Urethane (METH)acrylate resin composition

Abstract

To provide a resin composition capable of reducing hazard and exhibiting superior mechanical characteristics (compressive strength).SOLUTION: A urethane (meth)acrylate resin composition comprising a urethane (meth)acrylate (1), a polymerizable monomer (2), an amine compound (3), and a polymerization inhibitor (4), wherein the urethane (meth)acrylate (1) has a number average molecular weight of 2000 to 5000, and the polymerizable monomer (2) includes a (meth)acrylic polymerizable monomer having an aromatic ring structure in its molecule.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a urethane (meth)acrylate resin composition. More particularly, the present invention relates to a urethane (meth)acrylate resin composition for use in filler repair. [Background technology]

[0002] Among railway tracks, slab track is made by installing a concrete roadbed and a concrete flat plate (track slab) between a cement and asphalt mortar layer, and then installing rails on top of that via track pads. This mortar layer deteriorates quickly over time, especially on the outer periphery, and requires frequent repairs. Synthetic resin mortar, made from synthetic resin and aggregate, is often used for repairs. Previously used synthetic resins were known to contain large amounts of methyl methacrylate, which has a low flash point and is highly volatile (see JP 2018-059301 A). This posed a risk of fire and explosion during processing. Furthermore, simply replacing methyl methacrylate with a polymerizable monomer with a high flash point did not result in a filling layer with equivalent mechanical properties (see JP 2023-021920 A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-059301 [Patent Document 2] Japanese Patent Publication No. 2023-021920 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a resin composition that reduces risk and has excellent mechanical properties (compressive strength). [Means for solving the problem]

[0005] As a result of investigations, the inventors have found that the above problems can be solved by using a specific urethane (meth)acrylate and a polymerizable monomer. [1] A urethane(meth)acrylate resin composition comprising a urethane(meth)acrylate (1), a polymerizable monomer (2), an amine compound (3), and a polymerization inhibitor (4), The number average molecular weight of the urethane (meth)acrylate (1) is 2000 to 5000, The polymerizable monomer (2) contains a (meth)acrylic acid-based polymerizable monomer having an aromatic ring structure in the molecule. Urethane (meth)acrylate resin composition. [2] The urethane (meth)acrylate resin composition according to [1] above, wherein the amine compound (3) has an aniline skeleton. [3] The urethane (meth)acrylate resin composition according to [1] or [2] above, for use in repairing fillers. [Effects of the Invention]

[0006] According to the present invention, a resin composition that reduces risk and has excellent mechanical properties (compressive strength) can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following description in any way as long as it does not deviate from the gist of the present invention. In the present invention, "(meth)acrylate" refers to "acrylate" and "methacrylate". Similarly, "(meth)acrylic acid ester" refers to "acrylic acid ester" and "methacrylic acid ester".

[0008] The urethane (meth)acrylate (1) used in the urethane (meth)acrylate resin composition of the present invention includes urethane (meth)acrylates obtained by reacting polyisocyanate, polyol, and hydroxyl group-containing (meth)acrylic acid. The polyisocyanate is a compound having two or more isocyanate groups per molecule, and examples thereof 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. Other examples include adduct compounds of the above compounds with water or trimethylolpropane, and trimer cyclized compounds. From the standpoint of ease of reaction control, isophorone diisocyanate is preferred. These polyisocyanates may be used alone or in combination of two or more. The polyol is a compound having two or more hydroxyl groups in one molecule, and examples thereof include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyhexamethylene glycol, addition reaction products of bisphenols and alkylene oxides, polyester polyols, and polycarbonate diols. Among these polyols, polyalkylene glycols are preferred, and polypropylene glycol is more preferred, from the viewpoint of flexibility, etc. These polyols may be used alone or in combination of two or more. Examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, an adduct of ε-caprolactone and 2-hydroxyethyl (meth)acrylate, etc. These hydroxyl group-containing (meth)acrylates may be used alone or in combination of two or more. When obtaining the urethane (meth)acrylate (1), an allyl group-containing alcohol may be further used, if necessary. Examples of allyl group-containing alcohols 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. These allyl group-containing alcohols may be used alone or in combination of two or more. The urethane (meth)acrylate (1) of the present invention has a number average molecular weight of 2,000 to 5,000, preferably 2,500 to 5,000. The content of the urethane (meth)acrylate (1) in the urethane (meth)acrylate resin composition is preferably 50 to 60% by mass, more preferably 52 to 56% by mass.

[0009] Examples of (meth)acrylic acid-based polymerizable monomers having an aromatic ring structure in the molecule used in the urethane (meth)acrylate resin composition of the present invention include phenyl (meth)acrylate, 4-hydroxyphenyl (meth)acrylate, naphthyl (meth)acrylate, cresyl (meth)acrylate, anthracenyl (meth)acrylate, cumyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenylethyl (meth)acrylate, anthrylmethyl (meth)acrylate, salicyl (meth)acrylate, furyl (meth)acrylate, furfuryl (meth)acrylate, etc. These (meth)acrylic acid-based polymerizable monomers may be used alone or in combination of two or more. The content of the (meth)acrylic acid-based polymerizable monomer having an aromatic ring structure in the molecule in the urethane (meth)acrylate resin composition is preferably 40 to 50 mass %, more preferably 44 to 48 mass %.

[0010] The polymerizable monomer (2) used in the urethane (meth)acrylate resin composition of the present invention may further contain another polymerizable monomer in addition to the (meth)acrylic acid-based polymerizable monomer having an aromatic ring structure in the molecule. Examples of the other polymerizable monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, dicyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, allyl (meth)acrylate, propargyl (meth)acrylate, piperonyl (meth)acrylate, salicyl (meth)acrylate, Examples of the polymerizable monomer include (meth)acrylic acid esters such as furyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, pyranyl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, cumyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate, as well as (meth)acrylic acid amides such as (meth)acrylic acid amide, N,N-dimethylamide (meth)acrylic acid amide, N,N-diethylamide (meth)acrylic acid amide, N,N-dipropylamide (meth)acrylic acid amide, N,N-di-i-propylamide (meth)acrylic acid amide, and anthracenylamide (meth)acrylic acid. These polymerizable monomers may be used alone or in combination of two or more. The content of the polymerizable monomer (2) in the urethane (meth)acrylate resin composition is preferably 0 to 10% by mass, more preferably 0 to 5% by mass.

[0011] Examples of the amine compound (3) used in the urethane (meth)acrylate resin composition of the present invention include N,N-dimethylaniline, N,N-diethylaniline, N,N-dimethyl-p-toluidine, N,N-di(hydroxyethyl)-p-toluidine, N,N-di(β-hydroxyethyl)aniline, N,N-di(β-hydroxypropyl)aniline, N,N-di(β-hydroxypropyl)-p-toluidine, N,N-dihydroxypropyl-p-toluidine, and N,N-diisopropylol-p-toluidine. The amine compound (3) preferably has an aniline skeleton. These amine compounds (3) may be used alone or in combination. The content of the amine compound (3) in the urethane (meth)acrylate resin composition is preferably 0.2 to 2 mass %, more preferably 0.3 to 1 mass %.

[0012] The polymerization inhibitor (4) used in the urethane (meth)acrylate resin composition of the present invention is not particularly limited, and various inhibitors can be used, such as quinones, hydroquinones (polyhydric phenols), phenols, organic and inorganic copper salts, amidines, hydrazine salts, quaternary ammonium salts, amines, nitro compounds, oximes, sulfur, amine hydrochlorides, and the like, and these can be used alone or in combination of two or more. The content of the polymerization inhibitor (4) in the urethane (meth)acrylate resin composition is preferably 0.005 to 0.1% by mass, and more preferably 0.02 to 0.05% by mass.

[0013] The urethane (meth)acrylate resin composition of the present invention may further contain conventionally known additives such as catalysts, stabilizers, antifoaming agents, waxes, etc., as required. The urethane (meth)acrylate resin composition of the present invention can be obtained by mixing the above-mentioned components while heating as necessary.

[0014] The urethane (meth)acrylate resin composition of the present invention can be used to repair defects in the filling layer of slab track, and can also be used as a repair material for cracks in various structures, defective road areas, etc. The repair method is not particularly limited, but can be carried out by a method in which the urethane (meth)acrylate resin composition of the present invention is injected into the filling layer of a slab track and then cured. For example, the urethane (meth)acrylate resin composition of the present invention is mixed with a curing accelerator, a curing agent, and aggregate, and then injected, filled, and cured.

[0015] The curing agent may be a known radical polymerization initiator such as an organic peroxide or an azo compound. Examples of the organic peroxide include ketone peroxide, perbenzoate, hydroperoxide, diacyl peroxide, peroxyketal, hydroperoxide, diallyl peroxide, peroxyester, and peroxydicarbonate. More specific examples include methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl perbenzoate, dibenzoyl peroxide (also referred to as benzoyl peroxide), benzoyl m-methylbenzoyl peroxide, m-toluoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3,3-isopropyl hydroperoxide, t-butyl hydroperoxide, dicumyl hydroperoxide, acetyl peroxide, bis(4-t-butylcyclohexyl)peroxydicarbonate, diisopropyl peroxydicarbonate, isobutyl peroxide, 3,3,5-trimethylhexanoyl peroxide, and lauryl peroxide. Examples of the azo compound include azobisisobutyronitri, azobis(2,4-dimethylvaleronitrile), azobis(2-methylbutyronitrile), and azobiscarbonamide. [Example]

[0016] Hereinafter, one embodiment of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0017] (Synthesis Example 1) A glass reaction vessel equipped with a stirrer, a heater, a condenser, a thermometer, and a gas inlet tube was charged with 148 parts by mass of isophorone diisocyanate, 779 parts by mass of polypropylene glycol having a number average molecular weight of 2000, 72 parts by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of dibutylhydroxytoluene, and 0.05 parts by mass of dibutyltin dilaurate. The mixture was heated with stirring while blowing air into it, and the temperature was maintained at 100 to 102°C to allow the reaction to proceed. The reaction was monitored by IR, and the absorption of the isocyanate group (2250 cm) was monitored. -1 The reaction was terminated when the temperature (approximately) became constant, and the mixture was cooled to obtain urethane methacrylate (UA-1: number average molecular weight 3600).

[0018] (Synthesis Example 2) A glass reaction vessel equipped with a stirrer, a heater, a condenser, a thermometer, and a gas inlet tube was charged with 118 parts by mass of isophorone diisocyanate, 809 parts by mass of polypropylene glycol having a number average molecular weight of 3000, 72 parts by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of dibutylhydroxytoluene, and 0.05 parts by mass of dibutyltin dilaurate. The mixture was heated with stirring while blowing air into it, and the temperature was maintained at 100 to 102°C to allow the reaction to proceed. The reaction was monitored by IR, and the absorption of the isocyanate group (2250 cm) was monitored. -1 The reaction was terminated when the temperature (approximately) became constant, and the mixture was cooled to obtain urethane methacrylate (UA-2: number average molecular weight 3600).

[0019] (Synthesis Example 3) A glass reaction vessel equipped with a stirrer, a heater, a condenser, a thermometer, and a gas inlet tube was charged with 165 parts by mass of 4,4-methanediphenyl diisocyanate, 762 parts by mass of polypropylene glycol having a number average molecular weight of 2000, 72 parts by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of dibutylhydroxytoluene, and 0.05 parts by mass of dibutyltin dilaurate. The mixture was heated with stirring while blowing air into it, and the temperature was maintained at 100 to 102°C to allow the reaction to proceed. The reaction was monitored by IR, and the absorption of the isocyanate group (2250 cm) was monitored. -1 The reaction was terminated when the temperature (approximately) became constant, and the mixture was cooled to obtain urethane methacrylate (UA-3: number average molecular weight 3600).

[0020] (Synthesis Example 4) A glass reaction vessel equipped with a stirrer, a heater, a condenser, a thermometer, and a gas inlet tube was charged with 261 parts by mass of isophorone diisocyanate, 586 parts by mass of polypropylene glycol having a number average molecular weight of 1000, 153 parts by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of dibutylhydroxytoluene, and 0.05 parts by mass of dibutyltin dilaurate. The mixture was heated with stirring while blowing air into it, and the temperature was maintained at 100 to 102°C to allow the reaction to proceed. The reaction was monitored by IR, and the absorption of the isocyanate group (2250 cm) was monitored. -1 The reaction was terminated when the temperature (approximately) became constant, and the mixture was cooled to obtain urethane methacrylate (UA-4: number average molecular weight 1800).

[0021] (Synthesis Example 5) A glass reaction vessel equipped with a stirrer, a heater, a condenser, a thermometer, and a gas inlet tube was charged with 100 parts by mass of isophorone diisocyanate, 853 parts by mass of polypropylene glycol having a number average molecular weight of 3000, 47 parts by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of dibutylhydroxytoluene, and 0.05 parts by mass of dibutyltin dilaurate. The mixture was heated with stirring while blowing air into it, and the temperature was maintained at 100 to 102°C to allow the reaction to proceed. The reaction was monitored by IR, and the absorption of the isocyanate group (2250 cm) was monitored. -1 The reaction was terminated when the temperature (approximately) became constant, and the mixture was cooled to obtain urethane methacrylate (UA-5: number average molecular weight 5500).

[0022] (Examples 1 and 2 and Comparative Examples 1 to 5) Urethane (meth)acrylate, polymerizable monomer, N,N-di(hydroxyethyl)-p-toluidine as an amine compound, calcium carbonate, and Niper FF (50% benzoyl peroxide powder manufactured by NOF Corporation) as a curing agent were mixed in the proportions (parts by mass) shown in Table 1, and a compound casting plate was produced in accordance with JIS K 6919 5.2.3. The compound cast slabs prepared by the above method were machined to obtain test specimens in accordance with JIS K 6911 5.19.1. Compression tests were conducted at a test speed of 5 mm per minute to determine the strength (MPa). The spring constant was measured using the static spring constant measurement method (forward travel method) in accordance with JIS K 6385, Test Method for Anti-Vibration Rubber. Test specimens were machined from the compound cast slabs to obtain specimens measuring 100 mm x 100 mm x 25 mm. The results are shown in Table 1. The flash point of the composition was measured in accordance with JIS K2265-2:2007, "Determination of flash point - Part 2: Rapid equilibrium closed-circuit method," and evaluated according to the following criteria. (Evaluation criteria) ○: Flash point 70℃ or higher △: Flash point 21℃ or higher but less than 70℃ ×: Flash point below 21°C

[0023] [Table 1]

Claims

1. A urethane(meth)acrylate resin composition comprising a urethane(meth)acrylate (1), a polymerizable monomer (2), an amine compound (3), and a polymerization inhibitor (4), the number average molecular weight of the urethane (meth)acrylate (1) is 2,000 to 5,000; A urethane (meth)acrylate resin composition, wherein the polymerizable monomer (2) contains a (meth)acrylic acid-based polymerizable monomer having an aromatic ring structure in the molecule.

2. The urethane (meth)acrylate resin composition according to claim 1, wherein the amine compound (3) has an aniline skeleton.

3. 3. The urethane (meth)acrylate resin composition according to claim 1 or 2, which is used for repairing filler materials.

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