阅读说明：本技术 有机el显示装置用粘合剂组合物、有机el显示装置用粘合剂层、带有机el显示装置用粘合剂层的偏振膜、及有机el显示装置 (Adhesive composition for organic EL display device, adhesive layer for organic EL display device, polarizing film with adhesive layer for organic EL display device, and organic EL display device ) 是由 藤田昌邦 形见普史 外山雄祐 于 2018-05-23 设计创作，主要内容包括：本发明涉及一种有机EL显示装置用粘合剂组合物,其含有：基础聚合物、自由基产生剂、以及选自分子结构中的羟基为0～3个的紫外线吸收剂(a)及吸收光谱的最大吸收波长存在于380～430nm的波长区域的色素化合物(b)中的至少1种化合物(A)。本发明的有机EL显示装置用粘合剂组合物用于有机EL显示装置,可抑制有机EL元件的劣化,并且可抑制外观良品率降低、在加热耐久性中产生发泡等。(The present invention relates to an adhesive composition for an organic EL display device, comprising: a base polymer, a radical generator, and at least 1 compound (A) selected from an ultraviolet absorber (a) having a molecular structure in which 0 to 3 hydroxyl groups are present, and a dye compound (b) having an absorption spectrum in which the maximum absorption wavelength is in the wavelength region of 380 to 430 nm. The adhesive composition for organic EL display devices of the present invention is used in organic EL display devices, and can suppress deterioration of organic EL elements, decrease in yield of good appearance, and generation of foam in heat durability.)

1. An adhesive composition for an organic EL display device, comprising:

a base polymer,

A radical generator, and

at least 1 compound (A) selected from an ultraviolet absorbent (a) having 0 to 3 hydroxyl groups in the molecular structure and a dye compound (b) having an absorption spectrum with a maximum absorption wavelength in a wavelength region of 380 to 430 nm.

2. The adhesive composition for organic EL display devices according to claim 1,

the compound (a) contains both the ultraviolet absorber (a) and the dye compound (b).

3. The adhesive composition for organic EL display device according to claim 1 or 2, wherein,

the maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber (a) is in a wavelength region of 300-400 nm.

4. The adhesive composition for organic EL display device according to any one of claims 1 to 3, wherein,

the free radical generator is a peroxide.

5. The adhesive composition for organic EL display device according to any one of claims 1 to 4,

the base polymer is a (meth) acrylic polymer.

6. The adhesive composition for organic EL display device according to any one of claims 1 to 5,

the radical generator is contained in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the base polymer.

7. The adhesive composition for organic EL display device according to any one of claims 1 to 6, wherein,

the composition contains 0.1 to 25 parts by weight of the compound (A) per 100 parts by weight of the base polymer.

8. The adhesive composition for organic EL display device according to any one of claims 1 to 7, further comprising an antioxidant.

9. The adhesive composition for organic EL display device according to any one of claims 1 to 8, further comprising a crosslinking agent.

10. An adhesive layer for an organic EL display device, which is formed from the adhesive composition for an organic EL display device according to any one of claims 1 to 9.

11. The pressure-sensitive adhesive layer for an organic EL display device according to claim 10, wherein the average transmittance at a wavelength of 300 to 400nm is 12% or less, the average transmittance at a wavelength of 400 to 430nm is 30% or less, and the average transmittance at a wavelength of 430 to 450nm is 70% or more.

12. The pressure-sensitive adhesive layer for an organic EL display device according to claim 10, wherein the average transmittance at a wavelength of 300 to 400nm is 12% or less, the average transmittance at a wavelength of 400 to 430nm is more than 30% and 95% or less, and the average transmittance at a wavelength of 430 to 450nm is 80% or more.

13. A polarizing film with an adhesive layer for an organic EL display device, comprising a polarizing film and the adhesive layer for an organic EL display device according to any one of claims 10 to 12.

14. The polarizing film with an adhesive layer for an organic EL display device according to claim 13, wherein the polarizing film has a transparent protective film on one surface of a polarizer and a retardation film on the other surface, and the adhesive layer for an organic EL display device is provided on a surface of the retardation film opposite to the surface in contact with the polarizer and/or on a surface of the transparent protective film opposite to the surface in contact with the polarizer.

15. The polarizing film with an adhesive layer for an organic EL display device according to claim 13, which has in order: 1 st adhesive layer, transparent protective film, polarizer, 2 nd adhesive layer, phase difference film, 3 rd adhesive layer,

at least one of the 1 st adhesive layer, the 2 nd adhesive layer, and the 3 rd adhesive layer is the adhesive layer for the organic EL display device.

16. The polarizing film with an adhesive layer for an organic EL display device according to claim 14 or 15, wherein,

the phase difference film is an 1/4 wave plate, and the polarizing film is a circular polarizing film.

17. An organic EL display device using at least one of the pressure-sensitive adhesive layer for organic EL display device described in any one of claims 10 to 12, or the polarizing film with the pressure-sensitive adhesive layer for organic EL display device described in any one of claims 13 to 16.

Technical Field

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

Background

In recent years, organic EL display devices having an organic EL panel mounted thereon have been widely used for various applications such as mobile phones, car navigation devices, monitors for computers, and televisions. In order to suppress reflection of external light at a metal electrode (cathode) and to make the light look like a mirror surface, an organic EL display device is generally provided with a circularly polarizing plate (a laminate of a polarizing plate and 1/4 wave plates, or the like) on the viewing-side surface of an organic EL panel. Further, a decorative panel or the like may be further laminated on the circularly polarizing plate laminated on the viewing side surface of the organic EL panel. The components of the organic EL display device such as the circularly polarizing plate and the decorative panel are generally laminated via a bonding material such as an adhesive layer or an adhesive layer.

In an image display device such as an organic EL display device, there are cases where constituent members and the like in the image display device are deteriorated by incident ultraviolet light, and it is known to provide a layer containing an ultraviolet absorber in order to suppress the deterioration by ultraviolet light. Specifically, for example, a transparent double-sided adhesive sheet for an image display device is known, which has at least 1 ultraviolet absorbing layer, and has a light transmittance of 30% or less at a wavelength of 380nm and a visible light transmittance of 80% or more at a longer wavelength side than a wavelength of 430nm (see, for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

Generally, an adhesive composition suitable for a transparent double-sided adhesive sheet for an image display device contains a base polymer such as a (meth) acrylic polymer. In addition, in the adhesive composition, a radical generator (e.g., peroxide) as a crosslinking agent may be used in addition to the base polymer to form a radically crosslinked adhesive layer. In addition, when a (meth) acrylic polymer is used as the base polymer, a radical polymerization initiator is contained in the adhesive composition because a monomer component is prepared by curing the (meth) acrylic polymer with heat or radiation.

However, when an ultraviolet absorber is contained in the pressure-sensitive adhesive composition containing a radical generator, the gel fraction (degree of crosslinking) of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition tends to decrease due to the ultraviolet absorber. When the decrease in the gel fraction (degree of crosslinking) of the pressure-sensitive adhesive layer becomes large, the pressure-sensitive adhesive layer may have defects such as a decrease in the yield of good appearance due to paste indentation and paste stain during processing, and foaming due to heat durability.

Accordingly, an object of the present invention is to provide a binder composition for an organic EL display device, which can suppress deterioration of an organic EL element, and can suppress a decrease in a yield of good appearance and generation of foam in heat durability, when used in an organic EL display device.

Further, the present invention aims to provide an adhesive layer for an organic EL display device formed from the adhesive composition, a polarizing film with an adhesive layer having a polarizing film and an adhesive layer for an organic EL display device, and an organic EL display device including the adhesive layer and/or the polarizing film with an adhesive layer.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found the following binder composition for organic EL display devices, and have completed the present invention.

That is, the present invention relates to a binder composition for an organic EL display device, comprising: a base polymer, a radical generator, and at least 1 compound (A) selected from an ultraviolet absorber (a) having a molecular structure in which 0 to 3 hydroxyl groups are present, and a dye compound (b) having an absorption spectrum in which the maximum absorption wavelength is in the wavelength region of 380 to 430 nm.

In the binder composition for organic EL display devices, the compound (a) preferably contains both the ultraviolet absorber (a) and the dye compound (b).

In the adhesive composition for organic EL display devices, the maximum absorption wavelength of the absorption spectrum of the ultraviolet absorber (a) is preferably in a wavelength region of 300 to 400 nm.

In the binder composition for an organic EL display device, a peroxide may be used as the radical generator.

In the binder composition for organic EL display devices, a (meth) acrylic polymer may be used as the base polymer.

In the binder composition for an organic EL display device, the radical generator is preferably contained in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the base polymer.

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

The adhesive composition for organic EL display devices may further contain an antioxidant.

The binder composition for organic EL display devices may further contain a crosslinking agent.

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

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

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

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

In the polarizing film with an adhesive layer for an organic EL display device, it is preferable that the polarizing film has a transparent protective film on one surface of a polarizer and a retardation film on the other surface, and the adhesive layer for an organic EL display device is provided on a surface of the retardation film opposite to the surface in contact with the polarizer and/or on a surface of the transparent protective film opposite to the surface in contact with the polarizer.

The polarizing film with an adhesive layer for an organic EL display device preferably comprises a1 st adhesive layer, a transparent protective film, a polarizer, a2 nd adhesive layer, a retardation film, and a3 rd adhesive layer in this order,

at least one of the 1 st adhesive layer, the 2 nd adhesive layer, and the 3 rd adhesive layer is the adhesive layer for the organic EL display device.

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

The present invention also relates to an organic EL display device using at least one of the above-described adhesive layer for an organic EL display device or the above-described polarizing film with an adhesive layer for an organic EL display device. ADVANTAGEOUS EFFECTS OF INVENTION

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

The pressure-sensitive adhesive composition for organic EL display devices of the present invention contains a radical generator such as a peroxide. The radical generator can function as a crosslinking agent for the (meth) acrylic polymer base polymer, for example, and can control the gel fraction of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to a desired range, thereby forming a pressure-sensitive adhesive layer having good appearance.

As described above, since the ultraviolet absorber and/or the dye compound and the radical generator are present together in the pressure-sensitive adhesive composition for an organic EL display device of the present invention, the gel fraction of the pressure-sensitive adhesive layer obtained may be lowered. However, in the adhesive composition for an organic EL display device of the present invention, the ultraviolet absorber (a) having 0 to 3 hydroxyl groups in the molecular structure is selected and used as the ultraviolet absorber. That is, in the present invention, it is considered that the decrease in the gel fraction is caused by the decrease in the degree of crosslinking due to the deactivation of the radical generated by the radical generator, which is caused by the hydrogen-donating group of the ultraviolet absorber, and the inhibition of crosslinking of the radical generator by the ultraviolet absorber is suppressed by selecting and using the ultraviolet absorber (a) in which the hydroxyl group related to the hydrogen-donating group is 3 or less.

As a result, the adhesive composition for organic EL display devices of the present invention can provide an adhesive layer for organic EL display devices that can suppress a decrease in the yield of good appearance and can prevent foaming or the like from occurring during heating durability. Therefore, the organic EL display device using the pressure-sensitive adhesive layer for an organic EL display device and/or the polarizing film with a pressure-sensitive adhesive layer including the pressure-sensitive adhesive layer for an organic EL display device of the present invention has excellent weather-resistant deterioration properties and can have a long life.

Drawings

Fig. 1(a) to (c) are cross-sectional views schematically showing one embodiment of the polarizing film with 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.

Description of the symbols

Polarizing film with adhesive layer for organic EL display device

2 adhesive layer

3 transparent protective film

4 polarizer

5 phase difference film

6 polarizing film

7 cover glass or cover plastic

8 organic EL panel

9 adhesive layer

10 sensor layer

Detailed Description

1. Adhesive composition for organic EL display device

The binder composition for an organic EL display device of the present invention comprises: a base polymer, a radical generator, and at least 1 compound (A) selected from an ultraviolet absorber (a) having a molecular structure in which 0 to 3 hydroxyl groups are present, and a dye compound (b) having an absorption spectrum in which the maximum absorption wavelength is in the wavelength region of 380 to 430 nm.

The binder composition for an organic EL display device of the present invention contains a base polymer as a main component. The main component is a component contained in the largest proportion in the total solid content of the adhesive composition, and for example, it means a component accounting for more than 50% by weight, and further, accounting for more than 70% by weight of the total solid content of the adhesive composition.

The base polymer used in the present invention is not particularly limited, and examples of the type of the adhesive composition include: rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinyl pyrrolidone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, and the like. Among these pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferably used from the viewpoint of excellent optical transparency, adhesion properties such as appropriate adhesiveness, cohesiveness and adhesiveness, and excellent weather resistance and heat resistance. In the present invention, an acrylic adhesive composition containing a (meth) acrylic polymer as a base polymer is preferable.

< (meth) acrylic polymer

The (meth) acrylic polymer usually contains an alkyl (meth) acrylate as a monomer unit as a main component. The term (meth) acrylate refers to acrylate and/or methacrylate, and the meaning of (meth) acrylate in the present invention is the same.

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

In addition, from the viewpoint of adhesion characteristics, durability, adjustment of retardation, adjustment of refractive index, and the like, alkyl (meth) acrylates containing an aromatic ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate can be used.

For the purpose of improving adhesiveness and heat resistance, 1 or more kinds of comonomers having a polymerizable functional group containing an unsaturated double bond such as a (meth) acryloyl group or a vinyl group may be introduced into the (meth) acrylic polymer by copolymerization. Specific examples of such comonomers include: hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) methyl acrylate; carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, (meth) sulfopropyl acrylate, and (meth) acryloyloxynaphthalenesulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate, and the like.

Examples of the monomer to be modified include: (N-substituted) amide monomers such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide and N-methylol propane (meth) acrylamide; alkylaminoalkyl (meth) acrylate monomers such as aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; alkoxyalkyl (meth) acrylate monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; succinimide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, and N-acryloylmorpholine; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-dodecylmaleimide and N-phenylmaleimide; and itaconimide monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-dodecylitaconimide.

Further, as the modifying monomer, it is also possible to use: vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyl

Vinyl monomers such as oxazole, vinyl morpholine, N-vinylcarboxylic acid amides, styrene, alpha-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol acrylate monomers such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine-containing (meth) acrylate, silicone (meth) acrylate, and 2-methoxyethyl acrylate. Further, isoprene, butadiene, isobutylene, vinyl ether and the like are exemplified.

Examples of the copolymerizable monomer other than those described above include silane-based monomers containing a silicon atom. Examples of the silane monomer include: 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-acryloxydecyltrimethoxysilane, 10-methacryloxydecyltriethoxysilane, 10-acryloxydecyltriethoxysilane, and the like.

In addition, as comonomers, it is possible to use: a polyfunctional monomer having 2 or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups, such as an esterified product of a polyol and (meth) acrylic acid, for example, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, bisphenol a diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate, and a polyester (meth) acrylate obtained by adding 2 or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups to the same skeleton as the monomer component, such as a polyester, epoxy, urethane Epoxy (meth) acrylates, urethane (meth) acrylates, and the like.

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

Among these comonomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. The hydroxyl group-containing monomer and the carboxyl group-containing monomer may be used in combination. In the case where the adhesive composition contains a crosslinking agent, these comonomers become reaction sites with the crosslinking agent. Since the reactivity of the hydroxyl group-containing monomer, carboxyl group-containing monomer, or the like with the intermolecular crosslinking agent is sufficient, it is preferable to improve the cohesive property and heat resistance of the obtained pressure-sensitive adhesive layer. From the viewpoint of reworkability, a hydroxyl group-containing monomer is preferable, and from the viewpoint of compatibility between durability and reworkability, a carboxyl group-containing monomer is preferable.

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

As the (meth) acrylic polymer of the present invention, a polymer having a weight average molecular weight in the range of 50 to 300 ten thousand can be usually used. In view of durability, particularly heat resistance, it is preferable to use a polymer having a weight average molecular weight of 70 to 270 ten thousand. More preferably 80 to 250 ten thousand. When the weight average molecular weight is less than 50 ten thousand, it is not preferable from the viewpoint of heat resistance. When the weight average molecular weight is more than 300 ten thousand, a large amount of a diluting solvent is required to adjust the viscosity for coating, which is not preferable because the cost increases. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

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

In the solution polymerization, for example, ethyl acetate, toluene, or the like can be used as a polymerization solvent. As a specific example of the solution polymerization, a polymerization initiator is added to the reaction under an inert gas stream such as nitrogen, and the reaction is usually carried out at a temperature of about 50 to 70 ℃ for about 5 to 30 hours.

The polymerization initiator, chain transfer agent, emulsifier, and the like used in the radical polymerization are not particularly limited and may be appropriately selected and used. The weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of the polymerization initiator, the amount of the chain transfer agent, the reaction conditions, and the like, and the amount of the polymerization initiator, the amount of the chain transfer agent, the reaction conditions, and the like can be appropriately adjusted depending on the kind of the (meth) acrylic polymer.

Examples of the radical polymerization initiator include: 2,2 ' -azobisisobutyronitrile, 2 ' -azobis (2-amidinopropane) dihydrochloride, 2 ' -azobis [2- (5-methyl-2-imidazolin-2-yl) propane ] dihydrochloride, 2 ' -azobis (2-methylpropionamidine) disulfate, 2 ' -azobis (N, N ' -dimethyleneisobutylamidine), 2 ' -azobis [ N- (2-carboxyethyl) -2-methylpropionamidine ] hydrate (manufactured by Wako pure chemical industries, Ltd., VA-057) and other azo initiators, potassium persulfate, persulfate such as ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-tert-butylcyclohexyl) peroxydicarbonate, di (2-ethyl-2-methyl-2-amidinopropane), Di-sec-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,3, 3-tetramethylbutyl peroxy2-ethylhexanoate, bis (4-methylbenzoyl) peroxide, dibenzoyl peroxide, tert-butyl peroxyisobutyrate, peroxide initiators such as 1, 1-di (tert-hexylperoxy) cyclohexane, tert-butyl hydroperoxide, and hydrogen peroxide, redox initiators comprising a combination of a peroxide such as a combination of a persulfate and sodium bisulfite, and a combination of a peroxide and sodium ascorbate, and a reducing agent, and the like, but the present invention is not limited thereto.

The radical polymerization initiator may be used alone or in combination of 2 or more, and the total content thereof is preferably about 0.005 to 1 part by weight, more preferably about 0.02 to 0.5 part by weight, based on 100 parts by weight of the monomer.

Examples of the chain transfer agent include: dodecyl mercaptan, glycidyl mercaptan, thioglycolic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2, 3-dimercapto-1-propanol, and the like. The chain transfer agent may be used alone or in combination of 2 or more, and the total content thereof is preferably about 0.1 part by weight or less based on 100 parts by weight of the total amount of the monomer components.

Examples of the emulsifier used in the emulsion polymerization include: anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate and sodium polyoxyethylene alkylphenyl ether sulfate, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester and polyoxyethylene-polyoxypropylene block polymer, and the like. These emulsifiers may be used alone in1 kind, or may be used in combination in 2 or more kinds.

Further, as the reactive emulsifier, emulsifiers having a radical polymerizable functional group such as an acryl group or an allyl ether group introduced thereto include, for example: AQUALON HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all manufactured by first Industrial pharmaceutical Co., Ltd.), ADEKA REASOAP SE10N (manufactured by Asahi electro chemical Co., Ltd.), and the like. The reactive emulsifier is preferably incorporated into the polymer chain after polymerization, thereby improving water resistance. The amount of the emulsifier used is preferably 0.3 to 5 parts by weight, and more preferably 0.5 to 1 part by weight, based on 100 parts by weight of the total amount of the monomer components, from the viewpoint of polymerization stability and mechanical stability.

< free radical Generator >

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

The radical generator may generate radical active species by heating or light irradiation and cause crosslinking of the (meth) acrylic polymer in the adhesive composition. The radical generator is preferably a peroxide having a 1-minute half-life temperature of 80 to 160 ℃ and more preferably a peroxide having a 1-minute half-life temperature of 90 to 140 ℃ in view of handling and stability.

Examples of the peroxide include: di (4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1 ℃ C.), di-sec-butyl peroxydicarbonate (1-minute half-life temperature: 92.4 ℃ C.), t-butyl peroxyneodecanoate (1-minute half-life temperature: 103.5 ℃ C.), t-hexyl peroxypivalate (1-minute half-life temperature: 109.1 ℃ C.), t-butyl peroxypivalate (1-minute half-life temperature: 110.3 ℃ C.), dilauroyl peroxide (1-minute half-life temperature: 116.4 ℃ C.), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4 ℃ C.), 1,3, 3-tetramethylbutyl peroxy-2-ethylhexanoate (1-minute half-life temperature: 124.3 ℃ C.), di (4-methylbenzoyl) peroxide (1-minute half-life temperature: 128.2 ℃ C.), dibenzoyl peroxide (1-minute half-life temperature: 130.0 ℃ C.) T-butyl peroxyisobutyrate (1-minute half-life temperature: 136.1 ℃ C.), 1-bis (t-hexylperoxy) cyclohexane (1-minute half-life temperature: 149.2 ℃ C.), and the like. Among them, bis (4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1 ℃ C.), dilauroyl peroxide (1-minute half-life temperature: 116.4 ℃ C.), dibenzoyl peroxide (1-minute half-life temperature: 130.0 ℃ C.) and the like are preferably used, particularly, from the viewpoint of excellent crosslinking reaction efficiency.

The half-life of the peroxide is an index for the decomposition rate of the peroxide, and means the time until the residual amount of the peroxide becomes half. Regarding the decomposition temperature at which the half-life is obtained at an arbitrary time or the half-life time at an arbitrary temperature, it is described in a product catalog of manufacturers and the like, for example, in "catalog of organic peroxide products (anion カタロ グ) of japan grease corporation, version 9 (month 5 2003), and the like.

The content of the radical generator (particularly, peroxide) in the pressure-sensitive adhesive composition of the present invention can be determined in consideration of the gel fraction and the like in order to adjust the processability, reworkability, crosslinking stability, releasability and the like of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. If the content of the radical generator (particularly peroxide) is increased, it is preferable to ensure the gel fraction (crosslinking degree) of the pressure-sensitive adhesive layer to be obtained, but if it is too high, the peeling force of the release film (separator) suitable for the pressure-sensitive adhesive layer tends to increase. In general, the content of the radical generator is preferably 0.01 to 2 parts by weight, more preferably 0.01 to 1 part by weight, still more preferably 0.05 to 0.8 part by weight, and still more preferably 0.1 to 0.6 part by weight, based on 100 parts by weight of the base polymer (e.g., (meth) acrylic polymer).

In the above-mentioned (meth) acrylic polymer, a radical polymerization initiator (radical generator) that is not used in the polymerization reaction in the production of the (meth) acrylic polymer may remain in some cases. The residual radical generator can be used as a radical generator in the adhesive composition. In this case, the amount of the residual radical generating agent can be quantified, and the radical generating agent can be appropriately blended in accordance with the content of the residual radical generating agent.

The amount of peroxide decomposition remaining after the reaction treatment can be measured by, for example, HPLC (high performance liquid chromatography).

More specifically, for example, the adhesive composition after the reaction treatment may be taken out by about 0.2g each time, immersed in 10mL of ethyl acetate, extracted at 25 ℃ for 3 hours with shaking at 120rpm with a shaker, and then allowed to stand at room temperature for 3 days. Subsequently, 10mL of acetonitrile was added, the mixture was shaken at 120rpm for 30 minutes at 25 ℃, and about 10. mu.L of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into HPLC and analyzed to obtain the amount of peroxide after the reaction treatment.

< Compound (A) >

The adhesive composition of the present invention contains at least 1 compound (A) selected from an ultraviolet absorber (a) having a molecular structure in which 0 to 3 hydroxyl groups are present and a dye compound (b) having an absorption spectrum in which the maximum absorption wavelength is in the wavelength range of 380 to 430 nm. As described above, the ultraviolet absorber (a) having 0 to 3 hydroxyl groups in the molecular structure is effective in reducing the hydrogen-donating groups responsible for deactivating the radicals and suppressing the inhibition of crosslinking by the radical generator. For example, when an isocyanate-based crosslinking agent reactive with a hydroxyl group is blended, 0 to 3 hydroxyl groups are also preferable in terms of suppressing inhibition of crosslinking by the crosslinking agent. The ultraviolet absorber (a) preferably has no free radical other than hydroxyl group in its molecular structureA compound of a phenyl group having an inactivated hydrogen-donating group. The phenyl group not contained in the molecular structure represents a phenyl group having no substituent (-C)₆H₅) Phenyl, phenylene and the like having a substituent are not excluded. In addition, as in the ultraviolet absorber (a), the dye compound (b) is preferably a compound having a small number of hydrogen-donating groups such as hydroxyl groups and phenyl groups (0 to 3 hydroxyl groups) or no hydrogen-donating groups in the molecular structure, from the viewpoint of preventing the inhibition of crosslinking of the radical generator.

The amount of the compound (a) related to the ultraviolet absorber (a) and/or the dye compound (b) is preferably 0.1 to 25 parts by weight, more preferably about 0.5 to 20 parts by weight, and still more preferably about 2 to 10 parts by weight, based on 100 parts by weight of the base polymer (e.g., (meth) acrylic polymer).

The ultraviolet absorber (a) may be used alone or in combination of 2 or more. When the ultraviolet absorber (a) is used alone as the compound (a), the total content of the ultraviolet absorber (a) is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, even more preferably 0.1 to 5 parts by weight, and even more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of a base polymer (e.g., a (meth) acrylic polymer). When the amount of the ultraviolet absorber (a) added is in the above range, the ultraviolet absorbing function of the pressure-sensitive adhesive layer can be sufficiently exhibited, and when ultraviolet polymerization is performed, the polymerization is not inhibited, which is preferable.

The dye compounds (b) may be used alone or in combination of 2 or more. When the pigment compound (b) is used alone as the compound (a), the total content of the pigment compound (b) is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, even more preferably 0.1 to 5 parts by weight, and even more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of a base polymer (e.g., a (meth) acrylic polymer). When the amount of the dye compound (b) added is in the above range, light in a region that does not affect light emission of the organic EL element can be sufficiently absorbed, and the use of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is preferable because deterioration of the organic EL element can be suppressed.

Either the ultraviolet absorber (a) or the dye compound (b) may be used, or the ultraviolet absorber (a) and the dye compound (b) may be used in combination. Although the ultraviolet absorber (a) can absorb light having a wavelength of 380nm, for example, it cannot sufficiently absorb light having a wavelength range (380nm to 430nm) shorter than a light-emitting region (longer than 430nm) of the organic EL element, and this transmitted light may deteriorate. The pigment compound (b) can suppress the transmission of light having a wavelength (380nm to 430nm) on the shorter wavelength side than the emission region (wavelength side longer than 430nm) of the organic EL element, and the transmittance of visible light in the emission region of the organic EL element can be sufficiently ensured by using the ultraviolet absorber (a) and the pigment compound (b) in combination.

In the present invention, by using such a dye compound (b) in combination with the ultraviolet absorber (a2), light in a region (wavelength 380nm to 430nm) that does not affect the light emission of the organic EL element can be sufficiently absorbed, and a light-emitting region (longer wavelength side than 430nm) of the organic EL element can also be sufficiently transmitted, and as a result, degradation by external light of the organic EL element can be suppressed. When the ultraviolet absorber (a) and the dye compound (b) are used in combination, the total amount of the ultraviolet absorber (a) and the dye compound (b) is preferably controlled within a range that is the amount of the compound (a) to be blended. The ultraviolet absorber (a) is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and still more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of a base polymer (e.g., (meth) acrylic polymer). The colorant compound (b) is preferably about 0.1 to 10 parts by weight, more preferably about 0.1 to 5 parts by weight, and still more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the base polymer (e.g., (meth) acrylic polymer).

< ultraviolet absorber (a) >

The ultraviolet absorber (a) is not particularly limited as long as it has 0 to 3 hydroxyl groups in its molecular structure, and examples thereof include: triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, oxybenzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and the like, and 1 kind or a combination of 2 or more kinds thereof may be used. Of these, at least 1 ultraviolet absorber selected from triazine ultraviolet absorbers having 2 or less hydroxyl groups in1 molecule and benzotriazole ultraviolet absorbers having 1 benzotriazole skeleton in1 molecule is preferable because the solubility in monomers used for forming the acrylic pressure-sensitive adhesive composition is good and the ultraviolet absorption ability at a wavelength of about 380nm is high.

Specific examples of the triazine-based ultraviolet absorber having not more than 2 hydroxyl groups in1 molecule include 2, 4-bis- [ {4- (4-ethylhexyloxy) -4-hydroxy } -phenyl ] -6- (4-methoxyphenyl) -1,3, 5-triazine (manufactured by BASF corporation), 2, 4-bis [ 2-hydroxy-4-butoxyphenyl ] -6- (2, 4-dibutoxyphenyl) -1,3, 5-triazine (TINUVIN460 manufactured by BASF corporation), reaction products of 2- (4, 6-bis (2, 4-dimethylphenyl) -1,3, 5-triazin-2-yl) -5-hydroxyphenyl and [ (C10-C16 (mainly C12-C13) alkoxy) methyl ] ethylene oxide (TINUVIN 400 vin, tin, BASF corporation), 2- [4, 6-bis (2, 4-dimethylphenyl) -1,3, 5-triazin-2-yl ] -5- [3- (dodecyloxy) -2-hydroxypropoxy ] phenol), a reaction product of 2- (2, 4-dihydroxyphenyl) -4, 6-bis- (2, 4-dimethylphenyl) -1,3, 5-triazine and 2-ethylhexyl epoxypropionate (TINUVIN 405, BASF corporation), 2- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) -5- [ (hexyl) oxy ] phenol (TINUVIN 1577, BASF corporation), 2- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) -5- [2- (2-ethylhexanoyloxy) ethoxy ] phenol (ADK STAB LA46, manufactured by ADEKA), 2- (2-hydroxy-4- [ 1-octyloxycarbonylethoxy ] phenyl) -4, 6-bis (4-phenylphenyl) -1,3, 5-triazine (TINUVIN 479, manufactured by BASF corporation), and the like.

Examples of the benzotriazole-based ultraviolet absorber having 1 benzotriazole skeleton in its molecule include 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3, 3-tetramethylbutyl) phenol (TINUVIN928, manufactured by BASF Co.), 2- (2-hydroxy-5-tert-butylphenyl) -2H-benzotriazole (TINUVIN PS, manufactured by BASF Co.), ester compounds (TINUVIN 384-2, manufactured by BASF Co.) of phenylpropionic acid and 3- (2H-benzotriazol-2-yl) -5- (1, 1-dimethylethyl) -4-hydroxy (C7-9 side chain and linear alkyl group), 2- (2H-benzotriazol-2-yl) -4, 6-bis (1-methyl-1-phenylethyl) phenol (TINUVIN 900, manufactured by BASF corporation), 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3, 3-tetramethylbutyl) phenol (TINUVIN928, manufactured by BASF corporation), a reaction product of methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate/polyethylene glycol 300 (TINUVIN1130, manufactured by BASF corporation), 2- (2H-benzotriazol-2-yl) P-cresol (TINUVIN P, BASF corporation, BASF corporation), 2 (2H-benzotriazol-2-yl) -4, 6-bis (1-methyl-1-phenylethyl) phenol (TINUVIN 234, BASF corporation), 2- [ 5-chloro (2H) -benzotriazol-2-yl ] -4-methyl-6- (tert-butyl) phenol (TINUVIN 326, BASF corporation), 2- (2H-benzotriazol-2-yl) -4, 6-di-tert-amylphenol (TINUVIN 328, BASF corporation), 2- (2H-benzotriazol-2-yl) -4- (1,1,3, 3-tetramethylbutyl) phenol (TINUVIN 329, BASF corporation), 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4 A reaction product of methyl (p-hydroxyphenyl) propionate and polyethylene glycol 300 (TINUVIN 213, BASF), 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol (TINUVIN 571, BASF), 2- [ 2-hydroxy-3- (3,4,5, 6-tetrahydrophthalimido-methyl) -5-methylphenyl ] benzotriazole (Sumisorb250, Sumitomo chemical Co., Ltd.), and the like.

Examples of the benzophenone-based ultraviolet absorber (benzophenone-based compound) and the oxybenzone-based ultraviolet absorber (oxybenzone-based compound) include: 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (acid anhydride and trihydrate salts), 2-hydroxy-4-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2' -dihydroxy-4, 4-dimethoxybenzophenone and the like.

Examples of the salicylate ultraviolet absorbers (salicylate-based compounds) include: 2, 4-di-tert-butylphenyl 3, 5-di-tert-butyl-4-hydroxybenzoate (TINUVIN 120, BASF).

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, and the like.

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

< pigment Compound (b) >

The dye compound (b) is not particularly limited as long as it has an absorption spectrum having a maximum absorption wavelength in a wavelength region of 380 to 430nm, and is preferably a compound having a small or no hydrogen-donating group such as a hydroxyl group or a phenyl group in its molecular structure, as in the ultraviolet absorber (a). The maximum absorption wavelength is an absorption maximum wavelength at which the maximum absorbance is exhibited when there are a plurality of maximum absorptions in the spectral absorption spectrum in the wavelength region of 300 to 460 nm.

The dye compound (b) preferably has an absorption spectrum having a maximum absorption wavelength in a wavelength region of 380 to 420 nm. The dye compound (b) is not particularly limited as long as it has the above wavelength characteristics, and is preferably a material having no fluorescent or phosphorescent properties (photoluminescence) such that the material does not inhibit the display properties of the organic EL device.

The half-width of the dye compound (b) is not particularly limited, but is preferably 80nm or less, more preferably 5 to 70nm, and still more preferably 10 to 60 nm. When the half-value width of the dye compound is in the above range, light in a region that does not affect light emission of the organic EL element can be sufficiently absorbed, and light having a wavelength longer than 430nm can be controlled to sufficiently transmit. The following method was used as a method for measuring the half width.

< half-value Width measurement method >

The half-value width of the dye compound (b) was measured from the transmission absorption spectrum of a dye compound solution under the following conditions using an ultraviolet-visible spectrophotometer (U-4100, manufactured by Hitachi High-Tech Sciences). The wavelength interval (full width at half maximum) between 2 points at which the peak becomes 50% was defined as the half-value width of the dye compound from the spectral spectrum measured by adjusting the concentration so that the absorbance at the maximum absorption wavelength became 1.0.

(measurement conditions)

Solvent: toluene or chloroform

Pool: quartz pool

Optical path length: 10mm

Examples of the pigment compound (b) include organic pigment compounds and inorganic pigment compounds, and among these, organic pigment compounds are preferable from the viewpoint of maintaining dispersibility and transparency to resin components such as a base polymer.

Examples of the organic dye compounds include azomethine compounds, indole compounds, cinnamic acid compounds, pyrimidine compounds, porphyrin compounds, phthalocyanine compounds, and the like.

As the organic dye compound, commercially available products can be suitably used, and specifically, as the indole compound, BONASOR UA3911 (trade name, maximum absorption wavelength of absorption spectrum: 398nm, half width: 48nm, manufactured by Orient chemical industries, Ltd.) can be mentioned, as the cinnamic acid compound, SOM-5-0106 (trade name, maximum absorption wavelength of absorption spectrum: 416nm, half width: 50nm, manufactured by Orient chemical industries, Ltd.) can be mentioned, as the porphyrin compound, FDB-001 (trade name, maximum absorption wavelength of absorption spectrum: 420nm, half width: 14nm, manufactured by Hitacea chemical industries, Ltd.) can be mentioned, as the phthalocyanine compound, merocyanine compound (trade name: FDB-009, maximum absorption wavelength of absorption spectrum: 394nm, half width: 43nm, manufactured by Hitacea chemical industries, Ltd.) can be mentioned, And polymethine compounds (trade name: DAA-247, maximum absorption wavelength of absorption spectrum: 389nm, half width: 49.5nm, manufactured by Hill chemical Co., Ltd.), among which the above phthalocyanine compounds are preferable from the viewpoint of suppressing the inhibition of crosslinking and optical reliability, and polymethine compounds are particularly preferable.

< antioxidant >

An antioxidant may be blended in the adhesive composition of the present invention. The antioxidant can prevent inhibition by oxygen of radicals generated from the radical generator, ensure a stable gel fraction (degree of crosslinking), suppress increase in peel strength of a release film (separator) applied to the pressure-sensitive adhesive layer, and improve the gel fraction.

Examples of the antioxidant include: at least one antioxidant selected from the group consisting of phenolic, phosphorus, sulfur and amine antioxidants is used. Among them, a phenol antioxidant is preferable.

Specific examples of the phenolic antioxidant include: 2, 6-di-t-butyl-p-cresol, 2, 6-di-t-butyl-4-ethylphenol, 2, 6-dicyclohexyl-4-methylphenol, 2, 6-diisopropyl-4-ethylphenol, 2, 6-di-t-amyl-4-methylphenol, 2, 6-di-t-octyl-4-n-propylphenol, 2, 6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-4-ethyl-6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, 2, 6-di-t-butyl-4-ethylphenol and the like as monocyclic phenol compounds, Styrenated mixed cresols, DL- α -tocopherol, β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid stearyl ester, and the like; 2,2 '-methylenebis (4-methyl-6-tert-butylphenol), 4' -butylidenebis (3-methyl-6-tert-butylphenol), 4 '-thiobis (3-methyl-6-tert-butylphenol), 2' -thiobis (4-methyl-6-tert-butylphenol), 4 '-methylenebis (2, 6-di-tert-butylphenol), 2' -methylenebis [6- (1-methylcyclohexyl) p-cresol ], 2 '-ethylenebis (4, 6-di-tert-butylphenol), 2' -butylidenebis (2-tert-butyl-4-methylphenol), 3, 6-dioxaoctamethylenebis [3- (3-tert-butyl-4-hydroxy- 5-methylphenyl) propionate ], triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ], 1, 6-hexanediol bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2' -thiodiethylene bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], and the like; 1,1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-tris (2, 6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3, 5-tris [ (3, 5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl ] isocyanurate, tris (4-t-butyl-2, 6-dimethyl-3-hydroxybenzyl) isocyanurate, 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, and the like as the tricyclic phenol compound; tetrakis [ methylene-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] methane as a tetracyclophenol compound, and the like; calcium bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate) and nickel bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate) are examples of the phosphorus-containing phenol compound.

Specific examples of the phosphorus antioxidant include: trioctyl phosphite, trilauryl phosphite, tris (tridecyl) phosphite, triisodecyl phosphite, phenyldiisooctyl phosphite, phenyldiisodecyl phosphite, phenylditridecyl phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2, 4-di-tert-butylphenyl) phosphite, tris (butoxyethyl) phosphite, tetrakis (tridecyl) -4,4 ' -butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, 4 ' -isopropylidenediphenol alkyl phosphite (in which the number of carbon atoms in the alkyl group is about 12 to 15), 4 ' -isopropylidenebis (2-tert-butylphenyl) bis (nonylphenyl) phosphite, Tris (biphenyl) phosphite, tetrakis (tridecyl) -1,1, 3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butane bisphosphite, tris (3, 5-di-tert-butyl-4-hydroxyphenyl) phosphite, hydrogenated-4, 4 ' -isopropylidenediphenol polyphosphite, bis (octylphenyl) bis [4,4 ' -butylidenebis (3-methyl-6-tert-butylphenol) ]1, 6-hexanediol bisphosphite, hexa (tridecyl) -1,1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenol) bisphosphite, tris [4,4 ' -isopropylidenebis (2-tert-butylphenol) ] phosphite, and mixtures thereof, Tris (1, 3-distearoyloxyisopropyl) phosphite, 9, 10-dihydro-9-phosphaphenanthrene-10-oxide, tetrakis (2, 4-di-t-butylphenyl) -4,4 '-biphenylene diphosphonite, distearyl pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, phenyl 4, 4' -isopropylidenediphenol pentaerythritol diphosphite, bis (2, 4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, phenyl bisphenol A-pentaerythritol diphosphite, and the like.

As the sulfur antioxidant, a dialkyl thiodipropionate and a polyol ester of an alkylthiopropionic acid are preferably used. The dialkyl thiodipropionate used herein is preferably a dialkyl thiodipropionate having an alkyl group having 6 to 20 carbon atoms, and the polyol ester of an alkylthiopropionic acid is preferably a polyol ester of an alkylthiopropionic acid having an alkyl group having 4 to 20 carbon atoms. In this case, examples of the polyol constituting the polyol ester include: glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, trishydroxyethyl isocyanurate, and the like. Examples of such dialkyl thiodipropionate include: dilauryl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, and the like. On the other hand, as the polyol ester of alkylthiopropionic acid, for example: glycerol tributylthiopropionate, glycerol trioctylthiopropionate, glycerol trilaurylthiopropionate, glycerol tristearylthiopropionate, trimethylolethane tributylthiopropionate, trimethylolethane trioctylthiopropionate, trimethylolethane trilaurylthiopropionate, trimethylolethane tristearylthiopropionate, pentaerythritol tetrabutylthiopropionate, pentaerythritol tetraoctylthiopropionate, pentaerythritol tetralaurylthiopropionate, pentaerythritol tetrastearylthiopropionate, and the like.

Specific examples of the amine antioxidant include: bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, polycondensates of dimethyl succinate with 1- (2-hydroxyethyl) -4-hydroxy-2, 2,6, 6-tetramethylpiperidineethanol, N ', N ", N '" -tetrakis- (4, 6-bis (butyl- (N-methyl-2, 2,6, 6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4, 7-diazacyclodecane-1, 10-diamine, dibutylamine-1, 3, 5-triazine-N, N ' -bis (2,2,6, 6-tetramethyl-4-piperidyl-1, 6-hexamethylenediamine with N- (2, polycondensates of 2,6, 6-tetramethyl-4-piperidyl) butylamine, poly [ {6- (1,1,3, 3-tetramethylbutyl) amino-1, 3, 5-triazine-2, 4-diyl } { (2,2,6, 6-tetramethyl-4-piperidyl) imino } hexamethylene { (2,2,6, 6-tetramethyl-4-piperidyl) imino } ], tetrakis (2,2,6, 6-tetramethyl-4-piperidyl) -1,2,3, 4-butane tetracarboxylic acid ester, 2,6, 6-tetramethyl-4-piperidyl benzoate, bis (1,2,6, 6-pentamethyl-4-piperidyl) -2- (3, 5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid Esters, bis (N-methyl-2, 2,6, 6-tetramethyl-4-piperidyl) sebacate, 1 ' - (1, 2-ethanediyl) bis (3,3,5, 5-tetramethylpiperazinone), (mixed 2,2,6, 6-tetramethyl-4-piperidyl/tridecyl) -1,2,3, 4-butanetetracarboxylate, (mixed 1,2,2,6, 6-pentamethyl-4-piperidyl/tridecyl) -1,2,3, 4-butanetetracarboxylate, mixed [2,2,6, 6-tetramethyl-4-piperidyl/β, β, β ', β ' -tetramethyl-3, 9- [2,4,8, 10-tetraoxaspiro (5,5) undecane ] diethyl ] -1,2,3, 4-butanetetracarboxylate, mixed [1,2,2,6, 6-pentamethyl-4-piperidinyl/β, β, β ', β ' -tetramethyl-3, 9- [2,4,8, 10-tetraoxaspiro (5,5) undecane ] diethyl ] -1,2,3, 4-butanetetracarboxylate, N ' -bis (3-aminopropyl) ethylenediamine-2, 4-bis [ N-butyl-N- (1,2,2,6, 6-pentamethyl-4-piperidinyl) amino ] -6-chloro-1, 3, 5-triazine condensate, poly [ 6-N-morpholino-1, 3, 5-triazine-2, 4-diyl ] [ (2,2,6, 6-tetramethyl-4-piperidyl) imino ] hexamethylene [ (2,2,6, 6-tetramethyl-4-piperidyl) imide ], a condensate of N, N' -bis (2,2,6, 6-tetramethyl-4-piperidyl) hexamethylenediamine and 1, 2-dibromoethane, [ N- (2,2,6, 6-tetramethyl-4-piperidyl) -2-methyl-2- (2,2,6, 6-tetramethyl-4-piperidyl) imino ] propionamide, and the like.

The content of the antioxidant in the adhesive composition of the present invention is determined from the viewpoint of preventing color fading due to the above-mentioned radical generator. In general, the content of the antioxidant is preferably in the range of 0.03 parts by weight or more per 100 parts by weight of the (meth) acrylic polymer. On the other hand, if the content of the antioxidant is too large, the ratio of radicals generated from the radical generator is increased. As a result, crosslinking of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is easily inhibited, and the gel fraction of the pressure-sensitive adhesive layer is reduced, which tends to cause appearance defects. From this viewpoint, the content of the antioxidant is preferably 5 parts by weight or less, and more preferably 1.5 parts by weight or less, based on 100 parts by weight of the (meth) acrylic polymer. From the viewpoint of ensuring the gel fraction and preventing discoloration of the pigment, the content of the antioxidant is preferably 0.05 to 1.5 parts by weight, more preferably 0.2 to 1.0 part by weight, and still more preferably 0.3 to 0.8 part by weight, based on 100 parts by weight of the base polymer (e.g., a (meth) acrylic polymer).

< crosslinking agent >

The adhesive composition of the present invention may contain a crosslinking agent (excluding the above-mentioned radical generator). In the present invention, when an isocyanate-based crosslinking agent is used in combination as the crosslinking agent, inhibition of radical crosslinking by oxygen can be more effectively suppressed by the antioxidant, and a three-dimensional crosslinked network of the adhesive layer can be efficiently formed by the isocyanate-based crosslinking agent. As a result, appearance abnormality at the end of the polarizing film can be more effectively prevented.

The crosslinking agent includes an isocyanate crosslinking agent, an epoxy crosslinking agent, a silicone crosslinking,

Crosslinking agents such as oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyl etherified melamine crosslinking agents and metal chelate crosslinking agents. The crosslinking agent may be used alone in1 kind, or in combination of 2 or more kinds. Among these, isocyanate-based crosslinking agents are preferably used.

The crosslinking agent can be used singly or in combination of 2 or more, and the total content thereof is preferably 5 parts by weight or less, more preferably 0.01 to 5 parts by weight, even more preferably 0.01 to 4 parts by weight, and particularly preferably 0.02 to 3 parts by weight, based on 100 parts by weight of the base polymer (e.g., a (meth) acrylic polymer).

The isocyanate-based crosslinking agent is a compound having 2 or more isocyanate groups (including an isocyanate-regenerating functional group in which an isocyanate group is temporarily protected by a blocking agent, polymerization, or the like) in1 molecule. Examples of the isocyanate crosslinking agent include aromatic isocyanates such as toluene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, examples thereof include: lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentene diisocyanate, cyclohexene diisocyanate and isophorone diisocyanate, aromatic diisocyanates such as 2, 4-tolylene diisocyanate, 4' -diphenylmethane diisocyanate, xylylene diisocyanate and polymethylene polyphenyl isocyanate, trimethylolpropane/tolylene diisocyanate trimer adduct (trade name: CORONATE L, manufactured by NIPPON POLYURETHANE INDUSTRIAL CO., LTD.), trimethylolpropane/hexamethylene diisocyanate trimer adduct (trade name: CORONATE HL, manufactured by NIPPON POLYURETHANE INDUSTRIAL CO., LTD.), isocyanate adducts such as hexamethylene diisocyanate isocyanurate (trade name: CORONATE, manufactured by HXOP, HXOP), Trimethylolpropane adduct of xylylenediisocyanate (trade name: D110N, manufactured by Mitsui chemical Co., Ltd.), trimethylolpropane adduct of hexamethylene diisocyanate (trade name: D160N, manufactured by Mitsui chemical Co., Ltd.); polyether polyisocyanates, polyester polyisocyanates, adducts thereof with various polyols, and polyfunctional polyisocyanates such as isocyanurate bonds, biuret bonds, and allophanate bonds.

Further, a silane coupling agent may be contained in the adhesive composition of the present invention. The amount of the silane coupling agent blended is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, and still 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.

Examples of the silane coupling agent include: (meth) acrylic-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, amino-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1, 3-dimethylbutylidene) propylamine and N-phenyl-gamma-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, and the like, Isocyanate-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane, and the like.

The adhesive composition of the present invention may contain, in addition to the above components, suitable additives according to the use. Examples thereof include: tackifiers (for example, tackifiers that are solid, semi-solid, or liquid at ordinary temperatures formed from rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenol resins, and the like); fillers such as hollow glass spheres; a plasticizer; an anti-aging agent; light Stabilizers (HALS); antioxidants, and the like.

2. Adhesive layer for organic EL display device

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

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and the pressure-sensitive adhesive layer can be formed by a method generally used in the art. Specifically, the adhesive composition may be formed by applying the adhesive composition to at least one surface of a substrate and drying a coating film formed from the adhesive composition; or by irradiation with active energy rays such as ultraviolet rays.

The substrate is not particularly limited, and for example, the following can be suitably used: various substrates such as a release film and a transparent resin film substrate, and a polarizing film described later are used as the substrate.

Examples of the constituent material of the release film include: resin films such as polyethylene, polypropylene, polyethylene terephthalate and polyester films, porous materials such as paper, cloth and nonwoven fabrics, and suitable sheets such as nets, foamed sheets, metal foils and laminates thereof, and the like.

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

The thickness of the release film is usually 5 to 200 μm, preferably about 5 to 100 μm. The release film may be subjected to release and stain-proofing treatment using a release agent of silicone type, fluorine type, long chain alkyl type or fatty acid amide type, silica powder or the like, or antistatic treatment of coating type, mixing type, vapor deposition type or the like, as required. In particular, the surface of the release film may be appropriately subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment, thereby further improving the releasability from the pressure-sensitive adhesive layer.

The transparent resin film substrate is not particularly limited, and various transparent resin films can be used. The resin film is formed of 1 film. Examples of the material include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyacrylate resins, and polyphenylene sulfide resins. Of these, particularly preferred are polyester-based resins, polyimide-based resins, and polyether sulfone-based resins.

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

The method for applying the adhesive composition to the substrate may be any known suitable method such as roll coating, roll-and-lick coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, blade coating, air knife coating, curtain coating, die lip coating, and die coating, and is not particularly limited.

When the adhesive layer is formed by drying the coating film formed from the adhesive composition, the drying conditions (temperature and time) are not particularly limited, and may be appropriately set according to the composition, concentration, and the like of the adhesive composition, and for example, the drying is performed at about 60 to 170 ℃, preferably at 60 to 150 ℃ for 1 to 60 minutes, preferably 2 to 30 minutes. In the case where the pressure-sensitive adhesive composition is an ultraviolet-curable pressure-sensitive adhesive composition, the pressure-sensitive adhesive layer may be formed by irradiating the coating film with ultraviolet light.

From the viewpoint of ensuring the function of absorbing light having a wavelength of less than 430nm, the thickness of the pressure-sensitive adhesive layer is preferably 5 μm or more, more preferably 50 μm or more, still more preferably 100 μm or more, and particularly preferably 150 μm or more. The upper limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1mm or less. When the thickness of the pressure-sensitive adhesive layer is more than 1mm, it is not preferable because it is difficult to transmit ultraviolet rays, and it takes time to polymerize the monomer component, and problems occur in workability, winding-up in the process, and transportability, and productivity may be deteriorated.

The gel fraction of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably 40% or more, more preferably 60% or more, still more preferably 75% or more, and particularly preferably 85% or more. When the gel fraction of the pressure-sensitive adhesive layer is small, the cohesive force is poor, and there is a case where the processability and the handleability are problematic. From the viewpoint of preventing appearance defects such as paste dents, the gel fraction immediately after the formation of the pressure-sensitive adhesive layer on the coating film of the pressure-sensitive adhesive composition by heat drying or ultraviolet irradiation is preferably 60% or more, more preferably 63% or more, still more preferably 66% or more, and particularly preferably 70% or more.

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

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

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

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

Here, the "average transmittance at a wavelength of 300 to 400 nm" means an average value of transmittance obtained by measuring transmittance at a 1nm pitch in a region at a wavelength of 300 to 400 nm. The same applies to the average transmittance in other wavelength regions.

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

In the case where the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a release film until it is ready for actual use.

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

The polarizing film with an adhesive layer for an organic EL display device of the present invention comprises a polarizing film and the adhesive layer for an organic EL display device.

As the pressure-sensitive adhesive layer for organic EL display devices, the pressure-sensitive adhesive layer for organic EL display devices described above can be suitably used. In addition, in the case where the adhesive layer is formed on a substrate other than the polarizing film, the adhesive layer may be attached to the polarizing film and transferred. The release film can be used as it is as a separator for a polarizing film having an adhesive layer, and the process can be simplified.

The polarizing film is not particularly limited, and may be a polarizing film having a polarizer and a transparent protective film provided on at least one surface of the polarizer.

(1) Polarizer

The polarizer is not particularly limited, and various polarizers can be used. Examples of the polarizer include films obtained by uniaxially stretching hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene-vinyl acetate copolymer partially saponified films, and polyene oriented films such as polyvinyl alcohol dehydrated products and polyvinyl chloride desalted products, and the like. Among them, a polarizer made of a dichroic material such as a polyvinyl alcohol film and iodine is preferable. The thickness of these polarizers is not particularly limited, but is usually about 5 to 80 μm.

The polarizer obtained by uniaxially stretching the polyvinyl alcohol film dyed with iodine can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous iodine solution and stretching it to 3 to 7 times the original length. The sheet may be immersed in an aqueous solution of potassium iodide or the like optionally containing boric acid, zinc sulfate, zinc chloride, or the like as necessary. Further, the polyvinyl alcohol film may be immersed in water and washed with water before dyeing, if necessary. By washing the polyvinyl alcohol film with water, it is possible to wash off dirt and an anti-blocking agent on the surface of the polyvinyl alcohol film, and also to swell the polyvinyl alcohol film and prevent unevenness such as uneven dyeing. The stretching may be performed after the dyeing with iodine, or may be performed while dyeing, or may be performed after the stretching with iodine. Stretching may be carried out in an aqueous solution or water bath of boric acid, potassium iodide, or the like.

In the present invention, a thin polarizer having a thickness of 10 μm or less may be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer is preferable in that it has excellent durability because of its small thickness unevenness, excellent visibility, and small dimensional change, and further, it can be made thin as the thickness of the polarizing film.

Typical thin polarizers include thin polarizing films described in japanese patent laid-open nos. 51-069644, 2000-338329, 2010/100917, 2010/100917, 4751481, 2012-073563. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol resin (hereinafter, also referred to as PVA-based resin) layer and a stretching resin base material in a state of a laminate, and a step of dyeing. With this production method, even if the PVA-based resin layer is thin, it can be stretched without causing troubles such as breakage due to stretching, because it is supported by the resin base material for stretching.

As the thin polarizing film, in a manufacturing method including a step of stretching in a state of a laminate and a step of dyeing, in view of being able to improve polarizing performance by stretching at a high magnification, a thin polarizer obtained by a manufacturing method including a step of stretching in an aqueous boric acid solution as described in wo 2010/100917 pamphlet, wo 2010/100917 pamphlet, or jp 4751481 a and jp 2012-073563 a is preferable, and in particular, a thin polarizer obtained by a manufacturing method including a step of stretching in an auxiliary gas atmosphere before stretching in an aqueous boric acid solution as described in jp 4751481 a and jp 2012-0763 a is particularly preferable.

(2) Transparent protective film

As the transparent protective film, a conventionally used transparent protective film can be suitably used. Specifically, the transparent protective film is preferably formed of a material having transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like, and examples thereof include: polyester polymers such AS polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such AS cellulose diacetate and cellulose triacetate, acrylic polymers such AS polymethyl methacrylate, styrene polymers such AS polystyrene and acrylonitrile-styrene copolymer (AS resin), and polycarbonate polymers. Further, polyolefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, ethylene-propylene copolymers, etc., vinyl chloride polymers, polyamide polymers such as nylon, aromatic polyamide, etc., imide polymers, sulfone polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, polyaryl ester polymers, polyoxymethylene polymers, epoxy polymers, or mixtures of the above polymers may be cited as examples of the polymer forming the transparent protective film. The transparent protective film may be formed as a cured layer of a thermosetting or ultraviolet-curable resin such as acrylic, urethane, acrylic urethane, epoxy, or silicone.

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

The polarizer and the transparent protective film are preferably bonded together by an aqueous adhesive or the like. Examples of the aqueous adhesive include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latexes, aqueous polyurethanes, and aqueous polyesters. In addition to the above, examples of the adhesive for the polarizer and the transparent protective film include an ultraviolet curing adhesive, an electron beam curing adhesive, and the like. The adhesive for electron beam-curable polarizing film exhibits suitable adhesiveness to the above-described various visible-side transparent protective films. In addition, the adhesive used in the present invention may contain a metal compound filler.

The transparent protective film may be subjected to a hard coat layer, antireflection treatment, adhesion prevention treatment, treatment for diffusion or antiglare purpose on the surface thereof not bonded to the polarizer.

As the transparent protective film, any transparent protective film having a retardation and capable of functioning as an optical compensation layer can be used. In the case of using a transparent protective film having a retardation, the retardation characteristics thereof can be appropriately adjusted to a value required for optical compensation. As the retardation film, a stretched film can be suitably used. When the refractive index in the slow axis direction is nx, the refractive index in the in-plane fast axis direction is ny, and the refractive index in the thickness direction is nz, a retardation film satisfying the relationship of nx ═ ny > nz, nx > nz > ny, nz ═ nx > ny, nz > nx > ny, and nz > nx ═ ny can be selected and used according to various uses. In addition, nx ═ ny means not only that nx and ny are completely the same, but also that nx and ny are substantially the same. In addition, ny-nz means not only that ny is completely the same as nz, but also that ny is actually the same as nz.

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

When a retardation film is used as the transparent protective film, it is preferable to use a retardation film in which a transparent protective film is provided on one surface of the polarizer and a retardation film is provided on the other surface. In this case, the position of the pressure-sensitive adhesive layer is not particularly limited, and the pressure-sensitive adhesive layer may be provided on the surface of the transparent protective film opposite to the surface in contact with the polarizer, or may be provided on the surface of the retardation film opposite to the surface in contact with the polarizer.

Fig. 1(a) to (c) show an example of a specific structure of the polarizing film with an adhesive layer for an organic EL display device according to the present invention. Examples thereof include: the polarizing film 1 with an adhesive layer for an organic EL display device is formed by sequentially laminating layers such as an adhesive layer 2/a transparent protective film 3/a polarizer 4/a phase difference film 5 shown in fig. 1(a), a transparent protective film 3/a polarizer 4/a phase difference film 5/an adhesive layer 2 shown in fig. 1(b), and an adhesive layer 2/a transparent protective film 3/a polarizer 4/a phase difference film 5/an adhesive layer 2 shown in fig. 1 (c). In fig. 1(a) and (b), the pressure-sensitive adhesive layer 2 is the pressure-sensitive adhesive layer for an organic EL display device of the present invention, and in fig. 1(c), at least 1 of the 2 pressure-sensitive adhesive layers 2 present may be the pressure-sensitive adhesive layer for an organic EL display device of the present invention, or 2 of them may be the pressure-sensitive adhesive layer for an organic EL display device of the present invention. In fig. 1, the polarizing film 6 is a one-side protective polarizing film composed of the polarizer 4 and the transparent protective film 3, but is not limited thereto, and may be a two-side protective polarizing film further having a transparent protective film between the polarizer 4 and the phase difference film 5. As described above, various functional layers such as a hard coat layer may be formed on the surface of the transparent protective film 3 not in contact with the polarizer 4.

In the case where the retardation film is laminated on the polarizer via an adhesive layer, the adhesive layer may be an adhesive layer for an organic EL display device of the present invention. That is, the polarizing film with an adhesive layer for an organic EL display device may have a1 st adhesive layer, a transparent protective film, a polarizer, a2 nd adhesive layer, a retardation film, and a3 rd adhesive layer in this order, and at least one of the 1 st adhesive layer, the 2 nd adhesive layer, and the 3 rd adhesive layer may be the adhesive layer for an organic EL display device.

4. Organic EL display device

The organic EL display device of the present invention uses at least 1 pressure-sensitive adhesive layer for an organic EL display device of the present invention and/or a polarizing film with a pressure-sensitive adhesive layer for an organic EL display device of the present invention.

Examples of specific configurations of the organic EL display device include, for example, as shown in fig. 2 to 4, 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 element 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 (fig. 3); an organic EL display device is formed by sequentially laminating layers of cover glass or cover plastic 7, adhesive layer 2, sensor ー layer 10, adhesive layer 2, transparent protective film 3, polarizer 4, retardation film 5, adhesive layer 2, and organic EL display panel 8 (fig. 4). At least 1 of the pressure-sensitive adhesive layers 2 in the above-described configurations may be the pressure-sensitive adhesive layer of the present invention, or all of the pressure-sensitive adhesive layers 2 may be the pressure-sensitive adhesive layer of the present invention. The organic EL display device of the present invention may further include various functional layers such as a protective film and a hard coat layer in addition to the above. In addition, an adhesive layer and/or an adhesive layer can be used as appropriate for laminating the layers. As the adhesive layer other than the adhesive layer of the present invention, a general adhesive layer used in the art can be suitably used.