JP5370811B2 - Active energy ray-curable pressure-sensitive adhesive composition - Google Patents

Abstract

The present invention provides an active energy line solidification type adhesive composition suitable to be used as adhesive agents. When the composition is prepared, polymerization retardaton will not be occurred basically, molecular weight may becomes larger, heat-proof retentivity, adhesion force with nonpolar adhesion bodies such as polyolefin and/or curved surface adhesion force as well as antifogging character of the composition are all excellent. Relative to 100 weight parts of active energy line solidification type monomer (a), the active energy line solidification type adhesive composition contains 0.01-5 weight parts of light polymerization initiator (b) and 2-30 weight parts of hydrogenated rosin resinoid (c) which softening point is more than 115 DEG C, and in the active energy line solidification type monomer (a), the content of (methyl) acroleic acid alkyl ester genus where the alkyl contains 2-12 carbon atoms is more than 50 wt% of the whole content.

Description

The present invention relates to an active energy ray-curable pressure-sensitive adhesive composition. The active energy ray-curable pressure-sensitive adhesive composition of the present invention is used as various adhesives / adhesives (hereinafter referred to as pressure-sensitive adhesives and adhesives in the present specification) such as labels, sheets, tapes, inks, paints, etc. It can also be used as a binder.

In recent years, curing systems using active energy rays such as ultraviolet rays and electron beams have been widely used in various fields in terms of energy saving and excellent productivity, and pressure sensitive adhesives (adhesives) and electronic It is also used in the manufacture of component sealants, printed circuit boards, semiconductor wafer dicing tapes, and the like.

An acrylic polymer obtained from a monomer mainly composed of (meth) acrylic acid alkyl esters having an alkyl group having 2 to 12 carbon atoms generally used as a pressure-sensitive adhesive is a tackifier resin (also referred to as a pressure-sensitive adhesive). Although it can become a pressure-sensitive adhesive even if not added, there is a problem that the adhesive force to nonpolar adherends such as polyethylene and polypropylene is insufficient.
Therefore, tackifying resins such as rosin and rosin derivatives (rosin-based resins), petroleum resins, terpene resins and terpene resin derivatives (terpene-based resins) are often used. In particular, in the case of acrylic-based adhesives / adhesives, rosin-based resins are preferably used because of their good compatibility with acrylic resins.

However, in general, the tackifying resin exhibits polymerization inhibition at the time of acrylic polymerization, and the molecular weight of the resulting acrylic polymer is decreased or the residual acrylic monomer is increased. It was very difficult to obtain a well-balanced pressure-sensitive adhesive.

The same applies to not only active energy ray-curable pressure-sensitive adhesives but also solution-polymerized and emulsion-polymerized acrylic pressure-sensitive adhesives, but a method of polymerizing acrylic polymers first and then adding a tackifying resin later. Thus, the desired performance is obtained. These have no problem with adhesive performance, but in recent years it is necessary to cope with restrictions on air pollution and environmental problems from the consideration of the global environment, and the organic solvent contained and energy consumption during heating and drying have become issues. ing. In addition, the heat during drying may have an adverse effect on the substrate, and the method of producing a pressure-sensitive adhesive sheet by photopolymerization using active energy rays is advantageous in terms of safety, environment, and quality. ing.

However, in the case of an active energy ray-curable pressure-sensitive adhesive, from the production mechanism, a tackifying resin must be added before the acrylic polymerization (pre-addition method), and the polymerization inhibition property has been sufficient so far. No tackifying resin was seen.

In the above-mentioned pre-addition method, rosin resin and other tackifying resins act as chain transfer agents for the polymerization reaction. Molecular weight has become difficult. As a result, the resulting acrylic polymer composition has low viscosity and adhesiveness due to cohesive force and the like. In addition, since acrylic monomers remain, there is a problem of having an odor. In contrast, the applicant has found a method for producing an acrylic polymer composition containing a rosin resin by the above-described pre-addition method with almost no polymerization inhibition (see Patent Document 1). .)

However, even acrylic polymer compositions produced by these methods have sufficient curved surface adhesion to the curved surfaces of non-polar adherends such as polyolefins in recent automotive interior members and building materials. That's not true.
In addition, when used as an automobile interior member, it has sufficient antifogging properties against the phenomenon (fogging) that volatilizes inside the heated car and condenses on the inner surface of the window glass that is cooled by the outside air, and becomes clouded white to obstruct visibility. I don't have it.
JP 2000-327708 A

In the production of an active energy ray-curable acrylic pressure-sensitive adhesive composition, the present invention makes it possible to increase the molecular weight of an acrylic polymer with almost no inhibition of polymerization, heat resistance holding power, non-polar deposition of polyolefin, etc. It is an object of the present invention to provide an active energy ray-curable pressure-sensitive adhesive composition suitable as a viscosity / adhesive having excellent viscosity / adhesion properties such as adhesion to a body, curved surface adhesion, and fogging prevention properties.

The present inventor has made various studies on the active energy ray-curable pressure-sensitive adhesive composition. The reason why it is difficult to increase the molecular weight of the acrylic polymer is the presence of double bonds in the rosin resin used as a tackifier. It is found that this is because the polymerization is inhibited, and by reducing the number of double bonds by hydrogenating the rosin resin, it becomes possible to increase the molecular weight of the acrylic polymer, In addition, by setting the softening point to a specific range, it has been found that it has high curved surface adhesiveness as an active energy ray-curable pressure-sensitive adhesive composition while having heat resistance and curved surface adhesive strength. The inventors have arrived at the present invention by conceiving that the problem can be solved.

That is, the present invention 1 is based on 100 parts by weight of the active energy ray-curable monomer (a) containing 50% by weight or more of (meth) acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms. An active energy ray-curable pressure-sensitive adhesive composition containing 0.01 to 5 parts by weight of a polymerization initiator (b), comprising 2 to 30 parts by weight of a hydrogenated rosin resin (c) having a softening point of 115 ° C. or higher It is an energy ray-curable pressure-sensitive adhesive composition.

The present invention 2 is the active energy ray-curable pressure-sensitive adhesive composition according to the present invention 1, which contains 5 to 200 parts by weight of an acrylic polymer (d) having a weight average molecular weight of 50000 or more.

Invention 3 is the active energy ray-curable pressure-sensitive adhesive composition according to Invention 1 or 2, which contains 0.01 to 10 parts by weight of the crosslinking agent (e).

Invention 4 is an active energy ray-curable pressure-sensitive adhesive composition according to any one of Inventions 1 to 3, wherein the hydrogenated rosin resin (c) is a hydrogenated polymerized rosin ester.

Invention 5 is an active energy ray according to any one of Inventions 1 to 4, wherein the content of a component having a weight average molecular weight of 260 or less contained in the hydrogenated rosin resin (c) is less than 1.0% by weight. It is a curable pressure-sensitive adhesive composition.
The present invention is described in detail below.

Since the active energy ray-curable pressure-sensitive adhesive composition of the present invention has the above-described configuration, polymerization inhibition hardly occurs and the acrylic polymer has a high molecular weight, so that the pre-addition method can be performed with simpler production equipment and processes. This makes it possible to produce an active energy ray-curable pressure-sensitive adhesive composition. Further, the obtained acrylic polymer is excellent in sticking / adhesiveness and antifogging properties such as heat-resistant holding power, holding power to non-polar adherends such as polyolefin, curved surface adhesion, etc., and is suitable as a sticky / adhesive. .

The active energy ray-curable pressure-sensitive adhesive composition of the present invention comprises an active energy ray-curable monomer (a) (hereinafter also referred to as component (a)), a photopolymerization initiator (b) (hereinafter referred to as (b). Component) and a hydrogenated rosin resin (c) (hereinafter also referred to as component (c)).

The component (a) contains 50% by weight or more of (meth) acrylic acid alkyl esters having an alkyl group having 2 to 12 carbon atoms. If it is less than 50% by weight, a suitable pressure-sensitive adhesive is hardly obtained.

The alkyl group having 2 to 12 carbon atoms is ethyl, propyl, isopropyl, butyl, isobutyl, isoamyl, hexyl, heptyl, 2-ethylhexyl, isooctyl, isononyl, isodecyl. is there. Preferably, it is a C2-C10 alkyl group, such as a butyl group and 2-ethylhexyl group. In addition, the said (a) component can use the said (meth) acrylic-acid alkyl ester one type or in mixture of 2 or more types.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention can use a monomer other than the component (a) together with the component (a).
The monomer is not particularly limited. For example, a carboxyl group-containing monomer, an acid anhydride group-containing monomer, a sulfonic acid group-containing monomer, a phosphate group-containing monomer, a hydroxyl group-containing monomer, an amide Examples thereof include a monomer, a succinimide monomer, a vinyl monomer, a cyano (meth) acrylate monomer, and a (meth) acrylate monomer having an alkyl group having 13 or more carbon atoms.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, and crotonic acid.
Examples of the acid anhydride group-containing monomer include maleic anhydride and itaconic anhydride.
Examples of the sulfonic acid group-containing monomer include 2- (meth) acrylamide-2-methylpropanesulfonic acid, sulfopropyl (meth) acrylate, and the like.
Examples of the phosphate group-containing monomer include 2-hydroxyethyl (meth) acryloyl phosphate.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (meta ) 8-hydroxyoctyl acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) -methyl (meth) acrylate, and the like.

Examples of the amide monomer include N-substituted (meth) acrylamide such as (meth) acrylamide and N-methylol (meth) acrylamide. Examples of succinimide monomers include N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, and the like. Vinyl monomers include vinyl acetate, N-vinyl pyrrolidone, N-vinyl carboxylic acid amides, styrene, N-vinyl caprolactam and the like. Cyano (meth) acrylate monomers include (meth) acrylonitrile and the like.

The component (b) is not particularly limited as long as it can be decomposed by active energy rays to generate radicals to initiate polymerization, and known components can be used. Specifically, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane- 1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6- Examples include trimethylbenzoyl-diphenyl-phosphine oxide, 4-methylbenzophenone and the like.
In addition, it is preferable to add (b) component suitably before the hardening process by active energy.

The component (c) has a softening point of 115 ° C. or higher. As a result, an active energy ray curable type that provides a pressure-sensitive adhesive having good curved surface adhesion and heat-resistant holding force to polyolefins that are non-polar adherends such as polypropylene and polyethylene over a wide temperature range The pressure-sensitive adhesive composition can be used, and can be used in various environments. When the softening point is lower than 115 ° C., the heat-resistant holding force and curved surface adhesive force of the adhesive / adhesive obtained from the active energy ray-curable pressure-sensitive adhesive composition are reduced. Preferably, it is 125 degreeC-165 degreeC, More preferably, it is 125 degreeC-145 degreeC. The softening point is a value measured by the ring and ball method (JIS-K5902).

The component (c) is not particularly limited as long as it is a hydrogenated rosin resin, and a known one can be used. Examples of the rosin resin include natural rosins such as gum rosin, tall oil rosin, and wood rosin, as well as processing natural rosins by at least one of polymerization, modification, disproportionation, and esterification methods. Rosins (hereinafter also referred to as processed rosins), rosin metal salts obtained by reacting natural rosins and processed rosins with metals such as calcium, magnesium, zinc and the like. The rosin resin may be used alone or in combination of two or more. In the case of producing a rosin resin through two or more methods among the methods of polymerization, modification, disproportionation, and esterification, the order of the methods is not particularly limited, and is based on a known method. Can do. For example, it may be polymerized after modifying natural rosins or processed rosins, or esterified after polymerization.

The method for producing polymerized rosins (hereinafter also referred to as polymerized rosin) is not particularly limited, and a known method can be employed. For example, a method of heating the natural rosin or a rosin obtained by processing the natural rosin by at least one method among modification, disproportionation, and esterification using a polymerization catalyst. It does not specifically limit as a polymerization catalyst, A well-known thing can be used. Specific examples include acids such as sulfuric acid, phosphoric acid and hydrofluoric acid, and metal halides such as boron fluoride, aluminum chloride and zinc chloride.

The production method of the modified rosins (hereinafter also referred to as modified rosins) is not particularly limited, and a known method may be adopted. Usually, natural rosin or processed rosins and phenols or unsaturated acids are mixed. Then, a heating method is used. The phenols are not particularly limited, and specific examples include phenol and alkylphenol. The unsaturated acid is not particularly limited, and specific examples include fumaric acid, maleic acid, and (meth) acrylic acid.

The method for producing the disproportionated rosins is not particularly limited, and a known method may be adopted. Usually, natural rosin or processed rosins are present in the presence of a reduction catalyst such as nickel, platinum, palladium, or a carbon catalyst. The method of making it saponify by making it react at 220-250 degreeC for 2 to 6 hours without adding hydrogen below is mentioned.

The manufacturing method of esterified rosins (hereinafter also referred to as rosin ester) is not particularly limited, and a known method can be employed. Usually, natural rosin or processed rosins and alcohol are mixed and heated in the presence of an esterification catalyst as necessary. Examples of the esterification catalyst include acid catalysts such as acetic acid and p-toluenesulfonic acid, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, and alkaline earth such as calcium hydroxide and magnesium hydroxide. Metal oxides such as metal hydroxides, calcium oxide, magnesium oxide, zinc oxide, lead oxide and tin oxide can be used.

Examples of the alcohol include aliphatic monovalent or polyhydric alcohols having 1 to 20 carbon atoms, such as methanol, ethanol, isopropyl alcohol, isoamyl alcohol, n-hexyl alcohol, 2-ethylhexyl alcohol, and n-octyl alcohol. Monohydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and neopentyl glycol; trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane And tetravalent alcohols such as pentaerythritol and diglycerin.

As the component (c), it is preferable to use a hydrogenated polymerized rosin ester. By using a hydrogenated polymerized rosin ester, even if a resin with a high softening point is used, compatibility with other rosin resins is better, so the active energy ray-curable pressure-sensitive adhesive composition of the present invention has an adhesive strength. And has an excellent effect in that a well-adhesive with a balanced surface can be easily obtained.

The hydrogenated polymerized rosin ester is a compound obtained by hydrogenating at least one compound obtained by reacting the polymerized rosin with the following alcohol and esterifying it (hereinafter also referred to as polymerized rosin ester). It is.

The method for producing the component (c) is not particularly limited as long as it is a method for producing a rosin resin by hydrogenation. Usually, in the presence of a known hydrogen source, a hydrogenation catalyst is used as necessary. The hydrogenation reaction may be performed at about 1 to 30 MPa. Examples of the hydrogen source include lithium aluminum hydride in addition to hydrogen gas.

The hydrogenation reaction may be performed by a known hydrogenation method for the rosin resin. For example, the rosin resin can be heated in a sealed container in the presence of a hydrogenation catalyst and, if necessary, a natural hydrocarbon organic solvent or an aromatic hydrocarbon organic solvent. It does not specifically limit as a natural hydrocarbon type organic solvent, For example, aliphatic or alicyclic saturated hydrocarbon type organic solvents, such as n-pentane, n-hexane, a cyclohexane, a decalin, are mentioned. The aromatic hydrocarbon organic solvent is not particularly limited, and examples thereof include toluene, xylene, alkylbenzene, dialkylbenzene and the like.

The hydrogen pressure during the hydrogenation reaction is usually about 1 MPa to 25 MPa, preferably 5 MPa to 20 MPa. When the hydrogen pressure is less than 1 MPa, the hydrogenation reaction is insufficient, and a hydrogenated polymerized rosin compound having excellent hue, odor, and heat resistance cannot be obtained. On the other hand, when the pressure is 25 MPa or more, a facility more stringent than safety is required, which is not preferable from the viewpoint of manufacturing.

The reaction temperature in the hydrogenation reaction is usually about 100 to 300 ° C, preferably 150 to 280 ° C. Below 100 ° C., the hydrogenation reaction is insufficient, and a hydrogenated polymerized rosin compound having excellent hue, odor and heat resistance cannot be obtained. Moreover, decomposition | disassembly of a polymerization rosin type compound advances at 300 degreeC or more is unpreferable.
The reaction time in the hydrogenation reaction is usually about 1 to 5 hours, preferably 2 to 4 hours.

As the hydrogenation reaction catalyst, various known catalysts can be used without particular limitation. For example, a supported catalyst in which palladium, rhodium, platinum or the like is supported on carbon or alumina, a metal powder such as nickel or platinum, or an iodide such as iodine or iron iodide can be exemplified. In order to obtain a hydrogenated polymerized rosin compound having excellent color tone and stability upon heating, palladium-based, rhodium-based, platinum-based, and nickel-based catalysts are preferable. Specifically, palladium carbon, rhodium carbon, platinum It is preferable to use carbon or stabilized nickel. The amount of the catalyst used is usually about 0.01 to 10% by weight, preferably 0.5 to 5% by weight, based on the polymerized rosin compound.

The component (c) can also be obtained by esterifying the compound obtained by reacting the polymerized rosin at least once with the hydrogenation and the alcohol.

The amount of the component (b) includes about 0.01 to 5 parts by weight with respect to 100 parts by weight of the component (a).

The amount of the component (c) is about 2 to 30 parts by weight with respect to 100 parts by weight of the component (a). The component (c) is less likely to act as a chain transfer agent for the polymerization reaction because it has fewer double bonds than rosins due to hydrogenation, prevents polymerization inhibition of the component (a), and the high molecular weight of the acrylic polymer Is realized. As a result, the obtained active energy ray-curable pressure-sensitive adhesive composition can provide a sticky / adhesive having good stickiness / adhesiveness. When the amount is less than 2 parts by weight, the effect of the tackifier resin does not sufficiently appear, and when it exceeds 30 parts by weight, the balance of the adhesive performance may be deteriorated. Preferably, it is 5 to 20 parts by weight.

In the active energy ray-curable pressure-sensitive adhesive composition of the present invention, the content of the component having a weight average molecular weight of 260 or less contained in the component (c) is preferably less than 1.0% by weight. Thereby, since the softening point of (c) component raises, it becomes possible to set it as the active energy ray hardening-type adhesive composition which provides the adhesive which has high heat-resistant retention. Preferably, it is less than 0.5% by weight. When the content of the component having a weight average molecular weight of 260 or less is 1.0% by weight or more, an active energy ray-curable pressure-sensitive adhesive composition that provides a pressure-sensitive adhesive having sufficient heat resistance can not be obtained.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention contains about 5 to 200 parts by weight of an acrylic polymer (d) having a weight average molecular weight of 50000 or more (hereinafter also referred to as component (d)). As a result, it becomes possible to increase the molecular weight of the acrylic polymer, and thus the resulting acrylic polymer composition can have a viscosity / adhesiveness due to cohesive force and the like within a suitable range as a pressure-sensitive adhesive. Become.
The component (d) may be an acrylic polymer obtained by polymerizing the component (a) by irradiation with active energy rays in the presence of the component (b).

The active energy ray-curable pressure-sensitive adhesive composition of the present invention also contains about 0.01 to 10 parts by weight of a crosslinking agent (e) (hereinafter also referred to as component (e)). As a result, the cohesive force can be improved, and the heat-resistant holding force and the like can be further increased.

Examples of the component (e) include polyfunctional vinyl compounds, compounds containing an epoxy group, and compounds having an isocyanate group.

Examples of polyfunctional vinyl compounds include, for example, trimethylolpropane triacrylate, hexanediol diacrylate, polyethylene diol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, dipentaerythritol hexaacrylate, and the like. Can be mentioned.

Examples of the compound containing an epoxy group include ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline. Diamine glycidylamine, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N′-diamineglycidylaminomethyl) cyclohexane and the like.

Examples of the compound containing an isocyanate group include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, isophorone diisocyanate, diphenylmethane isocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyisocyanate. Examples thereof include phenyl isocyanate.
In addition, the said (e) component can be suitably added before the hardening process by active energy.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention may further contain a surface conditioner, an antifoaming agent, etc., and a reactive or non-reactive inorganic filler for improving optical properties and physical properties, A reactive or non-reactive organic filler may be blended. Moreover, when hardening by ultraviolet irradiation, it is preferable to adjust by adding a photosensitizer etc. further.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention can be made into a pressure-sensitive adhesive by curing by irradiating active energy rays after being applied to various substrates by a known method and dried. For example, when a film is used, for example, it is applied on various film substrates so that the weight after drying is 0.1 to 30 g / m ² , preferably 1 to 20 g / m ^2, and after drying. An adhesive is obtained by irradiating an active energy ray to form a cured film.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention can be used for various known substrates. Specifically, for example, plastic (polycarbonate, polymethyl methacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine resin, triacetyl cellulose resin, ABS resin, AS resin, norbornene resin, etc.) and the like can be mentioned.

The application method of the active energy ray-curable pressure-sensitive adhesive composition of the present invention is not particularly limited, and a known method can be adopted, for example, bar coater coating, Mayer bar coating, air knife coating, gravure coating. And the like, reverse gravure coating, offset printing, flexographic printing, screen printing method and the like.

Examples of the active energy rays include ultraviolet rays and electron beams. When curing by ultraviolet rays, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, etc. is used as a light source, and the amount of light and the arrangement of the light source are adjusted as necessary. It is preferable to cure at a conveyance speed of about 5 to 50 m / min with respect to one lamp having a light quantity of 80 to 160 W / cm. On the other hand, in the case of curing with an electron beam, it is preferably cured with an electron beam accelerator having an accelerating voltage of usually 10 to 300 kV at a conveyance speed of 5 to 50 m / min.

Vegetable oil or fatty acid ester can be mix | blended with the active energy ray hardening-type adhesive composition of this invention as needed. The vegetable oil, fatty acid ester thereof, and modified products thereof used in the present invention will be described. Vegetable oil is triglyceride in which at least one fatty acid is a fatty acid having at least one carbon-carbon unsaturated bond in triglycerides of glycerin and fatty acid. Oil, linseed oil, eno oil, oil deer oil, olive oil, cacao oil, kapok oil, kayak oil, mustard oil, kyounin oil, kiri oil, kukui oil, walnut oil, poppy oil, sesame oil, safflower oil, radish seed oil, Soybean oil, Daifucho oil, Camellia oil, Corn oil, Rapeseed oil, Niger oil, Nuka oil, Palm oil, Castor oil, Sunflower oil, Grape seed oil, Gentia oil, Pine seed oil, Cottonseed oil, Palm oil, Peanut oil, Examples include dehydrated castor oil. Further preferred vegetable oils are vegetable oils having an iodine value of at least 100 or more (in parentheses indicate the oil value quoted from the Occupational Chemicals Manual: Nikkan Kogyo Shimbun), Asa oil (149 or more), Linseed oil (over 170), Eno oil (over 192), deer oil (over 140), Kapok oil (85-102), kaya oil (over 130), mustard oil (over 101), Kyonin oil (97-109) , Kiri oil (145 or higher), kukui oil (136 or higher), walnut oil (143 or higher), poppy oil (131 or higher), sesame oil (104 or higher), safflower oil (130 or higher), radish seed oil (98 to 112) ), Soybean oil (117 or more), large fusuko oil (101), corn oil (109 or more), rapeseed oil (97 to 107), niger oil (126 or more), nuka oil (92 to 11) ), Sunflower oil (125 or more), grape seed oil (124 or more), gentian oil (93 to 105), pine seed oil (146 or more), cottonseed oil (99 to 113), peanut oil (84 to 102), dehydrated castor Oil (147 or more) is preferably used, and more preferably a vegetable oil having an iodine value of 120 or more. By setting the iodine value to 120 or more, it is possible to further improve the drying property by oxidative polymerization of the curable composition.

Examples of fatty acid esters include fatty acid monoesters obtained by ester reaction of saturated or unsaturated fatty acids obtained by hydrolysis of vegetable oils and saturated or unsaturated alcohols, and are liquid at normal temperature (20 to 25 ° C.). And fatty acid monoesters having a boiling point of 200 ° C. or higher at normal pressure (101.3 kPa), and specific examples of such fatty acid esters include hexyl butyrate, heptyl butyrate, hexyl butyrate, octyl butyrate as saturated fatty acid monoesters. Butyl caproate, acyl caproate, hexyl caproate, heptyl caproate, octyl caproate, nonyl caproate, propyl enanthate, butyl enanthate, amyl enanthate, hexyl enanthate, heptyl enanthate, octyl enanthate, capryl Ethyl acetate, vinyl caprylate, Propyl phosphate, isopylpyl caprylate, butyl caprylate, amyl caprylate, hexyl caprylate, heptyl caprylate, octyl caprylate, methyl pelargonate, ethyl pelargonate, vinyl pelargonate, propyl pelargonate, butyl pelargonate, pelargonic acid Amyl, heptyl pelargonate, methyl caprate, ethyl caprate, vinyl caprate, propyl caprate, isopropyl caprate, butyl caprate, hexyl caprate, heptyl caprate, methyl laurate, ethyl laurate, vinyl laurate, Examples include propyl laurate, isopropyl laurate, butyl laurate, isoamyl laurate, hexyl laurate, and 2-ethyl-hexyl laurate.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “parts” means “parts by weight” unless otherwise specified.

Production Example 1
97 parts of butyl acrylate, 3 parts of acrylic acid, and 0.15 part of Darocur 1173 (photoinitiator) are charged into a four-necked flask equipped with a stirrer, nitrogen gas introduction tube, cooling tube and thermometer, and irradiated with ultraviolet rays. Polymerized syrup 1 (acrylic polymer) was obtained. The component having a weight average molecular weight of 50000 or more as measured by gel permeation chromatography (GPC) was 12 parts by weight.

Production Example 2
A 3 liter autoclave was charged with 1000 g of polymerized rosin ester ("Pencel D-125" manufactured by Arakawa Chemical Industry Co., Ltd.) and 30 g of 5% palladium carbon (water content 50%). After pressurizing to 10 MPa, the temperature was raised to 260 ° C. with stirring, and hydrogenation was performed at the same temperature for 3 hours to obtain a hydrogenated rosin resin 1 having an acid value of 15 and a softening point of 122 ° C.

Production Example 3
Hydrogenation rosin resin having an acid value of 19 and a softening point of 154 ° C. was obtained by performing hydrogenation in the same manner as in Production Example 2 except that the polymerized rosin ester was changed to Pencel D-160 (manufactured by Arakawa Chemical Industries) in Production Example 2. 2 was obtained.

Production Example 4
In Production Example 2, hydrogenation was carried out in the same manner as in Production Example 2 except that the polymerized rosin ester was changed to a modified rosin ester (“Arakawa Chemical Industries,” “Superester A-125”), oxidation 14 and softening point 123 ° C. The hydrogenated rosin resin 3 was obtained.

Production Example 5
The hydrogenated rosin-based resin 1 obtained in Production Example 2 was charged into a reaction vessel equipped with a stirrer, a condenser, a thermometer, a nitrogen introduction tube and a water vapor introduction tube, and then heated to 280 ° C., and 0.1 MPa Of water was blown for 3 hours, and water and the like were removed under reduced pressure to obtain a hydrogenated rosin resin 4 having an acid value of 11 and a softening point of 136 ° C.

Production Example 6
In Production Example 2, hydrogenation was carried out in the same manner as in Production Example 2 except that the polymerized rosin ester was changed to a modified rosin ester (“Arakawa Chemical Industries,“ Superester A-100 ”), and the oxidation was 8 and the softening point was 96 ° C. The hydrogenated rosin resin 5 was obtained.

Example 1
100 g of syrup 1 obtained in Production Example 1, 10 g of hydrogenated rosin resin 1 obtained in Production Example 2 as a tackifier, and 0.2 g of Darocur 1173 as a photoinitiator are mixed into an active energy ray curable type A pressure-sensitive adhesive composition was obtained. This was applied to one side of a 38 μm thick PET film with a thickness of 30 μm, and irradiated with ultraviolet rays to obtain an adhesive tape.

Examples 2-4
An adhesive tape was obtained in the same manner as in Example 1 except that the tackifier was changed to hydrogenated rosin resins 2 to 4 obtained in Production Examples 3 to 5.

Example 5
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that 0.2 g of the mixture of Example 1 and trimethylolpropane triacrylate was added as a crosslinking agent.

Comparative Example 1
100 g of syrup 1 obtained in Production Example 1 and 0.2 g of photoinitiator Darocur 1173 were blended, and an adhesive tape was obtained in the same manner as Example 1.

Comparative Example 2
An adhesive tape was obtained in the same manner as in Example 1 except that the hydrogenated rosin resin 1 was replaced with a non-hydrogenated rosin resin (Arakawa Chemical Industries, [Pencel D-125]).

Comparative Example 3
An adhesive tape was obtained in the same manner as in Example 1 except that the hydrogenated rosin resin 1 was replaced with a hydrogenated rosin resin 5.

The weight average molecular weight was calculated as a polystyrene equivalent value obtained from a standard polystyrene calibration curve by the GPC method. The GPC method was measured under the following conditions.
Analyzer: HLC-8120 (manufactured by Tosoh Corporation)
Column: TSKgelSuperHM-Lx 3 eluent: tetrahydrofuran injection Sample concentration: 5 mg / mL
Flow rate: 0.6mL / min
Injection volume: 100 μL
Column temperature: 40 ° C
Detector: RI

(Softening point)
It was measured by the ring and ball method of JIS K 2531.

Using the adhesive tapes obtained in Examples and Comparative Examples, the adhesive properties were evaluated by the following test methods. The evaluation results are shown in Table 1.

(Adhesive strength)
A sample tape (width 25 mm × length 100 mm) was prepared from the sample tape film, a 3 kg roller was reciprocated once on a polyethylene plate, and measured at 23 ° C. and 65% RH. The film was pulled at a peeling speed of 300 mm / min, and the 180 ° peel adhesive strength (g / 25 mm) was measured.

(Heat resistant holding power)
The sample tape film was pasted on a stainless steel plate with a width of 25 mm and a length of 25 mm, a load of 2 kg was applied at 40 ° C., the temperature was raised by 2 ° C. per minute, and the dropped temperature was measured.

(Curved surface adhesion)
A sample tape (width 20 mm × length 28 mm) is produced from the sample tape film, and this is bent and attached to a polypropylene cylinder having a diameter of 12 mm, and the tape lift (mm) after 3 days at 40 ° C. It was measured.

(Fogging prevention)
About 20 g of adhesive tape was put in a glass bottle with an internal volume of 140 mL, covered with a glass plate, heated at 105 ° C. for 24 hours, and the change of the glass plate was evaluated visually. The evaluation criteria are as follows.
1: No change 2: There is a slight amount of cloudiness 3: There is a clear cloudiness

In the above-mentioned Examples and Comparative Examples, polymerized rosin esters “Pencel D-125” and “Pencel D-160” manufactured by Arakawa Chemical Industries, Ltd. as hydrogenated rosin resins, modified rosin ester “Superester” manufactured by Arakawa Chemical Industries, Ltd. A-125 "and" Superester A-100 "hydrides are used, but the acrylic polymer composition obtained has a heat resistance as long as it is a hydrogenated rosin resin that exhibits the effects of the present invention. As long as it is excellent in adhesiveness and antifogging properties such as strength, holding power against nonpolar adherends such as polyolefin, curved surface adhesiveness, etc., and can be suitably used as an adhesive and adhesive, the above The mechanism in which the viscosity and adhesiveness are in a suitable range is the same. Therefore, if the softening point of the hydrogenated rosin resin is 115 ° C. or higher, it can be said that the advantageous effects of the present invention are surely exhibited. At least as hydrogenated rosin resins, polymerized rosin esters “Pencel D-125” and “Pencel D-160” manufactured by Arakawa Chemical Industries, modified rosin esters “Super Ester A-125”, “Superester” manufactured by Arakawa Chemical Industries, Ltd. In the case of using a hydride of “A-100”, the advantageous effects of the present invention are sufficiently demonstrated by the above-mentioned Examples and Comparative Examples, and the technical significance of the present invention is supported.

Claims (5)

Photopolymerization initiator (b) 0 with respect to 100 parts by weight of active energy ray-curable monomer (a) containing 50% by weight or more of (meth) acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms An active energy ray-curable pressure-sensitive adhesive composition containing 0.01 to 5 parts by weight,
An active energy ray-curable pressure-sensitive adhesive composition comprising 2 to 30 parts by weight of a hydrogenated rosin resin (c) having a softening point of 115 ° C. or higher. The active energy ray-curable pressure-sensitive adhesive composition according to claim 1, comprising 5 to 200 parts by weight of an acrylic polymer (d) having a weight average molecular weight of 50000 or more. The active energy ray-curable pressure-sensitive adhesive composition according to claim 1, comprising 0.01 to 10 parts by weight of a crosslinking agent (e). The active energy ray-curable pressure-sensitive adhesive composition according to claim 1, wherein the hydrogenated rosin resin (c) is a hydrogenated polymerized rosin ester. The active energy according to any one of claims 1 to 4, wherein the content of the component having a weight average molecular weight of 260 or less contained in the hydrogenated rosin resin (c) is less than 1.0% by weight. A wire-curable pressure-sensitive adhesive composition.