JP5483565B2 - Active energy ray-curable pressure-sensitive adhesive resin composition, pressure-sensitive adhesive obtained thereby, and pressure-sensitive adhesive sheet - Google Patents

Description

The present invention relates to a resin composition for an active energy ray-curable pressure-sensitive adhesive . More specifically, the present invention has good adhesion and heat resistance to low-polar adherends such as polyolefins in addition to metals, and a product. An active energy ray-curable pressure-sensitive adhesive resin composition (hereinafter referred to as “active energy ray-curable resin composition”) , which has excellent adhesion stability such that there is little variation in adhesion between lots, and is obtained thereby. The present invention relates to an adhesive and an adhesive sheet.

  Acrylic pressure-sensitive adhesive is mainly composed of acrylic polymer, so it has excellent durability such as light resistance, weather resistance, and oil resistance. The pressure-sensitive adhesive tape using this acrylic pressure-sensitive adhesive has the above durability. In addition, it has excellent physical properties such as adhesive strength and cohesive strength, so it is widely used.

  As such an acrylic pressure-sensitive adhesive, for example, a pressure-sensitive adhesive made of an active energy ray-curable pressure-sensitive adhesive composition is disclosed (see Patent Document 1). This pressure-sensitive adhesive composition is an active energy ray-polymerizable composition comprising an acrylic polymer, a monofunctional ethylenically unsaturated monomer, a polyfunctional (meth) acrylate compound, and a photopolymerization initiator, It is a pressure-sensitive adhesive obtained by utilizing a curing reaction by active energy ray irradiation.

JP 2007-217674 A

However, when trying to obtain a pressure-sensitive adhesive by ultraviolet irradiation using the above active energy ray-polymerizable composition, a larger amount of irradiation is required compared to the normal irradiation amount (integrated light amount is about 800 mJ / cm ² ). The production efficiency was still not satisfactory.

  Further, in the production of the pressure-sensitive adhesive by the above technique, since the adhesive force is likely to vary depending on the product lot, a pressure-sensitive adhesive having stable physical properties with no variation in the adhesive force is desired.

  The present invention has been made in view of such circumstances, and an active energy having a stable adhesive force with no variation even when sufficient adhesive physical properties are obtained even with a small irradiation amount (integrated light amount) of active energy rays. The object is to provide a linear curable resin composition, a pressure-sensitive adhesive obtained thereby, and a pressure-sensitive adhesive sheet.

In order to achieve the above object, the present invention provides an active energy containing an acrylic resin (A), an ethylenically unsaturated compound (B) having one ethylenically unsaturated group, and a photopolymerization initiator (C). a line-curable resin composition, a weight-average molecular weight of the acrylic resin (a) (Mw) is Ri der 500,000 or more, one closed the acrylic resin (a) and an ethylenically unsaturated group The blending ratio with the ethylenically unsaturated compound (B) is (A) :( B) = 5: 95 to 50:50 (weight ratio), and triazine photopolymerization is initiated as the photopolymerization initiator (C). An active energy ray-curable resin composition using an agent is a first gist.

  The second gist of the present invention is a pressure-sensitive adhesive obtained by irradiating the active energy ray-curable resin composition with active energy rays.

  Furthermore, this invention makes the 3rd summary the adhesive sheet which has a layer which consists of a base material and the said adhesive.

The inventor has conducted a series of studies on a pressure-sensitive adhesive composition having strong adhesiveness. For example, the present inventors have studied a pressure-sensitive adhesive composition exhibiting strong adhesiveness as shown in Patent Document 1. However, the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition shown in Patent Document 1 exhibits good pressure-sensitive adhesive properties. However, in order to obtain a pressure-sensitive adhesive having the above-mentioned pressure-sensitive adhesive properties, an activity that requires a large amount of accumulated light is obtained. We had to irradiate energy rays, which was not satisfactory in terms of production efficiency. Under such circumstances, the present inventor obtains an active energy ray-curable resin composition capable of obtaining a pressure-sensitive adhesive having good pressure-sensitive adhesive properties even with irradiation with a smaller integrated light amount than conventional. Therefore, research was conducted focusing on various component materials constituting the resin composition. As a result, an acrylic polymer having a weight average molecular weight (Mw) of a certain value or more is used, and the blending ratio of the acrylic polymer and an ethylenically unsaturated compound having one ethylenically unsaturated group is a specific ratio. It was found that the above-described object could be achieved by using a triazine photopolymerization initiator as a photopolymerization initiator (weight ratio), and the present invention was achieved.

Thus, the active energy ray-curable resin composition of the present invention comprises an acrylic resin (A), an ethylenically unsaturated compound (B) having one ethylenically unsaturated group, and a photopolymerization initiator (C). a radiation-curable resin composition containing the above weight average molecular weight of the acrylic resin (a) (Mw) of 500,000 or more der is, the acrylic resin (a) and the ethylenically unsaturated The blending ratio with the ethylenically unsaturated compound (B) having one group is (A) :( B) = 5: 95 to 50:50 (weight ratio), and the photopolymerization initiator (C) A triazine photopolymerization initiator is used. For this reason, the active energy ray-curable resin composition of the present invention can provide a pressure-sensitive adhesive having sufficient adhesive properties even when the irradiation amount of the active energy ray is an integrated light amount that is less than that of the conventional one. And the thing stable also regarding the adhesive physical property can be obtained.

  Furthermore, when an ethylenically unsaturated compound (D) having two or more ethylenically unsaturated groups is used, control of adhesive properties such as adhesive strength becomes easy.

  Further, when at least one of an alkylphenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator is used together with the triazine photopolymerization initiator as the photopolymerization initiator (C), the adhesive properties are further improved. It becomes like this.

  And when the said active energy ray hardening-type resin composition is a non-solvent type which does not contain a solvent, not only the drying process can be shortened in manufacture of an adhesive, but it will also consider the global environment.

  In addition, when the pressure-sensitive adhesive of the present invention is obtained by irradiating the active energy ray-curable resin composition with active energy rays, it has sufficient strong adhesiveness and has stable adhesive properties. Thus, it becomes highly practical.

  Furthermore, a pressure-sensitive adhesive sheet having a base material and a layer made of the above-mentioned pressure-sensitive adhesive has sufficient strong pressure-sensitive adhesive properties and stable pressure-sensitive adhesive properties, and is highly practical as a pressure-sensitive adhesive sheet. It becomes.

  Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to this embodiment.

  The active energy ray-curable resin composition of the present invention (hereinafter sometimes abbreviated as “resin composition”) includes an acrylic resin (A) and an ethylenically unsaturated compound (B) having one ethylenically unsaturated group. And a photopolymerization initiator (C). First, each component material which comprises the said active energy ray hardening-type resin composition is demonstrated.

<< Acrylic resin (A) >>
The acrylic resin (A) used in the present invention is a polymer obtained by copolymerizing a (meth) acrylic acid ester monomer (a1) and, if necessary, another copolymerizable monomer (a2). .

  In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate.

  Examples of the (meth) acrylic acid ester monomer (a1) include, for example, aliphatic (meth) acrylic acid ester monomers such as (meth) acrylic acid alkyl esters, and aromatic (meth) acrylic acid phenyl esters ( And (meth) acrylic acid ester monomers.

  About the said (meth) acrylic-acid alkylester, it is preferable that carbon number of an alkyl group is 1-12 normally, especially 1-8, Furthermore, it is preferable that it is 2-8, Specifically, methyl (meth) acrylate , Ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, n-octyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, etc. can give. Examples of (meth) acrylic acid phenyl ester include benzyl (meth) acrylate and phenoxyethyl (meth) acrylate.

  Other (meth) acrylic acid ester monomers include tetrahydrofurfuryl (meth) acrylate and the like. These can be used alone or in combination of two or more.

  Among the above (meth) acrylic acid ester monomers (a1), n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable in terms of copolymerizability, adhesive properties, ease of handling, and availability of raw materials. N-butyl (meth) acrylate is preferably used from the viewpoint of excellent antistatic performance.

  Examples of the other copolymerizable monomer (a2) include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an oxyalkylene group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, a nitrogen-containing monomer, a glycidyl group-containing monomer, and a phosphate group. -Containing monomers, functional group-containing monomers such as sulfonic acid group-containing monomers, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene , Vinyl pyridine, vinyl pyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acrylic chloride, methyl vinyl ketone, N-acrylamidomethyltrimethylammonium Chloride, allyl trimethyl ammonium chloride, are exemplified monomers such as dimethylallyl vinyl ketone, one selected from these or two or more may be used. Preferably, acrylonitrile or a hydroxyl group-containing unsaturated monomer, particularly 2-hydroxyethyl methacrylate is used.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl ( (Meth) acrylate, 10-hydroxydecyl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate and other (meth) acrylic acid hydroxyalkyl esters, caprolactone-modified 2-hydroxyethyl (meth) acrylate, etc. Monomers containing primary hydroxyl groups such as caprolactone-modified monomers, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, etc. 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3 -Secondary hydroxyl group-containing monomers such as phenoxypropyl (meth) acrylate; tertiary hydroxyl group-containing monomers such as 2,2-dimethyl-2-hydroxyethyl (meth) acrylate.

  Also, polyethylene glycol derivatives such as diethylene glycol (meth) acrylate and polyethylene glycol mono (meth) acrylate, polypropylene glycol derivatives such as polypropylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol-mono (meth) acrylate, poly (ethylene glycol) An oxyalkylene-modified hydroxyl group-containing monomer such as -tetramethylene glycol) mono (meth) acrylate or poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate may be used.

  Examples of the carboxyl group-containing monomer include Michael addition of acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid, cinnamic acid, and (meth) acrylic acid. (Eg, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc.), 2- (meth) acryloyloxyethyl dicarboxylic acid monoester (eg, 2-acryloyloxyethyl) Succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahi Rofutaru acid monoester, 2-methacryloyloxyethyl hexahydrophthalic acid mono ester) and the like. Such a carboxyl group-containing monomer may be used as an acid, or may be used in the form of a salt neutralized with an alkali.

  When the carboxyl group-containing monomer is used, after copolymerization and polymerization, the carboxyl group derived from the carboxyl group-containing monomer is neutralized with a neutralizing agent to obtain a partially neutralized product or a completely neutralized product. It is preferable to do.

Examples of the neutralizing agent include ammonia, alkaline ammonium salts and primary amines such as monoethylamine and monoethanolamine; secondary amines such as diethylamine and diethanolamine; triethylamine, triethanolamine, N, N, N′-trimethylethylenediamine Tertiary amines such as N-methyldiethanolamine and N, N-diethylhydroxylamine; amino compounds having a plurality of nitrogen atoms in one molecule such as diamine and polyethyleneimine; amine compounds such as cyclic amino compounds such as pyridine; Examples thereof include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide.
Among these neutralizing agents, alkali metal hydroxides are preferable from the viewpoint of antistatic ability after neutralization, and potassium hydroxide is particularly preferably used because of compatibility with acrylic resins.

  Examples of the oxyalkylene group-containing monomer include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, and 2-butoxy. Diethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, octoxypolyethylene glycol -Polypropylene glycol mono (meth) acrylate, Lauroxy polyethylene glycol mono (meth) acrylate, steer Aliphatic (meth) acrylic acid esters such as loxypolyethyleneglycol mono (meth) acrylate, 2-phenoxyethyl (meth) acrylate, phenoxypolyethyleneglycol (meth) acrylate, phenoxypolyethyleneglycol-polypropyleneglycol (meth) acrylate, Examples thereof include acrylic acid esters of aromatic (meth) acrylates such as nonylphenol ethylene oxide adduct (meth) acrylate.

  Examples of the amide group-containing monomer include acrylamide, methacrylamide, N- (n-butoxyalkyl) acrylamide, N- (n-butoxyalkyl) methacrylamide, N, N-dimethyl (meth) acrylamide, N, N- Examples include diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, acrylamide-3-methylbutylmethylamine, dimethylaminoalkylacrylamide, dimethylaminoalkylmethacrylamide and the like.

  Examples of the amino group-containing monomer include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and a quaternized product thereof.

  Examples of the nitrogen-containing monomer include acryloylmorpholine.

  Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether.

  Examples of the phosphoric acid group-containing monomer include 2- (meth) acryloyloxyethyl acid phosphate, bis (2- (meth) acryloyloxyethyl) acid phosphate, and the like.

  Examples of the sulfonic acid group-containing monomer include olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid, and salts thereof. .

  Thus, the acrylic resin (A) according to the present invention is obtained by copolymerizing the above (meth) acrylic acid ester monomer (a1) and, if necessary, other copolymerizable monomer (a2). can get. As a specific copolymer component ratio constituting the acrylic resin (A), the (meth) acrylic acid ester monomer (a1) is 75 to 100% by weight, particularly 80 to 93%, based on the entire copolymer component. It is preferable that it is weight%, Furthermore, it is 85-90 weight%. When the amount of the (meth) acrylic acid ester monomer (a1) is too small, the molecular weight does not increase and the viscosity tends to decrease.

  The obtained acrylic resin (A) must have a weight average molecular weight (Mw) of 500,000 or more. Especially preferably, it is 850,000 or more, More preferably, it is 1 million or more, Most preferably, it is 1.2 million or more. This is because if the weight average molecular weight of the acrylic resin (A) is too small, the cohesive force of the pressure-sensitive adhesive obtained by irradiation with active energy rays is insufficient.

  On the other hand, the upper limit of the weight average molecular weight (Mw) of the acrylic resin (A) is preferably 3 million or less, particularly 2.5 million or less, and more preferably 2 million or less. This is because if the weight average molecular weight of the acrylic resin (A) is too large, it is difficult to obtain a uniformly compatible resin composition.

  In the present invention, the degree of dispersion (Mw / Mn) of the acrylic resin (A) is preferably 7 or less, particularly 5 or less, and further preferably 4 or less. This is because if the degree of dispersion (Mw / Mn) of the acrylic resin (A) is too large, there is a tendency that the shake due to the active energy ray irradiation conditions of cohesive force and adhesive properties increases. The lower limit of the degree of dispersion (Mw / Mn) is usually 2. In addition, said Mn means a number average molecular weight.

  The acrylic resin (A) can be produced by methods well known to those skilled in the art, such as solution radical polymerization, suspension polymerization, bulk polymerization, and emulsion polymerization. Among these, suspension polymerization is preferably used as a method for producing the acrylic resin (A) satisfying the above conditions because a polymer having a high degree of polymerization can be obtained and the produced polymer can be easily isolated. The acrylic resin (A) is preferably a dry resin obtained by suspension polymerization.

  In the polymerization, a dispersion stabilizer such as polyvinyl alcohol and a polymerization initiator such as azobisisobutyronitrile can be added as necessary.

  In general, the acrylic resin used in the resin composition is often produced by solvent-based polymerization using an organic solvent at the time of production. When such a solvent-based polymerized acrylic resin is used in the pressure-sensitive adhesive composition, it is necessary to dry the pressure-sensitive adhesive solution at a high temperature, so a lot of energy is required, and the organic solvent is easily flammable. In addition, it causes air pollution and requires a large-scale solvent recovery device and safety device. However, when the acrylic resin (A) of dry resin obtained by the suspension polymerization is used, a resin composition can be produced without containing such an organic solvent.

  In the present invention, the glass transition temperature (Tg) of the acrylic resin (A) is preferably in the range of −60 to 20 ° C., particularly −60 to 0 ° C., more preferably −55 to − It is preferably within the range of 10 ° C. This is because if the glass transition temperature (Tg) of the acrylic resin (A) is too low, the tendency to be inferior in cohesive force is seen, and conversely, if it is too high, the pressure-sensitive adhesive tends to become brittle.

In the present invention, the weight average molecular weight means a weight average molecular weight in terms of standard polystyrene molecular weight. Specifically, high-performance liquid chromatography (manufactured by Waters, Japan, “Waters 2695 (main body)” and “Waters 2414 (detection)). Column): Shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plates / piece, filler material: styrene-divinyl It is measured by using three series of benzene copolymer and filler particle size: 10 μm. Similarly, the number average molecular weight is measured using the above measuring apparatus.

  In the present invention, the glass transition temperature is calculated from the Fox equation.

<< Ethylenically unsaturated compound (B) having one ethylenically unsaturated group >>
The ethylenically unsaturated compound (B) having one ethylenically unsaturated group used in the present invention (hereinafter sometimes abbreviated as “monofunctional ethylenically unsaturated compound (B)”), together with the above (A), It is used as a monomer constituting the active energy ray-curable resin composition. The monofunctional ethylenically unsaturated compound (B) is composed of (meth) acrylic acid alkyl ester (b1) and, if necessary, other copolymerizable monomer (b2) at room temperature (25 ° C. ± 10 ° C.). It is a liquid or solid monomer.

  Examples of the (meth) acrylic acid alkyl ester (b1) include usually (meth) acrylic acid alkyl esters having 1 to 30 carbon atoms in the alkyl group, specifically, ethyl (meth) acrylate, n-propyl. (Meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, 2-ethylhexyl (meth) ) Acrylate, nonyl (meth) acrylate, n-decyl (meth) acrylate, iso-decyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl (meth) acrylate, isobornyl (meth) acrylate and the like. Among them, (meth) acrylic acid alkyl esters having preferably 2 to 20 carbon atoms, particularly preferably 4 to 18 carbon atoms, and more preferably 4 to 10 carbon atoms are preferable. Among these, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and n-butyl (meth) acrylate are particularly preferably used. One or more of these (meth) acrylic acid alkyl esters (b1) are used.

  Moreover, as said (meth) acrylic-acid alkylester (b1), glass transition temperature (Tg), such as cyclohexyl (meth) acrylate, methyl (meth) acrylate, isobornyl (meth) acrylate, tert-butyl (meth) acrylate, is high. Use of a monomer is preferable in that even when the film thickness at the time of coating is increased, excellent holding power can be exhibited after curing.

  Other copolymerizable monomers (b2) include, for example, (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide-N-glycolic acid, cinnamic acid, (meth) Michael adduct of acrylic acid (for example, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc.), 2- (meth) acryloyloxyethyldicarboxylic acid monoester (for example, 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydride Carboxyl group-containing unsaturated monomers such as phthalic acid monoester and 2-methacryloyloxyethyl hexahydrophthalic acid monoester); 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl ( (Meth) acrylates such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate and (4-hydroxymethylcyclohexyl) methyl (meth) acrylate Caprolactone-modified monomers such as acrylic acid hydroxyalkyl ester, caprolactone-modified 2-hydroxyethyl (meth) acrylate, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, N-methylol ( 1) Primary hydroxyl group-containing monomers such as acrylamide and N-hydroxyethyl (meth) acrylamide; 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate Secondary hydroxyl group-containing monomers such as 2-chloro-2-hydroxypropyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate; 2,2-dimethyl-2-hydroxyethyl (meth) acrylate and the like Tertiary hydroxyl group-containing monomers; glycidyl group-containing unsaturated monomers such as glycidyl (meth) acrylate and allyl glycidyl (meth) acrylate; t-butylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylamino Amino group-containing monomers such as noethyl (meth) acrylate; 2- (acetoacetoxy) ethyl (meth) acrylate, acetoacetyl group-containing monomers such as allyl acetoacetate; 2-methoxyethyl (meth) acrylate, 3-methoxyethyl (meta) ) Alkoxy (poly) alkylene glycol mono (meth) acrylates such as acrylate and methoxydiethylene glycol (meth) acrylate; Allyl compounds such as N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinylketone; N-vinyl Vinyl monomers such as pyrrolidone, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl acetate, styrene; (meth) acrylic other than (b1) Alkyl ester monomers, etc. can be mentioned, one selected from these or two or more may be used. Among these, (meth) acrylic acid is preferably used.

  Thus, the monofunctional ethylenically unsaturated compound (B) according to the present invention comprises the above (meth) acrylic acid alkyl ester (b1) and, if necessary, further another copolymerizable monomer (b2). . As a specific blending ratio, the blending amount of the (meth) acrylic acid alkyl ester (b1) is 75 to 100% by weight, particularly 80 to 93% by weight, based on the whole monofunctional ethylenically unsaturated compound (B). Further, it is preferably 85 to 90% by weight. When the amount of the (meth) acrylic acid alkyl ester (b1) is too small, the molecular weight does not increase and the viscosity tends to be low.

  In particular, in applications where moderate tackiness is required, other copolymerizability is included in 100 parts by weight (hereinafter abbreviated as “part”) of the acrylic resin (A) and the monofunctional ethylenically unsaturated compound (B). It is preferable that the monomer (b2) contains 1 to 20 parts, particularly 3 to 10 parts. The other copolymerizable monomer (b2) is preferably a carboxyl group-containing unsaturated monomer, particularly preferably acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide- N-glycolic acid and cinnamic acid are preferable, and acrylic acid and methacrylic acid are more preferable.

  Furthermore, in the above-mentioned monofunctional ethylenically unsaturated compound (B), in applications where antistatic performance is required for the pressure-sensitive adhesive, an oxyalkylene chain-containing monomer (b3) is used or a large amount of hydroxyl-containing monomer (b4) is used. By using the antistatic performance, it is possible to impart antistatic performance.

  As said oxyalkylene chain containing monomer (b3), the monofunctional monomer containing the oxyalkylene chain represented by following General formula (1) is mention | raise | lifted, for example.

  X in the general formula (1) is an alkylene group, and an alkylene group having 1 to 10 carbon atoms, particularly 2 to 8 carbon atoms is preferable, and an ethylene group, a propylene group, or a tetramethylene group is particularly preferable. In the case where n is a polyoxyalkylene chain moiety having 2 or more, a homopolymer of the same oxyalkylene chain may be used, or different oxyalkylene chains may be copolymerized randomly or in a block form.

  N in the general formula (1) is an integer of 1 or more, preferably 1 to 100, particularly preferably 5 to 50. If the value of n is too small, the antistatic ability tends to be insufficient, and if it is too large, the durability tends to be insufficient.

  A in the general formula (1) is a (meth) acryloyl group or an alkenyl group. As the alkenyl group, those having 2 to 6 carbon atoms, for example, a vinyl group or an allyl group are usually used. Among these, a methacryloyl group, an acryloyl group, and an allyl group are preferable, and a methacryloyl group and an acryloyl group are particularly preferable.

  B in the general formula (1) is a hydrogen atom, an alkyl group, a phenyl group, or an acyl group. As the alkyl group, those having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms are usually used. Among these, a hydrogen atom, a methyl group, and an ethyl group are preferable.

As specific examples of the monofunctional monomer containing the oxyalkylene chain,
[A: In the case of (meth) acryloyl group]
For example, polyethylene glycol derivatives such as polyethylene glycol mono (meth) acrylate, polypropylene glycol derivatives such as polypropylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol-mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) mono Examples include (meth) acrylate, poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate, alkoxy polyethylene glycol (meth) acrylate such as methoxypolyethylene glycol mono (meth) acrylate and ethoxypolyethylene glycol mono (meth) acrylate. .

[A: In the case of an alkenyl group]
Examples thereof include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether, polypropylene glycol derivatives such as polypropylene glycol monoallyl ether, and polyethylene glycol-polypropylene glycol-monoallyl ether. These may be used alone or in combination of two or more.

  Among these, the polyethylene glycol derivative is preferably an alkoxylated product of polyethylene glycol, more preferably methoxypolyethylene glycol monoacrylate, and the ethylene oxide addition mole number n is 5 to 500, particularly 5 to 100, more preferably 6 to 30 is preferable in terms of the balance between antistatic ability and durability. If the ethylene oxide addition mole number n is too small, the antistatic ability tends to be inferior, and if it is too large, the durability tends to deteriorate. Furthermore, A is preferably a (meth) acryloyl group from the viewpoint of excellent curability.

  Moreover, as a weight average molecular weight of the monofunctional monomer containing the oxyalkylene chain shown by the said General formula (1), 100-20000 are preferable normally, Especially 200-10000, Furthermore, 400-2000 are preferable. When the weight average molecular weight is too small, the antistatic ability tends to be inferior. When the weight average molecular weight is too large, the crystallinity becomes high and the handling tends to be difficult. The weight average molecular weight is measured in the same manner as described above.

  The content of the oxyalkylene chain-containing monomer (b3) is such that the oxyalkylene chain-containing monomer (b3) is 100 parts in total for the acrylic tree (A) and the monofunctional ethylenically unsaturated compound (B). In general, it may be 5 to 40 parts, preferably 10 to 35 parts, particularly preferably 15 to 30 parts. If the content is too large, the compatibility tends to decrease, and if it is too small, the antistatic performance tends to be inferior. There is.

  As the hydroxyl group-containing monomer (b4), the same hydroxyl group-containing monomers as exemplified in the other copolymerizable monomer (b2) can be used, and the content of the hydroxyl group-containing monomer (b4) is as follows. The hydroxyl group-containing monomer (b4) is usually 5 to 50 parts, preferably 10 to 40 parts, particularly preferably with respect to 100 parts in total of the acrylic resin (A) and the monofunctional ethylenically unsaturated compound (B). May be 15 to 30 parts. If the content is too large, the compatibility tends to decrease, and if it is too small, the antistatic performance tends to be inferior.

  In applications where high holding power is required, it is preferable to use a monomer having a high glass transition temperature (Tg) from the viewpoint of increasing the cohesive strength of the resin. Specifically, the glass transition temperature (Tg) is preferably 0 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 80 ° C. or higher. The upper limit of the glass transition temperature (Tg) is usually 150 ° C. from the viewpoint of preventing the surface tack of the adhesive from being lowered and preventing the initial adhesive force from being lowered. The monomer having a high glass transition temperature (Tg) is a glass transition temperature when the monomer is a homopolymer.

  In the present invention, as the monofunctional ethylenically unsaturated compound (B), the glass transition temperature (Tg) when only the monofunctional ethylenically unsaturated compound (B) is copolymerized is within the range of −90 to 0 ° C. It is preferable to use those that are in the range of −80 to −10 ° C., more preferably −70 to −20 ° C. This is because if the glass transition temperature (Tg) is too low, the tendency to be inferior in cohesive force is seen, and conversely, if it is too high, sufficient adhesive strength tends to be not obtained.

As a compounding ratio of the acrylic resin (A) and the monofunctional ethylenically unsaturated compound (B), the acrylic resin (A): monofunctional ethylenically unsaturated compound (B) is 5:95 to 50:50 ( a weight ratio), in particular 7: 93-45: 55 (weight ratio), more 10: 90-40: is preferably 60 (weight ratio). If the blending ratio of the acrylic resin (A) is too small, the viscosity is too low and tends to be a hindrance to coating. Conversely, if too large, the viscosity tends to be a hindrance to coating. This is because seen.

  Moreover, in this invention, the difference of the glass transition temperature (Tg) of acrylic resin (A) and the glass transition temperature (Tg) at the time of superposing | polymerizing only a monofunctional ethylenically unsaturated compound (B) is 10 degreeC. As described above, in particular, 20 ° C. or higher, more preferably 30 ° C. or higher, is preferable from the viewpoint of reducing the adhesive property fluctuation. This is because if the difference in the glass transition temperature (Tg) is too small, there is a tendency that the variation in adhesiveness tends to increase. In addition, the upper limit of the difference in the glass transition temperature (Tg) is usually 200 ° C.

<< Photopolymerization initiator (C) >>
As the photopolymerization initiator (C) used in the present invention, a triazine photopolymerization initiator that generates radicals by the action of active energy rays such as light is used as an essential component.

  Examples of the triazine photopolymerization initiator include 2,4,6-trisubstituted-s-triazines represented by the following general formula (a).

  Examples of the alkyl group include an alkyl group having 1 to 10 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an n-hexyl group, and the like. It is done. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, an aryl group, a heteroaryl group, and the like. A halogen atom, more preferably a chlorine atom or a bromine atom, specifically, a trichloromethyl group, a tribromomethyl group, an α, α, β-trichloroethyl group, or the like.

  Examples of the aryl group include those having 6 to 20 carbon atoms, specifically phenyl group, p-methoxyphenyl group, p-methylthiophenyl group, p-chlorophenyl group, 4-biphenylyl group, naphthyl group, 4 -Methoxy-1-naphthyl group and the like. The aryl group may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, and a heteroaryl group.

  As said alkenyl group, C2-C12 things, such as a vinyl group, an allyl group, 2-phenylethenyl group, are mention | raise | lifted, for example. Furthermore, as said alkoxy group, C1-C10 things, such as a methoxy group, an ethoxy group, a butoxy group, are mention | raise | lifted, for example. The alkenyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, an aryl group, and a heteroaryl group.

  As said alkoxy group, a C1-C10 alkoxy group, for example, a methoxy group, an ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group etc. are mention | raise | lifted, for example. The alkoxy group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group, a sulfanyl group, an aryl group, a heteroaryl group, and the like.

  The monohalogen-substituted methyl group, dihalogen-substituted methyl group or trihalogen-substituted methyl group includes chloromethyl group, bromomethyl group, iodomethyl group, dichloromethyl group, dibromomethyl group, diiodomethyl group, trichloromethyl group, tribromomethyl. Group and triiodomethyl group. Of these, a trichloromethyl group substituted with a chlorine atom is preferred.

  Such 2,4,6-trisubstituted-s-triazines represented by the general formula (a) are, for example, Journal of American Chemical Society 72, 3257-3528 (1950), Journal of American Chemical Society 74, 5633-5636 (1952), Juatus Lieblgs Annalen der Chemie 577, 77-95 (1952).

Specific examples of the 2,4,6-trisubstituted-s-triazine represented by the general formula (a) include 2,4,6-tris (trichloromethyl) -s-triazine, 2,4, 6-tris (tribromomethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-methyl-s-triazine, 2,4-bis (tribromomethyl) -6-methyl-s-triazine, 2,4-bis (trichloromethyl) -6- (p-tolyl) -s-triazine, 2,4-bis (trichloromethyl) -6-n-propyl-s-triazine, 2- (α, α, β -Trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine 2,4,6-tri 2,4,6-trisubstituted-s-triazine photoinitiators having only aliphatic substituents such as (bromomethyl) -s-triazine and 2,4,6-tris (chloromethyl) -s-triazine 2,4-bis (trichloromethyl) -6-phenyl-s-triazine, 2,4-bis (trichloromethyl) -6- (p-methoxyphenyl) -s-triazine, 2,4-bis (trichloromethyl) ) -6- (p-methylthiophenyl) -s-triazine, 2,4-bis (trichloromethyl) -6- (p-chlorophenyl) -s-triazine, 2,4-bis (trichloromethyl) -6- ( 2 ', 4'-dichlorophenyl) -s-triazine, 2- (p-bromophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (tribromomethyl) -6-phenyl-s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2,4-bis (trichloromethyl) -6- [2- (p-methoxyphenyl) ethenyl] -S-triazine, 2,4-bis (trichloromethyl) -6- [2- (o-methoxyphenyl) ethenyl] -s-triazine, 2- [2- (p-butoxyphenyl) ethenyl] -bis ( Trichloromethyl) -s-triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -2,4-bis (trichloromethyl) -s-triazine, 2- [2- (3,4,5- Trimethoxyphenyl) ethenyl] -2,4-bis (trichloromethyl) -s-triazine, 2- (1-naphthyl) -2,4-bis (trichloromethyl) -s-triazine, 2- ( 4-biphenylyl) -2,4-bis (trichloromethyl) -s-triazine, 2- (4′-methoxy-1′-naphthyl) -2,4-bis (trichloromethyl) -s-triazine, 2,4 -Bis (trichloromethyl) -6- (p-methoxynaphthyl) -s-triazine, 2,4-bis (trichloromethyl) -6- (piperonyl) -s-triazine, 2,4-bis (trichloromethyl)- 2,4,6-trisubstituted s-triazine photopolymerization initiator having an aromatic substituent such as 6- (p-methoxystyryl) -s-triazine,
Etc.
These may be used alone or in combination of two or more.

  Of these, it is preferable to use a 2,4,6-trisubstituted-s-triazine-based photopolymerization initiator having an aromatic substituent as the triazine-based photopolymerization initiator. It is particularly preferable to use 2,4-bis (trichloromethyl) -6- (p-methoxyphenyl) -s-triazine from the viewpoint of little compatibility.

  Furthermore, in the present invention, as the photopolymerization initiator (C), together with the above triazine photopolymerization initiator, other photopolymerization initiators such as alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators. Etc. can be used together. In particular, considering the physical properties of the adhesive, it is preferable to use at least one of the alkylphenone photopolymerization initiator and the acylphosphine oxide photopolymerization initiator together with the triazine photopolymerization initiator. Among these, the combination of the triazine photopolymerization initiator and the alkylphenone photopolymerization initiator is preferable.

  Examples of the alkylphenone photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -(4-Isopropylenephenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxy Ethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, methylphenylglyoxy 4- (2-hydroxyethoxy) phenyl- (2-hydroxy) 2-propyl) ketone, 4-benzoyl-4'-methyl diphenyl sulfide, and the like. Further, benzophenone, 4-phenylbenzophenone, hydroxybenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 3,3 ′, 4,4′-tetra ( t-butylperoxycarbonyl) benzophenone and the like. These may be used alone or in combination of two or more. Of these, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone benzophenone, methylbenzophenone, and 2,4,6-trimethylbenzophenone are preferably used.

  Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like. . These may be used alone or in combination of two or more.

  A combination ratio (x: y) of the triazine photopolymerization initiator (x) and at least one of the alkylphenone photopolymerization initiator and the acylphosphine oxide photopolymerization initiator (y). Is preferably set in the range of x: y = 1: 1 to 1: 5, particularly preferably x: y = 1: 2 to 1: 4. That is, if the amount of the triazine photopolymerization initiator (x) is too small, it tends to be difficult to obtain a pressure sensitive adhesive having sufficient adhesive properties by irradiation with an active energy ray having a low integrated light amount. This is because when the initiator (x) is too much, the yellowing of the coating film becomes severe or the adhesive strength tends to decrease.

  If necessary, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethyl as an auxiliary for the photopolymerization initiator (C). Aminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthio It is also possible to use xanthone, 2,4-diisopropylthioxanthone and the like together.

  The content of the photopolymerization initiator (C) in the present invention is such that when the above triazine photopolymerization initiator is used alone as the photopolymerization initiator (C), the acrylic resin (A) and the monofunctional ethylenic unsaturated The amount is preferably 0.01 to 0.5 part, more preferably 0.05 to 0.45 part, still more preferably 0.1 to 0.4 part with respect to 100 parts of the total amount of the compound (B). Particularly preferred is 0.15 to 0.35 part. When the content of the photopolymerization initiator (C) is too small, there is a tendency that the polymerization due to irradiation with active energy rays such as ultraviolet rays tends to vary, and conversely, if it is too much, a further effect can be obtained. It is a waste of time.

  On the other hand, when at least one of the alkylphenone photopolymerization initiator and the acylphosphine oxide photopolymerization initiator is used in combination with the triazine photopolymerization initiator as the photopolymerization initiator (C), an acrylic resin ( It is preferable that it is 0.1-3 parts with respect to 100 parts of total amount of A) and a monofunctional ethylenically unsaturated compound (B), More preferably, it is 0.3-2 parts, More preferably, it is 0.5. ~ 1 part. When the content of the photopolymerization initiator (C) is too small, there is a tendency that the polymerization due to irradiation with active energy rays such as ultraviolet rays tends to vary, and conversely, if it is too much, a further effect can be obtained. It is a waste of time.

  In the present invention, as the monomer constituting the active energy ray-curable resin composition, together with the components (A) to (C) described above, an ethylenically unsaturated compound having two or more ethylenically unsaturated groups (D ) May be used.

<< Ethylenically unsaturated compound (D) having two or more ethylenically unsaturated groups >>
The above-mentioned ethylenically unsaturated compound (D) having two or more ethylenically unsaturated groups (hereinafter sometimes abbreviated as “polyfunctional ethylenically unsaturated compound (D)”) is the monofunctional ethylenically unsaturated compound described above. Like the saturated compound (B), it is a liquid or solid monomer.

  Examples of the polyfunctional ethylenically unsaturated compound (D) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol. Di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide modified bisphenol A type di (meth) Acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate , Pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid modified neopentyl glycol Bifunctional (meth) acrylic monomers such as di (meth) acrylate; trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl Terupori (meth) acrylate such as trifunctional or more (meth) acrylic monomer, and the like. In addition to the above, polyfunctional (meth) acrylate compounds such as urethane (meth) acrylate compounds and epoxy (meth) acrylate compounds can also be used. Among them, trifunctional or higher (meth) acrylic monomers are preferable, and trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and pentaerythritol tri (meth) acrylate are particularly preferable. Moreover, these can be used individually or in combination of 2 or more types.

  Content of the said polyfunctional ethylenically unsaturated compound (D) is the range of 0.005-5 parts with respect to a total of 100 parts of acrylic resin (A) and a monofunctional ethylenically unsaturated compound (B). It is preferably 0.01 to 5 parts, more preferably 0.1 to 3 parts. When there is too much content of the said polyfunctional ethylenically unsaturated compound (D), there exists a tendency for adhesive force to become low too much.

  Furthermore, an ionic compound (E) can be blended with the (A) to (C) and (D) for the purpose of imparting antistatic performance to the resin composition of the present invention.

<< Ionic compound (E) >>
The ionic compound (E) may be any compound having ionicity, for example, an alkali metal salt, an alkaline earth metal salt, a quaternary ammonium salt, an aliphatic sulfonate, a higher acid salt of an organic acid or an inorganic acid. Alcohol sulfate ester, higher alcohol alkylene oxide adduct sulfate ester salt, higher alcohol phosphate ester salt, higher alcohol alcohol alkylene oxide adduct phosphate ester salt, alkylbetaine compound, alkylimidazoline compound, alkylalanine compound, polyvinylbenzyl cation Examples thereof include polyacrylic acid type cationic compounds. Among these, alkali metal salts, alkaline earth metal salts, and quaternary ammonium salts are preferably used, and alkali metal salts are particularly preferably used.

Examples of the alkali metal salt include a cation selected from Li ⁺ , Na ⁺ and K ⁺ and Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , SCN ⁻ , ClO ₄ ⁻ and CF ₃ SO _{3. ^{-, (CF 3 sO 2)}} 2 N -, (CF 3 sO 2) 3 C - metal salt composed of anions selected from is suitably used. Among these, LiBr, LiI, LiBF ₄ , LiPF ₆ , LiSCN, LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (CF ₃ ) are excellent in ion conductivity and excellent in antistatic function. A lithium salt such as SO ₂ ) ₃ C is preferably used.

  Examples of the alkaline earth metal salt include calcium salt, magnesium salt and halides thereof.

  Examples of the quaternary ammonium salt include quaternary ammonium such as tetraalkyl ammonium sulfonic acid, alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, trialkyl benzyl ammonium salt, alkyl pyridinium salt, and (poly) oxyalkylene trialkyl ammonium salt. A salt is preferably used.

  These ionic compounds (E) may be used alone or in combination of two or more.

  Furthermore, an ionic liquid can be used as the ionic compound (E). The ionic liquid in this invention represents the ionic substance which consists of a cation component and an anion component which hold | maintain a liquid at the fixed temperature of the range of 0-150 degreeC.

  The cation component is not particularly limited, and cations used in general ionic liquids are used. Examples of the cation include a cation of a heterocyclic compound, particularly a cation of a 1- to 5-membered heterocyclic compound containing 1 to 5 heteroatoms, particularly a nitrogen atom as a heteroatom. Examples thereof include cations of 1 to 5 membered heterocyclic compounds containing 1 to 5 heteroatoms, and among them, imidazolium cation, pyrrolidinium cation, piperidinium cation, pyridinium cation and the like are preferable. It is also preferable to use a chain-like quaternary ammonium cation or quaternary phosphonium cation. Among these, imidazolium cation, pyridinium cation, quaternary ammonium cation, and quaternary phosphonium cation are preferable, and imidazolium cation is particularly preferable in terms of low viscosity.

On the other hand, the anion component is not particularly limited. For example, Cl ⁻ , Br ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , _{^{CH 3 COO -, CF 3 COO}} -, CH 3 SO 3 - CF 3 SO 3 -, (CF 3 SO 2) 2 N -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF ₆ ⁻ , TaF ₆ ⁻ , F (HF) n ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF _{3 SO 2) (CF 3 CO} ) N - it is possible to use an anion commonly used in ionic liquids and the like.

  Further, as the ionic liquid used in the present invention, an ionic liquid containing a polymerizable unsaturated group can also be used. For example, 1- (2- (meth) acryloyloxyethyl) -3-octylimidazolium bromide (Meth) acrylic imidazolium cation systems such as halogen salts of (meth) acryloyloxyethyl-3-alkylimidazolium such as 1- (2- (meth) acryloyloxyethyl) -3-octylimidazolium chloride Compounds, vinylimidazolium cation compounds such as 1-butyl-3-vinylimidazolium tetrafluoroborate (1B3VIBF4), 1-butyl-3-vinylimidazolium trifluoromethanesulfonimide (1B3VITFSI), and halogen ions as anionic components An ionic liquid consisting ofWhen these ionic liquids having a polymerizable unsaturated group are used, they are involved in the polymerization by irradiation with active energy rays, which is preferable without causing bleed out.

  The content of the ionic compound (E) is preferably 0.01 to 5 parts with respect to a total of 100 parts of the acrylic resin (A) and the monofunctional ethylenically unsaturated compound (B). Preferably it is 0.05-3 parts, Most preferably, it is 0.1-1.5 parts. If the content of the ionic compound (E) is too small, the effect of imparting antistatic performance tends to be difficult to obtain, and if the content of the ionic compound (E) is too large, the adhesive physical properties may decrease. , Tend to cause glue residue.

  In addition, the resin composition of the present invention is one that is crosslinked by irradiating active energy rays instead of the conventional method of crosslinking an acrylic resin using a general crosslinking agent. In order to enhance the properties, the cross-linking agent may be blended in a small amount compared to the conventional case, that is, in an amount range that does not extend the aging time, but it is usually preferable to use without using the cross-linking agent.

  Examples of the crosslinking agent include isocyanate-based, epoxy-based, metal salts, metal alkoxides, aldehyde-based compounds, non-amino resin-based amino compounds, urea-based, metal chelate-based, melamine-based, and aziridin-based crosslinkers. You can give the agent.

  Further, in the present invention, other pressure-sensitive adhesives, urethane resins, rosins, rosin esters, hydrogenated rosin esters, phenol resins, aromatic modified terpene resins, aliphatic petroleum resins, alicyclic rings, as long as the effects of the present invention are not impaired. It is possible to add tackifiers such as group petroleum resins, styrene resins and xylene resins, known additives, and compounds that cause coloration or discoloration upon irradiation with ultraviolet rays or radiation.

  By using the above component materials, the active energy ray-curable resin composition of the present invention is obtained.

<< Method for producing active energy ray-curable resin composition, pressure-sensitive adhesive and pressure-sensitive adhesive sheet >>
The active energy ray-curable resin composition of the present invention includes the acrylic resin (A), the monofunctional ethylenically unsaturated compound (B), the photopolymerization initiator (C), and a multicomponent compounded as necessary. It can be obtained by mixing other components such as a functional ethylenically unsaturated compound (D) and an ionic compound (E).

  The active energy ray-curable resin composition does not substantially contain water, an aqueous solvent, or an organic solvent, and usually the acrylic resin (A) in the monofunctional ethylenically unsaturated compound (B). , The photopolymerization initiator (C), and other components such as a polyfunctional ethylenically unsaturated compound (D) and an ionic compound (E) blended as necessary are dissolved or uniformly dispersed. Is preferred. This active energy ray-curable resin composition comprises an acrylic resin (A), a monofunctional ethylenically unsaturated compound (B), a photopolymerization initiator (C), and a polyfunctional ethylenically unsaturated compound appropriately blended as necessary. Other components such as the saturated compound (D) and the ionic compound (E) can be prepared by heating and mixing at room temperature (25 ° C. ± 10 ° C.) or, in some cases, from room temperature to 60 ° C. . More preferably, each component except the photopolymerization initiator (C) is preliminarily mixed (0.5 to 30 hours) at room temperature or in advance, and then mixed with the photopolymerization initiator (C). The active energy ray-curable resin composition is prepared.

  The active energy ray-curable resin composition is a viscous liquid composition. Therefore, the active energy ray-curable resin composition of the present invention can be applied to a substrate as it is. In some cases, it may be diluted with an organic solvent. However, it is preferable that the organic solvent is not contained, that is, a non-solvent system is used from the viewpoint of workability of adhesive production and compatibility with the global environment. In addition, if the acrylic resin (A) of dry resin obtained by the above-mentioned suspension polymerization etc. is used, the said active energy ray hardening-type resin composition can be manufactured, without containing an organic solvent.

  Furthermore, the said active energy ray hardening-type resin composition becomes an active energy ray irradiation polymer by irradiating an active energy ray, and has the adhesive performance as an adhesive.

  When irradiating active energy rays, as active energy rays, rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, electromagnetic waves such as X rays and γ rays, electron beams, proton rays, neutron rays, etc. can be used. However, curing by ultraviolet irradiation is advantageous from the viewpoint of curing speed, availability of an irradiation device, price, and the like.

  For ultraviolet irradiation, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp, or the like that emits light in a wavelength range of 150 to 450 nm can be used.

In the present invention, the exposure dose of the actinic energy ray, it is preferable that the integrated light quantity is 1000 mJ / cm ² or less, particularly 900 mJ / cm ² or less, and more preferably at 800 mJ / cm ² or less. When there is too much said irradiation amount, there exists a tendency for a burden to become large in facilities, such as cost and an apparatus. In addition, the minimum of the integrated light quantity of active energy ray irradiation amount is 50 mJ / cm < ² > normally.

  The pressure-sensitive adhesive which is an active energy ray-irradiated polymer after being crosslinked by irradiation with active energy rays preferably has a gel fraction of 40 to 100% by weight, particularly 50 to 100% by weight, and more preferably 60 to 60%. It is preferably 100% by weight. This is because if the gel fraction is too small, the peelability of the pressure-sensitive adhesive tends to be reduced due to insufficient cohesive force.

  In addition, the said gel fraction becomes a standard of a crosslinking degree, and is computed with the following method. That is, an adhesive sheet (not provided with a separator) obtained as described below is wrapped in a 200 mesh SUS wire mesh, immersed in toluene at 23 ° C. for 24 hours, and the insoluble adhesive component remaining in the wire mesh The weight percentage is taken as the gel fraction. At this time, the weight of the substrate is subtracted.

  Here, in adjusting the gel fraction of such a pressure-sensitive adhesive to the above range, adjusting the irradiation amount and irradiation intensity of the active energy ray, using a photopolymerization initiator alone or in combination, This can be achieved by adjusting the ratio when each photopolymerization initiator is used in combination, and by adjusting the amount of the photopolymerization initiator.

  The irradiation amount and irradiation intensity of the active energy ray, the composition ratio of the photopolymerization initiator, and the addition amount need to be balanced because the gel fraction changes due to the respective interactions.

  In the present invention, as described above, the active energy ray-curable resin composition is used to irradiate active energy rays, thereby having adhesive performance as an adhesive. Specifically, for example, After applying or impregnating the active energy ray-curable resin composition to the base material, the active energy ray is irradiated to produce a pressure sensitive adhesive sheet having a pressure sensitive adhesive layer formed on the base material. It is pasted together.

  In the present invention, the “sheet” is not particularly distinguished from “film” or “tape”, but is described as meaning including these.

  The material of the base material is not particularly limited as long as it is a material forming a sheet. For example, aluminum, copper, iron metal foil, polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer Polyester resins such as coalescence, polyolefin resins such as polyethylene, polypropylene, polymethylpentene, polyfluorinated ethylene resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene, polyamides such as nylon 6, nylon 6,6, and poly Cellulose such as vinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, vinyl polymers such as polyvinyl alcohol and vinylon, cellulose triacetate, cellophane, etc. Resin, polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, polybutyl acrylate and other acrylic resins, polystyrene, polycarbonate, polyarylate, polyimide and other synthetic resin sheets, fine paper, glassine paper, etc. Examples thereof include a single layer or a multilayer such as paper, glass fiber, natural fiber, and synthetic fiber.

  Among these, in consideration of price, a sheet of polyethylene terephthalate, polyethylene, polypropylene, or the like is preferably used.

  In addition, in order to improve the anchoring property of the pressure-sensitive adhesive layer to the base material, the surface of the base material is treated to improve known easy tackiness such as corona discharge treatment, plasma treatment, primer coating, degreasing treatment, and surface roughening treatment. In addition, an antistatic layer may be provided for antistatic.

  Although the thickness of the said base material is suitably set according to a use, a material, etc., generally it is 500 micrometers or less, Preferably it is 5-300 micrometers, More preferably, the thickness of about 10-200 micrometers can be illustrated.

  Moreover, although the thickness of the said adhesive layer formed on a base material is suitably set according to a use, generally it is 5-400 micrometers, Preferably it is 10-300 micrometers. This is because if the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive physical properties are difficult to stabilize, and if the thickness is too thick, there is a tendency that adhesive residue tends to occur.

  In particular, when the thickness of the pressure-sensitive adhesive layer is 100 μm or more, a monomer having a high glass transition temperature (Tg) of 0 ° C. or more when a homopolymer is obtained as the monofunctional ethylenically unsaturated compound (B). The use of compounds such as cyclohexyl (meth) acrylate, methyl (meth) acrylate, isobornyl (meth) acrylate, and tert-butyl (meth) acrylate increases the cohesive strength of the pressure-sensitive adhesive layer, thereby increasing the holding power and heat resistance. It is preferable at an excellent point.

  The pressure-sensitive adhesive strength of the pressure-sensitive adhesive sheet using the pressure-sensitive adhesive of the present invention is usually preferably 1 to 50 (N / 25 mm), particularly 2 to 40 (N / 25 mm), and more preferably 3 to 30 (N / 25 mm). ) Is preferable.

  The said adhesive force is measured as follows according to JISZ-0273, for example. First, the obtained pressure-sensitive adhesive sheet was cut into 25 mm × 100 mm, and this was then applied to a stainless steel plate (SUS304BA plate) as an adherend using a 2 kg rubber roller in an atmosphere of 23 ° C. and 50% relative humidity. A test piece is produced by pressure bonding by reciprocating. After leaving this test piece for 30 minutes in the same atmosphere, a 180 degree peel test is performed at a peel speed of 0.3 m / min, and the adhesive strength (N / 25 mm) is measured.

  A separator can be laminated on the surface of the pressure-sensitive adhesive sheet for the purpose of protecting the pressure-sensitive adhesive layer from contamination until the pressure-sensitive adhesive sheet using the pressure-sensitive adhesive of the present invention is bonded to an adherend. As the separator, those obtained by releasing the synthetic resin sheet, paper, cloth, nonwoven fabric and the like exemplified in the base material can be used.

  As described above, a pressure-sensitive adhesive sheet using the pressure-sensitive adhesive of the present invention is obtained by applying or impregnating a base material with an active energy ray-curable resin composition and irradiating active energy rays. When the active energy ray-curable resin composition is in the form of a solution, a direct coating method in which a solution-like active energy ray-curable resin composition is directly applied to a substrate or a solution-like active energy ray-curable resin composition After the resin composition is applied to the separator, it is laminated on the base material by a transfer coating method in which the resin composition is bonded to the base material.

  In the direct coating method, an active energy ray-curable resin composition is applied to a base material, and after heating and drying as necessary, a separator is bonded. The coating is performed by a conventional method such as roll coating, die coating, gravure coating, comma coating, or screen printing.

  On the other hand, in the transfer coating method, the base material is bonded after coating the active energy ray-curable resin composition. About the coating method, the method similar to direct coating can be used.

  The type of adherend to which the adhesive of the present invention can be used is not particularly limited. For example, aluminum, copper, iron metal foil, polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer Polyester resins such as coalescence, polyolefin resins such as polyethylene, polypropylene, polymethylpentene, polyfluorinated ethylene resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene, polyamides such as nylon 6, nylon 6,6, and poly Vinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, vinyl polymers such as polyvinyl alcohol and vinylon, cellulose-based trees such as cellulose triacetate and cellophane , Polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, acrylic resins such as polybutyl acrylate, polystyrene, polycarbonate, polyarylate, synthetic resin sheet or plate such as polyimide and the like.

  As described above, the pressure-sensitive adhesive of the present invention is used for labels / sheets, tapes, building materials, packaging materials, electronics, display panels, optical film bonding, shock absorption layers, glass scattering prevention layers, metal plates. It is used for glass plates, synthetic resin plates, laminated steel plates and the like, and can be suitably used as an adhesive.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.

[Manufacture of acrylic resin (A)]
Into a glass four-necked round-bottom flask equipped with a stirrer, 300 parts of water was dissolved, 0.7 parts of polyvinyl alcohol was dissolved as a dispersion stabilizer, and the mixture was stirred at 300 rpm with a stirring blade. A monomer mixture consisting of 8 parts, acrylonitrile 7.2 parts, 2-hydroxyethyl methacrylate 5 parts and 0.9 part of N, N'-azobisisobutyronitrile as a polymerization initiator are charged all together and suspended. A liquid was prepared.

  The suspension was allowed to react with stirring for 4 hours while the temperature in the reaction system was raised to 68 ° C. while stirring was continued. Then, it cooled to room temperature (about 25 degreeC). Next, the reaction product was separated into solid and liquid, sufficiently washed with water, and then dried at 70 ° C. for 12 hours using a dryer to obtain a bulk acrylic resin (A). The resulting acrylic resin (A) had a weight average molecular weight (Mw) of 1.3 million, a dispersity (Mw / Mn) of 4.6, and a glass transition temperature of −47 ° C.

  Using the acrylic resin (A) obtained as described above, each active energy ray-curable resin composition and pressure-sensitive adhesive sheet were produced according to the following examples and comparative examples.

[Example 1]
10 parts of acrylic resin (A) produced as described above, 41.7 parts of n-butyl acrylate (n-BA) as monofunctional ethylenically unsaturated compound (B), 41 of 2-ethylhexyl acrylate (2EHA) 7 parts and 6.6 parts of acrylic acid (AAc) were put into a container equipped with a stirrer, and stirred and mixed for 24 hours to dissolve. To this solution, 0.3 part of 2,4-bis (trichloromethyl) -6- (p-methoxyphenyl) -s-triazine (manufactured by Nippon Sebel Hegner, Triazine A) as a photopolymerization initiator (C) was mixed. By doing so, an active energy ray-curable resin composition was obtained.

The active energy ray-curable resin composition obtained above was applied on a polyethylene terephthalate (PET) substrate having a thickness of 25 μm so as to have a thickness of 25 μm. Furthermore, the coated surface was coated so that the release-treated surface was in contact with the coated surface, using a PET substrate that had been subjected to a release treatment. Then, using the ultraviolet irradiation apparatus shown below, it is photopolymerized by irradiating ultraviolet rays so that the integrated light quantity becomes 600 mJ / cm ² from a high pressure mercury lamp adjusted so that the irradiation intensity becomes 200 mW / cm ^2. A sheet was obtained.
<Ultraviolet irradiation device>
Eye Grandage ECS-301G1 (I Graphics)
<Irradiation conditions>
80 W / cm (high pressure mercury lamp) × 18 cmH, irradiation intensity 200 mW / cm ²

[Example 2]
In Example 1, the integrated light quantity of ultraviolet irradiation was set to 800 mJ / cm ² . Other than that was carried out similarly to Example 1, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

Example 3
In Example 1, as a photopolymerization initiator (C), 2-hydroxy-2-methyl-1-phenyl-propan-1-one [trade name: “Darocur 1173”; Ciba Specialty together with 0.3 part of triazine A] -Chemicals Inc.] (D-1173) 1 part was used together. Other than that was carried out similarly to Example 1, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

Example 4
In Example 3, the integrated light quantity of ultraviolet irradiation was set to 800 mJ / cm ² . Other than that was carried out similarly to Example 3, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

Example 5
In Example 3, in addition to the acrylic resin (A), the monofunctional ethylenically unsaturated compound (B), and the photopolymerization initiator (C), trimethylolpropane tris, which is a polyfunctional ethylenically unsaturated compound (D), is used. 0.3 parts of acrylate (TMPTA) was used. Other than that was carried out similarly to Example 3, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

Example 6
In Example 4, in addition to the acrylic resin (A), the monofunctional ethylenically unsaturated compound (B), and the photopolymerization initiator (C), trimethylolpropane tris, which is a polyfunctional ethylenically unsaturated compound (D), is used. 0.3 parts of acrylate (TMPTA) was used. Other than that was carried out similarly to Example 4, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

[Comparative Example 1]
An active energy ray-curable resin composition was obtained in the same manner as in Example 1 except that 1 part of D-1173 was used instead of triazine A which is the photopolymerization initiator (C) of Example 1.

[Comparative Example 2]
An active energy ray-curable resin composition was obtained in the same manner as in Example 2 except that 1 part of D-1173 was used instead of triazine A which is the photopolymerization initiator (C) of Example 2.

[Comparative Example 3]
An active energy ray-curable resin composition was obtained in the same manner as in Example 5 except that only 1 part of D-1173 was used as the photopolymerization initiator (C) in Example 5.

[Comparative Example 4]
An active energy ray-curable resin composition was obtained in the same manner as in Example 6 except that only 1 part of D-1173 was used as the photopolymerization initiator (C) of Example 6.

[Comparative Example 5]
In Comparative Example 1, the integrated light amount of ultraviolet irradiation was 2400 mJ / cm ² . Other than that was carried out similarly to Example 1, and obtained the active energy ray hardening-type resin composition and the adhesive sheet.

  The blending ratio of each of the component materials used in the examples and comparative examples is shown in Table 1 below.

  About the adhesive sheet obtained by said Example and comparative example, while performing the evaluation of an adhesive characteristic (measurement of adhesive force) by the following method, the gel fraction of the adhesive layer was measured, and the result was combined. The results are shown in Table 1 below.

[Evaluation test of adhesive sheet]
(1) Adhesive force Adhesive force was measured according to JIS Z-0273. That is, after the obtained pressure-sensitive adhesive sheet was cut into 25 mm × 100 mm, this was applied to a stainless steel plate (SUS304BA plate) as an adherend using a 2 kg rubber roller in an atmosphere of 23 ° C. and 50% relative humidity. A test piece was prepared by pressure bonding by reciprocating. The test piece was allowed to stand for 30 minutes in the same atmosphere, and then subjected to a 180 ° peel test at a peel rate of 0.3 m / min, and the adhesive strength (N / 25 mm) was measured.

(2) Gel fraction After the obtained pressure-sensitive adhesive sheet was cut into 50 mm × 50 mm, the pressure-sensitive adhesive layer side of this pressure-sensitive adhesive sheet was avoided from the central portion in the longitudinal direction of a 60 × 100 mm SUS mesh sheet (200 mesh). The test piece was prepared by pasting the mesh sheet and then folding the mesh sheet from the center to wrap the adhesive sheet. The test piece is immersed in a sealed container containing 180 g of toluene at 23 ° C. for 24 hours, and the weight percentage of the insoluble adhesive component remaining in the mesh sheet is defined as the gel fraction. At this time, the weight of the substrate is subtracted.

Example 7
10 parts of acrylic resin (A), 30 parts of n-butyl acrylate (n-BA) as monofunctional ethylenically unsaturated compound (B), 35 parts of 2-ethylhexyl acrylate (2EHA), 15 isobornyl acrylate (IBXA) Part and 10 parts of acrylic acid (AAc) were put into a container equipped with a stirrer and stirred and mixed for 24 hours to dissolve. To this solution, 0.05 part of 2,4-bis (trichloromethyl) -6- (p-methoxyphenyl) -s-triazine (manufactured by Nippon Sebel Hegner, Triazine A) as a photopolymerization initiator (C), 0.95 part of 2,4,6-trimethylbenzoyl-diphenyl-phosphinoxide (Darocur TPO, manufactured by Ciba Specialty Chemicals) (D-TPO) was also used. Furthermore, active energy ray-curable resin composition was obtained by mixing 0.3 part of trimethylolpropane triacrylate (TMPTA) which is a polyfunctional ethylenically unsaturated compound (D).

The active energy ray-curable resin composition obtained above was coated on a polyethylene terephthalate (PET) substrate having a thickness of 50 μm so as to have a thickness of 200 μm. Furthermore, the coated surface was coated so that the release-treated surface was in contact with the coated surface, using a PET substrate that had been subjected to a release treatment. Thereafter, ultraviolet light was irradiated from a high-pressure mercury lamp adjusted so that the irradiation intensity was 200 mW / cm ² and the integrated light amount was 800 mJ / cm ^2, and photopolymerization was performed to obtain an adhesive sheet.

[Evaluation test of adhesive sheet (Example 7)]
The adhesive strength and gel fraction of the obtained adhesive sheet (Example 7) were measured according to the method described above. Moreover, regarding the obtained adhesive sheet (Example 7), the following holding force test was performed and measured. These evaluation results (adhesive strength, gel fraction, holding power) are shown together with the blending ratio of the component materials of Example 7 in Table 2 below.

(3) Holding power test The obtained pressure-sensitive adhesive sheet was applied to SUS304 as an adherend according to JIS Z-0273, and pasted at a pasting area of 25 mm x 25 mm, and left at 80 ° C for 20 minutes, and then a 1 kg load was applied. The deviation (mm) after 24 hours was measured. Usually, the deviation (mm) after 24 hours is required to be 1 mm or less.

From the above results, in all embodiments, the integrated quantity of light in the ultraviolet irradiation despite small dose compared with the conventional of 600 mJ / cm ² or 800 mJ / cm ^2, shows a good adhesion, also high It can be seen that the gel fraction has been reached. In particular, in Examples 3 and 4 in which only the monofunctional ethylenically unsaturated compound (B) was used as the monomer component, and D-1173 was used in combination with triazine A as the photopolymerization initiator (C), the adhesive force was further improved. The result which shows was obtained. Moreover, in Example 7, even when the film thickness was relatively thick at 200 μm, a result showing a sufficient adhesive force and holding force with a low irradiation amount was obtained.

On the other hand, among Comparative Examples 1 to 5 using D-1173 without using a triazine photopolymerization initiator (triazine A) as the photopolymerization initiator (C), Comparative Examples 1 and 2 have an integrated light amount. Since UV irradiation is 600 mJ / cm ² or 800 mJ / cm ² , the polymerization reaction due to UV irradiation is insufficient, there are many unreacted components, interfacial peeling occurs on the base material, and the gel fraction is also higher than in the examples. The result was extremely low. In Comparative Examples 3 and 4, the adhesive strength showed a certain value, but the polymerization reaction due to ultraviolet irradiation was insufficient, and there were many low molecular weight components, so the sticking caused by this was confirmed and strong. It turns out that it is unsuitable for use as an adhesive sheet. Then, in Comparative Example 5 in which the ultraviolet light irradiation with an integrated light amount of 2400 mJ / cm ² was performed, interface peeling occurred in the base material and the gel fraction was 0 as in Comparative Examples 1 and 2.

  The present invention provides an active energy ray-curable resin composition having excellent adhesive properties obtained with a small amount of active energy ray irradiation and having a stable adhesive force, and an adhesive exhibiting strong adhesiveness obtained thereby, and It provides adhesive sheets, for labels and sheets, for tapes, for building materials, for packaging materials, for electronics, display panels, optical film bonding, shock absorbing layers, glass scattering prevention layers, metal plates, glass plates It is very useful for adhesives used for synthetic resin plates, laminated steel plates and the like.

Claims (8)

A resin composition for an active energy ray-curable pressure-sensitive adhesive comprising an acrylic resin (A), an ethylenically unsaturated compound (B) having one ethylenically unsaturated group, and a photopolymerization initiator (C). the weight average molecular weight of the acrylic resin (a) (Mw) is Ri der 500,000, the acrylic resin (a) and the ethylenically unsaturated compound having one ethylenically unsaturated group and (B) The mixing ratio of (A) :( B) = 5: 95 to 50:50 (weight ratio), and a triazine photopolymerization initiator is used as the photopolymerization initiator (C). A resin composition for an energy ray curable pressure-sensitive adhesive . The resin composition for an active energy ray-curable adhesive according to claim 1, wherein the acrylic resin (A) is a dry resin obtained by suspension polymerization. Furthermore, the resin composition for active energy ray hardening-type adhesives of Claim 1 or 2 containing the ethylenically unsaturated compound (D) which has 2 or more of ethylenically unsaturated groups. The active energy ray according to any one of claims 1 to 3, further comprising at least one of an alkylphenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator as the photopolymerization initiator (C). A resin composition for a curable adhesive . The resin composition for active energy ray hardening-type adhesives as described in any one of Claims 1-4 which does not contain a solvent. A pressure-sensitive adhesive obtained by irradiating the active energy ray-curable pressure-sensitive adhesive resin composition according to any one of claims 1 to 5 with active energy rays. The pressure-sensitive adhesive according to claim 6, wherein the irradiation with the active energy ray has an integrated light quantity of 1000 mJ / cm ² or less.   A pressure-sensitive adhesive sheet comprising a base material and a layer made of the pressure-sensitive adhesive according to claim 6.