JP5038797B2 - Adhesive composition, adhesive layer and method for producing the same, and optical member with adhesive - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive composition having a low light reflection loss at the interface with an optical member and a low moisture content after the crosslinking treatment. Moreover, this invention relates to the adhesive layer formed with the said adhesive composition, and its manufacturing method. Furthermore, this invention provides the optical member with an adhesive which has the said adhesive layer, and an image display apparatus using the same.

  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. Examples of the image display device include a liquid crystal display device, an organic EL display device, and a PDP (plasma display).

  When various optical members, liquid crystal panels, various light sources, diffusion plates, and the like are bonded together, an acrylic adhesive is used because of its excellent transparency and weather resistance.

  However, the refractive index of the optical member is usually 1.52 to 1.55 for glass, 1.54 for polycarbonate, and about 1.50 for triacetyl cellulose, and the refractive index of acrylic adhesive is about 1.47. Since there is a large difference, a difference in refractive index occurs at the interface between the optical member and the pressure-sensitive adhesive. When light enters at a shallow angle, there is a problem that effective use of light is hindered.

  In order to solve such problems, various attempts have been made to create an acrylic pressure-sensitive adhesive having a high refractive index. Such attempts can be broadly divided into a method of using an acrylic copolymer having a high refractive index by copolymerizing a high refractive index monomer as a base polymer of an acrylic pressure-sensitive adhesive, and an ordinary acrylic polymer having a low refractive index. A method of increasing the refractive index of an acrylic pressure-sensitive adhesive by adding a refractive index adjusting agent to a copolymer has been studied.

  For example, as an example of the former, an acrylic adhesive having a refractive index of 1.48 or more using an acrylic copolymer obtained by copolymerizing a monomer having an aromatic group substituted or not substituted with bromine as a base polymer. An agent is disclosed (for example, see Patent Document 1). Further, an acrylic pressure-sensitive adhesive having a refractive index of 1.49 to 1.60 using an acrylic copolymer copolymerized with an aromatic group-containing monomer is disclosed as a base polymer (see, for example, Patent Document 2). . Further, an acrylic pressure-sensitive adhesive having a refractive index of 1.50 to 1.55 using an acrylic copolymer obtained by copolymerizing 40 to 90% by weight of an aromatic group monomer is disclosed (for example, see Patent Document 3). .

  However, like the acrylic pressure-sensitive adhesives disclosed in these patent documents, the pressure-sensitive adhesive copolymerized with an aromatic-containing monomer has a high glass transition temperature (Tg), so it is difficult to balance the pressure-sensitive adhesive properties. The amount that can be copolymerized is very limited. A monomer substituted with bromine can also be used, but from the viewpoint of environmental measures, the movement of non-halogen is active mainly in electrical and electronic applications, which is not preferable.

  On the other hand, as the latter example, an acrylic pressure-sensitive adhesive to which a tackifier is added to adjust the refractive index and adhesive strength of the pressure-sensitive adhesive is disclosed (for example, see Patent Documents 4 and 5). An acrylic pressure-sensitive adhesive in which a styrene-based oligomer having a molecular weight of 900 or less is added as a refractive index adjusting agent to a polymer-based polymer is disclosed (for example, see Patent Document 6).

  However, like the acrylic pressure-sensitive adhesives disclosed in these patent documents, when adjusting the refractive index with an additive such as a tackifier, there are problems such as compatibility with the pressure-sensitive adhesive. Specifically, for example, when a large amount of a refractive index adjusting agent is added, the acrylic pressure-sensitive adhesive becomes cloudy and the adhesive strength is reduced, so that the amount used thereof is limited.

Special table 2003-535921 gazette JP 2002-173656 A JP 2003-13029 A JP 2000-321960 A JP 2002-14225 A JP 2003-342546 A

  Therefore, the present invention exhibits excellent adhesive properties after the crosslinking treatment in order to cope with the above-mentioned problems, does not cause defects such as foaming, floating and peeling in the heating test / humidification test, and has excellent durability and optical properties. An object of the present invention is to provide a pressure-sensitive adhesive composition for an optical member having a low light reflection loss at the interface with the member and a low moisture content.

  Moreover, an object of this invention is to provide the adhesive layer formed with the said adhesive composition, and its manufacturing method. Furthermore, an object of this invention is to provide the optical member with an adhesive which has the said adhesive layer, and an image display apparatus using the same.

  In order to achieve the above-mentioned object, the present inventors diligently studied the constitution of the pressure-sensitive adhesive composition, and as a result, found the following pressure-sensitive adhesive composition and pressure-sensitive adhesive layer, and completed the present invention.

That is, the pressure-sensitive adhesive composition of the present invention is for an optical member,
The base polymer is a (meth) acrylic polymer having a glass transition temperature of 0 ° C. or lower and containing, as a monomer unit, a (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment in the side chain.

In addition, the method for producing the pressure-sensitive adhesive composition for optical members of the present invention,
Including a step of forming a layer made of the above-mentioned pressure-sensitive adhesive composition for optical members on one side or both sides of a support, and a step of subjecting the layer made of the pressure-sensitive adhesive composition for optical members to an organic peroxide crosslinking treatment. Features.

  According to the present invention, as shown in the results of the examples, the adhesive composition containing a modified (meth) acrylic polymer having a specific monomer composition as a base polymer is cross-linked to float by heat treatment or high-humidity treatment. The pressure-sensitive adhesive layer is excellent in durability without peeling or peeling, and has improved light reflection loss and moisture content at the interface with the optical member.

  The base polymer in the pressure-sensitive adhesive composition of the present invention has a glass transition temperature of 0 ° C. or less, and includes a (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment in a side chain as a monomer unit. . By using the (meth) acrylic polymer as a base polymer, it is possible to obtain a pressure-sensitive adhesive layer in which adhesiveness, durability, reflection loss, improvement in moisture content, and the like are arranged in a balanced manner.

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

The terpenes of the present invention are generic names of compounds extracted from plant essential oil components and based on the isoprene rule represented by the molecular formula of C ₅ H ₈ .

  In the present invention, a (meth) acrylic monomer ((meth) acrylate) having a terpene skeleton structure in which the side chain is hydrogenated may be used alone or by being copolymerized with a copolymerizable monomer. However, the weight ratio of the monomer unit in the whole (meth) acrylic polymer is 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight, still more preferably 20% by weight. . When the ratio in the copolymerization is less than 5% by weight, the effect of controlling the refractive index may be low, which is not preferable.

  The (meth) acrylic polymer is preferably a (meth) acrylic polymer containing 0.05 to 2% by weight of a hydroxyl group-containing monomer as a monomer unit.

  Furthermore, the (meth) acrylic polymer is preferably a (meth) acrylic polymer containing 0.05 to 2% by weight of a carboxyl group-containing monomer as a monomer unit.

  Moreover, in the adhesive composition of this invention, it is preferable to contain 0.02-2 weight part of organic peroxides with respect to 100 weight part of said base polymers.

  Moreover, in the adhesive composition of this invention, it is preferable to contain 0.01-2 weight part of isocyanate type crosslinking agents and / or an epoxy type crosslinking agent with respect to 100 weight part of said base polymers.

  The isocyanate-based crosslinking agent in the present invention is an isocyanate compound having in its molecule two or more isocyanate groups (including isocyanate-regenerating functional groups that are temporarily protected by blocking the isocyanate groups and quantifying them). Say.

  Moreover, the epoxy-type crosslinking agent in this invention means the epoxy compound which has 2 or more epoxy in 1 molecule.

  Moreover, in the adhesive composition of this invention, it is preferable to contain 0.01-3 weight part of silane coupling agents with respect to 100 weight part of said base polymers.

  On the other hand, the pressure-sensitive adhesive layer of the present invention is obtained by crosslinking the pressure-sensitive adhesive composition described above. According to the pressure-sensitive adhesive layer of the present invention, it is obtained by crosslinking a pressure-sensitive adhesive composition that exhibits the above-described effects, so that it is excellent in removability and workability, and is not floated or peeled off by heat treatment or high-humidity treatment. The pressure-sensitive adhesive layer is excellent in durability and does not occur, and has improved light reflection loss and moisture content at the interface with the optical member. Moreover, in order to produce the above effects, it is particularly suitable for use as an optical member.

  Furthermore, in the said adhesive layer, it is preferable that the gel fraction of the said adhesive layer is 45 to 90 weight%.

  In the pressure-sensitive adhesive layer, the water content of the pressure-sensitive adhesive layer is preferably 0.19% by weight or less.

  On the other hand, the method for producing a pressure-sensitive adhesive layer of the present invention includes, for example, a step of forming a layer made of any one of the above-mentioned pressure-sensitive adhesive compositions on one side or both sides of a support, and a layer made of the pressure-sensitive adhesive composition. It can obtain by using the manufacturing method including the process of carrying out an organic peroxide bridge | crosslinking process. By using such a manufacturing method, it has excellent removability and workability, does not cause floating or peeling due to heat treatment or high humidity treatment, has excellent durability, light reflection loss or moisture at the interface with the optical member A pressure-sensitive adhesive layer with an improved rate can be obtained easily.

  In the present invention, the peroxide crosslinking treatment refers to a treatment in which the organic peroxide is decomposed by heat or light irradiation to generate radicals to crosslink the base polymer. Moreover, it is preferable that the said peroxide crosslinking process is a process which decomposes | disassembles the said organic peroxide 75weight% or more.

  Furthermore, in the pressure-sensitive adhesive layer obtained by the above production method, the pressure-sensitive adhesive layer preferably has a gel fraction of 45 to 90% by weight.

  Moreover, the optical member with an adhesive of the present invention is characterized in that the above-mentioned adhesive layer is formed on one side or both sides of the optical member. According to the pressure-sensitive adhesive optical member of the present invention, since it has a pressure-sensitive adhesive layer that exhibits the above-described effects, it is excellent in removability and workability, and does not float or peel off due to heat treatment or high-humidity treatment. It becomes an optical member with an adhesive which is excellent in durability and has improved reflection loss of light and moisture content at the interface with the optical member.

  In addition, 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 optical member with an adhesive, and even if stored for a long period of time or in a high temperature / high humidity state, Even when the optical display device is peeled off and the image display apparatus is reused, high durability without foaming is exhibited, and the adhesive force is not increased, and the film can be easily peeled off without adversely affecting the apparatus.

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

The pressure-sensitive adhesive composition of the present invention is for an optical member,
The base polymer is a (meth) acrylic polymer having a glass transition temperature of 0 ° C. or lower and containing, as a monomer unit, a (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment in the side chain.

  The pressure-sensitive adhesive composition of the present invention is based on a (meth) acrylic polymer having a glass transition temperature of 0 ° C. or less and containing (meth) acrylate as a monomer unit containing a terpene skeleton subjected to hydrogenation treatment in the side chain. It is used as a polymer. By using the (meth) acrylic polymer as a base polymer, it is possible to obtain a pressure-sensitive adhesive layer in which adhesiveness, durability, reflection loss, improvement in moisture content, and the like are arranged in a balanced manner.

The terpenes of the present invention are generic names of compounds extracted from plant essential oil components and based on the isoprene rule represented by the molecular formula of C ₅ H ₈ .

  Specifically, for example, monoterpenes include α-pinene, β-pinene, carene, γ-terpinene, d-limonene, dipinten, terpinolene, β-phenolandlene, pufferene, camphene, myrcene, etc. Examples of sesquiterpenes include Longifolen. These may be used singly or in combination of two or more.

  In addition, the (meth) acrylate used in the present invention and containing a terpene skeleton that has been subjected to hydrogenation treatment on the side chain can be appropriately obtained by a known method without any particular limitation. For example, it can be obtained by an esterification reaction between the corresponding terpene alcohol and (meth) acrylic acid. The (meth) acrylate containing a terpene skeleton that has been subjected to hydrogenation treatment on the side chain thus obtained can be appropriately used without particular limitation.

  The (meth) acrylate containing a terpene skeleton that has been subjected to hydrogenation treatment on the side chain thus obtained can be appropriately used without particular limitation.

  In addition, as the (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment on the side chain, a homopolymer having a glass transition temperature (Tg) of 0 ° C. or lower may be used. May be used. Use of the monomer having a glass transition temperature (Tg) of 0 ° C. or lower of the homopolymer is effective in improving the tackiness of the pressure-sensitive adhesive layer, while the glass transition temperature (Tg) of the homopolymer is 0 ° C. Use of an excess monomer is effective in improving durability (particularly heat resistance). Moreover, the upper limit of the glass transition temperature (Tg) of the homopolymer of the above monomer that can be used in the present invention is about 180 ° C., and it is preferable to use one having a glass transition temperature of about 150 ° C. or less. When the glass transition temperature (Tg) of the homopolymer exceeds 180 ° C., it is necessary to reduce the amount used in order to make the entire glass transition temperature (Tg) of the base polymer 0 ° C. or less. In some cases, it is difficult to improve the refractive index. An example (the following formulas (1) and (2)) of the monomer that can be used in the present invention is shown below.

  In the present invention, the (meth) acrylic monomer ((meth) acrylate) having a terpene skeleton structure in which the side chain is hydrogenated may be used alone or copolymerized with a copolymerizable monomer. Although it may be used, it contains 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight, and even more preferably 20% by weight as the weight ratio of monomer units in the whole (meth) acrylic polymer. It is. If the ratio in the copolymerization is less than 1% by weight, the effect of controlling the refractive index may be low, which may not be preferable.

  Moreover, the said (meth) acrylic-type polymer can be made into the (meth) acrylic-type polymer which contains a hydroxyl-containing monomer further as a monomer unit.

  In the present invention, the (meth) acrylic polymer is preferably a (meth) acrylic polymer containing 0.05 to 2% by weight of a hydroxyl group-containing monomer as a monomer unit, and more preferably 0.05 to 2%. It contains 1.5% by weight, more preferably 0.1 to 1% by weight. When the content of the hydroxyl acid-containing monomer exceeds 2% by weight, the crosslinking density with the isocyanate-based crosslinking agent or the epoxy-based crosslinking agent becomes too high, and the stress relaxation property may be inferior. On the other hand, if the content of the hydroxyl-containing monomer is less than 0.01% by weight, the reactivity with the crosslinking agent becomes poor, and the durability may be adversely affected.

  The hydroxyl group-containing monomer is a polymerizable monomer having one or more hydroxyl groups in the monomer structure.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxypropyl ( (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, such as diethylene glycol monomethyl ether, and the like. Of these, 4-hydroxybutyl (meth) acrylate, 6-hydroxypropyl (meth) acrylate, and the like are preferable.

  Moreover, the said (meth) acrylic-type polymer can be made into the (meth) acrylic-type polymer which contains a carboxyl group-containing monomer further as a monomer unit.

  In the present invention, the (meth) acrylic polymer is preferably a (meth) acrylic polymer containing 0.05 to 2% by weight of a carboxyl group-containing monomer as a monomer unit, more preferably 0.05. -1.5 weight%, More preferably, it contains 0.1-1 weight%. When content of the said carboxyl group containing monomer exceeds 2 weight%, it may be inferior to stress relaxation property. On the other hand, when the content of the carboxyl group-containing monomer is less than 0.01% by weight, the crosslinking stability becomes poor and the durability may be adversely affected.

  The carboxyl group-containing monomer is a polymerizable monomer having one or more carboxyl groups in the monomer structure.

  Examples of the carboxyl group-containing monomer 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.

  Further, in the (meth) acrylic polymer of the present invention, as a monomer other than the above-mentioned monomers, a polymerizable monomer for adjusting the glass transition point and peelability of the (meth) acrylic polymer, etc. Can be used within a range not impairing the above.

  Examples of other polymerizable monomers used in the (meth) acrylic polymer of the present invention include acrylic acid alkyl esters having 2 to 14 carbon atoms, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and cyano. Adhesion improvement and cross-linking such as cohesive strength and heat resistance improving components such as group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, and epoxy group-containing monomers A component having a functional group serving as a linking base point can be appropriately used. Among them, those having a ring structure such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, styrene and the like have a high refractive index of the homopolymer, and further improvement of the refractive index can be expected by copolymerization. These monomer compounds may be used alone or in admixture of two or more.

As the acrylic acid alkyl ester having an alkyl group having 2 to 14 carbon atoms, as a monomer unit, a general formula CH ₂ ═C (R ¹ ) COOR ² (where R ¹ is hydrogen or a methyl group, R ² is carbon number) 2 to 14 alkyl groups).

In the above general formula, R ¹ is hydrogen or a methyl group. In the above general formula, R ² is an alkyl group having 2 to 14 carbon atoms, preferably 3 to 12 carbon atoms, and more preferably 4 to 9 carbon atoms. The alkyl group for R ² may be either linear or branched, but is preferably branched because of its low glass transition point.

Specific examples of the (meth) acrylic monomer represented by the general formula CH ₂ ═C (R ¹ ) COOR ² include, for example, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl ( (Meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, isoamyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate , N-dode (Meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc. can give.

  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, and (meth). Examples include acryloyloxynaphthalene sulfonic acid.

  Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl 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 amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-diethylmethacrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, diacetone (meth) ) Acrylamide, N-vinylacetamide, N, N′-methylenebis (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-vinylcaprolactam, N-vinyl-2-pyrrolidone and the like.

  Examples of amino group-containing monomers include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and N- (meth) acryloylmorpholine. It is done.

  Examples of the imide group-containing monomer include N-cyclohexylmaleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, and itaconimide.

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

  Examples of the (meth) acrylic monomer having an alkyl group having 1 or 15 carbon atoms include methyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, and the like.

  The above other polymerizable monomers may be used alone or in combination of two or more, but the total content is 0 to 0 in the entire monomer of the (meth) acrylic polymer. It is preferably 50% by weight, more preferably 0 to 35% by weight, and still more preferably 0 to 25% by weight.

  The (meth) acrylic polymer preferably has a weight average molecular weight of 500,000 or more, more preferably 700,000 to 3,000,000, and even more preferably 800,000 to 2.7 million. If the weight average molecular weight is less than 600,000, durability may be poor. On the other hand, from the viewpoint of workability, the weight average molecular weight is preferably 3 million or less. In addition, the polymer obtained by emulsion polymerization is difficult to measure by the current GPC, and the weight average molecular weight does not fall within this range, and even if the molecular weight is 3 million or more, there is no problem in workability. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

  In addition, the glass transition temperature (Tg) of the (meth) acrylic polymer is 0 ° C. or lower, preferably −10 ° C. or lower, more preferably −20 ° C. or lower (usually −60 ° C.) because the adhesive performance is easily balanced. It is desirable that When the glass transition temperature is higher than 0 ° C., the pressure-sensitive adhesive layer becomes hard at room temperature, and sufficient adhesiveness may not be maintained. 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.

  In addition, the glass transition temperature (Tg) of the homopolymer of (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment on the side chain in the present invention is determined by using a DSC (Differential Scanning Calorimetry) analyzer as shown in the Examples. And measured. In the temperature raising process, the temperature at which heat absorption starts is defined as the glass transition temperature (Tg).

  The production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  In solution polymerization, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is carried out under an inert gas stream such as nitrogen, as a polymerization initiator, for example, azobisisobutyronitrile 0.01 to 0.2 parts per 100 parts by weight of the total amount of monomers. Addition of parts by weight is usually performed at about 50 to 70 ° C. for about 8 to 30 hours.

  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-butylperoxydicarbonate, 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 such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide and other peroxide initiators, a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate Redox initiators that combine products and reducing agents Kill, but is not limited to these.

  In addition, when an organic peroxide is used as a polymerization initiator, it is possible to use the remaining organic peroxide in the crosslinking reaction without being used in the polymerization reaction. Then, it can be re-added as necessary to obtain a predetermined amount of organic peroxide.

  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 0.6 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 (meth) 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 4 parts by weight.

  Examples of the emulsifier used for emulsion polymerization 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 polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer are listed. 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 (all of which are manufactured by 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 of the present invention is based on the (meth) acrylic polymer as described above.

  Moreover, the adhesive composition of this invention can contain an organic peroxide.

  The organic peroxide of the present invention can be used as appropriate as long as it generates radical active species by heating or light irradiation to advance the crosslinking of the base polymer of the pressure-sensitive adhesive composition. In view of the above, it is preferable to use an organic peroxide having a one-minute half-life temperature of 80 ° C to 160 ° C, and more preferable to use an organic peroxide having a temperature of 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 organic peroxide remains, which may cause crosslinking over time.

  Examples of the organic 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 par Oxide (1 minute half-life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyrate Peroxy-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 half-life of the organic peroxide is an index representing the decomposition rate of the organic peroxide, and means the time until the remaining amount of the organic peroxide is halved. 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) ".

  The organic peroxide may be used alone or as a mixture of two or more. However, the total content of the organic peroxide is 100 parts by weight of the base polymer. It is preferable to contain 0.02 to 2 parts by weight, more preferably 0.05 to 1.0 parts by weight, and still more preferably 0.08 to 0.6 parts by weight. If the amount is less than 0.02 parts by weight, the cross-linking may be insufficient and the durability may be poor. On the other hand, if the amount exceeds 2 parts by weight, the cross-linking may be excessive and the adhesiveness may be poor.

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

  More specifically, for example, about 0.2 g of the pressure-sensitive adhesive composition after the reaction treatment is taken out, immersed in 10 ml of ethyl acetate, extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker, and then at room temperature. Leave 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. It can be the amount of organic peroxide.

  The pressure-sensitive adhesive composition of the present invention preferably contains an isocyanate-based crosslinking agent and / or an epoxy-based crosslinking agent for the purpose of further improving the adhesive strength and durability.

  The isocyanate-based crosslinking agent in the present invention is an isocyanate compound having in its molecule two or more isocyanate groups (including isocyanate-regenerating functional groups that are temporarily protected by blocking the isocyanate groups and quantifying them). Say.

  Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate. Of these, aliphatic isocyanates and alicyclic isocyanates are particularly preferably used since the crosslinked product becomes transparent.

  More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (trade name Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene dii Isocyanurate of cyanate (product name: Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.) And polyisocyanates polyfunctionalized with allophanate bonds.

  Examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, spiroglycol diglycidyl ether, and the like.

  In addition, the epoxy-type crosslinking agent in this invention means the epoxy compound which has 2 or more epoxy in 1 molecule.

  The isocyanate-based crosslinking agent and / or epoxy-based crosslinking agent may be used alone or in combination of two or more, but the total content is 100 parts by weight of the base polymer. On the other hand, the total amount of the isocyanate crosslinking agent and / or the epoxy crosslinking agent is preferably 0.01 to 2 parts by weight, more preferably 0.015 to 1 part by weight, and 0.02 to 0. More preferably, it contains 8 parts by weight. If the content is less than 0.01 parts by weight, the elastic modulus at high temperature may be reduced and heat resistance may not be obtained. On the other hand, if the content exceeds 2 parts by weight, room temperature to high temperature In some cases, the elastic modulus of the liquid crystal cell is increased, the stress relaxation property is lowered, and the warpage of the liquid crystal cell is increased.

  In the present invention, the cross-linking agent (organic peroxide, or when using an isocyanate-based cross-linking agent or an epoxy-based cross-linking agent is used so that the gel fraction of the cross-linked pressure-sensitive adhesive layer is 45 to 90% by weight. The amount of the crosslinking agent added is preferably adjusted to 47 to 85% by weight, and the amount of the crosslinking agent added to be 50 to 80% by weight. It is more preferable to adjust. If the gel fraction is less than 45% by weight, the cohesive force is reduced, so that the durability may be inferior. If it exceeds 90% by weight, the adhesiveness may be inferior.

The gel fraction of the pressure-sensitive adhesive composition in the present invention was measured and calculated as follows. About 0.1 g of the pressure-sensitive adhesive layer immediately after the crosslinking treatment was taken and weighed to calculate a value obtained by subtracting the weight of the low molecular weight polymer (calculated from the blended amount) to obtain W ₁ (g). Next, the membrane was wrapped in a microporous tetrafluoroethylene membrane, immersed in a membrane weight W ₂ (g) of about 50 ml of ethyl acetate at 23 ° C. for 2 days, and then the soluble component was extracted. Then removed the adhesive layer with the film, which was dried for 2 hours at 120 ° C., was measured total weight W _{3 (g).} From these measured values, the gel fraction (% by weight) of the pressure-sensitive adhesive layer was determined according to the following formula. Moreover, the gel fraction (weight%) after storing for 1 week at room temperature after coating was measured.
Gel fraction (% by weight) = [(W ₃ −W ₂ ) / W ₁ ] × 100.

  In order to adjust to a predetermined gel fraction, not only the amount of organic peroxide, isocyanate crosslinking agent and / or epoxy crosslinking agent added, but also the effects of crosslinking treatment temperature and crosslinking treatment time must be fully considered. There is a need.

  The adjustment of the crosslinking treatment temperature and the crosslinking treatment time is, for example, preferably set so that the decomposition amount of the organic peroxide contained in the pressure-sensitive adhesive composition is 75% by weight or more, and 80% by weight or more. It is more preferable to set it, and it is more preferable to set it to be 85% by weight or more. When the decomposition amount of the organic peroxide is less than 75% by weight, the amount of the organic peroxide remaining in the pressure-sensitive adhesive composition increases, and a crosslinking reaction over time occurs even after the crosslinking treatment (resulting in 90 In excess of% by weight), etc., which is not preferable.

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

  Thus, depending on the organic peroxide used, the crosslinking treatment temperature and crosslinking treatment time can be calculated by theoretical calculation from the half-life (half-life time) assuming that the organic peroxide is linearly proportional. The amount 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.

  In the pressure-sensitive adhesive composition of the present invention, a silane coupling agent can be used for the purpose of further improving adhesive strength and durability. As the silane coupling agent, known ones can be appropriately used without particular limitation.

  Specifically, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Epoxy group-containing silane coupling agents such as methoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3- Amino group-containing silane coupling agents such as dimethylbutylidene) propylamine, (meth) acryl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-isocyanatopropyl Triethoxysilane etc. Such Inshianeto 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 100 parts by weight of the (meth) acrylic polymer. It is preferable to contain 0.01-1 weight part of silane coupling agents, it is more preferable to contain 0.02-0.6 weight part, and it is further more preferable to contain 0.05-0.3 weight part. By using the silane coupling agent in the above range, it can be more reliably improved cohesive strength and durability, but if less than 0.01 parts by weight, the durability may be inferior, On the other hand, when the amount exceeds 1 part by weight, the adhesive force to an optical member such as a liquid crystal cell may increase excessively, resulting in poor removability.

  Furthermore, the pressure-sensitive adhesive composition of the present invention may contain other known additives, such as powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surfaces. Applications that use lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, etc. Depending on the case, it can be added appropriately. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

  The pressure-sensitive adhesive composition of the present invention has the above-described configuration.

  On the other hand, the pressure-sensitive adhesive layer of the present invention is obtained by crosslinking the pressure-sensitive adhesive composition as described above. At that time, the pressure-sensitive adhesive composition is generally crosslinked after application of the pressure-sensitive adhesive composition, but it is also possible to transfer the pressure-sensitive adhesive layer comprising the crosslinked pressure-sensitive adhesive composition to a support or the like. is there.

  The method of forming the pressure-sensitive adhesive layer on the support (optical member, separator, etc.) is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to a release-treated separator and the like, and the polymerization solvent is dried and removed. The adhesive layer is prepared by a method of transferring the adhesive layer to a support, or a method of applying the adhesive composition to the support and drying and removing the polymerization solvent to form the adhesive layer on the support. When applying and drying an adhesive on the optical member, care should be taken because the optical member may deteriorate in characteristics due to heat applied to the optical member. Thereafter, an aging treatment may be performed for the purpose of adjusting the crosslinking reaction of the pressure-sensitive adhesive layer. In addition, when producing an optical member with a pressure-sensitive adhesive by applying the pressure-sensitive adhesive composition on a support, one or more solvents other than the polymerization solvent are contained in the composition so that the composition can be uniformly coated on the support. (Solvent) may be newly added.

  Examples of the support used in the present invention include plastic substrates such as polyethylene terephthalate (PET) and polyester film, porous materials such as paper and nonwoven fabric, and optical members.

  The plastic substrate is not particularly limited as long as it can be formed into a sheet shape or a film shape. For example, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene Polyolefin films such as propylene copolymer, ethylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl alcohol copolymer, polyethylene terephthalate, polyethylene naphthalate, poly Polyester film such as butylene terephthalate, polyacrylate film, polystyrene film, nylon 6, nylon 6,6, polyamide film such as partially aromatic polyamide, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate Such as ball titanate film, and the like. The thickness of the film is usually about 4 to 100 μm, preferably about 4 to 25 μm.

  For plastic substrates, if necessary, silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agents, mold release with silica powder, etc., acid treatment, acid treatment, alkali treatment, primer treatment, Anti-adhesive treatment such as corona treatment, plasma treatment and ultraviolet treatment, coating type, kneading type, vapor deposition type and the like can also be carried out.

  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 of this invention, the well-known method used for manufacture of adhesive sheets is used. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

  In addition, for example, a step of forming a layer made of the pressure-sensitive adhesive composition described above on one side or both sides on a support (optical member, separator, etc.) and a layer made of the pressure-sensitive adhesive composition are peroxidized. The pressure-sensitive adhesive layer of the present invention can be obtained by using a production method including a step of subjecting a product to crosslinking. By using such a production method, the above-mentioned excellent adhesive properties, in particular, even when the adhesive layer is thinned, an adhesive having excellent durability that does not float or peel off due to heat treatment or high-humidity treatment. An agent layer can be obtained.

  Furthermore, the organic peroxide crosslinking treatment is preferably a treatment for decomposing 75% by weight or more of the organic peroxide.

  Moreover, in the said adhesive layer, it is preferable that the thickness of the said adhesive layer is 2-500 micrometers, and it is more preferable that it is 5-100 micrometers.

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

  Furthermore, when the pressure-sensitive adhesive is exposed on such a surface, the pressure-sensitive adhesive layer may be protected with a sheet (release sheet, separator, release liner) that has been subjected to a release treatment until practical use.

  As a constituent material of the separator, for example, a plastic film such as polyethylene, polypropylene, polyethylene terephthalate, and a polyester film, a porous material such as paper, cloth, and nonwoven fabric, a net, a foamed sheet, a metal foil, and a laminate thereof, as appropriate. A thin film can be used, but a plastic film is preferably used because of its excellent surface smoothness.

  The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-polymer are used. Examples thereof include a polymer 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 preferably 5 to 200 μm, and in terms of cutability, the thicker the separator thickness is, the more the stress concentration at the time of cutting is alleviated.

  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 a silicone treatment, a long-chain alkyl treatment, a fluorine treatment, or an aliphatic amide, the peelability from the pressure-sensitive adhesive layer can be further enhanced. Furthermore, it is preferable from the viewpoint of surface smoothness that the release treatment such as silicone, long chain alkyl, fluorine, or aliphatic amide is appropriately used for the release treatment.

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

  The pressure-sensitive adhesive layer in the present invention requires aging after these properties have undergone coating, drying, crosslinking, and transfer processes by crosslinking the above-mentioned pressure-sensitive adhesive composition with the above-mentioned crosslinking agent and organic peroxide. However, the pressure-sensitive adhesive layer is excellent in productivity that punching and slitting can be performed quickly.

  In the present invention, as shown in Examples, the refractive index of the pressure-sensitive adhesive layer was measured using an Abbe refractometer.

  Furthermore, the water content of the pressure-sensitive adhesive layer is preferably 0.19% by weight or less, and more preferably 0.18% by weight or less. When the water content exceeds 0.19% by weight, bubbles due to water are likely to be generated in the heating test. On the other hand, if the elastic modulus of the pressure-sensitive adhesive layer is increased and hardened in order to suppress the generation of bubbles, it is not preferable because it is difficult to balance the stress relaxation property.

In addition, the measurement of the said moisture content was performed as follows.
Apparatus: Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., AQ-2100 (main body) + EV-2000 (vaporization section))
・ Electrolyte: Hydranal Aqualite (Hiranuma Sangyo Co., Ltd.)
-Counter electrode liquid: Aqualite CN (manufactured by Hiranuma Sangyo Co., Ltd.)
-Vaporization part temperature: 150 ° C
・ Sample size: 0.2-0.6g
・ Evaluation room atmosphere: 23 ℃ ± 2 ℃, 55% ± 5% RH
The water content was calculated by dividing the detected water weight (g) by the sample weight (g).

  Furthermore, the pressure-sensitive adhesive composition and pressure-sensitive adhesive layer of the present invention are particularly suitable for use as an optical member because they exhibit the above-described effects.

  Moreover, the optical member with an adhesive of this invention forms the adhesive layer which has said structure in the single side | surface or both surfaces of an optical member. Since the optical member with pressure-sensitive adhesive of the present invention includes a pressure-sensitive adhesive layer that exhibits the above-described effects, it has excellent removability and workability, and does not float or peel off due to heat treatment or high humidity treatment. It is excellent in the property, and the reflection loss of light and the moisture content at the interface with the optical member are improved.

  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, the optical member includes an optical film such as 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−nz) · d (where nx is the refractive index in the slow axis direction in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a direction retardation value 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 external light from reflecting on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, roughening 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 method or a compounding 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 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 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-oriented polyester-based liquid crystalline polymers, discotic polymers, and cholesteric polymers that have a structure in which a mesogenic group is bonded to 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 in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflective) polarizing plate and a retardation plate, as described above. In addition, an optical member such as an elliptically polarizing plate is advantageous in that it is excellent in quality stability, laminating workability and the like, and can improve the manufacturing efficiency of a liquid crystal display device and 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.

  In addition, from the viewpoint of achieving a wide viewing angle with good visibility, an optical compensation position in which an alignment layer of a liquid crystal polymer, particularly an optically anisotropic layer composed of a tilted alignment layer of a discotic liquid crystal polymer, is supported by a triacetyl cellulose film. A phase difference 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 on the surface of the brightness enhancement film is further inverted through a reflective layer provided on the rear side thereof, and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light in 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 reflective 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 simultaneously 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 directly incident on the polarizing plate with the polarization axis aligned, 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 linearly polarized via a retardation plate in order to suppress absorption loss. It is preferable to make it enter into a 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 phase difference layer which functions as a half-wave plate, etc. can be obtained by the superimposition method. 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, a cholesteric liquid crystal layer that has a reflection wavelength different from each other and has an arrangement structure in which two layers or three or more layers are overlapped to obtain a layer that reflects circularly polarized light in a wide wavelength range such as a visible light region. Based on this, transmitted circularly polarized light in a wide wavelength range can be obtained.

  Moreover, the polarizing plate may consist of what laminated | stacked the polarizing plate and the optical layer of 2 layers or 3 layers or more like the above-mentioned 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 semi-transmissive 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 the 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 and an adhesive layer of the optical member with an adhesive 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. It may be one having a UV absorbing ability by a method such as a method of treating with a UV absorber.

  The optical member with an adhesive 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 optical member with an adhesive, 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 this 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.

  Appropriate liquid crystal display devices such as a liquid crystal display device in which an optical member with an adhesive is disposed on one side or both sides of a liquid crystal cell, and a backlight or 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 between 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.

  In order to improve the anchoring force when such an optical member is bonded to the above-mentioned pressure-sensitive adhesive layer, the surface of the optical member may be subjected to easy attachment treatment such as corona treatment or plasma treatment, or undercoating treatment.

  In addition, 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 optical member with an adhesive, and even if stored for a long period of time or in a high temperature / high humidity state, Even when the optical display device is peeled off and the image display apparatus is reused, high durability without foaming is exhibited, and the adhesive force is not increased, and the film can be easily peeled off without adversely affecting the apparatus.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below. In addition, the evaluation item in an Example etc. measured as follows.

<Measurement of molecular weight>
The weight average molecular weight of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography).
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, G7000H _XL- H + GMH _XL- H + GMH _XL
Column size: 7.8mmφ x 30cm each (total 90cm)
-Column temperature: 40 ° C
・ Flow rate: 0.8ml / min
・ Injection volume: 100 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
-Data processing device: HLC-8020GPC manufactured by Tosoh Corporation
The molecular weight was calculated in terms of polystyrene.

<Measurement of glass transition temperature (Tg)>
The glass transition temperature (Tg) of a homopolymer of (meth) acrylate containing a terpene skeleton subjected to hydrogenation treatment on the side chain in the examples was measured using a DSC (Differential Scanning Calorimetry) analyzer under the following conditions. It was. In the temperature raising process, the temperature at which heat absorption starts is defined as the glass transition temperature (Tg).
・ Device: Seiko Electronics Co., Ltd., DSC6200
Sample weight: 7 to 13 mg
・ Raising rate: 5 ° C / min
・ Nitrogen flow rate: 60-70 mL / min
・ Cooling method: Use liquid nitrogen.

<Measurement of gel fraction>
The gel fraction of the pressure-sensitive adhesive composition in the examples was measured and calculated as follows. About 0.1 g of the pressure-sensitive adhesive layer immediately after the crosslinking treatment was taken and weighed to calculate a value obtained by subtracting the weight of the low molecular weight polymer (calculated from the blended amount) to obtain W ₁ (g). Next, the membrane was wrapped in a microporous tetrafluoroethylene membrane, immersed in a membrane weight W ₂ (g) of about 50 ml of ethyl acetate at 23 ° C. for 2 days, and then the soluble component was extracted. Then removed the adhesive layer with the film, which was dried for 2 hours at 120 ° C., was measured total weight W _{3 (g).} From these measured values, the gel fraction (% by weight) of the pressure-sensitive adhesive layer was determined according to the following formula. Moreover, the gel fraction (weight%) after storing for 1 week at room temperature after coating was measured.
Gel fraction (% by weight) = [(W ₃ −W ₂ ) / W ₁ ] × 100.

<Measurement of organic peroxide decomposition amount>
The amount of organic peroxide decomposition after the thermal decomposition treatment was measured by HPLC (high performance liquid chromatography).

Specifically, about 0.2 g each of the pressure-sensitive adhesive composition before and after the decomposition treatment was taken out, immersed in 10 ml of ethyl acetate, and extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker. Let stand for 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 decrease in the amount of organic peroxide was defined as the amount of organic peroxide decomposition.
・ Apparatus: HPL CCPM / UV8000, manufactured by Tosoh Corporation
Column: NUCLEOSIL 7C18 (4.6 mmφ × 250 mm) manufactured by MACHEREY-NAGEL
・ Column flow rate: 1 ml / min
Column pressure: 41 kg / cm ²
-Column temperature: 40 ° C
・ Injection volume: 10 μl
Eluent: water / acetonitrile = 30/70
Injection sample concentration: 0.01% by weight
Detector: UV detector (230 nm).

<Measurement of refractive index>
The refractive index of the pressure-sensitive adhesive layer produced in each example / comparative example was measured using the Abbe refractive system under the following conditions.
・ Measurement wavelength: Sodium D line (589nm)
・ Measurement atmosphere: 23 ± 2 ℃
Measurement apparatus: Multi-wavelength Abbe refractometer (DR-M4 or NAR-1T) manufactured by ATAGO.

<Measurement of water content>
The moisture content (% by weight) of the pressure-sensitive adhesive layer in the examples was measured under the following conditions using a Karl Fischer moisture meter.
Apparatus: Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., AQ-2100 (main body) + EV-2000 (vaporization section))
・ Electrolyte: Hydranal Aqualite (Hiranuma Sangyo Co., Ltd.)
-Counter electrode liquid: Aqualite CN (manufactured by Hiranuma Sangyo Co., Ltd.)
-Vaporization part temperature: 150 ° C
・ Sample size: 0.2-0.6g
・ Evaluation room atmosphere: 23 ℃ ± 2 ℃, 55% ± 5% RH
The water content was calculated by dividing the detected water weight (g) by the sample weight (g).

<Measurement of adhesive strength>
The optical film with pressure-sensitive adhesive (width 25 mm) obtained in Examples and Comparative Examples was attached to acrylic-free glass (Corning Corp., # 1737, thickness: 0.7 mm) by reciprocating 1 roll with a 2 kg roller. . Thereafter, the film was treated in an autoclave at 50 ° C. and 0.5 Mpa for 15 minutes, and then allowed to stand for 3 hours in an atmosphere of 23 ° C. × 50% RH.

<Durability: Humidification test>
An optical member with an adhesive cut into a 15-inch size (length 24 cm x width 32 cm) was attached to acrylic-free glass (Corning Corp., 1737, thickness: 0.7 mm), and then an autoclave at 50 ° C x 0.5 MPa For 15 minutes, and then stored in an atmosphere of 60 ° C. × 90% RH for 500 hours, and then returned to room temperature (about 25 ° C.) to obtain a sample for evaluation. The moisture resistance test is evaluated visually, and the evaluation criteria are as follows.
・ If the optical member does not float or peel: ○
When the optical member is lifted or peeled off: x.

<Durability: Heat test>
An optical member with an adhesive cut into a 15-inch size (length 24 cm x width 32 cm) was attached to acrylic-free glass (Corning Corp., 1737, thickness: 0.7 mm), and then an autoclave at 50 ° C x 0.5 MPa Was stored for 15 minutes at 80 ° C. and then for 500 hours in an atmosphere at 80 ° C., and then returned to room temperature (about 25 ° C.) to obtain a sample for evaluation. The moisture resistance test is evaluated visually, and the evaluation criteria are as follows.
・ If the optical member does not float or peel: ○
When the optical member is lifted or peeled off: x.

[Example 1]
(Preparation of acrylic polymer)
[Acrylic polymer (I)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 100 parts by weight of hydrogenated terpene acrylate (1) (glass transition temperature (Tg): −24 ° C., the following formula (1)) , 0.2 parts by weight of 4-hydroxybutyl acrylate, 0.1 part by weight of 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 200 parts by weight of ethyl acetate were added slowly. Nitrogen gas was introduced into the flask and sufficiently substituted with nitrogen, and then a polymerization reaction was carried out for 9 hours while maintaining the liquid temperature in the flask at around 60 ° C. to prepare an acrylic polymer (I) solution. The acrylic polymer (I) had a weight average molecular weight of 860,000 and a glass transition temperature (Tg) of −24 ° C.

(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of the solid content of the acrylic polymer (I) solution, and as a crosslinking agent An acrylic pressure-sensitive adhesive solution (1) was prepared by uniformly mixing and stirring 0.3 parts by weight of a trimethylolpropane adduct of tolylene diisocyanate (D-101N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (1) is applied to one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 74 weight%, and the moisture content was 0.046 weight%.

[Example 2]
(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of the solid content of the acrylic polymer (I) solution, and as a crosslinking agent An acrylic pressure-sensitive adhesive solution (2) was prepared by uniformly mixing and stirring 1.0 part by weight of a trimethylolpropane adduct of tolylene diisocyanate (D-101N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (2) is applied to one side of a polyethylene-terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) that has been subjected to silicone treatment, dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 78 weight%, and the moisture content was 0.046 weight%.

Example 3
(Preparation of acrylic polymer)
[Acrylic polymer (II)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube and a condenser, hydrogenated terpene acrylate (1) (glass transition temperature (Tg): −24 ° C.) 50 parts by weight, butyl acrylate 50 parts by weight , 0.3 part by weight of acrylic acid, 0.3 part by weight of 4-hydroxybutyl acrylate, 0.1 part by weight of 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, acetic acid After charging 200 parts by weight of ethyl and introducing nitrogen gas with gentle stirring to sufficiently replace the nitrogen, a polymerization reaction is carried out for 10 hours while keeping the liquid temperature in the flask at around 60 ° C., and acrylic polymer (II) A solution was prepared. The acrylic polymer (II) had a weight average molecular weight of 1.35 million and a glass transition temperature (Tg) of −40 ° C.

(Preparation of adhesive composition)
0.08 parts by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) as a silane coupling agent with respect to 100 parts by weight of the solid content of the acrylic polymer (II) solution, dibenzoyl peroxide 0.25 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.), and 0.06 weight of trimethylolpropane adduct of hexamethylene diisocyanate as a cross-linking agent (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (3).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (3) was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 72% by weight, the water content was 0.129% by weight, and the decomposition rate of the peroxide during drying was about 88% by weight (calculated value). It was.

Example 4
(Preparation of adhesive composition)
To 100 parts by weight of the solid content of the acrylic polymer (II) solution, 0.08 parts by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone, KBM403) as a silane coupling agent, hexamethylene diisocyanate An acrylic pressure-sensitive adhesive solution (4) was prepared by uniformly mixing and stirring 0.3 parts by weight of a trimethylolpropane adduct (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (4) is applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 74 weight%, and the moisture content was 0.129 weight%.

Example 5
(Preparation of acrylic polymer)
[Acrylic polymer (III)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 70 parts by weight of hydrogenated terpene acrylate (1) (glass transition temperature (Tg): −24 ° C.), 30 parts by weight of butyl acrylate , 0.3 part by weight of acrylic acid, 0.3 part by weight of 4-hydroxybutyl acrylate, 0.1 part by weight of 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, acetic acid After charging 200 parts by weight of ethyl and introducing nitrogen gas with gentle agitation to sufficiently replace the nitrogen, a polymerization reaction was carried out for 10 hours while maintaining the liquid temperature in the flask at around 60 ° C., and acrylic polymer (III) A solution was prepared. The acrylic polymer (III) had a weight average molecular weight of 1,200,000 and a glass transition temperature (Tg) of −35 ° C.

(Preparation of adhesive composition)
0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone Co., Ltd., KBM403) as a silane coupling agent with respect to 100 parts by weight of the solid content of the acrylic polymer (III) solution, dibenzoyl peroxide 0.25 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.), and 0.06 weight of trimethylolpropane adduct of hexamethylene diisocyanate as a cross-linking agent (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (5).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (5) was applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 72% by weight, the water content was 0.165% by weight, and the decomposition rate of peroxide during drying was about 88% by weight (calculated value). It was.

Example 6
(Preparation of adhesive composition)
0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone Co., Ltd., KBM403) as a silane coupling agent with respect to 100 parts by weight of the solid content of the acrylic polymer (III) solution, dibenzoyl peroxide 0.25 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.), and 0.3 weight of trimethylolpropane adduct of hexamethylene diisocyanate as a crosslinking agent (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (6).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (6) was applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 74 weight%, and the moisture content was 0.165 weight%.

Example 7
(Preparation of acrylic polymer)
[Acrylic polymer (IV)]
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 butyl acrylate, hydrogenated terpene acrylate (2) (glass transition temperature (Tg): 73 ° C., the following formula (2 )) 10 parts by weight, 0.5 parts by weight of 4-hydroxybutyl acrylate, 0.5 parts by weight of acrylic acid, 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator 1 part by weight and 200 parts by weight of ethyl acetate were charged, nitrogen gas was introduced while gently stirring, and the atmosphere was sufficiently substituted with nitrogen. Then, the temperature of the liquid in the flask was kept at around 60 ° C., and a polymerization reaction was carried out for 9 hours. A base polymer (IV) solution was prepared. The acrylic polymer (IV) had a weight average molecular weight of 1,780,000 and a glass transition temperature (Tg) of −47 ° C.

(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of a solid content of the acrylic polymer (IV) solution, and a crosslinking agent An acrylic pressure-sensitive adhesive solution (7) was prepared by uniformly mixing and stirring 0.15 parts by weight of a trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (7) was applied on one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 71 weight%, and the moisture content was 0.191 weight%.

Example 8
(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of a solid content of the acrylic polymer (IV) solution, and a crosslinking agent 0.04 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.), 0.25 weight by weight of dibenzoyl peroxide (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (8).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (8) was applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 59% by weight, the water content was 0.191% by weight, and the decomposition rate of peroxide during drying was about 99% by weight (calculated value). It was.

Example 9
(Preparation of acrylic polymer)
[Acrylic polymer (V)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 70 parts by weight of butyl acrylate, hydrogenated terpene acrylate (manufactured by Yashara Chemical Co., HPMPA, glass transition temperature (Tg): 73 ° C.) 20 Part by weight, 0.5 part by weight of 4-hydroxybutyl acrylate, 0.5 part by weight of acrylic acid, 0.1 part by weight of 2,2′-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator Then, 200 parts by weight of ethyl acetate was added, nitrogen gas was introduced while gently stirring, and the atmosphere was sufficiently substituted with nitrogen. Then, the temperature of the liquid in the flask was kept at around 60 ° C., and a polymerization reaction was performed for 9 hours. V) A solution was prepared. The acrylic polymer (V) had a weight average molecular weight of 1.13 million and a glass transition temperature (Tg) of −25 ° C.

(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of a solid content of the acrylic polymer (V) solution, and as a crosslinking agent 0.04 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.), 0.25 weight by weight of dibenzoyl peroxide (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (9).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (9) was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 65% by weight, the water content was 0.17% by weight, and the decomposition rate of the peroxide during drying was about 99% by weight (calculated value). It was.

Example 10
(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) and 100 parts by weight of a solid content of the acrylic polymer (V) solution, and as a crosslinking agent An acrylic pressure-sensitive adhesive solution (10) was prepared by uniformly mixing and stirring 0.3 part by weight of a trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (10) was applied on one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 74 weight%, and the moisture content was 0.17 weight%.

[Comparative Example 1]
(Preparation of acrylic polymer)
[Acrylic polymer (VI)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 100 parts by weight of butyl acrylate, 0.5 parts by weight of 4-hydroxybutyl acrylate, and 2,2′-azobis as a polymerization initiator After charging 0.1 parts by weight of isobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) and 200 parts by weight of ethyl acetate and introducing nitrogen gas with gentle stirring, the temperature of the liquid in the flask was adjusted. A polymerization reaction was carried out for 9 hours while maintaining the temperature at around 60 ° C. to prepare an acrylic polymer (VI) solution. The acrylic polymer (VI) had a weight average molecular weight of 1.6 million and a glass transition temperature (Tg) of −56 ° C.

(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., KBM403) with respect to 100 parts by weight of the solid content of the acrylic polymer (VI) solution, and as a crosslinking agent 0.08 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.), 0.25 weight of dibenzoyl peroxide (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (11).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (11) was applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 73% by weight, the water content was 0.217% by weight, and the decomposition rate of the peroxide during drying was about 88% by weight (calculated value). It was.

[Comparative Example 2]
(Preparation of adhesive composition)
With respect to 100 parts by weight of the solid content of the acrylic polymer (VI) solution, 10 parts by weight of Crystallex 1120 (manufactured by Eastman Chemical Co.) as a refractive index adjusting agent, and 3-glycidoxypropyltrimethoxy as a silane coupling agent 0.08 part by weight of silane (manufactured by Shin-Etsu Silicone, KBM403), 0.08 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) as a crosslinking agent, dibenzoyl peroxide ( 0.25 parts by weight of Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) was uniformly mixed and stirred to prepare an acrylic pressure-sensitive adhesive solution (12).

(Preparation of optical member with adhesive)
Next, the acrylic adhesive solution (12) was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 130 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 52% by weight, the water content was 0.16% by weight, and the decomposition rate of the peroxide during drying was about 88% by weight (calculated value). It was. Moreover, since the said adhesive layer was cloudy and diffusely reflected, the refractive index could not be measured.

[Comparative Example 3]
(Preparation of acrylic polymer)
[Acrylic polymer (VII)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 100 parts by weight of butyl acrylate, 0.5 parts by weight of acrylic acid, and 2,2′-azobisisobutyroyl as a polymerization initiator Nitrile (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 parts by weight and ethyl acetate 200 parts by weight were charged, nitrogen gas was introduced with gentle stirring, and the atmosphere was sufficiently replaced with nitrogen. The polymerization reaction was carried out for 9 hours to prepare an acrylic polymer (VII) solution. The acrylic polymer (VII) had a weight average molecular weight of 1,700,000 and a glass transition temperature (Tg) of −51 ° C.

(Preparation of adhesive composition)
As a silane coupling agent, 0.08 part by weight of 3-glycidoxypropyltrimethoxysilane (KBE403, Shin-Etsu Silicone Co., Ltd.) and 100 parts by weight of a solid content of the acrylic polymer (VII) solution 0.08 part by weight of trimethylolpropane adduct of tolylene diisocyanate (D-101N, manufactured by Mitsui Takeda Chemical Co., Ltd.), 0.25 weight of dibenzoyl peroxide (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) The parts were mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (13).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (13) was applied to one side of a polyethylene-treated terephthalate (PET) film (manufactured by Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 58% by weight, the water content was 0.23% by weight, and the decomposition rate of peroxide during drying was about 99% by weight (calculated value). It was.

[Comparative Example 4]
(Preparation of adhesive composition)
With respect to 100 parts by weight of the solid content of the acrylic polymer (VII) solution, 30 parts by weight of Crystallex 1120 (manufactured by Eastman Chemical Co.) as a refractive index adjusting agent and 3-glycidoxypropyltrimethoxy as a silane coupling agent 0.08 part by weight of silane (manufactured by Shin-Etsu Silicone, KBM403), 0.1 part by weight of trimethylolpropane adduct of tolylene diisocyanate as a crosslinking agent (D-101N, manufactured by Mitsui Takeda Chemical Co., Ltd.), dibenzoyl peroxide ( 0.25 parts by weight of Wako Pure Chemical Industries, Ltd., 1 minute half life: 130 ° C.) were uniformly mixed and stirred to prepare an acrylic pressure-sensitive adhesive solution (14).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (14) was applied to one side of a polyethylene-treated terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm) subjected to silicone treatment, dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 52% by weight, the water content was 0.23% by weight, and the decomposition rate of the peroxide during drying was about 99% by weight (calculated value). It was. Moreover, since the said adhesive layer was cloudy and diffusely reflected, the refractive index could not be measured.

Example 11
(Preparation of acrylic polymer)
[Acrylic polymer (VIII)]
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 80 parts by weight of butyl acrylate, hydrogenated terpene acrylate (3) (the following chemical formula (3), glass transition temperature (Tg): 65 ℃, the following formula (3), manufactured by Yashara Chemical Co., Ltd., HCPA) 20 parts by weight, 0.5 part by weight of acrylic acid, 0.5 part by weight of 4-hydroxybutyl acrylate, 2,2′-azobisisobutyrate as a polymerization initiator First, 0.1 part by weight of nitrile (manufactured by Wako Pure Chemical Industries, Ltd.) and 200 parts by weight of ethyl acetate were added, and nitrogen gas was introduced while gently stirring, followed by thorough nitrogen substitution. The polymerization reaction was carried out for 9 hours while maintaining the vicinity to prepare an acrylic polymer (VIII) solution. The acrylic polymer (VIII) had a weight average molecular weight of 1.70 million and a glass transition temperature (Tg) of −43 ° C.

(Preparation of adhesive composition)
For 100 parts by weight of the solid content of the acrylic polymer (VIII) solution, 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane (KBE403, Shin-Etsu Silicone Co., Ltd.) as a silane coupling agent, and as a crosslinking agent 0.15 parts by weight of hexamethylene diisocyanate trimethylolpropane adduct (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) was uniformly mixed and stirred to prepare an acrylic pressure-sensitive adhesive solution (15).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (15) was applied on one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 60 weight%, and the moisture content was 0.169 weight%.

Example 12
(Preparation of adhesive composition)
For 100 parts by weight of the solid content of the acrylic polymer (VIII) solution, 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane (KBE403, Shin-Etsu Silicone Co., Ltd.) as a silane coupling agent, and as a crosslinking agent Trimethylolpropane adduct of hexamethylene diisocyanate (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.) 0.06 parts by weight, and dibenzoyl peroxide (manufactured by Wako Pure Chemical Industries, Ltd., 1 minute half-life: 130 ° C.) 0.25 Part by weight was mixed and stirred uniformly to prepare an acrylic pressure-sensitive adhesive solution (16).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (16) was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. At this time, the gel fraction of the pressure-sensitive adhesive layer was 49% by weight, the water content was 0.168% by weight, and the decomposition rate of the peroxide during drying was about 99% by weight (calculated value). It was.

Example 13
(Preparation of adhesive composition)
For 100 parts by weight of the solid content of the acrylic polymer (VIII) solution, 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane (KBE403, Shin-Etsu Silicone Co., Ltd.) as a silane coupling agent, and as a crosslinking agent An acrylic pressure-sensitive adhesive solution (17) was prepared by uniformly mixing and stirring 0.3 parts by weight of hexamethylene diisocyanate trimethylolpropane adduct (D-160N, manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (17) was applied on one side of a silicone-treated polyethylene terephthalate (PET) film (Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 78 weight%, and the moisture content was 0.169 weight%.

Example 14
(Preparation of acrylic polymer)
[Acrylic polymer (IX)]
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 150 parts by weight of water and 3 parts by weight of dipotassium alkenyl oxalate (Latemul ASK, manufactured by Kao Corporation) are dissolved, and butyl acrylate is dissolved therein. 80 parts by weight, hydrogenated terpene acrylate (2) (the above chemical formula (2), Yashara Chemical Co., HPMPA) 20 parts by weight, acrylic acid 0.5 parts by weight, 4-hydroxybutyl acrylate 0.5 parts by weight, lauryl mercaptan 0 A monomer emulsion in which 0.005 part by weight was emulsified was charged, and nitrogen gas was introduced while gently stirring to sufficiently substitute nitrogen. Thereafter, a polymerization initiator solution prepared by adding 0.5 parts by weight of methanol and 1 part by weight of water to 0.01 parts by weight of VA061 (manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble polymerization initiator was added. Polymerization reaction is performed for 8 hours while maintaining the liquid temperature at around 50 to 55 ° C, and further polymerization reaction is performed for 2 hours while maintaining the liquid temperature in the flask at around 60 to 65 ° C. An emulsion liquid containing a dispersion polymer) was obtained.

  Next, while stirring the above aqueous dispersion, hydrochloric acid is added and the pH is kept at 1 to take out the agglomerated polymer, and it is immersed in running water for 3 days while washing with hand, and then decompressed. Purified acrylic polymer (IX) was prepared by drying under reduced pressure in a drier. The acrylic polymer (IX) had a weight average molecular weight of 1,200,000 and a glass transition temperature of −47 ° C. The purified acrylic polymer (IX) was dissolved in toluene to prepare an acrylic polymer (IX) solution.

(Preparation of adhesive composition)
For 100 parts by weight of the solid content of the acrylic polymer (IX) solution, 0.1 part by weight of 3-glycidoxypropyltrimethoxysilane (KBE403, manufactured by Shin-Etsu Silicone) as a silane coupling agent, and as a crosslinking agent An acrylic pressure-sensitive adhesive solution (18) was prepared by uniformly mixing and stirring 1 part by weight of a trimethylolpropane adduct of hexamethylene diisocyanate (D-160N manufactured by Mitsui Takeda Chemical Co., Ltd.).

(Preparation of optical member with adhesive)
Next, the acrylic pressure-sensitive adhesive solution (18) was applied on one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc., thickness: 38 μm), dried at 150 ° C. for 3 minutes, and dried. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed later.

  The said adhesive layer was transcribe | transferred to the surface of a polarizing plate, and the optical member with an adhesive was produced. In addition, the gel fraction of the adhesive layer at this time was 65 weight%, and the moisture content was 0.173 weight%.

  According to the above method, the pressure-sensitive adhesive strength, durability, and refractive index of the produced optical film with pressure-sensitive adhesive were measured and evaluated. The obtained results are shown in Table 1.

  From the results of Table 1 above, when the optical film with pressure-sensitive adhesive prepared according to the present invention was used (Examples 1 to 10), in any example, excellent adhesive properties were exhibited after the crosslinking treatment, and the heating test -It was found in the humidification test that defects such as foaming, floating and peeling did not occur, the durability was excellent, the light reflection loss at the interface with the optical member was small, and the moisture content was low.

  On the other hand, when an optical film with a pressure-sensitive adhesive that does not satisfy the configuration of the present invention is used (Comparative Examples 1 to 4), transparency and durability deteriorate when trying to adjust the refractive index, and each characteristic is balanced. It was found that it was difficult to express well.

Claims (16)

Glass transition temperature is not more 0 ℃ less, containing terpenes skeletons hydrogenation treatment in the side chain (meth) acrylate as a monomer unit (meth) The pressure-sensitive adhesive for an optical member containing an acrylic polymer as a base polymer A pressure-sensitive adhesive layer for an optical member, obtained by crosslinking the composition and having a gel fraction of 45 to 90% by weight. The pressure-sensitive adhesive layer for an optical member according to claim 1, wherein the (meth) acrylic polymer is a (meth) acrylic polymer further containing 0.05 to 2% by weight of a hydroxyl group-containing monomer as a monomer unit. The pressure-sensitive adhesive layer for an optical member according to claim 1 or 2, wherein the (meth) acrylic polymer is a (meth) acrylic polymer further containing 0.05 to 2% by weight of a carboxyl group-containing monomer as a monomer unit. . The base polymer 100 parts by weight of an isocyanate crosslinking agent and / or an optical member for the pressure-sensitive adhesive layer according to any one of the epoxy crosslinking agent 0.01-2 claims 1 to 3, containing parts. The base polymer 100 parts by weight, the optical member for the pressure-sensitive adhesive layer according to any one of claims 1 to 4 containing an organic peroxide 0.02 to 2 parts by weight. The base polymer 100 parts by weight, the optical member for the pressure-sensitive adhesive layer according to any one of claims 1 to 5 containing silane coupling agent 0.01 to 0.3 parts by weight. The pressure-sensitive adhesive layer for an optical member according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer has a water content of 0.19% by weight or less. A base polymer is a (meth) acrylic polymer having a monomer unit of (meth) acrylate having a terpene skeleton having a glass transition temperature of 0 ° C. or lower and a side chain hydrogenated on one side or both sides of a support. And forming a layer made of the pressure-sensitive adhesive composition for an optical member containing 0.02 to 2 parts by weight of an organic peroxide with respect to 100 parts by weight of the base polymer, and the pressure-sensitive adhesive composition for the optical member. And a step of subjecting the layer to an organic peroxide crosslinking treatment. The method for producing a pressure-sensitive adhesive layer for an optical member according to claim 8, wherein the (meth) acrylic polymer is a (meth) acrylic polymer further containing 0.05 to 2% by weight of a hydroxyl group-containing monomer as a monomer unit. . The pressure-sensitive adhesive layer for an optical member according to claim 8 or 9, wherein the (meth) acrylic polymer is a (meth) acrylic polymer further containing 0.05 to 2% by weight of a carboxyl group-containing monomer as a monomer unit. Manufacturing method. The pressure-sensitive adhesive composition for an optical member according to any one of claims 8 to 10, containing 0.01 to 2 parts by weight of an isocyanate-based crosslinking agent and / or an epoxy-based crosslinking agent with respect to 100 parts by weight of the base polymer. The manufacturing method of the adhesive layer for optical members of description. The said adhesive composition for optical members contains 0.01-0.3 weight part of silane coupling agents with respect to 100 weight part of said base polymers, For optical members of any one of Claims 8-11. Manufacturing method of an adhesive layer. The method for producing a pressure-sensitive adhesive layer for an optical member according to any one of claims 8 to 12, wherein the organic peroxide crosslinking treatment is a treatment for decomposing the organic peroxide by 75% by weight or more. The gel fraction of the said adhesive layer for optical members is 45 to 90 weight%, The manufacturing method of the adhesive layer for optical members of any one of Claims 8-13 . An optical member with an adhesive, characterized in that an optical member for the pressure-sensitive adhesive layer is formed on one or both sides of the optical member according to any one of claims 1-7. An image display device using at least one optical member with an adhesive according to claim 15 .