Resin composition for slab type track

Abstract

To provide a resin composition for a slab type track capable of forming a cured body which is excellent in easy destructiveness while having a high Young's modulus and can be suitably used for the slab type track.SOLUTION: A resin composition for a slab type track comprises an urethane (meth) acrylate resin (A) having a weight average molecular weight (Mw) of 2,700-8,000, a radically polymerizable monomer (B), an inorganic filler (C), and a curing agent (D).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition for a slab-type track. [Background technology]

[0002] Slab-type track is a type of track structure used for bullet trains, etc. In slab-type track, the roadbed (hereinafter, these structures are also referred to as "roadbed structures") is an elevated structure, underground structure, bridge, etc. constructed of concrete, and a filling layer made of cement asphalt mortar (hereinafter, also referred to as "CA mortar") is provided in the gap between the roadbed structure and the track slab.

[0003] Specifically, as shown in Figure 1, this type of slab track has a track slab 24 installed on the top surface of a roadbed structure 20 with a filling layer 22 in between, and a pair of track rails 30, 30 arranged on the top surface of the track slab 24. The track slab 24 has cutouts 26, 26 at both ends, and protrusions 28 installed at predetermined intervals on the roadbed structure 20 and the cutouts 26 of the track slab 24 are aligned.

[0004] The filling layer 22 is formed, for example, by lifting the track slab 24 to a predetermined position above the roadbed side structure 20, filling the gap created between the track slab 24 and the roadbed side structure 20 with CA mortar, which is a filler, through filling holes (not shown) that have been formed in advance in the track slab 24, and then hardening the CA mortar. The filling layer 22 may also be formed by lifting the track slab 24 to a predetermined position above the roadbed side structure 20, placing a bag such as a nonwoven fabric into which CA mortar has been poured in advance in the gap that has formed between the track slab 24 and the roadbed side structure 20, and allowing it to solidify in the gap.

[0005] CA mortar is brittle and prone to deterioration due to frost damage due to its porous structure. This deterioration progresses particularly rapidly in extremely cold regions, and in some cases, the deterioration width of the filler layer (the length from the edge of the filler layer that is scraped away during repair) can progress to just below the rail.

[0006] One way to repair this deterioration is to remove the deteriorated parts of the CA mortar and fill the gap with organic materials. One of the reasons organic materials are used as repair materials is that they form a denser structure than CA mortar, making them less susceptible to water penetration.

[0007] As organic materials for the slab track, for example, materials described in Patent Documents 1 and 2 are known. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 11-256504 [Patent Document 2] Japanese Patent Application Publication No. 2018-44431 Summary of the Invention [Problem to be solved by the invention]

[0009] However, when the infill layer is repaired using a conventional organic material as described in Patent Document 1, etc., it has been found that the repaired area does not have the appropriate hardness (Young's modulus) to support the load of a train, particularly when the repaired infill layer is located directly below the rail. Slab-type tracks with infill layers that do not have the appropriate hardness (Young's modulus) have the problem that they may suffer from poor ride comfort due to impacts such as tailgating caused by trains passing by.

[0010] Furthermore, filler layers repaired using organic materials can also deteriorate. When such deterioration occurs, or when a filler layer repaired using organic materials can no longer achieve its intended purpose due to land uplift, subsidence, earthquakes, or other factors, it may be necessary to destroy and remove the filler layer using power tools or the like, and form a new filler layer. When such destruction of the filler layer is necessary, filler layers formed from conventional organic materials, such as those described in Patent Document 2, are tough and difficult to destroy, creating a bottleneck in repair work. For this reason, there is room for further improvement in the removal performance (ease of destruction) of filler layers formed from conventional organic materials, such as those described in Patent Document 2, using power tools or the like.

[0011] In addition, when a filling layer (hardened body) formed from a conventional organic material has a high Young's modulus, it is difficult to break, but when it is easy to break, it has a low Young's modulus, so it has not been possible to achieve both a high Young's modulus and excellent breakability.

[0012] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a resin composition for slab-type track that has a high Young's modulus, excellent fragility, and is capable of forming a cured product that can be suitably used for slab-type track. [Means for solving the problem]

[0013] The present inventors have conducted extensive research to solve the above problems. As a result, they have found that the above problems can be solved by using a specific resin composition, and have completed the present invention. Examples of the present invention are as follows.

[0014] [1] A resin composition for slab-type track, comprising: a urethane (meth)acrylate resin (A) having a weight-average molecular weight (Mw) of 2,700 to 8,000; a radical polymerizable monomer (B); an inorganic filler (C); and a curing agent (D).

[0015] [2] The resin composition for a slab-type track according to [1], wherein the radical polymerizable monomer (B) contains a polyfunctional (meth)acrylate monomer.

[0016] [3] The resin composition for a slab-type track according to [1] or [2], wherein the inorganic filler (C) contains at least one selected from calcium carbonate, cement, and silica.

[0017] [4] The resin composition for a slab-type track according to any one of [1] to [3], which satisfies the following requirement (1): Requirement (1): The Young's modulus of the cured resin composition for slab-type track is 850 to 3,000 N / mm 2 is [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a resin composition for slab-type track that has a high Young's modulus and excellent fragility, and is capable of forming a cured product that can be suitably used for slab-type track. According to the present invention, a high Young's modulus (850 to 3,000 N / mm 2 This hardened body can adequately support the track slab when used as a filling layer between the track slab and the roadbed structure, thereby suppressing the sideways movements that occur when trains run, and enabling the formation of a slab-type track that provides a comfortable ride. Furthermore, according to the present invention, since a hardened body having excellent destructibility can be formed, when repair work becomes necessary, in which the hardened body is destroyed and removed and a new filling layer is formed, the filling layer can be easily destroyed, and the repair work can be easily performed. Note that, although it is preferable to compare the destructibility between hardened bodies having similar Young's moduli, according to the present invention, a hardened body having excellent destructibility can be formed compared with conventional hardened bodies having similar Young's moduli. Furthermore, because the resin composition for slab-type track according to the present invention has sufficient fluidity, it can be particularly well-suited for use as a material to be poured between a track slab and a roadbed structure. This not only facilitates repairs to slab-type track, but also hardens in a state of close contact with the existing filler layer made of CA mortar, forming a hardened body without gaps between the track slab and the roadbed structure. Since voids in the filler layer allow water to seep into the filler layer and accumulate, making the layer more susceptible to frost damage, it is desirable for the repaired filler layer to have as few voids as possible. Because the filler layer formed with the resin composition for slab-type track according to the present invention has reduced voids, it is less susceptible to frost damage and has excellent durability. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing, in partial cross section, an example of the structure of a slab-type track. DETAILED DESCRIPTION OF THE INVENTION

[0020] <Resin composition for slab-type track> The resin composition for slab-type track according to the present invention (hereinafter also referred to as "the composition") contains a urethane (meth)acrylate resin (A) (hereinafter also referred to as "component (A)"; the same applies to other components) having a weight-average molecular weight (Mw) of 2,700 to 8,000, a radically polymerizable monomer (B), an inorganic filler (C), and a curing agent (D).

[0021] The present composition is used for slab-type track, and can be used when newly installing slab-type track or when repairing slab-type track, and can be suitably used when repairing slab-type track. Specifically, the present composition is preferably a composition for forming a cured resin body between a roadbed side structure and a track slab.

[0022] The hardened resin body between the roadbed side structure and the track slab refers to the hardened resin body formed between the roadbed side structure 20 and the track slab 24 in Figure 1, and refers to the filling layer 22 (at least a part of it). In the early stages of manufacturing a slab-type track, the filling layer 22 is often made of CA mortar, which is obtained by mixing cement, asphalt emulsion, and fine aggregate. However, this CA mortar layer deteriorates, and so to repair the deteriorated layer, the deteriorated layer is usually scraped away and then a hardened resin body is formed from the composition.

[0023] The present composition may be a one-component composition, but is preferably a two-component or higher composition, more preferably a two-component composition, from the viewpoint of excellent storage stability, etc. When the present composition is a two-component or higher composition, typically, components (A) and (B) are blended into a base component, and component (D) is blended into a curing agent component, and the present composition can be prepared by mixing the base component and the curing agent component. When the present composition is a two-component composition, component (C) may be blended with the curing agent component, but it is preferable to blend it with the main component, as this makes it easier to form a cured product with uniform physical properties.

[0024] <Urethane (meth)acrylate resin (A)> Component (A) can be a urethane (meth)acrylate resin having a radical-reactive unsaturated group. Specific examples of component (A) include a radical-reactive unsaturated group-containing oligomer obtained by reacting a raw material compound containing a polyisocyanate with at least one selected from a polyhydroxy compound and a polyhydric alcohol, followed by reaction of the remaining isocyanate group with a radical-reactive unsaturated group-containing monomer such as a hydroxyl group-containing (meth)acrylic compound. During this reaction, a hydroxyl group-containing allyl ether compound or the like can be used together with the hydroxyl group-containing (meth)acrylic compound, if necessary. Component (A) may also be a resin obtained by reacting raw material compounds containing a polyisocyanate, at least one selected from a polyhydroxy compound and a polyhydric alcohol, and a hydroxyl group-containing (meth)acrylic compound, and then reacting unreacted hydroxy groups derived from the polyhydroxy compound or the polyhydric alcohol with a polyisocyanate, etc. During this reaction, a hydroxyl group-containing allyl ether compound, etc. may also be used together with the hydroxyl group-containing (meth)acrylic compound, if necessary. The component (A) may be used alone or in combination of two or more.

[0025] In this specification, "(meth)acrylic" means acrylic and / or methacrylic. Similar expressions (e.g., (meth)acrylate) have similar meanings. In other words, a urethane (meth)acrylate resin refers to a urethane acrylate resin and / or a urethane methacrylate resin.

[0026] The weight average molecular weight (Mw) of component (A) is 2,700 to 8,000, preferably 2,800 to 7,000, and more preferably 3,000 to 5,500. The Mw can be measured using gel permeation chromatography (GPC), specifically, by the method described in the examples below. When component (A) having an Mw within the above range is used, a cured product having a high Young's modulus and excellent breakability can be easily formed.

[0027] The number of functional groups in component (A) is not particularly limited, but is preferably 2 to 3 functional groups, as this allows for the easy formation of a cured product that has a high Young's modulus and is less susceptible to shrinkage on curing. Component (A) preferably contains a bifunctional resin, and in this case may contain a trifunctional resin. The functional group refers to a radical-reactive unsaturated group.

[0028] Examples of the polyisocyanate include 2,4-tolylene diisocyanate and its isomers, diphenylmethane diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Among these, diphenylmethane diisocyanate is preferred from the viewpoint of cost, etc. Commercially available polyisocyanates include Burnock D-750 (manufactured by DIC Corporation), Crisvon NK (manufactured by DIC Corporation), Desmodur L (manufactured by Sumika Bayer Urethane Co., Ltd.), Coronate L (manufactured by Tosoh Corporation), Takenate D102 (manufactured by Takeda Pharmaceutical Co., Ltd.), Isonate 143L (manufactured by Mitsubishi Chemical Corporation), and the Duranate series (manufactured by Asahi Kasei Chemicals Corporation). The polyisocyanates may be used alone or in combination of two or more.

[0029] Examples of the polyhydroxy compound include polyester polyols and polyether polyols. Specific examples include a glycerin-ethylene oxide adduct, a glycerin-propylene oxide adduct, a glycerin-tetrahydrofuran adduct, a glycerin-ethylene oxide-propylene oxide adduct, a trimethylolpropane-ethylene oxide adduct, a trimethylolpropane-propylene oxide adduct, a trimethylolpropane-tetrahydrofuran adduct, a trimethylolpropane-ethylene oxide-propylene oxide adduct, a dipentaerythritol ethylene oxide adduct, a dipentaerythritol propylene oxide adduct, a dipentaerythritol tetrahydrofuran adduct, and a dipentaerythritol ethylene oxide-propylene oxide adduct. The polyhydroxy compounds may be used alone or in combination of two or more.

[0030] Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,3-butanediol, an adduct of bisphenol A with propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, paraxylene glycol, bicyclohexyl-4,4-diol, 2,6-decalin glycol, and 2,7-decalin glycol. The polyhydric alcohols may be used alone or in combination of two or more.

[0031] The hydroxyl group-containing (meth)acrylic compound is preferably a hydroxyl group-containing (meth)acrylic acid ester. Specific examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, di(meth)acrylate of tris(hydroxyethyl)isocyanuric acid, pentaerythritol tri(meth)acrylate, glycerin mono(meth)acrylate, and the Blemmer series (manufactured by NOF Corporation). The hydroxyl group-containing (meth)acrylic compounds may be used alone or in combination of two or more.

[0032] Specific examples of the hydroxyl group-containing allyl ether compound include ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, tripropylene glycol monoallyl ether, polypropylene glycol monoallyl ether, 1,2-butylene glycol monoallyl ether, 1,3-butylene glycol monoallyl ether, hexylene glycol monoallyl ether, octylene glycol monoallyl ether, trimethylolpropane diallyl ether, glycerin diallyl ether, and pentaerythritol triallyl ether. The hydroxyl group-containing allyl ether compounds may be used alone or in combination of two or more.

[0033] The content of component (A) is preferably 10 to 30% by mass, more preferably 11 to 20% by mass, relative to 100% by mass of the solid content of the composition, from the viewpoint of being able to easily form a cured product having a high Young's modulus and excellent breakability. In this specification, the solid content of the present composition refers to the components other than the solvent in the present composition.

[0034] When preparing the present composition (main component), a urethane (meth)acrylate resin itself may be used as the raw material for component (A). Alternatively, from the viewpoint of improving the physical properties of the resulting composition, such as hardness and breakability, a urethane (meth)acrylate resin composition containing one or more urethane (meth)acrylate resins and one or more radically polymerizable monomers (B) described below may be used.

[0035] <Radical polymerizable monomer (B)> Component (B) includes a monomer containing an ethylenically unsaturated group. The ethylenically unsaturated group is preferably a (meth)acryloyl group, a vinyl group, an allyl group, or a styryl group, more preferably a (meth)acryloyl group or a vinyl group, and even more preferably a (meth)acryloyl group. Component (B) may contain only one type of ethylenically unsaturated group, or may contain two or more types. The component (B) may be used alone or in combination of two or more.

[0036] Component (B) may be a monofunctional radical polymerizable monomer or a polyfunctional (i.e., bifunctional or higher) radical polymerizable monomer, or a combination of these. From the viewpoints of excellent weather resistance and ease of forming a cured product having a high Young's modulus, component (B) preferably contains a polyfunctional radical polymerizable monomer, and more preferably contains a polyfunctional (meth)acrylate monomer. The polyfunctional radical polymerizable monomer is preferably a difunctional to hexafunctional radical polymerizable monomer, more preferably a difunctional to tetrafunctional radical polymerizable monomer. Component (B) preferably contains a difunctional radical polymerizable monomer. Here, the polyfunctional radical polymerizable monomer means a radical polymerizable monomer having two or more ethylenically unsaturated groups in one molecule.

[0037] The weight average molecular weight (Mw) of component (B) is preferably 100-1,000, more preferably 150-700, and even more preferably 200-400. The Mw can be measured using gel permeation chromatography (GPC). By using component (B) having an Mw within the above range, the present composition can be easily obtained with low viscosity and sufficient fluidity, making the present composition particularly suitable for use as a material to be poured between a track slab and a roadbed structure.

[0038] Examples of component (B) include styrene-based monomers such as styrene, α-, o-, m-, or p-alkyl derivatives of styrene, nitro derivatives, cyano derivatives, amide derivatives, ester derivatives, chlorostyrene, vinyltoluene, and divinylbenzene; dienes such as butadiene, 2,3-dimethylbutadiene, isoprene, and chloroprene; methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, and s-(meth)acrylate. ec-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, phenyl (meth)acrylate, naphthyl (meth)acrylate, anthracenyl (meth)acrylate, anthranil (meth)acrylate, piperonyl (meth)acrylate, salicyl (meth)acrylate, furyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofuryl (meth)acrylate, pyranyl (meth)acrylate, (meth)acryloylmorpholine, benzyl (meth)acrylate, phenethyl (meth)acrylate, cresyl (meth)acrylate, (Meth)acrylic acid esters such as 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, triphenylmethyl (meth)acrylate, cumyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate;(Meth)acrylic acid amides such as (meth)acrylic acid amide, (meth)acrylic acid-N,N-dimethylamide, (meth)acrylic acid-N,N-diethylamide, (meth)acrylic acid-N,N-dipropylamide, (meth)acrylic acid-N,N-di-i-propylamide, and (meth)acrylic acid anthracenylamide; vinyl compounds such as (meth)acrylic acid anilide, acrylonitrile, methacrylonitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, and vinyl acetate; unsaturated dicarboxylic acid diesters such as diethyl citraconate, diethyl maleate, diethyl fumarate, and diethyl itaconate; monomaleimide compounds such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide; and N-(meth)acryloylphthalimide.

[0039] A preferred embodiment of component (B) is a (meth)acrylic acid ester compound having two or more (meth)acryloyl groups in the molecule. Specific examples include various polyols such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol propoxylate di(meth)acrylate, glycerin di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, and trimethylolpropane tri(meth)acrylate. (Meth)acrylic acid esters; tricyclodecane dimethanol di(meth)acrylate; 2,2-bis[4-(methacryloyloxyethoxy)phenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.: BPE-100), 2,2-bis[4-(methacryloyloxydiethoxy)phenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.: BPE-200), 2,2-bis[4-(methacryloyloxypolyethoxy)phenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.: BPE-500), 2,2-bis[4-(acryloyloxydiethoxy)phenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.: A-BPE-4), and 2,2-bis[4-(acryloyloxypolyethoxy)phenyl]propane (manufactured by Shin-Nakamura Chemical Co., Ltd.: A-BPE-10).

[0040] Component (B) preferably contains (meth)acrylic acid esters of various polyols, and is preferably a compound that does not contain an alicyclic structure, because it has a high Young's modulus and can easily form a cured product with excellent weather resistance.

[0041] The content of component (B) is preferably 5 to 45 mass %, more preferably 10 to 30 mass %, based on 100 mass % of the solid content of the composition, from the viewpoints that the composition has low viscosity and sufficient fluidity, and a cured product having a high Young's modulus and excellent weather resistance and water resistance can be easily formed. When component (B) contains a polyfunctional (meth)acrylate monomer, the content of the polyfunctional (meth)acrylate monomer is preferably 5 to 45 mass %, more preferably 10 to 30 mass %, relative to 100 mass % of the solid content of the composition, from the viewpoint of easily obtaining a cured product having a high Young's modulus and excellent breakability. Furthermore, when component (B) contains a monofunctional (meth)acrylate monomer, the content of the monofunctional (meth)acrylate monomer is preferably 0.5 to 15 mass %, more preferably 2 to 10 mass %, relative to 100 mass % of the solid content of the composition, from the viewpoint of being able to easily form a cured product with excellent weather resistance.

[0042] <Inorganic filler (C)> Examples of component (C) include the following inorganic pigments and cements. Component (C) preferably contains at least one selected from inorganic pigments and cements, and more preferably contains at least one selected from calcium carbonate, cement, and silica, from the viewpoint of being able to easily form a hardened body having a high Young's modulus. Among these, component (C) preferably contains at least one selected from calcium carbonate and cement, from the viewpoint of being able to easily form a hardened body having a higher Young's modulus, and more preferably contains calcium carbonate, from the viewpoint of being able to easily obtain a hardened body that is well balanced between a high Young's modulus and breakability. Furthermore, when the present composition contains an ultraviolet absorber described below, it is more preferable that component (C) contains calcium carbonate, since this makes it possible to easily form a cured product having excellent weather resistance and a high Young's modulus. The component (C) may be used alone or in combination of two or more.

[0043] The content of component (C) is preferably 40 to 80% by mass, more preferably 50 to 73% by mass, relative to 100% by mass of the solid content of the composition, and is preferably 100 to 650 parts by mass, more preferably 300 to 600 parts by mass, relative to 100 parts by mass of component (A). When the content of component (C) is within the above range, a cured product having a high Young's modulus and excellent breakability can be easily formed.

[0044] [Inorganic pigments] Examples of inorganic pigments include silica, calcium carbonate, silica sand, mica, potassium feldspar, wollastonite, kaolin, clay, bentonite, titanium oxide, zinc oxide, magnesium carbonate, and barium sulfate. Among these, calcium carbonate is preferred because it has low oil absorption and can easily form a hardened body that has a high Young's modulus and excellent breakability.

[0045] The inorganic pigment has an average particle size (50% diameter of the weight-cumulative particle size distribution) measured in accordance with JIS K 5101 Testing Methods for Pigments, Part 14, Sieve Residue, of preferably 10 to 120 μm, more preferably 30 to 100 μm, and even more preferably 45 to 85 μm, from the viewpoints that a composition having a small cure shrinkage rate can be easily obtained and a cured product having a high Young's modulus can be easily formed.

[0046] [cement] The cement is not particularly limited, but a suitable example is hydraulic cement, such as Portland cement (including ordinary, early strength, ultra-early strength, moderate heat, low heat, and sulfate-resistant Portland cement), alumina cement, white cement, lime-blended cement, blast furnace cement, colloidal cement, silica cement, fly ash cement, and slag cement.

[0047] Cement is usually a powder, and its specific surface area is, for example, 3000 to 6000 g / cm when measured by the specific surface area test of JIS R 5201:2015. 2 is.

[0048] <Curing agent (D)> Component (D) is not particularly limited as long as it can cure component (A), and specific examples include radical polymerization initiators. The component (D) may be used alone or in combination of two or more.

[0049] Examples of component (D) include known organic peroxides, and the organic peroxides are preferably compounds having a 10-hour half-life temperature of 30 to 180°C. Examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, diallyl peroxide, diacyl peroxide, peroxyester, and peroxydicarbonate. Component (D) also includes known azo compounds.

[0050] Specific examples of component (D) include benzoyl peroxide, dibenzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3,3-isopropyl hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, dicumyl hydroperoxide, peroxide, acetyl peroxide, bis(4-tert-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, isobutyl peroxide, 3,3,5-trimethylhexanoyl peroxide, lauryl peroxide, benzoyl-m-methylbenzoyl peroxide, m-toluoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, tert-butyl peroxybenzoate, azobisisobutyronitrile, and azobiscarbonamide.

[0051] The content of component (D) is preferably 1 to 10 parts by mass, more preferably 2 to 6 parts by mass, per 100 parts by mass of component (A), from the viewpoints that the present composition having excellent fast-curing properties can be easily obtained, and that curing proceeds sufficiently to easily form a cured product having a high Young's modulus and excellent strength, toughness, etc. The content of component (D) refers to the amount of component (D) used when preparing the present composition, that is, the amount of component (D) in the present composition before reaction or decomposition occurs; specifically, the amount relative to component (A) when the present composition is prepared without heating (e.g., at 23°C or below).

[0052] <Other ingredients> The composition may contain other components in addition to the components (A) to (D) as needed, provided that the object of the present invention is not impaired. Examples of such other components include a polymer (E1) having structural units derived from vinyl carboxylate, an acrylic polymer (E2) having structural units derived from (meth)acrylic acid ester, an ultraviolet absorber, a light stabilizer, a surfactant, a catalyst (curing accelerator), an antifoaming agent, a dispersant, a moisture adsorbent, a surface conditioner (leveling agent), a rheology control agent, a plasticizer, a thiol compound, and a solvent. The other components may each be used alone or in combination of two or more. When the present composition is a two-component or higher composition, these other components may be blended into the curing agent component, but are preferably blended into the main component.

[0053] [Polymers (E1) and (E2)] The composition may contain at least one selected from a polymer (E1) having a structural unit derived from vinyl carboxylate and an acrylic polymer (E2) having a structural unit derived from a (meth)acrylic acid ester (hereinafter, polymers (E1) and (E2) may also be referred to as "component (E)"). By using component (E) together with the components (A) to (D), cure shrinkage during curing of the present composition can be easily suppressed. When the present composition contains a polymer (E1), the polymer (E1) may be one type or two or more types, and when the present composition contains a polymer (E2), the polymer (E2) may be one type or two or more types.

[0054] As component (E), the polymer (E1) is more preferred, since it allows the present composition to be easily obtained with less cure shrinkage. The polymer (E1) is a polymer other than the component (A), and examples of the polymer (E1) include modified polyvinyl carboxylates; and copolymers using vinyl carboxylates and radically polymerizable monomers other than vinyl carboxylates. From the viewpoint of being able to suppress cure shrinkage, the component (E1) is preferably a polymer other than polyvinyl carboxylate that is 100% vinyl carboxylate-derived structural units and is unmodified.

[0055] In addition, if the cured body formed from the present composition deteriorates or if the cured body formed from the present composition can no longer achieve its intended purpose due to uplift / subsidence of the land, earthquakes, etc., it may become necessary to destroy and remove the cured body using power tools, etc., and form a new cured body. When such destruction of the cured body is necessary, cured bodies formed from conventional resin compositions such as those described in the above patent documents are tough and cannot be easily destroyed. The polymer (E1) is preferably solid at 23°C, from the viewpoint of being able to easily form a cured product with excellent fragility, and is further preferably a polymer that is completely insoluble in polar monomers (e.g., when 70 parts by mass of the polymer (E1) is dissolved in 100 parts by mass of a polar monomer [e.g., 2-hydroxyethyl methacrylate] at 23°C, it is completely insoluble). When such a polymer (E1) is mixed with the component (A) or the component (B), it is believed that both a portion that dissolves in these components and a portion that remains undissolved and solid are present. The latter portion that remains solid is believed to generate microvoids (voids) and crazes (small cracks) when the composition is cured, thereby improving the fragility of the composition.

[0056] Examples of the modified polyvinyl carboxylate include partially saponified products obtained by saponifying a portion of polyvinyl carboxylate, acid-modified products obtained by acid-modifying polyvinyl carboxylate or the partially saponified product, and hydrophobic group-modified products obtained by adding a hydrophobic group such as an acetoacetyl group to polyvinyl carboxylate or the partially saponified product.

[0057] Examples of the vinyl carboxylate include vinyl acetate, vinyl pivalate, vinyl monochloroacetate, vinyl crotonate, vinyl propionate, vinyl versatate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl octylate, and vinyl cinnamate, and among these, vinyl acetate is preferred. The vinyl carboxylates may be used alone or in combination of two or more.

[0058] Examples of the radically polymerizable monomer other than vinyl carboxylate include ethylene, styrene, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. The radically polymerizable monomer other than vinyl carboxylate may be used alone or in combination of two or more kinds. The copolymer of vinyl carboxylate and a radically polymerizable monomer other than vinyl carboxylate may be an acid-modified product obtained by acid-modifying the copolymer, or a hydrophobic group-modified product obtained by adding a hydrophobic group to the copolymer.

[0059] The polymer (E2) is a polymer other than the component (A) and the polymer (E1), and examples of the polymer (E2) include (co)polymers of (meth)acrylic acid esters and modified products thereof. The modified products may be acid-modified products obtained by modifying the (co)polymers with an acid, or hydrophobic-group-modified products obtained by adding hydrophobic groups to the copolymers. The polymer (E2) is preferably a (meth)acrylic acid ester (co)polymer having a weight-average molecular weight of about 10,000 to 100,000, because it acts like a plasticizer and can contribute to stress relaxation.

[0060] Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, and allyl (meth)acrylate. acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and these may be used alone or in combination of two or more.

[0061] When the present composition contains component (E), the content of component (E) is preferably 3 to 30 parts by mass, more preferably 5 to 30 parts by mass, even more preferably 7 to 27 parts by mass, and particularly preferably 10 to 24 parts by mass per 100 parts by mass of component (A), from the viewpoint that a present composition having a smaller cure shrinkage rate can be easily obtained, etc.

[0062] When the present composition contains component (E) and an ultraviolet absorber described below, the content of component (E) is preferably 1 to 30 parts by mass, more preferably 1.5 to 20 parts by mass, and particularly preferably 2 to 10 parts by mass per 100 parts by mass of component (A), from the viewpoint of being able to easily form a cured product having excellent weather resistance and a high Young's modulus.

[0063] When preparing the present composition containing component (E) (main component), the polymer (E1) and / or the polymer (E2) themselves may be used as the raw material for component (E). Alternatively, from the viewpoint of improving the physical properties such as hardness and breakability of the present composition obtained, a polymer composition containing at least one selected from the polymer (E1) and the polymer (E2) and one or more of the above-mentioned component (B) may be used. The content of component (B) in the polymer composition is preferably less than 50% by mass, more preferably 35 to 45% by mass, relative to 100% by mass of the polymer composition, from the viewpoint that a cured product excellent in hardness and breakability can be easily obtained.

[0064] Furthermore, when preparing the present composition (main component) containing component (E), a polymer mixture containing at least one selected from polymers (E1) and (E2) and one or more solvents may be used as the raw material for component (E), but when using such a polymer mixture, it is preferable that the content of organic solvent is small, since this makes it easier to obtain the present composition with a smaller cure shrinkage rate. Specifically, the content of solvent relative to 100% by mass of the polymer mixture is preferably less than 5% by mass, and more preferably no solvent is contained.

[0065] As the component (E), a product obtained by synthesis using a known method or a commercially available product may be used. Examples of commercially available products include Sakunoru SA09A (manufactured by Denka Co., Ltd., vinyl acetate resin), Denka ASR M-4 (manufactured by Denka Co., Ltd., acid-modified vinyl acetate resin), Modiper SV30B (manufactured by NOF Corporation, styrene-vinyl acetate block copolymer), HV Polymer D-100 (manufactured by Denka Co., Ltd., hydrophobically modified polyvinyl alcohol (modified polyvinyl acetate having a saponification degree of 86.5 to 89 mol%)), Daicalac 8506 (manufactured by Daido Chemical Industry Co., Ltd., polymer composition containing an acrylic copolymer), BYK-350 (manufactured by BYK Japan KK, (meth)acrylic acid ester copolymer), BYK-356 (manufactured by BYK Japan KK, (meth)acrylic acid ester copolymer), and BYK-361N (manufactured by BYK Japan KK, (meth)acrylic acid ester copolymer). These commercially available products are at least one polymer itself selected from polymer (E1) and polymer (E2), the polymer composition, or a polymer mixture in which the solvent amount is within the above range, and are different from known defoaming agents.

[0066] [UV absorber] The composition may contain an ultraviolet absorber. The ultraviolet absorber is not particularly limited, and conventionally known ultraviolet absorbers can be used. Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers. Benzotriazole-based ultraviolet absorbers are preferred from the viewpoint of being able to easily form a cured product with excellent weather resistance.

[0067] Examples of the benzotriazole-based ultraviolet absorber include 2-[2'-hydroxy-5'-(methacryloyloxymethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxypropyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyhexyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyhexyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-tert-butyl-3'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-tert-butyl-3'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-5-chloro-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-5-methoxy-2H-benzotriazole, 2-[2'-hydroxy 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-5-cyano-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-5-tert-butyl-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-5-nitro-2H-benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, benzenepropanoic acid and 3-(2H-benzotriazole-2- Examples of suitable ester compounds include 2-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy(C7-9 side chain and straight chain alkyl) ester compounds, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, and methyl 5-(2H-benzotriazol-2-yl)-4-hydroxy-3-tert-butylbenzenepropanoate.

[0068] When the present composition contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.5 to 10 parts by mass, more preferably 1.5 to 7 parts by mass, and particularly preferably 2.0 to 4.0 parts by mass per 100 parts by mass of component (A), from the viewpoint of being able to easily form a cured product having excellent weather resistance and a high Young's modulus.

[0069] [Light stabilizer] The composition may contain a light stabilizer. The light stabilizer is not particularly limited, and any conventionally known light stabilizer can be used. Examples of light stabilizers include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, 1-[2-[3-(3,5-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4,5]decane-2,4-dione, bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di- tert-Butyl-4-hydroxybenzyl)-2-n-butylmalonate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (Mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl)-1,2,3,4-butanetetracarboxylate, Mixed{1,2,2,6,6-pentamethyl-4-piperidyl / β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}-1,2,3,4-butanetetracarboxylate, (Mixed 2,2,6,6-Tetramethyl-4-piperidyl / tridecyl)-1,2,3,4-butanetetracarboxylate, Mixed{2,2,6,6-tetramethyl-4-piperidyl / β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}-1,2,3,4-butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, poly[(6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl)][(2,2,6,6-Tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)iminol], polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, N,N',N'',N'''-tetrakis-(4,6-bis-(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazine- 2-yl)-4,7-diazadecane-1,10-diamine, polycondensate of dibutylamine-1,3,5-triazine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethylpiperidyl)butylamine, and decanedioic acid bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)ester.

[0070] When the present composition contains a light stabilizer, the content of the light stabilizer is preferably 0.2 to 5 parts by mass, more preferably 0.7 to 3 parts by mass, and particularly preferably 1 to 2 parts by mass, per 100 parts by mass of component (A), from the viewpoint of being able to easily form a cured product having excellent weather resistance and a high Young's modulus.

[0071] [Surfactants] The composition may contain a surfactant, such as an anionic or nonionic surfactant.

[0072] Examples of the anionic surfactant include sodium alkylbenzenesulfonate, sodium fatty acid, sodium aliphatic dibasic acid, sodium polyoxyethylene alkyl ether sulfonate, polycarboxylic acid or its sodium salt.

[0073] Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene propylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene propylene alkenyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene carboxylic acid esters, sorbitan esters, and polyoxyethylene sorbitan esters.

[0074] Among these, polyoxyethylene oleyl ether and polyoxyethylene lauryl ether are preferred as surfactants, since they can easily form a cured product having a high Young's modulus.

[0075] When the present composition contains a surfactant, the content of the surfactant is preferably 0.1 to 3.4 parts by mass, more preferably 0.2 to 3.0 parts by mass, even more preferably 0.4 to 2.8 parts by mass, still more preferably 0.7 to 2.6 parts by mass, and particularly preferably 1.0 to 2.4 parts by mass, per 100 parts by mass of component (A), from the viewpoint of being able to easily form a cured product with a high Young's modulus, etc.

[0076] [catalyst] The present composition may contain a catalyst (cure accelerator) that accelerates the reaction between the components (A) and (D). Examples of such catalysts include amine catalysts, tin carboxylates, carboxylates of metals other than tin, and 1,8-diazabicyclo[5,4,0]undecene-7 (DBU) salts.

[0077] The amine catalyst includes tertiary amines, specific examples of which include aromatic tertiary amines, triethylamine, triethylenediamine, and tetramethylbutanediamine. Among these, aromatic tertiary amines are preferred.

[0078] Examples of the aromatic tertiary amine include N-methyl-N-β-hydroxyethylaniline, N-butyl-N-β-hydroxyethylaniline, N-methyl-N-β-hydroxyethyl-p-toluidine, N-butyl-N-β-hydroxyethyl-p-toluidine, N-methyl-N-β-hydroxypropylaniline, N-methyl-N-β-hydroxypropyl-p-toluidine, N,N-di(β-hydroxyethyl)aniline, N,N-di(β-hydroxypropyl)aniline, N,N-di(β-hydroxyethyl)-p-toluidine, N,N-di(β-hydroxypropyl)-p-toluidine, N,N-diisopropylrol-p-toluidine, N,N-di(β-hydroxyethyl)-p-anisidine, N,N-dimethylaniline, and N,N-dimethyl-p-toluidine. Among these, N,N-di(β-hydroxyethyl)-p-toluidine and N,N-di(β-hydroxypropyl)-p-toluidine are particularly preferred because they allow the present composition to be easily obtained with excellent low-temperature curing properties.

[0079] Examples of the tin carboxylate include dibutyltin dilaurate, dibutyltin diacetate, and tin octylate. Examples of the metal carboxylates other than tin include cobalt octylate, manganese octylate, and zinc octylate. Examples of the DBU salt include DBU-stearate, DBU-oleate, and DBU-formate.

[0080] When the composition contains a catalyst, the content of the catalyst is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 2 parts by mass, per 100 parts by mass of component (A), from the viewpoint of easily obtaining a composition that is excellent in pourability (filling) and curability, particularly low-temperature curing. When the composition contains an amine catalyst, the content of the amine catalyst is preferably 0.3 to 1.5 parts by mass, more preferably 0.6 to 1.2 parts by mass, per 100 parts by mass of component (A). When the composition contains a metal carboxylate (including tin carboxylate), the content of the metal carboxylate is preferably 0.02 to 0.07 parts by mass, more preferably 0.03 to 0.05 parts by mass, per 100 parts by mass of component (A).

[0081] [Antifoaming agent] The present composition may contain an antifoaming agent. From the viewpoint of easily forming a cured product that can maintain a high Young's modulus for a long period of time, it is preferable that the cured product obtained from the present composition be free of bubbles.

[0082] Examples of types of antifoaming agents include silicone-based antifoaming agents and mineral oil-based antifoaming agents. The defoaming agent may be water-based, solvent-based, or solventless, but solventless silicone-based defoaming agents are preferred in order to suppress shrinkage during curing when forming a cured product.

[0083] When the present composition contains an antifoaming agent, the content of the antifoaming agent is preferably 0.1 to 2 parts by mass, and more preferably 0.5 to 1.5 parts by mass, per 100 parts by mass of component (A), from the viewpoint of being able to easily form a cured product having a high Young's modulus, etc.

[0084] [solvent] When the present composition contains a solvent (e.g., water, organic solvent), the content of the solvent is preferably small, since this makes it easier to obtain a present composition with a smaller cure shrinkage rate, etc. Specifically, the content of the solvent in 100% by mass of the present composition is preferably less than 5% by mass, and more preferably less than 1% by mass.

[0085] <Method for preparing the present composition> The present composition can be prepared by mixing the above components (A) to (D) and, if necessary, the above other components. When the component (E) is blended in the present composition, the component (E) itself may be used, or the above-mentioned polymer composition or polymer mixture may be used.

[0086] The method of mixing is not particularly limited, but if air is taken in when preparing the main component or curing agent component, or when mixing the main component and the curing agent component, air bubbles will remain in the resulting cured body, which will tend to cause cracks and settling. Therefore, it is preferable to reduce the amount of air taken in the composition by performing a degassing step when preparing the main component or the curing agent component, or by stirring at low speed when mixing the main component and the curing agent component.

[0087] <Cured body> The present composition is usually used as a hardened product by hardening the composition, which is usually formed in the gap between the track slab and the roadbed side structure. This composition produces a hardened product with a high Young's modulus. Therefore, by using this hardened product as a filling layer between a track slab and a roadbed structure, the track slab can be adequately supported, suppressing vibrations and other issues that occur when a train is running, and providing a comfortable ride.

[0088] When curing the present composition, heating may be used to shorten the curing time, but it is usually sufficient to leave the composition at room temperature for 20 minutes to 1 hour without heating. The composition has excellent curing properties at room temperature, allowing it to cure in a short time at room temperature, making it suitable for use on slab-type tracks, particularly for repairing slab-type tracks.

[0089] When the present composition is used to repair a slab-type track, a method can be employed in which the composition is filled into the repair area of the filling layer between the track slab and the roadbed side structure, and then hardened to form a hardened body. There are no particular restrictions on the method for filling the repaired area of the filling layer with this composition, and any conventionally known method can be used. For example, a picture frame repair method can be used in which the deteriorated portion of the filling layer is first scraped away, a formwork is placed to surround the scraped-away area, and the composition is poured into the formwork to fill it. In addition to the method using a formwork, other methods that can be used include placing a bag of nonwoven fabric or the like in advance at the repair location, filling the bag with the present composition and allowing it to harden, placing an embedded formwork of foam molding or the like at the repair location, filling the inner repair area with the present composition and allowing it to harden, and attaching an adhesive sheet to the side opening of the repair location from the outside, filling the inner repair area with the present composition and allowing it to harden.

[0090] The Young's modulus is the relationship between stress and strain when an object is stretched or compressed. In a graph with stress on the vertical axis and strain on the horizontal axis, the range in which the relationship is proportional is the elastic range, and the slope of the graph is the Young's modulus. The Young's modulus is used as an index of how easily an object deforms.

[0091] The Young's modulus of the cured body was measured using a φ50 × 100 mm cured body at a room temperature of 23°C and a displacement rate of 1 mm / min using a compressometer. The stress was 0.01 to 0.1 N / mm 2 This value is calculated from the increase in strain in the range of stress 0.01 to 0.1 N / mm 2 The graph in the range is a quadratic curve that is close to linear, so the 0.1N / mm 2 The slope of the tangent at is the Young's modulus.

[0092] The composition has a Young's modulus of 850 to 3,000 N / mm 2 It is preferable that the composition be such that: The Young's modulus of the hardened body is preferably 850 to 3,000 N / mm because it has a high Young's modulus and can adequately support the track slab. 2 , more preferably 1,500 to 2,700 N / mm 2and the hardened body has a Young's modulus similar to that of CA mortar, so it is more preferably 2,000 to 2,500 N / mm 2 is. If the Young's modulus is below the range, the hardened body may not be able to adequately support the track slab, whereas if the Young's modulus is above the range, the load from the track slab may be concentrated on the repaired area due to the Young's modulus being too high, which may result in damage to the track slab. The Young's modulus of the cured body is 2,000 to 2,500 N / mm 2 In this case, even when the hardened body is used in the vicinity of immediately below the rail, the track slab can be sufficiently supported, and the effect of suppressing the tailwind when the train is running is high, making it possible to provide a slab-type track with a more comfortable ride.

[0093] The displacement of the cured product measured by the method described in the examples below is preferably 3.0 mm or less, more preferably 2.5 mm or less, and the lower limit is preferably as small as possible, for example, 0.5 mm. The maximum compressive stress of the cured body, measured by the method described in the examples below, is preferably 80 MPa or less, more preferably 70 MPa or less, and even more preferably 65 MPa or less. The lower limit is preferably as small as possible, for example, 5 MPa. The value of the maximum compressive stress (MPa) / displacement (mm) of the cured body is preferably 5 to 50, and more preferably 6 to 40. A hardened body having a displacement amount, maximum compressive stress, and / or maximum compressive stress / displacement amount within the above ranges can be said to be a hardened body with excellent destructibility, which can be easily destroyed with a power tool, etc., because when the hardened body is destroyed with a power tool, etc., the power tool, etc. is less likely to be repelled by the hardened body, and the scraped hardened body is less likely to stick to the power tool, etc. [Example]

[0094] Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0095] The raw materials used are as follows:

[0096] The weight average molecular weight (Mw) of the following urethane (meth)acrylate resins (A) and (a) is a value measured using gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh Corporation, HLC-8220GPC Column: Tosoh Corporation, Super H2000 + H4000 (inner diameter 6 mm, length 15 cm) Developing solvent: tetrahydrofuran (THF) Column thermostat temperature: 40℃ ·Flow rate: 0.5mL / min Control: Monodisperse polystyrene Detector: Refractive index detector

[0097] <Urethane (meth)acrylate resin (A) and (a)> "Urethane (meth)acrylate resin (A-1)": MIRAMER SC2565 (manufactured by MIWON, aliphatic urethane acrylate resin, bifunctional, Mw=5,200) "Urethane (meth)acrylate resin (A-2)": Shiko UV-6640B (manufactured by Mitsubishi Chemical Corporation, polyether-based urethane acrylate resin, bifunctional, Mw=5,000) "Urethane (meth)acrylate resin (A-3)": MIRAMER MU-3603 (manufactured by MIWON, aromatic urethane acrylate resin, bifunctional, Mw=3,300) "Urethane (meth)acrylate resin (a-1)": ARTRESIN CWD-8E26 (manufactured by Negami Chemical Industrial Co., Ltd., tetrafunctional, Mw=20,000) "Urethane (meth)acrylate resin (a-2)": ARTRESIN CWD-48N (manufactured by Negami Chemical Industries, Ltd., trifunctional, Mw=8,600) "Urethane (meth)acrylate resin (a-3)": a resin composition containing 70% by mass of urethane acrylate resin (trifunctional, Mw=2,000), 25% by mass of tripropylene glycol diacrylate (TPGDA), and 5% by mass of 2-hydroxypropyl acrylate "Urethane (meth)acrylate resin (a-4)": a resin composition containing 70% by mass of a urethane acrylate resin (bifunctional, Mw=2,300) and 30% by mass of TPGDA "Urethane (meth)acrylate resin (a-5)": a resin composition containing 70% by mass of urethane acrylate resin (bifunctional, Mw=2,200) and 30% by mass of phenoxy polyethylene glycol acrylate

[0098] <Radical polymerizable monomer (B)> "Radical polymerizable monomer (B-1)": MIRAMER M-220 (manufactured by MIWON, TPGDA, bifunctional, Mw=300) Radical polymerizable monomer (B-2): GX-8301S (Dai-ichi Kogyo Seiyaku Co., Ltd., methoxytriethylene glycol acrylate, monofunctional, Mw=218) Radical polymerizable monomer (B-3): Light Acrylate P-200A (Kyoeisha Chemical Co., Ltd., phenoxy polyethylene glycol acrylate, monofunctional, Mw=280) Radical polymerizable monomer (B-4): M-202 (manufactured by MIWON, neopentyl glycol propoxylate diacrylate, bifunctional, Mw=252.3)

[0099] <Inorganic filler (C)> Calcium carbonate: G-100 (Sankyo Flour Milling Co., Ltd., calcium carbonate sand, average particle size: 65 μm) "Portland cement": Ordinary Portland cement (manufactured by Katei Kagaku Kogyo Co., Ltd.) Silica: Silica TK-1 (manufactured by Tono Silica Powder Industry Cooperative Association, silicon dioxide)

[0100] <Curing agent (D)> Hardener: Kadox B-40ES (manufactured by Kayaku Nouryon Co., Ltd., contains benzoyl peroxide, active ingredient amount: 40% by mass)

[0101] <Other ingredients> "Polymer (E1-1)": HV Polymer D-100S (manufactured by Denka Co., Ltd., hydrophobically modified polyvinyl alcohol (modified polyvinyl acetate with a saponification degree of 86.5 to 89 mol%)) Polymer (E1-2): Modiper SV30B (styrene-vinyl acetate block copolymer, manufactured by NOF Corporation) "UV absorber": Tinuvin 1130 (manufactured by BASF Japan Ltd., benzotriazole-based UV absorber) Light stabilizer: Tinuvin 123 (BASF Japan Ltd., hindered amine light stabilizer) "Surfactant": Emulgen 104P (Kao Corporation, ether-type nonionic surfactant, polyoxyethylene lauryl ether, active ingredient content: 100% by mass) Antifoaming agent: BYK-1799 (BYK, a mixture of hydrophobic particles and foam-busting polysiloxane) "Amine catalyst": N,N-di(β-hydroxyethyl)-p-toluidine (Tokyo Chemical Industry Co., Ltd.) diluted with TPGDA to 30% of the active ingredient amount Metal catalyst: Rigolac Cobalt O (manufactured by Resonac Co., Ltd., 8% cobalt octylate)

[0102] [Example 1] A resin composition was prepared by adding 23 parts by mass of urethane (meth)acrylate resin (A-1), 27 parts by mass of radical polymerizable monomer (B-4), 100 parts by mass of Portland cement, 5 parts by mass of polymer (E1-1), 0.5 parts by mass of surfactant, 0.2 parts by mass of antifoaming agent, 0.3 parts by mass of amine catalyst, and 0.125 parts by mass of metal catalyst to a container and stirring and mixing, and then adding 1 part by mass of curing agent and stirring and mixing thoroughly.

[0103] [Examples 2 to 25 and Comparative Examples 1 to 7] Resin compositions were prepared in the same manner as in Example 1, except that the raw materials shown in Tables 1 to 4 below were used in the amounts shown in Table 1 (numbers, parts by mass).

[0104] <Young's modulus> The resin compositions obtained in Examples 1 to 25 and Comparative Examples 1 to 7 were poured into plastic molds for molding concrete specimens, cured at room temperature for 60 minutes, and then cured at 60°C for 3 hours to produce hardened bodies measuring φ50 mm and height 100 mm.

[0105] The hardened body prepared above was used and measured at a room temperature of 23°C, a displacement rate of 1 mm / min, and a stress range of 0.01 to 0.44 N / mm using a Servo Pulser EHF-EG10-20L (Shimadzu Corporation) and a Compressometer CM-5 (Tokyo Measuring Instruments Research Institute). 2 Preliminary loading was carried out twice. Then, stress was measured using a compressometer at a displacement rate of 1 mm / min. 2 The Young's modulus was calculated from the increase in strain in the range of stress 0.01 to 0.1 N / mm. 2 The graph in the range is a quadratic curve that is close to linear, so the 0.1N / mm 2 The slope of the tangent at this point was taken as Young's modulus. Young's modulus: 850 to 3,000 N / mm 2 The results were evaluated as ◯ when they were within the above range, and as × when they were outside the above range. The results are shown in Tables 1 to 4.

[0106] <Easily destructible> Type A3 multipurpose test pieces as defined in JIS K 7139:2009 "Plastics - Test Pieces" were prepared from the resin compositions obtained in Examples 1 to 25 and Comparative Examples 1 to 7, and then cut into 10 x 10 x 4 mm pieces to prepare test pieces. The size of the prepared test pieces was measured using a vernier caliper, and the test pieces used were those whose length (which should have been 10 mm) was 10 ± 0.2 mm, whose width (which should have been 10 mm) was 10 ± 0.2 mm, and whose thickness was within the range of 4 ± 0.2 mm. Based on the procedure specified in JIS K 7181:2011 "Plastics - Determination of Compression Properties," the prepared specimen was placed in a compression testing machine (Autograph AGS-X10kN, manufactured by Shimadzu Corporation) with the length of the specimen aligned in the compression direction, and compressed at a displacement rate of 1 mm / min until the specimen broke, at which point the displacement and maximum load (maximum compressive stress) were measured. The displacement of the specimen was measured from the position where the load began to be applied to the specimen, up to the position where the maximum load was applied. The fragility was evaluated based on the following criteria, and the results are shown in Tables 1 to 4. The smaller the maximum compressive stress and displacement, the better the fragility. A maximum compressive stress of 80 MPa or less and a displacement of 3 mm or less were evaluated as having sufficient fragility. The maximum compressive stress was calculated using the following formula. Maximum compressive stress (MPa) = Maximum compressive force (N) / Cross-sectional area of test piece (mm 2 )

[0107] <Weather resistance> A concrete slab measuring 70 mm × 70 mm × 10 mm (thickness) was prepared. The resin compositions obtained in Examples 20 to 25 were poured onto the surface of this concrete slab to a thickness of 5 mm and cured at room temperature for 12 hours to prepare weathering test specimens in which a cured resin composition was formed on the surface of the concrete slab. Next, a xenon accelerated weathering tester (model: Xenon Weather Meter X75, WX7.5 lamp, manufactured by Suga Test Instruments Co., Ltd.) was used to set the cured resin composition side of the prepared weathering test specimen so that it was irradiated by the xenon lamp, and a 4000-hour weathering test was performed in accordance with JIS K 5600-7-7:2008 (accelerated weathering resistance and accelerated light resistance (xenon lamp method)). The weather resistance was evaluated based on the following criteria, and the results are shown in Table 4. (Evaluation criteria) ○: No cracks, splits or warpage in the cured resin composition ×: The cured resin composition has cracks, splits, or warpage.

[0108] [Table 1]

[0109] [Table 2]

[0110] [Table 3]

[0111] [Table 4] [Explanation of symbols]

[0112] 10: Slab track 20: Roadbed side structure 22: Filled layer 24: Track slab 26: Notch 28:Protrusion 30: Track rail

Claims

1. A resin composition for slab-type track, comprising: a urethane (meth)acrylate resin (A) having a weight-average molecular weight (Mw) of 2,700 to 8,000; a radical polymerizable monomer (B); an inorganic filler (C); and a curing agent (D).

2. The resin composition for a slab-type track according to claim 1, wherein the radical polymerizable monomer (B) includes a polyfunctional (meth)acrylate monomer.

3. 2. The resin composition for a slab-type track according to claim 1, wherein the inorganic filler (C) comprises at least one selected from calcium carbonate, cement, and silica.

4. The resin composition for a slab-type track according to any one of claims 1 to 3, which satisfies the following requirement (1): Requirement (1): The Young's modulus of the cured resin composition for a slab-type track is 850 to 3,000 N / mm 2 is

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