KR20160067894A - Ultraviolet curable adhesive composition, adhesive film and method for producing adhesive film - Google Patents

Abstract

A problem to be solved by the present invention is to provide an ultraviolet-curing pressure-sensitive adhesive composition which can obtain an adhesive film excellent in cutting property. (A1) containing a polycarbonate polyol (a1-1) and a polyether polyol (a1-2), a polyisocyanate (a2), and a (meth) acrylic compound having an isocyanate group or a hydroxyl group (Meth) acrylate (A), a photopolymerization initiator (B) and an organic solvent (C) obtained by reacting a urethane (meth) acrylate. Further, the present invention relates to a process for producing an ultraviolet-curing pressure-sensitive adhesive composition, which comprises applying the ultraviolet-curing pressure-sensitive adhesive composition onto a substrate, drying the organic solvent (C) And then irradiated with ultraviolet rays. The present invention also provides a method for producing a pressure-sensitive adhesive film.

Description

TECHNICAL FIELD [0001] The present invention relates to an ultraviolet curable pressure-sensitive adhesive composition, an ultraviolet curable pressure-sensitive adhesive composition, an adhesive film,

The present invention relates to an ultraviolet-curing pressure-sensitive adhesive composition which can obtain an adhesive film excellent in cutting property.

Unlike conventional solvent-based pressure-sensitive adhesives and water-based pressure-sensitive adhesives, ultraviolet curable pressure-sensitive adhesives do not require an aging time and can be expected to have high productivity. Therefore, attention has been paid to applications such as bonding of optical members.

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

The above-mentioned pressure-sensitive adhesives can exhibit tackiness immediately after curing of ultraviolet rays, and thus are excellent in productivity. Further, the pressure-sensitive adhesives can be thickened more easily than conventional pressure-sensitive adhesives, .

However, when the pressure-sensitive adhesive layer is formed into a thick film, there are many cases in which the curability inside the film becomes insufficient, and there is a problem that a paste remaining in the cutter occurs when cutting the pressure-sensitive adhesive film.

Japanese Patent Application Laid-Open No. 2006-104296

A problem to be solved by the present invention is to provide an ultraviolet-curing pressure-sensitive adhesive composition which can obtain an adhesive film excellent in cutting property.

(A1) containing a polycarbonate polyol (a1-1) and a polyether polyol (a1-2), a polyisocyanate (a2), and a (meth) acrylic compound having an isocyanate group or a hydroxyl group (Meth) acrylate (A), a photopolymerization initiator (B) and an organic solvent (C) obtained by reacting a urethane (meth) acrylate obtained by the reaction of the above-mentioned urethane (meth) acrylate and an adhesive film obtained therefrom.

Further, the present invention relates to a process for producing an ultraviolet-curing pressure-sensitive adhesive composition, which comprises applying the ultraviolet-curing pressure-sensitive adhesive composition onto a substrate, drying the organic solvent (C) And then irradiated with ultraviolet rays. The present invention also provides a method for producing a pressure-sensitive adhesive film.

The pressure-sensitive adhesive film obtained by the ultraviolet-curing pressure-sensitive adhesive composition of the present invention is excellent in cutting property because it does not remain in the paste even when cut. In addition, when the above specific production method is used, an adhesive film excellent in step-following property can be obtained.

Therefore, the ultraviolet-curing pressure-sensitive adhesive composition of the present invention can be suitably used as a pressure-sensitive adhesive for use in an optical member, and particularly relates to an IT related product such as a touch panel, a liquid crystal display, a plasma display, an organic EL, Can be suitably used for the production of

The ultraviolet-curable pressure-sensitive adhesive composition of the present invention comprises a polyol (a1) containing a polycarbonate polyol (a1-1) and a polyether polyol (a1-2), a polyisocyanate (a2), and an isocyanate group or a (Meth) acrylate (A), a photopolymerization initiator (B), and an organic solvent (C) obtained by reacting an acrylic compound (a3)

As the polycarbonate polyol (a1-1), for example, a product obtained by reacting a carbonate ester and / or phosgene with a compound having two or more hydroxyl groups can be used.

As the carbonic ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used. These carbonic esters may be used alone or in combination of two or more.

Examples of the compound having two or more hydroxyl groups include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, Propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 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- , 2-methyl-1,8-octanediol, and other aliphatic polyols; Alicyclic polyols such as 1,2-cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanedimethanol, cycloheptanediol, cyclooctanediol, and hydroxypropylcyclohexanol; Aromatic polyols such as bisphenol A, bisphenol F, and 4,4'-biphenol, and the like. These compounds may be used alone or in combination of two or more. As the compound having two or more hydroxyl groups, it is preferable to use an aliphatic polyol and / or an alicyclic polyol in view of further improving the cutting property, and 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol. It is more preferable to use at least one compound selected from the group consisting of 1,4-cyclohexanedimethanol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol.

The number average molecular weight of the polycarbonate polyol (a1-1) is preferably in the range of 500 to 5,000, more preferably in the range of 600 to 3,000, more preferably in the range of 600 to 3,000, in view of further improving the cutting property and the adhesive property. More preferably in the range of 700 to 2,000. The number average molecular weight of the polycarbonate polyol (a1-1) is measured by a gel permeation chromatography (GPC) method under the following conditions.

Measurement apparatus: High-speed GPC apparatus ("HLC-8220GPC" manufactured by Tosoh Corporation)

Column: The following column of Tosoh Corporation was connected in series.

"TSKgel G5000" (7.8 mm ID × 30 cm) × 1

"TSKgel G4000" (7.8 mm ID × 30 cm) × 1

"TSKgel G3000" (7.8 mm ID × 30 cm) × 1

"TSKgel G2000" (7.8 mm I.D. × 30 cm) × 1

Detector: RI (differential refractometer)

Column temperature: 40 DEG C

Eluent: tetrahydrofuran (THF)

Flow rate: 1.0 ml / min

Injection amount: 100 占 퐇 (tetrahydrofuran solution with 0.4 mass% of sample concentration)

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

(Standard polystyrene)

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

Quot; TSKgel standard polystyrene A-1000 " manufactured by Tosoh Corporation

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

Quot; TSKgel Standard Polystyrene A-5000 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-1 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-2 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-4 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-10 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-20 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-40 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-80 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-128 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-288 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-550 " manufactured by Tosoh Corporation

As the polyether polyol (a1-2), for example, one or more kinds of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide may be subjected to addition polymerization with a compound having two or more hydroxyl groups The resulting product; Polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran; Modified polytetramethylene glycol obtained by copolymerizing tetrahydrofuran and alkyl-substituted tetrahydrofuran; And modified polytetramethylene glycol obtained by copolymerizing neopentyl glycol and tetrahydrofuran. These polyether polyols may be used alone or in combination of two or more. Among them, it is preferable to use at least one polyether polyol selected from the group consisting of polyethylene glycol, polypropylene glycol and polytetramethylene glycol in view of further improving the adhesive property and the stepwise following property.

The number average molecular weight of the polyether polyol (a1-2) is preferably in the range of 200 to 5,000 in order to further improve the adhesive property and the step-following ability. The number average molecular weight of the polyether polyol (a1-2) represents a value obtained by measurement in the same manner as the number average molecular weight of the polycarbonate polyol (a1-1).

The mass ratio [(a1-1) / (a1-2)] between the polycarbonate polyol (a1-1) and the polyether polyol (a1-2) Is preferably in the range of 90 to 90/10, more preferably in the range of 20/80 to 60/40.

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

Examples of the other polyols include polyester polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, dimer diols, polyacrylic polyols, and the like. These polyols may be used alone or in combination of two or more.

The total content of the polycarbonate polyol (a1-1) and the polyether polyol (a1-2) in the polyol (a1) is preferably at least 50 mass% of the polyol (a1) from the viewpoints of cutting property and adhesive property And more preferably not less than 70% by mass.

Examples of the polyisocyanate (a2) include aromatic polyisocyanates such as xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and naphthalene diisocyanate; Alicyclic or alicyclic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, diisocyanatomethylcyclohexane and tetramethyl xylylene diisocyanate; Polyisocyanate and the like can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, alicyclic polyisocyanates are preferably used in view of further improving the cutting property and the adhesive property, and it is preferable to use alicyclic polyisocyanates such as 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, cyclohexane diisocyanate And at least one polyisocyanate selected from the group consisting of diisocyanatomethylcyclohexane is more preferably used.

The (meth) acrylic compound (a3) having an isocyanate group or a hydroxyl group is used for the purpose of introducing a (meth) acryloyl group into urethane (meth) acrylate (A).

Examples of the (meth) acrylic compound having an isocyanate group that can be used as the compound (a3) include 2- (meth) acryloyloxyethyl isocyanate, 2- (2- (meth) acryloyloxyethyloxy) Ethyl isocyanate, and 1,1-bis ((meth) acryloyloxymethyl) ethyl isocyanate. These compounds may be used alone or in combination of two or more. Of these, it is preferable to use 2- (meth) acryloyloxyethyl isocyanate from the viewpoint of easiness of obtaining raw materials, and from the viewpoint of curability, it is more preferable to use 2-acryloyloxyethyl isocyanate.

Examples of the (meth) acrylic compound having a hydroxyl group that can be used as the compound (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Having a hydroxyl group such as (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate and hydroxyethyl acrylamide Alkyl (meth) acrylate; Polyfunctional (meth) acrylates having a hydroxyl group such as trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate; Polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, and the like. These compounds may be used alone or in combination of two or more. Of these, acrylic acid (meth) alkyl esters having a hydroxyl group are preferably used from the viewpoints of ease of raw material availability, curability and adhesive property, and it is preferable to use acrylic acid (meth) Is more preferable.

Examples of the method for producing the urethane (meth) acrylate (A) in the case of using the (meth) acrylic compound having an isocyanate group as the compound (a3) include a method in which the polyol (a1) and the polyisocyanate (Meth) acrylic compound (a3) having an isocyanate group is fed, mixed, and reacted with the isocyanate group-containing urethane prepolymer to obtain a urethane prepolymer having a hydroxyl group . Any of the above-mentioned reactions may be conducted under the conditions of, for example, 20 to 120 캜 for 30 minutes to 24 hours.

Examples of the method for producing the urethane (meth) acrylate (A) in the case of using the (meth) acrylic compound having a hydroxyl group as the compound (a3) include a method in which the polyol (a1) (A1) and the polyisocyanate (a2) are reacted with each other in the absence of a solvent or by a method in which the acrylic compound (a3) is introduced into the reaction system and then the polyisocyanate (a2) A method in which a urethane prepolymer having an isocyanate group is obtained by a polymerization method and then the above (meth) acrylic compound (a3) having a hydroxyl group is supplied, mixed, and reacted. Any of the above-mentioned reactions may be conducted under the conditions of, for example, 20 to 120 캜 for 30 minutes to 24 hours.

The urethane (meth) acrylate (A) may be produced in the presence of an organic solvent (C) to be described later.

The reaction of the polyol (a1), the polyisocyanate (a2) and the (meth) acrylic compound (a3) in the case of using the (meth) acrylic compound having a hydroxyl group as the compound (a3) (isocyanate group / hydroxyl group total amount) of the total amount of the hydroxyl group of the polyisocyanate (a1) and the hydroxyl group of the (meth) acrylic compound (a3) and the isocyanate group of the polyisocyanate (a2) is in the range of 0.75 to 1 Is preferable for controlling the molecular weight of the urethane (meth) acrylate (A) to be obtained, and more preferably in the range of 0.79 to 0.995. When the equivalent ratio is more than 1, the reaction may be carried out. In this case, it is preferable to use an alcohol such as methanol for the purpose of deactivating the isocyanate group of the urethane (meth) acrylate (A).

The reaction of the polyol (a1), the polyisocyanate (a2) and the (meth) acrylic compound (a3) in the case of using the (meth) acrylic compound having isocyanate as the compound (a3) (The total amount of isocyanate group / hydroxyl group) of the hydroxyl group of the polyol (a1) with the total of the isocyanate groups of the polyisocyanate (a2) and the (meth) acrylic compound (a3) is in the range of 0.75 to 1 Is preferable for controlling the molecular weight of the urethane (meth) acrylate (A) to be obtained, and more preferably in the range of 0.79 to 0.995. When the equivalent ratio is more than 1, the reaction may be carried out. In this case, it is preferable to use an alcohol such as methanol for the purpose of deactivating the isocyanate group of the urethane (meth) acrylate (A).

When urethane (meth) acrylate (A) is produced, a polymerization inhibitor, an urethanation catalyst, or the like may be used if necessary.

Examples of the polymerization inhibitor include 3,5-bis tert-butyl-4-hydroxytoluene, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether (methoquinone), para tert- butyl catechol methoxyphenol , 2,6-ditert-butylcresol, phenothiazine, tetramethylthiuram disulfide, diphenylamine, dinitrobenzene and the like can be used. These polymerization inhibitors may be used alone or in combination of two or more.

Examples of the urethanization catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine and N-methylmorpholine; Metal salts such as potassium acetate, zinc stearate and tin octylate; Organometallic compounds such as dibutyltin laurate and zirconium tetraacetylacetonate can be used. These urethanization catalysts may be used alone or in combination of two or more.

The urethane (meth) acrylate (A) has a (meth) acryloyl group for promoting radical polymerization by light irradiation or heating. The (meth) acryloyl group equivalent of the urethane (meth) acrylate (A) is preferably in the range of 1,000 to 50,000 g / eq. In view of further improving the cutting property, the adhesive property and the step- And more preferably in the range of 3,000 to 25,000 g / eq. The (meth) acryloyl group equivalent is preferably such that the total mass of the polyol (a1), the polyisocyanate (a2) and the (meth) acrylic compound (a3) is present in the urethane (meth) (Meth) acrylate group.

In the present invention, the term "(meth) acrylic compound" refers to one or both of a methacrylic compound and an acrylic compound, and "(meth) acrylate" refers to one or both of methacrylate and acrylate (Meth) acryloyl group "refers to one or both of a methacryloyl group and an acryloyl group, and the term" (meth) acrylic acid "refers to one or both of methacrylic acid and acrylic acid, Monomers "refers to one or both of a methacrylic monomer and an acrylic monomer.

The ratio of the mass of the urethane bond in the urethane (meth) acrylate (A) is preferably in the range of 4 to 20 mass% of the total amount of the urethane (meth) acrylate (A) from the viewpoint of further improving the cutting property, By mass to 20% by mass, and more preferably 5% by mass to 15% by mass. The urethane bonding amount of the urethane (meth) acrylate (A) is preferably within a range of from 1 to 100 parts by mass, based on the total mass of the polyol (a1), the polyisocyanate (a2) and the (meth) acrylic compound (a3) Represents the mass ratio of the urethane bond structure occupied.

The weight average molecular weight of the urethane (meth) acrylate (A) is preferably in the range of 5,000 to 100,000, more preferably in the range of 15,000 to 50,000, in view of further improving the cutting property, the adhesive property and the step- More preferable. The weight average molecular weight of the urethane (meth) acrylate (A) is a value obtained by measuring the number average molecular weight of the polycarbonate polyol (a1-1).

The photopolymerization initiator (B) initiates radical polymerization of the urethane (meth) acrylate (A) by generating radicals by optical irradiation or heating.

Examples of the photopolymerization initiator (B) include 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan- Phenyl) -2-hydroxy-2-methylpropane-1-one, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) -phenyl (2- Acetophenone compounds such as 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone and 2,2-dimethoxy-2-phenylacetophenone; Benzoin compounds such as benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; Benzoquinone compounds such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenylsulfide and 3,3'-dimethyl- Phenone compounds; Thioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-di Thioxanthone compounds such as isopropyl thioxanthone; (4-aminobenzophenone,? -Acyloxime ester, benzyl, methylbenzoylformate ("Baia Cure 55"), 4,4'-dimethylaminothioxanthone Anthraquinone compounds such as ethyl anthraquinone; Acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; 3,3 ', 4,4'-tetra (tert-butylperoxycarbonyl) benzophenone, and acrylated benzophenone. These photopolymerization initiators may be used alone or in combination of two or more.

As the photopolymerization initiator (B), 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2 , 4,6-trimethylbenzoyldiphenylphosphine oxide, and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide is preferably used, and it is preferable to use at least one photopolymerization initiator selected from the group consisting of 2,4 , And 6-trimethylbenzoyldiphenylphosphine oxide are more preferable.

The amount of the photopolymerization initiator (B) to be used is preferably in the range of 0.1 to 20 parts by mass based on 100 parts by mass of the urethane (meth) acrylate (A) More preferably 15 parts by mass.

Examples of the organic solvent (C) include toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, hexane, acetone, cyclohexanone, 3-pentanone, acetonitrile, propionitrile, isobutyronitrile, Rhenitrile, dimethylsulfoxide, dimethylformamide, and the like can be used. These organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent (C) to be used is preferably 60% by mass or less, more preferably 5 to 50% by mass in the ultraviolet curing pressure-sensitive adhesive composition, from the viewpoint of further improving drying and coating properties.

The ultraviolet curable pressure sensitive adhesive composition of the present invention contains the urethane (meth) acrylate (A), the photopolymerization initiator (B) and the organic solvent (C) as essential components, but may contain other additives .

Examples of the other additives include silane coupling agents, antioxidants, light stabilizers, rust inhibitors, thixotropic agents, sensitizers, polymerization inhibitors, leveling agents, tackifiers, antistatic agents and flame retardants . These additives may be used alone or in combination of two or more. Among them, it is preferable that the ultraviolet-curable pressure-sensitive adhesive composition of the present invention contains a silane coupling agent (D) when it is used in applications requiring high adhesive properties after moisture-heat treatment. When the ultraviolet ray hardening type pressure-sensitive adhesive composition of the present invention is used for applications requiring resistance to moisture-wet heat yellowing, antioxidant (E) and light stabilizer (F) are preferably contained.

Examples of the silane coupling agent (D) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- A silane coupling agent having an epoxy group such as isopropylmethyldimethoxysilane; (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- , 2- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 2- Silane coupling agents having an alicyclic epoxy group such as silane, 2- (3,4-epoxycyclohexyl) propyltriethoxysilane and 2- (3,4-epoxycyclohexyl) propylmethyldiethoxysilane; Vinyl trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, Silicon alkoxy oligomers, and the like. These silane coupling agents may be used alone or in combination of two or more. Among them, it is preferable to use a silane coupling agent having an epoxy group and / or a silane coupling agent having an alicyclic epoxy group from the viewpoint of further improving the adhesive force after anti-wet heat treatment, and 2- (3,4-epoxycyclohexyl ) Is selected from the group consisting of ethyl triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane It is more preferable to use at least one silane coupling agent.

The amount of the silane coupling agent (D) to be used is preferably in the range of 0.01 to 10 parts by mass based on 100 parts by mass of the urethane (meth) acrylate (A) from the viewpoint of further improving the adhesion after heat- More preferably 0.05 to 5 parts by mass, and still more preferably 0.05 to 1 part by mass.

Examples of the antioxidant (E) include a hindered phenol compound (primary antioxidant) that captures radicals generated by thermal degradation (thermal deterioration), a phosphorus compound that decomposes peroxides generated by thermal heating, a sulfur compound ) Can be used.

Examples of the hindered phenol compound include triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl [3- [3- (3,5-di -tert- butyl-4-hydroxyphenyl) propionate], benzene propanoic acid 3,5-bis (1,1-dimethylethyl) -4-hydroxy--C ₇ -C ₉ branched alkyl esters, 4,6-bis (dodecyl thiomethyl) -o- cresol, N- amine reaction product of benzene and 2,4,4-trimethyl pentene, 2-butyl-6-t- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 3,9- 1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro [5.5-undecane, 2,6-di-tert-butyl-4-methylphenol, 2,2'- Methylene bis (4-methyl-6-tert-butylphenol), 2,5-di -tert-amylhydroquinone and the like can be used. These compounds may be used alone or in combination of two or more.

Examples of the phosphorus compound include triphenylphosphine, bis (2,4-di-tert-butyl-6-methylphenyl) ethyl = phosphite, triphenylphosphite, trisnonylphenylphosphite, tris (2,4-dibutyl-5-methylphenyl) phosphite, tris [2- tert -butyl-4- (3-butyl- (2,4-di-tert-butylphenyl) phosphite, tridecylphosphite, octyldiphenylphosphite, di (decyl) monophenyl phosphite, di ) Pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-dibutylphenyl) pentaerythritol diphosphite, bis (2,6-dibutyl-4-methylphenyl) pentaerythritol (2,4,6-tributylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, tetra (tridecyl) (Tridecyl) -4,1'-n-butylidenebis (2-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2,4-dibutylphenyl) biphenylene diphosphonite, 9,10-dihydro-9-oxa-10- (4,6-butylphenyl) -2-ethylhexylphosphite, 2,2'-methylenebis (4,6-butylphenyl) -octadecyl Tris (2, 4, 8, 10-tetrakisbutyldibenzo [d, f] [(4,6-dibutylphenyl) fluorophosphite, 1,3,2] dioxaphospepin-6-yl) oxy] ethyl) amine, 2-ethyl-2-butylpropylene glycol and a phosphite of 2,4,6-tributylphenol. These compounds may be used alone or in combination of two or more.

Examples of the sulfur compound include, for example, titanyl-3,3'-thiopropionate, dilauryl-3,3'-thiodipropionate, lauryl thiodidonate, Thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, tetrakis-methylene-3-laurylthiopropionate 3,3'-thiodipropionate, laurylstearyl-3,3'-thiodipropionate, bis [2-methyl-4- ( 3-n-alkylthiopropionyloxy) -5-t-butylphenyl] sulfide,? -Laurylthiopropionate, 2- mercaptobenzoimidazole, 2- mercapto- Dioctadecyl-3,3'-thiodipropionate, and the like. These compounds may be used alone or in combination of two or more.

Among them, it is preferable to use a phosphorus compound from the viewpoint of further improving the adhesion and the resistance to moisture and heat sulfur change, and it is preferable to use triphenylphosphine, bis (2,4-di-tert- It is more preferable to use at least one antioxidant selected from the group consisting of trimethyl phosphine, ethyl phosphite and tris (2,4-di-tert-butylphenyl) phosphite, Di-tert-butyl-6-methylphenyl) ethyl ethylphosphite is more preferably used.

The amount of the antioxidant (E) to be used is preferably in the range of 0.01 to 10 parts by mass relative to 100 parts by mass of the urethane (meth) acrylate (A) .

The light stabilizer (F) captures radicals generated by photo-degradation (photodegradation), and includes, for example, radical scavengers such as thiol compounds, thioether compounds and hindered amine compounds; Benzophenone compounds, benzoate compounds and the like can be used. These light stabilizers may be used alone or in combination of two or more. Among them, it is preferable to use a hindered amine compound in order to further improve resistance to moisture-wet heat sulfur.

Examples of the hindered amine compound include cyclohexane and N-butyl peroxide 2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro-1,3,5- (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester, 1,1-dimethyl A hindered amine compound having an amino ether group such as a reaction product of ethyl hydroperoxide and octane; N-acetyl-type hindered amine compounds such as N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione; Bis (1,2,2,6,6-pentamethyl-4-piperidyl) = decanedioate, bis (1,2,2,6,6, (1,1-dimethylethyl) -4-hydroxyphenyl] methyl} butyl malonate, succinic acid dimethyl 1- (2-hydroxyethyl) -4- Tetramethylpiperidine polycondensate, propanedioic acid ester of [{4-methoxyphenyl} methylene] -bis (1,2,2,6,6-pentamethyl-4-piperidyl) Alkyl hindered amine compounds and the like can be used. These compounds may be used alone or in combination of two or more.

The amount of the light stabilizer (F) to be used is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the urethane (meth) acrylate (A) .

The viscosity of the ultraviolet-curing pressure-sensitive 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. The viscosity is a value measured by a B-type viscometer at 25 캜.

Next, a method for producing the pressure-sensitive adhesive film of the present invention will be described.

The pressure-sensitive adhesive film is obtained by a step of drying the organic solvent (C) in the ultraviolet-curing pressure-sensitive adhesive composition and a step of curing the composition by irradiating ultraviolet rays.

As a method for producing the above adhesive film, an ultraviolet-curable adhesive film is obtained by drying the organic solvent (C) after coating the substrate with the ultraviolet-curing pressure-sensitive adhesive composition in that an adhesive film excellent in step- , A method of pasting the adhesive layer of the ultraviolet-curable adhesive film to the substrate and then irradiating ultraviolet rays to obtain an adhesive film. According to this method, when the ultraviolet-curable adhesive film before curing is cured with a step such as a printed step as a substrate to be pasted thereafter, the ultraviolet curing-type adhesive film is adhered without leaving a gap in the stepped portion, It is possible to obtain an adhesive film excellent in step-following property.

In the present invention, the state after the organic solvent is dried and before the ultraviolet curing is referred to as an " ultraviolet curable adhesive film ", and the state after the ultraviolet curing is referred to as an " adhesive film ".

As the above substrate, for example, a plastic substrate, a flexible printed substrate, a glass substrate, a substrate obtained by subjecting these substrates to a releasing treatment, a substrate obtained by depositing ITO (indium tin oxide), or the like can be used. Further, the same substrate may be used for both sides of the adhesive layer, or a separate substrate may be used.

Examples of the plastic substrate include acrylic resin, PC (polycarbonate), PBT (polybutylene terephthalate), PPS (polyphenylenesulfide), modified PPE (polyphenylene ether), PET (polyethylene terephthalate) Plastic films, antireflection films, antifouling films, films of transparent conductive films constituting touch panels, and the like, which can be obtained using COP (cycloolefin polymer) and TAC (triacetylcellulose) as raw materials can be used.

As a method of applying the ultraviolet-curable pressure-sensitive adhesive composition to the substrate, a method of applying the ultraviolet-curable pressure-sensitive adhesive composition using an applicator, a roll coater, a knife coater, a gravure coater or the like can be used. After the coating, the obtained laminate is placed in a drier or the like, and the organic solvent (C) is dried by drying at a temperature of 50 to 130 캜 for 1 to 30 minutes to obtain an ultraviolet curing type pressure-sensitive adhesive film before ultraviolet curing.

Examples of the ultraviolet-curable pressure-sensitive adhesive film, the storage elastic modulus in that it is possible to improve further the step followability, in 60 ℃, preferably 5 × 10 ⁴ ㎩ or less when measured at a frequency 1㎐, 1 × 10 ³ To 5 x 10 < ⁴ > Pa. A method of measuring the storage elastic modulus of the ultraviolet-curing type pressure-sensitive adhesive film will be described in Examples.

Further, the ultraviolet-setting type pressure-sensitive adhesive film can further improve the cutting property and the step-following property, so that the storage elastic modulus at 30 ° C is preferably 5 × 10 ⁴ Pa or more when measured at a frequency of 1 Hz And more preferably in the range of 5 x 10 < ^-4 > to 5 x 10 < ⁶ > Pa.

After the obtained ultraviolet-curable pressure-sensitive adhesive film is attached to the substrate, the ultraviolet-curable pressure-sensitive adhesive film may be pressed and subjected to autoclave processing, if necessary.

Thereafter, ultraviolet ray irradiation is performed to obtain a pressure-sensitive adhesive film. Examples of the ultraviolet ray irradiation method include a known ultraviolet light irradiation such as a xenon lamp, a xenon-mercury lamp, a metal halide lamp, a high pressure mercury lamp, And a method of using the device.

The irradiation dose of the ultraviolet ray is preferably in the range of 0.05 to 5 J / cm 2, more preferably 0.1 to 3 J / cm 2, particularly preferably 0.3 to 1.5 J / cm 2. The irradiation amount of ultraviolet ray is based on the value measured in a wavelength range of 300 to 390 nm using a UV checker "UVR-N1" manufactured by GS Kasei Co., Ltd.

The thickness of the pressure-sensitive adhesive film obtained by the above method is appropriately determined depending on the intended use, but is preferably in the range of approximately 10 to 500 占 퐉.

Further, as the adhesive film, the cutting property in that it can even be further improved, and the storage elastic modulus at 30 ℃, preferably when measured at a frequency 1㎐ more than ^{1 × 10 4 ㎩, 1 ×} 10 4 To 5.0 x 10 < ⁷ > Pa is more preferable. A method of measuring the storage elastic modulus of the pressure-sensitive adhesive film will be described in Examples.

Further, as the adhesive film, in that it is possible to improve further the step-followability, and the storage modulus, it is preferred if it is measured at a frequency not less than 1 × 10 ⁴ ㎩ 1㎐ in 100 ℃, 1 × 10 ⁴ in the range of ~5 × 10 ⁵ ㎩ it is more preferable. A method of measuring the storage elastic modulus of the pressure-sensitive adhesive film will be described in Examples.

As described above, the pressure-sensitive adhesive film obtained by using the ultraviolet-curing pressure-sensitive adhesive composition of the present invention is excellent in cutting property because it does not remain in the paste even when cut. In addition, when the above specific production method is used, an adhesive film excellent in step-following property can be obtained.

Therefore, the ultraviolet-curing pressure-sensitive adhesive composition of the present invention can be suitably used as a pressure-sensitive adhesive for use in an optical member, and can be suitably used in the manufacture of IT related products such as touch panels, liquid crystal displays, plasma displays, organic EL, It can be used for personal use.

[Example]

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

[Synthesis Example 1]

≪ Synthesis of urethane acrylate (A-1) >

46.4 parts by mass of polypropylene glycol (number average molecular weight: 2,000, hereinafter abbreviated as "PPG2000") was added to a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube and a thermometer, Dimethanol cyclohexane, 1,6-hexanediol and dimethyl carbonate, number average molecular weight 900, hereinafter abbreviated as " UM-90 " ), 0.8 parts by mass of 2-hydroxyethyl acrylate (hereinafter abbreviated as "HEA"), 0.3 part by mass of 2,6-di-tert-butyl-cresol, 0.05 parts by mass of p-methoxyphenol ≪ / RTI > After the temperature in the reaction vessel was raised to 40 캜, 14.7 parts by mass of isophorone diisocyanate (hereinafter abbreviated as " IPDI ") was added. Then, 0.1 part by mass of dioctyltin dinneodecanate was added, and the temperature was raised to 80 占 폚 over 1 hour. Thereafter, the mixture was held at 80 DEG C for 12 hours to confirm that all the isocyanate groups had disappeared and then cooled to obtain urethane acrylate (A-1). The obtained urethane acrylate (A-1) was found to have an equivalent number of acryloyl groups of 15,000 (number of digits of the significant digits was rounded off, the molecular weight of 2-hydroxyethyl acrylate was 116.1, the same applies hereinafter) 26,000.

[Synthesis Example 2]

≪ Synthesis of urethane acrylate (A-2) >

33.7 parts by mass of PPG2000, 28.1 parts by mass of polytetramethylene glycol (number average molecular weight: 650, hereinafter abbreviated as " PTMG650 "), 50 parts by mass of polyethylene glycol 16.0 parts by mass, hereinafter referred to as " PEG400 "), 0.55 parts by mass of HEA, 0.3 parts by mass of 2,6-di-tert- . After the temperature in the reaction vessel was raised to 40 캜, 22.2 parts by mass of IPDI was added. Then, 0.1 part by mass of dioctyltin dinneodecanate was added, and the temperature was raised to 80 占 폚 over 1 hour. Thereafter, the mixture was held at 80 DEG C for 12 hours to confirm that all the isocyanate groups had disappeared, followed by cooling to obtain urethane acrylate (A-2). The resulting urethane acrylate (A-2) had an equivalent number of acryloyl groups of 21,000 and a weight average molecular weight of 28,000.

[Example 1]

≪ Preparation of UV-curable pressure-sensitive adhesive composition >

A reaction vessel equipped with a stirrer, a reflux condenser and a thermometer was heated to 80 deg. C in the vessel temperature, 100 parts by mass of the urethane acrylate (A-1) and 67 parts by mass of ethyl acetate were added and stirred until uniform. Thereafter, the mixture was cooled to room temperature, and 0.5 parts by mass of 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide (hereinafter abbreviated as "(B-1)") , 0.5 parts by mass of 6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester and 0.5 parts by mass of triphenylphosphine were added successively, and the mixture was stirred until uniform. Thereafter, the mixture was filtered through a 200-mesh netting to obtain an ultraviolet curable pressure-sensitive adhesive composition.

[Comparative Example 1]

An ultraviolet curable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that the urethane acrylate (A-1) used was changed to urethane acrylate (A-2).

[Method of producing ultraviolet curable adhesive film]

Curable pressure-sensitive adhesive resin composition obtained in Examples and Comparative Examples was coated on the surface of a 50 占 퐉 -thick polyethylene terephthalate film (release PET50) having a thickness of 100 占 퐉 after drying the organic solvent, And dried in a drier for 5 minutes to obtain an ultraviolet curable adhesive film.

[Evaluation method of cutting property]

The ultraviolet curing type pressure-sensitive adhesive film was further bonded to the release PET 50. Next, ultraviolet light was irradiated so that the accumulated light quantity of the wavelength of the UV-A region was 1 J / cm 2 to obtain a laminate having an adhesive film. The obtained laminate was cut by a cutter, and the presence or absence of a paste remaining on the blade of the cutter was visually observed. In addition, when the pool remnant was not confirmed, it was evaluated as " T ", and when the pool remnant was confirmed, it was evaluated as " F ".

[Evaluation method of stepwise followability]

The ultraviolet curing type pressure-sensitive adhesive film was laminated to a polyethylene terephthalate film (PET100) having a thickness of 100 占 퐉 to prepare an adhesive film in which PET100 was adhered to one side. The specimens were cut to a length of 50 mm and a width of 40 mm. Apart from this, a frame of 40 mm in length, 30 mm in width, and 5 mm in width was cut from PET 50. The rim having a thickness of 50 탆 was placed on a glass plate, and the test piece was reciprocated by 2 kg rolls × 2 from above, and attached with PET 100 and the test piece so that the rim of the thickness of 50 탆 was sandwiched therebetween. This was autoclaved for 20 minutes under the conditions of 50 占 폚 and 0.5 MPa. Thereafter, ultraviolet light was irradiated from the glass plate side so that the accumulated light quantity of the wavelength of the UV-A region after the glass plate was dropped to 1 J / cm 2 to obtain a laminate having an adhesive film. The laminate thus obtained was allowed to stand in an atmosphere at 80 占 폚 for 24 hours, and the inside of the rim of the thickness of 50 占 퐉 was observed with the naked eye, and the followability to the step of 50 占 퐉 was evaluated as follows.

"A": No lifting from the step, no mixing of bubbles

"B": There is no lift from the step, but the presence of air bubbles is partially confirmed

&Quot; C ": prominent incorporation of air bubbles

[Method of measuring storage elastic modulus of ultraviolet curable adhesive film (before ultraviolet ray irradiation)] [

The pressure-sensitive adhesive layer of the ultraviolet-curing type pressure-sensitive adhesive film was superimposed on the test piece until the thickness became 1 mm under light shielding. The storage elastic modulus of the obtained test piece was measured using an ARES viscoelasticity measuring apparatus (manufactured by Japan Instruments Japan Ltd.) according to JIS K7198-1991, at a heating rate of 2 占 폚 / min, a measuring frequency of 1 Hz, -100 to 200 캜, strain; 0.5%.

[Method of measuring the storage elastic modulus of an adhesive film (after ultraviolet irradiation)] [

The pressure-sensitive adhesive film obtained in the above-mentioned [evaluation method of cutting property] was superimposed until a thickness of 1 mm was used as a test piece. The storage elastic modulus of the obtained test piece was measured using an ARES viscoelasticity measuring apparatus (manufactured by Japan Instruments Japan Ltd.) according to JIS K7198-1991, at a heating rate of 2 占 폚 / min, a measuring frequency of 1 Hz, -100 to 200 캜, strain; 0.5%.

[Table 1]

The adhesive film of Example 1 of the present invention was found to be excellent in cutting property and step traceability.

On the other hand, in Comparative Example 1, the polycarbonate polyol was not used, but the cutting property was poor.

Claims (9)

(A1) containing a polycarbonate polyol (a1-1) and a polyether polyol (a1-2), a polyisocyanate (a2) and a (meth) acrylic compound (a3) having an isocyanate group or a hydroxyl group are reacted (A), a photopolymerization initiator (B) and an organic solvent (C), wherein the urethane (meth) acrylate (A) (A1-1) / (a1-2) of the polycarbonate polyol (a1-1) and the polyether polyol (a1-2) is in the range of 10/90 to 90/10, Composition. The method according to claim 1,
Wherein the (meth) acryloyl group equivalent of the urethane (meth) acrylate (A) is in the range of 1,000 to 50,000 g / eq. A pressure-sensitive adhesive film obtained by applying (coating) an ultraviolet-curing pressure-sensitive adhesive composition according to any one of claims 1 to 3 onto a substrate, and drying and irradiating ultraviolet rays. 5. The method of claim 4,
Wherein the storage elastic modulus at 30 DEG C is 1 x 10 < ⁴ > Pa or more when measured at a frequency of 1 Hz. 5. The method of claim 4,
Wherein the storage elastic modulus at 100 deg. C is 1 x 10 < ⁴ > Pa or more when measured at a frequency of 1 Hz. An ultraviolet curing pressure-sensitive adhesive composition according to any one of claims 1 to 3, which is applied onto a substrate, drying the organic solvent (C) to obtain an ultraviolet-curable pressure-sensitive adhesive film, Is adhered to a base material, and then irradiated with ultraviolet rays, thereby obtaining a pressure-sensitive adhesive film. 8. The method of claim 7,
Wherein the substrate to which the adhesive layer of the ultraviolet-curable adhesive film is pasted has a step. 8. The method of claim 7,
Wherein the ultraviolet curing type pressure-sensitive adhesive film has a storage elastic modulus at 60 ° C of 5 x 10 ⁴ Pa or less when measured at a frequency of 1 Hz.