CN106103623A - Polarizer adhesive composition, bonding sheet and the polarizer with adhesive phase - Google Patents

Abstract

The present invention provides a kind of warpage (bending) that can suppress liquid crystal cell and can form the polarizer adhesive composition of adhesive phase of excellent in te pins of durability.Polarizer adhesive composition is characterised by, is obtained and utilized the degree of branching that gel permeation chromatography/multi-angle laser light scattering detector (GPC MALS) measures (methyl) acrylic copolymer below 0.55, (B1) isocyanate compound and (B2) metallo-chelate by the monomer component copolymerization of (methyl) alkyl acrylate that the carbon number comprising alkyl is 4～18 and carboxyl group-containing monomer containing (A).

Description

Polarizer adhesive composition, bonding sheet and the polarizer with adhesive phase

Technical field

The present invention relates to polarizer adhesive composition.

Background technology

Liquid crystal cell has liquid crystal layer by the structure clamped by 2 pieces of substrates (such as glass plate), and polarizer is via adhesive Layer adheres to the surface of described substrate.Polarizer lacks dimensionally stable due to easy thermal contraction under hot and humid thermal environment Property, warpage can occur at liquid crystal cell.In recent years, as the slimming of liquid crystal cell (for example constitutes the substrate of liquid crystal cell Slimming) and the slimming of polarizer, the warpage of the liquid crystal cell under hot and humid thermal environment becomes all the more problem.Liquid crystal The reason that structure cell warpage can enumerate such as adhesive phase cannot catch up with the thermal contraction (change in size) of polarizer, adhesive phase should It is low that power alleviates characteristic.

In addition, under hot and humid thermal environment, the interface being susceptible to polarizer with substrate produces bubble or bonding The unfavorable conditions such as oxidant layer fracture, polarizer stripping.So, it is desirable to polarizer adhesive has high-durability.

The generally means of suppression liquid crystal cell warpage can enumerate the highly-flexible using the change in size coping with polarizer The method of property adhesive phase.But, the cohesiveness of this adhesive phase is not enough, can produce durability and deteriorate and processability deterioration Etc. problem.

For example, patent document 1 with the stress relief characteristic caused by the change in size of durability or optics (glass Warpage), releasable be problem, disclose containing specific (methyl) acrylic polymer and isocyanates crosslinking agent Pressure sensitive adhesive composition for optical members, pressure sensitive adhesive, patent document 2, discloses as problem with heavy industry fissility (リ ワ Network) or durability Adhesive composition containing specific copolymer, metal-chelating species curing agent and isocyanates curing agent.

Prior art literature

Patent document

Patent document 1: Japanese Patent Laid-Open 2006-219526 publication

Patent document 2: Japanese Patent Laid-Open 2009-132752 publication

Content of the invention

The technical problem to be solved

The problem of the present invention is to provide a kind of warpage (bending) that can suppress liquid crystal cell and can form durability The polarizer adhesive composition of excellent adhesive phase, the polarizer use with the adhesive phase being formed by described composition Bonding sheet and the polarizer with adhesive phase with described adhesive phase.

Solve the technical scheme that technical problem is used

The present inventor conducts in-depth research for solving above-mentioned technical problem.It is found that using the degree of branching specific In the range of (methyl) acrylic copolymer and by isocyanate compound and metallo-chelate the field being used as crosslinking agent Under conjunction, the warpage (bending) of liquid crystal cell can be suppressed, and the adhesive phase of excellent in te pins of durability can be formed.Above-mentioned patent literary composition Offer not mentioned any content with regard to this degree of branching in 1 and 2.That is, the inventors discovered that, by use, there is following specific structure The polarizer adhesive composition becoming can solve the problem that above-mentioned technical problem, thus completes invention.

For example, following [1]～[9] of the present invention.

[1] a kind of polarizer adhesive composition, it is characterised in that containing (A) is 4～18 by the carbon number comprising alkyl (methyl) alkyl acrylate and the monomer component copolymerization of carboxyl group-containing monomer obtain and utilize gel permeation chromatography/multi-angle (methyl) acrylic copolymer below 0.55 for the degree of branching that laser light scattering detector (GPC-MALS) measures and (B1) Isocyanate compound and (B2) metallo-chelate.

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

[3] above-mentioned [1] or [2] described in polarizer adhesive composition, wherein, described (methyl) acrylic compounds is common The weight average molecular weight (Mw) that polymers (A) utilizes gel permeation chromatography (GPC method) to measure is 200,000～1,500,000.

[4] the polarizer adhesive composition described in any one of above-mentioned [1]～[3], wherein, described (methyl) third The degree of branching that olefin(e) acid analog copolymer (A) utilizes GPC-MALS to measure is 0.10～0.54.

[5] the polarizer adhesive composition described in any one of above-mentioned [1]～[4], wherein, described (methyl) third Olefin(e) acid analog copolymer (A) be also with carboxyl group-containing monomer beyond the copolymer that obtains of the monomer copolymerization of polar functionalities.

[6] the polarizer adhesive composition described in any one of above-mentioned [1]～[5], wherein, containing of peroxide Amount relative to (methyl) acrylic copolymers (A) of 100 mass parts below 0.1 mass parts.

[7] the polarizer adhesive composition described in any one of above-mentioned [1]～[6], wherein, by described polarizer Gel fraction with the adhesive of adhesive composition formation is 20～70 mass %.

[8] a kind of polarizer bonding sheet, it is characterised in that have by described in any one of above-mentioned [1]～[7] is inclined The adhesive phase that the piece adhesive composition that shakes is formed.

[9] a kind of polarizer with adhesive phase, it is characterised in that there is polarizer and at described polarizer at least The adhesive phase being formed with adhesive composition by the polarizer described in any one of above-mentioned [1]～[7] on the face of one side.

The effect of invention

Utilize the present invention, it is possible to provide a kind of warpage (bending) that can suppress liquid crystal cell and excellent in te pins of durability can be formed Adhesive phase polarizer adhesive composition, have the adhesive phase being formed by above-mentioned composition polarizer bonding Piece and the polarizer with adhesive phase with above-mentioned adhesive phase.

Detailed description of the invention

Below, to the polarizer adhesive composition of the present invention, polarizer bonding sheet and inclined with adhesive phase The piece that shakes illustrates.Hereinafter, the polarizer adhesive composition of the present invention is also referred to as " adhesive composition ", this Bright polarizer bonding sheet is also referred to as " bonding sheet ".

[polarizer adhesive composition]

The polarizer adhesive composition of the present invention contains (methyl) acrylic copolymer (A), isocyanates chemical combination Thing (B1) and metallo-chelate (B2).Above-mentioned adhesive composition as required also can be containing selected from silane coupler (C), anti-quiet At least one in electricity agent (D) and organic solvent (E).

Hereinafter also isocyanate compound (B1) and metallo-chelate (B2) are referred to as " crosslinking agent (B) ".This In bright, by by (methyl) acrylic copolymer (A) and these crosslinking agents and with and crosslinking forms adhesive phase.

[(methyl) acrylic copolymer (A)]

(methyl) acrylic copolymer (A) is by (methyl) alkyl acrylate that the carbon number comprising alkyl is 4～18 The copolymer that monomer component copolymerization with carboxyl group-containing monomer obtains.As the monomer component of copolymer (A), other also can enumerate and contain The monomer of the polar functionalities beyond carboxylic monomer, other monomers in addition.

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

(methyl) acrylic copolymer (A) utilizes gel permeation chromatography/multi-angle laser light scattering detector (GPC- MALS) degree of branching measuring below 0.55, preferably 0.10～0.54, more preferably 0.20～0.53, particularly preferably It is 0.30～0.53.The detailed content of degree of branching condition determination is recorded in embodiment.

The degree of branching shows the index that polymer is branched shape or linearity, is branched shape when the degree of branching is below 0.55 Polymer, is linearity polymer during more than 0.55.In addition, in branched shaped polymer, be polymerized under the little occasion of degree of branching numerical value The branch of thing molecule is many, is shown as having high side chain, and under the big occasion of degree of branching numerical value, the branch of polymer molecule is few, is shown as There is low side chain.

The degree of branching (methyl) acrylic copolymer (A) within the above range has characteristics that (1) at room temperature Because of a large amount of generation that interweave produced by the mutual side chain of polymer molecule, even if its result is polymer molecular weight and adhesive phase Gel fraction is designed to low, and the coherency of polymer is also able to maintain that, obtains adhesion characteristic, processes adhesive phase punching press etc. Property, the deformation of adhesive phase and the excellent adhesive phase of keeping property such as extrusion is few；(2) polymer under high temperature (for example: 60 DEG C) The mutual above-mentioned interlaced sections of molecule relaxes, and therefore adhesive phase presents excellent flexibility (curved in the warpage of polarizer Bent) suppression aspect is excellent, simultaneously because the above-mentioned intertexture of part residual and present excellent durability.

With regard to above-mentioned (1) and (2), in the present invention, a part for crosslinking agent uses metallo-chelate (B2), utilizes Coordinate bond between (methyl) acrylic copolymer (A)/metallo-chelate (B2) forms crosslinking (quasi-crosslink (Japanese: doubtful Frame)).Therefore, when above-mentioned room temperature, described crosslinking is maintained, and polymer plays coherency, and described in when above-mentioned high temperature Crosslinked part releasing, adhesive phase presents more excellent flexibility.

Warpage with regard to polarizer is suppressed this point, thus it is speculated that caused by being due to the fact that.With at such as polarizer/viscous The such structure of mixture layer/clung body use glass plate illustrate as a example by the occasion of clung body.Polarizer and glass The respective percent thermal shrinkage of plate is different, and the percent thermal shrinkage (change in size) of polarizer is generally big than glass plate.Lack at adhesive phase Under the occasion of the flexibility under hot and humid thermal environment, adhesive phase cannot catch up with the change in size of polarizer, it is impossible to alleviates Stress at adhesive phase, stress concentrates on glass plate, and therefore warpage occurs on a glass.And use the adhesive of the present invention The adhesive phase that composition is formed contains high branched-chain polymer and uses metallo-chelate in a part for crosslinking agent, because of The part releasing of the lax and above-mentioned crosslinking of a part for this above-mentioned intertexture under hot and humid thermal environment, so adhesive Layer can catch up with the change in size of polarizer, so stress will not be produced, stress is not centered on glass plate.In addition, polarizer is also Shrink without anisotropically uniform heat, the birefringence of polarizer will not be induced.As described above, in the present invention, adhesive Layer can absorb alleviation stress with the change in size of polarizer, (negative thus without applying excessive stress to glass plate Lotus), thus it is speculated that this is related to the suppression to glass plate warpage.

The adhesive composition of the present invention is applicable to constitute substrate and the polarization of liquid crystal cell owing to having above characteristic The laminating purposes of piece.Even if particularly the thickness at the glass plate of the liquid crystal cell constituting slimming is little to about 0.1～1.0mm Occasion under, be also applied for the laminating purposes of this substrate and polarizer.

" (methyl) alkyl acrylate "

As (methyl) alkyl acrylate, (methyl) alkyl acrylate that the carbon number of alkyl can be used to be 4～18 (CH₂=CR¹-COOR²；R¹For hydrogen atom or methyl, R²Alkyl for carbon number is 4～18), wherein, the carbon number of abovementioned alkyl enters one Step is preferably 4～12.

As (methyl) alkyl acrylate that the carbon number of alkyl is 4～18, the such as positive fourth of (methyl) acrylic acid can be enumerated 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 undecyl ester, (methyl) lauryl base Ester, (methyl) octadecyl acrylate, (methyl) acrylic acid isooctadecane base ester.These materials can be used alone a kind, it is possible to Use two or more.

In 100 mass % of the monomer component forming (methyl) acrylic copolymer (A), the carbon number of alkyl is 4～18 The total amount of (methyl) alkyl acrylate from the viewpoint of presenting good bonding force and durability, preferably 99.8～ 20 mass %, more preferably 99.5～30 mass %, be still more preferably 99～50 mass %.

As the monomer component of (methyl) acrylic copolymer (A), (methyl) that the carbon number of alkyl can be used to be 1～3 Alkyl acrylate (CH₂=CR³-COOR⁴；R³For hydrogen atom or methyl, R⁴Alkyl for carbon number is 1～3).

As (methyl) alkyl acrylate that the carbon number of alkyl is 1～3, can enumerate such as (methyl) methyl acrylate, (methyl) ethyl acrylate, (methyl) n-propyl, (methyl) isopropyl acrylate.These materials can be used alone a kind, It is used as two or more.

The carbon number of alkyl be the consumption of (methyl) alkyl acrylate of 1～3 from the viewpoint of stress relief characteristic, In the monomer component of 100 mass % preferably below 60 mass %, further preferably below 50 mass %, still more preferably Below 40 mass %.

" carboxyl group-containing monomer "

As carboxyl group-containing monomer, can enumerate for example (methyl) β-acryloxypropionic acid, (methyl) acrylic acid 5-carboxylic pentyl ester, (methyl) third containing carboxyl such as succinic acid list (methyl) acryloyl-oxy ethyl ester, single (methyl) acrylic acid ω-carboxyl pla-pcl Olefin(e) acid ester；Acrylic acid, methacrylic acid, itaconic acid, butenoic acid, fumaric acid, maleic acid.

Carboxyl group-containing monomer in this specification also includes the monomer of the anhydride group being condensed containing 2 carboxyl dehydration, The such as carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride can be enumerated.

Carboxyl group-containing monomer can be used alone a kind, it is possible to use two or more.

This carboxyl contained in carboxyl group-containing monomer is handed over as with isocyanate compound (B1) or metallo-chelate (B2) The cross-linking functional group of connection plays a role.The consumption of carboxyl group-containing monomer in the monomer component of 100 mass % be preferably 0.01～ 15 mass %, more preferably 0.05～10 mass %, be still more preferably 0.1～5 mass %.For example, (methyl) third The acid number of olefin(e) acid analog copolymer (A) is preferably 0.1～117mgKOH/g, more preferably 0.4～78mmKOH/g.

If the consumption of carboxyl group-containing monomer is below above-mentioned higher limit, then by (methyl) acrylic copolymer (A) and friendship The crosslink density that connection agent (B) is formed will not become too high, can obtain the adhesive phase of stress relief excellent.If containing carboxylic The consumption of base monomer more than above-mentioned lower limit, then can be effectively formed cross-linked structure, is had suitably strong at normal temperatures The adhesive phase of degree.

" monomer of polar functionalities "

As the monomer of polar functionalities, can enumerate beyond such as hydroxyl monomer, carboxyl group-containing monomer containing acid-based monomers, Emulsion stability, amide-containing monomer, the monomer of nitrogenous system heterocycle, cyano-containing monomer.As the monomer of polar functionalities, preferably Use has the list of the polar group (cross-linking functional group) that the cross-linking functional group can being had reacts with crosslinking agent (B) Body.

(methyl) acrylic copolymer (A) preferably by with carboxyl group-containing monomer, simultaneously also with this monomer beyond contain The copolymer that the monomer copolymerization of polar group obtains.Wherein, from the viewpoint improving the base material adaptation with blooming such as polarizer Consider, preferably while using carboxyl group-containing monomer, also use hydroxyl monomer.

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

This hydroxyl contained in hydroxyl monomer is as the isocyanates contained with isocyanate compound (B1) Base crosslinked cross-linking functional group play a role.The consumption of hydroxyl monomer in the monomer component of 100 mass % be preferably 0～ 15 mass %, more preferably 0.05～10 mass %, be still more preferably 0.1～7 mass %.If hydroxyl monomer Consumption below above-mentioned higher limit, then formed by (methyl) acrylic copolymer (A) and isocyanate compound (B1) Crosslink density will not become too high, can obtain the adhesive phase of stress relief excellent.If the consumption of hydroxyl monomer More than above-mentioned lower limit, then can be effectively formed cross-linked structure, be there is the adhesive phase of suitable intensity at normal temperatures.

As the acidic group in this specification, such as phosphate, sulfate can be enumerated.As phosphorous acid-based monomers, can enumerate Side chain has (methyl) acrylic monomer of phosphate, as sulfur-bearing acid-based monomers, can enumerate and there is on side chain sulphur (methyl) acrylic monomer of acidic group.

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-ethyl (methyl) acrylamide, N-propyl group (methyl) acrylamide, N-hexyl (methyl) third Acrylamide.As the monomer of nitrogenous system heterocycle, such as pyrrolidones, acryloyl morpholine, caprolactam can be enumerated.As Cyano-containing monomer, can enumerate such as cyano group (methyl) acrylate, (methyl) acrylonitrile.

The monomer of polar functionalities can be used alone a kind, it is possible to use two or more.

" other monomers "

The monomer component forming (methyl) acrylic copolymer (A) is not damaging (methyl) acrylic copolymer (A) Physical property in the range of can be containing such as (methyl) alkyl acrylate epoxide alkyl ester, single many alkylene glycols of (methyl) alkyl acrylate epoxide Ester (ア Le U キ シ Port リ ア Le キ レ Application グ リ U Le モ ノ (メ タ) ア Network リ レ ト), contain ester ring type group or aromatic ring Other (methyl) acrylate such as (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 acrylate, (methyl) acrylic acid 2-ethoxy ethyl ester, (methyl) acrylic acid 3-methoxyl group propyl ester, (methyl) propylene Acid 3-ethyoxyl propyl ester, (methyl) acrylic acid 4-methoxybutyl, (methyl) acrylic acid 4-Ethoxybutyl.

As list (methyl) alkyl acrylate epoxide many alkylene glycols ester, 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.

In above-mentioned copolymerization, total consumption of other (methyl) acrylate above-mentioned preferably exists in the monomer component of 100 mass % Below 60 mass %, further preferably below 40 mass %.

In addition, in the range of not damaging the physical property of (methyl) acrylic copolymer (A), it is possible to use such as benzene second Alkene, methyl styrene, dimethyl styrene, trimethyl styrene, propylstyrene, butylstyrene, hexyl benzene ethene, heptyl The ring-alkylated styrenes such as styrene and octyl styrene, fluorobenzene ethene, chlorostyrene, bromstyrol, Dowspray 9, iodobenzene second The styrene monomers such as alkene, nitrostyrolene, acetylbenzene ethene and methoxy styrene；The copolymerizable lists such as vinyl acetate Body.

In above-mentioned copolymerization, total consumption of above-mentioned co-polymerized monomer in the monomer component of 100 mass % preferably in 40 matter Amount below %, further preferably below 20 mass %.

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

" manufacturing condition of (methyl) acrylic copolymer (A) "

(methyl) acrylic copolymer (A) preferably passes through above-mentioned common in the presence of peroxide type polymerization initiator Copolymer obtained by poly-.That is, by using peroxide type polymerization initiator as polymerization initiator, have and obtain the degree of branching The tendency of copolymer within the above range.

(methyl) acrylic copolymer (A) may utilize such as solution polymerization process, mass polymerization, emulsion polymerization, hangs The known so far polymerizations such as floating polymerization manufacture, wherein preferred solution polymerization process.Specifically, it is by polymer solvent and list Body becomes to be distributed in reaction vessel, adds polymerization initiator under the inert gas atmospheres such as nitrogen, and reaction starts temperature and is set as Usual 40～100 DEG C, preferably 50～80 DEG C, make reaction system maintain at a temperature of usual 50～90 DEG C, preferably 70～90 DEG C React 4～20 hours.

As peroxide type polymerization initiator, can enumerate for example:

Two (peroxidating 2-ter /-butylisopropyl) benzene, dicumyl peroxide, 2,5-dimethyl-2,5-two (peroxidating uncle Butyl) the dialkyl group peroxidating such as hexane, tert-butyl cumyl peroxide, two tertiary hexyl peroxide, di-tert-butyl peroxide (for example: the compound representing with R-O-O-R, the R in formula is separately the substituted alkyl of alkyl or aryl to species；With R- The compound that O-O-A-O-O-R represents, the R in formula is separately the substituted alkyl of alkyl or aryl, and A is the hydrocarbon of divalent Base)；

Diisobutyl peroxide, two (3,5,5-trimethyl acetyl base) peroxide, dilauroyl peroxide, peroxidating Dibenzoyl, benzoyl (3-methyl benzoyl) peroxide, two (3-methyl benzoyl) peroxide, two (4-first Base benzoyl) diacyl peroxide class (for example: the compound representing with R-COO-OCO-R, the R in formula such as peroxide It is separately alkyl or aryl)；

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

The withered ester of peroxidating neodecanoic acid, peroxidating neodecanoic acid 1,1,3,3-tetramethyl butyl ester, the tertiary own ester of peroxidating neodecanoic acid, mistake The oxidation neodecanoic acid tert-butyl ester, the new heptanoic acid tert-butyl ester of peroxidating, the tertiary own ester of peroxidating neopentanoic acid, tert-Butyl peroxypivalate, mistake Oxidation-2 ethyl hexanoic acid 1,1,3,3-tetramethyl butyl ester, 2,5-dimethyl-2,5-two (peroxidating 2-ethyl hexyl acyl group) hexane, The tertiary own ester of peroxidating 2 ethyl hexanoic acid, the peroxidating 2 ethyl hexanoic acid tert-butyl ester, the peroxidating 3,5,5 Trimethylhexanoic acid tert-butyl ester, mistake The oxidation laurate tert-butyl ester, the tertiary own ester of perbenzoic acid, 2,5-dimethyl-2,5-two (benzoyl peroxide base) hexane, mistake The peroxyesters such as the acetic oxide tert-butyl ester, peroxidating 3-methylbenzoate, peroxidized t-butyl perbenzoate (for example: With R¹-O-O-CO-R²The compound representing, the R in formula¹For the substituted alkyl of alkyl or aryl, R²For alkyl, aryl or aryl Substituted alkyl；The compound representing with R-CO-O-O-A-O-O-CO-R, the R in formula is separately alkyl or aryl, A Alkyl for divalent)；

The tertiary own ester of isopropyl peroxide list carbonic acid, isopropyl peroxide list t-butyl carbonate, peroxidating-2-ethylhexyl list (for example: the compound representing with R-O-O-COO-R, the R in formula is separately for the peroxidating monocarbonate classes such as t-butyl carbonate For alkyl).

In peroxide type polymerization initiator, owing to (methyl) acrylic copolymer of high side chain can be obtained, thus Preferably peroxyesters, the peroxide type polymerization initiator further preferably representing with following formula (1).

[formula 1]

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

With in the peroxide type polymerization initiator that formula (1) represents, preferably tert-Butyl peroxypivalate, peroxidating new penta The tertiary own ester of acid, new peroxide tert-butyl caprate, the new heptanoic acid tert-butyl ester of peroxidating, peroxide-2-ethyl hexanoic acid tert-butyl, peroxidating The withered ester of neodecanoic acid, owing to can obtain the copolymer of high side chain, thus particularly preferred tert-Butyl peroxypivalate, peroxidating are new The tertiary own ester of valeric 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 a kind, it is possible to use two or more.In addition, be also not limited in polymerization In repeatedly add peroxide type polymerization initiator.

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 can be enumerated, 2 '-azodiisobutyronitrile, 2,2 '-azo two (4-methoxyl group-2,4-methyl pentane nitrile), 2,2 '-azo two (2-cyclopropyl propionitrile), 2,2 '-azo two (2,4-dimethyl-penten Nitrile), 2,2 '-azo two (2-methylbutyronitrile), 1,1 '-azo two (hexamethylene-1-nitrile), 2-(carbamoyl azo) isobutyronitrile, 2-phenylazo-4-methoxyl group-2,4-methyl pentane nitrile, two acidified 2,2 '-azos two (2-amidine propane), 2,2 '-azo Two (N, N '-dimethyleneisobutylamidine), 2,2 '-azo two [2-methyl-N-(2-ethoxy)-propionamide], 2,2 '-azo two (isobutyramide) dihydrate, 4,4 '-azo two (4-cyanopentanoic acid), 2,2 '-azo two (2-cyano group propyl alcohol), dimethyl-2, The azo-compounds such as 2 '-azo two (2 Methylpropionic acid ester), 2,2 '-azo two [2-methyl-N-(2-ethoxy) propionamide].This A little polymerization initiators can be used alone a kind, it is possible to use two or more.

Relative to the monomer component of formation (methyl) acrylic copolymer (A) of 100 mass parts, with usual 0.001～5 Mass parts, the amount of preferably 0.005～3 mass parts use peroxide type polymerization initiator.In addition, azo-initiator is preferably not Use, its consumption relative to the peroxide type polymerization initiator of 100 mass parts preferably below 0.5 mass parts, excellent further It is selected in below 0.2 mass parts, be still more preferably 0 mass parts.But, for the purpose of reducing the monomer reacting later half middle remaining It is then used for not limiting.In addition, in above-mentioned polymerisation, it is also possible to suitably add and add polymerization initiator, chain tra nsfer Agent, monomer component, polymer solvent.

As for the polymer solvent in polymerisation in solution, such as benzene,toluene,xylene etc. can be enumerated aromatic hydrocarbon；Just The aliphatic hydrocarbons such as pentane, n-hexane, normal heptane, normal octane；The ester ring type hydrocarbon such as pentamethylene, hexamethylene, cycloheptane, cyclooctane Class；Diethyl ether, diisopropyl ether, 1,2-dimethoxy-ethane, butyl oxide, oxolane, dioxane (dioxane), methyl phenyl ethers anisole, benzene The ethers such as ether, diphenyl ether；The halogenated hydrocarbons such as chloroform, carbon tetrachloride, 1,2-dichloroethanes, chlorobenzene；Ethyl acetate, acetic acid third The esters such as ester, butyl acetate, methyl propionate；The ketones such as acetone, MEK, diethyl ketone, methylisobutylketone, cyclohexanone；N, N-bis- The amide-types such as NMF, DMAC N,N' dimethyl acetamide, 1-METHYLPYRROLIDONE；The nitrile such as acetonitrile, benzonitrile；Diformazan is sub- The sulfoxide type such as sulfone, sulfolane.These polymer solvents can be used alone a kind, it is possible to use two or more.

In the adhesive composition of the present invention, cause as polymerization when manufacturing (methyl) acrylic copolymer (A) The available following formula of the reacted survival rate (%) of the peroxide type polymerization initiator elapsed time t that agent is preferably used is tried to achieve.

Survival rate (%)=exp (-k_dT) × 100 (%)

In formula, k_dFor thermal decomposition rate constant, with Arrhenius formula k_d=A × exp (-Δ E/RT) represents, wherein A For frequency factor, Δ E is the activation energy of polymerization initiator in pyrolysis, and R is gas constant (8.314J/ mole of K), T For absolute temperature (K)；T is the reaction time.

Can use in such as Japan Oil Co (Japan Oil Co) organic peroxide catalogue (the 10th edition) described Numerical value obtain frequency factor (A) and the activation energy (Δ E) of above-mentioned peroxide type polymerization initiator.For example, peroxidating new penta The Δ of tert-butyl acrylate E=119.1kJ/ mole, A=6.93 × 10¹⁷Hour^-1, the Δ E=of the tertiary own ester of peroxidating neopentanoic acid 118.5kJ/ mole, A=6.45 × 10¹⁷Hour^-1, Δ E=105.3kJ/ mole of the withered ester of peroxidating neodecanoic acid, A=3.94 × 10¹⁶Hour^-1。

So, owing to the k at given temperature can be calculated_d, it is thus possible to calculate at given temperature through out-of-date according to above formula Between the survival rate (%) of reacted peroxide type polymerization initiator of t.Therefore, it is possible to used in by above-mentioned copolymerization Amount × the survival rate (%) of peroxide type polymerization initiator calculates peroxide type polymerization contained in adhesive composition The remaining quantity of initiator.

" physical property of (methyl) acrylic copolymer (A) and content "

(methyl) acrylic copolymer (A) utilizes the weight average molecular weight (Mw) that GPC method measures with polystyrene conversion value Meter is usually 200,000～1,500,000, preferably 400,000～1,300,000, more preferably 500,000～1,100,000.Due to copolymer (A) i.e. Make Mw also have high side chain within the above range, thus can moderately be interweaved between copolymer (A) chain, adhesive phase Durability or processability will not deteriorate.Particularly when Mw is more than 400,000, then can obtain the high adhesive phase of coherency.

(methyl) acrylic copolymer (A) utilizes the molecular weight distribution (Mw/Mn) that GPC method measures generally below 50, Preferably below 30, further preferably below 20.

The glass transition temperature (Tg) of (methyl) acrylic copolymer (A) can be by the monomer for example constituting this polymer Unit and content ratio thereof utilize Fox formula to calculate.For example, it is possible to according to the glass transition temperature tried to achieve by Fox formula (Tg) condition reaching usually-70～0 DEG C, preferably-60～-30 DEG C synthesizes (methyl) acrylic copolymer (A).Logical Cross use and there is (methyl) acrylic copolymer (A) of such glass transition temperature (Tg), can obtain under normal temperature viscous The excellent adhesive composition of conjunction property.

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 of (methyl) acrylic copolymer (A), Tg₁、Tg₂、……、Tg_mServe as reasons The glass transition temperature of the homopolymers that each monomer is constituted, W₁、W₂、……、W_mFor deriving from construction unit above-mentioned of each monomer Weight fraction in copolymer (A).

The glass transition temperature of the homopolymers being made up of each monomer in above-mentioned Fox formula can use such as " polymer hand Volume " numerical value described in (Polymer Handbook) fourth edition (Wiley-Interscience 1999).

The content of (methyl) acrylic copolymer (A) in the adhesive composition of the present invention being somebody's turn to do in 100 mass % Composition is usually in the solid constituent in addition to organic solvent (E) 50～99.99 mass %, more preferably 60～ 99.95 mass %, particularly preferably 80～99.90 mass %.If the content of (methyl) acrylic copolymer (A) is above-mentioned In the range of, then can obtain the balance of the performance as adhesive, and adhesion characteristic is excellent.

[isocyanate compound (B1)]

As isocyanate compound (B1), generally use isocyanation esterification more than 2 for the isocyanates radix in 1 molecule Compound.Make (methyl) acrylic copolymer (A) crosslinked by utilizing isocyanate compound (B1), crosslinked can be formed (network polymers).

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

As the diisocyanate cpd that isocyanates radix in 1 molecule is 2, for example aliphatic two isocyanic acids can be enumerated Ester, alicyclic diisocyanate, aromatic diisocyanates.As aliphatic vulcabond, can enumerate ethylidene diisocyanate, Tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2-methyl isophthalic acid, 5-pentane two is different Cyanate, 3-methyl isophthalic acid, the carbon number such as 5-pentane diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate is 4 The aliphatic vulcabond of～30.As alicyclic diisocyanate, IPDI, cyclopenta two can be enumerated different Cyanate, cyclohexyl diisocyanate, the sub-XDI of hydrogenation, HTDI, hydrogenation hexichol first The carbon numbers such as alkane diisocyanate, the hydrogenation sub-XDI of tetramethyl are the alicyclic diisocyanate of 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 The aromatic diisocyanates of～30

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

In addition, as isocyanate compound (B1), can enumerate such as isocyanates radix 2 or more than 3 above-mentioned different The polymer (such as dimer or tripolymer, biuret body, isocyanuric acid ester body) of cyanate esters, derivative are (for example many The addition reaction product of diisocyanate cpd more than unit's alcohol and 2 molecules), polymer.As many in said derivative Unit's alcohol, low molecular weight polyols can enumerate the alcohol of more than the such as ternarys 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 The biuret body of base PIC, hexamethylene diisocyanate or toluene di-isocyanate(TDI) or isocyanuric acid ester body, three hydroxyls Methylpropane and product (the such as toluene di-isocyanate(TDI) or Asia of toluene di-isocyanate(TDI) or sub-XDI Three molecule addition products of XDI), the product (example of trimethylolpropane and hexamethylene diisocyanate The three molecule addition products such as hexamethylene diisocyanate), polyethers PIC, polyester PIC.

In isocyanate compound (B1), can carry on good curing performance and this aspect of light leak performance, preferably trihydroxy methyl third (chemical society (is ground) by Soken Chemical & Engineering Co., Ltd. for alkane and the product of toluene di-isocyanate(TDI) or sub-XDI The L-45 manufacturing, the TD-75 etc. that Soken Chemical & Engineering Co., Ltd. manufactures), hexamethylene diisocyanate or toluene di-isocyanate(TDI) Isocyanuric acid ester body (TSE-100 that Asahi Chemical Industry Co., Ltd (Asahi Chemical Industry Gong She) manufactures, Japanese polyurethane strain formula meeting Society (Japan Port リ ウ レ タ Application society) manufacture 2050 etc.).

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

[metallo-chelate (B2)]

In the present invention, a part of crosslinking agent (B) uses metallo-chelate (B2).Metallo-chelate (B2) is by joining Position key makes (methyl) acrylic copolymer (A) crosslinked.Therefore, during high temperature above-mentioned crosslinking a part releasing, adhesive phase in Reveal more excellent flexibility.

As metallo-chelate (B2), can enumerate such as alkoxide, acetylacetone,2,4-pentanedione, ethyl acetoacetate etc. to aluminium, iron, copper, The compound of the polyvalent metal coordination such as zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium.Wherein, particularly preferred aluminium chelate compound (is combined Grind the M-12AT etc. that KCC manufactures).Specifically, aluminium isopropoxide, secondary butyric acid aluminium, acetoacetate aluminium ethide can be enumerated Diisopropyl ester, tri ethylacetoacetate aluminium, praseodynium aluminium.

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

In the adhesive composition of the present invention, the total content phase of isocyanate compound (B1) and metallo-chelate (B2) 0.01～5 mass parts is usually for (methyl) acrylic copolymers (A) of 100 mass parts, more preferably 0.05～ 2.5 mass parts, are still more preferably 0.1～1 mass parts.If this content is within the above range, then durable in easy acquirement It is preferred on property and this aspect of the balance of stress relief characteristic.

In the adhesive composition of the present invention, the content of metallo-chelate (B2) is relative to the isocyanates of 100 mass parts Compound (B1) is usually 10～1000 mass parts, more preferably 50～600 mass parts, be still more preferably 100～ 400 mass parts.If this content is within the above range, then in amount of bow suppression and improve the base material with blooming such as polarizer It is preferred on this aspect of adaptation.

[silane coupler (C)]

Preferably the polarizer adhesive composition of the present invention is possibly together with silane coupler (C).Silane coupler (C) makes to glue The clung body strong bond such as mixture layer and glass plate, contribute to preventing the stripping under high humid and warm environment.

As silane coupler (C), such as vinyltrimethoxy silane, VTES, first can be enumerated The silane coupler containing polymerism unsaturated group such as base acryloxypropyl trimethoxy silane；3-glycidoxy third Base trimethoxy silane, 3-glycidoxypropyl group triethoxysilane, 3-glycidoxypropyl dimethoxysilane, 3-glycidoxypropyl diethoxy silane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane etc. contain epoxy The silane coupler of base；3-TSL 8330, N-(2-amino-ethyl)-3-TSL 8330, The silane coupler containing amino such as N-(2-amino-ethyl)-3-amino propyl methyl dimethoxysilane；3-chloro propyl group three The silane coupler containing halogen such as methoxy silane.

The content of the silane coupler (C) in the polarizer adhesive composition of the present invention is relative to 100 mass parts (methyl) acrylic copolymer (A) generally below 1 mass parts, preferably 0.01～1 mass parts, more preferably 0.05 ～0.5 mass parts.If content is within the above range, then has and prevent polarizer under high humid and warm environment from peeling off or hot environment The tendency that lower silane coupler (C) is oozed out.

[antistatic agent (D)]

Antistatic agent can be used to for example reduce the sheet resistance value of polarizer adhesive composition of the present invention (D).Antistatic agent (D) can enumerate such as surfactant, ionic compound, electric conductive polymer.

As surfactant, can enumerate such as quaternary ammonium salt, amidoquat salt, pyridine salt, have primary amino radical～ The cationic surface active agent of the cationic groups such as tertiary amino；There are sulphonate-base, sulfuric ester alkali, phosphate alkali etc. The anionic surfactant of anionic group；Alkyl betaines bases, alkyl imidazole betaines, alkyl amine Amphoteric surfactant, fatty acid glycerine esters, sorbitan fatty acid ester class, the polyoxy second such as class, amino acid sulfuric acid ester Allylic alkylation amine, polyoxyethylene alkyl amine fatty acid ester, N-ethoxy-N-2-hydroxyalkyl amine, alkyl diethanolamide class Deng nonionic surface active agent.

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

Ionic compound is made up of cationic moiety and anionicsite, and at room temperature (23 DEG C/50%RH) are in solid-state Or any one in liquid.

The cationic moiety constituting ionic compound both can be appointing in mineral-type cation or organic cation One, it is also possible to be both.Mineral-type cation preferred as alkali ion and alkaline-earth metal ion, further preferred antistatic The excellent Li of property⁺、Na⁺And K⁺.As organic cation, such as pyridylium, piperidines cation, pyrrolidones can be enumerated Cationoid, pyrrolin cation, pyrroles's cation, glyoxaline cation, tetrahydropyrimidine cation, dihydro-pyrimidin cation, pyrrole Azoles cation, pyrazine cation (ピ ラ ゾ リ ニ ウ system カ チ オ Application), tetraalkylammonium cation, trialkylsulfonium cation, four alkane Base phosphine cation and their derivative.

As long as constitute ionic compound anionicsite can with cationic moiety ionic bonding and form ion The material of type compound is then not specially 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 is preferred because providing the ionic compound of low melting point, particularly preferably (F₂SO₂)₂N^-(CF₃SO₂)₂N^-。

Ionic compound preferred bis-trifluoromethylsulfoandimide lithium, double difluoro sulfimide lithium, three (trifyls) Methane lithium, bis-trifluoromethylsulfoandimide potassium, double difluoro sulfimide potassium, hexafluorophosphoric acid 1-ethylpyridine, hexafluorophosphoric acid 1-butyl Pyridine, hexafluorophosphoric acid 1-hexyl-4-picoline, hexafluorophosphoric acid 1-octyl group-4-picoline, 1-octyl group-4-picoline two Fluorine sulfimide, 1-octyl group-4-picoline bis-trifluoromethylsulfoandimide, tetrafluoro boric acid (N, N-diethyl-N-methyl-N-(2- Methoxy ethyl) ammonium, N, N-diethyl-N-methyl-N-(2-methoxy ethyl) 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-picoline, three Fluorine 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.

The content of the antistatic agent (D) in the polarizer adhesive composition of the present invention is relative to (the first of 100 mass parts Base) acrylic copolymer (A) 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 regulate its coating.Organic solvent can Enumerate the polymer solvent of explanation in (methyl) acrylic copolymer (A) hurdle.For example, can be by containing of obtaining in above-mentioned copolymerization Have polymer solution and isocyanate compound (B1) and the metal-chelating of (methyl) acrylic copolymer (A) and polymer solvent Thing (B2) mixing carrys out modulating adhesive composition.In the adhesive composition of the present invention, the content of organic solvent is usually 50～ 90 mass %, preferably 60～85 mass %.

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

[peroxide]

(peroxide is crosslinked preferably not to blend the peroxide as crosslinking agent in the adhesive composition of the present invention Agent).The content of peroxide includes that the peroxide type polymerization being used during the synthesis of (methyl) acrylic copolymer (A) draws Send out including the remaining quantity of agent, relative to (methyl) acrylic copolymers (A) of 100 mass parts preferably below 0.1 mass parts, Further preferably below 0.05 mass parts, still more preferably below 0.01 mass parts.By using isocyanates chemical combination Thing (B1) and metallo-chelate (B2) do not use peroxide crosslinking agent as crosslinking agent, can suppress because of the peroxide of residual Compound and the deterioration of adhesive phase that causes.

[additive]

The adhesive composition of the present invention is in addition to mentioned component, in the range of not damaging effect of the present invention, also may be used Containing beyond antioxidant, light stabilizer, preventing metal corrosion agent, tackifier, plasticizer, crosslinking accelerator, above-mentioned (A) One kind or two or more in (methyl) acrylic polymer and heavy industry remover (Japanese: リ ワ Network).

[modulation of polarizer adhesive composition]

The polarizer adhesive composition of the present invention can be by utilizing known so far method to (methyl) acrylic compounds Copolymer (A) and isocyanate compound (B1) and metallo-chelate (B2) and other compositions using as desired are carried out Mixing is modulated.Can enumerate for example obtained containing this polymer when synthesis (methyl) acrylic copolymer (A) In polymer solution blend isocyanate compound (B1) with metallo-chelate (B2) and use as desired other become Point.

The gel fraction of the adhesive being formed by the adhesive composition of the present invention is preferably 20～70 mass %, further It is preferably 24～60 mass %, be still more preferably 30～55 mass %.Above-mentioned gel fraction is for example to remember according to embodiment The condition carrying is measured the numerical value obtaining to the adhesive being used.

[adhesive phase]

The adhesive phase of the present invention can be obtained by for example carrying out the cross-linking reaction in above-mentioned adhesive composition, specifically It is can be by making (methyl) acrylic polymer (A) crosslinking with isocyanate compound (B1) and metallo-chelate (B2) Arrive.

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

Adhesive phase is preferably formed under the following conditions.It is coated on the adhesive composition of the present invention on supporting mass, After pasting cover layer on the film that formed under these conditions, usual 5～60 DEG C, preferably 15～40 DEG C and usual 30～ Maintenance usual more than 3 days, preferably 7～10 days in the environment of 70%RH, preferably 40～70%RH.If in curing as described above Under the conditions of carry out crosslinking, then can be efficiently formed crosslinked (network polymers).

As the coating process of adhesive composition, known method can be used, for example, pass through spin-coating method, cutter coating, 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, the such as polyester films such as polyethylene terephthalate (PET) can be enumerated；Poly-second The plastic foil of the polyolefin films etc. such as alkene, polypropylene, vinyl-vinyl acetate copolymer.

The adhesive phase being formed by the adhesive composition of the present invention is from suppression polarizer distortion, cohesiveness, bonding force, again From the viewpoint of fissility, gel fraction is preferably 20～70 mass %, more preferably 24～60 mass %, further It is preferably 30～55 mass %.Owing to (methyl) acrylic copolymer (A) is even if gel fraction also has within the above range High side chain, thus can moderately be interweaved between the side chain of copolymer (A), durability or the processability of adhesive phase will not Deteriorate.Particularly when gel fraction is more than 30 mass %, then can obtain the high adhesive phase of coherency.If gel divides Number exceeds above-mentioned scope, then adhesive phase cannot fully absorb and alleviate by the change in size of polarizer under hot and humid thermal environment Caused stress.

[polarizer bonding sheet]

The polarizer bonding sheet of the present invention has the adhesive phase being formed by above-mentioned polarizer adhesive composition.Make For bonding sheet, can enumerate and for example only there is the double-sided adhesive sheet of above-mentioned adhesive phase, there is base material and be formed on base material two sides Above-mentioned adhesive phase double-sided adhesive sheet, there is base material and the one side of the above-mentioned adhesive phase being formed on the face of base material one side Bonding sheet and these bonding sheets are pasted with the cover layer through lift-off processing with base material on the face not contacted of adhesive phase Bonding sheet.

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

The formation condition of the adhesive phase condition described with [adhesive phase] hurdle is identical.

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

[with the polarizer of adhesive phase]

The polarizer with adhesive phase of the present invention is characterized by polarizer and at above-mentioned polarizer at least The adhesive phase being formed by polarizer adhesive composition of the present invention on the face of side.In addition, in this specification, " polarizer " Use with the implication comprising " polarizing coating ".

Polarizer can use known so far polarizing coating.Can enumerate and for example have by making to be made up of polyvinyl alcohol resin Film in multilayer containing stretched film and the diaphragm being configured in above-mentioned stretched film obtained from stretching after polarized component Film.As polyvinyl alcohol resin, such as polyvinyl alcohol, polyvinyl formal, Pioloform, polyvinyl acetal, ethene second can be enumerated Vinyl acetate copolymer saponified.Polarized component can enumerate such as iodine or dichroic dye.As diaphragm, can enumerate for example The cellulose membranes such as tri acetyl cellulose, polycarbonate membrane, poly (ether sulfone) film.

The thickness of polarizer is usually 30～250 μm, preferably 50～200 μm.

The method forming adhesive phase on polarizer surface is not particularly limited, and can enumerate use direct stick coating method etc. partially Shaking makes its method being dried, is had the polarizer bonding sheet of the present invention after being coated with above-mentioned adhesive composition on piece surface Adhesive phase be transferred to polarizer surface after make its method curing.Be dried and cooking conditions or gel fraction scope etc. with Condition described in [adhesive phase] hurdle is identical.

The thickness of the adhesive phase being formed on polarizer is usually 5～75 μm in terms of dry film thickness, preferably 10～50 μ m.As long as in addition, on the face of the adhesive phase at least one party that is formed at polarizer, adhesive phase can be enumerated and is only formed at partially The shake form on piece one side, adhesive phase is formed at the form on polarizer two sides.

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

By the polarizer with adhesive phase of the present invention obtaining in the manner described above is arranged on the base of liquid crystal cell Plate manufactures liquid crystal cell on surface.Here liquid crystal cell has liquid crystal layer by the construction clamped by 2 pieces of substrates.

The substrate with liquid crystal cell can enumerate such as glass plate.The thickness of substrate is usually 0.1～1mm, is preferably 0.15～0.8mm.Especially in the present invention, sticking up of polarizer and substrate can be suppressed by using above-mentioned adhesive composition Bent.Therefore, though above-mentioned adhesive composition under the little occasion of substrate thickness (for example: below 0.8mm, preferably 0.15～ 0.7mm), it is also possible to be suitably used for the laminating of polarizer and substrate.

Embodiment

Carry out more specific description to the present invention below based on embodiment, but the present invention is not limited to these embodiments.With In the record of lower embodiment etc., if no special instructions, " part " expression " mass parts ".

[GPC and GPC-MALS]

Gel permeation chromatography (GPC method) is used to utilize gel permeation chromatography/multi-angle laser light according to following condition Weight average molecular weight (Mw) and number-average molecular weight (Mn) to (methyl) acrylic copolymer for the scatter detector (GPC-MALS) is entered Row measures, and obtains the degree of branching according to following condition.

Determinator: HLC-8320GPC (TOSOH Co., Ltd's (ソ (strain)) production)

The composition of GPC post: 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: 1.0mL/ minute

Column temperature: 40 DEG C

Sample solution concentration: 1.5% (w/v) (diluting with oxolane)

Mobile phase solvent: oxolane

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

Polystyrene standard conversion (measures the occasion of Mw and Mn)

[synthesis example 1]

98.8 parts of propylene are added in the reaction unit possessing mixer, reflux cooler, thermometer and nitrogen ingress pipe Acid N-butyl, 1 part of acrylic acid 4-hydroxy butyl ester, 0.2 part of acrylic acid and 100 parts of ethyl acetate solvents, import nitrogen and rise Temperature is to 80 DEG C.Then, add the tert-Butyl peroxypivalate of 0.1 part, carry out the polymerization of 6 hours in a nitrogen atmosphere in 80 DEG C Reaction.After reaction terminates, being diluted with ethyl acetate, prepared solid component concentration is the polymer solution of 30 mass %.Institute The weight average molecular weight (Mw) of (methyl) the acrylic copolymer A obtaining is 700,000, and molecular weight distribution (Mw/Mn) is 7.1, branched Degree is 0.51, and acid number is 1.6mgKOH/g.

[synthesis example 2～12]

Except the monomer component used in polymerisation and polymerization initiator are changed to content described in table 1 with Outward, synthesizing according to the mode identical with synthesis example 1, prepared solid component concentration is the polymer solution of 30 mass %.Knot Fruit is shown in table 1.

[table 1]

[embodiment 1]

(1) modulation of adhesive composition

By (methyl) acrylic polymer solution (solid component concentration is 30 mass %) being obtained by synthesis example 1 and (methyl) acrylic polymer contained relative in this solution of 100 parts (solid constituent amounts) is 0.05 part, and (solid becomes Component) as isocyanate compound Soken Chemical & Engineering Co., Ltd. manufacture " TD-75 " (solid constituent is 75 mass %, Ethyl acetate solution), 0.14 part (solid constituent amount) as metallo-chelate Soken Chemical & Engineering Co., Ltd. manufacture " M- 12AT " (solid constituent is 10 mass %, toluene, acetylacetone,2,4-pentanedione solution), the SHIN-ETSU HANTOTAI's chemistry work as silane coupler of 0.2 part " KBM-403 " (solid constituent is 100%) and the conduct of 1 part that industry Co., Ltd. (SHIN-ETSU HANTOTAI's chemistry work (strain)) manufactures are prevented " AS-804 " (solid constituent is 100%) that Di-ichi Kogyo Seiyaku Co., Ltd.'s (the first work (strain)) of electrostatic agent manufactures Mix, obtain adhesive composition.

(2) making of bonding sheet

After froth breaking, with scraper in the upper coating of polyethylene terephthalate film (PET film) through lift-off processing by upper State the adhesive composition that (1) obtains, be dried 3 minutes at 90 DEG C, form the film that desciccator diaphragm thickness is 20 μm.At film Fit through the PET film of lift-off processing on the reverse side of the sticking veneer of above-mentioned PET film further, quiet under 23 DEG C/50%RH environment Put 7 days after curing, obtain having by the bonding sheet of the adhesive phase that the thickness clamped by 2 pieces of PET film is 20 μm.

(3) making of the polarizer with adhesive phase

After froth breaking, with scraper in the upper coating of polyethylene terephthalate film (PET film) through lift-off processing by upper State the adhesive composition that (1) obtains, be dried 3 minutes at 90 DEG C, form the piece with the film that desciccator diaphragm thickness is 20 μm. Make sheet above and polarizer (thickness: 110 μm, Rotating fields: tri acetyl cellulose film/polyvinyl alcohol film/tri acetyl cellulose Film) fit in the way of making above-mentioned film connect with polarizer, stand after within 7 days, curing under conditions of 23 DEG C/50%RH, Obtain having the polarizer with adhesive phase of PET film and adhesive phase that thickness is 20 μm and polarizer.

[embodiment 2～11, comparative example 1～2]

Except (methyl) acrylic polymer solution in embodiment 1 being changed to by gathering that synthesis example 2～12 obtains Polymer solution and by blend composition be changed to content described in table 2 beyond, obtain according to the same manner as in Example 1 The polarizer of adhesive composition, bonding sheet and band adhesive phase.

[evaluation]

[gel fraction]

The adhesive gathering about 0.1g from the bonding sheet being obtained by embodiment comparative example is placed in sample bottle, adds The ethyl acetate of 30mL after shaking 4 hours, was carried out by the content to this sample bottle for the 200 stainless steel wire nettings of purpose Filter, measures dry weight carry out the drying of 2 hours to the residue on wire netting after at 100 DEG C.Following formula is utilized to obtain bonding The gel fraction of agent.

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

[creep value]

By the polarizer with adhesive phase that obtained by embodiment comparative example (by PET film/adhesive phase/polarizer The duplexer constituting) cut into the size of wide 10mm × long 100mm, peel off the above-mentioned PET film through lift-off processing, through alkali So that above-mentioned adhesive phase connects with above-mentioned glass plate and fitting area reaches the mode of 10mm × 10mm on the glass plate processing Fit, obtain evaluation bonding processing polarizer test film.

To evaluation bonding processing polarizer test film carry out autoclave process (50 DEG C, 5 atmospheric pressure), 23 DEG C/ 24 hours are stood under 50%RH atmosphere.Then above-mentioned test film is set to fixing card in the chamber BOX of micro-creep analyzer The a length of 15mm of disc portion.With tensile load, the stretching time of 1000 seconds of 800g, along be parallel to this polarizer with above-mentioned Above-mentioned evaluation in above-mentioned test film is bonded by the composition surface between glass and the direction for the length direction of above-mentioned polarizer Processing polarizer is pullled, and measures the deviation distance (μm) of the above-mentioned glass plate of above-mentioned test film and the fitting part of polarizer As creep value.

[mensuration of bonding force]

By the polarizer with adhesive phase that obtained by embodiment comparative example (by PET film/adhesive phase/polarizer structure The duplexer becoming) cut into the size of 70mm × 25mm, prepare test film.PET film is peeled off from test film, will with laminating roll The duplexer being made up of adhesive phase/polarizer is bonded to the glass plate of 2mm with glass plate in the way of making adhesive phase connect One side on.Obtained duplexer is being adjusted to the autoclave of 50 DEG C/5 atmospheric pressure holding 20 minutes.Then, 23 DEG C/50%RH environment under place after 1 hour, along relative to the direction that glass pane surface is 90 DEG C with the speed of 300mm/ minute Polarizer end is pullled by degree, measures bonding force (peel strength).

[bending (warpage)]

By the polarizer with adhesive phase that obtained by embodiment comparative example (by PET film/adhesive phase/polarizer structure The duplexer becoming) cut into the size in 35mm × 400mm (tensile axis direction), prepare test film.PET film is shelled from test film From the duplexer being made up of adhesive phase/polarizer being bonded in the way of making adhesive phase connect with glass plate with laminating roll To the one side of the glass plate of 0.7mm, 40mm × 410mm.Obtained duplexer is being placed under 23 DEG C/50%RH environment After 24 hours, keep 72 hours in the stove of 60 DEG C.It is fixed on unilateral end on metope perpendicular to the ground, use ruler The amount tilting opposite side extremities is measured.Implement to measure after just taking out from stove and after 24 hours.

[endurancing]

By the polarizer with adhesive phase that obtained by embodiment comparative example (by PET film/adhesive phase/polarizer structure The duplexer becoming) cut into the size of 150mm × 250mm, prepare test film.PET film is peeled off from test film, uses laminating roll The duplexer being made up of adhesive phase/polarizer is bonded in the way of making adhesive phase connect with glass plate the glass of 2mm On the one side of plate.Obtained duplexer is adjusted to the autoclave of 50 DEG C/5 atmospheric pressure holding 20 minutes, prepares examination Test plate.Make 2 pieces of identical breadboards.By above-mentioned breadboard, under conditions of temperature is 80 DEG C, (heat resistance) or temperature are 60 DEG C/humidity under conditions of be 90%RH (humidity resistance) place 500 hours, according to following benchmark, foaming and fracture are entered Row is observed and evaluates.Foaming occurs under the hypodynamic occasion of cohesion, breaks at and occurs under the not enough occasion of stress relief.

(foaming)

AA: have no foaming completely.

BB: foaming area is less than overall 1%.

CC: foaming area overall more than 1% less than 5%.

DD: foaming area is overall more than 5%.

(fracture)

AA: have no fracture completely.

BB: area of fracture is less than overall 1%.

CC: area of fracture overall more than 1% less than 5%.

DD: area of fracture is overall more than 5%.

[table 2]

In table 2, the amount of peroxide type polymerization initiator calculates by the following method.By above-mentioned survival rate formula: exp (- k_dT) × 100 (%) calculate, for example in embodiment 1, and k_d=A × exp (-Δ E/RT), A=6.93 × 10¹⁷Hour^-1, Δ E= 119.1kJ/ mole, R=8.314J/ mole of K, T=353K, reaction time t=6 hour, used in above-mentioned copolymerization The amount × survival rate (%) of peroxide type polymerization initiator calculate 5 × 10^-3Mass parts.

Comparative example 1 and 2 employs (methyl) acrylic copolymer that the degree of branching is 0.59.Therefore, at gel fraction In high system (comparative example 1), bending evaluation difference (more than 5.0mm) after 24 hours, although in addition, in durability evaluation not Observe foaming, but there occurs to rupture in many places.And in the low system (comparative example 2) of gel fraction, there occurs a large amount of foaming.

Owing to the copolymer in comparative example 1 is linear polymer, presenting of cohesiveness only relies upon crosslinking agent and copolymerization The bonding of Wu Zhong functional group.Therefore, gel fraction must be set to height to maintain cohesiveness.But, gel fraction is high When, due to stress relief characteristic step-down in the system of comparative example 1, therefore observe the deterioration of bending and durability (resistance to fracture).

And in an embodiment, owing to employing the degree of branching (methyl) acrylic copolymer below 0.55, and by different Cyanate esters and metallo-chelate are simultaneously used as crosslinking agent, and the therefore bending after 24 hours is evaluated high (below 3.0mm), resistance to In long property evaluation, the generation of foaming and fracture is also within the scope of can allow for.

Produce a large amount of side chain by making polymer, increase being bonded between crosslinking agent and functional group in copolymer, utilize and prop up Change part there occurs intertexture, even if therefore also presenting cohesiveness under low gel fraction.Accordingly, because it is slow to interweave under high temperature Solve, thus bendability is good and also shows the tendency that durability improves.

Claims (9)

1. a polarizer adhesive composition, it is characterised in that contain:

(A) the monomer component copolymerization by (methyl) alkyl acrylate that the carbon number comprising alkyl is 4～18 and carboxyl group-containing monomer Obtain and utilize the degree of branching that gel permeation chromatography/multi-angle laser light scattering detector (GPC-MALS) measures 0.55 (methyl) acrylic copolymer below,

(B1) isocyanate compound and

(B2) metallo-chelate.

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

3. polarizer adhesive composition as claimed in claim 1 or 2, it is characterised in that described (methyl) acrylic compounds The weight average molecular weight (Mw) that copolymer (A) utilizes gel permeation chromatography (GPC method) to measure is 200,000～1,500,000.

4. the polarizer adhesive composition as according to any one of claims 1 to 3, it is characterised in that described (methyl) The degree of branching that acrylic copolymer (A) utilizes GPC-MALS to measure is 0.10～0.54.

5. the polarizer adhesive composition as according to any one of Claims 1 to 4, it is characterised in that described (methyl) Acrylic copolymer (A) be also with carboxyl group-containing monomer beyond the copolymer that obtains of the monomer copolymerization of polar functionalities.

6. the polarizer adhesive composition as according to any one of Claims 1 to 5, it is characterised in that peroxide Content relative to (methyl) acrylic copolymers (A) of 100 mass parts below 0.1 mass parts.

7. the polarizer adhesive composition as according to any one of claim 1～6, it is characterised in that by described polarization The gel fraction of the adhesive that piece adhesive composition is formed is 20～70 mass %.

8. a polarizer bonding sheet, it is characterised in that have and used by the polarizer according to any one of claim 1～7 The adhesive phase that adhesive composition is formed.

9. the polarizer with adhesive phase, it is characterised in that there is polarizer and at least one party at described polarizer The adhesive phase being formed by the adhesive composition of the polarizer according to any one of claim 1～7 on face.