CN107148585A - Polarizer adhesive composition and the polarizer with adhesive phase - Google Patents

Abstract

The present invention provides one kind and can be formed and can suppress the polarizer adhesive composition of liquid crystal cell warpage (bending) and the adhesive phase of excellent in te pins of durability, the structure that at least one party that described adhesive layer is applicable in the polarizer diaphragm that is generally formed on polarizer two sides is removed.The polarizer adhesive composition is used to be formed the adhesive phase directly connected with polarizer, and the polarizer adhesive composition contains：(A) (methyl) acrylic copolymer of the degree of branching for being obtained and being determined by gel permeation chromatography/multi-angle laser light scattering detector (GPC MALS) for the monomer component copolymerization of 4~18 (methyl) alkyl acrylate and monomer containing cross-linking functional group by the carbon number comprising alkyl below 0.55, and (B) crosslinking agent.

Description

Polarizer adhesive composition and the polarizer with adhesive phase

Technical field

Polarizer the present invention relates to polarizer adhesive composition and with adhesive phase etc..

Background technology

Liquid crystal cell have liquid crystal layer by two pieces of substrates (for example：Glass plate) clamped by construction.Constitute liquid crystal cell On substrate surface polarizer is pasted with via adhesive phase.So far, in order to improve the mechanical property and optical durability of polarizer, It is typically employed in the polarizer diaphragm of stacking tri acetyl cellulose etc. on the polarizer two sides with polarization function Structure.

In recent years, with the slimming and the slimming of polarizer of liquid crystal cell, liquid crystal is brilliant under hot and humid thermal environment The warpage of born of the same parents turns into a big problem.The reason for occurring warpage as liquid crystal cell, can enumerate answering for for example conventional adhesive phase Power relaxation properties are low, it is impossible to fully relax the stress produced by the thermal contraction of polarizer (change in size).

On the other hand, for the slimming requirement of polarizer, attempt to save the polarization member to be formed on polarizer two sides Part diaphragm.However, the polarizer of unprotect film due to adhesive phase is directly contacted with polarizer and in hot and humid heat Not only can easily occur sticking up for liquid crystal cell as the thermal contraction of polarizer is over the binder layer by big stress under environment Song, is also easy to a problem that fracture, stripping of polarizer for occurring adhesive phase.

One kind has been recorded in patent document 1 by making to be formed by specific acrylic polymer and isocyanate compound Adhesive composition crosslink reaction obtained from gel fraction more than 1% less than 50% bonding used for optical part Agent.Described in patent document 1, by above-mentioned composition, the stress produced due to the change in size of polarizing coating can be relaxed, is suppressed Light leak.However, it not should be particularly mentioned that saving on polarizer diaphragm.

A kind of adhesion type with polarizer and the adhesive phase being arranged on the polarizer is recorded in patent document 2 inclined Shake piece, and the polarizer, which has, only there is transparent protective film, described adhesive layer to be arranged on no institute on the one side of polarizer State the composition on the polarizer of transparent protective film side.However, it not should be particularly mentioned that the province with the transparent protective film The warpage issues for the liquid crystal cell for going and producing.

Prior art literature

Patent document

Patent document 1：Japanese Patent Laid-Open 2004-091500 publications

Patent document 2：Japanese Patent Laid-Open 2012-247574 publications

The content of the invention

The technical problems to be solved by the invention

The technical problems to be solved by the invention are to provide one kind and can be formed that liquid crystal cell warpage (bending) can be suppressed And the polarizer adhesive composition of the adhesive phase of excellent in te pins of durability, described adhesive layer is applicable to be generally formed in partially The structure that at least one party in the polarizer diaphragm on element two sides that shakes is removed.

Solve the technical scheme that technical problem is used

The present inventor has made intensive studies to solve above-mentioned technical problem.As a result find using the degree of branching specific In the range of (methyl) acrylic copolymer and using crosslinking agent occasion under, can be formed can suppress above-mentioned liquid crystal cell The adhesive phase of warpage (bending) and excellent in te pins of durability.All do not refer to any on this degree of branching in above-mentioned patent document 1 and 2 Content.

That is, the inventors discovered that, can be solved by using the polarizer adhesive composition with following specific composition Certainly above-mentioned technical problem, so as to complete invention.

The present invention is, for example, following [1]~[8].

[1] a kind of polarizer adhesive composition, it is used to form the adhesive phase directly connected with polarizer, institute Polarizer adhesive composition is stated to contain：(A) by the carbon number comprising alkyl for 4~18 (methyl) alkyl acrylate and contain The monomer component copolymerization of the monomer of crosslinking property functional group is obtained and by gel permeation chromatography/multi-angle laser light scattering (methyl) acrylic copolymer of the degree of branching that detector (GPC-MALS) is determined below 0.55, and (B) crosslinking agent.

[2] the polarizer adhesive composition described in above-mentioned [1], wherein, (methyl) acrylic copolymer (A) be The copolymer obtained in the presence of peroxide type polymerization initiator by the copolymerization.

[3] the polarizer adhesive composition described in above-mentioned [1] or [2], wherein, crosslinking agent (B), which is included, is selected from isocyanide At least one of ester compound (B1) and metallo-chelate (B2).

[4] the polarizer adhesive composition any one of above-mentioned [1]~[3], wherein, used by the polarizer The gel fraction of the adhesive of adhesive composition formation is more than 50 mass %.

[5] a kind of polarizer adhesive phase, it is formed as the adhesive composition any one of [1]~[4].

[6] the polarizer adhesive phase described in above-mentioned [5], its storage modulus at 23 DEG C is in more than 0.1MPa, 85 Storage modulus at DEG C is designated as G' in below 0.05MPa, and by the storage modulus at T DEG C of temperature_T, by the energy storage mould at T+1 DEG C Amount is designated as G'_T+1When, temperature T always meets G' when in the range of 23~50 DEG C_T/G'_T+1＜ 1.07.

[7] a kind of polarizer bonding sheet, it has the adhesive phase described in above-mentioned [5] or [6].

[8] a kind of polarizer with adhesive phase, it is above-mentioned at least one side of polarizer with being directly layered in [5] or the adhesive phase described in [6].

The effect of invention

Pass through the present invention, it is possible to provide one kind, which can be formed, can suppress the viscous of liquid crystal cell warpage (bending) and excellent in te pins of durability The polarizer adhesive composition of mixture layer, described adhesive layer is applicable to be generally formed in inclined on polarizer two sides The structure that at least one party in element protection film that shakes is removed.Used in addition, may also provide the polarizer formed by the composition Adhesive phase, the polarizer with described adhesive layer are with bonding sheet and with described adhesive layer with adhesive phase Polarizer.

Embodiment

Below, to the present invention polarizer adhesive composition, polarizer adhesive phase, polarizer bonding sheet with And the polarizer with adhesive phase is illustrated.Hereinafter, the polarizer adhesive composition of the present invention, polarizer are used viscous Mixture layer and polarizer are also referred to as " adhesive composition ", " adhesive phase " and " bonding sheet " with bonding sheet.

[polarizer adhesive composition]

The polarizer adhesive composition of the present invention contains (methyl) acrylic copolymer (A) being described below With crosslinking agent (B).Above-mentioned composition can also contain in silane coupler (C) and antistatic agent (D) at least as needed One kind, can also contain organic solvent (E).

[(methyl) acrylic copolymer (A)]

(methyl) acrylic copolymer (A) be comprising alkyl carbon number for 4~18 (methyl) alkyl acrylate and The copolymer of the monomer component of monomer containing crosslinkable groups, is obtained by above-mentioned monomer component copolymerization.Above-mentioned copolymer (A) is led to Often with the construction unit from above-mentioned (methyl) alkyl acrylate and from the above-mentioned monomer containing cross-linking functional group Construction unit.

Acrylic acid and methacrylic acid are referred to as in this specification and are denoted as " (methyl) acrylic acid ".In addition, by polymer Included in the construction unit from certain monomer a be denoted as " monomer a units ".

The branch that copolymer (A) is determined by gel permeation chromatography/multi-angle laser light scattering detector (GPC-MALS) Change degree is below 0.55, preferably 0.10~0.54, more preferably 0.20~0.53, particularly preferably 0.30~0.53.

The so-called degree of branching, refers to be depicted as using the GPC-MALS radiuss of turn (nm) determined and molecular weight (g/mol) By the longitudinal axis of radius of turn, molecular weight straight line (hereinafter also referred to " radius of turn and molecule obtained from the log-log graph of transverse axis The double-log straight line of amount ") slope.In theory, the slope of the above-mentioned straight line of straight chain molecule is 1, the smaller branched degree of slope It is higher.

The detailed content of degree of branching condition determination is recorded in embodiment.

The degree of branching shows that polymer is branched shape or linear index, is branched shape when the degree of branching is below 0.55 Polymer, is straight line shaped polymer during more than 0.55.In addition, for branched shaped polymer, gathering under the small occasion of degree of branching numerical value The branch of adduct molecule is more, is shown as with high side chain, and the branch of polymer molecule is few under the big occasion of degree of branching numerical value, display For with low side chain.

The copolymer (A) of the degree of branching within the above range has following characteristic：(1) in room temperature because of polymer molecule phase Intertexture produced by mutual side chain largely occurs, the result is that the coherency of polymer is maintained, and can obtain adhesion characteristic, right Adhesive phase carries out the excellent adhesive phase of keeping property such as processability, the deformation of adhesive phase and extrusion be few of punching press etc.；(2) exist High temperature is (for example：60 DEG C) under the above-mentioned intertexture of polymer molecule each other part relaxation, therefore adhesive phase shows Excellent flexibility is simultaneously excellent in terms of warpage (bending) suppression of the clung body produced with the thermal contraction of polarizer, Simultaneously because the above-mentioned intertexture of part residual, adhesive phase shows excellent durability (such as heat resistance, humidity resistance).

Warpage on clung body is suppressed this point, thus it is speculated that be due to the following reasons.With in such as polarizer/bonding In structure as oxidant layer/clung body using glass plate as the occasion of clung body exemplified by illustrate.Polarizer and glass The respective percent thermal shrinkage of plate is different, and the percent thermal shrinkage (change in size) of polarizer is generally bigger than glass plate.In adhesive break Under the occasion of flexibility under weary hot and humid thermal environment, adhesive phase can not keep up with the change in size of polarizer, as a result Lead to not relax the stress at adhesive phase, in glass plate warpage occurs on a glass for stress concentration.And use this The adhesive phase that invention adhesive composition is formed contains high branched-chain polymer, the above-mentioned intertexture under hot and humid thermal environment A part relaxation, adhesive phase can keep up with the change in size of polarizer, thus will not produce stress, and stress is not centered on Glass plate.In addition, polarizer will not induce the birefringence of polarizer also without anisotropically uniform thermal contraction.

As described above, in the present invention, adhesive phase can relax stress with the change in size of polarizer, from without Excessive stress (load) can be applied to glass plate, therefore speculate that this is related to the suppression to glass slab warping.

Substrate and polarization of the adhesive composition of the present invention due to being applied to constitute liquid crystal cell with above characteristic The laminating purposes of element.Particularly even in thickness as low as below 1mm of glass plate for the liquid crystal cell for constituting slimming or so Occasion under, be also applied for the purposes of fitting of the substrate and polarizer.

《(methyl) alkyl acrylate》

As (methyl) alkyl acrylate, (methyl) alkyl acrylate that the carbon number that alkyl can be used is 4~18 (CH₂=CR¹-COOR²；R¹For hydrogen atom or methyl, R²The alkyl for being 4~18 for carbon number), wherein, the carbon number of abovementioned alkyl enters one Step is preferably 4~12.

(methyl) alkyl acrylate for being 4~18 as the carbon number of alkyl, can enumerate such as positive fourth of (methyl) acrylic acid Ester, (methyl) isobutyl acrylate, (methyl) tert-butyl acrylate, (methyl) amyl acrylate, (methyl) Hexyl 2-propenoate, (methyl) heptylacrylate, (methyl) 2-EHA, (methyl) 2-ethyl hexyl acrylate, (methyl) Isooctyl acrylate monomer, (methyl) acrylic acid nonyl ester, (methyl) decyl acrylate, (methyl) acrylic acid hendecane base ester, (methyl) lauryl base Ester, (methyl) octadecyl acrylate, (methyl) acrylic acid isooctadecane base ester.These materials can be used alone one kind, It can be used two or more.

In the mass % of monomer component 100 of copolymer (A), the carbon number of alkyl is 4~18 (methyl) alkyl acrylate Consumption from the viewpoint of good bonding force and durability is presented, preferably 99.8~20 mass %, further preferably It is still more preferably 99~50 mass % for 99.5~30 mass %.

As the monomer component for forming copolymer (A), the carbon number that it is also possible to use alkyl is 1~3 (methyl) alkyl acrylate Base ester (CH₂=CR³-COOR⁴；R³For hydrogen atom or methyl, R⁴The alkyl for being 1~3 for carbon number).

As alkyl carbon number be 1~3 (methyl) alkyl acrylate, can enumerate such as (methyl) methyl acrylate, (methyl) ethyl acrylate, (methyl) n-propyl, (methyl) isopropyl acrylate.These materials can be used alone one Kind, it is possible to use it is two or more.

In the mass % of monomer component 100 for forming copolymer (A), the carbon number of alkyl is 1~3 (methyl) acrylic acid alkyl The consumption of ester is from the viewpoint of stress relaxation properties, preferably in below 60 mass %, further preferably in below 50 mass %, Still more preferably in below 40 mass %.

《Monomer containing cross-linking functional group》

The monomer component for forming copolymer (A) is also included with the cross-linking functional group's that can be reacted with crosslinking agent (B) Monomer, the i.e. also monomer containing cross-linking functional group.

As the monomer containing cross-linking functional group, such as hydroxyl monomer can be enumerated, containing acid-based monomers, list containing amino Body, amide-containing monomer, nitrogenous system's heterocyclic monomer, cyano-containing monomer.As the acidic group in this specification, such as carboxylic can be enumerated Base, anhydride group, phosphate, sulfate.

As hydroxyl monomer, (methyl) acrylate of such as hydroxyl can be enumerated, specifically, can be enumerated (methyl) Acrylic acid 2- hydroxyl ethyl esters, (methyl) acrylic acid 3- hydroxypropyl acrylates, (methyl) acrylic acid 4- hydroxy butyl esters, (methyl) acrylic acid 6- hydroxyls oneself (methyl) hydroxyalkyl acrylates such as ester, (methyl) acrylic acid 8- hydroxyl monooctyl esters.The carbon number of hydroxyalkyl in (methyl) hydroxyalkyl acrylate Usually 2~8, preferably 2~6.

As carboxyl group-containing monomer, it can enumerate for example：(methyl) β-acryloxypropionic acid, (methyl) acrylic acid 5- carboxylics penta (the first containing carboxyl such as ester, succinic acid list (methyl) acryloyloxyethyl ester, list (methyl) acrylic acid ω-carboxyl pla-pcl Base) acrylate；Acrylic acid, methacrylic acid, itaconic acid, butenoic acid, fumaric acid, maleic acid., can as monomer containing anhydride group Enumerate such as maleic anhydride, itaconic anhydride.As phosphorous acid-based monomers, (methyl) third on side chain with phosphate can be enumerated Alkene acrylic monomer, as sulfur-bearing acid-based monomers, can enumerate (methyl) acrylic monomer on side chain with sulfate.

As emulsion stability, such as (methyl) acrylate, (methyl) acrylic acid diethyl can be enumerated (methyl) acrylate containing amino such as base amino ethyl ester.As amide-containing monomer, can enumerate such as (methyl) acrylamide, N- methyl (methyl) acrylamide, N- ethyls (methyl) acrylamide, N- propyl group (methyl) acrylamide, N- hexyls (methyl) third Acrylamide.As nitrogenous system's heterocyclic monomer, such as vinyl pyrrolidone, acryloyl morpholine, caprolactam can be enumerated. As cyano-containing monomer, such as cyano group (methyl) acrylate, (methyl) acrylonitrile can be enumerated.

Monomer containing cross-linking functional group can be used alone one kind, it is possible to use two or more.

In the mass % of monomer component 100 for forming copolymer (A), the consumption of the monomer containing cross-linking functional group is preferably 0.01~15 mass %, more preferably 0.05~10 mass %, more preferably 0.1~5 mass %.If containing bridging property The consumption of the monomer of functional group is below above-mentioned higher limit, then the crosslink density formed by copolymer (A) and crosslinking agent (B) will not Become too high, the excellent adhesive phase of stress relaxation properties can be obtained.If the consumption of the monomer containing cross-linking functional group More than above-mentioned lower limit, then cross-linked structure can be effectively formed, obtain the adhesive phase at normal temperatures with appropriate intensity.

《Other monomers》

Such as (first can also be contained in the range of copolymer (A) physical property is not damaged by forming the monomer component of copolymer (A) Base) alkyl acrylate epoxide alkyl ester, singly (methyl) alkyl acrylate epoxide many alkylene glycols esters (ア Le U キ シ Port リ ア Le キ レ Application グ リ コ ー Le モ ノ (メ タ) ア Network リ レ ー ト), other (first such as (methyl) acrylate containing ester ring type group or aromatic ring Base) acrylate.That is, described copolymer (A) can also have the construction unit from other (methyl) acrylate.

As (methyl) alkyl acrylate epoxide alkyl ester, such as (methyl) methoxyethyl methyl esters, (methyl) third can be enumerated Olefin(e) acid 2- methoxy acrylates, (methyl) acrylic acid 2- ethoxy ethyl esters, (methyl) acrylic acid 3- methoxyl groups propyl ester, (methyl) propylene Sour 3- ethyoxyls propyl ester, (methyl) acrylic acid 4- methoxybutyls, (methyl) acrylic acid 4- Ethoxybutyls.

As many alkylene glycols esters of list (methyl) alkyl acrylate epoxide, for example single (methyl) methoxyethyl two can be enumerated Glycol ester, list (methyl) methoxyethyl DPG ester, single (methyl) ethioxy triglycol ester, single (first Base) ethioxy binaryglycol ester, singly (methyl) methoxyethyl triglycol ester.

As (methyl) acrylate containing ester ring type group or aromatic ring, such as (methyl) acrylate can be enumerated Ester, (methyl) benzyl acrylate, (methyl) phenyl acrylate.By using (methyl) acrylate containing aromatic ring, Neng Gouti The resistance to light leakage energy of highly adhesive layer.

In the mass % of monomer component 100 for forming copolymer (A), total consumption of above-mentioned other (methyl) acrylate is preferred In below 60 mass %, more preferably in below 40 mass %.

In addition, example can also be contained in the range of copolymer (A) physical property is not damaged by forming the monomer component of copolymer (A) Such as styrene monomer, vinyl acetate co-polymerized monomer.That is, described copolymer (A), which can also have, comes from the copolymerizable The construction unit of monomer.

As styrene monomer, it can enumerate for example：Styrene, methyl styrene, dimethyl styrene, trimethyl first The ring-alkylated styrenes such as styrene, propylstyrene, butylstyrene, hexyl styrene, heptyl styrene, octyl styrene；Fluorine The halogenated styrenes such as styrene, chlorostyrene, bromstyrol, Dowspray 9, iodobenzene ethene；Nitrostyrolene, acetylbenzene Ethene, methoxy styrene.

In the mass % of monomer component 100 for forming copolymer (A), total consumption of above-mentioned co-polymerized monomer is preferably in 40 matter Below % is measured, more preferably in below 20 mass %.

Other monomers can be used alone one kind, it is possible to use two or more.

《The manufacturing condition of (methyl) acrylic copolymer (A)》

(methyl) acrylic copolymer (A) is preferably by above-mentioned common in the presence of peroxide type polymerization initiator Gather resulting copolymer.That is, by using peroxide type polymerization initiator as polymerization initiator, with obtaining the degree of branching The tendency of copolymer within the above range.

(methyl) acrylic copolymer (A) can be for example, by solution polymerization process, mass polymerization, emulsion polymerization, outstanding Known polymerization is manufactured so far for floating polymerization etc., wherein it is preferred that solution polymerization process.Specifically, it is by polymer solvent and list Body adds polymerization initiator into being distributed into reaction vessel under the inert gas atmospheres such as nitrogen, and reacting initial temperature is set as Usual 40~100 DEG C, preferably 50~80 DEG C, reaction system is set to maintain at a temperature of usual 50~90 DEG C, preferably 70~90 DEG C Reaction 4~20 hours.In addition, in above-mentioned polymerisation, can also suitably add addition polymerization initiator, chain-transferring agent, list Body composition, polymer solvent.

As peroxide type polymerization initiator, it can enumerate for example：

Two (peroxidating 2- ter /-butylisopropyls) benzene, dicumyl peroxide, (the peroxidating uncles of 2,5- dimethyl -2,5- two Butyl) the dialkyl group peroxidating such as hexane, tert-butyl cumyl peroxide, two tertiary hexyl peroxide, di-tert-butyl peroxide Species are (for example：The alkyl that R in the compound represented with R-O-O-R, formula separately replaces for alkyl or aryl；With R- The alkyl that R in the compound that O-O-A-O-O-R is represented, formula separately replaces for alkyl or aryl, A is the hydrocarbon of divalent Base)；

Two isobutyryl peroxides, peroxidating two (3,5,5- trimethyl acetyls), dilauroyl peroxide, peroxidating two Benzoyl, benzoyl (3- methyl benzoyls) peroxide, two (3- methyl benzoyls) peroxide, two (4- methyl Benzoyl) the diacyl peroxide class such as peroxide is (for example：R points in the compound represented with R-COO-OCO-R, formula Alkyl or aryl independently is not it)；

Peroxy dicarbonate di-n-propyl ester, di-isopropyl peroxydicarbonate, (the 4- t-butylcyclohexyls of dicetyl peroxydicarbonate two Base) peroxy dicarbonate such as ester, dicetyl peroxydicarbonate two (2- ethylhexyls) ester, peroxide-butyl carbonate is (for example： R in the compound represented with R-OCO-O-O-COO-R, formula is separately alkyl or cycloalkyl)；

Cumyl peroxyneodecanoate, peroxidating neodecanoic acid 1,1,3,3- tetramethyls butyl ester, peroxidating neodecanoic acid uncle oneself Ester, new peroxide tert-butyl caprate, the new heptanoic acid tert-butyl ester of peroxidating, the tertiary own ester of peroxidating neopentanoic acid, the tertiary fourth of peroxidating neopentanoic acid Ester, peroxidating -2 ethyl hexanoic acid 1,1,3,3- tetramethyls butyl ester, 2,5- dimethyl -2,5- two (peroxidating 2- ethyl hexyls acyl group) The tertiary own ester of hexane, peroxidating 2 ethyl hexanoic acid, the peroxidating 2 ethyl hexanoic acid tert-butyl ester, the tertiary fourth of peroxidating 3,5,5 Trimethylhexanoic acid The tertiary own ester of ester, the peroxylauric acid tert-butyl ester, perbenzoic acid, 2,5- dimethyl -2,5- two (benzoyl peroxide) hexane, Peroxyesters (the examples such as peroxide acetic acid butyl ester, peroxidating 3- methylbenzoates, peroxidized t-butyl perbenzoate Such as：With R¹-O-O-CO-R²R in the compound of expression, formula¹The alkyl replaced for alkyl or aryl, R²For alkyl, aryl or virtue The alkyl of base substitution；R in the compound represented with R-CO-O-O-A-O-O-CO-R, formula is separately alkyl or aryl, A is the alkyl of divalent)；

The tertiary own ester of isopropyl peroxide single carbon acid, isopropyl peroxide single carbon tert-butyl acrylate, peroxidating -2- ethylhexyl lists The peroxidating monocarbonate such as t-butyl carbonate class is (for example：R in the compound represented with R-O-O-COO-R, formula is separately For alkyl).

In peroxide type polymerization initiator, due to (methyl) acrylic copolymer of high side chain can be obtained, thus It is preferred that peroxyesters, the peroxide type polymerization initiator further preferably represented with following formula (1).

In formula (1), R^A~R^FIt is separately hydrogen atom, alkyl or aryl, due to the copolymerization of high side chain can be obtained Thing, thus preferably alkyl, phenyl of the carbon number for 1~10, further preferred carbon number is 1~8 alkyl, still more preferably carbon number For 1~4 alkyl, particularly preferred carbon number is 1~2 alkyl.

In the peroxide type polymerization initiator represented with formula (1), preferably tert-Butyl peroxypivalate, peroxidating new penta Sour tertiary own ester, new peroxide tert-butyl caprate, the new heptanoic acid tert-butyl ester of peroxidating, peroxide -2-ethyl hexanoic acid tert-butyl, peroxidating Neodecanoic acid isopropyl phenyl ester, due to the copolymer of high side chain, thus particularly preferably tert-Butyl peroxypivalate, peroxide can be obtained Change the tertiary own ester of neopentanoic acid, new peroxide tert-butyl caprate, the new heptanoic acid tert-butyl ester of peroxidating, peroxide -2-ethyl hexanoic acid tert-butyl.

Peroxide type polymerization initiator can be used alone one kind, it is possible to use two or more.In addition, being also not limited in poly- Peroxide type polymerization initiator is repeatedly added in conjunction.

As polymerization initiator, as long as the degree of branching is within the above range, peroxide type initiators can also used Use azo-initiator simultaneously.As azo-initiator, such as 2,2'- azodiisobutyronitriles, 2,2'- azos two can be enumerated (4- methoxyl group -2,4- methyl pentane nitriles), 2,2'- azos two (2- cyclopropyl propionitrile), (the 2,4- dimethyl-pentens of 2,2'- azos two Nitrile), 2,2'- azos two (2- methylbutyronitriles), 1,1'- azos two (hexamethylene -1- nitriles), 2- (carbamoyl azo) isobutyronitrile, 2- phenylazo -4- methoxyl group -2,4- methyl pentane nitriles, two acidified 2,2'- azos two (2- amidine propanes), 2,2'- azos Two (N, N'- dimethyleneisobutylamidines), 2,2'- azos two [2- methyl-N- (2- ethoxys)-propionamide], 2,2'- azos two (isobutyramide) dihydrate, 4,4'- azos two (4- cyanopentanoic acids), 2,2'- azos two (2- cyano group propyl alcohol), dimethyl -2, 2'- azos two (2 Methylpropionic acid ester) etc..These polymerization initiators can be used alone one kind, it is possible to use two or more.

Peroxide type polymerization initiator is relative to the matter of monomer component 100 for forming (methyl) acrylic copolymer (A) Part is measured, is used with usual 0.001~5 mass parts, the amount of preferably 0.005~3 mass parts.In addition, azo-initiator is preferably not Use, its consumption relative to the mass parts of peroxide type polymerization initiator 100 preferably below 0.5 mass parts, further preferably It is still more preferably 0 mass parts below 0.2 mass parts.But, for the purpose of reducing the later half middle remaining monomer of reaction then It is used for not limiting.

As polymer solvent, it can enumerate for example：The aromatic hydrocarbons such as benzene,toluene,xylene；Pentane, n-hexane, positive heptan The aliphatic hydrocarbons such as alkane, normal octane；The ester ring type hydro carbons such as pentamethylene, hexamethylene, cycloheptane, cyclooctane；Diethyl ether, diisopropyl ether, The ethers such as 1,2- dimethoxy-ethanes, butyl oxide, tetrahydrofuran, dioxanes (dioxane), methyl phenyl ethers anisole, phenetole, diphenyl ether； The halogenated hydrocarbons such as chloroform, carbon tetrachloride, 1,2- dichloroethanes, chlorobenzene；Ethyl acetate, propyl acetate, butyl acetate, methyl propionate Etc. esters；The ketones such as acetone, MEK, diethyl ketone, methylisobutylketone, cyclohexanone；N,N-dimethylformamide, N, N- dimethyl The amide-types such as acetamide, 1-METHYLPYRROLIDONE；The nitriles such as acetonitrile, benzonitrile；Sulfoxide types such as dimethyl sulfoxide, sulfolane etc..This A little polymer solvents can be used alone one kind, it is possible to use two or more.

《The physical property and content of (methyl) acrylic copolymer (A)》

The weight average molecular weight (Mw) that (methyl) acrylic copolymer (A) is determined by GPC method is with polystyrene scaled value Meter is usually 200,000~1,500,000, preferably 400,000~1,300,000, more preferably 500,000~1,100,000.Because copolymer (A) is Can moderately it be interweaved between hyper branched polymer, thus copolymer (A) chain, the processability of adhesive phase will not deteriorate. Particularly if Mw is more than 400,000, then the high adhesive phase of coherency can be obtained.

The molecular weight distribution (Mw/Mn) that (methyl) acrylic copolymer (A) is determined by GPC method generally below 50, Preferably 10~40, more preferably 10~30.

The glass transition temperature (Tg) of (methyl) acrylic copolymer (A) can be by for example constituting the monomer of the copolymer Unit and its content ratio are calculated according to Fox formula.For example, can be according to the glass transition temperature tried to achieve by Fox formula (Tg) generally -70~0 DEG C, preferably -60~-30 DEG C of condition is reached to synthesize (methyl) acrylic copolymer (A).By making With (methyl) acrylic copolymer (A) with such glass transition temperature (Tg), cohesive under normal temperature can be obtained Excellent adhesive composition.

Fox formula：

1/Tg=(W₁/Tg₁)+(W₂/Tg₂)+……+(W_m/Tg_m)

W₁+W₂+……+W_m=1

In formula, Tg is the glass transition temperature (unit of (methyl) acrylic copolymer (A)：K), Tg₁、Tg₂、……、 Tg_mFor the glass transition temperature (unit for the homopolymer being made up of each monomer：K), W₁、W₂、……、W_mFor from each monomer Weight fraction in the above-mentioned copolymer (A) of construction unit.As the weight fraction of the construction unit from each monomer, it can be used Ingredient proportion of each single phase for whole monomers when copolymer is synthesized.

The glass transition temperature for the homopolymer being made up of in above-mentioned Fox formula each monomer can be used for example《Polymer hand Volume (Polymer Handbook)》Described numerical value in fourth edition (Wiley-Interscience 2003).

In the adhesive composition of the present invention, the content of (methyl) acrylic copolymer (A) is removed in the composition to be had It is usually 50~99.99 mass %, more preferably 60~99.95 matter in the mass % of solid constituent 100 beyond machine solvent (E) Measure %, particularly preferably 80~99.90 mass %.If the content of (methyl) acrylic copolymer (A) is within the above range, The balance of the performance as adhesive can be then obtained, and adhesion characteristic is excellent.

[crosslinking agent (B)]

The adhesive composition of the present invention also contains crosslinking agent (B).

Crosslinking agent (B) as long as can have with (methyl) acrylic copolymer (A) come from contain bridging property official The composition that the cross-linking functional group for the monomer that can be rolled into a ball crosslinks reaction is just not particularly limited, and can enumerate such as isocyanation esterification Compound (B1), metallo-chelate (B2), epoxide (B3).

Crosslinking agent (B) can be used alone one kind, it is possible to use two or more.

In crosslinking agent (B), at least one in isocyanate compound (B1) and metallo-chelate (B2) is preferably used Kind, more preferably and with isocyanate compound (B1) and metallo-chelate (B2).

It is preferred that by the covalent bond based on isocyanate compound (B1) come to (methyl) acrylic copolymer (A) formation Crosslinking, and/or by the coordinate bond based on metallo-chelate (B2) come accurate to (methyl) acrylic copolymer (A) formation It is crosslinked (Japanese：Doubtful frame Bridge).

In the adhesive composition of the present invention, the content of crosslinking agent (B) is relative to (methyl) acrylic copolymer (A) 100 mass parts are usually 0.01~5 mass parts, more preferably 0.05~2.5 mass parts, more preferably 0.1~1 mass Part.If the content is within the above range, the balance of durability and stress relaxation properties is easily obtained, thus preferably.

《Isocyanate compound (B1)》

As isocyanate compound (B1), usually using isocyanation esterification of the isocyanates radix more than 2 in 1 molecule Compound.By being crosslinked (methyl) acrylic copolymer (A) by isocyanate compound (B1), crosslinked (net can be formed Shaped polymer).

The isocyanates radix of isocyanate compound (B1) is generally more than 2, preferably 2~8, more preferably 3 ~6.If isocyanates radix is within the above range, in (methyl) acrylic copolymer (A) and isocyanate compound (B1) it is preferred on this aspect of cross-linking reaction efficiency and keeping on this aspect of the flexibility of adhesive phase.

As the diisocyanate cpd that isocyanates radix in 1 molecule is 2, for example aliphatic two isocyanic acid can be enumerated Ester, alicyclic diisocyanate, aromatic diisocyanates.As aliphatic vulcabond, can enumerate ethylidene diisocyanate, Tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2- methyl isophthalic acids, 5- pentanes two are different Cyanate, 3- methyl isophthalic acids, the carbon number such as 5- pentane diisocyanates, 2,2,4- trimethyl -1,6- hexamethylene diisocyanates are 4 ~30 aliphatic vulcabond.As alicyclic diisocyanate, IPDI, cyclopenta two can be enumerated different Cyanate, cyclohexyl diisocyanate, the sub- XDI of hydrogenation, hydrogenated toluene diisocyanate, hydrogenation hexichol first The alicyclic diisocyanate that the carbon numbers such as alkane diisocyanate, the sub- XDI of hydrogenation tetramethyl are 7~30.As Aromatic diisocyanates, can enumerate for example phenylene vulcabond, toluene di-isocyanate(TDI), sub- XDI, The carbon numbers such as naphthalene diisocyanate, diphenyl ether diisocyanate, '-diphenylmethane diisocyanate, diphenylpropane diisocyanate are 8 ~30 aromatic diisocyanates

As isocyanate compound of the isocyanates radix more than 3 in 1 molecule, such as aromatics polyisocyanate can be enumerated Ester, aliphatic polymeric isocyanate, alicyclic polymeric isocyanate.Specifically, 2,4,6- triisocyanate toluene, 1,3,5- can be enumerated Triisocyanate benzene, 4,4', 4 "-triphenylmethane triisocyanate.

In addition, as isocyanate compound (B1), can enumerate such as isocyanates radix 2 or more than 3 it is above-mentioned different Polymer (such as dimer or tripolymer, biuret body, isocyanuric acid ester body), the derivative of cyanate esters are (such as more The addition reaction product of diisocyanate cpd more than first alcohol and 2 molecules), polymer.As many in said derivative First alcohol, low molecular weight polyols can enumerate the alcohol more than ternary such as trimethylolpropane, glycerine, pentaerythrite；High score Sub- weight polyalcohol can enumerate such as PPG, PEPA, acrylic polyol, polybutadiene polyol, poly- isoamyl Diene polyol.

Such isocyanate compound can enumerate the tripolymer of such as '-diphenylmethane diisocyanate, polymethylene polyphenyl Biuret body or isocyanuric acid ester body, three hydroxyls of base PIC, hexamethylene diisocyanate or toluene di-isocyanate(TDI) Methylpropane and toluene di-isocyanate(TDI) or reaction product (such as toluene di-isocyanate(TDI) or Asia of sub- XDI Three molecule addition products of XDI), the reaction product (example of trimethylolpropane and hexamethylene diisocyanate As hexamethylene diisocyanate three molecule addition products), polyethers PIC, polyester PIC.

In isocyanate compound (B1), on it can carry good curing performance this aspect, preferably trimethylolpropane and toluene two The L- of reaction product (Soken Chemical ＆ Engineering Co., Ltd. (Integrated are ground chemical (strain)) manufacture of isocyanates or sub- XDI 45, TD-75 etc. of Soken Chemical ＆ Engineering Co., Ltd.'s manufacture), the isocyanide urea of hexamethylene diisocyanate or toluene di-isocyanate(TDI) Acid esters body (TSE-100, Nippon Polyurethane Industry Co., Ltd. (the Japanese Port リ of Asahi Kasei Corporation's (Asahi Chemical Industry (strain)) manufacture ウ レ タ Application industry (strain)) manufacture 2050 etc.).

Isocyanate compound (B1) can be used alone one kind, it is possible to use two or more.

In the adhesive composition of the present invention, the content of isocyanate compound (B1) is common relative to (methyl) acrylic compounds The mass parts of polymers (A) 100 are preferably below 5 mass parts, further preferably below 2.5 mass parts, still more preferably in 1 matter Measure below part, particularly preferably below 0.5 mass parts.If the content is within the above range, durability is easily obtained with answering The balance of power relaxation properties, thus preferably.The use of lower limit when above-mentioned (B1) is, for example, 0.001 mass parts, preferably 0.01 Mass parts.

《Metallo-chelate (B2)》

As metallo-chelate (B2), can enumerate such as alkoxide, acetylacetone,2,4-pentanedione, ethyl acetoacetate to aluminium, iron, copper, The compound of the polyvalent metal coordinations such as zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium.

Wherein, the preferred aluminium chelate compound M-12AT of manufacture (Soken Chemical ＆ Engineering Co., Ltd. etc.).Specifically, isopropyl can be enumerated Aluminium alcoholates, secondary butyric acid aluminium, acetoacetate aluminium ethide diisopropyl ester, tri ethylacetoacetate aluminium, praseodynium aluminium.

Metallo-chelate (B2) can be used alone one kind, it is possible to use two or more.

Metallo-chelate (B2) makes (methyl) acrylic copolymer (A) be crosslinked (quasi-crosslink) by coordinate bond.Using Under occasion of the metallo-chelate (B2) as crosslinking agent (B), in room temperature, the crosslinking is maintained, and polymer plays cohesion Property, and a part for the crosslinking is released in high temperature, adhesive phase shows more excellent flexibility.

In the adhesive composition of the present invention, the content of metallo-chelate (B2) is relative to (methyl) acrylic copolymer (A) 100 mass parts are preferably below 5 mass parts, further preferably below 2.5 mass parts, still more preferably in 1 mass parts Hereinafter, particularly preferably below 0.5 mass parts.If the content is within the above range, easily obtains durability and delay with stress With the balance of characteristic, thus preferably.The use of lower limit when above-mentioned (B2) is, for example, 0.001 mass parts, preferably 0.01 mass Part.

In the adhesive composition of the present invention, isocyanate compound (B1) and metallo-chelate (B2) are being used as friendship Under the occasion for joining agent (B), the content of above-mentioned (B2) is typically larger than 0 mass parts and 1000 relative to above-mentioned (B1) 100 mass parts Below mass parts, further preferably greater than 0 mass parts and below 600 mass parts, still more preferably more than 0 mass parts and Below 400 mass parts.If the content is within the above range, is suppressing amount of bow and improving polarizer and adhesive phase Between adaptation this aspect on be preferred.

《Epoxide (B3)》

As epoxide (B3), usually using epoxide of the 1 molecule epoxy group number more than 2.It can enumerate Such as ethylene glycol diglycidylether, polyethyleneglycol diglycidylether, glycerin diglycidyl ether, glycerine three-glycidyl Ether, 1,3- couples of (N, N- diglycidyl amino methyl) hexamethylenes, N, N, N', N'- four glycidyl groups m-xylene diamine, N, N, N', N'- four glycidyl group aminophenyl methane, triglycidyl isocyanurate, a N, N- diglycidyl amino Phenyl glycidyl ether, N, N- diglycidyls toluidines, N, N- diglycidylanilines.

In the adhesive composition of the present invention, the content of epoxide (B3) is relative to (methyl) acrylic copolymer (A) 100 mass parts are preferably below 2 mass parts, further preferably below 1 mass parts, still more preferably in 0.5 mass parts Below.The use of lower limit when above-mentioned (B3) is, for example, 0.001 mass parts, preferably 0.01 mass parts.

[silane coupler (C)]

The polarizer of present invention adhesive composition preferably also contains silane coupler (C).Silane coupler (C) makes to glue The clung body strong bond such as mixture layer and glass plate, helps to prevent the stripping under high humid and warm environment.

As silane coupler (C), it can enumerate for example：Vinyltrimethoxy silane, VTES, first The silane couplers containing polymerism unsaturated group such as base acryloxypropyl trimethoxy silane；3- glycidoxies third Base trimethoxy silane, 3- glycidoxypropyl groups triethoxysilane, 3- glycidoxypropyls dimethoxysilane, 3- glycidoxypropyls diethoxy silane, 2- (3,4- epoxycyclohexyls) ethyl trimethoxy silane etc. contain epoxy The silane coupler of base；3- TSL 8330s, N- (2- amino-ethyls) -3- TSL 8330s, The silane couplers containing amino such as N- (2- amino-ethyls) -3- amino propyl methyl dimethoxysilanes；3- chloros propyl group three The silane coupler containing halogen such as methoxy silane.

In the adhesive composition of the present invention, the content of silane coupler (C) is relative to (methyl) acrylic copolymer (A) 100 mass parts are generally below 1 mass parts, preferably 0.01~1 mass parts, more preferably 0.05~0.5 mass Part.If content is within the above range, with prevent under high humid and warm environment polarizer to peel off or hot environment under it is silane coupled The tendency that agent (C) is oozed out.

[antistatic agent (D)]

It can be used to for example reduce the sheet resistance value of the adhesive phase formed by the adhesive composition of the present invention Antistatic agent (D).As antistatic agent (D), such as surfactant, ionic compound, electric conductive polymer can be enumerated.

As surfactant, it can enumerate for example：Quaternary ammonium salt, amidoquat salt, pyridine salt, with primary amino radical~ The cationic surface active agent of the cationic groups such as tertiary amino；With sulphonate-base, sulfuric ester alkali, phosphate alkali etc. The anionic surfactant of anionic group；Alkyl betaines bases, alkyl imidazole betaines, alkyl amine The amphoteric surfactantes such as class, amino acid sulfuric acid ester；Fatty acid glycerine esters, sorbitan fatty acid ester class, polyoxy second Allylic alkylation amine, polyoxyethylene alkyl amine fatty acid ester, N- ethoxy-N-2- hydroxyalkyls amine, alkyl diethanolamide class Deng nonionic surface active agent.

In addition, surfactant can also enumerate the reactive emulsifier with polymerizable group, it is also possible to use makes containing upper State polymer types of surfactants obtained from the monomer component molecular weight of surfactant or reactive emulsifier.

Ionic compound is made up of cationic moiety and anionicsite, and (23 DEG C/50%RH) can be in solid-state at room temperature Any of or liquid.

The cationic moiety for constituting ionic compound both can be any in inorganic cationoid or organic cationoid Person or both.Inorganic cationoid preferred as alkali ion and alkaline-earth metal ion, more preferably excellent electrostatic prevention property Li⁺、Na⁺And K⁺.As organic cationoid, can enumerate for example pyridylium, piperidines cation, pyrrolidonium cation, Pyrroles's cation moiety, pyrroles's cation, glyoxaline cation, tetrahydropyrimidine cation, dihydro-pyrimidin cation, pyrazoles cation, Dihydropyazolo cation (ピ ラ ゾ リ ニ ウ system カ チ オ Application), tetraalkylammonium cation, trialkylsulfonium cation, tetraalkyl Phosphine cation and their derivative.

As constitute ionic compound anionicsite, as long as can with cationic moiety ionic bonding and formed from The material of sub- compound is not particularly limited.Specifically, F can be enumerated^-、Cl^-、Br^-、I^-、AlCl₄ ^-、Al₂Cl₇ ^-、BF₄ ^-、 PF₆ ^-、SCN^-、ClO₄ ^-、NO₃ ^-、CH₃COO^-、CF₃COO^-、CH₃SO₃ ^-、CF₃SO₃ ^-、(CF₃SO₂)₂N^-、(F₂SO₂)₂N^-、(CF₃SO₂)₃C^-、AsF₆ ^-、SbF₆ ^-、NbF₆ ^-、TaF₆ ^-、F(HF)_n ^-、(CN)₂N^-、C₄F₉SO₃ ^-、(C₂F₅SO₂)₂N^-、C₃F₇COO^-(CF₃SO₂) (CF₃CO)N^-.Wherein, the anion containing fluorine atom because the ionic compound of low melting point can be provided and it is preferred that, particularly preferably (F₂SO₂)₂N^-(CF₃SO₂)₂N^-。

The preferred bis-trifluoromethylsulfoandimide lithium of ionic compound, double difluoro sulfimide lithiums, three (trifyl) first Alkane lithium, bis-trifluoromethylsulfoandimide potassium, double difluoro sulfimide potassium, 1- ethylpyridines hexafluorophosphate, 1- butyl-pyridinium hexafluoros Phosphate, 1- hexyl -4- picolines hexafluorophosphate, 1- octyl group -4- picolines hexafluorophosphate, 1- octyl group -4- methyl Pyridine difluoro sulfimide, 1- octyl group -4- picolines bis-trifluoromethylsulfoandimide, (N, N- diethyl-N- methyl-N- (2- first Epoxide ethyl) ammonium tetrafluoroborate, N, N- diethyl-N- methyl-N- (2- methoxy ethyls) ammonium bis-trifluoromethylsulfoandimide, 1- Octylpyridinium fluorine thionyl imide (1- オ Network チ Le ピ リ ジ ニ ウ system Off Le オ ロ ス ホ ニ ウ system イ ミ De), 1- octyl group -3- first Yl pyridines, trifluoro thionyl imide (ト リ Off Le オ ロ ス Le ホ ニ ウ system イ ミ De).

As electric conductive polymer, such as polythiophene, polyaniline, polypyrrole and their derivative can be enumerated.

In the adhesive composition of the present invention, the content of antistatic agent (D) is relative to (methyl) acrylic copolymer (A) 100 mass parts are generally below 3 mass parts, preferably 0.01~3 mass parts, more preferably 0.05~2.5 mass parts.

[organic solvent (E)]

The adhesive composition of the present invention preferably comprises organic solvent (E) to adjust its coating.Organic solvent can Enumerate the polymer solvent illustrated in the column of (methyl) acrylic copolymer (A) one.For example, can be by containing for being obtained in above-mentioned copolymerization The polymer solution of (methyl) acrylic copolymer (A) and polymer solvent carrys out modulating adhesive with crosslinking agent (B) mixing and combined Thing.In the adhesive composition of the present invention, the content of organic solvent (E) is usually 50~90 mass %, preferably 60~85 matter Measure %.

In addition, " solid constituent " in this specification refers to have in composition contained in adhesive composition except above-mentioned Whole compositions beyond machine solvent (E), " solid component concentration " refers to above-mentioned solid constituent relative to the matter of adhesive composition 100 Measure % ratio.

[additive]

The adhesive composition of the present invention in the range of effect of the present invention is not damaged, may be used also in addition to mentioned component Containing beyond antioxidant, light stabilizer, preventing metal corrosion agent, tackifier, plasticizer, crosslinking accelerator, above-mentioned (A) (methyl) acrylic polymer and agent (リ ワ ー Network drug of doing over again) one or both of more than.

[modulation of polarizer adhesive composition]

The present invention adhesive composition can by using known method so far to (methyl) acrylic copolymer (A) with Crosslinking agent (B) and the other compositions used as needed are mixed to modulate.It can enumerate for example to synthesis (methyl) third Crosslinking agent (B) is blended in the polymer solution containing the polymer obtained by when olefin(e) acid analog copolymer (A) and as needed And the other compositions used.

The gel fraction of the adhesive formed by the adhesive composition of the present invention is preferably greater than 50 mass %, more preferably greatly In 50 mass % and in below 80 mass %, more preferably 60~75 mass %.Gel fraction is for example according to embodiment The condition of record is measured obtained numerical value to the adhesive gathered.

[polarizer adhesive phase]

The polarizer of the present invention is formed with adhesive phase by above-mentioned adhesive composition.By using the adhesive of the present invention Composition, can form the adhesive phase with following storage modulus characteristic.

Storage modulus (G'1) at 23 DEG C of adhesive phase of the present invention preferably in more than 0.1MPa, more preferably 0.1~ 0.2MPa, particularly preferably 0.1~0.15MPa；Storage modulus (G'2) at 85 DEG C is preferably in below 0.05MPa, more preferably 0.05~0.02MPa, particularly preferably 0.05~0.03MPa.

Storage modulus of the adhesive phase of the present invention at T DEG C of temperature is designated as G'_T, at T+1 DEG C storage modulus note For G'_T+1When, temperature T preferably always meets G' when in the range of 23~50 DEG C_T/G'_T+1＜ 1.07, more preferably always meets 1 ≤G'_T/G'_T+1≤1.05。

Above-mentioned storage modulus is that it is about 1.0mm's to make thickness for example, by above-mentioned adhesive phase is mutually repeatedly fitted Layered product, by the value calculated to the dynamic viscoelastic spectrogram that the layered product is measured.

Storage modulus (G'1) at 23 DEG C causes the hard under the normal temperature of the adhesive phase of the present invention within the above range Excellent, processability is improved.For example, when being cut to adhesive phase, can prevent adhesive attachment from cutting on blade Or adhesive phase wire drawing the problems such as.

Storage modulus (G'2) at 85 DEG C causes the adhesive phase of the present invention to have in high temperature environments within the above range Sufficient flexibility, it is thus possible to fully relax the stress produced by the thermal contraction of polarizer (change in size).Therefore, i.e., Make exposure in high temperature environments, can also mitigate the warpage of clung body, and be not susceptible to the fracture of adhesive phase, adhesive phase from Stripping on polarizer.

G' is always met in the range of 23~50 DEG C_T/G'_T+1＜ 1.07 means the modulus change in the temperature range It is small, deformation and the extrusion of adhesive phase can be suppressed.

By the adhesive phase that is formed of adhesive composition of the present invention from suppression polarizer distortion, cohesiveness, bonding force, again From the viewpoint of fissility, gel fraction is preferably greater than 50 mass %, more preferably greater than 50 mass % and in below 80 mass %, More preferably 60~75 mass %.If gel fraction is within the above range, adhesive phase shows excellent durable Property.Even if in addition, gel fraction is within the above range, due between the side chain of (methyl) acrylic copolymer (A) under high temperature Part relaxation, adhesive phase also shows excellent stress relaxation properties.

The adhesive phase of the present invention can be obtained for example, by carrying out the cross-linking reaction in above-mentioned adhesive composition, specifically It is to obtain by using crosslinking agent (B) (methyl) acrylic polymer (A) crosslinking.

The formation condition of adhesive phase is for example as described below.The adhesive composition of the present invention is coated on supporting mass, Temperature is different according to solvent species, but generally 50~150 DEG C, preferably at 60~100 DEG C carry out be usually 1~10 minute, The drying of preferably 2~7 minutes and remove solvent, formed film.The thickness of dry coating is usually 5~75 μm, preferably 10 ~50 μm.

Adhesive phase is preferably formed under the following conditions.The adhesive composition of the present invention is coated on supporting mass, On the film formed under above-mentioned condition after stickup cover layer, at usual 5~60 DEG C, preferably 15~40 DEG C and usual 30~70% Conserved in the environment of RH, preferably 40~70%RH usual more than 3 days, preferably 7~10 days.If in cooking conditions as described above It is lower to be crosslinked, then crosslinked (network polymers) can be efficiently formed.

As the coating method of adhesive composition, known method can be used, for example, passes through spin-coating method, cutter painting method, roller Coating, stick coating method, scraper coating, die coating method, gravure coating method etc. form the coating drying means of specific thickness.

As supporting mass and cover layer, it can enumerate for example：The polyester films such as polyethylene terephthalate (PET)；Poly- second The plastic foil of the polyolefin films such as alkene, polypropylene, vinyl-vinyl acetate copolymer etc..

[polarizer bonding sheet]

The polarizer of the present invention has the adhesive phase formed by above-mentioned adhesive composition with bonding sheet.It is used as bonding Piece, can enumerate for example only the double-sided adhesive sheet with above-mentioned adhesive phase, with base material and be formed at above-mentioned on base material two sides The double-sided adhesive sheet of adhesive phase, the one side bonding sheet with base material and the above-mentioned adhesive phase being formed in base material one side, with And these bonding sheets are pasted with the bonding sheet of the cover layer by lift-off processing on the face not contacted with base material of adhesive phase.

As base material and cover layer, it can enumerate for example：The polyester films such as polyethylene terephthalate (PET)；Polyethylene, The plastic foil of the polyolefin films such as polypropylene, vinyl-vinyl acetate copolymer etc..

The formation condition of adhesive phase is identical with condition described in [polarizer adhesive phase] column.

The thickness of adhesive phase is usually 5~75 μm, preferably 10~50 μm from the viewpoint of bond properties is maintained.Base The thickness of material and cover layer is not particularly limited, but usually 10~125 μm, preferably 25~75 μm.

[polarizer with adhesive phase]

The present invention the polarizer with adhesive phase have directly be layered at least one side of polarizer by this hair The adhesive phase of bright adhesive composition formation.In addition, in this specification, " polarizer " is made with the implication comprising " polarizing coating " With.

As polarizer, polarizing coating known so far can be used.Can enumerate for example polarizer in itself, with polarizer With the multilayer film of polarizer diaphragm of the configuration on polarizer.In the present invention, due to above-mentioned adhesive phase with polarization The mode that element directly connects is configured, can enumerate only on the one side of polarizer configure polarizer diaphragm composition, partially Shake and do not configure the composition of polarizer diaphragm on element two sides.

As polarizer, it can enumerate and contain it in the film for for example making to be made up of polyvinyl alcohol resin after polarized component Stretched film obtained from stretching.As polyvinyl alcohol resin, such as polyvinyl alcohol, polyvinyl formal, poly- second can be enumerated Ketene acetal, EVAc it is saponified.As polarized component, such as iodine or dichroism dye can be enumerated Material.

As polarizer diaphragm, the film being for example made up of thermoplastic resin can be enumerated., can example as thermoplastic resin Citing such as tri acetyl cellulose celluosic resin, polyester resin, polyethersulfone resin, polysulfone resin, polycarbonate resin, gather Amide resin, polyimide resin, vistanex, (methyl) acrylic resin, cyclic polyolefin resin (borneol alkenes tree Fat), polyarylate resin, polystyrene resin, polyvinyl alcohol resin and the two or more mixing in these resins Thing.

The thickness of polarizer is usually 10~200 μm, preferably 50~100 μm.In the present invention, it can save to be formed inclined The polarizer diaphragm shaken on element, it is thus possible to be thinned polarizer.

In the present invention, above-mentioned adhesive phase is formed in the way of directly connecting with polarizer.Glued as the band of the present invention The polarizer of mixture layer, can enumerate for example following composition：Polarizer diaphragm, polarizer and above-mentioned adhesive phase layer successively Folded composition；What above-mentioned adhesive phase, polarizer diaphragm, polarizer and above-mentioned adhesive phase were stacked gradually Constitute；The composition that above-mentioned adhesive phase, polarizer and above-mentioned adhesive phase are stacked gradually.In these compositions, bonding Above-mentioned cover layer is can also configure in oxidant layer as outermost layer.

The method for forming adhesive phase on polarizer surface is not particularly limited, and can enumerate and be existed using direct stick coating method etc. The method for making it dry and cure after above-mentioned adhesive composition is coated with polarizer surface, the polarizer of the present invention is used and glued The adhesive phase that closing piece has is transferred to the method for curing it behind polarizer surface.Dry and cooking conditions or gel point Several scope etc. is identical with condition described in [polarizer adhesive phase] column.

The thickness of adhesive phase is usually 5~75 μm, preferably 10~50 μm in terms of dry film thickness.In addition, adhesive phase Connect at least one side of polarizer with polarizer and formed, adhesive phase can be enumerated and be only formed at polarizer Form, adhesive phase on one side are formed at the form on polarizer two sides.

Furthermore it is also possible to which such as protective layer, antiglare layer, phase separation layer, angle of visibility are laminated on above-mentioned polarizer improves layer Deng the layer with other functions.

By the base that the polarizer of the invention with adhesive phase obtained in the manner described above is arranged on to liquid crystal cell Liquid crystal cell is manufactured in plate surface.Here liquid crystal cell has liquid crystal layer by the construction clamped by two pieces of substrates.

Substrate with liquid crystal cell can enumerate such as glass plate.The thickness of substrate is usually 0.05~3mm, is preferably 0.2~1mm.In the present invention, by using above-mentioned adhesive composition, it is directly laminated even in adhesive phase in polarizer On occasion under, can also suppress the warpage of polarizer and substrate.Therefore, above-mentioned adhesive composition is small even in substrate thickness Occasion under (for example：Below 1mm, preferably 0.2~1mm), it can also be suitably used for fitting for polarizer and substrate.

[embodiment]

Below, more specific description is carried out to the present invention based on embodiment, but the invention is not restricted to these embodiments.Below In the record of embodiment etc., unless otherwise instructed, " part " expression " mass parts ".

[GPC and GPC-MALS]

For (methyl) acrylic copolymer, by gel permeation chromatography (GPC method) according to following condition gels Permeation chromatography/multi-angle laser light scattering detector (GPC-MALS) determines weight average molecular weight (Mw) and number-average molecular weight (Mn) slope of the double-log straight line of radius of turn and molecular weight, and according to following conditions is calculated, the degree of branching is obtained.

Determine device：HLC-8320GPC (TOSOH Co., Ltd (East ソ ー (strain)) is produced)

The composition of GPC posts：Following 4 pedestals (all being produced by TOSOH Co., Ltd)

(1) TSKgel HxL-H (guard column)

(2)TSKgel GMHxL

(3)TSKgel GMHxL

(4)TSKgel G2500HxL

Flow velocity：1.0 ml/min

Column temperature：40℃

Sample solution concentration：1.5% (w/v) (being diluted with tetrahydrofuran)

Mobile phase solvent：Tetrahydrofuran

Detector：DAWN HELEOS (MALS detectors)+Optilab rEX (RI detectors)

Polystyrene standard conversion (occasion for determining Mw and Mn)

[synthesis example 1]

76.8 parts of propylene are added into the reaction unit for possessing mixer, reflux cooler, thermometer and nitrogen ingress pipe Sour N-butyl, 20 parts of benzyl acrylates, 3 parts of acrylic acid, 0.2 part of acrylic acid 2- hydroxyl ethyl ester and 100 parts of ethyl acetate solvents, on one side Nitrogen is imported while being warming up to 80 DEG C.Then, the tert-Butyl peroxypivalate of 0.1 part of addition, in a nitrogen atmosphere in 80 DEG C The polymerisation of progress 6 hours.After reaction terminates, it is diluted with ethyl acetate, it is 30 mass % that solid component concentration, which is made, Polymer solution.Resulting (methyl) acrylic copolymer A1 weight average molecular weight (Mw) is 670,000, molecular weight distribution (Mw/Mn) it is 13, the degree of branching is 0.48.

[synthesis example 2~5]

Except by the monomer component and polymerization initiator used in polymerisation be changed in table 1 described content with Outside, synthesized according to the identical mode of synthesis example 1, the polymer solution that solid component concentration is 30 mass % is made.Knot Fruit is shown in table 1.

[table 1]

[embodiment 1]

(1) modulation of adhesive composition

By the polymer solution obtained in synthesis example 1 (solid component concentration is 30 mass %), relative to institute in the solution 100 parts of (methyl) the acrylic copolymer A1 (solid constituent amount) contained is crosslinked for the conduct of 0.07 part (solid constituent amount) " TD-75 " (solid constituent be 75 mass %, ethyl acetate solution) of Soken Chemical ＆ Engineering Co., Ltd.'s manufacture of agent and 0.2 part (Gu Body component amount) " M-12AT " and 0.2 part of Shin-Etsu Chemial Co., Ltd's (SHIN-ETSU HANTOTAI's chemical industry as silane coupler (strain)) " KBM-403 " (solid constituent be 100 mass %) of manufacture mixed, and obtains adhesive composition.

(2) making of bonding sheet

In the polyethylene terephthalate film (PET film) Jing Guo lift-off processing, the bonding that will be obtained in above-mentioned (1) Scraper for coating is used after agent composition froth breaking, is dried 3 minutes at 90 DEG C, the film that dry film thickness is 20 μm is formed.In film The PET film fitted again by lift-off processing on the reverse side of the sticking veneer of above-mentioned PET film, 7 days are stood under 23 DEG C/50%RH environment After being cured, obtain with by bonding sheet of the thickness clamped by 2 pieces of PET films for 20 μm of adhesive phase.

(3) making of the polarizer with adhesive phase

In the polyethylene terephthalate film (PET film) Jing Guo lift-off processing, the bonding that will be obtained in above-mentioned (1) Scraper for coating is used after agent composition froth breaking, is dried 3 minutes at 90 DEG C, the piece for 20 μm of film with dry film thickness is formed Material.So that the coated surface of the sheet material with by the polyvinyl alcohol film as polarizer and the triacetyl as polarizer diaphragm The mode that the polyvinyl alcohol film one side for the double-deck polarizer for constituting (thickness is 60 μm) that base cellulose membrane is constituted connects is pasted Close, stand under conditions of the 23 DEG C/50%RH after being cured within 7 days, obtain with PET film, the adhesive phase that thickness is 20 μm, The polarizer with adhesive phase of polarizer and polarizer diaphragm.

[embodiment 2~3, comparative example 1~3]

Except by the polymer solution in embodiment 1 be changed to the polymer solution that is obtained in synthesis example 2~5 and/or Person is changed to composition is blended beyond content described in table 2, and adhesive combination is obtained according to the same manner as in Example 1 Thing, bonding sheet and the polarizer with adhesive phase.

[evaluation]

[gel fraction]

The adhesive that about 0.1g is gathered in the bonding sheet obtained from embodiment comparative example is placed in sample bottle, is added Shake 4 hours, the content of the sample bottle was carried out with 200 purposes stainless steel wire netting after 30mL ethyl acetate then Filter, dry weight is determined after the drying for carrying out 2 hours to the residue on wire netting at 100 DEG C.Bonding is obtained according to following formula The gel fraction of agent.

Gel fraction (%)=(dry weight/adhesive collection weight) × 100 (%)

[storage modulus]

In the bonding sheet that will be obtained in embodiment comparative example thickness for 20 μm adhesive phase 23 DEG C/50%RH ring Mutually repeatedly laminating, is handled 20 minutes in the autoclave of 50 DEG C/5 atmospheric pressure under border, and the adhesive that thickness is 1.0mm is made Layer." the Physica MCR300 ", according to dynamic based on JIS K7244 manufactured by using Anton Paar company (Anton Paar) State determination of viscoelasticity method (condition be temperature range -40~160 DEG C, 3.67 DEG C/min of programming rate, frequency 1Hz) is determined The thickness for 1.0mm adhesive phase viscoplasticity spectrogram, temperature be 23 DEG C and 85 DEG C at storage modulus, 23~50 DEG C In the range of G'_T/G'_T+1Maximum.

[measure of bonding force]

By obtained in embodiment comparative example with adhesive phase polarizer (by PET film/adhesive phase/polarizer/ The layered product that polarizer diaphragm is constituted) 70mm × 25mm size is cut into, test film is made.By PET film from test film It is upper peel off, with laminating roll by the layered product being made up of adhesive phase/polarizer/polarizer diaphragm so that adhesive phase with The mode that glass plate connects is conformed on the one side for the glass plate that thickness is 2mm.By resulting layered product adjust to 50 DEG C/ Kept for 20 minutes in the autoclave of 5 atmospheric pressure.Then, after being placed 1 hour under 23 DEG C/50%RH environment, along relative Polarizer end is pullled with the speed of 300 mm/mins for 90 ° of direction in glass pane surface, bonding force (stripping is determined From intensity).

[endurancing (experiment of heat resistance humidity resistance)]

By obtained in embodiment comparative example with adhesive phase polarizer (by PET film/adhesive phase/polarizer/ The layered product that polarizer diaphragm is constituted) 150mm × 250mm size is cut into, test film is made.By PET film from experiment On piece peel off, with laminating roll by the layered product being made up of adhesive phase/polarizer/polarizer diaphragm so that adhesive phase The mode connected with glass plate is conformed on the one side for the glass plate that thickness is 0.5mm.By resulting layered product adjust to Kept for 20 minutes in the autoclave of 50 DEG C/5 atmospheric pressure, breadboard is made.Two pieces of identical breadboards are made.By above-mentioned experiment Plate is that (heat resistance) or temperature are that 60 DEG C/humidity is that (humidity resistance) is placed under conditions of 90%RH under conditions of 80 DEG C in temperature 500 hours, observation evaluation is carried out to foaming, the generation for tilting and peeling off according to following benchmark.

·AA：Not it was observed that the bad order situation such as foaming, tilting, stripping

·BB：It was observed that the bad order situation such as a small amount of foaming, tilting, stripping

·CC：It was observed that the bad order situation such as obvious foaming, tilting, stripping

[light leak experiment]

By 2 pieces obtained in the embodiment comparative example polarizers with adhesive (by PET film/adhesive phase/polarization member The layered product that part/polarizer diaphragm is constituted) 310mm × 385mm size is cut into, test film is made.By PET film from examination Test on piece peel off, with laminating roll by the layered product being made up of adhesive phase/polarizer/polarizer diaphragm so that polarization axle The mode that mutually orthogonal and adhesive phase connects with glass plate is conformed on the both sides for the glass plate that thickness is 0.5mm.By gained To layered product adjusting into the autoclave of 50 DEG C/5 atmospheric pressure keep 20 minutes, breadboard is made.The breadboard is existed Temperature is observed light leak to be placed 500 hours under conditions of 80 DEG C according to following benchmark.

AA：Not it was observed that light leak

BB：It was observed that a small amount of light leak

CC：It was observed that obvious light leak

[warpage (bending) experiment]

By obtained in embodiment comparative example with adhesive phase polarizer (by PET film/adhesive phase/polarizer/ The layered product that polarizer diaphragm is constituted) size of 35mm × 400mm (stretching direction of principal axis) is cut into, test film is made.Will PET film is peeled off from test film, the layered product that will be made up of with laminating roll adhesive phase/polarizer/polarizer diaphragm Thickness is conformed in the way of adhesive phase is connected with glass plate as on the one side of 0.7mm 40mm × 410mm glass plate. After resulting layered product is placed 24 hours under 23 DEG C/50%RH environment, kept for 72 hours in 60 DEG C of stove.Will Unilateral end is fixed on metope perpendicular to the ground, and the amount tilted with ruler to opposite side extremities is measured.According to Lower benchmark is observed warpage (bending).

AA：The tilting of end is in below 3mm

BB：The tilting of end is more than 3mm and less than 5mm

CC：The tilting of end is in more than 5mm

[processability (cutting property)]

The bonding that will be obtained using Thomson bicker with 50mm × 50mm Thomson blade in embodiment comparative example Piece cuts into 30 pieces.Shape after cutting immediately to end is observed, by paste-extruded or end ulceration at one in 30 pieces, viscous Also unobserved situation is determined as AA to mixture layer defect, it will be observed that the situation of drawbacks described above is determined as CC.

[bonding morphotropism]

10 pieces of stacking cuts into the polarizer with adhesive phase obtained in 100mm × 100mm embodiment comparative example, Impose and placed 24 hours after 1kg heavy burden thereon, the extrusion of adhesive phase is visually observed according to following benchmark.

AA：Not it was observed that adhesive phase is extruded

BB：It was observed that a small amount of adhesive phase extrusion

CC：It was observed that obvious adhesive phase extrusion

[table 2]

Claims (8)

1. a kind of polarizer adhesive composition, it is used to form the adhesive phase directly connected with polarizer, described inclined The piece adhesive composition that shakes contains：

(A) by (methyl) alkyl acrylate of the carbon number comprising alkyl for 4~18 and monomer containing cross-linking functional group What monomer component copolymerization was obtained and determined by gel permeation chromatography/multi-angle laser light scattering detector (GPC-MALS) (methyl) acrylic copolymer of the degree of branching below 0.55, and

(B) crosslinking agent.

2. polarizer adhesive composition as claimed in claim 1, it is characterised in that (methyl) acrylic copolymer (A) it is the copolymer that is obtained in the presence of peroxide type polymerization initiator by the copolymerization.

3. polarizer adhesive composition as claimed in claim 1 or 2, it is characterised in that crosslinking agent (B) is included selected from different At least one of cyanate esters (B1) and metallo-chelate (B2).

4. such as polarizer adhesive composition according to any one of claims 1 to 3, it is characterised in that by the polarization The gel fraction for the adhesive that piece is formed with adhesive composition is more than 50 mass %.

5. a kind of polarizer adhesive phase, it is formed by adhesive composition according to any one of claims 1 to 4.

6. polarizer adhesive phase as claimed in claim 5, it is characterised in that

Storage modulus at 23 DEG C in more than 0.1MPa,

Storage modulus at 85 DEG C in below 0.05MPa, and

Storage modulus at T DEG C of temperature is designated as G'_T, the storage modulus at T+1 DEG C is designated as G'_T+1When, temperature T is at 23~50 DEG C In the range of when always meet G'_T/G'_T+1＜ 1.07.

7. a kind of polarizer bonding sheet, it has the adhesive phase described in claim 5 or 6.

8. a kind of polarizer with adhesive phase, it has the claim 5 being directly layered at least one side of polarizer Or the adhesive phase described in 6.