TWI660851B - Polarizing plate with adhesive and liquid crystal display device - Google Patents

Abstract

The present invention provides a polarizing plate with an adhesive capable of suppressing a decrease in optical performance of a polarizer layer even when an ionic compound is contained in an adhesive composition forming an adhesive layer.

It comprises, in order, a polarizer layer, a first protective layer that is a hardened material of a curable resin composition containing an active energy ray-curable compound, and an adhesive layer composed of an adhesive composition containing an ionic compound. . The polarizer layer may include a second protective layer on a 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 is used as one of the optical elements constituting a liquid crystal display device. A polarizing plate is generally used in a state where a double-area layer transparent resin film of a polarizer layer is used as a protective layer, and is incorporated in a liquid crystal display device. As described in 186133 (Patent Document 1), a polarizing plate in which a protective layer is laminated only on one side of a polarizer layer.

However, in general, a polarizing plate is formed with an adhesive layer formed on the outermost layer, and is circulated in a state in which a release film is adhered to the adhesive layer. Before bonding to the liquid crystal cell, the release film was peeled from the polarizing plate and bonded to the liquid crystal cell via the exposed adhesive layer. Such a polarizing plate has a problem of generating static electricity when the release film is peeled and bonded to a liquid crystal cell. Therefore, for example, there has been proposed a method for forming an adhesive film as described in Japanese Patent Application Laid-Open No. 2009-251281 (Patent Document 2). A method for compounding an ionic compound in an adhesive of an agent layer to impart an antistatic function.

Generally, in the polarizing plate described in Patent Document 1, The adhesive layer is laminated on the surface of the polarizer layer where the protective layer is not laminated (the side opposite to the surface of the laminated protective layer). However, when an ionic compound is formulated in the adhesive composition forming the adhesive layer, the The influence of the compound, especially the optical performance of the polarizer in the moist-heat resistance test, has a problem. With regard to such a problem, for example, Japanese Patent Application Laid-Open No. 2014-32360 (Patent Document 3) describes that the degradation of performance can be suppressed by selecting the composition of the ionic compound to be formulated. However, due to the limitation of the ionic compound, the composition of the adhesive composition may have problems of poor compatibility or reduced adhesive force, which may cause peeling or lifting of the polarizing plate in a heat resistance test.

[Prior technical literature] [Patent Literature]

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

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

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

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

The inventors of the present case have conducted in-depth studies in order to achieve the above-mentioned object, and as a result, found that the polarizer layer and the A protective layer of a cured product of a curable resin composition containing an active energy ray-curable compound is provided between the adhesive layers formed by the adhesive composition, which can suppress the deterioration of the polarizer layer under humid and hot conditions to complete this invention.

That is, from one perspective, the present invention provides A polarizing plate with an adhesive is sequentially provided with: a polarizer layer; a first protective layer, which is a hardened product of a curable resin composition containing an active energy ray-curable compound; and an adhesive layer, which contains ions It is composed of an adhesive composition of a sexual compound.

In the above-mentioned polarizer with an adhesive, the polarizer layer The 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-mentioned active energy ray-curable compound contains A cationically polymerizable compound is preferred. The cationically polymerizable compound is more preferably a compound containing a compound having at least one ethylene oxide ring.

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

In the above-mentioned polarizer with an adhesive, the first protection is 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 higher.

The polarizing plate with an adhesive of the present invention can be The layer side is bonded to a liquid crystal cell or the like. Therefore, until its use, its adhesive A release film having a release treatment laminated on top of each other is preferred.

The above-mentioned polarizing plate with adhesive can be applied to liquid The crystal unit serves 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 any of the above-mentioned polarizing plates with an adhesive. As one of its preferable forms, a polarizing plate with an adhesive is attached to a liquid crystal cell on 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 having significantly reduced optical properties of the polarizer layer, or the protective layer is present between the adhesive layer and the polarizer layer When the thickness is thin, the deterioration of the optical performance 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 sequentially laminated: a polarizer 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. In addition, 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 addition, in this specification, a curable resin composition containing an active energy ray-curable compound may be referred to simply as a "curable resin composition", and a curable resin composition containing an active energy ray-curable compound may be cured. The material is only referred to as "hardened product of curable resin composition". The following explains the respective components. member.

[Polarizer layer]

The polarizer layer system may be one obtained by adsorbing and aligning a dichroic dye to a uniaxially stretched polyvinyl alcohol resin. In the present invention, the thickness of the polarizer layer is generally 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 polarizer layer is used in which a dichroic dye is adsorbed and aligned with a polyvinyl alcohol-based resin layer, the polyvinyl alcohol-based resin monomer may be stretched, or polyethylene may be coated on a substrate or the like. After the solution of the alcohol-based resin is dried, the substrate is stretched together with the substrate to remove the substrate. When stretched together with the substrate, it becomes easy to produce a polarizer layer having a thickness of 7 μm or less.

Examples of the substrate include polyterephthalic acid. Ethylene film, polycarbonate film, cellulose triacetate film, norbornene film, polyester film, polystyrene film, etc.

Polyvinyl alcohol-based as a polyvinyl alcohol-based resin layer As the resin, a saponified polyvinyl acetate resin can be used. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith can be listed. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamide having an ammonium group.

The degree of saponification of polyvinyl alcohol resin can be 80 mol% or more Above, it is preferably in the range of 90 to 99.5 mole%, more preferably in the range of 94 to 99. Moire% range. When the degree of saponification is less than 80 mol%, the water resistance and humidity and heat resistance of the obtained polarizing plate may decrease. When the degree of saponification exceeds 99.5 mol%, the dyeing speed may be slowed, productivity may be lowered, and a polarizer layer having sufficient polarizing performance may not be obtained.

The so-called saponification degree refers to the ratio of the acetic acid group (acetoxy: -OCOCH ₃ ) contained in the polyvinyl acetate-based resin of the polyvinyl alcohol-based resin to the hydroxyl group in the unit ratio (mole) according to the saponification step. %) Is defined by the following formula. In addition, the degree of saponification can be obtained in accordance with JIS K 6726: 1994 "Polyvinyl alcohol test method", which indicates that the higher the degree of saponification, the higher the ratio of the hydroxyl groups, and therefore the lower the ratio of the acetic acid group that inhibits crystallization.

Saponification degree (mol%) = 100 × (hydroxyl number) / (hydroxyl number + acetic acid group number)

The polyvinyl alcohol-based resin may be a part of modified polyvinyl alcohol, for example, it may be used: modified from olefins such as ethylene and propylene; modified from unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; Modified ones such as alkyl esters of unsaturated carboxylic acids and acrylamide. The modification ratio of the polyvinyl alcohol-based resin is preferably less than 30 mol%, and more preferably less than 10%. When the modification exceeds 30 mol%, the dichroic pigment tends to be difficult to adsorb, and a polarizer layer having sufficient polarizing performance may not be obtained.

The average degree of polymerization of the polyvinyl alcohol-based resin is preferably about 100 to 10,000, more preferably 1500 to 8000, and even more preferably 2000 to 5000. The average degree of polymerization of the polyvinyl alcohol-based resin can also be determined in accordance with JIS K 6726: 1994 "Polyvinyl alcohol test method". When the average degree of polymerization is less than 100, it is difficult to obtain better polarization performance, and the average degree of polymerization exceeds At 10,000, the solubility in a solvent is deteriorated, and it is difficult to form a polyvinyl alcohol-based resin layer.

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

The dichroic pigment contained in the polarizer 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, 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. A dichroic pigment can be used individually by 1 type or in combination of 2 or more types.

[First protective layer]

As described above, the first protective layer laminated on one side 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 that can be hardened by irradiation of active energy rays (for example, ultraviolet rays, visible light, electron rays, X-rays, and the like). The active energy ray-curable compound may be a compound containing a cationically polymerizable compound, a compound containing a radically polymerizable compound, or both.

Examples of the cationically polymerizable compound include: A compound having at least one ethylene oxide ring in the molecule (hereinafter sometimes referred to as "oxetane compound"), a compound having at least one epoxy group in the molecule (hereinafter sometimes referred to as simply "oxetane compound") "Epoxy compounds"), etc.

In addition, as examples of the radical polymerizable compound, Examples: A compound having at least one (meth) acrylic acid group in the molecule (hereinafter sometimes referred to as "(meth) acrylic compound"), and having one (meth) acrylic acid group in the molecule. Amine-based compounds (hereinafter sometimes referred to as "(meth) acrylamidoamine-based compounds") and the like. In addition, "(meth) acrylic" means methacrylic or acrylic, "(meth) acryloxy" means methacryl or oxy, and (meth) acryl Amine means methacrylamide or acrylamide.

Among these, oxetane compounds and / or (form In the case of an acrylic acid-based compound, the effect of suppressing the decrease in the optical performance of the polarizer layer is significant.

An oxetane compound has at least 1 in the molecule Compounds of an ethylene oxide ring (4-membered cyclic ether) include, for example, 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [(3-ethyl-3-oxo Heterobutyl) methoxymethyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, di [(3-ethyl-3-oxetanyl ) Methyl] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, phenol novolak oxetane, and the like. These oxetane compounds can be easily obtained from commercially available products, and are all represented by the 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 ", and the like.

The amount of the oxetane compound is not particularly limited It is generally 90% by weight or less, preferably 20 to 80% by weight, based on the entire cationically polymerizable compound. The curable resin composition may be added to the oxetane compound described above, and may contain an epoxy compound. By adding an epoxy compound, the adhesiveness of a curable resin composition and a polarizer layer becomes more favorable.

The epoxy-based compound is not particularly limited. However, aromatic epoxy compounds, glycidyl ethers of polyhydric alcohols having an alicyclic ring, aliphatic epoxy compounds, and epoxy compounds having an alicyclic epoxy compound can be listed.

Examples of the aromatic epoxy compound include bisphenol A Diglycidyl ether, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S as bisphenol epoxy resin; phenol novolac epoxy resin, Methylphenol novolac epoxy resin and hydroxybenzaldehyde novolac epoxy novolac epoxy resin; glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether and ring of tetrahydroxydiphenyl ketone Polyfunctional epoxy resin such as oxidized polyvinyl phenol.

The glycidyl ether of a polyhydric alcohol having an alicyclic ring may be An aromatic polyol is obtained by glycidyl etherification of a nuclear hydrogenated polyhydroxy compound obtained by selectively performing a hydrogenation reaction on an aromatic ring in the presence of a catalyst and under pressure. Examples of the aromatic polyol include bisphenol compounds such as bisphenol A, bisphenol F, and bisphenol S; phenol novolac resins, methylphenol novolac resins, and phenol novolac resins such as hydroxybenzaldehyde phenol novolac resin Varnish-type resin; polyfunctional compounds like tetrahydroxydiphenylmethane, tetrahydroxydiphenyl ketone, and polyvinylphenol. The alicyclic polyol obtained by subjecting the aromatic ring of these aromatic polyols to a hydrogenation reaction with epichlorohydrin can react as an glycidyl ether. Preferred examples of the glycidyl ether of a polyhydric alcohol having an alicyclic ring include hydrogenated bisphenol A diglycidyl ether.

The aliphatic epoxy compound may be an aliphatic polyhydric alcohol or 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 trimethylolpropane Ether; diglycidyl ether of polyethylene glycol; diglycidyl ether of propylene glycol; diglycidyl ether of neopentyl glycol; ethylene glycol, propylene glycol, or glycerol due to the addition of aliphatic polyols 1 or 2 Polyglycidyl ethers of polyether polyols obtained from more than one type of alkylene oxide (ethylene oxide or propylene oxide).

Moreover, the monofunctional epoxy compound represented by following formula (I) can also be mentioned 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 or 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 typical example of the monofunctional epoxy compound represented by the formula (I) is 2-ethylhexyl glycidyl ether.

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

A compound in which (CH ₂ ) _n in the formula (II) is bonded to other chemical structures after removing one or more hydrogen atoms is a alicyclic epoxy compound. One or more hydrogen atoms in (CH ₂ ) _n forming an alicyclic ring may be appropriately substituted by a linear alkyl group such as a methyl group or an ethyl group.

In the epoxy compound as described above, alicyclic epoxidation Compounds, that is, compounds having at least one epoxy group bonded to an alicyclic ring, especially those having epoxy cyclohexane [n = 4 in the above formula (II)] or epoxy cycloheptane Epoxy compound [n = 5 in the above formula (II)] due to its hardenability The hardened material of the resin composition has a higher modulus of elasticity, and a protective layer having excellent adhesiveness with a polarizer layer is easily obtained, so it is more suitable for use. Specific examples of the alicyclic epoxy compound will be described below. Here, the compound names are listed first, and then the corresponding chemical formulas are listed. The same symbols are attached to the compound names and the corresponding chemical formulas.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy -6-methylcyclohexane carboxylic acid ester; C: ethylidene bis (3,4-epoxycyclohexane carboxylate); D: bis (3,4-epoxycyclohexylmethyl) hexane Acid esters; 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-tetra Trispiro [5.2.2.5.2.2] Icosane; I: 3- (3,4-epoxycyclohexyl) -8,9-epoxy-1,5-di Spiro [5.5] undecane; J: 4-vinylcyclohexene dioxide; K: limonene dioxide; L: bis (2,3-epoxycyclopentyl) ether; M: dicyclopentyl dioxide Diene.

In the curable resin composition, the epoxy compound may be alone Use 1 type or 2 or more types together.

The compounding amount of the epoxy compound is not particularly limited, except that The entire cationically polymerizable compound is based on 90% by weight or less, and preferably 20 to 80% by weight. When the active energy ray-curable compound is used as a reference, the compounding amount of the cationically polymerizable compound is usually 100% by weight or less, and preferably 30 to 90% by weight.

The curable resin composition is compounded with oxetane When a cationic polymerizable compound such as an epoxy 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 to consider the deformation caused by the heat resistance or expansion of the polarizer layer will be reduced, and the first protective layer can be formed on the polarizer with good adhesion. On the floor. In addition, since the photocationic polymerization initiator has a catalytic effect with light, even if it is mixed with the curable resin composition, it has excellent storage stability and workability.

Photo-cationic polymerization initiator Irradiation of active energy rays such as external rays, X-rays, and electron rays to generate cationic species or easy acid, and start a polymerization reaction of a cationically polymerizable compound. The photocationic polymerization initiator may be of any type, but specific examples include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; iron-arene complexes, and the like.

Examples of the aromatic diazonium salt include the following Compound.

Benzenediazonium hexafluoroantimonate; Benzenediazonium hexafluorophosphate; benzenediazonium hexafluoroborate and so on.

Examples of the aromatic iodonium salt include the following Compound.

Diphenyliodonium (pentafluorophenyl) borate; diphenyliodonium hexafluorophosphate; diphenyliodonium hexafluoroantimonate; bis (4-nonylphenyl) iodonium hexafluorophosphate Salt, etc.

Examples of the aromatic sulfonium salt include the following Compound.

Triphenylphosphonium hexafluorophosphate; triphenylphosphonium hexafluoroantimonate; triphenylphosphonium (pentafluorophenyl) borate; 4,4'-bis [diphenyldihydrosulfanyl ] Diphenyl sulfide bishexafluorophosphate; 4,4'-bis [bis (β-hydroxyethoxy) phenyl dihydrothio] diphenyl sulfide bishexafluoroantimonate; 4,4 '-Bis [bis (β-hydroxyethoxy) phenyldihydrothio] diphenylsulfide dihexafluorophosphate; 7- [bis (p-tolylmethyl) dihydrothio] -2- Isopropyloxanthanone hexafluoroantimonate; 7- [bis (p-toluenyl) dihydrothio] -2-isopropyloxanthanone (pentafluorophenyl) borate ; 4-phenylcarbonyl-4'-diphenyldihydrothio-diphenylsulfide hexafluorophosphorus Acid salt; 4- (p-third butylphenylcarbonyl) -4'-diphenyldihydrothio-diphenylsulfide hexafluoroantimonate; 4- (p-third butylphenylcarbonyl) -4'-bis (p-toluenylmethyl) dihydrothio-diphenylsulfide (pentafluorophenyl) borate and the like.

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

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

These photocationic polymerization initiators can be easily obtained from commercially available products, and are each represented by a trade name. For example, "KAYARAD (registered trademark) PCI-220" and "KAYARAD (registered (Trademark) PCI-620 ";" UVI-6990 "sold by The Dow Chemical Company;" UVACURE 1590 "sold by Daicel Saitech (stock);" 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 Soda Japan 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 individually Or it mixes 2 or more types and uses it. Among these, especially the aromatic sulfonium salt has ultraviolet absorption characteristics even in a wavelength range of 300 nm or more, so it can be hardened with excellent hardenability, good mechanical strength, or good adhesion to the polarizer layer It is suitable for use because it is a hardened resin composition.

The amount of the photocationic polymerization initiator is The total of 100 parts by weight of the cationically polymerizable compound containing the epoxy compound or oxetane compound is usually 0.5 to 20 parts by weight, and preferably 1 to 6 parts by weight. When the blending amount of the photocationic polymerization initiator is small, the curing is insufficient, and the mechanical strength and the adhesiveness between the first protective layer and the polarizer layer tend to decrease. On the other hand, when the amount of the photocationic polymerization initiator is too much, the optical properties of the polarizer layer may be reduced.

The curable resin composition includes radical polymerization When the compound is an active energy ray-curable compound, the radical polymerizable compound may be, for example, a (meth) acrylic compound or a (meth) acrylamido compound. Examples of the (meth) acrylic compound include (meth) acrylic acid ester monomers having at least one (meth) acryloxy group in the molecule, and obtained by reacting two or more kinds of compounds having a functional group. A (meth) acrylate oligomer having at least two (meth) acryloxy groups in the molecule. These systems can be used individually or in combination of 2 or more types. When two or more kinds of (meth) acrylic compounds are used in combination, two or more kinds of (meth) acrylate monomers may be used, and two or more kinds of (meth) acrylate oligomers may be used. One or more kinds of meth) acrylate monomers and one or more kinds of (meth) acrylate oligomers. In addition, "(meth) acrylate" means methacrylate or acrylic acid ester.

In the (meth) acrylic acid ester monomer: A monofunctional (meth) acrylate monomer having one (meth) acryloxy group in the inside, a bifunctional (meth) acrylate monomer having two (meth) acryloxy groups in the molecule, and A polyfunctional (meth) acrylate monomer having three or more (meth) acryloxy groups in the molecule.

Specific as a monofunctional (meth) acrylate monomer Examples include tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (methyl Base) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, meth (meth) acrylate, ethyl (meth) Acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, third butyl (meth) acrylate, 2-ethylhexyl (methyl Base) acrylate, isononyl (meth) acrylate, cyclohexyl (meth) acrylate, 1,4-cyclohexanedimethanol monoacrylate, dicyclopentenyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, benzyl (meth) acrylate, pentenyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxy Ethyl (meth) acrylate, dimethylamino ethyl (meth) acrylate, ethyl carbitol (meth) acrylate, trimethylol propylene mono (meth) acrylate, neopentyl Tetraol mono (meth) acrylate, phenoxy polyethylene glycol (formaldehyde ) Acrylate and the like.

As a monofunctional (meth) acrylate monomer, (Meth) acrylate monomers having a carboxyl group. Examples of the monofunctional (meth) acrylate monomer containing a carboxyl group include 2- (meth) acryloxyethyl phthalic acid Ester, 2- (meth) acryloxyethylhexahydrophthalate, carboxyethyl (meth) acrylate, 2- (meth) acryloxyethyl succinate, N- (formaldehyde) Group) acryloxy-N ', N'-dicarboxymethyl p-phenylene diamine ester, 4- (meth) acryloxyethyl trimellitate, and the like.

As the (meth) acrylamide-based compound, N- Substituted (meth) acrylamide. N-substituted (meth) acrylamide is (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 the nitrogen atom of (meth) acrylamide. This ring is in addition to the carbon atom and the nitrogen atom of (meth) acrylamide It may have an oxygen atom as a ring member. Furthermore, the carbon atoms constituting the ring may be bonded by a substituent such as an alkyl group or a pendant oxygen group (= O). N-substituted (meth) acrylamide is generally produced by the reaction of (meth) acrylic acid or its chloride with a primary or secondary amine.

The N-substituted (meth) acrylamide is particularly preferable as shown 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, Q ³ represents an alkyl group having 1 to 6 carbon atoms which may have a hydroxyl group or an amine group, Alternatively, Q ² and Q ³ may form a 5-membered ring or a 6-membered ring having a nitrogen atom and an oxygen atom bonded thereto as ring members. When Q ² is an alkyl group, and when 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, as long as they have 3 or more carbon atoms. In the case where Q ³ is an alkyl group having a hydroxyl group, a hydroxyalkyl group corresponds to this. In the case where Q ³ is an alkyl group having an amine group, the amino alkyl group, the N-alkylamino alkyl group, and the N, N dialkylamino alkyl group correspond to them. When Q ² and Q ³ are brought together and have a nitrogen atom and an oxygen atom having equal bonds as a 5-membered ring or 6-membered ring constituting a ring, if an example of the 5-membered ring or 6-membered ring is revealed at the N-position, In the form of a group attached to a carbonyl group (C = O), there are 1-pyrrolidinyl (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-) and so on.

Specific examples of N-substituted (meth) acrylamidoamine corresponding to the above formula (III), Q ² is a hydrogen atom, and Q ³ is an alkyl group are listed as: N-methyl (meth) acrylamido Amine, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-third butyl (meth) acryl Amidoamine, N-hexyl (meth) acrylamidonium and the like. Similarly, specific examples of N-substituted (meth) acrylamide where Q ² and Q ³ are both alkyl groups include N, N-dimethyl (meth) acrylamide, N, N -Diethyl (meth) acrylamide and the like.

Similarly, specific examples of N-substituted (meth) acrylamidonium in which Q ² is a hydrogen atom and Q ³ is an alkyl group having a hydroxyl group include N-hydroxymethyl (meth) acrylamidonium , N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, and the like. Similarly, specific examples of N-substituted (meth) acrylamidonium in which Q ² is a hydrogen atom and Q ³ is an alkyl group having an amine group include N- [2- (N, N-dimethylformate) Methylamino) ethyl] (meth) acrylamide, N- [2- (N, N-diethylamino) ethyl] (meth) acrylamide, N- [3- (N, N-dimethylamino) propyl] (meth) acrylamide, N- [1-methyl-1- (N, N-dimethylamino) ethyl] (meth) acrylamide Wait.

In addition, specific examples of N-substituted (meth) acrylamidonium in which Q ² and Q ³ in the formula (III) are joined together to form a 5-membered ring or a 6-membered ring together with the nitrogen atom to which they are bonded. Yes: N-propenylpyrrolidine, 3-propenyl-2-yl Oxazolidinone, 4-propenylmorpholine, N-propenylpiperidine, N-methacrylpiperidine and the like.

Of the above-mentioned N-substituted (meth) acrylamidoniums, preferred N-hydroxyalkyl (meth) acrylamide like N-hydroxymethacrylamide and N- (2-hydroxyethyl) acrylamide, and N, N-dimethylacrylamide And N, N-diethylacrylamide, N, N-dialkyl (meth) acrylamide, particularly N- (2-hydroxyethyl) acrylamide or N, N-dimethylformamide Acrylamide.

Others, like N-dodecyl (meth) acrylamide N-alkyl (meth) acrylamide of long chain alkyl, or N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propyl Both oxymethyl) acrylamide and N- (alkoxyalkyl) (meth) acrylamide like N- (butoxymethyl) acrylamine can be used as active energy ray hardeners The compound is N-substituted (meth) acrylamide.

Typical bifunctional (meth) acrylate monomers are alkanediol di (meth) acrylate, polyoxyalkanediol di (meth) acrylate, and halogen-substituted alkanediol di (meth) acrylic acid. Esters, di (meth) acrylates of aliphatic polyols, di (meth) acrylates of hydrogenated dicyclopentadiene or tricyclodecanedialkanol, di Alkanediol or di Di (meth) acrylates of alkanedialkanols, alkylene oxide adducts of bisphenol A or bisphenol F, di (meth) acrylates, epoxy bis (formaldehyde) of bisphenol A or bisphenol F Group) acrylate and the like.

More specific examples of bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,3-butanediol 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 (meth) Acrylate, trimethylolpropane di (meth) acrylate, neopentaerythritol di (meth) acrylate, bis (trimethylol) propane di (meth) acrylate, diethylene glycol di ( (Meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, polysiloxane di (meth) acrylate, di (meth) acrylic acid of neopentyl glycol tert-valerate Ester, 2,2-bis [4- (meth) acryloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloxyethoxyethoxyethoxy Cyclohexyl] propane, hydrogenated dicyclopentadienyl di (meth) acrylate, tricyclodecane dimethyl di (Meth) acrylate, 1,3-di Alkane-2,5-diyldi (meth) acrylate [alias di Alkanediol di (meth) acrylate], acetal compound of hydroxyl pivalaldehyde and trimethylolpropane [Chemical name 2- (2-hydroxy-1,1-dimethylethyl ) -5-ethyl-5-hydroxymethyl-1,3-di Alkane] di (meth) acrylate, gins (hydroxyethyl) isotricyanate di (meth) acrylate, and the like.

As a trifunctional or higher polyfunctional (meth) acrylate mono Body, representative: eg glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, bis (trimethylol) propane tri (meth) acrylate, bis (trimethylol) Propyl) propane tetra (meth) acrylate, neopentaerythritol tri (meth) acrylate, neopentaerythritol tetra (meth) acrylate, dinepentaerythritol tetra (meth) acrylate, dixin Pentaerythritol penta (meth) acrylate and dinepentaerythritol hexa (Meth) acrylate-like poly (meth) acrylates with tri- or higher-functional aliphatic polyols, others: poly (meth) acrylates with tri- or higher-functional halogen-substituted polyols, glycerine alkylene oxide addition Tris (meth) acrylate, trimethylolpropane alkylene oxide adducts tris (meth) acrylate, 1,1,1-ginseng ((meth) acryloxyethoxyethoxy Ethoxy] propane, ginseng (hydroxyethyl) trimeric isocyanate tri (meth) acrylates and the like.

On the other hand, among (meth) acrylate oligomers, there is ammonia Ester (meth) acrylate oligomer, polyester (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, and the like.

Urethane (meth) acrylate oligomer refers to the molecule A compound having a urethane bond (-NHCOO-) and at least two (meth) acrylic fluorenyloxy groups. Specifically, it may be a urethane reaction product of a hydroxyl group-containing (meth) acrylic acid ester monomer and polyisocyanate having at least one (meth) acryloxy group and at least one hydroxyl group in the molecule, Or, a urethane compound containing an isocyanate group at the end 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, respectively. ) Product of urethane reaction of acrylate monomer and the like.

Hydroxyl-containing (methyl) used in urethane reaction Examples of the acrylate monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 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 (meth) acrylic acid containing hydroxyl groups Examples of the polyisocyanate in the urethanization reaction of an ester monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylphenyl diisocyanate, Xylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates in these diisocyanates (such as hydrogenated methylphenyl diisocyanate, hydrogenated xylene diisocyanate, etc.), triphenylmethane triisocyanate, dibenzoyl Di- or tri-isocyanates such as phenyltriisocyanate, and polyisocyanates obtained by quantifying the above-mentioned diisocyanates.

In addition, by reacting with polyisocyanate, it is used as As the polyol used for the urethane compound containing an isocyanate group at its terminal, in addition to aromatic, aliphatic, and alicyclic polyols, polyester polyols, polyether polyols, and the like can also be used. Examples of the aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, Trimethylolethane, trimethylolpropane, bis (trimethylol) propane, neopentaerythritol, dinepentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylol Butyric acid, glycerol, hydrogenated bisphenol A, etc.

Polyester polyols are It is obtained by dehydration condensation reaction of a carboxylic acid or its anhydride. Examples of polyprotic acids or their anhydrides are shown in the note "(anhydride)" for those that can be anhydrous. Examples include: succinic acid (anhydride), adipic acid, maleic acid (anhydride), and 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 glycols, polyether polyols can also be Polyoxygenates obtained by the reaction of the above-mentioned polyols or dihydroxybenzenes with alkylene oxides Alkyl-modified polyols and the like.

Polyester (meth) acrylate oligomer refers to the molecule A compound having an ester bond and at least two (meth) acrylic fluorenyloxy groups. Specifically, it can be obtained by a dehydration condensation reaction using a (meth) acrylic acid, a polyprotic acid or an anhydride thereof, and a polyhydric alcohol. Examples of the polyprotic acid or its anhydride used in the dehydration condensation reaction are shown in the note "(anhydride)" if it can be an anhydride. Examples include: succinic acid (anhydride), adipic acid (anhydride), and maleic acid ( Anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), phthalic acid (anhydride), isophthalic acid (anhydride) ), Terephthalic acid (anhydride), etc. 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, neopentaerythritol, dipentaerythritol, dimethylol heptane, trimethylolpropanoic acid, diamine Hydroxymethyl butyric acid, glycerol, hydrogenated bisphenol A, etc.

Epoxy (meth) acrylate oligomers can be polycondensed It is obtained by the addition reaction of hydroglyceryl ether and (meth) acrylic acid, and has at least two (meth) acrylic acid 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 entire active energy ray-curable compound is used as a reference, the blending amount of the radical polymerizable compound is usually 100% by weight or less, and 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 preferable to mix a photoradical polymerization initiator. As the photo-radical polymerization initiator, any active polymer such as a (meth) acrylic compound can be polymerized by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron rays. A conventionally known one can be used. Specific examples of the photoradical polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, and 1- (4-isopropylphenyl). 2-hydroxy-2-methylpropane-1-one, 2-methyl-1- [4- (methylthio) phenyl-2-morpholinylpropane-1-one, and 2-hydroxy-2- Methyl-1-phenylpropane-1-one-like acetophenone-based initiators; diphenylmethanone, 4- Diphenyl ketone and 4,4'-diamino diphenyl ketone-like diphenyl ketone-based initiators; such as benzamyl propyl ether and benzamidine ether Ether-based initiators; oxanthrone-based initiators such as 4-isopropyloxanthrone; other, xanthones, fluorenone, camphorquinone, benzaldehyde, anthraquinone, etc.

These photo-radical polymerization initiators can be easily obtained from commercial products Obtained and expressed by product names, 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 blending amount of the photo-radical polymerization initiator is The total amount of radical polymerizable compounds such as acryl-based compounds is 100 parts by weight, usually 0.5 to 20 parts by weight, and preferably 1 to 6 parts by weight. When the blending amount of the photo radical polymerization initiator is small, the curing is insufficient, and the mechanical strength and the adhesion between the protective layer and the polarizer layer tend to decrease. When the amount of the photoradical polymerization initiator is too large, the active energy ray-curable compound in the curable resin composition will be relatively small. The durability of optical characteristics may be reduced.

In addition, the curable resin composition can convert the above-mentioned oxo ring A butane compound, an oxetane compound, and an epoxy compound are used in combination with the aforementioned radically polymerizable (meth) acrylic compound. By using these in combination, the effect of increasing the hardness and mechanical strength of the first protective layer can be expected, and adjustment of the viscosity and curing speed of the curable resin composition can be made easier.

(Other ingredients)

The curable resin composition may further contain a photosensitizer as needed. By adjusting the photosensitizer, the reactivity of cationic polymerization and / or 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 carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreducible pigments.

In addition, the curable resin composition may be added with a general Well-known polymer additives used in polymers. Examples of the polymer additive include primary antioxidants such as phenol or amine, secondary antioxidants based on sulfur, hindered amine light stabilizers (HALS), such as benzophenone, and benzotriazole. And benzoate-based ultraviolet absorbers.

Oxidation may be added to the curable resin composition Silicon particles. By adding silica fine particles, the hardness and mechanical strength of the obtained protective layer can be further improved. The silicon oxide fine particles can be formulated in a curable resin composition as a liquid substance dispersed in an organic solvent, for example.

The surface of the silica particles can also have hydroxyl groups, epoxy Reactive functional groups such as a methyl group, a (meth) acrylfluorenyl group, and a vinyl group. The particle diameter of the silicon oxide fine particles is usually 100 nm or less, and preferably about 5 to 50 nm. When the particle diameter of the fine particles is larger than 100 nm, there is a tendency that an optically transparent protective layer cannot be obtained.

When using organic-soluble silica particles, the The silicon oxide concentration is not particularly limited, and it can be obtained from commercially available products, for example, about 20 to 40% by weight.

Furthermore, the curable resin composition may contain a solvent, if necessary. Agent. The solvent is appropriately selected in consideration of the solubility of the components constituting the curable resin composition. Examples of common solvents include: aliphatic hydrocarbons such as n-hexane or cyclohexane; aromatic hydrocarbons such as toluene or xylene; such as methanol, ethanol, propanol, isopropanol, and Alcohols like n-butanol; ketones like acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters like methyl acetate, ethyl acetate, and butyl gallate; Sulfur, ethyl sulfa and butyl sulfa, such as dichloromethane or chloroform halogenated hydrocarbons. The blending ratio of the solvent is appropriately determined from the viewpoint of film-forming properties, such as viscosity adjustment for processing purposes.

The curable resin composition may contain a leveling agent as necessary. Agent. When the curable resin composition is applied to a polarizing film or a substrate, when the wetting property is not sufficient on the polarizing film or the substrate, or when the surface property of the cured product of the curable resin composition is not good, it is necessary to add a finishing agent. Leveling agents can improve these problems. As the leveling agent, various compounds such as a polysiloxane system, a fluorine system, a polyether system, an acrylic copolymer system, and a titanate system can be used. These leveling agents can be individually Use or mix two or more types.

Relative to the active energy contained in the curable resin composition The amount of the line-curing compound is 100 parts by weight, the leveling agent is preferably 0.01 to 1 part by weight, more preferably 0.1 to 0.7 part by weight, and even more preferably 0.2 to 0.5 part by weight. When the added amount is less than 0.01 part by weight, the improvement of wettability and surface properties tends to be insufficient, and when the added amount is more than 1 part by weight, the adhesiveness of the polarizing film and the protective layer tends to decrease.

Hardening of such active energy ray hardening compound The glass transition temperature (Tg) of the first protective layer of the cured product of the resin composition is preferably 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 reduction of the 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, and more It is preferably 1 to 5 μm, and more preferably 1.5 to 3 μm. When the thickness of the first protective layer is less than 0.1 μm, the suppression of reduction in durability and optical performance may be insufficient. On the other hand, when the thickness of the first protective layer is more than 10 μm, the effect of reducing the thickness and weight of the polarizing plate may be small.

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

[Adhesive layer]

In the present invention, an adhesive layer is formed on a surface of the first protective layer opposite to the polarizer layer. The polarizing plate with an adhesive of the present invention can be attached to, for example, a liquid crystal cell via the adhesive layer. As the adhesive (composition) forming the adhesive layer, an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyether, or the like can be used as a base polymer. Among them, it is selected to use, such as acrylic adhesives, excellent optical transparency and adhesion, and maintain moderate wettability and adhesion, more weather resistance and heat resistance, etc., and under heating or humidifying conditions It is preferable that peeling problems such as floating or peeling do not occur. In an acrylic adhesive, an alkyl ester of (meth) acrylic acid having an alkyl group having a carbon number of 20 or less such as methyl, ethyl, and butyl, and (meth) acrylic acid or (meth) acrylic acid An acrylic copolymer having a functional group-containing acrylic monomer having a weight average molecular weight of 100,000 or more, which is prepared such that the glass transition temperature is preferably 25 ° C or lower, and more preferably 0 ° C or lower. , Can be used as a base polymer.

The formation of the adhesive layer can be performed in the following manner, For example, the adhesive composition including the above-mentioned base polymer is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a solution of 10 to 40% by weight, and then an adhesive is formed on the release film in advance. Layer, and the adhesive layer is moved onto the transparent resin film, thereby forming an adhesive layer. In addition to the above-mentioned base polymer, the crosslinking agent is generally formulated in the adhesive. When bonding liquid crystal cells, it is better to mix silane coupling agent. Adhesive The thickness of the layer is determined depending on the adhesion force and the like, and is usually in the range of 1 to 50 μm.

In the present invention, the The adhesive composition forms an adhesive layer. An ionic compound is composed of a cationic component (organic or inorganic cation) and an anionic component (organic or inorganic anion). In the following, ionic compounds having organic cations are exemplified in the structure of each organic cation as shown below.

Pyridinium salt:

1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium tri Fluoromethylsulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethylsulfonyl) fluorenimide salt, 1-butyl-3-methylpyridinium bis (pentafluoroethyl) Sulfofluorenyl) phosphonium imine salt, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-hexylpyridinium tetrafluoroborate, 1-hexylpyridinium hexafluorophosphate, 1-hexyl-4 -Methyl-pyridinium bis (fluorosulfonyl) fluorenimide salt, 1-octylpyridinium hexafluorophosphate, 1-butylpyridinium N- (trifluoromethylsulfonyl) trifluoroacetamidine Amine salt, 1-butyl-3-methylpyridinium N- (trifluoromethylsulfonyl) trifluoroacetamidamine salt, and the like.

Imidazolium salts:

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 trifluoromethylsulfonate, 1- Ethyl-3-methylimidazolium perfluorobutylsulfonate, 1-ethyl-3-methylimidazolium p-toluenesulfonate, 1-ethyl-3-methylimidazolium dicyanamide salt, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) fluorenimide salt, 1-ethyl-3-methylimidazolium bis (pentafluoroethylsulfonyl) sulfonium imine Salt, 1-ethyl-3-methylimidazolium (trifluoromethylsulfonyl) methyl, 1-ethyl-3-methylimidazolium N- (trifluoromethylsulfonyl) trifluoro Acetylamine salt, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexa Fluorophosphate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoro Methanesulfonate, 1-butyl-3-methylimidazolium perfluorobutylsulfonate Acid salt, 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) fluorenimide 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) phosphonium imine salt, and the like.

Pyrrolidinium salts:

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

Quaternary ammonium salt:

Tetrabutylammonium hexafluorophosphate, tetrabutylammonium p-toluenesulfonate, tetrahexylammonium bis (trifluoromethylsulfonyl) sulfonium imine salt, N, N-diethyl-N-methyl- N- (2-methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethylsulfonium) Stilbene) imine salt, diallyldimethylammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethyl) Sulfofluorenyl) phosphonium imine salt, diallyldimethylammonium bis (pentafluoroethylsulfonyl) phosphonium imine salt, Diallyldimethylammonium N- (trifluoromethylsulfonyl) trifluoroacetamide salt, glycidyltrimethylammonium trifluoromethylsulfonate, glycidyltrimethylammonium bis ( Trifluoromethylsulfonyl) sulfonium imine salt, glycidyl trimethylammonium bis (pentafluoroethylsulfonyl) phosphonium imine salt, glycidyl trimethylammonium N- (trifluoromethylsulfonate) (Fluorenyl) trifluoroacetamidine salt, N, N-dimethyl-N-ethyl-N-propylammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-dimethyl -N-ethyl-N-butylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethyl Sulfofluorenyl) phosphonium imine salt, N, N-dimethyl-N-ethyl-N-hexylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dimethyl-N -Ethyl-N-heptylammonium bis (trifluoromethylsulfonyl) sulfonium imine salt, N, N-dimethyl-N-ethyl-N-nonylammonium bis (trifluoromethylsulfonylsulfonium) Sulfonium) imine salt, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-dimethyl-N-propyl -N-butylammonium bis (trifluoromethylsulfonyl) fluorenimide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethylsulfonyl) XI Imine salt, N, N-dimethyl-N-propyl-N-hexylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dimethyl-N-propyl-N -Heptylammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethylsulfonyl) sulfonium imine salt N, N-dimethyl-N-butyl-N-heptylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dimethyl-N-heptyl-N-hexyl Ammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-dimethyl-N, N-dihexyl ammonium bis (trifluoromethylsulfonyl) fluorenimide salt, trimethylheptyl Ammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethylsulfonyl) fluorenimide salt, N, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-diethyl-N-methyl-N-heptyl Ammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-diethyl-N-propyl-N-heptylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, triethyl Propylammonium bis (trifluoromethylsulfonyl) fluorene imine salt, triethylheptylammonium bis (trifluoromethylsulfonyl) fluorene imine salt, Triethylheptylammonium bis (trifluoromethylsulfonyl) fluorene imine salt, N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromethylsulfonyl) fluorene Imine salt, N, N-dipropyl-N-methyl-N-heptylammonium bis (trifluoromethylsulfonyl) sulfonium imine salt, N, N-dipropyl-N-butyl- N-hexylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dipropyl-N, N-dihexylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N , N-Dibutyl-N-methyl-N-heptylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, N, N-dibutyl-N-methyl-N-hexylammonium bis (Trifluoromethylsulfonyl) sulfonium imine salt, trioctylmethylammonium bis (trifluoromethylsulfonyl) phosphonium imine salt, trioctylmethylammonium hexafluorophosphate, N-methyl -N-ethyl-N-propyl-N-heptylammonium bis (trifluoromethylsulfonyl) fluorene imine salt, (2-hydroxyethyl) trimethylammonium bis (trifluoromethylsulfonium) Group) phosphonium imine salt, (2-hydroxyethyl) trimethylammonium dimethyl phosphinate, 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) fluorenimide, Lithium bis (pentafluoroethylsulfonyl) fluorene imine salt, lithium ginseng (trifluoromethylsulfonyl) methyl body, potassium bis (fluorosulfonyl) fluorene imine salt, and the like.

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

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

When the anionic component constituting the ionic compound is hexafluorophosphate, the performance of the polarizer layer tends to be significantly reduced. Even in the case of using such an adhesive composition containing an ionic compound, the polarizing plate with an adhesive of the present invention can effectively suppress the performance of the polarizer layer with the first protective layer.

The adhesive may be blended with fillers, pigments, colorants, antioxidants, ultraviolet absorbers, and the like composed of inorganic powders such as glass fibers, glass beads, resin beads, and metal powders, if necessary. Examples of the ultraviolet absorber include a salicylate-based compound, a benzophenone-based compound, Benzotriazole-based compounds, cyanoacrylate-based compounds, nickel complex compounds, and the like.

[Second protective layer]

The second protective layer is formed on the surface of the polarizer layer opposite to the side on which the first protective layer is laminated. As the second protective layer, a cellulose acetate resin, a cycloolefin resin, a polyolefin resin, an acrylic resin, a polyimide resin, a polycarbonate resin, and a polyester resin can be used without particular limitation. A thermoplastic resin film which has been widely used in this field in the past as a suitable material for forming a protective layer. Moreover, like the above-mentioned first protective layer, 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 viewpoints of mass productivity and adhesiveness, among the above, it is preferable to use a cellulose acetate-based resin film or a cycloolefin-based resin film as the second protective layer. From the standpoint of ease of providing a surface treatment layer and optical characteristics, it is more preferable to use a cellulose acetate-based resin film as the second protective layer.

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

As such a cellulose acetate resin film, an appropriate one can be used. Commercially available. Examples of suitable commercially available products include "Fujitac (registered trademark) TD80", "Fujitac (registered trademark) TD80UF", "Fujitac (registered trademark) TD80UZ") sold by Fujifilm (Stock), and Konica Minolta Opto ( Shares) "KC8UX2M", "KC8UY" (the above are all trade names), etc.

Cycloolefins suitable for the second protective layer The resin refers to a thermoplastic resin (also referred to as a thermoplastic cycloolefin-based resin) having a monomer unit composed of a cyclic olefin (cycloolefin) such as norbornene and a polycyclic norbornene-based monomer. The cycloolefin-based resin may be a ring-opened polymer of the above-mentioned cyclic olefin, a hydrogenated product of a ring-opened copolymer using two or more kinds of cyclic olefins, or a cyclic olefin and an aromatic compound having a chain olefin, a vinyl group, or the like. Addition polymer. It is also effective to introduce a polar group.

Use cyclic olefins and aromatics with chain olefins and vinyls When the second protective layer is formed by a copolymer of an aromatic compound, examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene, and urethane. Substituted styrene and the like. In such a copolymer, the monomer unit composed of a cycloolefin may be 50 mol% or less (preferably 15 to 50 mol%). In particular, when a tertiary 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 may be as described above, and may be relatively small. the amount. In such a terpolymer, a monomer unit composed of a chain olefin is usually 5 to 80 mol%, and a monomer unit composed of an aromatic compound having a vinyl group is usually 5 to 80 mol%.

Cycloolefin-based resins may be appropriately selected from commercially available products, For example, "TOPAS (registered trademark)" [made by Topas Advanced Polymers GmbH], "ARTON (registered trademark)" [made by JSR (stock)], "ZEONOR (ZEONOR) (registered trademark)", and "ZEONEX (ZEONEX) (registered trademark) (Trademark) "[The above are made by Japan ZEON (Stock)]," Apelle (registered trademark) "[Mitsui Chemical (Stock)] (All of the above Is the product name). When forming such a cycloolefin-based resin into 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" [the above are manufactured by Sekisui Chemical Industry Co., Ltd.]; Commercial products of thin wax made of resin can also be used.

The cycloolefin-based resin film may be uniaxially stretched or biaxially stretched. 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 like ethylene or propylene A polymer in which a hydrocarbon is a main monomer 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 based on methyl methacrylate A polymer of a monomer may be a copolymer of methyl methacrylate and an acrylate such as methyl acrylate, in addition to a homopolymer of methyl methacrylate.

Polyimide resins are based on A polymer is typically a polymer of tetracarboxylic acid 2 anhydride and diamine to form a polyamic acid precursor of polyfluorene imine, and then dehydration / cyclization (fluorine imine) reaction And the winner.

Polycarbonate resin is based on The polymer is typically obtained by condensation polymerization of bisphenol A and phosgene.

Polyester resins are produced by the condensation polymerization of a dibasic acid and a diol. The resulting polymer is typically polyethylene terephthalate.

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

The second protective layer described above has a thin thickness It is more preferable, but when it is too thin, the strength tends to decrease and the workability tends to be poor, and when it is too thick, it tends to reduce the transparency or the weight of the polarizing plate becomes large. From such a viewpoint, when the thickness of the second protective layer in the polarizing plate of the present invention is made of a thermoplastic resin film, it is usually 5 to 100 μm, preferably 10 μm or more, and more preferably 80 μm or less, and more preferably 50 μm or less. On the other hand, when the second protective layer is made of a cured product of a curable resin composition, its thickness may be set to 10 μm or less.

In addition, the second protective layer may be a pair of polarizers that are adhered to the polarizer. The surface on the opposite side is subjected to surface treatments 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 thereof, or the like may be formed on the surface of the second protective layer opposite to the surface to which the polarizer layer is adhered.

[Adhesion between polarizer layer and second protective layer]

When a thermoplastic resin film is used as the second protective layer, the polarizer layer and the second protective layer are bonded using an appropriate adhesive or adhesive. When bonding these films, in order to improve the adhesion, they are protected by a polarizing film and / or a second protection. The bonding surface of the layer can be appropriately applied with surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (inflammation) treatment, saponification treatment, and solvent treatment. Examples of the saponification treatment include a method of immersion in an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide.

Used for bonding polarizer layer and second protective layer The adhesive system is not particularly limited, and examples thereof include a curable resin composition (active energy ray-curable adhesive agent) containing an active energy ray-curable compound, or an aqueous adhesive agent in which an adhesive component is dissolved or dispersed in water Water-based adhesive).

As an active energy ray hardening adhesive, it can be used with The curable resin composition forming the first protective layer is the same. The curable resin composition used in the formation of the first protective layer, and the active energy ray-curable adhesive used in the bonding of the polarizer layer and the second protective layer may be the same or different.

Examples of the water-based adhesive include polyethylene. An adhesive composition containing an alcohol-based resin or a urethane resin as a main component.

Use polyvinyl alcohol resin as the main agent of water-based adhesive In the case of components, in addition to the polyvinyl alcohol homopolymer obtained by saponification of polyvinyl acetate homopolymer of polyvinyl acetate, polyvinyl alcohol-based resins can also be listed as vinyl acetate and other copolymers copolymerizable therewith. Copolymers of monomers, etc. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and acrylamide having an ammonium group. It is preferred that the polyvinyl alcohol resin used as the adhesive has a moderate degree of polymerization. For example, when it is a 4% by weight aqueous solution, the viscosity is Between 4 and 50mPa. The range of sec is better, 6 to 30 mPa. The range of sec is even better.

It is also preferable to use a modified polyvinyl alcohol tree. fat. Examples of suitable modified polyvinyl alcohol-based resins include polyvinyl alcohol-based resins modified with acetamidine, polyvinyl alcohol-based resins modified with anions, and polyvinyl alcohol-based resins modified with cations. . 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 contain Two or more of the modified polyvinyl alcohol-based resins described above may also include unmodified polyvinyl alcohol-based resins (specifically, fully or partially saponified polyvinyl acetate) and the modified polyethylene described above Both of alcohol-based resins.

The polyvinyl alcohol-based resin constituting the water-based adhesive can be obtained from It is appropriately selected from commercially available products and used. Specific examples include "PVA-117H", "KL-318", "KM-118", and "CM-318" sold by Kuraray; "GOHSENOL" sold by Nippon Synthetic Chemical Industry Co., Ltd. (Registered trademark) NH-20 "," GOHSEFIMER Z "series," GOHSEFIMER (registered trademark) K-210 "and" GOHSENAL (registered trademark) T-330 "(the above are all trade names), etc.

Water-based adhesive based on polyvinyl alcohol resin It may contain a crosslinking agent. According to the type of functional group, compounds that can be used as cross-linking agents are, for example, isocyanate compounds having at least two isocyanate groups (-NCO) in the molecule; at least two epoxy groups (cross-linked) in the molecule. -O-) epoxy compounds; mono- or di-aldehydes; organic titanium compounds; such as magnesium, calcium, Inorganic salts of divalent or trivalent metals of iron, nickel, zinc and aluminum; metal rhenium of glyoxylic acid; methylol melamine, etc.

Among these crosslinking agents, it is suitable to use: Polyamide epoxy resin is the first epoxy compound, or an alkali metal or alkaline earth metal salt of aldehydes, methylolmelamine, glyoxylic acid, etc.

The crosslinking agent is preferably dissolved together with the polyvinyl alcohol resin. Forms an adhesive in water. However, as described below, the amount of the crosslinking agent in the aqueous solution is only a small amount. Therefore, as long as it has a solubility of at least about 0.1% by weight with respect to water, it can be used as a crosslinking agent. Of course, as the cross-linking agent used in the present invention, a compound having solubility in water, which is generally referred to as a degree of water solubility, is more suitable.

The blending amount of the crosslinking agent depends on the type of the polyvinyl alcohol resin. It is appropriately designed based on the like, and is usually about 5 to 60 parts by weight, and preferably 10 to 50 parts by weight based on 100 parts by weight of the polyvinyl alcohol resin. When the crosslinking agent is blended in this range, good adhesion is obtained. When the amount of the cross-linking agent is too large, the reaction of the cross-linking agent proceeds in a short period of time, so that the adhesive tends to be saponified at an initial stage. As a result, the pot life becomes extremely short and it is difficult to use it industrially.

Among the water-based adhesives, Within the range, conventionally known and suitable additives such as a silane coupling agent, a plasticizer, an antistatic agent, and fine particles may be blended.

Use urethane resin as main component of water-based adhesive In this case, examples of suitable adhesives include a mixture of a polyester-based ionic polymer-type urethane resin and a compound having a glycidyloxy group. here The so-called 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 into the urethane resin. Such an ionic polymer type urethane resin is emulsified directly into water without using an emulsifier to form an emulsion. Therefore, it is suitable for use as an aqueous adhesive. The use of a polyester-based ionic polymer-type urethane resin as an adhesive between a polarizer layer and a protective layer is described in, for example, Japanese Patent Laid-Open No. 2005-070140, Japanese Patent No. 4432487, and Japanese Patent Laid-Open No. 2005-208456. Bulletin.

Thickness of the adhesive layer obtained after drying or hardening The degree is usually about 0.01 to 5 μm, but can be set to 1 μm or less when using an aqueous adhesive. On the other hand, when using an active-energy-ray-curable adhesive, it is more preferable that it is 2 micrometers or less, and it is more preferable that it is 1 micrometer or less. If the adhesive layer is too thin, there may be insufficient adhesion. On the other hand, if the adhesive layer is too thick, the appearance of the polarizing plate may be poor.

The lamination of the polarizer layer and the second protective layer can also pass through The aforementioned adhesive layer is used. In this case, the adhesive composition preferably does not contain the ionic compound.

[Manufacturing method of polarizing plate with adhesive]

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

(i) a step of layering a first protective layer on a single area of the polarizer layer; (ii) a step of layering a second protective layer on another area of the polarizer layer; (iii) a step of laminating an adhesive layer on the surface of the first protective layer opposite to the polarizer layer.

In the step (i), after the coating layer forming step, The cloth layer bonding step, the hardening step, and the substrate removing step can be a first protective layer on a single area of the polarizer layer.

In the coating layer forming step, the substrate The curable resin composition of the active energy ray-curable compound forming the first protective layer is dried as necessary, and a coating layer of the curable resin composition is provided on the surface of the substrate. Here, as the substrate, in addition to the aforementioned substrate, for example, a metal tape, a glass plate, or the like can be used. The surface of the substrate on which the curable resin composition is applied may be subjected to, for example, a release treatment.

In the coating layer bonding step, the above-mentioned coating layer is formed. In the step, the coating layer and the polarizer layer formed on the substrate are bonded to each other to produce a laminated body in which polarizer layers / coating layers / base materials are sequentially laminated. In addition, in the above step, when step (ii) is performed before step (i), the laminated system has a second protective layer on a surface of the polarizer layer on the side opposite to the coating layer.

In the hardening step, for the laminated body, for example, from a substrate The first protective layer is formed by irradiating or heating active energy rays such as visible light, ultraviolet rays, X-rays, and electron rays, thereby curing a coating layer made of a curable resin composition. Then, in the substrate removing step, the substrate on the first protective layer is removed.

In addition, as another method for performing step (i), it may be listed. For example, the curable resin composition forming the first protective layer is directly applied to the polarizer layer, and active energy rays are irradiated or heated. A method for hardening a coating layer composed of a composition to form a first protective layer. According to this method, the first protective layer can be formed even without using a substrate.

The step (ii) is performed when the second protective layer is laminated on the polarizer. When a thermoplastic resin film is used as the second protective layer, the second protective layer is laminated via an adhesive layer. The second protective layer is laminated as described below. First, an adhesive composition is coated on the bonding surface of the second protective layer, and dried if necessary. Next, the polarizer layer and the second protective layer are laminated through the adhesive composition to produce a laminated body of sequentially laminated polarizer layer / adhesive composition / second protective layer, and then dried or dried. The laminated body is irradiated with active energy rays such as visible light, ultraviolet rays, X-rays, and electron rays, or is heated to harden the adhesive composition to adhere the polarizer layer and the second protective layer. At this time, a drying step may be provided as needed. In addition, when the step (i) is performed before the step (ii), the laminated system has a first protective layer on a surface of the polarizer layer opposite to the coating layer. Since an active energy ray-curable adhesive is used for bonding the polarizer layer and the second protective layer, a drying step is not required, so that manufacturing efficiency can be expected to be improved.

In addition, as a method different from the above, an adhesive composition may be directly coated on the bonding surface of the polarizer layer, a second protective layer may be laminated through the composition, and then dried or irradiated with active energy rays. Or a method of heating and curing the adhesive to adhere the polarizer layer and the second protective layer. That is, in this method, if necessary, a drying step can be provided.

In the step (ii), when the cured product of the curable resin composition containing the active energy ray-curable compound is used as the second protective layer, the same method as in the step (i) can be performed.

The first protective layer and the second protective layer can be formed simultaneously. to make. When the second protective layer is a thermoplastic resin film, the laminated body (second protective layer / adhesive composition / polarizer layer / curable resin forming the first protective layer) obtained through the above steps (i) and (ii) The coating layer / base material of the composition), for example, can be irradiated with active energy rays or heated from the base material side to harden the adhesive composition and the coating layer at the same time.

The second protective layer is a cured product of a curable resin composition In the case of the laminated body (substrate / coating layer of the curable resin composition forming the second protective layer / the polarizing plate layer / the forming of the first protective layer) obtained through the steps (i) and (ii) above, The coating layer / base material of the resin composition) can be irradiated with active energy rays or heated from one or both sides of the base material side to harden the coating layer at the same time. According to this method, the hardening step can be completed in one time, so it is expected that the manufacturing efficiency can be further improved.

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

As a method different from the coating method described above, 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 pressing with a roller or the like. Method. In this method, as the material of the roller, metal, rubber, or the like can be used. In the case of rollers, when a pair of rollers is used (when the laminate passes between the rollers), the rollers can be the same Or a different material.

Forming the first or third part by irradiating active energy rays The hardening resin composition of the two protective layers and / or the above-mentioned adhesive composition are not particularly limited in the light source system to be used, but can be used for those having a light emission distribution at 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 ultra-high-pressure mercury lamp, a fluorescent lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The intensity of light irradiation of the active energy ray may vary depending on the composition of the radiation, but it is preferably irradiation in a wavelength region effective for activating the photoradical polymerization initiator and / or the photocationic polymerization initiator. The strength is 10 to 2500 mW / cm ² . When the light irradiation intensity is less than 10 mW / cm ² , the reaction time will be too long, and when it is more than 2500 mW / cm ² , the hardening resin is due to the heat radiated by the lamp and the heat generated during the polymerization of the hardening resin composition or the adhesive composition. The composition or the adhesive composition may cause yellowing and deterioration of the polarizer layer.

The light irradiation time of the curable resin composition or the adhesive composition is controlled by each composition irradiated, but it is not particularly limited, but it is preferable that the cumulative light amount expressed by the product of the irradiation intensity and the irradiation time is 10 to 2500mJ / cm ² to set the mode. When the accumulated light amount is less than 10 mJ / cm ² , the generation of active species from the polymerization initiator is insufficient, and the obtained protective layer and the adhesive layer may have insufficient curing. In addition, when the accumulated light amount is more than 2500 mJ / cm ² , the irradiation time becomes very long, which is not conducive to improving productivity. In addition, it is preferable that the irradiation of the active energy ray is performed within a range that does not reduce various properties such as the polarization degree and transmittance of the polarizer layer.

In the above project (iii), the first protective layer and the polarizer On the opposite side of the layer, an adhesive layer can be laminated to obtain an adhesive-attached polarizing plate. The lamination of the adhesive layer can be performed by, for example, a method using a release film or a method of applying an adhesive composition on the first protective layer. The method of using a release film is, for example, applying the aforementioned adhesive composition to the release-treated surface of the release film to which the release treatment has been applied to form an adhesive layer, and then to the obtained adhesive layer. The first protective layer of the polarizing plate is laminated. In addition, the method of coating the adhesive composition on the first protective layer can be performed by, for example, applying the 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 preferable to protect the adhesive layer in advance by laminating the release film with the obtained adhesive.

The polarizing plate with an adhesive of the present invention can be applied to a liquid crystal The unit and the like constitute a liquid crystal display device, but until it is used, it is preferable to laminate the above-mentioned release film on the side of the adhesive layer and protect it in advance. The release film used here may be a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate as a base. Material, and applying a release treatment such as silicone treatment to the bonding surface of the base film and the adhesive layer. In addition, the adhesive layer was sandwiched between two release films in advance, and the release film on either side was peeled off if necessary, 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 application forms includes a form in which a glass substrate is laminated with an adhesive layer interposed therebetween. In order to laminate a polarizing plate with an adhesive on a 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, anti-glare glass, and glass for sunglasses. Among them, a polarizing plate with an adhesive is laminated on a glass substrate on the front side (identification side) of the liquid crystal cell, and an optical laminate 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, alkali-free glass is preferably used in the liquid crystal cell.

The polarizer with the adhesive of the present invention can be arranged in a liquid crystal Unit on one or both sides. The polarizing plates disposed on both sides of the liquid crystal cell may be the same or different. In addition, the polarizing plate with the adhesive agent of the present invention may be arranged on one side of the liquid crystal cell, and different polarizing plates may be arranged on the opposite side of the liquid crystal cell.

(Example)

Hereinafter, the present invention will be specifically described with examples. However, the present invention is not limited to the following examples. In the examples, parts and% indicating the usage amount and content are based on weight unless otherwise specified.

First, examples of the prepared curable resin composition are listed. In the preparation of the curable resin composition, the following compounds were used.

<Active energy ray hardening 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 Asia Synthesis.

"OXT-212": 2-ethylhexyloxetane, obtained from East Asia Synthesis.

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

"DMAA": N, N-dimethylacrylamide, obtained from Xingren (shares).

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

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

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

"OXT-101": 3-ethyl-3-hydroxymethyloxetane, obtained from East Asia Synthesis.

<Photocationic polymerization initiator>

"ADEKA OPTOMER (registered trademark) SP-150": 4,4'-bis [diphenyldihydrothio] diphenylsulfide dihexafluorophosphate-based photocationic polymerization initiator, with propylene carbonate solution The form is obtained by ADEKA.

<Photo radical polymerization initiator>

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

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

<Other ingredients>

"SH710": Polysiloxane based leveling agent, obtained by Dow Corning Toray (stock).

[Production Example 1] Preparation of Curable Resin Compositions A to V

Each of the following components was mixed to prepare curable resin compositions A to V, respectively. The photocationic polymerization initiator "ADEKA OPTOMER SP-150" uses a propylene carbonate solution, but it is shown below in terms of its effective ingredient amount.

<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 servings

<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 more than 99.9 mol%, and a thickness of 30 μm is stretched to about 4 times in a dry unidirectional direction. Further, it is directly maintained in a stretched state and immersed in pure water at 40 ° C After 15 minutes, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 10/100 at 28 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 7.5 / 100 at 68 ° C. for 300 seconds. Next, it was washed with pure water at 10 ° C for 20 seconds, and then dried at 65 ° C to prepare a polarizing film that adsorbed and aligned iodine on a uniaxially stretched polyvinyl alcohol film. The thickness of the polarizing film was 11 μm.

Next, examples of preparation adhesives are listed. Among polyvinyl alcohol and epoxy-based crosslinking agents, the following compounds are used.

<Polyvinyl alcohol>

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

<Epoxy-based crosslinking agent>

"Sumirez resin (registered trademark) 650": a water-soluble polyamido epoxy resin (aqueous solution having a solid content of 30%), which was obtained from Sumitomo Chemical Co., Ltd.

[Production Example 3] Preparation of water-based adhesive

The following components were mixed to prepare an aqueous adhesive. The epoxy-based cross-linking agent "Sumirez resin 650" uses an aqueous solution, but it is shown below in terms of its effective component amount.

<Aqueous Adhesive>

[Production Example 4] Production of Polarizing Plate A

On one side of the polarizer layer prepared in Manufacturing Example 2, the water-based adhesive prepared in Manufacturing Example 3 was applied, and a protective layer made of saponified cellulose triacetate [Konica Minolta Opto ), KC2UA, 25 μm 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) Fabrication of polarizing plate

Using a bar coater, the curable resin composition A prepared in Production Example 1 was applied to a cycloolefin resin film having a thickness of 50 μm so that the film thickness after curing was about 1 μm [manufactured by ZEON Corporation] Trade name of "ZEONOR (registered trademark)"]. The coated surface was bonded to the polarizer layer side of the polarizing plate A produced in Production Example 4 to produce a laminated body. An ultraviolet irradiation device using an attached conveyor [the lamp system uses a "D bulb" manufactured by Fusion UV Systems] was irradiated with ultraviolet rays from the cycloolefin-based resin film side of the laminate so that the accumulated light amount was 500 mJ / cm ² After the curable resin composition is cured, the cycloolefin-based resin film is peeled from the laminate. In this way, a polarizing plate composed of a first protective layer (a cured product of a curable resin composition), a polarizer layer, an adhesive layer, and a second protective layer was produced.

Next, on the first protective layer side of the polarizing plate prepared in (1), an ionic compound was blended, and a layer of an acrylic adhesive that imparted an antistatic function was provided. Use the following as the isocyanate-based crosslinking agent, silane coupling agent, and antistatic agent formulated in the adhesive.

<Isocyanate-based crosslinking agent>

Coronate (registered trademark) L: ethyl acetate solution of trimethylolpropane adduct of methylenediphenyl diisocyanate (solid content concentration: 75%), obtained from Japan Polyurethane Co., Ltd.

<Silane coupling agent>

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

<Antistatic agent>

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

(2) Formation of adhesive layer

An organic solvent solution of an acrylic adhesive made by adding an isocyanate-based crosslinking agent, a silane coupling agent, and an antistatic agent to a copolymer of butyl acrylate, methyl acrylate, acrylic acid, and hydroxyethyl acrylate, and applying the Release treatment of a 38 μm thick polyethylene terephthalate film [trade name "SP-PLR382050", obtained from LINTEC (strand), called release film]], using a die seam coater Coating was performed so that the thickness after drying became 20 μm, and a sheet-shaped adhesive agent with a release film was prepared. Next, on the first protective layer of the polarizing plate prepared in the above (1), the surfaces of the sheet-shaped adhesive obtained on the opposite side of the release film (adhesive surface) were bonded to each other by a laminator, and the temperature was Ageing was performed at 23 ° C. and a relative humidity of 65% for 7 days 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.

[Example 8]

Using a bar coater, the curable resin composition F prepared in Production Example 1 was applied to the polarizer layer side of the polarizing plate A produced in Production Example 4 so that the cured film thickness became approximately 2 μm. . From the side of the curable resin composition of this laminate, an ultraviolet irradiation device with an attached conveyor was used [the lamp system uses "D bulb" manufactured by Fusion UV System Co., Ltd.], and the environment was nitrogenized and the accumulated light amount was 500 mJ / cm ² The system is irradiated with ultraviolet rays to cure the curable resin composition. In this way, a polarizing plate composed of a first protective layer, a polarizer layer, an adhesive layer, and a second protective layer was fabricated. Except for the above, durability evaluation was performed in the same manner as in Example 1. The results are summarized in Table 1.

[Examples 9 to 24]

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

[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, the release film was peeled off, and the alkali-free glass was bonded with the adhesive layer side [trade name of Corning Corporation] EAGLE XG (registered trademark) "]. This sample was subjected to an 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 for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 55%. Install the optional "Film Holder with Polarizing Film" to a UV-visible spectrophotometer [product name "UV2450" of Shimadzu Corporation] to measure the polarizing plate in the range of 380 to 700 nm for this sample. The transmission spectra in the transmission axis direction and the absorption axis direction were obtained from the polarization spectra Py (unit:%). The optical performance in this state was used as the initial Py. The optical performance (post-test Py) after standing for 100 hours in an environment of 60 ° C and a relative humidity of 90% was measured. The degree of polarization change ΔPy was calculated from the following formula. The results are shown in the table. 1 in the "△ Py" column. The optical performance was measured after further standing for 150 hours at a temperature of 60 ° C and a relative humidity of 90% (total standing for 250 hours), and the change in polarization degree ΔPy was calculated. The results are also shown in the "△ Py" column of Table 1. .

△ Py = initial Py-post-test Py

<Measurement of glass transition temperature (Tg) of the first protective layer>

Two cycloolefin resin films having a thickness of 50 μm, which were the same as those used in Example 1, were prepared. Next, 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 that the cured film thicknesses became 2 μm, respectively, and the coated surfaces were applied. The film was overlapped with another film, and ultraviolet rays were irradiated from one side in accordance with Example 1 so that the accumulated light amount became 250 mJ / cm ² to harden the curable resin composition. Next, the film enclosing the cured product was peeled off, 5 mg of the cured product was scraped off, and then placed in an aluminum-covered lid-type container, which was sealed by being pressed and sealed to prepare a measurement sample.

Using a differential scanning calorimeter (DSC) "EXSTAR-6000 DSC6220" sold by SII NanoTechnology Co., Ltd., and placing the above-mentioned container containing the measurement sample thereon, reducing the temperature from 20 ° C to -60 ° C while excluding nitrogen. After reaching -60 ° C for 1 minute, the temperature was raised from -60 ° C to 200 ° C at a rate of 10 ° C / min. If it reached 200 ° C, the temperature was immediately reduced 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 the Transition Temperature of Plastics" was determined, and this was set as the first protective layer (hardened Glass transition temperature). The results are shown in the "Tg" column of Table 1.

<Measurement of water contact angle of the first protective layer>

Two cycloolefin resin films having a thickness of 50 μm, which were the same as those used in Example 1, were prepared. Next, 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 that the cured film thicknesses became 2 μm, respectively, and the coated surfaces were applied. The film was overlapped with another film, and ultraviolet rays were irradiated from one side in accordance with Example 1 so that the accumulated light amount became 250 mJ / cm ² to harden the curable resin composition. Next, the film enclosing this hardened | cured material was peeled, and the water contact angle after dripping 8 microliters of water was measured for the hardened | cured material using the fully automatic contact angle measuring device [product name "OCA35" made by DataPhysics company]. The results are shown in the "Water contact angle" column of Table 1.

As can be seen from Table 1, compared to the absence of the first protective layer In Example 1, after 100 hours of testing, 0.20% and 250 hours of testing, the polarization decreased by 1.53%. However, the examples of the laminated first protective layer were smaller than the comparative examples, and the The thicker the thickness, the greater the tendency. Moreover, in Examples 4 and 5 in which an oxetane-based compound was used alone or in combination with an epoxy-based compound, the degree of polarization after the 100-hour test was reduced to 0%, and the effect of suppressing the decrease in optical performance was apparent. In Examples 6 to 8 containing an acrylic compound, it was found that even if the film thickness was 2 μm, the reduction in polarization could be suppressed, and in Examples 7 and 8 with a high Tg, the reduction in polarization remained after the 100-hour test. It is 0%, and like the oxetane-based compound, the effect of suppressing the decrease in optical performance is remarkably exhibited. Again, water contact In Examples 1 to 22 having an angle of 60 ° or more, it was found that the polarization degree after the 250-hour test was reduced to 0.5% or less, and the effect of suppressing the decrease in optical performance was apparent.

Claims (11)

A polarizing plate with an adhesive is sequentially 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 ionicity The compound is composed of an adhesive composition, wherein the water contact angle of the first protective layer is 60 ° or more. According to the polarizing plate with an adhesive according to item 1 of the scope of the patent application, the polarizer layer is provided with a second protective layer on a surface opposite to the first protective layer. The adhesive-attached polarizing plate according to item 2 of the scope of patent application, 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 adhesive-attached polarizing plate according to item 4 of the scope of patent application, wherein the ionic polymerizable compound includes a compound having at least one ethylene oxide ring. The polarizing plate with an adhesive according to any one of claims 1 to 3, wherein the active energy ray-curable compound contains ((meth) acrylic acid) (Meth) acrylic compounds. According to the polarizing plate with an adhesive according to any one of claims 1 to 3 of the scope of patent application, wherein the glass transition temperature of the first protective layer is 23 ° C. or higher. According to the polarizing plate with an adhesive according to any one of claims 1 to 3 in the scope of patent application, wherein the thickness of the first protective layer is 0.1 to 10 μm. The polarizing plate with an adhesive according to any one of claims 1 to 3 of the scope of application for a patent, wherein a release film is laminated on the adhesive. A liquid crystal display device is provided with a liquid crystal cell and a polarizing plate with an adhesive as described in any one of claims 1 to 8 of the scope of patent application. The liquid crystal display device according to item 10 of the scope of patent application, wherein the polarizer with the adhesive is bonded to the liquid crystal cell on the side of the adhesive layer.