TWI510582B - Adhesive composition and optical member using the same - Google Patents

Description

Adhesive composition and optical member using the same Field of invention

The present invention relates to an adhesive composition and an optical member using the same. More specifically, the present invention relates to an adhesive composition excellent in heat resistance and flexibility and an optical member using the same.

Background of the invention

Recently, the use of flat panel displays (FPDs) such as liquid crystal display devices (LCDs), plasma display panels (PDPs), and organic EL devices is expanding. Along with this, the adhesive used in the FPD is required to improve the durability of the adhesive. Further, when the adhesive is used in an LCD, it is also required to prevent leakage characteristics due to shrinkage of the polarizing plate.

Patent Document 1 discloses an adhesive composition comprising: a copolymerization composition comprising an alkyl acrylate monomer as a main component and an ethylenically unsaturated monomer capable of reacting with an isocyanate group; and an isocyanate group-containing composition A carbodiimide compound. According to the above Patent Document 1, the ethylenically unsaturated monomer capable of reacting with an isocyanate group is described, and based on the copolymer composition, (I) 2 to 6 wt% of a hydroxyalkyl (meth)acrylate And (II) 0.5 to 1% by weight of a carboxyl group-containing monomer. The adhesive composition of the above-mentioned Patent Document 1 is suitable for adhering inorganic materials such as glass, ceramics, floor tiles, etc., because of high crosslinking speed, high cohesive force and strong adhesion force, and has a cohesive force to start rapidly and in a normal state. It has excellent adhesion, water resistance, and moisture resistance, and does not cause heat resistance of expansion and floating at high temperatures, and has no advantage of causing residual paste when peeled off from the adherend.

Prior technical literature Patent literature

[Patent Document 1] Japanese Patent No. 4067173

However, the adhesive layer formed of the adhesive composition described in Patent Document 1 has a problem of poor light leakage resistance and durability such as defects such as peeling over time, particularly when used in a polarizing plate.

The present invention has been made in view of the above circumstances, and an adhesive composition capable of forming an adhesive layer excellent in light leakage resistance and durability is provided.

In order to solve the above problems, the inventors of the present invention conducted intensive studies. As a result, it has been found that an adhesive composition containing a (meth)acrylic copolymer having a specific composition and a carbodiimide-based crosslinking agent can exhibit excellent light leakage resistance and durability, and is completed. this invention.

That is, the present invention is an adhesive composition containing 100 parts by mass of a (meth)acrylic copolymer and 0.05 to 5 parts by mass of a carbodiimide crosslinking agent, and the (meth)acrylic acid The copolymer is composed of 0 to 9 parts by mass of a carboxyl group-containing monomer, 0 to 1.8 parts by mass of a hydroxyl group-containing (meth)acrylic monomer, and 99.9 to 89.2 parts by mass of a (meth) acrylate monomer. (However, the total amount of the carboxyl group-containing monomer and the hydroxyl group-containing (meth)acrylic monomer is not 0 parts by mass), and the weight average molecular weight is 1,000,000 to 2,000,000.

The adhesive composition of the present invention has excellent flexibility and durability. Therefore, the adhesive layer formed of the adhesive composition of the present invention has excellent light leakage resistance because it has flexibility in shrinkage of the polarizing plate which can follow the lapse of time. In addition to this, the adhesive composition of the present invention has excellent durability, and the expansion and floating of the adhesive layer due to heat treatment and high-humidity treatment hardly occur.

Form for implementing the invention

The present invention is an adhesive composition comprising 100 parts by mass of a (meth)acrylic copolymer and 0.05 to 5 parts by mass of a carbodiimide crosslinking agent, the (meth)acrylic copolymer It is composed of 0 to 9 parts by mass of a carboxyl group-containing monomer, 0 to 1.8 parts by mass of a hydroxyl group-containing (meth)acrylic monomer, and 99.9 to 89.2 parts by mass of a (meth)acrylic acid ester monomer (but The total amount of the carboxyl group-containing monomer and the hydroxyl group-containing (meth)acrylic monomer may not be 0 parts by mass), and the weight average molecular weight is from 1,000,000 to 2,000,000. The present invention is characterized in that the amount of the hydroxyl group-containing (meth)acrylic monomer constituting the (meth)acrylic copolymer is 1.8% by mass or less based on the total amount of the monomers of the copolymer. By controlling the amount of the hydroxyl group-containing (meth)acrylic monomer, it is possible to impart flexibility to the adhesive layer which can follow the shrinkage of the polarizing plate, and to impart excellent light leakage resistance and durability to the adhesive layer. Sex. Further, the present invention is characterized in that a carbodiimide crosslinking agent is used as a crosslinking agent. Thereby, the (meth)acrylic copolymer can be crosslinked in a linear and appropriate degree of crosslinking, and the adhesive layer can be provided with flexibility and durability of shrinkage of the polarizing plate which can follow the temporality. The joint structure is capable of imparting excellent light leakage resistance to the adhesive layer. Therefore, the adhesive layer formed using the adhesive composition of the present invention can exhibit excellent light leakage resistance as an adhesive for optical members. In addition, since the adhesive layer formed using the adhesive composition of the present invention has excellent durability, the expansion and floating of the adhesive layer due to heat treatment and high-humidity treatment hardly occur.

Hereinafter, each component of the adhesive composition of the present invention will be described in detail. Further, in the present specification, the term "(meth)acrylate" is a generic term for acrylate and methacrylate. Similarly, a (meth)-containing compound such as (meth)acrylic acid is a generic term for a compound having a "methyl group" in the name and a compound having no "methyl group".

(A) (meth)acrylic copolymer

The (meth)acrylic copolymer (hereinafter also referred to simply as "component (A)") used in the present invention is composed of 0 to 9 parts by mass of (a-1) carboxyl group-containing monomer, 0 to 1.8. (a-2) a hydroxyl group-containing (meth)acrylic monomer and 99.9 to 89.2 parts by mass of (a-3) (meth) acrylate monomer (but a carboxyl group-containing monomer and The total amount of the (meth)acrylic monomer of the hydroxyl group may not be 0 parts by mass). Further, the (meth)acrylic copolymer has a weight average molecular weight of 1,000,000 to 2,000,000.

(a-1) a monomer having a carboxyl group

The carboxyl group-containing monomer of the present invention (hereinafter also referred to as "component (a-1)") is an unsaturated monomer having at least one carboxyl group in the molecule. Specific examples of the carboxyl group-containing monomer are not limited to the following, and examples thereof include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, and croton. Acid, itaconic acid, itaconic anhydride, myristoleic acid, palmitoleic acid and oleic acid. These may be used alone or in combination of two or more.

Among these, (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, crotonic acid, itaconic acid, and itaconic anhydride are preferred. (Meth)acrylic acid is more preferred.

In the present invention, the amount of the carboxyl group-containing monomer is 0 to 9 parts by mass, preferably 0.1 to 8 parts by mass, more preferably 0.2 to 5 parts by mass. When the amount used is more than 9 parts by mass, since the carboxyl group in the copolymer (A) becomes excessive, the crosslinking point obtained by reacting the carboxyl group with the carbodiimide crosslinking agent (B) becomes excessive, resulting in the present invention. The adhesive composition has a low softness and a low light leakage resistance of the adhesive layer.

(a-2) hydroxyl group-containing (meth)acrylic monomer

The hydroxyl group-containing (meth)acrylic monomer (hereinafter, also referred to as "component (a-2)") of the present invention is an acrylic monomer having a hydroxyl group in a molecule. Specific examples of the hydroxyl group-containing (meth)acrylic monomer are not limited to the following, and examples thereof include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate, and 1,6. - hexanediol mono(meth) acrylate, neopentyl alcohol tri(meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, three Hydroxymethylpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (A) 2-hydroxy-3-phenoxyphenyl acrylate, 4-hydroxycyclohexyl (meth) acrylate, N-2-hydroxyethyl (meth) acrylamide, cyclohexane dimethanol monoacrylate In addition, a compound containing a glycidyl group such as an alkyl epoxidized propyl ether, an allyl epoxidized propyl ether or a glycidyl (meth) acrylate may be exemplified by a (meth)acrylic acid plus The compound obtained by the reaction is obtained. These may be used alone or in combination of two or more.

Among these, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl(meth)acrylamide, cyclohexanedimethanol monoacrylate More preferably, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and N-2-hydroxyethyl(meth)acrylamide are more preferable.

The amount of the hydroxyl group-containing (meth)acrylic monomer to be used is 0 to 1.8 parts by mass, preferably 0.1 to 1.5 parts by mass, more preferably 0.1 to 1.4 parts by mass. When the amount used is more than 1.8 parts by mass, since the hydroxyl group in the copolymer (A) becomes excessive, the crosslinking point obtained by reacting the hydroxyl group with the carbodiimide crosslinking agent (B) becomes excessive, resulting in the present invention. The adhesive composition has low softness and low light leakage resistance and durability of the adhesive layer.

(a-3) (meth) acrylate monomer

The (meth) acrylate monomer (hereinafter also referred to as "component (a-3)") of the present invention is an ester of (meth)acrylic acid having no hydroxyl group in the molecule. Specific examples of the (meth) acrylate monomer are not limited to the following, and examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (methyl). Isopropyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, N-heptyl (meth)acrylate, n-octyl (meth)acrylate, third octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, (A) Isodecyl acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate , dodecyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, 4-n-butylcyclohexyl (meth)acrylate, 2-ethylhexyldigan Alcohol (meth) acrylate, butoxyethyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-(meth) acrylate (2-methoxyethoxy)ethyl ester, (methyl) propyl 2-(2-butoxyethoxy)ethyl acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-tetramethyl (meth)acrylate Phenyl phenyl ester, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, poly(ethylene oxide) monoalkyl ether (meth) acrylate, polypropylene oxide monoalkyl ether (Meth)acrylate, trifluoroethyl (meth)acrylate, pentafluorohydroxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, 2,3-di(meth)acrylate Bromopropyl ester, tribromophenyl (meth)acrylate, and the like. These may be used alone or in combination of two or more.

Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, and (meth) Methyl acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are more preferred.

The amount of the (meth) acrylate monomer is from 99.9 to 89.2 parts by mass, preferably from 99.8 to 90.5 parts by mass, more preferably from 99.7 to 93.6 parts by mass.

The method for producing the (meth)acrylic copolymer (A) is not particularly limited, and the following well-known methods can be used: a solution polymerization method using a polymerization initiator, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, Film polymerization method, spray polymerization method, and the like. Examples of the method of controlling the polymerization include an adiabatic polymerization method, a temperature-controlled polymerization method, and an isothermal polymerization method. Further, in addition to the polymerization initiation method, a method of starting the polymerization by irradiation with radiation, electron rays, ultraviolet rays or the like can be employed. Among them, since the molecular weight is easily adjusted and the amount of impurities is small, a solution polymerization method using a polymerization initiator is preferred. For example, it is preferable to use 0.01 to 0.50 parts by mass of a polymerization initiator, and nitrogen gas, by using ethyl acetate, toluene, methyl ethyl ketone or the like as a solvent, and 100 parts by mass based on the total amount of the monomers. The reaction is carried out, for example, at a reaction temperature of 60 to 90 ° C for 3 to 10 hours. Examples of the polymerization initiator include azo such as azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylisobutyronitrile), and azobiscyanovaleric acid. a compound; a third butyl peroxy triacetate, a third butyl peroxybenzoate, a third butyl peroxy-2-ethylhexanoate, a di-tert-butylperoxide, a cumene hydroperoxide An organic peroxide such as benzamidine peroxide or t-butyl hydroperoxide; an inorganic peroxide such as hydrogen peroxide, ammonium persulfate, potassium persulfate or sodium persulfate. These systems may be used alone or in combination of two or more.

Other monomers copolymerizable with the above (a-1) to (a-3) can be used as necessary. The other single system is not particularly limited, and specific examples thereof include an epoxy group-containing acrylic monomer such as glycidyl (meth)acrylate or methyl glycidyl (meth)acrylate; Methyl) dimethylaminoethyl acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate, methacrylic acid methacrylate Acrylic monomer having an amine group such as oxyethyltrimethylammonium; (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) propylene oxime An acrylic monomer having a guanamine group such as an amine, N,N-methylenebis(meth)acrylamide or the like; a 2-methylpropenyloxyethyl diphenyl phosphate (meth) acrylate, a phosphoric acid Acrylic monomer having a phosphate group such as methacrylic acid methoxyethyl ester (meth) acrylate or tripropylene methoxy ethoxyethyl (meth) acrylate; sodium sulfonate (meth) acrylate An acrylic monomer having a sulfonic acid group such as 2-sulfonic acid ethyl (meth)acrylate or sodium 2-propenylamine-2-methylpropanesulfonate; urethane (meth) acrylate Carbamate Acrylic monomer; methacrylic vinyl monomer having a phenyl group such as p-t-butylphenyl (meth)acrylate or o-biphenyl (meth)acrylate; 2-ethyl fluorenyl (meth)acrylate Ethyl ethoxyethyl ester, vinyl trimethoxy decane, vinyl triethoxy decane, vinyl ginseng (β-methoxyethyl) decane, vinyl triethyl decyl decane, methacryloxy group a vinyl monomer having a decyl group such as propyltrimethoxydecane; styrene, chlorostyrene, α-methylstyrene, vinyltoluene, vinyl chloride, vinyl acetate, vinyl propionate, acrylonitrile, ethylene Pyridine and the like. These other single systems may be used alone or in combination of two or more.

Among these other monomers, (meth) acrylamide, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, 2-ethyl fluorenyl (meth) acrylate Ethyl methoxyethyl ester is preferred, and (meth) acrylamide, dimethylaminoethyl (meth) acrylate, and 2-ethyl decyl ethoxyethyl (meth) acrylate are more preferred.

The amount of use of the other monomer is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, based on 100 parts by mass of the total of the components (a-1) to (a-3). It is particularly good for 0.3 to 2 parts by mass.

The weight average molecular weight (Mw) of the (meth)acrylic copolymer (A) obtained by copolymerizing the above components is 1,000,000 to 2,000,000, preferably 1.1 million to 1.8 million, and 1.2 million. 1.7 million is better. When the weight average molecular weight is less than 1,000,000, the heat resistance is insufficient. On the other hand, when the weight average molecular weight is more than 2,000,000, the adhesiveness is low and the fit is low. Further, in the present invention, the weight average molecular weight is a value obtained by converting the polystyrene measured by the method described in the examples.

Further, the total amount of the components (a-1) and the component (a-2) used may not be 0 parts by mass). In other words, it means that at least one of the constituent unit derived from the component (a-1) and the constituent unit of the component (a-2) must be contained in the (meth)acrylic copolymer (A). The total amount of the component (a-1), the component (a-2), and the component (a-3) is preferably 100 parts by mass.

The above component (A) may be used singly or in combination of two or more kinds of polymers.

(B) carbodiimide crosslinking agent

In addition to the component (A), the adhesive composition of the present invention contains a carbodiimide-based crosslinking agent (hereinafter also referred to as "ingredient (B)"). The carbodiimide crosslinking agent is reacted with a hydroxyl group and/or a carboxyl group in the above (meth)acrylic copolymer (A) to form a crosslinked structure.

The carbodiimide crosslinking agent (B) used in the present invention is not particularly limited. Specifically, for example, a compound having two or more carbodiimide groups (-N=C=N-) in the molecule can be suitably used, and a well-known polycarbodiimide can be used.

Further, as the carbodiimide compound, a high molecular weight polycarbodiimide produced by decarbonation condensation reaction of a diisocyanate in the presence of a carbodiimide catalyst can also be used.

Examples of such a compound include a polycarbodiimide obtained by subjecting a diisocyanate to a decarbonation condensation reaction.

As the diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4 can be used. , 4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-toluene Isocyanate, 2,6-toluene diisocyanate, 1-methoxyphenyl 2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tetramethylbenzylidene One of diisocyanates or a mixture of two or more of them.

As the carbon diazide imidization catalyst, 1-phenyl-2-cyclophosphene-1-oxide, 3-methyl-2-cyclophosphene-1-oxide, 1-ethyl-3- can be used. A cyclophosphene oxide such as methyl-2-cyclophosphene-1-oxide, 1-ethyl-2-cyclophosphene-1-oxide or such 3-cyclophosphene isomer.

Such a high molecular weight polycarbodiimide can be synthesized or a commercially available product can be used. As a commercial item of the component (B), for example, the CARBODILITE (registered trademark) series manufactured by Nikko Textile Chemical Co., Ltd., among which CARBODILITE (registered trademark) V-01, V-03, V-05, V-07, V The -09 system is excellent in compatibility with an organic solvent, and is preferred.

In the present invention, the amount of the component (B) is 0.05 to 5 parts by mass based on 100 parts by mass of the component (A). In this range, an appropriate crosslinked structure can be formed to achieve more excellent heat resistance. When the amount of the above-described carbodiimide-based crosslinking agent (B) is less than 0.05 parts by mass, a sufficient crosslinked structure cannot be formed and heat resistance is lowered. On the other hand, when the amount is more than 5 parts by mass, the crosslinking reaction proceeds excessively, and the adhesive strength is lowered, and the shrinkage of the polarizing plate over time cannot be followed, resulting in deterioration of light leakage resistance and durability. The blending amount is preferably 0.1 to 4 parts by mass, more preferably 0.1 to 3 parts by mass.

(C) Isocyanate crosslinking agent

In addition to the above components (A) and (B), the pressure-sensitive adhesive composition of the present invention preferably contains an isocyanate crosslinking agent (C) (hereinafter also referred to as "ingredient (C)"). By adding the isocyanate crosslinking agent (C), the light leakage resistance and durability of the obtained adhesive layer are further improved.

The component (C) used in the present invention is not particularly limited. Specific examples thereof include triallyl isocyanate, dimer acid diisocyanate, 2,4-toluene diisocyanate (2,4-TDI), and 2,6-toluene diisocyanate (2,6-TDI). 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylene diisocyanate, two Aromatic diisocyanates such as toluene diisocyanate (XDI), tetramethyl xylene diisocyanate (TMXDI), toluidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI); hexamethylene diisocyanate (HDI), aliphatic diisocyanate such as trimethylhexamethylene diisocyanate (TMHDI), diazonic acid diisocyanate, norbornane diisocyanate (NBDI); trans cyclohexane-1,4-di Alicyclic diisocyanates such as isocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI), H12-MDI (hydrogenated MDI); carbodiimide modified diisocyanates of the above diisocyanates Or such isocyanurate-modified diisocyanates. Further, an adduct of the above-described isocyanate compound and a polyhydric alcohol compound such as trimethylolpropane, a biuret or an isocyanurate of the isocyanate compound are also suitably used.

The above component (C) can be synthesized or a commercially available product can be used. As a commercial item of the component (C), for example, CORONATE (registered trademark) L, CORONATE (registered trademark) HL, CORONATE (registered trademark) 2030, CORONATE (registered trademark) 2031 (above, manufactured by Japan POLYURETHANE INDUSTRIAL CO., LTD.) ), TAKENATE (registered trademark) D-102, TAKENATE (registered trademark) D-110N, TAKENATE (registered trademark) D-200, TAKENATE (registered trademark) D-202 (above, Mitsui Chemicals POLYURETHANE AG), DURANATE ( Trademark) 24A-100, DURANATE (trademark) TPA-100, DURANATE (trademark) TKA-100, DURANATE (trademark) P301-75E, DURANATE (trademark) E402-90T, DURANATE (trademark) E405-80T, DURANATE (trademark) TSE-100, DURANATE (trademark) D-101, DURANATE (trademark) D-201 (above, Asahi Kasei Chemical Co., Ltd.).

Among these components (C), CORONATE (registered trademark) L, CORONATE (registered trademark) HL, TAKENATE (registered trademark) D-110N, and DURANATE (trademark) 24A-100 are preferred, and CORONATE (registered trademark) L is used. TAKENATE (registered trademark) D-110N is better, and CORONATE (registered trademark) L is particularly good. Further, these components (C) may be used singly or in combination of two or more.

The amount used in the case of using the component (C) is 0.05 to 5 parts by mass based on 100 parts by mass of the component (A). Within this range, the adhesive composition of the present invention can have excellent light leakage resistance and durability. The blending amount is preferably 0.1 to 4 parts by mass, more preferably 0.15 to 3 parts by mass.

Further, the adhesive composition of the present invention may contain a decane coupling agent in addition to the above components. By using a decane coupling agent, the reactivity is improved, and the mechanical strength and adhesion of the crosslinked product can be improved. Such a decane coupling agent is not particularly limited. Specific examples thereof include methyltrimethoxydecane, dimethyldimethoxydecane, trimethylmethoxydecane, n-propyltrimethoxydecane, ethyltrimethoxydecane, and diethyldiamine. Ethoxy decane, n-butyltrimethoxydecane, n-hexyltriethoxydecane, n-octyltrimethoxydecane, phenyltrimethoxydecane, diphenyldimethoxydecane, cyclohexylmethyldi Methoxy decane, vinyl trichloro decane, vinyl trimethoxy decane, vinyl triethoxy decane, vinyl ginseng (β-methoxyethoxy) decane, β-(3,4-epoxy Ethylcyclohexyl)ethyltrimethoxydecane, γ-glycidoxypropyltrimethoxydecane, γ-glycidoxypropyltriethoxydecane, γ-methylpropenyloxypropyl Methyldimethoxydecane, γ-methylpropenyloxypropyltrimethoxydecane, γ-methylpropenyloxypropylmethyldiethoxydecane, γ-methylpropenyloxypropane Triethoxy decane, γ-propylene methoxypropyl triethoxy decane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxydecane, N-β-(amine Ethyl)-γ-aminopropyl Methoxydecane, N-β-(aminoethyl)-γ-aminopropyltriethoxydecane, γ-aminopropyltrimethoxydecane, γ-aminopropyltriethoxydecane, N-benzene Base-γ-aminopropyltrimethoxydecane, γ-chloropropyltrimethoxydecane, γ-hydrothiopropyltrimethoxydecane, γ-hydrothiopropylmethyldimethoxydecane, double -(3-[Triethoxydecyl]propyl)tetrasulfide, γ-isocyanatepropyltriethoxydecane, and the like. Further, a decane coupling agent having a functional group having an epoxy group (epoxypropyl group), an amine group, a thiol group, a (meth) acryl fluorenyl group or the like, and a component having a reactivity capable of reacting with the functional group can also be used. A functional group-containing decane coupling agent, another decane coupling agent, a polyisocyanate or the like, and a compound having a hydrolyzable decyl group obtained by reacting each functional group in an arbitrary ratio.

The above decane coupling agent can be synthesized or a commercially available product can be used. Examples of commercially available decane coupling agents include KBM-303, KBM-403, KBE-402, KBM-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM-802, and KBM. -803, KBE-846, KBE-9007 (above, Shin-Etsu Chemical Co., Ltd.).

Among these decane coupling agents, KBM-303, KBM-403, KBE-402, KBM-403, KBM-5103, KBM-573, KBM-802, KBM-803, KBE-846, and KBE-9007 are used. Good, with KBM-403 as better. In addition, the decane coupling agent may be used singly or in combination of two or more.

In the present invention, the amount of the above decane coupling agent used is not particularly limited. Specifically, the compounding amount of the decane coupling agent is preferably 0 to 1 part by mass, more preferably 0 to 0.5 part by mass, and 0 to 0.1 by mass, based on the total amount of the component (A) to the component (C). The serving is better. In this range, excellent heat resistance and adhesion can be exhibited. When the amount of the above decane coupling agent (C) is more than 1 part by mass, the heat resistance may be lowered.

The adhesive composition of the present invention may contain, for example, a hardening accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, an antioxidant, an antioxidant, in addition to or in place of the above-described decane coupling agent. Stabilizer, adhesion-imparting resin, modified resin (polyol resin, phenol resin, acrylic resin, polyester resin, polyolefin resin, epoxy resin, epoxidized polybutadiene resin, etc.), leveling agent, defoamer , plasticizers, dyes, pigments (coloring pigments, filler pigments, etc.), treating agents, UV blocking agents, fluorescent whitening agents, dispersing agents, thermal stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, lubricants And solvent additives. In the above, examples of the curing accelerator include dibutyltin dilaurate, JCS-50 (manufactured by Seongbuk Chemical Industry Co., Ltd.), FORMAT TK-1 (manufactured by Mitsui Chemicals POLYURETHANE Co., Ltd.), and the like. Examples of the ionic liquid include cerium ions, pyridinium ions, pyrrolidinium ions, imidazolium ions, cerium ions, ammonium ions, isouronium ions, and thiurium ions. Examples of the cationic component such as piperidinium ion, pyrazolium ion, and cesium ion, and examples of the anion component include a halogen ion, a nitrate ion, a sulfate ion, a phosphate ion, a perchlorate ion, a thiocyanate ion, and a thiosulfuric acid. A substance having an anion component such as an ion, a sulfite ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a formic acid ion, an oxalic acid ion, an acetic acid ion, a trifluoroacetic acid ion, or an alkylsulfonic acid ion. Examples of the antioxidant include dibutylhydroxytoluene (BHT), IRGANOX (registered trademark) 1010, IRGANOX (registered trademark) 1035FF, and IRGANOX (registered trademark) 565 (all of which are manufactured by CIBA SPECIALTY CHEMICALS). . Examples of the adhesion-imparting resin include rosins such as citronellic acid, polymerized citronellic acid, and citronellate, terpene resins, terpene phenol resins, aromatic hydrocarbon resins, aliphatic saturated hydrocarbon resins, and petroleum resins. . When the additive is used, the amount of the additive to be used is not particularly limited, and is, for example, 0.1 to 20 parts by mass based on 100 parts by mass of the total of the components (A) to (C).

The adhesive composition of the present invention can be produced by mixing the above components in batches, or sequentially mixing the components, or mixing any of the plurality of components, mixing the remaining components, and stirring them to form a homogeneous mixture. . More specifically, it can be prepared by heating as necessary, for example, heating to a temperature of 30 to 40 ° C and stirring for 10 minutes to 5 hours until uniform using a stirrer or the like.

The adhesive composition of the present invention can be used for bonding various substrates. Examples of the substrate that can be used herein include glass, plastic, paper, metal foil, and the like. As a glass, a normal inorganic glass is mentioned. Examples of the plastic material in the plastic film include a polyvinyl chloride resin, a polyvinylidene chloride, a cellulose resin, an acrylic resin, a cycloolefin resin, a non-crystalline polyolefin resin, polyethylene, and polypropylene. Polystyrene, ABS resin, polyamide, polyester, polycarbonate, polyurethane, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and chlorinated polypropylene. The amorphous polyolefin-based resin is usually a polymerized unit of a cyclic polyolefin such as norbornene and a polycyclic norbornene-based monomer, and may be a copolymer of a cyclic olefin and a chain cyclic olefin. As a commercially available non-crystalline polyolefin-based resin, there are JSR Corporation's trade name ARTON, Japan's ZEON Co., Ltd.'s ZEONEX (registered trademark), ZEONOR (registered trademark), Mitsui Chemicals' APO, and APEL (registered trademark). Wait. A film formed of a non-crystalline polyolefin-based resin is used as a film, and a well-known method such as a solvent casting method or a melt extrusion method can be suitably used. Further, as the paper, mold paper, fine paper, kraft paper, art coated paper, cast coated paper, pure white web, parchment paper, water resistant paper, cellophane (glassine) can be used. Paper) and corrugated paper. As a metal foil, an aluminum foil etc. are mentioned, for example.

Accordingly, the present invention provides an optical member comprising an adhesive layer formed of the adhesive composition of the present invention.

As the optical member, for example, a polarizing plate, a phase difference plate, an optical film for a plasma display, a conductive film for a touch panel, or the like can be suitably used. Among them, the adhesive composition of the present invention is excellent in adhesion to a polarizing plate and glass. Of course, the present invention is not limited to the above-described embodiments, and can be used in the subsequent steps of other members.

The adhesive composition of the present invention can also be used to form an adhesive layer directly on one or both sides of the optical member, or can be used to previously form an adhesive layer on the release film and transfer it to one side of the optical member. Or two sides.

The application of the adhesive composition of the present invention may be carried out according to a known method, and examples thereof include a natural coater, a knife belt coater, a floating knife, and a roll type. Knife over roll, blade felt coater, spray coating, dipping, kiss roll, squeeze roll, reverse roll coating, airblade, curtain flow applicator, doctor blade, winding Various coating methods for devices such as wire bars, die coaters, comma coaters, BAKER adjustable applicators, and gravure coaters. Further, the coating thickness (thickness after drying) of the adhesive composition of the present invention may be selected according to the substrate to be used and the use, and is preferably 5 to 30 μm, more preferably 15 to 25 μm.

The viscosity of the adhesive composition of the present invention is not particularly limited. However, considering the easiness of coating, the ease of controlling the film thickness of the adhesive layer formed of the composition, etc., the viscosity at 25 ° C is preferably 500 to 5000 mPa ‧ and more preferably 1000 to 3000 mPa ‧ s good.

The adhesive layer obtained from the adhesive composition of the present invention is obtained by crosslinking the above-mentioned adhesive composition. In this case, the crosslinking of the adhesive composition is usually carried out after the application of the adhesive composition, and the adhesive layer composed of the crosslinked adhesive composition can be transferred to a substrate or the like. The crosslinking of the adhesive composition is usually carried out by standing at a temperature of 20 to 40 ° C, a relative humidity of 30 to 70% RH, and a normal pressure (atmospheric pressure).

Since the adhesive composition of the present invention exhibits excellent flexibility, particularly when used in a polarizing plate, it is possible to obtain excellent light leakage resistance by following the shrinkage of the polarizing plate over time.

In addition, since the adhesive composition of the present invention has excellent durability, the expansion and floating of the adhesive layer due to the heat treatment and the high-humidity treatment hardly occur.

[Examples]

The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following embodiments.

Further, the measurement of the solid content and viscosity of the polymer solution obtained in the synthesis example and the weight average molecular weight of the polymer (A) was carried out by the following method.

<solid content>

In a well-called glass dish, about 1 g of the polymer solution is weighed. After drying at 105 ° C for 1 hour, it was returned to room temperature and finely weighed the total mass of the glass dish and the residual solid content. The mass of the glass dish is set to X, the total mass of the glass dish and the polymer solution before drying is set to Y, and the total mass of the glass dish and the residual solid content is Z, and the solid is calculated from the following formula ingredient.

[Number 1]

<viscosity>

The polymer solution placed in the glass bottle was tempered to 25 ° C and measured using a B-type viscometer.

<weight average molecular weight>

The measurement was carried out in accordance with the measurement method and the measurement conditions in Table 1 below.

[Table 1]

Device: Gel Permeation Chromatography (GPC) (Machine No. GPC-16)

Detector: Differential refractive index detector RI (Model 8020, TOSOH Co., Ltd. Sensitivity 32)

UV absorption detector UV (2487, Water 215nm, sensitivity 0.2AUFS)

Pipe column: TSKgel GMHXL (2 pieces) made by TOSOH Co., Ltd., G2500HXL (1 piece)

(S/N M0052, M0051, N0010, Φ7.8mm×30cm)

Solvent: tetrahydrofuran (made by Wako Pure Chemical Industries Co., Ltd.)

Flow rate: 1.0mL/min

Column temperature: 23 ° C

Sample [concentration] about 0.2%

[Dissolved] Stir slowly at room temperature.

[Solubility] Dissolution (visual confirmation)

[Filter] Filter using a 0.45 μm filter.

Injection volume: 0.200mL

Standard sample: monodisperse styrene

Data Processing: GPC Data Processing System

(Synthesis Example 1)

In a flask equipped with a refluxing machine and a stirrer, 99 parts by mass of n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 1 part by mass of 2-hydroxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), and 120 parts by mass of ethyl acetate were charged. . Subsequently, while heating to 65 ° C while nitrogen substitution was carried out, 0.04 parts by mass of azobisisobutyronitrile (AIBN) was added, and polymerization was carried out for 6 hours while maintaining 65 °C. After completion of the polymerization reaction, 280 parts by mass of ethyl acetate was added and diluted to obtain a solution of a polymer (sample name: A-1). The solid content of the obtained polymer solution was 20% by mass, and the viscosity was 4500 mPa·s. Further, the obtained polymer (A-1) had a weight average molecular weight of 1.6 million.

(Synthesis Example 2~18)

In Synthesis Example 1, a solution of the polymer (A-2) to (A-18) was obtained by the same operation as in Synthesis Example 1, except that the composition of the monomer component was changed to the composition shown in Table 1. . Further, the solid content and viscosity of the obtained polymer (A-2) to (A-18) solution and the weight average molecular weight of the polymers (A-2) to (A-18) were measured. The results are shown in Table 2. Further, in Table 2 below, "BA" is butyl acrylate; "2EHA" is 2-ethylhexyl acrylate; "HEA" is 2-hydroxyethyl acrylate; "4HBA" is 4-hydroxybutyl acrylate; HEAA" is N-2-hydroxyethyl acrylamide; "AA" is acrylic acid.

(Example 1)

500 parts by mass (100 parts by mass of the solid content of the polymer) in the polymer solution obtained in the above Synthesis Example 1, and 1 part by mass of the carbodiimide-based crosslinking agent (B), that is, carbon diazide Amine (registered trademark) V-01 (manufactured by Nisshinbo Chemical Co., Ltd., sample name B-1), 0.2 parts by mass of isocyanate crosslinking agent (C), that is, CORONATE (registered trademark) L (trimethylolpropane/toluene) Isocyanate trimer adduct, manufactured by Japan POLYURETHANE INDUSTRIAL CO., LTD., sample name C-1) and 0.1 part by mass of decane coupling agent, namely KBM-403 (3-glycidoxypropylmethyldiethoxy) The mixture of decane and Shin-Etsu Chemical Co., Ltd. was mixed at room temperature (25 ° C) for 10 minutes to obtain a solution in which the adhesive composition was dissolved.

This solution was applied to a PET film (Mitsubishi Chemical POLYESTER FILM Co., Ltd., MRF38, thickness: 38 μm) so as to have a thickness of 25 μm after drying, and dried at 90 ° C for 3 minutes to form an adhesive layer. And attached to a polarizing plate to manufacture a polarizing plate with an adhesive layer.

(Examples 2 to 10, Comparative Examples 1 to 8)

In addition to the composition ratio shown in the following Table 2, the polymer synthesized by the above synthesis example, a carbodiimide crosslinking agent, an isocyanate crosslinking agent, a carbodiimide crosslinking agent, and A solution prepared by dissolving the adhesive composition and a polarizing plate with an adhesive layer were prepared in the same manner as in Example 1 except for a crosslinking agent other than the isocyanate crosslinking agent and a decane coupling agent. Further, the details of the carbodiimide-based crosslinking agents B-2 and B-3 and the other crosslinking agent D-1 are shown in Table 3 below.

[table 3] ‧Carbodiamine crosslinker (B)

B-2: CARBODILITE (registered trademark) V-05 (made by Nisshinbo Chemical Co., Ltd.)

B-3: CARBODILITE (registered trademark) V-09 (made by Nisshinbo Chemical Co., Ltd.)

‧Other crosslinkers

D-3: TETRAD X (manufactured by Mitsubishi Gas Chemical Co., Ltd., N, N, N', N'-tetraepoxypropylm-xylenediamine)

The polarizing plates with the adhesive layers of Examples 1 to 10 and Comparative Examples 1 to 8 obtained as described above were evaluated for each performance in accordance with the following method.

1. Metal corrosion inhibition ‧ prevention

The adhesive layer of the surface protective film which was left to stand in an environment of 23 ° C and 50% RH for 7 days was stuck on an aluminum foil, and left in an environment of 60 ° C and 90% RH for 2 days, and the corrosive property at this time was observed. In addition, in each of the following Tables 4, "○" indicates no change, and "X" indicates whitening.

2. Light leakage resistance

The polarizing plate having the adhesive layer after being left in an environment of 23° C. and 50% RH for 7 days was cut into 120 mm (polarizing plate MD direction) × 60 mm, and 120 mm (polarizing plate TD direction) × 60 mm, each of which was mutually The surfaces of the glass sheets were bonded to each other in an overlapping manner, and autoclaved at 50 ° C and 0.49 MPa (5 kg/cm ² ) for 20 minutes. Subsequently, the appearance after standing for 120 hours and 500 hours in an environment of 80 ° C was observed. In each of the following Tables 4, "◎" indicates that no light leakage was observed after 120 hours and 500 hours, "○" indicates that no light leakage was observed after 120 hours, and "X" indicates that light leakage was observed. .

3. Durability

The polarizing plate having an adhesive layer after being left in an environment of 23° C. and 50% RH for 7 days was cut into 120 mm (polarizing plate MD direction) × 60 mm, and bonded to a glass plate at 50° C. and 0.49 MPa (5 kg). The conditions of /cm ² ) were autoclaved for 20 minutes. Subsequently, the appearance after leaving for 120 hours in an environment of 100 ° C or 80 ° C and 90% RH was observed. In each of the following Tables 4, "○" indicates that no foaming, floating, and peeling were observed, and "X" indicates that foaming, floating, and peeling were observed.

4. Adhesion

The polarizing plate having an adhesive layer after being left in an environment of 23° C. and 50% RH for 7 days was cut into a width of 25 mm, bonded to a glass plate, and subjected to conditions of 50° C. and 0.49 MPa (5 kg/cm ² ). The autoclave was treated for 20 minutes. The adhesion test was carried out by using a tensile tester at a peeling angle of 90 degrees and a peeling speed of 0.3 m/min in an environment of 23 ° C and 50% RH according to the adhesive tape ‧ adhesive sheet test method described in JIS Z2037 (2000) .

5. Adhesion to the substrate

Observe the above 4. The adhesion when measuring the adhesion. In each of the following Tables 4, "○" indicates that the adhesive is not completely peeled off from the substrate, and "X" indicates that the adhesive is peeled off from the substrate.

6. Viscous contamination

The contact angle of the glass plate surface before and after the measurement of the adhesion force was measured. In the following Table 4, each of the following shows that "○" indicates that the contact angle of the glass plate surface before and after the measurement of the adhesion is not changed, and "x" indicates that the contact angle of the glass plate surface before and after the measurement of the adhesion is changed.

7. Low temperature stability

The polarizing plate having an adhesive layer after being left in an environment of 23° C. and 50% RH for 7 days was cut into 120 mm (polarizing plate MD direction) × 60 mm, and bonded to a glass plate at 50° C. and 0.49 MPa (5 kg). The conditions of /cm ² ) were autoclaved for 20 minutes. Subsequently, the appearance after leaving for 120 hours at -40 ° C was observed. In the following Table 4, each of the following shows that "○" indicates that no foaming, floating, peeling, and recrystallized materials were observed, and "X" indicates that foaming, floating, peeling, and recrystallized matter were observed. .

8.Rework

Observe the peeling state at the time of measuring the adhesion. In Table 4 below, each of them is indicated as follows, "○" indicates that interface failure was observed, and "X" indicates that adhesive was observed to adhere to glass plate (adhesive) and/or agglutination failure. .

9. Gel fraction

The peeling-treated polyester film was used instead of the polarizing plate having the adhesive layer produced in each of the examples and the comparative examples, and the gel fraction after 7 days of coating was measured. The gel fraction was obtained by weighing an adhesive composition of about 0.1 g in an environment of 23 ° C and 50% RH, and measuring the weight W ₁ (g). This was taken to a vial and about 30 g of ethyl acetate was added and left for 24 hours. The contents of the sample bottle after a predetermined period of time were filtered using a 200 mesh stainless steel wire mesh (the weight of the film was set to W ₂ ), and the wire mesh and the residue were dried at 90 ° C for 1 hour. The overall weight W ₃ (g). The gel fraction was calculated from these measured values in accordance with the following formula 2.

[Number 2]

Each evaluation result was sorted out and shown in Table 4. Further, in Comparative Example 6 in Table 4, gelation occurred at the time of production of the adhesive layer, and various evaluations could not be performed.

As is clear from the above Table 4, the polarizing plate of the adhesive composition of the present invention was used as compared with the polarizing plate of the adhesive composition (Comparative Examples 1 to 8) which was outside the scope of the present invention (Example 1~) 10) Excellent in light leakage resistance and durability. In particular, the adhesive layer obtained from the adhesive compositions of Examples 1, 2, 3, 5, 6, 8, and 10 containing the isocyanate crosslinking agent (C) is more resistant to light leakage.

Claims (2)

An adhesive composition comprising 100 parts by mass of a (meth)acrylic copolymer, 0.05 to 5 parts by mass of a carbodiimide crosslinking agent, and 0.05 to 5 parts by mass of an isocyanate crosslinking agent, wherein The (meth)acrylic copolymer is composed of 0 to 9 parts by mass of a carboxyl group-containing monomer, 0.1 to 1.8 parts by mass of a hydroxyl group-containing (meth)acrylic monomer, and 99.9 to 89.2 parts by mass of (meth). It is composed of an acrylate monomer and has a weight average molecular weight of 1,000,000 to 2,000,000. An optical member comprising: an adhesive layer formed of the adhesive composition of claim 1 of the patent application.