Curable compositions, coating compositions, and their cured products

Abstract

To provide an acrylic curable composition which has low flammability of a curable composition and excellent mechanical properties, weather resistance and gasoline resistance of a cured product, and is useful as a civil engineering and construction material such as a coating material, a coated floor material, a road surface paving material, a wall material and a repair filler material.SOLUTION: There is provided a curable composition which comprises one or more compounds selected from an acrylic monomer having one or more functional groups selected from a hydroxyl group, an alkoxy group, a carboxy group and a (meth)acryloyl group, an acrylic monomer having an alkyl group having 2 to 6 carbon atoms and a (meth)acryloyl group and having no hydroxy group, no alkoxy group and no carboxy group and an acrylic polymer having 10 mass% or more of a constituent unit derived from a compound having an alkyl group having 2 to 18 carbon atoms and a (meth)acryloyl group, a urethane (meth)acrylate, an epoxy (meth)acrylate and a polyester (meth)acrylate as a copolymerization component and a reducing agent in a specific ratio.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition, a coating composition, and cured products thereof.

Background Art

[0002] Conventionally, methods using synthetic resins such as unsaturated polyester resins, epoxy resins, and polyurethane resins have been known for coating floors, walls, and the like. However, unsaturated polyester resins are excellent in solvent resistance but inferior in weather resistance and have poor low-temperature workability. Epoxy resins are excellent in adhesion to the substrate but inferior in weather resistance, have a long curing time, and are inferior in curability at low temperatures. Polyurethane resins are excellent in elasticity and flexibility but have a long curing time.

[0003] Therefore, instead of these resins, acrylic curable compositions that have a short curing time, excellent low-temperature curability, and excellent weather and chemical resistance are generally used. However, acrylic curable compositions generally contain methyl methacrylate, which has a high flammability, and there is a risk of fire due to ignition.

[0004] On the other hand, various acrylic curable compositions that do not contain methyl methacrylate have been proposed. For example, Patent Document 1 describes an acrylic resin concrete composition mainly composed of (meth)acrylates having an alkylcyclohexyl skeleton. However, the composition described in Patent Document 1 tends to have poor curability on the surface of the cured film.

[0005] Patent Document 2 describes a composition containing isobornyl methacrylate and hydroxypropyl methacrylate as monomers. Patent Document 3 describes a synthetic resin composition for polymer concrete containing an alkyl (meth)acrylate having 6 to 16 carbon atoms. However, neither of the compositions described in Patent Documents 2 and 3 has a sufficient effect on reducing odor and tends to have poor curability on the film surface.

[0006] Patent Document 4 describes a curable resin composition containing polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate. Patent Document 5 describes a resin composition containing dicyclopentenyloxyalkyl(meth)acrylate. However, neither of the compositions described in Patent Documents 4 nor 5 exhibits sufficient curability of the surface of the coating film.

[0007] Patent document 6 describes a resin composition containing tetrahydrofurfuryl methacrylate. However, it had problems such as poor toughness of the cured product, making it impossible to achieve both strength and elongation, and insufficient weather resistance of the cured product.

[0008] Patent document 7 describes a resin composition containing 2-phenoxyethyl methacrylate. However, it had the problem of insufficient weather resistance of the cured product. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 1-141851 [Patent Document 2] Japanese Patent Application Publication No. 5-186539 [Patent Document 3] Japanese Patent Application Publication No. 6-329456 [Patent Document 4] Japanese Patent Application Publication No. 10-87770 [Patent Document 5] Japanese Patent Application Publication No. 10-158364 [Patent Document 6] Japanese Patent Publication No. 2015-78264 [Patent Document 7] Japanese Patent Publication No. 2004-203949 [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention has been made to solve the above-mentioned problems, and aims to provide an acrylic-based curable composition that has low flammability, excellent mechanical properties, weather resistance, and gasoline resistance of the cured product, and is useful as a civil engineering and construction material such as a coating material, floor coating material, road paving material, wall material, and repair filler. [Means for solving the problem]

[0011] The present invention is summarized in the following [1] to [8]. [1] Hydroxyl group, Alco tree Compound A is an acrylic monomer having one or more functional groups selected from a carboxyl group and a (meth)acryloyl group, and has an alkyl group with 2 to 6 carbon atoms and a (meth)acryloyl group, a hydroxyl group, an alcohol group, and tree The compound comprises compound B, an acrylic monomer that does not have either a C group or a carboxyl group; one or more compounds C selected from acrylic polymers, urethane (meth)acrylates, epoxy (meth)acrylates, and polyester (meth)acrylates, which have 10% by mass or more of constituent units derived from compounds having C2-C18 alkyl groups and (meth)acryloyl groups as copolymer components; and a reducing agent D. The total of 100% by mass of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C contains 5 to 60% by mass of compound A, 10 to 90% by mass of compound B, and 5 to 60% by mass of compound C. A curable composition comprising 0.01 to 20 parts by mass of the reducing agent D with respect to a total of 100 parts by mass of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. [2] The curable composition according to [1], comprising 0.01 to 5 parts by mass of wax E per 100 parts by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. [3] The curable composition according to [1] or [2], wherein the flash point is 15°C or higher. [4] A curable composition according to any one of [1] to [3], wherein compound A has a hydroxyl group and a (meth)acryloyl group. [5] The curable composition according to any one of [1] to [4], wherein the compound B has a branched alkyl group having 4 carbon atoms and a (meth)acryloyl group. [6] The curable composition according to any one of [1] to [5], wherein the compound B contains i-butyl (meth)acrylate. [7] A coating composition containing the curable composition according to any one of [1] to [6]. [8] A cured product of the curable composition according to any one of [1] to [6] or the coating composition according to [7], wherein the cured product has a thickness of 0.1 to 20 cm. [Advantages of the Invention]

[0012] According to the present invention, there is provided an acrylic curable composition having low flammability of the curable composition, excellent mechanical properties, weather resistance and gasoline resistance of the cured product, and being useful as a civil engineering and construction material such as a coating material, a coated floor material, a road paving material, a wall material, and a repair filler. [Embodiments for Carrying Out the Invention]

[0013] Hereinafter, embodiments of the present invention will be described in detail. In the present invention, “(meth)acry” is a general term for “acry and methacry”. In addition, “~” indicating a numerical range means including the numerical values described before and after it as a lower limit value and an upper limit value.

[0014] The curable composition of the present invention contains the following compounds A to C and a reducing agent D as essential components. The curable composition of the present invention may contain, as optional components, radical polymerizable compounds other than compounds A to C and polymers other than compound C.

[0015] (Compound A) Compound A used in the present invention has a hydroxy group, an alcohol treeThis is an acrylic monomer having one or more functional groups selected from a carboxyl group and a (meth)acryloyl group. Among these, acrylic monomers having a hydroxyl group are preferred from the viewpoint of gasoline resistance.

[0016] Specific examples of compound A include acrylic monomers having hydroxyl groups such as (meth)acrylate-2-hydroxyethyl, (meth)acrylate-2-hydroxypropyl, (meth)acrylate-4-hydroxybutyl, (meth)acrylate-hydroxyhexyl, (meth)acrylate-phenoxydiethylene glycol, (meth)acrylate-phenoxypolyethylene glycol, (meth)acrylate-nonylphenoxypolyethylene glycol, and (meth)acrylate-phenoxypolypropylene glycol; acrylic monomers having alkoxy groups such as (meth)acrylate-methoxyethyl, (meth)acrylate-ethoxyethyl, and (meth)acrylate-butoxyethyl; and acrylic monomers having carboxyl groups such as (meth)acrylic acid and 2-(meth)acryloyloxyethyl acid phosphate. Compound A may be used alone or in combination of two or more types.

[0017] The content of compound A in the curable composition of the present invention is 5 to 60% by mass, based on 100% by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. If the content of compound A is 5% by mass or more, gasoline resistance is improved. If the content of compound A is 60% by mass or less, the mechanical properties (maximum tensile strength) of the cured product are improved. The content of compound A is preferably 10 to 40% by mass, and more preferably 15 to 30% by mass. The lower and upper limits of the content of compound A can be arbitrarily combined.

[0018] (Compound B) Compound B used in the present invention has an alkyl group having 2 to 6 carbon atoms and a (meth)acryloyl group, and a hydroxyl group, an alcohol group. tree It is an acrylic monomer that does not contain either a carboxyl group or a carboxyl group.

[0019] From the viewpoint of flammability, the number of carbon atoms in the alkyl group of compound B is preferably 3 or more. On the other hand, from the viewpoint of the mechanical properties (maximum tensile strength) of the cured product, the number of carbon atoms in the alkyl group of compound B is preferably 5 or less. Furthermore, for these reasons, the number of carbon atoms in the alkyl group of compound B is particularly preferably 4. Furthermore, from the viewpoint of the strength of the cured product, a (meth)acrylic acid ester compound is preferred as compound B.

[0020] Specific examples of compound B include (meth)acrylic acid ester compounds having a linear alkyl group such as ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate; (meth)acrylic acid ester compounds having a branched alkyl group such as i-propyl (meth)acrylate, i-butyl (meth)acrylate, and t-butyl (meth)acrylate; and (meth)acrylic acid ester compounds having an aliphatic cyclic alkyl group such as cyclohexyl (meth)acrylate.

[0021] Among these, n-butyl (meth)acrylate, i-butyl (meth)acrylate, and t-butyl (meth)acrylate, which have a C4 alkyl group and a (meth)acryloyl group, are preferred from the viewpoint of flammability and the mechanical properties (maximum tensile strength) of the cured product. I-butyl (meth)acrylate and t-butyl (meth)acrylate, which have a branched alkyl group and a (meth)acryloyl group, are more preferred. I-butyl (meth)acrylate is even more preferred, and i-butyl methacrylate is particularly preferred. Compound B may be used alone or in combination of two or more types.

[0022] The content of compound B in the curable composition of the present invention is 10 to 90% by mass, based on 100% by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. If the content of compound B is 10% by mass or more, the viscosity of the curable composition will be lower, resulting in good workability during painting. If the content of compound B is 90% by mass or less, the curability of the curable composition and the strength of the cured product will be improved. The content of compound B is preferably 20 to 75% by mass, and more preferably 30 to 60% by mass. The lower and upper limits of the content of compound B can be arbitrarily combined.

[0023] (Compound C) Compound C used in the present invention is one or more compounds selected from acrylic polymers (hereinafter also referred to as "acrylic polymer P"), urethane (meth)acrylate, epoxy (meth)acrylate, and polyester (meth)acrylate, having 10% by mass or more of constituent units derived from a compound having an alkyl group with 2 to 18 carbon atoms and a (meth)acryloyl group (hereinafter also referred to as "compound m") as copolymer components.

[0024] From the viewpoint of the mechanical properties (maximum tensile strength) and weather resistance of the cured product, an acrylic polymer P is preferred as compound C. The mass ratio of constituent units derived from compound m to the total mass of the acrylic polymer P is 10% by mass or more, preferably 20% by mass or more, and more preferably 40% by mass or more, from the viewpoint of solubility in compound B. Furthermore, from the viewpoint of the mechanical properties (maximum tensile strength) of the cured product, the number of carbon atoms in the alkyl group of compound m is preferably 2 to 8, and more preferably 4 to 6.

[0025] Specific examples of compound m used in acrylic polymer P include, for example, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. Compound m may be used alone or in combination of two or more compounds.

[0026] The copolymer components other than compound m used in the acrylic polymer P are not particularly limited as long as they are copolymerizable compounds. Specifically, examples include methyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, styrene, vinyltoluene, and vinyl acetate. The copolymer components other than compound m may be used individually or in combination of two or more.

[0027] Acrylic polymer P can be obtained by polymerizing these copolymer components (monomers) using various conventionally known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization.

[0028] From the viewpoint of the paintability of the curable composition, the mass-average molecular weight of the acrylic polymer P is preferably 5,000 to 200,000, and more preferably 10,000 to 180,000. The lower and upper limits of the mass-average molecular weight of the acrylic polymer P can be arbitrarily combined. In this specification, the mass-average molecular weight of a polymer refers to the value obtained by dissolving the polymer in a solvent (tetrahydrofuran), measuring the molecular weight by gel permuration chromatography (GPC), and then converting that value to polystyrene equivalent.

[0029] In addition to the acrylic polymer P, urethane (meth)acrylate, epoxy (meth)acrylate, and polyester (meth)acrylate can be used as compound C in this invention.

[0030] Urethane (meth)acrylates can be obtained, for example, by the reaction of a polyol with a polyisocyanate and a (meth)acrylate having a hydroxyl group. The polyol used to synthesize urethane (meth)acrylate is a compound having two or more hydroxyl groups in one molecule. Examples of the polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyhexamethylene glycol; addition reaction products of dihydric phenols such as bisphenol A, bisphenol F, and bisphenol S with alkylene oxides such as ethylene oxide and propylene oxide; and polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, butylene glycol, and methylpentanediol, and phthalic acid, isophthalic acid, and tetrahydrophthalic acid. Examples include polyester polyols obtained by reaction with acids, polybasic acids such as succinic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, and trimellitic acid, and their anhydrides; polylactone diols obtained from alkylene glycols and lactones; and polycarbonate diols having carbonate bonds obtained by reaction with diols such as butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and cyclohexanedimethanol, and carbonate-forming agents such as phosgene and dimethyl carbonate. These polyols may be used individually or in combination of two or more.

[0031] Among these polyols, polycarbonate diols are preferred from the viewpoint of curability, and polycarbonate diols synthesized using butanediol, pentanediol, or hexanediol are more preferred. Furthermore, polybutylene glycol is preferred from the viewpoint of the mechanical properties (elongation at break) of the cured product at low temperatures.

[0032] Polyisocyanates used to synthesize urethane (meth)acrylates are compounds having two or more isocyanate groups in one molecule. Examples of such polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, and isophorone diisocyanate. Adduct compounds and trimerized compounds of these compounds with water or trimethylolpropane can also be used as polyisocyanates. These polyisocyanates may be used individually or in combination of two or more.

[0033] Examples of hydroxyl group-containing (meth)acrylates used to synthesize urethane (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and adducts of ε-caprolactone and 2-hydroxyethyl (meth)acrylate. These hydroxyl group-containing (meth)acrylates may be used individually or in combination of two or more.

[0034] Furthermore, if necessary, an alcohol having an allyl group may be used instead of a (meth)acrylate having a hydroxyl group. Examples of alcohols having an allyl group include allyl alcohol, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, polypropylene glycol monoallyl ether, glycerin monoallyl ether, glycerin diallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, pentaerythritol monoallyl ether, pentaerythritol diallyl ether, and pentaerythritol triallyl ether.

[0035] Epoxy (meth)acrylate can be obtained, for example, by the reaction of an epoxy resin with (meth)acrylic acid. Examples of the epoxy resin include bisphenol-type epoxy resins and novolac-type epoxy resins.

[0036] Polyester (meth)acrylates can be obtained, for example, by reacting a polybasic acid or its anhydride with a polyhydric alcohol compound and (meth)acrylic acid or glycidyl (meth)acrylate by known methods. Examples of polybasic acids include phthalic acid, isophthalic acid, tetrahydrophthalic acid, succinic acid, maleic acid, fumaric acid, and adipic acid. Examples of polybasic acid anhydrides include the anhydrides of the aforementioned polybasic acids. Examples of polyhydric alcohols include ethylene glycol and propylene glycol.

[0037] There are no particular restrictions on the molecular weight of urethane (meth)acrylate, epoxy (meth)acrylate, and polyester (meth)acrylate, but from the viewpoint of workability during painting, it is preferable that their mass-average molecular weight be 30,000 or less.

[0038] The content of compound C in the curable composition of the present invention is 5 to 60% by mass, based on 100% by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. From the viewpoint of the mechanical properties (elongation at breaking point) of the curable composition, the content of compound C is preferably 10 to 50% by mass, and more preferably 15 to 40% by mass, based on the above total of 100% by mass. The lower and upper limits of the content of compound C can be arbitrarily combined.

[0039] (Reducing agent D) The reducing agent D used in the present invention can accelerate the curing reaction. Examples of reducing agent C include amines such as N,N-dimethyl-p-toluidine, N,N-di(2-hydroxyethyl)-p-toluidine, N,N-di(2-hydroxypropyl)-p-toluidine, tri-n-butylamine, N-ethyl-N-hydroxyethylaniline, and N,N-dimethylaniline; and polyvalent metal catalysts such as cobalt naphthenate, cobalt octoate, and cobalt acetoacetylate. These may be used individually or in combination of two or more.

[0040] The amount of reducing agent D added is 0.01 to 20 parts by mass per 100 parts by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. From the viewpoint of balancing curability, pot life, and workability, the amount of reducing agent D added is preferably 0.1 to 5 parts by mass, and more preferably 0.2 to 2 parts by mass, per 100 parts by mass of the total of compounds A to C, optional radical polymerizable compounds other than compounds A to C, and polymers other than compound C. The lower and upper limits of the amount of reducing agent D added can be arbitrarily combined.

[0041] (Radical polymerizable compounds other than compounds A-C) The curable composition of the present invention may contain, as an optional component, a radical polymerizable compound other than compounds A to C. The radical polymerizable compound other than compounds A to C is not particularly limited as long as it is a compound that exhibits radical polymerizability. Specifically, for example, methyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, i-octyl (meth)acrylate, n-nonyl (meth)acrylate, i-nonyl (meth)acrylate, n-decyl (meth)acrylate, i-decyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, dicyclopentenyl (meth)acrylate, 2-dicyclopentenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentane (meth)acrylate, adamantyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenylphenyl (meth)acrylate, (meth)acrylate (Meth) Phenylphenoxyethyl acrylate, (meth)phenoxybenzyl acrylate, (meth)phenylbenzyl acrylate, (meth)naphthyl acrylate, (meth)methyl (1-naphthyl)acrylate, (meth)tetrahydrofurfuryl acrylate, (meth)glycidyl acrylate, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, (meth)trifluoroethyl acrylate, (meth)heptadecafluorodecyl acrylate, (meth)acryloylmorpholine, di(meth)ethylene glycol, di(meth)acrylate, di(meth)propylene glycol, di(meth)acrylate, 1,3-butylene glycol, di(meth)acrylate, 1,4-butanediol, di(meth)acrylate, 1,6-hexanediol, di(meth)acrylate9-nonanediol, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, dibutylene glycol di(meth)acrylate, tributylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, bisphenol A ethylene oxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, tricyclodecane di(meth)acrylate, di(meth)acrylate Examples of (meth)acrylate compounds other than component A include trifunctional (meth)acrylates such as tanol, polycarbonate di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tri(meth)acrylate ethoxylated isocyanurate, and ε-caprolactone-modified tris((meth)acrooxyethyl) isocyanurate; tetrafunctional (meth)acrylates such as ditrimethylolpropane tetra(meth)acrylate; pentafunctional (meth)acrylates such as dipentaerythritol penta(meth)acrylate; and hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate; as well as monomers having vinyl groups such as styrene, α-methylstyrene, acrylonitrile, and vinyl acetate. Radical polymerizable compounds other than compounds A to C may be used individually or in combination of two or more.

[0042] The content of radical polymerizable compounds other than compounds A to C in the curable composition of the present invention is preferably 0 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass, based on 100% by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. The lower and upper limits of the content of radical polymerizable compounds other than compounds A to C can be arbitrarily combined.

[0043] (Wax E) The curable composition of the present invention may contain wax E in addition to compounds A to C, radical polymerizable compounds other than compounds A to C, polymers other than compound C, and reducing agent D. Wax E has an air barrier effect and enhances curability. Specific examples of wax E include paraffins, polyethylenes, and higher fatty acids such as stearic acid, with paraffin wax being preferred from the viewpoint of air barrier properties. These waxes may be used individually or in combination of two or more types.

[0044] From the viewpoint of air barrier effect and economic efficiency, the amount of wax E added is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the total of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C. The lower and upper limits of the amount of wax E added can be arbitrarily combined.

[0045] The curable composition of the present invention may further contain various additives, such as silane coupling agents, plasticizers, ultraviolet absorbers, antioxidants, antistatic agents, lubricants, mold release agents, dyes, pigments, defoamers, polymerization inhibitors, fillers, and polymers other than compound C, for the purpose of improving various properties.

[0046] From the viewpoint of flammability, the curable composition of the present invention preferably has a flash point of 15°C or higher. In this invention, the flash point of the curable composition refers to the flash point (minimum flash point) of the compound with the lowest flash point among the radical polymerizable compounds (compounds A to C, and radical polymerizable compounds other than compounds A to C) that are present in 5% by mass or more of the total amount of the curable composition.

[0047] One method for producing the curable composition of the present invention is to mix and stir the above-mentioned compounds using a commonly used stirrer.

[0048] One method for curing the curable composition of the present invention is to use a conventionally known redox catalyst. Examples of curing agents used for curing include organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, and cumene hydroperoxide; and azo compounds such as diazobisisobutyronitrile. Benzoyl peroxide is preferred as a curing agent from the viewpoint of low-temperature curing and short-time curing. From the viewpoint of handling, it is preferable to use the benzoyl peroxide as an inert liquid or solid, in the form of a solution diluted to a concentration of about 25-50% by mass, a paste, or a powder.

[0049] The curing agent may be added immediately before curing the curable composition. From the viewpoint of balancing curing properties with pot life and workability, the amount of curing agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the curing composition.

[0050] The applications of the curable composition of the present invention are not particularly limited, but it can be suitably used in civil engineering and construction materials such as coatings, floor coatings, road paving materials, wall materials, and repair fillers. For example, if a coating is manufactured using the curable composition of the present invention as a coating composition, the coating will have low flammability in addition to the inherent properties of acrylic coating compositions, such as low-temperature curability, weather resistance, and chemical resistance.

[0051] The cured product of the present invention is a cured product of the curable composition of the present invention. The cured product of the present invention is not particularly limited other than being a cured product of the curable composition of the present invention. The thickness of the cured product of the present invention is preferably 0.1 to 20 cm. If the thickness of the cured product is 0.1 cm or more, stickiness is less likely to occur on the surface of the cured product. Also, if the thickness of the cured product is 20 cm or less, stickiness is less likely to occur on the surface of the cured product. [Examples]

[0052] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following description, "parts" means "parts by mass".

[0053] <abbreviation> The abbreviations for the materials used in the examples are shown below. (Compound A) 2-HPMA: 2-hydroxypropyl methacrylate (product name: Acryester HP, manufactured by Mitsubishi Chemical Corporation, flash point: 106°C (value listed in SDS), SDS revision date: April 1, 2021) 2-MTMA: 2-methoxyethyl methacrylate (product name: Acryester MT, manufactured by Mitsubishi Chemical Corporation, flash point: 66.5°C (value listed in SDS), SDS revision date: April 1, 2021)

[0054] (Compound B) i-BMA: i-butyl methacrylate (product name: Acryester IB, manufactured by Mitsubishi Chemical Corporation, flash point: 45°C (value listed in SDS), SDS revision date: April 1, 2017) t-BMA: t-butyl methacrylate (product name: Acryester TB, manufactured by Mitsubishi Chemical Corporation, flash point: 29.5°C (value listed in SDS), SDS revision date: April 1, 2017) n-BMA: n-butyl methacrylate (product name: Acryester B, manufactured by Mitsubishi Chemical Corporation, flash point: 51°C (value listed in SDS), SDS revision date: April 1, 2017) EMA: Ethyl methacrylate (Trade name: Acryester E, manufactured by Mitsubishi Chemical Corporation, Flash point: 20.5°C (value listed in SDS), SDS revision date: April 1, 2017) CHMA: Cyclohexyl methacrylate (Trade name: Acryester CH, manufactured by Mitsubishi Chemical Corporation, Flash point: 78°C (value listed in SDS), SDS revision date: April 1, 2021)

[0055] (Compound C) Polymer 1: Acrylic polymer with copolymerization ratio (mass ratio) of methyl methacrylate / n-butyl methacrylate = 40 / 60 (mass-average molecular weight 65,000) Polymer 2: Acrylic polymer with copolymerization ratio (mass ratio) of methyl methacrylate / n-butyl methacrylate = 60 / 40 (mass-average molecular weight 42,000) Polymer 3: Acrylic polymer with copolymerization ratio (mass ratio) of methyl methacrylate / n-butyl methacrylate = 80 / 20 (mass-average molecular weight 82,000) Polymer 4: Acrylic polymer with copolymerization ratio (mass ratio) of methyl methacrylate / n-butyl methacrylate = 20 / 80 (mass-average molecular weight 140,000) SUA-017: Urethane acrylate (Product name: EXCELATE SUA-017, manufactured by Asia Industries Co., Ltd., flash point: 130℃ (solidification) (value listed in SDS), SDS revision date: August 6, 2016) ETERCURE6240: Epoxy acrylate (Product name: ETERCURE6240, manufactured by ETERNAL MATERIALS Co., LTD, flash point: over 110°C (value stated in SDS), SDS revision date: May 9, 2018)

[0056] (Reducing agent D) PTEO: N,N-di(2-hydroxyethyl)-p-toluidine (manufactured by Nippon Emulsifier Co., Ltd., "product name: PTEO")

[0057] (Wax E) Wax 1: Paraffin wax with a melting point of 55°C (Product name: Paraffin Wax 115, manufactured by Nippon Seiro Co., Ltd.) Wax 2: Paraffin wax with a melting point of 66°C (Product name: Paraffin Wax 130, manufactured by Nippon Seiro Co., Ltd.) Wax 3: Paraffin wax with a melting point of 75°C (Product name: Paraffin Wax 150, manufactured by Nippon Seiro Co., Ltd.) Wax 4: Wax dispersion (Product name: BYK-S780, manufactured by Big Chemie Japan Co., Ltd.)

[0058] (Radical polymerizable compounds other than compounds A-C) PDE150: Triethylene glycol dimethacrylate (Product name: Bremmer PDE-150, manufactured by NOF Corporation, flash point: 176°C (value listed in SDS), SDS revision date: March 23, 2016) PDP400N: Polypropylene glycol dimethacrylate (Product name: Bremmer PDP-400N, manufactured by NOF Corporation, Flash point: 207°C (value listed in SDS), SDS revision date: July 9, 2015) PHEMA: 2-phenoxyethyl methacrylate (product name: Light Ester PO, manufactured by Kyoeisha Chemical Co., Ltd., flash point: 100°C (value listed in SDS), SDS revision date: October 21, 2015) FA-512M: Dicyclopentenyloxyethyl methacrylate (Product name: Funcryl FA-512M, manufactured by Hitachi Chemical Co., Ltd., flash point: 176°C (value listed in SDS), SDS revision date: February 27, 2009) FA-513M: Tricyclo[5.2.1.02,6]deca-8-yl=methacrylate (Product name: Funcryl FA-513M, manufactured by Hitachi Chemical Co., Ltd., flash point: 145℃ (value listed in SDS), SDS revision date: June 12, 2014) THFMA: Tetrahydrofurfuryl methacrylate (Trade name: Acryester THF, manufactured by Mitsubishi Chemical Corporation, Flash point: 106°C (value listed in SDS), SDS revision date: April 1, 2017) M-120: 2-ethylhexyl carbitol acrylate (product name: Aronics M-120, manufactured by Toagosei Co., Ltd., flash point: 140℃ (value listed in SDS), SDS revision date: November 17, 2008) SLMA: A mixture of lauryl methacrylate and tridecyl methacrylate (Trade name: Acryester SL, manufactured by Mitsubishi Chemical Corporation, Flash point: 150°C (value stated in SDS), SDS revision date: April 1, 2017) BPE-4: Acrylic acid ester of ethylene oxide-modified bisphenol A (Trade name: New Frontier BPE-4, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polymerizes and does not show a flash point (value stated in SDS), cited SDS revision date: July 9, 2019)

[0059] (Polymers other than compound C) Polymer 5: Acrylic polymer with a composition of 100% methyl methacrylate (weight-average molecular weight 40,000)

[0060] (Other ingredients) MEHQ: 4-Methoxyphenol BHT: 2,6-di-t-butyl-4-methylphenol Karenz MT-PE1: Pentaerythritol tetrakis (3-mercaptobutyrate) FCS-42: Organic amide compound (Product name: Riken Resin FCS-42, manufactured by Miki Riken Kogyo Co., Ltd.) BYK-1752: Silicone resin (Product name: BYK-1752, manufactured by BYK Chemie Japan Co., Ltd.)

[0061] <Manufacturing of syrup composition (S-1)> In a reaction vessel equipped with a condenser, 19 parts of 2-HPMA as compound A, 50 parts of i-BMA as compound B, 0.4 parts of PTEO as reducing agent D, and 0.5 parts of wax 1, 0.4 parts of wax 2, and 0.3 parts of wax 3 as wax E. Furthermore, 5 parts of PDE150 as a radical polymerizable compound other than compounds A and B, and 0.01 parts of MEHQ as an additive were added. While stirring these compounds in the reaction vessel, 26 parts of polymer 1 as compound C were added. Next, the solution in the reaction vessel was heated to 60°C and stirred for 2 hours while maintaining the temperature at 60°C. After confirming that polymer 1 was completely dissolved, the solution in the reaction vessel was cooled to 23°C to obtain syrup composition (S-1).

[0062] <Manufacturing of syrup compositions (S-2) to (S-20)> Syrup compositions (S-2) to (S-20) were obtained in the same manner as the production of syrup composition (S-1), except that the proportions of each component were as shown in Tables 1 to 3. The numbers in Tables 1 to 3 represent the mass parts of each component.

[0063] [Table 1]

[0064] [Table 2]

[0065] [Table 3]

[0066] [Examples 1-12, Comparative Examples 1-8] To 100 parts of each syrup composition (S-1) to (S-20), 2 parts of Percadox CH-50L (a mixture of benzoyl peroxide and dicyclohexyl phthalate, manufactured by Kayaku Akzo Co., Ltd., trade name, benzoyl peroxide content: 50% by mass) was added as a curing agent, and then the mixture was obtained to obtain a curable composition. The flammability of the obtained curable composition was evaluated according to the following evaluation method. Furthermore, a cured product was prepared using the curable composition according to the following evaluation method, and the mechanical properties, weather resistance, and gasoline resistance of the obtained cured product were evaluated. The evaluation results are shown in Tables 4 and 5.

[0067] <Evaluation Method> Each of the examples and comparative examples was evaluated according to the following evaluation method. (1)Flammability Among the radical polymerizable compounds present in 5% by mass or more of the total amount of the curable composition, the flash point of the radical polymerizable compound with the lowest flash point was defined as the minimum flash point, and flammability was evaluated according to the following evaluation criteria. The flash points of each radical polymerizable compound were adopted from the values ​​listed in the Safety Data Sheet (SDS) issued by each manufacturer. (Evaluation Criteria) ◎: Minimum flash point of 35℃ or higher ○: Minimum flash point is 25°C or higher, but less than 35°C. △: Minimum flash point is 15°C or higher, but less than 25°C. ×: Minimum flash point is below 15°C

[0068] (2) Mechanical properties The curable composition was poured into a cell cast at 23°C and cured. Five dumbbell-shaped pieces (Type 1) were formed from the cured resin material, which had a thickness of 3 mm, using a punching tool specified in JIS K 6251 "Vulcanized Rubber and Thermoplastic Rubber". Tensile tests were performed on five molded test specimens using a tensile testing machine (manufactured by A&D Company, Limited; product name: "Tensilon Universal Tensile Testing Machine") to determine the maximum tensile strength (unit: N / mm²). 2 The tensile speed was measured and the mechanical properties were evaluated according to the following evaluation criteria. However, although the tensile speed specified in JIS K 6251 is 500 mm / min, in this invention the tensile speed was 20 mm / min. (Evaluation Criteria) ◎: Maximum tensile strength is 25 N / mm² 2 That's all. ○: Maximum tensile strength is 20 N / mm 2 More than 25N / mm 2 less than △: Maximum tensile strength is 15 N / mm 2 More than 20N / mm 2 less than ×: Maximum tensile strength is 15 N / mm² 2 less than

[0069] (3) Weather resistance Under conditions of 23°C, a curable composition was applied to an acrylic plate (manufactured by Mitsubishi Chemical Corporation, product name: "White Acrylite") to a thickness of 300 μm using an applicator and cured to obtain a test specimen. The painted surface of the test specimen was irradiated with a xenon lamp for 300 hours in accordance with JIS A 6909 7.18 Weathering Resistance Test Method A. Furthermore, the yellowness (YI) of the painted surface of the test specimen was measured using a spectrophotometer (manufactured by Konica Minolta Japan, product name: "CM-5") in accordance with the old JIS K 7105 (JIS K 7373), and the weather resistance was evaluated according to the following evaluation criteria. (Evaluation Criteria) ○: YI is less than 10 ×: YI is 10 or more

[0070] (4) Gasoline resistance Under conditions of 23°C, a curable composition was applied to an acrylic plate (manufactured by Mitsubishi Chemical Corporation, product name: "White Acrylite") to a thickness of 300 μm using an applicator and cured to obtain a test specimen. Silicone grease was applied to the lower end of a polytetrafluoroethylene cylinder (outer diameter 22 mm, inner diameter 18 mm, height 10 mm), and the cylinder was attached to the coated surface of the test specimen. Then, 1.5 mL of regular gasoline (manufactured by Showa Shell Sekiyu K.K.) was poured into the cylinder. Furthermore, silicone grease (product name: MOLYKOTE High Vacuum Grease, manufactured by DuPont-Toray Specialty Materials Co., Ltd.) was applied to the upper end of the cylinder, and a polyethylene terephthalate film was attached to seal it. As described above, the test specimen was left undisturbed for one week at 23°C with the coating film in contact with regular gasoline. After that, the cylinder was removed, the regular gasoline was absorbed using a dropper, and the specimen was allowed to air dry for 24 hours. The condition of the coating film in the part of the test specimen that had been in contact with regular gasoline was checked and evaluated according to the following evaluation criteria. (Evaluation Criteria) ○: The paint film remained. ×: The paint film has dissolved and disappeared.

[0071] [Table 4]

[0072] [Table 5]

[0073] As shown in Table 4, the curable compositions prepared in Examples 1 to 12 had low flammability, and their cured products exhibited good mechanical strength, weather resistance, and gasoline resistance. On the other hand, as shown in Table 5, the curable composition prepared in Comparative Example 1 did not contain compounds A and C, but contained polymers other than compound C. As a result, the resin liquid separated, and it was not possible to evaluate the mechanical properties and weather resistance of the cured product. The curable composition prepared in Comparative Example 2 did not contain compounds A and B, and therefore its cured product had poor weather resistance. Furthermore, because the curable composition prepared in Comparative Example 2 had poor weather resistance, its gasoline resistance was not evaluated. The curable compositions prepared in Comparative Examples 3 and 4 did not contain compounds A to C, and therefore their cured products exhibited poor weather resistance. Furthermore, because the curable compositions prepared in Comparative Examples 3 and 4 had poor weather resistance, their gasoline resistance was not evaluated. The curable composition prepared in Comparative Example 5 did not contain compounds A and B, and therefore its cured product had poor mechanical properties and weather resistance. Furthermore, because the curable composition prepared in Comparative Example 5 had poor weather resistance, its gasoline resistance was not evaluated. The curable compositions prepared in Comparative Examples 6 and 7 did not contain compounds A and B, and therefore their cured products had poor mechanical properties. Furthermore, because the curable compositions prepared in Comparative Examples 6 and 7 had poor mechanical properties, their weather resistance and gasoline resistance were not evaluated. The curable composition prepared in Comparative Example 8 did not contain compound A, and therefore its cured product had poor gasoline resistance. [Industrial applicability]

[0074] The curable composition of the present invention has low flammability, excellent mechanical properties, weather resistance, and gasoline resistance of the cured product, and can be suitably used as a civil engineering and construction material such as a coating material, floor coating material, road paving material, wall material, and repair filler, making it extremely important from an industrial perspective.

Claims

1. A curable composition comprising: compound A, which is an acrylic monomer having one or more functional groups selected from hydroxyl groups, alkoxy groups, and carboxyl groups and a (meth)acryloyl group; compound B, which is i-butyl (meth)acrylate or n-butyl (meth)acrylate; compound C, which is an acrylic polymer, urethane (meth)acrylate, and polyester (meth)acrylate having 10% by mass or more of constituent units derived from compounds having an alkyl group with 2 to 18 carbon atoms and a (meth)acryloyl group as a copolymer component; and a reducing agent D. The total of 100% by mass of the compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C contains 5 to 60% by mass of compound A, 10 to 90% by mass of compound B, and 5 to 60% by mass of compound C. The reducing agent D is contained in a total of 100 parts by mass of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C, with respect to 0.01 to 20 parts by mass of the reducing agent D. A curable composition wherein, among the radical polymerizable compounds contained in 5% by mass or more of the total amount of the curable composition, the compound with the lowest flash point has a flash point of 15°C or higher.

2. The curable composition according to claim 1, comprising 0.01 to 5 parts by mass of wax E with respect to a total of 100 parts by mass of compounds A to C, radical polymerizable compounds other than compounds A to C, and polymers other than compound C.

3. The curable composition according to claim 1 or 2, wherein compound A has a hydroxyl group and a (meth)acryloyl group.

4. The curable composition according to any one of claims 1 to 3, wherein compound B has a branched alkyl group having 4 carbon atoms and a (meth)acryloyl group.

5. The curable composition according to any one of claims 1 to 4, wherein the compound B comprises (meth)acrylate-i-butyl.

6. A coating composition comprising the curable composition according to any one of claims 1 to 5.

7. A cured product of a curable composition according to any one of claims 1 to 5, or a coating composition according to claim 6, wherein the cured product has a thickness of 0.1 to 20 cm.

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