KR102648801B1 - Adhesive layer for organic electroluminescent display device, polarizing film equipped with adhesive layer for organic electroluminescent display device, and organic electroluminescent display device - Google Patents

Abstract

The adhesive composition for an organic EL display device of the present invention contains a base polymer, an ultraviolet absorber, and a pigment compound whose maximum absorption wavelength of the absorption spectrum exists in the wavelength range of 380 to 430 nm. When the adhesive composition for an organic EL display device of the present invention is used in an organic EL display device, deterioration of the organic EL element can be suppressed and a highly transparent adhesive layer for an organic EL display device can be formed. In addition, a polarizing film with an adhesive layer having an adhesive layer for an organic EL display device, a polarizing film, and an adhesive layer for an organic EL display device formed from the adhesive composition, and an organic EL display comprising the adhesive layer and/or a polarizing film with an adhesive layer. Devices can be provided.

Description

An adhesive layer for an organic EL display device, a polarizing film having an adhesive layer for an organic EL display device, and an organic EL display device DEVICE}

The present invention relates to an adhesive composition for an organic EL (electroluminescence) display device (OLED). Additionally, 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. Additionally, the present invention relates to an organic EL display device using the pressure-sensitive adhesive layer and/or the polarizing film.

In recent years, organic EL display devices equipped with organic EL panels have been widely used in various applications such as mobile phones, car navigation devices, personal computer monitors, and televisions. Organic EL display devices usually use a circular polarizer (a laminate of a polarizer and a quarter wave plate, etc.) on the viewing side surface of the organic EL panel to suppress external light from being reflected from the metal electrode (cathode) and being viewed as a mirror surface. ) is placed. Additionally, a decorative panel or the like may be additionally laminated on the circular polarizer laminated on the viewing side surface of the organic EL panel. The structural members of an organic EL display device, such as the circular polarizer or decorative panel, are usually laminated with a bonding material such as an adhesive layer or an adhesive layer interposed therebetween.

In image display devices such as organic EL display devices, structural members, etc. within the image display device may be deteriorated due to incident ultraviolet light. In order to suppress deterioration due to the ultraviolet light, a layer containing an ultraviolet absorber is used. It is known to form Specifically, for example, a transparent double-sided adhesive sheet for an image display device that has at least one layer of ultraviolet absorption layer, has a light transmittance of 30% or less at a wavelength of 380 nm, and has a visible light transmittance of 80% or more on the longer wavelength side than the wavelength of 430 nm. (For example, see Patent Document 1), an adhesive sheet having an adhesive layer containing an acrylic polymer and a triazine-based ultraviolet absorber is known (for example, see Patent Document 2).

Japanese Patent Publication No. 2012-211305 Japanese Patent Publication No. 2013-75978

The adhesive sheets described in Patent Documents 1 and 2 are capable of controlling 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 elements may deteriorate due to long-term use. It wasn't enough. This means that although the adhesive sheets described in Patent Documents 1 and 2 can absorb light with a wavelength of 380 nm, light in the wavelength range (380 nm to 430 nm) is shorter than the light emitting region of the organic EL element (longer wavelength than 430 nm). It is thought that this is not sufficiently absorbed and deterioration occurs due to the transmitted light.

Therefore, in order to suppress deterioration of the organic EL element, the transmission of light with a shorter wavelength side (380 nm to 430 nm) is suppressed than the light emitting region (longer wavelength side than 430 nm) of the organic EL element, and It is necessary to use a layer that can sufficiently secure visible light transmittance and has high transparency in an organic EL display device.

Therefore, the present invention provides an adhesive composition for an organic EL display device, which can suppress the deterioration of the organic EL element and form a highly transparent adhesive layer for the organic EL display device when used in the organic EL display device. The purpose is to provide In addition, an organic EL display device comprising an adhesive layer for an organic EL display device formed from the adhesive composition, a polarizing film, a polarizing film with an adhesive layer having an adhesive layer for an organic EL display device, and the adhesive layer and/or a polarizing film with an adhesive layer. The purpose is to provide an EL display device.

As a result of intensive studies to solve the above problems, the present inventors have discovered the following adhesive composition for an organic EL display device and completed the present invention.

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

It is preferable that the base polymer is a (meth)acrylic polymer.

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

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

In the adhesive layer for an organic EL display device, it is preferable that the average transmittance of the wavelength of 300 to 400 nm is 5% or less, the average transmittance of the wavelength of 450 to 500 nm is 70% or more, and the average transmittance of the wavelength of 500 to 780 nm is 80% or more. do.

Furthermore, the average transmittance is 5% or less for a wavelength of 300 to 400 nm, an average transmittance of 30% or less for a wavelength of 400 nm to 430 nm, an average transmittance of 70% or more for a wavelength of 450 to 500 nm, and 500 to 780 nm. A type having an average transmittance of 80% or more can be used.

Furthermore, the average transmittance is 5% or less for the wavelength of 300 to 400 nm, the average transmittance for the wavelength of 400 to 430 nm is more than 30% and 75% or less, and the average transmittance for the wavelength of 450 to 500 nm is 80% or more, and the average transmittance is 80% or more for the wavelength of 450 to 500 nm. One having an average transmittance of 80% or more from 500 to 780 nm can be used.

Furthermore, the present invention relates to a polarizing film having a pressure-sensitive adhesive layer for an organic EL display device, characterized by having a polarizing film and the pressure-sensitive adhesive layer for an organic EL display device.

The polarizing film has a transparent protective film formed on one side of the polarizer and a retardation film on the other side, and the adhesive layer for an organic EL display device has a side opposite to the side of the retardation film in contact with the polarizer, And/or it is preferably formed on the side opposite to the side in contact with the polarizer of the transparent protective film.

The polarizing film having the adhesive layer for an organic EL display device has a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, a retardation film, and a third adhesive layer in this order,

It is preferable that at least one of the first, second, and third adhesive layers is the adhesive layer for the organic EL display device.

It is preferable that the retardation film is a quarter wave plate and the polarizing film is a circularly polarizing film.

Furthermore, the present invention relates to an organic EL display device characterized by using at least one of the adhesive layer for an organic EL display device or a polarizing film having the adhesive layer for an organic EL display device.

When the adhesive composition for an organic EL display device of the present invention is used in an organic EL display device, deterioration of the organic EL element can be suppressed and a highly transparent adhesive layer for an organic EL display device can be formed. Therefore, the organic EL display device using the adhesive layer for an organic EL display device and/or the polarizing film with an adhesive layer containing the adhesive layer for an organic EL display device of the present invention has excellent weather resistance to deterioration and can have a longer life. .

1(a) to 1(c) are cross-sectional views schematically showing one embodiment of a polarizing film having an adhesive layer for an organic EL display device of the present invention.
Fig. 2 is a cross-sectional view schematically showing one embodiment of the organic EL display device of the present invention.
Fig. 3 is a cross-sectional view schematically showing one embodiment of the organic EL display device of the present invention.
Fig. 4 is a cross-sectional view schematically showing one embodiment of the organic EL display device of the present invention.

1. Adhesive composition for organic EL display device

The adhesive composition for an organic EL display device of the present invention is characterized by comprising a base polymer, an ultraviolet absorber, and a pigment compound whose maximum absorption wavelength of the absorption spectrum is present in the wavelength range of 380 to 430 nm. Here, the maximum absorption wavelength means the absorption maximum wavelength that shows the maximum absorbance among the spectral absorption spectra in the wavelength range of 300 to 460 nm when there are multiple absorption maximums.

The base polymer used in the present invention is not particularly limited, and types of adhesive composition include, for example, rubber-based adhesives, acrylic adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, and polyvinyl. Examples include pyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives. Among these adhesives, acrylic adhesives are preferably used because they are excellent in optical transparency, exhibit moderate adhesion, cohesiveness, and adhesive properties, and are excellent in weather resistance, heat resistance, etc. In the present invention, it is preferable that it is an acrylic adhesive composition containing a (meth)acrylic polymer as a base polymer.

The acrylic adhesive composition preferably contains, for example, a partial polymer of a monomer component containing an alkyl (meth)acrylate and/or a (meth)acrylic polymer obtained from the monomer component, an ultraviolet absorber, and a coloring compound.

(1) Partial polymerization of monomer components and (meth)acrylic polymer

The acrylic adhesive composition includes a partial polymerization of a monomer component containing alkyl (meth)acrylate and/or a (meth)acrylic polymer obtained from the monomer component.

Examples of the alkyl (meth)acrylate include those having a straight-chain or branched alkyl group of 1 to 24 carbon atoms at the ester terminal. Alkyl (meth)acrylates can be used individually or in combination of two or more types. In addition, “alkyl (meth)acrylate” refers to alkyl acrylate and/or alkyl methacrylate, and has the same meaning as (meth) of the present invention.

Examples of the alkyl (meth)acrylate include the above-mentioned linear or branched alkyl (meth)acrylates having 1 to 24 carbon atoms. Among these, alkyl (meth)acrylates with 1 to 9 carbon atoms are preferable, alkyl (meth)acrylates with 4 to 9 carbon atoms are more preferable, and branched alkyl (meth)acrylates with 4 to 9 carbon atoms are even more preferable. desirable. The alkyl (meth)acrylate is preferable because it is easy to balance the adhesive properties. For example, as alkyl (meth)acrylate having 4 to 9 carbon atoms, specific examples include n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, and 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 mentioned, and these can be used individually or in combination of two or more types.

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

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

The copolymerization monomer may include, for example, a cyclic nitrogen-containing monomer. As the cyclic nitrogen-containing monomer, those having a polymerizable functional group having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also having a cyclic nitrogen structure can be used without particular limitation. The cyclic nitrogen structure preferably has a nitrogen atom in the cyclic structure. Examples of the cyclic nitrogen-containing monomer include lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; Vinyl monomers having nitrogen-containing heterocycles such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine can be mentioned. Additionally, (meth)acrylic monomers containing heterocycles such as morpholine ring, piperidine ring, pyrrolidine ring, and piperazine ring can be mentioned. Specifically, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine, etc. are mentioned. Among the above cyclic nitrogen-containing monomers, lactam-based vinyl monomers are preferable.

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

The monomer component used in the present invention may include a hydroxyl group-containing monomer as a monofunctional monomer component. As the hydroxyl group-containing monomer, those having a polymerizable functional group having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also having a hydroxyl group can be used without particular limitation. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. ) Acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12- Hydroxyalkyl (meth)acrylates such as hydroxylauryl (meth)acrylate; Hydroxyalkylcycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate can be mentioned. In addition, hydroxyethyl (meth)acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, etc. are mentioned. These can be used alone or in combination. Among these, hydroxyalkyl (meth)acrylate is suitable.

In the present invention, the hydroxyl group-containing monomer is preferably 1% by weight or more, and is preferably 2% by weight or more in terms of increasing adhesion and cohesion, based on the total amount of monofunctional monomer components forming the (meth)acrylic polymer. It is more preferable, and it is even more preferable that it is 3 weight% or more. On the other hand, if the amount of the hydroxyl group-containing monomer increases too much, the adhesive layer may become hard and the adhesive strength may decrease, and the viscosity of the adhesive may become too high or gelation may occur. It is preferably 30% by weight or less, more preferably 27% by weight or less, and even more preferably 25% by weight or less, based on the total amount of monofunctional monomer components forming the (meth)acrylic polymer.

In addition, the monomer component forming the (meth)acrylic polymer may contain other functional group-containing monomers as monofunctional monomers, and examples include carboxyl group-containing monomers and monomers having a cyclic ether group.

As the carboxyl group-containing monomer, those having a polymerizable functional group having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also having a carboxyl group can be used without particular limitation. Examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. It can be used alone or in combination. Itaconic acid and maleic acid can be used in their anhydrides. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is especially preferable. In addition, as the monomer component used in the production of the (meth)acrylic polymer of the present invention, a carboxyl group-containing monomer may be used arbitrarily, and it is not necessary to use a carboxyl group-containing monomer.

As the monomer having a cyclic ether group, a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group, and also having a cyclic ether group such as an epoxy group or an oxetane group can be used without particular limitation. Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate glycidyl ether. . Examples of the oxetane group-containing monomer include 3-oxetanylmethyl (meth)acrylate, 3-methyl-oxetanylmethyl (meth)acrylate, 3-ethyl-oxetanylmethyl (meth)acrylate, 3-Butyl-oxetanylmethyl (meth)acrylate, 3-hexyl-oxetanylmethyl (meth)acrylate, etc. are mentioned. These 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 30% by weight or less, and more preferably 27% by weight or less, based on the total amount of the monofunctional monomer component forming the (meth)acrylic polymer. , 25% by weight or less is more preferable.

In the monomer component forming the (meth)acrylic polymer of the present invention, examples of the copolymerization monomer include CH ₂ =C(R ¹ )COOR ² (wherein R ¹ is hydrogen or a methyl group and R ² is substituted with 1 to 3 carbon atoms) and alkyl (meth)acrylate represented by an alkyl group or a cyclic cycloalkyl group.

Here, the substituent for 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. Although there is no limitation as an aryl group, a phenyl group is preferable.

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

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

Other copolymerization monomers include vinyl acetate, vinyl propionate, styrene, and α-methylstyrene; Glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; Acrylic acid ester monomers such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate; Amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. can also be used. Additionally, as the copolymerization monomer, a monomer having a cyclic structure such as terpene (meth)acrylate and dicyclofentanyl (meth)acrylate can be used.

Additionally, silane-based monomers containing silicon atoms, etc. can be mentioned. As silane monomers, for example, 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8- Vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltrimethoxysilane Ethoxysilane, 10-acryloyloxydecyltriethoxysilane, etc. are mentioned.

The monomer component forming the (meth)acrylic polymer of the present invention may contain, in addition to the above-mentioned monofunctional monomers, polyfunctional monomers as needed in order to adjust the cohesive force of the adhesive.

A polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group, for example, (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, tetramethylolpropane tri(meth)acrylate Ester compounds of polyhydric alcohols and (meth)acrylic acid, such as methylolmethane tri(meth)acrylate; Allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyldi(meth)acrylate, hexyldi(meth)acrylate, etc. there is. Among these, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be used suitably. Polyfunctional monomers can be used individually or in combination of two or more types.

The amount of the polyfunctional monomer used varies depending on its molecular weight, number of functional groups, etc., but it is preferably used in an amount of 3 parts by weight or less, more preferably 2 parts by weight or less, and 1 part by weight, based on a total of 100 parts by weight of the monofunctional monomer. 2 or less is more preferable. The lower limit is not particularly limited, but is preferably 0 part by weight or more, and more preferably 0.001 part by weight or more. When the amount of polyfunctional monomer used is within the above range, adhesion can be improved.

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

Additionally, in the present invention, partial polymers of the above monomer components can also be suitably used.

When the (meth)acrylic polymer is produced by radical polymerization, polymerization can be performed by appropriately adding a polymerization initiator, chain transfer agent, emulsifier, etc. used in radical polymerization to the monomer component. The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of the (meth)acrylic polymer can be controlled depending on the usage amount of the polymerization initiator and chain transfer agent, and reaction conditions, and the usage amount is adjusted appropriately depending on their types.

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

As a thermal polymerization initiator used in solution polymerization, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2- Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovalerian 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'-azo Bis(N,N'-dimethyleneisobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (VA-057, Wako Pure Chemical Industries, Ltd. azo-based initiators such as those manufactured by Co., Ltd.; Persulfate such as potassium persulfate and ammonium persulfate, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate Nate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3, 3-Tetramethylbutylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy) Peroxide-based initiators such as cyclohexane, t-butylhydroperoxide, and hydrogen peroxide, and redox-based initiators combining peroxides and reducing agents, such as a combination of persulfate and sodium bisulfite, and a combination of peroxide and sodium ascorbate. However, it is not limited to these.

The polymerization initiator may be used alone or in combination of two or more types, but is preferably about 1 part by weight or less, and about 0.005 to 1 part by weight, based on 100 parts by weight of the total amount of monomer components. More preferably, it is further preferably about 0.02 to 0.5 parts by weight.

In addition, when using 2,2'-azobisisobutyronitrile as a polymerization initiator, the amount of the polymerization initiator used is preferably about 0.2 parts by weight or less, based on 100 parts by weight of the total amount of monomer components, and is 0.06 to 0.06 parts by weight. It is more preferable to set it to about 0.2 parts by weight.

As chain transfer agents, for example, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolic acid, 2,3-dimercapto-1-propanol, etc. can be mentioned. The chain transfer agent may be used individually or in combination of two or more types, but the total content is about 0.3 parts by weight or less with respect to 100 parts by weight of the total amount of the monomer component.

In addition, as emulsifiers used in emulsion polymerization, for example, anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkyl phenyl ether sulfate. , nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used individually or two or more types may be used in combination.

In addition, as a reactive emulsifier, it is an emulsifier into which radical polymerizable functional groups such as propenyl group and allyl ether group are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05, BC- 10, BC-20 (above, all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekarya Soph SE10N (manufactured by ADEKA Corporation), etc. The amount of emulsifier used is preferably 5 parts by weight or less based on 100 parts by weight of the total amount of monomer components.

Additionally, when the (meth)acrylic polymer is produced by radiation polymerization, it can be produced by polymerizing the monomer component by irradiating radiation such as electron beams or ultraviolet rays (UV). Among these, ultraviolet polymerization is preferable. Hereinafter, ultraviolet polymerization, which is a preferred mode among radiation polymerizations, will be described.

When performing ultraviolet polymerization, it is preferable to include a photopolymerization initiator in the monomer component from the advantage that the polymerization time can be shortened. Therefore, when performing ultraviolet polymerization, for example, an ultraviolet curable acrylic adhesive composition comprising a monomer component containing the alkyl (meth)acrylate and/or a partial polymerization of the monomer component, an ultraviolet absorber, a colorant compound, and a photopolymerization initiator. It is preferably formed by ultraviolet polymerization. The pressure-sensitive adhesive layer formed by ultraviolet polymerization of the UV-curable acrylic pressure-sensitive adhesive composition can be formed to be thicker than 150 μm, and is preferable because the pressure-sensitive adhesive layer can be formed with a wide range of thicknesses.

The photopolymerization initiator is not particularly limited, but preferably contains a photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more. When the pressure-sensitive adhesive composition contains an ultraviolet absorber or a dye compound, when ultraviolet polymerization is performed, the ultraviolet rays are absorbed by the ultraviolet absorber or the dye compound, making it impossible to polymerize sufficiently. However, a photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more is preferable because it can sufficiently polymerize despite containing an ultraviolet absorber or a colorant compound.

As a photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure819, manufactured by BASF), 2,4,6-trimethylbenzoyl-diphenyl-phos and pin oxide (LUCIRIN TPO, manufactured by BASF).

The photopolymerization initiator (A) having an absorption band at the wavelength of 400 nm or more may be used individually, or two or more types may be mixed.

In addition, the addition amount of the photopolymerization initiator (A) having an absorption band at the wavelength of 400 nm or more is not particularly limited, but is preferably less than the addition amount of the ultraviolet absorber or colorant compound described later, and has a monofunctional effect to form a (meth)acrylic polymer. It is preferably about 0.005 to 1 part by weight, and more preferably about 0.02 to 0.8 parts by weight, based on 100 parts by weight of the monomer component. It is preferable that the addition amount of the photopolymerization initiator (A) is within the above range because ultraviolet polymerization can sufficiently proceed.

Additionally, the photopolymerization initiator may contain a photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm. The photopolymerization initiator (B) is not particularly limited as long as it generates radicals with ultraviolet rays to initiate photopolymerization and has an absorption band at a wavelength of less than 400 nm, and any commonly used photopolymerization initiator can be suitably used. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization. Initiators, thioxanthone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, etc. can be used.

Specifically, benzoin ether-based photopolymerization initiators include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-1. , 2-diphenylethan-1-one, anisole methyl ether, etc.

Acetophenone-based photopolymerization initiators include, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-phenoxydichloroacetophenone. -t-butyldichloroacetophenone, etc. can be mentioned.

As an α-ketol photopolymerization initiator, for example, 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-hydroxy-2-methylpropane-1- You can lift your whole back.

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

Examples of the benzoin-based photopolymerization initiator include benzoin.

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

Benzophenone-based photopolymerization initiators include, for example, benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone.

Ketal-based photopolymerization initiators include benzyldimethylketal and the like.

Thioxanthone-based photopolymerization initiators include, for example, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, and 2,4-dichlorothioxanthone. Includes oxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, etc.

Acylphosphine oxide-based photopolymerization initiators include, for example, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like.

The photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm can be used individually or in combination of two or more types. The photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm can be added within a range that does not impair the effect of the present invention, but the addition amount is based on 100 parts by weight of the monofunctional monomer component that forms the (meth)acrylic polymer. , it is preferably about 0.005 to 0.5 parts by weight, and more preferably about 0.02 to 0.2 parts by weight.

In the present invention, when ultraviolet polymerization of the monomer component, a photopolymerization initiator (B) having an absorption band at a wavelength of less than 400 nm is first added to the monomer component, and a partially polymerized product (preliminary product) of the monomer component is produced by irradiating ultraviolet rays. It is preferable to carry out ultraviolet polymerization by adding a photopolymerization initiator (A), an ultraviolet absorber, and a colorant compound having an absorption band at the wavelength of 400 nm or more to the polymer composition. When adding the photopolymerization initiator (A) having an absorption band at a wavelength of 400 nm or more to a partially polymerized product (prepolymer composition) of monomer components partially polymerized by UV irradiation, it is preferable to add the photopolymerization initiator after dissolving it in the monomer. .

(2) UV absorber

The ultraviolet absorber is not particularly limited and includes, for example, a triazine-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, an oxybenzophenone-based ultraviolet absorber, a salicylic acid ester-based ultraviolet absorber, and a cyanoacrylate-based ultraviolet absorber. These can be mentioned, and these can be used individually or in combination of two or more types. Among these, triazine-based ultraviolet absorbers and benzotriazole-based ultraviolet absorbers are preferred, and triazine-based ultraviolet absorbers having two or less hydroxyl groups per molecule, and benzotriazole-based ultraviolet absorbers having one benzotriazole skeleton per molecule. At least one type of ultraviolet absorber selected from the group consisting of is preferable because it has good solubility in the monomer used to form the acrylic adhesive composition and has a high ultraviolet ray absorption ability around a wavelength of 380 nm.

As a triazine-based ultraviolet absorber having two or less hydroxyl groups per molecule, specifically, 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-dibu Toxyphenyl)-1,3,5-triazine (TINUVIN460, manufactured by BASF), 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)- Reaction product of 5-hydroxyphenyl and [(C10-C16 (mainly C12-C13) alkyloxy)methyl]oxirane (TINUVIN400, manufactured by BASF), 2-[4,6-bis(2,4-dimethylphenyl) -1,3,5-triazin-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), 2-(2,4-dihydroxyphenyl)-4 ,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine and (2-ethylhexyl)-glycidic acid ester reaction product (TINUVIN405, manufactured by BASF), 2-(4,6- Diphenyl-1,3,5-triazin-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-octyloxy Carbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (TINUVIN479, manufactured by BASF).

In addition, as a benzotriazole-based ultraviolet absorber having one benzotriazole skeleton in one molecule, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-( 1,1,3,3-Tetramethylbutyl)phenol (TINUVIN928, manufactured by BASF), 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (TINUVIN PS, manufactured by BASF), benzene Ester compound of propanoic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 branched and straight chain alkyl) (TINUVIN384-2, BASF 1st), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN900, manufactured by BASF), 2-(2H-benzotriazole-2 -yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN928, manufactured by BASF), methyl-3-(3-(2H- Benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate/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-butyl)phenol (TINUVIN326, manufactured by BASF), 2-(2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol (TINUVIN328, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN329) , 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.).

In addition, the benzophenone-based ultraviolet absorber (benzophenone-based compound) and oxybenzophenone-based ultraviolet absorber (oxybenzophenone-based compound) include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4- Methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (anhydrous and trihydrate), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzo Phenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4-dimethoxybenzophenone, etc. You can.

In addition, examples of the salicylic acid ester-based ultraviolet absorbers (salicylic acid ester-based compounds) include phenyl-2-acryloyloxybenzoate, phenyl-2-acryloyloxy-3-methylbenzoate, and phenyl-2-acryl. Loyloxy-4-methylbenzoate, phenyl-2-acryloyloxy-5-methylbenzoate, phenyl-2-acryloyloxy-3-methoxybenzoate, phenyl-2-hydroxybenzoate, Phenyl-2-hydroxy-3-methylbenzoate, phenyl-2-hydroxy-4-methylbenzoate, phenyl-2-hydroxy-5-methylbenzoate, phenyl-2-hydroxy-3-methoxy Benzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate (TINUVIN120, manufactured by BASF), etc.

Examples of the cyanoacrylate-based ultraviolet absorber (cyanoacrylate-based compound) include alkyl-2-cyanoacrylate, cycloalkyl-2-cyanoacrylate, alkoxyalkyl-2-cyanoacrylate, Alkenyl-2-cyanoacrylate, alkynyl-2-cyanoacrylate, etc. can be mentioned.

The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber is preferably in the wavelength range of 300 to 400 nm, and more preferably in the wavelength range of 320 to 380 nm. The method of measuring the maximum absorption wavelength is the same as the method of measuring the pigment-based compound described later.

The ultraviolet absorber may be used alone or in combination of two or more types, but the total content is 0.1 to 5 parts by weight based on 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer. It is preferable that it is about 0.5 to 3 parts by weight, and it is more preferable that it is about 0.5 to 3 parts by weight. By setting the addition amount of the ultraviolet absorber within the above range, the ultraviolet absorbing function of the pressure-sensitive adhesive layer can be sufficiently exercised, and when ultraviolet polymerization is performed, it is preferable because it does not interfere with the polymerization.

(3) Pigment compounds

The dye compound used in the present invention may be any compound whose maximum absorption wavelength in the absorption spectrum is in the wavelength range of 380 to 430 nm, and is not particularly limited. It is more preferable that the maximum absorption wavelength of the absorption spectrum of a pigment compound exists in the wavelength range of 380-420 nm. In the present invention, by using this colorant compound and the above ultraviolet absorber in combination, it is possible to sufficiently absorb light in the region (wavelength 380 nm to 430 nm) that does not affect the light emission of the organic EL element, and further improve the light emission of the organic EL element. The region (longer wavelength side than 430 nm) is sufficiently transparent, and as a result, deterioration of the organic EL element due to external light can be suppressed. Additionally, the dye compound is not particularly limited as long as it has the above-mentioned wavelength characteristics, but a material that does not impair the display properties of the organic EL device and does not have fluorescence or phosphorescence performance (photoluminescence) is preferred.

Moreover, the half width of the dye compound is not particularly limited, but is preferably 80 nm or less, more preferably 5 to 70 nm, and even more preferably 10 to 60 nm. It is preferable that the half width of the dye compound is within the above range because it allows control to sufficiently transmit light with a wavelength longer than 430 nm while sufficiently absorbing light in a region that does not affect the light emission of the organic EL element. In addition, the method of measuring the half width is as described below.

<Method of measuring half width>

The half width of the dye compound was measured from the transmission and absorption spectrum of the solution of the dye compound under the following conditions using an ultraviolet-visible spectrophotometer (U-4100, manufactured by Hitachi High-Tech Science Co., Ltd.). From the spectral spectrum measured by adjusting the concentration so that the absorbance at the maximum absorption wavelength was 1.0, the interval (full width at half maximum) of the wavelength between two points that is 50% of the peak value was taken as the half width of the dye compound.

(Measuring conditions)

Solvent: Toluene or chloroform

Cell: Quartz Cell

Optical path length: 10mm

The dye compound may be any compound whose maximum absorption wavelength of the absorption spectrum exists in the wavelength range of 380 to 430 nm, and its structure is not particularly limited. Examples of the dye compound include organic dye compounds and inorganic dye compounds. Among these, organic dye compounds are preferable from the viewpoint of maintaining dispersibility and transparency in resin components such as base polymers.

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

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

The above-mentioned coloring compound may be used alone or in mixture of two or more types, but the total content is 0.01 to 10 parts by weight based on 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer. It is preferable that it is about 0.02 to 5 parts by weight, and it is more preferable that it is about 0.02 to 5 parts by weight. By keeping the amount of the dye compound added within the above range, light in a region that does not affect the light emission of the organic EL element can be sufficiently absorbed, and by using an adhesive layer formed from the adhesive composition, deterioration of the organic EL element can be suppressed. It is desirable because it is possible.

(4) Silane coupling agent

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

As the silane coupling agent, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxy Silane coupling agents containing epoxy groups such as cyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl- Amino group-containing silane coupling agents such as N-(1,3-dimethylbutylidene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-methacryloxy Silane coupling agents containing (meth)acrylic groups such as propyltriethoxysilane, and silane coupling agents containing isocyanate groups such as 3-isocyanate propyltriethoxysilane.

(5) Cross-linking agent

The adhesive composition of the present invention may contain a crosslinking agent. Crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, silicone-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, silane-based crosslinking agents, alkyl etherified melamine-based crosslinking agents, metal chelate-based crosslinking agents, and peroxides. Crosslinking agents can be used singly or in combination of two or more. Among these, an isocyanate-based crosslinking agent is preferably used.

The crosslinking agent may be used individually, or two or more types may be mixed, but the total content is 5 parts by weight or less based on 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer. is preferable, 0.01 to 5 parts by weight is more preferable, 0.01 to 4 parts by weight is still more preferable, and 0.02 to 3 parts by weight is particularly preferable.

An isocyanate-based crosslinking agent refers to a compound having two or more isocyanate groups (including isocyanate regenerative functional groups temporarily protected by blocking agents or quantization, etc.) in one molecule. Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate, 2,4- Aromatic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenylisocyanate, trimethylolpropane/tolylene diisocyanate trimer adduct (product name: Coronate L, (manufactured by Nippon Polyurethane Kogyo Co., Ltd.), trimethylolpropane/hexamethylene diisocyanate trimer adduct (brand name: Coronate HL, manufactured by Nippon Polyurethane Kogyo Co., Ltd.), isocyanurate form of hexamethylene diisocyanate ( Product name: Isocyanate adduct such as Coronate HX, manufactured by Nippon Polyurethane Kogyo Co., Ltd., trimethylolpropane adduct of xylylene diisocyanate (product name: D110N, manufactured by Mitsui Chemicals Co., Ltd.), hexamethylene diisocyanate Trimethylolpropane adduct (trade name: D160N, manufactured by Mitsui Chemicals Co., Ltd.); Examples include polyether polyisocyanate, polyester polyisocyanate, adducts thereof with various polyols, and polyisocyanates polyfunctionalized with isocyanurate linkages, biuret linkages, allophanate linkages, etc.

(6) Other additives

In addition to the above components, the adhesive composition of the present invention may contain appropriate additives depending on the intended use. For example, tackifiers (those that are solid, semi-solid, or liquid at room temperature, including, for example, rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenol resins, etc.); Fillers such as hollow glass balloons; plasticizer; Anti-aging agents; Light stabilizers (HALS); Antioxidants, etc. can be mentioned.

In the present invention, the adhesive composition is preferably adjusted to a viscosity suitable for operations such as application on a substrate. The viscosity of the adhesive composition is adjusted, for example, by adding various polymers such as thickening additives or polyfunctional monomers, or by partially polymerizing the monomer components in the adhesive composition. In addition, the partial polymerization may be performed before or after adding various polymers such as thickening additives or polyfunctional monomers. Since the viscosity of the pressure-sensitive adhesive composition changes depending on the amount of additives, etc., the polymerization rate when partially polymerizing the monomer component in the pressure-sensitive adhesive composition cannot be determined unilaterally, but as a goal, it is preferably about 20% or less, and is preferably 3 to 3%. About 20% is more preferable, and about 5 to 15% is more preferable. If it exceeds 20%, the viscosity becomes too high, making application to a base material difficult.

2. Adhesive layer for organic EL display device

The adhesive layer for an organic EL display device of the present invention is characterized by being formed from the adhesive composition for an organic EL display device.

The method of forming the adhesive layer is not particularly limited, and can be formed by a method usually used in this field. Specifically, the adhesive composition can be applied to at least one side of a substrate, and the coating film formed from the adhesive composition can be formed by drying, or 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, and a polarizing film described later can also be suitably used as the substrate.

Constituent materials of the release film include, for example, resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, porous materials such as paper, fabric, and nonwoven fabric, nets, foam sheets, metal foil, and laminates thereof. Appropriate thin-walled bodies such as these can be mentioned, but resin films are suitably used in that they have excellent surface smoothness.

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

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

The transparent resin film base material is not particularly limited, but various resin films having transparency are used. The resin film is formed of one layer of film. For example, the materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, and polyolefins. type resin, (meth)acrylic resin, polyvinyl chloride type resin, polyvinylidene chloride type resin, polystyrene type resin, polyvinyl alcohol type resin, polyarylate type resin, polyphenylene sulfide type resin, etc. Among these, polyester-based resins, polyimide-based resins, and polyethersulfone-based resins are particularly preferable.

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

Methods for applying the adhesive composition on the substrate include roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, and lip. Known appropriate methods such as coat and die coater can be used, and there is no particular limitation.

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

When the adhesive composition is an ultraviolet curable adhesive composition and is formed by irradiating ultraviolet rays to a coating film formed from the ultraviolet curable adhesive composition, the illuminance of the irradiated ultraviolet rays is preferably 5 mW/cm2 or more. If the illuminance of the ultraviolet rays is less than 5 mW/cm2, the polymerization reaction time becomes long and productivity may decrease. Additionally, the illuminance of the ultraviolet rays is preferably 200 mW/cm2 or less. When the illuminance of the ultraviolet ray exceeds 200 mW/cm2, the photopolymerization initiator is rapidly consumed, so the polymer may have a low molecular weight and its holding power, especially at high temperatures, may decrease. In addition, it is preferable that the accumulated light amount of ultraviolet rays is 100 mJ/cm2 to 5000 mJ/cm2.

The ultraviolet lamp used in the present invention is not particularly limited, but an LED lamp is preferable. Since the LED lamp is a lamp with lower heat emission compared to other ultraviolet lamps, the temperature during polymerization of the adhesive layer can be suppressed. Therefore, low molecular weight of the polymer can be prevented, the cohesive strength of the pressure-sensitive adhesive layer can be prevented from decreasing, and the holding power at high temperatures when used as a pressure-sensitive adhesive sheet can be increased. Additionally, it is also possible to combine multiple ultraviolet lamps. Additionally, by intermittently irradiating ultraviolet rays, a bright period in which ultraviolet rays are irradiated and a dark period in which ultraviolet rays are not irradiated can be prepared.

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

In the present invention, the peak wavelength of ultraviolet rays irradiated to the ultraviolet curable adhesive composition is preferably within the range of 200 to 500 nm, and more preferably within the range of 300 to 450 nm. If the peak wavelength of ultraviolet rays exceeds 500 nm, the photopolymerization initiator may not decompose and the polymerization reaction may not start. Additionally, if the peak wavelength of ultraviolet rays is less than 200 nm, the polymer chain may be broken and the adhesive properties may deteriorate.

Since the reaction is inhibited by oxygen in the air, in order to block oxygen, it is preferable to form a release film or the like on the coating film formed from the ultraviolet curable acrylic pressure-sensitive adhesive composition, or to perform the photopolymerization reaction in a nitrogen atmosphere. Examples of the release film include those described above. In addition, when a release film is used, the release film can be used as is as a separator for a polarizing film with an adhesive layer.

In addition, when the ultraviolet curable adhesive composition used in the present invention contains a photopolymerization initiator (B), a monomer component containing an alkyl (meth)acrylate and the photopolymerization initiator (B) (referred to as “pre-addition polymerization initiator”) (in some cases) is irradiated with ultraviolet rays to form a partial polymerization product of the monomer component, and the partial polymerization product of the monomer component is added with an ultraviolet absorber, a dye compound, and a photopolymerization initiator having an absorption band at a wavelength of 400 nm or more ( A) (sometimes referred to as a “post-addition polymerization initiator”) is preferably added to produce an ultraviolet curable adhesive composition. The polymerization rate of the partially polymerized product is preferably about 20% or less, more preferably about 3 to 20%, and even more preferably about 5 to 15%. The ultraviolet irradiation conditions were as described above.

As described above, when forming an adhesive layer with an ultraviolet curable adhesive composition containing a photopolymerization initiator (B), the polymerization rate of the monomer component can be increased by polymerizing in two steps as described above, and also the final manufactured The UV absorption function of the adhesive layer can be improved.

From the viewpoint of securing the function of absorbing light with a wavelength of less than 430 nm, the thickness of the adhesive layer is preferably 12 ㎛ or more, more preferably 50 ㎛ or more, still more preferably 100 ㎛ or more, and especially preferably 150 ㎛ or more. do. The upper limit of the thickness of the adhesive layer is not particularly limited, but is preferably 1 mm or less. If the thickness of the adhesive layer exceeds 1 mm, it is difficult to transmit ultraviolet rays, polymerization of the monomer component takes time, and problems may arise in processability, winding and transport in the process, and productivity may decrease, so it is not desirable. not.

The gel fraction of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably 35% or more, more preferably 50% or more, even more preferably 75% or more, and especially preferably 85% or more. If the gel fraction of the pressure-sensitive adhesive layer is small, cohesion may decrease and problems may arise in processability and handling.

The adhesive layer preferably has a haze value measured at a thickness of 25 μm of 2% or less, more preferably 0 to 1.5%, and still more preferably 0 to 1%. When the haze is in the above range, it is preferable because the adhesive layer has high transparency.

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

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

Additionally, the average transmittance of the adhesive layer at a wavelength of 400 to 430 nm or less can be designed according to the characteristics required for an organic EL display device. For example, from the viewpoint of sufficiently absorbing light in a region that does not affect the light emission of the organic EL element, suppressing deterioration of the organic EL element, and protecting it, the average transmittance of the adhesive layer for a wavelength of 400 to 430 nm or less is 30. It is preferable that it is % or less, and it is more preferable that it is 20% or less. Meanwhile, from the viewpoint of protecting the organic EL element from ultraviolet light and suppressing coloring of the organic EL element, the average transmittance of the adhesive layer at a wavelength of 400 to 430 nm or less is preferably greater than 30% and 75% or less, and greater than 30% 65%. It is more preferable that it is % or less.

Here, the above-mentioned “average transmittance of a wavelength of 300 to 400 nm” refers to the average value of the transmittance measured by measuring the transmittance at a pitch of 1 nm in the region of the wavelength of 300 to 400 nm. The same applies to the average transmittance in other wavelength ranges.

By having the above-mentioned transmittance, the adhesive layer of the present invention can sufficiently absorb light in a region that does not affect the light emission of the organic EL device, and can also sufficiently transmit the light-emitting region (longer wavelength side than 430 nm) of the organic EL device. Therefore, deterioration of the organic EL element due to external light can be suppressed.

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

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

The polarizing film having an adhesive layer for an organic EL display device of the present invention is characterized by having a polarizing film and the adhesive layer for an organic EL display device.

As the adhesive layer for an organic EL display device, the ones described above can be suitably used. In addition, when the adhesive layer is formed on a substrate other than a polarizing film, the adhesive layer can be transferred by bonding to the polarizing film. In addition, the release film can be used as a separator for a polarizing film with an adhesive layer, enabling simplification in the process.

The polarizing film is not particularly limited, but includes a polarizer and a film having a transparent protective film on at least one side of the polarizer.

(1) Polarizer

The polarizer is not particularly limited, and various types of polarizers can be used. As a polarizer, for example, a dichroic substance such as iodine or a dichroic dye is adsorbed onto a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, or an ethylene/vinyl acetate copolymer-based partially saponified film. Examples include axially stretched polyene-based oriented films, such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride films. Among these, a polarizer containing a polyvinyl alcohol-based film and a dichroic substance such as iodine is suitable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and stretching it uniaxially can be produced, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine, dyeing it, and stretching it to 3 to 7 times the original length. If necessary, it may be immersed in an aqueous solution such as potassium iodide, which may contain boric acid, zinc sulfate, zinc chloride, etc. Additionally, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed before dyeing. By washing the polyvinyl alcohol-based film with water, contaminants and anti-blocking agents on the surface of the polyvinyl alcohol-based film can be cleaned, and swelling of the polyvinyl alcohol-based film also has the effect of preventing unevenness such as staining in dyeing. Stretching may be carried out after dyeing with iodine, may be carried out while dyeing, or may be carried out after stretching and then dyed with iodine. It can be stretched in an aqueous solution such as boric acid or potassium iodide or in a water bath.

Additionally, in the present invention, a thin polarizer with a thickness of 10 μm or less can also be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer has little thickness unevenness, is excellent in visibility, and has excellent durability due to little dimensional change, and is also preferable in that the thickness of the polarizing film can be reduced.

As a thin polarizer, representative examples include Japanese Patent Application Publication No. 51-069644, Japanese Patent Application Publication No. 2000-338329, International Publication No. 2010/100917 Pamphlet, International Publication No. 2010/100917 Pamphlet, or Japanese Patent Application Publication No. 2000-338329. A thin polarizing film described in Patent No. 4751481 or Japanese Patent Application Laid-Open No. 2012-073563 is included. These thin polarizing films can be obtained by a manufacturing method that includes a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a resin substrate for stretching in the state of a laminate, and a dyeing step. With this manufacturing method, even if the PVA-based resin layer is thin, it becomes possible to stretch without problems such as breakage during stretching because it is supported by the resin base material for stretching.

As the thin polarizing film, it can be stretched at a high magnification and its polarization performance can be improved even among manufacturing methods that include a step of stretching in a laminate state and a dyeing step, International Publication No. 2010/100917 Pamphlet, International Publication No. 2010/100917. It is preferable to obtain it by a manufacturing method including a step of stretching in an aqueous boric acid solution as described in the pamphlet of Publication No. 2010/100917, the specification of Japanese Patent No. 4751481, or the Japanese Patent Publication No. 2012-073563, especially the Japanese Patent Publication. It is preferably obtained by a manufacturing method described in Specification No. 4751481 or Japanese Patent Application Laid-Open No. 2012-073563 that includes a step of auxiliary stretching in air before stretching in an aqueous solution of boric acid.

(2) Transparent protective film

Regarding the transparent protective film, those conventionally used can be appropriately used. Specifically, a transparent protective film formed of a material excellent in transparency, mechanical strength, thermal stability, moisture barrier, isotropy, etc. is preferred, for example, polyester polymers such as polyethylene terephthalate or polyethylene naphthalate, diacetyl Cellulose-based polymers such as cellulose and triacetylcellulose, acrylic polymers such as polymethyl methacrylate, styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin), and polycarbonate-based polymers. there is. In addition, polyolefin-based polymers such as polyethylene, polypropylene, polyolefins with cyclo or norbornene structures, ethylene-propylene copolymers, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamide, imide-based polymers, and alcohol. Phone-based polymer, polyether sulfone-based polymer, polyether ether ketone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, vinylidene chloride-based polymer, vinyl butyral-based polymer, arylate-based polymer, polyoxymethylene-based polymer, Epoxy-based polymers or blends of these polymers can also be cited as examples of polymers that form the transparent protective film. The transparent protective film can also be formed as a cured layer of a thermosetting type or ultraviolet curing type resin such as acrylic, urethane, acrylic urethane, epoxy, or silicone.

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

It is preferable to bring the polarizer and the transparent protective film into close contact through a water-based adhesive or the like. Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl latex-based adhesives, water-based polyurethane, and water-based polyester. In addition to the above, examples of adhesives for the polarizer and the transparent protective film include ultraviolet curing adhesives and electron beam curing adhesives. The adhesive for electron beam curable polarizing film exhibits suitable adhesiveness to the above-mentioned various viewing-side transparent protective films. Additionally, 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 attached may be treated with a hard coat layer, anti-reflection treatment, anti-sticking, diffusion or anti-glare treatment.

Additionally, as the transparent protective film, any film that has a phase difference and can function as an optical compensation layer can be used. When 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 such a retardation film, a stretched film can be suitably used. In the retardation film, when the refractive index in the slow axis direction is nx, the refractive index in the fast axis direction in the plane is ny, and the refractive index in the thickness direction is nz, nx=ny>nz, nx>ny>nz, nx>ny= Those that satisfy the relationships nz, nx>nz>ny, nz=nx>ny, nz>nx>ny, and nz>nx=ny are selected and used according to various purposes. In addition, nx=ny includes not only the case where nx and ny are completely the same, but also the case where nx and ny are substantially the same. Additionally, ny=nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

When the polarizing film used in the present invention is used as a circular polarizer for anti-reflection of an organic EL display device, the retardation film is 1 with the front retardation of the transparent protective film at 1/4 wavelength (about 100 to 170 nm). It is preferable that it is a /4 wave plate.

When using a retardation film as a transparent protective film, a transparent protective film formed on one side of a polarizer and a retardation film on the other side can be suitably used. In that case, the installation location of the adhesive layer is not particularly limited, and may be formed on the surface opposite to the surface in contact with the polarizer of the transparent protective film, or may be formed on the surface opposite to the surface in contact with the polarizer of the retardation film. However, from the viewpoint of suppressing deterioration of the organic EL element, it is preferable that it is formed on at least one side or both sides.

An example of a specific configuration of a polarizing film having an adhesive layer for an organic EL display device of the present invention is shown in Figs. 1(a) to 1(c). As shown in Figure 1 (a), adhesive layer (2)/transparent protective film (3)/polarizer (4)/retardation film (5), as shown in Figure 1 (b), transparent protection Film (3)/polarizer (4)/retardation film (5)/adhesive layer (2), as shown in Figure 1 (c), adhesive layer (2)/transparent protective film (3)/polarizer (4) )/retardation film (5)/adhesive layer (2); and a polarizing film (1) having an adhesive layer for an organic EL display device in which each layer is laminated in this order. In Figures 1 (a) and (b), the pressure-sensitive adhesive layer 2 is a pressure-sensitive adhesive layer for an organic EL display device of the present invention, and in Figure 1 (c), among the two pressure-sensitive adhesive layers 2. At least one may be the adhesive layer for an organic EL display device of the present invention, and both may be the adhesive layer for an organic EL display device of the present invention. In addition, in FIG. 1, the polarizing film 6 is a one-sided protective polarizing film composed of the polarizer 4 and the transparent protective film 3, but it is not limited to this, and the polarizing film 6 includes the polarizer 4 and the retardation film 5. ) may be a double protective polarizing film further having a transparent protective film in between. In addition, as described above, various functional layers such as a hard coat 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 retardation film is laminated on a polarizer through an adhesive layer, the adhesive layer may be the adhesive layer for an organic EL display device of the present invention. That is, the polarizing film having an adhesive layer for an organic EL display device has a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, a retardation film, and a third adhesive layer in this order,

At least one of the first, second, and third adhesive layers 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 adhesive layer for an organic EL display device of the present invention and/or a polarizing film having an adhesive layer for an organic EL display device of the present invention.

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

<Example>

Below, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all parts and % in each example are based on weight.

Preparation Example 1 (Preparation of acrylic 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) as a photopolymerization initiator. , 0.035 parts by weight of 1-hydroxycyclohexylphenylketone (brand name: Irgacure 184, having an absorption band at a wavelength of 200 to 370 nm, manufactured by BASF), 2,2-dimethoxy-1,2-diphenylethane-1- After mixing 0.035 parts by weight of Irgacure 651 (product name: Irgacure 651, having an absorption band at a wavelength of 200 to 380 nm, manufactured by BASF), the viscosity (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) was about 20 Pa. By irradiating ultraviolet rays until s, a prepolymer composition in which part of the above monomer components was polymerized (polymerization rate: 8%) was obtained. Next, 0.15 parts by weight of hexanediol diacrylate (HDDA) and 0.3 parts by weight of a silane coupling agent (Product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to the prepolymer composition and mixed to form an acrylic adhesive composition. (a) was obtained.

Preparation Example 2 (Preparation of acrylic adhesive composition (b))

In a separable flask equipped with a thermometer, stirrer, reflux condenser, and nitrogen gas introduction pipe, 95 parts by weight of butylacrylate, 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. After the addition, nitrogen gas was flowed and nitrogen substitution was performed for about 1 hour while stirring. After that, the flask was heated at 60°C and reacted for 7 hours to obtain an acrylic polymer with a weight average molecular weight (Mw) of 1.1 million.

To the acrylic polymer solution (solid content is 100 parts by weight), 0.8 parts by weight of trimethylolpropantolylene diisocyanate (Product name: Coronate L, manufactured by Nippon Polyurethane Kogyo Co., Ltd.) as an isocyanate-based crosslinking agent, and a silane coupling agent ( A solution of the adhesive composition (b) was prepared by adding 0.1 part by weight of product name: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Preparation Example 3 (Preparation of adhesive layer (B1-1))

The adhesive composition (b) solution obtained in Preparation Example 2 was applied onto a 38 ㎛ thick separator (polyethylene terephthalate film with a peeling surface) so that the thickness after drying was 12 ㎛, and dried at 100°C for 3 minutes. The solvent was removed and an adhesive layer was obtained. After that, crosslinking treatment was performed by heating at 50°C for 48 hours. Hereinafter, this adhesive layer is referred to as “organic EL display panel side adhesive layer (B1-1).”

Preparation Example 4 (Preparation of adhesive layer (B1-2))

The adhesive composition (b) solution obtained in Preparation Example 2 was applied on a 38 ㎛ thick separator (polyethylene terephthalate film with surface release treatment) so that the thickness after drying was 23 ㎛, and dried at 100°C for 3 minutes. The solvent was removed and an adhesive layer was obtained. After that, crosslinking treatment was performed by heating at 50°C for 48 hours. Hereinafter, this adhesive layer is referred to as “organic EL display panel side adhesive layer (B1-2).”

Example 1

(Preparation of adhesive composition (A))

Regarding the acrylic adhesive composition (a) obtained in Preparation Example 1 (the monomer component forming the acrylic polymer is 100 parts by weight), 2,4-bis-[{4-) dissolved in butyl acrylate to a solid content of 15% (4-ethylhexyloxy)-4-hydroxy}-phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (Product name: Tinosorb S, “ultraviolet absorber” in Tables 1 and 2 (b1)”, maximum absorption wavelength of absorption spectrum: 346 nm, manufactured by BASF Japan, 0.7 parts by weight (solid weight), and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (product name: Irgacure 819) , having an absorption band at a wavelength of 200 to 450 nm, manufactured by BASF Japan) and BONASORB UA3911 (brand name, indole compound, table) dissolved in N-vinyl-2-pyrrolidone (NVP) to a solid content of 5%. 0.5 parts by weight (solid weight) of "color compound (c1)" of 1 and 2, maximum absorption wavelength of absorption spectrum: 398 nm, half width: 48 nm, manufactured by Orient Chemical Industry Co., Ltd.) was added and stirred to form an adhesive composition ( A) was obtained.

The pressure-sensitive adhesive composition (A) was applied onto the peel-treated film of the release film so that the thickness after forming the pressure-sensitive adhesive layer was 150 μm, and then the release film was bonded to the surface of the pressure-sensitive adhesive composition layer. After that, ultraviolet ray irradiation was performed under the conditions of illuminance: 6.5 mW/cm 2, light quantity: 1500 mJ/cm 2, and peak wavelength: 350 nm, and the adhesive composition layer was photocured to form an adhesive layer (A-1).

Example 2

BONASORB UA3912 (brand name, indole compound, “color compound (c2)” in Tables 1 and 2) was absorbed by dissolving the color compound (c) in N-vinyl-2-pyrrolidone (NVP) to a solid content of 10%. Example 1, except that 2.5 parts by weight (solid weight) of the spectrum (maximum absorption wavelength: 386 nm, half width: 53 nm, manufactured by Orient Chemical Industry Co., Ltd.) was applied so that the thickness after forming the adhesive layer was 100 μm. In the same manner as above, an adhesive layer (A-2) was formed.

Example 3

The type of ultraviolet absorber of Example 1 was dissolved in butyl acrylate to a solid content of 15%, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4- Changed to (1,1,3,3-tetramethylbutyl)phenol (Product name: Tinuvin 928, “UV absorber (b2)” in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 349 nm, manufactured by BASF Japan), The addition amount was 1.5 parts by weight (solid weight). In addition, the type of colorant compound is a cinnamic acid-based compound (sample name: SOM-5-0103, “colorant compound (c3)” in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 416nm, half width: 50nm, Orient Gag. An adhesive layer (A-3) was prepared in the same manner as in Example 1 except that 0.2 parts by weight (solid weight) was added directly and applied so that the thickness after forming the adhesive layer was 100 μm. ) was formed.

Example 4

The amount of ultraviolet absorber (b1) added in Example 1 was changed to 3.0 parts by weight (solid weight), and the type of coloring compound was dissolved in N-vinyl-2-pyrrolidone (NVP) to a solid content of 1%. Porphyrin System compound (sample name: FDB-001, “pigment compound (c4)” in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 420 nm, half width: 14 nm, manufactured by Yamada Chemical Industry Co., Ltd.) 0.1 part by weight ( Solid content weight), an adhesive layer (A-4) was formed in the same manner as in Example 1, except that the adhesive layer was applied so that the thickness after formation was 100 μm.

Example 5

(Preparation of adhesive composition (B))

Regarding the solution of the adhesive composition (b) obtained in Preparation Example 2 (the monomer component forming the acrylic polymer is 100 parts by weight), 2,4-bis-[{4-(4-ethylhexyloxy)-4- Hydroxy}-phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (Product name: Tinosorb S, “UV absorber (b1)” in Tables 1 and 2, maximum absorption wavelength in the absorption spectrum : 3 parts by weight (solid weight) of 346 nm, manufactured by BASF Japan, BONASORB UA3912 (brand name, indole compound, “pigment compound (c2)” in Tables 1 and 2, maximum absorption wavelength of absorption spectrum: 386 nm, half width: 0.8 parts by weight (solid weight) (53 nm, manufactured by Orient Chemical Co., Ltd.) was directly added and stirred to obtain an adhesive composition (B) solution.

The obtained pressure-sensitive adhesive composition (B) solution was applied onto a 38-μm-thick separator (polyethylene terephthalate-based film with a peeling surface) so that the thickness after drying was 25 μm, and dried at 120°C for 3 minutes to remove the solvent. and obtained an adhesive layer. After that, crosslinking treatment was performed by heating at 50°C for 48 hours. An adhesive layer (B) was formed.

Comparative Example 1

An adhesive layer (A1-1) was formed in the same manner as in Example 1, except that only the acrylic adhesive composition (a) containing neither the ultraviolet absorber (b1) nor the coloring compound (c1) of Example 1 was used.

Comparative Example 2

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

Comparative Example 3

An adhesive layer (A1-2) was formed in the same manner as in Example 1, except that the dye compound (c1) of Example 1 was not included and the adhesive layer was applied so that the thickness after formation was 100 μm.

Comparative Example 4

A pressure-sensitive adhesive layer (A1-3) was formed in the same manner as in Example 3, except that the colorant compound (c3) was not included and the thickness after formation of the pressure-sensitive adhesive layer was 150 μm.

Comparative Example 5

Example 1, except that the ultraviolet absorber (b1) of Example 1 was not included, the addition amount of the colorant compound (c1) was 0.3 parts by weight (solid weight), and the adhesive layer was applied so that the thickness after formation was 100 μm. In the same manner as above, an adhesive layer (A1-4) was formed.

Comparative Example 6

An 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 included and the addition amount of the dye compound (c2) was 0.5 parts by weight (solid weight). .

Comparative Example 7

An 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 included.

Comparative Example 8

An 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 included.

Example 6

(Manufacture of adhesive layer (A-5))

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

(Manufacture of polarizing film (P))

A cycloolefin polymer (COP) film with a thickness of 25 μm is bonded to the viewing side of a polarizer containing a stretched polyvinyl alcohol film with a thickness of 5 μm impregnated with iodine using a polyvinyl alcohol-based adhesive, and the organic EL display of the polarizer is displayed. An acrylic film with a thickness of 20 μm was laminated on the panel side surface using a polyvinyl alcohol-based adhesive to form a polarizing film (P). The polarization degree of the polarizing film was 99.995.

(Manufacture of polarizing film with adhesive layer)

The pressure-sensitive adhesive layer (A-5) prepared above was laminated on the viewing side of the polarizing film (P) (i.e., the surface of the cycloolefin polymer (COP) film with a thickness of 25 μm). An image display side adhesive layer (B1-1) is laminated on the organic EL display panel side surface of the polarizing film (P) (i.e., the surface of an acrylic film with a thickness of 20 μm), and a retardation film (thickness: 56 μm) is further applied. , material: polycarbonate) and the image display unit side adhesive layer (B1-2) were laminated to form a polarizing film with an adhesive layer. The obtained polarizing film with an adhesive layer is adhesive layer (A-5)/polarizing film (P)/organic EL display panel side adhesive layer (B1-1)/retardation film/organic EL display panel side adhesive layer (B1-2). ) had the composition of

Example 7

An adhesive layer (A-6) was formed in the same manner as in Example 2, except that the addition amount of the dye compound (c2) in Example 2 was 0.5 parts by weight (solid content weight). Additionally, 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

An adhesive layer (A1-8) was formed in the same manner as in Example 6, except that the adhesive layer (A-5) of Example 6 did not contain the pigment compound (c1). Additionally, 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 evaluation was performed about the obtained adhesive layer and the polarizing film with an adhesive layer.

<Measurement of transmittance of adhesive layer>

The release film of the adhesive layer obtained in the examples and comparative examples was peeled off, the adhesive layer was installed in a measuring jig, and measured with a spectrophotometer (product name: U4100, manufactured by Hitachi High Technologies Co., Ltd.). The transmittance was measured in a wavelength range of 300 nm to 780 nm.

<Measurement of transmittance of polarizing film with adhesive layer>

The release film of the polarizing film with an adhesive layer obtained in the examples and comparative examples was peeled and measured with a spectrophotometer (product name: U4100, manufactured by Hitachi High Technologies Co., Ltd.). The transmittance was measured in a wavelength range of 350 nm to 780 nm.

<Adhesiveness>

Sheet pieces with a length of 100 mm and a width of 20 mm were cut from the adhesive layers obtained in the examples and comparative examples. Next, the release film on one side of the adhesive layer was peeled off, and a PET film (brand name: Lumiror S-10, thickness: 25 μm, manufactured by Toray Co., Ltd.) was attached (backed). Next, the release film on the other side was peeled off and pressed against a glass plate (Product name: Soda-lime glass #0050, manufactured by Matsunami Glass Kogyo Co., Ltd.) as a test plate under the pressing conditions of 2 kg roller and 1 round trip, forming a test plate/adhesive. Samples consisting of layer (A)/PET film were fabricated. The obtained sample was autoclaved (50°C, 0.5 MPa, 15 minutes) and then allowed to cool in an atmosphere of 23°C and 50% R.H. for 30 minutes. After cooling, using a tensile tester (device name: Autograph AG-IS, manufactured by Shimadzu Seisakusho Co., Ltd.), in an atmosphere of 23°C and 50% R.H., in accordance with JIS Z0237, tensile speed 300 mm/min, peeling angle Under 180° conditions, the adhesive sheet (adhesive layer/PET film) was peeled from the test panel, and the 180° peel adhesive force (N/20 mm) was measured.

<Total light transmittance, haze>

One release film was peeled from the adhesive layer obtained in the examples and comparative examples, and a slide glass (product name: white polishing No.1, thickness: 0.8 to 1.0 mm, total light transmittance: 92%, haze: 0.2%, Matsu It was bonded to Nami Glass High School Co., Ltd.). Additionally, the other release film was peeled off to produce a test piece with a layer structure of adhesive layer/slide glass. The total light transmittance and haze value in the visible light region of the test piece were measured using a haze meter (device name: HM-150, manufactured by Murakami Shikisai Genkyusho Co., Ltd.).

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

Claims (10)

An adhesive layer for an organic EL display device, characterized in that it is formed from an adhesive composition for an organic EL display device,
The adhesive composition for an organic EL display device includes a base polymer, an ultraviolet absorber, and a pigment compound whose maximum absorption wavelength of the absorption spectrum is present in the wavelength range of 380 to 430 nm,
The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber is in the wavelength range of 300 to 400 nm,
The adhesive layer for an organic EL display device has an average transmittance of 5% or less for a wavelength of 300 to 400 nm, an average transmittance of 30% or less for a wavelength of 400 nm to 430 nm, an average transmittance of 70% or more for a wavelength of 450 to 500 nm, and a wavelength of 500 nm. An adhesive layer for an organic EL display device, characterized in that the average transmittance from 780 nm to 80% is 80% or more. An adhesive layer for an organic EL display device, characterized in that it is formed from an adhesive composition for an organic EL display device,
The adhesive composition for an organic EL display device includes a base polymer, an ultraviolet absorber, and a pigment compound whose maximum absorption wavelength of the absorption spectrum is present in the wavelength range of 380 to 430 nm,
The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber is in the wavelength range of 300 to 400 nm,
The average transmittance of the adhesive layer for the organic EL display device is 5% or less for a wavelength of 300 to 400 nm, the average transmittance is more than 30% and 75% or less for the wavelength of 400 nm to 430 nm, and the average transmittance is 80% or more for the wavelength of 450 to 500 nm. , An adhesive layer for an organic EL display device, characterized in that the average transmittance of a wavelength of 500 to 780 nm is 80% or more. The pressure-sensitive adhesive layer for an organic EL display device according to claim 1 or 2, wherein the base polymer is a (meth)acrylic polymer. A polarizing film having a pressure-sensitive adhesive layer for an organic EL display device, comprising a polarizing film and the pressure-sensitive adhesive layer for an organic EL display device according to claim 1 or 2. The method of claim 4, wherein the polarizing film has a transparent protective film formed on one side of the polarizer and a retardation film on the other side, and the adhesive layer for an organic EL display device is in contact with the polarizer of the retardation film. A polarizing film having an adhesive layer for an organic EL display device, which is provided on a surface opposite to the surface and/or a surface opposite to the surface in contact with the polarizer of the transparent protective film. The polarizing film according to claim 4, having an adhesive layer for an organic EL display device comprising a first adhesive layer, a transparent protective film, a polarizer, a second adhesive layer, a retardation film, and a third adhesive layer in this order, wherein the first adhesive layer A polarizing film having an adhesive layer for an organic EL display device, wherein at least one of the adhesive layer, the second adhesive layer, and the third adhesive layer is the adhesive layer for an organic EL display device. The polarizing film with an adhesive layer for an organic EL display device according to claim 5, wherein the retardation film is a quarter wave plate and the polarizing film is a circularly polarizing film. The polarizing film with an adhesive layer for an organic EL display device according to claim 6, wherein the retardation film is a quarter wave plate and the polarizing film is a circularly polarizing film. An organic EL display device comprising at least one polarizing film having an adhesive layer for an organic EL display device according to claim 1 or 2. An organic EL display device comprising at least one polarizing film having an adhesive layer for an organic EL display device according to claim 4.