1.1 to 3 times.

The polyolefin-based resin is a polymer containing a principal olefin such as ethylene or propylene as a main monomer, and may be a homopolymer or a copolymer. Among them, typical examples are homopolymers of propylene and copolymers in which a small amount of ethylene is copolymerized with propylene.

The acrylic resin is a polymer containing methyl methacrylate as a main monomer and may be a homopolymer of methyl methacrylate as well as a copolymer of methyl methacrylate and an acrylic acid ester such as methyl acrylate.

The polyimide resin is a polymer having an imide bond in the main chain and is obtained by polymerizing a tetracarboxylic acid dianhydride and a diamine to prepare a polyamic acid (polyamic acid) which is a precursor of the polyimide, followed by dehydration and cyclization (imidization) Which is obtained by the reaction.

The polycarbonate resin is a polymer having a carbonate bond in the main chain and is typically obtained by condensation polymerization of bisphenol A with phosgene.

The polyester-based resin is a polymer obtained by condensation polymerization of a dibasic acid and a dihydric alcohol, and polyethylene terephthalate is representative.

On the other hand, when the second protective layer is formed of a cured product of the curable resin composition, the same materials as described for the curable resin composition for forming the first protective layer can be used. The curable resin composition for forming the second protective layer and the curable resin composition for forming the first protective layer may be the same or different.

It is preferable that the second protective layer described above has a small thickness. However, if the second protective layer is too thin, the strength tends to deteriorate and workability tends to be poor. When the second protective layer is too thick, the transparency tends to decrease or the weight of the polarizing plate tends to increase have. From this point of view, the thickness of the second protective layer in the polarizing plate of the present invention is usually 5 to 100 占 퐉, preferably 10 占 퐉 or more, more preferably 80 占 퐉 or less Preferably 50 mu m or less. On the other hand, when the second protective layer is constituted of a cured product of the curable resin composition, its thickness may be 10 탆 or less.

The second protective layer may be a surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment on the surface opposite to the surface to be adhered to the polarizer layer. A coat layer made of a liquid crystalline compound or its high molecular weight compound or the like may be formed on the surface of the second protective layer opposite to the surface adhering to the polarizer layer.

[Bonding of polarizer layer and second protective layer]

When a thermoplastic resin film is used as the second protective layer, the polarizer layer and the second protective layer are bonded together using a suitable adhesive or a pressure-sensitive adhesive. When these films are bonded to each other, the bonding surfaces of the polarizing film and / or the second protective layer are subjected to a plasma treatment, a corona treatment, an ultraviolet irradiation treatment, a flame treatment, a saponification treatment, May be appropriately performed. As the saponification treatment, there may be mentioned a method of immersing in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide.

The adhesive used for bonding the polarizer layer and the second protective layer is not particularly limited. For example, a curable resin composition (active energy ray curable adhesive) containing an active energy ray curable compound and a curable resin composition (Water-based adhesive).

As the active energy ray curable adhesive, the same curable resin composition as the above-mentioned first protective layer can be used. The curable resin composition used for forming the first protective layer and the active energy ray curable adhesive used for bonding the polarizer layer and the second protective layer may be the same or different.

As the water-based adhesive, an adhesive composition using a polyvinyl alcohol-based resin or a urethane resin as a main component may be mentioned.

When a polyvinyl alcohol-based resin is used as the main component of the water-based adhesive, the polyvinyl alcohol-based resin may be a vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate which is a homopolymer of vinyl acetate, And the like. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, acrylamides having an ammonium group, and the like. The polyvinyl alcohol-based resin used for the adhesive preferably has an appropriate degree of polymerization. For example, when a 4 wt% aqueous solution is used, the viscosity of the polyvinyl alcohol-based resin is preferably in the range of 4 to 50 mPa · sec, more preferably in the range of 6 to 30 mPa Sec. ≪ / RTI >

In addition, a modified polyvinyl alcohol-based resin can be preferably used. Suitable examples of the modified polyvinyl alcohol-based resin include an acetoacetyl-modified polyvinyl alcohol-based resin, an anion-modified polyvinyl alcohol-based resin, and a cation-modified polyvinyl alcohol-based resin. Use of such a modified polyvinyl alcohol-based resin tends to provide an effect of improving the water resistance of the adhesive layer.

The water-based adhesive used in the present invention may, of course, be composed of two or more modified polyvinyl alcohol resins as described above, and may further include unmodified polyvinyl alcohol-based resins (specifically, Cargo) and the modified polyvinyl alcohol-based resin described above.

The polyvinyl alcohol resin constituting the water-based adhesive can be appropriately selected and used from commercially available products. Concretely, for example, "PVA-117H", "KL-318", "KM-118" and "CM-318" sold by Kuraray Co., Ltd. are sold by Seiko Kagaku Co., &Quot; Koseiln (registered trademark) NH-20 ", "Kosefima Z" series, "Kosefima (registered trademark) K- ) And the like.

A water-based adhesive containing a polyvinyl alcohol-based resin as a main component may contain a crosslinking agent. Examples of the functional group which can be a crosslinking agent include isocyanato compounds having at least two isocyanato groups (-NCO) in the molecule; An epoxy compound having at least two epoxy groups (-O- in cross-linking) in the molecule; Mono- or di-aldehydes; An organic titanium compound; Inorganic salts of divalent or trivalent metals such as magnesium, calcium, iron, nickel, zinc and aluminum; Metal salts of glyoxylic acid; Methylol melamine and the like.

Among these crosslinking agents, epoxy compounds including the above-mentioned water-soluble polyamide epoxy resin, and alkali metal or alkaline earth metal salts of aldehydes, methylol melamine, and glyoxylic acid are suitably used.

The crosslinking agent is preferably dissolved in water together with the polyvinyl alcohol-based resin to form an adhesive. However, as described below, the amount of the crosslinking agent in the aqueous solution may be small, so that it may be used as a crosslinking agent if it has, for example, a solubility of at least about 0.1% by weight with respect to water. Of course, a compound having solubility in water to the extent that it is generally referred to as water-soluble is preferable as the crosslinking agent used in the present invention.

The blending amount of the crosslinking agent is appropriately designed according to the kind of the polyvinyl alcohol-based resin, and is usually about 5 to 60 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the polyvinyl alcohol-based resin. When a cross-linking agent is blended in this range, good adhesion can be obtained. If the blending amount of the crosslinking agent is excessively large, the reaction of the crosslinking agent proceeds in a short time, and the adhesive tends to gel early. As a result, the port life is extremely reduced and industrial use becomes difficult.

The water-based adhesive may be blended with conventionally known suitable additives such as a silane coupling agent, a plasticizer, an antistatic agent, and a fine particle within a range that does not impair the effect of the present invention.

When a urethane resin is used as a main component of the water-based adhesive, examples of suitable adhesives include a mixture of a polyester-based ionomer-type urethane resin and a compound having a glycidyloxy group. The polyester-based ionomer-type urethane resin referred to here is a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced into the urethane resin. Such an ionomeric urethane resin emulsifies directly in water without using an emulsifier, so that the emulsion is suitably used for an aqueous adhesive. The use of a polyester-based ionomer-type urethane resin as an adhesive for the polarizer layer and the protective layer is described, for example, in Japanese Patent Application Laid-Open Nos. 2005-070140, 4432487, and 2005-208456 .

The thickness of the adhesive layer obtained after drying or curing is usually about 0.01 to 5 mu m, but it can be 1 mu m or less when an aqueous adhesive is used. On the other hand, even when an active energy ray-curable adhesive is used, it is preferably 2 m or less, more preferably 1 m or less. If the adhesive layer is too thin, the adhesion may be insufficient. On the other hand, if the adhesive layer is too thick, the appearance of the polarizer may be poor.

The bonding of the polarizer layer and the second protective layer may be performed through the above-described pressure-sensitive adhesive layer. In this case, it is preferable that the above-mentioned ionic compound is not contained in the pressure-sensitive adhesive composition.

[Production method of polarizer with adhesive]

The polarizing plate of the present invention can be produced through the following steps (i) to (iii). Here, the order of the steps (i) and (ii) is not particularly limited, and the step (ii) may be performed first, or these steps may be performed at the same time. In the case where the second protective layer is not laminated on the polarizer layer, step (ii) is unnecessary.

(i) a step of laminating a first protective layer on one side of the polarizer layer,

(ii) a step of laminating a second protective layer on the other surface of the polarizer layer,

(iii) a step of laminating a pressure-sensitive adhesive layer on the surface of the first protective layer opposite to the polarizer layer.

In the above step (i), the first protective layer may be laminated on one side of the polarizer layer through a coating layer forming step, a coating layer joining step, a curing step and a substrate removing step.

In the coating layer forming step, a curable resin composition containing an active energy ray-curable compound for forming the first protective layer is coated on a substrate and, if necessary, dried to form a coated layer of the curable resin composition on the surface of the substrate. Here, besides the above-described substrate, for example, a metal belt, a glass plate, or the like can be used as the substrate. The surface of the substrate on which the curable resin composition is coated may be subjected to, for example, peeling treatment.

In the application layer bonding step, the application layer formed on the substrate and the polarizer layer are bonded to each other in the above-mentioned application layer formation step to prepare a laminate layered in the order of the polarizer layer / the application layer / the substrate. In the above step, when the step (ii) is performed before the step (i), the laminate has the second protective layer on the surface opposite to the coated layer of the polarizer layer.

In the curing step, the coating layer composed of the curable resin composition is cured by irradiating or heating the active material such as visible light, ultraviolet light, X-rays, electron beams, or the like from the substrate side to the laminate, . In the following substrate removal step, the substrate on the first protective layer is removed.

As another method for carrying out the step (i), the curable resin composition for forming the first protective layer is directly coated on the polarizer layer, and the coating layer comprising the curable resin composition is cured by irradiating or heating the active energy ray , And a method of forming the first protective layer. According to this method, the first protective layer can be formed without using a substrate.

The above-mentioned step (ii) is carried out when the second protective layer is laminated on the polarizer layer. When the thermoplastic resin film is employed as the second protective layer, the second protective layer is laminated through the adhesive layer. The lamination of the second protective layer is carried out as follows. First, an adhesive composition is coated on the bonding surface of the second protective layer, and if necessary, this is dried. Then, the polarizer layer and the second protective layer are bonded to each other through the adhesive composition to form a laminate in which the polarizer layer / the adhesive composition / the second protective layer are laminated in this order, and then the laminate is dried, The adhesive composition is cured by irradiating or heating an active energy ray such as visible light, ultraviolet ray, X-ray or electron beam to bond the polarizer layer and the second protective layer. At this time, a drying step may be provided if necessary. When the above step (i) is performed before the step (ii), the laminate has the first protective layer on the surface opposite to the coated layer of the polarizer layer. When an active energy ray-curable adhesive is used for bonding the polarizer layer and the second protective layer, there is no need to carry out a drying step, so that the production efficiency can be improved.

In addition, as a method other than the above, the adhesive composition is applied directly on the bonding surface of the polarizer layer, the second protective layer is laminated thereon, and then dried, or the adhesive is cured , And the polarizer layer and the second protective layer are bonded to each other. Also in this method, there can be provided a step of drying if necessary.

When a cured product of the curable resin composition containing the active energy ray-curable compound as the second protective layer is employed in the step (ii), the same process as in the above-mentioned step (i) can be employed.

The first protective layer and the second protective layer may be formed at the same time. When the second protective layer is a thermoplastic resin film, the laminate obtained through the above-described steps (i) and (ii) (the second protective layer / adhesive composition / polarizer layer / the first protective layer) The adhesive composition and the coating layer can be cured at the same time, for example, by irradiating or heating the active energy ray from the substrate side.

When the second protective layer is a cured product of the curable resin composition, the laminate obtained by the above steps (i) and (ii) (the coating layer of the curable resin composition forming the substrate / the second protective layer / the polarizer layer / 1 coating layer / base material of the curable resin composition forming the protective layer) can be cured simultaneously by irradiating or heating the active energy ray from one or both of the base materials. According to this method, since the curing process is completed once, the manufacturing efficiency can be further improved.

In the present invention, the curing resin composition containing the active energy ray-curable compound forming the first or second protective layer and the method of coating the adhesive composition for bonding the polarizer layer and the second protective layer are not particularly limited, , Doctor blade, wire bar, die coater, comma coater, and gravure coater.

Further, as a method other than the coating method described above, the curable resin composition or the adhesive composition described above may be dropped between the polarizer layer and the substrate or between the polarizer layer and the second protective layer, There is also a way to expand it. In this method, metal, rubber, or the like can be used as the material of the roll. As a roll, when a pair of rolls is used (when the laminate passes between rolls), these rolls may be the same material or different materials.

When the curing resin composition for forming the first or second protective layer and / or the adhesive composition described above is cured by irradiation of an active energy ray, the light source used is not particularly limited, Can be used. Specific examples thereof include low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, chemical lamps, black light lamps, microwave excited mercury lamps, and metal halide lamps.

The light irradiation intensity of the active energy ray may be different depending on the composition to be irradiated. It is preferable that the irradiation intensity in the wavelength range effective for activation of the photo radical polymerization initiator and / or the photo cation polymerization initiator is 10 to 2500 mW / cm 2. If the light irradiation intensity is less than 10 mW / cm 2, the reaction time becomes long. If the irradiation intensity exceeds 2500 mW / cm 2, heat radiated from the lamp and heat generated during polymerization of the curable resin composition or adhesive composition, There is a possibility of causing yellowing of the composition or deterioration of the polarizer layer.

The light irradiation time to the curable resin composition or the adhesive composition is controlled for each composition to be irradiated and is not particularly limited, but is set so that the integrated light amount expressed by the product of the irradiation intensity and the irradiation time is 10 to 2500 mJ / . If the integrated amount of light is less than 10 mJ / cm 2, the generation of active species derived from the polymerization initiator is not sufficient, and the curing of the resulting protective layer or adhesive layer may be insufficient. If the accumulated light quantity exceeds 2500 mJ / cm 2, the irradiation time becomes very long, which is disadvantageous for the productivity improvement. The irradiation of the active energy ray is preferably performed within a range in which various performances such as the polarization degree and the transmittance of the polarizer layer are not deteriorated.

In the above step (iii), a pressure-sensitive adhesive layer may be laminated on the surface of the first protective layer opposite to the polarizer layer to obtain a polarizer with a pressure-sensitive adhesive. The lamination of the pressure-sensitive adhesive layer can be performed, for example, by a method using a release film, a method of applying a pressure-sensitive adhesive composition on the first protective layer, and the like. The method of using the release film can be carried out, for example, by applying the above-mentioned pressure-sensitive adhesive composition to the release-treated surface of the release film subjected to the release treatment to form a pressure-sensitive adhesive layer and then laminating the first protective layer of the polarizing plate on the obtained pressure- have. The method of applying the pressure-sensitive adhesive composition on the first protective layer can be carried out, for example, by applying a pressure-sensitive adhesive composition to the bonding surface of the first protective layer of the polarizing plate to form a pressure-sensitive adhesive layer. In this method, it is preferable to laminate a release film on the obtained pressure-sensitive adhesive layer to protect the surface of the pressure-sensitive adhesive layer.

The polarizing plate with a pressure-sensitive adhesive of the present invention can be applied to a liquid crystal cell or the like to constitute a liquid crystal display device, but it is preferable that the above-mentioned release film is laminated and protected on the pressure- The release film to be used herein may be a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, and the like as a base, and a silicone And a mold release process such as a process may be performed. In addition, one of the two release films may be peeled off and adhered to the polarizer, if necessary, with the pressure-sensitive adhesive layer interposed therebetween.

[Liquid crystal display device]

The polarizer with a pressure-sensitive adhesive of the present invention can be applied to a glass substrate. One suitable application form is, for example, a lamination on a glass substrate through a pressure-sensitive adhesive layer. In order to laminate the polarizing plate with a pressure-sensitive adhesive on a glass substrate, for example, the release film may be peeled off from the polarizing plate with a pressure-sensitive adhesive to bond the surface of the exposed pressure-sensitive adhesive layer to the surface of the glass substrate. Examples of the glass substrate include a glass substrate constituting a liquid crystal cell, an antireflection glass, a glass for sunglasses, and the like. Among them, an optical laminate comprising a polarizing plate with a pressure-sensitive adhesive laminated on a glass substrate on the front side (viewing side) of a liquid crystal cell and another polarizing plate with a pressure-sensitive adhesive laminated on a glass substrate on the back side of the liquid crystal cell, (Liquid crystal panel) for the liquid crystal panel. Examples of the material of the glass substrate include soda lime glass, low alkali glass, and alkali-free glass. Non-alkali glass is suitably used for the liquid crystal cell.

The polarizing plate with a pressure-sensitive adhesive of the present invention can be disposed on one side or both sides of the liquid crystal cell. The polarizing plates provided on both sides of the liquid crystal cell may be the same or different. Further, the polarizing plate with a pressure-sensitive adhesive of the present invention may be disposed on one side of the liquid crystal cell, and another polarizing plate may be disposed on the opposite side of the liquid crystal cell.

[Example]

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. In the examples, parts and percentages indicating amounts used or contents are based on weight unless specifically noted.

First, an example in which a curable resin composition is prepared is shown. The following compounds were used for the preparation of the curable resin composition.

<Active Energy ray-curable compound>

"SEROCIDE (registered trademark) 2021P ": 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, available from Daicel Chemical Industries, Ltd.

"OXT-221 ": bis (3-ethyl-3-oxetanylmethyl) ether obtained from Doagosei Co.,

"OXT-212 ": 2-ethylhexyloxetane, obtained from Toagosei Co., Ltd.

"A-DCP": tricyclodecane dimethanol diacrylate, obtained from Shin Nakamura Kagaku Co., Ltd.

"DMAA ": obtained from N, N-dimethylacrylamide, Kojin Co., Ltd.

"4HBA ": 4-hydroxybutyl acrylate, available from NIPPON GASE CO., LTD.

"UV-3700B ": Bifunctional urethane acrylate obtained from Nippon Goishakagaku Kogyo Co., Ltd.

"CHDMMA ": 1,4-cyclohexanedimethanol monoacrylate, available from NIPPON GASE CO., LTD.

"OXT-101": 3-ethyl-3-hydroxymethyloxetane, obtained from Toagosei Co., Ltd.

<Gwangyang Ion Polymerization Initiator>

"ADEKA OPTOMA (registered trademark) SP-150 ": 4,4'-bis [diphenylsulfonio] diphenyl sulfide bishexafluorophosphate based photocationic polymerization initiator, propylene carbonate solution ) Obtained from ADEKA.

&Lt; Photo radical polymerization initiator &gt;

"IRGACURE (R) 907": 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one obtained from BASF Japan.

"DARACURE (R) 1173": 2-hydroxy-2-methyl-1-phenyl-propan-1-one obtained from BASF Japan.

&Lt; Other components &gt;

"SH710 ": silicone leveling agent available from Dow Corning, Dow Corning.

[Preparation Example 1] Preparation of curable resin compositions A to V

The following components were mixed to prepare curable resin compositions A to V, respectively. The photocationic polymerization initiator "Adeka Optoma SP-150" is a solution of propylene carbonate, which is hereinafter referred to as the effective ingredient amount.

<Curable resin composition A>

"Suloxide (registered trademark) 2021P" 100 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition B>

"OXT-221" 100 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition C>

"Suloxide (registered trademark) 2021P" 70 parts

"OXT-221" 30 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition D>

"DMAA" Part 15

"4HBA" 40 copies

"UV-3700B" 10 copies

"CHDMMA" 35

"Irgacure (R) 907" Part 3

"SH710" 0.2 part

&Lt; Curable resin composition E &gt;

"Suloxide (registered trademark) 2021P" 35

"OXT-221" Part 15

"A-DCP" 50 parts

"ADEKA OPTOMA (registered trademark) SP-150" 1.13 part

"DARACURE (R) 1173" 2.25 part

"SH710" 0.2 part

<Curable resin composition F>

"A-DCP" 100 copies

"DARACURE (R) 1173" 4.5 parts

"SH710" 0.2 part

&Lt; Curable resin composition G &gt;

"Suloxide (registered trademark) 2021P" 80 parts

"A-DCP" 20 copies

"ADEKA OPTOMA (registered trademark) SP-150" 1.8 part

"DARACURE (R) 1173" 0.9 part

"SH710" 0.2 part

<Curable resin composition H>

"Suloxide (registered trademark) 2021P" 60 parts

"A-DCP" 40 copies

"ADEKA OPTOMA (registered trademark) SP-150" 1.35 part

"Dauro Cure 1173" 1.8 part

"SH710" 0.2 part

&Lt; Curable resin composition I &gt;

"Suloxide (registered trademark) 2021P" 40 copies

"A-DCP" 60 parts

"ADEKA OPTOMA (registered trademark) SP-150" 0.9 part

"Dauro Cure 1173" 2.7

"SH710"   0.2 part

<Curable resin composition J>

"OXT-221" 65

"OXT-212" 35

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition K>

"OXT-221" 80 parts

"OXT-212" 20 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition L>

"OXT-221" 95 parts

"OXT-212" Part 5

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition M>

"Suloxide (registered trademark) 2021P" 60 parts

"OXT-221" 40 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition N>

"Suloxide (registered trademark) 2021P" 40 copies

"OXT-221" 60 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

&Lt; Curable resin composition O &gt;

"Suloxide (registered trademark) 2021P" 20 copies

"OXT-221" 80 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

&Lt; Curable resin composition P &gt;

"Suloxide (registered trademark) 2021P" 60 parts

"OXT-212" 40 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition Q>

"Suloxide (registered trademark) 2021P" 40 copies

"OXT-212" 60 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

&Lt; Curable resin composition R &gt;

"Suloxide (registered trademark) 2021P" 20 copies

"OXT-212" 80 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition S>

"Suloxide (registered trademark) 2021P" 80 parts

"OXT-101" 20 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition T>

"Suloxide (registered trademark) 2021P" 60 parts

"OXT-101" 40 copies

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition U>

"Suloxide (registered trademark) 2021P" 40 copies

"OXT-101" 60 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

<Curable resin composition V>

"Suloxide (registered trademark) 2021P" 20 copies

"OXT-101" 80 parts

"ADEKA OPTOMA (registered trademark) SP-150" 2.25 part

"SH710" 0.2 part

[Production Example 2] Production of polarizer layer (polarizing film)

A polyvinyl alcohol film having an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol% or more and a thickness of 30 탆 was uniaxially stretched by about 4 times in a dry manner and immersed in pure water at 40 캜 for 1 minute while maintaining the tension, And immersed in an aqueous solution of iodine / potassium iodide / water at a weight ratio of 0.05 / 10/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution of 8.5 / 7.5 / 100 weight ratio of potassium iodide / boric acid / water at 68 DEG C for 300 seconds. Subsequently, the film was washed with pure water at 10 占 폚 for 20 seconds, and then dried at 65 占 폚 to produce a polarizing film in which iodine was adsorbed and aligned on the uniaxially stretched polyvinyl alcohol film. The thickness of the polarizing film was 11 mu m.

Next, an example of preparing an adhesive is shown. The following compounds were used for polyvinyl alcohol and epoxy crosslinking agents.

<Polyvinyl alcohol>

"Kurarupofal (registered trademark) KL318 ": carboxyl group-modified polyvinyl alcohol, available from Kuraray Co., Ltd.

&Lt; Epoxy crosslinking agent &

"Sumirez resin (registered trademark) 650 ": Water-soluble polyamide epoxy resin (aqueous solution having a solid content concentration of 30%), obtained from Sumika Chemtex Co., Ltd.

[Preparation Example 3] Preparation of aqueous adhesive

The following components were mixed to prepare an aqueous adhesive. The epoxy-based crosslinking agent "Sumirez resin 650" is an aqueous solution.

<Water-based adhesive>

"pure" 100 copies

"Kurarupofal (registered trademark) KL318" 1.8 part

"Sumirez resin (registered trademark) 650" 0.9 part

[Production Example 4] Production of polarizing plate A

A water-based adhesive prepared in Production Example 3 was applied to one side of the polarizer layer prepared in Production Example 2, and a protective layer made of saponified triacetylcellulose (KC2UA, manufactured by Konica Minolta Opt .; thickness: 25 m, Referred to as a second protective layer). This was dried at 60 DEG C for 6 minutes to prepare a polarizing plate A having a second protective layer on one side.

[Example 1]

(1) Production of Polarizer

The curable resin composition A prepared in Preparation Example 1 was applied to one surface of a cycloolefin resin film (trade name "ZEONOR (registered trademark)", manufactured by Nippon Zeon Co., Ltd.) having a thickness of 50 μm by using a bar coater Was about 1 占 퐉. And laminated on the side of the polarizer layer of the polarizing plate A produced in Production Example 4 on the coated surface. On the cycloolefin resin film side of this laminate, ultraviolet light was irradiated using an ultraviolet light irradiation device equipped with a belt conveyor (lamp: "D bulb" manufactured by Fusion UV Systems Co., Ltd.) so as to obtain an integrated light quantity of 500 mJ / , The curable resin composition was cured, and then the cycloolefin resin film was peeled from the laminate. Thus, a polarizing plate comprising the first protective layer (cured product of the curable resin composition) / polarizer layer / adhesive layer / second protective layer was produced.

Then, on the first protective layer side of the polarizing plate produced in (1), an acrylic pressure sensitive adhesive layer having an antistatic function mixed with an ionic compound was provided. As the isocyanate crosslinking agent, silane coupling agent and antistatic agent to be blended in the pressure-sensitive adhesive, the following were used.

<Isocyanate Crosslinking Agent>

Coronate (registered trademark) L: Trimethylol propane of tolylene diisocyanate An ethyl acetate solution (solid content concentration: 75%) of the duct body was obtained from Nippon Polyurethane Co., Ltd.

<Silane coupling agent>

KBM-403: 3-glycidoxypropyltrimethoxysilane, liquid, available from Shin-Etsu Chemical Kagaku Co., Ltd.

<Antistatic agent>

1-hexylpyridinium hexafluorophosphate, a compound represented by the following formula.

(2) Formation of a pressure-sensitive adhesive layer

An organic solvent solution of an acrylic pressure-sensitive adhesive obtained by adding an isocyanate-based crosslinking agent, a silane coupling agent and an antistatic agent to a copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate, The release-treated surface of a polyethylene terephthalate film (trade name "SP-PLR382050", available from Lintec Co., Ltd., referred to as release film) was coated with a die coater so as to have a thickness of 20 μm after drying, . Subsequently, the surface of the first protective layer of the polarizing plate prepared in (1) above was adhered to the side (pressure-sensitive adhesive side) opposite to the release film of the sheet-type pressure-sensitive adhesive obtained above by a laminator, C for 7 days to obtain a polarizing plate provided with a pressure-sensitive adhesive layer.

[Examples 2 to 7]

A polarizing plate was produced in the same manner as in Example 1, except that the curable resin composition and the first protective layer shown in Table 1 were changed to the thicknesses.

[Example 8]

The curable resin composition F prepared in Preparation Example 1 was coated on the side of the polarizer layer of the polarizing plate A produced in Production Example 4 so that the film thickness after curing was about 2 탆 by using a bar coater. From the side of the curable resin composition of this laminate, an ultraviolet ray irradiating device equipped with a belt conveyor (lamp: "D bulb" manufactured by Fusion UV Systems Co., Ltd.) was used and ultraviolet rays were irradiated under a nitrogen atmosphere to an accumulated light quantity of 500 mJ / To cure the curable resin composition. Thus, a polarizing plate comprising the first protective layer / polarizer layer / adhesive layer / second protective layer was produced. Except for this, the durability evaluation was carried out in the same manner as in Example 1, and the results are summarized in Table 1.

[Examples 9 to 24]

A polarizing plate was produced in the same manner as in Example 2 except that the curable resin composition shown in Table 1 was used.

[Comparative Example 1]

A polarizing plate was produced in the same manner as in Example 1 except that the first protective layer was not laminated, that is, a pressure-sensitive adhesive was directly laminated on the polarizer layer.

&Lt; Evaluation of optical durability of polarizer &

The polarizing plate provided with the pressure-sensitive adhesive layer prepared in the above (2) was cut into a size of 30 mm x 30 mm, the release film was peeled off, and a non-alkali glass (trade name: ) "). The sample was subjected to autoclave treatment at a temperature of 50 캜 and a pressure of 5 kgf / cm 2 (490.3 kPa) for 1 hour, and then left to stand for 24 hours under an environment of a temperature of 23 캜 and a relative humidity of 55%. With respect to this sample, an optional accessory "film holder with a polarizing film" was set on a spectrophotometer (product name "UV2450" manufactured by Shimadzu Corporation), and a polarizing plate with a wavelength of 380 to 700 nm The transmission spectra in the transmission axis direction and the absorption axis direction were measured, and the polarization degree Py (unit:%) was determined based on these measurements. The optical performance in this state was set as the initial Py and the optical performance (Py after the test) after standing at 60 DEG C for 90 hours under an environment of relative humidity of 90% was measured to calculate the polarization degree change? Quot;? Py &quot; in Table 1. The optical performance at 60 DEG C and 90% relative humidity was further maintained for 150 hours (for a total of 250 hours) and the optical performance was measured to calculate the polarization degree change DELTA Py. .

ΔPy = initial Py - Py after test

&Lt; Measurement of Glass Transition Temperature (Tg) of First Protective Layer &gt;

Two sheets of cycloolefin resin films having the same thickness of 50 탆 as used in Example 1 were prepared. Then, the curable resin compositions A to V prepared in Production Example 1 were coated on the surface of one film using a bar coater so that the film thickness after curing became 2 mu m each, another one film was superimposed on the coated surface, The curable resin composition was cured by irradiating ultraviolet light so that the accumulated light quantity was 250 mJ / cm 2 from one side in accordance with Example 1. Subsequently, the film sandwiched by the cured product was peeled off. 5 mg of the cured product was scraped off, placed in an aluminum push cover type container, and pressed tightly to seal the sample.

Using a differential scanning calorimeter (DSC) "EXSTAR-6000 DSC6220" sold by SII Eye Nanotechnology Co., Ltd., a container containing the sample for measurement described above was set therein, and while nitrogen gas was purged, 20 The temperature was lowered from -60 ° C to -60 ° C, reached -60 ° C, and then maintained for 1 minute. Then, the temperature was raised from -60 ° C to 200 ° C at a rate of 10 ° C / minute, . Then, the midpoint glass transition temperature defined in JIS K 7121-1987 &quot; Method of measuring transition temperature of plastic &quot; is obtained from the DSC curve when the temperature is raised from -60 ° C to 200 ° C, ). &Lt; / RTI &gt; The results are shown in the column of &quot; Tg &quot;

&Lt; Measurement of water contact angle of first protective layer &

Two sheets of cycloolefin resin films having the same thickness of 50 탆 as used in Example 1 were prepared. Then, the curable resin compositions A to V prepared in Production Example 1 were coated on the surface of one film using a bar coater so that the film thickness after curing became 2 占 퐉, another film was superimposed on the coated surface, The curable resin composition was cured by irradiating ultraviolet light so that the accumulated light quantity was 250 mJ / cm 2 from one side in accordance with Example 1. Subsequently, the film having the cured product sandwiched therebetween was peeled off, and 8 μL of water was added dropwise to the cured product by using a full automatic contact angle measuring device (trade name "OCA35", manufactured by Data Physics Co., Ltd.) The contact angle of water after the measurement was measured. The results are shown in the "water contact angle" column of Table 1.

It can be seen from Table 1 that in the comparative example 1 without the first protective layer, the degree of polarization was 0.20% after 100 hours of testing and 1.53% after 250 hours of testing, while all of the examples in which the first protective layer was laminated It can be seen that the amount of decrease is smaller than that of the comparative example and the tendency is larger as the thickness of the first protective layer is thicker. In Examples 4 and 5 in which the oxetane-based compound alone or in combination with the epoxy compound was used, the decrease in the degree of polarization after 100 hours of testing was 0%, and the effect of suppressing the deterioration in optical performance was remarkable. In Examples 6 to 8 containing an acrylic compound, the decrease in polarization degree was suppressed even when the film thickness was 2 占 퐉. In Examples 7 and 8 in which Tg was particularly high, the decrease in the degree of polarization after 100 hours of testing was 0% , The effect of suppressing the deterioration of the optical performance is remarkably exhibited as in the case of the oxetane-based compound. In Examples 1 to 22 in which the water contact angle is 60 占 or more, the decrease in the degree of polarization after the 250-hour test is 0.5% or less, which shows that the effect of suppressing the deterioration of the optical performance is remarkable.

Claims (12)

A pressure-sensitive adhesive layer comprising a polarizer layer, a first protective layer which is a cured product of a curable resin composition containing an active energy ray-curable compound and a pressure-sensitive adhesive composition containing an ionic compound in this order. The polarizer according to claim 1, wherein the polarizer layer has a second protective layer on a surface opposite to the first protective layer. The polarizer according to claim 2, wherein the second protective layer is a transparent resin film formed of a thermoplastic resin. 4. The polarizer according to any one of claims 1 to 3, wherein the active energy ray-curable compound comprises a cationic polymerizable compound. 5. The polarizer according to claim 4, wherein the cationic polymerizable compound comprises a compound having at least one oxirane ring. The polarizing plate according to any one of claims 1 to 5, wherein the active energy ray-curable compound comprises a (meth) acrylic compound having at least one (meth) acryloyloxy group. The polarizer according to any one of claims 1 to 6, wherein the first protective layer has a glass transition temperature of 23 ° C or higher. The polarizer according to any one of claims 1 to 7, wherein the first protective layer has a thickness of 0.1 to 10 占 퐉. The polarizer according to any one of claims 1 to 8, wherein the first protective layer has a water contact angle of 60 ° or more. 10. The polarizer according to any one of claims 1 to 9, wherein a release film is laminated on the pressure-sensitive adhesive layer. A liquid crystal display comprising a liquid crystal cell and the polarizer with a pressure-sensitive adhesive according to any one of claims 1 to 9. The liquid crystal display device according to claim 11, wherein the polarizing plate with a pressure-sensitive adhesive is bonded to the liquid crystal cell on the pressure-sensitive adhesive layer side.