Polymer particles, method for producing the polymer particles, and resin composition

Abstract

To provide a polymer particle that gives a cured product of a resin composition having excellent toughness, and a method for producing the same.SOLUTION: A polymer particle contains a polymer containing a constitutional unit based on a predetermined monofunctional urethane metacrylate, with an average particle size of 50-500 μm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to polymer particles, a method for producing the polymer particles, and a resin composition containing the polymer particles.

Background Art

[0002] Resins exhibit various physical and chemical properties depending on their structures and are utilized in various fields such as industrial products and daily necessities. For example, epoxy resins have characteristics such as high dimensional stability, insulation, water resistance, and chemical resistance, and are therefore widely used as insulation materials and encapsulation materials in electronic devices. They are also used in paints, adhesives, composite materials, etc. Furthermore, they are also used as molding materials for obtaining molded bodies by optical three-dimensional modeling using 3D printers, etc.

[0003] On the other hand, epoxy resins have the drawback of low toughness and being prone to brittle fracture. For this reason, techniques for improving the toughness of epoxy resins have been studied, and as one means, a method of adding a modifier such as rubber particles to an epoxy resin has been proposed. For example, Patent Document 1 discloses an epoxy resin composition containing a bisphenol E type epoxy resin, rubber fine particles, and a curing agent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the epoxy resin composition described in Patent Document 1, a sufficient toughness improvement effect cannot be obtained, and further improvement is required.

[0006] The present invention solves such problems, and an object thereof is to provide polymer particles capable of obtaining a cured product of a resin composition excellent in toughness, a method for producing the polymer particles, and a resin composition containing the polymer particles. [Means for Solving the Problems]

[0007] The present invention is based on the finding that a cured product of a resin composition excellent in toughness can be obtained by using polymer particles containing a polymer containing a structural unit based on a predetermined urethane acrylate having a polyether chain and a urethane bond.

[0008] The present invention provides the following means. [1] Polymer particles having an average particle diameter of 50 to 500 μm and containing a polymer containing a structural unit based on a monofunctional urethane (meth) acrylate, wherein the monofunctional urethane (meth) acrylate is one or more monomers selected from the reaction products of the following (i) to (iii). (i) An equimolar reaction product of a polyether monool and a compound having a (meth) acryloyloxy group, wherein the compound having a (meth) acryloyloxy group has one isocyanate group in one molecule and one or two (meth) acryloyloxy groups in one molecule. (ii) An equimolar reaction product of a polyether monool, a diisocyanate and a compound having a (meth) acryloyloxy group, wherein the compound having a (meth) acryloyloxy group has a group that reacts with one isocyanate group in one molecule and one or two (meth) acryloyloxy groups in one molecule. (iii) An equimolar reaction product of a polyether polyol and a compound having a (meth) acryloyloxy group, wherein the compound having a (meth) acryloyloxy group has one isocyanate group in one molecule and one or two (meth) acryloyloxy groups in one molecule. [2] The content of the structural unit based on the monofunctional urethane (meth)acrylate contained in the polymer is 70% by mass or more, and the polymer particles according to the above [1]. [3] The monofunctional urethane (meth)acrylate has a number average molecular weight of 3,000 to 30,000, and the polymer particles according to the above [1] or [2]. [4] The monofunctional urethane (meth)acrylate has a glass transition temperature of -55°C or lower, and the polymer particles according to any one of the above [1] to [3]. [5] The monofunctional urethane (meth)acrylate has a storage elastic modulus E'(25°C) of 70 to 450 kPa at 25°C, and the polymer particles according to any one of the above [1] to [4]. [6] A resin composition containing the polymer particles according to any one of the above [1] to [5] and a resin. [7] The content of the polymer particles is 1 to 100 parts by mass with respect to 100 parts by mass of the resin, and the resin composition according to the above [6]. [8] The resin is at least one selected from the group consisting of an epoxy resin, a polycarbonate resin, an acrylic resin, a phenol resin, polystyrene, and a polyolefin, and the resin composition according to the above [6] or [7]. [9] A cured product obtained by curing the resin composition according to any one of the above [6] to [8].

[10] An article provided with the cured product according to the above [9].

[11] A method for producing polymer particles, in which a monofunctional urethane (meth)acrylate is polymerized in the presence of water, a surfactant, and an initiator to obtain polymer particles having an average particle diameter of 50 to 500 μm. The monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i) to (iii), and a method for producing polymer particles. (i) An equimolar reaction product of a polyether monoalcohol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. A reaction product. (ii) An equimolar reaction product of a polyether monoalcohol, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule. (iii) An equimolar reaction product of a polyether polyol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule.

Advantages of the Invention

[0009] According to the present invention, polymer particles capable of obtaining a cured product of a resin composition excellent in toughness, a method for producing the polymer particles, and a resin composition containing the polymer particles can be provided.

Embodiments for Carrying Out the Invention

[0010] The definitions and meanings of the terms and notations in this specification are shown below. The term “(meth)acryloyloxy group” is a general term for an acryloyloxy group and a methacryloyloxy group. The term “(meth)acrylate” is a general term for an acrylate and a methacrylate. The term “number of functional groups” means the number of (meth)acryloyloxy groups in one molecule, unless otherwise specified. The term “average number of functional groups” means the average number of (meth)acryloyloxy groups in one molecule, with the formula weight or number average molecular weight based on the chemical formula being taken as one unit, unless otherwise specified. "Mono-functional urethane (meth)acrylate" means a urethane (meth)acrylate having an average functionality of substantially 1 in one molecule. A urethane (meth)acrylate having an average functionality of 0.7 to 1.4, preferably 0.8 to 1.3 in one molecule is regarded as a urethane (meth)acrylate having substantially one (meth)acryloyloxy group in one molecule, that is, a mono-functional urethane (meth)acrylate. "Equimolar reaction product" means that the molar ratio of the reacting compounds is substantially 1. A reaction product having a molar ratio of 0.7 to 1.4, preferably 0.8 to 1.3 is regarded as an equimolar reaction product. Similarly, "the number of moles of the reacting groups (or compounds) is equal" means that the molar ratio of the reacting groups (or compounds) is substantially 1. When the molar ratio is 0.7 to 1.4, preferably 0.8 to 1.3, the number of moles of the reacting groups (or compounds) is regarded as equal. The "hydroxyl value" is determined by measurement in accordance with JIS K 1557:2007. The "molecular weight in terms of hydroxyl value" is a value calculated from the formula 56100 / (hydroxyl value)×(number of active hydrogens of the initiator). In the reaction between an isocyanate group-containing compound and a hydroxyl group-containing compound, the "NCO index" is a value obtained by multiplying by 100 the equivalent ratio of the isocyanate groups of the isocyanate group-containing compound to the hydroxyl groups of the hydroxyl group-containing compound. "Molecular weight" means, unless otherwise specified, the formula weight based on the chemical formula, or in the case of a compound having a molecular weight distribution, the number average molecular weight. The "number average molecular weight" is the polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC) based on a calibration curve prepared using a standard polystyrene sample.

[0011] [Polymer particles] The polymer particles of the present invention are polymer particles having an average particle diameter of 200 to 500 μm, including a polymer containing a structural unit based on mono-functional urethane (meth)acrylate, The mono-functional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i) to (iii). (i) An equimolar reaction product of a polyether monoalcohol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (ii) An equimolar reaction product of a polyether monoalcohol, a diisocyanate and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (iii) An equimolar reaction product of a polyether polyol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0012] The monofunctional urethane (meth)acrylate has a flexible graft chain that does not contribute to crosslinking, resulting in a low glass transition temperature, a small temperature dependence of the storage modulus in a wide temperature range of -20 to 80 °C, and a small residual strain. Therefore, when polymer particles containing a polymer unit based on the monofunctional urethane (meth)acrylate are added to a resin, it is presumed that the toughness of the resin can be improved well. Further, from the viewpoint of more rapid progress of polymerization, the (meth)acryloyloxy group of the monofunctional urethane (meth)acrylate is preferably an acryloyloxy group.

[0013] The monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of (i) to (iii) above (hereinafter also referred to as "monomer 1-1", "monomer 1-2" and "monomer 1-3"). The monofunctional urethane (meth)acrylate may be used alone or in combination of two or more.

[0014] <Monomer 1-1> Monomer 1-1 is the reaction product of (i), and is an equimolar reaction product of polyether monoalcohol (i-1) and a compound (i-2) having a (meth)acryloyloxy group. The compound (i-2) having a (meth)acryloyloxy group is a compound having one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0015] As monomer 1-1, a compound represented by formula (1) is preferable.

[0016] [Chemical formula]

[0017] In formula (1), R 1 is a monovalent organic group having one or two (meth)acryloyloxy groups. R 12 is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms. A plurality of R 12 present in one molecule may be the same as or different from each other. When two or more types of R 12 are present in one molecule, the chain of -OR 12 - may be block or random. R 12 is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, more preferably one or more selected from an ethylene group and a propylene group.

[0018] Also, (OR 12 ) is preferably a unit based on monomer a having one epoxy group and an ether bond other than the ether bond of the epoxy group in one molecule. The unit based on monomer a is preferably a unit represented by formula (11). One type of monomer a may be used, or two or more types may be used in combination.

[0019] [Chemical formula]

[0020] In formula (11), R 101 is a monovalent group represented by -R 103 -O-R 104 and R 102 is a hydrogen atom or a monovalent group represented by -R 105 -O-R 106 R 103 and R 105 are each independently a linear or branched alkylene group having 1 to 3 carbon atoms, and R 104 and R 106 are each independently a linear or branched alkyl group having 1 to 18 carbon atoms. As the alkylene groups of R 103 and R 105 each is independently preferably a methylene group, an ethylene group, an n-propylene group or an isopropylene group, more preferably a methylene group or an ethylene group, still more preferably a methylene group. The number of carbon atoms of R 104 and R 106 are each independently preferably 1 to 14, more preferably 1 to 12, still more preferably 2 to 10. Examples of the linear alkyl groups of R 104 and R 106 include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-octyl group, an n-decyl group, a lauryl group, a cetyl group, and a stearyl group, and are preferably each independently a methyl group, an ethyl group or an n-butyl group. The branched alkyl group has a structure in which a hydrogen atom (excluding the hydrogen atom bonded to the terminal carbon) in the linear alkyl group is substituted with an alkyl group. Examples of the substituting alkyl group include a methyl group and an ethyl group. The branched alkyl group is preferably a 2-ethylhexyl group.

[0021] The monomer a is preferably a monomer represented by formula (12).

[0022]

Chemical formula

[0023] R in formula (12) 101 and R 102 are the same as R 101 and R 102 in formula (11).

[0024] Examples of the monomer represented by formula (12) include methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, and hexyl glycidyl ether. From the viewpoint of the toughness of the cured product of the resin composition, butyl glycidyl ether or 2-ethylhexyl glycidyl ether is preferable.

[0025] In formula (1), R 13 is an alkyl group having 1 to 20 carbon atoms. R 13 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a methyl group, an ethyl group, or a butyl group, and still more preferably a butyl group. a is an integer of 20 to 600, preferably an integer of 35 to 500, and more preferably an integer of 65 to 250.

[0026] (Polyether monoalcohol (i-1)) The polyether monoalcohol (i-1) in monomer 1-1 is a compound having an initiator residue, a polyether chain, and a hydroxyl group corresponding to the number of active hydrogens of the initiator, which is obtained by ring-opening polymerization of an alkylene oxide and / or the monomer a with an initiator having an active hydrogen-containing group and having one or more active hydrogens.

[0027] Examples of the active hydrogen-containing group of the initiator include a hydroxyl group, a carboxy group, and an amino group having one hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group of the initiator is preferably a hydroxyl group or a carboxy group, more preferably a hydroxyl group, and still more preferably an alcoholic hydroxyl group.

[0028] Examples of the initiator having one active hydrogen atom include monohydric alcohols, monohydric phenols, monohydric carboxylic acids, amine compounds having one hydrogen atom bonded to a nitrogen atom, and the like. The initiator is preferably a monohydric aliphatic alcohol or a monohydric aliphatic carboxylic acid, more preferably a monohydric aliphatic alcohol. Also, a polyoxyalkylene monool having a lower molecular weight than the target polyether monool may be used as the initiator.

[0029] The number of carbon atoms of the monohydric aliphatic alcohol as the initiator is preferably 1 to 20, more preferably 2 to 8. Specific examples of the monohydric aliphatic alcohol as the initiator include ethanol, propanol, 2-propanol, n-butanol, and the like. The number of carbon atoms of the monohydric aliphatic carboxylic acid as the initiator, including the carbon atom of the carboxy group, is preferably 2 to 20, more preferably 2 to 8.

[0030] When the alkylene oxide and the monomer a undergo ring-opening polymerization, the ratio of the mass of the monomer a to the total mass of both is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 10 to 80% by mass from the viewpoint of the toughness of the cured product of the resin composition.

[0031] The number of carbon atoms of the alkylene oxide is preferably 2 to 8, more preferably 2 to 4. Specific examples of the alkylene oxide include propylene oxide, ethylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide.

[0032] The oxyalkylene group in the polyether monool (i-1) preferably consists of only an oxypropylene group or a combination of an oxypropylene group and other groups. The oxyalkylene group other than the oxypropylene group is preferably an oxyethylene group. The proportion of the oxypropylene group to all oxyalkylene groups in the polyether monoalcohol (i-1) is preferably 50 to 100% by mass, more preferably 60 to 100% by mass. When the initiator is a polyoxyalkylene monoalcohol having a lower molecular weight than the target polyether monoalcohol, the oxyalkylene groups in the initiator are regarded as the oxyalkylene groups in the obtained polyether monoalcohol.

[0033] In the polyether monoalcohol (i-1), a polyoxyalkylene monoalcohol with a low hydroxyl value, that is, a high molecular weight polyoxyalkylene monoalcohol, can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, preferably propylene oxide, in the presence of a double metal cyanide complex catalyst using an initiator. Examples of the polyoxyalkylene monoalcohol with a low hydroxyl value include polyoxyalkylene monoalcohols with a hydroxyl value of 40 mgKOH / g or less. A polyoxyalkylene monoalcohol with a low hydroxyl value having an oxyethylene group can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, preferably propylene oxide, in the presence of a double metal cyanide complex catalyst using a polyoxyalkylene monoalcohol with a high hydroxyl value having an oxyethylene group, for example, a polyoxyalkylene monoalcohol with a hydroxyl value of 50 mgKOH / g or more, as an initiator. In the above polyether monoalcohol, the polyoxyalkylene monoalcohol with a high hydroxyl value and the polyoxyalkylene monoalcohol with a high hydroxyl value as the initiator can also be produced using an alkali catalyst such as potassium hydroxide.

[0034] In the production of polyoxyalkylene monoalcohol, initiators and alkylene oxides introduced into the reaction system are usually those with low water content obtained by removing water through reduced-pressure degassing or the like. Generally, in the production of polyoxyalkylene monoalcohol, the lower the water content of the initiator, the more preferable it is, preferably 500 ppm by mass or less, more preferably 300 ppm by mass or less. When the water content is within the above range, the production amount of polyoxyalkylene diol generated from water is suppressed. As a result, the production amount of by-products caused by polyoxyalkylene diol is suppressed, and it is easy to adjust the upper limit of the average number of hydroxyl groups of the obtained polyoxyalkylene monoalcohol to 1.2 or less.

[0035] The lower the water content of the polyether monoalcohol (i-1) used as a raw material for monomer 1-1, the more preferable it is. For the polyether monoalcohol (i-1), it is preferably 300 ppm by mass or less, more preferably 250 ppm by mass or less, and even more preferably 50 to 200 ppm by mass. When the water content is within the above range, the generation of by-products of water and isocyanate group-containing compounds is small, and the stability of the reaction product, monomer 1-1, is improved. Furthermore, it is easy to suppress the change in the appearance of the resin composition over time, and it is easy to obtain a cured product of a highly tough resin composition.

[0036] The average number of hydroxyl groups in one molecule of the polyether monoalcohol (i-1) is preferably 0.80 to 1.20, more preferably 0.90 to 1.10. The hydroxyl value of the polyether monoalcohol (i-1) is preferably 1.6 to 18.1 mgKOH / g, more preferably 2.8 to 14.0 mgKOH / g, and even more preferably 3.1 to 11.2 mgKOH / g.

[0037] The polyether monoalcohol (i-1) in monomer 1-1 may be a mixture of two or more polyether monoalcohols. In this case, each polyether monoalcohol is preferably a polyoxyalkylene monoalcohol included in the above category.

[0038] Examples of the polyether monoalcohol (i-1) include those represented by the formula (1a).

[0039]

Chemical formula

[0040] In the formula (1a), R 12 , R 13 and a are the same as the same symbols in the formula (1).

[0041] ((Compound (i-2) having a (meth)acryloyloxy group)) The compound (i-2) having a (meth)acryloyloxy group is a compound having one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. Examples of the compound (i-2) having a (meth)acryloyloxy group preferably include (meth)acrylates having an isocyanate group bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, more preferably isocyanate alkyl (meth)acrylates. The number of carbon atoms of the alkylene group excluding the isocyanate group of the isocyanate alkyl group is preferably 8 or less, more preferably 4 or less.

[0042] Examples of the compound (i-2) having a (meth)acryloyloxy group include, for example, the compounds represented by the formula (1b).

[0043]

Chemical formula

[0044] In the formula (1b), R 11 is a hydrogen atom or a methyl group, preferably a hydrogen atom. s is an integer of 1 to 4, preferably an integer of 1 to 2.

[0045] Specific examples of the compound (i-2) having a (meth)acryloyloxy group include 2-isocyanatoethyl (meth)acrylate, isocyanatomethyl methacrylate, and the like. Commercially available products include, for example, "Karezz (registered trademark; hereinafter, the notation is omitted) AOI" and "Karezz MOI" (both manufactured by Showa Denko K.K.).

[0046] Examples of the compound (i-2) having a (meth)acryloyloxy group also include the compound represented by the formula (1c).

[0047] [Chemical formula]

[0048] In the formula (1c), R 11 is a hydrogen atom or a methyl group, preferably a hydrogen atom. R 14 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a methyl group. t is an integer from 1 to 8, preferably an integer from 1 to 4, more preferably an integer from 1 to 2. u is an integer from 0 to 4, preferably an integer from 0 to 2.

[0049] Specific examples of the compound (i-2) having a (meth)acryloyloxy group include 2,2-(bisacryloyloxymethyl)propyl isocyanate and 1,1-(bisacryloyloxymethyl)ethyl isocyanate (trade name "Karezz BEI", manufactured by Showa Denko K.K.), and preferably 1,1-(bisacryloyloxymethyl)ethyl isocyanate.

[0050] As the monomer 1-1, for example, when the polyether monoalcohol (i-1) is polyoxypropylene monoalcohol, it is preferably at least one selected from the compounds represented by the formula (1-1-1), the formula (1-1-2), and the formula (1-1-3).

[0051] [Chemical formula]

[0052] In formulas (1-1-1), (1-1-2), and (1-1-3), m, n1, and n2 are each independently, preferably an integer from 20 to 600, more preferably an integer from 35 to 500, and even more preferably an integer from 65 to 250. Bu is a butyl group.

[0053] <Monomer 1-2> Monomer 1-2 is the reaction product of (ii), and is an equimolar reaction product of polyether monoalcohol (ii-1), diisocyanate (ii-2), and a compound (ii-3) having a (meth)acryloyloxy group. The compound (ii-3) having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule.

[0054] As Monomer 1-2, a compound represented by formula (2) is preferred.

[0055]

Chemical formula

[0056] In formula (2), R 2 is a monovalent organic group having one or two (meth)acryloyloxy groups. R 22 is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms. A plurality of Rs 22 present in one molecule may be the same as or different from each other. When two or more types of Rs 22 are present in one molecule, the chain of -OR 22 - may be block or random. R 22is preferably at least one selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, more preferably at least one selected from an ethylene group and a propylene group. Also, (OR 22 ) is preferably a unit based on monomer a having one epoxy group and an ether bond other than the ether bond of the epoxy group in one molecule, in the same manner as (OR 12 ) in Formula (1). A preferred embodiment of monomer a is the same as in the case of monomer 1-1. R 23 is an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 2 to 8 carbon atoms, more preferably a butyl group. R 24 is a divalent group obtained by removing two isocyanate groups from a diisocyanate. Examples of the diisocyanate will be described later. b is an integer of 20 to 600, preferably an integer of 35 to 500, more preferably an integer of 65 to 250.

[0057] (Polyether monoalcohol (ii-1)) Polyether monoalcohol (ii-1) is the same as polyether monoalcohol (i-1) in monomer 1-1, and the preferred embodiments are also the same.

[0058] Examples of polyether monoalcohol (ii-1) include those represented by Formula (2a).

[0059] [Chemical formula]

[0060] In Formula (2a), R 22 , R 23 and b have the same meanings as the same symbols in Formula (2).

[0061] (Diisocyanate (ii-2)) Diisocyanate (ii-2) is a compound having two isocyanate groups in one molecule. Examples of the diisocyanate (ii-2) include non-yellowing aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and various modified products of these diisocyanates (modified products having two isocyanate groups). The diisocyanate may be used alone or in combination of two or more. From the viewpoint of the toughness of the cured product of the resin composition, the diisocyanate (ii-2) is preferably at least one selected from aliphatic diisocyanates and alicyclic diisocyanates.

[0062] Specific examples of the non-yellowing aromatic diisocyanate include xylylene diisocyanate and tetramethylxylylene diisocyanate. Specific examples of the above aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Examples of the alicyclic diisocyanate include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate.

[0063] Examples of the diisocyanate (ii-2) include, for example, a compound represented by the formula (2b).

[0064]

Chemical formula

[0065] In the formula (2b), R 24 has the same meaning as the same symbol in the formula (2). From the viewpoint of the toughness of the cured product of the resin composition, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate are preferred as the above diisocyanate.

[0066] (Compound (ii-3) having a (meth)acryloyloxy group) The compound (ii-3) having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule. Examples of the group that reacts with the isocyanate group include a hydroxyl group and an amino group having a nitrogen atom to which a hydrogen atom is bonded. The number of hydroxyl groups and the number of hydrogen atoms bonded to the nitrogen atom in the group that reacts with the isocyanate group are preferably each one. Further, the group that reacts with the isocyanate group is preferably a hydroxyl group bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group.

[0067] As the compound (ii-3) having a (meth)acryloyloxy group, hydroxyalkyl (meth)acrylate and hydroxycycloalkyl (meth)acrylate are preferable, and hydroxyalkyl (meth)acrylate having 8 or less carbon atoms in the hydroxyalkyl group is particularly preferable.

[0068] Examples of the compound (ii-3) having a (meth)acryloyloxy group include a compound represented by formula (2c).

[0069]

Chemical formula

[0070] In formula (2c), R 21 is a hydrogen atom or a methyl group, preferably a hydrogen atom. p is an integer of 1 to 4, preferably an integer of 1 to 2.

[0071] Specific examples of the compound (ii-3) having a (meth)acryloyloxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and the like. Commercially available products include Light Ester HO-250(N), Light Ester HOP(N), Light Ester HOA(N), Light Ester HOP-A(N), Light Ester HOB(N) (all manufactured by Kyoeisha Chemical Co., Ltd.), and 4-HBA (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

[0072] Examples of the compound (ii-3) having a (meth)acryloyloxy group also include the compound represented by formula (2d).

[0073] [Chemical formula]

[0074] In formula (2d), R 21 is a hydrogen atom or a methyl group, preferably a hydrogen atom. R 25 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a methyl group. q is an integer of 1 to 8, preferably an integer of 1 to 4, more preferably an integer of 1 to 2. r is an integer of 0 to 4, preferably an integer of 0 to 2.

[0075] Specific examples of the compound (ii-3) having a (meth)acryloyloxy group include 2,2-(bisacryloyloxymethyl)propan-1-ol and 1,1-(bisacryloyloxymethyl)ethan-1-ol, preferably 1,1-(bisacryloyloxymethyl)ethan-1-ol.

[0076] <Monomer 1-3> Monomers 1-3 are the reaction products of (iii), which are equimolar reaction products of a polyether polyol (iii-1) and a compound (iii-2) having a (meth)acryloyloxy group. The compound (iii-2) having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0077] As the monomer 1-3, a compound represented by the formula (III) is preferable. R 3 -NH-C(=O)-Z 1 ···(III) In the formula (III), R 3 is a monovalent organic group having one or two (meth)acryloyloxy groups. Z 1 is the residue of the polyether polyol obtained by removing one hydrogen atom from one of the hydroxyl groups in the polyether polyol.

[0078] More preferably, the monomer 1-3 is a compound represented by the formula (3).

[0079]

Chemical formula

[0080] In the formula (3), R 3 is the same as R 3 in the formula (III). R 32 is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms. A plurality of R 32 present in one molecule may be the same as or different from each other. When two or more types of R 32 are present in one molecule, the chain of -OR 32 - may be block or random. R 32is preferably at least one selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, more preferably at least one selected from an ethylene group and a propylene group. Also, (OR 32 ) is preferably a unit based on monomer a having one epoxy group and an ether bond other than the ether bond of the epoxy group in one molecule, in the same manner as (OR 12 ) in formula (1). A preferred embodiment of monomer a is the same as in the case of monomer 1-1. c is an integer from 20 to 600, preferably an integer from 35 to 500, more preferably an integer from 65 to 250.

[0081] (Polyether polyol (iii-1)) Polyether polyol (iii-1) is a compound having an active hydrogen-containing group, and obtained by ring-opening polymerization of an alkylene oxide and / or the above monomer a with an initiator having two or more active hydrogens, and having an initiator residue, a polyether chain, and a hydroxyl group corresponding to the number of active hydrogens of the initiator.

[0082] The alkylene oxide is preferably an alkylene oxide having 2 to 4 carbon atoms. Specific examples of the alkylene oxide having 2 to 4 carbon atoms include propylene oxide, ethylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide. Also, monomer a is preferably the monomer represented by the above formula (12). Examples of the monomer represented by formula (12) include methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, and hexyl glycidyl ether. From the viewpoint of the toughness of the cured product of the resin composition, it is preferably butyl glycidyl ether or 2-ethylhexyl glycidyl ether.

[0083] When the alkylene oxide and the monomer a undergo ring-opening polymerization, the ratio of the mass of the monomer a to the total mass of the two is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 10 to 80% by mass from the viewpoint of the toughness of the cured product of the resin composition.

[0084] Examples of the active hydrogen-containing group possessed by the initiator include a hydroxyl group, a carboxy group, and an amino group having a hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group possessed by the initiator is preferably a hydroxyl group, and more preferably an alcoholic hydroxyl group.

[0085] Examples of the initiator having two or more active hydrogens include water, polyhydric alcohols, polyhydric phenols, polyhydric carboxylic acids, and amine compounds having two or more hydrogen atoms bonded to a nitrogen atom. The initiator is preferably water or a divalent aliphatic alcohol, and more preferably a divalent aliphatic alcohol. Also, a polyoxyalkylene polyol having a lower molecular weight than the target polyether polyol may be used as the initiator.

[0086] The number of carbon atoms of the divalent aliphatic alcohol as the initiator is preferably 2 to 8. Specific examples of the divalent aliphatic alcohol as the initiator include polypropylene glycols such as ethylene glycol, propylene glycol, dipropylene glycol, and 1,4-butanediol.

[0087] The oxyalkylene group in the polyether polyol (iii-1) preferably consists of only an oxypropylene group or a combination of an oxypropylene group and other groups. The oxyalkylene group other than the oxypropylene group is preferably one or more selected from an oxyethylene group and an oxytetramethylene group. The ratio of the oxypropylene group to all the oxyalkylene groups in the polyether polyol is preferably 50 to 100% by mass, and more preferably 80 to 100% by mass. In addition, when the initiator is a polyoxyalkylene polyol having a lower molecular weight than the target polyether polyol, the oxyalkylene groups in the initiator are regarded as the oxyalkylene groups in the obtained polyether polyol.

[0088] Among the polyether polyols (iii-1), the polyoxyalkylene polyol having a low hydroxyl value, that is, a high molecular weight, can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, preferably propylene oxide, in the presence of a double metal cyanide complex catalyst using an initiator. Examples of the polyoxyalkylene polyol having a low hydroxyl value include polyoxyalkylene polyols having a hydroxyl value of 40 mgKOH / g or less. Among the polyether polyols (iii-1), the polyoxyalkylene polyol having a low hydroxyl value and having an oxyethylene group can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, preferably propylene oxide, in the presence of a double metal cyanide complex catalyst using a polyoxyalkylene polyol having a high hydroxyl value having an oxyethylene group, for example, a polyoxyalkylene polyol having a hydroxyl value of 50 mgKOH / g or more, as an initiator. Among the polyether polyols (iii-1), the polyoxyalkylene polyol having a high hydroxyl value and the polyoxyalkylene polyol having a high hydroxyl value as an initiator can also be produced using an alkali catalyst such as potassium hydroxide.

[0089] The average number of hydroxyl groups per molecule of the polyether polyol (iii-1) is preferably 1.60 to 2.00, more preferably 1.70 to 2.00, and even more preferably 1.80 to 1.96. A polyether polyol having an average number of hydroxyl groups per molecule of 1.60 to 2.00 may be referred to as a polyether diol. The hydroxyl value of the polyether polyol (iii-1) is preferably 1.6 to 18.1 mgKOH / g, more preferably 2.8 to 14 mgKOH / g.

[0090] The polyether polyol (iii-1) may be a mixture of two or more polyether polyols. In this case, each polyether polyol is preferably a polyether polyol included in the above range.

[0091] Examples of the polyether polyol (iii-1) include those represented by formula (3a).

[0092] [Chemical formula]

[0093] In formula (3a), R 32 and c have the same meanings as the same symbols in formula (3).

[0094] (Compound (iii-2) having a (meth)acryloyloxy group) The compound (iii-2) having a (meth)acryloyloxy group is a compound having one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. The compound (iii-2) having a (meth)acryloyloxy group is the same as the compound (i-2) having a (meth)acryloyloxy group in the monomer 1-1, and the preferred embodiments are also the same.

[0095] From the viewpoint of obtaining a cured product of a resin composition excellent in toughness, the content of the structural unit based on the monofunctional urethane (meth)acrylate contained in the polymer is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and may be 100% by mass.

[0096] From the viewpoint of obtaining a cured product of a resin composition excellent in toughness, the molecular weight of the monofunctional urethane (meth) acrylate is preferably 3,000 to 30,000, more preferably 4,000 to 25,000, and still more preferably 5,000 to 20,000. When two or more monomers (monofunctional urethane (meth) acrylate) are used in combination, it is preferable that the molecular weight of each is within the above range.

[0097] From the viewpoint of obtaining a cured product of a resin composition excellent in toughness, the glass transition temperature of the monofunctional urethane (meth) acrylate is preferably -55°C or lower, more preferably -85 to -58°C, and still more preferably -80 to -60°C.

[0098] From the viewpoint of obtaining a cured product of a resin composition excellent in toughness, the storage elastic modulus E'(25°C) of the monofunctional urethane (meth) acrylate at 25°C is preferably 70 to 450 kPa, more preferably 80 to 400 MPa, and still more preferably 85 to 350 MPa. The glass transition temperature and storage elastic modulus of the monofunctional urethane acrylate are values determined by dynamic viscoelasticity measurement.

[0099] The polymer may further contain a structural unit based on one or more second monomers selected from the reaction products of the following (iv) and (v) (hereinafter also referred to as "monomer 2-1" and "monomer 2-2"). The second monomer may be used alone or in combination of two or more. (iv) A reaction product of a polyether polyol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule, and the number of moles of the hydroxyl groups of the polyether polyol is equal to the number of moles of the compound having a (meth)acryloyloxy group. (v) A reaction product of a polyol (A), a polyisocyanate, and a compound having a (meth)acryloyloxy group, wherein the polyol (A) is at least one selected from polyoxyalkylene polyols, polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols; the compound having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule; and the total number of moles of the hydroxyl groups of the polyol (A) and the groups that react with the isocyanate groups of the compound having a (meth)acryloyloxy group is equal to the number of moles of the isocyanate groups of the polyisocyanate.

[0100] The second monomer is a polyfunctional urethane (meth)acrylate having two or more (meth)acryloyloxy groups and can act as a crosslinkable monomer for crosslinking the first monomer. Polymer particles containing structural units based on the first monomer and structural units based on the second monomer make the cured product of the resin composition containing the polymer particles excellent in toughness.

[0101] From the viewpoint of making the toughness of the cured product more excellent, the molecular weight of the second monomer is preferably from 6,000 to 60,000, more preferably from 8,000 to 40,000, and still more preferably from 10,000 to 34,000.

[0102] <Monomer 2-1> Monomer 2-1 is a reaction product of (iv), which is a reaction product of a polyether polyol (iv-1) and a compound having a (meth)acryloyloxy group (iv-2). The compound having a (meth)acryloyloxy group (iv-2) has one isocyanate group in one molecule and has one or two (meth)acryloyloxy groups in one molecule, and the number of moles of the hydroxyl groups of the polyether polyol (iv-1) is equal to the number of moles of the compound having a (meth)acryloyloxy group (iv-2).

[0103] As the monomer 2-1, a compound represented by the formula (IV) is preferable. R 4 -NHC(=O)-Z-C(=O)NH-R 4 ···(IV) In the formula (IV), R 4 is a monovalent organic group having one or two (meth)acryloyloxy groups. Z is a residue of the polyether polyol (iv-1) excluding two hydrogen atoms from two hydroxyl groups in the polyether polyol (iv-1).

[0104] As the monomer 2-1, a compound represented by the formula (4) is more preferable.

[0105]

Chemical formula

[0106] In the formula (4), R 4 is the same as R 4 in the formula (IV). R 42 is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms. A plurality of R 42 present in one molecule may be the same as or different from each other. When two or more types of R 42 are present in one molecule, the chain of -OR 42 - may be block or random. R 42 is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 42 ) is preferably a unit based on the monomer a, in the same manner as (OR 12 ) in the formula (1). A preferable embodiment of the monomer a is the same as that of the monomer 1-1. d is an integer of 20 to 600. d is preferably an integer of 35 to 500, more preferably an integer of 65 to 250.

[0107] The polyether polyol (iv-1) is the same as the polyether polyol (iii-1) in Monomers 1-3, and the preferred embodiments are also the same.

[0108] The compound (iv-2) having a (meth)acryloyloxy group is the same as the compound (i-2) having a (meth)acryloyloxy group in Monomer 1-1, and the preferred embodiments are also the same.

[0109] <Monomer 2-2> Monomer 2-2 is a reaction product of (v), and is a reaction product of a polyol (A), a polyisocyanate (v-1), and a compound (v-2) having a (meth)acryloyloxy group. The polyol (A) is one or more selected from polyether polyols, polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols. The compound (v-2) having a (meth)acryloyloxy group is a compound having a group that reacts with one isocyanate group in one molecule and having one or two (meth)acryloyloxy groups in one molecule. The total number of moles of the hydroxyl group of the polyol (A) and the group that reacts with the isocyanate group of the compound (v-2) having a (meth)acryloyloxy group is equal to the number of moles of the isocyanate group of the polyisocyanate (v-1).

[0110] As Monomer 2-2, a compound represented by formula (5) is preferred.

[0111] [Chemical formula]

[0112] In formula (5), R 5 is a monovalent organic group having one or two (meth)acryloyloxy groups. R 52is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms. A plurality of Rs present in one molecule 52 may be the same as or different from each other. When two or more types of Rs 52 are present in one molecule, the chain of -OR 52 - may be a block or random. R 52 is preferably at least one selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 52 ) is preferably a unit based on the monomer a, similar to (OR 12 ) in the formula (1). The preferred embodiment of the monomer a is the same as that in the case of the monomer 1-1. R 54 is a divalent group obtained by removing two isocyanate groups from a diisocyanate. The diisocyanate is the same as the diisocyanate in the monomer 1-2, and the preferred embodiment is also the same. e is an integer of 20 to 600. e is preferably an integer of 35 to 500, more preferably an integer of 65 to 250.

[0113] Among the polyols (A), the polyether polyol is the same as the polyether polyol (iii-1) in the monomer 1-3, and the preferred embodiment is also the same. Regarding the polyether polyol, polyester polyol, poly(meth)acrylic polyol, polycarbonate polyol, castor oil-based polyol, and polyolefin polyol in the polyol (A), those described in

[0016] to

[0028] of JP-A-2020-37689 can be used without particular limitation. As the polyether polyol, a polymer polyol in which a polymer having units based on a (meth)acrylate monomer is dispersed in the polyether polyol can also be used. The polymer polyol may be a commercially available product, and examples thereof include the "Artiflow (registered trademark)" series, the "Sharpflow (registered trademark)" series (both manufactured by Sanyo Chemical Industries, Ltd.), the "Excenol (registered trademark)" series (manufactured by AGC Inc.), and the like.

[0114] The polyisocyanate (v-1) is a compound having two or more isocyanate groups in one molecule. As the polyisocyanate, a compound having two or three isocyanate groups in one molecule is preferable, and a diisocyanate is more preferable. The diisocyanate is the same as the diisocyanate (ii-2) in Monomer 1-2, and the preferable embodiments are also the same. Specific examples of the polyisocyanate (v-1) include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, and isophorone diisocyanate. From the viewpoint of easily adjusting the elongation and strength of the cured product of the resin composition, hexamethylene diisocyanate or isophorone diisocyanate is preferable.

[0115] When the polymer contains a structural unit based on a second monomer, the content of the structural unit based on the second monomer contained in the polymer is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, from the viewpoint of obtaining a cured product of a resin composition having excellent toughness.

[0116] From the viewpoint of obtaining a cured product of a resin composition having excellent toughness, the polymer particles of the present invention preferably contain 70% by mass or more of the polymer, more preferably 80% by mass or more, still more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0117] The polymer particles of the present invention have an average particle diameter of 50 to 500 μm, preferably 80 to 450 μm, more preferably 100 to 400 μm, and even more preferably 150 to 380 μm. When the average particle diameter of the polymer particles is 50 μm or more, they are more easily and uniformly mixed in the resin to be mixed, and when it is 500 μm or less, aggregation of the polymer particles is less likely to occur and the stability is higher. In addition, the average particle diameter in this specification is the arithmetic average value of the particle diameters obtained from image analysis, and specifically, it can be determined by the method described in the examples.

[0118] [Method for producing polymer particles] The method for producing the polymer particles of the present invention is a method of polymerizing a monofunctional urethane (meth) acrylate in the presence of water, a surfactant, and an initiator to obtain polymer particles having an average particle diameter of 50 to 500 μm, wherein the monofunctional urethane (meth) acrylate is one or more monomers selected from the reaction products of (i) to (iii).

[0119] As the monofunctional urethane (meth) acrylate, those described in the section of [Polymer particles] can be used. The surfactant is not particularly limited, and examples include cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants. Among these, from the viewpoint of easily forming polymer particles having a desired average particle diameter, anionic surfactants and nonionic surfactants are preferred. The surfactant may be used alone or in combination of two or more.

[0120] Examples of the cationic surfactant include alkylammonium acetates, alkyldimethylbenzylammonium salts, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkylpyridinium salts, oxyalkylene alkylamines, polyoxyalkylene alkylamines, and the like.

[0121] Examples of the anionic surfactant include fatty acid sodium soaps such as sodium stearate soap; alkyl sulfates such as sodium lauryl sulfate; alpha-sulfo fatty acid ester salts; alkyl ether sulfates; sodium alkylbenzene sulfonates; sodium alkylnaphthalene sulfonates; dialkyl sulfosuccinates; alkyl phosphates; alkyl diphenyl ether disulfonates and the like.

[0122] Examples of the nonionic surfactant include polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether, sorbitan fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyglycerin fatty acid ester, polyoxyalkylene glycol fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene polyoxypropylene copolymer and the like.

[0123] Examples of the zwitterionic surfactant include alkyl carboxy betaines and the like.

[0124] From the viewpoint of easily forming polymer particles having a desired average particle diameter, the content of the surfactant is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and still more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the monofunctional urethane (meth) acrylate.

[0125] Examples of the initiator include radical polymerization initiators. The radical polymerization initiator is not particularly limited, and examples thereof include photopolymerization initiators and thermal polymerization initiators.

[0126] From the viewpoint of controlling the polymerization reaction, the photopolymerization initiator is preferably one that can be used by ultraviolet irradiation with a wavelength of 380 nm or less. The photopolymerization initiator may be used alone or in combination of two or more. Examples of the photopolymerization initiator include those described in paragraphs

[0147] to

[0151] of International Publication No. 2018 / 173896. As the photopolymerization initiator, a hydrogen abstraction type photopolymerization initiator in which the photoexcited initiator and the hydrogen donor in the system form an excited complex and the hydrogen of the hydrogen donor is transferred is preferable. Specific examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloyloxybenzophenone, 4-[2-((meth)acryloyloxy)ethoxy]benzophenone, 4-(meth)acryloyloxy-4'-methoxybenzophenone, methyl 2-benzoylbenzoate, and methyl benzoylformate. Also, from the viewpoint of high sensitivity to light, as the photopolymerization initiator, acylphosphine oxide-based photoinitiators such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide are preferable. The photopolymerization initiator may be used alone or in combination of two or more.

[0127] As the thermal polymerization initiator, known thermal polymerization initiators used for the polymerization of (meth)acrylate can be used by known methods. For example, azo compounds such as 2,2'-azobisbutyronitrile; peroxides such as benzoyl peroxide, bis(4-t-butylcyclohexyl)peroxydicarbonate, and 1,1,3,3-tetramethylperoxy 2-ethylhexanoate can be mentioned. The thermal polymerization initiator may be used alone or in combination of two or more.

[0128] From the viewpoint of an appropriate polymerization rate, the content of the initiator is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and still more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the monofunctional urethane (meth)acrylate.

[0129] As the polymerization method, the emulsion polymerization method is preferred. For example, water, monofunctional urethane (meth) acrylate, a surfactant, and an initiator are added to a reaction vessel and mixed, and the resulting emulsion is irradiated with ultraviolet light for polymerization.

[0130] The irradiation dose of ultraviolet light is preferably 0.01 to 10 J / cm 2 and more preferably 0.05 to 9.5 J / cm 2 and even more preferably 0.1 to 9 J / cm 2 When the irradiation dose is 0.01 J / cm 2 or more, the polymerization proceeds sufficiently, and when it is 10 J / cm 2 or less, desired polymer particles can be obtained in a shorter time.

[0131] [Resin Composition] The resin composition of the present invention contains the polymer particles of the present invention described above and a resin. Therefore, a cured product excellent in toughness can be obtained. When a solution containing a monomer is added to the curable composition containing the resin to form a cured product, the curing conditions of the resin and the curing conditions of the solution containing the monomer may be different. In this case, it is necessary to cure in multiple steps under each condition. On the other hand, the resin composition of the present invention is not only easy to handle by adding one or more monomers selected from the reaction products of (i) to (iii) in the form of particles in advance, but also a cured product can be obtained in one step.

[0132] The content of the polymer particles is preferably 1 to 100 parts by mass, more preferably 1 to 70 parts by mass, even more preferably 5 to 40 parts by mass, and still more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the resin. When the content of the polymer particles is 1 part by mass or more with respect to 100 parts by mass of the resin, the toughness of the cured product can be made better, and when it is 100 parts by mass or less, the strength of the cured product can be sufficiently maintained.

[0133] The resin used in the present invention is not particularly limited, and examples thereof include epoxy resins, polycarbonate resins, acrylic resins, phenolic resins, polystyrene, polyolefins, and the like. Among these, from the viewpoint of obtaining the effects of the present invention, at least one selected from the group consisting of epoxy resins, acrylic resins, and phenolic resins is preferable.

[0134] The epoxy resin is a monomer, oligomer, or polymer having two or more epoxy groups in one molecule, and is not particularly limited, and known ones can be used. Examples of the epoxy resin include aromatic epoxy compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, resorcinol diglycidyl ether, catechol diglycidyl ether, hydroquinone diglycidyl ether, 4-tert-butylphenyl glycidyl ether, phthalic acid diglycidyl, phenol novolac type epoxy resin, cresol novolac type epoxy resin, fluorene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin; aliphatic epoxy compounds such as 1,2-propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether; alicyclic epoxy compounds such as 1,2-cyclohexanedicarboxylic acid diglycidyl, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, limonene dioxide, dicyclopentadiene dioxide, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoint of ease of handling and the like, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and bisphenol A type epoxy resin are preferable.

[0135] From the viewpoint of better strength and toughness of the cured product, the content of the epoxy resin is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, and still more preferably 80 to 97% by mass based on the total amount of the resin composition.

[0136] When the resin composition of the present invention contains an epoxy resin, it is preferable that the resin composition further contains an epoxy resin curing agent. As the epoxy resin curing agent, known ones can be used, and depending on the type of epoxy resin and the use of the cured product of the resin composition, etc., for example, amines, imidazoles, acid anhydrides, cationic polymerization initiators, etc. can be mentioned. Among these, from the viewpoint of good curability, etc., a cationic polymerization initiator is preferably used.

[0137] As the cationic polymerization initiator, a photo cationic polymerization initiator or a thermal cationic polymerization initiator is preferably used. When using a photo polymerization initiator, the resin composition can be cured rapidly without heating it to a high temperature, and no thermal damage is caused to the periphery of the resin composition. From the viewpoint of controlling the polymerization reaction, those that can be used by ultraviolet irradiation with a wavelength of 380 nm or less are preferable as the photo polymerization initiator. On the other hand, when using a thermal polymerization initiator, the resin composition can be cured by heating, etc. even in places where irradiation with ultraviolet rays, visible light, etc. is difficult. From the viewpoint of controlling the polymerization reaction, those that can be used by heating within the range of 50 to 120 °C are preferable as the thermal polymerization initiator.

[0138] <Photo cationic polymerization initiator> The photo cationic polymerization initiator has a structure in which a cationic part that absorbs light and an anionic part that becomes a source of acid are paired, and is also called a photo acid generator. Examples of the photo cationic polymerization initiator include diazonium salt-based compounds, iodonium salt-based compounds, sulfonium salt-based compounds, phosphonium salt-based compounds, selenium salt-based compounds, oxonium salt-based compounds, ammonium salt-based compounds, bromine salt-based compounds, etc. These can be used alone or in combination of two or more.

[0139] Among these, from the viewpoint of good curability, a sulfonium salt compound is preferably used. Examples of the sulfonium salt compound include arylsulfonium salts such as (4-hydroxyphenyl)methylbenzylsulfonium salt, triphenylsulfonium salt, diphenyl[4-(phenylthio)phenyl]sulfonium salt, 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium salt, tri-p-tolylsulfonium salt, etc., and a triarylsulfonium salt is preferably used.

[0140] Specific examples of the photo cationic polymerization initiator include (4-hydroxyphenyl)methylbenzylsulfonium tetrakis(pentafluorophenyl)borate, 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-(phenylthio)phenyl diphenylsulfonium phenyltris(pentafluorophenyl)borate, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium phenyltris(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenylsulfonium] hexafluoroantimonate, diphenyl[4-(phenylthio)phenyl]sulfonium tris(pentafluoroethyl) trifluorophosphate, diphenyl[4-(phenylthio)phenyl]sulfonium tetrakis(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate, 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tris(pentafluoroethyl) trifluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfide phenyltris(pentafluorophenyl)borate, [4-(2-thioxanthonylthio)phenyl]phenyl-2-thioxanthonylsulfonium phenyltris(pentafluorophenyl)borate, etc. In addition, for example, commercially available products such as product names "CPI (registered trademark; hereinafter, notation omitted)-101A", "CPI-100P", "CPI-110P", "CPI-200K" (manufactured by Sun Apro Co., Ltd.), product names "CYRACURE UVI-6990", "CYRACURE UVI-6992" (manufactured by Dow Chemical Company), product name "UVACURE1590" (manufactured by Daicel Ornex Co., Ltd.), product names "CD-1010", "CD-1011", "CD-1012" (manufactured by Arkema); product name "Irgacure (registered trademark; hereinafter, notation omitted) 264" (manufactured by BASF), product name "CIT-1682" (manufactured by Nippon Soda Co., Ltd.), product name "PHOTOINITIATOR 2074" (manufactured by Rhodia Japan Co., Ltd.) are preferably used.

[0141] <Thermal cationic polymerization initiator> A thermal cationic polymerization initiator is a compound that generates an acid by heating to initiate the polymerization reaction of an epoxy compound, and has a structure in which a cationic part that absorbs heat and an anionic part that serves as a source of the acid form a pair.

[0142] Examples of the thermal cationic polymerization initiator include iodonium salt-based compounds, sulfonium salt-based compounds, etc. These may be used alone or in combination of two or more.

[0143] Specific examples of the thermal cationic polymerization initiator include 4-hydroxyphenyl-methyl-benzylsulfonium phenyltris(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-(2-methylbenzyl)sulfonium phenyltris(pentafluorophenyl)borate, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium phenyltris(pentafluorophenyl)borate, p-methoxycarbonyloxyphenyl-benzyl-methylsulfonium phenyltris(pentafluorophenyl)borate, and the like.

[0144] From the perspective of an appropriate curing rate, the content of the epoxy resin curing agent in the resin composition is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and even more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin.

[0145] 〔Other Components〕 From the perspectives of good handleability and toughness of the cured product, the resin composition may contain other components in addition to the above polymer particles, resin, and, if necessary, the epoxy resin curing agent. Examples of other components include colorants such as pigments and dyes, silane coupling agents, tackifying resins, antioxidants, light stabilizers, metal deactivators, rust preventives, anti-aging agents, moisture absorbers, hydrolysis inhibitors, antistatic agents, defoaming agents, fillers, and the like. These other components in the resin composition can be blended in a content within a range that does not impair the effects of the present invention. Note that the resin composition may contain a solvent, but from the perspectives of drying property and suppression of deterioration of peripheral members during curing, etc., especially when it is for three-dimensional shaping, etc., it is preferably not contained. The content of the solvent is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less in 100 parts by mass of the resin composition.

[0146] [Method for Producing Resin Composition] The resin composition of the present invention can be produced by uniformly mixing polymer particles, resin, and, if necessary, an epoxy resin curing agent and other components using a known mixing device such as a self-revolving stirring and defoaming device, a homogenizer, a planetary mixer, a three-roll mill, a bead mill, etc. Each compounding component in the resin composition may be mixed simultaneously or may be mixed by sequential addition.

[0147] [Cured Product of Resin Composition] The cured product of the present invention can be rapidly cured by subjecting the above-described resin composition of the present invention to light irradiation or heat treatment to obtain a cured product.

[0148] When curing a resin composition by irradiating it with light, the light source can be appropriately set according to the light absorption ability of the photoinitiator. For example, ultraviolet light-emitting diodes (LEDs), low-pressure mercury lamps, high-pressure mercury lamps, mercury xenon lamps, metal halide lamps, tungsten lamps, arc lamps, excimer lamps, excimer lasers, semiconductor lasers, YAG lasers, laser systems combining a laser and a nonlinear optical crystal, high-frequency induction ultraviolet generators, etc. can be used as the light source. The integrated light quantity is, for example, 0.01~5 J / cm 2 or so. After irradiating with light, heat treatment may be further performed. By performing heat treatment, it can be cured better. Usually, the heating temperature is about 40~200 °C and the heating time is about 1 minute~15 hours. Also, by standing at room temperature (about 15~25 °C) for about 1~48 hours, the curability can be improved.

[0149] When curing the resin composition by heat treatment, usually, the heating temperature is about 40~250 °C and the heating time is about 5 minutes~24 hours. Preferably, when the heating temperature is high, the heating time is shortened, and when the heating temperature is low, the heating time is lengthened.

[0150] [Applications] Examples of the applications of the resin composition include insulating materials and encapsulating materials in electronic devices, adhesives, pressure-sensitive adhesives, paints, etc. It can also be suitably used as a shaping material for obtaining a shaped body by optical three-dimensional shaping using a 3D printer or the like. Examples of articles provided with the cured product of the resin composition and the applications of the cured product include various base materials such as metals, resin films, glass, paper, and wood provided with the cured coating film by the above paint; surface protection films, hard coats, antifouling films, and antireflection films for semiconductor elements, organic electroluminescence elements, and organic thin-film solar cell elements, etc.; various optical members such as lenses, prisms, filters, optical waveguides, light guide plates, light diffusing plates, diffraction elements, etc.; interlayer insulators; protective insulating films for printed wiring boards; casting materials, etc. In such articles and applications, the excellent properties of the cured product of the resin composition of the present invention, that is, high toughness, can be well exhibited.

Example

[0151] Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited by the following examples.

[0152] 〔Raw material compounds〕 Details of the raw material compounds used in Production Example 1 and Examples 1 to 5 are as follows. · DMC-TBA: Zinc hexacyanocobaltate-tert-butyl alcohol complex · AOI: 2-Acryloyloxyethyl isocyanate; "Karenz AOI", manufactured by Showa Denko K.K. · Radical polymerization initiator: 2-Hydroxy-2-methylpropiophenone; "Irgacure 1173", manufactured by BASF; Photo radical polymerization initiator · Surfactant: Surfactant mainly composed of sodium polyoxyalkylene alkyl ether sulfate, containing alkyl hydroxysulfobetaine, alkyl glucoside and polyoxyethylene alkyl ether, active ingredient 29%, "Family Fresh", manufactured by Kao Corporation; Anionic surfactant · Epoxy resin A-1: Bisphenol A diglycidyl ether; manufactured by Tokyo Chemical Industry Co., Ltd. · Epoxy resin A-2: Bisphenol A type epoxy resin; "jER (registered trademark) 828", manufactured by Mitsubishi Chemical Corporation · Epoxy resin curing agent: Triarylsulfonium salt of a special phosphorus-based anion having a perfluoroalkyl group; "CPI-200K", manufactured by San-Apro Ltd.; Photo cationic polymerization initiator (photoacid generator), 50 mass% propylene carbonate solution · Mixture of rubber particles and epoxy resin: Masterbatch type resin in which 20 parts by mass of crosslinked acrylic rubber particles having a particle diameter of 0.3 μm are dispersed and blended with respect to 100 parts by mass of bisphenol A type epoxy resin; "Acryset (registered trademark) BPA328", manufactured by Nippon Shokubai Co., Ltd. · Acrylic rubber particles: Acrylic particles having an average particle diameter of 10 μm, "Eposter (registered trademark) MA1010", manufactured by Nippon Shokubai Co., Ltd.

[0153] [Production Example 1] Production of Polymer Particles Into a pressure reactor equipped with a stirrer and a nitrogen inlet tube, 0.2 g of DMC-TBA and 30 g of n-butanol as an initiator were placed, and 3970 g of propylene oxide was introduced at a constant rate over 7 hours at 130°C under a nitrogen atmosphere. After confirming that the internal pressure drop of the pressure reactor had stopped, 4000 g of polyoxypropylene monool (hydroxyl value 5.6 mgKOH / g, hydroxyl value-converted molecular weight 10,000, average number of hydroxyl groups 1.08) was obtained. Into a reaction vessel equipped with a stirrer and a nitrogen inlet tube, 964.9 g of the polyoxypropylene monool, 13.1 g of AOI (NCO index 100), and 0.08 g of a 25% by mass toluene solution of bismuth 2-ethylhexanoate were placed, and the mixture was stirred at 70°C for 3 hours to obtain a monofunctional urethane acrylate (number average molecular weight 16,000, glass transition temperature -69°C, E’(25°C) 150 kPa).

[0154] To a beaker, 10 parts by mass of the obtained monofunctional urethane acrylate, 90 parts by mass of ion-exchanged water, 0.5 part by mass of a surfactant, and 0.5 part by mass of a radical polymerization initiator (Irgacure 1173) were added and mixed to obtain an emulsion. While stirring the obtained emulsion with a stirrer, it was irradiated with a chemical lamp having an illuminance of 7 mW / cm 2 for 20 minutes to cure the monofunctional urethane acrylate. Subsequently, after filtering with filter paper, washing with acetone, and air-drying, polymer particles having an average particle diameter of 350 μm in which the monofunctional urethane acrylate was cured were obtained.

[0155] The number average molecular weight of the monofunctional urethane acrylate obtained in Production Example 1 was measured under the following measurement conditions by gel permeation chromatography (GPC). <Measurement Conditions> · Instrument used: "HLC-8120GPC", manufactured by Tosoh Corporation · Columns used: The following two types of columns were connected in series in order 「TSKgel (registered trademark) G7000H XL 」, manufactured by Tosoh Corporation, 1 piece 「TSKgel (Registered Trademark) GMH XL 」, manufactured by Tosoh Corporation, 2 columns · Column temperature: 40 °C · Detector: Differential refractive index (RI) detector · Eluent: Tetrahydrofuran · Flow rate: 0.8 mL / min · Sample concentration: 0.5 mass% · Sample injection volume: 100 μL · Standard sample: Polystyrene

[0156] Also, the glass transition temperature and storage modulus of the monofunctional urethane acrylate were determined as follows by dynamic viscoelasticity measurement. To 100 parts by mass of the monofunctional urethane acrylate, 0.3 parts by mass of a photo radical polymerization initiator ("Irgacure 819", manufactured by BASF) was added and mixed with a planetary stirrer. The obtained mixed solution was irradiated with a conveyor type UV irradiator (manufactured by Oak Manufacturing Co., Ltd.; mercury xenon lamp, illuminance 100 mW / cm 2 , integrated light amount 3 J / cm 2 ) to obtain a cured sample of the monofunctional urethane acrylate (homopolymer; length 15 mm, width 5 mm, thickness 2 mm). For the cured sample, the storage modulus (at 25 °C) and loss modulus were measured with a dynamic viscoelasticity measuring device ("EXSTAR TMA / SS6100", manufactured by Hitachi High-Tech Science Corporation; tensile mode, temperature range: -80 to 130 °C, heating rate: 3 °C / min, measurement frequency: 1 Hz, strain: 1%), and the temperature at the peak was taken as the glass transition temperature.

[0157] The average particle diameter of the polymer particles obtained in Production Example 1 was measured with a microscope VHX-1000 manufactured by Keyence Corporation. Specifically, 5 g of the polymer particles obtained in Production Example 1 were placed on a slide glass, and the polymer particles were further covered with a cover glass. Observation was carried out from above the cover glass using the above microscope. From the obtained observation image, the particle diameters of any 10 polymer particles were measured, and the average value was calculated.

[0158] [Example 1] 11 parts by mass of the polymer particles obtained in Production Example 1, 100 parts by mass of epoxy resin A-1, and 6.7 parts by mass (solid content: 3.35 parts by mass) of an epoxy resin curing agent (CPI-200K) were added and mixed to produce the resin composition of Example 1.

[0159] [Example 2] 11 parts by mass of the polymer particles obtained in Production Example 1, 100 parts by mass of epoxy resin A-2, and 6.7 parts by mass (solid content: 3.35 parts by mass) of an epoxy resin curing agent (CPI-200K) were added and mixed to produce the resin composition of Example 2.

[0160] [Example 3] 100 parts by volume of epoxy resin A-1 and 6.7 parts by mass (solid content: 3.35 parts by mass) of an epoxy resin curing agent (CPI-200K) were added and mixed to produce the resin composition of Example 3.

[0161] [Example 4] 66.6 parts by mass of a mixture of rubber particles and an epoxy resin (Acryset (registered trademark) BPA328), 44.4 parts by mass of epoxy resin A-1, and 6.7 parts by mass (solid content: 3.35 parts by mass) of an epoxy resin curing agent (CPI-200K) were added and mixed to produce the resin composition of Example 4.

[0162] [Example 5] 11 parts by mass of acrylic rubber particles (Epothane (registered trademark) MA1010), 100 parts by mass of epoxy resin A-2, and 6.7 parts by mass (solid content: 3.35 parts by mass) of an epoxy resin curing agent (CPI-200K) were added and mixed to produce the resin composition of Example 5.

[0163] [Evaluation] Test specimens were prepared using the resin compositions produced in Examples 1 to 5, and evaluations were performed by the following various tests. The evaluation results are shown in Table 1. Examples 1 and 2 are examples, and Examples 3 to 5 are comparative examples. [Preparation of Test Specimen] The resin composition was poured into a mold with a polyethylene film attached, and a glass plate with a polyethylene film attached was overlapped so that the polyethylene film side faced the resin composition. Under a nitrogen gas atmosphere, ultraviolet rays were irradiated from the glass plate side using a conveyor-type UV irradiator (manufactured by Okou Seisakusho Co., Ltd.; mercury xenon lamp, illuminance 100 mW / cm 2 , integrated light quantity 3 J / cm 2 ). After standing for 12 hours, the polyethylene films on both sides were peeled off to obtain a test piece of a cured product of the resin composition with a length of 90 mm, a width of 5 mm, and a thickness of 200 μm.

[0164] [Tensile Test] A tensile test of the test piece was carried out using a tensile testing machine (Tensilon universal testing machine "RTG-1310", manufactured by A&D Co., Ltd.; tensile speed 300 mm / min, chuck distance 20 mm), and the tensile strength (TS) and elongation at break were measured. It can be said that the higher the tensile strength and the elongation at break, the higher the toughness. The tensile strength and elongation at break were evaluated according to the following criteria. (Tensile Strength) A: 35 MPa or more B: Less than 35 MPa (Elongation at Break) A: Elongation at break is 5% or more B: Elongation at break is less than 5%

[0165] [Table 1]

[0166] It can be seen that the cured product of the resin composition containing the polymer particles of the present invention is excellent in toughness.

Claims

1. Polymer particles with an average particle diameter of 50 to 500 μm, comprising a polymer containing a structural unit based on a monofunctional urethane (meth)acrylate, wherein the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i) to (iii). (i) An equimolar reaction product of a polyether monool and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one (meth)acryloyloxy group in one molecule. (ii) An equimolar reaction product of a polyether monool, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and one (meth)acryloyloxy group in one molecule. (iii) An equimolar reaction product of a polyether polyol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one (meth)acryloyloxy group in one molecule.

2. The polymer particles according to claim 1, wherein the content of the structural unit based on the monofunctional urethane (meth)acrylate contained in the polymer is 70% by mass or more.

3. The polymer particles according to claim 1 or 2, wherein the monofunctional urethane (meth)acrylate has a number average molecular weight of 3,000 to 30,000.

4. The polymer particles according to any one of claims 1 to 3, wherein the monofunctional urethane (meth)acrylate has a glass transition temperature of -55°C or lower.

5. The polymer particles according to any one of claims 1 to 4, wherein the monofunctional urethane (meth) acrylate has a storage elastic modulus E'(25°C) at 25°C of 70 to 450 kPa.

6. A resin composition comprising the polymer particles according to any one of claims 1 to 5 and a resin.

7. The resin composition according to claim 6, wherein the content of the polymer particles is 1 to 100 parts by mass with respect to 100 parts by mass of the resin.

8. The resin composition according to claim 6 or 7, wherein the resin is at least one selected from the group consisting of an epoxy resin, a polycarbonate resin, an acrylic resin, a phenolic resin, polystyrene, and a polyolefin.

9. A cured product obtained by curing the resin composition according to any one of claims 6 to 8.

10. An article provided with the cured product according to claim 9.

11. A method for producing polymer particles, comprising polymerizing a monofunctional urethane (meth) acrylate in the presence of water, a surfactant, and an initiator to obtain polymer particles having an average particle diameter of 50 to 500 μm. The method for producing polymer particles, wherein the monofunctional urethane (meth) acrylate is one or more monomers selected from the reaction products of the following (i) to (iii). (i) An equimolar reaction product of a polyether monool and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group and one (meth)acryloyloxy group in one molecule. (ii) An equimolar reaction product of a polyether monoalcohol, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has a group that reacts with one isocyanate group in one molecule and has one (meth)acryloyloxy group in one molecule. (iii) An equimolar reaction product of a polyether polyol and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and has one (meth)acryloyloxy group in one molecule.

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