TW201529784A - Ultraviolet curable adhesive composition, adhesive film and method for producing adhesive film - Google Patents

Abstract

The present invention addresses the problem of providing an ultraviolet curable adhesive composition which is capable of providing an adhesive film that has excellent cutting properties and resistance to wet heat whitening. The present invention provides an ultraviolet curable adhesive composition which is characterized by containing: a urethane (meth)acrylate (A) that is obtained by reacting a polyol (a1) that contains a polycarbonate polyol (a1-1), a polyisocyanate (a2) and a (meth)acrylic compound (a3) having an isocyanate group or a hydroxyl group; a (meth)acrylic compound (B) that has two or more (meth)acryloyl groups; a photopolymerization initiator (C); and an organic solvent (D). The present invention also provides a method for producing an adhesive film which is characterized in that an adhesive film is obtained by: applying the above-described ultraviolet curable adhesive composition to a base; then drying the organic solvent (C) so as to obtain an ultraviolet curable adhesive film; and subsequently bonding an adhesive layer of the ultraviolet curable adhesive film to the base and irradiating the ultraviolet curable adhesive film with ultraviolet light after the bonding.

Description

Ultraviolet curing adhesive composition, adhesive film and adhesive film manufacturing method

The present invention relates to an ultraviolet curable adhesive composition which can provide an adhesive film which is excellent in cuttability and wet heat whitening resistance.

Unlike the conventional solvent-based adhesives or water-based adhesives, the ultraviolet-curable adhesives are expected to have high productivity because they do not require aging time. Therefore, attention has been paid to applications such as bonding of optical members.

As the ultraviolet curable adhesive, for example, an adhesive obtained by using a solventless adhesive composition containing urethane acrylate, an acrylic monomer, and a photopolymerization initiator is known (for example, reference) Patent Document 1.).

The adhesive has the following advantages: the ultraviolet ray hardens and then exhibits adhesiveness, thereby having excellent high productivity; and the film thickness of the adhesive layer is easier than that of the conventional adhesive. It can be expected to be highly functional and the like.

However, when the film of the adhesive layer is thickened, there are many cases in which the internal hardenability of the film is insufficient, and there may be a problem that residual glue is generated on the cutting machine when the adhesive film is cut, or In the case of long-term use under wet heat conditions, there may be problems such as whitening. [Prior Technical Literature] [Patent Literature]

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

[The problem that the invention wants to solve]

The problem to be solved by the present invention is to provide an ultraviolet curable adhesive composition which can obtain an adhesive film which is excellent in cuttability and wet heat whitening resistance. [Means for solving problems]

The present invention provides an ultraviolet curable adhesive composition, and an adhesive film obtained therefrom, wherein the ultraviolet curable adhesive composition is characterized by ethyl urethane (meth) acrylate (A), a (meth)acrylic compound (B) having two or more (meth)acrylinyl groups, a photopolymerization initiator (C), and an organic solvent (D); the ethyl urethane (methyl) The acrylate (A) reacts a polyol (a1) containing a polycarbonate polyol (a1-1), a polyisocyanate (a2), and a (meth)acrylic compound (a3) having an isocyanate group or a hydroxyl group. Got it.

Moreover, the present invention provides a method for producing an adhesive film, which is characterized in that the ultraviolet curable adhesive composition is applied to a substrate, and then the organic solvent (D) is dried to obtain an ultraviolet curable adhesive film. Then, the adhesive layer of the ultraviolet curable adhesive film is attached to the substrate, and then obtained by ultraviolet irradiation. [Effects of the Invention]

The adhesive film obtained by the ultraviolet curable adhesive composition of the present invention is excellent in cuttability even if it is cut without residue. In addition, it is difficult to whiten when used for a long time under humid heat conditions. Further, when this specific manufacturing method is used, an adhesive film having a higher level of adhesion and higher adhesion can be obtained.

Therefore, the ultraviolet curable adhesive composition of the present invention can be suitably used as an adhesive used in an optical member, and can be suitably used in, for example, a touch panel, a liquid crystal display, a plasma display, an organic EL, Manufacture of IT-related products such as personal computers and mobile phones.

The ultraviolet curable adhesive composition of the present invention contains an ethyl urethane (meth) acrylate (A), a (meth) acryl compound (B) having two or more (meth) acryl fluorenyl groups, a photopolymerization initiator (C), and an organic solvent (D); the urethane (meth) acrylate (A) is a polyol (a1) containing a polycarbonate polyol (a1-1), The polyisocyanate (a2) and a (meth)acrylic compound (a3) having an isocyanate group or a hydroxyl group are obtained by reaction.

As the polycarbonate polyol (a1-1), for example, a carbonate and/or phosgene can be used, and a compound having two or more hydroxyl groups is reacted.

As the carbonate, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonate, diphenyl carbonate or the like can be used. These carbonates may be used singly or in combination of two or more.

Further, as the compound having two or more hydroxyl groups, for example, ethylene glycol, diethylene glycol, triethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propanediol, dipropylene glycol can be used. , tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexane Alcohol, 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- An aliphatic polyol such as propylene glycol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol or 2-methyl-1,8-octanediol; 1,2- An alicyclic polyol such as cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanedimethanol, cycloheptanediol, cyclooctanediol, hydroxypropylcyclohexanol; bisphenol A An aromatic polyol such as bisphenol F or 4,4'-bisphenol. These compounds may be used singly or in combination of two or more. As a compound having two or more hydroxyl groups, it is preferable to use an aliphatic polyhydric alcohol and/or an alicyclic polyhydric alcohol from the viewpoint of further improving the cutting property, and it is selected from 1,4-butanediol. One or more compounds selected from the group consisting of 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol are more preferable.

The number average molecular weight of the polycarbonate polyol (a1-1) is preferably in the range of 500 to 5,000 and 600 to 3,000 in view of further improving the cutting property, the wet heat whitening property, and the adhesive property. Better, the range of 700~2,000 is even better. Further, the number average molecular weight of the polycarbonate polyol (a1-1) is represented by a value 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 column manufactured by Tosoh Corporation was 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 Mobile phase: tetrahydrofuran (THF) Flow rate: 1.0 mL / min Injection volume: 100 μL ( A sample concentration of 0.4% by mass in tetrahydrofuran) Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard Polystyrene) "TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation" TSKgel Standard Polystyrene A-1000 manufactured by Tosoh Corporation" Tosoh Corporation Limited "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation" TSKgel Standard Polymer manufactured by Tosoh Corporation Styrene F-1" "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation. "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation. Tosoh Corporation Limited "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation" TSKgel Standard Polymer manufactured by Tosoh Corporation Styrene F-40" "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation" TSKgel standard manufactured by Tosoh Corporation Polystyrene F-128" "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation. "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

The amount of the polycarbonate polyol (a1-1) to be used is preferably in the range of 10 to 60% by mass in view of further improving the cutting property and the moist heat whitening property. .

In addition to the polycarbonate polyol (a1-1), the polyhydric alcohol (a1) preferably contains a polyether polyol from the viewpoint of further improving wet heat whitening resistance, cutting property, and adhesive property. A1-2) is ideal.

For the polyether polyol (a1-2), for example, one or two or more kinds of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide may be added to the compound having two or more hydroxyl groups. a product obtained by polymerization; a polytetrahydrofuran obtained by ring-opening polymerization of tetrahydrofuran; a modified polytetrahydrofuran obtained by copolymerizing tetrahydrofuran with an alkyl-substituted tetrahydrofuran; and a modification obtained by copolymerizing neopentyl glycol and tetrahydrofuran. Polytetrahydrofuran and the like. These polyether polyols may be used singly or in combination of two or more. Among these, in view of further improving the adhesion property, the height difference dependency, and the moist heat whitening resistance, it is preferable to use one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran. More than one type of polyether polyol is preferred.

The number average molecular weight of the polyether polyol (a1-2) is preferably in the range of 200 to 5,000 from the viewpoint of further improving the adhesion property and the dependency of the height difference. In addition, the number average molecular weight of the polyether polyol (a1-2) is a value measured in the same manner as the number average molecular weight of the polycarbonate polyol (a1-1).

As the mass ratio [(a1-1)/(a1-2)] of the polycarbonate polyol (a1-1) to the polyether polyol (a1-2), consideration of the cutting property, the adhesive property, and the resistance The viewpoint of wet heat whitening is preferably in the range of 10/90 to 90/10, and the range of 20/80 to 60/40 is better.

The polyol (a1) preferably contains the polycarbonate polyol (a1-1), and preferably contains the polyether polyol (a1-2), but may contain other polyols as needed.

As the other polyol, for example, a polyester polyol, a polybutadiene polyol, a hydrogenated polybutadiene polyol, a dimer diol, a polypropylene decyl polyol or the like can be used. These polyols may be used singly or in combination of two or more.

As the polyisocyanate (a2), for example, an aromatic polyisocyanate such as phenyldimethyl diisocyanate, phenyl diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate or naphthalene diisocyanate; hexamethylene diisocyanate or an amine can be used. Fats such as diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, tetramethyl dimethyl diisocyanate Group or alicyclic polyisocyanate, and the like. These polyisocyanates may be used singly or in combination of two or more. Among these, in view of the viewpoint of further improving the cutting property and the adhesive property, it is preferred to use an alicyclic polyisocyanate selected from 4,4'-dicyclohexylmethane diisocyanate, isophor. One or more kinds of polyisocyanates in the group consisting of keto diisocyanate, cyclohexane diisocyanate, and methylcyclohexane diisocyanate are more preferable.

The purpose of using the (meth)acrylic compound (a3) having an isocyanate group or a hydroxyl group is to introduce a (meth)acryl oxime group into the urethane (meth) acrylate (A).

As the (meth)acrylic compound having an isocyanate group which can be used as the compound (a3), for example, 2-(meth)acryloyloxyethyl isocyanate or 2-(2-(methyl) isocyanate can be used. ) propylene oxiranyloxy) ethyl ester, 1,1-bis((meth) propylene oxymethyl) ethyl isocyanate, and the like. These compounds may be used singly or in combination of two or more. Among these, from the viewpoint of easiness of obtaining raw materials, it is preferred to use 2-(meth)acryloyloxyethyl isocyanate, and from the viewpoint of curability, 2-acryloyloxyethyl isocyanate is used. good.

As the (meth)acrylic compound having a hydroxyl group which can be used as the compound (a3), for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or (meth)acrylic acid can be used. 3-hydroxypropyl ester, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyethyl acrylamide, etc. having a hydroxyl group ( Alkyl methacrylate; trimethylolpropyl bis(meth)acrylate, neopentyl tris(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc. Functional (meth) acrylate; polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, and the like. These compounds may be used singly or in combination of two or more. Among these, in view of ease of availability of raw materials, curability, and adhesive properties, it is preferred to use a (meth)alkyl acrylate having a hydroxyl group, and 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are used. Better.

When a (meth)acrylic acid compound having an isocyanate group is used as the compound (a3), as a method for producing the ethyl urethane (meth) acrylate (A), for example, the polyol can be used without a solvent ( A1) after the polyisocyanate (a2) is fed, by reacting it to obtain an urethane prepolymer having a hydroxyl group, and then supplying the (meth)acrylic compound (a3) having an isocyanate group, by A method of mixing, reacting, and the like. Any of the above reactions may, for example, be carried out at 20 to 120 ° C for 30 minutes to 24 hours.

When a (meth)acrylic compound having a hydroxyl group is used as the compound (a3), as the method for producing the ethyl urethane (meth)acrylate (A), for example, the polyol can be used without a solvent ( A1) a method in which the polyisocyanate (a2) is supplied after the (meth)acrylic compound (a3) is fed to a reaction system, and the mixture is produced by mixing and reacting; or in the absence of a solvent, The polyol (a1) is reacted with the polyisocyanate (a2) to obtain an urethane prepolymer having an isocyanate group, and then the (meth)acrylic compound (a3) having a hydroxyl group is supplied, by mixing, A method in which the reaction is carried out, and the like. Any of the above reactions can be carried out, for example, at 20 to 120 ° C for 30 minutes to 24 hours.

The production of the urethane (meth) acrylate (A) can also be carried out in the presence of an organic solvent (D) to be described later.

When a (meth)acrylic compound having a hydroxyl group is used as the compound (a3), the polyol (a1) and the polyisocyanate (a2) are reacted with the (meth)acrylic compound (a3) as in the polyol. (a1) The total amount of the hydroxyl group of the (meth)acrylic compound (a3) and the equivalent ratio of the isocyanate group of the polyisocyanate (a2) (the total amount of isocyanate groups/hydroxy groups) is When it is carried out in the range of 0.75 to 1, it is preferable to control the molecular weight of the ethyl urethane (meth) acrylate (A) obtained, and the range of 0.79 to 0.995 is more preferable. Further, when the equivalent ratio exceeds 1, the reaction can be carried out. However, in order to inactivate the isocyanate group of the urethane (meth)acrylate (A), it is preferred to use an alcohol such as methanol.

Further, when a (meth)acrylic compound having an isocyanate is used as the compound (a3), the reaction of the polyol (a1) with the polyisocyanate (a2) and the (meth)acrylic compound (a3) is as The equivalent ratio of the hydroxyl group of the polyol (a1) to the total isocyanate groups of the polyisocyanate (a2) and the (meth)acrylic compound (a3) [total amount of isocyanate groups / hydroxyl group] is 0.75 to 1 The range of the molecular weight of the urethane (meth) acrylate (A) obtained is preferably in the range of 0.79 to 0.995. Further, when the equivalent ratio exceeds 1, the reaction can be carried out. However, in order to inactivate the isocyanate group of the urethane (meth)acrylate (A), it is preferred to use an alcohol such as methanol.

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

As the polymerization inhibitor, for example, 3,5-di-tertiary butyl-4-hydroxytoluene, hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether (methoquinone), p-three can be used. Butyl catechol methoxyphenol, 2,6-di(tributyl) cresol, thiophene (phenothiazine), tetramethylammonium sulfide, diphenylamine, dinitrobenzene, and the like. These polymerization inhibitors may be used singly or in combination of two or more.

As the urethane catalyst, for example, triethylamine, triethylenediamine, and N-methyl can be used. A nitrogen-containing compound such as N-methylmorpholine; a metal salt such as potassium acetate, zinc stearate or tin octylate; an organic metal compound such as dibutyltin laurate or zirconium tetraacetylacetonate; These urethane catalysts may be used singly or in combination of two or more.

The urethane (meth) acrylate (A) is a (meth) acrylonitrile group which polymerizes a radical by light irradiation or heating. In view of the (meth) acrylonitrile base equivalent of the urethane (meth) acrylate (A), it is considered that the cutting property, the adhesive property, and the height difference dependency can be further improved. The range of 1,000 to 50,000 g/eq., and the range of 3,000 to 25,000 g/eq. is better. Further, the (meth) acrylonitrile group equivalent system is obtained by dividing the total mass of the polyol (a1) and the polyisocyanate (a2) and the (meth)acrylic compound (a3) by the presence of the urethane ( The value obtained by the equivalent of the (meth)acrylic group in the methyl (meth)acrylate (A).

Further, in the present invention, "(meth)acrylic compound" means one or both of a methacrylic compound and an acrylic compound, and "(meth)acrylate" means methyl acrylate and acrylate. One or both, "(meth)acrylylene" means one or both of a methacryloyl group and an acryloyl group, and "(meth)acrylic" means a methacrylic acid and an acrylic acid. One or both of them, "(meth)acrylic monomer" means one or both of a methacrylic monomer and an acrylic monomer.

As the mass ratio of the urethane bond in the ethyl urethane (meth) acrylate (A), it is considered to further improve the cutting property, the adhesive property, and the attachment of the height difference. The total amount of ethyl formate (meth) acrylate (A) is in the range of 4 to 20% by mass, and more preferably in the range of 5 to 15% by mass. Further, the amount of the urethane bond of the urethane (meth) acrylate (A) is expressed relative to the polyol (a1) and the polyisocyanate (a2) and the (meth) acrylate compound. The total mass of (a3) is the mass ratio of the urethane bond structure in the raw material.

The weight average molecular weight of the urethane (meth) acrylate (A) is preferably in the range of 5,000 to 100,000, and 15,000, in view of further improving the cutting property, the adhesive property, and the height difference. The range of ~50,000 is better. The weight average molecular weight of the urethane (meth) acrylate (A) is a value obtained by the same measurement as the number average molecular weight of the polycarbonate polyol (a1-1).

The (meth)acrylic compound (B) having two or more (meth)acrylonium groups is a component required to impart excellent wet heat whitening resistance. As the (meth)acrylic compound (a3), for example, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, and di(a) can be used. Trimethylol propyl acrylate, hexanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-decanediol di(meth)acrylate 1,10-decanediol di(meth)acrylate, trimethylolpropyl tri(meth)acrylate, pentaerythritol di(meth)acrylate, neopentyl tris(meth)acrylate Alcohol ester, neopentyl tetra(meth)acrylate, bis(trimethylolpropyl)di(meth)acrylate, bis(trimethylolpropyl)tri(meth)acrylate, four Bis(trimethylolpropyl)(meth)acrylate, dinekapentyl di(meth)acrylate, dipentaerythritol tris(meth)acrylate, disodium tetra(meth)acrylate Aliphatic polyfunctional (meth) acrylates such as pentaerythritol ester, pentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate; isocyanuric acid ginseng (2- Polyfunctional having an isocyanurate structure such as (meth)acryloyloxyethyl ester Base (meth) acrylate and the like. These (meth)acrylic compounds may be used singly or in combination of two or more. Among these, in view of the viewpoint of further improving the wet heat whitening resistance, it is preferred to use a polyfunctional group (methyl) selected from an aliphatic polyfunctional (meth) acrylate and an isocyanurate structure. One or more of the group consisting of acrylates is preferably selected from the group consisting of neopentyl glycol (meth)acrylate, neopentyl tetra(meth)acrylate, and isocyanuric acid (2). One or more (meth)acrylic compounds in the group consisting of -(meth)acryloyloxyethyl) ester are more preferable. Further, in the present invention, the "polyfunctional group" means having two or more (meth) acrylonitrile groups, preferably from 2 to 8, more preferably from 2 to 6.

The content of the (meth)acrylic acid compound (B) is preferably 1 to 100 parts by mass of the ethyl urethane (meth)acrylate (A) from the viewpoint of further improving the wet heat whitening resistance. The range of 30 parts by mass, and the range of 5 to 20 parts by mass is more preferable.

The photopolymerization initiator (C) generates a radical by light irradiation or heating, and the radical of the urethane (meth) acrylate (A) starts to polymerize.

As the photopolymerization initiator (C), for example, 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropanyl-1- can be used. Ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropanyl-1-one, 1-hydroxycyclohexyl phenyl ketone, 4-(2-hydroxyethoxy)-phenyl (2-hydroxy-2-propyl) ketone, 2-methyl-[4-(methylthio)phenyl]-2- Acetophenone compound such as morpholino-1-propanone, 2,2-dimethoxy-2-phenylacetophenone; benzoin, benzoin methyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzoin Benzoin compounds such as ether; benzophenone, benzamidine benzoic acid, methotrexate benzoic acid, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzylidene-4' a benzophenone compound such as methyl diphenyl sulfide or 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chloro-thioxanthone, 2, 4-Dichloro-thioxanthone, 2-methyl-thioxanthone, 2,4-dimethyl-thioxanthone, 2,4-diethyl-thioxanthone, isopropyl-thioxanthone, a thioxanthone compound such as 2,4-diisopropyl-thioxanthone; 4,4'-dimethylamine-thioxanthone (alias = Michler's ketone), 4,4'-diethylamine benzophenone, Α-acyloxime ester, benzil, methyl benzalkoniumcarboxylate (“Vicure 55”), anthracene compound such as 2-ethylhydrazine; 2, 4, Ruthenium phosphine oxide compound such as 6-trimethylbenzimidyl phosphine oxide or bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide 3,3 ', 4,4'-tetra (three-butylperoxy-carbonyl) benzophenone, acrylated benzophenone. These photopolymerization initiators may be used singly or in combination of two or more.

As the photopolymerization initiator (C), from the viewpoint of further improving the adhesion property and the curability, it is preferred to use a solvent selected from 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzimidyl diphenylphosphine oxide and bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide More than one photopolymerization initiator in the group, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide is more preferable.

The amount of use of the photopolymerization initiator (C) is preferably from 0.1 to 20 by mass based on 100 parts by mass of the ethyl urethane (meth) acrylate (A). The range of parts is preferably in the range of 0.2 to 15 parts by mass.

As the organic solvent (D), for example, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, hexane, acetone, cyclohexanone, 3-pentanone, acetonitrile, propionitrile, isobutyronitrile, or the like can be used. Valeronitrile, dimethyl hydrazine, dimethylformamide, and the like. These organic solvents may be used singly or in combination of two or more.

The amount of use of the organic solvent (D) is preferably 60% by mass or less, and more preferably 5 to 50% by mass in terms of the ultraviolet curable adhesive composition, from the viewpoint of further improving the drying property and the coating property. .

The ultraviolet curable adhesive composition of the present invention contains the urethane (meth) acrylate (A), the (meth) acrylate compound (B), and the photopolymerization initiator (C). The organic solvent (D) is an essential component, but may contain other additives as needed.

As such other additives, for example, a decane coupling agent, an antioxidant, a photostabilizer, a rust inhibitor, a thixotropic agent, a sensitizer, a polymerization inhibitor, a leveling agent, a tackifier, and an antistatic can be used. Agent, flame retardant, etc. These additives may be used singly or in combination of two or more. Among these, the ultraviolet curable adhesive composition of the present invention preferably contains a decane coupling agent (E) when it is used for applications requiring high adhesion properties after moist heat resistance. Further, when the ultraviolet curable adhesive composition of the present invention is used for applications requiring moisture and heat yellowing resistance, it is preferred to contain an antioxidant (F) and a light stabilizer (G).

As the decane coupling agent (E), for example, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethoxydecane, 3-glycidoxypropyl group can be used. a decane coupling agent having an epoxy group such as methyl diethoxy decane or 3-glycidoxy propyl methyl dimethoxy decane; 2-(3,4-epoxycyclohexyl)ethyltriethyl Oxydecane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxydecane, 2-(3, 4-epoxycyclohexyl)ethylmethyldiethoxydecane, 2-(3,4-epoxycyclohexyl)propyltrimethoxydecane, 2-(3,4-epoxycyclohexyl)propyl Methyldimethoxydecane, 2-(3,4-epoxycyclohexyl)propyltriethoxydecane, 2-(3,4-epoxycyclohexyl)propylmethyldiethoxydecane, etc. A decane coupling agent having an alicyclic epoxy group; vinyl trichlorodecane, vinyl trimethoxy decane, vinyl triethoxy decane, p-styryl trimethoxy decane, 3-methyl propylene methoxy propylene Methyldimethoxydecane, 3-methylpropenyloxypropyltrimethoxydecane, 3-methylpropenyloxypropylmethyldi Oxydecane, 3-methylpropenyloxypropyltriethoxydecane, 3-propenyloxypropyltrimethoxydecane, 3-mercaptopropylmethyldimethoxydecane, 3-mercaptopropane Trimethoxy decane, anthrone oxime alkoxy oligomer, and the like. These decane coupling agents may be used singly or in combination of two or more. Among these, in view of further improving the adhesion after moisture and heat resistance, it is preferred to use a decane coupling agent having an epoxy group and/or a decane coupling agent having an alicyclic epoxy group, which is selected from the group consisting of 2- (3,4-epoxycyclohexyl)ethyltriethoxydecane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-glycidoxypropyltrimethoxydecane Further, one or more kinds of decane coupling agents in the group consisting of 3-glycidoxypropyltriethoxydecane are more preferable.

In view of the amount of use of the decane coupling agent (E), it is preferable to further improve the adhesion after moisture heat resistance, and it is preferable to use 100 parts by mass of the urethane (meth) acrylate (A). In the range of 0.01 to 10 parts by mass, the range of 0.05 to 5 parts by mass is more preferable, and the range of 0.05 to 1 part by mass is more preferable.

As the antioxidant (F), a hindered phenol compound (primary antioxidant) which traps a radical generated by thermal deterioration, and a phosphorus compound or a sulfur compound which decomposes a peroxide generated by thermal deterioration can be used. (secondary antioxidant) and the like.

As the hindered phenol compound, for example, triethylene glycol ether-bis-[3-(3-tris-butyl-5-methyl-4-hydroxyphenyl)propionate], neopentyltetradecanoate can be used. [3-(3,5-di(tributyl)-4-hydroxyphenyl)propionate, octadecyl[3-(3,5-di(tri-butyl)-4-hydroxybenzene) Propionate, thiodiethyl bis[3-(3,5-di(tri-butyl)-4-hydroxyphenyl)propionate], phenylpropionic acid-3,5-bis (1) ,1-dimethylethyl)-4-hydroxy-C ₇ -C ₉ branched alkyl ester, 4,6-bis(dodecylthiomethyl)-o-cresol, N-phenylaniline and Reaction product of 2,4,4-trimethylpentene, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylbenzene Acrylate, 3,9-bis[2-[3-(tris-butyl-4-hydroxy-5-methylphenyl)propenyloxy]-1,1-dimethylethyl]2, 4,8,10-tetraoxaspiro[5.5]undecane (3,9-bis[2-[3-(t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro[5.5]undecane), 2,6-di(tributyl)-4-methylphenol, 2,2'-methylenebis(4-methyl-6- Tertiary butyl phenol), 2,5-di-p-pentyl hydroquinone, and the like. These compounds may be used singly or in combination of two or more.

As the phosphorus compound, for example, triphenylphosphine, bis(2,4-di(tributyl)-6-methylphenyl)phosphite, triphenyl phosphite, decyl phenyl phosphite can be used. , ginseng (2,4-dibutylphenyl) phosphite, ginseng (2,4-dibutyl-5-methylphenyl) phosphite, ginseng [2-tert-butyl-4-( 3-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, ginseng (2,4-di(tributyl)phenyl)phosphite, sub Tridecyl phosphate, octyl diphenyl phosphite, di(indenyl) monophenyl phosphite, ditridecyl neopentyl diphosphate, bis(indenyl) neopentyl Tetrahydrin diphosphite, bis(2,4-dibutylphenyl)neopentanol diphosphite, bis(2,6-dibutyl-4-methylphenyl)neopentanol Phosphite, bis(2,4,6-tributylphenyl)neopentanol diphosphite, bis(2,4-diisopropylphenyl)neopentanediol diphosphite, tetra ( Tridecyl)isopropylidenediphenol diphosphite, tetrakis(tridecyl)-4,4'-n-butylene bis(2-butyl-5-methylphenol) diphosphite, Hexatridecyl-1,1,3-glycol(2-methyl-4-hydroxy-5-butylphenyl)butane triphosphite, Bismuth(2,4-dibutylphenyl)biphenyl diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylene Bis(4,6-butylphenyl)-2-ethylhexyl phosphite, 2,2'-methylenebis(4,6-butylphenyl)-octadecylphosphite, 2 , 2'-ethylenebis(4,6-dibutylphenyl)fluorophosphite, ginseng (2-[(2,4,8,10-decylbutyldibenzo[d,f][ 1,3,2]dioxaphosphino-6-yl)oxy]ethyl)amine (tris(2-[(2,4,8,10-tetrakisbutyldibenzo[d,f][1,3, 2] dioxaphosphepin-6-yl)oxy]ethyl)amine), 2-ethyl-2-butylpropanediol and phosphite of 2,4,6-tributylphenol. These compounds may be used singly or in combination of two or more.

As the sulfur compound, for example, di(dodecyl)-3,3'-thiopropionate, dilauryl-3,3'-thiodipropionate, dilaurylthio disulfate can be used. Ester, di(tridecyl)-3,3'-thiodipropionate, bis-myristyl-3,3'-thiodipropionate, distearyl-3,3'-sulfur Dipropionate, 肆-methylene-3-lauryl thiopropionate methane, distearyl-3,3'-methyl-3,3'-thiodipropionate, lauryl Stearyl-3,3'-thiodipropionate, bis[2-methyl-4-(3-n-alkylthiopropoxy)-5-tert-butylphenyl] sulfide, --lauryl thiopropionate, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, di(octadecyl)-3,3'-thiodipropionate, and the like. These compounds may be used singly or in combination of two or more.

Among these, considering the viewpoint of further improving the adhesion and resistance to damp heat yellowing, it is preferred to use a phosphorus compound; the use is selected from triphenylphosphine, bis(2,4-di(tri-butyl)- More preferably one or more antioxidants in the group consisting of ethyl 6-methylphenyl)phosphite and ginseng (2,4-di(tributyl)phenyl)phosphite; using triphenylphosphine Further, ethyl bis(2,4-di(tributyl)-6-methylphenyl)phosphite is more preferred.

In view of the amount of use of the antioxidant (F), it is considered that the urethane (meth) acrylate (A) is preferably 0.01 to 100 parts by mass in terms of the heat-resistant heat yellowing resistance. The range of 10 parts by mass is ideal.

The light stabilizer (G) is a radical scavenger which is caused by photodegradation, and a radical scavenger such as a thiol compound, a thioether compound or a hindered amine compound; a benzophenone compound; An ultraviolet absorber such as a benzoate compound. These light stabilizers may be used singly or in combination of two or more. Among these, in view of further improving the resistance to wet heat yellowing, it is preferred to use a hindered amine compound.

As the hindered amine compound, for example, cyclohexane and N-butyl 2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro 1,3,5 can be used. a reaction product of a reaction product of triazine with 2-aminoethanol, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidyl) sebacate, 1, a hindered amine compound having an amine ether group such as a reaction product of 1-dimethylethyl hydroperoxide and octane; N-ethylindenyl-3-dodecyl-1-(2,2,6,6 -N-ethylhydrazine-based hindered amine compound such as tetramethyl-4-piperidyl)pyrrolidine-2,5-dione; bis(1,2,2,6,6-pentamethyl-4-piperidin Pyridyl) sebacate, bis(1,2,2,6,6,-pentamethyl-4-piperidinyl){[3,5-bis(1,1-dimethylethyl)- 4-hydroxyphenyl]methyl}malonic acid butyl ester, dimethyl succinate, 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensation N-alkyl hindered amine of [{4-methoxyphenyl}methylene]-bis(1,2,2,6,6-pentamethyl-4-piperidinyl) malonate Compounds, etc. These compounds may be used singly or in combination of two or more.

In view of the amount of use of the light stabilizer (G), it is considered that the urethane (meth) acrylate (A) is preferably 0.01 with respect to 100 parts by mass of the urethane (meth) acrylate (A). The range of ~10 parts by mass is ideal.

The viscosity of the ultraviolet curable adhesive composition of the present invention is preferably in the range of 500 to 30,000 mPa·s, and more preferably in the range of 1,000 to 20,000 mPa·s, from the viewpoint of coatability and workability. In addition, the viscosity indicates a value measured by a B-type viscometer at 25 °C.

Next, a method of producing the adhesive film of the present invention will be described.

The adhesive film is obtained by a step of drying the organic solvent (D) in the ultraviolet curable adhesive composition, and a step of curing the composition by irradiating ultraviolet rays.

In addition, as a method of producing the adhesive film, in view of obtaining an adhesive film having excellent adhesion with respect to height difference, it is preferable to apply the ultraviolet curable adhesive composition to a substrate, and then to use an organic solvent ( D) It is preferred to dry the ultraviolet-curable adhesive film, and then attach the adhesive layer of the ultraviolet-curable adhesive film to the substrate, and then obtain an adhesive film by ultraviolet irradiation. According to this method, when the ultraviolet curable adhesive film before the ultraviolet curing is used, if the height difference such as the printing height difference is used as the substrate to be attached later, the ultraviolet curable adhesive film can be used. The adhesive film is adhered without leaving a gap in the height difference, so that an adhesive film having excellent height difference and low adhesion can be obtained.

Further, in the present invention, the state after drying the organic solvent and before the ultraviolet curing is referred to as "ultraviolet curing type adhesive film"; and the state after ultraviolet curing is referred to as "adhesive film".

As the substrate, for example, a plastic substrate, a flexographic printed substrate, a glass substrate, a substrate subjected to release treatment on the substrates, or an evaporated ITO (oxidation) can be used. A substrate such as indium tin). In addition, the same substrate may be used on both sides of the adhesive layer, and different substrates may be used.

As the plastic substrate, for example, acrylic resin, PC (polycarbonate), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), modified PPE (polyphenylene ether) can be used. ), PET (polyethylene terephthalate), COP (cycloolefin polymer), TAC (triethylene fluorene cellulose), etc., as a raw material, a plastic film, an anti-reflection film, an anti-fouling film, and a touch control A film of a transparent conductive film of a panel or the like.

The method of applying the ultraviolet curable adhesive composition to the substrate may, for example, be a coating method using a coater, a roll coater, a knife coater, a gravure coater or the like. . After the coating, the obtained laminate is placed in a dryer or the like, and dried at a temperature of 50 to 130 ° C for 1 to 30 minutes to dry the organic solvent (D), whereby ultraviolet rays before ultraviolet curing can be obtained. Hardened adhesive film.

As the ultraviolet curable adhesive film, in view of further improving the dependency of the height difference, the storage elastic modulus at 60 ° C measured at a frequency of 1 Hz is preferably 5 × 10 ⁴ Pa or less, 1 The range of ×10 ³ to 5 × 10 ⁴ Pa is more preferable. Moreover, the method of measuring the storage elastic modulus of the ultraviolet curable adhesive film is described in the examples.

In addition, as the ultraviolet curable adhesive film, it is considered that the storage elastic modulus at 30 ° C measured at a frequency of 1 Hz is preferably 5 × 10 ⁴ Pa or more in view of further improving the cutting property and the dependency of the height difference. The range of 5 × 10 ⁴ ~ 5 × 10 ⁶ Pa is more preferable.

After the obtained ultraviolet curable adhesive film is attached to the substrate, the two are pressure-bonded, and an autoclave treatment may be applied as needed.

After that, an adhesive film can be obtained by ultraviolet irradiation. Examples of the ultraviolet irradiation method include a known 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. method.

As the ultraviolet irradiation amount is suitably 0.05 ~ 5J / cm ² is desirable, 0.1 ~ 3J / cm ² more preferably, particularly preferably the range of 0.3 ~ 1.5J / cm ² of. In addition, the amount of ultraviolet light irradiation was measured using a UV detector "UVR-N1" manufactured by GS Yuasa International Ltd., and a value measured in a wavelength range of 300 to 390 nm was used as a reference.

The thickness of the adhesive film obtained by the above method can be appropriately determined depending on the use for use, but it is preferably in the range of 10 to 500 μm.

Further, as the adhesive film, in view of further improving the cutting property, the storage elastic modulus at 30 ° C measured at a frequency of 1 Hz is preferably 1 × 10 ⁴ Pa or more, 1 × 10 ⁴ to 5.0 × 10 ⁷ The range of Pa is better. Moreover, the measuring method of the storage elastic modulus of this adhesive film is described in the Example.

Further, as the adhesive film, in view of further improving the attachment of the height difference, the storage elastic modulus at 100 ° C measured at a frequency of 1 Hz is preferably 1 × 10 ⁴ Pa or more, 1 × 10 ⁴ - 5 . The range of ×10 ⁵ Pa is better. Moreover, the measuring method of the storage elastic modulus of this adhesive film is described in the Example.

As described above, the adhesive film obtained by using the ultraviolet curable adhesive composition of the present invention is excellent in cuttability even if it is cut without residue. Further, in the case of using this specific production method, an adhesive film having a higher level of adhesion and higher adhesion can be obtained.

Therefore, the ultraviolet curable adhesive composition of the present invention can be suitably used as an adhesive used in an optical member, and is particularly applicable to a touch panel, a liquid crystal display, a plasma display, an organic electroluminescence, a personal computer. , the manufacture of IT related products such as mobile phones. [Examples]

Hereinafter, the present invention will be described in more detail using examples.

[Synthesis Example 1] <Synthesis of urethane acrylate (A-1)> In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas introduction tube, and a thermometer, 46.4 parts by mass of polypropylene glycol was added (the number average molecular weight was 2,000, hereinafter referred to as "PPG2000".), 38.1 parts by mass of polycarbonate polyol ("ETERNACOLL UM-90 (3/1)" manufactured by Ube Industries, Ltd., 1 , a reaction product of 4-dimethylcyclohexane, 1,6-hexanediol and dimethyl carbonate, having a number average molecular weight of 900, hereinafter abbreviated as "UM-90"., 0.8 parts by mass of 2- Hydroxyethyl acrylate (hereinafter abbreviated as "HEA"), 0.3 parts by mass of 2,6-di(tributyl)cresol, and 0.05 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 14.7 parts by mass of isophorone diisocyanate (hereinafter abbreviated as "IPDI") was added. At this time, 0.1 part by mass of dioctyltin dicaprate was added, and the temperature was raised to 80 ° C over 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 the urethane acrylate (A-1) was obtained by cooling. The equivalent weight of the obtained urethane acrylate (A-1)-based fluorenyl group was 15,000 (rounded to a significant number of 2 digits. The molecular weight of 2-hydroxyethyl acrylate was 116.1. The same applies hereinafter.), weight The average molecular weight is 26,000.

[Synthesis Example 2] <Synthesis of Ethyl Formate Ethyl Acrylate (A-2)> In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas introduction tube, and a thermometer, 33.7 parts by mass of PPG 2000 and 28.1 parts by mass were added. Tetrahydrofuran (number average molecular weight: 650, hereinafter abbreviated as "PTMG650"), 16.0 parts by mass of polyethylene glycol (number average molecular weight: 400, hereinafter abbreviated as "PEG400"), 0.55 parts by mass of HEA, 0.3 parts by mass 2,6-di(tributyl) cresol, 0.05 parts by mass of p-methoxyphenol. After the temperature in the reaction vessel was raised to 40 ° C, 22.2 parts by mass of IPDI was added. At this time, 0.1 part by mass of dioctyltin dicaprate was added, and the temperature was raised to 80 ° C over 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 the urethane acrylate (A-2) was obtained by cooling. The obtained urethane acrylate (A-2)-based acrylonitrile group had an equivalent weight of 21,000 and a weight average molecular weight of 28,000.

[Example 1] <Preparation of ultraviolet curable adhesive composition> A reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer was heated to a temperature of 80 ° C in the vessel, and 100 parts by mass of the aforementioned urethane acrylic acid was added. The ester (A-1) and 67 parts by mass of ethyl acetate were stirred until homogeneous. Thereafter, the mixture was cooled to room temperature, and 10 parts by mass of a mixture of neopentyl glycol triacrylate and neopentyl glycol tetraacrylate was added in this order under stirring (Toagosei Co., Ltd.) ARONIX M-305", hereinafter abbreviated as "(B-1)".), 0.5 parts by mass of 2,4,6-trimethylbenzimidyldiphenyl-phosphine oxide (hereinafter abbreviated as "(C- 1)"), 0.5 parts by mass of bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidyl) sebacate, 0.5 parts by mass of triphenylphosphine Stir until uniform. Thereafter, the mixture was filtered through a 200 mesh metal mesh to obtain an ultraviolet curable adhesive composition.

[Example 2] The same procedure as in Example except that (2-propenyloxyethyl) isocyanurate (hereinafter abbreviated as "(B-2)") was used instead of (B-1) The ultraviolet curable adhesive composition was obtained by the process.

[Comparative Example 1] A reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer was heated to a temperature of 80 ° C in the vessel, and 100 parts by mass of the above-mentioned urethane acrylate (A-2) and 67 parts by mass of acetic acid were added. Ethyl ester and stir until homogeneous. Thereafter, the mixture was cooled to room temperature, and 0.5 parts by mass of 2,4,6-trimethylbenzimidyldiphenylphosphine oxide and 0.5 parts by mass of sebacic acid bis(2,2, were added in this order with stirring. 6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, 0.5 parts by mass of triphenylphosphine, and stirred until homogeneous. Thereafter, the mixture was filtered through a 200 mesh metal mesh to obtain an ultraviolet curable adhesive composition.

[Comparative Example 2] An ultraviolet curable adhesive composition was obtained in the same manner as in Example 1 except that the M-305 was not used.

[Method for Producing UV Curing Adhesive Film] The composition of the ultraviolet curable adhesive obtained in the examples and the comparative examples was applied to a polyethylene terephthalate having a thickness of 50 μm after being subjected to a release treatment. On the surface of the ester (released PET 50), the film thickness after drying the organic solvent was 100 μm, and the film was dried in a dryer at 80 ° C for 5 minutes to obtain an ultraviolet curable adhesive film.

[Evaluation Method of Cutting Property] This ultraviolet curable adhesive film was further bonded to the release PET 50. Then, ultraviolet light irradiation was performed so that the cumulative light amount of the wavelength of the UV-A segment was 1 J/cm ² to obtain a laminate having an adhesive film. The obtained laminate was cut by a cutter to visually observe the presence or absence of residual glue on the cutting edge of the cutter. In addition, the case where no residue was confirmed was rated as "T", and the case where the residual glue was confirmed was rated as "F".

[Evaluation Method of Height and Depth Attachment] The ultraviolet curable adhesive film was bonded to a polyethylene terephthalate film (PET 100) having a thickness of 100 μm to prepare an adhesive film in which PET 100 was bonded to one side. This was cut into a test piece by cutting it by 50 mm in length and 40 mm in width. In addition, a frame of 40 mm in length, 30 mm in width, and 5 mm in width was cut out by PET 50. The frame having a thickness of 50 μm was placed on a glass plate, and the test piece was attached by a 2 kg roller × 2 round trip from above, and the PET 100 and the test piece were sandwiched by the frame having a thickness of 50 μm. This was subjected to a high temperature and high pressure treatment at 50 ° C and 0.5 MPa for 20 minutes. Thereafter, ultraviolet irradiation was performed, and the cumulative light amount of the wavelength of the UV-A segment projected from the glass plate side to the glass plate was 1 J/cm ² to obtain a laminate having an adhesive film. The obtained laminate was placed under an ambient gas of 80 ° C for 24 hours to visually observe the inner portion of the frame having a thickness of 50 μm, and the appendage of the height difference of 50 μm was evaluated as follows. "A": No floating from the height difference, and no air bubbles are mixed in. "B": It did not float from the height difference, but it was confirmed that some bubbles were mixed in. "C": There are significant bubbles mixed in.

[Method for Measuring Storage Elastic Modulus of Ultraviolet-Curable Adhesive Film (Before Ultraviolet Irradiation)] The adhesive layer of the ultraviolet-curable adhesive film was superposed in a light-shielded manner to have a thickness of 1 mm to obtain a test piece. The obtained test piece was subjected to an ARES viscoelasticity measuring apparatus (manufactured by TA Instruments Japan Inc.) at a temperature increase rate of 2 ° C / min, a measurement frequency of 1 Hz, a temperature range of 0 to 100 ° C, and strain. The measurement was carried out under conditions of 0.5%.

[Method of Measuring the Storage Elastic Modulus of the Adhesive Film (After Ultraviolet Irradiation)] The adhesive film obtained in the [Method for Assessing the Cutting Property] was superposed to have a thickness of 1 mm to obtain a test piece. The obtained test piece was subjected to an ARES viscoelasticity measuring apparatus (TA Instruments Japan Inc.) at a temperature increase rate of 2 ° C/min, a measurement frequency of 1 Hz, and a temperature range of 0 to 100 ° C. The measurement was carried out under the conditions of a strain of 0.5%.

[Evaluation Method of Moisture-Resistant Whitening Property] The ultraviolet-curable adhesive film was bonded to a polyethylene terephthalate film (PET 100) having a thickness of 100 μm to prepare an adhesive film in which PET 100 was bonded to one side. This was cut in a length of 50 mm and a width of 40 mm, and the release PET 50 was peeled off and attached to a glass plate to serve as a test piece. The obtained test piece was irradiated with ultraviolet rays, and the cumulative light amount of the wavelength of the UV-A section projected from the glass plate side to the glass plate was set to 1 J/cm ² to obtain a laminate having an adhesive film. The haze (haze 1) was measured using a turbidity meter "NDH5000" manufactured by Nippon Denshoku Industries Co., Ltd., and placed in an ambient gas at 85 ° C and a humidity of 85% for 100 hours. It was taken out under an ambient gas of 23 ° C and a humidity of 50%. After taking out, the haze meter "NDH5000" manufactured by Nippon Denshoku Industries Co., Ltd. was used for 10 minutes, and the haze of the adhesive film was measured in accordance with JIS K7361-1-1997 (haze 2 ). In addition, the case where the difference between the haze 1 and the haze 2 is 1% or less is rated as "T", and when it exceeds 1%, it is evaluated as "F".

In the first and second embodiments of the adhesive film of the present invention, the cutting property, the moist heat whitening property, and the height difference are excellent.

On the other hand, in Comparative Example 1, the polycarbonate polyol (a1-1) and the (meth)acrylic compound (B) were not used, and the cutting property was poor.

In Comparative Example 2, the form of the (meth)acrylic compound (B) was not used, and the wet heat whitening resistance was poor.

Claims (12)

An ultraviolet curable adhesive composition characterized by: (meth)acrylic acid compound (B) containing urethane (meth) acrylate (A) and having two or more (meth) acrylonitrile groups (B) a photopolymerization initiator (C) and an organic solvent (D); the urethane (meth) acrylate (A) is a polyol (a1) containing a polycarbonate polyol (a1-1) The polyisocyanate (a2) and the (meth)acrylic compound (a3) having an isocyanate group or a hydroxyl group are obtained by reaction. The ultraviolet curable adhesive composition according to claim 1, wherein the polyol (a1) further contains a polyether polyol (a1-2). The ultraviolet curable adhesive composition of claim 2, wherein the mass ratio of the polycarbonate polyol (a1-1) to the polyether polyol (a1-2) [(a1-1) /(a1-2)] is a range of 10/90 to 90/10. The ultraviolet curing adhesive composition according to claim 1, wherein the ethyl methacrylate (A) has a (meth) acrylonitrile equivalent of 1,000 to 50,000 g/eq. The scope. The ultraviolet curable adhesive composition according to claim 1, wherein the (meth)acrylic compound (B) is contained in an amount of 100 parts by mass of the ethyl urethane (meth) acrylate ( A) is in the range of 1 to 30 parts by mass. The ultraviolet curing adhesive composition according to the first aspect of the invention, wherein the (meth)acrylic compound (B) is selected from the group consisting of aliphatic polyfunctional (meth) acrylates and having isocyanuric acid One or more of the group consisting of polyfunctional (meth) acrylates having an acid ester structure. An adhesive film which is obtained by applying an ultraviolet curable adhesive composition according to any one of claims 1 to 6 to a substrate, and drying and ultraviolet irradiation. . The adhesive film of claim 7, wherein the storage elastic modulus at 30 ° C measured at a frequency of 1 Hz is 1 × 10 ⁴ Pa or more. The adhesive film of claim 7, wherein the storage elastic modulus at 100 ° C measured at a frequency of 1 Hz is 1 × 10 ⁴ Pa or more. A method for producing an adhesive film, which comprises drying an organic solvent (D) by applying an ultraviolet curable adhesive composition according to any one of claims 1 to 6 to a substrate. An ultraviolet curable adhesive film is obtained, and then the adhesive layer of the ultraviolet curable adhesive film is attached to a substrate, followed by ultraviolet irradiation. The method for producing an adhesive film according to claim 10, wherein the substrate to which the adhesive layer of the ultraviolet curable adhesive film is attached has a height difference. The method for producing an adhesive film according to claim 10, wherein the ultraviolet curable adhesive film has a storage elastic modulus of 60° C. measured at a frequency of 1 Hz of 5×10 ⁴ Pa or less.