TW201418397A - Resin composition for uv-cured adhesive and adhesive - Google Patents

Abstract

This invention provides a resin composition for a UV-cured adhesive which has excellent adherence which will not fall off because of aging. Furthermore, the resin composition for UV-cured adhesive has good performance of anti yellowing. The resin composition for UV-cured adhesive is characterized in that the resin composition for UV-cured adhesive of the urethane (meth) acrylate resin (A), (methyl) acrylic monomer (B) and photopolymerization initiator are prepared from reaction between polyatomic alcohol (a) and polyisocyanate (b) and acrylic compounds with oxhydryl (methyl) acrylic compounds (c), and the weight ratio of the light stabilizer (D) and the antioxidant (E) is 95/5-5/95.

Description

Resin composition and adhesive for ultraviolet curing adhesive

The present invention relates to a resin composition and an adhesive for an ultraviolet curing adhesive which is excellent in adhesion and yellowing resistance.

In an optical related product represented by a touch panel or a liquid crystal display, a large number of optical members having various types of materials and shapes have been used in connection with their high functionality.

In the pasting of the optical member, the adhesive has been conventionally used. However, the industry needs an adhesive having excellent adhesion regardless of the material and shape of the part.

Further, in the manufacture of the above optical related products, in recent years, it has become a big problem to increase the productivity of the final product. This is because the adhesive which has been conventionally used usually contains a solvent such as a solvent or water. Therefore, after the adhesive is applied onto the surface of the substrate or the like, the solvent contained in the adhesive is removed. A large amount of time is required in the step, which is a cause of a decrease in the production efficiency of the final product.

As an adhesive which can improve the production efficiency of the above products, an ultraviolet curing adhesive is known. The ultraviolet curable adhesive is characterized in that it does not usually contain a solvent such as a solvent or water. Therefore, when the adhesive layer is formed, the step of removing the solvent is not required.

As a level of adhesion that can be used in the manufacture of the above-mentioned products and the like, and As compared with an adhesive which can improve the production efficiency of the final product, for example, an adhesive composition is known which is characterized in that it is characterized by 100 parts relative to a monomer having an unsaturated double bond. In addition, the high molecular weight body having a weight average molecular weight of 20,000 or more having a urethane bond and having an unsaturated double bond at the polymer terminal is 5 parts by mass or more and 200 parts by mass or less (see, for example, Patent Document 1).

However, the above-mentioned adhesive composition may not exhibit sufficient adhesive force due to the material of the substrate or the like, and may cause peeling over time depending on the material and shape of the substrate, and may be parallel to the above. The problem of the displacement of the substrate caused by the lateral force of the surface of the substrate, or yellowing over time.

Prior technical literature

Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-104296

An object of the present invention is to provide a resin composition for an ultraviolet curable adhesive which is excellent in the level of peeling over time without causing peeling of a substrate made of various materials. Excellent adhesion and yellowing resistance.

In the course of intensive research to solve the above problems, the inventors of the present invention have advanced research by focusing on the types of additives.

As a result, it has been found that an adhesive having excellent adhesion and yellowing resistance can be obtained by including a light stabilizer and an antioxidant in a specific ratio.

That is, the present invention provides a resin composition for an ultraviolet curable adhesive, characterized in that A polyurethane (meth)acrylate resin (A) or (meth)acrylic acid obtained by reacting a polyol (a) with a polyisocyanate (b) and a (meth)acrylic compound (c) having a hydroxyl group The resin composition for the ultraviolet curable adhesive of the monomer (B) and the photopolymerization initiator (C) further contains a light stabilizer (D) in a range of 95/5 to 5/95 by mass ratio. And an antioxidant (E); the present invention also provides an adhesive.

The adhesive obtained by using the resin composition for ultraviolet curable adhesives of the present invention is a material which has excellent adhesion and retention and is excellent in yellowing resistance. In particular, yellowing resistance (light yellowing resistance, heat yellowing resistance) is excellent even after long-term light exposure and after heat exposure.

The adhesive obtained by using the resin composition for an ultraviolet curable adhesive of the present invention can be preferably used as an adhesive used in an optical member. In particular, it can be suitably used in the manufacture of touch panels, liquid crystal displays, plasma displays, organic ELs, personal computers, mobile phones, and the like.

First, the polyurethane (meth) acrylate resin (A) used in the present invention will be described.

Examples of the polyhydric alcohol (a) include a polyester polyol, a polyether polyol, a polycarbonate polyol, a polyacryl polyol, and a polybutadiene polyol. These may be used singly or in combination. 2 or more types. Among them, a polyether polyol or a polycarbonate polyol is preferably used from the viewpoint of further improving the adhesion, the holding power, the followability of the height difference, and the whitening resistance.

Examples of the polyether polyol include addition polymerization of one or two or more kinds of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to a compound having two or more active hydrogens. The obtained product is a polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, and the tetrahydrofuran and the alkyl group are taken. A modified polytetramethylene glycol obtained by copolymerization of tetrahydrofuran, a modified polytetramethylene glycol obtained by copolymerizing neopentyl glycol and tetrahydrofuran, or the like.

Examples of the compound having two or more active hydrogens include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol, 1,3-propanediol, and dipropylene glycol. Tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1 , 11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol , 3-methyl-1,5-pentanediol, 2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol 1, 2-methyl-1,8-octanediol, hydroquinone, resorcinol, bisphenol A, bisphenol F, 4,4'-bisphenol, and other relatively low molecular weight dihydroxy compounds, 1, 2-cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanediol, cycloheptanediol, cyclooctanediol, 1,4-cyclohexanedimethanol, hydroxypropylcyclohexane Alcohol, tricyclo[5,2,1,0,2,6]decane-dimethanol, bicyclo[4,3,0]-nonanediol, dicyclohexanediol, tricyclo[5,3, 1,1]dodecanediol, bicyclo[4,3,0] Alkanediethanol, tricyclo[5,3,1,1]dodecane-diethanol, hydroxypropyltricyclo[5,3,1,1]dodecanol, spiro[3,4]octanediol, Alicyclic cyclohexanediol, 1,1'-bicyclohexylidenediol, cyclohexanetriol, hydrogenated bisphenol A, 1,3-adamantanediol, etc. Polyol polyols such as alcohol, polyethylene glycol, polypropylene glycol, polybutylene glycol, polyester polyols such as polyhexamethylene adipate, polybutylene succinate, and polycaprolactone.

Among them, from the viewpoint of imparting good adhesion properties, it is more preferred to use an aliphatic polyether polyol, and more preferably a polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran.

The number average molecular weight of the polyether polyol is preferably in the range of 500 to 3,000, more preferably in the range of 500 to 2,000, still more preferably in the range of 500 to 1,500. Further, the number average molecular weight of the above polyether polyol is a value obtained by gel permeation chromatography (GPC) in terms of polystyrene.

The polycarbonate polyol may, for example, be a compound obtained by reacting a carbonate and/or carbonium chloride with a compound having two or more active hydrogens.

Examples of the above carbonates include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonates, and diphenyl carbonate.

The hydroxyl value of the polycarbonate polyol is preferably from 30 to 230 mgKOH/g, more preferably from 50 to 230 mgKOH/g, from the viewpoint of adhesion and the like. Further, the hydroxyl value of the above polycarbonate polyol represents a value measured in accordance with JIS K0070.

Examples of the polyisocyanate (b) include aromatic diisocyanates such as xylylene diisocyanate, phenyl diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, and 1,6-hexane. Isocyanate, diamate diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, diisocyanate methylcyclohexane, tetramethylphthalate An aliphatic group such as a diisocyanate or a diisocyanate having an alicyclic structure may be used alone or in combination of two or more. Among them, diisocyanate having an alicyclic structure, more preferably 4,4'-dicyclohexylmethane diisocyanate, is preferably used from the viewpoint of achieving excellent adhesion and retention, and improving heat-resistant yellowing. Falconone diisocyanate, cyclohexane diisocyanate, diisocyanate methylcyclohexane.

The (meth)acrylic compound (c) having a hydroxyl group is a compound used for introducing a (meth)acrylonyl group into the above-mentioned polyurethane (meth)acrylate resin (A), and has an isocyanate group. The hydroxyl group of the reaction.

Examples of the (meth)acrylic compound having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl acrylate, and (methyl). a (meth)acrylic acid alkyl ester having a hydroxyl group such as 3-hydroxybutyl acrylate, 4-hydroxybutyl (meth)acrylate or 6-hydroxyhexyl acrylate, trimethylolpropane di(meth)acrylate, A polyfunctional (meth)acrylate having a hydroxyl group such as pentaerythritol tri(meth)acrylate or dipentaerythritol penta(meth)acrylate, polyethylene glycol monoacrylate or polypropylene glycol monoacrylate. Among them, from the viewpoint of the curability of ultraviolet rays, it is more preferable to use an acrylic compound having a hydroxyl group, and it is more preferably acrylic from the viewpoints of easiness in obtaining a raw material, curability, and imparting good adhesion properties. 2-Hydroxyethyl ester or 4-hydroxybutyl acrylate.

The method for producing the above-mentioned polyurethane (meth) acrylate resin (A) includes, for example, a method in which the above polyol (a) and the above (meth)acrylic compound (c) are added without a solvent. a method in which the polyisocyanate (b) is supplied to the reaction system, and the mixture is mixed and reacted to produce the mixture; and the polyol (a) is reacted with the polyisocyanate (b) without a solvent. Further, a method of producing a polyurethane prepolymer having an isocyanate group at a molecular terminal and then supplying the above (meth)acrylic compound (c) by mixing and reacting them is obtained. In any of the above methods, the above reaction is preferably carried out at a temperature of from 20 to 120 ° C for about 30 minutes to 24 hours.

The production of the above-mentioned polyurethane (meth) acrylate resin (A) can also be carried out in the presence of an organic solvent or an aqueous medium. Further, it may be produced in the presence of a (meth)acrylic monomer (B) to be described later instead of an organic solvent or an aqueous medium. In the case of producing a laminate, it is not necessary to remove the organic solvent or the aqueous medium, and the production step can be simplified. Therefore, it is preferable to carry out the solvent-free or from the viewpoint of suppressing the viscosity in the reaction system, preferably (meth) It is carried out in the presence of an acrylic monomer (B).

The reaction of the above polyol (a), the above polyisocyanate (b), and the above (meth)acrylic compound (c) is controlled from the viewpoint of controlling the molecular weight of the obtained polyurethane (meth) acrylate resin (A). The hydroxyl group of the polyol (a) and the total amount of the hydroxyl groups of the (meth)acrylic compound (c) and the equivalent ratio of the isocyanate groups of the polyisocyanate (b) are preferably [isocyanate groups/ The total amount of hydroxyl groups is in the range of from 0.75 to 1.00, more preferably in the range of from 0.79 to 0.95. Further, although it is also possible to react them when the above equivalent ratio exceeds 1, in this case, methanol is preferably used for the purpose of deactivating the terminal isocyanate group of the polyurethane (meth) acrylate resin (A). Wait for alcohol. In this case, the hydroxyl group of the polyol (a) and the hydroxyl group of the (meth)acrylic compound (c) and the total amount of the hydroxyl groups of the alcohol and the equivalent ratio of the polyisocyanate group are preferably used. [Total amount of isocyanate group / hydroxyl group] was adjusted to the above range.

In addition, as the alcohol which can be used for the purpose of deactivating the terminal isocyanate group of the above-mentioned polyurethane (meth) acrylate resin (A), for example, methanol, ethanol, propanol, butanol or the like can be used. A monofunctional alcohol such as a monofunctional alcohol, 1,2-propanediol or 1,3-butanediol, which contains a hydroxyl group of a first order and a second stage, or the like.

Further, in the production of the polyurethane (meth) acrylate resin (A), a polymerization inhibitor, an urethanization catalyst or the like may be used as needed.

As the polymerization inhibitor, for example, 3,5-di-t-butyl-4-hydroxytoluene, hydroquinone, methyl hydroquinone, hydroquinone monomethicone (methoquinone), and third can be used. Butyl catechol methoxy phenol, 2,6-di-t-butyl cresol, phenothiazine , tetramethylthiuram disulfide, diphenylamine, dinitrobenzene, and the like.

As the above urethanation catalyst, for example, triethylamine, triethylenediamine, N-methyl can be used. A nitrogen-containing compound such as a porphyrin; a metal salt such as potassium acetate, zinc stearate or tin octylate; or an organometallic compound such as dibutyltin dilaurate.

The polyurethane (meth) acrylate resin (A) has a (meth) acrylonitrile group which promotes radical polymerization by light irradiation or heating. The equivalent of the (meth) acrylonitrile group is preferably in the range of 1,000 to 20,000, more preferably in the range of 5,000 to 17,000, and still more preferably in the range of 6,000 to 16,000, from the viewpoint of adhesive properties or other physical properties. range. Further, the equivalent of the above (meth) acrylonitrile group means that the total mass of the above polyol (a), polyisocyanate (b) and (meth)acrylic compound (c) is divided by the above-mentioned polyurethane (methyl group). The value obtained by the equivalent of the (meth) acrylonitrile group in the acrylate resin (A), and the unit is g/eq.

In the present invention, the term "(meth)acrylic compound" means one or both of a methacrylic compound and an acrylic compound, and the term "(meth)acrylate" means methacrylate and One or both of the acrylates, the "(meth)acryl fluorenyl group" means one or both of a methacryl fluorenyl group and an acryl fluorenyl group, and the "(meth)acrylic acid" means methacrylic acid and acrylic acid. One or both of the "(meth)acrylic monomers" means one or both of a methacrylic monomer and an acrylic monomer.

The weight average molecular weight of the above-mentioned polyurethane (meth) acrylate resin (A) is preferably from the viewpoint of achieving excellent adhesion and holding power and imparting good coating workability. The range of 5,000 to 50,000, more preferably 7,000 to 45,000, further preferably 10,000 to 40,000, more preferably 12,000 to 3,5000. Further, the weight average molecular weight of the above-mentioned polyurethane (meth) acrylate resin (A) is a value obtained by gel permeation chromatography (GPC) in terms of polystyrene.

Hereinafter, the (meth)acrylic monomer (B) used in the present invention will be described.

Examples of the (meth)acrylic monomer (B) include methyl acrylate (glass transition temperature (Tg): 10 ° C), ethyl acrylate (-24 ° C), and propyl acrylate (-37 ° C). , isopropyl acrylate (-6 ° C), butyl acrylate (-49 ° C), second butyl acrylate (-22 ° C), isobutyl acrylate (-24 ° C), 2-ethyl butyl acrylate (- 50 ° C), n-amyl acrylate (-57 ° C), hexyl acrylate (-57 ° C), 2-ethylhexyl acrylate (-50 ° C), heptyl acrylate (-60 ° C), octyl acrylate (- 65 ° C), 2-octyl acrylate (-45 ° C), decyl acrylate (-58 ° C), dodecyl acrylate (-3 ° C), 3-methoxybutyl acrylate (-56 ° C), 2-methoxyethyl acrylate (-50 ° C), 3-methoxypropyl acrylate (-75 ° C), 2-methoxybutyl acrylate (-32 ° C), 3-methylbutyl acrylate ( -45 ° C), benzyl acrylate (6 ° C), amyl methacrylate (-5 ° C), hexyl methacrylate (-5 ° C), 2-ethylhexyl methacrylate (-10 ° C) ( The above transfer of Tg value from Polymer Handbook (4th ed.), 2-hydroxyethyl acrylate (HEA; -15 ° C), 2-hydroxypropyl acrylate (HPA; -7 ° C), 4-hydroxybutyl acrylate ( 4HBA;-32 ), isooctyl acrylate (IOAA; -58 ° C), lauryl acrylate (LA; 15 ° C), stearyl acrylate (STA; -58 ° C), tetrahydrofurfuryl acrylate (Viscoat # 150; -12 ° C Benzyl acrylate (Viscoat # 160; 6 ° C), ethyl carbitol acrylate (Viscoat # 190; -67 ° C), phenoxyethyl acrylate (Viscoat # 192; -22 ° C) (above is Osaka Organic chemical industry (share) system, transfer Tg value from the same company HP), methoxy polyethylene glycol acrylate (EO 9mol, AM-90G; -71 ° C), phenoxy polyethylene glycol acrylate ( AMP-20GY; -8 ° C) (The above is the new Nakamura Chemical Industry Co., Ltd., transfer Tg value from the same company HP), isoamyl acrylate (IAA; -45 ° C), ethoxy ethoxy-diethylene glycol Ester (EC-A; -70 ° C) (the above is manufactured by Kyoeisha Chemical Co., Ltd., transferring Tg value from the same company HP), neopentyl acrylate (22 ° C), cyclohexyl acrylate (19 ° C), Cetyl acrylate (35 ° C), isobornyl acrylate (94 ° C), phenyl acrylate (57 ° C), acrylamide (165 ° C), benzyl methacrylate (54 ° C), methacrylic acid Ester (105 ° C), ethyl methacrylate (65 ° C), methacryl Propyl acrylate (35 ° C), isopropyl methacrylate (81 ° C), butyl methacrylate (20 ° C), isobutyl methacrylate (53 ° C), second butyl methacrylate (60 ° C ), tert-butyl methacrylate (118 ° C), cyclohexyl methacrylate (83 ° C), 2-hydroxyethyl methacrylate (85 ° C), isobornyl methacrylate (110 ° C) (above) Transfer of Tg value from Polymer Handbook (4 ^th ed.), T-butyl acrylate (TBA; 41 ° C) (above is made by Osaka Organic Chemical Industry Co., Ltd., transfer Tg value from the same company HP), acrylic acid 2 -Hydroxy-3-phenoxypropyl ester (M-600A; 17 ° C) (The above is manufactured by Kyoeisha Chemical Co., Ltd., reproduces the Tg value from the same company HP), dimethyl methacrylate (DMAA; 119 °C), acrylonitrile Porphyrin (ACMO; 145 ° C), dimethylaminopropyl acrylamide (DMAPAA; 134 ° C), isopropyl acrylamide (NIPAM; 134 ° C), diethyl acrylamide (DEAA; 81 ° C) , hydroxyethyl acrylamide (HEAA; 98 ° C) (above is (manufactured by the company), from the same company HP transferred Tg value) and so on. These monomers may be used alone or in combination of two or more. Further, the value of Tg is a value indicating the Tg of the homopolymer of the (meth)acrylic monomer, and is described by the Polymer Handbook (4th ed.) and the (meth)acrylic monomer manufacturer's homepage. Value.

As the (meth)acrylic monomer (B), methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like are preferably used from the viewpoints of adhesion, retention, and other physical properties. 2-methoxyethyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, more preferably selected from the group consisting of butyl acrylate, 2-ethylhexyl acrylate, dimethyl methacrylate, propylene oxime base One or more of phenyl, dimethylaminopropyl acrylamide, isopropyl acrylamide, diethyl acrylamide, hydroxyethyl acrylamide, and cyclohexyl acrylate.

The amount of the (meth)acrylic monomer (B) to be used is compared with the above-mentioned polyurethane (meth)acrylate resin from the viewpoint of imparting excellent adhesion and retention and imparting coatability based on viscosity or the like. (A) 100 parts by mass, preferably used in the range of 30 to 200 parts by mass, more preferably in the range of 50 to 150 parts by mass, still more preferably in the range of 70 to 130 parts by mass.

The photopolymerization initiator (C) used in the present invention will be described below.

The photopolymerization initiator (C) generates radicals by light irradiation, heating, or the like, and initiates radical polymerization of the polyurethane (meth) acrylate resin (A) and the (meth) acryl monomer (B).

Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, diethoxyacetophenone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one. -(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 4-(2-hydroxyethoxy)-phenyl (2- Hydroxy-2-propyl)one, 2-methyl-[4-(methylthio)phenyl]-2- Acetophenones such as phenyl-1-propanone, 2,2-dimethoxy-2-phenylacetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin such as benzoin isobutyl ether; benzophenone, benzamidine benzoic acid, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, 4-benzylidene group -4'-methyldiphenyl sulfide, benzophenones such as 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2,4- Dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropyl Thioxanthone such as thioxanthone; 4,4'-dimethylamino thioxanthone (alias = Mie's ketone), 4,4'-diethylaminobenzophenone, α-mercaptopurine Ester, benzophenone, methyl benzoate ("VICURE 55"), 2-ethyl hydrazine and the like; 2,4,6-trimethylbenzimidyl diphenyl phosphine oxide (" LUCIRIN TPO"), bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide ("IRGACURE 819") and other fluorenylphosphine oxides; 3,3',4,4'-four (Third butyl peroxycarbonyl) benzophenone ["BTTB" manufactured by Nippon Oil & Fat Co., Ltd.], propylene oxime Ketones.

As the photopolymerization initiator, 2-hydroxy-2-methyl group is preferably used from the viewpoint of achieving excellent adhesion and retention, preventing discoloration of the adhesive layer over time, and improving curability. 1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzene Methyl fluorenyl)-phenylphosphine oxide.

The amount of use of the photopolymerization initiator (C) is preferably from 0.1 to 20 parts by mass, more preferably from 0.5 to 15 parts by mass per 100 parts by mass of the above-mentioned polyurethane (meth) acrylate resin (A). The range of parts by mass is more preferably in the range of 1 to 5 parts by mass.

In addition, as the amount of use of the photopolymerization initiator (C), from the viewpoint of initial yellowing resistance (transparency), etc., the mass ratio to the light stabilizer (D) to be described later [(C)/(D)] It is preferably in the range of 95/5 to 20/80, more preferably in the range of 85/15 to 50/50.

The light stabilizer (D) used in the present invention will be described below.

The light stabilizer (D) is a substance that traps radicals generated by photodegradation, and examples thereof include a radical scavenger such as a thiol compound, a thioether compound, and a hindered amine compound, and a benzophenone compound and benzophenone. An ultraviolet absorber such as an acid ester compound may be used alone or in combination of two or more. Among them, a hindered amine compound is preferably used from the viewpoint of maintaining excellent adhesion and retention, and further improving yellowing resistance after light exposure.

Examples of the hindered amine compound include cyclohexane and N-butyl 2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro 1,3. 5-three The reaction product of the reaction product with 2-aminoethanol (trade name: Tinuvin (registered trademark) 152 (manufactured by BASF Japan Co., Ltd.), bismuth azelaic acid (2,2,6,6-tetramethyl-1) -(octyloxy)-4-piperidinyl)ester (trade name: Tinuvin (registered trademark) 123 (manufactured by BASF), 1,1-dimethylethylhydroperoxide and octane A hindered amine compound having an aminoether group, such as a reaction product, N-acetamido-3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine -2,5-dione (trade name: Hostavin (registered trademark) 3058 (manufactured by Clariant Japan)) N-acetyl group-based hindered amine compound, double (1, 2, 2, 6, 6-five Methyl-4-piperidinyl) sebacate (trade name: Tinuvin (registered trademark) 765 (manufactured by BASF Japan), bis(1,2,2,6,6'-pentamethyl- 4-piperidinyl){[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}butylmalonate (trade name: Tinuvin (registered trademark) 144 (BASF Japan Co., Ltd.), dimethyl succinate / 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (trade name: Tinuvin (registered trademark) 622LD (manufactured by BASF Japan Co., Ltd.), malonic acid [{4-methoxyphenyl}methylene]-bis(1,2,2,6,6-pentamethyl- 4-piperidine The N-alkyl hindered amine compound of the ester (trade name: Hostavin (registered trademark) PR-31 (manufactured by Clariant Japan Co., Ltd.)). Among them, from the viewpoint of maintaining excellent adhesion and retention, and further improving the yellowing resistance after light exposure, it is preferred to use an N-alkyl hindered amine compound, preferably selected from the group consisting of double (1, 2). ,2,6,6-pentamethyl-4-piperidinyl) sebacate and dimethyl succinate/1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6 One or more kinds of light stabilizers in the tetramethyl piperidine polycondensate.

The amount of the light stabilizer (D) to be used is preferably from 0.01 to 10 in terms of 100 parts by mass of the above-mentioned polyurethane (meth)acrylate resin (A) from the viewpoint of imparting yellowing resistance after light exposure. It is used in the range of parts by mass, more preferably in the range of 0.1 to 5 parts by mass.

The antioxidant (E) used in the present invention will be described below.

Examples of the antioxidant (E) include a hindered phenol compound (primary antioxidant) that traps a radical generated by thermal deterioration, and a phosphorus compound or a sulfur compound that decomposes a peroxide generated by thermal deterioration. The secondary antioxidants and the like may be used alone or in combination of two or more.

The hindered phenol compound is, for example, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX (registered trademark) 245 (manufactured by BASF Japan Co., Ltd.), pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (trade name: IRGANOX (registered trademark) 1010 (BASF Japan ( ))), octadecyl [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (trade name: IRGANOX (registered trademark) 1076 (BASF Japan) )), thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX (registered trademark) 1035 (BASF Japan) ), phenylpropionic acid-3,5-bis(1,1-dimethylethyl)-4-hydroxy-C ₇ -C ₉ side chain alkyl ester (trade name: IRGANOX (registered trademark) 1135 (BASF Japan) ())), 4,6-bis(dodecylthiomethyl)-o-cresol (trade name: IRGANOX (registered trademark) 1726 (manufactured by BASF Japan), N-phenylaniline and Reaction product of 2,4,4-trimethylpentene (trade name: IRGANOX (registered trademark) 5057 (manufactured by BASF Japan), 2-tert-butyl-6-(3-tert-butyl) -2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (trade name: Su Milizer (registered trademark) GM (manufactured by Sumitomo Chemical Co., Ltd.), 3,9-bis[2-[3-(t-butyl-4-hydroxy-5-methylphenyl)propionate]-1 ,1-dimethylethyl]2,4,8,10-tetraoxaspiro[5‧5]undecane (trade name: Sumilizer (registered trademark) GA-80 (Sumitomo Chemical Co., Ltd.)) , 2,6-di-t-butyl-4-methylphenol (trade name: Noclac 200 (made by Ouchi Emerging Chemical Industry Co., Ltd.)), 2,2'-methylenebis(4-methyl- 6-Tertibutylphenol) (trade name: Noclac NS-6 (made by Ouchi Emerging Chemical Industry Co., Ltd.)), 2,5-di-third amyl hydroquinone (trade name: Noclac DAH ( Ouchi Emerging Chemical Industry Co., Ltd.).

Examples of the phosphorus compound include triphenylphosphine, bis(2,4-di-t-butyl-6-methylphenyl)ethylphosphite, triphenylphosphite, and tridecylbenzene. Phosphite, tris(2,4-dibutylphenyl)phosphite, tris(2,4-dibutyl-5-methylphenyl)phosphite, tris[2-t-butyl -4-(3-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tris(2,4-di-t-butylphenyl)phosphite Ester, tridecyl phosphite, octyl diphenyl phosphite, bis(indenyl)monophenylphosphite, ditridecylpentaerythritol diphosphite, bis(nonylphenyl) Pentaerythritol diphosphite, bis(2,4-dibutylphenyl)pentaerythritol diphosphite, bis(2,6-dibutyl-4-methylphenyl)pentaerythritol diphosphite, bis ( 2,4,6-tributylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetrakis(tridecyl)isopropylidene diphenol II Phosphite, tetrakis(tridecyl)-4,4'-n-butylene bis(2-butyl-5-methylphenol) diphosphite, hexakis(tridecyl)-1,1, 3-tris(2-methyl-4-hydroxy-5-butyl Phenyl)butane triphosphite, tetrakis(2,4-dibutylphenyl)biphenyldiphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Oxide, 2,2'-methylenebis(4,6-butylphenyl)-2-ethylhexylphosphite, 2,2'-methylenebis(4,6-butylphenyl )-octadecyl phosphite, 2,2'-ethylenebis(4,6-dibutylphenyl)fluorophosphite, three (2-[(2,4,8,10-four) Butyl dibenzo[d,f][1,3,2] Phosphorhyl-6-yl)oxy]ethyl)amine, 2-ethyl-2-butylpropanediol and phosphite of 2,4,6-tributylphenol.

Examples of the sulfur compound include, for example, dodecyl 3,3'-thiopropionate, dilauryl 3,3'-thiodipropionate, and lauryl thiodithionate. , 3,3'-ditridecyl thiodipropionate, 3,3'-thiodipropionate dimyristyl ester, 3,3'-thiodipropionate distearyl ester, Tetra-methylene-3-laurylthiopropionate methane, distearyl-3,3'-methyl-3,3'-thiodipropionate, lauryl stearyl-based 3,3'-thiodipropionate, bis[2-methyl-4-(3-n-alkylthiopropoxy)-5-tert-butylphenyl] sulfide, β-lauric Thiopropionate, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, dioctadecyl-3,3'-thiodipropionate, and the like.

Among them, from the viewpoint of maintaining excellent adhesion and retention, and further improving yellowing resistance after heat exposure, it is preferred to use a phosphorus compound, and more preferably, it is selected from triphenylphosphine and bis (2, One or more antioxidants of 4-di-tert-butyl-6-methylphenyl)ethyl phosphite and tris(2,4-di-t-butylphenyl) phosphite are particularly preferably used. Triphenylphosphine, bis(2,4-di-t-butyl-6-methylphenyl)ethyl phosphite.

The amount of the antioxidant (E) to be used and the mass ratio [(D)/(E)] of the light stabilizer (D) must be in the range of 95/5 to 5/95, and in the case where the above range is exceeded Can't get Resistant to yellowing. In addition, the mass ratio is more preferably in the range of 80/20 to 20/80, and still more preferably in the range of 70/30 to 30/70, from the viewpoint of further improving heat-resistant yellowing and light-resistant yellowing.

Hereinafter, the resin composition for an ultraviolet curable adhesive of the present invention will be described.

The resin composition for an ultraviolet curable adhesive of the present invention can be produced, for example, by a method such as, after separately producing a polyurethane (meth) acrylate resin (A), a (meth)acrylic acid single a method of mixing the body (B), the photopolymerization initiator (C), the light stabilizer (D), and the antioxidant (E); or in the presence of a part or all of the (meth)acrylic monomer (B), A method of producing a polyurethane (meth) acrylate resin (A) and mixing a polymerization initiator (C), a light stabilizer (D), and an antioxidant (E).

The resin composition for the ultraviolet curable adhesive obtained by the above method is not particularly limited, but is preferably 500 to 20,000 mPa from the viewpoint of good coatability and good handling of the adhesive solution at the time of application. The range of ‧ s is more preferably in the range of 1,000 to 15,000 mPa ‧ s, and in order to further improve the followability of the height difference, it is preferably in the range of 5,000 to 10,000 mPa ‧ s Further, the above viscosity means a value measured by a B-type viscometer at 25 °C.

Further, the resin composition for an ultraviolet curable adhesive of the present invention may contain other additives in addition to the above substances.

As the above other additives, for example, a rust inhibitor, a thixotropic agent, a sensitizer, a polymerization inhibitor, a hardener, a hardening accelerator, a leveling agent, a tackifier, a wax, a heat stabilizer, an antistatic agent can be used. , flame retardant, foam stabilizer, antifoaming agent, preservative, anti-blocking agent, decane coupling agent, etc.

Further, the resin composition for an ultraviolet curable adhesive of the present invention may be the above-mentioned polyurethane (meth)acrylate resin (A), the above (meth)acrylic monomer (B), and the above photopolymerization initiator. (C), a light stabilizer (D), an antioxidant (E), and other additives as described above, which are dissolved or dispersed in a solvent such as an organic solvent or an aqueous medium, however, In the above (meth)acrylic monomer (B), a composition obtained by dissolving or dispersing the above-mentioned polyurethane (meth)acrylate resin (A), the photopolymerization initiator (C), or the like is When the laminate is bonded to produce a laminate, the step of removing the solvent contained in the binder is not required, and the production efficiency of the laminate can be improved, which is preferable.

The resin composition for an ultraviolet curable adhesive of the present invention can be cured by irradiation with energy rays such as ultraviolet rays.

As a method of curing the resin composition for an ultraviolet curable adhesive of the present invention, for example, a predetermined ultraviolet light irradiation device such as a xenon lamp, a xenon-mercury lamp, a metal halide lamp, a high pressure mercury lamp, or a low pressure mercury lamp can be used to illuminate the regulation. The ultraviolet rays harden it.

The ultraviolet irradiation is preferably from 0.05 ~ 5J / cm ^2, more preferably 0.1 ~ 3J / cm ^2, particularly preferably in a range of 0.3 ~ 1.5J / cm ² of. Further, the amount of ultraviolet irradiation was measured based on a value measured using an illuminometer "UV Power Pak PP2000" (UV-A (320 to 390 nm)) manufactured by EIT Corporation.

Further, when the resin composition for an ultraviolet curable adhesive of the present invention contains the above-described other additives, it may be further heated by heating at about 40 to 80 ° C after the ultraviolet rays are irradiated as needed. Promotes hardening.

The base material which can form the adhesive layer by coating the resin composition for ultraviolet-ray-curing adhesives of this invention is a plastic base material, a flexible printing base material, glass substrate, and vapor-deposited on these base materials. A substrate having ITO or the like.

Examples of the plastic substrate include a base material composed of an acrylic resin or the like which is generally used, PC (polycarbonate), PBT (polybutylene terephthalate), and PPS (polyphenylene sulfide). PPE (polyphenylene ether), PET (polyethylene terephthalate), COP (cycloolefin polymer), TAC (triethylene cellulose), anti-reflection film or sheet, antifouling film or sheet, A film or sheet of a transparent conductive film constituting the touch panel.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples.

[Synthesis Example 1]

<Synthesis of Polyurethane Acrylate Resin (A-1)>

To a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 706 parts by mass of a polycarbonate polyol ("Duranate T5652", manufactured by Asahi Kasei Chemicals Co., Ltd., number average molecular weight: 2,000), 1,4-butyl 8.0 parts by mass of a diol, 13.6 parts by mass of 2-hydroxyethyl acrylate, 2 parts by mass of 2,6-di-t-butyl-cresol, and 0.3 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 97 parts by mass of isophorone diisocyanate was added. Then, 0.1 part by mass of dioctyltin dicaptanate was added, and it was heated to 80 ° C for 1 hour. Thereafter, the mixture was kept at 80 ° C for 12 hours, and it was confirmed that all the isocyanate groups disappeared, and then cooled to obtain a polyurethane acrylate resin (A-1). The equivalent weight of the acrylonitrile group of the obtained polyurethane acrylate resin (A-1) was 7039 (the decimal point was rounded off. The molecular weight of 2-hydroxyethyl acrylate was 116.1. The same applies hereinafter), and the weight average molecular weight was 22,000.

[Synthesis Example 2]

<Synthesis of Polyurethane Acrylate Resin (A-2)>

To a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, and a thermometer, 460 parts by mass of polytetramethylene glycol (number average molecular weight: 1,000), 6.5 parts by mass of 2-hydroxyethyl acrylate, and 2,6-di 2 parts by mass of tributyl-cresol and 0.3 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 105 parts by mass of isophorone diisocyanate was added. Then, 0.1 part by mass of dioctyltin dicaptanate was added, and it was heated to 80 ° C for 1 hour. Thereafter, the mixture was kept at 80 ° C for 12 hours, and it was confirmed that all the isocyanate groups disappeared, and then cooled to obtain a polyurethane acrylate resin (A-2). The obtained urethane acrylate resin (A-2) had an acrylonitrile group equivalent of 10,208 and a weight average molecular weight of 26,000.

[Synthesis Example 3]

<Synthesis of Polyurethane Acrylate Resin (A-3)>

Add to a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer 465 parts by mass of polycarbonate polyol ("Duranate T5651", manufactured by Asahi Kasei Chemicals Co., Ltd., number average molecular weight: 1,000), 9.5 parts by mass of 2-hydroxyethyl acrylate, and 2,6-di-t-butyl-cresol 2 And 0.3 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 102 parts by mass of isophorone diisocyanate was added. Then, 0.1 part by mass of dioctyltin dicaptanate was added, and it was heated to 80 ° C for 1 hour. Thereafter, the mixture was kept at 80 ° C for 12 hours, and it was confirmed that all of the isocyanate groups disappeared, and then cooled to obtain a polyurethane acrylate resin (A-3). The obtained urethane acrylate resin (A-3) had an acrylonitrile group equivalent of 7,045 and a weight average molecular weight of 20,000.

[Synthesis Example 4]

<Synthesis of Polyurethane Acrylate Resin (A-4)>

To a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, and a thermometer, 470 parts by mass of polytetramethylene glycol (number average molecular weight: 1,000), 9.5 parts by mass of 2-hydroxyethyl acrylate, and 2,6-di 2 parts by mass of tributyl-cresol and 0.3 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 102 parts by mass of isophorone diisocyanate was added. Then, 0.1 part by mass of dioctyltin dicaptanate was added, and it was heated to 80 ° C for 1 hour. Thereafter, the mixture was kept at 80 ° C for 12 hours, and it was confirmed that all of the isocyanate groups disappeared, and then cooled to obtain a polyurethane acrylate resin (A-4). The obtained urethane acrylate resin (A-4) had an acrylonitrile group equivalent of 7,107 and a weight average molecular weight of 19,000.

[Example 1]

To a vessel equipped with a stirrer, a reflux condenser, and a thermometer, 100 parts by mass of a polyurethane acrylate resin (A-1) synthesized by the above-described method, 70 parts by mass of butyl acrylate, and an acryl ring were added to a vessel at a temperature of 80 ° C. 35 parts by mass of the ester was stirred until uniform. Thereafter, it was cooled to room temperature, and 4 parts by mass of 2,4,6-trimethylbenzimidyldiphenylphosphine oxide was added under stirring, and bis(1,2,2,6,6-pentamethyl- 0.5 parts by mass of 4-piperidinyl) sebacate and 1.5 parts by mass of triphenylphosphine were stirred until uniform. Thereafter, the mixture was filtered through a 200-mesh metal net to obtain a resin composition for an ultraviolet curable adhesive.

[Examples 2 to 6 and Comparative Examples 1 to 2]

The type of the polyurethane acrylate resin to be used, the type of the (meth)acrylic monomer, and The amount of the photopolymerization initiator, the type and amount of the photostabilizer, and the type and amount of the antioxidant were changed as shown in Table 1, except that the ultraviolet curable adhesive was obtained in the same manner as in Example 1. Resin composition.

[Method for measuring weight average molecular weight]

The weight average molecular weight of the polyol and the polyurethane acrylate resin used in the examples and/or comparative examples was measured by a gel permeation chromatography (GPC) method under the following conditions.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)

Chromatography column: The following chromatography columns manufactured by Tosoh Corporation were used in series.

"TSKgel G5000" (7.8mmI.D.×30cm) × 1

"TSKgel G4000" (7.8mmI.D.×30cm) × 1

"TSKgel G3000" (7.8mmI.D.×30cm) × 1

"TSKgel G2000" (7.8mmI.D.×30cm) × 1

Detector: RI (differential refractometer)

Column temperature: 40 ° C

Eluent: tetrahydrofuran (THF)

Flow rate: 1.0 mL/min

Injection amount: 100 μL (sample concentration 0.4% by mass in tetrahydrofuran solution)

Standard sample: A calibration curve was prepared using the standard polystyrene described below.

(standard polystyrene)

"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene A-1000" made by Tosoh Corporation

"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene A-5000" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-1" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-2" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-4" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-10" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-20" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-40" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-80" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-128" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-288" made by Tosoh Corporation

"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[How to make adhesive film]

The surface of the 50 μm-thick polyethylene terephthalate film (release PET 50) which had been subjected to release treatment on the surface was applied in the examples and comparative examples so that the film thickness after ultraviolet irradiation was 175 μm. The resin composition for the ultraviolet curing adhesive is bonded to the release PET 50. Thereafter, UV irradiation was carried out so that the cumulative light amount of the wavelength of the UV-A region after the release of the PET 50 was 1 J/cm ² by the UV irradiation device, thereby forming an adhesive film.

[Method for measuring adhesion]

One surface of the adhesive film produced by the above method was bonded to a polyethylene terephthalate film (PET75) having a thickness of 75 μm to form an adhesive film having a PET75 substrate bonded to one surface. This was cut into a width of 25 mm, and the obtained material was used as a test piece. The test piece was attached to a glass plate or a polycarbonate (PC) plate as a adherend, respectively, by reciprocating 2 kg rolls x 2 times. After attaching for 1 hour, the 180-degree peel strength was measured in an environment of 23 ° C and 50% RH as a bonding force.

[Measurement method of retention force]

The test piece produced by the same method as the test piece used in the above-mentioned measurement method of the adhesive force was laminated on the mirror-processed stainless steel plate so that the adhesive area thereof was 25 mm × 25 mm, by 50% at 23 ° C. The 2 kg rolls were reciprocated twice in an RH environment and they were bonded together.

Then, in a test piece attached to the above stainless steel plate in an environment of 70 ° C, a load of 500 g was applied in the 0° direction (shear direction) with respect to the above stainless steel plate, and the test piece was measured from the stainless steel plate. The time before the slip is set, and the holding time is set as the holding force.

[Method for measuring initial yellowing degree (b*)]

The adhesive film prepared by the above method was attached to a glass plate, and then one release PET 50 was peeled off, and the obtained material was used as a test piece. In the test piece, the initial yellowing degree (B*) was measured in accordance with JIS K 7105 using a light source C, a field of view of 2°, and a "split spectrophotometer" CM-5000d (manufactured by Konika Minolta Sensing Co., Ltd.).

[Method for measuring light yellowing resistance (b*(UV))]

The adhesive film prepared by the above method was attached to a glass plate, and then one release PET 50 was peeled off, and the obtained material was used as a test piece. The test piece was allowed to stand under the conditions of a UV carbon arc lamp, a black panel temperature of 63 ° C, and a UV fading meter "U48AU" (manufactured by Suga Test Instruments Co., Ltd.) for 250 hours and 500 hours in accordance with JIS A 1415. Thereafter, the light yellowing resistance (b*(UV)) was measured in accordance with JIS K 7105 in the same manner as the above method.

[Heat resistance yellowing degree (measurement method of b* (heat)]

The adhesive film prepared by the above method was attached to a glass plate, and allowed to stand in an environment of 85 ° C × 85% RH for 250 hours and 500 hours. Thereafter, one release of the release PET 50 was peeled off, and the heat yellowing resistance (b* (heat)) was measured in accordance with JIS K 7105 in the same manner as the above-described method.

Moreover, the translated words in Table 1 are explained.

BA: butyl acrylate

ACMO: Acrylate Porphyrin

DMAA: dimethyl methacrylate

CHA: cyclohexyl acrylate

C-1: 2,4,6-trimethylbenzimidyldiphenylphosphine oxide

C-2: 2-hydroxy-2-methyl-1-phenylpropan-1-one

Tinuvin 765: bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate

Tinuvin 123: bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) sebacate

Tinuvin 622LD: dimethyl succinate / 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate

TPP: triphenylphosphine

Irgafos 38: bis(2,4-di-t-butyl-6-methylphenyl)ethyl phosphite

Irganox 1035; 2,2'-thiodiethylbis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]

It is understood that the adhesive obtained by using the resin composition for an ultraviolet curable adhesive of the present invention is excellent in adhesion, initial yellowing, yellowing resistance, and heat yellowing resistance.

On the other hand, Comparative Example 1 was found to be in an aspect containing no antioxidant, and particularly, it was resistant to light yellowing and poor heat-resistant yellowing.

Further, it was found that Comparative Example 2 is a state in which no light stabilizer is contained, and particularly, it is resistant to light yellowing and heat yellowing.

Claims (6)

A resin composition for an ultraviolet curable adhesive, comprising a polyurethane obtained by reacting a polyol (a) with a polyisocyanate (b) and a (meth)acrylic compound (c) having a hydroxyl group ( The resin composition for the ultraviolet curable adhesive of the methyl acrylate resin (A), the (meth)acrylic monomer (B), and the photopolymerization initiator (C) is also 95 in terms of mass ratio. The light stabilizer (D) and antioxidant (E) are included in the range of /5~5/95. The resin composition for an ultraviolet curable adhesive according to the first aspect of the invention, wherein the light stabilizer (D) is an N-alkyl hindered amine compound. The resin composition for an ultraviolet curing adhesive according to the second aspect of the invention, wherein the N-alkyl hindered amine compound is selected from the group consisting of bis(1,2,2,6,6-pentamethyl- 4-piperidinyl) sebacate and dimethyl succinate ‧ 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate One or more of the groups. The resin composition for an ultraviolet curing adhesive according to the first aspect of the invention, wherein the antioxidant (E) is a phosphorus compound. The resin composition for an ultraviolet curing adhesive according to claim 4, wherein the phosphorus compound is selected from the group consisting of triphenylphosphine and bis(2,4-di-t-butyl-6-methylbenzene). One or more of the group consisting of ethyl group = phosphite and tris(2,4-di-t-butylphenyl) phosphite. An adhesive which is obtained by using a resin composition for an ultraviolet curable adhesive according to any one of claims 1 to 5 of the invention.