TW201605643A - Polarizing plate with adhesive and liquid crystal display device - Google Patents

Abstract

The present invention provides a polarizing plate with adhesive, which capable of suppressing decreasing of optical performance of a polarizer layer even an adhesive composition forming an adhesive layer including an ionic compound. The polarizing plate with adhesive, contains in this order: a polarizer layer, a first protective layer containing a cured article of a curable resin composition containing an active energy ray curable compound, and an adhesive layer including an adhesive composition containing an ionic compound. The polarizer layer may contain a second protective layer on the surface opposite to the first protective layer.

Description

Polarizing plate with adhesive and liquid crystal display device

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

A polarizing plate can be used as one of optical elements constituting a liquid crystal display device. The polarizing plate is usually incorporated in a liquid crystal display device in a state in which a double-layer transparent resin film of a polarizer layer is used as a protective layer. However, as a result of thinness and light weight, for example, a Japanese Patent Application Laid-Open No. 10- In the case of the polarizing plate layer, the polarizing plate of the protective layer is laminated only on the side of the polarizer layer.

However, in general, a polarizing plate is formed with an adhesive layer on the outermost layer, and is further distributed in a state in which the release film is attached to the adhesive layer. Before bonding the liquid crystal cell, the release film is peeled off from the polarizing plate, and the exposed adhesive layer is interposed to adhere to the liquid crystal cell. When such a polarizing plate is bonded to a liquid crystal cell by peeling off the release film, there is a problem that static electricity is generated. Therefore, it is proposed to form an adhesive as described in JP-A-2009-251281 (Patent Document 2). The adhesive of the agent layer is formulated with an ionic compound to impart an antistatic function.

Generally, in the polarizing plate described in Patent Document 1, Adhesive layer is laminated on the surface of the uncovered protective layer of the polarizer layer (the side opposite to the surface of the build-up protective layer), but the ionic compound is formulated when the adhesive composition forming the adhesive layer is formulated with an ionic compound The effect of the compound, especially in the heat and humidity resistance test, has a problem of lowering the optical properties of the polarizer. In the above-mentioned Japanese Patent Publication No. 2014-32360 (Patent Document 3), it is described that the performance can be suppressed by selecting the composition of the formulated ionic compound. However, by the limitation of the ionic compound, the composition of the adhesive composition may be deteriorated in compatibility or the adhesive force may be lowered, and the problem of peeling or lifting of the polarizing plate may occur in the heat resistance test.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-186133

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-251281

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2014-32360

The object of the present invention is to suppress the deterioration of the optical properties of the polarizer layer even when the ionic compound is contained in the adhesive composition forming the adhesive layer.

The inventors of the present invention have conducted in-depth discussions to achieve the above-mentioned objects, and as a result, it has been found that the polarizing layer and the ionic compound are contained. Between the adhesive layers formed by the adhesive composition, a protective layer of a cured product of a curable resin composition containing an active energy ray-curable compound is provided to suppress deterioration of the polarizer layer under moist heat conditions to complete this invention.

That is, from one of the viewpoints, the present invention provides A polarizing plate with an adhesive, which is provided with: 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 an adhesive layer which contains ions The composition of the adhesive of the compound.

In the above polarizing plate with an adhesive, a polarizing layer A second protective layer may be provided on a surface opposite to the first protective layer. The second protective layer is preferably a transparent resin film formed of a thermoplastic resin.

The above active energy ray-curable compound is included A cationically polymerizable compound is preferred. The cationically polymerizable compound is more preferably a compound containing a compound having at least one oxirane ring.

Further, any of the above active energy ray-curable compounds The material is preferably a (meth)acrylic compound containing at least one (meth)acryloxy group.

In the above polarizing plate with an adhesive, the first protection The glass transition temperature of the layer is preferably 23 ° C or higher, and the thickness of the first protective layer is preferably 0.1 to 10 μm, and the water contact angle of the first protective layer is preferably 60 or more.

The polarizing plate with an adhesive of the present invention can be used in the adhesive thereof The liquid crystal cell or the like is attached to the layer side. Therefore, until the time of use, in its adhesive A release film having a release treatment applied to the layer is preferred.

The above polarizing plate with an adhesive can be applied to a liquid The crystal unit is used as a liquid crystal display device. That is, from another viewpoint, the present invention provides a liquid crystal display device including a liquid crystal cell and a polarizing plate with any of the above-mentioned adhesives. As one of the preferable embodiments, a polarizing plate with an adhesive attached to the liquid crystal cell is attached to the side of the adhesive layer.

According to the present invention, even when the adhesive layer is formed of an adhesive composition containing an ionic compound in which the optical characteristics of the polarizer layer are remarkably lowered, or a protective layer between the adhesive layer and the polarizer layer When the thickness is thin, deterioration of optical properties of the polarizer layer can be suppressed, and the liquid crystal display device can be made thinner and lighter.

The polarizing plate of the present invention is formed by sequentially laminating a polarizing film layer, a first protective layer of a cured product of a curable resin composition containing an active energy ray-curable compound, and an adhesive composition containing an ionic compound. Adhesive layer. Further, if necessary, a second protective layer is laminated on the surface of the polarizer layer opposite to the surface on which the first protective layer is laminated. In the present specification, the curable resin composition containing the active energy ray-curable compound is simply referred to as a "curable resin composition", and the curable resin composition containing the active energy ray-curable compound is hardened. The object is simply referred to as "cured material of a curable resin composition." The following describes the various components. member.

[Polarized film layer]

The polarizer layer may be a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and uniaxially stretched. In the present invention, the thickness of the polarizer layer is usually 30 μm or less, preferably 25 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less, and particularly preferably 7 μm or less. In addition, when a dichroic dye is used to adsorb a polyvinyl alcohol-based resin layer as a polarizer layer, the polyvinyl alcohol-based resin monomer can be stretched, or a polyethylene can be coated on a substrate or the like. After drying the solution of the alcohol resin, the substrate is stretched together with the substrate to remove the substrate. When stretching together with a substrate, it becomes easy to produce a polarizer layer having a thickness of 7 μm or less.

As the above substrate, for example, polyterephthalic acid An ethylenediester film, a polycarbonate film, a cellulose triacetate film, a norbornene film, a polyester film, a polystyrene film, or the like.

As a polyvinyl alcohol constituting a polyvinyl alcohol-based resin layer The resin can be saponified using a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to the polyvinyl acetate of a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith can be listed. Examples of the other monomer copolymerizable with vinyl acetate include an unsaturated carboxylic acid, an olefin, a vinyl ether, an unsaturated sulfonic acid, and an acrylamide having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin may be 80 mol% Above, preferably in the range of 90 to 99.5 mol%, more preferably 94 to 99 Mole% range. When the degree of saponification is less than 80 mol%, the water resistance and moist heat resistance of the obtained polarizing plate are lowered. When the degree of saponification exceeds 99.5 mol%, the dyeing speed may be slow, the productivity may be lowered, and a polarizing layer having sufficient polarizing properties may not be obtained.

The degree of saponification is a ratio of the ratio of the acetic acid group (acetoxy group: -OCOCH ₃ ) contained in the polyvinyl acetate-based resin of the raw material of the polyvinyl alcohol-based resin to the hydroxyl group according to the saponification step. %) Representation, as defined by the following formula. Further, the degree of saponification can be determined in accordance with JIS K 6726:1994 "Test method for polyvinyl alcohol", and the higher the degree of saponification, the higher the ratio of hydroxyl groups, and therefore the lower the ratio of the acetate group which inhibits crystallization.

Degree of saponification (% by mole) = 100 × (hydroxyl number) / (hydroxyl number + number of acetate groups)

The polyvinyl alcohol-based resin may be a partially modified modified polyvinyl alcohol, for example, it may be modified from an olefin such as ethylene or propylene; and modified with an unsaturated carboxylic acid such as acrylic acid, acrylic acid or crotonic acid; An alkyl ester of an unsaturated carboxylic acid, acrylamide or the like is modified. The ratio of the modification of the polyvinyl alcohol-based resin is preferably less than 30 mol%, more preferably less than 10%. When the modification is performed in excess of 30 mol%, there is a tendency that it is difficult to adsorb the dichroic dye, and a polarizing layer having sufficient polarizing performance cannot be obtained.

The average degree of polymerization of the polyvinyl alcohol-based resin is preferably from about 100 to 10,000, more preferably from 1,500 to 8,000, still more preferably from 2,000 to 5,000. The average degree of polymerization of the polyvinyl alcohol-based resin can also be determined in accordance with JIS K 6726:1994 "Test method for polyvinyl alcohol". When the average degree of polymerization is less than 100, there is a tendency that it is difficult to obtain better polarizing performance, and the average degree of polymerization exceeds At 10,000 hours, the solubility in the solvent is deteriorated, and it tends to be difficult to form a polyvinyl alcohol-based resin layer.

In the present invention, it can be used as a polyvinyl alcohol resin. A suitable commercial product. Examples of suitable commercial products are indicated by the trade name, and include: "PVA124" and "PVA117" (both saponification degree: 98 to 99 mol%) and "PVA624" (saponification degree) manufactured by KURARAY. : 95 to 96 mol %), "PVA617" (saponification degree: 94.5 to 95.5 mol%); "N-300" and "NH-18" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. (both saponification degree: 98 to 99 mol%), "AH-22" (saponification degree: 97.5 to 98.5 mol%), "AH-26" (saponification degree: 97 to 98.8 mol%); JAPAN VAM & POVAL (share) system "JC-33" (saponification degree: 99% or more), "JF-17", "JF-17L" and "JF-20" (both saponification degree: 98 to 99% by mole), "JM -26" (saponification degree: 95.5 to 97.5 mol%), "JM-33" (saponification degree: 93.5 to 95.5 mol%), "JP-45" (saponification degree: 86.5 to 89.5 mol%), and the like.

The dichroic dye contained in the polarizing layer (adsorption alignment) may be iodine or a dichroic organic dye. Specific examples of the dichroic organic dye include Red BR, Red LR, Red R, Pink LB, Rubin BL, Bordeaux GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, and Green LG. Violet LB, Violet B, Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Sulphur Blue G, Sulphur Blue GL, Sulphur Orange GL, Direct Sky Blue, Direct First Orange S, First Black. The dichroic dye may be used alone or in combination of two or more.

[first protective layer]

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

Examples of the cationically polymerizable compound include: a compound having at least one oxirane ring in the molecule (hereinafter sometimes referred to simply as "oxetane compound") and a compound having at least one epoxy group in the molecule (hereinafter sometimes referred to as a compound) "Epoxy compound").

Moreover, as an example of a radically polymerizable compound, it can be listed A compound having at least one (meth)acryloxy group in the molecule (hereinafter sometimes referred to simply as "(meth)acrylic compound)" and having one (meth)acryl oxime in the molecule An amine group compound (hereinafter sometimes referred to as "(meth) acrylamide compound)" or the like. Further, "(meth)acrylic" means methacrylic or acrylic, "(meth)acryloxy" means methacryloxy or acryloxy, (meth) propylene oxime Amino group means methacrylamidoamine or acrylamide.

Among these, oxetane compounds and/or (a In the case of the acrylic compound, the effect of suppressing the decrease in optical performance of the polarizer layer is remarkable.

The oxetane compound has at least 1 in the molecule Examples of the compound of the oxirane ring (4-membered cyclic ether) include, for example, 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxo) Heterocyclobutane)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, bis[(3-ethyl-3-oxetanyl) ) methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxetane, and the like. These oxetane compounds can be easily obtained from commercially available products, and are represented by trade names sold by East Asia Synthetic Co., Ltd., for example, "ARON OXETANE (registered trademark) OXT-101", "ARON OXETANE (registered) Trademarks) OXT-121", "ARON OXETANE (registered trademark) OXT-211", "ARON OXETANE (registered trademark) OXT-221", "ARON OXETANE (registered trademark) OXT-212", etc.

The amount of oxetane compound is not limited The system is usually 90% by weight or less, preferably 20 to 80% by weight based on the total of the cationically polymerizable compound. Further, the curable resin composition may be added to the above oxetane compound and contain an epoxy compound. By adding an epoxy compound, the adhesion between the curable resin composition and the polarizer layer is further improved.

The epoxy compound is not particularly limited. However, an aromatic epoxy compound, a glycidyl ether of a polyhydric alcohol having an alicyclic ring, an aliphatic epoxy compound, an epoxy compound having an alicyclic epoxy compound, and the like can be listed.

Examples of the aromatic epoxy compound include, for example, bisphenol A. Diglycidyl ether, diglycidyl ether of bisphenol F and diglycidyl ether bisphenol epoxy resin of bisphenol S; phenol novolac epoxy resin, Methylphenol novolac epoxy resin and hydroxybenzaldehyde phenol novolac epoxy resin epoxy resin varnish type epoxy resin; glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxydiphenyl ketone and ring An oxidized polyvinyl phenol-like polyfunctional epoxy resin or the like.

The glycidyl ether of the polyol having an alicyclic ring may be The aromatic polyhydric alcohol is obtained by glycidyl etherification of a nuclear hydrogenated polyhydroxy compound obtained by selectively hydrogenating an aromatic ring in the presence of a catalyst under pressure. Examples of the aromatic polyol include bisphenol A, bisphenol F, and bisphenol S-like bisphenol type compounds; phenol novolak resin, methylphenol novolak resin, and hydroxybenzaldehyde phenol novolac resin-like phenolic resin; A varnish type resin; a polyfunctional compound such as tetrahydroxydiphenylmethane, tetrahydroxydiphenyl ketone or polyvinylphenol. The alicyclic polyol obtained by hydrogenating the aromatic ring of the aromatic polyol is reacted with epichlorohydrin to obtain a glycidyl ether. Preferred examples of the glycidyl ether of the polyol having such an alicyclic ring include hydrogenated bisphenol A diglycidyl ether.

The aliphatic epoxy compound may be an aliphatic polyol or A polyglycidyl ether of an alkylene oxide adduct. More specifically, diglycidyl ether of 1,4-butanediol; diglycidyl ether of 1,6-hexanediol; triglycidyl ether of glycerol; triglycidyl of trimethylolpropane Ether; diglycidyl ether of polyethylene glycol; diglycidyl ether of propylene glycol; diglycidyl ether of neopentyl glycol; ethylene glycol, propylene glycol or glycerol by aliphatic or polyhydric alcohol addition 1 or 2 A polyglycidyl ether of a polyether polyol obtained by using the above alkylene oxide (ethylene oxide or propylene oxide).

Further, the monofunctional epoxy compound represented by the following formula (I) may also be exemplified as an aliphatic epoxy compound. R ¹ is an alkyl group having 1 to 15 carbon atoms. The alkyl group may be a straight chain, and may be a branched chain when the carbon number is 3 or more. The alkyl group is preferably 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, a branched alkyl group is preferred. A representative example of the monofunctional epoxy compound represented by the formula (I) is 2-ethylhexyl glycidyl ether.

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

The compound in which (CH ₂ ) _n in the formula (II) is bonded to another chemical structure by removing one or a plurality of hydrogen atoms can be an alicyclic epoxy compound. Further, one or a plurality of hydrogen atoms of (CH ₂ ) _n forming an alicyclic ring may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group.

Epoxy epoxidation of epoxy compounds as described above a compound, that is, a compound having at least one epoxy group bonded to an alicyclic ring, preferably having an epoxycyclohexane [n=4 in the above formula (II)] or an epoxy group An epoxy compound of the alkane [n=5 in the above formula (II)], due to hardenability The cured product having a resin composition has a high modulus of elasticity and is easy to obtain a protective layer having excellent adhesion to the polarizer layer, and thus is more suitably used. Specific examples of the alicyclic epoxy compound are disclosed below. Here, the compound name is listed first, and then the corresponding chemical formulas are listed, and the same reference numerals are attached to the compound name and the chemical formula corresponding thereto.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy -6-methylcyclohexanecarboxylate; C: exoethyl bis(3,4-epoxycyclohexanecarboxylate); D: bis(3,4-epoxycyclohexylmethyl)hexane Acid ester; 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-four Trispirocyclo [5.2.2.5.2.2] behenane; I: 3-(3,4-epoxycyclohexyl)-8,9-epoxy-1,5-di Spiro[5.5]undecane; J: 4-vinylcyclohexene dioxide; K: liminene; L: bis(2,3-epoxycyclopentyl) ether; M: dicyclopentane dioxide Diene.

In the curable resin composition, the epoxy compound can be used alone Use one type or two or more types together.

There is no particular limitation on the amount of epoxy compound to be formulated. The cationically polymerizable compound is usually 90% by weight or less, preferably 20 to 80% by weight based on the total amount. In addition, when the active energy ray-curable compound is used as a standard, the amount of the cationically polymerizable compound is usually 100% by weight or less, preferably 30% to 90% by weight.

The curable resin composition contains an oxetane compound When a cationically polymerizable compound such as a compound or an epoxy compound is used as the active energy ray-curable compound, a photocationic polymerization initiator is usually added to the curable resin composition. When a photocationic polymerization initiator is used, since a protective layer can be formed at normal temperature, the need for deformation due to heat resistance or expansion of the polarizer layer is reduced, and the first protective layer can be formed on the polarizer with good adhesion. On the floor. Further, since the photocationic polymerization initiator has a catalytic action by light, it has excellent storage stability and workability even when it is mixed with the curable resin composition.

Photocationic polymerization initiator by visible light, purple Irradiation of an active energy ray such as an external line, an X-ray, or an electron beam generates a cationic species or a Lewis acid, and starts polymerization of a cationically polymerizable compound. The photocationic polymerization initiator may be of any type. However, specific examples thereof include aromatic diazonium salts; aromatic iodonium salts and aromatic sulfonium salts; and iron-aromatic hydrocarbon complexes.

Examples of the aromatic diazonium salt include the following Compound.

Benzyldiazonium hexafluoroantimonate; Benzene diazo hexafluorophosphate; benzene diazo hexafluoroborate.

Examples of the aromatic iodonium salt include the following Compound.

Diphenyliodonium (pentafluorophenyl)borate; diphenyliodonium hexafluorophosphate; diphenyliodonium hexafluoroantimonate; bis(4-mercaptophenyl)iodonium hexafluorophosphate Salt and so on.

Examples of the aromatic onium salt include the following Compound.

Triphenylsulfonium hexafluorophosphate; triphenylsulfonium hexafluoroantimonate; triphenylsulfonium (pentafluorophenyl)borate; 4,4'-bis[diphenyldihydrothio Diphenyl sulfide dihexafluorophosphate; 4,4'-bis[bis(β-hydroxyethoxy)phenyldihydrothio]diphenyl sulfide dihexafluoroantimonate; 4,4 '-bis[bis(β-hydroxyethoxy)phenyldihydrothio]diphenyl sulfide dihexafluorophosphate; 7-[bis(p-tolylmethyl)dihydrothio]-2- Isopropyl oxazetomone hexafluoroantimonate; 7-[bis(p-tolylmethylhydrazolyl)dihydrothio]-2-isopropyloxythiazinone oxime (pentafluorophenyl)borate ; 4-phenylcarbonyl-4'-diphenyldihydrothio-diphenyl sulfide hexafluorophosphate Acid salt; 4-(p-tert-butylphenylcarbonyl)-4'-diphenyldihydrothio-diphenyl sulfide hexafluoroantimonate; 4-(p-tert-butylphenylcarbonyl) -4'-bis(p-tolylmethyl) dihydrothio-diphenyl sulfide quinone (pentafluorophenyl) borate.

Further, examples of the iron-aromatic hydrocarbon complex include the following compounds.

Xylene-cyclopentadienyl iron(II) hexafluoroantimonate; cumene-cyclopentadienyl iron (II) hexafluorophosphate; xylene-cyclopentadienyl iron (II) ginseng Trifluoromethylsulfonyl) Wait.

Such a photo-cationic polymerization initiator can be easily obtained from a commercially available product, and is represented by a brand name, for example, "KAYARAD (registered trademark) PCI-220" and "KAYARAD (registered) sold by Nippon Kayaku Co., Ltd. Trademark) PCI-620"; "UVI-6990" sold by The Dow Chemical Company; "UVACURE 1590" sold by Daicel Saitech Co., Ltd.; "ADEKA OPTOMER (registered trademark) SP-150 sold by ADEKA "And" ADEKA OPTOMER (registered trademark) SP-170"; "CI-5102", "CIT-1370", "CIT-1682", "CIP-1866S", "CIP-2048S" sold by Japan's Soda Co., Ltd. "and" CIP-2064S"; "DPI-101", "DPI-102", "DPI-103", "DPI-105", "MPI-103", "MPI-105" sold by MIDORI Chemical Co., Ltd. ", "BBI-101", "BBI-102", "BBI-103", "BBI-105", "TPS-101", "TPS-102", "TPS-103", "TPS-105", "MDS-103", "MDS-105", "DTS-102" and "DTS-103"; "PI-2074" sold by Rhodia.

These photocationic polymerization initiators can be used separately Or use in combination of 2 or more types. Among these, in particular, the aromatic sulfonium salt has ultraviolet absorbing properties even in the wavelength region of 300 nm or more, so that it can be provided with hardenability, good mechanical strength, or good adhesion to the polarizing sheet. It is suitable for use because it is a cured product of a resin composition.

The amount of photocationic polymerization initiator, relative to the package The total of 100 parts by weight of the cationically polymerizable compound containing an epoxy compound or an oxetane compound is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight. When the amount of the photocationic polymerization initiator is small, the curing is insufficient, and the mechanical strength or the adhesion between the first protective layer and the polarizer layer tends to be lowered. On the other hand, when the amount of the photocationic polymerization initiator is too large, the optical properties of the polarizing sheet may be lowered.

The curable resin composition contains radical polymerizable When the compound is an active energy ray-curable compound, the radically polymerizable compound may be, for example, a (meth)acrylic compound or a (meth)acrylamide compound. Examples of the (meth)acrylic compound include a (meth) acrylate monomer having at least one (meth) propylene fluorenyloxy group in the molecule, and a compound obtained by reacting two or more kinds of functional groups. Further, it has a (meth) acrylate oligomer having at least two (meth) acryloxy groups in the molecule. These may be used alone or in combination of two or more. When two or more kinds of (meth)acrylic-based compounds are used in combination, two or more kinds of (meth)acrylate monomers may be used, or two or more kinds of (meth)acrylate oligomers may be used, and of course, they may be used in combination ( One or more kinds of methyl acrylate monomers and one or more kinds of (meth) acrylate oligomers. In addition, "(meth) acrylate" means methacrylate or acrylic acid ester.

Among the above (meth) acrylate monomers, there are: a monofunctional (meth) acrylate monomer having one (meth) acryloxy group and a bifunctional (meth) acrylate monomer having two (meth) acryloxy groups in the molecule; A polyfunctional (meth) acrylate monomer having three or more (meth) acryloxy groups in the molecule.

Specific as a monofunctional (meth) acrylate monomer For example, tetrahydroindenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (A) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, methyl (meth) acrylate, ethyl (methyl) Acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (A) Acrylate, isodecyl (meth) acrylate, cyclohexyl (meth) acrylate, 1,4-cyclohexane dimethanol monoacrylate, dicyclopentenyl (meth) acrylate, two Cyclopentenyl (meth) acrylate, benzyl (meth) acrylate, pentenyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxy Ethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, ethyl carbitol (meth) acrylate, trimethylol propylene mono (meth) acrylate, neopentyl Tetraol mono (meth) acrylate, phenoxy polyethylene glycol (A ) Acrylate and the like.

As a monofunctional (meth) acrylate monomer, it can be used A (meth) acrylate monomer having a carboxyl group. As the monofunctional (meth) acrylate monomer having a carboxyl group, 2-(methyl) propylene oxy oxyethyl decanoic acid is exemplified. Ester, 2-(methyl)propenyloxyethyl hexahydrophthalate, carboxyethyl (meth) acrylate, 2-(meth) propylene methoxyethyl succinate, N-(A) Base) propylene methoxy-N', N'-dicarboxymethyl p-phenylenediamine, 4-(meth) propylene methoxyethyl trimellitate, and the like.

As the (meth)acrylamide compound, N- can be used. Substituted (meth) acrylamide. The N-substituted (meth) acrylamide is a (meth) acrylamide having a substituent at the N-position. A representative example of the substituent is an alkyl group which may be further substituted, but may form a ring together with a nitrogen atom of (meth) acrylamide, which is in addition to a carbon atom and a nitrogen atom of (meth) acrylamide. It may also have an oxygen atom as a ring member. Further, among the carbon atoms constituting the ring, a substituent such as an alkyl group or a pendant oxy group (=O) may be bonded. The N-substituted (meth) acrylamide can be generally produced by the reaction of (meth)acrylic acid or its chloride with a primary or secondary amine.

The N-substituted (meth) acrylamide is preferably the one represented by the following formula (III). In 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 amine group. Or Q ² and Q ³ together have a nitrogen atom and an oxygen atom bonded thereto as a 5-membered ring or a 6-membered ring. When Q ² is an alkyl group and Q ³ is an alkyl group which may have a hydroxyl group or an amine group, the respective alkyl groups may be linear or branched if they have a carbon number of 3 or more. In the case where Q ³ is an alkyl group having a hydroxyl group, a hydroxyalkyl group is in accordance therewith. In the case where Q ³ is an alkyl group having an amine group, an aminoalkyl group, an N-alkylaminoalkyl group and an N,N dialkylaminoalkyl group are in accordance therewith. When Q ² and Q ^{3 are} together and have a nitrogen atom and an oxygen atom bonded thereto as a 5-membered ring or a 6-membered ring of a ring member, an example of a 5-membered ring or a 6-membered ring is disclosed in the N-position. In the form of a group attached to a carbonyl group (C=O), there are 1-pyrrolidinyl groups (C ₄ H ₈ N-), 2- 2-oxazolidone-3-yl [C ₂ H ₄ OC(=O)N-], N -hexahydropyridyl (C ₅ H ₁₀ N-), morpholinyl (C ₂ H ₄ OC ₂ H ₄ N-).

Specific examples of the N-substituted (meth) acrylamide which corresponds to the above formula (III) and wherein Q ² is a hydrogen atom and Q ³ is an alkyl group are as follows: N-methyl(meth)acryl oxime Amine, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-tert-butyl (meth) propylene Indoleamine, N-hexyl (meth) acrylamide, and the like. Similarly, specific examples of the N-substituted (meth) acrylamide having the same alkyl group as Q ² and Q ³ are as follows: N,N-dimethyl(meth)acrylamide, N,N -Diethyl(meth)acrylamide or the like.

Similarly, a specific example of the N-substituted (meth) acrylamide having Q ² as a hydrogen atom and Q ³ being an alkyl group having a hydroxyl group is exemplified by N-hydroxymethyl (meth) acrylamide. N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, and the like. Similarly, a specific example of N-substituted (meth) acrylamide having Q ² as a hydrogen atom and Q ³ being an alkyl group having an amine group is exemplified by N-[2-(N,N-dimethyl Amino]ethyl](meth)acrylamide, N-[2-(N,N-diethylamino)ethyl](methyl)propenylamine, N-[3-(N, N-Dimethylamino)propyl](meth)acrylamide, N-[1-methyl-1-(N,N-dimethylamino)ethyl](methyl)propenamide Wait.

Further, specific examples of the N-substituted (meth) acrylamide which form a 5-membered ring or a 6-membered ring together with Q ² and Q ³ in the formula (III) together with the nitrogen atom bonded thereto are listed. There are: N-propylene decyl pyrrolidine, 3-propenyl fluoren-2- An oxazolidinone, 4-propenyl hydrazinoline, N-propylene hydrazinopiperidine, N-methylpropenylpiperidine, and the like.

Among the above N-substituted (meth) acrylamides, preferred N-hydroxyalkyl (meth) acrylamide such as N-hydroxymethyl acrylamide and N-(2-hydroxyethyl) acrylamide, and, for example, N,N-dimethyl decylamine And N,N-diethyl acrylamide amine N,N-dialkyl (meth) acrylamide, particularly preferably N-(2-hydroxyethyl) acrylamide or N,N-dimethyl Acrylamide.

Other, such as N-dodecyl (meth) acrylamide Long-chain alkyl N-alkyl (meth) acrylamide, or such as N-(methoxymethyl) acrylamide, N-(ethoxymethyl) acrylamide, N-(propyl Oxymethyl) acrylamide and N-(alkoxyalkyl) acrylamide N-(alkoxyalkyl)(meth) acrylamide can be used as the active energy ray hardenability N-substituted (meth) acrylamide of the compound.

As the bifunctional (meth) acrylate monomer, alkanediol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, halogen-substituted alkanediol di(meth)acrylic acid are representative. Di(meth) acrylate of ester, aliphatic polyol, di(meth) acrylate of hydrogenated dicyclopentadiene or tricyclodecane dialkyl alcohol, two Alkylene glycol or two a di(meth) acrylate of an alkyl dialkanol, a di(meth) acrylate of an alkylene oxide adduct of bisphenol A or bisphenol F, an epoxy group of bisphenol A or bisphenol F Base) acrylate and the like.

More specific examples of the bifunctional (meth) acrylate monomer include ethylene glycol di(meth) acrylate, 1,3-butylene glycol di(meth) acrylate, and 1,4- Butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(methyl) Acrylate, trimethylolpropane di(meth)acrylate, neopentyl alcohol di(meth)acrylate, bis(trimethylol)propane di(meth)acrylate, diethylene glycol di( Methyl) acrylate, triethylene glycol di(meth) acrylate, dipropylene glycol di(meth) acrylate, tripropylene glycol di(meth) acrylate, polyethylene glycol di(meth) acrylate, Di(meth)acrylic acid of polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, polyfluorene di(meth)acrylate, hydroxypivalate neopentyl glycol ester Ester, 2,2-bis[4-(methyl)propenyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(methyl)propenyloxyethoxyethoxy Cyclohexyl]propane, hydrogenated dicyclopentadienyl di(meth) acrylate, tricyclodecane dimethyl (meth) acrylate, 1,3-two Alkane-2,5-diyldi(meth)acrylate [alias two Alkanediol di(meth)acrylate], hydroxyl pivalaldehyde and trimethylolpropane acetal compound [chemical name 2-(2-hydroxy-1,1-dimethyl group B) Base)-5-ethyl-5-hydroxymethyl-1,3-di Di(meth)acrylate, hydroxy(hydroxyethyl)isocyanate di(meth)acrylate, etc. of alkane].

As a trifunctional or higher polyfunctional (meth) acrylate single Representative, such as: triglyceride (meth) acrylate, trimethylolpropane tri (meth) acrylate, bis (trimethylol) propane tri (meth) acrylate, di (trishydroxyl) Propane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, two new Pentaerythritol penta (meth) acrylate and dipentaerythritol Poly(meth)acrylate of a trifunctional or higher aliphatic polyol such as (meth)acrylate, and other: poly(meth)acrylate of a trifunctional or higher halogen-substituted polyol, and alkylene oxide addition of glycerin Tris(meth)acrylate, tris(meth)acrylate of trimethylolpropane alkylene oxide adduct, 1,1,1-cis[(meth)acryloxyethoxyethoxy Ethoxy]propane, hydroxy(hydroxyethyl)trimeric isocyanate tri(meth)acrylate, and the like.

On the other hand, in the (meth) acrylate oligomer, there is ammonia. An ester (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, an epoxy (meth) acrylate oligomer, or the like.

Urethane (meth) acrylate oligomer refers to intramolecular A compound having a urethane bond (-NHCOO-) and at least two (meth) propylene fluorenyloxy groups. Specifically, it may be a urethanization reaction product of a (meth) acrylate monomer having at least one (meth) acryloxy group and at least one hydroxyl group in the molecule and a polyisocyanate. Or a urethane compound having an isocyanate group at the terminal obtained by reacting a polyhydric alcohol with a polyisocyanate, and a methyl group having at least one (meth) acryloxy group and at least one hydroxyl group in the molecule. A urethane esterification reaction product of an acrylate monomer or the like.

a hydroxyl group-containing (methyl) used as a urethanization reaction Examples of the acrylate monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-benzene. Oxypropyl (meth) acrylate, glycerol di(meth) acrylate, trimethylolpropane di (meth) acrylate, neopentyl alcohol tri (meth) acrylate, dipentaerythritol Penta(meth)acrylate and the like.

Provided with such a hydroxyl group-containing (meth) propylene The polyisocyanate in the urethanization reaction of the acid ester monomer may, for example, be hexamethylene diisocyanate, diazonic acid diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate or methylphenyl phenyl diisocyanate. Di-n-butyl diisocyanate, a diisocyanate obtained by hydrogenating an aromatic isocyanate in such a diisocyanate (for example, hydrogenated methylphenyl diisocyanate, hydrogenated xylene diisocyanate, etc.), triphenylmethane triisocyanate, diphenyl A di- or tri-isocyanate such as a benzene triisocyanate or a polyisocyanate obtained by multiquantifying the above diisocyanate.

Also, by reacting with a polyisocyanate, As the polyol used for the urethane compound containing an isocyanate group at the end, a polyester polyol, a polyether polyol, or the like can be used in addition to the aromatic, aliphatic, and alicyclic polyols. Examples of the aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and neopentyl glycol. Trimethylolethane, trimethylolpropane, bis(trimethylol)propane, pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dihydroxyl Butyric acid, glycerin, hydrogenated bisphenol A, and the like.

Polyester polyols are made of the above polyols and polymorphs Dehydration condensation reaction of a sub-acid or its anhydride. An example of a polyprotic acid or an anhydride thereof is given by the note "(anhydride)", which is succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride). ), trimellitic acid (anhydride), pyromellitic acid (anhydride), phthalic acid (anhydride), isophthalic acid (anhydride), terephthalic acid (anhydride), hexahydrophthalic acid (anhydride) )Wait.

In addition to polyalkylene glycol, the polyether polyol can also be Polyoxyl obtained by reaction of a polyol or a dihydroxybenzene with an alkylene oxide Alkyl modified polyols and the like.

Polyester (meth) acrylate oligomer refers to intramolecular A compound having an ester bond and at least two (meth) propylene fluorenyloxy groups. Specifically, it can be obtained by a dehydration condensation reaction using (meth)acrylic acid, a polyproton acid or an anhydride thereof, and a polyhydric alcohol. An example of a polyprotic acid or an anhydride thereof used in the dehydration condensation reaction is exemplified by succinic acid (anhydride), adipic acid (anhydride), and maleic acid (hereinafter referred to as "anhydride"). Anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), phthalic acid (anhydride), isophthalic acid (anhydride) ), terephthalic acid (anhydride), and the like. Further, examples of the polyhydric alcohol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and neopentyl Alcohol, trimethylolethane, trimethylolpropane, bis(trimethylol)propane, neopentyl alcohol, dipentaerythritol, dimethylol heptane, trimethylolpropionic acid, two Hydroxymethyl butyric acid, glycerin, hydrogenated bisphenol A, and the like.

Epoxy (meth) acrylate oligomers can be polycondensed It is obtained by an addition reaction of glyceryl ether and (meth)acrylic acid, and has at least two (meth) acryloxy 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, and bisphenol. A diglycidyl ether and the like. When the active energy ray-curable compound is used as a standard, the amount of the radically polymerizable compound is usually 100% by weight or less, preferably 10% to 70% by weight.

When the curable resin composition contains a radical polymerizable compound as an active energy ray-curable compound, it is preferred to prepare a photoradical polymerization initiator. As the photoradical polymerization initiator, the radical polymerizable compound such as a (meth)acrylic compound may be polymerized by irradiation with an active energy ray such as visible light, ultraviolet light, X-ray or electron beam. Anyone known in the art can be used. Specific examples of the photoradical polymerization initiator include, for example, acetophenone, 3-methylacetophenone, benzyldimethylketal, 1-(4-isopropylphenyl). 2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl-2-morpholinylpropan-1-one and 2-hydroxy-2- Methyl-1-phenylpropan-1-one-like acetophenone-based initiator; diphenyl ketone, 4- Diphenyl ketone and 4,4'-diaminodiphenyl ketone-like diphenyl ketone-based initiator; such as benzhydryl propyl ether and benzhydryl ether An ether-based initiator; an oxythiazinone-based initiator such as 4-isopropyloxazepinone; and others, xanthone, anthrone, camphorquinone, benzaldehyde, anthraquinone, and the like.

These photoradical polymerization initiators are easily available from commercial products For example, "IRGACURE (registered trademark) 184", "IRGACURE (registered trademark) 907", "DAROCUR (registered trademark) 1173", and "Lucirin (registered trademark) TPO" manufactured by BASF Corporation are listed. Wait.

The amount of photoradical polymerization initiator, relative to (A The total amount of the radically polymerizable compound such as an acrylic compound is 100 parts by weight, usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight. When the amount of the photoradical polymerization initiator is small, the hardening is insufficient, and the mechanical strength or the adhesion between the protective layer and the polarizer layer tends to be lowered. When the amount of the photoradical polymerization initiator is too large, the active energy ray-curable compound in the curable resin composition is relatively small, and the obtained polarizing plate is obtained. The durability of optical properties is reduced.

Further, the curable resin composition may be the above-mentioned oxygen heterocyclic ring A butane compound, an oxetane compound, and an epoxy compound are used in combination with the above-mentioned radically polymerizable (meth)acrylic compound. By using these together, the effect of improving the hardness and mechanical strength of the first protective layer can be expected, and the viscosity and the curing speed of the curable resin composition can be adjusted more easily.

(other ingredients)

The curable resin composition may further contain a photosensitizer as needed. By blending the photosensitizer, the reactivity of the cationic polymerization and/or the radical polymerization is improved, and 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 persulfide compound, a redox compound, an azo and a diazo compound, a halogen compound, and a photoreducible dye.

Further, in the curable resin composition, it is also possible to add a usual A well-known polymer additive used in polymers. Examples of the polymer additive include a primary antioxidant such as a phenol type or an amine system, a sulfur secondary antioxidant, a hindered amine light stabilizer (HALS), a benzophenone type, and a benzotriazole system. And a benzoate-like ultraviolet absorber or the like.

Oxidation may also be added to the above curable resin composition 矽Microparticles. By adding cerium oxide microparticles, the hardness and mechanical strength of the obtained protective layer can be further improved. The cerium oxide fine particles can be adjusted, for example, to a curable resin composition as a liquid substance dispersed in an organic solvent.

The surface of the cerium oxide microparticles may also have a hydroxyl group or an epoxy group. A reactive functional group such as a (meth)acryloyl group or a vinyl group. Further, the particle size of the cerium oxide microparticles is usually 100 nm or less, preferably about 5 to 50 nm. When the particle diameter of the fine particles is more than 100 nm, there is a tendency that an optically transparent protective layer cannot be obtained.

When using cerium oxide microparticles dispersed in organic solution, The concentration of cerium oxide is not particularly limited, and may be, for example, about 20 to 40% by weight which can be obtained from a commercial product.

Further, the curable resin composition may be dissolved as needed Agent. The solvent is appropriately selected in consideration of the solubility of the component constituting the curable resin composition. Examples of the general solvent include aliphatic hydrocarbons such as n-hexane or cyclohexane; aromatic hydrocarbons such as toluene or xylene; such as methanol, ethanol, propanol, and isopropanol; a butanol-like alcohol; such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone ketones; such as methyl acetate, ethyl acetate and butyl phthalate esters; such as methyl celluloid Su, Ethyl sulphate and butyl acesulfame-like scorpion sulphate; halogenated hydrocarbons such as methylene chloride or chloroform. The blending ratio of the solvent is appropriately determined from the viewpoints of viscosity adjustment such as film forming property for the purpose of processing.

Further, the curable resin composition may contain leveling as needed Agent. When the curable resin composition is applied onto a polarizing film or a substrate, when the wettability is lacking on the polarizing film or the substrate, or when the surface property of the cured product of the curable resin composition is not good, Flat agents can improve their problems. As the leveling agent, various compounds such as a polyfluorene type, a fluorine type, a polyether type, an acrylic copolymer type, and a titanate type can be used. These levelers can be separately Use or mix two or more types and use them.

Relative to the active energy contained in the curable resin composition The amount of the linear curable compound is 100 parts by weight, and 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, more preferably 0.2 to 0.5 part by weight. When the amount is less than 0.01 part by weight, the improvement in wettability and surface properties tends to be insufficient, and when the amount is more than 1 part by weight, the adhesion between the polarizing film and the protective layer tends to be lowered.

Hardening of such active energy ray-curable compounds The first protective layer of the cured product of the resin composition preferably has a glass transition temperature (Tg) of 23 ° C or higher, more preferably 40 ° C or higher, still more preferably 50 ° C or higher, and particularly preferably 60 ° C or higher. When the glass transition temperature of the first protective layer is less than 23 ° C, the suppression of the decrease in optical performance of the polarizer layer tends to be insufficient. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

The thickness of the first protective layer is preferably 0.1 to 10 μm, more It is preferably from 1 to 5 μm, more preferably from 1.5 to 3 μm. When the thickness of the first protective layer is less than 0.1 μm, the reduction in durability and optical performance may be insufficient. On the other hand, when the thickness is more than 10 μm, the effect of thinning and weight reduction of the polarizing plate may be small.

The water contact angle of the first protective layer is preferably 60° or more, and more Preferably, it is 60° to 95°, and more preferably 60° to 80°. When the water contact angle of the first protective layer is less than 60°, the suppression of the decrease in optical performance may be insufficient. On the other hand, when the water contact angle is more than 95°, the adhesion to the polarizer may be insufficient. The tendency. The method of forming the first protective layer using the curable resin composition is as described later.

[Adhesive layer]

In the present invention, an adhesive layer is formed on the surface of the first protective layer opposite to the polarizer layer. The polarizing plate with an adhesive according to the present invention can be bonded to, for example, a liquid crystal cell via the adhesive layer. Among the adhesives (compositions) forming the adhesive layer, an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyether or the like can be used as the base polymer. Among them, in order to selectively use an acrylic adhesive, it is excellent in optical transparency and adhesion, and maintains moderate wettability and adhesion, and has weather resistance, heat resistance, and the like, and is heated or humidified. It is preferred that the peeling problem such as floating or peeling does not occur. In the acrylic adhesive, an alkyl ester of (meth)acrylic acid having an alkyl group having a carbon number of 20 or less, such as a methyl group, an ethyl group, and a butyl group, and (meth)acrylic acid or (meth)acrylic acid An acrylic copolymer having a weight average molecular weight of 100,000 or more, which is a functional group-containing acrylic monomer, such as a hydroxyethyl ester or the like, which has a glass transition temperature of preferably 25° C. or lower, more preferably 0° C. or lower. It can be used as a base polymer.

The formation of the adhesive layer can be carried out by the following means. For example, after the above-mentioned base polymer-containing adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a solution of 10 to 40% by weight, an adhesive is preliminarily formed on the release film. The layer moves the adhesive layer onto the transparent resin film, thereby forming an adhesive layer. In addition to the above-mentioned base polymer in the adhesive, a crosslinking agent is generally formulated. It is also preferred to formulate a decane coupling agent when the liquid crystal cell is to be bonded. Adhesive The thickness of the layer is determined depending on its adhesion and the like, and is usually in the range of 1 to 50 μm.

In the present invention, it is composed of a viscous compound containing an ionic compound. The composition of the agent forms an adhesive layer. The ionic compound is composed of a cationic component (organic cation or inorganic cation) and an anionic component (organic anion or inorganic anion). Hereinafter, the ionic compound having an organic cation, as exemplified in the structure of each organic cation, is as follows.

Pyridinium salt:

1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium Fluoromethylsulfonate, 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl) sulfoximine, 1-butyl-3-methylpyridinium bis(pentafluoroethyl) Sulfhydryl) sulfinium imide, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-hexylpyridinium tetrafluoroborate, 1-hexylpyridinium hexafluorophosphate, 1-hexyl-4 -Methyl-pyridinium bis(fluorosulfonyl) quinone imide, 1-octylpyridinium hexafluorophosphate, 1-butylpyridinium N-(trifluoromethylsulfonyl)trifluoroacetamidine An amine salt, 1-butyl-3-methylpyridinium N-(trifluoromethylsulfonyl)trifluoroacetamide salt, and the like.

Imidazolium salt:

1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium acetate, 1-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 salt, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) sulfoximine, 1-ethyl-3-methylimidazolium bis(pentafluoroethylsulfonyl) quinone Salt, 1-ethyl-3-methylimidazolium (trifluoromethylsulfonyl)methyl, 1-ethyl-3-methylimidazolium N-(trifluoromethylsulfonyl)trifluoro Acetamine salt, 1-butyl-3-methylimidazolium methylsulfonate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium Fluorophosphate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoride Methanesulfonate, 1-butyl-3-methylimidazolium perfluorobutylsulfonate Acid salt, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) sulfimine salt, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methyl Imidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-2,3 - dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl) sulfimine salt, and the like.

Pyrrolidinium salt:

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

Quaternary ammonium salt:

Tetrabutylammonium hexafluorophosphate, tetrabutylammonium p-toluenesulfonate, tetrahexylammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-diethyl-N-methyl- N-(2-methoxyethyl)ammonium tetrafluoroborate, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonate) Iridium imide salt, diallyldimethylammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis(trifluoromethyl) Sulfhydryl) quinone imide salt, diallyldimethylammonium bis(pentafluoroethylsulfonyl) sulfimine salt, Diallyldimethylammonium N-(trifluoromethylsulfonyl)trifluoroacetamide, glycidyltrimethylammonium trifluoromethanesulfonate, glycidyltrimethylammonium bis ( Trifluoromethylsulfonyl) sulfinium imide salt, glycidyl trimethylammonium bis(pentafluoroethylsulfonyl) sulfinium imide, glycidyl trimethylammonium N-(trifluoromethylsulfonate Mercapto) trifluoroacetamide salt, N,N-dimethyl-N-ethyl-N-propylammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl -N-ethyl-N-butylammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-ethyl-N-heptyl ammonium bis(trifluoromethyl Sulfhydryl) quinone imide salt, N,N-dimethyl-N-ethyl-N-hexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N -ethyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-ethyl-N-decyl ammonium bis(trifluoromethylsulfonate) Iridium imine salt, N,N-dimethyl-N,N-dipropylammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-propyl -N-butylammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-dimethyl-N-propyl-N-pentyl ammonium bis(trifluoromethylsulfonyl)醯 Imine salt, N,N-dimethyl-N-propyl-N-hexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-propyl-N -heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-butyl-N-hexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt , N,N-Dimethyl-N-butyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dimethyl-N-heptyl-N-hexyl Ammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-dimethyl-N,N-dihexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, trimethylglycol Alkyl ammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-diethyl-N-methyl-N-propyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-Diethyl-N-methyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-diethyl-N-methyl-N-heptyl Ammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-diethyl-N-propyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, triethyl Propyl ammonium bis(trifluoromethylsulfonyl) sulfimine salt, triethylheptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, Triethylheptyl ammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-dipropyl-N-methyl-N-ethylammonium bis(trifluoromethylsulfonyl) fluorene Imine salt, N,N-dipropyl-N-methyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dipropyl-N-butyl- N-hexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N,N-dipropyl-N,N-dihexyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, N , N-dibutyl-N-methyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfimine salt, N,N-dibutyl-N-methyl-N-hexylammonium double (trifluoromethylsulfonyl) quinone imide, trioctylmethylammonium bis(trifluoromethylsulfonyl) sulfinium salt, trioctylmethylammonium hexafluorophosphate, N-methyl -N-ethyl-N-propyl-N-heptyl ammonium bis(trifluoromethylsulfonyl) sulfinium salt, (2-hydroxyethyl)trimethylammonium bis(trifluoromethylsulfonate) A quinone imine salt, (2-hydroxyethyl)trimethylammonium dimethylphosphinate, and the like.

Examples of the ionic compound having an inorganic cation are listed below.

Lithium bromide, lithium iodide, Lithium tetrafluoroborate, lithium hexafluorophosphate, lithium isothiocyanate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethylsulfonyl) sulfinium salt, Lithium bis(pentafluoroethylsulfonyl) sulfinium imide, lithium ginseng (trifluoromethylsulfonyl) methylate, potassium bis(fluorosulfonyl) quinone imide salt, and the like.

The ionic compound having an organic cation and an inorganic cation, as listed above, has a relative ion (anion), respectively. The anion may be an organic anion or an inorganic anion as described above. Specific examples thereof include those shown in the above-exemplified ionic compounds.

These ionic compounds can be used individually or in combination of 2 or more types, respectively.

When the anion component constituting the ionic compound is hexafluorophosphate, the performance of the polarizer layer tends to be remarkably lowered. The polarizing plate with an adhesive according to the present invention can effectively suppress the deterioration of the performance of the polarizing sheet layer by the first protective layer even when such an adhesive composition containing an ionic compound is used.

The adhesive may be formulated with a filler, a pigment, a colorant, an antioxidant, an ultraviolet absorber, or the like, which is composed of an inorganic powder such as glass fiber, glass beads, resin beads, or metal powder, as needed. Examples of the ultraviolet absorber include a salicylate-based compound and a benzophenone-based compound. A benzotriazole-based compound, a cyanoacrylate-based compound, a nickel complex compound, or the like.

[Second protective layer]

The second protective layer is laminated on the surface of the polarizer layer opposite to the side on which the first protective layer is laminated. The second protective layer is not particularly limited, and a cellulose acetate resin, a cycloolefin resin, a polyolefin resin, an acrylic resin, a polyimide resin, a polycarbonate resin, or a polyester resin can be used. A thermoplastic resin film composed of a suitable material for forming a protective layer is widely used in the field. Further, similarly to the first protective layer described above, the second protective layer may be composed of a cured product of a curable resin composition containing an active energy ray-curable compound. From the viewpoint of mass productivity and adhesion, among the above, it is preferred to use a cellulose acetate resin film or a cycloolefin resin film as the second protective layer. Moreover, it is more preferable to use a cellulose acetate-based resin film as the second protective layer from the viewpoint of easiness in providing the surface treatment layer and optical characteristics.

In the present invention, it can be suitably used as the second protective layer The cellulose acetate-based resin film is a film composed of a part or a complete acetate of cellulose, and examples thereof include a cellulose triacetate film and a cellulose diacetate film.

As such a cellulose acetate-based resin film, it can be suitably used Commercial products. For example, "Fujitac (registered trademark) TD80", "Fujitac (registered trademark) TD80UF", "Fujitac (registered trademark) TD80UZ", "Konica Minolta Opto" sold by Fujifilm Co., Ltd.; Stocks "KC8UX2M" and "KC8UY" (all of which are trade names) sold.

Moreover, it can be suitably used in the cycloolefin system of the second protective layer. The resin refers to a thermoplastic resin (also referred to as a thermoplastic cycloolefin resin) having a monomer unit composed of a cyclic olefin (cycloolefin) such as a norbornene or a polycyclic norbornene-based monomer. The cycloolefin resin may be a ring-opening polymer of the above cycloolefin, a hydrogenated product of a ring-opening copolymer using two or more kinds of cyclic olefins, or a cyclic olefin, an aromatic compound having a chain olefin or a vinyl group, or the like. Addition polymer. Also, it is effective to introduce a polar base.

Using cycloolefins with aromatic olefins and vinyl groups When a copolymer of a fragrant compound is used to form a second protective layer, examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene, and nucleus. Base substituted styrene and the like. In such a copolymer, the monomer unit composed of a cyclic olefin may be 50 mol% or less (preferably 15 to 50 mol%). In particular, when a ternary copolymer of a cyclic olefin and an aromatic compound having a chain olefin and a vinyl group is used to form the second protective layer, the monomer unit composed of the cyclic olefin can be relatively small as described above. the amount. In such a terpolymer, the monomer unit composed of a chain olefin is usually 5 to 80 mol%, and the monomer unit composed of an aromatic compound having a vinyl group is usually 5 to 80 mol%.

As the cycloolefin resin, a suitable commercial product can be suitably used. For example, "TOPAS (registered trademark)" [manufactured by Topas Advanced Polymers GmbH], "ARTON (registered trademark)" [JSR (share) system], "ZEONOR (ZEONOR) (registered trademark)", and "ZEONEX (ZEONEX) (registered) Trademark) "[The above is Japanese ZEON (share) system], "Apelle (registered trademark)" [Mitsui Chemical (share) system] (above For the product name) and so on. When such a cycloolefin-based resin is formed into a film and used as a film, a known method such as a solution casting method or a melt extrusion method can be suitably used. In addition, for example, "Esushina (registered trademark)" and "SCA40" [above are Sekisui Chemical Industry Co., Ltd.], "ZEONORFILM (registered trademark)" [Japan ZEON Co., Ltd.], etc. Commercially available thin waxes made of resin can also be used.

The above cycloolefin resin film may be uniaxially stretched or doubled To the stretcher. The stretching ratio at this time is usually 1.1 to 5 times, preferably 1.1 to 3 times.

Polyolefin resin is a chain olefin such as ethylene or propylene The hydrocarbon is a polymer of the main monomer and may be a homopolymer or a copolymer. Among them, a homopolymer of propylene or a copolymer of a small amount of ethylene copolymerized with propylene is typical.

Acrylic resin is based on methyl methacrylate The polymer of the monomer may be a copolymer of methyl methacrylate and a acrylate such as methyl acrylate in addition to a homopolymer of methyl methacrylate.

Polyimine resin is based on a quinone bond in the main chain A polymer, which is typically obtained by polymerizing a tetracarboxylic acid 2 anhydride with a diamine to form a polyamic acid of a precursor of polyimine, and then performing a dehydration/cyclization reaction. And get it.

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

Polyester resin is a condensation polymerization of dibasic acid and glycol The resulting polymer is representative of polyethylene terephthalate.

On the other hand, a cured product of a curable resin composition When the second protective layer is formed, the same can be used for the description of the curable resin composition for forming the first protective layer. 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.

The second protective layer described above has a thin thickness It is preferable that when it is too thin, there is a tendency that the strength is lowered and the workability is not good, and when it is too thick, the transparency is lowered or the weight of the polarizing plate tends to be large. From such a viewpoint, the thickness of the second protective layer in the polarizing plate of the present invention is usually 5 to 100 μm, preferably 10 μm or more, and more preferably 80 μm or less, more preferably, when it is composed of a thermoplastic resin film. 50 μm or less. On the other hand, when the second protective layer is composed of a cured product of a curable resin composition, the thickness thereof may be 10 μm or less.

Moreover, the second protective layer can be paired and adhered to the polarizer layer The surface of the opposite side of the surface is subjected to surface treatment such as anti-glare treatment, hard coating treatment, antistatic treatment, and anti-reflection treatment. A coating layer composed of a liquid crystal compound, a high molecular weight compound or the like may be formed on the surface of the second protective layer opposite to the surface to which the polarizing plate layer is adhered.

[Next to the polarizer layer and the 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 an adhesive. When the films are bonded, in order to improve the adhesion, the polarizing film and/or the second protection The bonding surface of the layer can be appropriately subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (inflammation) treatment, saponification treatment, solvent treatment, and the like. As the saponification treatment, a method of immersing in an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide can be mentioned.

Used for bonding the polarizer layer and the second protective layer The subsequent agent is not particularly limited, and examples thereof include a curable resin composition containing an active energy ray-curable compound (active energy ray-curable adhesive), or an aqueous adhesive which dissolves or disperses the adhesive component in water ( Aqueous adhesive)).

As an active energy ray-curable adhesive, it can be used with The curable resin composition forming the first protective layer is the same. 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.

Further, as the aqueous adhesive, polyethylene is used. An adhesive composition containing an alcohol resin or a urethane resin as a main component.

Using polyvinyl alcohol-based resin as the main ingredient of the aqueous adhesive In the case of a component, the polyvinyl alcohol-based resin may be a vinyl alcohol homopolymer obtained by saponifying a polyvinyl acetate of a homopolymer of vinyl acetate, and may also include vinyl acetate and other copolymerizable copolymers. a copolymer of a monomer or the like. Examples of the other monomer copolymerized with vinyl acetate include an unsaturated carboxylic acid, an unsaturated sulfonic acid, an olefin, a vinyl ether, and an acrylamide having an ammonium group. The polyvinyl alcohol-based resin used in the subsequent agent is preferably a moderate degree of polymerization. For example, when it is an aqueous solution having a concentration of 4% by weight, the viscosity is At 4 to 50 mPa. The range of sec is better, at 6 to 30 mPa. The scope of sec is further better.

Further, it is preferred to use a modified polyvinyl alcohol tree. fat. Examples of a suitable modified polyvinyl alcohol-based resin include a polyvinyl alcohol-based resin modified with an ethylene oxime group, an anion-modified polyvinyl alcohol-based resin, and a cationically modified polyvinyl alcohol-based resin. . When such a modified polyvinyl alcohol-based resin is used, the effect of improving the water resistance of the adhesive layer is easily obtained.

Of course, the aqueous adhesive used in the present invention may comprise Two or more of the above-mentioned modified polyvinyl alcohol-based resins may further contain an unmodified polyvinyl alcohol-based resin (specifically, a wholly or partial saponified product of polyvinyl acetate) and the above modified polyethylene. Both of the alcohol resins.

a polyvinyl alcohol-based resin constituting an aqueous adhesive, which can be obtained from It is appropriately selected and used among commercially available products. Specifically, for example, "PVA-117H", "KL-318", "KM-118", and "CM-318" sold by kuraray; "GOHSENOL" sold by the Japanese synthetic chemical industry (shares) (registered trademark) NH-20", "GOHSEFIMER Z" series, "GOHSEFIMER (registered trademark) K-210" and "GOHSENAL (registered trademark) T-330" (all of which are trade names).

Aqueous adhesive containing polyvinyl alcohol resin as main component Among them, a crosslinking agent may be contained. If a compound which can be a crosslinking agent is disclosed depending on the type of the functional group, for example, an isocyanate compound having at least two isocyanato groups (-NCO) in the molecule; at least two epoxy groups in the molecule (crosslinked) -O-) epoxy compound; mono- or di-aldehyde; organotitanium compound; such as magnesium, calcium, a divalent or trivalent metal inorganic salt of iron, nickel, zinc and aluminum; a metal hydrazine of glyoxylic acid; a methylol melamine or the like.

Among these crosslinking agents, it is suitable to use: water soluble in the above A polyamine-based epoxy resin is an epoxy compound, or an aldehyde, methylol melamine, an alkali metal or an alkaline earth metal salt of glyoxylic acid.

The crosslinking agent is preferably dissolved together with the polyvinyl alcohol resin An adhesive is formed in water. However, as described below, the amount of the crosslinking agent in the aqueous solution is only a small amount, so that it can be used as a crosslinking agent as long as it has a solubility of, for example, at least about 0.1% by weight. Of course, the crosslinking agent used in the present invention is preferably a compound having a solubility in water which is generally referred to as water solubility.

The amount of the crosslinking agent is based on the type of the polyvinyl alcohol resin. It is suitably designed to be, for example, about 5 to 60 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the polyvinyl alcohol-based resin. When the crosslinking agent is blended in this range, good adhesion is obtained. When the amount of the crosslinking agent is too large, the reaction of the crosslinking agent proceeds in a short period of time, and the adhesive tends to be initially saponified. As a result, the pot life is extremely short and it is difficult to industrially use it.

In the aqueous adhesive, without impairing the effects of the present invention In the range, conventionally known additives such as a decane coupling agent, a plasticizer, an antistatic agent, and fine particles may be blended.

Use urethane resin as the main component of the aqueous adhesive In the case of a suitable adhesive, a mixture of a polyester-based ionic polymer type urethane resin and a compound having a glycidyloxy group can be mentioned. here The polyester-based ionic polymer type urethane resin is a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced therein. Such an ionic polymer type urethane resin is emulsified directly into water to form an emulsion without using an emulsifier, and is therefore suitably used for an aqueous adhesive. The use of a polyester-based ionic polymer type urethane resin for a polarizer layer and a protective layer is described in, for example, JP-A-2005-070140, Japanese Patent No. 4432487, and JP-A-2005-208456. In the bulletin.

Thickness of the adhesive layer obtained after drying or hardening The degree is usually about 0.01 to 5 μm, but it can be set to 1 μm or less when an aqueous adhesive is used. On the other hand, when an active energy ray-curable adhesive is used, it is preferably 2 μm or less, and more preferably 1 μm or less. When the underlayer is too thin, there is a fear that the film is insufficient. On the other hand, when the adhesive layer is too thick, the polarizing plate may have an appearance defect.

The polarizer layer and the second protective layer are also adhered to The aforementioned adhesive layer is carried out. In this case, it is preferred that the adhesive composition does not contain the ionic compound.

[Method of Manufacturing Polarizing Plate with Adhesive]

The polarizing plate of the present invention can be produced by the following steps (i) to (iii). Further, the order of the steps (i) and (ii) is not particularly limited, and the step (ii) may be performed first, or the steps may be simultaneously performed. Further, when the second protective layer is not laminated on the polarizer layer, the step (ii) is not required.

(i) a step of the first protective layer of the single-layer layer of the polarizer layer; (ii) a step of the second protective layer of the other area of the polarizer layer; (iii) a step of laminating an adhesive layer on the opposite side of the first protective layer from the polarizer layer.

In the above step (i), after the coating layer forming step, coating The layer bonding step, the hardening step, and the substrate removing step may be applied to the first protective layer of the single-layer layer of the polarizing sheet layer.

In the coating layer forming step, coating the substrate on the substrate The curable resin composition of the active energy ray-curable compound which is the first protective layer is dried as needed, and a coating layer of a curable resin composition is provided on the surface of the substrate. Here, as the substrate, for example, a metal belt, a glass plate or the like can be used in addition to the above-mentioned base material. Further, the surface of the substrate coated with the curable resin composition may be subjected to, for example, a release treatment.

In the coating layer bonding step, the coating layer is formed In the step, the coating layer formed on the substrate and the polarizer layer are bonded to each other to form a laminated body of the laminated polarizer layer/coating layer/substrate. Further, in the above step, when the step (ii) is performed earlier than the step (i), the layered system has a second protective layer on the side of the polarizer layer opposite to the coating layer.

In the hardening step, for the laminate, for example, from a substrate The active energy ray such as visible light, ultraviolet ray, X-ray, or electron beam is irradiated or heated to cure the coating layer composed of the curable resin composition to form the first protective layer. Next, in the substrate removal step, the removal of the substrate on the first protective layer is performed.

Also, as another method of performing step (i), it is also possible to The curable resin composition forming the first protective layer is directly applied to the polarizer layer, and irradiates or heats the active energy ray, whereby the curable resin is made A method in which a coating layer composed of a composition is hardened to form a first protective layer. According to this method, the first protective layer can be formed even without using a substrate.

The above step (ii) is carried out when the polarizer is laminated on the second protective layer. When a thermoplastic resin film is used as the second protective layer, the second protective layer is laminated via the adhesive layer. The layering of the second protective layer is carried out as follows. First, an adhesive composition is applied to the bonding surface of the second protective layer, and dried as needed. Next, the polarizer layer and the second protective layer are bonded to each other by interposing the adhesive composition, and a laminated body of the laminated polarizer layer/adhesive composition/second protective layer is sequentially formed, and then dried or The laminate is irradiated with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams or heated to cure the adhesive composition to bond the polarizer layer and the second protective layer. At this time, a drying step may be provided as needed. Further, when the above step (i) is carried out earlier than the step (ii), the layered system has a first protective layer on the side of the polarizer layer opposite to the coating layer. Since the active energy ray-curable adhesive is used in combination with the polarizer layer and the second protective layer, it is not necessary to provide a drying step, so that it is expected to improve the manufacturing efficiency.

Moreover, as a method different from the above, the adhesive composition is directly applied to the bonding surface of the polarizing plate layer, and the second protective layer is laminated by interposing the composition, and then dried or irradiated with active energy rays. Or a method of heating to cure the adhesive to bond the polarizer layer and the second protective layer. That is, in the method, the drying step can be set as needed.

In the step (ii), when a cured product of a curable resin composition containing an active energy ray-curable compound is used as the second protective layer, it can be carried out in the same manner as in the above step (i).

The first protective layer and the second protective layer may be simultaneously shaped to make. When the second protective layer is a thermoplastic resin film, the laminate obtained by the above steps (i) and (ii) (second protective layer/adhesive composition/polarizing sheet/curable resin forming the first protective layer) For example, the coating layer/substrate of the composition can be irradiated with an active energy ray or heated from the substrate side to simultaneously cure the adhesive composition and the coating layer.

The second protective layer is a cured product of a curable resin composition In the case of the layered body obtained by the above steps (i) and (ii) (coating layer/coating layer of the curable resin composition forming the second protective layer/polarizing sheet layer/curing property of forming the first protective layer) The coating layer/substrate of the resin composition can be irradiated with active energy rays or heating from one side or both sides of the substrate side to cure the coating layer at the same time. According to such a method, the hardening step can be completed once, and it is expected that the manufacturing efficiency can be further improved.

In the present invention, it will contain a first or second protection The method of applying the adhesive composition of the active energy ray-curable compound of the layer and the adhesive composition to which the polarizer layer and the second protective layer are bonded is not particularly limited, and for example, a doctor blade or a bar coat can be used. Various coating methods such as cloth machine, die coater, angle wheel coater, and gravure coater.

Moreover, as a method different from the above coating method, The above-mentioned curable resin composition or adhesive composition is dropped between the polarizer layer and the substrate, or between the polarizer layer and the second protective layer, and then uniformly expanded by a roller or the like. The method. In this method, as the material of the roller, metal or rubber or the like can be used. In the case of a roller, when a pair of rollers are used (when the laminate passes between the rollers), the rollers can be the same Material or different material.

Forming the first or the first by irradiating the active energy ray When the curable resin composition of the second protective layer and/or the above-described adhesive composition are cured, the light source to be used is not particularly limited, but may be used for a light-emitting distribution having a wavelength of 400 nm or less. Specific examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a fluorescent lamp, a black light lamp, a microwave excited mercury lamp, and a metal halide lamp.

The light irradiation intensity of the active energy ray may vary depending on the respective components to be irradiated, but it is preferably an irradiation of a wavelength region effective for activation of the photoradical polymerization initiator and/or photocationic polymerization initiator Those having a strength of 10 to 2500 mW/cm ² . When the light irradiation intensity is less than 10 mW/cm ² , the reaction time is too long, and when it is more than 2500 mW/cm ² , the heat of the lamp and the heat generation during the polymerization of the curable resin composition or the adhesive composition, the curable resin The composition or the composition of the adhesive has a possibility of causing yellowing and deterioration of the polarizing sheet.

The light irradiation time of the curable resin composition or the composition of the adhesive is controlled by each of the irradiated components, but is not particularly limited, but it is preferably such that the cumulative amount of light represented by the product of the irradiation intensity and the irradiation time becomes 10 to Set by 2500mJ/cm ² . When the cumulative amount of light is less than 10 mJ/cm ² , the generation of the active species from the polymerization initiator is insufficient, and the hardening of the obtained protective layer and the adhesive layer may be insufficient. Further, when the cumulative light amount is more than 2,500 mJ/cm ² , the irradiation time becomes extremely long, which is disadvantageous for improving productivity. Further, it is preferable that the irradiation of the active energy ray is performed within a range in which various properties such as the degree of polarization and the transmittance of the polarizer layer are not lowered.

In the above item (iii), the first protective layer and the polarizer On the opposite side of the layer, an adhesive layer can be laminated to obtain a polarizing plate with an adhesive. The lamination of the adhesive layer can be carried out, for example, by a method using a release film or a method of applying an adhesive composition on the first protective layer. In the method of using a release film, the adhesive layer can be formed by, for example, applying the adhesive composition to the release treatment surface of the release film which has been subjected to the release treatment to form an adhesive layer. The first protective layer of the laminated polarizing plate is carried out. Further, the method of applying the adhesive composition to the first protective layer can be carried out by, for example, applying an adhesive composition to the bonding surface of the first protective layer of the polarizing plate to form an adhesive layer. In this method, it is preferred to preliminarily protect the adhesive layer in order to obtain a layered release film of the adhesive.

The polarizing plate with adhesive of the invention can be applied to liquid crystal The liquid crystal display device is constituted by a unit or the like, and it is preferable to laminate the release film on the side of the adhesive layer beforehand and to protect it in advance. The release film used herein may be a film composed of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate. The material is applied to a bonding surface of the substrate film and the adhesive layer, and a release treatment such as a polyoxygen treatment. Further, the adhesive layer was sandwiched between two release films in advance, and the release film on either side was peeled off as needed, and then attached to the polarizing plate.

[Liquid Crystal Display Device]

The polarizing plate with an adhesive of the present invention can be applied to a glass substrate. As One of suitable suitable forms is, for example, a form in which a layer of a pressure-sensitive adhesive layer is laminated on a glass substrate. In order to laminate the polarizing plate with an adhesive to the glass substrate, for example, the release film may be peeled off from the above-mentioned polarizing plate with an adhesive, and the exposed adhesive layer may be bonded to the surface of the glass substrate. Examples of the glass substrate include a glass substrate constituting a liquid crystal cell, an antiglare glass, and a glass for sunglasses. Wherein, a polarizing plate with an adhesive layer attached to the glass substrate on the front side (identification side) of the liquid crystal cell, and an optical layered body formed by laminating another polarizing plate with an adhesive on the glass substrate on the back side of the liquid crystal cell can be used. It is preferable as a panel (liquid crystal panel) for a liquid crystal display device. Examples of the material of the glass substrate include soda lime glass, low alkali glass, and alkali-free glass. However, it is preferable to use an alkali-free glass in the liquid crystal cell.

The polarizing plate with an adhesive of the present invention can be disposed on the liquid crystal One side or both sides of the unit. The polarizing plates disposed on both sides of the liquid crystal cell may be the same or different. Further, the polarizing plate to which the adhesive of the present invention is applied may be disposed on one side of the liquid crystal cell, and different polarizing plates may be disposed on the opposite side of the liquid crystal cell.

(Example)

Hereinafter, the present invention will be specifically described by way of examples. However, the invention is not limited to the following embodiments. In the examples, the parts and % of the amount used and the content are indicated, unless otherwise stated.

First, an example of a composition for preparing a curable resin is listed. In the preparation of the curable resin composition, the following compounds were used.

<Active energy ray-curable compound>

"Celloxide (registered trademark) 2021P": 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, obtained from Daicel Chemical Co., Ltd.

"OXT-221": bis(3-ethyl-3-oxetanylmethyl)ether. Obtained by East Asian Synthetic (Shares).

"OXT-212": 2-ethylhexyloxybutane, obtained from East Asian Synthetic Co., Ltd.

"A-DCP": Tricyclodecane dimethanol diacrylate obtained from Shin-Nakamura Chemical Co., Ltd.

"DMAA": N,N-dimethyl methacrylate, obtained from Xingren (share).

"4HBA": 4-hydroxybutyl acrylate obtained from Nippon Kasei Co., Ltd.

"UV-3700B": a bifunctional urethane acrylate obtained by the Japan Synthetic Chemical Industry Co., Ltd.

"CHDMMA": 1,4-cyclohexane dimethanol monoacrylate obtained from Nippon Kasei Co., Ltd.

"OXT-101": 3-ethyl-3-hydroxymethyloxetane, obtained from East Asia Synthetic Co., Ltd.

<Photocationic polymerization initiator>

"ADEKA OPTOMER (registered trademark) SP-150": 4,4'-bis[diphenyldihydrothio]diphenyl sulfide bishexafluorophosphate photocationic polymerization initiator, with propylene carbonate solution The form was obtained by (share) ADEKA.

<Photoradical polymerization initiator>

"IRGACURE (registered trademark) 907": 2-methyl-1-[4-(methylthio)benzene Benzyl-2-morpholinylpropan-1-one, obtained from BASF Japan.

"DAROCUR (registered trademark) 1173": 2-hydroxy-2-methyl-1-phenyl-propan-1-one, obtained from BASF Japan.

<Other ingredients>

"SH710": Polyoxane leveling agent, available from Dow Corning Toray.

[Manufacturing Example 1] Modification of Curable Resin Compositions A to V

The following components were mixed and prepared into the curable resin compositions A to V, respectively. The photocationic polymerization initiator "ADEKA OPTOMER SP-150" is a propylene carbonate solution, and the following is expressed by the amount of the active ingredient.

<Curable resin composition A>

<Curable resin composition B>

<Curable resin composition C>

<Curable resin composition D>

<Curable resin composition E>

<Curable resin composition F>

"SH710" 0.2 parts

<Curable resin composition G>

<Curable resin composition H>

<Curable resin composition I>

<Curable resin composition J>

<Curable resin composition K>

<Curable resin composition L>

<Curable resin composition M>

<Curable resin composition N>

<Curable resin composition O>

<Curable resin composition P>

<Curable resin composition Q>

<Curable resin composition R>

<Curable resin composition S>

<Curable resin composition T>

<Curable resin composition U>

<Curable resin composition V>

[Manufacturing Example 2] Production of a 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 μm was stretched in a uniaxial manner to about 4 times in a dry state, and further kept in a stretched state and immersed in pure water at 40 ° C. After a minute, it was further immersed in an aqueous solution of iodine/potassium iodide/water in a weight ratio of 0.05/10/100 at 28 ° C for 60 seconds. Then, it was immersed at 68 ° C for 300 seconds in an aqueous solution of potassium iodide / boric acid / water in a weight ratio of 8.5 / 7.5 / 100. Then, it was washed with pure water of 10 ° C for 20 seconds, and then dried at 65 ° C to prepare a polarizing film in which iodine was adsorbed to the uniaxially stretched polyvinyl alcohol film. The thickness of the polarizing film was 11 μm.

Next, an example of modulating the adhesive is listed. Among the polyvinyl alcohol and the epoxy crosslinking agent, the following compounds are used.

<polyvinyl alcohol>

"KURARAY POVAL (registered trademark) KL318": a carboxyl-modified polyvinyl alcohol obtained from KURARAY.

<epoxy crosslinking agent>

"Sumirez resin (registered trademark) 650": a water-soluble polyamine epoxy resin (an aqueous solution having a solid concentration of 30%) obtained from Chem Chemex.

[Manufacturing Example 3] Preparation of Aqueous Adhesive

The following components were mixed to prepare an aqueous binder. The epoxy-based crosslinking agent "Sumirez resin 650" is an aqueous solution, and the following is expressed by the amount of the active ingredient.

<Aqueous adhesive>

[Manufacturing Example 4] Production of Polarizing Plate A

The surface of the polarizer layer produced in Production Example 2 was coated with the aqueous adhesive prepared in Production Example 3, and bonded to a protective layer composed of cellulose saponified by cellulose acylate [Konica Minolta Opto ), KC2UA, 25μm thick, called the second protective layer]. This was dried at 60 ° C for 6 minutes to prepare a polarizing plate A having a second protective layer on one side.

[Example 1] (1) Production of polarizing plate

The curable resin composition A prepared in the production example 1 was applied to a cycloolefin resin film having a thickness of 50 μm so as to have a film thickness after curing of about 1 μm by a bar coater [Japan ZEON Co., Ltd. One side of the product name "ZEONOR (registered trademark)"]. The coated surface was bonded to the side of the polarizing plate of the polarizing plate A produced in Production Example 4 to prepare a laminated body. The ultraviolet ray irradiation apparatus of the attached conveyor [the light system is "D bulb" manufactured by Fusion UV Systems Co., Ltd.] is irradiated with ultraviolet rays from the side of the cycloolefin resin film of the laminate to have a cumulative light amount of 500 mJ/cm ² . The curable resin composition is cured, and then the cycloolefin resin film is peeled off from the laminate. In this manner, a polarizing plate composed of a first protective layer (cured material of a curable resin composition) / a polarizer layer / an adhesive layer / a second protective layer was produced.

Next, on the first protective layer side of the polarizing plate produced in (1), an ionic compound was prepared, and a layer of an acrylic adhesive imparting an antistatic function was provided. The following are used as an isocyanate crosslinking agent, a decane coupling agent, and an antistatic agent formulated in an adhesive.

<Isocyanate crosslinking agent>

Coronate (registered trademark) L: an ethyl acetate solution of a trimethylolpropane adduct of methyl phenyl diisocyanate (solid content concentration: 75%), obtained from Japanese Polyurethane Co., Ltd.

<Chane coupling agent>

KBM-403: 3-glycidoxypropyltrimethoxydecane, liquid, obtained from Shin-Etsu Chemical Co., Ltd.

<antistatic agent>

1-hexylpyridinium Hexafluorophosphate, a compound of the formula below.

(2) Formation of adhesive layer

An organic solvent solution of an acrylic adhesive obtained by adding an isocyanate crosslinking agent, a decane coupling agent, and an antistatic agent to a copolymer of butyl acrylate, methyl acrylate, acrylic acid, and hydroxyethyl acrylate, and having been applied thereto Release-treated 38 μm thick polyethylene terephthalate film [trade name "SP-PLR382050", obtained from LINTEC (share), called release film] release treatment surface, using die coater The thickness after drying was 20 μm, and the sheet-like adhesive of the release film was prepared. Next, in the first protective layer of the polarizing plate produced in the above (1), the surface (adhesive surface) opposite to the release film of the above-mentioned sheet-like adhesive is bonded to each other by a laminator, and then at a temperature. The laminate was aged for 7 days at 23 ° C and a relative humidity of 65% to obtain a polarizing plate provided with an adhesive layer.

[Examples 2 to 7]

In Example 1, a polarizing plate was produced in the same manner as in Example 1 except that the thickness of the curable resin composition and the first protective layer described in Table 1 was changed.

[Embodiment 8]

The curable resin composition F prepared in the production example 1 was applied to the side of the polarizer layer of the polarizing plate A produced in Production Example 4, and the film thickness after curing was about 2 μm. . From the side of the curable resin composition of the laminate, an ultraviolet irradiation device (the "D bulb" manufactured by Fusion UV Systems Co., Ltd.) was used, and the amount of accumulated light was 500 mJ/cm ² . The ultraviolet light is irradiated to harden the curable resin composition. In this manner, a polarizing plate composed of a first protective layer/polarizing sheet/adhesive layer/second protective layer was fabricated. Except for the above, durability evaluation was carried out in the same manner as in Example 1, and the results were summarized in Table 1.

[Examples 9 to 24]

In the second embodiment, a polarizing plate was produced in the same manner as in Example 2 except that the curable resin composition described in Table 1 was changed.

[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, the adhesive was directly laminated on the polarizer layer.

<Evaluation of Optical Durability of Polarizing Plate>

The polarizing plate provided with the adhesive layer prepared in the above (2) was cut into a size of 30 mm × 30 mm, and the release film was peeled off, and the adhesive layer side was attached to the alkali-free glass [trade name of Corning Co., Ltd." EAGLE XG (registered trademark)"]. The sample was subjected to autoclave treatment at a temperature of 50 ° C and a pressure of 5 kgf / cm ² (490.3 kPa) for 1 hour, and then left to stand in an environment of a temperature of 23 ° C and a relative humidity of 55% for 24 hours. Install the optional film holder with polarizing film to the UV-Vis spectrophotometer [product name "UV2450" of Shimadzu Corporation) to measure the polarizing plate in the range of 380 to 700 nm. The transmission spectrum of the transmission axis direction and the absorption axis direction is obtained, and the degree of polarization Py (unit: %) is obtained based on these. The optical performance in this state was measured as the initial Py, and the optical properties (Py after the test) after standing for 100 hours in an environment of 60 ° C and a relative humidity of 90% were measured, and the change in the degree of polarization ΔPy was calculated from the following formula. 1 in the "△Py" column. The optical performance after further standing for 60 hours in an environment of 60 ° C and a relative humidity of 90% (total standing for 250 hours) was measured, and the change in polarization degree ΔPy was calculated. The results are also shown in the column of "ΔPy" in Table 1. .

△Py = initial Py-Py after test

<Measurement of Glass Transition Temperature (Tg) of First Protective Layer>

Two sheets of a cycloolefin resin film having a thickness of 50 μm as used in Example 1 were prepared. Then, the surface of the film was coated with a bar coater, and the curable resin compositions A to V prepared in Production Example 1 were applied so as to have a film thickness of 2 μm after curing, and the coated surface was coated. In the same manner as in the first embodiment, the ultraviolet light was irradiated so as to have a cumulative light amount of 250 mJ/cm ² to cure the curable resin composition. Next, the film which sandwiched the cured product was peeled off, and 5 mg of the cured product was scraped off, and then placed in a lid-shaped container in which aluminum was pressed, and sealed, and a sample for measurement was prepared.

A differential scanning calorimeter (DSC) "EXSTAR-6000 DSC6220" sold by SII NanoTechnology Co., Ltd. was used, and the container in which the above-mentioned measurement sample was placed was placed, and the temperature was lowered from 20 ° C to -60 ° C while removing nitrogen gas. After reaching -60 ° C for 1 minute, the temperature was raised from -60 ° C to 200 ° C at a temperature increase rate of 10 ° C / minute. If it reached 200 ° C, it was immediately cooled to 20 ° C. Then, from the DSC curve when the temperature was raised from -60 ° C to 200 ° C, the intermediate point glass transition temperature specified in JIS K 7121-1987 "Method for Measuring Transfer Temperature of Plastics" was determined, and this was made into the first protective layer (hardening). The glass transition temperature of the material). The results are shown in the "Tg" column of Table 1.

<Measurement of Water Contact Angle of First Protective Layer>

Two sheets of a cycloolefin resin film having a thickness of 50 μm as used in Example 1 were prepared. Then, the surface of one of the films was coated with a bar coater, and the curable resin compositions A to V prepared in Production Example 1 were applied so as to have a film thickness of 2 μm after curing. In the same manner as in the first embodiment, the ultraviolet ray was irradiated to the film of the other sheet so that the cumulative amount of light became 250 mJ/cm ² to cure the curable resin composition. Next, the film in which the cured product was sandwiched was peeled off, and a water contact angle of 8 μL of the dropped water and allowed to stand for 180 seconds was measured on the cured product using a fully automatic contact angle measuring apparatus [product name "OCA35" manufactured by DataPhysics Co., Ltd.]. The results are shown in the "water contact angle" column of Table 1.

It can be seen from Table 1 that comparison with no first protective layer In Example 1, after the 100-hour test, the degree of polarization decreased by 1.53% after the 0.20%, 250-time test, however, the examples of the first protective layer were lower than the comparative example, and the first protective layer was The thicker the thickness, the greater the tendency. Further, in Examples 4 and 5 in which the oxetane-based compound was used alone or in combination with the epoxy-based compound, the degree of polarization after the 100-hour test was lowered to 0%, and the effect of suppressing the decrease in optical performance was remarkably exhibited. Further, in Examples 6 to 8 containing an acrylic compound, it was found that the decrease in the degree of polarization can be suppressed even when the film thickness is 2 μm, and in particular, in Examples 7 and 8 in which the Tg is high, the degree of polarization after the test for 100 hours is still lowered. When it is 0%, the effect of suppressing a decrease in optical performance is remarkably exhibited similarly to the oxetane compound. Again, water contact In Examples 1 to 22 in which the angle was 60° or more, it was found that the decrease in the degree of polarization after the 250-hour test was 0.5% or less, and the effect of suppressing the decrease in optical performance was remarkably exhibited.

Claims (12)

A polarizing plate with an adhesive, which is provided with: 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 an adhesive layer containing an ionic property The composition of the adhesive of the compound. The polarizing plate with an adhesive according to claim 1, wherein the polarizer layer is provided with a second protective layer on a surface opposite to the first protective layer. The polarizing plate with an adhesive according to claim 2, wherein the second protective layer is a transparent resin film formed of a thermoplastic resin. The polarizing plate with an adhesive according to any one of claims 1 to 3, wherein the active energy ray-curable compound contains a cationically polymerizable compound. The polarizing plate with an adhesive according to claim 4, wherein the ionic polymerizable compound contains a compound having at least one oxirane ring. The polarizing plate with an adhesive according to any one of claims 1 to 5, wherein the active energy ray-curable compound contains at least one (meth) acryloxy group ( Methyl) acrylic compound. The polarizing plate with an adhesive 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 polarizing plate with an adhesive according to any one of claims 1 to 7, wherein the first protective layer has a thickness of 0.1 to 10 μm. The polarizing plate with an adhesive according to any one of claims 1 to 8, wherein the first protective layer has a water contact angle of 60 or more. The polarizing plate with an adhesive according to any one of claims 1 to 9, wherein the adhesive layer is provided with a release film. A liquid crystal display device comprising a liquid crystal cell and a polarizing plate with an adhesive according to any one of claims 1 to 9. The liquid crystal display device according to claim 11, wherein the polarizing plate with the adhesive is attached to the liquid crystal cell on the side of the adhesive layer.