JP2021138909A - Active energy ray-curable resin composition, pressure-sensitive adhesive composition and pressure-sensitive adhesive - Google Patents

Abstract

To provide an active energy ray-curable resin composition that uses a urethane (meth)acrylate compound made from raw material of plant origin, and has adhesion to various members, particularly excellent adhesion as an adhesive.SOLUTION: An active energy ray-curable resin composition contains a urethane (meth)acrylate compound (A). The urethane (meth)acrylate compound (A) is a reactant among a polyester polyol (a1) containing a dimer acid-derived structural site, a polyvalent isocyanate (a2) and a hydroxy group-containing (meth)acrylate (a3), and has a number average molecular weight of 7000-25000.SELECTED DRAWING: None

Description

The present invention relates to an active energy ray-curable resin composition, and more specifically, it contains a urethane (meth) acrylate-based compound made of a plant-derived raw material, and has adhesion to various members, particularly an adhesive. It relates to an active energy ray-curable resin composition having a good adhesive strength when it is used.

Conventionally, urethane (meth) acrylate compounds obtained by reacting diol compounds such as polyester diols and polyether diols, diisocyanate compounds such as isophorone diisocyanate and diphenylmethane diisocyanate, and hydroxyl group-containing (meth) acrylate compounds such as hydroxyethyl acrylate have been active. Known as an energy ray-curable resin composition, it is used in applications such as paints, coating agents, and adhesives.

However, many urethane (meth) acrylate compounds are composed of petroleum-derived raw materials, and the current situation is that they are not considered for environmental problems such as global warming.
In addition, while research on urethane (meth) acrylate-based compounds using plant-derived raw materials is being actively conducted, urethane (meth) acrylate-based compounds using polyester polyols using dimer acid, which is a plant-derived raw material, are being actively conducted. Compounds have been proposed (see, for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 5-43336 Japanese Unexamined Patent Publication No. 2010-100711 Japanese Unexamined Patent Publication No. 5-262884

However, the active energy ray-curable resin composition containing the urethane (meth) acrylate-based compound in Patent Documents 1 to 3 is inferior in the adhesive strength of the obtained adhesive, and is compatible with both environmental friendliness and adhesive physical characteristics. From this point of view, further improvement was required.

Therefore, under such a background, the present invention uses a urethane (meth) acrylate-based compound made of a plant-derived raw material, and has adhesiveness to various members, particularly good adhesive strength when used as an adhesive. It is an object of the present invention to provide an active energy ray-curable resin composition, and to provide a pressure-sensitive adhesive composition using the active energy ray-curable resin composition, and further to provide a pressure-sensitive adhesive.

However, as a result of intensive studies to solve the above problems, the present inventors have found that the active energy ray-curable resin composition containing a urethane (meth) acrylate-based compound contains a structural moiety derived from dimer acid. A reaction product of a polyester polyol (a1), a polyhydric isocyanate (a2), and a hydroxyl group-containing (meth) acrylate (a3), which is environmentally friendly by using a urethane (meth) acrylate compound having a large number average molecular weight. The present invention has been completed by finding that it is suitable, but has good adhesion to various members, particularly good adhesive strength when used as an adhesive.

That is, the gist of the present invention is an active energy ray-curable resin composition containing a urethane (meth) acrylate-based compound (A), wherein the urethane (meth) acrylate-based compound (A) has a structure derived from dimer acid. An active energy ray-curable resin composition which is a reaction product of a polyester polyol (a1) containing a moiety, a polyhydric isocyanate (a2) and a hydroxyl group-containing (meth) acrylate (a3) and has a number average molecular weight of 7,000 to 25,000. It is about.

Further, the present invention relates to a pressure-sensitive adhesive composition comprising the active energy ray-curable resin composition and a pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive composition.

In the present invention, a urethane (meth) acrylate compound (A) having a large molecular weight is prepared to form an active energy ray-curable resin composition, but it is generally used as a plant-derived raw material such as dimer acid or dimer diol. Urethane (meth) acrylate compounds using commonly used compounds may contain impurities because they are derived from plants, and if the molecular weight is increased, they may gel or the impurities may adversely affect the adhesive properties. Due to concerns, it is usually difficult to select a urethane (meth) acrylate-based compound with a large molecular weight, but surprisingly, while maintaining environmental friendliness, the molecular weight is also improved and the adhesive strength is increased. They found that they could also improve.

The active energy ray-curable resin composition of the present invention uses a plant-derived dimer acid and contains a polyester polyol (a1), a polyhydric isocyanate (a2), and a hydroxyl group-containing (meth) acrylate containing a dimer acid-derived structural site. The reaction product of (a3), which is an active energy ray-curable resin composition containing a urethane (meth) acrylate-based compound having a number average molecular weight in a predetermined range. Therefore, although it is suitable for the environment, it has good adhesion to various members, especially when it is used as an adhesive, and various coating agents, paints, inks, adhesives, etc. An active energy ray-curable resin composition that can be applied to applications. In particular, the active energy ray-curable resin composition of the present invention is useful as an adhesive because it has good adhesive strength.

Hereinafter, embodiments for carrying out the present invention will be specifically described, but the present invention is not limited thereto.

In the present invention, (meth) acrylic means acrylic or methacryl, and (meth) acrylate means acrylate or methacrylate, respectively.

The active energy ray-curable resin composition of the present invention contains a urethane (meth) acrylate-based compound (A), and preferably further contains an ethylenically unsaturated monomer (B).
Hereinafter, each component will be described.

<Urethane (meth) acrylate compound (A)>
The urethane (meth) acrylate compound (A) in the present invention is a reaction product of a polyester polyol (a1) containing a structural moiety derived from dimer acid, a polyhydric isocyanate (a2) and a hydroxyl group-containing (meth) acrylate (a3). Is.

Examples of the polyester polyol (a1) containing the structural site derived from dimer acid include (1) one obtained by a polycondensation reaction between dimer acid and a polyhydric alcohol, and (2) dimer diol obtained by reducing dimer acid. Examples thereof include those obtained by a polycondensation reaction of a valent carboxylic acid, and among them, (1) is mentioned in terms of availability.

Examples of the dimer acid include a thermal dimer acid of an unsaturated fatty acid and a hydrogenated dimer acid to which the unsaturated fatty acid is hydrogenated. Specifically, it is a dimer containing unsaturated fatty acids having 10 to 24 carbon atoms, preferably around 18 as main components, and for example, unsaturated fatty acids such as oleic acids, linoleic acids, linolenic acids, and erucic acids. It is a dicarboxylic acid derived from. Examples of the main dimer acid include those having 36 and 44 carbon atoms.

Examples of polyhydric alcohols that undergo a polycondensation reaction with dimer acid include aliphatic or alicyclic polyhydric alcohols having 2 to 40 carbon atoms, such as ethylene glycol, 1,3-propanediol, and 1,4-butanediol. 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1, , 12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecandiol, 1,18-octadecandiol, 1,20-eicosanediol, etc. Linear polyhydric alcohols; 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 2-ethyl-1,6 -Hexanediol, 2,4-diethyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, dimerdiol, etc. Polyhydric alcohol having a branched chain having 4 to 40 carbon atoms; 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and the like having a cyclic structure in a molecule having 4 to 20 carbon atoms. Polyhydric alcohols contained; examples thereof include diethylene glycol, triethylene glycol, polytetramethylene ether glycol, dimerdiol and the like. These polyhydric alcohols may be used alone or in combination of two or more. Among them, linear polyhydric alcohols having 2 to 10 carbon atoms, especially 1,3-propanediol and 1,4-butanediol, are used in terms of availability and adhesive strength when used as an adhesive. 1,6-Hexanediol and polyhydric alcohols having a branched chain having 4 to 10 carbon atoms, particularly neopentyl glycol are preferably used.

That is, the polyester polyol (a1) containing the structural moiety derived from dimer acid is selected from dimer acid, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol. It is particularly preferable that it is a polycondensate with at least one kind of glycol.

Examples of the polyvalent carboxylic acid that undergoes a polycondensation reaction with dimerdiol include malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecandioic acid. Alicyclic dicarboxylic acid such as aliphatic dicarboxylic acid; 1,4-cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, trimellitic acid, flangecarboxylic acid, etc. Aromatic dicarboxylic acid and the like can be mentioned. Of these, succinic acid, adipic acid, and sebacic acid are preferably used in terms of availability and adhesive strength when used as an adhesive.

In the present invention, the term "carboxylic acid" includes, in addition to carboxylic acid, derivatives of carboxylic acid such as carboxylic acid salt, carboxylic acid anhydride, carboxylic acid halide, and carboxylic acid ester.

In the present invention, the number average molecular weight of the polyester polyol (a1) containing a structural portion derived from dimer acid is preferably 800 to 5000, particularly 1000 to 5000 in terms of handleability and adhesive strength when used as an adhesive. It is preferably 4000, more preferably 2000 to 3000. If the number average molecular weight is too small, the adhesive strength tends to be low when used as a pressure-sensitive adhesive, and if it is too large, the viscosity of the polyester polyol (a1) tends to be high, and the handleability and reactivity tend to be lowered.

The above number average molecular weight can be obtained from the hydroxyl value. The hydroxyl value can be measured by a method using an acetylation reagent or a phthalation reagent in accordance with JIS K1557-1 (2007).

Examples of the polyisocyanate (a2) used in the present invention include aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane. Alicyclic polyvalent isocyanates such as diisocyanate, isophorone diisocyanate, norbornene diisocyanate; tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylenedi isocyanate, naphthalene diisocyanate, etc. Examples thereof include polyisocyanates such as aromatic polyisocyanates, trimeric compounds of the polyisocyanates, and multimer compounds of the polyisocyanates. Further, allophanate type polyisocyanate, burette type polyisocyanate and the like can also be mentioned. These can be used alone or in combination of two or more.

Among these, aliphatic polyvalent isocyanates and alicyclic polyvalent isocyanates are preferable in terms of adhesive properties when used as a pressure-sensitive adhesive, and further, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, and hexa. Methylene diisocyanate is preferable, and isophorone diisocyanate is particularly preferable.

Examples of the hydroxyl group-containing (meth) acrylate (a3) used in the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl ( Hydroxyalkyl (meth) acrylates such as meta) acrylates and 6-hydroxyhexyl (meth) acrylates, 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalate, caprolactone-modified 2-hydroxyethyl (Meta) acrylate, dipropylene glycol (meth) acrylate, fatty acid-modified-glycidyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxy A hydroxyl group-containing (meth) acrylate containing one ethylenically unsaturated group such as propyl (meth) acrylate; an ethylenically unsaturated group such as glycerindi (meth) acrylate and 2-hydroxy-3-acryloyl-oxypropyl methacrylate. Two hydroxyl group-containing (meth) acrylates; pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, ethylene oxide-modified pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone Examples thereof include hydroxyl group-containing (meth) acrylate containing three or more ethylenically unsaturated groups such as modified dipentaerythritol penta (meth) acrylate and ethylene oxide-modified dipentaerythritol penta (meth) acrylate. These can be used alone or in combination of two or more.

Among these, a hydroxyl group-containing (meth) acrylate containing one ethylenically unsaturated group is preferable, and a hydroxyalkyl (meth) acrylate is preferably used, particularly from the viewpoint of tacky properties when used as a pressure-sensitive adhesive. Hydroxyalkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl group, particularly 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate, are preferable.

The urethane (meth) acrylate compound (A) in the present invention can be obtained by reacting the above components (a1) to (a3). The production method may be produced according to a known method. Specifically, it can be manufactured as follows.

For example, (i) the above-mentioned method in which the polyester polyol (a1), the polyhydric isocyanate (a2), and the hydroxyl group-containing (meth) acrylate (a3) are collectively or separately charged into a reactor and reacted, (ii) the polyester polyol (a1). ) And the polyhydric isocyanate (a2) in advance to react with the terminal isocyanate group-containing reaction product obtained by reacting the hydroxyl group-containing (meth) acrylate (a3). Examples thereof include a method of reacting a polyester polyol (a1) with a reaction product obtained by reacting the contained (meth) acrylate (a3) in advance, but in terms of reaction stability and reduction of by-products, etc. To (ii) is preferable.

Regarding the method (ii) above, the reaction between the polyester polyol (a1) and the multivalent isocyanate (a2) can be reacted using a known reaction means. At that time, for example, the molar ratio of the isocyanate group in the polyhydric isocyanate compound (a2) to the hydroxyl group in the polyester polyol (a1) is usually about 2n: (2n-2) (n is an integer of 2 or more). This leaves an isocyanate group and enables an addition reaction with the hydroxyl group-containing (meth) acrylate (a3).

The molar ratio is such that n is 4 or more and 10 or less. The lower limit is preferably 5, more preferably 6. The upper limit is preferably 9, more preferably 8, and even more preferably 7. If the molar ratio is too small, the adhesive strength tends to be low when used as an adhesive, and if it is too large, the viscosity of the active energy ray-curable resin composition tends to be high and the handleability tends to be low.

The reaction molar ratio of the terminal isocyanate group-containing reaction product to the hydroxyl group-containing (meth) acrylate (a3) is, for example, that the terminal isocyanate group-containing reaction product has two isocyanate groups and the hydroxyl group-containing (meth) acrylate (a3). When the number of hydroxyl groups is one, the amount of the terminal isocyanate group-containing reaction product: the hydroxyl group-containing (meth) acrylate compound (a3) is usually about 1: 2, and the isocyanate group of the terminal isocyanate group-containing reaction product is usually about 1: 2. When there are three and the hydroxyl group-containing (meth) acrylate (a3) has one hydroxyl group, the terminal isocyanate group-containing reaction product: the hydroxyl group-containing (meth) acrylate compound (a3) is usually about 1: 3. be.

In the addition reaction between the terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth) acrylate (a3), the reaction is terminated when the residual isocyanate group content of the reaction system is usually 0.3% by weight or less. Thereby, the urethane (meth) acrylate compound (A) of the present invention can be obtained.

In the present invention, in the reaction of the polyester polyol (a1) with the polyhydric isocyanate (a2), and further in the reaction of the terminal isocyanate group-containing reaction product with the hydroxyl group-containing (meth) acrylate (a3), the object of accelerating the reaction. It is also preferable to use a catalyst in.

Examples of such a catalyst include organic metal compounds such as dibutyltin dilaurate, trimethyltin hydroxide, and tetra-n-butyltin, zinc octylate, tin octylate, cobalt naphthenate, bismuth chloride, and bismuth chloride. Metal salt, triethylamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene, N, N, N', N'-tetramethyl- In addition to amine-based catalysts such as 1,3-butanediamine and N-ethylmorpholine, bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, etc., organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate, 2- Ethylhexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanoic acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, stearate bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, bismuth acetate salt, Examples thereof include bismuth-based catalysts such as organic acid bismuth salts such as bismuth libis neodecanoate and bismuth salt of disalicylic acid. Among these, dibutyltin dilaurate and 1,8-diazabicyclo [5,4,0] undecene are preferable.

Further, in the reaction between the polyester polyol (a1) and the polyhydric isocyanate (a2), and further in the reaction between the terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth) acrylate (a3), it reacts with the isocyanate group. Organic solvents having no functional groups, for example, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as aromatics such as toluene and xylene can be used.

The reaction temperature is usually 30 to 90 ° C., preferably 40 to 80 ° C., and the reaction time is usually 2 to 12 hours, preferably 3 to 10 hours.

Thus, the urethane (meth) acrylate compound (A) can be obtained.

In the present invention, it is important that the number average molecular weight of the urethane (meth) acrylate-based compound (A) obtained above is 7,000 to 25,000, particularly preferably 1000 to 23000, still more preferably 12000 to 22000, and particularly. It is preferably 1500 to 20000. If the number average molecular weight is too small, the adhesive strength of the adhesive will be low, and if it is too large, the viscosity of the resin composition will be high and the handling will be poor, or the gel will be due to impurities contained in the plant-derived dimer acid. There is a problem such as conversion.

The weight average molecular weight of the urethane (meth) acrylate-based compound (A) is preferably 1500 to 100,000, particularly preferably 2000 to 90000, and further preferably 30,000 to 80,000. If the weight average molecular weight is too small, the adhesive strength of the adhesive tends to be low, and if it is too large, the viscosity of the resin composition becomes high and the handleability deteriorates, or it is contained in the plant-derived dimer acid. There is a tendency for problems such as gelation due to impurities to occur.

The above number average molecular weight and weight average molecular weight are the number average molecular weight and weight average molecular weight converted into standard polystyrene molecular weight, and are shown on a high performance liquid chromatograph (“ACQUITY APC system” manufactured by Waters), column: ACQUITY APC XT. It is measured by using four series of 450 × 1, ACQUITY APC XT 200 × 1, and ACQUITY APC XT 45 × 2. At that time, when the object to be measured contains the ethylenically unsaturated monomer (B) described later, the number average molecular weight and the weight average molecular weight are obtained by excluding the ethylenically unsaturated monomer (B).

<Ethylene unsaturated monomer (B)>
The ethylenically unsaturated monomer (B) used in the present invention may be an ethylenically unsaturated monomer having one or more ethylenically unsaturated groups in one molecule, and may be, for example, a monofunctional monomer or a bifunctional monomer. Examples include trifunctional or higher functional monomers.

The monofunctional monomer may be a monomer containing one ethylenically unsaturated group, for example, styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, and acrylonitrile. , Vinyl acetate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy -2-Hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (Meta) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl ( Meta) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenolethylene Oxide-modified (meth) acrylate, nonylphenol propylene oxide-modified (meth) acrylate, half-ester (meth) acrylate of phthalic acid derivatives such as 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, tetrahydrofurfuryl (meth) acrylate, Carbitol (meth) acrylate, benzyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide, N-methylol Examples thereof include (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2- (meth) acryloyloxyethyl acid phosphate monoester and the like.

In addition to the monofunctional monomer described above, a Michael adduct of acrylic acid or a 2-acryloyloxyethyl dicarboxylic acid monoester can also be mentioned. Examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, and acrylic acid trimmer. , Methacrylate trimmer, Acrylic acid tetramer, Methacrylate tetramer and the like. Examples of the 2-acryloyloxyethyl dicarboxylic acid monoester, which is a carboxylic acid having a specific substituent, include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples thereof include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Further, oligoester acrylate can also be mentioned.

The bifunctional monomer may be a monomer containing two ethylenically unsaturated groups, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol. Di (meth) acrylate, 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, 1,6-hexanediol ethylene oxide modified di (meth) acrylate, 1 , 9-Nonandiol 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, di phthalate Examples thereof include glycidyl ester di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and 2- (meth) acryloyloxyethyl acid phosphate diester.

The trifunctional or higher functional monomer may be a monomer containing three or more ethylenically unsaturated groups. For example, trimethylpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth). Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylol propane, glycerin polyglycidyl ether poly (meth) acrylate, isocyanurate ethylene oxide-modified triacrylate, ethylene Oxide-modified dipentaerythritol penta (meth) acrylate, ethylene oxide-modified dipentaerythritol hexa (meth) acrylate, ethylene oxide-modified pentaerythritol tri (meth) acrylate, ethylene oxide-modified pentaerythritol tetra (meth) acrylate, caprolactone-modified dipentaerythritol Penta (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tetra (meth) acrylate, succinic acid-modified pentaerythritol tri (meth) acrylate, etc. Be done.

Further, as the ethylenically unsaturated monomer (B), a urethane (meth) acrylate compound obtained by reacting a polyisocyanate compound and a (meth) acrylate compound containing one hydroxyl group, a polyisocyanate compound, 1 A urethane (meth) acrylate-based compound obtained by reacting a (meth) acrylate-based compound containing individual hydroxyl groups and a polyol-based compound (however, the urethane (meth) acrylate-based compound (A) is excluded) may be used. ..

These ethylenically unsaturated monomers (B) may be used alone or in combination of two or more. Further, the ethylenically unsaturated monomer (B) may be separately blended with the urethane (meth) acrylate-based compound (A), or may be used as a raw material for producing the urethane (meth) acrylate-based compound (A) at the time of production. Part or all may be present in the system. Further, it may be contained as a reaction solvent in the above reactions (a1) to (a3).

In the present invention, the content of the ethylenically unsaturated monomer (B) is 20 to 150 weight by weight in terms of adhesive strength when used as an adhesive with respect to 100 parts by weight of the urethane (meth) acrylate-based compound (A). The amount is preferably 30 to 100 parts by weight, more preferably 40 to 80 parts by weight. If the content of the ethylenically unsaturated monomer (B) is too small or too large, it tends to be difficult to obtain sufficient adhesive strength when used as an adhesive.

<Photopolymerization initiator (C)>
In the present invention, it is preferable to further contain a photopolymerization initiator (C) in order to carry out curing by active energy rays more efficiently.

Examples of the photopolymerization initiator (C) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 4- (2-hydroxyethoxy) -phenyl- (2). -Hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-) Morphorinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2 -Methyl-1-propane-1-one, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propane-1-one , 2,2-Dimethoxy-1,2-diphenylethane-1-one, acetophenones such as phenylglycylic acid methyl ester; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. Classes; benzophenone, methyl o-benzoyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2 , 4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethanamineium bromide, (4-benzoylbenzyl) trimethylammonium chloride And other benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy). Thioxanthones such as -3,4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4 Acylphosphs such as -trimethyl-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide Onoxides; etc. As for these photopolymerization initiators (C), only one kind may be used alone, or two or more kinds may be used in combination.

In addition, as these auxiliaries, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethyl benzoic acid, 4-dimethylaminobenzoic acid Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanson Etc. can be used together.

Among these, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, benzoin isopropyl ether, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- It is preferable to use phenylpropane-1-one.

The content of the photopolymerization initiator (C) is 0.1 to 40 parts by weight with respect to 100 parts by weight in total of the urethane (meth) acrylate compound (A) and the ethylenically unsaturated monomer (B). It is preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight. If the content of the photopolymerization initiator (C) is too small, curing tends to be poor, and if it is too large, solution stability tends to decrease such as precipitation during coating, or embrittlement or coloring. Prone to problems.

Regarding the method for mixing the urethane (meth) acrylate compound (A), the ethylenically unsaturated monomer (B), and the photopolymerization initiator (C) in producing the active energy ray-curable composition obtained in the present invention. Is not particularly limited, and can be mixed by various methods. For example, each component can be mixed all at once, or any component can be mixed first and then the remaining components can be appropriately selected.

Thus, the active energy ray-curable resin composition of the present invention is obtained.
Further, if necessary, a surface conditioner, a leveling agent, a polymerization inhibitor and the like can be further added.

The surface conditioner is not particularly limited, and examples thereof include alkyd resin and the like.
Such an alkyd resin has an action of imparting a film-forming property at the time of coating and an action of improving the adhesiveness with a metal thin film surface.

As the leveling agent, a known general leveling agent can be used as long as it has an effect of imparting wettability to the substrate of the coating liquid and an effect of lowering the surface tension. For example, a silicone-modified resin, a fluorine-modified resin, etc. An alkyl-modified resin or the like can be used. These can be used alone or in combination of two or more.

Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolucinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, methoxyphenol, and 2,6-di. Examples thereof include -t-butyl-p-cresol, mono-t-butylhydroquinone, and pt-butylcatechol. Of these, methoxyphenol and 2,6-di-t-butyl-p-cresol are preferable. These can be used alone or in combination of two or more.

The active energy ray-curable resin composition of the present invention is cured by applying it on various substrates, drying it, and then irradiating it with active energy rays.

The method for applying the active energy ray-curable resin composition is not particularly limited, and for example, spray, shower, dipping, roll, spin, curtain, flow, slit, die, gravure, comma, dispenser, etc. Wet coating methods such as screen printing, inkjet printing and the like can be mentioned.

The above coating can be carried out by blending an organic solvent and adjusting the viscosity, if necessary, and examples of the organic solvent include methanol, ethanol, propanol, n-butanol, i-butanol and the like. Alcohols, acetone, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone and other ketones, ethyl cellosolve and other cellosolves, toluene, xylene and other aromatics, propylene glycol monomethyl ether and other glycol ethers, methyl acetate, ethyl acetate, etc. Examples thereof include acetate esters such as butyl acetate and diacetone alcohols. These organic solvents may be used alone or in combination of two or more.

When the active energy ray-curable resin composition is a solid or a high-viscosity liquid, a hot melt method or the like is used in which the active energy ray-curable resin composition is heated to reduce its viscosity and then coated by the above method. Can also be mentioned.

As such active energy rays, for example, far ultraviolet rays, ultraviolet rays, near ultraviolet rays, rays such as infrared rays, electromagnetic waves such as X-rays and γ-rays, electron beams, proton rays, neutron rays and the like can be used. Curing by ultraviolet irradiation is advantageous because of the availability and price of the irradiation device. When electron beam irradiation is performed, it can be cured without using the photopolymerization initiator (C).

As a method of curing by ultraviolet irradiation, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp, an LED, etc. that emit light in the wavelength range of 150 to 450 nm are used. It suffices to irradiate about 30 to 3,000 mJ / cm ^2.
After the irradiation with ultraviolet rays, heating can be performed as necessary to complete the curing.

The film thickness of the cured coating film is usually 1 to 300 μm, preferably 2 to 250 μm, and more preferably 5 to 200 μm in consideration of light transmission so that the photopolymerization initiator (C) reacts uniformly.

In the present invention, the glass transition temperature (Tg) of the cured product of the active energy ray-curable resin composition is preferably −30 ° C. or higher, more preferably −30 to 50 ° C., still more preferably −20 to 45 ° C., particularly. It is preferably −10 to 40 ° C., particularly preferably 0 to 30 ° C. When the glass transition temperature (Tg) deviates from the above range, the adhesive strength tends to decrease when the adhesive is used.

The method for measuring the glass transition temperature (Tg) is as follows.
That is, the active energy ray-curable resin composition is applied to an easily adhesive-treated polyethylene terephthalate (PET) film (thickness 125 μm) so that the film thickness after curing is 100 μm using an applicator, and a desktop UV irradiation device (top UV irradiation device). Ultraviolet rays under the condition of 80 W / cm (high pressure mercury lamp) x 18 cm H x 1.9 m / min x 3 Pass (cumulative irradiation amount 2,400 mJ / cm ^{2) by "Conveyor type desktop irradiation device" manufactured by iGraphics Co., Ltd.} A test piece having a length of 20 mm and a width of 3 mm was cut out from an adhesive sheet for measuring adhesive strength, which was produced by irradiating and curing the test piece. Using the tensile mode of "DVA-225", the measurement was performed at a frequency of 1 Hz, a heating rate of 3 ° C./min, and a strain of 0.1%. The ratio (tan δ) of the loss elastic modulus) is obtained, and the maximum peak temperature of this tan δ is defined as the glass transition temperature (° C.).

The gel fraction after curing of the active energy ray-curable resin composition is preferably 10% by weight or more, more preferably 20 to 95% by weight, still more preferably 30 from the viewpoint of durability and adhesive strength. It is ~ 90% by weight, particularly preferably 40 ~ 85% by weight. If the gel fraction is too low, the cohesive force tends to decrease and the durability tends to decrease. If the gel fraction is too high, there is a concern that the adhesive strength will decrease due to the increase in cohesive force.

The gel fraction is a measure of the degree of cross-linking, and is calculated by, for example, the following method. That is, a cured coating film (without a separator) formed by forming a cured coating on a polymer sheet (for example, PET film) as a base material is wrapped in a 200 mesh SUS wire net and contained in toluene. The gel fraction is defined as the weight percentage of the insoluble cured coating film component remaining in the wire net after immersion with respect to the weight of the cured coating film component before immersion at 23 ° C. for 24 hours. However, the weight of the base material is deducted.

The active energy ray-curable resin composition of the present invention uses plant-derived dimer acid and is an active energy ray-curable resin composition with reduced environmental load. The biomass ratio can be expressed by the ratio of the number of carbons derived from plants to the total carbon contained in the active energy ray-curable resin composition, preferably 30 C% (C% represents the ratio of carbon) or more. It is more preferably 40 C% or more, further preferably 50 C% or more, particularly preferably 60 C% or more, and particularly preferably 70 C% or more. The biomass ratio is the active energy of the polyester polyol (a1) containing the structural site derived from dimer acid, the polyhydric isocyanate (a2), the hydroxyl group-containing (meth) acrylate (a3), and the ethylenically unsaturated monomer (B). It can be calculated by calculating the ratio of the carbon number of the raw material derived from the plant from the carbon number of all the raw materials constituting the linear curable resin composition. More accurately, it can be measured by the method specified in ASTM D6866.

Examples of the base material to which the active energy ray-curable resin composition obtained in the present invention is applied include a polyolefin resin, a polyester resin, a polycarbonate resin, an acrylonitrile butadiene styrene copolymer (ABS), and a polystyrene resin. , Polycarbonate resin, etc. and their molded products (film, sheet, cup, etc.), metal base material (metal vapor deposition layer, metal plate (copper, stainless steel (SUS304, SUSBA, etc.), aluminum, zinc, magnesium, etc.)), Examples thereof include glass and the like and their composite base materials.

In the present invention, the active energy ray-curable resin composition containing the urethane (meth) acrylate-based compound (A) has adhesion to various members, particularly good adhesive strength when used as an adhesive. It is an active energy ray-curable resin composition that can be applied to various uses such as coating agents, paints, inks, and adhesives, and is particularly useful as an adhesive because it has good adhesive strength.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In the example, "part" and "%" mean a weight standard.
The number average molecular weight, weight average molecular weight, viscosity, and gel fraction of the urethane (meth) acrylate compound were measured according to the above method, and the biomass ratio was calculated by the above method.

The following polyester polyols (a1) containing structural sites derived from dimer acid were prepared.
"Priplast 1838": Dimeric polyester polyol manufactured by CRODA (hydroxyl value 60.0 mgKOH / g, number average molecular weight 1870)
"Priplast 3196": manufactured by CRODA, dimer acid-based polyester polyol (hydroxyl value 37.0 mgKOH / g, number average molecular weight 3032)
"Priplast 3199": manufactured by CRODA, dimer acid-based polyester polyol (hydroxyl value 56.0 mgKOH / g, number average molecular weight 2004)

<Example 1>
[Preparation of urethane acrylate (A-1)]
In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 43.7 parts of isophorone diisocyanate (IPDI) as a polyhydric isocyanate, 306.6 parts of "Priplast 1838" as a polyester polyol, and an ethylenically unsaturated monomer (B-1). 90 parts of butyl acrylate (BA), 0.02 part of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 part of dibutyltin dilaurate as a reaction catalyst were added and reacted at 80 ° C. .. When the residual isocyanate group becomes 0.6% or less, the temperature is cooled to 70 ° C., 9.7 parts of 4-hydroxybutyl acrylate (4HBA) as a hydroxyl group-containing (meth) acrylate, and 4-methoxyphenol 0. as a polymerization inhibitor. 18 parts were added and reacted at 70 ° C., and when the residual isocyanate group became 0.1% or less, the reaction was terminated to obtain a composition containing urethane acrylate (A-1).

[Preparation of active energy ray-curable resin composition]
35 parts of isobornyl acrylate (IBOA) as the ethylenically unsaturated monomer (B-2) and light with respect to 100 parts of the total amount of the urethane acrylate (A-1) and the ethylenically unsaturated monomer (B-1). Four parts of 1-hydroxy-cyclohexyl-phenyl-ketone were uniformly mixed as the polymerization initiator (C) to obtain an active energy ray-curable resin composition.
The adhesiveness of the obtained active energy ray-curable resin composition was evaluated as follows.

[Adhesive]
(Preparation of adhesive sheet for measuring adhesive strength)
The obtained active energy ray-curable resin composition is applied to an easily adhesive-treated polyethylene terephthalate (PET) film (thickness 125 μm) so that the film thickness after curing is 100 μm, using an applicator, and a desktop UV irradiation device is used. Under the condition of 80 W / cm (high-pressure mercury lamp) x 18 cm H x 1.9 m / min x 3 Pass (integrated irradiation amount 2,400 mJ / cm ^{2) with (Igraphics, "conveyor type desktop irradiation device")} By irradiating with ultraviolet rays and curing, an adhesive sheet for measuring adhesive strength was obtained.

(Test method)
After cutting the obtained adhesive sheet for measuring adhesive strength to 25 mm × 100 mm, it reciprocates twice on 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. The test piece was prepared by crimping. After allowing this test piece to stand in the same atmosphere for 30 minutes, a 180-degree peeling test was performed at a peeling speed of 0.3 m / min, and the adhesive strength (N / 25 mm) was measured. The measurement results are shown in Table 1.

<Examples 2 to 6 and Comparative Examples 1 to 2>
In Example 1, polyester polyol (a1), polyhydric isocyanate (a2), hydroxyl group-containing (meth) acrylate (a3), ethylenically unsaturated monomer (B-1), ethylenically unsaturated monomer (B-2), The same procedure was carried out except that the type of reaction catalyst and the amount charged were changed as shown in Tables 1 and 2, to obtain an active energy ray-curable resin composition.
The adhesiveness of the obtained active energy ray-curable resin composition was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

The abbreviations in Tables 1 and 2 are as follows.
IPDI: Isophorone diisocyanate 4HBA: 4-Hydroxybutyl acrylate HEA: 2-Hydroxyethyl acrylate BA: Butyl acrylate IBOA: Isobornyl acrylate IDAA: Isodecyl acrylate DBTL: Dibutyltin dilaurate

From the results of Tables 1 and 2 above, the active energy ray-curable resin compositions of Examples 1 to 6 are urethane acrylates obtained by using a polyester polyol having a structural portion derived from a dimer, and are suitable for environmental friendliness. However, the active energy ray-curable resin compositions of Comparative Examples 1 and 2 have a number average molecular weight of urethane acrylate, whereas they have good adhesive strength when used as an adhesive. Since it was too small, its adhesive strength as an adhesive was inferior.

The active energy ray-curable resin composition of the present invention is suitable for the environment, but has adhesiveness to various members, particularly good adhesive strength when used as an adhesive, and is a coating agent. , An active energy ray-curable resin composition that can be applied to various uses such as paints, inks, and adhesives. In particular, the active energy ray-curable resin composition of the present invention is useful as an adhesive because it has good adhesive strength.

Claims (8)

An active energy ray-curable resin composition containing a urethane (meth) acrylate compound (A), wherein the urethane (meth) acrylate compound (A) is a polyester polyol (a1) containing a structural moiety derived from dimer acid. ), Polyhydric isocyanate (a2) and hydroxyl group-containing (meth) acrylate (a3), the active energy ray-curable resin composition having a number average molecular weight of 7,000 to 25,000. The active energy ray-curable resin composition according to claim 1, wherein the polyvalent isocyanate (a2) is at least one of an aliphatic polyhydric isocyanate and an alicyclic polyvalent isocyanate. The polyester polyol (a1) containing the structural site derived from dimer acid is at least one selected from dimer acid, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol. The active energy ray-curable resin composition according to claim 1 or 2, which is a polycondensate product with glycol of the above. The active energy ray-curable resin composition according to any one of claims 1 to 3, further comprising an ethylenically unsaturated monomer (B). The active energy ray-curable resin composition according to any one of claims 1 to 4, further comprising a photopolymerization initiator (C). The active energy ray-curable resin composition according to any one of claims 1 to 5, wherein the glass transition temperature of the cured product of the active energy ray-curable resin composition is −30 ° C. or higher. A pressure-sensitive adhesive composition comprising the active energy ray-curable resin composition according to any one of claims 1 to 6. A pressure-sensitive adhesive according to claim 7, wherein the pressure-sensitive adhesive composition is cured.