JP2006169428A - Adhesive composition for optical member, adhesive layer for optical member and its production process, optical member with adhesive, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for an optical member that can improve coatability without particularly increasing the amount of a solvent when applied, can maintain durability and preferably is excellent even in machinability, to provide an adhesive layer formed using the composition and a process for producing the adhesive layer, to provide an adhesive type optical member having the adhesive layer formed thereon and to provide an image display device using the optical member. <P>SOLUTION: The adhesive composition for an optical member comprises a (meth)acrylic polymer containing 60 wt.% or more alkyl acrylate having a 2-4C alkyl group as a monomer unit and having a weight-average molecular weight of 1,500,000 or more wherein the proportion of the component having a molecular weight of 100,000 or less is 20 wt.% or less and an organic solvent wherein a 6-9C hydrocarbon solvent is contained in an amount of 20-60 wt.% based on the total amount of the organic solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive composition for optical members. Moreover, this invention relates to the adhesive layer for optical members formed with the said adhesive composition for optical members, and its manufacturing method. Furthermore, the present invention relates to an adhesive optical member having the adhesive layer, and further to an image display device such as a liquid crystal display device, an organic EL display device, and a PDP using the adhesive optical member. Examples of the optical member include a polarizing plate, a retardation plate, an optical compensation film, a brightness enhancement film, and those in which these are laminated.

  The pressure-sensitive adhesive layer used for optics is required to have a high level of thickness and surface uniformity, and it is applied at a low concentration so that the viscosity of the polymer solution is low in order to improve coating properties. ing. However, in recent years, in reality, it is desirable to reduce the use of organic solvents as much as possible in consideration of the environment.

  In addition, as adhesives that do not use organic solvents, emulsion adhesives that use aqueous dispersion media and UV polymerization type adhesives that do not contain solvents are known. However, such as water resistance problems and thickness uniformity, It is not yet ready for use.

  On the other hand, as a device for preventing the viscosity of the polymer solution from increasing even when the polymer concentration is increased, there is a method of reducing the molecular weight of the polymer. However, optical members used in liquid crystal display devices and the like, such as polarizing plates and retardation plates, are attached to liquid crystal cells via an adhesive, and the expansion and contraction of optical members is large under heating and humidification conditions. After sticking, there is a tendency to float or peel off. For this reason, the pressure-sensitive adhesive for optical members is required to have durability that can be applied under heating conditions and humidification conditions, and it is difficult to lower the molecular weight. For example, when an acrylic polymer is used as an optical pressure-sensitive adhesive, a polymer component having a weight average molecular weight of 100,000 or less and 15% by weight or less is disclosed (for example, see Patent Document 1).

  In addition, as an adhesive for attaching an optical member, an acrylic adhesive is generally used for advantages such as durability and transparency, and a crosslinking treatment is performed to give an appropriate cohesive force. It is normal. As a crosslinking method for such an acrylic pressure-sensitive adhesive, various crosslinking agents are selected and used, and a review of functional groups of the acrylic polymer and the crosslinking method has been published (for example, see Non-Patent Document 1). .

  Specific examples of the crosslinking agent for the adhesive for attaching an optical member include isocyanate compounds, epoxy compounds, aldehyde compounds, amine compounds, metal salts, metal alkoxides, ammonium salts, and hydrazine compounds (see Patent Document 2). ), Glycidyl compounds, isocyanate compounds, aziridine compounds, metal chelates and the like are also known (see Patent Document 3).

  However, these crosslinking agents require a certain aging treatment in order to develop a cohesive force. The optical member is usually subjected to various processing such as slitting and punching after forming the pressure-sensitive adhesive layer. If these processings are performed in a state where aging is insufficient, the cohesive force of the pressure-sensitive adhesive is insufficient, so that the pressure-sensitive adhesive may be taken off by the cutting blade or protrude from the cut surface. That is, the aging treatment is essential, and there is a problem that productivity is remarkably hindered due to such a process.

  On the other hand, organic peroxides are exemplified as crosslinking agents for rubber-based adhesives and silicone-based adhesives as crosslinking methods for adhesives, but are not described as crosslinking agents for acrylic adhesives (for example, Patent Document 2).

  As a peroxide cross-linking of an acrylic pressure-sensitive adhesive, a tape pressure-sensitive adhesive composition comprising a heat reaction product of an acrylic copolymer and an organic peroxide in the range of 1 to 6% by weight is known (for example, a patent (Ref. 4).

  Moreover, the pressure-sensitive adhesive layer having a gel fraction of less than 40% by weight, in which 0.01 to 10 parts by weight of an organic pressure-sensitive adhesive that does not proceed with a crosslinking reaction at 60 to 100 ° C. is transferred to a breathable substrate. A method is disclosed in which a pressure-sensitive adhesive is softened by heating and impregnated into a base material, and then crosslinked to obtain a breathable pressure-sensitive adhesive (see, for example, Patent Document 5).

  Furthermore, the olefin part is also cross-linked to an acrylic polymer obtained by copolymerizing a monomer having an olefin polymer in the side chain and an acrylate with an organic peroxide having a 10-hour half-life of 110 ° C. or less, thereby coagulating the olefin part. Has been disclosed (for example, see Patent Document 6).

However, there is no known example in which the pressure-sensitive adhesive to be bonded to the optical member stabilizes characteristics by crosslinking with peroxide, has little change with time, and improves productivity.
JP-A 64-66283 JP-A-8-199131 JP 2003-49141 A Japanese Patent Publication No. 35-4876 JP 2000-17237 A JP 2003-13027 A Adhesive Handbook (2nd edition), edited by Adhesive Tape Industry Association, 1995.10.12. Page 147 Adhesive Handbook (2nd edition), edited by Adhesive Tape Industry Association, 1995.10.12. Pages 121 and 159

  Accordingly, an object of the present invention is to improve the coating property without particularly increasing the amount of solvent during coating, and to maintain durability, and preferably has excellent workability. It is providing the adhesive composition, the adhesive layer formed using this, and its manufacturing method. Furthermore, the objective of this invention is providing the adhesive optical member in which the said adhesive layer was formed, and an image display apparatus using the same.

  In order to achieve the above-mentioned object, the present inventors have intensively studied the constitution of the pressure-sensitive adhesive composition, and as a result, found that the above-mentioned object can be achieved by using the following pressure-sensitive adhesive composition for optical members. It came to be completed.

That is, the pressure-sensitive adhesive composition for optical members of the present invention is
An acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms is contained in an amount of 60% by weight or more as a monomer unit, and the proportion of components having a weight average molecular weight of 1.5 million or more and a molecular weight of 100,000 or less is 20% by weight (meta ) In a pressure-sensitive adhesive composition containing an acrylic polymer and an organic solvent,
20 to 60% by weight of the C6-C9 hydrocarbon solvent is contained in the total amount of the organic solvent.

  According to the pressure-sensitive adhesive composition for optical members of the present invention, a C6-C9 hydrocarbon solvent is used for a (meth) acrylic polymer having a specific configuration, and an appropriate amount thereof is used. ) The spread of the molecular chain can be sufficiently reduced without precipitating the acrylic polymer, and the coating property can be improved by reducing the viscosity without particularly increasing the amount of the solvent during coating. At that time, since the weight average molecular weight of the acrylic polymer is sufficiently increased and the low molecular weight component is reduced, the durability of the resulting pressure-sensitive adhesive layer can be maintained, and the crosslinkability of the acrylic polymer is improved.

  The (meth) acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer. Further, (meth) acrylate refers to acrylate and / or methacrylate, and (meth) alkyl acrylate refers to alkyl acrylate and / or alkyl methacrylate.

  Moreover, the C6-C9 hydrocarbon solvent in the present invention refers to a hydrocarbon solvent having 6 to 9 carbon atoms in one molecule.

  In the above, it is preferable that the acrylic polymer contains 0.2 to 7% by weight of an unsaturated carboxylic acid as a monomer unit. By copolymerizing an appropriate amount of such an unsaturated carboxylic acid, the adhesive force to the liquid crystal cell can be controlled to some extent while maintaining durability even when the molecular chain of the acrylic polymer is small. .

  Moreover, in the adhesive composition for optical members of this invention, it is preferable to contain 0.01-1 weight part of silane coupling agents with respect to 100 weight part of said (meth) acrylic-type polymers. By adding an appropriate amount of the silane coupling agent, the adhesion to the adherend and the durability can be more reliably improved.

  Furthermore, the pressure-sensitive adhesive composition for an optical member of the present invention preferably further contains 0.02 to 2 parts by weight of a peroxide with respect to 100 parts by weight of the (meth) acrylic polymer. By having such a configuration, it is possible to more reliably improve the adhesiveness and durability with the adherend due to the durability maintenance effect, coating property, and workability (punching workability).

  It is preferable that the pressure-sensitive adhesive composition for an optical member of the present invention further contains 0.01 to 5 parts by weight of a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer. By using a cross-linking agent, it is possible to more reliably improve prevention of adhesive residue (removability), durability, and workability (punching workability) during peeling.

  On the other hand, the pressure-sensitive adhesive layer for an optical member of the present invention includes, for example, a step of forming a layer made of the pressure-sensitive adhesive composition for an optical member according to any one of the above on a single-sided or double-sided surface on a release-treated support, It is obtained by using a production method including a step of heat-treating a layer made of the pressure-sensitive adhesive composition for optical members so that the decomposition amount of the peroxide in the pressure-sensitive adhesive composition for optical members is 75% by weight or more. be able to. By using such a production method, it is possible to reduce the viscosity and improve the coating properties without particularly increasing the amount of the solvent during the coating due to the above-described effects. Moreover, the adhesive layer for optical members which balances the above-mentioned outstanding removability and durability in good balance can be obtained.

  Moreover, the pressure-sensitive adhesive layer for optical members of the present invention is characterized by being formed by crosslinking the pressure-sensitive adhesive composition for optical members described above. According to the pressure-sensitive adhesive layer for optical members of the present invention, the pressure-sensitive adhesive composition exhibiting the above-described effects is cross-linked, so that the above-mentioned excellent durability and coating properties are aligned in a well-balanced manner. Become a layer. Therefore, it is particularly useful as a re-peelable pressure-sensitive adhesive layer for optical members.

  Furthermore, the pressure-sensitive adhesive layer for an optical member of the present invention has a workability (punching workability) without causing the pressure-sensitive adhesive to adhere to the cutting blade and chip or protrude from the cut surface when punching. Is also excellent.

  Furthermore, the optical member with pressure-sensitive adhesive for optical members of the present invention is characterized in that the above-mentioned pressure-sensitive adhesive layer for optical members is formed on one side or both sides of the optical member. According to the optical member with a pressure-sensitive adhesive of the present invention, since the pressure-sensitive adhesive layer having the above-described effects is provided, the pressure-sensitive adhesive for an optical member excellent in the above-described excellent durability, coating property, and workability (punching workability). It becomes an optical member with an agent.

  Moreover, the image display apparatus of the present invention uses at least one of the above adhesive optical members for optical members. The image display device of the present invention is a liquid crystal display device, an organic EL display device, a PDP or the like using the above-mentioned optical member with an adhesive. In this case, the coating property can be improved and the durability can be maintained without particularly increasing the amount of the solvent.

  Hereinafter, embodiments of the present invention will be described in detail.

That is, the pressure-sensitive adhesive composition for optical members of the present invention is
An acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms is contained in an amount of 60% by weight or more as a monomer unit, and the proportion of components having a weight average molecular weight of 1.5 million or more and a molecular weight of 100,000 or less is 20% by weight (meta ) In a pressure-sensitive adhesive composition containing an acrylic polymer and an organic solvent,
20 to 60% by weight of the C6-C9 hydrocarbon solvent is contained in the total amount of the organic solvent.

  The (meth) acrylic polymer in the present invention contains 60% by weight or more of a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms as a monomer unit, has a weight average molecular weight of 1.5 million or more, and a molecular weight of 10 A (meth) acrylic polymer having a component ratio of 10,000 or less is 20 wt% or less.

  The (meth) acrylic acid alkyl ester serving as the monomer unit of the (meth) acrylic polymer is preferably a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms, and either linear or branched is used. it can.

  The (meth) acrylic polymer is such that the (meth) acrylic acid alkyl ester is copolymerized in an amount of 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more. It is preferable because the viscosity of the product can be lowered efficiently.

  Examples of the alkyl (meth) acrylate having an alkyl group having 2 to 4 carbon atoms include ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t -Butyl (meth) acrylate, isobutyl (meth) acrylate, etc. are mention | raise | lifted. These compounds may be used alone or in combination of two or more.

  The acrylic polymer preferably contains 0.2 to 7% by weight, more preferably 0.5 to 5% by weight, of unsaturated carboxylic acid as a monomer unit. If the content of the unsaturated carboxylic acid exceeds 7% by weight, the adhesive force to the liquid crystal cell becomes too large or too hard, which is not preferable. On the other hand, if it is less than 0.2% by weight, the durability is adversely affected.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Of these, acrylic acid and methacrylic acid are particularly preferably used. These compounds may be used alone or in combination of two or more.

  Furthermore, as the unsaturated carboxylic acid, for example, an acid anhydride group-containing monomer such as maleic anhydride or itaconic anhydride may be appropriately used.

  Other polymerizable monomers other than the above-mentioned alkyl (meth) acrylate and unsaturated carboxylic acid monomer (B) include a polymerizable monomer for adjusting the glass transition point and peelability of the (meth) acrylic polymer. It can be used within a range not impairing the effects of the present invention.

  Examples of other polymerizable monomers used in the (meth) acrylic polymer of the present invention include aggregation of sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, and the like. Works as an adhesive strength improver and a crosslinking base point for components that improve strength and heat resistance, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. A component having a functional group can be used as appropriate. Furthermore, an alkyl (meth) acrylate having an alkyl group having 1 carbon number and 5 or more carbon atoms can be appropriately used. These monomer compounds may be used alone or in admixture of two or more.

  Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth And acryloyloxynaphthalene sulfonic acid.

  Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate.

  Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

  Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl laurate, vinyl pyrrolidone, and the like.

  Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethyl styrene, α-methyl styrene, and the like.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl ( (Meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide N-hydroxy (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether Tell, and the like.

  Examples of amide group-containing monomers include acrylamide, methacrylamide, diethyl acrylamide, N-vinyl pyrrolidone, N, N-dimethyl acrylamide, N, N-dimethyl methacrylamide, N, N-diethyl acrylamide, N, N-diethyl methacryl. Examples thereof include amide, N, N′-methylenebisacrylamide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide and the like.

  Examples of the amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N- (meth) acryloylmorpholine, and (meth) acrylic acid aminoalkyl ester. Etc.

  Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether.

  Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and the like.

  Examples of the alkyl (meth) acrylate having an alkyl group having 1 carbon atom include methyl (meth) acrylate.

  Examples of the alkyl (meth) acrylate having an alkyl group having 5 or more carbon atoms include hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, and isooctyl ( (Meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n- Examples include tetradecyl (meth) acrylate.

  In the present invention, other polymerizable monomers may be used alone or in combination of two or more, but the total content is 0 to 5% by weight as a monomer unit. It is preferable that it is 0 to 3% by weight.

  Furthermore, examples of copolymerizable monomers other than the above include silane monomers containing silicon atoms. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

  The silane monomer may be used alone, or two or more kinds may be mixed and used. However, the total content of the silane monomer is 0.00 with respect to 100 parts by weight of the (meth) acrylic polymer. It is preferable that it is 1-3 weight part, and it is more preferable that it is 0.5-2 weight part. Copolymerization of a silane monomer is preferable for improving durability.

  The (meth) acrylic polymer used in the present invention has a weight average molecular weight of 1.5 million or more, preferably 2 million or more, more preferably 2.3 million or more. When the weight average molecular weight is less than 1,500,000, the durability tends to be poor, and the adhesive force tends to be generated due to the reduced cohesive force of the pressure-sensitive adhesive composition. On the other hand, from the viewpoint of workability, the weight average molecular weight is preferably 5 million or less.

  Further, the component ratio of the (meth) acrylic polymer having a molecular weight of 100,000 or less is 20% by weight or less, preferably 10% by weight or less, more preferably 7% by weight or less from the viewpoint of crosslinkability. Further, in the present invention, since the entanglement of molecular chains is reduced by adding a poor solvent, if there are many low molecular weight products, the crosslinkability between polymer molecular chains becomes very poor, so there are few low molecular weight products. Moderate.

  The molecular weight of the polymer in the present invention refers to that measured by the method described in Examples. Moreover, the component ratio of molecular weight 100,000 or less also refers to what was measured by the method as described in an Example.

  In addition, the glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or lower (usually −100 ° C. or higher), preferably −10 ° C. or lower for the reason that it is easy to balance the adhesive performance. When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow and the wetting to the polarizing plate is insufficient, and there is a tendency to cause blisters generated between the polarizing plate and the pressure-sensitive adhesive composition layer of the pressure-sensitive adhesive sheet. is there. In addition, the glass transition temperature (Tg) of a (meth) acrylic-type polymer can be adjusted in the said range by changing the monomer component and composition ratio to be used suitably.

  For the production of such a (meth) acrylic polymer, known radical polymerization methods such as solution polymerization, bulk polymerization, and emulsion polymerization can be appropriately selected, but it is preferable to select a radical polymerization method using an organic solvent. This is because in a polymerization method using water as represented by emulsion polymerization, it is necessary to dry the water once and then add a predetermined amount of the solvent of the present invention, which is not economical.

  Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  As the radical polymerization agent, various known azo and peroxide types can be used.

  As a specific example of solution polymerization, for example, a polymerization initiator such as azobisinbutyronitrile is used in an amount of about 0.01 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of monomers. As the polymerization solvent, for example, a good solvent such as ethyl acetate, toluene, cyclohexane, methyl ethyl ketone, or the like is used. The reaction is usually carried out at about 50 to 70 ° C. for about 8 to 15 hours under an inert gas stream such as nitrogen. The residual monomer after polymerization is regarded as a good solvent for the acrylic polymer.

  The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used.

  Examples of the polymerization initiator used in the present invention include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- ( 5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutylamidine ), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057), azo initiators, potassium persulfate, ammonium persulfate Persulfate such as di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di- sec-butyl peroxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1, 1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t- Hexylperoxy) peroxide initiators such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, peroxides such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate, Redox initiators combined with reducing agents can be listed , But it is not limited thereto.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. Is preferably about 0.02 to 0.5 parts by weight.

  In the present invention, a chain transfer agent may be used in the polymerization. By using a chain transfer agent, the molecular weight of the acrylic polymer can be appropriately adjusted.

  Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol.

  These chain transfer agents may be used alone or in admixture of two or more, but the total content is 0.01-0. About 1 part by weight.

  Examples of the emulsifier used in the present invention include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxyethylene. Nonionic emulsifiers such as alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene-polyoxypropylene block polymers, and the like can be mentioned. These emulsifiers may be used alone or in combination of two or more.

  Furthermore, as reactive emulsifiers, as emulsifiers into which radical polymerizable functional groups such as propenyl groups and allyl ether groups are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05 BC-10, BC-20 (Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria Soap SE10N (Asahi Denka Kogyo Co., Ltd.) and the like. Reactive emulsifiers are preferable because they are incorporated into the polymer chain after polymerization and thus have improved water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight with respect to 100 parts by weight of the monomer in view of polymerization stability and mechanical stability.

  The pressure-sensitive adhesive composition for optical members of the present invention is based on the (meth) acrylic polymer as described above.

  The term “used in the present invention” refers to a hydrocarbon solvent having 6 to 9 carbon atoms in one molecule, and any linear, branched, or cyclic hydrocarbon can be used as appropriate.

  In general, it is known that a polymer domain expands in a good solvent and conversely contracts in a poor solvent to lower the viscosity of the solution. Also in the present invention, when a poor solvent is added, the viscosity decreases, so that a good coated surface can be obtained even with a small amount of solvent.

  As the hydrocarbon solvent of the present invention, a C6-C9 hydrocarbon solvent is used, preferably a C6-C8 hydrocarbon solvent, more preferably a C6-C7 hydrocarbon solvent. . A hydrocarbon solvent having fewer carbon atoms than C6 tends to have poor coating stability because the boiling point is too low. On the other hand, in a hydrocarbon solvent having a carbon number higher than that of C9, the boiling point becomes too high, so that the solvent remains in the pressure-sensitive adhesive layer even after drying, the pressure-sensitive adhesive properties are deteriorated, and the durability is inferior (for example, durability). There is a tendency for defects such as foaming to occur in the test). Also, if the difference in boiling point from the good solvent that dissolves the (meth) acrylic polymer is large, the good solvent will vaporize and evaporate first during coating, and the polymer will precipitate and the coating properties will be reduced. Sometimes it gets worse.

  Specific examples of the C6-C9 hydrocarbon solvent include 3-methylpentane, n-hexane, 2,4-dimethylpentane, and 2,2,3-trimethylbutane. 3,3-dimethylpentane, 2-methylhexane, 2,3-dimethylpentane, 3-methylhexane, n-heptane, 2,2-dimethylhexane, 2,5-dimethylhexane, 2,4-dimethylhexane, 3 , 3-dimethylhexane, 2,3,4-trimethylpentane, 2,3,3-trimethylpentane, 2,3-dimethylhexane, 2-methyl-3-ethylpentane, 2-methylheptane, 4-methylheptane, 3,4-dimethylhexane, 3-methylheptane, 2,2,5-trimethylhexane, n-octane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, IP solvent (manufactured by Idemitsu Kosan), Cactus solvent (Japan Energy) Etc.). These hydrocarbon solvents may be used alone or in combination of two or more.

  In the present invention, the hydrocarbon solvent is prepared so as to be 20% to 60% by weight of the total amount of the organic solvent, preferably 40% to 55% by weight, and preferably 40% to 50% by weight. More preferred. If it is less than 20% by weight of the total amount of the organic solvent, the effect of reducing the viscosity of the solution is small, and the amount of the organic solvent used cannot be reduced. On the other hand, if it exceeds 60% by weight of the total amount of the organic solvent, the (meth) acrylic polymer is precipitated, and a uniform coated surface cannot be obtained.

  Further, the solvent other than the hydrocarbon solvent used in preparing the (meth) acrylic polymer solution is not particularly limited as long as it is a solvent capable of dissolving the (meth) acrylic polymer. Toluene, ethyl acetate, etc. used at the time of polymerization of the acrylic polymer can also be used as appropriate.

  Thus, although it is known that the addition of a poor solvent such as a hydrocarbon decreases the viscosity, the main reason why the poor solvent is not actually used is that the addition of the poor solvent causes the polymer molecular chains to It is presumed that it is difficult to form a crosslinked structure. That is, in a poor solvent such as hydrocarbon, the entanglement of molecular chains is reduced, and the formation of a crosslinked structure between polymer molecular chains is very difficult to occur, and as a result, it is assumed that the durability is deteriorated. . For this reason, in the present invention, it is very important to control the molecular weight of the (meth) acrylic polymer that is the base polymer, and the component ratio of the (meth) acrylic polymer having a weight average molecular weight of 1,500,000 or more and a molecular weight of 100,000 or less. Is 20% by weight or less to solve the above problem.

  In the pressure-sensitive adhesive composition for an optical member of the present invention, a silane coupling agent may be appropriately added as an optional component. As such a silane coupling agent, known ones can be appropriately used without particular limitation.

  For example, epoxy such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Group-containing silane coupling agent, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propyl Amino group-containing silane coupling agents such as amines, (meth) acryl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, and 3-isocyanatopropyltriethoxysilane Insiane Such as preparative group-containing silane coupling agent. Use of such a silane coupling agent is preferable for improving durability.

  The silane coupling agent may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the monomer mixture of the (meth) acrylic polymer. The content is preferably 0.01 to 1 part by weight, more preferably 0.02 to 0.6 part by weight, and still more preferably 0.05 to 0.3 part by weight. When the amount is less than 0.01 part by weight, it is difficult to improve the durability. On the other hand, when the amount exceeds 1 part by weight, the adhesion to the liquid crystal cell tends to increase and the removability is poor.

  In the present invention, a peroxide can be used in order to impart more excellent productivity (such as punching workability).

  The peroxide of the present invention can be used as appropriate as long as it generates radical active species by heating and allows the crosslinking of the base polymer of the pressure-sensitive adhesive composition to proceed, but taking into consideration workability and stability. It is preferable to use a peroxide having a one-minute half-life temperature of 80 ° C. to 160 ° C., and more preferable to use a peroxide having a 90 ° C. to 140 ° C. If the half-life temperature for 1 minute is too low, the reaction proceeds at the time of storage before coating and drying, and the viscosity may become high and the coating may become impossible. On the other hand, if the half-life temperature is too high, Since the temperature becomes high, side reactions occur, and a large amount of unreacted peroxide remains, which may cause cross-linking over time.

  Examples of the peroxide used in the present invention include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate ( 1 minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 ° C.), t-hexyl peroxypivalate (half-life temperature for 1 minute: 109.1 ° C.), t-butyl peroxypivalate (half-life temperature for 1 minute: 110.3 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyl Oxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.). Especially, since the crosslinking reaction efficiency is excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) and the like are preferably used.

  The peroxide may be used alone, or two or more kinds may be mixed and used, but the total content is 0.1% relative to 100 parts by weight of the (meth) acrylic polymer. It is preferably 02 to 2 parts by weight, more preferably 0.05 to 1 part by weight, and further preferably 0.1 to 0.5 part by weight. If less than 0.02 parts by weight, the progress of the crosslinking reaction may be inadequate and may be inferior in durability. On the other hand, if it exceeds 2 parts by weight, the crosslinking structure may be excessive and inferior in adhesiveness. Neither is preferred.

  In addition, when a peroxide is used as a polymerization initiator, it is possible to use the remaining peroxide for the crosslinking reaction without being used in the polymerization reaction. If necessary, it can be added again and used in a predetermined amount of peroxide.

  The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

  In addition, as a measuring method of the decomposition amount of the peroxide which remain | survives after reaction processing, it can measure by HPLC (high performance liquid chromatography), for example.

  Although it is not clear about the crosslinking formation by such a peroxide, it is presumed as follows. In such peroxide crosslinking, first, radicals (active species) generated from the peroxide cause a hydrogen abstraction reaction of the polymer skeleton to generate radicals in the polymer skeleton, and the radicals on the polymer skeleton are coupled. Crosslinking is formed, the entire polymer skeleton is taken into the crosslinked structure, and the entire pressure-sensitive adhesive is uniformly crosslinked. As a result, even if processing such as punching is performed immediately after the cross-linking treatment, the adhesive can adhere to the cutting blade, and the post-processing paste will not show any performance, and the predetermined cross-linking treatment should be performed. Therefore, it is estimated that the characteristics are stabilized because no cross-linking reaction occurs over time.

  The pressure-sensitive adhesive composition of the present invention is more excellent in heat resistance by cross-linking the above (meth) acrylic polymer with a peroxide, but other cross-linking agents can be used in combination. As the crosslinking agent used in the present invention, a polyisocyanate compound, an epoxy compound, an oxazoline compound, a melamine resin, an aziridine derivative, a metal chelate compound, and the like are used. Of these, polyisocyanate compounds are preferably used from the viewpoints of improving adhesive properties and improving anchoring force with the optical member and the polarizing plate. In particular, when an acrylic polymer is produced, a hydroxyl group-containing monomer such as 2-hydroxyethyl acrylate is copolymerized to introduce a hydroxyl group into the acrylic polymer. It is preferable to form a crosslinked structure of the polymer. These compounds may be used alone or in combination.

  The polyisocyanate-based crosslinking agent refers to an isocyanate compound having two or more isocyanate groups (including isocyanate-regenerating functional groups in which isocyanate groups are temporarily protected by quantification, etc.) in one molecule. .

  Examples of the isocyanate compound include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, aliphatic isocyanates such as hexamethylene diisocyanate, and diisocyanate adducts to various polyols.

  More specifically, examples of the isocyanate compound include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate, Aromatic diisocyanates such as 4-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Coronate HL), hexamethylene diisocyanate Over the door of the isocyanurate body (Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HX), and the like, such as isocyanate adducts such as. Furthermore, adducts of various polyols of these isocyanate compounds can be mentioned. These isocyanate compounds may be used alone or in combination of two or more.

  Examples of the oxazoline compound include 2-oxazoline, 3-oxazoline, 4-oxazoline, 5-keto-3-oxazoline, and Epocros (manufactured by Nippon Shokubai Co., Ltd.). These compounds may be used alone or in combination.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (manufactured by Mitsubishi Gas Chemical Company, trade name: TETRAD-X) and 1,3-bis (N, N-diglycidyl). Aminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.). These compounds may be used alone or in combination.

  Examples of the melamine resin include hexamethylol melamine. Examples of the aziridine derivative include a commercial product name HDU (manufactured by Mutual Pharmaceutical Company), a product name TAZM (manufactured by Mutual Pharmaceutical Company), and a product name TAZO (manufactured by Mutual Pharmaceutical Company). These compounds may be used alone or in combination.

  Examples of the aziridine derivative include a commercial product name HDU (manufactured by Mutual Pharmaceutical Company), a product name TAZM (manufactured by Mutual Pharmaceutical Company), and a product name TAZO (manufactured by Mutual Pharmaceutical Company). These compounds may be used alone or in combination of two or more.

  Examples of the metal chelate compound include aluminum, iron, tin, titanium, and nickel as metal components, and acetylene, methyl acetoacetate, and ethyl lactate as chelate components. These compounds may be used alone or in combination.

  The amount of these crosslinking agents to be used is appropriately selected depending on the balance with the (meth) acrylic polymer to be crosslinked and further depending on the intended use as an optical member with an adhesive. In order to obtain sufficient heat resistance due to the cohesive strength of the (meth) acrylic polymer, it is generally contained in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. Preferably, 0.02 to 2 parts by weight is contained. When the content is less than 0.01 parts by weight, the crosslinking formation by the crosslinking agent becomes insufficient, the cohesive strength of the pressure-sensitive adhesive composition becomes small, and sufficient heat resistance may not be obtained. There is a tendency to cause the rest. On the other hand, when the content exceeds 5 parts by weight, the cohesive force of the polymer is large, the fluidity is lowered, the wettability to the adherend is insufficient, and it tends to cause peeling.

  In the present invention, the addition amount of the crosslinking agent so that the gel fraction of the pressure-sensitive adhesive layer after the crosslinking treatment by heating is 35 to 90% by weight, preferably 40 to 85% by weight, more preferably 40 to 70% by weight. The gel fraction after treatment such as aging is 40 to 90% by weight, preferably 45 to 85% by weight. When the gel fraction of the pressure-sensitive adhesive layer after the crosslinking treatment by heating is smaller than 35% by weight, the processability tends to be inferior, and when it exceeds 90% by weight, the adhesiveness tends to be inferior.

The gel fraction of the pressure-sensitive adhesive composition in the present invention means the weight W ₂ after drying the pressure-sensitive adhesive layer after immersing the dry weight W ₁ (g) of the pressure-sensitive adhesive layer in ethyl acetate, and drying the pressure-sensitive adhesive layer from ethyl acetate. (G) is measured and calculated by the following formula.

Gel fraction (% by weight) = (W ₂ / W ₁ ) × 100

More specifically, a pressure-sensitive adhesive layer W ₁ (g) (about 500 mg) after crosslinking was collected. Next, the pressure-sensitive adhesive layer was immersed in ethyl acetate at about 23 ° C. for 7 days, and then the pressure-sensitive adhesive layer was taken out and dried at 130 ° C. for 2 hours. W ₂ (g) of the obtained pressure-sensitive adhesive layer Was measured. By applying W ₁ and W ₂ to the above formula, the gel fraction (% by weight) was determined.

  In order to adjust to a predetermined gel fraction, it is necessary to fully consider the influence of the crosslinking treatment temperature and the crosslinking treatment time as well as adjusting the addition amount of the peroxide and the crosslinking agent.

  The adjustment of the crosslinking treatment temperature and the crosslinking treatment time is, for example, preferably set so that the decomposition amount of the peroxide contained in the optical member pressure-sensitive adhesive composition is 75% by weight or more, and 80% by weight or more. More preferably, the setting is more preferably 85% by weight or more. When the amount of peroxide decomposition is less than 75% by weight, the amount of peroxide remaining in the pressure-sensitive adhesive composition for optical members increases, and as a result, a crosslinking reaction over time occurs even after the crosslinking treatment. In some cases, the gel fraction exceeds 90% by weight, which is not preferable.

  More specifically, for example, at a crosslinking treatment temperature of 1 minute half-life temperature, the decomposition amount of peroxide is 50% by weight in 1 minute, and the decomposition amount of peroxide is 75% by weight in 2 minutes. A crosslinking treatment time of 2 minutes or more is required. For example, if the half-life of the peroxide at the crosslinking treatment temperature (half-life) is 30 seconds, a crosslinking treatment time of 1 minute or more is required. For example, the half-life of the peroxide at the crosslinking treatment temperature If the (half time) is 5 minutes, a crosslinking treatment time of 10 minutes or more is required.

  Thus, the crosslinking treatment temperature and crosslinking treatment time can be calculated by theoretical calculation from the half-life (half-life time) assuming that the peroxide is linearly proportional to the peroxide used. It can be adjusted as appropriate. On the other hand, the higher the temperature, the higher the possibility of side reactions, so the crosslinking treatment temperature is preferably 170 ° C. or lower.

  Moreover, this crosslinking process may be performed at the temperature at the time of the drying process of an adhesive layer, and you may carry out by providing a crosslinking process process separately after a drying process.

  The crosslinking treatment time can be set in consideration of productivity and workability, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.

  Furthermore, the pressure-sensitive adhesive composition for optical members of the present invention may contain other known additives, such as powders such as colorants and pigments, dyes, surfactants, plasticizers, and adhesive properties. Giving agents, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, etc. Can be added as appropriate according to the intended use.

  On the other hand, the pressure-sensitive adhesive layer for optical members of the present invention is formed by crosslinking the pressure-sensitive adhesive composition for optical members as described above. At that time, the pressure-sensitive adhesive composition for optical members is generally crosslinked after the application of the pressure-sensitive adhesive composition for optical members, but the pressure-sensitive adhesive for optical members comprising the pressure-sensitive adhesive composition for optical members after crosslinking. It is also possible to transfer the layer to an optical member or the like.

  The method for forming the pressure-sensitive adhesive layer for the optical member on the optical member (or separator, support film, etc.) is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to a release-treated separator, and the polymerization solvent is dried. It is prepared by a method of removing and forming a pressure-sensitive adhesive layer on an optical member, or a method of applying the pressure-sensitive adhesive composition on an optical member and drying and removing a polymerization solvent to form a pressure-sensitive adhesive layer on the optical member. The Thereafter, if necessary, curing (aging treatment) may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer or adjusting the crosslinking reaction. In addition, when the pressure-sensitive adhesive composition is coated on an optical member (or separator, support film, etc.) to produce pressure-sensitive adhesive sheets, it can be uniformly coated on the optical member (or separator, support film, etc.) One or more solvents (solvents) other than the polymerization solvent may be newly added to the composition.

  Examples of the solvent used in the present invention include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, isopropanol, water and the like. . These solvents may be used alone or in combination of two or more.

  Moreover, as a formation method of the adhesive layer for optical members of this invention, the well-known method used for manufacture of adhesive sheets is used. Specifically, for example, methods such as roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, extrusion coat method using a die coater, etc. Can be given.

  Further, for example, a step of forming a layer made of the pressure-sensitive adhesive composition for an optical member described above on one side or both sides on a release-treated support (a release-treated sheet), and the pressure-sensitive adhesive for the optical member The optical member of the present invention can be obtained by using a manufacturing method including a step of heat-treating a layer made of the pressure-sensitive adhesive composition for optical members so that the decomposition amount of peroxide in the composition is 75% by weight or more. A pressure-sensitive adhesive layer can be obtained. By using such a production method, it is possible to obtain a pressure-sensitive adhesive layer for an optical member that balances the above-described excellent removability, durability, and stress relaxation properties in a balanced manner.

  The surface of the pressure-sensitive adhesive layer may be subjected to easy attachment treatment such as corona treatment or plasma treatment.

  In addition, in this invention, it produces so that the thickness after drying of the said adhesive layer for optical members may be set to 2-500 micrometers, Preferably it is about 5-100 micrometers.

  When the pressure-sensitive adhesive is exposed on such a surface, the pressure-sensitive adhesive layer may be protected with a release-treated sheet (release sheet, separator, release liner) until it is put to practical use.

  As a constituent material of the separator (release sheet, release liner), for example, a plastic film such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, a porous material such as paper, cloth, and nonwoven fabric, a net, a foamed sheet, a metal foil, and Suitable thin leaf bodies such as these laminates can be mentioned, and a plastic film is preferably used from the viewpoint of excellent surface smoothness.

  The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer. Examples thereof include a coalesced film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm.

  For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, when the surface of the separator is appropriately subjected to a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the peelability from the pressure-sensitive adhesive layer can be further improved.

  In the above production method, the release-treated sheet (release sheet, separator, release liner) can be used as it is as a separator for an optical member with an adhesive, and the process can be simplified.

  Moreover, the optical member with an adhesive of this invention forms the adhesive layer for optical members which has said structure on the single side | surface or both surfaces of an optical member.

  As the optical member, those used for forming an image display device such as a liquid crystal display device are used, and the type thereof is not particularly limited. For example, examples of the optical member include a polarizing plate. As the polarizing plate, one having a transparent protective film on one side or both sides of a polarizer is generally used.

  The polarizer is not particularly limited, and various types can be used. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films, and two colors such as iodine and dichroic dyes. Examples include polyene-based oriented films such as those obtained by adsorbing volatile substances and uniaxially stretched, polyvinyl alcohol dehydrated products, and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride and the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

  As a material for forming the transparent protective film provided on one side or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) -Based polymer, polycarbonate-based polymer and the like. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like are also examples of polymers that form the transparent protective film. The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.

  Moreover, the polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a substitution in the side chain And / or a resin composition containing an unsubstituted phenyl and a thermoplastic resin having a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used.

  Although the thickness of a protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin layer property. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable.

  Moreover, it is preferable that a protective film has as little color as possible. Therefore, Rth = [(nx + ny) / 2−nz] · d (where nx and ny are the main refractive index in the plane of the film, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a retardation value in the film thickness direction of −90 nm to +75 nm is preferably used. By using a film having a thickness direction retardation value (Rth) of −90 nm to +75 nm, the coloring (optical coloring) of the polarizing plate caused by the protective film can be almost eliminated. The thickness direction retardation value (Rth) is more preferably −80 nm to +60 nm, and particularly preferably −70 nm to +45 nm.

  As the protective film, a cellulose polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. A triacetyl cellulose film is particularly preferable. In addition, when providing a protective film in the both sides of a polarizer, the protective film which consists of the same polymer material may be used by the front and back, and the protective film which consists of a different polymer material etc. may be used. The polarizer and the protective film are usually in close contact with each other through an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester.

  The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat layer, an antireflection treatment, an antisticking treatment, or a treatment for diffusion or antiglare.

  Hard coat treatment is applied for the purpose of preventing scratches on the surface of the polarizing plate. For example, a transparent protective film with a cured film excellent in hardness, sliding properties, etc. with an appropriate ultraviolet curable resin such as acrylic or silicone It can be formed by a method of adding to the surface of the film. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the conventional art. Further, the anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

  Anti-glare treatment is applied for the purpose of preventing the external light from being reflected on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, the surface is roughened by sandblasting or embossing. It can be formed by imparting a fine concavo-convex structure to the surface of the transparent protective film by an appropriate method such as a blending method of transparent fine particles. The fine particles to be included in the formation of the surface fine concavo-convex structure are, for example, conductive composed of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide or the like having an average particle size of 0.5 to 50 μm. Transparent fine particles such as inorganic fine particles and organic fine particles made of a crosslinked or uncrosslinked polymer may be used. When forming a surface fine uneven structure, the amount of fine particles used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine uneven structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

  The antireflection layer, antisticking layer, diffusion layer, antiglare layer, and the like can be provided on the transparent protective film itself, or can be provided separately from the transparent protective film as an optical layer.

  In addition, examples of the optical member of the present invention include a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), a viewing angle compensation film, and a brightness enhancement film. What becomes an optical layer which may be used for the formation of is mentioned. These can be used alone as the optical member of the present invention, and can be laminated on the polarizing plate for practical use and used in one or more layers.

  In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a polarizing plate is further laminated with a reflecting plate or a semi-transmissive reflecting plate, an elliptical polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on a polarizing plate, a polarizing plate A wide viewing angle polarizing plate in which a viewing angle compensation film is further laminated on a plate, or a polarizing plate in which a brightness enhancement film is further laminated on a polarizing plate is preferable.

  A reflective polarizing plate is a polarizing plate provided with a reflective layer, and is used to form a liquid crystal display device or the like that reflects incident light from the viewing side (display side). Thus, there is an advantage that it is easy to reduce the thickness of the liquid crystal display device. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is attached to one surface of the polarizing plate via a transparent protective layer, if necessary.

  Specific examples of the reflective polarizing plate include those in which a reflective layer is formed by attaching a foil or a vapor deposition film made of a reflective metal such as aluminum on one side of a transparent protective film matted as necessary. Moreover, the transparent protective film contains fine particles so as to have a surface fine concavo-convex structure and a reflective layer having a fine concavo-convex structure thereon. The reflective layer having the fine concavo-convex structure has an advantage that incident light is diffused by irregular reflection to prevent directivity and glaring appearance and to suppress unevenness in brightness and darkness. Moreover, the transparent protective film containing fine particles also has an advantage that incident light and its reflected light are diffused when passing through it and light and dark unevenness can be further suppressed. The reflective layer of the fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film can be formed by, for example, depositing metal by an appropriate method such as a vapor deposition method such as a vacuum vapor deposition method, an ion plating method, a sputtering method, or a plating method. It can be performed by a method of directly attaching to the surface of the transparent protective layer.

  Instead of the method of directly applying the reflecting plate to the transparent protective film of the polarizing plate, the reflecting plate can be used as a reflecting sheet provided with a reflecting layer on an appropriate film according to the transparent film. Since the reflective layer is usually made of metal, the usage form in which the reflective surface is covered with a transparent protective film, a polarizing plate, etc. prevents the decrease in reflectance due to oxidation, and thus the long-term sustainability of the initial reflectance. In addition, it is more preferable to avoid a separate attachment of the protective layer.

  The transflective polarizing plate can be obtained by using a transflective reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell, and displays an image by reflecting incident light from the viewing side (display side) when a liquid crystal display device is used in a relatively bright atmosphere. In a relatively dark atmosphere, a liquid crystal display device or the like that displays an image using a built-in light source such as a backlight built in the back side of the transflective polarizing plate can be formed. In other words, the transflective polarizing plate can save the energy of using a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device that can be used with a built-in light source in a relatively dark atmosphere. It is.

  An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on a polarizing plate will be described. A phase difference plate or the like is used when changing linearly polarized light to elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The elliptically polarizing plate is effectively used for black-and-white display without the above color by compensating (preventing) the coloration (blue or yellow) generated by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device. It is done. Further, the one in which the three-dimensional refractive index is controlled is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which the image is displayed in color, and also has an antireflection function.

  Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm.

  Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene resin, or binary, ternary various copolymers, graft copolymers Examples thereof include polymers and blends. These polymer materials become oriented products (stretched films) by stretching or the like.

  Examples of the liquid crystalline polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. It is done. Specific examples of main-chain liquid crystalline polymers include nematic alignment polyester liquid crystalline polymers, discotic polymers, cholesteric polymers, etc., which have a structure in which mesogenic groups are bonded at a spacer portion that imparts flexibility. It is done. Specific examples of the side chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment imparting paraffin through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a substituted cyclic compound unit. These liquid crystalline polymers can be obtained by, for example, applying a solution of a liquid crystalline polymer on an alignment surface such as one obtained by rubbing the surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate or one obtained by obliquely depositing silicon oxide. This is done by developing and heat treatment.

  The retardation plate may have an appropriate retardation according to the purpose of use, such as for the purpose of compensating for coloring or viewing angle due to birefringence of various wavelength plates and liquid crystal layers, for example. In this case, the retardation plate may be laminated to control optical characteristics such as retardation.

  The elliptical polarizing plate and the reflective elliptical polarizing plate are obtained by laminating a polarizing plate or a reflective polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate can also be formed by sequentially laminating them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflection type) polarizing plate and a retardation plate. An optical member such as an elliptically polarizing plate is advantageous in that it is excellent in quality stability, laminating workability, etc., and can improve the manufacturing efficiency of a liquid crystal display device or the like.

  The viewing angle compensation film is a film for widening the viewing angle so that an image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed from a slightly oblique direction rather than perpendicular to the screen. Examples of such a viewing angle compensation phase difference plate include a phase difference plate, an alignment film such as a liquid crystal polymer, and a support in which an alignment layer such as a liquid crystal polymer is supported on a transparent substrate. A normal retardation plate uses a birefringent polymer film uniaxially stretched in the plane direction, whereas a retardation plate used as a viewing angle compensation film stretches biaxially in the plane direction. Birefringent polymer film, biaxially stretched film such as polymer with birefringence with a controlled refractive index in the thickness direction that is uniaxially stretched in the plane direction and stretched in the thickness direction, etc. Used. Examples of the tilted alignment film include a film obtained by bonding a heat shrink film to a polymer film and stretching or / and shrinking the polymer film under the action of the contraction force by heating, or a film obtained by obliquely aligning a liquid crystal polymer. Can be given. The raw material polymer for the phase difference plate is the same as the polymer described in the previous phase difference plate, preventing coloration due to a change in the viewing angle based on the phase difference by the liquid crystal cell and expanding the viewing angle for good visual recognition. An appropriate one for the purpose can be used.

  Also, from the viewpoint of achieving a wide viewing angle with good visibility, an optically compensated phase difference in which a liquid crystal polymer alignment layer, in particular an optically anisotropic layer composed of a discotic liquid crystal polymer gradient alignment layer, is supported by a triacetylcellulose film. A plate can be preferably used.

  A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is usually provided on the back side of a liquid crystal cell. The brightness enhancement film reflects a linearly polarized light with a predetermined polarization axis or a circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and transmits other light. In addition, a polarizing plate in which a brightness enhancement film is laminated with a polarizing plate allows light from a light source such as a backlight to enter to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. The The light reflected from the surface of the brightness enhancement film is further inverted through a reflective layer provided behind the brightness enhancement film and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light having a predetermined polarization state. The brightness can be improved by increasing the amount of light transmitted through the improvement film and increasing the amount of light that can be used for liquid crystal display image display by supplying polarized light that is difficult to absorb into the polarizer. is there. That is, when light is incident through the polarizer from the back side of the liquid crystal cell without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost polarized. It is absorbed by the polarizer and does not pass through the polarizer. That is, although depending on the characteristics of the polarizer used, approximately 50% of the light is absorbed by the polarizer, and accordingly, the amount of light that can be used for liquid crystal image display is reduced, resulting in a dark image. In the brightness enhancement film, light having a polarization direction that is absorbed by the polarizer is reflected once by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflection layer provided on the rear side thereof. Repeatedly re-enter the brightness enhancement film, and the brightness enhancement film transmits only polarized light whose polarization direction is such that the polarization direction of light reflected and inverted between the two can pass through the polarizer. Therefore, light such as a backlight can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.

  A diffusion plate may be provided between the brightness enhancement film and the reflective layer. The polarized light reflected by the brightness enhancement film is directed to the reflective layer or the like, but the installed diffuser plate uniformly diffuses the light passing therethrough and at the same time cancels the polarized state and becomes a non-polarized state. That is, the diffuser plate returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the natural light state is directed to the reflection layer and the like, reflected through the reflection layer and the like, and again passes through the diffusion plate and reenters the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffuser plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., at the same time, the unevenness of the brightness of the display screen is reduced, A uniform and bright screen can be provided. By providing such a diffuser plate, it is considered that the first incident light has a moderate increase in the number of repetitions of reflection, and in combination with the diffusion function of the diffuser plate, a uniform bright display screen can be provided.

  As the brightness enhancement film, for example, a dielectric multilayer thin film or a multilayer laminate of thin film films having different refractive index anisotropy, such as a characteristic that transmits linearly polarized light having a predetermined polarization axis and reflects other light. Such as a cholesteric liquid crystal polymer alignment film or a film substrate whose alignment liquid crystal layer is supported on a film substrate, which reflects either left-handed or right-handed circularly polarized light and transmits other light. Appropriate ones such as those shown can be used.

  Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis as described above, the transmitted light is incident on the polarizing plate with the polarization axis aligned as it is, thereby efficiently transmitting while suppressing absorption loss due to the polarizing plate. Can be made. On the other hand, in a brightness enhancement film of a type that emits circularly polarized light such as a cholesteric liquid crystal layer, it can be directly incident on a polarizer, but the circularly polarized light is converted into linearly polarized light through a retardation plate in order to suppress absorption loss. It is preferably incident on the polarizing plate. Note that circularly polarized light can be converted to linearly polarized light by using a quarter wave plate as the retardation plate.

  A retardation plate that functions as a quarter-wave plate in a wide wavelength range such as a visible light region has, for example, a retardation layer that functions as a quarter-wave plate for light-color light with a wavelength of 550 nm and other retardation characteristics. The phase difference layer shown, for example, the method of superposing | stacking the phase difference layer which functions as a half-wave plate, etc. can obtain. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.

  In addition, the cholesteric liquid crystal layer can also be obtained by reflecting circularly polarized light in a wide wavelength range such as a visible light region by combining two or more layers having different reflection wavelengths and overlapping the structure. Based on this, transmitted circularly polarized light in a wide wavelength range can be obtained.

  Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers like the above-described polarization separation type polarizing plate. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-mentioned reflective polarizing plate or transflective polarizing plate and a retardation plate are combined may be used.

  The optical member in which the optical layer is laminated on the polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device and the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as a pressure-sensitive adhesive layer can be used. When adhering the polarizing plate and the other optical layer, their optical axes can be set at an appropriate arrangement angle in accordance with the target phase difference characteristic.

  In addition, in each layer such as an optical member or an adhesive layer of the adhesive optical member of the present invention, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex compound, etc. What gave the ultraviolet absorptivity by systems, such as a system processed with a ultraviolet absorber, etc. may be used.

  The pressure-sensitive adhesive optical member of the present invention can be preferably used for forming various image display devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an adhesive optical member, and an illumination system as necessary, and incorporating a drive circuit. There is no limitation in particular except the point which uses the optical member by invention, It can apply to the former. As the liquid crystal cell, for example, an arbitrary type such as a TN type, an STN type, or a π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which an adhesive optical member is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflector used in an illumination system can be formed. In that case, the optical member by this invention can be installed in the one side or both sides of a liquid crystal cell. When optical members are provided on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer of appropriate parts such as a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a backlight at an appropriate position. Alternatively, two or more layers can be arranged.

  Next, an organic electroluminescence device (organic EL display device) will be described. Generally, in an organic EL display device, a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitter (organic electroluminescent light emitter). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Or a combination of such a light emitting layer and an electron injection layer composed of a perylene derivative, or a combination of these hole injection layer, light emitting layer, and electron injection layer. Are known.

  In organic EL display devices, holes and electrons are injected into the organic light-emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the phosphor material. Then, light is emitted on the principle that the excited fluorescent material emits light when returning to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

  In an organic EL display device, in order to extract light emitted from the organic light emitting layer, at least one of the electrodes must be transparent, and a transparent electrode usually formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. It is used as. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually metal electrodes such as Mg—Ag and Al—Li are used.

  In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate. The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device comprising an organic electroluminescent light emitting device comprising a transparent electrode on the surface side of an organic light emitting layer that emits light upon application of a voltage and a metal electrode on the back side of the organic light emitting layer, the surface of the transparent electrode While providing a polarizing plate on the side, a retardation plate can be provided between the transparent electrode and the polarizing plate.

  Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, the mirror surface of the metal electrode can be completely shielded by configuring the retardation plate with a quarter-wave plate and adjusting the angle formed by the polarization direction of the polarizing plate and the retardation plate to π / 4. .

  That is, only the linearly polarized light component of the external light incident on the organic EL display device is transmitted by the polarizing plate. This linearly polarized light becomes generally elliptically polarized light by the phase difference plate, but becomes circularly polarized light particularly when the phase difference plate is a quarter wavelength plate and the angle formed by the polarization direction of the polarizing plate and the phase difference plate is π / 4. .

  This circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, is again transmitted through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized light again on the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot permeate | transmit a polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

  Hereinafter, examples and the like specifically showing the configuration and effects of the present invention will be described, but the present invention is not limited thereto. In addition, the evaluation item in an Example etc. measured as follows.

<Measurement of molecular weight>
The molecular weight was measured by GPC (gel permeation chromatography).

Analyzing device: manufactured by Tosoh Corporation, HLC-8120GPC
column:
Sample column;
Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
Column size: 7.8 mmφ x 30 cm each (total 90 cm)
Flow rate: 0.8ml / min
Injection sample concentration: about 0.1% by weight
Injection volume: 100 μl
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Detector: Differential refractometer (RI)
The molecular weight was calculated in terms of polystyrene.

  In addition, the component ratio (weight fraction (Area%)) having a weight average molecular weight of 100,000 or less was calculated by the following data processing apparatus using the result of the GPC measurement.

  Data processing device: GPC-8020 manufactured by Tosoh Corporation

<Measurement of peroxide decomposition amount (decomposition rate)>
The decomposition amount (decomposition rate) of the peroxide after the thermal decomposition treatment was measured by HPLC (High Performance Liquid Chromatography) as described below.

  About 0.2 g of each pressure-sensitive adhesive composition before and after the decomposition treatment was taken out, immersed in 10 ml of ethyl acetate, extracted with shaking at 25 ° C. and 120 rpm for 3 hours, and then allowed to stand at room temperature for 3 days. Next, 10 ml of acetonitrile was added, shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into the HPLC for analysis. The change in the amount of peroxide was defined as the amount of peroxide decomposition.

Further, the ratio value ((P ₁ / P ₀ ) × 100 (% by weight)) obtained by dividing the value P ₁ (g) after the decomposition treatment by the value P ₀ (g) before the decomposition treatment is used as the peroxide. The decomposition rate (% by weight) was used.

Equipment: HPL CCPM / UV8000, manufactured by Tosoh Corporation
column:
Sample column;
NUCLEOSIL 7C18 (manufactured by MACHEREY-NAGEL, 4.6 mmφ × 250 mm)
Flow rate: 1.0ml / min
Column pressure: 41 kg / cm ²
Column temperature: 40 ° C
Eluent: Water / acetonitrile = 30/70
Injection volume: 10 μl
Injection sample concentration: 0.01% by weight
Detector: UV detector (230 nm)

<Measurement of gel fraction>
W ₁ g (about 0.1 g) of the pressure-sensitive adhesive layer prepared in each Example / Comparative Example was taken out and immersed in ethyl acetate at room temperature (about 25 ° C.) for 1 week. Thereafter, the pressure-sensitive adhesive layer that has been soaked is taken out from ethyl acetate, and the weight W ₂ g after drying at 130 ° C. for 2 hours is measured, and the value calculated as (W ₂ / W ₁ ) × 100 (% by weight) is calculated. The gel fraction (% by weight) was used.

<Evaluation of viscosity>
The viscosity of the prepared adhesive solution was measured with a viscometer (manufactured by Toki Sangyo Co., Ltd., TV-20 type, spindle type).

Rotor: THH-14
Rotation speed: 10rpm
Shear rate: 2.5 / s
Measurement temperature: 23 ° C

<Evaluation of coatability>
The viscosity was evaluated based on the viscosity value at the time of the viscosity measurement. The evaluation criteria are as follows.

When the viscosity is 10,000 mPa · s or less: ○
When the viscosity exceeds 10,000 mPa · s: ×
When a uniform coated surface cannot be obtained (such as when a polymer is deposited): ×

<Durability evaluation>
The produced optical member was cut into a size of 240 mm in length and 320 mm in width (15-inch size) and attached to a non-alkali glass plate (Corning Corp., 1737, size: 250 × 350 mm, thickness: 0.7 mm), Autoclave treatment was performed at 50 ° C. and a pressure of 0.5 MPa for 30 minutes. Thereafter, the sample was stored for 500 hours in an atmosphere of 60 ° C. × 90% RH and then returned to room temperature (about 25 ° C.) to obtain a sample for evaluation.

  The adhesion state of the sample for evaluation to the glass plate was visually observed and evaluated. The evaluation criteria are as follows.

The optical member did not float or peel off. : ○
When the optical member was slightly lifted or peeled off, but it did not hinder the use of the present invention.
Match: △
The optical member was lifted or peeled off. : ×

<Evaluation of workability>
The produced optical member was subjected to a punching process using a press machine without performing an aging process.

  The state of the cutting blade during the processing was visually evaluated. The evaluation criteria are as follows.

When there is no adhesion / breakage of the adhesive layer: ○
When adhesion / breakage of the pressure-sensitive adhesive layer was slightly observed, but there was no problem in the use of the present invention:
△
When adhesion / breakage of adhesive layer is observed: ×

<Preparation of (meth) acrylic polymer>
[Acrylic polymer (A)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube and a condenser, n-butyl acrylate 80 parts by weight, 2-ethylhexyl acrylate 15 parts by weight, acrylic acid 5 parts by weight, 2-hydroxyethyl acrylate 0 0.08 part by weight, 0.12 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator, 210 parts by weight of ethyl acetate, and after introducing nitrogen gas while gently stirring, A polymerization reaction was carried out for 10 hours while maintaining the liquid temperature in the flask at 56 ° C. to prepare an acrylic polymer (A) solution. The acrylic polymer (A) had a weight average molecular weight of 2.2 million and a component ratio of 100,000 or less was 2% by weight. The polymer concentration after polymerization was 32% by weight.

[Acrylic polymer (B)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube and a condenser, 90 parts by weight of n-butyl acrylate, 10 parts by weight of ethyl acrylate, 1 part by weight of acrylic acid, 0.08 of 2-hydroxyethyl acrylate Part by weight, 0.35 parts by weight of benzoyl peroxide as a polymerization initiator and 200 parts by weight of ethyl acetate were added, and nitrogen gas was introduced with gentle stirring to replace the nitrogen, and then the liquid temperature in the flask was maintained at 56 ° C. For 10 hours to prepare an acrylic polymer (B) solution. The acrylic polymer (B) had a weight average molecular weight of 2.4 million and a component ratio of 100,000 or less was 3% by weight. The polymer concentration after polymerization was 34% by weight.

[Example 1]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 283 parts by weight of heptane and 73 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (1). At this time, the proportion of heptane in the total amount of the organic solvent was 50% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (1), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (2).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (2) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic adhesive solution (2) had a viscosity of 4900 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 71 weight%, and the decomposition rate of dibenzoyl peroxide was 84 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Example 2]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 227 parts by weight of heptane and 130 parts by weight of ethyl acetate were added and uniformly mixed and stirred to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (3). At this time, the proportion of heptane in the total amount of the organic solvent was 40% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (3), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (4).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (4) was applied to one side of a silicone-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (4) had a viscosity of 6500 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 71 weight%, and the decomposition rate of dibenzoyl peroxide was 84 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 3
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 283 parts by weight of heptane and 73 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (5). At this time, the proportion of heptane in the total amount of the organic solvent was 50% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (5), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (Half-life: 130 ° C.) 0.3 parts by weight, 0.5 part by weight of trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a cross-linking agent was added and mixed and stirred uniformly. An acrylic pressure-sensitive adhesive solution (6) was prepared.

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (6) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (6) had a viscosity of 4900 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 82 weight%, and the decomposition rate of dibenzoyl peroxide was 84 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 4
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 142 parts by weight of heptane and 215 parts by weight of ethyl acetate were added and uniformly mixed and stirred to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (7). At this time, the proportion of heptane in the total amount of the organic solvent was 25% by weight.

  Then, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (7), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (Half-life: 130 ° C.) 0.3 parts by weight, trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a crosslinking agent was added and mixed and stirred uniformly. An acrylic pressure-sensitive adhesive solution (8) was prepared.

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (8) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (8) had a viscosity of 9500 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 75 weight%, and the decomposition rate of dibenzoyl peroxide was 80 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Reference Example 1]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (5), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide as a peroxide (halved for 1 minute) Period: 130 ° C.) 5 parts by weight was added and mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (9).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (9) is applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying is A 25 μm pressure-sensitive adhesive layer was formed. In addition, the viscosity of the said acrylic adhesive solution (9) was 4900 mPa * s, and there was no problem in applicability | paintability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 94 weight%, and the decomposition rate of dibenzoyl peroxide was 82 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Reference Example 2]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (5), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent and dibenzoyl peroxide as a peroxide (half-life for 1 minute) : 130 ° C.) 0.3 parts by weight was added and mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (10).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (10) was applied to one side of a silicone-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 90 ° C. for 2 minutes. A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (10) had a viscosity of 4900 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 53 weight%, and the decomposition rate of dibenzoyl peroxide was 38 weight%. Moreover, the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, As a result, the gel fraction rose to 88 weight%.

[Reference Example 3]
(Preparation of pressure-sensitive adhesive solution for optical members)
100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (5), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and trimethylolpropane / tolylene diisocyanate trimer as a crosslinking agent 0.8 part by weight of an adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) was added and mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (11).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (11) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (11) had a viscosity of 4900 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 75 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 5
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 283 parts by weight of hexane and 73 parts by weight of ethyl acetate were added and uniformly mixed and stirred to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (12). At this time, the ratio of hexane in the total amount of the organic solvent was 50% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (12), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (13).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (13) was applied to one side of a polyethylene-treated polyethylene terephthalate film (Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (13) had a viscosity of 3700 mPa · s, and there was no problem in coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 73 weight%, and the decomposition rate of dibenzoyl peroxide was 83 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 6
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 283 parts by weight of cyclohexane and 73 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (14). At this time, the ratio of cyclohexane in the total amount of the organic solvent was 50% by weight.

  Subsequently, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (14), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (15).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (15) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (15) had a viscosity of 7800 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 76 weight%, and the decomposition rate of dibenzoyl peroxide was 83 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 7
(Preparation of pressure-sensitive adhesive solution for optical members)
Cactus solvent (manufactured by Japan Energy) 283 parts by weight and ethyl acetate 73 parts by weight were added to 310 parts by weight of the acrylic polymer (A) solution, and the mixture was uniformly mixed and stirred. A 15% by weight acrylic adhesive solution (16 ) Was prepared. At this time, the ratio of the cactus solvent in the total amount of the organic solvent was 50% by weight.

  Subsequently, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (16), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (17).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (17) is applied to one side of a silicone-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 140 ° C. for 2 minutes. A 25 μm pressure-sensitive adhesive layer was formed. In addition, the viscosity of the said acrylic adhesive solution (17) was 4900 mPa * s, and there was no problem in coating property.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 75 weight%, and the decomposition rate of dibenzoyl peroxide was 83 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Reference Example 4]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 523 parts by weight of ethyl acetate was added and uniformly mixed and stirred to prepare a 12% by weight acrylic pressure-sensitive adhesive solution (18).

  Subsequently, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (18), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (19).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (19) is applied to one side of a silicone-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 140 ° C. for 2 minutes. A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (19) had a viscosity of 6700 mPa · s, and there was no problem in coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 76 weight%, and the decomposition rate of dibenzoyl peroxide was 83 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Comparative Example 1]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 357 parts by weight of ethyl acetate was added and uniformly mixed and stirred to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (20).

  Next, 100 parts by weight of solid content of the acrylic pressure-sensitive adhesive solution (20), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (21).

(Preparation of optical member with adhesive)
The acrylic adhesive solution (21) was applied to one side of a silicone-treated polyethylene terephthalate film (Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (21) had a viscosity of 25000 mPa · s, and there was a significant problem in coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 78 weight%, and the decomposition rate of dibenzoyl peroxide was 84 weight%.

[Comparative Example 2]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 57 parts by weight of heptane and 300 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (22). At this time, the proportion of heptane in the total amount of the organic solvent was 10% by weight.

  Subsequently, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (22), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (23).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (23) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The viscosity of the acrylic pressure-sensitive adhesive solution (23) was very high at 21000 mPa · s, and there was a big problem in coatability.

  In addition, the gel fraction of the said adhesive layer was 77 weight%, and the decomposition rate of dibenzoyl peroxide was 80 weight%.

[Comparative Example 3]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 357 parts by weight of heptane was added and uniformly mixed and stirred to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (24). At this time, the proportion of heptane in the total amount of the organic solvent was 63% by weight.

  Subsequently, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (24), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (25).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (25) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The viscosity of the acrylic pressure-sensitive adhesive solution (25) was 3900 mPa · s. However, a polymer was deposited during coating, and a uniform coating surface could not be obtained. .

  In addition, the gel fraction of the said adhesive layer was 75 weight%, and the decomposition rate of dibenzoyl peroxide was 82 weight%.

[Comparative Example 4]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 310 parts by weight of the acrylic polymer (A) solution, 227 parts by weight of decane and 130 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (26). At this time, the ratio of decane in the total amount of the organic solvent was 40% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (26), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (A half life: 130 degreeC) 0.3 weight part was added, and it mixed and stirred uniformly, and prepared the acrylic adhesive solution (27).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (27) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The viscosity of the acrylic pressure-sensitive adhesive solution (27) was 5500 mPa · s. However, a polymer was deposited during coating, and a uniform coating surface could not be obtained, resulting in a large problem in coating properties. .

  In addition, the gel fraction of the said adhesive layer was 75 weight%, and the decomposition rate of dibenzoyl peroxide was 84 weight%.

Example 8
(Preparation of pressure-sensitive adhesive solution for optical members)
To 301 parts by weight of the acrylic polymer (B) solution, 258 parts by weight of heptane and 115 parts by weight of ethyl acetate were added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (28). At this time, the proportion of heptane in the total amount of the organic solvent was 45% by weight.

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (28), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (Half-life: 130 ° C.) 0.3 parts by weight, trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a crosslinking agent was added and mixed and stirred uniformly. An acrylic pressure-sensitive adhesive solution (29) was prepared.

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (29) is applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 140 ° C. for 2 minutes to obtain a thickness after drying. A 25 μm pressure-sensitive adhesive layer was formed. In addition, the viscosity of the said acrylic adhesive solution (29) was 1830 mPa * s, and there was no problem in applicability | paintability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 83 weight%, and the decomposition rate of dibenzoyl peroxide was 83 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

Example 9
(Preparation of pressure-sensitive adhesive solution for optical members)
100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (28), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and di (4-t-butylcyclohexyl) as a peroxide 0.2 parts by weight of peroxydicarbonate (half-life of 1 minute: 92.1 ° C.), 0.8 weight of trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a crosslinking agent Part was added and mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (30).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (30) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 140 ° C. for 2 minutes to obtain a thickness after drying. A 25 μm pressure-sensitive adhesive layer was formed. In addition, the viscosity of the said acrylic adhesive solution (30) was 1830 mPa * s, and there was no problem in applicability | paintability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 83 weight%, and the decomposition rate of di (4-t-butylcyclohexyl) peroxydicarbonate was 95 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Reference Example 5]
(Preparation of pressure-sensitive adhesive solution for optical members)
100 parts by weight of solid content of the acrylic pressure-sensitive adhesive solution (28), 0.3 parts by weight of dibenzoyl peroxide (1 minute half-life: 130 ° C.) as a peroxide, and trimethylolpropane / tolylene diisocyanate as a crosslinking agent 0.8 parts by weight of a trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) was added and uniformly mixed and stirred to prepare an acrylic pressure-sensitive adhesive solution (31).

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (31) is applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm) and heated at 140 ° C. for 2 minutes. A 25 μm pressure-sensitive adhesive layer was formed. The acrylic pressure-sensitive adhesive solution (31) had a viscosity of 1830 mPa · s, and there was no problem with the coatability.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 80 weight%, and the decomposition rate of dibenzoyl peroxide was 88 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Reference Example 6]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 301 parts by weight of the acrylic polymer (B) solution, 540 parts by weight of ethyl acetate was added and uniformly mixed and stirred to prepare a 12% by weight acrylic pressure-sensitive adhesive solution (32).

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (32), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (Half-life: 130 ° C.) 0.3 parts by weight, trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a crosslinking agent was added and mixed and stirred uniformly. An acrylic pressure-sensitive adhesive solution (33) was prepared.

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (33) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. In addition, the viscosity of the said acrylic adhesive solution (33) was 2300 mPa * s, and there was no problem in coating property.

  Subsequently, the said adhesive layer was transcribe | transferred to the surface of the polarizing film, and the optical member with an adhesive was produced. In addition, the gel fraction of the said adhesive layer was 80 weight%, and the decomposition rate of dibenzoyl peroxide was 88 weight%. Moreover, even if the said adhesive layer was preserve | saved for one month in a 60 degreeC environment, the increase in the gel fraction was not observed.

[Comparative Example 5]
(Preparation of pressure-sensitive adhesive solution for optical members)
To 301 parts by weight of the acrylic polymer (B) solution, 373 parts by weight of ethyl acetate was added and mixed and stirred uniformly to prepare a 15% by weight acrylic pressure-sensitive adhesive solution (34).

  Next, 100 parts by weight of the solid content of the acrylic pressure-sensitive adhesive solution (34), 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent, and dibenzoyl peroxide (1 minute as a peroxide) (Half-life: 130 ° C.) 0.3 parts by weight, trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L) as a crosslinking agent was added and mixed and stirred uniformly. An acrylic pressure-sensitive adhesive solution (35) was prepared.

(Preparation of optical member with adhesive)
The acrylic pressure-sensitive adhesive solution (35) was applied to one side of a polyethylene-treated polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 38 μm), heated at 140 ° C. for 2 minutes, and the thickness after drying was A 25 μm pressure-sensitive adhesive layer was formed. The viscosity of the acrylic pressure-sensitive adhesive solution (35) was very high at 16000 mPa · s, and there was a big problem in coatability.

  In addition, the gel fraction of the said adhesive layer was 80 weight%, and the decomposition rate of dibenzoyl peroxide was 88 weight%.

  Table 1 shows the configurations of the above examples and comparative examples and the obtained results.

上記表１の結果より、本発明によって作製された粘着剤付光学部材を用いた場合（実施例１〜９）、いずれの実施例においても、溶媒量を削減しながらも、低粘度で良好な塗工面を得る事ができ、かつ耐久性、加工性も良好であることが分かる。

From the results of Table 1 above, when using the optical member with pressure-sensitive adhesive produced according to the present invention (Examples 1 to 9), in any of the examples, the amount of the solvent is reduced and the viscosity is low and good. It can be seen that a coated surface can be obtained, and durability and workability are also good.

  On the other hand, when an optical member with an adhesive that does not satisfy the configuration of the present invention is used (Comparative Examples 1 to 5), in any of the comparative examples, the viscosity is high and the coating cannot be performed uniformly. It can be seen that it is difficult to obtain a good coated surface due to unevenness.

Claims (9)

It contains 60% by weight or more of a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 4 carbon atoms as a monomer unit, and the proportion of components having a weight average molecular weight of 1.5 million or more and a molecular weight of 100,000 or less is 20% or less. In the pressure-sensitive adhesive composition containing a certain (meth) acrylic polymer and an organic solvent,
A C6 to C9 hydrocarbon solvent is contained in an amount of 20 to 60% by weight in the total amount of the organic solvent.   The pressure-sensitive adhesive composition for an optical member according to claim 1, wherein the (meth) acrylic polymer contains 0.2 to 7% by weight of unsaturated carboxylic acid as a monomer unit.   The pressure-sensitive adhesive composition for an optical member according to claim 1 or 2, further comprising 0.01 to 1 part by weight of a silane coupling agent with respect to 100 parts by weight of the (meth) acrylic polymer.   The pressure-sensitive adhesive composition for an optical member according to any one of claims 1 to 3, further comprising 0.02 to 2 parts by weight of a peroxide with respect to 100 parts by weight of the (meth) acrylic polymer.   The pressure-sensitive adhesive composition for an optical member according to any one of claims 1 to 4, further comprising 0.1 to 5 parts by weight of a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer.   The process of forming the layer which consists of an adhesive composition for optical members of Claim 4 or 5 on the single side | surface or both surfaces on the peeling support body, and decomposition | disassembly of the peroxide in the said adhesive composition for optical members And a step of heat-treating the layer made of the pressure-sensitive adhesive composition for optical members so that the amount is 75% by weight or more.   An optical member pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for optical members according to claim 1.   6. An optical with pressure-sensitive adhesive, wherein the pressure-sensitive adhesive layer for an optical member formed by crosslinking the pressure-sensitive adhesive composition for an optical member according to claim 1 is formed on one side or both sides of the optical member. Element.   An image display device using at least one optical member with an adhesive according to claim 8.