TW201132723A - Adhesive composition for polarizing plate and polarizing plate using the same - Google Patents

Abstract

Provided is an adhesive composition for a polarizing plate with which it is possible to form an adhesive layer having excellent durability to short-term aging and light leakage prevention properties. The adhesive composition for a polarizing plate includes the following components (A) and (B): (A) 100 parts by mass of a (meth)acrylic polymer that is obtained by copolymerization of at least 1 to 10 mass% of a carboxyl group-containing monomer and that has a weight-average molecular weight between 300,000 and 1,500,000; and (B) 4 to 20 parts by mass of a tolylene diisocyanate compound having an isocyanurate structure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition for a polarizing plate, and more particularly to a polarizing agent capable of forming an adhesive layer having excellent optical properties by short-term ripening. The adhesive composition for the board, and the polarizing plate obtained using the same. [Prior Art] The liquid crystal element has a structure in which a liquid crystal material is sandwiched between two substrates, and a polarizing plate is bonded to the surface of the substrate via an adhesive layer. In recent years, liquid crystal elements have been expanded and used for vehicles, outdoor meters, computer monitors, and televisions. Therefore, the use environment is extremely strict. Since the polarizing plate has a multilayer structure of different materials, it lacks dimensional stability from the characteristics of the constituent materials. In particular, in the environment of high temperature and high humidity, the stress is concentrated by the contraction of the polarizing plate, and the birefringence of the polarizing plate is induced, and the adhesive itself is also aligned by stress concentration to generate birefringence, so stress concentration A stain (light leakage) is generated at the end to degrade the display quality. Further, in this environment, it is easy to cause problems such as foaming at the interface between the polarizing plate and the glass or peeling of the polarizing plate. Therefore, an adhesive for a polarizing plate is required to have excellent light leakage prevention and durability. Further, in order to find the above-mentioned light leakage prevention property and durability when forming an adhesive layer on a polarizing plate, it is necessary to provide a polarizing plate to apply a state of an adhesive composition, for example, it is cured by a step of aging at room temperature for one week. However, there will be problems of reduced productivity and increased stocks during the long-term ripening period. In order to solve this problem, it has been proposed to promote a hardening method by further containing a carboxyl group in a hydroxyl group-containing acrylic polymer in a mixture of a hydroxyl group-containing acrylic polymer and a-5-201132723 isocyanate crosslinking agent (Patent Document) 1). However, in this technique, the amount of the isocyanate-based crosslinking agent to be added is reduced, so that sufficient light leakage resistance and durability cannot be obtained by the aging process in a short period of time. Further, it has been disclosed that an acrylic-based polymer containing a hydroxyl group and a carboxyl group and an aliphatic or alicyclic polyisocyanate-based or trimeric isocyanate-based compound can shorten the adhesive composition for a surface protective film during curing ( Patent Document 2). However, since the amount of the carboxyl group of the acrylic-based polymer used in the adhesive composition is limited, it is not suitable for use in bonding a polarizing plate to glass. When the above-mentioned aliphatic or alicyclic polyfunctional isocyanate-based or trimeric isocyanate-based compound is added to the adhesive having 1 or more parts of the carboxyl group of the present invention, the thermal life is prone to be shortened and it is not practical. Others have disclosed an adhesive composition for an optical film in which an isocyanate compound is added to an acrylic group-containing polymer having a carboxyl group (Patent Documents 3 and 4). However, the aim of these technologies is to improve correctness and light leakage prevention, and does not consider shortening during ripening. Therefore, the adhesive compositions disclosed in these documents are not sufficiently optically compatible by short-term ripening. . [Patent Document 1] JP-A-2005-247909 (Patent Document 3) Japanese Patent Laid-Open No. Hei. No. Hei. Bulletin

S -6-201132723 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION Therefore, it is desired to form an adhesive composition for a polarizing plate which can form an adhesive layer having excellent durability and light leakage resistance by aging for a short period of time. An object of the present invention is to provide an adhesive composition for such a polarizing plate. Solution to Problem In order to solve the above problems, the inventors of the present invention have intensively reviewed and found that a methylenediphenyl diisocyanate compound having a trimeric isocyanate structure is used as a crosslinking agent, and it has a carboxyl group with respect to a molecular weight having a specific range. When the amount of the acrylic-based polymer added is large, the adhesive layer having excellent durability and light leakage resistance can be formed even in a short period of time, and the present invention has been completed. That is, the present invention is characterized in that the following components (A) and (B) (A) have a weight average molecular weight of from 1 to 1% by mass of a monomer having at least a carboxyl group of from 300,000 to 1,500,000 ( Methyl)acrylic-based polymer 1 part by mass (B) The adhesive composition for polarizing plates of 4 to 20 parts by mass of a methylenediphenyl diisocyanate compound having a trimeric isocyanate structure. Further, in the present invention, a polarizing plate obtained by providing an adhesive layer formed of the above-mentioned adhesive composition for a polarizing plate is provided on at least one surface of the polarizing film. EFFECT OF THE INVENTION 201132723 By using the adhesive composition of the present invention, the polarizing plate can effectively prevent light leakage even under high temperature and high humidity conditions, and has excellent durability, and can suppress foaming and peeling of the adhesive layer. In addition, the hardening speed is faster, and the ripening period can be greatly shortened, so that the productivity can be significantly improved and the inventory can be reduced. MODE FOR CARRYING OUT THE INVENTION The component (A) used in the adhesive composition for a polarizing plate of the present invention is obtained by copolymerizing at least a monomer having a carboxyl group. The above carboxyl group-containing monomer such as (meth)acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Itaconic acid, crotonic acid, maleic acid, fumaric acid, and maleic anhydride. The content of the monomer having a carboxyl group is from 1 to 10% by mass (hereinafter referred to as "%"), preferably from 2 to 8%, more preferably the total of the constituent monomers of the component (A) acrylic-based polymer. 2 to 6%. When it is less than 1%, it will not be easy to obtain cohesive force. When it is more than 10%, the cohesive force will be too high and the adhesion will be improved. Component (A) Other constituent monomers of the acrylic-based polymer, such as alkyl (meth)acrylate, monomer having a hydroxyl group, a monomer containing a benzene ring, an alkoxy (meth)acrylate, and an amine a monomer, a monomer containing a guanamine, and the like. The above alkyl (meth)acrylate is preferably one having a carbon number of 1 to 12.

S -8- 201132723 A branchable alkyl group, such as, for example, 'methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (A) Acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (methyl) Acrylate, octyl (meth) acrylate, mercapto (meth) acrylate, mercapto (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate. Among these, the use of butyl acrylate or methacrylate makes it possible to have a good balance of adhesion and durability. The content of the (meth)acrylic acid alkyl ester is from 10 to 99%, preferably from 50 to 98.5%, based on the total of the constituent monomers of the component (A) acrylic polymer. When the amount is less than 10%, the adhesion and durability will not be balanced, and when it is more than 99%, the durability will be deteriorated. The above hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate ' 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy butyl ( Methyl) acrylate, 6-hydroxyhexyl (meth) acrylate, 1,4-cyclohexane dimethanol mono (meth) acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono ( Methyl) acrylate, allyl alcohol, etc., can further increase the gel fraction by copolymerizing such a hydroxyl group-containing monomer. Among these, it is preferred to use 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate to have good copolymerization with alkyl (meth) acrylate. The content of the hydroxyl group-containing monomer is from 〇 to 1%, preferably from 0.05 to 1%, based on the entire constituent monomers of the component (A) acrylic-based polymer. When it is more than 1%, the gel fraction is too high and the joint property is lowered. Under high temperature and high humidity, 201132723 may cause peeling. The above benzene ring-containing monomer has orthogonal solid birefringence, so that birefringence of the (meth)acryl-based polymer can be reduced by copolymerization. Specifically, for example, phenyl acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenoxy diethylene glycol (meth) acrylate, ethylene oxide modified oxime Phenolic (meth) acrylate, hydroxyethylated naphthol acrylate, biphenyl (meth) acrylate, styrene, vinyl toluene, 0!-methyl styrene, and the like. Among these, benzyl acrylate and phenoxyethyl acrylate are preferably used because they have good compatibility with the alkyl (meth) acrylate and the copolymerization property does not lower the transparency. The content of the monomer containing a benzene ring is from 〇 to 40%, preferably from 0 to 30%, based on the entire constituent monomers of the component (A) acrylic-based polymer. More than 40% will not give proper adhesion. The above (meth)acrylic acid alkoxy esters such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate And 3-methoxypropyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and the like. The content of the alkoxylate (meth)acrylate is from 〇 to 90%, preferably from 0 to 80%, based on the total of the constituent monomers of the component (A) acrylic-based polymer. The above-mentioned monomer having an amine group is, for example, dimethylaminoethyl (meth)acrylate or diethylamino(meth)acrylate. The above-mentioned monomer containing a guanamine is, for example, (meth) acrylamide, (meth) N-methylol acrylamide or the like. The amount of the monomer containing the amine group and the monomer containing the guanamine group is relative to the composition of the component (A) acrylic polymer.

S -10- 201132723 The total amount of monomers is up to 1%. The component (Α) of the present invention can be obtained by polymerizing a mixture of the above monomer components by a previously known polymerization method such as a solution polymerization method, a bulk polymerization method, an emulsion polymerization method or a suspension polymerization method. Among these, it is preferably produced by a solution polymerization method or a bulk polymerization method which does not contain a polymerization stabilizer such as an emulsifier or a suspending agent. The weight average molecular weight (Mw) of the component (Α) obtained above is from 300,000 to 1,500,000, preferably from 400,000 to 1,200,000. When the weight average molecular weight is less than 300,000, the durability is deteriorated. When it is more than 1.5 million, the viscosity is increased and it is not easy to handle. Further, the weight average molecular weight in the present specification means the enthalpy obtained by the measurement method described in the examples. Further, the glass transition temperature of the acrylic-based polymer of the component (A) is preferably 〇 ° C or lower, more preferably -2 0 ° C or lower, and particularly preferably -8 0 to -3 0 ° C. When the glass transition temperature is higher than 〇 ° C, the adhesion of the resulting adhesive to the substrate or the flexibility of the adhesive layer is lowered, and peeling or floating occurs from the substrate. Further, the glass transition temperature in this specification is calculated by the following FOX formula. (FOX type) l/Tg = Wa/Tga + Wb/Tgb + ··· T g : glass transition temperature of copolymer

Tga, Tgb, ...: glass transition temperature of homopolymer of monomer a, monomer b, ...

Wa, Wb, ...: weight fraction of monomer a, monomer b, ... The component (B) used in the present invention has a trimeric isocyanate structure of methyl-11 - 201132723 phenyl diisocyanate compound also contains 'a Various modifications of the compound containing a trimeric isocyanate ring in the structure formed by the polymerization of phenyldiisocyanate 3 are carried out. The compound of the component (B) can be obtained by the method described in JP-A-H08-193114, International Publication No. 2006/137767, and the like, and the compound corresponding to the component (B) such as the listed Koloa 342. , Koloa 2 03 0 (all manufactured by Japan Polyurethane Industrial Co., Ltd.) and the like. In the adhesive composition for a polarizing plate of the present invention, the component (B) is added in an amount of 4 to 20 parts, preferably 6 to 15 parts, per 100 parts by mass of the component (A) (hereinafter referred to as "parts"). . Less than 4 parts will result in poor light leakage performance, and more than 20 parts will make the cohesive force higher. Further, in the adhesive composition for a polarizing plate of the present invention, a crosslinking agent other than the above component (B) (ingredient (C)) can be used. Such a crosslinking agent is, for example, a methyl diisocyanate crosslinking agent (except for a trimeric isocyanate structure), an epoxy crosslinking agent, or an anthracycline crosslinking agent, and one or two of them can be used. More than one species. The above-mentioned methylphenyl diisocyanate crosslinking agent (except for a structure having a trimeric isocyanate structure) such as methylphenyl diisocyanate and the isocyanate obtained by addition reaction with a polyvalent alcohol such as dimethylolpropane or pentaerythritol a compound 'titrated compound, or an amino carbamic acid obtained by addition reaction with a known polyether polyol or polyester polyol, allyl polyol, polybutadiene polyol, polyisoprene polyol, etc. A derivative such as an ester prepolymer type isocyanate compound. By using such a methylphenyl diisocyanate crosslinking agent (except for a material having a trimeric isocyanate structure), adhesion to a substrate can be improved, and peeling or the like can be suppressed. Methyl phenyl diisocyanate

S -12- 201132723 Ester, trimethylolpropane methyl phenyl diisocyanate, etc. In the adhesive composition for a polarizing plate of the present invention, the methyl phenyl diisocyanate crosslinking agent (except for the structure having a trimeric isocyanate structure) is preferably added in an amount of 1 in relation to the component (B). : 3 to 3 : 1. When the addition ratio exceeds the range, it takes a long period of time to mature, and peeling occurs under high temperature and high humidity. The above epoxy crosslinking agent such as bisphenol A epichlorohydrin type epoxy resin, ethyl diglycidyl ether 'polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diamine glycidylamine, N,N,N',N'-tetraglycidyl a compound having two or more epoxy groups in a molecule such as -m-xylylenediamine or 1,3-bis(N,N'-diamine glycidylaminomethyl)cyclohexane. The gel fraction can be further increased by using these epoxy-based crosslinking agents. Among these, N,N,N',N'-tetraglycidyl-m-extended xylylenediamine, anthracene, 3-bis(N,N'-diamine glycidylaminomethyl) Cyclohexane is preferred. In the adhesive composition for a polarizing plate of the present invention, the epoxy crosslinking agent is added in an amount of from 0 to 1%, preferably from 0.05 to 0.5%, based on the component (B). When the amount of addition exceeds this range, it takes a long period of time to mature, and peeling occurs under high temperature and high humidity. The above-mentioned anthracycline-based crosslinking agent is, for example, 1,1'-(methyl-di-P-phenylene)bis-3,3-azacyclopropyl urea, 〗 〖; Methyl)bis-3,3-azetidyl urea, 2,4,6-triazacyclopropenyl-1,3,5-triazine, trimethylolpropane-tri-(2-nitrogen Heterocyclic propionate) and the like. The gel fraction can be further increased by the use of such a guanidinium-propane-crosslinking-13-201132723. In the adhesive composition for a polarizing plate of the present invention, the anthracycline crosslinking agent is added in an amount of from 0 to 1%, preferably from 0.05 to 0.5%, based on the component (B). When the amount of addition exceeds this range, the ripening period is prolonged, and peeling or the like occurs under high temperature and high humidity. The adhesive composition for a polarizing plate of the present invention is preferably a decane coupling agent (D) having a group reactive with a carboxyl group contained in the acrylic polymer of the component (A). By using this, the adhesive can be firmly bonded to the glass to prevent peeling in a hot and humid environment. Specifically, for example, 3-glycidoxypropyltrimethoxydecane, 3·glycidoxypropyltriethoxydecane, 3-glycidoxypropylmethyldiethoxydecane, 2- An epoxy group-containing decane coupling agent such as (3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-aminopropyltrimethoxydecane, N-2 (aminoethyl) 3-amine An amine group-containing decane coupling agent such as propyltrimethoxydecane or the like. In the adhesive composition for a polarizing plate of the present invention, the amount of the decane coupling agent (D) to be added is 0.05 to 1 part, preferably 0.1 to 0.5 part, per 100 parts of the component (A). When the amount is less than 0.05 parts, peeling tends to occur in a hot and humid environment. When more than one part, the decane coupling agent overflows in a high temperature environment, and conversely, peeling is liable to occur. The adhesive composition for a polarizing plate of the present invention is prepared by adding the above components (A), (B) and, if necessary, the components (C), (D) or any other components, and mixing them according to a usual method. . Any component such as an antioxidant, an ultraviolet absorber, a plasticizer, an antistatic agent or the like can be used, and these can be added without departing from the effects of the present invention.

S-14-201132723 The adhesive sheet for a polarizing plate of the present invention obtained from the obtained adhesive composition for a polarizing plate is applied to the support at least one side by a usual method, and dried and cooked. Formed as an adhesive layer. Drying is generally carried out at 80 to 110 ° C for 2 to 10 minutes. Moreover, the adhesive composition of the present invention can greatly shorten the ripening period compared with the prior art, for example, it can be sufficiently cured by aging 1 to 3 angels under conditions of 23 ° C and 50% RH, and has good adhesion and An optically compatible adhesive layer. The gel fraction of the adhesive layer after the ripening is preferably from 60 to 90%, more preferably from 65 to 85%. Beyond this range, the durability is deteriorated and peeled off. Further, the gel fraction in the present specification means the enthalpy obtained by the measurement method described in the examples. The support used may be a polyester film having a surface treated with a release treatment. The thickness of the adhesive layer is generally from 10 to 30 μm, preferably from 15 to 25 μm. Further, the polarizing plate of the present invention can be obtained by providing an adhesive layer formed of the above-mentioned adhesive composition for a polarizing plate on at least one surface of a polarizing film. The thickness of the adhesive layer disposed on the polarizing film is generally 10 to 30 / zm, preferably 15 to 25 μm. When the adhesive layer is provided on the polarizing film, the adhesive composition may be applied to the polarizing film, dried, matured, or the coating film dried after being applied to the support may be attached to the polarizing film, and then matured. The conditions for formation, drying, ripening, and gel fraction are as described above. Further, the polarizing film used in the present invention may be a layer having another function of lamination, and specifically includes an elliptically polarizing film, a retardation film, and the like. The liquid crystal element was produced by disposing the polarizing plate of the present invention obtained above on the surface of the substrate of the liquid crystal cell. The -15-201132723 type of the liquid crystal element using the polarizing plate of the present invention is not particularly limited, and may be of the TN type, the VA type, or the IPS type. This liquid crystal element is a liquid crystal display device which is configured to leak light by a member such as a backlight. The adhesive composition for a polarizing plate of the present invention can be formed by shortly forming an adhesive having excellent light leakage preventing property and durability. That is, an excessive amount of an isocyanate compound added from the adhesive is a polyurea derived from an isononate compound. The polyurea will physically bind to the entanglement of the binder and hold the same general structure. However, it is inferred that the phenyl ester compound having a trimeric isocyanate structure will also have a mesh structure due to the same entanglement. The polyurea having a trimeric isocyanate structure of methyl phenyl diisocyanate can have high elasticity and control birefringence, so availability, and reactivity of the methyl phenyl diisomer having a trimeric isocyanate structure It is higher than other isocyanate-based compounds, and it can be expected to be greatly shortened by the formation reaction of polyurea. [Embodiment] Hereinafter, the present invention will be described in more detail by way of examples, but the examples are as follows. Acrylic-based polymer: When the butyl acrylate is 97 parts by mass, the acrylic acid 3 or the OCB type, and the reason for producing the mature layer during the reduction period, the woven diisocyanate of the main polymer of the agent is formed. . Because of the good anti-leakage cyanate esterification by the ester compound, the crosslinking reaction period is accelerated. Non-limited parts of the invention, acetic acid

S -16-201132723 100 parts by mass of ethyl ester and 0.04 parts by mass of n-dodecyl mercaptan (NDM) were placed in a flask equipped with a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux cooling tube. The contents of the flask were heated to 60. (:. Under agitation, a polymerization initiator azobisisobutyronitrile (AIBN) O mass part which is sufficiently substituted by nitrogen is added to the flask, and the temperature of the contents in the flask is maintained at 60 ° C for 10 hours by heating and cooling. Finally, ethyl acetate 1 〇〇 part of 'acrylic-based polymer A1 solution was added. The weight average molecular weight (Mw) of the acrylic acid-based polymer A1 was measured by the following GPC measurement conditions, and the number average molecular weight (Μη) 'Required dispersion (Mw/Mn). The non-volatile content (ηV) and viscosity were measured by the following method. The measurement results 倂 monomer composition is shown in Table i. <GPC measurement conditions> :HLC-8120GPC (manufactured by Tosoh Corporation) GPC column structure: The following five columns (all manufactured by Tosoh Corporation) (1) TSK-GEL HXL-H (standby column)

(2) TSK-GEL G7000HXL

(3) TSK-GEL GMHXL

(4) TSK-GEL GMHXL

(5) TSK-GEL G2500HXL

Sample concentration. Diluted to four gas 咲 为 〇 / mg / cm 3 mobile phase solvent: tetrahydrofuran flow: 1 m 1 / mi η column temperature: 40 ° C • 17- 201132723 < method for determination of non-volatile components > 1 g of the acrylic-based copolymer solution was placed in a rectangular dish (nl) after the weigh scale, and the amount was measured (n2), and then heated at 105 ° C for 3 hours. Thereafter, the rectangular plate was placed in a dry box at room temperature for 1 hour, and the total weight after heating (n3) was measured again. The nonvolatile matter was calculated from the following formula using the obtained weight measurement 値 (η 1 to η 3 ). Nonvolatile content (%) = 100 χ [weight after heating (n3-nl) / weight before heating (n2-nl)] <Method for measuring viscosity> Measured at room temperature using a Β-type viscometer. Production Examples 2 to 6 Except for the monomer composition shown in Table 1, the same production example! The acrylic acid-based polymer Α2 to Α6 was obtained. The Mw, Μ, nonvolatile content, and viscosity of the polymer were measured in the same manner as in the production example, and the results are shown in Table 1. Comparative Production Examples 1 to 4 In addition to the monomer composition changes shown in Table 1, the acrylic acid-based polymers B1 to Β4 solutions were obtained in the same manner as in the production examples. The Mw 不η nonvolatile component and viscosity of the polymer were measured in the same manner as in the production example, and the results are shown in Table 。.

S -18- 201132723 [Table 1] Comparison of manufacturing examples · Construction example 1 2 3 4 5 6 1 2 3 4 BA 97.0 96.8 96.5 94 91.8 68.7 96.8 87.8 99.3 95 AA 3 3 3 5.5 8 3 3 12 0.5 3 Monomer Composition HEA 0 0.2 0,5 0.5 0.2 0.2 0.2 0.2 0.2 2 2 BzA POA MEA 0.1 nV (%) 32.0 31.5 33.0 32.0 31.8 33.7 32.8 30.9 30.9 31.6 Vis (Pa· s) 8.3 8.5 8.7 8.9 10.3 3.2 1.9 14.5 6.4 8,9 (10,000) 51.5 50.8 49.8 51.2 50.0 50.3 22.1 49.7 50.4 50.9 Mw/Mr 1 3.0 2.9 3.1 3.2 2.3 2.2 2.7 2.8 2.8 2.6 The symbols in the table refer to the following. BA : butyl acrylate AA : acrylic acid HE A : 2-carboxyethyl acrylate B z A : benzyl acrylate P 〇 A: phenoxyethyl acrylate MEA: acrylic acid methoxyethyl ester example 1 Make a polarizing plate with an adhesive layer. (Preparation of the adhesive composition) Methylphenylene diisocyanate (TDI) was added to 100 parts by mass of the acrylic acid-based polymer A1 (solid content) of the acrylic-based polymer A1 solution obtained in Production Example 1. 5 parts by mass of a carboxylate modified product of Kolona 342 (manufactured by Nippon Polyurethane Co., Ltd.) and KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) for a sand compound coupling agent, 2 parts by mass, Admixed with the adhesive composition. (Preparation of polarizing plate) -19- 201132723 After defoaming, it was applied to the peeled polyester resin using a doctor blade, followed by drying at 90 ° C for 3 minutes. After drying, it was applied to a polarizing plate, and then it was aged at room temperature of 23 ° C and a humidity of 50% to obtain a polarizing plate having an adhesive layer. The ripening period is 1 day, 3 days, and 7 days. Examples 2 to 12 In the same manner as in the Example 2 except that the acrylic-based polymer and the crosslinking agent were changed as shown in Table 2, an adhesive composition was obtained. Further, the obtained adhesive composition was used. A polarizing plate having an adhesive layer was produced in the same manner as in Example 1. Comparative Examples 1 to 1 1 An adhesive composition was obtained in the same manner as in Example 1 except that the acrylic-based polymer and the crosslinking agent were changed as shown in Table 3. Further, using the obtained adhesive composition, a polarizing plate having an adhesive layer was prepared as in Example 1. Test Example 1 The polarizing plates obtained in Examples 1 to 12 and Comparative Examples 1 to 1 were evaluated by the following methods, and cooked. The period is durability and light leakage prevention for one day and seven days. These results are shown in Tables 2 and 3. <Evaluation Method of Durability> After the polarizing plate having the adhesive layer was cut into a size of 150 mm x 250 mm, it was attached to one side of the glass plate using a laminating roll, and then stored in an autoclave adjusted to 5 (TC, 5 atmosphere). 20 minutes, make a test board. Make the same

After the conditions of S -20- 201132723, the two test plates were placed at a temperature of 60 ° C, humidity of 95% RH (heat-resistant humidity) and temperature of 85 ° C (heat resistance) 500 small visual observation Whether peeling or the like occurs is evaluated on the basis of the following criteria. (reference) 〇: No foaming, peeling, cracking △: slight foaming, peeling, cracking X: comprehensive foaming, peeling, cracking < evaluation method of light leakage prevention> U model: 5 0 ° C, 5 test plate case, and then use the laminating roller to directly cross the Nicole position to adhere the polarizer plate of 2 primer layers to the 19-inch white TN monitor g BenQ FP93VW) On the inside of the table, the second is stored in a pressure cooker adjusted to air pressure for 20 minutes to prepare a test plate. The film was placed at 7 ° C for 500 hours to visually observe light leakage and evaluated on the basis of the following criteria. (reference) 〇: no light leakage △: partial light leakage X: comprehensive light leakage-21 - 201132723 [Table 2] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Acrylic-based polymer Α1 Α1 Α2 Α2 Α2 Α2 Α2 Α2 A3 Α4 Α5 Α6 L-45 - - - - - 4 8 — One• One-one Koloa 342 5 8 8 16 - 8 4 8 8 8 8 8 Koloa 2〇3〇 Koloa – 8 — — A — — — TD-75 — A _ _ One E-5XM One 0.02 _ - One one Toki-ΪΟΟ ΚΒΜ-403 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0-2 0.2 0.2 Heat resistance (heating 1 day π day) 0/0 0/0 〇/〇0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 Heat resistance (cooked into 1曰/7Β) 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0 /0 0/0 0/0 0/0 0/0 Light leakage (cooked old / 7Β) Δ/Ο 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/0 0/ 0 0/0 0/0 The code number in the table refers to the following. L·-45 : TDI isocyanuric acid vinegar (manufactured by Kyoritsu Chemical Co., Ltd.) Koloa 3 4 2 : TDI-based trimeric isocyanate modified product (made by Japan Polyurethane Co., Ltd.) Koloa 2 〇 3 〇: TDI isocyanuric acid ester (made by Japan Polyurethane Co., Ltd.) Koloa 2 0 4 1 : Polyme MDI (made by Japan Polyurethane Co., Ltd.) TD-7 5 : XDI system E- 5 X Μ : Epoxy-based cross-linking agent (manufactured by Kyoei Chemical Co., Ltd.) Tirana TPA - 1 0 0 : HD^ Trimeric isocyanuric acid (made by Asahi Kasei Corporation) « BM - 4 0 3· brothel coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) -22- 201132723 [Table 3] Comparative Example Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Acrylic based polymer 1 A2 A2 A2 A2 A2 A2 A2 B1 Θ2 B3 B4 U-45 8 - — One 8 One — One Koloa 3« - One - 2 24 2 8 8 B 8 Kolo That 2030 - - one one Kolo that 2041 - one eight one one TD-75 one one eight eight - one _ one one one _ E-5XM - - _ _ Tono TPA-100 ' ~ - — - - - - KBM-403 0.2 0,2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Heat resistance (cooked curry) + 1 〇/〇*1 Δ/Δ 0/0 0/0 χ/Δ 0/0 Λ/Δ 0/0 Moisture and heat resistance (cooked into 1曰卿*1 x/〇*1 *1 Δ/〇X/ X x/O 0/0 X / X 0/0 X /X Light leakage (cooked into 1曰/ 7曰〉 *1 X/O *1 *1 X/X 0/0 x/OX/X 0/0 X/X 0/0 *1 Gelation cannot be applied Test Example 2 Evaluation by the following method The adhesion of the polarizing plate having the adhesive layer after 1 day, 3 days, and 7 days after the aging of Examples 1 to 12 and Comparative Examples 1 to 1 was evaluated by the following methods from Examples 1 to 2 2 And the gel fraction of the adhesive layer formed by the adhesive composition obtained in Comparative Examples 1 to 1 after 1 day, 3 days, and 7 days of aging, and the results are shown in Table 4. <Measurement of Adhesion Method> A polarizing plate having an adhesive layer was cut into a size of 70 mm x 25 mm to prepare a test piece. After peeling off the polyester film from the test piece, it was laminated on one side of the glass plate using a laminating roll, and stored in an autoclave adjusted to 50 ° C and 5 atmospheres for 20 -23 - 201132723 minutes. Next, it was placed in an environment of 2 3 ° C and 50% RH for 1 hour, and then stretched at a speed of 300 mm/min in a direction of 90 ° C to measure the peel strength. <Method for Measuring Gel Fraction> The obtained adhesive composition was applied onto the surface of the peeled polyester after drying to a thickness of 2 Ο μ m, and the other surface was adhered and peeled off after drying. The polyester film was aged at 23 ° C and 50% RH for 1 day, 3 days, and 7 days to prepare test pieces. The test piece was placed in the sample vial with an adhesive of about o.lg. After shaking for 30 hours with ethyl acetate 30 cc, the contents of the sample vial were filtered through a 200 mesh stainless steel gold mesh to dry the residue on the gold mesh. After 2 hours, the dry weight was measured and found by the following formula. Gel fraction (%) = (dry weight / weight of adhesive taken) χ 100

S -24- 201132723 [Table 4] Adhesion (N/25mm) Na (%) 1 day 3 days 7 days 1 day 3 days 7 days Example 1 12.0 12.5 12.5 75 76 80 Example 2 11.5 12.0 12.5 80 81 85 Example 3 11.0 11.5 11.0 86 85 85 Example 4 8.0 7.0 6.0 90 90 90 Example 5 2.5 2.0 2.0 93 93 93 Example 6 7.5 7.4 7.5 85 85 85 Example 7 8.5 9.0 9.5 79 80 82 Example 8 11.0 11.5 11.0 86 85 86 Example 9 10.5 11.0 10.5 87 87 87 Example 10 11.2 11.5 10.9 89 90 90 Yellow Example 11 10.0 10.0 10.0 83 83 83 Example 12 10.7 11.7 10.2 86 85 83 Comparative Example 1·* - - - - - - Comparative Example 2 16.7 13.8 10.5 80 88 90 Comparative Example 3·2 - One 96 96 98 Comparative Example - One - One - Comparative Example 5 8.2 9.3 8.0 80 77 78 Comparative Example 6 6.6 6.8 6.5 91 90 90 Comparative Example 7 15Ό 12.0 10.5 78 82 85 Comparative Example 8 13.2 13.8 13.7 65 65 65 Comparative Example 9 4.0 4.2 4.2 90 91 91 Comparative Example 10 13.0 14.0 14.0 65 66 69 Comparison Side 1 3.0 3.5 3.5 95 96 96 <<2 Gel The coating was not able to be coated, and the polarizing plates of Comparative Examples 1 to 1 were not mature enough after being aged for 1 day at normal temperature. Anti-light leakage and durability, Examples 1 to 2 can achieve good light leakage resistance and durability after 1 day of ripening, and the adhesion and gel fraction can be stabilized even after ripening for 1 day. Maintain these performances. INDUSTRIAL APPLICABILITY The adhesive composition of the present invention can be formed by short-term aging. 'Energy-25-201132723 Effectively preventing light leakage and having excellent durability, and suppressing adhesion of foaming or peeling under high temperature and high humidity conditions Agent layer. Therefore, the article is suitable for use as an adhesive composition for a polarizing plate.

S -26-

Claims (1)

201132723 VII. Patent application scope: 1. An adhesive composition for a polarizing plate, which is characterized by containing the following components (A) and (B) (A) copolymerizing at least 1% by mass of a monomer having at least a carboxyl group The obtained (meth)acryl-based polymer having a weight average molecular weight of 300,000 to 1,500,000 parts by mass (B) is 4 to 20 parts by mass of a methylphenylene diisocyanate compound having a trimeric isocyanate structure. 2. The adhesive composition for a polarizing plate according to item 1 of the patent application, wherein the component (A) is obtained by copolymerization with a hydroxyl group-containing (meth)acrylic monomer 〇.〇5 to 1% by mass. By. 3. The adhesive composition for a polarizing plate according to the first aspect of the patent application, which further comprises a component (C) methyl phenyl diisocyanate crosslinking agent (except for a trimeric isocyanate structure), epoxy bonding One or two or more kinds of crosslinking agents selected from the group consisting of a crosslinking agent and an anthracycline-based crosslinking agent. 4. The adhesive composition for a polarizing plate according to any one of claims 1 to 3, which further comprises a component (D) decane coupling agent. 5. An adhesive sheet for a polarizing plate, which is formed by providing an adhesive layer formed of an adhesive composition for a polarizing plate of the first application of Patent Application No. 1 on at least one side of the support. A polarizing plate comprising an adhesive layer formed of an adhesive composition for a polarizing plate of the first application of Patent Application No. 1 on at least one side of a polarizing film. 7. A method of manufacturing a liquid crystal cell, characterized in that a liquid crystal cell is provided on a surface of a substrate -27-201132723, and at least one surface of the polarizing film is provided with the following components (A) and (B): (A) A (meth)acrylic polymer having a weight average molecular weight of from 1 to 1% by mass of a monomer having at least a carboxyl group of from 300 to 1,500,000 parts by mass (B) having three A polarizing plate obtained from an adhesive layer formed of an adhesive composition of 4 to 20 parts by mass of a polyphenylene diisocyanate compound having a polyisocyanate structure. 8. A method for reducing light leakage of a liquid crystal display device, characterized in that a substrate surface of the liquid crystal cell is provided, and at least one surface of the polarizing film is provided with the following components (A) and (B): (A) a (meth)acrylic-based polymer having a weight average molecular weight of from 1 to 10% by mass of a monomer having at least a carboxyl group of from 300,000 to 1,500,000 parts by weight (B) having a trimeric isocyanate structure A polarizing plate obtained by forming an adhesive layer of 4 to 20 parts by mass of an adhesive composition of a phenyl diisocyanate compound" S -28- 201132723 4: Representative drawings: (1) The designated representative circle of the case is: none (two The symbol of the symbol of this representative circle is simple: no 201132723 If there is a chemical formula in the case of this case, please reveal the chemical formula that best shows the characteristics of the invention: no S -4-