CN116144292A - Adhesive layer for organic EL display device, polarizing film with adhesive layer for organic EL display device, and organic EL display device - Google Patents

Abstract

The present invention relates to an adhesive layer for an organic EL display device, a polarizing film with an adhesive layer for an organic EL display device, and an organic EL display device. The adhesive composition for an organic EL display device of the present invention includes a base polymer, an ultraviolet absorber, and a pigment compound whose absorption spectrum has a maximum absorption wavelength within a wavelength range of 380 nm to 430 nm. The adhesive composition for an organic EL display device of the present invention can form an adhesive layer for an organic EL display device that can inhibit the organic EL element from being degradation, and has high transparency. In addition, it is possible to provide an adhesive layer for an organic EL display device formed from the adhesive composition, a polarizing film with an adhesive layer having a polarizing film and an adhesive layer for an organic EL display device, and an adhesive layer comprising the adhesive composition. An organic EL display device with a mixture layer and/or a polarizing film with an adhesive layer.

Description

Adhesive layer for organic EL display device, polarizing film with adhesive layer for organic EL display device, and organic EL display device

This application is a divisional application of the Chinese patent application with application date of December 22, 2016 and application number 201680075203.4.

Technical Field

The present invention relates to an adhesive composition for an organic EL (electroluminescent) display device (OLED). In addition, the present invention relates to an adhesive layer for an organic EL display device formed from the adhesive composition for an organic EL display device, and a polarizing film with an adhesive layer having the adhesive layer. In addition, the present invention relates to an organic EL display device using the adhesive layer and/or the polarizing film.

Background Art

In recent years, the organic EL display device equipped with an organic EL panel has been widely used in various applications such as mobile phones, navigation devices, monitors for personal computers, and televisions. For organic EL display devices, usually, in order to suppress the situation where external light is reflected by a metal electrode (cathode) and visually recognized as a mirror surface, a circular polarizing plate (a laminate of a polarizing plate and a quarter wave plate, etc.) is configured on the visual recognition side surface of the organic EL panel. In addition, sometimes a decorative panel is further laminated on the circular polarizing plate laminated on the visual recognition side surface of the organic EL panel. The constituent components of the organic EL display devices such as the above-mentioned circular polarizing plate and the decorative panel are usually laminated via bonding materials such as adhesive layers and adhesive layers.

In an image display device such as an organic EL display device, components in the image display device may deteriorate due to incident ultraviolet light, and it is known that a layer containing an ultraviolet absorber is provided to suppress the degradation caused by ultraviolet light. Specifically, for example, the following adhesive sheets are known: a transparent double-sided adhesive sheet for an image display device, which has at least one ultraviolet absorbing layer, a light transmittance of 380 nm or less, and a visible light transmittance of 80% or more on the longer wavelength side than 430 nm (see, for example, Patent Document 1); an adhesive sheet having an adhesive layer containing an acrylic polymer and a triazine ultraviolet absorber (see, for example, Patent Document 2).

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2012-211305

Patent Document 2: Japanese Patent Application Publication No. 2013-75978

Summary of the invention

Problems to be solved by the invention

The adhesive sheets described in Patent Documents 1 and 2 can control the transmittance of light with a wavelength of 380 nm, but when the adhesive sheets are used in an organic EL display device, the organic EL element may deteriorate due to long-term use, and thus the adhesive sheets are not satisfactory. This is believed to be because, although the adhesive sheets described in Patent Documents 1 and 2 can absorb light with a wavelength of 380 nm, light in a wavelength range (380 nm to 430 nm) closer to the shorter wavelength side than the emission range of the organic EL element (closer to the longer wavelength side than 430 nm) is not fully absorbed, and deterioration occurs due to the transmitted light.

Therefore, in order to suppress the degradation of organic EL elements, it is necessary to use a layer in the organic EL display device that suppresses the transmission of light with wavelengths closer to the shorter wavelength side (380nm to 430nm) than the light emission range of the organic EL element (closer to the longer wavelength side than 430nm), can fully ensure the transmittance of visible light within the light emission range of the above-mentioned organic EL element, and has high transparency.

Therefore, the object of the present invention is to provide an adhesive composition for an organic EL display device, the adhesive composition for an organic EL display device can form an adhesive layer for an organic EL display device, the adhesive layer for an organic EL display device can suppress the degradation of an organic EL element by being used in an organic EL display device, and has high transparency. In addition, the object of the present invention is to provide an adhesive layer for an organic EL display device formed from the above-mentioned adhesive composition, a polarizing film with an adhesive layer having a polarizing film and an adhesive layer for an organic EL display device, and an organic EL display device comprising the above-mentioned adhesive layer and/or the above-mentioned polarizing film with an adhesive layer.

Means for solving problems

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found the following adhesive composition for organic EL display devices, thereby completing the present invention.

That is, the present invention relates to an adhesive composition for an organic EL display device, characterized in that the adhesive composition for an organic EL display device comprises a base polymer, an ultraviolet absorber and a pigment compound, and the maximum absorption wavelength of the absorption spectrum of the pigment compound exists in the wavelength range of 380nm to 430nm.

The base polymer is preferably a (meth)acrylic polymer.

It is preferred that the maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber exists in the wavelength range of 300 nm to 400 nm.

The present invention also relates to an adhesive layer for an organic EL display device, characterized in that the adhesive layer for an organic EL display device is formed from the adhesive composition for an organic EL display device.

In the above-mentioned adhesive layer for organic EL display device, the average transmittance at wavelengths of 300nm to 400nm is preferably 5% or less, the average transmittance at wavelengths of 450nm to 500nm is preferably 70% or more, and the average transmittance at wavelengths of 500nm to 780nm is preferably 80% or more.

In addition, regarding the above-mentioned average transmittance, the average transmittance at a wavelength of 300nm to 400nm can be 5% or less, the average transmittance at a wavelength of 400nm to 430nm can be 30% or less, the average transmittance at a wavelength of 450nm to 500nm can be 70% or more, and the average transmittance at a wavelength of 500nm to 780nm can be 80% or more.

In addition, regarding the above-mentioned average transmittance, the average transmittance at a wavelength of 300nm to 400nm can be less than 5%, the average transmittance at a wavelength of 400nm to 430nm can be greater than 30% and less than or equal to 75%, the average transmittance at a wavelength of 450nm to 500nm can be greater than 80%, and the average transmittance at a wavelength of 500nm to 780nm can be greater than 80%.

The present invention also relates to a polarizing film with an adhesive layer for an organic EL display device, characterized in that the polarizing film with an adhesive layer for an organic EL display device comprises a polarizing film and the adhesive layer for an organic EL display device.

Preferably, the polarizing film is a polarizing film having a transparent protective film on one surface of a polarizer and a phase difference film on the other surface, and the adhesive layer for the organic EL display device is arranged on the surface of the phase difference film opposite to the surface in contact with the polarizer and/or on the surface of the transparent protective film opposite to the surface in contact with the polarizer.

Preferably, the polarizing film with an adhesive layer for an organic EL display device comprises a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, a phase difference film, and a third adhesive layer in this order, and

At least one of the first adhesive layer, the second adhesive layer, and the third adhesive layer is the adhesive layer for an organic EL display device.

It is preferred that the retardation film is a quarter wave plate, and the polarizing film is a circular polarization film.

The present invention also relates to an organic EL display device, characterized in that the organic EL display device uses at least one of the above-mentioned pressure-sensitive adhesive layer for an organic EL display device or the above-mentioned polarizing film with a pressure-sensitive adhesive layer for an organic EL display device.

Effects of the Invention

The adhesive composition for an organic EL display device of the present invention can form an adhesive layer for an organic EL display device, and the adhesive layer for an organic EL display device can suppress the degradation of an organic EL element by being used in an organic EL display device, and has high transparency. Therefore, an organic EL display device using the adhesive layer for an organic EL display device of the present invention and/or a polarizing film with an adhesive layer including the adhesive layer for an organic EL display device has excellent weathering degradation resistance and can achieve a long life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1( a ) to ( c ) are cross-sectional views schematically showing one embodiment of the polarizing film with a pressure-sensitive adhesive layer for an organic EL display device of the present invention.

FIG. 2 is a cross-sectional view schematically showing an embodiment of an organic EL display device according to the present invention.

FIG. 3 is a cross-sectional view schematically showing an embodiment of an organic EL display device according to the present invention.

FIG. 4 is a cross-sectional view schematically showing an embodiment of an organic EL display device according to the present invention.

DETAILED DESCRIPTION

1. Adhesive composition for organic EL display device

The adhesive composition for an organic EL display device of the present invention is characterized in that it comprises a base polymer, an ultraviolet absorber and a pigment compound, wherein the maximum absorption wavelength of the absorption spectrum of the pigment compound exists in the wavelength range of 380nm to 430nm. Here, the maximum absorption wavelength refers to the absorption maximum wavelength showing the maximum absorbance when there are multiple absorption maxima in the spectral absorption spectrum within the wavelength range of 300nm to 460nm.

As the base polymer used in the present invention, there is no particular limitation, and as the type of adhesive composition, for example, rubber adhesives, acrylic adhesives, polysiloxane adhesives, polyurethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, cellulose adhesives, etc. can be cited. Among these adhesives, acrylic adhesives are preferably used from the perspective of excellent optical transparency, showing appropriate adhesive properties such as adhesion, cohesion and tackiness, weather resistance and heat resistance. In the present invention, an acrylic adhesive composition containing a (meth) acrylic polymer as a base polymer is preferred.

The acrylic pressure-sensitive adhesive composition preferably contains, for example, a partially polymerized product of a monomer component containing an alkyl (meth)acrylate and/or a (meth)acrylic polymer obtained from the monomer component, a UV absorber, and a pigment compound.

(1) Partially polymerized monomer components and (meth)acrylic acid polymers

The acrylic pressure-sensitive adhesive composition includes a partially polymerized product of a monomer component containing an alkyl (meth)acrylate and/or a (meth)acrylic polymer obtained from the monomer component.

As the above-mentioned alkyl (meth)acrylate, there can be exemplified an alkyl (meth)acrylate having a linear or branched alkyl group with 1 to 24 carbon atoms at the end of the ester. The alkyl (meth)acrylate can be used alone or in combination of two or more. It should be noted that "alkyl (meth)acrylate" refers to alkyl acrylate and/or alkyl methacrylate, and (meth) in the present invention has the same meaning.

As the above-mentioned alkyl (meth)acrylate, the above-mentioned linear or branched alkyl (meth)acrylate having 1 to 24 carbon atoms can be cited. Among them, alkyl (meth)acrylate having 1 to 9 carbon atoms is preferred, alkyl (meth)acrylate having 4 to 9 carbon atoms is more preferred, and alkyl (meth)acrylate having 4 to 9 carbon atoms and having a branch is further preferred. The alkyl (meth)acrylate is preferred from the perspective of easily obtaining a balance of adhesive properties. For example, as alkyl (meth)acrylate having 4 to 9 carbon atoms, specifically, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, etc. can be cited, and one of them can be used alone or in combination of two or more.

In the present invention, the amount of the alkyl (meth)acrylate having an alkyl group having 1 to 24 carbon atoms at the ester terminal is preferably 40% by weight or more, more preferably 50% by weight or more, and even more preferably 60% by weight or more, based on the total amount of the monofunctional monomer components forming the (meth)acrylic polymer.

The monomer components may contain a comonomer other than the alkyl (meth)acrylate as a monofunctional monomer component. The comonomer may be used as the remainder of the alkyl (meth)acrylate in the monomer components.

唑、乙烯基吗啉等具有含氮杂环的乙烯基类单体等。另外，可以列举含有吗啉环、哌啶环、吡咯烷环、哌嗪环等杂环的(甲基)丙烯酸类单体。具体而言，可以列举N-丙烯酰基吗啉、N-丙烯酰基哌啶、N-甲基丙烯酰基哌啶、N-丙烯酰基吡咯烷等。上述环状含氮单体中，优选内酰胺类乙烯基单体。As the comonomer, for example, a cyclic nitrogen-containing monomer may be included. As the above-mentioned cyclic nitrogen-containing monomer, a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and having a cyclic nitrogen structure may be used without particular limitation. The cyclic nitrogen structure preferably has a nitrogen atom in the cyclic structure. As the cyclic nitrogen-containing monomer, for example, lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyl

Examples of the present invention include vinyl monomers having nitrogen-containing heterocycles such as oxazole and vinyl morpholine. In addition, (meth) acrylic monomers containing heterocycles such as morpholine rings, piperidine rings, pyrrolidine rings, and piperazine rings can be cited. Specifically, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine can be cited. Among the above-mentioned cyclic nitrogen-containing monomers, lactam vinyl monomers are preferred.

In the present invention, the cyclic nitrogen-containing monomer is preferably 0.5 to 50 wt %, more preferably 0.5 to 40 wt %, and even more preferably 0.5 to 30 wt % based on the total amount of monofunctional monomer components forming the (meth)acrylic polymer.

The monomer components used in the present invention may include hydroxyl-containing monomers as monofunctional monomer components. As hydroxyl-containing monomers, monomers containing polymerizable functional groups having unsaturated double bonds such as (meth) acryloyl or vinyl groups and having hydroxyl groups may be used without particular limitation. As hydroxyl-containing monomers, for example, (meth) 2-hydroxyethyl acrylate, (meth) 2-hydroxypropyl acrylate, (meth) 2-hydroxybutyl acrylate, (meth) 3-hydroxypropyl acrylate, (meth) 4-hydroxybutyl acrylate, (meth) 6-hydroxyhexyl acrylate, (meth) 8-hydroxyoctyl acrylate, (meth) 10-hydroxydecyl acrylate, (meth) 12-hydroxylauryl acrylate and other (meth) hydroxyalkyl acrylates; (meth) hydroxyalkyl cycloalkyl acrylates such as (meth) (4-hydroxymethylcyclohexyl) methyl acrylate. In addition, hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like may be cited. These hydroxyl-containing monomers may be used alone or in combination. Among them, hydroxyalkyl (meth)acrylates are preferred.

In the present invention, from the perspective of improving adhesive strength and cohesive strength, the hydroxyl-containing monomer is preferably 1% by weight or more, more preferably 2% by weight or more, and even more preferably 3% by weight or more, relative to the total amount of the monofunctional monomer components forming the (meth) acrylic polymer. On the other hand, when the hydroxyl-containing monomer is too much, the adhesive layer may become hard and the adhesive strength may decrease, and the viscosity of the adhesive may be too high or gelation may occur. Therefore, the hydroxyl-containing monomer is preferably 30% by weight or less, more preferably 27% by weight or less, and even more preferably 25% by weight or less, relative to the total amount of the monofunctional monomer components forming the (meth) acrylic polymer.

The monomer components forming the (meth)acrylic polymer may contain other functional group-containing monomers as monofunctional monomers, for example, carboxyl group-containing monomers and monomers having a cyclic ether group.

As carboxyl-containing monomers, monomers containing polymerizable functional groups having unsaturated double bonds such as (meth) acryloyl or vinyl and having carboxyl groups can be used without particular limitation. As carboxyl-containing monomers, for example, (meth) acrylic acid, (meth) carboxyethyl acrylate, (meth) carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc. can be cited, and these carboxyl-containing monomers can be used alone or in combination. For itaconic acid and maleic acid, their anhydrides can be used. Among them, acrylic acid and methacrylic acid are preferred, and acrylic acid is particularly preferred. It should be noted that carboxyl-containing monomers can be optionally used in the monomer components used in the manufacture of the (meth) acrylic polymer of the present invention, and on the other hand, carboxyl-containing monomers can also be omitted.

As a monomer having a cyclic ether group, a monomer containing a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a cyclic ether group such as an epoxy group or an oxetane group can be used without particular limitation. As an epoxy-containing monomer, for example, glycidyl (meth) acrylate, 3,4-epoxycyclohexyl methyl (meth) acrylate, 4-hydroxybutyl glycidyl ether (meth) acrylate, etc. can be cited. As an oxetane-containing monomer, for example, 3-oxetane methyl (meth) acrylate, 3-methyloxetane methyl (meth) acrylate, 3-ethyloxetane methyl (meth) acrylate, 3-butyloxetane methyl (meth) acrylate, 3-hexyloxetane methyl (meth) acrylate, etc. can be cited. These monomers having a cyclic ether group can be used alone or in combination.

In the present invention, the carboxyl group-containing monomer and the monomer having a cyclic ether group are preferably contained in an amount of 30 wt % or less, more preferably 27 wt % or less, and even more preferably 25 wt % or less, based on the total amount of the monofunctional monomer components forming the (meth)acrylic polymer.

Among the monomer components forming the (meth)acrylic polymer of the present invention, examples of the comonomer include (meth)acrylic acid alkyl esters represented by CH ₂ ═C(R ¹ )COOR ² (wherein R ¹ represents hydrogen or methyl, and R ² represents a substituted alkyl group having 1 to 3 carbon atoms or a cyclic cycloalkyl group).

Here, the substituent of the substituted alkyl group having 1 to 3 carbon atoms as R ² is preferably an aryl group having 3 to 8 carbon atoms or an aryloxy group having 3 to 8 carbon atoms. The aryl group is not limited, but is preferably a phenyl group.

Examples of such monomers represented by CH ₂ =C(R ¹ )COOR ² include phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. These monomers can be used alone or in combination.

In the present invention, the (meth)acrylate represented by CH ₂ =C(R ¹ )COOR ² may be used in an amount of 50 wt % or less, preferably 45 wt % or less, more preferably 40 wt % or less, and further preferably 35 wt % or less, based on the total amount of the monofunctional monomer components forming the (meth)acrylic polymer.

As other comonomers, vinyl acetate, vinyl propionate, styrene, α-methylstyrene, glycol acrylate monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, polysiloxane (meth)acrylate, 2-methoxyethyl acrylate, acrylate monomers, amide-containing monomers, amino-containing monomers, imide-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. In addition, as comonomers, monomers having a cyclic structure such as terpene (meth)acrylate and tetrahydrodicyclopentadienyl (meth)acrylate can be used.

In addition, silane monomers containing silicon atoms can be cited. Examples of silane monomers include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-acryloxydecyltrimethoxysilane, 10-methacryloxydecyltriethoxysilane, and 10-acryloxydecyltriethoxysilane.

The monomer components forming the (meth)acrylic polymer of the present invention may contain, in addition to the monofunctional monomers exemplified above, a polyfunctional monomer as necessary in order to adjust the cohesive force of the pressure-sensitive adhesive.

The multifunctional monomer is a monomer having at least two polymerizable functional groups having unsaturated double bonds such as (meth)acryloyl groups or vinyl groups, and examples thereof include: ester compounds of polyols and (meth)acrylic acid such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butanediol di(meth)acrylate, and hexanediol di(meth)acrylate; Among them, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be preferably used. The polyfunctional monomer can be used alone or in combination of two or more.

The usage amount of the multifunctional monomer varies according to its molecular weight, number of functional groups, etc., and is preferably used in an amount of 3 parts by weight or less, more preferably 2 parts by weight or less, and further preferably 1 part by weight or less relative to a total of 100 parts by weight of the monofunctional monomer. In addition, there is no particular restriction as a lower limit, but it is preferably 0 parts by weight or more, and more preferably 0.001 parts by weight or more. By the usage amount of the multifunctional monomer being within the above range, the adhesive force can be improved.

The (meth)acrylic polymer can be produced by a known production method such as solution polymerization, radiation polymerization such as ultraviolet (UV) polymerization, bulk polymerization, various free radical polymerizations such as emulsion polymerization, etc. The obtained (meth)acrylic polymer can be any of a random copolymer, a block copolymer, a graft copolymer, etc.

In the present invention, partial polymers of the above-mentioned monomer components may also be used appropriately.

When the (meth) acrylic polymer is produced by free radical polymerization, a polymerization initiator, chain transfer agent, emulsifier, etc. used in the free radical polymerization may be appropriately added to the monomer components to perform polymerization. The polymerization initiator, chain transfer agent, emulsifier, etc. used in the free radical polymerization are not particularly limited and may be appropriately selected for use. It should be noted that the weight average molecular weight of the (meth) acrylic polymer may be controlled by the amount of the polymerization initiator and chain transfer agent used and the reaction conditions, and the amount used may be appropriately adjusted according to their types.

For example, in solution polymerization, ethyl acetate, toluene, etc. are used as polymerization solvents. As a specific example of solution polymerization, a polymerization initiator is added under a stream of an inert gas such as nitrogen, and the reaction is usually carried out under reaction conditions of about 50° C. to about 70° C. and about 5 hours to about 30 hours.

Examples of the thermal polymerization initiator used in solution polymerization and the like include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis(4-cyanovaleric acid), azobisisovaleronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine), and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.); Peroxide initiators include persulfates such as potassium sulfate and ammonium persulfate, di(2-ethylhexyl) peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, dibenzoyl peroxide, tert-butyl peroxyisobutyrate, 1,1-di(tert-hexylperoxy)cyclohexane, tert-butyl hydroperoxide, hydrogen peroxide, and the like; and redox initiators obtained by combining peroxides with reducing agents, such as combinations of persulfates and sodium bisulfite, and combinations of peroxides and sodium ascorbate. However, the invention is not limited thereto.

The above-mentioned polymerization initiator can be used alone or in combination of two or more. The amount of the above-mentioned polymerization initiator used is preferably about 1 part by weight or less, more preferably about 0.005 part by weight to about 1 part by weight, and further preferably about 0.02 part by weight to about 0.5 part by weight, relative to 100 parts by weight of the total amount of the monomer components.

When 2,2'-azobisisobutyronitrile is used as the polymerization initiator, the amount of the polymerization initiator used is preferably about 0.2 parts by weight or less, more preferably about 0.06 to 0.2 parts by weight, based on 100 parts by weight of the total amount of the monomer components.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, thioglycolic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol, etc. The chain transfer agent may be used alone or in combination of two or more, and the total content is about 0.3 parts by weight or less relative to 100 parts by weight of the total amount of the monomer components.

In addition, as the emulsifier used in the case of emulsion polymerization, for example, there can be mentioned: anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate; nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block polymer, etc. These emulsifiers may be used alone or in combination of two or more.

In addition, as a reactive emulsifier, as an emulsifier introduced with a radical polymerizable functional group such as an acrylic group or an allyl ether group, specifically, there are Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), ADEKA REASOAP SE10N (manufactured by ADEKA Corporation), etc. The amount of the emulsifier used is preferably 5 parts by weight or less relative to 100 parts by weight of the total amount of the monomer components.

In addition, when the (meth)acrylic polymer is produced by radiation polymerization, it can be produced by irradiating the monomer components with radiation such as electron beams, ultraviolet rays (UV) and polymerizing them. Among them, ultraviolet polymerization is preferred. The following describes ultraviolet polymerization as a preferred embodiment of radiation polymerization.

When ultraviolet polymerization is performed, it is preferred that a photopolymerization initiator is contained in the monomer component because of the advantage of being able to shorten the polymerization time. Therefore, when ultraviolet polymerization is performed, it is preferred to form the adhesive layer by ultraviolet polymerization of, for example, an ultraviolet curable acrylic adhesive composition comprising the above-mentioned monomer component containing the (meth) alkyl acrylate and/or a partial polymer of the above-mentioned monomer component, an ultraviolet absorber, a pigment compound, and a photopolymerization initiator. The adhesive layer formed by ultraviolet polymerization of the above-mentioned ultraviolet curable acrylic adhesive composition can also form a thicker adhesive layer of 150 μm or more, and is preferred because it can form an adhesive layer with a wide thickness range.

As for the above-mentioned photopolymerization initiator, there is no particular limitation, but it is preferred to contain a photopolymerization initiator (A) having an absorption band at a wavelength of more than 400 nm. When a UV absorber or a pigment compound is contained in the adhesive composition, when UV polymerization is performed, the UV rays are absorbed by the UV absorber or the pigment compound, and polymerization cannot be fully performed. However, if it is a photopolymerization initiator (A) having an absorption band at a wavelength of more than 400 nm, polymerization can be fully performed despite the inclusion of a UV absorber or a pigment compound, and therefore it is preferred.

Examples of the photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or longer include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Irgacure 819, manufactured by BASF) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (LUCIRIN TPO, manufactured by BASF).

The photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or longer may be used alone or in combination of two or more.

In addition, the amount of the photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more is not particularly limited, but is preferably less than the amount of the ultraviolet absorber or pigment compound described later, and is preferably about 0.005 to 1 part by weight, more preferably about 0.02 to 0.8 parts by weight, relative to 100 parts by weight of the monofunctional monomer component forming the (meth) acrylic polymer. When the amount of the photopolymerization initiator (A) is within the above range, ultraviolet polymerization can be fully carried out, which is preferred.

In addition, the above-mentioned photopolymerization initiator may contain a photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm. As for the photopolymerization initiator (B), there is no particular limitation as long as it generates free radicals under the action of ultraviolet rays to initiate photopolymerization and has an absorption band at a wavelength of less than 400 nm, and any one of the commonly used photopolymerization initiators can be appropriately used. For example, benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α-ketol photopolymerization initiators, photoactive oxime photopolymerization initiators, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, etc. can be used.

Specific examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisoin methyl ether.

Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-tert-butyldichloroacetophenone.

Examples of the α-ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-hydroxy-2-methylpropane-1-one.

Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime.

As a benzoin type photopolymerization initiator, benzoin etc. are mentioned, for example.

Examples of the benzyl-based photopolymerization initiator include benzil and the like.

Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, and α-hydroxycyclohexyl phenyl ketone.

The ketal-based photopolymerization initiator includes benzyl dimethyl ketal and the like.

Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

The photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm may be used alone or in combination of two or more. The photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm may be added within a range that does not impair the effects of the present invention, and the amount added is preferably about 0.005 to 0.5 parts by weight, more preferably about 0.02 to 0.2 parts by weight, relative to 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer.

In the present invention, when the above-mentioned monomer component is subjected to ultraviolet polymerization, it is preferred that: a photopolymerization initiator (B) having an absorption band at a wavelength less than 400 nm is first added to the above-mentioned monomer component, ultraviolet rays are irradiated to polymerize a part of it to obtain a partial polymer (prepolymer composition) of the monomer component, and the above-mentioned photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more, an ultraviolet absorber and a pigment compound are added to the prepolymer composition to perform ultraviolet polymerization. When the above-mentioned photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more is added to the partial polymer (prepolymer composition) of the monomer component obtained by irradiating ultraviolet rays for partial polymerization, it is preferred that the above-mentioned photopolymerization initiator is dissolved in the monomer before adding.

(2) Ultraviolet light absorber

As for the above-mentioned ultraviolet absorber, there is no particular limitation, for example, triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, hydroxybenzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, etc. can be listed, and these ultraviolet absorbers can be used alone or in combination of two or more. Among them, triazine ultraviolet absorbers and benzotriazole ultraviolet absorbers are preferred, and at least one ultraviolet absorber selected from the group consisting of triazine ultraviolet absorbers having two or less hydroxyl groups in one molecule and benzotriazole ultraviolet absorbers having one benzotriazole skeleton in one molecule is preferred, because it has good solubility in the monomer used in the formation of the acrylic adhesive composition and has high ultraviolet absorption ability near the wavelength of 380nm.

Specific examples of triazine ultraviolet absorbers 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-hydroxyphenyl and [(C ₁₀ -C ₁₆ (mainly C ₁₂ -C ₁₃ )alkyloxy)methyl] ethylene oxide reaction product (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 reaction product with 2-ethylhexyl glycidate (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-phenylphenyl)-1,3,5-triazine (TINUVIN479, manufactured by BASF);

In addition, as benzotriazole-based ultraviolet absorbers having one benzotriazole skeleton in one molecule, there can be mentioned: 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), ester compound of phenylpropionic acid and 3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl) (TINUVIN 384-2, manufactured by BASF); 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN 900, manufactured by BASF); 2-(2H-benzotriazole- 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN928, manufactured by BASF); 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionic acid methyl ester/polyethylene glycol 300 reaction product (TINUVIN1130, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-p-cresol (TINUVIN P, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, manufactured by BASF); 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-tert-butylphenol (TINUVIN326, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol (TINUVIN328, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN UVIN329, manufactured by BASF); reaction product of methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol 300 (TINUVIN213, manufactured by BASF); 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (TINUVIN571, manufactured by BASF); 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole (Sumisorb250, manufactured by Sumitomo Chemical Co., Ltd.), etc.

In addition, examples of the benzophenone-based ultraviolet absorbers (benzophenone-based compounds) and hydroxybenzophenone-based ultraviolet absorbers (hydroxybenzophenone-based compounds) include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (anhydrous salt and trihydrate salt), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, and 2,2'-dihydroxy-4,4-dimethoxybenzophenone.

In addition, examples of the salicylate ultraviolet absorber (salicylate compound) include phenyl 2-acryloxybenzoate, phenyl 2-acryloxy-3-methylbenzoate, phenyl 2-acryloxy-4-methylbenzoate, phenyl 2-acryloxy-5-methylbenzoate, phenyl 2-acryloxy-3-methoxybenzoate, phenyl 2-hydroxybenzoate, phenyl 2-hydroxy-3-methylbenzoate, phenyl 2-hydroxy-4-methylbenzoate, phenyl 2-hydroxy-5-methylbenzoate, phenyl 2-hydroxy-3-methoxybenzoate, phenyl 3,5-di-tert-butyl-4-hydroxybenzoate (TINUVIN120, manufactured by BASF), and the like.

Examples of the cyanoacrylate ultraviolet absorber (cyanoacrylate compound) include 2-cyanoacrylate alkyl esters, 2-cyanoacrylate cycloalkyl esters, 2-cyanoacrylate alkoxyalkyl esters, 2-cyanoacrylate alkenyl esters, and 2-cyanoacrylate alkynyl esters.

The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber is preferably present in the wavelength range of 300 nm to 400 nm, more preferably in the wavelength range of 320 nm to 380 nm. The maximum absorption wavelength is measured in the same manner as the measurement method for the pigment compound described below.

The above-mentioned ultraviolet absorber can be used alone or in combination of two or more, and the content as a whole is preferably about 0.1 to about 5 parts by weight, more preferably about 0.5 to about 3 parts by weight, relative to 100 parts by weight of the monofunctional monomer component forming the (meth) acrylic polymer. By setting the addition amount of the ultraviolet absorber within the above range, the ultraviolet absorption function of the adhesive layer can be fully exerted, and when ultraviolet polymerization is performed, the polymerization is not hindered, so it is preferred.

(3) Pigment compounds

As for the pigment compound used in the present invention, there is no particular restriction as long as the maximum absorption wavelength of the absorption spectrum is present in the wavelength range of 380nm to 430nm. The maximum absorption wavelength of the absorption spectrum of the pigment compound is more preferably present in the wavelength range of 380nm to 420nm. In the present invention, by using such a pigment compound in combination with the above-mentioned ultraviolet absorber, it is possible to fully absorb the light in the range (wavelength 380nm to 430nm) that has no effect on the luminescence of the organic EL element, and the luminescence range of the organic EL element (closer to the long wavelength side than 430nm) can be fully transmitted, and as a result, the degradation of the organic EL element caused by external light can be suppressed. In addition, as long as the pigment compound has the above-mentioned wavelength characteristics, there is no particular restriction, and it is preferred that the material that does not hinder the display of the organic EL element and does not have fluorescence and phosphorescence performance (photoluminescence) is a material.

In addition, the half-peak width of the above-mentioned pigment compound is not particularly limited, and is preferably below 80nm, more preferably 5nm～70nm, and further preferably 10nm～60nm. By the half-peak width of the pigment compound being in the above-mentioned range, it is possible to control as follows: fully absorb the light in the range that does not affect the luminescence of the organic EL element, and fully transmit the light closer to the long wavelength side than 430nm, so it is preferred. It should be noted that the determination method of the half-peak width utilizes the method described below.

<Method for measuring half peak width>

About the half-peak width of pigment compound, use ultraviolet visible spectrophotometer (U-4100, Hitachi High-Tech Co., Ltd. manufacture), under the following conditions, measured by the transmission absorption spectrum of pigment compound solution.By adjusting the concentration in a way that the absorbance of maximum absorption wavelength is 1.0 and measuring the spectral spectrum, the spacing (half-peak full width) of the wavelength between two points that will reach 50% of the peak value is used as the half-peak width of this pigment compound.

(Measurement conditions)

Solvent: Toluene or Chloroform

Cuvette: Quartz cuvette

Optical path length: 10mm

As above-mentioned pigment compound, as long as the maximum absorption wavelength of absorption spectrum is present in the compound in the wavelength range of 380nm～430nm, its structure etc. are not particularly limited.As above-mentioned pigment compound, for example can enumerate organic pigment compound, inorganic pigment compound, wherein, from the viewpoint of dispersibility and transparency maintenance in resin components such as base polymer, preferred organic pigment compound.

Examples of the organic pigment compound include azomethine compounds, indole compounds, cinnamic acid compounds, pyrimidine compounds, and porphyrin compounds.

As the above-mentioned organic pigment compound, a commercially available organic pigment compound can be appropriately used. Specifically, as the above-mentioned indole compound, BONASORB UA3911 (trade name, maximum absorption wavelength of absorption spectrum: 398nm, half-peak width: 48nm, manufactured by Orient Chemical Industry Co., Ltd.) and BONASORB UA3912 (trade name, maximum absorption wavelength of absorption spectrum: 386nm, half-peak width: 53nm, manufactured by Orient Chemical Industry Co., Ltd.) can be listed. As the cinnamic acid compound, SOM-5-0106 (trade name, maximum absorption wavelength of absorption spectrum: 416nm, half-peak width: 50nm, manufactured by Orient Chemical Industry Co., Ltd.) can be listed. As the porphyrin compound, FDB-001 (trade name, maximum absorption wavelength of absorption spectrum: 420nm, half-peak width: 14nm, manufactured by Yamada Chemical Industry Co., Ltd.) can be listed.

The pigment compound can be used alone or in combination of two or more, and the content as a whole is preferably about 0.01 to about 10 parts by weight, more preferably about 0.02 to about 5 parts by weight, relative to 100 parts by weight of the monofunctional monomer component forming the (meth) acrylic polymer. By setting the added amount of the pigment compound to the above range, it is possible to fully absorb light in a range that has no effect on the luminescence of the organic EL element, and by using an adhesive layer formed by the adhesive composition, it is possible to suppress the degradation of the organic EL element, so it is preferred.

(4) Silane coupling agent

In addition, the adhesive composition of the present invention may contain a silane coupling agent. The amount of the silane coupling agent is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, and further preferably 0.02 to 0.6 parts by weight, relative to 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer.

Examples of the silane coupling agent include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acryloyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

(5) Cross-linking agent

唑啉类交联剂、氮丙啶类交联剂、硅烷类交联剂、烷基醚化三聚氰胺类交联剂、金属螯合物类交联剂、过氧化物等交联剂。交联剂可以单独使用一种或组合使用两种以上。其中，优选使用异氰酸酯类交联剂。The adhesive composition of the present invention may contain a crosslinking agent. The crosslinking agent includes isocyanate crosslinking agents, epoxy crosslinking agents, polysiloxane crosslinking agents,

Azoline crosslinking agent, aziridine crosslinking agent, silane crosslinking agent, alkyl etherified melamine crosslinking agent, metal chelate crosslinking agent, peroxide and the like crosslinking agent. The crosslinking agent can be used alone or in combination of two or more. Among them, isocyanate crosslinking agents are preferably used.

The cross-linking agent may be used alone or in combination of two or more. The total content 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, based on 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer.

An isocyanate crosslinking agent refers to a compound having two or more isocyanate groups (including isocyanate regeneration functional groups in which the isocyanate groups are temporarily protected by a blocking agent or polymerization) in one molecule. Examples of the isocyanate crosslinking agent include aromatic isocyanates such as toluene diisocyanate and xylylene diisocyanate, alicyclic 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; aromatic diisocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; trimethylolpropane/toluene diisocyanate trimer adduct (trade name: CORONATE L, manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane/hexamethylene diisocyanate trimer adduct (trade name: CORONATE HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), isocyanurate form of hexamethylene diisocyanate (trade name: CORONATE HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), HX, manufactured by Nippon Polyurethane Industry Co., Ltd.), isocyanate adducts such as trimethylolpropane adduct of xylylene diisocyanate (trade name: D110N, manufactured by Mitsui Chemicals, Inc.), trimethylolpropane adduct of hexamethylene diisocyanate (trade name: D160N, manufactured by Mitsui Chemicals, Inc.); polyether polyisocyanates, polyester polyisocyanates, and adducts thereof with various polyols, polyisocyanates obtained by multifunctionalization using isocyanurate bonds, biuret bonds, allophanate bonds, etc.

(6) Other additives

In addition to the above-mentioned components, the adhesive composition of the present invention may contain appropriate additives according to the application. For example, tackifiers (such as rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenol resins, etc., which are solid, semi-solid or liquid at room temperature); fillers such as hollow glass microspheres; plasticizers; anti-aging agents; light stabilizers (HALS); antioxidants, etc. can be listed.

In the present invention, for the above-mentioned adhesive composition, it is preferred to adjust the viscosity to a suitable viscosity for operations such as coating on a substrate. The viscosity of the adhesive composition is adjusted, for example, by adding various polymers or multifunctional monomers such as thickening additives, or partially polymerizing the monomer components in the adhesive composition. It should be noted that the partial polymerization can be performed before or after the addition of various polymers or multifunctional monomers such as thickening additives. The viscosity of the above-mentioned adhesive composition varies depending on the amount of additives, etc., so the polymerization rate when the monomer components in the adhesive composition are partially polymerized cannot be uniquely determined. As a rough benchmark, it is preferably about 20% or less, more preferably about 3% to about 20%, and further preferably about 5% to about 15%. When it is greater than 20%, the viscosity becomes too high, so it is difficult to apply to the substrate.

2. Adhesive layer for organic EL display device

The adhesive layer for an organic EL display device of the present invention is characterized in that the adhesive layer for an organic EL display device is formed from the above-mentioned adhesive composition for an organic EL display device.

There is no particular limitation on the method for forming the adhesive layer, and the adhesive layer can be formed by a method commonly used in the art. Specifically, the adhesive layer can be formed by applying the adhesive composition to at least one side of the substrate and drying the coating film formed by the adhesive composition; or, the adhesive layer can be formed by irradiating active energy rays such as ultraviolet rays.

The substrate is not particularly limited, and for example, various substrates such as a release film and a transparent resin film substrate, or a polarizing film described below can be appropriately used as the substrate.

As the constituent material of the above-mentioned release film, for example, resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabrics, meshes, foam sheets, metal foils, and appropriate thin paper-like materials (thin sheets) such as laminates thereof can be listed. From the perspective of excellent surface smoothness, it is preferred to use a resin film.

Examples of the resin film include polyethylene films, polypropylene films, polybutylene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, and ethylene-vinyl acetate copolymer films.

The thickness of the release film is usually 5 μm to 200 μm, preferably about 5 μm to about 100 μm. The release film may be subjected to release and antifouling treatment using silicone, fluorine-containing, long-chain alkyl or fatty acid amide release agents, silica powder, etc., or antistatic treatment such as coating, kneading, and vapor deposition, as required. In particular, by appropriately subjecting the surface of the release film to a release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment, the releasability from the adhesive layer can be further improved.

As the above-mentioned transparent resin film substrate, there is no particular restriction, and various resin films with transparency are used. The resin film is formed by a layer of film. As its material, for example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (methyl) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, etc. can be cited. Among these, polyester resins, polyimide resins and polyether sulfone resins are particularly preferred.

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

The method for coating the above-mentioned adhesive composition on the above-mentioned substrate can use a known appropriate method such as roller coating, roller lick coating, gravure coating, reverse coating, roller brush, spraying, dip roller coating, scraper bar coating, scraper coating, air knife coating, curtain coating, lip die coating, and die coater, without any particular limitation.

When the above-mentioned adhesive layer is formed by drying a coating film formed by the above-mentioned adhesive composition, the drying conditions (temperature, time) are not particularly limited and can be appropriately set according to the composition, concentration, etc. of the adhesive composition, for example, at about 60°C to about 170°C, preferably 60°C to 150°C, for 1 minute to 60 minutes, preferably 2 minutes to 30 minutes.

In the case where the above-mentioned adhesive composition is an ultraviolet curing adhesive composition and is formed by irradiating ultraviolet rays to a coating film formed by the ultraviolet curing adhesive composition, the irradiation intensity of the ultraviolet rays is preferably 5mW/ ^cm2 or more. When the irradiance of the ultraviolet rays is less than 5mW/ ^cm2 , the polymerization reaction time becomes long and sometimes the productivity is poor. It should be noted that the irradiance of the ultraviolet rays is preferably 200mW/cm2 ^or less. When the irradiance of the ultraviolet rays is greater than 200mW/ ^cm2 , the photopolymerization initiator is rapidly consumed, so that sometimes the polymer is low in molecular weight, and the retention force at high temperature is reduced. In addition, the cumulative light amount of ultraviolet rays is preferably 100mJ/ ^cm2 to 5000mJ/ ^cm2 .

The ultraviolet lamp used in the present invention is not particularly limited, and LED lamp is preferred. Compared with other ultraviolet lamps, LED lamps are lamps that release less heat, so the temperature in the polymerization of the adhesive layer can be suppressed. Therefore, it is possible to prevent the low molecular weight of the polymer, prevent the reduction of the cohesive force of the adhesive layer, and improve the holding power at high temperatures when the adhesive sheet is made. In addition, a plurality of ultraviolet lamps can also be combined. In addition, ultraviolet rays can also be irradiated intermittently, and a bright period for irradiating ultraviolet rays and a dark period for not irradiating ultraviolet rays can be set.

In the present invention, the final polymerization rate of the monomer components in the ultraviolet curable adhesive composition is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

In the present invention, the peak wavelength of ultraviolet rays irradiated to the ultraviolet curable adhesive composition is preferably in the range of 200nm to 500nm, more preferably in the range of 300nm to 450nm. When the peak wavelength of ultraviolet rays is greater than 500nm, the photopolymerization initiator may not decompose and the polymerization reaction may not be initiated. In addition, when the peak wavelength of ultraviolet rays is less than 200nm, the polymer chain may be cut and the adhesive properties may be reduced.

The reaction is inhibited by oxygen in the air. Therefore, in order to block oxygen, it is preferred to form a release film on the coating film formed by the ultraviolet curable acrylic adhesive composition, or to perform the photopolymerization reaction under a nitrogen atmosphere. As the release film, the above-mentioned release film can be cited. It should be noted that when a release film is used, the release film can be directly used as a spacer of the polarizing film with an adhesive layer.

In addition, when the ultraviolet curable adhesive composition used in the present invention contains a photopolymerization initiator (B), it is preferred that: a composition containing a monomer component containing an alkyl (meth)acrylate and the above-mentioned photopolymerization initiator (B) (sometimes also referred to as "pre-added polymerization initiator") is irradiated with ultraviolet rays to form a partial polymer of the above-mentioned monomer component, and an ultraviolet absorber, a pigment compound, and a photopolymerization initiator (A) having an absorption band at a wavelength of more than 400 nm (sometimes also referred to as "post-added polymerization initiator") are added to the partial polymer of the above-mentioned monomer component to prepare the ultraviolet curable adhesive composition. The polymerization rate of the partial polymer is preferably about 20% or less, more preferably about 3% to about 20%, and further preferably about 5% to about 15%. The ultraviolet irradiation conditions are as described above.

As described above, when forming a pressure-sensitive adhesive layer from a UV-curable pressure-sensitive adhesive composition containing a photopolymerization initiator (B), polymerization in two steps as described above can increase the polymerization rate of the monomer components and improve the ultraviolet absorption function of the pressure-sensitive adhesive layer finally produced.

From the viewpoint of ensuring the function of absorbing light with a wavelength less than 430nm, the thickness of the adhesive layer is preferably 12μm or more, more preferably 50μm or more, further preferably 100μm or more, and particularly preferably 150μm or more. The upper limit of the thickness of the adhesive layer is not particularly limited, but is preferably 1mm or less. When the thickness of the adhesive layer is greater than 1mm, ultraviolet rays are difficult to transmit, and the polymerization of the monomer components takes time. In addition, problems arise in terms of processability, winding in the process, and transportability, and sometimes poor productivity, so it is not preferred.

The gel fraction of the adhesive layer of the present invention is not particularly limited, but is preferably 35% or more, more preferably 50% or more, further preferably 75% or more, and particularly preferably 85% or more. When the gel fraction of the adhesive layer is small, the cohesive force is poor, and processability and handling properties may be problematic.

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%. The pressure-sensitive adhesive layer preferably has high transparency when the haze is within the above range.

The average transmittance of the adhesive layer at a wavelength of 300 nm to 400 nm is preferably 5% or less, more preferably 2% or less. When the transmittance of the adhesive layer is within the above range, it can fully absorb light in a range that has no effect on the luminescence of the organic EL element, thereby suppressing the degradation of the organic EL element.

The average transmittance of the adhesive layer at a wavelength of 450 nm to 500 nm is preferably 70% or more, more preferably 75% or more, and the average transmittance at a wavelength of 500 nm to 780 nm is preferably 80% or more, more preferably 85% or more. When the transmittance of the adhesive layer is within the above range, light can be fully transmitted within the light emission range of the organic EL element (closer to the long wavelength side than 430 nm), and the organic EL display device using the adhesive layer can emit sufficient light.

In addition, the average transmittance of the above-mentioned adhesive layer at a wavelength of 400nm to 430nm or less can be designed according to the characteristics required by the organic EL display device. For example, from the viewpoint of fully absorbing light in a range that has no effect on the luminescence of the organic EL element and suppressing the degradation of the organic EL element for protection, the average transmittance of the above-mentioned adhesive layer at a wavelength of 400nm to 430nm is preferably 30% or less, and more preferably 20% or less. On the other hand, from the viewpoint of protecting the organic EL element from ultraviolet light and suppressing the coloring of the organic EL element, the average transmittance of the above-mentioned adhesive layer at a wavelength of 400nm to 430nm or less is preferably greater than 30% and less than or equal to 75%, and more preferably greater than 30% and less than or equal to 65%.

Here, the “average transmittance at a wavelength of 300 nm to 400 nm” refers to the average transmittance measured at a 1 nm interval within the wavelength range of 300 nm to 400 nm. The same applies to the average transmittance in other wavelength ranges.

The adhesive layer of the present invention, by having the above-mentioned transmittance, can fully absorb light in a range that has no effect on the luminescence of the organic EL element, and can fully transmit the luminescence range of the organic EL element (closer to the long wavelength side than 430nm), thereby suppressing the degradation of the organic EL element caused by external light.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a release film until it is actually used.

3. Polarizing film with adhesive layer for organic EL display device

The polarizing film with an organic EL display device pressure-sensitive adhesive layer of the present invention is characterized by comprising a polarizing film and the above-mentioned organic EL display device pressure-sensitive adhesive layer.

As the adhesive layer for the organic EL display device, the above-mentioned adhesive layer can be used appropriately. In addition, when the adhesive layer is formed on a substrate other than the polarizing film, the adhesive layer can be transferred by lamination to the polarizing film. In addition, the above-mentioned release film can be directly used as a spacer of the polarizing film with an adhesive layer, which can simplify the process.

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

(1) Polarizer

There is no particular limitation on the polarizer, and various polarizers can be used. As polarizers, for example, a polarizer obtained by uniaxially stretching a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, and a partially saponified film of an ethylene-vinyl acetate copolymer after adsorbing a dichromatic substance such as iodine or a dichromatic dye, a polyolefin oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride, etc., can be cited. Among them, a polarizer containing a polyvinyl alcohol film and a dichromatic substance such as iodine is preferred. The thickness of these polarizers is not particularly limited, and is usually about 5 μm to about 80 μm.

The polarizer obtained by dyeing the polyvinyl alcohol film with iodine and uniaxially stretching can be made, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine for dyeing and stretching to 3 to 7 times the original length. It can also be immersed in an aqueous solution of potassium iodide, etc., which can contain boric acid or zinc sulfate, zinc chloride, etc. as needed. Further, the polyvinyl alcohol film can be immersed in water and washed with water before dyeing as needed. The stains and anti-blocking agents on the surface of the polyvinyl alcohol film can be washed away by washing the polyvinyl alcohol film with water. In addition, it also has the effect of preventing uneven dyeing by swelling the polyvinyl alcohol film. Stretching can be carried out after dyeing with iodine, or it can be stretched while dyeing, and it can also be dyed with iodine after stretching. It can be stretched in an aqueous solution or a water bath of boric acid, potassium iodide, etc.

In addition, in the present invention, a thin polarizer with a thickness of 10 μm or less can also be used. From the perspective of thinning, the thickness is preferably 1 μm to 7 μm. Such a thin polarizer has less uneven thickness, excellent visual recognition, and less dimensional change, so it is excellent in durability. In addition, it is preferred from the perspective of achieving thinning as a polarizing film.

As thin polarizers, representative examples include thin polarizing films described in Japanese Patent Application Publication No. 51-069644, Japanese Patent Application Publication No. 2000-338329, International Publication No. 2010/100917, International Publication No. 2010/100917, Japanese Patent No. 4751481, and Japanese Patent Application Publication No. 2012-073563. These thin polarizing films can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol resin (hereinafter also referred to as a PVA resin) layer and a stretching resin substrate in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA resin layer is thin, it can be stretched without problems such as breakage caused by stretching by being supported by the stretching resin substrate.

As for the above-mentioned thin polarizing film, in the manufacturing method including the steps of stretching and dyeing in the state of a laminate, in terms of being able to stretch at a high ratio to improve the polarization performance, a polarizing film obtained by a manufacturing method including a step of stretching in an aqueous boric acid solution as described in International Publication No. 2010/100917, International Publication No. 2010/100917, or Japanese Patent No. 4751481 and Japanese Patent Gazette No. 2012-073563 is preferred, and a polarizing film obtained by a manufacturing method including a step of auxiliary stretching in air before stretching in an aqueous boric acid solution as described in Japanese Patent No. 4751481 and Japanese Patent Gazette No. 2012-073563 is particularly preferred.

(2) Transparent protective film

As for the transparent protective film, the conventionally used transparent protective film can be appropriately used. Specifically, the transparent protective film is preferably formed of a material having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc., for example, polyester polymers such as polyethylene terephthalate or polyethylene naphthalate, cellulose polymers such as diacetyl cellulose or triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene or acrylonitrile-styrene copolymer (AS resin), polycarbonate polymers, etc. In addition, examples of polymers forming the transparent protective film include polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, polyolefin polymers such as ethylene-propylene copolymers, vinyl chloride polymers, amide polymers such as nylon or aromatic polyamide, imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, or blends of the above polymers. The transparent protective film can also be formed in the form of a cured layer of a thermosetting or ultraviolet curing resin such as acrylic, polyurethane, acrylic polyurethane, epoxy, or polysiloxane.

The thickness of the transparent protective film can be appropriately determined, and is generally about 1 μm to 500 μm in view of strength, workability such as handling properties, and thin film properties.

The polarizer and the transparent protective film are preferably adhered via an aqueous adhesive or the like. As aqueous adhesives, isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latexes, aqueous polyurethanes, aqueous polyesters, etc. can be exemplified. In addition to the above, adhesives for the polarizer and the transparent protective film include: ultraviolet curing adhesives, electron beam curing adhesives, etc. Electron beam curing polarizing film adhesives show suitable adhesion to the various visual recognition side transparent protective films. In addition, 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 coating or anti-reflection treatment, or treatment for the purpose of anti-sticking, diffusion or anti-glare.

In addition, as the above-mentioned transparent protective film, any transparent protective film having a phase difference and capable of functioning as an optical compensation layer can be used. In the case of using a transparent protective film having a phase difference, its phase difference characteristics can be appropriately adjusted to the value required for optical compensation. As the phase difference film, a stretched film can be appropriately used. Regarding the above-mentioned phase difference film, when the refractive index in the slow axis direction is set to nx, the refractive index in the fast axis direction in the plane is set to ny, and the refractive index in the thickness direction is set to nz, a phase difference film satisfying the relationship of nx=ny>nz, nx>ny>nz, nx>ny=nz, nx>nz>ny, nz=nx>ny, nz>nx>ny, nz>nx=ny is selected according to various uses. It should be noted that nx=ny not only includes the case where nx is exactly the same as ny, but also includes the case where nx is substantially the same as ny. In addition, ny=nz not only includes the case where ny is the same as nz, but also includes the case where ny is substantially the same as nz.

When the polarizing film used in the present invention is used as a circular polarizing plate for antireflection in an organic EL display device, the retardation film is preferably a quarter-wave plate in which the front retardation of the transparent protective film is set to a quarter wavelength (about 100 nm to about 170 nm).

When a phase difference film is used as a transparent protective film, a polarizing film having a transparent protective film provided on one surface of a polarizer and a phase difference film provided on the other surface can be appropriately used. In addition, in this case, the position of the adhesive layer is not particularly limited, and it can be provided on the surface of the transparent protective film opposite to the surface in contact with the polarizer, or on the surface of the phase difference film opposite to the surface in contact with the polarizer. From the viewpoint of suppressing the degradation of the organic EL element, it is preferably provided on at least one surface or on both surfaces.

An example of the specific structure of the polarizing film with an adhesive layer for an organic EL display device of the present invention is shown in Figures 1(a) to (c). Examples include polarizing films 1 with an adhesive layer for an organic EL display device obtained by laminating the layers in the order of adhesive layer 2/transparent protective film 3/polarizer 4/phase difference film 5 as shown in Figure 1(a), in the order of transparent protective film 3/polarizer 4/phase difference film 5/adhesive layer 2 as shown in Figure 1(b), and in the order of adhesive layer 2/transparent protective film 3/polarizer 4/phase difference film 5/adhesive layer 2 as shown in Figure 1(c). In the above Figures 1(a) and (b), the adhesive layer 2 is the adhesive layer for the organic EL display device of the present invention. In Figure 1(c), at least one of the two adhesive layers 2 may be the adhesive layer for the organic EL display device of the present invention, or both of them may be the adhesive layers for the organic EL display device of the present invention. 1, the polarizing film 6 is a single-sided protective polarizing film composed of a polarizer 4 and a transparent protective film 3, but is not limited thereto, and may be a double-sided protective polarizing film further having a transparent protective film between the polarizer 4 and the phase difference film 5. In addition, as described above, various functional layers such as a hard coating layer may be formed on the surface of the transparent protective film 3 that is not in contact with the polarizer 4.

In addition, when the phase difference film is laminated on the polarizer via an adhesive layer, the adhesive layer may be the adhesive layer for the organic EL display device of the present invention. That is, the polarizing film with an adhesive layer for an organic EL display device sequentially comprises a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, a phase difference film, and a third adhesive layer, and at least one of the first adhesive layer, the second adhesive layer, and the third adhesive layer may be the adhesive layer for the organic EL display device.

4. Organic EL display device

The organic EL display device of the present invention is characterized by using at least one of the pressure-sensitive adhesive layer for an organic EL display device of the present invention and/or the polarizing film with a pressure-sensitive adhesive layer for an organic EL display device of the present invention.

As an example of a specific structure of an organic EL display device, for example, an organic EL display device obtained by stacking each layer in the following order as shown in Figures 2 to 4 can be cited: protective glass or protective plastic 7/adhesive layer 2/transparent protective film 3/polarizer 4/phase difference film 5/adhesive layer 2/organic EL display panel (OLED element panel) 8 (Figure 2); protective glass or protective plastic 7/adhesive layer 9/transparent protective film 3/polarizer 4/phase difference film 5/adhesive layer 2/organic EL display panel 8 (Figure 3); protective glass or protective plastic 7/adhesive layer 2/sensor layer 10/adhesive layer 2/transparent protective film 3/polarizer 4/phase difference film 5/adhesive layer 2/organic EL display panel 8 (Figure 4). At least one of the adhesive layers 2 in the above-mentioned structures can be the adhesive layer of the present invention, or all adhesive layers 2 can be the adhesive layers of the present invention. In addition, the organic EL display device of the present invention may also include various functional layers such as protective films and hard coatings in addition to the above. In addition, in the stacking of each layer, an adhesive layer and/or adhesive layer can be used appropriately. As the pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer of the present invention, a pressure-sensitive adhesive layer generally used in the art can be appropriately used.

Example

The present invention will be described in detail below by way of examples, but the present invention is not limited to these examples. It should be noted that the parts and % in each example are based on weight.

Production Example 1 (Production of Acrylic Pressure-Sensitive Adhesive Composition (a))

A monomer mixture consisting of 78 parts by weight of 2-ethylhexyl acrylate (2EHA), 18 parts by weight of N-vinyl-2-pyrrolidone (NVP) and 15 parts by weight of 2-hydroxyethyl acrylate (HEA) was mixed with 0.035 parts by weight of 1-hydroxycyclohexyl phenyl ketone (trade name: IRGACURE 184, having an absorption band in the wavelength range of 200 nm to 370 nm, manufactured by BASF) and 0.035 parts by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name: IRGACURE 651, having an absorption band in the wavelength range of 200 nm to 380 nm, manufactured by BASF) as a photopolymerization initiator, and then irradiated with ultraviolet rays until the viscosity (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) reached about 20 Pa·s, thereby obtaining a prepolymer composition (polymerization rate: 8%) in which part of the above monomer components were polymerized. Next, 0.15 parts by weight of hexanediol diacrylate (HDDA) and 0.3 parts by weight of a silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to the prepolymer composition and mixed to obtain an acrylic pressure-sensitive adhesive composition (a).

Production Example 2 (Production of Acrylic Pressure-Sensitive Adhesive Composition (b))

In a separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet 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 233 parts by weight of ethyl acetate were added, and then nitrogen was introduced and nitrogen replacement was performed for about 1 hour while stirring. Then, the flask was heated to 60°C and reacted for 7 hours to obtain an acrylic polymer with a weight average molecular weight (Mw) of 1.1 million.

0.8 parts by weight of trimethylolpropane toluene diisocyanate (trade name: CORONATE L, manufactured by Nippon Polyurethane Industries, Ltd.) and 0.1 parts by weight of a silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to the above-mentioned acrylic polymer solution (solid content was 100 parts by weight) as an isocyanate crosslinking agent to prepare an adhesive composition (b) solution.

Production Example 3 (Production of Adhesive Layer (B1-1))

The adhesive composition (b) solution obtained in Manufacturing Example 2 was applied to a 38 μm thick spacer (polyethylene terephthalate film with a release treatment on the surface) in such a manner that the thickness after drying was 12 μm, and dried at 100° C. for 3 minutes to remove the solvent, thereby obtaining an adhesive layer. Then, the adhesive layer was heated at 50° C. for 48 hours for cross-linking treatment. Hereinafter, the adhesive layer is referred to as the "organic EL display panel side adhesive layer (B1-1)".

Production Example 4 (Production of Adhesive Layer (B1-2))

The adhesive composition (b) solution obtained in Manufacturing Example 2 was applied to a 38 μm thick spacer (polyethylene terephthalate film with a release treatment on the surface) in such a manner that the thickness after drying was 23 μm, and dried at 100° C. for 3 minutes to remove the solvent, thereby obtaining an adhesive layer. Then, the adhesive layer was heated at 50° C. for 48 hours for cross-linking treatment. Hereinafter, the adhesive layer is referred to as the "organic EL display panel side adhesive layer (B1-2)".

Example 1

(Manufacture of Adhesive Composition (A))

To the acrylic pressure-sensitive adhesive composition (a) obtained in Production Example 1 (the monomer components forming the acrylic polymer are set to 100 parts by weight), 0.7 parts by weight (solid content weight) of 2,4-bis[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (trade name: Tinosorb S, "ultraviolet absorber (b1)" in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 346 nm, manufactured by BASF Japan Co., Ltd.) dissolved in butyl acrylate so as to have a solid content of 15%, 0.3 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (trade name: IRGACURE 819, having an absorption band in the wavelength range of 200 nm to 450 nm, manufactured by BASF Japan Co., Ltd.), and BONASORB dissolved in N-vinyl-2-pyrrolidone (NVP) so as to have a solid content of 5% were added. UA3911 (trade name, indole compound, "pigment compound (c1)" in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 398 nm, half-peak width: 48 nm, manufactured by Orient Chemical Industry Co., Ltd.) 0.5 parts by weight (solid content weight) was added and stirred to obtain an adhesive composition (A).

The adhesive composition (A) was applied onto the release film of the release film so that the thickness of the adhesive layer after formation was 150 μm, and then the release film was attached to the surface of the adhesive composition layer. Then, the adhesive composition layer was photocured by ultraviolet irradiation under the conditions of illumination: 6.5 mW/cm ² , light quantity: 1500 mJ/cm ² , and peak wavelength: 350 nm, thereby forming an adhesive layer (A-1).

Example 2

The pigment compound (c) was set to 2.5 parts by weight (solid content weight) of BONASORB UA3912 (trade name, indole compound, "pigment compound (c2)" in Tables 1 and 2, maximum absorption wavelength of the absorption spectrum: 386 nm, half-peak width: 53 nm, manufactured by Orient Chemical Industries, Ltd.) dissolved in N-vinyl-2-pyrrolidone (NVP) so that the solid content was 10%, and the adhesive layer (A-2) was formed in the same manner as in Example 1, except that the coating was performed so that the thickness of the adhesive layer after formation was 100 μm.

Example 3

The type of the ultraviolet absorber in Example 1 was changed to 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name: Tinuvin 928, "ultraviolet absorber (b2)" in Tables 1 and 2, maximum absorption wavelength of the absorption spectrum: 349 nm, manufactured by BASF Japan Co., Ltd.) dissolved in butyl acrylate so as to have a solid content of 15%, and the added amount was set to 1.5 parts by weight (solid content weight). In addition, the type of pigment compound was changed to a cinnamic acid compound (sample name: SOM-5-0103, "pigment compound (c3)" in Tables 1 and 2, maximum absorption wavelength of the absorption spectrum: 416 nm, half-peak width: 50 nm, manufactured by Orient Chemical Industry Co., Ltd.), 0.2 parts by weight (solid content weight) was directly added, and the adhesive layer (A-3) was formed in the same manner as in Example 1 except that the coating was performed so that the thickness of the adhesive layer after formation was 100 μm.

Example 4

The amount of the ultraviolet absorber (b1) added in Example 1 was changed to 3.0 parts by weight (solid content weight), the type of pigment compound was set to 0.1 parts by weight (solid content weight) of a porphyrin compound (sample name: FDB-001, "pigment compound (c4)" in Tables 1 and 2, maximum absorption wavelength of the absorption spectrum: 420 nm, half-peak width: 14 nm, manufactured by Yamada Chemical Industries, Ltd.) dissolved in N-vinyl-2-pyrrolidone (NVP) in a manner such that the solid content was 1%, and the adhesive layer (A-4) was formed in the same manner as in Example 1 except that the coating was performed so that the thickness of the adhesive layer after formation was 100 μm.

Example 5

(Manufacture of Adhesive Composition (B))

To the adhesive composition (b) solution obtained in Production Example 2 (the monomer component forming the acrylic polymer is set to 100 parts by weight), 3 parts by weight (solid content weight) of 2,4-bis[{4-(4-ethylhexyloxy)-4-hydroxy}phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (trade name: Tinosorb S, "ultraviolet absorber (b1)" in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 346 nm, manufactured by BASF Japan Co., Ltd.) and 0.8 parts by weight (solid content weight) of BONASORB UA3912 (trade name, indole compound, "pigment compound (c2)" in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 386 nm, half-peak width: 53 nm, manufactured by Orient Chemical Industry Co., Ltd.) were added directly and stirred to obtain an adhesive composition (B) solution.

The obtained adhesive composition (B) solution was applied to a separator (polyethylene terephthalate film with a release treatment on the surface) with a thickness of 38 μm so that the thickness after drying was 25 μm, and the solvent was removed by drying at 120° C. for 3 minutes to obtain an adhesive layer. Then, the adhesive layer was heated at 50° C. for 48 hours for cross-linking treatment. An adhesive layer (B) was formed.

Comparative Example 1

A pressure-sensitive adhesive layer (A1-1) was formed in the same manner as in Example 1 except that the ultraviolet absorber (b1) and the pigment compound (c1) of Example 1 were not contained and only the acrylic pressure-sensitive adhesive composition (a) was used.

Comparative Example 2

The organic EL display panel-side pressure-sensitive adhesive layer (B1-2) of Production Example 3 was used.

Comparative Example 3

A pressure-sensitive adhesive layer (A1-2) was formed in the same manner as in Example 1 except that the coloring matter compound (c1) of Example 1 was not contained and the pressure-sensitive adhesive layer was applied so as to have a thickness of 100 μm after formation.

Comparative Example 4

A pressure-sensitive adhesive layer (A1-3) was formed in the same manner as in Example 3 except that the coloring matter compound (c3) was not contained and the pressure-sensitive adhesive layer was applied so as to have a thickness of 150 μm after formation.

Comparative Example 5

An adhesive layer (A1-4) was formed in the same manner as in Example 1 except that the ultraviolet absorber (b1) of Example 1 was not contained, the amount of the pigment compound (c1) added was set to 0.3 parts by weight (solid content weight), and the adhesive layer was applied so that the thickness after formation was 100 μm.

Comparative Example 6

A pressure-sensitive adhesive layer (A1-5) was formed in the same manner as in Example 2 except that the ultraviolet absorber (b1) of Example 2 was not contained and the added amount of the pigment compound (c2) was changed to 0.5 parts by weight (solid content weight).

Comparative Example 7

A pressure-sensitive adhesive layer (A1-6) was formed in the same manner as in Example 3, except that the ultraviolet absorber (b2) of Example 3 was not contained.

Comparative Example 8

A pressure-sensitive adhesive layer (A1-7) was formed in the same manner as in Example 4 except that the ultraviolet absorber (b1) of Example 4 was not contained.

Example 6

(Manufacturing of Adhesive Layer (A-5))

An adhesive layer (A-5) was formed in the same manner as in Example 1 except that the amount of the dye compound (c1) in Example 1 was set to 0.7 parts by weight (solid content weight) and the adhesive layer was applied so that the thickness after formation was 100 μm.

(Manufacture of Polarizing Film (P))

A 25 μm thick cycloolefin polymer (COP) film was attached to the visual recognition side of a polarizer including a 5 μm thick stretched polyvinyl alcohol film impregnated with iodine using a polyvinyl alcohol adhesive, and a 20 μm thick acrylic film was laminated on the organic EL display panel side of the polarizer using a polyvinyl alcohol adhesive to prepare a polarizing film (P). The polarization degree of the polarizing film was 99.995.

(Manufacture of Polarizing Film with Adhesive Layer)

The above-made adhesive layer (A-5) is laminated on the visual recognition side of the above-mentioned polarizing film (P) (i.e., the surface of the cycloolefin polymer (COP) film with a thickness of 25 μm). The image display side adhesive layer (B1-1) is laminated on the surface of the organic EL display panel side of the above-mentioned polarizing film (P) (i.e., the surface of the acrylic film with a thickness of 20 μm), and a phase difference film (thickness: 56 μm, material: polycarbonate) and an image display side adhesive layer (B1-2) are further laminated to form a polarizing film with an adhesive layer. The obtained polarizing film with an adhesive layer has a structure of adhesive layer (A-5)/polarizing film (P)/organic EL display panel side adhesive layer (B1-1)/phase difference film/organic EL display panel side adhesive layer (B1-2).

Example 7

The adhesive layer (A-6) was formed in the same manner as in Example 2 except that the amount of the pigment compound (c2) added was set to 0.5 parts by weight (solid content weight). In addition, a polarizing film with an adhesive layer was formed in the same manner as in Example 6 except that the adhesive layer (A-6) was used.

Comparative Example 9

The adhesive layer (A-5) of Example 6 did not contain the pigment compound (c1), and an adhesive layer (A1-8) was formed in the same manner as in Example 6. In addition, a polarizing film with an adhesive layer was formed in the same manner as in Example 6 except that the adhesive layer (A1-8) was used.

The following evaluations were performed on the obtained pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer-attached polarizing film.

<Measurement of Transmittance of Adhesive Layer>

The release films of the adhesive layers obtained in Examples and Comparative Examples were peeled off, and the adhesive layers were attached to a measuring jig and measured using a spectrophotometer (product name: U4100, manufactured by Hitachi High-Technologies Corporation). The transmittance was measured in the wavelength range of 300 nm to 780 nm.

<Measurement of Transmittance of Polarizing Film with Adhesive Layer>

The release films of the pressure-sensitive adhesive layer-attached polarizing films obtained in Examples and Comparative Examples were peeled off and measured using a spectrophotometer (product name: U4100, manufactured by Hitachi High-Technologies Corporation). The transmittance was measured in the wavelength range of 350 nm to 780 nm.

<Adhesiveness>

A sheet of 100 mm in length and 20 mm in width was cut from the adhesive layer obtained in the examples and comparative examples. Next, one release film of the adhesive layer was peeled off, and a PET film (trade name: Lumirror S-10, thickness: 25 μm, manufactured by Toray Industries, Ltd.) was pasted (backed). Next, the other release film was peeled off and pressed onto a glass plate (trade name: soda-lime glass #0050, manufactured by Matsunami Glass Industries, Ltd.) as a test plate under the condition of one reciprocating press with a 2 kg roller, to prepare a sample consisting of a test plate/adhesive layer (A)/PET film. The obtained sample was subjected to autoclave treatment (50°C, 0.5 MPa, 15 minutes), and then naturally cooled for 30 minutes in an atmosphere of 23°C and 50% R.H. After natural cooling, the adhesive sheet (adhesive layer/PET film) was peeled off from the test plate using a tensile testing machine (device name: Autograph AG-IS, manufactured by Shimadzu Corporation) at 23°C, 50% R.H. atmosphere at a tensile speed of 300 mm/min and a peeling angle of 180° in accordance with JIS Z0237, and the 180° peeling strength (N/20 mm) was measured.

<Total light transmittance, haze>

One release film was peeled off from the adhesive layer obtained in the examples and comparative examples, and the film was bonded to a slide glass (trade name: White Grinding No. 1, thickness: 0.8 mm to 1.0 mm, total light transmittance: 92%, haze: 0.2%, manufactured by Matsunami Glass Industries, Ltd.). The other release film was further peeled off to prepare a test piece having a layer structure of adhesive layer/slide glass. The total light transmittance and haze value of the test piece in the visible light range were measured using a haze meter (device name: HM-150, manufactured by Murakami Color Laboratory, Ltd.).

Reference numerals

1 Polarizing film with adhesive layer for organic EL display device

2 Adhesive layer

3. Transparent protective film

4 Polarizer

5. Retardation Film

6 Polarizing film

7 Protective glass or protective plastic

8 Organic EL Panel

9 Adhesive layer

10 Sensor Layer

Claims (8)

1. An adhesive layer for an organic EL display device, the adhesive layer for an organic EL display device being formed from an adhesive composition for an organic EL display device, characterized in that The adhesive composition for an organic EL display device includes a base polymer, an ultraviolet absorber, and a pigment compound, and the maximum absorption wavelength of the absorption spectrum of the pigment compound exists within a wavelength range of 380nm to 430nm, The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber exists in the wavelength range of 300nm～400nm, The adhesive layer for an organic EL display device has an average transmittance of 5% or less at a wavelength of 300nm to 400nm, an average transmittance of 30% or less at a wavelength of 400nm to 430nm, and an average transmittance of at least 70% at a wavelength of 450nm to 500nm. , the average transmittance of wavelength 500nm～780nm is more than 80%. 2. An adhesive layer for an organic EL display device, wherein the adhesive layer for an organic EL display device is formed from an adhesive composition for an organic EL display device, characterized in that The adhesive composition for an organic EL display device includes a base polymer, an ultraviolet absorber, and a pigment compound, and the maximum absorption wavelength of the absorption spectrum of the pigment compound exists within a wavelength range of 380nm to 430nm, The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber exists in the wavelength range of 300nm～400nm, The average transmittance of the adhesive layer for an organic EL display device with a wavelength of 300nm to 400nm is 5% or less, the average transmittance of a wavelength of 400nm to 430nm is greater than 30% and less than or equal to 75%, and the average transmittance of a wavelength of 450nm to 500nm It is 80% or more, and the average transmittance at a wavelength of 500 nm to 780 nm is 80% or more. 3. The adhesive layer for an organic EL display device according to claim 1 or 2, wherein the base polymer is a (meth)acrylic polymer. 4. A polarizing film with an adhesive layer for an organic EL display device, characterized in that, the polarizing film with an adhesive layer for an organic EL display device has a polarizing film and any one of claims 1 to 3. The adhesive layer for an organic EL display device according to one item. 5. the polarizing film that has organic EL display device adhesive layer as claimed in claim 4, described polarizing film is provided with transparent protective film on one face of polarizer, and has phase phase on the other face Polarizing film of poor film, characterized in that, The adhesive layer for an organic EL display device is provided on the surface of the phase difference film opposite to the surface contacting the polarizer and/or the surface of the transparent protective film opposite to the surface contacting the polarizer . 6. The polarizing film with an adhesive layer for an organic EL display device as claimed in claim 4, which has a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, and a phase film successively. A polarizing film with an adhesive layer for an organic EL display device, such as a poor film and a third adhesive layer, is characterized in that At least one of the first adhesive layer, the second adhesive layer, and the third adhesive layer is the adhesive layer for an organic EL display device. 7. the polarizing film with organic EL display device adhesive layer as claimed in claim 5 or 6, is characterized in that, described retardation film is 1/4 wave plate, and described polarizing film is circularly polarized membrane. 8. An organic EL display device, characterized in that the organic EL display device uses the adhesive layer for an organic EL display device according to any one of claims 1 to 3, or the adhesive layer according to any one of claims 4 to 7. At least one of the polarizing films with an adhesive layer for an organic EL display device according to any one of the above.

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