JP2024109223A - Resin composition for railway track - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for railway tracks, which can form a cured body that is excellent in adhesion not only to dry adherend but also to wet adherend, and can be suitably used for railway tracks.

SOLUTION: A resin composition for railway tracks includes urethane acrylate resin (A), inorganic pigment (B), curing agent (C), and nonionic surfactant (D) that is liquid at 20°C. The content of the nonionic surfactant (D) is 0.1-3.4 pts.mass per 100 pts.mass of the urethane acrylate resin (A).

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a resin composition for railway tracks.

Traditionally, railway tracks have been widely adopted in which elevated structures, underground structures, bridges, etc. constructed of concrete or the like serve as the roadbed (hereinafter, these structures are also referred to as "roadbed side structures"), a track slab made of concrete or the like is fixed onto this roadbed side structure via a filling layer, and track rails are fastened to this track slab.

Specifically, as shown in FIG. 1, this type of slab-type track has a track slab 24 provided on the upper surface of a roadbed structure 20 via a filling layer 22, and a pair of track rails 30, 30 are disposed on the upper surface of the track slab 24. The track slab 24 has cutouts 26, 26 at both ends, and protrusions 28 provided at a predetermined interval on the roadbed structure 20 and the cutouts 26 of the track slab 24 are aligned.

A resin composition is used to form a hardened resin body around the protrusions 28 of the roadbed side structure 20 of the slab-type track and a filling layer 22 between the roadbed side structure 20 and the track slab 24 for the purposes of adjusting the height of the track slab 24, preventing vertical vibration of the track slab 24 when trains pass over it, and preventing rainwater from entering.
The resin composition is also used to repair the deteriorated filling layer 22 .

Furthermore, in addition to slab-type tracks, other railway tracks include ballasted tracks that use sleepers, and resin compositions are also used in these tracks to fill the gaps that occur under the sleepers at the bottom of the rails to prevent vertical shaking when trains pass.

For example, compositions described in Patent Documents 1 and 2 are known as such resin compositions for railway tracks.

JP 2015-98527 A JP 2018-59301 A

For example, resin compositions for railway tracks are often used to repair slab-type track or ballast track that have already been laid. During such repairs, however, the adherend (hereinafter also simply referred to as "adherend") with which the cured body formed from the resin composition comes into contact may be in a wet state due to rainwater, water vapor, snow, etc., and such track in a wet state is prone to deterioration and therefore particularly in need of repair in many cases.
When using a railway track resin composition on such a wet adherend, it is necessary to apply the railway track resin composition to the adherend while it is still wet, since it is not possible to wait until the adherend dries. However, it has been found that when conventional resin compositions such as those described in Patent Documents 1 and 2 are used as the railway track resin composition, in particular resin compositions containing a polyurethane resin (a reactive curing type of polyol and polyisocyanate) or a urethane acrylate resin, the cured product obtained from the resin composition has poor adhesion to the adherend due to the effect of water present in the adherend, and is prone to falling off the railway track.

The present invention was made in consideration of the above problems, and aims to provide a resin composition for railway tracks that can form a cured product with excellent adhesion to substrates not only in dry conditions but also in wet conditions, and that can be suitably used for railway tracks.

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

[1] A composition comprising a urethane acrylate resin (A), an inorganic pigment (B), a curing agent (C), and a nonionic surfactant (D) that is liquid at 20°C;
The content of the nonionic surfactant (D) is 0.1 to 3.4 parts by mass based on 100 parts by mass of the urethane acrylate resin (A).
Resin composition for railway tracks.

[2] The resin composition for railway tracks described in [1] contains 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.

[3] The resin composition for railway tracks according to [1] or [2], wherein the nonionic surfactant (D) does not have a group reactive with the component (A).
[4] The resin composition for railway tracks according to any one of [1] to [3], wherein the HLB value of the nonionic surfactant (D) is 1 to 13.

[5] The resin composition for railway tracks according to any one of [1] to [4], wherein the spring constant of the cured product obtained from the resin composition for railway tracks is 15 to 80 MN/m.

[6] The resin composition for railway tracks according to any one of [1] to [5], wherein the adhesion retention calculated by the following formula (1) is 50% or more.
Adhesion retention rate = (Tw/Td) x 100 (1)
[In formula (1), Td is the maximum tensile strength (MPa) measured using a Construction Research Institute tensile tester when the resin composition for railway tracks was placed on the surface of a dried mortar board measuring 140 mm x 140 mm, cured at 23°C for 3 days, and the cured product (40 mm x 40 mm x 5 mm (thickness)) was peeled off from the mortar board, and Tw is the maximum tensile strength (MPa) measured in the same manner as Td, except that a mortar board measuring 140 mm x 140 mm in size was replaced by a mortar board measuring 140 mm x 140 mm in size, in which 1 g of water was applied to the mortar board and the entire surface of the mortar board was wetted with water.]

According to the present invention, it is possible to provide a resin composition for railway tracks which can form a cured product having excellent adhesion to an adherend not only in a dry state but also in a wet state and which can be suitably used for railway tracks.
In addition, the railway track resin composition according to the present invention has excellent injection (filling) properties, and therefore can be suitably used as a repair material for tracks, particularly slab-type tracks, and further as a material to be poured between a track slab and a roadbed structure, and not only can it easily repair slab-type tracks, but it also hardens in a state of close contact with the filling layer made of existing CA mortar, and has small hardening shrinkage. Therefore, it is possible to form a hardened body without gaps in the gap between the track slab and the roadbed structure, and the hardened body formed is resistant to frost damage caused by moisture and the like, and has excellent durability.
Furthermore, since repairs to the slab-type track need to be carried out in a short time, such as at night when trains are not running, rapid curing properties are required. The resin composition for railway tracks according to the present invention has excellent rapid curing properties, and is therefore preferable in this respect as well.
Furthermore, according to the present invention, a hardened body having a spring constant within the following range can be formed. When such a hardened body is used as a filling layer between a track slab and a roadbed side structure or as a filling layer under a sleeper, it can adequately support the track, suppress vibrations that occur when a train runs, and provide a track that provides a comfortable ride.

FIG. 1 is a perspective view, partially in section, showing an example of the structure of a slab-type track. FIG. 2 is a photograph showing a mold used when measuring the spring constant in the examples.

<Resin composition for railway tracks>
The resin composition for railway tracks according to the present invention (hereinafter also referred to as "the composition") contains a urethane acrylate resin (A) (hereinafter also referred to as "component (A)"; the same applies to other components), an inorganic pigment (B), a curing agent (C), and a nonionic surfactant (D) that is liquid at 20°C,
The content of the nonionic surfactant (D) is 0.1 to 3.4 parts by mass based on 100 parts by mass of the urethane acrylate resin (A).

The composition is used for railway tracks and can be suitably used when constructing new railway tracks or repairing railway tracks. The railway tracks include ballast tracks and slab-type tracks, with slab-type tracks being preferred.
Specifically, the composition is preferably a composition for forming a hardened resin body around a protrusion of a roadbed side structure of a slab-type track, a composition for forming a hardened resin body between a roadbed side structure and a track slab, or a composition for forming a hardened resin body under a sleeper, and is particularly preferably a composition for forming a hardened resin body between a roadbed side structure and a track slab.

The hardened resin body around the protrusion of the roadbed side structure of the slab-type track refers to the hardened resin body formed between the track slab 24 and the protrusion 28 in Figure 1, and the hardened resin body between the roadbed side structure and the track slab refers to (at least a part of) the filling layer 22.
In the initial stage of constructing the slab-type track, the filling layer 22 is often made of CA mortar obtained by mixing cement, asphalt emulsion, and fine aggregate, but since this layer made of CA mortar deteriorates, in order to repair this deteriorated layer, the deteriorated layer is usually scraped off and then a resin hardened body is formed with a repair composition. In other words, this repair composition is a suitable example of a composition for forming a resin hardened body between the roadbed structure and the track slab.

The present composition is preferably one which provides a cured product having a spring constant of 15 to 80 MN/m.
When the present composition is used as a composition for forming a resin cured body between the roadbed side structure and the track slab (when the cured body is used as a filling layer between the track slab and the roadbed side structure), the spring constant of the cured body is preferably 15 to 80 MN/m, more preferably 18 to 40 MN/m, from the viewpoints that the track can be sufficiently supported, the tailwind generated when a train is running can be suppressed, and a track that provides a comfortable ride can be obtained.
Furthermore, when the present composition is used as a composition for forming a resin hardened body around the protrusions of the roadbed side structure of the slab type track or as a composition for forming a resin hardened body under the sleepers (when the cured body is used as a filling layer around the protrusions of the roadbed side structure of the slab type track or as a filling layer under the sleepers), the track can be sufficiently supported, and vibrations and the like that occur when a train is running can be suppressed, thereby making it possible to obtain a track that provides a comfortable ride, and so on. Therefore, the spring constant of the cured body is more preferably 8 to 24 MN/m.
Specifically, the spring constant can be measured by the method described in the examples below.

The adhesive strength of the present composition to a dry adherend, measured by the method described in the Examples below, is preferably 1.00 MPa or more, more preferably 1.40 MPa or more, and the upper limit thereof is preferably 7.00 MPa.
If the adhesive strength to a dry substrate is within the above range, when the composition is used to construct a new railway track or to repair a railway track when the repair area is dry, the cured product obtained from the composition will adhere sufficiently to the substrate, making it easy to form a railway track that exhibits the desired physical properties over a long period of time.

The adhesive strength of the present composition to a wet adherend, measured by the method described in the Examples below, is preferably 0.70 MPa or more, more preferably 1.0 MPa or more, and even more preferably 1.40 MPa or more, with the upper limit being preferably 7.00 MPa.
When the adhesive strength to a wet adherend is within the above range, even if the adherend (repair area) is wet when the composition is used to repair a railway track, the cured product obtained from the composition will adhere sufficiently to the adherend in a wet state, making it easy to form a railway track that exhibits the desired physical properties over a long period of time.

The composition has an adhesion retention calculated by the following formula (1) of preferably 50% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. Since a larger upper limit is preferable, the upper limit is not particularly limited and may be 100%.
When the adhesion retention is within the above range, the desired hardened product can be formed without restrictions whether the adherend is dry or wet, and the desired hardened product can be obtained without changing the type of composition used depending on the state of the adherend, making it easy to form a railway track that exhibits the desired physical properties over a long period of time.

Adhesion retention rate = (Tw/Td) x 100 (1)
[In formula (1), Td is the maximum tensile strength (MPa) measured using a Construction Research Institute tensile tester when peeling off a cured body (40 mm x 40 mm x 5 mm (thickness)) obtained by placing the above-mentioned railway track resin composition on the surface of a dried mortar board having a size of 140 mm x 140 mm and curing it at 23°C for 3 days from the mortar board, and Tw is the maximum tensile strength (MPa) measured in the same manner as Td, except that a mortar board having a size of 140 mm x 140 mm was used in which 1 g of water was applied to the mortar board and the entire surface of the mortar board was wetted with water instead of the dried mortar board having a size of 140 mm x 140 mm.]

The present composition may be a one-component composition, but is preferably a two-component or more composition, more preferably a two-component composition, from the viewpoint of excellent storage stability, etc. When the present composition is a two-component or more composition, the components (A) and (D) are usually blended into a base component, and the component (C) 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 (B) may be blended in the curing agent component, but it is preferable to blend it in the main component, since a cured product having uniform physical properties can be easily obtained.

<Urethane acrylate resin (A)>
Component (A) may be a urethane 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 polyisocyanate and at least one selected from polyhydroxy compounds and polyhydric alcohols, and then reacting the excess isocyanato group with a radical reactive unsaturated group-containing monomer such as a hydroxyl group-containing (meth)acrylic compound. During this reaction, if necessary, a hydroxyl group-containing allyl ether compound may be used together with the hydroxyl group-containing (meth)acrylic compound.
Also included as component (A) is a resin obtained by reacting a raw material compound 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 the unreacted hydroxyl group derived from the polyhydroxy compound or the polyhydric alcohol with a polyisocyanate, etc. In this reaction, a hydroxyl group-containing allyl ether compound, etc. may 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.

In this specification, "(meth)acrylic" means acrylic and/or methacrylic. Similar expressions (e.g., (meth)acrylate) have similar meanings.
In this specification, the (meth)acrylic resin is also simply referred to as “acrylic resin.” In other words, the urethane acrylate resin refers to a urethane acrylate resin and/or a urethane methacrylate resin.

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), CRISBON 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 Duranate series (manufactured by Asahi Kasei Chemicals Corporation).
The polyisocyanates may be used alone or in combination of two or more kinds.

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

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 kinds.

The hydroxyl group-containing (meth)acrylic compound is preferably a hydroxyl group-containing (meth)acrylic acid ester, specific examples of which 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 kinds.

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 kinds.

The content of component (A) is preferably 10 to 34% by mass, more preferably 14 to 30% by mass, based on 100% by mass of the solid content of the composition, from the viewpoint of being able to easily form a cured product having a spring constant in the above range. If the content of component (A) is less than the above range, the viscosity of the composition may increase and the flowability may decrease. If the content of component (A) is more than the above range, the cure shrinkage of the cured product obtained from the composition may increase.
In this specification, the solid content of the present composition refers to the components other than the solvent in the present composition.

When preparing this composition (main component), a urethane acrylate resin itself may be used as the raw material for component (A), or a urethane acrylate resin composition containing one or more urethane acrylate resins and one or more radical polymerizable monomers may be used from the standpoint of improving the physical properties of the resulting composition, such as hardness, weather resistance, and water resistance, and adjusting the viscosity, etc.

The radical polymerizable monomer may be any monomer containing an ethylenically unsaturated group, and examples thereof 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, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, and methyl (meth)acrylate. ) isoamyl 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, anthranyl (meth)acrylate, piperonyl (meth)acrylate, salicyl (meth)acrylate, furyl (meth)acrylate, furfuryl (meth)acrylate, (Meth)acrylic acid esters such as tetrahydrofuryl acrylate, pyranyl (meth)acrylate, benzyl (meth)acrylate, phenethyl (meth)acrylate, cresyl (meth)acrylate, 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, and 2-hydroxypropyl (meth)acrylate; (meth)acrylic acid amide, N,N-dimethylamide (meth)acrylic acid, N,N-diethylamide (meth)acrylic acid, N,N (Meth)acrylic acid amides such as (meth)acrylic acid-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 citraconic acid, diethyl maleic acid, diethyl fumaric acid, and diethyl itaconate; monomaleimide compounds such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide; and N-(meth)acryloylphthalimide.

In addition, as the radical polymerizable monomer, a (meth)acrylic acid ester compound having two or more (meth)acryloyl groups in the molecule can also be used. Specific examples include (meth)acrylates of 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, glycerin di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, and trimethylolpropane tri(meth)acrylate. ) acrylic acid esters; 2,2-bis[4-(methacryloyloxyethoxy)phenyl]propane (Shin-Nakamura Chemical Co., Ltd.: BPE-100), 2,2-bis[4-(methacryloyloxy.diethoxy)phenyl]propane (Shin-Nakamura Chemical Co., Ltd.: BPE-200), 2,2-bis[4-(methacryloyloxy.polyethoxy)phenyl]propane (Shin-Nakamura Chemical Co., Ltd.: BPE-500), 2,2-bis[4-(acryloyloxy.diethoxy)phenyl]propane (Shin-Nakamura Chemical Co., Ltd.: A-BPE-4), 2,2-bis[4-(acryloyloxy.polyethoxy)phenyl]propane (Shin-Nakamura Chemical Co., Ltd.: A-BPE-10).

The content of the radical polymerizable monomer in the urethane acrylate resin composition is preferably 40 to 70% by mass, more preferably 50 to 60% by mass, based on 100% by mass of the urethane acrylate resin composition, because it is possible to reduce the viscosity and easily obtain a composition having excellent hardness, weather resistance, and water resistance.

<Inorganic pigment (B)>
Examples of component (B) include silica, calcium carbonate, quartz sand, mica, potassium feldspar, wollastonite, kaolin, clay, bentonite, titanium oxide, zinc oxide, magnesium carbonate, and barium sulfate. Among these, silica and calcium carbonate are preferred because they can provide a composition having excellent storage stability and economical properties, and can easily form a hardened body having a spring constant within the above range.
The component (B) may be used alone or in combination of two or more.

The average particle size (50% diameter of the weight cumulative particle size distribution) of component (B), measured in accordance with JIS K 5101 Pigment Test Method Part 14 Sieve Residue, is preferably 10 to 120 μm, more preferably 30 to 100 μm, and even more preferably 45 to 85 μm, from the viewpoints that the present composition having a small cure shrinkage rate can be easily obtained and that a cured body having a spring constant within the above range can be easily formed.

The content of component (B) is preferably 30 to 80% by mass, more preferably 50 to 65% by mass, relative to 100% by mass of the solid content of the composition, from the viewpoints that the composition can be easily obtained with a small cure shrinkage rate and a cured product with a spring constant within the above range can be easily formed, and the content is preferably 100 to 500 parts by mass, more preferably 180 to 450 parts by mass, relative to 100 parts by mass of component (A).

<Curing Agent (C)>
There are no particular limitations on component (C) as long as it can cure component (A), and specific examples include radical polymerization initiators.
The component (C) may be used alone or in combination of two or more.

Examples of the component (C) include known organic peroxides, preferably compounds having a 10-hour half-life temperature of 30 to 180° C.
Examples of the organic peroxide include ketone peroxides, peroxyketals, hydroperoxides, diallyl peroxides, diacyl peroxides, peroxy esters, and peroxydicarbonates.
Component (C) also includes known azo compounds.

Specific examples of component (C) include benzoyl peroxide, dibenzoyl 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 peroxide, dicumyl hydroperoxide, These include acetyl peroxide, bis(4-t-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, t-butyl peroxybenzoate, azobisisobutyronitrile, and azobiscarbonamide.

The content of component (C) is preferably 1 to 10 parts by mass, and more preferably 2 to 6 parts by mass, per 100 parts by mass of component (A), from the viewpoints that a composition having excellent fast curing properties can be easily obtained, curing proceeds sufficiently, the spring constant is within the above-mentioned range, and a cured product having excellent strength, toughness, etc. can be easily formed.
The content of component (C) refers to the amount of component (C) used when preparing the present composition, that is, the amount of component (C) in the present composition before it undergoes reaction, decomposition, or the like; specifically, it refers to the amount used relative to component (A) when the present composition is prepared without heating (e.g., at 23° C. or below).

<Nonionic Surfactant (D)>
There are no particular limitations on component (D) so long as it is a liquid at 20° C. and is a nonionic surfactant, and any conventionally known liquid nonionic surfactant can be used.
The component (D) may be used alone or in combination of two or more.

Here, a surfactant that is liquid at 20°C refers to a surfactant whose viscosity, measured at 20°C with a BII viscometer (BL II, manufactured by Toki Sangyo Co., Ltd.), is 100,000 mPa·s or less.
By using a surfactant that is liquid at 20° C., it is possible to easily form a cured product that has excellent adhesion, particularly to a wet adherend. On the other hand, it has been found that when a nonionic surfactant that is solid at 20° C. is used, the resulting cured product has reduced adhesion to a wet adherend.

Component (D) preferably does not have a group reactive with component (A) (e.g., amino group, amide group) in order to provide excellent adhesion to adherends in both dry and wet states and to easily form a cured product with a spring constant in the above range. If component (D) has a group reactive with component (A), it may react with component (A) when preparing the composition, and the above effect may not be achieved.

Examples of component (D) include polyoxyethylene alkyl ethers, polyoxyethylene propylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene propylene alkenyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene carboxylate esters, sorbitan esters, and polyoxyethylene sorbitan esters.

Among these, polyoxyethylene oleyl ether and polyoxyethylene lauryl ether are preferred as component (D) because they have excellent adhesion to substrates in both dry and wet states and can easily form a cured product with a spring constant within the above range.

The HLB value of component (D) is preferably 1 to 13, more preferably 3 to 13, and even more preferably 8 to 10, because it provides a well-balanced and excellent adhesive strength to adherends in both dry and wet states, and is particularly easy to form a cured product that has excellent adhesive strength to adherends in wet states.

Here, the HLB value stands for Hydrophile-Lipophile-Balance, and is a value that indicates the degree of hydrophilicity or lipophilicity of a compound. The smaller the HLB value, the higher the lipophilicity, and the larger the value, the higher the hydrophilicity.
The HLB value of the component (D) used in the following examples is a catalog value, and in this specification, the catalog value can be used as the HLB value. The HLB value can be determined, for example, by the Griffin method, and specifically, can be determined by the following formula.
HLB value = 20 x sum of formula weights of hydrophilic group moieties / molecular weight of nonionic surfactant

As the component (D), a product obtained by a conventionally known method or a commercially available product may be used.
Examples of the commercially available products include commercial products manufactured by NOF Corp., such as NONION OP-85R (sorbitan trioleate) and NONION OP-83RAT (sorbitan sesquioleate); and commercial products manufactured by Kao Corp., such as EMULGEN 404 (polyoxyethylene oleyl ether), EMULGEN 104P (polyoxyethylene lauryl ether), EMULGEN 108 (polyoxyethylene lauryl ether), EMULGEN 408 (polyoxyethylene oleyl ether), and EMULGEN 707 (polyoxyethylene alkyl ether).

The content of component (D) is 0.1 to 3.4 parts by mass, preferably 0.2 to 3.0 parts by mass, more preferably 0.4 to 2.8 parts by mass, even 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 viewpoints of being able to easily form a cured product that has a well-balanced adhesive strength to adherends in both dry and wet states, and in particular, has excellent adhesive strength to adherends in wet states.

<Other ingredients>
The composition may contain other components in addition to the components (A) to (D) as necessary, within the scope of the present invention. Examples of such other components include a polymer (E1) having a structural unit derived from vinyl carboxylate, an acrylic polymer (E2) having a structural unit derived from a (meth)acrylic acid ester, a radical polymerizable monomer, a thiol compound, a catalyst (curing accelerator), an antifoaming agent, a dispersant, a moisture adsorbent, a surface conditioner, a rheology control agent, a leveling agent, a plasticizer, a solvent, etc.
Each of the other components may be used alone or in combination of two or more.
When the present composition is a two-component or higher type composition, these other components may be blended in the hardener component, but are preferably blended in the main component.

[Polymers (E1) and (E2)]
The present composition may contain at least one selected from a polymer (E1) having a structural unit derived from a vinyl carboxylate and an acrylic polymer (E2) having a structural unit derived from a (meth)acrylic acid ester (hereinafter, the polymers (E1) and (E2) are also referred to as "component (E)").
By using the 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 of one type or two or more types, and when the present composition contains a polymer (E2), the polymer (E2) may be of one type or two or more types.

As component (E), the above polymer (E1) is more preferred from the viewpoint that the present composition having smaller cure shrinkage can be easily obtained.
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 suppressing cure shrinkage, the component (E1) is preferably a polymer other than polyvinyl carboxylate, which is 100% composed of structural units derived from vinyl carboxylate and is unmodified.

In addition, when the cured body formed from the present composition deteriorates or when the cured body formed from the present composition is no longer able to achieve the intended purpose due to land uplift, earthquake, etc., it may become necessary to destroy and remove the cured body using an electric tool or the like, and form a new cured body. When such destruction of the cured body is necessary, the cured bodies formed from the conventional resin compositions described in the above patent documents are tough and cannot be easily destroyed.
The polymer (E1) is preferably a solid at 23° C., from the viewpoint of being able to easily form a cured product having excellent fragility, and is further preferably a polymer that is not completely soluble in a polar monomer (e.g., when 70 parts by mass of the polymer (E1) are dissolved in 100 parts by mass of a polar monomer [e.g., 2-hydroxyethyl methacrylate] at 23° C., it is not completely soluble). It is considered that such a polymer (E1) has both a portion that dissolves in these components and a portion that does not dissolve and remains in a solid state when mixed with the component (A) or a radical polymerizable monomer contained in a urethane acrylate resin composition. It is considered that the latter portion that remains in a solid state generates minute voids (gaps) and crazes (small cracks) when the composition is cured, thereby improving the fragility of the composition.

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

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 kinds.

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 modifying the copolymer with an acid, or a hydrophobic group-modified product obtained by imparting a hydrophobic group to the copolymer.

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)polymer with an acid, or hydrophobic group-modified products obtained by adding hydrophobic groups to the copolymer.
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, from the viewpoints of having an action like a plasticizer and being able to contribute to stress relaxation.

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 can be used alone or in combination of two or more.

The total content of component (E) is preferably 5 to 30 parts by mass, 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), in order to easily obtain a composition having a smaller cure shrinkage rate.

In preparing the present composition (main component), the polymer (E1) and/or the polymer (E2) themselves may be used as a raw material for component (E). From the viewpoints of improving the physical properties such as hardness, weather resistance, and water resistance of the obtained present composition and adjusting the viscosity, etc., a polymer composition containing at least one selected from the polymer (E1) and the polymer (E2) and one or more radically polymerizable monomers may be used.
The content of the radical polymerizable monomer in the polymer composition is preferably less than 50% by mass, more preferably 35 to 45% by mass, based on 100% by mass of the polymer composition, from the viewpoints that the viscosity can be reduced and the present composition having excellent hardness, weather resistance, and water resistance can be easily obtained.
The radical polymerizable monomer is not particularly limited, but specific examples thereof include the same monomers as the radical polymerizable monomers exemplified in the section on component (A).

When preparing the present composition (main component), a polymer mixture containing at least one selected from polymer (E1) and polymer (E2) and one or more solvents may be used as the raw material for component (E). When using such a polymer mixture, it is preferable that the content of the organic solvent is small, since it is easy to obtain the present composition having a smaller cure shrinkage rate. Specifically, the content of the solvent relative to 100% by mass of the polymer mixture is preferably less than 5% by mass, and it is more preferable that the polymer mixture does not contain any solvent.

As the component (E), a compound obtained by synthesis using a known method or a commercially available product may be used.
Examples of the 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 Corp., 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%)), Dicalac 8506 (manufactured by Daido Chemical Industry Co., Ltd., polymer composition containing an acrylic copolymer), BYK-350 (manufactured by BYK Japan Co., Ltd., (meth)acrylic acid ester copolymer), BYK-356 (manufactured by BYK Japan Co., Ltd., (meth)acrylic acid ester copolymer), and BYK-361N (manufactured by BYK Japan Co., Ltd., (meth)acrylic acid ester copolymer).
These commercially available products are at least one polymer itself selected from the polymer (E1) and the polymer (E2), the above-mentioned polymer composition, or a polymer mixture having a solvent amount in the above-mentioned range, and are different from known defoaming agents.

[Radical polymerizable monomer]
The radical polymerizable monomer is not particularly limited, but specific examples thereof include the same monomers as the radical polymerizable monomers exemplified in the section on component (A).

[Thiol compounds]
The thiol compound is not particularly limited, and examples thereof include monofunctional thiol compounds such as decanethiol, dodecanethiol, octanethiol, and hexadecanethiol; bifunctional thiol compounds such as tetraethylene glycol bis(3-mercaptopropionate) and 1,4-bis(3-mercaptobutyryloxy)butane; trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, and 1,3,5-tris(3-mercaptobutyryl) trifunctional thiol compounds such as trimethylolpropane tris(3-mercaptobutyrate) and trimethylolethane tris(3-mercaptobutyrate); tetrafunctional thiol compounds such as pentaerythritol tetrakis(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutyrate); and hexafunctional thiol compounds such as dipentaerythritol hexakis(3-mercaptopropionate).
As the thiol compound, from the viewpoint of storage stability of the present composition to be obtained, a bifunctional or higher functional thiol compound is preferable, and a bifunctional to tetrafunctional thiol compound is more preferable.

As the thiol compound, a compound obtained by synthesis using a known method or a commercially available product may be used.
Examples of commercially available thiol compounds include dodecanethiol (monofunctional thiol compound), Karenz MT BD (manufactured by Showa Denko K.K., 1,4-bis(3-mercaptobutyryloxy)butane), Karenz MT NR (manufactured by Showa Denko K.K., 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione), Karenz MT Examples of the polyether ether ester include PE1 (manufactured by Showa Denko K.K., pentaerythritol tetrakis(3-mercaptobutyrate)), EGMP-4 (manufactured by SC Organic Chemical Co., Ltd., tetraethylene glycol bis(3-mercaptopropionate)), TMMP (manufactured by SC Organic Chemical Co., Ltd., trimethylolpropane tris(3-mercaptopropionate)), TEMPIC (manufactured by SC Organic Chemical Co., Ltd., tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate), PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetrakis(3-mercaptopropionate)), and DPMP (manufactured by SC Organic Chemical Co., Ltd., dipentaerythritol hexakis(3-mercaptopropionate)).

When the composition contains a thiol compound, the content of the thiol compound can be adjusted as appropriate within a range that does not impair the curability of the composition. The content varies depending on the type of thiol compound, but is preferably 0.5 to 20 parts by mass, and more preferably 6 to 12 parts by mass, per 100 parts by mass of component (A), from the viewpoint of easily obtaining a composition having a smaller cure shrinkage rate, etc.

[catalyst]
The present composition may contain a catalyst (curing accelerator) that accelerates the reaction between the components (A) and (C).
Such catalysts include amine catalysts, tin carboxylates, metal carboxylates other than tin, and 1,8-diazabicyclo[5,4,0]undecene-7 (DBU) salts.

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.

Examples of the aromatic tertiary amine include N-methyl-N-β-hydroxyethyl aniline, N-butyl-N-β-hydroxyethyl aniline, N-methyl-N-β-hydroxyethyl-p-toluidine, N-butyl-N-β-hydroxyethyl-p-toluidine, N-methyl-N-β-hydroxypropyl aniline, 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-diisopropylol-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 composition to be easily obtained with excellent low-temperature curing properties.

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.
The DBU salts include DBU-stearate, DBU-oleate, DBU-formate and the like.

When the present 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 being able to easily obtain a present composition that is excellent in injectability (filling) property, curability, and particularly low-temperature curability.

[solvent]
When the present composition contains a solvent (e.g., water, organic solvent), the content of the solvent is preferably small from the viewpoint that the present composition having a smaller cure shrinkage rate can be easily obtained, 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.

Method for preparing the composition
The present composition can be prepared by mixing the above-mentioned components (A) to (D) and, if necessary, the above-mentioned other components.
In addition, the present composition can be prepared by mixing component (A) and at least one selected from the urethane acrylate resin compositions described above; component (B); component (C); component (D); and, if necessary, the other components described above.
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.

The method of mixing is not particularly limited, but if air is taken in when preparing the main component or when mixing the main component and the hardener component, air bubbles will remain in the resulting hardened body, which tends to cause cracks and settling. Therefore, it is preferable to reduce the amount of air taken in by the composition by performing a degassing process when preparing the main component or by stirring at low speed when mixing the main component and the hardener component.

<Hardened body>
The present composition is usually used in the form of a cured product obtained by curing the present composition.
The shape and thickness of the cured body may be appropriately selected depending on the location where the cured body is to be provided.

The hardened body can be formed, for example, by placing the composition in the location where the hardened body is to be formed and then hardening the composition.

Examples of the substrate with which the hardened body comes into contact include the roadbed structure, the protrusions of the roadbed structure, the track slabs, and the sleepers, and examples of the materials for these include concrete (including mortar), resin (e.g., long glass fiber reinforced plastic foam), wood, etc.
The composition of the present invention can form a cured product that has excellent adhesion to railway track components made of these materials, whether these components are in a dry or wet state.

The method for placing the present composition at the location where a resin cured body is to be formed is not particularly limited, but examples include a method in which, if necessary, a formwork or a bag such as a nonwoven fabric is placed so that the present composition does not flow out of the predetermined location, and then the present composition is poured in (filled).
For example, specific examples of the formation of a hardened body to be applied to a track include a method of filling the present composition between the track slab 24 and the protrusion 28 in Fig. 1 after installing a formwork or a bag such as a nonwoven fabric so that the present composition does not flow out of a predetermined place, a method of filling the present composition between the roadbed side structure 20 and the track slab 24, a method of filling the present composition under the sleepers, etc. When filling the present composition between the roadbed side structure 20 and the track slab 24 or under the sleepers, the track slab 24 or the sleepers may be lifted to a predetermined position as necessary before filling the present composition.

The method for forming the hardened body may be a method for repairing a deteriorated layer by scraping off a deteriorated portion (deteriorated layer) of a layer such as a filling layer made of CA mortar on a track, filling the scraped-off area with the present composition, and forming a hardened body (filled layer), i.e., a method for repairing a deteriorated layer.
There are no particular limitations on the method for filling the deteriorated layer with the present composition, and any conventionally known method can be used. For example, there is a picture frame repair method in which the deteriorated layer is first scraped off, a formwork or the like is placed to surround the scraped-off area, and the present composition is poured into the inside of the formwork or the like to fill it.
In addition to the method using the above-mentioned 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 from the outside to the side opening of the repair location, filling the inner repair area with the present composition and allowing it to harden.

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 and can be cured in a short time at room temperature, making it suitable for use in railway tracks, slab-type tracks, and particularly for repairing slab-type tracks.

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

The raw materials used are as follows:

<Urethane acrylate resin (A)>
As the urethane acrylate resin (A), the following urethane acrylate resin composition (A-1) or (A-2) containing a urethane acrylate resin was used.
"Urethane acrylate resin composition (A-1)": a resin composition containing 46% by mass of urethane acrylate resin, 25% by mass of 2-ethylhexyl acrylate, 12% by mass of 2-hydroxyethyl methacrylate, 12% by mass of n-butyl methacrylate, and 5% by mass of lauryl methacrylate. "Urethane acrylate resin composition (A-2)": a resin composition containing 80.0% by mass of urethane acrylate resin and 20.0% by mass of tripropylene glycol diacrylate (TPGDA).

<Inorganic pigment (B)>
"Inorganic pigment": G-100 (manufactured by Sankyo Flour Milling Co., Ltd., sand-like calcium carbonate, average particle size: 65 μm)

<Curing Agent (C)>
"Hardening agent": Perkadox L-40ES (manufactured by Kayaku Nouryon Co., Ltd., contains benzoyl peroxide, active ingredient amount: 40% by mass)

<Surfactant (D)>
"Surfactant (D-1)": Nonion OP-85R (NOF Corporation, sorbitan trioleate, nonionic, liquid, HLB value: 1.8, active ingredient amount: 100% by mass)
"Surfactant (D-2)": Nonion OP-83RAT (NOF Corporation, sorbitan sesquioleate, nonionic, liquid, HLB value: 3.7, active ingredient amount: 100% by mass)
"Surfactant (D-3)": Emulgen 404 (Kao Corporation, polyoxyethylene oleyl ether, nonionic, liquid, HLB value: 8.8, active ingredient amount: 100% by mass)
"Surfactant (D-4)": Emulgen 104P (Kao Corporation, polyoxyethylene lauryl ether, nonionic, liquid, HLB value: 9.6, active ingredient amount: 100% by mass)
"Surfactant (D-5)": Emulgen 108 (Kao Corporation, polyoxyethylene lauryl ether, nonionic, liquid, HLB value: 12.1, active ingredient amount: 100% by mass)
"Surfactant (D-6)": Emulgen 408 (Kao Corporation, polyoxyethylene oleyl ether, nonionic, liquid, HLB value: 10.0, active ingredient amount: 100% by mass)
"Surfactant (D-7)": Emulgen 707 (Kao Corporation, polyoxyethylene alkyl ether, nonionic, liquid, HLB value: 12.1, active ingredient amount: 100% by mass)

<Surfactant (D') Other Than Surfactant (D)>
"Surfactant (D'-1)": Perex OT-P (Kao Corporation, sodium dioctyl sulfosuccinate, anionic, liquid, active ingredient amount: 100% by mass)
"Surfactant (D'-2)": Oleoyl Sarcosine 221P (NOF Corporation, N-oleyl-N-methylglycine, anionic, liquid, active ingredient amount: 100% by mass)
"Surfactant (D'-3)": Rapisol A-80 (manufactured by NOF Corporation, sodium di-2-ethylhexyl-sulfosuccinate, anionic, liquid, active ingredient amount: 80.0% by mass)
"Surfactant (D'-4)": Neurex Soft 5S (NOF Corporation, linear alkylbenzene sulfonic acid, anionic, liquid, active ingredient amount: 96.0% by mass)
"Surfactant (D'-5)": Adekamin 4DAC-85 (manufactured by ADEKA CORPORATION, alkyl cation (di-long chain alkyl ammonium chloride), cationic, liquid, active ingredient amount: 85.0% by mass)
"Surfactant (D'-6)": Adekamin SF-106 (manufactured by ADEKA CORPORATION, ester type cation, cationic, liquid, active ingredient amount: 100% by mass)
"Surfactant (D'-7)": Cationic 2-OLR (NOF Corp., dioleyldimethylammonium chloride, cationic, liquid, active ingredient amount: 75.0% by mass)
"Surfactant (D'-8)": Nonion E-202 (NOF Corporation, polyoxyethylene oleyl ether, nonionic, solid, HLB value: 4.9, active ingredient amount: 100% by mass)
"Surfactant (D'-9)": Emulgen 120 (Kao Corporation, polyoxyethylene lauryl ether, nonionic, solid, HLB value: 15.3, active ingredient amount: 100% by mass)
"Surfactant (D'-10)": ADEKA AMPHORTH PB-30L (manufactured by ADEKA CORPORATION, lauryl amidopropyl acetate betaine, amphoteric, liquid, active ingredient amount: 30.0% by mass)

<Other ingredients>
"Polymer (E1-1)": HV Polymer D-100S (manufactured by Denka Co., Ltd., hydrophobic group-modified polyvinyl alcohol (modified polyvinyl acetate with a saponification degree of 86.5 to 89 mol%))
"Polymer composition (E2-1)": Dicalac 8506 (manufactured by Daido Chemical Industry Co., Ltd., acrylic copolymer 60% by mass, tripropylene glycol diacrylate 40% by mass)
"Amine catalyst": 70% by mass of N,N-di(β-hydroxyethyl)-p-toluidine (manufactured by Showa Denko K.K.) diluted with 30% by mass of 2-hydroxyethyl methacrylate "Metal catalyst": Rigolac Cobalt O (manufactured by Showa Denko K.K., 8% cobalt octylate)

[Example 1]
A container was charged with 50 parts by mass of the urethane acrylate resin composition (A-1), and then 0.35 parts by mass of the amine catalyst, 0.125 parts by mass of the metal catalyst, 5 parts by mass of the polymer (E1-1), 82.8 parts by mass of the inorganic pigment, and 0.5 parts by mass of the surfactant (D-1) were added and mixed by stirring, and then 1.25 parts by mass of a curing agent was added and thoroughly stirred and mixed to prepare a resin composition.

[Examples 2 to 15 and Comparative Examples 1 to 16]
Resin compositions were prepared in the same manner as in Example 1, except that the raw materials shown in Table 1 or 2 below were used in the amounts (numbers, parts by mass) shown in Table 1 or 2.

<Spring constant>
First, each part of the mold shown in Fig. 2 (the white parts in Fig. 2) was cleaned using a parts cleaner, and the parts that would become the inner surfaces after assembly were release-treated with KF-96-SP (a silicone release agent) manufactured by Shin-Etsu Chemical Co., Ltd. Each release-treated part was fastened and fixed with fixing fixtures using bolts so that it would have the shape shown in Fig. 2 (100 mm x 100 mm x 25 mm (thickness)). At this time, the mold was formed without overtightening the fixing fixtures so that the bolts would not become loose and no gaps would be created.

Next, the prepared resin composition was poured into the formed mold. At this time, the resin composition was poured so that the amount of the resin composition poured was exactly the same as the size of the mold.
The resin composition was poured into a mold, left at room temperature for about 3 days, and the surface of the resin composition was touched to confirm hardening. The mold was then removed to produce three molded bodies. The mold was carefully removed so that the molded body obtained would not crack or chip. The size of the molded body produced was measured using a caliper. When the length of the molded body, which should have been 100 mm, was 100±1 mm and the thickness was 25±0.5 mm, the molded body was used to perform a spring constant measurement test.

Each of the produced molded bodies was placed in a compression tester (Servo Pulser EHF-EG10-2-L, manufactured by Shimadzu Corporation) so that the length direction of the molded body was the compression direction, and 30 seconds after applying a preload of 4.4 kN twice, the molded body was loaded up to 4.4 kN at a displacement rate of 1 mm/min. The deflection of the molded body at loads of 0.98 kN and 3.92 kN was measured using a laser displacement meter (HL-G103-AC, manufactured by Panasonic Corporation, gauge length: 100 mm), and the spring constant was calculated from the following formula. The results are shown in Tables 1 and 2.
Spring constant (MN/m) = (F2 (kN) - F1 (kN)) / (X2 (mm) - X1 (mm))
[F2 is a load of 3.92 kN, X2 is the deflection (mm) of the molded body at the load of 3.92 kN, F1 is a load of 0.98 kN, and X1 is the deflection (mm) of the molded body at the load of 0.98 kN.]

<Adhesive strength to dry substrate>
A 5 mm thick formwork was placed on a dried mortar board (ISO standard) with a size of 140 mm x 140 mm x 40 mm (thickness), and the prepared resin composition was placed (poured) inside the formwork. Then, it was cured at 23 ° C for 3 days to obtain a 5 mm thick cured body. A steel jig with a size of 40 mm x 40 mm was attached to three places near the center of the obtained cured body using instant adhesive, and the instant adhesive was cured for one day. Then, a cut was made along the edge of the steel jig from the cured body side to the mortar board, and the steel jig was pulled directly upward (in the lamination direction of the mortar board and the cured body) using a Kenken type tensile tester (BA-450D, manufactured by Marubishi Scientific Machinery Manufacturing Co., Ltd.), and the maximum tensile strength (MPa) was measured when the cured body peeled off from the dried mortar board. The average value (Td) of the maximum tensile strength at three places is shown in Table 1 or 2.
When this Td is 1.00 MPa or more, it can be said that there is no problem in practical use.

In addition, for Examples 1 to 9 and 15 and Comparative Examples 2 to 13, the ratio of the adhesive strength to the dry adherend in each test to the adhesive strength to the dry adherend in Comparative Example 1 (adhesive strength (%) relative to Comparative Example 1) is shown in Table 1 or 2.
For Examples 10 and 11, the ratio of the adhesive strength to the dry adherend in each test to the adhesive strength to the dry adherend in Comparative Example 14 (adhesive strength (%) relative to Comparative Example 14) is shown in Table 1.
For Examples 12 and 13, the ratio of the adhesive strength to the dry adherend in each test to the adhesive strength to the dry adherend in Comparative Example 15 (adhesive strength (%) relative to Comparative Example 15) is shown in Table 1.
For Example 14, the ratio of the adhesive strength to the dry adherend in Example 14 to the adhesive strength to the dry adherend in Comparative Example 16 (adhesive strength (%) to Comparative Example 16) is shown in Table 1.
When the adhesive strength (%) for each of Comparative Examples 1, 14, 15 and 16 was 90% or more, it was judged to be acceptable.

<Adhesive strength to wet substrate>
The maximum tensile strength (MPa) was measured when the hardened body peeled off from the wet mortar board in the same manner as the adhesive strength to the dry adherend, except that instead of a dry mortar board (ISO standard) measuring 140 mm x 140 mm x 40 mm (thickness), 1 g of water was applied to the mortar board and the entire surface of the mortar board was wetted with water (wet mortar board). The average value (Tw) of the maximum tensile strength at three points is shown in Table 1 or 2.
When this Tw is 0.70 MPa or more, it can be said that there is no problem in practical use.

<Adhesion retention rate>
The adhesion retention rate was calculated from the above values of Td and Tw according to the following formula (1).
Adhesion retention rate = (Tw/Td) x 100 (1)
When this adhesion retention rate is 50% or more, it can be said that there is no problem in practical use.

10: Slab-type track 20: Roadbed side structure 22: Filling layer 24: Track slab 26: Notch 28: Protrusion 30: Track rail

Claims (6)

The composition contains a urethane acrylate resin (A), an inorganic pigment (B), a curing agent (C), and a nonionic surfactant (D) that is liquid at 20°C,
The content of the nonionic surfactant (D) is 0.1 to 3.4 parts by mass based on 100 parts by mass of the urethane acrylate resin (A).
Resin composition for railway tracks. The resin composition for railway tracks according to claim 1, which contains 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. The railway track resin composition according to claim 1, wherein the nonionic surfactant (D) does not have a group reactive with the component (A). The resin composition for railway tracks according to claim 1, wherein the HLB value of the nonionic surfactant (D) is 1 to 13. The resin composition for railway tracks according to any one of claims 1 to 4, wherein the spring constant of the cured product obtained from the resin composition for railway tracks is 15 to 80 MN/m. The resin composition for railway tracks according to any one of claims 1 to 4, wherein the adhesion retention calculated by the following formula (1) is 50% or more.
Adhesion retention rate = (Tw/Td) x 100 (1)
[In formula (1), Td is the maximum tensile strength (MPa) measured using a Construction Research Institute tensile tester when peeling off a cured body (40 mm x 40 mm x 5 mm (thickness)) obtained by placing the above-mentioned railway track resin composition on the surface of a dried mortar board having a size of 140 mm x 140 mm and curing it at 23°C for 3 days from the mortar board, and Tw is the maximum tensile strength (MPa) measured in the same manner as Td, except that a mortar board having a size of 140 mm x 140 mm was used in which 1 g of water was applied to the mortar board and the entire surface of the mortar board was wetted with water instead of the dried mortar board having a size of 140 mm x 140 mm.]