KR101534335B1 - Adhesive composition, polarising plate comprising the same and display comprising the same - Google Patents

Abstract

An initial curability and an adhesive property of the polarizer are improved.
The present invention relates to an epoxy resin composition comprising 20 to 70 parts by mass of an epoxy resin and 30 to 80 parts by mass of an acrylic monomer (the total amount is 100 parts by mass), 1 to 7 parts by mass of a photoacid generator and 0.1 to 7 parts by mass of a photopolymerization initiator, A resorcinol type epoxy resin, a bisphenol S type epoxy resin, and a naphthalene type epoxy resin.

Description

[0001] The present invention relates to an adhesive for a polarizing plate, a polarizing plate including the same, and a display device including the polarizing plate.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an adhesive composition for bonding a polarizer and a protective film, which is used in producing a polarizer, and a polarizer and a display device including the same. More particularly, the present invention relates to an adhesive composition for a polarizing plate having excellent initial curability and adhesiveness, a polarizing plate using the same, and a display device including the same.

In recent years, flat displays such as liquid crystal displays and plasma displays have been widely used as display devices because they can save space and have high precision. Of these, liquid crystal displays are being developed with attention because they can save more power and have higher precision.

In a liquid crystal display panel, a polarizing plate serving as an optical shutter is used together with a liquid crystal to exert its function. The polarizing plate is provided with a polarizer and is an integral part of the liquid crystal display panel. Generally, polarizers are produced by uniaxially stretching a polyvinyl alcohol resin to a length of 5 to 6 times in a water tank, and therefore are prone to tearing in the stretching direction and have drawbacks. Therefore, the polarizer is used by forming a polarizing plate by adhering a protective film to its surface and / or its back surface. At that time, it is required that the polarizer is used for an adhesive for adhering a protective film to a polarizer.

As such an adhesive for a polarizing plate, for example, an adhesive for curing a curable component containing an N-substituted amide monomer having a specific structure by irradiation of active energy rays is known (see Patent Document 1). In Patent Document 1, it is described that the polarizer adhered using such N-substituted amide monomer has excellent durability under high temperature and high humidity. However, these N-substituted amide-based monomers are excellent in initial curability, but an adhesive obtained by finally curing is not sufficient in terms of adhesive strength.

An adhesive using an epoxy resin containing no aromatic ring as an adhesive for a polarizing plate is known (see Patent Document 2). Patent Document 2 discloses that when a protective film having a low moisture permeability is used by using an epoxy resin containing no aromatic ring, a polarizing plate having sufficient adhesive strength and no problem of defective appearance is obtained. However, it was found that the adhesive using an epoxy resin not containing an aromatic ring had an excellent adhesive strength but a poor initial curability.

And a radical polymerization initiator mainly comprising a monofunctional radically polymerizable compound and a compound comprising a compound having an alicyclic epoxy group and a cationic polymerizable compound not containing a (meth) acryloyl group, A photo-curable adhesive containing a photo cationic polymerization initiator is known (see Patent Document 3). Patent Document 3 discloses that the adhesive is excellent in not only the adhesion between the protective film and the polarizer but also the punching workability and water resistance. However, such an adhesive has good initial curability but is insufficient in adhesion to a specific film such as a polyethylene terephthalate film.

* Prior art literature

Patent Document 1: JP-A-2008-287207

Patent Document 2: JP-A-2004-245925

Patent Document 3: Japanese Laid-Open Patent Publication No. 2011-76058

However, since the polarizer is produced by stretching in a water tank as described above, it usually contains water. The polymerizable compound such as an epoxy resin which does not contain an aromatic ring and used in the above-mentioned prior art is cured by a certain amount of time after irradiation with an active energy ray. However, when used for a polarizing plate, There is a problem that it is not. This problem is caused when the polarizing plate is conveyed while being bent by a roll or a belt in the actual manufacturing process, resulting in peeling of the protective film, resulting in lowered yield and lowered processability.

On the other hand, in order to obtain a polarizing plate having sufficient durability even by long-term use and environmental changes of temperature and humidity, excellent adhesion is required for an adhesive composition. The N-substituted amide monomer used in Patent Document 1 is excellent in initial curability but has a drawback that adhesion between the polarizer and the protective film is slightly deteriorated.

Also in the case of the prior art of Patent Document 3 in which the alicyclic epoxy resin and the radical polymerizable compound are used together, the adhesive composition is still insufficient in terms of adhesiveness.

An object of the present invention is to provide an adhesive composition for a polarizing plate which is excellent in initial curability and adhesive property, in view of the above circumstances. Another object of the present invention is to provide a polarizer excellent in durability by using such an adhesive composition.

The inventors of the present invention have found that an adhesive for a polarizing plate excellent in initial curability and adhesiveness can be obtained by using an epoxy resin and an acrylic monomer having a specific structure in combination, thereby completing the present invention.

That is, the present invention relates to an epoxy resin composition comprising 20 to 70 parts by mass of an epoxy resin and 30 to 80 parts by mass (only 100 parts by mass) of an acrylic monomer, 1 to 7 parts by mass of a photo acid generator and 0.1 to 7 parts by mass of a photopolymerization initiator, Is an adhesive composition for a polarizing plate comprising at least one selected from the group consisting of a resorcinol type epoxy resin, a bisphenol S type epoxy resin and a naphthalene type epoxy resin.

The adhesive composition for a polarizing plate of the present invention can exhibit good initial curability and adhesiveness when used in a polarizing plate using various protective films by using an epoxy resin and an acrylic monomer having a specific structure in combination. Therefore, the polarizing plate using the adhesive composition of the present invention can be a polarizing plate having good adhesion with the protective film and high durability.

1 is a schematic view for explaining a manufacturing process of a polarizing plate in the embodiment.
Fig. 2 is a schematic view for explaining the method of the initial hardenability test in the examples. Fig.
3 is a schematic view for explaining the method of the hot water immersion test in the embodiment.

Hereinafter, the present invention will be described in detail with respect to each element.

(One) For polarizer  Adhesive composition

The first aspect of the present invention is a process for producing a photoresist composition comprising 20 to 70 parts by mass of an epoxy resin and 30 to 80 parts by mass of a (meth) acrylic monomer (wherein the total amount of the epoxy resin and the (meth) acrylic monomer is 100 parts by mass) And 0.1 to 7 parts by mass of a photopolymerization initiator, wherein the epoxy resin is at least one of a resorcinol type epoxy resin, a bisphenol S type epoxy resin and a naphthalene type epoxy resin.

As described above, the conventional adhesive for a polarizing plate is not yet sufficient in terms of compatibility between initial curability and adhesive property. In the present invention, both of the epoxy resin and the acrylic monomer having the specific structure are used at a specific ratio to realize both the initial curability and the adhesiveness. Among them, the epoxy resin having a specific structure contributes particularly to the improvement of the adhesion, and the acrylic monomer is considered to contribute particularly to the initial curability.

(A) an epoxy resin, (B) an acrylic monomer, (C) a photoacid generator, (D) a photopolymerization initiator and (E) an adhesive composition.

(A) an epoxy resin

It is considered that the epoxy resin used in the present invention contains at least one of a resorcinol type epoxy resin, a bisphenol S type epoxy resin and a naphthalene type epoxy resin, and particularly contributes to the improvement of the adhesion between the polarizer and the protective film as an adhesive for a polarizing plate .

As the resorcinol type epoxy resin, those represented by the following formula (1) can be used.

≪ Formula 1 >

Y ₁ and Y ₂ each independently represent an alkylene group having 1 to 10 carbon atoms, and any hydrogen atom of the alkylene may be substituted with a halogen atom, preferably 1 to 5 carbon atoms, more preferably 1 to 5 carbon atoms, An unsubstituted alkylene group having 1 to 2 carbon atoms. R ₁ represents a halogen atom or an alkyl group having 1 to 5 carbon atoms. X ₁ and X ₂ are epoxy groups represented by the following formula (2). n is an integer of 0-4.

(2)

Among the above-mentioned resorcinol-type epoxy resins, most preferred is the diglycidyl etherified resorcinol of the resorcinol represented by the following formula (3).

(3)

Since the resorcinol-type epoxy resin is an epoxy resin having a relatively small epoxy equivalent, it is considered that even when used in an adhesive for a polarizer, the cross-linking points per unit volume of the resulting cured product are further increased, thereby exhibiting a strong adhesive property.

The resorcinol type epoxy resin can be synthesized by, for example, reaction of resorcinol and epichlorohydrin, but a commercially available product may also be used. A commercially available product of the resorcinol-type epoxy resin of the formula (3) includes Denacol (registered trademark) EX-201 (manufactured by Nagase ChemteX Corporation).

As the naphthalene type epoxy resin, those represented by the following general formula (4) can be used.

≪ Formula 4 >

Y < ₃ > and Y < ₄ > each independently represent an alkylene group of 1 to 10 carbon atoms, and any hydrogen atom of the alkylene may be substituted with a halogen atom, preferably 1 to 5 carbon atoms, An unsubstituted alkylene group having 1 to 2 carbon atoms. R ₃ and R ₄ each independently represent a halogen atom or an alkyl group having 1 to 5 carbon atoms. X ₃ and X ₄ are the epoxy groups represented by the above formula (2). n and m are the same or different and are an integer of 0-3.

The naphthalene type epoxy resin is most preferably a diglycidyl etherified product of dihydroxynaphthalene represented by the following formula (5).

≪ Formula 5 >

It is considered that the naphthalene type epoxy resin contributes to the adhesion between the polarizing plate and the protective film because the naphthalene ring part easily mixes with the protective film and the polarizer material when used for an adhesive for a polarizing plate and the adhesion of the polarizing plate is considered to be improved.

The naphthalene type epoxy resin can be synthesized by, for example, reaction of dihydroxynaphthalene with epichlorohydrin, but a commercially available product may also be used. Examples of commercially available naphthalene type epoxy resins represented by the above formula (5) include Epiclon (registered trademark) HP-4032 and Epiclon (registered trademark) HP-4032D (manufactured by DIC Corporation).

As the bisphenol S type epoxy resin, those represented by the following formula (6) can be used.

(6)

Y ₅ and Y ₆ each independently represent an alkylene group having 1 to 10 carbon atoms, and any hydrogen atom of the alkylene may be substituted with a halogen atom, preferably 1 to 5 carbon atoms, more preferably 1 to 5 carbon atoms, An unsubstituted alkylene group having 1 to 2 carbon atoms. R ₅ and R ₆ each independently represent a halogen atom or an alkyl group having 1 to 5 carbon atoms. X ₅ and X ₆ are epoxy groups represented by the above formula (2). n and m are the same or different and are an integer of 0-4.

Among the above-mentioned bisphenol S type epoxy resins, the diglycidyl etherified bisphenol S is most preferably represented by the following formula (7).

≪ Formula 7 >

The bisphenol S type epoxy resin is considered to contribute to the adhesion between the polarizing plate and the protective film in the form of a hydrogen bond when the characteristic bonding portion of -SO ₂ - existing between the benzene rings is used in the adhesive for a polarizing plate, It is considered that the improvement of the adhesion is realized.

The bisphenol S type epoxy resin can be synthesized by, for example, reaction of bisphenol S with epichlorohydrin, but a commercially available product may also be used. A commercially available bisphenol S type epoxy resin represented by the above formula (7) includes Epiclon (registered trademark) EXA-1514 (manufactured by DIC Corporation). A commercially available product of another bisphenol S type epoxy resin which can be used in the present invention includes Denacol (registered trademark) EX-251 (manufactured by Nagase ChemteX Corporation).

Among the at least one member selected from the group consisting of the resorcinol type epoxy resin, bisphenol S type epoxy resin and naphthalene type epoxy resin, it is more preferable to use at least one member selected from the group consisting of resorcinol type epoxy resin and naphthalene type epoxy resin More preferably a resorcinol type epoxy resin. The resorcinol-type epoxy resin is most preferable in view of excellent adhesive property and reactivity when used in an adhesive for a polarizing plate.

The adhesive composition for a polarizing plate of the present invention may contain (a) other epoxy resin (b) in addition to the epoxy resin having the specific structure described above. (b) other epoxy resins are non-resorcinol-containing non-resorcinol-based resins, non-naphthalene-based non-naphthalene-based resins containing no naphthalene group, and non-bisphenol S-based epoxy resins not containing bisphenol S, For example, a glycidyl ether compound having a hydroxyl group or a glycidyl ether compound as a chain type compound, a glycidyl amino compound such as a compound having an amino group, a glycidyloxy group or an epoxy ethyl group bonded directly or via an alkylene group to a saturated carbon ring And alicyclic epoxy compounds. These other epoxy resins may be used alone or in combination of two or more.

More specifically, examples of the glycidyl ether compound include phenyl glycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, trimethylol propane triglycidyl ether, dicyclopentadiene dimethanol diglycidyl ether , Bisphenol A type diglycidyl ether, bisphenol F type diglycidyl ether, bisphenol AD type diglycidyl ether, glycidyl 3,3 ', 5,5'-tetramethyl-4,4'-biphenol Cydyl ether compounds can be used. Among other epoxy resins used in the present invention, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether are particularly preferable. The adhesiveness can be further improved by containing bisphenol A diglycidyl ether or bisphenol F type diglycidyl ether.

The bisphenol A type epoxy resin may be synthesized on its own, or a commercial product may be used. (Registered trademark) YD-128, YD-011 (manufactured by Yuka Shell Epoxy Co., Ltd.), Epoxy (registered trademark) 825, 828, 834, 1001, 1002, 1003, 1004, (Registered trademark) 840, 850, 1050, 3050, HM-101, EXA850CRP (manufactured by DIC Co., Ltd.), and the like were prepared in the same manner as in Example 1, except that YD-014, YD-017, YD- .

Also included are glycidyl ether compounds of phenol novolak resins, glycidyl ether compounds of cresol novolak resins, glycidyl ether compounds of phenol aralkyl resins, glycidyl ether compounds of naphthol aralkyl resins, phenol dicyclopentadiene Polyalicyclic glycidyl ether compounds such as glycidyl ether compounds of resins can also be used.

Also, glycidyl ether compounds of ethylene glycol, glycidyl ether compounds of diethylene glycol, glycidyl ether compounds of 1,4-butanediol, glycidyl ether compounds of 1,6-hexanediol, Cidyl ether cargo can also be used.

Also included are glycidyl amines of 1,3-phenylenediamine, glycidyl amines of 1,4-phenylenediamine, glycidyl amides and glycidyl ethers of 3-aminophenol, 4-aminophenols And glycidyl amino acids such as glycidyl amide and glycidyl ether.

Other epoxy resins other than the bisphenol A type epoxy resin may be commercially available products. Examples of commercially available epoxy resins include Epolite (registered trademark) series (manufactured by Kyowa Shikagaku Co., Ltd.), Epikote (registered trademark) series Epitol (registered trademark) series (manufactured by Shin-Nittsu Kagaku Co., Ltd.), ADEKA RESIN (registered trademark) series (manufactured by ADEKA Co., Ltd.) (Manufactured by Nissan Kagakuko Kogyo Co., Ltd.), DVE-3, CHVE (manufactured by BASF Japan Co., Ltd.), DEWA (registered trademark) series (manufactured by Nagase ChemteX Corporation), Dow Epoxy series (Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and Celllockide (registered trademark) series (manufactured by Daicel Co., Ltd.).

(A) 100 parts by mass of other epoxy resin (b) relative to the specific epoxy resin (at least one of the resorcinol type epoxy resin, the bisphenol S type epoxy resin and the naphthalene type epoxy resin) is used in combination with the above other epoxy resin (A) / (b) is preferably 99/1 to 20/80. That is, 20 to 99 parts by mass of (a) and 1 to 80 parts by mass of (b) may be contained in 100 parts by mass of (a) + (b). More preferably 75/25 to 25/75, further preferably 60/40 to 40/60, and most preferably 50/50. Within the above-mentioned range, good adhesion is exhibited.

The other epoxy resin (b) may be contained in an amount of 15 to 35 parts by mass based on 100 parts by mass of (a) + (b) + (B). (a) of 15 to 55 parts by mass, and (B) of 30 to 65 parts by mass.

(B) Acrylic Monomer

As the acrylic monomer, conventionally known ones can be used without particular limitation, as long as they exhibit radical polymerization. Typical examples thereof include monomers having a (meth) acryloyl group, a (meth) acrylamide group and the like, and include (meth) acrylic acid and its derivatives, (meth) acrylonitrile, (meth) acrylamide, . These monomers may be used alone, or two or more of them may be used.

More specifically, examples of the acrylic monomer include the following. (Meth) acrylic acid and its salts;

Acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, methylphenoxyethyl (meth) acrylate, n-propyl (meth) acrylate, (meth) acrylate, (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (Meth) acrylate, glycerol mono (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy- , Phenoxyethylene glycol di (meth) acrylate, diethylene glycol di Acrylates such as phenoxyethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, phenoxy triethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, nonaethylene glycol (Meth) acrylate, 1,3-butanediol di (meth) acrylate, di (meth) acrylate, dipropylene glycol di Acrylate, trimethylolpropane tri (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, isobornyl (meth) acrylate, N-vinylpyrrolidone, acryloylmorpholine, urethane (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate of a mono epsilon -caprolactone adduct of tetrahydrofurfuryl alcohol, (meth) acrylate of a di-epsilon-caprolactone adduct of tetrahydrofurfuryl alcohol, (meth) acrylate of a tetrahydrofurfuryl alcohol, (Meth) acrylate of a mono? -Methyl-? - valerolactone adduct, a (meth) acrylate of?,? - carboxy-polycaprolactone monoacrylate (Meth) acrylate ester-based compounds such as a (meth) acrylic acid ester-based compound;

Nitrile group-containing vinyl compounds such as acrylonitrile and methacrylonitrile; And

(Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N- Amide group-containing vinyl compounds such as isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, diacetone (meth) acrylamide and N, N-methylenebis (meth) acrylamide.

Among the above-mentioned ones, at least one of a hydroxyl group-containing acrylic monomer and a phenoxy group-containing acrylic monomer is more preferable in view of excellent initial curability and adhesion to a film as an adhesive composition for a polarizing plate, particularly 2-hydroxyethyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, methylphenoxyethyl (meth) acrylate and phenoxydiethylene glycol (meth) acrylate and 2-hydroxy- desirable.

The above acrylic monomer may be a commercially available product, and examples thereof include KAYARAD series (manufactured by Nippon Kayaku Co., Ltd.), NK ester series (manufactured by Shin Nakamura Kagakuko Kogyo Co., Ltd.) (Manufactured by Dai-ichi Kasei Kogyo Co., Ltd.), KRM series (manufactured by Daicel-Cotech Co., Ltd.), EB series, UVECRYL (registered trademark) series (Manufactured by Sankyo Seiko Kogyo Co., Ltd.), RCC series (manufactured by Grace Japan KK), Aronix (registered trademark) series (manufactured by Mitsubishi Chemical Corporation), Olex (registered trademark) Series (manufactured by Toagosei Co., Ltd.), and a light acrylate series (manufactured by Kyowa Shika Kakaku Co., Ltd.).

In the composition for a polarizing plate of the present invention, 20 to 70 parts by mass of the epoxy resin and 30 to 80 parts by mass of the acrylic monomer are contained (provided that the total amount of the epoxy resin and the acrylic monomer is 100 parts by mass). If the amount of the epoxy resin is larger than the above range, the initial curability of the adhesive is insufficient and the adhesive becomes opaque, which may limit the use of the polarizing plate. On the other hand, if the amount of the acrylic monomer is larger than the above-mentioned range, there is a possibility that the adhesive property of the polarizing plate becomes insufficient. The epoxy resin is preferably 25 to 70 parts by mass, more preferably 30 to 65 parts by mass, 40 to 60 parts by mass, and most preferably 50 parts by mass in the total of 100 parts by mass of the epoxy resin and the acrylic monomer, The monomer is preferably 75 to 30 parts by mass, more preferably 70 to 35 parts by mass, 60 to 40 parts by mass, and most preferably 50 parts by mass.

The adhesive composition for a polarizing plate of the present invention may further contain a rotaxane polymer. The lactic acid polymer is also referred to as a sliding material, and has a structure in which a straight-chain polymer having a molecule bonded thereto is passed through a ring of a plurality of annular molecules. In the present invention, among the lactic acid polymer having such a structure, those having a vinyl group-containing substituent bonded to a cyclic molecule portion as a functional side-chain can be used. The lactic acid polymer having such a vinyl group formula is preferable because it forms a supramolecular network and contributes to the improvement of the adhesiveness of the polarizer adhesive because the cyclic molecule moiety moves freely when radical polymerization is carried out together with the acrylic monomer.

Examples of the lactic acid polymer that can be used in the present invention include cyclodextrin, crown ether, cyclopentane, calixarene, cucurbituril and cyclic amide as the cyclic molecule and polyethylene glycol, alkyl chain, amide, And adamantanamine or the like is used as a stopper molecule. Of these, a cyclic dextrin as the cyclic molecule, polyethylene glycol as the axial molecule, and adamantanamine as the stopper molecule are more preferable because the rocotaxane polymer easily forms a network together with the acrylic monomer.

Commercially available products of the above-mentioned lactic acid polymers can be preferably used. Commercially available products to be used in the present invention include cyclomethicone as a cyclic molecule, polyethylene glycol as an axial molecule, adamantanamine as a stopper molecule, S1000, M1000, and SURUM (registered trademark) Superpolymer A1000 (manufactured by Advanced Soft Materials Co., Ltd.).

In the case of using a lactic acid polymer, the mass ratio of the acrylic monomer / the lactic acid polymer is preferably 99/1 to 70/30, more preferably 95/5 to 75/30, 25. That is, 70 to 99 parts by mass, preferably 75 to 95 parts by mass, of the acrylic monomer in the total of 100 parts by mass of the acrylic monomer and the lactic acid polymer, 1-30 parts by mass, and preferably 5-25 parts by mass . Within the above range, it is sufficient to obtain the effect of further improving the adhesiveness. If the compounding ratio of the rosin taxane polymer is not more than the upper limit, shrinkage of the polarizer during heat resistance can be suppressed without increasing the flexibility of the adhesive, and inconvenience such as cracking of the polarizer can be more reliably prevented.

When a cyclohexane polymer is used, the mass ratio of the acrylic monomer to the cyclohexane polymer may be 4: 1 to 9: 1.

When a taxane polymer is used, the mass ratio of the epoxy resin to the taxane polymer may be 5: 1 to 10: 1. The epoxy resin may include at least one of the above-mentioned epoxy resins (a) and (b). Preferably, the epoxy resin may be the sum of the above-mentioned epoxy resins (a) and (b).

The taxane polymer may be contained in an amount of 5 to 10 parts by mass based on 100 parts by mass of the sum of the epoxy resin, the acrylic monomer, and the cyclic acid polymer. The epoxy resin may include at least one of the above-mentioned epoxy resins (a) and (b). Preferably, the epoxy resin may be the sum of the above-mentioned epoxy resins (a) and (b). The epoxy resin may be contained in an amount of 20 to 70 parts by mass, preferably 50 to 55 parts by mass, and the acrylic monomer may be contained in an amount of 25 to 70 parts by mass, preferably 40 to 45 parts by mass.

(C) Photoacid generator

As the photoacid generator, conventionally known photoacid generators may be used without particular limitation. Specific examples thereof include aromatic diazonium salts, onium salts such as aromatic iodonium salts and aromatic sulfonium salts, iron-arene complexes and the like. These may be used alone or in combination of two or more.

Examples of the aromatic diazonium salt include benzene diazonium hexafluoroantimonate, benzene diazonium hexafluorophosphate, and benzene diazonium hexafluoroborate.

The aromatic iodonium salts include, for example, diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di (4-nonylphenyl) Hexafluorophosphate and the like.

The aromatic sulfonium salts include, for example, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, diphenyl [4- (phenylthio ) Phenyl] sulfonium hexafluoroantimonate, 4,4'-bis [diphenylsulfonio] diphenyl sulfide bishexafluorophosphate, 4,4'-bis [di (? - hydroxyethoxy ) Phenylsulfonio] diphenylsulfide bishexafluoroantimonate, 4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bishexafluorophosphate, 7 - [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate, 7- [di (p- tolyl) sulfonio] -2-isopropylthioxanthone Tetrakis (pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfone-diphenylsulfide hexafluorophosphate, 4- (p- ) -4'-diphenylsulfo-diphenylsulfide hexafluoroantimonate, 4- (p-tert-butylphenylcarbonyl) -4'-di (p-toluyl) Phenylsulfide tetrakis (pentafluorophenyl) borate, diphenyl [4- (phenylthio) phenyl] sulfonium, and the like.

Examples of the iron-arene complexes include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, xylene-cyclopentadienyl iron (II) -Tris (trifluoromethylsulfonyl) methanide, and the like.

For example, CPI-100P, 101A, 200K, 210S (manufactured by SANA PRO Co., Ltd.), KAYARAD (registered trademark) PCI-220 and PCI-620 (manufactured by Nippon Kayaku Co., Ltd.) CIP-1866S, 2048S, 2064S (manufactured by Nippon Soda Co., Ltd.), CI-5102, CIT-1370, 1682, , DPI-101, 102, 103, 105, MPI-103, 105, BBI-101, 102, 103, 105, TPS-101, 102, 103, 105, MDS-103, 105, DTS- Ltd.), PI-2074 (manufactured by Rhodia Japan KK), and the like.

The amount of the photoacid generator to be used is preferably from 1 to 7 parts by mass relative to 100 parts by mass of a total of 100 parts by mass of the epoxy resin (A) and the acrylic monomer (B) or 100 parts by mass of the total of 100 parts by mass of the epoxy resin (A), the acrylic monomer And more preferably 1 to 4 parts by mass. If the amount of the photoacid generator used is less than 1 part by mass, the curing property of the adhesive composition after ultraviolet irradiation is poor, and if it exceeds 7 parts by mass, the durability may be insufficient.

Further, in the adhesive composition of the present invention, a photosensitizer such as a thioxanone compound, a naphthalene compound, or an anthracene compound may be used in combination with the photopolymerization initiator to improve the reactivity of the polymerization reaction.

(D) Photopolymerization initiator

The adhesive composition of the present invention further comprises a photopolymerization initiator. The photopolymerization initiator is not particularly limited, and conventionally known photopolymerization initiators can be preferably used. The photopolymerization initiator may be used alone or in combination of two or more.

Specific examples of the photopolymerization initiator include inorganic peroxides such as hydrogen peroxide, potassium persulfate and ammonium persulfate, t-butyl hydroperoxide, t-dibutyl peroxide, cumene hydroperoxide, acetyl peroxide, benzoyl peroxide and lauroyl peroxide Organic peroxides such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride and azobisisanovaleric acid , Azo compounds such as acetophenone, benzoin, benzophenone, phosphine oxides, ketal, anthraquinone, thioxanthone compounds, 2,3-dialkyldione compounds, disulfide compounds, fluoro Aminic compounds, aromatic sulfoniums, ropindimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.

More specifically, it is preferable to use acetophenone, 3-methylacetophenone, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxy- (Methylthio) phenyl] -2-morpholinopropane-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; Benzophenones including benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; Benzoin ethers such as benzoin propyl ether and benzoin ethyl ether; Thioxanthones such as 4-isopropylthioxanthone; Xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, and the like.

Examples of the photopolymerization initiator include commercially available products such as IRGACURE (registered trademark) -184, 819, 907, 651, 1700, 1800, 819, 369, 261, DAROCUR-TPO (manufactured by BASF Japan KK) KIP150, TZT (manufactured by DKSH Japan KK), Kaya Cure (registered trademark) BMS, and DMBI (manufactured by Nippon Kayaku Co., Ltd.).

Examples of inorganic peroxides and organic peroxides include amines such as ethylamine, triethanolamine and dimethylaniline, polyamines, divalent iron salt compounds, organometallic compounds such as ammonia, triethylaluminum, triethylboron and diethylzinc, sodium sulfite, An appropriate reducing agent such as sodium chloride, cobalt naphthenate, sulfinic acid or mercaptane may be used in combination.

The photopolymerization initiator is used in an amount of 0.1 to 7 parts by mass based on 100 parts by mass of the total of 100 parts by mass of the epoxy resin (A) and the acrylic monomer (B) or 100 parts by mass of the total of the epoxy resin (A), the acrylic monomer , Preferably 0.5 to 2.5 parts by mass. If the amount of the photopolymerization initiator used is less than 0.1 part by mass, it is difficult to be cured even by ultraviolet irradiation, and if it exceeds 7 parts by mass, the durability may be insufficient.

In order to improve the reactivity of the polymerization reaction, the adhesive composition of the present invention may further contain, in addition to the photopolymerization initiator, a carbonyl compound, an organic sulfur compound, a persulfide compound, a redox compound, an azo compound and a diazo compound, A photosensitizer such as a dye may be used in combination.

(E) Method for producing adhesive composition

In order to produce the adhesive composition of the present invention, there is no particular limitation, and usually an adhesive composition can be obtained by mixing the above-mentioned specific epoxy resin, acrylic monomer, photoacid generator and photopolymerization initiator. An organic solvent may be appropriately used for viscosity control. The mixing method is not particularly limited, and it may be sufficiently mixed with stirring at room temperature (25 DEG C) until the liquid becomes homogeneous.

The adhesive composition for a polarizing plate of the present invention may further contain additives such as an ultraviolet absorber, an antioxidant, a heat stabilizer, a silane coupling agent, an inorganic filler, a softener, an antioxidant, an antioxidant, a stabilizer, A leveling agent, a defoaming agent, a plasticizer, a dye, a pigment (a coloring pigment, an extender pigment), a treating agent, a sunscreen agent, a fluorescent whitening agent, an antioxidant, an antioxidant, A dispersant, a light stabilizer, an antistatic agent, and a lubricant may be added.

(2) Polarizer

According to a second aspect of the present invention, there is provided a polarizing plate having a protective film and a polarizer adhered using the adhesive composition of the present invention. The polarizing plate of the present invention has excellent processability at the time of production and exhibits sufficient adhesion. Hereinafter, the structure of the polarizing plate of the present invention will be described.

(A) Polarizer

The polarizer is not particularly limited and a conventionally known polarizer can be used. For example, a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film or an ethylene / vinyl acetate copolymerization system partial saponification film is monofilamented by adsorbing a dichroic material such as iodine or a dichroic dye , A polyene-based oriented film such as a dehydrated product of polyvinyl alcohol, a dehydrochlorinated product of polyvinyl chloride, and the like.

Among them, a polarizer prepared by dyeing a polyvinyl alcohol film having an average degree of polymerization of 2000 to 2800 and a degree of saponification of 90 to 100 mol% with iodine and monoaxially stretching 5 to 6 times is particularly preferable. More specifically, such a polarizer is obtained by, for example, dipping a polyvinyl alcohol film in an aqueous solution of iodine, and stretching it. As the aqueous solution of iodine, for example, it is preferable to immerse in an aqueous solution of 0.1 to 1.0 mass% of iodine / potassium iodide. If necessary, it may be immersed in an aqueous solution of boric acid or potassium iodide at 50 to 70 ° C, or may be immersed in water at 25 to 35 ° C to prevent washing or staining. Stretching may be performed after dyeing with iodine, stretching while dyeing, or dyeing with iodine after stretching. After dyeing and stretching, it may be washed with water and dried at 35 to 55 ° C for about 1 to 10 minutes.

(B) Protective film

As the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, cellulose-based resins such as cellulose diacetate and cellulose triacetate, polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate, acrylic resins such as polymethyl methacrylate, polystyrene and acrylonitrile-styrene copolymer Polypropylene, a polyolefin having a cyclo or norbornene structure, a polyolefin-based resin such as an ethylene-propylene copolymer, a vinyl chloride-based resin, a nylon or an aromatic poly Amide resins, imide resins, sulfone resins, polyether sulfone resins, polyether ether ketone resins, polyphenylene sulfide resins, vinyl alcohol resins, vinylidene chloride resins, vinyl butyral resins , An allylate resin, a polyoxymethylene resin , An epoxy resin or a blend of the resin.

As the protective film for the polarizing plate, a cellulose resin or a cycloolefin polymer (COP film) or polyethylene terephthalate (PET film), which is an ester of cellulose and a fatty acid, is preferable. Examples of the cellulose-based resin include cellulose triacetate (TAC film), cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Of these, cellulose triacetate, polyethylene terephthalate and cycloolefin polymers are particularly preferable in terms of availability and cost. The cellulose triacetate may be saponified, but it is more preferably not saponified. Examples of the cycloolefin polymer include polymers obtained by hydrogenating a ring-opening polymer of tetracyclododecene disclosed in Japanese Examined Patent Publication No. 2-9619.

Examples of commercially available TAC films include UV-50, UV-80, SH-80, TD-80U, TD-TAC, UZ-TAC and KC series manufactured by Konica Minolta Opto Co., Commercially available products of the COP film include Aton (registered trademark) manufactured by JSR Corporation, Zeonex (registered trademark) series manufactured by Nippon Zeon Corporation, and Zeonoa (registered trademark) series. Commercially available products of the PET film include COSMO SHINE (registered trademark) series manufactured by Toyoboseki KK.

The surface of the protective film is preferably modified by a corona discharge treatment. The method of the corona discharge treatment is not particularly limited and can be carried out using a general corona discharge treatment apparatus (for example, manufactured by Kasuga Denshi KK). It is considered that an active group such as a hydroxyl group is formed on the surface of the protective film by the corona discharge treatment and this contributes more to the improvement of the adhesiveness. In the case of using saponified cellulose triacetate as the protective film, the corona discharge treatment is not necessarily required since it is expected to have the same effect as the corona discharge treatment. However, it is preferable in the manufacturing process that the saponification treatment is performed by corona discharge treatment of non-saponified cellulose triacetate because the process is complicated and costly.

The discharge amount in the corona treatment is not particularly limited, but is preferably 30 to 300 W · min / m ² , more preferably 50 to 250 W · min / m ² . Within such a range, adhesion of the protective film to the adhesive can be improved without deteriorating the protective film itself, which is preferable. Here, the discharge amount is a quantity for the object by the corona discharge determined by the following calculation, and the corona discharge power is determined on the basis of the discharge amount.

(Discharge amount) = (discharge electric power) / {(object processing speed) x (electrode length)}

(C) Production method of polarizing plate

The method for producing the polarizing plate is not particularly limited, and can be produced by bonding the protective film and the polarizer using the adhesive composition of the present invention according to a conventionally known method. The applied adhesive composition exhibits adhesiveness by ultraviolet irradiation to constitute an adhesive layer.

When the adhesive composition is applied, it may be applied to either the protective film or the polarizer, or it may be applied to both sides. The adhesive composition is preferably applied after drying so that the thickness of the adhesive layer is 10 nm to 5 m. The thickness of the adhesive layer is more preferably 500 nm to 3 占 퐉 in order to obtain a uniform in-plane thickness and also to obtain a sufficient adhesion force. The thickness of the adhesive layer can be adjusted by the solid content concentration in the adhesive composition solution or the application device of the adhesive composition. The thickness of the adhesive layer can be confirmed by observing a cross section by a scanning electron microscope (SEM). The method of applying the adhesive composition is not particularly limited, and various means such as a method of dropping the adhesive composition directly, a roll coating method, a spraying method, and a dipping method may be employed.

After applying the adhesive composition, the polarizer and the protective film are bonded together by a roll laminator or the like.

After bonding, the polarizer is irradiated with ultraviolet rays for curing the adhesive composition. Although a light source of ultraviolet rays is not particularly limited, low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, chemical lamps, black light lamps, microwave excited mercury lamps, metal halide lamps and the like having a light emission distribution with a wavelength of 400 nm or less can be used. The ultraviolet irradiation intensity is not particularly limited, but it is preferable that the ultraviolet irradiation amount in the wavelength range effective for activating the polymerization initiator is 100 to 2,000 mJ / cm 2. In this range, the reaction time is appropriate, and there is no possibility of causing deterioration of the adhesive itself or the polarizing film due to heat radiated from the lamp and heat generated during polymerization.

Since ultraviolet irradiation, the polarizing plate is stored at room temperature (23 ° C) for about 16 to 30 hours immediately after irradiation with ultraviolet rays, since the epoxy reaction proceeds with the epoxy resin. Upon completion of the curing, the polarizing plate is completed.

The present invention provides a display device including the polarizer.

Hereinafter, the present invention will be described with reference to examples and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments.

≪ Example 1 >

≪ Preparation of adhesive composition >

, 65 parts by mass of resorcinol epoxy resin (denacol (registered trademark) EX-201 manufactured by Nagase ChemteX Corporation) as an epoxy resin, 25 parts by mass of 2-hydroxyethyl acrylate (manufactured by Osaka Yuki Kagaku Co., Ltd.) , 10 parts by mass of phenoxyethyleneglycol acrylate (NK ester AMP-20GY manufactured by Shin Nakamura Co Ltd.), 3 parts by mass of a photo acid generator (CPI210S manufactured by SAN-A PRO), 10 parts by mass of a photopolymerization initiator (Irgacure (registered trademark) 907) were stirred and mixed in a constant-temperature chamber at 23 占 폚 and a humidity of 50% RH until they were visually uniformized to obtain an adhesive composition. The materials used and the compounding ratios thereof are shown in Table 1 below.

≪ Production of polarizing plate &

The polarizer was produced by the following method. A polyvinyl alcohol film having an average degree of polymerization of 2400 and a degree of saponification of 99.9% and having a thickness of 75 탆 was immersed in hot water at 28 캜 for 90 seconds to swell, followed by immersion in an aqueous solution having a concentration of 0.6% by weight of iodine / potassium iodide (weight ratio 2/3) And the polyvinyl alcohol film was dyed while being stretched 2.1 times. Thereafter, the resultant was stretched so as to have a total draw ratio of 5.8 in an aqueous solution of boric ester at 60 DEG C, washed with water and dried at 45 DEG C for 3 minutes to prepare a polarizer (thickness: 25 mu m).

1 is a schematic view showing a method of manufacturing a polarizing plate in this embodiment. 1, the polarizer 1 was sandwiched between the protective film 3 and the protective film 4 and the adhesive composition 2 thus obtained was applied onto the protective film 3 and the polarizer 1 and the protective film 4 4) and the polarizer 1 by dropping using an eyedropper, and they were joined together by a roll press equipped with rolls 6, 7. In this embodiment, a COP film (thickness 30 μm, manufactured by Nippon Zeon Co., Ltd.) was used as the protective film 3, and a cellulose triacetate film (TAC film, thickness 80 μm, manufactured by Fuji Film Co., Ltd.) was used as the protective film 4. The ultraviolet radiation pre-polarizing plate 5 bonded in this manner was irradiated with ultraviolet radiation having a dose of 1000 mJ / cm 2 (365 nm metal halide lamp) from the protective film 3 side. Further, the process from bonding of the polarizer to the protective film using the adhesive composition to ultraviolet irradiation was performed at 23 DEG C and a humidity of 50% RH.

After the ultraviolet irradiation, the polarizing plate was stored in a constant temperature chamber (23 ° C, 50% RH) for 24 hours, and the adhesive composition was cured to complete the polarizing plate. The thickness of the adhesive layer in the completed polarizing plate was 2.0 占 퐉.

The polarizing plate was subjected to an initial curing test immediately after irradiation with ultraviolet rays as described below, irradiated with ultraviolet rays, stored at room temperature for 24 hours, and subjected to a cutting test and a hot water immersion test. The evaluation results are shown in Table 1 described later.

≪ Examples 2 to 14 >

In Examples 2 to 14, an adhesive composition was prepared in the same manner as in Example 1 except that the materials and blending amounts shown in Tables 1 to 3 were used. Then, a protective film was bonded to each of the polarizers in the same manner as in Example 1 except that each of the obtained adhesive compositions was used and the protective film shown in Tables 1 to 3 was used. Ultraviolet rays were irradiated to the polarizer to complete the polarizer. Examples 2 to 14 were also evaluated by the same test as in Example 1. [

≪ Comparative Examples 1 to 4 >

In Comparative Examples 1 to 4, an adhesive composition was prepared in the same manner as in Example 1 except that the materials and blending amounts shown in Table 4 were used. Polarizers and protective films were bonded to each other in the same manner as in Example 1 except that the obtained adhesive composition was used and the protective film shown in Table 4 was used. Ultraviolet rays were irradiated to complete the polarizer. Comparative Examples 1 to 4 were also evaluated by the same test as in Example 1. [

<Initial Curability Test>

The polarizing plate immediately after the ultraviolet irradiation produced in Examples 1 to 14 and Comparative Examples 1 to 4 was bent so that the interval between the polarizing plates 8 bent as shown in Fig. 2 was 10 mm (R10 mm) It was judged by the naked eye. When no peeling was observed, it was indicated as &amp; cir &amp; The evaluation results are shown in Tables 1 to 4 below.

<Test of Foundation>

The polarizing plates produced in Examples 1 to 14 and Comparative Examples 1 to 4 were cut with a Thomson blade to a size of 50 mm x 50 mm, and the peeling state of the ends at the time of cutting was visually observed. As an evaluation criterion, 0.5 mm or less was passed. The evaluation results are shown in Tables 1 to 4.

<Hot water immersion test>

The polarizing plates produced in Examples 1 to 14 and Comparative Examples 1 to 4 were cut into 50 mm x 50 mm with a Thomson blade, immersed in a water bath at 60 DEG C and held for 2 hours. Then, each sample was taken out from the water bath to measure the shrinkage size of the polarizer. As shown in Fig. 3 (A), from the end of the polarizing plate 8 before test to the end of the polarizing plate 8 contracted in the stretching direction as shown in Fig. 3 (B), the shrinkage size 9 was determined. If the adhesiveness of the adhesive is high, the shrinkage is smaller and if the adhesive property is not sufficient, the shrinkage of the polarizing plate becomes larger. As a criterion for evaluation, it was decided that the shrinkage size was 2.0 mm or less. The evaluation results are shown in Tables 1 to 4.

Example 1 Example 2 Example 3 Example 4 Example 5
Epoxy resin Resor 65 50 35 25 15 Naphthalene type - - - - - Bisphenol S type - - - - - Bisphenol A type - - 15 25 35 Acrylic monomer 2HEA 25 25 25 25 25 AMP2OGY 10 25 25 25 25 MPOA - - - - - To taxane polymer S1000 - - - - - Photoacid generator CPI210S 3 3 3 3 3 Photopolymerization initiator Ig907 One One One One One Protective Film Composition
UV irradiation surface COP COP COP COP COP TAC TAC TAC TAC TAC Initial hardenability test ○ ○ ○ ○ ○ Cut test mm 0.5 0.4 0.3 0.3 0.4 Hot water immersion test mm 0.5 0.4 0.3 0.3 0.6 Resor new type: manufactured by Nagase Chemtex Co., Ltd.
Denacol EX-201 resorcinol diglycidyl ether
Naphthalene type: HP-4032D manufactured by DIC Co., Ltd. Naphthalene type epoxy resin
Bisphenol S type: EXA-1514 bisphenol type epoxy resin manufactured by DIC Co., Ltd.
Bisphenol A type: EXA-850CRP manufactured by DIC Co., Ltd. Bisphenol A type epoxy resin
2HEA: 2-hydroxyethyl acrylate
AMP2OGY: Shin-Nakamura Kagakuko Co., Ltd. NK ester AMP-2OGY
Phenoxy ethyleneglycol acrylate
MPOA: manufactured by Kayei Shakagaku Co., Ltd.
Light Acrylate MPO-A Methylphenoxyethyl acrylate
S1000: manufactured by Advanced Soft Materials Co., Ltd.
The cermet elastomer S1000
CPI 210S: CPI-210S manufactured by San A &
Ig 907: Irgacure 907 manufactured by BASF Corporation
COP: Cycloolefin polymer manufactured by Nippon Zeon Co., Ltd. Thickness 30 占 퐉
TAC: Cellulose triacetate manufactured by Fuji Film Co., Ltd. Thickness 80 占 퐉
PET: polyethylene terephthalate manufactured by Toyo Boseki Co., Ltd. Thickness 100 占 퐉

Example 6 Example 7 Example 8 Example 9 Example 10
Epoxy resin Resor 30 - - 25 - Naphthalene type - 25 - - 25 Bisphenol S type - - 25 - - Bisphenol A type - 25 25 25 25 Acrylic monomer 2HEA 35 25 25 25 25 AMP2OGY 35 25 25 - - MPOA - - - 25 25 To taxane polymer S1000 - - - - - Photoacid generator CPI210S 3 3 3 3 3 Photopolymerization initiator Ig907 One One One One One Protective Film Composition UV irradiation surface COP COP COP COP COP TAC TAC TAC TAC TAC Initial hardenability test ○ ○ ○ ○ ○ Cut test mm 0.5 0.5 0.5 0.2 0.3 Hot water immersion test mm 0.5 0.5 0.5 0.2 0.3

Example 11 Example 12 Example 13 Example 14
Epoxy resin Resor 25 25 25 25 Naphthalene type - - - - Bisphenol S type - - - - Bisphenol A type 25 25 25 25 Acrylic monomer 2HEA 20 25 25 25 AMP2OGY 20 20 25 - MPOA - - - 25 To taxane polymer S1000 10 5 - - Photoacid generator CPI210S 3 3 3 3 Photopolymerization initiator Ig907 One One One One Protective Film Composition UV irradiation surface COP COP COP COP TAC TAC PET PET Initial hardenability test ○ ○ ○ ○ Cut test mm 0.1 0 0.5 0.3 Hot water immersion test mm 0.1 0 0.5 0.3

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4
Epoxy resin Resor 80 10 - - Naphthalene type - - - - Bisphenol S type - - - - Bisphenol A type - - 80 - Acrylic monomer 2HEA 10 45 10 50 AMP2OGY 10 45 10 50 MPOA - - - - To taxane polymer S1000 - - - - Photoacid generator CPI210S 3 3 3 - Photopolymerization initiator Ig907 One 2 One 3 Protective Film Composition UV irradiation surface COP COP COP COP TAC TAC TAC TAC Initial hardenability test × ○ × ○ Cut test mm 0.4 1.0 0.5 2.0 Hot water immersion test mm 0.4 Peeling occurred 0.5 Peeling occurred

As shown in Tables 1 to 4, in Examples 1 to 14, good results were obtained in both the cutting test, the hot water immersion test and the initial curability test. On the other hand, in Comparative Example 3, which did not contain a specific epoxy resin, the initial curability was poor. In Comparative Example 4, which did not contain any epoxy resin, the results of the hot water immersion test and the cutting test did not satisfy the evaluation criteria, The result was falling. The initial curability was poor in Comparative Example 1 in which the content of the acrylic monomer was small, whereas in Comparative Example 2 in which the content of the specific epoxy resin was small, the initial curability was good, but the adhesiveness in the hot water immersion test and the cutting test was poor.

Further, in comparison with Example 8 using a bisphenol S type epoxy resin as a specific structure epoxy resin and Example 4 using a resorcinol type epoxy resin, it was found that Example 4 exhibited better adhesion as shown in the cutting test and the hot water immersion test Able to know. Furthermore, it can be seen that Example 9 is superior in adhesion as shown in the cutting test and the hot water immersion test, compared to Example 10 using naphthalene type epoxy resin and Example 9 using resorcinol type epoxy resin.

And Example 2 in which the mass ratio of the epoxy resin / acrylic monomer was 50/50 was slightly superior to that in Example 1 of 65/35 in the adhesion test shown in the cutting test and the hot water immersion test. Further, Examples 11 and 12 containing a roto-taxane polymer are superior to those of Example 4, which does not contain a roto-taxane polymer, and exhibit superior adhesion as shown in the cut test and the hot water immersion test.

As described above, from the comparison between the examples and the comparative examples, it was found that the adhesive composition of the present invention using an epoxy resin and an acrylic monomer having a specific structure in a specific ratio can achieve both excellent initial curability and adhesive property when used in a polarizing plate.

1: Polarizer 2: Adhesive composition solution
3, 4: protective film 5: ultraviolet ray pre-polarizer
6, 7: roll 8: polarizer
9: shrinkage size

Claims (13)

20 to 70 parts by mass of an epoxy resin,
30 to 80 parts by mass of an acrylic monomer,
Based on 100 parts by mass of the sum of the epoxy resin and the acrylic monomer,
1 to 7 parts by mass of a photo acid generator and
0.1 to 7 parts by mass of a photopolymerization initiator,
The epoxy resin includes at least one selected from the group consisting of (a) a resorcinol type epoxy resin, a bisphenol S type epoxy resin and a naphthalene type epoxy resin, (b) an aromatic compound having a hydroxyl group or a glycidyl Or other epoxy resin which is an alicyclic epoxy compound in which a glycidyloxy group or an epoxy ethyl group is bonded to a saturated carbon ring directly or via an alkylene group,
(a) and (b) of (a) at least one member selected from the group consisting of a resorcinol type epoxy resin, a bisphenol S type epoxy resin and a naphthalene type epoxy resin and (b) and b) is 99/1 to 20/80 in 100 parts by mass of the total of the components (a) and (b).
The adhesive composition for a polarizing plate according to claim 1, wherein the epoxy resin (a) comprises a resorcinol type epoxy resin.
The adhesive composition for a polarizing plate according to claim 1, wherein the resorcinol-type epoxy resin is represented by the following Formula 1:
&Lt; Formula 1 >

(Wherein, Y ₁ and Y ₂ each independently represent an alkylene group of 1 to 10 carbon atoms, R ₁ represents a halogen atom or an alkyl group of 1 to 5 carbon atoms, X ₁ and X ₂ represent an epoxy group N is an integer of 0-4.
(2)

).

The adhesive composition for a polarizing plate according to claim 1, wherein the bisphenol S type epoxy resin is represented by the following Formula 6:
(6)

(Wherein Y ₅ and Y ₆ each independently represent an alkylene group having 1 to 10 carbon atoms,
R ₅ and R ₆ each independently represent a halogen atom or an alkyl group having 1 to 5 carbon atoms,
X ₅ and X ₆ is an epoxy group represented by the following formula (2). n and m are the same or different and are an integer of 0-4.
(2)

).
The adhesive composition for a polarizing plate according to claim 1, wherein the naphthalene type epoxy resin is represented by the following Formula 4:
&Lt; Formula 4 >

(Wherein Y ₃ and Y ₄ each independently represent an alkylene group having 1 to 10 carbon atoms,
R ₃ and R ₄ each independently represent a halogen atom or an alkyl group having 1 to 5 carbon atoms,
X ₃ and X ₄ are epoxy groups represented by the following formula (2). n and m are the same or different and are an integer of 0-3.
(2)

).
delete delete The adhesive composition for a polarizing plate according to claim 1, wherein the composition for a polarizing plate further comprises a rotaxane polymer.
9. The method of claim 8, wherein the rotaxane polymer is one in which stopper molecules are bonded to axial molecules in which cyclic molecules are interposed,
Wherein the cyclic molecule comprises at least one of cyclodextrin, crown ether, cyclopan, calixarene, cucurbituril, cyclic amide,
Wherein the axial molecule comprises at least one of polyethylene glycol, alkyl chain, amide, and ammonium,
Wherein the stopper molecule comprises adamantane amine.
The adhesive composition for a polarizing plate according to claim 8, wherein the mass ratio of the lactic acid polymer to the acrylic monomer is 1/99 to 30/70 of 100 parts by mass of the sum of the lactic acid polymer and the acrylic monomer.
The adhesive composition for a polarizing plate according to claim 1, wherein the acrylic monomer comprises at least one of a hydroxyl group-containing acrylic monomer and a phenoxy group-containing acrylic monomer.
A polarizing plate comprising a protective film and a polarizer adhered using the adhesive composition for a polarizing plate according to any one of claims 1 to 5 and 8 to 11.
A display device comprising the polarizer of claim 12.

Images