JP6832246B2 - Adhesive composition for organic EL display device, adhesive layer for organic EL display device, polarizing film with adhesive layer for organic EL display device, and organic EL display device - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition for an organic EL (electroluminescence) display device (OLED). The present invention also relates to an organic EL display device pressure-sensitive adhesive layer formed from the organic EL display device pressure-sensitive adhesive composition, and a polarizing film with a pressure-sensitive adhesive layer having the pressure-sensitive adhesive layer. Furthermore, the present invention relates to an organic EL display device using the pressure-sensitive adhesive layer and / or the polarizing film.

In recent years, organic EL display devices equipped with organic EL panels have come to be widely used in various applications such as mobile phones, car navigation devices, personal computer monitors, and televisions. In an organic EL display device, usually, in order to prevent external light from being reflected by a metal electrode (cathode) and visually recognized as a mirror surface, a circular polarizing plate (polarizing plate and 1) is formed on the visible side surface of the organic EL panel. (A laminate of / 4 wave plates, etc.) is arranged. Further, a decorative panel or the like may be further laminated on the circular polarizing plate laminated on the visible side surface of the organic EL panel. The constituent members of the organic EL display device such as the circular polarizing plate and the decorative panel are usually laminated via a bonding material such as an adhesive layer or an adhesive layer.

In an image display device such as an organic EL display device, the components and the like in the image display device may be deteriorated by the incident ultraviolet light, and in order to suppress the deterioration due to the ultraviolet light, a layer containing an ultraviolet absorber. It is known to provide. Specifically, for example, it has at least one ultraviolet absorbing layer, has a light transmittance of 30% or less at a wavelength of 380 nm, and has a visible light transmittance of 80% or more on a wavelength side longer than the wavelength of 430 nm. A transparent double-sided adhesive sheet for an image display device (see, for example, Patent Document 1) is known.

JP 2012-2111305

Generally, the pressure-sensitive adhesive composition applied to a transparent double-sided pressure-sensitive adhesive sheet for an image display device contains a base polymer such as a (meth) acrylic polymer. Further, in the pressure-sensitive adhesive composition, a radical-crosslinked pressure-sensitive adhesive layer may be formed by using a radical generator (for example, peroxide) as a cross-linking agent in addition to the base polymer. When a (meth) acrylic polymer is used as the base polymer, a monomer component is prepared in the (meth) acrylic polymer by heat or radiation curing, so that radical polymerization is initiated in the pressure-sensitive adhesive composition. The agent is contained.

However, when an ultraviolet absorber is contained in the pressure-sensitive adhesive composition containing the radical generator, the gel fraction (crosslinking) of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition depends on the ultraviolet absorber. Degree) tends to decrease. When the decrease in the gel fraction (crosslinking degree) of the pressure-sensitive adhesive layer becomes large, the pressure-sensitive adhesive layer has problems such as a decrease in appearance yield due to adhesive dents and adhesive stains during processing, and the occurrence of foaming due to heating durability. was there.

Therefore, the present invention can suppress deterioration of the organic EL element by using it in an organic EL display device, and can suppress deterioration of appearance yield and generation of foaming due to heating durability. An object of the present invention is to provide a pressure-sensitive adhesive composition for a display device.

The present invention also provides a pressure-sensitive adhesive layer for an organic EL display device formed from the pressure-sensitive adhesive composition, and provides a polarizing film and a polarizing film with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer for an organic EL display device. It is an object of the present invention to provide an organic EL display device including the pressure-sensitive adhesive layer and / or a polarizing film with the pressure-sensitive adhesive layer.

As a result of diligent studies to solve the above problems, the present inventors have found the following pressure-sensitive adhesive composition for an organic EL display device, and have completed the present invention.

That is, the present invention exists in the base polymer, the radical generator, the ultraviolet absorber (a) having 0 to 3 hydroxyl groups in the molecular structure, and the maximum absorption wavelength of the absorption spectrum in the wavelength region of 380 to 430 nm. The present invention relates to a pressure-sensitive adhesive composition for an organic EL display device, which comprises at least one compound (A) selected from the dye compound (b).

In the pressure-sensitive adhesive composition for an organic EL display device, it is preferable that the compound (A) contains both the ultraviolet absorber (a) and the dye compound (b).

In the pressure-sensitive adhesive composition for an organic EL display device, it is preferable that the maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber (a) exists in a wavelength region of 300 to 400 nm.

In the pressure-sensitive adhesive composition for an organic EL display device, a peroxide can be used as the radical generator.

In the pressure-sensitive adhesive composition for an organic EL display device, a (meth) acrylic polymer can be used as the base polymer.

The pressure-sensitive adhesive composition for an organic EL display device preferably contains 0.01 to 2 parts by weight of the radical generator with respect to 100 parts by weight of the base polymer.

In the pressure-sensitive adhesive composition for an organic EL display device, it is preferable that the compound (A) is contained in an amount of 0.1 to 25 parts by weight based on 100 parts by weight of the base polymer.

The pressure-sensitive adhesive composition for an organic EL display device may further contain an antioxidant.

The pressure-sensitive adhesive composition for an organic EL display device may further contain a cross-linking agent.

The present invention also relates to an organic EL display device pressure-sensitive adhesive layer, which is formed from the organic EL display device pressure-sensitive adhesive composition.

The pressure-sensitive adhesive layer for an organic EL display device has an average transmittance of 12% or less at a wavelength of 300 to 400 nm, an average transmittance of 30% or less at a wavelength of 400 nm to 430 nm, and an average transmittance of 430 to 450 nm. It is preferably 70% or more.

The pressure-sensitive adhesive layer for an organic EL display device has an average transmittance of 12% or less at a wavelength of 300 to 400 nm, an average transmittance of more than 30% and 95% or less at a wavelength of 400 nm to 430 nm, and a wavelength of 430 to 450 nm. The average transmittance is preferably 80% or more.

The present invention also relates to a polarizing film having an adhesive layer for an organic EL display device and a polarizing film with an adhesive layer for an organic EL display device.

The polarizing film with an adhesive layer for an organic EL display device is such that the polarizing film is provided with a transparent protective film on one surface of a polarizer and has a retardation film on the other surface. It is preferable that the pressure-sensitive adhesive layer for a display device is provided on the surface of the retardation film opposite to the surface in contact with the polarizer and / or the surface of the transparent protective film opposite to the surface in contact with the polarizer.

The polarizing film with an adhesive layer for an organic EL display device is an organic EL display device having a first pressure-sensitive adhesive layer, a transparent protective film, a polarizer, a second pressure-sensitive adhesive layer, a retardation film, and a third pressure-sensitive adhesive layer in this order. A polarizing film with an adhesive layer for
Of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer, at least one pressure-sensitive adhesive layer is preferably the pressure-sensitive adhesive layer for an organic EL display device.

In the polarizing film with an adhesive layer for an organic EL display device, it is preferable that the retardation film is a 1/4 wave plate and the polarizing film is a circular polarizing film.

The present invention also relates to an organic EL display device characterized in that at least one polarizing film with an adhesive layer for an organic EL display device or a polarizing film with an adhesive layer for an organic EL display device is used.

The pressure-sensitive adhesive composition for an organic EL display device of the present invention contains an ultraviolet absorber (a) in addition to the base polymer. The ultraviolet absorber (a) can suppress deterioration due to ultraviolet light and suppress deterioration of the organic EL element. Further, the pressure-sensitive adhesive composition for an organic EL display device of the present invention has a maximum absorption wavelength of 380 to 430 nm in the absorption spectrum in place of the ultraviolet absorber (a) or in combination with the ultraviolet absorber (a). Contains the dye compound (b) present in the wavelength region. The dye compound (b) can also suppress deterioration due to ultraviolet light and suppress deterioration of the organic EL element.

Further, the pressure-sensitive adhesive composition for an organic EL display device of the present invention contains a radical generator such as a peroxide. The radical generator functions as a cross-linking agent for a base polymer such as, for example, a (meth) acrylic polymer, and controls the gel fraction of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition within a desired range. And can form a good-looking adhesive layer.

As described above, since the ultraviolet absorber and / or the dye compound and the radical generator coexist in the pressure-sensitive adhesive composition for the organic EL display device of the present invention, the gel fraction of the obtained pressure-sensitive adhesive layer is lowered. I am concerned. However, in the pressure-sensitive adhesive composition for an organic EL display device of the present invention, the ultraviolet absorber (a) having 0 to 3 hydroxyl groups in the molecular structure is selected and used as the ultraviolet absorber. That is, in the present invention, the decrease in the gel fraction is due to the decrease in the degree of cross-linking due to the inactivation of the radicals generated from the radical generator, and the cause of inactivating the radicals is the ultraviolet absorber. Considering that it is a hydrogen-donating group, the number of hydroxyl groups related to the hydrogen-donating group is 3 or less by selecting and using the ultraviolet absorber (a), thereby suppressing the inhibition of cross-linking of the radical generator by the ultraviolet absorber. ..

As a result, according to the pressure-sensitive adhesive composition for an organic EL display device of the present invention, a pressure-sensitive adhesive layer for an organic EL display device capable of suppressing a decrease in appearance yield and occurrence of foaming due to heating durability can be obtained. .. Therefore, the organic EL display device using the pressure-sensitive adhesive layer for the organic EL display device and / or the pressure-sensitive adhesive layer with the pressure-sensitive adhesive layer including the pressure-sensitive adhesive layer for the organic EL display device of the present invention has excellent weather resistance and deterioration resistance. The life can be extended.

(A)-(c) is a cross-sectional view schematically showing an embodiment of a polarizing film with an adhesive layer for an organic EL display device of the present invention. It is sectional drawing which shows typically one Embodiment of the organic EL display device of this invention. It is sectional drawing which shows typically one Embodiment of the organic EL display device of this invention. It is sectional drawing which shows typically one Embodiment of the organic EL display device of this invention.

1. 1. Adhesive Composition for Organic EL Display Device The adhesive composition for organic EL display device of the present invention comprises a base polymer, a radical generator, and an ultraviolet absorber having 0 to 3 hydroxyl groups in the molecular structure (a). It is characterized by containing at least one compound (A) selected from the dye compounds (b) having a maximum absorption wavelength of 380 to 430 nm in the absorption spectrum.

The pressure-sensitive adhesive composition for an organic EL display device of the present invention contains a base polymer as a main component. The main component refers to the component having the highest content ratio in the total solid content contained in the pressure-sensitive adhesive composition, for example, a component accounting for more than 50% by weight of the total solid content contained in the pressure-sensitive adhesive composition. In addition, it refers to a component that accounts for more than 70% by weight.

The base polymer used in the present invention is not particularly limited, and examples of the type of pressure-sensitive adhesive composition include rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and vinyl alkyl. Examples thereof include ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives. Among these adhesives, acrylic adhesives are preferably used because they have excellent optical transparency, exhibit appropriate adhesiveness, cohesiveness, and adhesiveness, and are excellent in weather resistance, heat resistance, and the like. .. In the present invention, it is preferable that the acrylic pressure-sensitive adhesive composition contains a (meth) acrylic polymer as a base polymer.

<(Meta) acrylic polymer>
The (meth) acrylic polymer usually contains an alkyl (meth) acrylate as a main component as a monomer unit. In addition, (meth) acrylate means acrylate and / or methacrylate, and has the same meaning as (meth) of the present invention.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include those having a linear or branched alkyl group having 1 to 18 carbon atoms. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3 to 9.

Further, from the viewpoints of adhesive properties, durability, adjustment of phase difference, adjustment of refractive index, etc., alkyl (meth) acrylate containing an aromatic ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate is used. be able to.

One or more of the (meth) acrylic polymers having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance. The copolymerization monomer of can be introduced by copolymerization. Specific examples of such a copolymerization monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6 (meth) acrylate. Hydroxyl group-containing monomers such as −hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methylacrylate Carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride. Group-containing monomer; caprolactone adduct of acrylic acid; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, ( Meta) Examples thereof include sulfonic acid group-containing monomers such as acryloyloxynaphthalene sulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.

In addition, (N-substituted) amides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylolpropane (meth) acrylamide. Monomer; (meth) alkylaminoalkyl-acrylate monomer such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate; (meth) acrylic (Meta) alkoxyalkyl-based monomers such as methoxyethyl acid and ethoxyethyl (meth) acrylate; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N-( Meta) Succinimide-based monomers such as acryloyl-8-oxyoctamethylene succinimide and N-acryloylmorpholin; maleimide-based monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide and N-phenylmaleimide; N-methylitacon Italonimide-based monomers such as imide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide, etc. As an example of the monomer of.

Further, as modified monomers, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazin, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholin, N- Vinyl-based monomers such as vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Glycol-based acrylic ester monomers such as (meth) polyethylene glycol acrylate, (meth) polypropylene glycol acrylate, (meth) methoxyethylene glycol acrylate, (meth) methoxypolypropylene glycol acrylate; (meth) tetrahydrofurfuryl acrylate, Acrylic acid ester-based monomers such as fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate can also be used. Further, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

Further, examples of the copolymerizable monomer other than the above include a silane-based monomer containing a silicon atom. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-Vinyloctyloxydecyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like.

Examples of the copolymerization monomer include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and neo. Pentyl glycol di (meth) acrylate, trimethyl propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Caprolactone-modified dipentaerythritol Hexa (meth) Acrylate and other (meth) acrylic acids and polyhydric alcohols such as esterified products such as (meth) acryloyl groups and vinyl groups and other unsaturated double bonds having two or more unsaturated double bonds. Polyester (meth) acrylates and epoxys (meth) acrylates and epoxys in which two or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups are added as functional groups similar to the monomer components to the skeletons of sex monomers, polyesters, epoxys, urethanes, etc. Meta) acrylate, urethane (meth) acrylate and the like can also be used.

The (meth) acrylic polymer contains alkyl (meth) acrylate as a main component in the weight ratio of all the constituent monomers, and the ratio of the copolymerized monomer in the (meth) acrylic polymer is not particularly limited, but the same. The proportion of the polymerized monomer is preferably about 0 to 20%, about 0.1 to 15%, and more preferably about 0.1 to 10% in terms of the weight ratio of all the constituent monomers.

Among these copolymerizable monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. A hydroxyl group-containing monomer and a carboxyl group-containing monomer can be used in combination. These copolymerizable monomers serve as reaction points with the cross-linking agent when the pressure-sensitive adhesive composition contains the cross-linking agent. Since the hydroxyl group-containing monomer and the carboxyl group-containing monomer are highly reactive with the intermolecular cross-linking agent, they are preferably used for improving the cohesiveness and heat resistance of the obtained pressure-sensitive adhesive layer. The hydroxyl group-containing monomer is preferable in terms of reworkability, and the carboxyl group-containing monomer is preferable in terms of achieving both durability and reworkability.

When a hydroxyl group-containing monomer is contained as the copolymerization monomer, the proportion thereof is preferably 0.01 to 15% by weight, more preferably 0.03 to 10% by weight, and further preferably 0.05 to 7% by weight. preferable. When the carboxyl group-containing monomer is contained as the copolymerization monomer, the proportion thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, and further preferably 0.2 to 6% by weight. preferable.

As the (meth) acrylic polymer of the present invention, those having a weight average molecular weight in the range of 500,000 to 3,000,000 are usually used. Considering durability, particularly heat resistance, it is preferable to use one having a weight average molecular weight of 700,000 to 2.7 million. Further, it is preferably 800,000 to 2.5 million. If the weight average molecular weight is less than 500,000, it is not preferable in terms of heat resistance. Further, when the weight average molecular weight is larger than 3 million, a large amount of diluting solvent is required to adjust the viscosity for coating, which is not preferable because it increases the cost. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

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

In solution polymerization, for example, ethyl acetate, toluene and the like are used as the polymerization solvent. As a specific example of solution polymerization, the reaction is carried out under an inert gas stream such as nitrogen, a polymerization initiator is added, and usually at about 50 to 70 ° C. under reaction conditions of about 5 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. The weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of the polymerization initiator and the chain transfer agent used, and the reaction conditions, and the amount of the (meth) acrylic polymer used is appropriately adjusted according to these types.

Examples of the radical polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, and 2,2'-azobis [2- (5-methyl-). 2-Imidazolin-2-yl) Propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2, Azo-based initiators such as 2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057), persulfates such as potassium persulfate and ammonium persulfate. Salt, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexyl Peroxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di ( Peroxides such as 4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butylhydroperoxide, hydrogen peroxide, etc. Examples include system initiators, redox-based initiators that combine peroxides and reducing agents, such as a combination of persulfate and sodium hydrogen sulfite, and a combination of peroxide and sodium ascorbate, but are limited to these. It is not something that is done.

The radical polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 weight by weight based on 100 parts by weight of the monomer. The amount is preferably about 0.02 to 0.5 parts by weight, and more preferably about 0.02 to 0.5 parts by weight.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglucolate, 2,3-dimercapto-1-propanol and the like. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 part by weight with respect to 100 parts by weight of the total amount of the monomer components. It is below the degree.

Examples of the emulsifier used in the case of emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy. Examples thereof include nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used alone or in combination of two or more.

Further, as an emulsifier into which a radically polymerizable functional group such as a propenyl group or an allyl ether group has been introduced as a reactive emulsifier, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05. , BC-10, BC-20 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Adecaria Soap SE10N (manufactured by Asahi Denko Co., Ltd.) and the like. Since the reactive emulsifier is incorporated into the polymer chain after polymerization, it has good water resistance and is preferable. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of the monomer components.

<Radical generator>
Examples of the radical generator to be blended in the pressure-sensitive adhesive composition of the present invention include the radical polymerization initiator used in the production of the (meth) acrylic polymer. Among the radical polymerization initiators, the radical generator to be blended in the pressure-sensitive adhesive composition is preferably a peroxide.

The radical generator can generate radically active species by heating or light irradiation to promote cross-linking of the (meth) acrylic polymer in the pressure-sensitive adhesive composition. As the radical generator, in consideration of workability and stability, it is preferable to use a peroxide having a half-life temperature of 80 ° C. to 160 ° C. for 1 minute, and a peroxide having a half-life temperature of 90 ° C. to 140 ° C. is used. It is more preferable to use it.

Examples of the peroxide include di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.) and di-sec-butylperoxydicarbonate (1 minute half-life temperature). : 92.4 ° C.), t-Butylperoxyneodecanoate (1 minute half-life temperature: 103.5 ° C.), t-hexylperoxypivalate (1 minute half-life temperature: 109.1 ° C.), t -Butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C), dilauroyl peroxide (1 minute half-life temperature: 116.4 ° C), di-n-octanoyl peroxide (1 minute half-life temperature) 117.4 ° C.), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C.), di (4-methylbenzoyl) peroxide (1) Minute half-life temperature: 128.2 ° C.), Dibenzoyl peroxide (1 minute half-life 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.) and the like. Among them, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.) and dilauroyl peroxide (1 minute half-life temperature: 116.) Since the cross-linking reaction efficiency is particularly excellent. 4 ° C.), dibenzoylperoxide (1 minute half-life temperature: 130.0 ° C.) and the like are preferably used.

The half-life of the peroxide is an index showing the decomposition rate of the peroxide, and means the time until the residual amount of the peroxide is halved. The decomposition temperature for obtaining a half-life at an arbitrary temperature and the half-life time at an arbitrary temperature are described in the manufacturer's catalog, etc. For example, "Organic peroxide catalog 9th edition" of Nippon Oil & Fats Co., Ltd. (May 2003) ”and so on.

The content of the radical generator (particularly peroxide) in the pressure-sensitive adhesive composition of the present invention adjusts the processability, reworkability, cross-linking stability, peelability, etc. of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Therefore, it is determined in consideration of the gel fraction and the like. Increasing the content of the radical generator (particularly peroxide) is preferable for ensuring the gel fraction (crosslinking degree) of the obtained pressure-sensitive adhesive layer, but if it is too large, it is applied to the pressure-sensitive adhesive layer. The peeling force of the mold film (separator) tends to increase. Usually, the content of the radical generator is preferably 0.01 to 2 parts by weight, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). It is preferably parts by weight, more preferably 0.05 to 0.8 parts by weight, and even more preferably 0.1 to 0.6 parts by weight.

In the (meth) acrylic polymer, a radical polymerization initiator (radical generator) that was not used in the polymerization reaction during the preparation of the (meth) acrylic polymer may remain. The residual radical generator can be used as a radical generator in the pressure-sensitive adhesive composition. In that case, the amount of the residual radical generator can be quantified, and the radical generator can be appropriately blended according to the content of the residual radical generator.

The amount of peroxide decomposition remaining after the reaction treatment can be measured by, for example, HPLC (High Performance Liquid Chromatography).

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 120 rpm for 3 hours at 25 ° C. with a shaker, and then at room temperature. Let stand for 3 days. Next, 10 mL of acetonitrile was added, and the mixture was shaken at 120 rpm for 30 minutes at 25 ° C., and about 10 μL of the extract obtained by filtering with a membrane filter (0.45 μm) was injected into HPLC for analysis, and after the reaction treatment. It can be the amount of peroxide.

<Compound (A)>
The pressure-sensitive adhesive composition of the present invention includes an ultraviolet absorber (a) having 0 to 3 hydroxyl groups in its molecular structure and a dye compound (b) having a maximum absorption wavelength of 380 to 430 nm in the absorption spectrum. At least one compound (A) selected from the above is blended. Regarding the ultraviolet absorber (a), the fact that the number of hydroxyl groups in the molecular structure is 0 to 3 reduces the hydrogen-donating groups that cause radical inactivation, and crosslinks the radical generator, as described above. It is effective in suppressing inhibition. Further, it is preferable that the number of hydroxyl groups is 0 to 3, for example, when an isocyanate-based cross-linking agent having reactivity with the hydroxyl group is blended, in order to suppress the cross-linking inhibition by the cross-linking agent. Further, as the ultraviolet absorber (a), it is preferable to use a compound having no phenyl group in the molecular structure as a hydrogen donating group that inactivates radicals other than the hydroxyl group. Incidentally, a phenyl group having no in the molecular structure is a phenyl (-C 6 _{H 5)} having no substituent, does not exclude a phenyl group or a phenylene group having a substituent. Further, the dye compound (b) also has few hydrogen donating groups such as hydroxyl groups and phenyl groups in the molecular structure from the viewpoint of preventing the inhibition of cross-linking of the radical generator, as in the case of the ultraviolet absorber (a). It is preferably a compound having 0 to 3 hydroxyl groups) or no hydroxyl group.

The blending amount of the ultraviolet absorber (a) and / or the dye compound (b) as the compound (A) is 0.1 with respect to 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). It is preferably about 25 parts by weight, preferably about 0.5 to 20 parts by weight, and more preferably about 2 to 10 parts by weight.

The ultraviolet absorber (a) may be used alone or in combination of two or more. When only the ultraviolet absorber (a) is used as the compound (A), the total content of the ultraviolet absorber (a) is based on 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). The amount is preferably 0.1 to 20 parts by weight, preferably 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and 0.5 to 3 parts by weight. Is more preferable. By setting the addition amount of the ultraviolet absorber (a) within the above range, the ultraviolet absorbing function of the pressure-sensitive adhesive layer can be sufficiently exhibited, and in the case of ultraviolet polymerization, it does not interfere with the polymerization. preferable.

The dye compound (b) may be used alone or in combination of two or more. When only the dye compound (b) is used as the compound (A), the total content of the dye compound (b) is based on 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). It is preferably 0.1 to 20 parts by weight, preferably 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and 0.5 to 3 parts by weight. More preferred. By setting the addition amount of the dye compound (b) within the above range, it is possible to sufficiently absorb the light in the region that does not affect the light emission of the organic EL element, and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is used. This is preferable because deterioration of the organic EL element can be suppressed.

Either one of the ultraviolet absorber (a) and the dye compound (b) can be used, but it is preferable to use the ultraviolet absorber (a) and the dye compound (b) in combination. According to the ultraviolet absorber (a), for example, although light having a wavelength of 380 nm can be absorbed, a wavelength region (380 nm to 430 nm) shorter than the light emitting region (longer wavelength side than 430 nm) of the organic EL element. The light is not sufficiently absorbed, and the transmitted light may cause deterioration. The dye compound (b) can suppress the transmission of light having a wavelength (380 nm to 430 nm) shorter than the light emitting region (longer wavelength side than 430 nm) of the organic EL element, and the ultraviolet absorber (a). ) And the dye compound (b) in combination, it is possible to sufficiently secure the transmittance of visible light in the light emitting region of the organic EL element.
In the present invention, by using such a dye compound (b) in combination with the ultraviolet absorber (a2), light in a region (wavelength 380 nm to 430 nm) that does not affect the light emission of the organic EL element is sufficiently absorbed. It is possible to sufficiently transmit the light emitting region (longer wavelength side than 430 nm) of the organic EL element, and as a result, deterioration of the organic EL element due to external light can be suppressed. When the ultraviolet absorber (a) and the dye compound (b) are used in combination, the total amount of the ultraviolet absorber (a) and the dye compound (b) is within the range of the blending amount of the compound (A). It is preferable to control as such. The ultraviolet absorber (a) is preferably 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). It is preferably 0.5 to 3 parts by weight, and more preferably 0.5 to 3 parts by weight. The dye compound (b) is preferably about 0.1 to 10 parts by weight, preferably about 0.1 to 5 parts by weight, based on 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). More preferably, it is more preferably 0.5 to 3 parts by weight.

<Ultraviolet absorber (a)>
The ultraviolet absorber (a) is not particularly limited as long as it has 0 to 3 hydroxyl groups in the molecular structure. For example, a triazine-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and an oxybenzophenone. Examples thereof include a system UV absorber, a salicylate ester UV absorber, a cyanoacrylate UV absorber, and the like, and these can be used alone or in combination of two or more. Among these, triazine-based UV absorbers and benzotriazole-based UV absorbers are preferable, triazine-based UV absorbers having two or less hydroxyl groups in one molecule, and benzo having one benzotriazole skeleton in one molecule. At least one ultraviolet absorber selected from the group consisting of triazole-based ultraviolet absorbers has good solubility in the monomer used for forming the acrylic pressure-sensitive adhesive composition, and has a wavelength of around 380 nm. It is preferable because it has a high ability to absorb ultraviolet rays.

Specific examples of the triazine-based ultraviolet absorber having two or less hydroxyl groups in one molecule include 2,4-bis- [{4- (4-ethylhexyloxy) -4-hydroxy} -phenyl] -6. -(4-methoxyphenyl) -1,3,5-triazine (Tinosorb S, manufactured by BASF), 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) ) -1,3,5-Triazine (TINUVIN 460, manufactured by BASF), 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine-2-yl) -5 Reaction product of hydroxyphenyl and [(C10-C16 (mainly C12-C13) alkyloxy) methyl] oxylane (TINUVIN400, manufactured by BASF), 2- [4,6-bis (2,4-dimethylphenyl)- 1,3,5-Triazine-2-yl] -5- [3- (dodecyloxy) -2-hydroxypropoxy] phenol), 2- (2,4-dihydroxyphenyl) -4,6-bis- (2) , 4-Dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) -glycidate ester reaction product (TINUVIN405, manufactured by BASF), 2- (4,6-diphenyl-1,3,5) -Triazine-2-yl) -5-[(hexyl) oxy] -phenol (TINUVIN1577, manufactured by BASF), 2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5-[ 2- (2-Ethylhexanoyloxy) ethoxy] -phenol (ADK STAB LA46, manufactured by ADEKA), 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4) −Phenolphenyl) -1,3,5-triazine (TINUVIN479, manufactured by BASF) and the like can be mentioned.

Further, as a benzotriazole-based ultraviolet absorber having one benzotriazole skeleton in one molecule, 2- (2H-benzotriazole-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-Tetramethylbutyl) phenol (TINUVIN 928, manufactured by BASF), 2- (2-hydroxy-5-tert-butylphenyl) -2H-benzotriazole (TINUVIN PS, manufactured by BASF) , Benzenepropanoic acid and ester compounds of 3- (2H-benzotriazole-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy (C7-9 side chain and linear alkyl) (TINUVIN 384-2) , BASF), 2- (2H-benzotriazole-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (TINUVIN900, BASF), 2- (2H-benzotriazole) -2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol (TINUVIN928, manufactured by BASF), methyl-3- (3-) Reaction product of (2H-benzotriazole-2-yl) -5-t-butyl-4-hydroxyphenyl) propionate / polyethylene glycol 300 (TINUVIN1130, manufactured by BASF), 2- (2H-benzotriazole-2-yl) ) -P-cresol (TINUVIN P, manufactured by BASF), 2 (2H-benzotriazole-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol (TINUVIN234, manufactured by BASF), 2- [5-Chloro (2H) -benzotriazole-2-yl] -4-methyl-6- (tert-butyl) phenol (TINUVIN326, manufactured by BASF), 2- (2H-benzotriazole-2-yl) -4,6-di-tert-pentylphenol (TINUVIN328, manufactured by BASF), 2- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (TINUVIN329) , BASF), Methyl 3- (3- (2H-benzotriazole-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol 300 reaction product (TINUVIN213, BASF) ), 2- (2H-benzotriazole-2-yl) -6- Dodecyl-4-methylphenol (TINUVIN571, manufactured by BASF), 2- [2-Hydroxy-3- (3,4,5,6-tetrahydrophthalimide-methyl) -5-methylphenyl] benzotriazole (Sumisorb250, Sumitomo Chemical) (Made by Kogyo Co., Ltd.) and the like.

Examples of the benzophenone-based ultraviolet absorber (benzophenone-based compound) and oxybenzophenone-based ultraviolet absorber (oxybenzophenone-based compound) include 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5. -Sulphonic acid (anhydrous and trihydrate), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4, Examples thereof include 4-dimethoxybenzophenone.

Examples of the salicylic acid ester-based ultraviolet absorber (salicylic acid ester-based compound) include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate (TINUVIN120, manufactured by BASF). ) Etc. can be mentioned.

Examples of the cyanoacrylate-based ultraviolet absorber (cyanoacrylate-based compound) include alkyl-2-cyanoacrylate, cycloalkyl-2-cyanoacrylate, alkoxyalkyl-2-cyanoacrylate, alkenyl-2-cyanoacrylate, and alkynyl-. 2-Cyanoacrylate and the like can be mentioned.

The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber (a) is preferably in the wavelength region of 300 to 400 nm, and more preferably in the wavelength region of 320 to 380 nm. The method for measuring the maximum absorption wavelength is the same as the method for measuring the dye-based compound described later.

<Dye compound (b)>
The dye compound (b) may be a compound having a maximum absorption wavelength of 380 to 430 nm in the absorption spectrum in a wavelength region of 380 to 430 nm, and is not particularly limited, but is a molecule like the ultraviolet absorber (a). It is preferable that the compound has few or no hydrogen donating groups such as a hydroxyl group and a phenyl group in the structure. The maximum absorption wavelength means the absorption maximum wavelength showing the maximum absorbance among a plurality of absorption maximums in the spectral absorption spectrum in the wavelength region of 300 to 460 nm.

The maximum absorption wavelength of the absorption spectrum of the dye compound (b) is more preferably present in the wavelength region of 380 to 420 nm. The dye compound (b) is not particularly limited as long as it has the wavelength characteristics, but a material that does not have fluorescence and phosphorescence performance (photoluminescence) that does not impair the displayability of the organic EL element is preferable.

The full width at half maximum of the dye compound (b) is not particularly limited, but is preferably 80 nm or less, more preferably 5 to 70 nm, and even more preferably 10 to 60 nm. When the half-value width of the dye compound is within the above range, it is possible to control the light in the region that does not affect the light emission of the organic EL element to be sufficiently transmitted while the light on the wavelength side longer than 430 nm is sufficiently transmitted. Therefore, it is preferable. The half-value width is measured by the method described below.
<Measurement method of half width>
The full width at half maximum of the dye compound (b) was measured from the transmitted absorption spectrum of the solution of the dye compound under the following conditions using an ultraviolet-visible spectrophotometer (U-4100, manufactured by Hitachi High-Tech Science Co., Ltd.). From the spectroscopic spectrum measured by adjusting the concentration so that the absorbance of the maximum absorption wavelength is 1.0, the wavelength interval (full width at half maximum) between two points that is 50% of the peak value was defined as the half width of the dye compound. ..
(Measurement condition)
Solvent: Toluene or chloroform Cell: Quartz cell Optical path length: 10 mm

Examples of the dye compound (b) include organic dye compounds and inorganic dye compounds. Among these, from the viewpoint of maintaining dispersibility and transparency in resin components such as base polymers, among these, there are cases. Organic dye compounds are preferred.

Examples of the organic dye compound include azomethine-based compounds, indole-based compounds, silicic acid-based compounds, pyrimidine-based compounds, porphyrin-based compounds, and cyanine-based compounds.

As the organic dye compound, a commercially available compound can be preferably used. Specifically, as the indole compound, BONASORB UA3911 (trade name, maximum absorption wavelength of absorption spectrum: 398 nm, full width at half maximum: 48nm, manufactured by Orient Chemical Industry Co., Ltd.
SOM-5-0106 (trade name, maximum absorption wavelength of absorption spectrum: 416 nm, half price width: 50 nm, manufactured by Orient Chemical Industry Co., Ltd.) was used as the silicate compound, and FDB-001 was used as the porphyrin compound. (Product name, maximum absorption wavelength of absorption spectrum: 420 nm, half price width: 14 nm, manufactured by Yamada Chemical Industry Co., Ltd.), as a cyanine compound, a merocyanine compound (trade name: FDB-009, maximum absorption wavelength of absorption spectrum) : 394 nm, half price width: 43 nm, manufactured by Yamada Chemical Industry Co., Ltd., polymethine compound (trade name: DAA-247, maximum absorption wavelength of absorption spectrum: 389 nm, half price width: 49.5 nm, manufactured by Yamada Chemical Industry Co., Ltd. ) And the like, and among them, the cyanine-based compound is preferable, and the polymethine compound is particularly preferable, from the viewpoint of suppressing cross-linking inhibition and optical reliability.

<Antioxidant>
An antioxidant to be blended in the pressure-sensitive adhesive composition of the present invention can be blended. The antioxidant can prevent the radicals generated from the radical generator from being inhibited by oxygen to ensure a stable gel fraction (crosslinking degree), and is a release film (separator) applied to the pressure-sensitive adhesive layer. ), The gel fraction can be increased while suppressing the increase in the peeling force.

Examples of the antioxidant include phenol-based, phosphorus-based, sulfur-based and amine-based antioxidants, and at least one of these is used. Of these, phenolic antioxidants are preferred.

Specific examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, and 2,6-, as monocyclic phenol compounds. Dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-t-amyl-4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-Dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-4-ethyl- 6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, styrene mixed cresol, DL-α-tocopherol, stearyl β- (3,5-di-t-butyl-4-hydroxy) As a bicyclic phenol compound such as phenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 4, 4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-thiobis (4-methyl-6-t-butylphenol), 4,4'-methylenebis (2,6-di-t-butylphenol) ), 2,2'-Methylenebis [6- (1-methylcyclohexyl) -p-cresol], 2,2'-Etilidenebis (4,6-di-t-butylphenol), 2,2'-Butylidenebis (2) -T-Butyl-4-methylphenol), 3,6-dioxaoctamethylenebis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], triethylene glycolbis [3-( 3-t-Butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2 ´-thiodiethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and the like as a tricyclic phenol compound, 1,1,3-tris (2-methyl-4-hydroxy) -5-t-Butylphenyl) butane, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris [(3,5) -Di-t-Butyl-4-hi Droxyphenyl) propionyloxyethyl] isocyanurate, tris (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3) , 5-Di-t-butyl-4-hydroxybenzyl) benzene and the like as tetracyclic phenol compounds, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane and the like. As phosphorus-containing phenol compounds, bis (ethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate) calcium, bis (ethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate) Benzyl and the like can be mentioned.

Specific examples of phosphorus-based antioxidants include trioctylphosphite, trilaurylphosphite, tristridecylphosphite, trisisodecylphosphite, phenyldiisooctylphosphite, phenyldiisodecylphosphite, and phenyldi (tridecyl) phos. Fight, diphenylisooctylphosphite, diphenylisodecylphosphite, diphenyltridecylphosphite, triphenylphosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (Butoxyethyl) phosphite, tetratridecyl-4,4'-butylidenebis (3-methyl-6-t-butylphenol) -diphosphite, 4,4'-isopropylidene-diphenolalkylphosphite (where alkyl is carbon) (Number 12 to 15), 4,4'-isopropyridenebis (2-t-butylphenol) di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-Methyl-5-t-butyl-4-hydroxyphenyl) butanediphosphite, tris (3,5-di-t-butyl-4-hydroxyphenyl) phosphite, hydrogenated-4,4'-isopropi Redendiphenol polyphosphite, bis (octylphenyl), bis [4,4'-butylidenebis (3-methyl-6-t-butylphenol)], 1,6-hexanediol diphosphite, hexatridecyl-1, 1,3-Tris (2-methyl-4-hydroxy-5-t-butylphenol) diphosphite, Tris [4,4'-isopropyridenebis (2-t-butylphenol)] phosphite, Tris (1,3-di) Stearoyloxyisopropyl) phosphite, 9,10-dihydro-9-phosphaphenanthrene-10-oxide, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, di Stearyl pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl 4,4'-isopropyridendiphenol pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) penta Ellisritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and phenylbi Examples thereof include sparphenol-A-pentaerythritol diphosphite.

As the sulfur-based antioxidant, it is preferable to use a polyhydric alcohol ester of dialkylthiodipropionate and alkylthiopropionic acid. The dialkylthiodipropionate used here is preferably a dialkylthiodipropionate having an alkyl group having 6 to 20 carbon atoms, and the polyhydric alcohol ester of alkylthiopropionic acid is an alkyl having 4 to 20 carbon atoms. Polyhydric alcohol esters of alkylthiopropionic acids with groups are preferred. In this case, examples of the polyhydric alcohol constituting the polyhydric alcohol ester include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, trishydroxyethyl isocyanurate and the like. Examples of such dialkylthiodipropionates include dilaurylthiodipropionate, dimyristylthiodipropionate, and distearylthiodipropionate. On the other hand, examples of the polyhydric alcohol ester of alkylthiopropionic acid include glycerin tributylthiopropionate, glycerin trioctylthiopropionate, glycerin trilaurylthiopropionate, glycerin tristearylthiopropionate, and trimethylolethane tributyl. Thiopropionate, Trimethylolethane Trioctylthiopropionate, Trimethylolethane Trilaurylthiopropionate, Trimethylolethane Tristearylthiopropionate, Pentaerythritol Tetrabutylthiopropionate, Pentaerythritol Tetraoctylthiopro Pionate, pentaerythritol tetralaurylthiopropionate, pentaerythritol tetrastearylthiopropionate and the like can be mentioned.

Specific examples of amine-based antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2. , 6,6-Tetramethylpiperidin Ethanol polycondensate, N, N ′, N ″, N ″ ″-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6) , 6-Tetramethylpiperidin-4-yl) amino) -triazine-2-yl) -4,7-diazadecan-1,10-diamine, dibutylamine, 1,3,5-triazine, N, N'-bis Polycondensate of (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [ {6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino } Hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4- Butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis- (1,2,6,6-pentamethyl-4-pepyridyl) -2- (3,5-di-t-) Butyl-4-hydroxybenzyl) -2-n-butylmalonate, bis- (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,1'-(1,2-) Ethandyl) bis (3,3,5,5-tetramethylpiperazinone), (mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetra Carboxylate, (mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mixed [2,2,6,6-tetra Methyl-4-piperidyl / β, β, β', β'-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl] -1,2,3 , 4-Butanetetracarboxylate, mixed [1,2,2,6,6-pentamethyl-4-piperidyl / β, β, β', β'-tetramethyl-3,9- [2,4,8 , 10-Tetraoxaspiro (5,5) undecane] diethyl] -1,2,3,4-butanetetraca Luboxylate, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6- Chloro-1,3,5-triazine condensate, poly [6-N-morpholyl-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) ) Imino] Hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imide], N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) Hexamethylenediamine , A condensate of 1,2-dibromoethane, [N- (2,2,6,6-tetramethyl-4-piperidyl) -2-methyl-2- (2,2,6,6-tetramethyl-) 4-piperidyl) imino] propionamide and the like can be mentioned.

The content of the antioxidant in the pressure-sensitive adhesive composition of the present invention is determined from the viewpoint of preventing the dye from fading due to the radical generator. Usually, the content of the antioxidant is preferably in the range of 0.03 parts by weight or more with respect to 100 parts by weight of the (meth) acrylic polymer. On the other hand, as the content of the antioxidant increases, the ratio of capturing radicals generated from the radical generator increases. As a result, cross-linking inhibition of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is likely to occur, the gel fraction of the pressure-sensitive adhesive layer is lowered, and the appearance tends to be poor. From this point of view, the content of the antioxidant is preferably in the range of 5 parts by weight or less, more preferably 1.5 parts by weight or less, based on 100 parts by weight of the (meth) acrylic polymer. From the viewpoint of both ensuring the gel fraction and preventing discoloration of the dye, the content of the antioxidant is 0.05 to 100 parts by weight of the base polymer (for example, (meth) acrylic polymer). It is preferably 1.5 parts by weight, more preferably 0.1 to 1.0 parts by weight, and further preferably 0.3 to 0.8 parts by weight.

<Crosslinking agent>
Furthermore, the pressure-sensitive adhesive composition of the present invention can contain a cross-linking agent (excluding the radical generator). In the present invention, when an isocyanate-based cross-linking agent is used in combination as the cross-linking agent, the pressure-sensitive adhesive layer is three-dimensionally cross-linked by the isocyanate-based cross-linking agent while effectively suppressing the inhibition of radical cross-linking by oxygen by the antioxidant. The network can be formed efficiently. As a result, it is possible to more effectively prevent the occurrence of an appearance abnormality at the edge of the polarizing film.

Examples of the cross-linking agent include isocyanate-based cross-linking agent, epoxy-based cross-linking agent, silicone-based cross-linking agent, oxazoline-based cross-linking agent, aziridine-based cross-linking agent, silane-based cross-linking agent, alkyl etherified melamine-based cross-linking agent, and metal chelate-based cross-linking agent. Contains agents. The cross-linking agent may be used alone or in combination of two or more. Among these, isocyanate-based cross-linking agents are preferably used.

The above-mentioned cross-linking agent may be used alone or in combination of two or more, but the content as a whole is the base polymer (for example, (meth) acrylic polymer) 100. It is preferably 5 parts by weight or less, more preferably 0.01 to 5 parts by weight, further preferably 0.01 to 4 parts by weight, and particularly preferably 0.02 to 3 parts by weight. ..

The isocyanate-based cross-linking agent refers to a compound having two or more isocyanate groups (including an isocyanate regenerated functional group in which the isocyanate group is temporarily protected by a blocking agent or quantification) in one molecule. Examples of the isocyanate-based cross-linking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, aliphatic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

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. ), Trimethylol propane / hexamethylene diisocyanate trimeric adduct (trade name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), isocyanurate of hexamethylene diisocyanate (trade name: Coronate HX, Nippon Polyurethane Industry Co., Ltd.) Isocyanate adduct such as (manufactured by), trimethylylene propane adduct of xylylene diisocyanate (trade name: D110N, manufactured by Mitsui Kagaku Co., Ltd.), trimethylol propane adduct of hexamethylene diisocyanate (trade name: D160N, Mitsui Chemicals Co., Ltd.) ); Polyether polyisocyanate, polyester polyisocyanate, additions of these to various polyols, polyisocyanate polyfunctionalized by isocyanurate bond, burette bond, allophanate bond and the like.

Further, the pressure-sensitive adhesive composition of the present invention may contain a silane coupling agent. The blending amount of the silane coupling agent is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the monofunctional monomer component forming the (meth) acrylic polymer. 0.02 to 0.6 parts by weight is more preferable.

Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2- (3,4 epoxycyclohexyl). Epoxy group-containing silane coupling agent such as ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1, Amino group-containing silane coupling agents such as 3-dimethylbutylidene) propylamine and N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane and the like ( Examples thereof include an acrylic group-containing silane coupling agent and an isocyanate group-containing silane coupling agent such as 3-isocyanatepropyltriethoxysilane.

In addition to the above-mentioned components, the pressure-sensitive adhesive composition of the present invention may contain an appropriate additive depending on the intended use. For example, tackifiers (eg, solid, semi-solid, or liquid at room temperature made of rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc.); fillers such as hollow glass balloons; plasticizers; aging. Inhibitors; light stabilizers (HALS); antioxidants and the like.

2. 2. Adhesive layer for organic EL display device The pressure-sensitive adhesive layer for organic EL display device of the present invention is characterized by being formed from the pressure-sensitive adhesive composition for organic EL display device.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and the pressure-sensitive adhesive layer can be formed by a method usually used in this field. Specifically, the pressure-sensitive adhesive composition is applied to at least one surface of a base material, and a coating film formed from the pressure-sensitive adhesive composition is dried to form, or is irradiated with active energy rays such as ultraviolet rays. Can be formed.

The base material is not particularly limited, and for example, various base materials such as a release film and a transparent resin film base material, and a polarizing film described later can be preferably used as the base material.

Examples of the constituent material of the release film include resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabrics, nets, foam sheets, metal foils, and laminates thereof. An appropriate thin leaf body or the like can be mentioned, but a resin film is preferably used from the viewpoint of excellent surface smoothness.

Examples of the resin film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl chloride copolymer film and the like can be mentioned.

The thickness of the release film is usually 5 to 200 μm, preferably about 5 to 100 μm. The release film may be subjected to a release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, etc. Antistatic treatment such as vapor deposition type can also be performed. In particular, the peelability from the pressure-sensitive adhesive layer can be further enhanced by appropriately performing a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the release film.

The transparent resin film base material is not particularly limited, but various transparent resin films are used. The resin film is formed of a single layer film. For example, as the material, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) acrylic resin. , Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyallylate resin, polyphenylene sulfide resin and the like. Of these, polyester-based resins, polyimide-based resins and polyether sulfone-based resins are particularly preferable.

The thickness of the film substrate is preferably 15 to 200 μm, more preferably 25 to 188 μm.

The method of applying the pressure-sensitive adhesive composition on the substrate is roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain. Any known and appropriate method such as a coat, a lip coat, and a die coater can be used, and the present invention is not particularly limited.

When the pressure-sensitive adhesive layer is formed by drying a coating film formed from the pressure-sensitive adhesive composition, the drying conditions (temperature, time) thereof are not particularly limited, and the composition of the pressure-sensitive adhesive composition, It can be appropriately set depending on the concentration and the like, and is, for example, about 60 to 170 ° C., preferably 60 to 150 ° C. for 1 to 60 minutes, preferably 2 to 30 minutes. In addition, when the pressure-sensitive adhesive composition is an ultraviolet curable pressure-sensitive adhesive composition, the coating film can be irradiated with ultraviolet rays to form a pressure-sensitive adhesive layer.

The thickness of the pressure-sensitive adhesive layer is preferably 5 μm or more, more preferably 50 μm or more, further preferably 100 μm or more, and even more preferably 150 μm, from the viewpoint of ensuring the function of absorbing light having a wavelength of less than 430 nm. The above is particularly preferable. The upper limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 mm or less. If the thickness of the pressure-sensitive adhesive layer exceeds 1 mm, it becomes difficult for ultraviolet rays to pass through, it takes time to polymerize the monomer components, and there are problems with processability, winding in the process, and transportability, resulting in poor productivity. Therefore, it is not preferable.

The gel fraction of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably 40% or more, more preferably 60% or more, still more preferably 75% or more. It is particularly preferably 85% or more. When the gel fraction of the pressure-sensitive adhesive layer is small, the cohesive force is inferior, and problems may occur in processability and handleability. Further, the gel fraction immediately after forming the pressure-sensitive adhesive layer by heating and drying the coating film of the pressure-sensitive adhesive composition or irradiating with ultraviolet rays is preferably 60% or more from the viewpoint of preventing appearance defects such as adhesive dents. , 63% or more, more preferably 66% or more, and particularly preferably 70% or more.

The haze value of the pressure-sensitive adhesive layer measured at a thickness of 25 μm is preferably 2% or less, more preferably 0 to 1.5%, and even more preferably 0 to 1%. It is preferable that the haze is in the above range because the pressure-sensitive adhesive layer has high transparency.

The average transmittance of the pressure-sensitive adhesive layer at a wavelength of 300 to 400 nm is preferably 12% or less, more preferably 5% or less, and even more preferably 2% or less. When the transmittance of the pressure-sensitive adhesive layer is within the above range, light in a region that does not affect the light emission of the organic EL element can be sufficiently absorbed, and deterioration of the organic EL element can be suppressed.

The average transmittance of the pressure-sensitive adhesive layer at a wavelength of 430 to 450 nm is preferably 70% or more, more preferably 75% or more, and the average transmittance at a wavelength of 500 to 780 nm is preferably 80% or more. , 85% or more is more preferable. When the transmittance of the pressure-sensitive adhesive layer is within the above range, light can be sufficiently transmitted in the light emitting region (longer wavelength side than 430 nm) of the organic EL element, and the organic EL display using the pressure-sensitive adhesive layer is used. The device can emit sufficient light.

Further, the average transmittance of the pressure-sensitive adhesive layer having a wavelength of 400 to 430 nm or less can be designed according to the characteristics required for the organic EL display device. For example, from the viewpoint of sufficiently absorbing light in a region that does not affect the light emission of the organic EL element to suppress and protect the deterioration of the organic EL element, the average transmittance of the pressure-sensitive adhesive layer having a wavelength of 400 to 430 nm or less is It is preferably 30% or less, and more preferably 20% or less. On the other hand, from the viewpoint of suppressing the coloring of the organic EL element while protecting the organic EL element from ultraviolet light, the average transmittance of the pressure-sensitive adhesive layer having a wavelength of 400 to 430 nm or less is more than 30% and 95% or less. Is preferable, and more preferably more than 50% and 90% or less.

Here, the "average transmittance at a wavelength of 300 to 400 nm" means a transmittance measured at a pitch of 1 nm in a region having a wavelength of 300 to 400 nm, and the average value of the measured transmittance. The same applies to the average transmittance in other wavelength regions.

Since the pressure-sensitive adhesive layer of the present invention has the transmittance, it can sufficiently absorb light in a region that does not affect the light emission of the organic EL element, and has a wavelength longer than the light emitting region (wavelength longer than 430 nm) of the organic EL element. The side) can be sufficiently transmitted, and deterioration of the organic EL element due to external light can be suppressed.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a release film until it is put into practical use.

3. 3. Polarizing film with adhesive layer for organic EL display device The polarizing film with adhesive layer for organic EL display device of the present invention is characterized by having a polarizing film and the pressure-sensitive adhesive layer for organic EL display device.

As the pressure-sensitive adhesive layer for the organic EL display device, the above-mentioned one can be preferably used. Further, when the pressure-sensitive adhesive layer is formed on a substrate other than the polarizing film, the pressure-sensitive adhesive layer can be attached to the polarizing film and transferred. Further, the release film can be used as it is as a separator for a polarizing film with an adhesive layer, which can simplify the process.

The polarizing film is not particularly limited, and examples thereof include a polarizing element and a polarizing film having a transparent protective film on at least one surface of the polarizing element.

(1) Polarizer The polarizer is not particularly limited, and various polarizers can be used. As the polarizer, for example, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymerization system partially saponified film, and a bicolor property of iodine or a bicolor dye are used. Examples thereof include a uniaxially stretched film by adsorbing a substance, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance 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-based film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like, which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. In addition to being able to clean the surface of the polyvinyl alcohol film and blocking inhibitors by washing the polyvinyl alcohol film with water, it also has the effect of preventing non-uniformity such as uneven dyeing by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. It can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

Further, in the present invention, a thin polarizer having a thickness of 10 μm or less can also be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. It is preferable that such a thin polarizing element has less uneven thickness, excellent visibility, excellent durability because there is little dimensional change, and the thickness of the polarizing film can be reduced.

Typical examples of the thin polarizer include Japanese Patent Application Laid-Open No. 51-06644, Japanese Patent Application Laid-Open No. 2000-338329, International Publication No. 2010/100917 Pamphlet, International Publication No. 2010/100917 Pamphlet, or Patent. Examples thereof include the thin polarizing film described in the specification of No. 4751481 and Japanese Patent Application Laid-Open No. 2012-073563. These thin polarizing films can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a resin base material for stretching in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching because it is supported by the stretching resin base material.

The thin polarizing film can be stretched at a high magnification and the polarization performance can be improved even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing, and the international publication No. 2010/100917 pamphlet. , International Publication No. 2010/100917, or those obtained by a production method including a step of stretching in an aqueous boric acid solution as described in Japanese Patent Application Laid-Open No. 4751481 and Japanese Patent Application Laid-Open No. 2012-0756363, particularly patented. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in an aqueous boric acid solution described in the specification of 4751481 and JP2012-0735663.

(2) Transparent protective film As the transparent protective film, those conventionally used can be appropriately used. Specifically, a transparent protective film formed of a material having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property, etc. is preferable, and for example, a polyester polymer such as polyethylene terephthalate or polyethylene naphthalate is preferable. , Cellular polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin), polycarbonate polymers 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, and sulfone polymers. , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, epoxy polymer, or Blends of the polymers and the like are also mentioned as examples of polymers forming the transparent protective film. The transparent protective film can also be formed as a cured layer of a thermosetting type or ultraviolet curable type resin such as acrylic type, urethane type, acrylic urethane type, epoxy type and silicone type.

The thickness of the transparent protective film can be appropriately determined, but is generally about 1 to 500 μm in terms of workability such as strength and handleability, and thin film property.

It is preferable that the polarizer and the transparent protective film are brought into close contact with each other via an aqueous adhesive or the like. Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, water-based polyurethanes, and water-based polyesters. In addition to the above, examples of the adhesive between the polarizer and the transparent protective film include an ultraviolet curable adhesive and an electron beam curable adhesive. The electron beam curable polarizing film adhesive exhibits suitable adhesiveness to the above-mentioned various visible side transparent protective films. Further, the adhesive used in the present invention may contain a metal compound filler.

The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat layer, antireflection treatment, anti-sticking treatment, or treatment for the purpose of diffusion or anti-glare.

Further, as the transparent protective film, any film having a phase difference and capable of functioning as an optical compensation layer can be used. When a transparent protective film having a phase difference is used, the phase difference characteristic can be appropriately adjusted to a value required for optical compensation. As such a retardation film, a stretched film can be preferably used. In the retardation film, when the refractive index in the slow axis direction is nx, the refractive index in the in-plane phase advance axis direction is ny, and the refractive index in the thickness direction is nz, nx = ny> nz, nx> ny. Those satisfying the relationship of> nz, nz> ny = nz, nz> nz> ny, nz = nz> ny, nz> nz> ny, nz> nx = ny are selected and used according to various uses. Be done. Note that nx = ny includes not only the case where nx and ny are completely the same, but also the case where nx and ny are substantially the same. Further, ny = nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

When the polarizing film used in the present invention is used as a circular polarizing plate for antireflection of an organic EL display device, the retardation film has a front retardation of a transparent protective film of 1/4 wavelength (about 100 to 170 nm). It is preferably a 1/4 wavelength plate.

When a retardation film is used as the transparent protective film, one in which the transparent protective film is provided on one surface of the polarizer and the retardation film is provided on the other surface can be preferably used. Further, in that case, the place where the pressure-sensitive adhesive layer is installed is not particularly limited, and may be provided on the surface opposite to the surface of the transparent protective film in contact with the polarizing element of the retardation film. Although it may be provided on the surface opposite to the surface in contact with the organic EL element, it is preferably provided on at least one surface or both surfaces from the viewpoint of suppressing deterioration of the organic EL element.

An example of a specific configuration of the polarizing film with an adhesive layer for an organic EL display device of the present invention is shown in FIGS. 1 (a) to 1 (c). As shown in FIG. 1 (a), the pressure-sensitive adhesive layer 2 / transparent protective film 3 / polarizer 4 / retardation film 5, and as shown in FIG. 1 (b), the transparent protective film 3 / polarizer 4 / retardation film 5. Film 5 / adhesive layer 2, as shown in FIG. 1C, each layer is in this order, such as adhesive layer 2 / transparent protective film 3 / polarizer 4 / retardation film 5 / adhesive layer 2. A laminated polarizing film 1 with an adhesive layer for an organic EL display device can be mentioned. In FIGS. 1 (a) and 1 (b), the pressure-sensitive adhesive layer 2 is the pressure-sensitive adhesive layer for an organic EL display device of the present invention, and in FIG. 1 (c), at least two pressure-sensitive adhesive layers 2 are provided. One may be the pressure-sensitive adhesive layer for the organic EL display device of the present invention, and both may be the pressure-sensitive adhesive layer for the organic EL display device of the present invention. Further, in FIG. 1, the polarizing film 6 is a one-sided protective polarizing film composed of a polarizing element 4 and a transparent protective film 3, but the present invention is not limited to this, and the polarizing element 4 and the retardation film 5 are used. It may be both protective polarizing films having a transparent protective film in between. Further, as described above, various functional layers such as a hard coat layer can be formed on the surface of the transparent protective film 3 that is not in contact with the polarizer 4.

Further, when the retardation film is laminated on the polarizer via the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer may be the pressure-sensitive adhesive layer for an organic EL display device of the present invention. That is, the polarizing film with the pressure-sensitive adhesive layer for an organic EL display device has a first pressure-sensitive adhesive layer, a transparent protective film, a polarizer, a second pressure-sensitive adhesive layer, a retardation film, and a third pressure-sensitive adhesive layer in this order.
At least one of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer may be the pressure-sensitive adhesive layer for an organic EL display device.

4. Organic EL Display Device The organic EL display device of the present invention uses at least one pressure-sensitive adhesive layer for an organic EL display device of the present invention and / or a polarizing film with an adhesive layer for an organic EL display device of the present invention. It is a feature.

As an example of a specific configuration of the organic EL display device, for example, as shown in FIGS. 2 to 4, a cover glass or a cover plastic 7 / an adhesive layer 2 / a transparent protective film 3 / a polarizer 4 / a retardation film 5 / Adhesive layer 2 / Organic EL display panel (OLED element panel) 8 (Fig. 2); Cover glass or cover plastic 7 / Adhesive layer 9 / Transparent protective film 3 / Polarizer 4 / Phase difference film 5 / Adhesive Layer 2 / Organic EL display panel 8 (Fig. 3); Cover glass or cover plastic 7 / Adhesive layer 2 / Sensor layer 10 / Adhesive layer 2 / Transparent protective film 3 / Polarizer 4 / Phase difference film 5 / Adhesive As shown in layer 2 / organic EL display panel 8 (FIG. 4); an organic EL display device in which each layer is laminated in this order can be mentioned. At least one of the pressure-sensitive adhesive layers 2 in each of the above configurations may be the pressure-sensitive adhesive layer of the present invention, and all the pressure-sensitive adhesive layers 2 may be the pressure-sensitive adhesive layer of the present invention. In addition to the above, the organic EL display device of the present invention may include various functional layers such as a protective film and a hard coat layer. In addition, an adhesive layer and / or an adhesive layer can be appropriately used in laminating each layer. As the pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer of the present invention, a normal pressure-sensitive adhesive layer used in the present field can be appropriately used.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In addition, each part and% in each example is based on weight.

<Measurement of weight average molecular weight of (meth) acrylic polymer>
The weight average molecular weight (Mw) of the (meth) acrylic polymer was measured by GPC (gel permeation chromatography). Mw / Mn was also measured in the same manner.
-Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
-Column: Made by Tosoh, G7000HXL + GMHXL + GMHXL
-Column size: 7.8 mm φ x 30 cm each, 90 cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8 mL / min
・ Injection amount: 100 μL
-Eluent: Tetrahydrofuran-Detector: Differential refractometer (RI)
・ Standard sample: Polystyrene

<Preparation of (meth) acrylic polymer (1)>
A monomer mixture containing 99 parts of butyl acrylate (BA) and 1 part of 4-hydroxybutyl acrylate (HBA) was charged into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer. Further, with respect to 100 parts of the monomer mixture, 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts of ethyl acetate, and nitrogen gas was introduced with gentle stirring to introduce nitrogen. After the substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to carry out a polymerization reaction (solid content concentration) of an acrylic polymer having a weight average molecular weight (Mw) of 1.8 million and Mw / Mn = 4.1. 30% by weight) was prepared.

<Preparation of (meth) acrylic polymer (2)>
94.8 parts of butyl acrylate (BA), 5 parts of acrylic acid (AA), and 0.2 of 2-hydroxyethyl acrylate (HEA) in a reaction vessel equipped with a condenser, nitrogen introduction tube, thermometer and stirrer. A monomer mixture containing a portion was charged. Further, 0.3 part of benzoyl peroxide (trade name: Niper BMT manufactured by Nippon Oil & Fat Co., Ltd.) was charged to 100 parts of the monomer mixture together with 100 parts of ethyl acetate, and nitrogen gas was introduced while gently stirring. After the nitrogen substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to obtain a solution of an acrylic polymer having a weight average molecular weight (Mw) of 2.2 million and Mw / Mn = 4.1. Solid content concentration 30% by weight) was prepared.

<Preparation of (meth) acrylic polymer (3)>
73.3 parts of butyl acrylate (BA), 21 parts of phenoxyethyl acrylate (PEA), 5 parts of N-vinylpyrrolidone (NVP), acrylic acid in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer. A monomer mixture containing 0.3 parts of (AA) and 0.4 parts of 4-hydroxybutyl acrylate (HBA) was charged. Further, with respect to 100 parts of the monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator is charged together with 100 parts of ethyl acetate, and nitrogen gas is added while gently stirring. After the introduction and nitrogen substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to carry out a polymerization reaction of an acrylic polymer having a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.8. (Solid content concentration 28% by weight) was prepared.

Example 1
(Preparation of adhesive composition)
With respect to 100 parts of the solid content of the solution of the acrylic polymer (1) produced above.
0.3 parts of radical generator (benzoyl peroxide, trade name NOF BMT manufactured by NOF CORPORATION),
0.1 part of isocyanate-based cross-linking agent (trade name: Takenate D110N manufactured by Mitsui Chemicals, Inc.),
As the ultraviolet absorber (a), 2,4-bis- [{4- (4-ethylhexyloxy) -4-hydroxy} -phenyl] -6- (4-methoxyphenyl) -1,3,5-triazine ( A pressure-sensitive adhesive composition was obtained by blending 2 parts of a trade name: Tinosorb S, manufactured by BASF, and 0.1 part of a silane coupling agent (KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.).

(Preparation of adhesive layer)
The pressure-sensitive adhesive composition is applied onto a 38 μm-thick separator (polyethylene terephthalate film whose surface has been peeled off: a release film) so that the dried thickness is 20 μm, and dried at 155 ° C. for 1 minute. The film was layered to remove the solvent to obtain a pressure-sensitive adhesive layer (A).

Immediately after the pressure-sensitive adhesive layer (A) was formed, the separator on which the pressure-sensitive adhesive layer (A) was formed was a cycloolefin polymer film / polarizer / acrylic resin film / pressure-sensitive adhesive layer (B) / retardation film. A polarizing film with an adhesive layer was produced by transferring to a polarizing film having a retardation film having a constitution. The structure of the obtained polarizing film with an adhesive layer is a cycloolefin polymer film / a polarizer / an acrylic resin film / an adhesive layer (B) / a retardation film / an adhesive layer (A).

The cycloolefin polymer film and the acrylic resin film on both sides of the polarizer were bonded together using a polyvinyl alcohol-based adhesive to obtain a polarizing film. In producing the polarizing film with the pressure-sensitive adhesive layer having the retardation film, the polarizing film and the retardation film were bonded together via the pressure-sensitive adhesive layer (B).

The constituent members of the polarizing film having the retardation film are as follows.

(Cycloolefin polymer film)
A cycloolefin polymer film having a thickness of 25 μm (trade name: Zeonoa Film, manufactured by Nippon Zeon Corporation) was used.

(Manufacturing of polarizer)
A polarizer made of a stretched polyvinyl alcohol film having a thickness of 5 μm impregnated with iodine was used. The single transmittance Y value of the polarizer (or the polarizing film to which the protective film was attached) was 42.4%, and the degree of polarization was 99.995.

(Acrylic resin film)
The resin pellet consisting of 100 parts by weight of the imidized MS resin described in Production Example 1 of JP-A-2010-284840 was dried at 100.5 kPa at 100 ° C. for 12 hours, and the die temperature was 270 ° C. using a single-screw extruder. It was extruded from a T-die and formed into a film (thickness 80 μm). Further, the film is stretched in an atmosphere of 150 ° C. in the transport direction (thickness 40 μm), and then stretched in an atmosphere of 150 ° C. in a direction orthogonal to the film transport direction to form an acrylic resin film having a thickness of 20 μm. Got

(Phase difference film)
A polycarbonate film having a thickness of 56 μm (“NRF” manufactured by Nitto Denko KK, in-plane retardation Re (550): 135 nm) was used.

(Preparation of Adhesive Composition for Forming Adhesive Layer (B))
In a separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction tube, 95 parts by weight of butyl acrylate, 5 parts by weight of acrylic acid, 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator, and After adding 233 parts by weight of ethyl acetate, nitrogen gas was allowed to flow, and nitrogen substitution was carried out for about 1 hour with stirring. Then, the flask was heated to 60 ° C. and reacted for 7 hours to obtain an acrylic polymer having a weight average molecular weight (Mw) of 1.1 million. To the above acrylic polymer solution (solid content is 100 parts by weight), as an isocyanate-based cross-linking agent, trimethylolpropane tolylene diisocyanate (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) 0.8 parts by weight. A pressure-sensitive adhesive composition (solution) was prepared by adding 0.1 part by weight of a silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd.).

(Manufacturing of adhesive layer (B))
The pressure-sensitive adhesive composition (solution) is applied onto a 38 μm-thick separator (polyethylene terephthalate film whose surface has been peeled off: a release film) so that the thickness after drying is 15 μm, and the temperature is 100 ° C. The solvent was removed from the dry layer for 3 minutes to obtain a pressure-sensitive adhesive layer (B).

Examples 2 to 13, Comparative Examples 1 to 3
In Example 1, in preparing the pressure-sensitive adhesive composition, the type of (meth) acrylic polymer, the type or amount of the cross-linking agent, the type or amount of the ultraviolet absorber, the type or amount of the dye compound, the antioxidant. The pressure-sensitive adhesive layer was formed in the same manner as in Example 1 except that the blending amount of the above was changed as shown in Table 1. Further, a polarizing film with an adhesive layer was produced in the same manner as in Example 1.

The pressure-sensitive adhesive layer (A) and the polarizing film with the pressure-sensitive adhesive layer obtained in the above Examples and Comparative Examples were evaluated as follows. The evaluation results are shown in Table 1.

<Measurement of transmittance of adhesive layer>
The separator was peeled off from the pressure-sensitive adhesive layer (A) obtained in Examples and Comparative Examples, the pressure-sensitive adhesive layer (A) was attached to a measuring jig, and a spectrophotometer (product name: U4100, Hitachi High-Technologies Corporation) Measured with Technologies). As for the transmittance, the transmittance in the wavelength range of 300 nm to 450 nm was measured. Table 1 shows the average transmittances at wavelengths of 300 nm to 400 nm, wavelengths of 400 nm to 430 nm, and wavelengths of 430 nm to 450 nm.

<Measurement of gel fraction>
For the gel fraction, take 0.2 g of the adhesive layer (A) and wrap it in a fluororesin (TEMISH NTF-1122, manufactured by Nitto Denko KK) (Wa) whose weight has been measured in advance so that the adhesive does not leak. After tying, the weight (Wb) was measured and placed in a sample bottle. 40 cc of ethyl acetate was added and the mixture was left for 7 days. Then, the fluororesin was taken out and dried on an aluminum cup at 130 ° C. for 2 hours, the weight (Wc) of the fluororesin containing the sample was measured, and the gel fraction was determined by the following formula (I).
Formula (I): Gel fraction = (Wc-Wa) / (Wb-Wa) x 100 (% by weight)
The gel fraction was measured immediately after the pressure-sensitive adhesive layer (A) was formed (within 4 hours) and after the pressure-sensitive adhesive layer (A) was formed and then left at room temperature (23 ° C.) for 1 week.

<Appearance yield>
The obtained polarizing film with an adhesive layer was punched into a square having a side length of 270 mm, and the adhesive dents on the adhesive layer (A), the adhesive chips on the edges, and the adhesive stains on the edges were determined as follows. Evaluated in.
○ ・ ・ ・ No problem.
Δ: Some appearance defects due to glueing, glue stains, and glue dents.
×: The appearance is significantly poor due to gluing, glue stains, and dents.

<Durability>
The separator is peeled off from the obtained polarizing film with an adhesive layer (length 290 mm x width 220 mm) so that the adhesive layer (A) side is cross-nicoled on both sides of a 0.7 mm thick non-alkali glass plate. I stuck it on. The sample was then autoclaved at 50 ° C. and 5 atm for 15 minutes for complete adhesion. After treating the sample under 85 conditions for 500 hours, the foaming, peeling, and floating states were visually observed according to the following criteria.
〇 ・ ・ ・ No foaming, peeling, floating, etc.
△ ・ ・ ・ There is no problem in practical use, but the level is slightly worse visually.
×: There is a problem in practical use.

<Peeling force>
A sheet piece having a length of 100 mm and a width of 50 mm was cut out from the obtained polarizing film with an adhesive layer and used as a sample. The obtained sample was subjected to a tensile tester (device name: Autograph AG-IS, manufactured by Shimadzu Corporation) at 23 ° C. and 50% R.M. in accordance with JIS Z0237. H. The separator was peeled off from the sample under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 °, and the peeling force (N / 50 mm) of 180 ° was measured.

The separator peeling force is preferably 0.02 to 1.0 (N / 50 mm). It is preferable that the separator peeling force is 0.02 (N / 50 mm) or more in order to suppress appearance defects due to the floating of the separator during processing and handling. On the other hand, it is preferable that the separator peeling force is 1.0 (N / 50 mm) or less in order to suppress the separation failure of the separator. The separator peeling force is more preferably 0.04 to 0.5 (N / 50 mm), further preferably 0.06 to 0.2 (N / 50 mm), and particularly preferably 0.08 to 0.15 (N). / 50 mm).

In Table 1,
The radical generator is benzoyl peroxide (trade name NOF BMT manufactured by NOF CORPORATION);
D110N is an isocyanate-based cross-linking agent (trade name: Takenate D110N manufactured by Mitsui Chemicals, Inc.);
C / L is an isocyanate-based cross-linking agent (trade name Coronate L manufactured by Tosoh Corporation);
The UV absorber a1 is 2,4-bis- [{4- (4-ethylhexyloxy) -4-hydroxy} -phenyl] -6- (4-methoxyphenyl) -1,3,5-triazine (commodity). Name: Tinosorb S, manufactured by BASF);
The UV absorber a2 is 2,2', 4,4'tetrahydroxybenzophenone (trade name: SeeSorb106, manufactured by Cipro Kasei Co., Ltd.);
The dye compound b1 is a merocyanine compound (trade name: FDB-009, maximum absorption wavelength of absorption spectrum: 394 nm, half width: 43 nm, manufactured by Yamada Chemical Industry Co., Ltd.);
The dye compound b2 is a polymethine compound (trade name: DAA-247, maximum absorption wavelength of absorption spectrum: 389 nm, half width: 49.5 nm, manufactured by Yamada Chemical Industry Co., Ltd.);
The dye compound b3 is an alkylphenyl indole cyanoacrinet derivative (indole compound) (trade name: BONASORB UA3912, maximum absorption wavelength of absorption spectrum: 386 nm, half width: 53 nm, manufactured by Orient Chemical Industry Co., Ltd.);
As the antioxidant, a phenolic antioxidant (trade name IRGANOX 1010 manufactured by BASF Japan Ltd.); is shown.

1 Polarizing film with adhesive layer for organic EL display device 2 Adhesive layer 3 Transparent protective film 4 Polarizer 5 Phase difference film 6 Polarizing film 7 Cover glass or cover plastic 8 Organic EL panel 9 Adhesive layer 10 Sensor layer

Claims (17)

The base polymer, the radical generator that generates radical active species by heating , the ultraviolet absorber (a) having 0 to 3 hydroxyl groups in the molecular structure, and the maximum absorption wavelength of the absorption spectrum in the wavelength region of 380 to 430 nm. A pressure-sensitive adhesive composition for an organic EL display device, which comprises at least one compound (A) selected from the existing dye compound (b).

The pressure-sensitive adhesive composition for an organic EL display device according to claim 1, wherein the compound (A) contains both the ultraviolet absorber (a) and the dye compound (b). The pressure-sensitive adhesive composition for an organic EL display device according to claim 1 or 2, wherein the maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber (a) exists in a wavelength region of 300 to 400 nm. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 3, wherein the radical generator is a peroxide. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 4, wherein the base polymer is a (meth) acrylic polymer. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 5, wherein the radical generator is contained in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the base polymer. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 6, wherein the compound (A) is contained in an amount of 0.1 to 25 parts by weight based on 100 parts by weight of the base polymer. .. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 7, further comprising an antioxidant. The pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 8, further comprising a cross-linking agent. The pressure-sensitive adhesive layer for an organic EL display device, which is formed from the pressure-sensitive adhesive composition for an organic EL display device according to any one of claims 1 to 9. Claims characterized in that the average transmittance at a wavelength of 300 to 400 nm is 12% or less, the average transmittance at a wavelength of 400 nm to 430 nm is 30% or less, and the average transmittance at a wavelength of 430 to 450 nm is 70% or more. Item 10. The pressure-sensitive adhesive layer for an organic EL display device according to Item 10. The average transmittance at a wavelength of 300 to 400 nm is 12% or less, the average transmittance at a wavelength of 400 nm to 430 nm is more than 30% and 95% or less, and the average transmittance at a wavelength of 430 to 450 nm is 80% or more. The pressure-sensitive adhesive layer for an organic EL display device according to claim 10. A polarizing film with an adhesive layer for an organic EL display device, which has a polarizing film and an adhesive layer for an organic EL display device according to any one of claims 10 to 12. The polarizing film has a transparent protective film provided on one surface of a polarizer and a retardation film on the other surface, and the pressure-sensitive adhesive layer for an organic EL display device is polarized light of the retardation film. The pressure-sensitive adhesive for an organic EL display device according to claim 13, wherein the adhesive is provided on the surface opposite to the surface in contact with the child and / or on the surface opposite to the surface in contact with the polarizer of the transparent protective film. Polarized film with layers. A polarizing film with an adhesive layer for an organic EL display device having a first adhesive layer, a transparent protective film, a polarizing element, a second adhesive layer, a retardation film, and a third adhesive layer in this order.
13. A thirteenth aspect of the present invention, wherein at least one of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer is the pressure-sensitive adhesive layer for an organic EL display device. The above-mentioned polarizing film with an adhesive layer for an organic EL display device. The polarizing film with an adhesive layer for an organic EL display device according to claim 14 or 15, wherein the retardation film is a 1/4 wave plate and the polarizing film is a circular polarizing film. At least one polarizing film with an adhesive layer for an organic EL display device according to any one of claims 10 to 12 or a polarizing film with an adhesive layer for an organic EL display device according to any one of claims 13 to 16 is used. An organic EL display device characterized by.

Images