JP7197097B1 - acrylic resin dispersion - Google Patents

Abstract

Kind Code: A1 An object of the present invention is to provide an acrylic resin dispersion that can uniformly fix ballast regardless of the position of the ballast in the case of fixing stacked ballast. The composition comprises acrylic resin particles (A) containing at least a (meth)acrylic acid alkyl ester monomer as a structural unit, a liquid medium (B), and a curing catalyst (C). The liquid medium (B) contains 50% by mass or more and 100% by mass or less of the polyether resin (B-1) whose terminal is modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B). and 0% by mass or more and 20% by mass or less of a liquid resin (B-2) having a crosslinkable silyl group in a side chain and a main chain composed of repeating units of —Si—O— bonds. [Selection drawing] Fig. 2

Description

The present invention relates to acrylic resin dispersions.

Conventionally, ballast (gravel and aggregate) used in railway tracks is fixed with a resin binder, an adhesive, or the like in order to prevent scattering of the ballast. When a train passes through the ballast track, the ballast is vibrated by the load of the train. As a result, the ballast fixed with a resin binder, adhesive, or the like may loosen. In recent years, water-based paints and water-based binders with reduced VOCs (volatile organic compounds) have been desired from the viewpoint of environmental protection and safety.

Therefore, Patent Document 1 proposes a one-liquid type solventless acrylic resin composition with reduced VOC components and room temperature curing properties for fixing gravel or aggregate.

JP 2018-016771 A

However, in the technique of Patent Document 1, when fixing the stacked ballasts with the solvent-free liquid acrylic resin composition, there is a problem that some of the ballasts cannot be fixed depending on the respective positions of the stacked ballasts.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an acrylic resin dispersion that can uniformly fix ballast regardless of the position of the ballast when fixing stacked ballast.

In order to achieve the object of the present invention, the acrylic resin dispersion of the present invention comprises acrylic resin particles (A) containing at least a (meth)acrylic acid alkyl ester monomer as a structural unit, and a liquid medium (B). , and a curing catalyst (C), wherein the liquid medium (B) is terminally modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B) A polyether resin (B-1) of 50% by mass or more and 100% by mass or less, a liquid resin (B- 2) is 0% by mass or more and 20% by mass or less, and the viscosity of the acrylic resin dispersion is 3150 mPa·s or more and 10400 mPa·s or less .

ADVANTAGE OF THE INVENTION According to this invention, the acrylic resin dispersion liquid which can fix ballast uniformly can be provided, without depending on the position of ballast, when fixing stacked ballast.

The figure explaining the hardening body obtained by fixing a crushed stone with the conventional acrylic resin solution. FIG. 4 is a diagram for explaining a cured body obtained by fixing crushed stone with the acrylic resin dispersion of the present invention.

Embodiments will be described in detail below. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined arbitrarily.

<Acrylic resin dispersion>
The acrylic resin dispersion of the present invention comprises acrylic resin particles (A) containing at least a (meth)acrylic acid alkyl ester monomer as a structural unit, a liquid medium (B), and a curing catalyst (C). , the liquid medium (B) is 50% by mass or more and 100% by mass or less of the polyether resin (B-1) whose terminal is modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B); 0% by mass or more and 20% by mass or less of a liquid resin (B-2) having crosslinkable silyl groups in side chains and having repeating units of -Si-O- bonds in the main chain.

Here, the mechanism by which the acrylic resin dispersion containing the liquid medium defined above improves the mechanical properties of a layer (hereinafter referred to as a cured film) made of the acrylic resin dispersion will be described.

In the acrylic resin dispersion of the present invention, the acrylic resin particles contain a polyfunctional monomer (eg, AMA) to reduce the compatibility of the acrylic resin particles with the liquid medium, thereby making the acrylic resin particles insoluble in the liquid medium. there is As a result, the acrylic resin particles composed of the (meth)acrylic acid alkyl ester monomer are dispersed in the liquid medium. That is, a colloidal liquid is formed using the acrylic resin particles as the dispersoid and the liquid medium as the medium. When the acrylic resin dispersion forms a cured film, the acrylic resin particles play the same role as a filler, so that the mechanical properties of the cured film are improved. In addition, by finely dividing the acrylic resin particles, it is possible to impart appropriate rubber elasticity and strength to the cured film. Specifically, a cured film satisfying a maximum strength of 0.5 MPa or more and a breaking elongation of 200% or more in a tensile test is obtained.

On the other hand, in a conventional acrylic resin solution, acrylic resin particles composed of a (meth)acrylic acid alkyl ester monomer are dissolved in the liquid medium. In this case, when the acrylic resin solution forms a cured film, the acrylic resin particles cannot function as a filler, so that the mechanical properties of the cured film are greatly reduced.

In general, for particles of a colloidal liquid, it is possible to measure the particle size and the like of the particles by a dynamic light scattering method or the like. However, in the acrylic resin dispersion of the present invention, since the liquid medium is a liquid resin, it is difficult to measure the acrylic resin particles. Therefore, whether or not the acrylic resin particles are dispersed in the liquid medium (liquid resin) was determined by visually confirming the appearance of the acrylic resin dispersion.

A method for judging whether or not acrylic resin particles are dispersed from the appearance of the acrylic resin dispersion will be described. For example, when acrylic resin particles are dispersed in a liquid medium, visible light entering the liquid medium is scattered by the acrylic resin particles. Therefore, the acrylic resin dispersion has a milky appearance. On the other hand, when the acrylic resin particles are not dispersed in the liquid medium but are compatible with the liquid medium, visible light entering the liquid medium is not scattered by the acrylic resin particles and is transmitted. Therefore, the appearance of the acrylic resin solution is transparent. Note that visible light refers to light having a wavelength of 360 to 830 nm.

(Liquid medium (B))
A liquid medium refers to a medium for dispersing acrylic resin particles. The liquid medium according to one embodiment includes a polyether resin (B-1) modified with a crosslinkable silyl group at the end, a crosslinkable silyl group in the side chain, and a repeating —Si—O— bond in the main chain. At least one of a liquid resin (B-2) consisting of units, a liquid polyalkylene glycol (B-3) having no crosslinkable silyl group, and a high boiling point plasticizer (B-4) having a boiling point of 180° C. or higher including.

(Polyether resin (B-1))
From the viewpoint of the balance of strength and elongation of the cured film, the liquid medium (B) according to one embodiment is a polyether resin ( B-1) in an amount of 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more. On the other hand, from the viewpoint of the balance of strength and elongation of the cured film, the liquid medium (B) according to one embodiment is a polymer whose terminal is modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B). Contains 100% by mass or less of the ether resin (B-1). For example, the liquid medium (B) according to one embodiment contains 50% by mass or more of a polyether resin (B-1) modified with a crosslinkable silyl group at the end relative to 100% by mass of the liquid medium (B), 100% by mass or less, preferably 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less.

By including the polyether resin within the above range in the liquid medium, it is possible to impart appropriate rubber elasticity to the cured film.

Polyether resins include, for example, polyoxyethylene and polyoxypropylene. The polyether resin may contain one of the above alone or two or more of them. The polyether resin according to one embodiment is polyoxypropylene from the viewpoint of improving the mechanical properties of the cured film.

A polyether resin has at least one crosslinkable silyl group in one molecule. From the viewpoint of improving the mechanical properties of the cured film, the polyether resin according to one embodiment preferably has a crosslinkable silyl group at the end of the polyether resin, and more preferably has a crosslinkable silyl group at the end of the polyether resin. have at both ends.

A crosslinkable silyl group undergoes a condensation reaction, for example, in the presence of moisture or the like using a curing catalyst or the like. Crosslinkable silyl groups according to one embodiment include, for example, hydrolyzable silyl groups and hydrolyzed silanol groups.

Hydrolyzable silyl groups are selected from the group consisting of, for example, hydrogen atoms, halogen atoms, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, mercapto groups and alkenyloxy groups. At least one hydrolyzable group comprises a group attached to a silicon atom.

The hydrolyzable silyl group is a group consisting of a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group and an alkenyloxy group, from the viewpoint of improving the mechanical properties of the cured film. is preferably an alkoxy group, more preferably a methoxy group.

In the hydrolyzable silyl group, 1 to 3 hydrolyzable groups can be bonded to one silicon atom. When one or two hydrolyzable groups are bonded to one silicon atom, groups other than the hydrolyzable groups that can be bonded to one silicon atom are not particularly limited. Groups that can be bonded to a single silicon atom include, for example, hydrocarbon groups.

The hydrolyzable silyl group according to one embodiment is preferably a dialkoxyalkylsilyl group, more preferably a dimethoxymethylsilyl group, from the viewpoint of improving the mechanical properties of the cured film.

(Liquid resin (B-2))
The liquid medium (B) according to one embodiment, from the viewpoint of the balance between the curing speed of the acrylic resin dispersion and the strength and elongation of the cured film, has crosslinkable silyl 0% by mass or more of a liquid resin (B-2) having a group and having a main chain composed of repeating units of —Si—O— bonds. On the other hand, from the viewpoint of the balance between the curing speed of the acrylic resin dispersion and the strength and elongation of the cured film, the liquid medium according to one embodiment has crosslinkable silyl 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less of a liquid resin (B-2) having a group and having a main chain composed of repeating units of —Si—O— bonds. For example, the liquid medium (B) according to one embodiment has a crosslinkable silyl group in a side chain and a repeating unit having a -Si-O- bond in the main chain relative to 100% by mass of the liquid medium (B). 0% by mass or more and 20% by mass or less, preferably 0% by mass or more and 15% by mass or less, more preferably 0% by mass or more and 10% by mass or less of the liquid resin (B-2) consisting of

When the liquid medium contains more than 20% by mass of the liquid resin, the curing speed is lowered in consideration of the viscosity of the acrylic resin dispersion. Thus, the liquid medium contains the liquid resin within the above range, so that the cross-linking reaction points can be suppressed and the curing speed of the acrylic resin dispersion can be controlled. The acrylic resin dispersion of the present invention is cured to the touch within 30 minutes after being applied to a given substrate. Furthermore, by appropriately controlling the curing rate of the acrylic resin dispersion, it is possible to firmly fix the ballast (for example, crushed stone) in the deep part (bottom side) of the hardened body, which will be described later.

The liquid resin has at least one crosslinkable silyl group per molecule of the liquid resin at a molecular terminal or side chain. Liquid resins include, for example, hydrolyzable alkoxysilyl group-containing liquid polysiloxanes and hydrolyzable alkoxysilyl group-containing liquid oligomers. The liquid resin may contain one of the above or two or more of them.

The crosslinkable silyl group may exist at the terminal of the liquid resin, may exist in the side chain, or may exist in both the terminal and the side chain. There may be at least one crosslinkable silyl group per molecule of the liquid resin. From the viewpoint of curing speed and cured physical properties, it is preferable that there are two or more crosslinkable silyl groups per molecule of the liquid resin on average.

(Liquid polyalkylene glycol (B-3))
From the viewpoint of the balance between the curing speed of the acrylic resin dispersion and the strength and elongation of the cured film, the liquid medium according to one embodiment is a liquid medium having no crosslinkable silyl group relative to 100% by mass of the liquid medium (B). Contains 0% by mass or more of polyalkylene glycol (B-3). On the other hand, the liquid medium according to one embodiment has a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B) from the viewpoint of the balance between the curing speed of the acrylic resin dispersion and the strength and elongation of the cured film. 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less of the liquid polyalkylene glycol (B-3). For example, the liquid medium (B) according to one embodiment contains 0% by mass or more of a liquid polyalkylene glycol (B-3) having no crosslinkable silyl group, 50% % by mass or less, preferably 0% by mass or more and 40% by mass or less, more preferably 0% by mass or more and 30% by mass or less.

When the liquid medium contains more than 50% by mass of liquid polyalkylene glycol having no crosslinkable silyl group, the curing speed is lowered in consideration of the viscosity of the acrylic resin dispersion.

The liquid polyalkylene glycol is not particularly limited as long as it is compatible with the polyether resin and the liquid resin. The polyalkylene glycol according to one embodiment is polypropylene glycol from the viewpoint of improving the mechanical properties of the cured film. Polyalkylene glycols may be used singly or in combination of two or more of the above. The viscosity of the acrylic resin dispersion of the present invention can be adjusted by including polyalkylene glycol in the liquid medium.

The liquid polyalkylene glycol may be a commercial product, for example, Polyglycol P2000P (weight average molecular weight 2000, manufactured by Dow Chemical), Uniol D-1000 (weight average molecular weight 1000, manufactured by NOF Corporation), Uniol D -2000 (weight average molecular weight 2000), Uniol D-4000 (weight average molecular weight 4000) and the like.

The weight average molecular weight of the liquid polyalkylene glycol is preferably 500-8000, more preferably 1000-4000.

(High boiling point plasticizer (B-4))
The liquid medium according to one embodiment has a boiling point of 180° C. or higher with respect to 100% by mass of the liquid medium (B), from the viewpoint of the balance between the viscosity of the acrylic resin dispersion and the strength and elongation of the cured film. Contains 0% by mass or more of the agent (B-4). On the other hand, the liquid medium according to one embodiment has a boiling point of 180° C. or higher with respect to 100% by mass of the liquid medium (B), from the viewpoint of the balance between the viscosity of the acrylic resin dispersion and the strength and elongation of the cured film. It contains 40% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less of the high boiling point plasticizer (B-4). For example, the liquid medium (B) according to one embodiment contains 0% by mass or more and 40% by mass of a high-boiling plasticizer (B-4) having a boiling point of 180° C. or higher with respect to 100% by mass of the liquid medium (B). % or less, preferably 0 mass % or more and 30 mass % or less, more preferably 0 mass % or more and 20 mass % or less.

If the liquid medium contains more than 40% by mass of a high boiling point plasticizer having a boiling point of 180° C. or higher, the high boiling point plasticizer bleeds out onto the surface of the cured film when the acrylic resin dispersion is cured. In addition, the high boiling point plasticizer may be discharged from the cured film under the influence of rainfall or the like.

A high boiling point plasticizer is a solvent having a boiling point of 180° C. or higher under atmospheric pressure. The high boiling point plasticizer is not particularly limited as long as it is compatible with the polyether resin, liquid resin, and polyalkylene glycol. The high boiling point plasticizer according to one embodiment preferably has a boiling point of 260° C. or higher at atmospheric pressure from the viewpoint of environmental conservation.

The high boiling point plasticizer can be appropriately selected from among hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents and the like. High-boiling plasticizers (B-4) include, for example, 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol. , 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, n-nonyl acetate, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, Diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether , triethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether , tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4- It includes butanediol diacetate, 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, γ-butyrolactone and the like, and one of these may be used alone or two or more of them may be used.

By containing a high boiling point plasticizer in the liquid medium, it becomes possible to appropriately adjust the viscosity of the acrylic resin dispersion of the present invention.

(Acrylic resin particles (A))
The acrylic resin dispersion according to one embodiment contains 5% by mass or more and 40% by mass or less, preferably 5% by mass or more and 30% by mass or less of the acrylic resin particles (A) with respect to 100% by mass of the acrylic resin dispersion. , more preferably 5% by mass or more and 20% by mass or less.

In this specification and the like, "acrylic resin particles (A)" are resin particles in which a monomer component containing at least (meth)acrylic acid ester as a polymerizable monomer is polymerized, and at least (meth)acrylic acid It has a structural unit derived from an ester. In this specification and the like, the term “(meth)acryl” means that both terms “acryl” and “methacryl” are included. Similarly, the term "(meth)acrylate" is meant to include both the terms "acrylate" and "methacrylate." The acrylic resin particles (A) may be polymer (homopolymer) particles obtained by polymerizing one type of polymerizable monomer ((meth)acrylic acid ester), or two or more types containing (meth)acrylic acid esters. Polymer (copolymer) particles obtained by polymerizing (copolymerizing) the polymerizable monomers may be used.

((Meth) acrylic ester-containing monomer (A-0))
(Meth)acrylic acid esters include, for example, (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid aralkyl esters, and (meth)acrylic acid Including aryl esters and other (meth)acrylic acid esters. The (meth)acrylic acid ester may be used alone or in combination of two or more of the above. In particular, the monomer component forming the acrylic resin particles (A) preferably contains at least (meth)acrylic acid alkyl ester.

(Meth)acrylic acid alkyl esters, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate , tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate ) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, n-dodecyl Linear or branched alkyl such as (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate (meth)acrylic acid alkyl esters having a ) including alicyclic (meth)acrylic acid alkyl esters such as acrylates. The (meth)acrylic acid alkyl ester may be used alone or in combination of two or more of the above. In particular, the (meth)acrylic acid alkyl ester is preferably a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 18 carbon atoms (more preferably 1 to 12 carbon atoms).

(Meth)acrylic acid hydroxyalkyl esters are, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3- including hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. . (Meth)acrylic acid hydroxyalkyl esters are used singly or in combination of two or more of the above.

(Meth)acrylic acid alkoxyalkyl esters are, for example, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, and 2- Including phenoxyethyl (meth)acrylate and the like. (Meth)acrylic acid alkoxyalkyl esters may be used alone or in combination of two or more of the above.

(Meth)acrylic acid aralkyl esters include, for example, benzyl (meth)acrylate, 2-phenylethyl (meth)acrylate, methylbenzyl (meth)acrylate, naphthylmethyl (meth)acrylate, and the like. (Meth)acrylic acid aralkyl esters may be used alone or in combination of two or more.

(Meth)acrylic acid aryl esters include, for example, phenyl (meth)acrylate, 4-hydroxyphenyl (meth)acrylate, tolyl (meth)acrylate, naphthyl (meth)acrylate, and the like. The (meth)acrylic acid aryl ester may be used alone or in combination of two or more of the above.

Other (meth)acrylic acid esters include polyalkylene glycol (meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and methoxypolyethylene glycol mono(meth)acrylate, 2- (meth)acrylic acid alkyl esters having a halogen atom such as chloroethyl (meth)acrylate, trifluoroethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, perfluorooctylethyl (meth)acrylate; - (dimethylamino) ethyl (meth) acrylate, 2- (diethylamino) ethyl (meth) acrylate, 3- (dimethylamino) propyl (meth) acrylate having an amino group (meth) acrylic acid esters, carboxyethyl (meth) ) acrylates, carboxy group-containing (meth)acrylic acid esters such as carboxypentyl (meth)acrylate, glycidyl (meth)acrylate, glycerin mono (meth)acrylate, 2-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexyl (Meth)acrylic acid esters having an epoxy group such as methyl (meth)acrylate and derivatives thereof, (meth)acrylates having a sulfonic acid group such as 2-sulfoethyl (meth)acrylate and 3-sulfopropyl (meth)acrylate, 2 -(Phosphonoxy)ethyl (meth)acrylate having a phosphoric acid group, (meth)acrylate having an isocyanate group such as 2-isocyanatoethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, etc. (meth)acrylate having a heterocyclic ring, methoxypolyethyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate and the like, and alkyl group- or aryl group-terminated polyalkylene glycol mono(meth)acrylates. Other (meth)acrylic acid esters are used singly or in combination of two or more of the above.

The acrylic resin particles (A) are resin particles in which a monomer component containing the above-mentioned (meth)acrylic acid ester and other polymerizable monomer copolymerizable with the (meth)acrylic acid ester is polymerized. good too. In this case, the acrylic resin particles (A) have a structural unit derived from the (meth)acrylic acid ester and a structural unit derived from another polymerizable monomer copolymerizable with the (meth)acrylic acid ester.

Other polymerizable monomers include, for example, unsaturated carboxylic acid-based monomers, unsaturated monomers having nitrogen atoms, styrene-based monomers, and the like. Other polymerizable monomers may be used singly or in combination of two or more of the above.

Unsaturated carboxylic acid-based monomers include, for example, unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and citraconic acid; Including anhydrides of saturated carboxylic acids, monoesters of unsaturated carboxylic acids such as maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monomethyl ester, and itaconic acid monobutyl ester. The unsaturated carboxylic acid-based monomers may be used singly or in combination of two or more of the above. The unsaturated carboxylic acid-based monomer according to one embodiment is preferably (meth)acrylic acid.

Unsaturated monomers having a nitrogen atom include, for example, unsaturated monomers having a cyano group such as acrylonitrile and methacrylonitrile, (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide , N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-methylol (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-[2 -Dimethylaminoethyl](meth)acrylamide, N-[3-dimethylaminopropyl](meth)acrylamide, diacetoneacrylamide, 4-acryloylmorpholine, and acrylamide monomers such as 4-methacryloylmorpholine, N-vinylacetamide And acetamide-based monomers having a vinyl group such as N-vinyl-N-methylacetamide, N-vinyl-2-pyrrolidone, 4-vinylpyridine, 1-vinylimidazole, 2-vinyl-2-oxazoline, and 2- Nitrogen-containing heterocyclic compounds having a vinyl group such as isopropenyl-2-oxazoline are included. The unsaturated monomer having a nitrogen atom may be used alone or in combination of two or more of the above.

Styrenic monomers include, for example, styrene, α-methylstyrene, o-, m-, p-methylstyrene, o-, m-, p-ethylstyrene, 4-tert-butylstyrene, o-, m- , p-hydroxystyrene, o-, m-, p-methoxystyrene, o-, m-, p-ethoxystyrene, o-, m-, p-chlorostyrene, o-, m-, p-bromostyrene, o-, m-, p-fluorostyrene, o-, m-, p-chloromethylstyrene, and the like. The styrenic monomer is used singly or in combination of two or more of the above. The styrenic monomer according to one embodiment is preferably styrene.

Other polymerizable monomers include, in addition to the above-mentioned unsaturated carboxylic acid monomers, unsaturated monomers having a nitrogen atom, and styrene monomers, for example, vinyl monomers, unsaturated alcohols , vinyl ether-based monomers, vinyl ester-based monomers, unsaturated monomers having epoxy groups, and unsaturated monomers having sulfonic acid groups.

Vinyl-based monomers include, for example, vinyl chloride and vinyl fluoride. Unsaturated alcohols include, for example, vinyl alcohol and allyl alcohol, and one of the above may be used alone or two or more of them may be used. Vinyl ether-based monomers include, for example, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, phenyl vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like, and one of the above alone Or two or more types are used. Vinyl ester monomers include, for example, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caprylate, vinyl laurate, vinyl stearate, and vinyl versatate. It is used alone or in combination of two or more. The unsaturated monomer having an epoxy group includes allyl glycidyl ether and the like, and one of the above may be used alone or in combination of two or more. Unsaturated monomers having a sulfonic acid group include, for example, vinylsulfonic acid, styrenesulfonic acid, allylsulfonic acid, methallylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, and the like. One of these is used alone or in combination of two or more.

Furthermore, the monomer component forming the acrylic resin particles (A) can contain a monomer capable of functioning as a cross-linking agent (cross-linking monomer) as a polymerizable monomer.

The crosslinkable monomer is a monomer having two or more polymerizable unsaturated bonds, such as 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1 ,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol Di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol Bifunctional (meth)acrylates such as di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and glycerin di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, penta Polyfunctional (meth)acrylates such as erythritol tetraacrylate and dipentaerythritol hexaacrylate, allyl (meth)acrylate, divinylbenzene and diallyl phthalate. The crosslinkable monomer is used singly or in combination of two or more of the above.

(Ethylenically unsaturated monomer having a crosslinkable silyl group (A-1))
The acrylic resin particles (A) further contain an ethylenically unsaturated monomer (A-1) having a crosslinkable silyl group as a structural unit. The ethylenically unsaturated monomer (A-1) having a crosslinkable silyl group may be any known monomer as long as it has a crosslinkable alkoxysilyl group, such as vinyltrimethoxysilane and vinyltriethoxysilane. , vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3- (meth)acryloxypropylmethyldiethoxysilane, 4-vinylphenyltrimethoxysilane, 3-(4-vinylphenyl)propyltrimethoxysilane, 4-vinylphenylmethyltrimethoxysilane, and the like.

An ethylenically unsaturated monomer having a crosslinkable silyl group is commercially available as a silane coupling agent, for example, 3-methacryloxypropyltrimethoxysilane (KBM-503 (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.). , 3-methacryloxypropylmethyldimethoxysilane (KBM-502 (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. As the ethylenically unsaturated monomer having a crosslinkable silyl group, one of the above may be used alone or in combination of two or more.

(Curing catalyst (C))
The curing catalyst is a component for accelerating the curing reaction of the moisture-curable acrylic resin dispersion of the present invention. The curing catalyst is not particularly limited as long as it is a substance that functions and acts as a curing catalyst.

Curing catalysts (C) containing metals are, for example, organotitanium and organotin compounds. Organotitaniums include, for example, titanate esters, tetrabutyl titanate, tetrapropyl titanate, tetraisopropyl titanate, and titanium tetraacetylacetonate. Organotin compounds include, for example, dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, dibutyltin dioctanoate, dibutyltin acetylacetonate, dibutyltin oxide and the corresponding dioctyltin compounds.

Metal-free curing catalysts (C) include, for example, basic compounds. Basic compounds include, for example, triethylamine, tributylamine, 1,4-diazabicyclo[2.2.2]octane, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[ 5.4.0]undec-7-ene, N,N-bis-(N,N-dimethyl-2-aminoethyl)methylamine, N,N-dimethylcyclohexylamine, N,N-dimethylphenylamine and N - contains ethylmorpholinine.

Curing catalysts (C) include as acidic compounds eg phosphoric acid and its esters, toluenesulfonic acid, sulfuric acid, nitric acid or other organic carboxylic acids such as acetic acid and benzoic acid.

The acrylic resin dispersion according to one embodiment contains 1 to 100 parts by mass, preferably 1 to 30 parts by mass, more preferably 3 to 20 parts by mass of the curing catalyst (C) with respect to 503 parts by mass of the acrylic resin dispersion. include. When the acrylic resin dispersion contains more than 30 parts by mass of the curing catalyst (C), the curing speed of the acrylic resin dispersion increases. Therefore, the acrylic resin dispersion cannot reach the deep part (bottom side) of the hardened body described later, and the hardening of the acrylic resin dispersion in the deep part of the hardened body may be insufficient. In addition, problems such as thickening, gelation, and curing may occur during storage of the acrylic resin dispersion.

(Polymerization initiator)
Polymerization initiators include, for example, 4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, benzoyl peroxide, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, oxide, t-butylperoxy-2-ethylhexanoate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, and t-butylperoxide Oil-soluble organic peroxides such as oxides, such as 2,2′-azobisisobutyronitrile, 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-(2,4- dimethyl-4-methoxyvaleronitrile) and other oil-soluble azo compounds. The oil-soluble polymerization initiator is preferably an oil-soluble azo compound. One of the above oil-soluble polymerization initiators may be used alone or in combination of two or more.

(chain transfer agent)
Chain transfer agents include, for example, octyl thioglycolate, methoxybutyl thioglycolate, octyl mercaptopropionate, methoxybutyl mercaptopropionate, stearyl mercaptan, mercaptans such as lauryl mercaptan, α-methylstyrene dimer, etc., from the above At least one selected may be used.

<Application>
The use of the acrylic resin dispersion according to one embodiment is for fixing at least one of gravel and aggregate.

In addition, the acrylic resin dispersion is cured at room temperature and does not have the problem of odor caused by solvents. Acrylic resin dispersions can be applied in coatings for architectural and civil engineering applications. In addition, acrylic resin dispersions are used as paints and binders that can be used in a wide range of outdoor applications. As described above, the acrylic resin dispersion is solvent-free, and is therefore excellent in environmental applicability and economic efficiency.

<Production of acrylic resin dispersion>
Table 1 provides a description of the abbreviations in Tables 2-5. Table 2 shows raw material formulations and test results of the acrylic resin dispersions of Examples 1 to 8. Table 3 shows raw material formulations and test results of the acrylic resin dispersions of Examples 9-15. Table 4 shows raw material formulations and test results of the acrylic resin dispersions of Examples 16-24. Table 5 shows the composition of raw materials such as the acrylic resin solutions of Comparative Examples 1 to 7 and the test results. Among the acrylic resin solutions and the like in Table 5, the acrylic resin solutions having a liquid appearance of "transparent" correspond to acrylic resin dispersions.

(Example 1)
Based on the raw material formulation of Example 1 in Table 2, 40 parts by mass of butyl acrylate (BA), 48 parts by mass of methyl methacrylate (MMA), 2 parts by mass of allyl methacrylate (AMA) as A-0 of A component, and A component 10 parts by mass of γ-methacryloxypropylmethyldimethoxysilane (trade name: KBM-502, manufactured by Shin-Etsu Chemical Co., Ltd.) as A-1 and 1 part by mass of lauryl mercaptan (L-SH) as a chain transfer agent were stirred and mixed. to prepare a monomer mixture. A four-necked separable flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel was charged with 200 parts by mass of MS Polymer S203H (trade name: manufactured by Kaneka Corporation) and Silyl SAT010 (trade name) as the B-1 component. : manufactured by Kaneka Corporation) 100 parts by mass, polypropylene glycol (trade name: Uniol D-2000, manufactured by NOF Corporation) as B-3 component 50 parts, tripropylene glycol n-butyl ether (trade name: manufactured by NOF Corporation) as component B-4 50 parts by mass of Dowanol TPnB (manufactured by Dow Chemical Japan Co., Ltd.) was charged. While stirring under a nitrogen atmosphere, the monomer mixture prepared above was added and mixed uniformly, and then 2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) was added as a polymerization initiator. .

Subsequently, the internal temperature of the separable flask was raised to 80° C., polymerization reaction was carried out over 8 hours, and then the mixture was cooled to room temperature to obtain a mixture. The acrylic resin dispersion had a viscosity of 6,500 mPa·s (25° C.) and a milky white appearance. The viscosity of the acrylic resin dispersion was measured using a Brookfield viscometer (trade name: BMII, manufactured by Toki Sangyo Co., Ltd.).

To 503 parts by mass of the acrylic resin dispersion, 3 parts by mass of titanium tetraisopropoxide (trade name: ORGATICS TA-8, manufactured by Matsumoto Fine Chemicals Co., Ltd.) was added as a curing catalyst and stirred to mix. was obtained.

The acrylic resin dispersions of Examples 2 to 24 and the acrylic resin solutions of Comparative Examples 1 to 7, etc. were obtained by the same process as in Example 1 based on the raw material formulations shown in Tables 2 to 5.

<Test method>
Using the acrylic resin dispersions of Examples 1 to 24 and the acrylic resin solutions of Comparative Examples 1 to 7, etc., performance evaluation was performed by performing the tests of Test Examples 1 to 4 below. Test Examples 1 to 4 are described below using acrylic resin dispersions. The performance of the acrylic resin solution and the like is evaluated by the same test as that for the acrylic resin dispersion, so a detailed description is omitted.

(Test Example 1 Curability)
Under the environment of 23° C. and 50% RH, the acrylic resin dispersion was applied to a thickness of about 1 mm on a glass plate. The time (minutes) until the coating film stopped adhering to the finger when the coating film on the glass substrate was touched with a finger (hardening to touch) was measured.

(Test Example 2 Deep hardening index)
The depth cure index of the acrylic resin dispersion was calculated using Equation 1 below.
C. I. = 1 ÷ (lnV ÷ Tc) (Formula 1)
Here, C.I. I. is the deep curing index, V is the viscosity of the acrylic resin dispersion at 25° C. (mPa·s), and Tc is the time (minutes) until finger-touch curing in the curability test.

The value of the deep hardening index is preferably between 1.0 and 3.0. A description will be given of the influence of the depth hardening index value outside the above range on the hardened body (a lump of crushed stone fixed by the acrylic resin dispersion) prepared in Test Example 3 described later.

For example, when the depth cure index value is less than 1.0, it indicates that the curing speed of the acrylic resin dispersion is fast. Therefore, the acrylic resin dispersion begins to harden while the acrylic resin dispersion is permeating the crushed stone on the surface of the container, so that the acrylic resin dispersion hardly penetrates into the crushed stone at the bottom of the container. In this case, the crushed stone on the surface of the container is fixed by the acrylic resin dispersion, but the crushed stone on the bottom of the container is not sufficiently fixed by the acrylic resin dispersion. In other words, the hardened body produced under this condition (when the value of the deep hardening index is less than 1.0) becomes brittle on the bottom side of the hardened body.

On the other hand, when the depth cure index value is greater than 3.0, it indicates that the curing speed of the acrylic resin dispersion is slow. Therefore, while the acrylic resin dispersion is permeating into the crushed stone on the surface of the container, the acrylic resin dispersion penetrates into the crushed stone at the bottom of the container without curing. In this case, the crushed stone on the surface of the container is not sufficiently fixed by the acrylic resin dispersion, and the crushed stone on the bottom of the container is fixed by the acrylic resin dispersion. In other words, the hardened body produced under this condition (when the value of the deep hardening index is greater than 3.0) is brittle on the surface layer side of the hardened body.

(Test Example 3 Deep Curability)
Crushed stones were packed into a container having an internal width of about 180 mm, a depth of about 100 mm, and a height of about 250 mm to a depth of 200 mm so as to have a specific gravity of 1.60 to 1.70 g/cm ³ . 72 g of an acrylic resin dispersion was evenly dispersed from above into a container filled with crushed stones, and cured in an atmosphere of 23° C. and 55% RH for 3 days. A hardened body (a lump in which crushed stone was fixed by the acrylic resin dispersion) was taken out from the container, and deep-part curability was evaluated according to the following evaluation criteria.
(Evaluation criteria)
○: The mass of crushed stone dropped from the hardened body is less than 5% of the total mass of the hardened body ×: The mass of crushed stone dropped from the hardened body is 5% or more of the total mass of the hardened body

(Test Example 4 Tensile strength and breaking elongation)
The acrylic resin dispersion was cured in an environment of 23° C. and 50% RH for 3 days to prepare a strip-shaped film sample (length of about 60 mm, width of about 10 mm, thickness of about 1.0 mm). Using a tensile tester (manufactured by A&D Co., Ltd., trade name "Tensilon universal tester RTG-1210"), the tensile test of the film sample is performed under the conditions of 23 ° C., tensile speed of 20 mm / min, and distance between chucks of 20 mm. was performed, and tensile strength (MPa) and elongation at break (%) were measured. The strength and elongation of the film samples were evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: Tensile strength of 0.5 MPa or more and breaking elongation of 200% or more ×: Tensile strength of 0.5 MPa or more and breaking elongation of 200% or more are not satisfied

<Test results>
Tables 2-4 show the test results of Examples 1-24. Table 5 shows the test results of Comparative Examples 1-7. The results in Tables 2 to 5 revealed the following. In the following, the term "curing properties" refers to the properties relating to the curing of acrylic resin dispersions (or acrylic resin solutions, etc.) as shown in Test Examples 1 to 3. Further, the mechanical properties refer to the strength and elongation properties of a cured film made of an acrylic resin dispersion (or an acrylic resin solution or the like) as shown in Test Example 4.

(Comparison between Example 1 and Comparative Example 1)
The curing properties and mechanical properties of Example 1 (with AMA) were better than Comparative Example 1 (without AMA). The appearance of the acrylic resin dispersion of Example 1 is milky white. On the other hand, the appearance of the acrylic resin solution of Comparative Example 1 is transparent. Thus, in Example 1, by including the polyfunctional monomer (AMA) in the acrylic resin particles, the acrylic resin particles become insoluble in the liquid medium and continue to exist in the form of fine particles. It is presumed that the physical characteristics have improved.

(Comparison between Example 1 and Comparative Example 2)
The curing properties and mechanical properties of Example 1 (containing BA, MMA, and AMA) were improved over Comparative Example 2 (containing BA, EA, and MMA). The appearance of the acrylic resin dispersion of Example 1 is milky white. On the other hand, the appearance of the acrylic resin solution of Comparative Example 2 is transparent. Thus, in Example 1, by including BA, MMA, and AMA in the acrylic resin particles, the acrylic resin particles are made insoluble in the liquid medium and continue to exist in the form of fine particles. It is presumed that the physical characteristics have improved.

Here, FIG. 1 shows a diagram for explaining a hardened body obtained by fixing crushed stone with a conventional acrylic resin solution or the like. FIG. 2 shows a diagram for explaining a cured body obtained by fixing crushed stone with the acrylic resin dispersion of the present invention. FIG. 1(a) shows cured bodies of Comparative Examples 1 and 2. FIG. In FIG. 1(a), the left half of the hardened body has collapsed, and crushed stones are scattered around the hardened body. On the other hand, the hardened body in FIG. 2 has a cylindrical shape, and crushed stones are not scattered around the hardened body. Thus, according to the present invention, it is possible to obtain a firm hardened body in which a series of crushed stones are firmly fixed from the surface layer to the bottom of the hardened body.

(Comparison between Example 19 and Comparative Example 3)
The curing and mechanical properties of Example 19 (with a small amount of B-2) were improved over Comparative Example 3 (with a large amount of B-2). The appearance of the acrylic resin dispersions of Example 19 and Comparative Example 3 is milky white. The proportion of B-2 in the B component of Example 19 is 12.5% by mass (= 100 × 50 parts by mass (B-2) / (300 parts by mass (B-1) + 50 parts by mass (B-2) + 50 Part by mass (B-3))). On the other hand, the proportion of B-2 in the B component of Comparative Example 3 is about 31.3% by mass (= 100 × 125 parts by mass (B-2) / (225 parts by mass (B-1) + 125 parts by mass (B -2) +50 parts by mass (B-3))). Thus, in Example 19, unlike Comparative Example 3, the acrylic resin particles were not compatible with the liquid medium by containing a small amount of B-2 in the liquid medium, so that the curing properties and mechanical properties were improved. It is speculated that

(Comparison between Example 19 and Comparative Example 4)
The curing properties of Example 19 (with a small amount of B-2) were improved over Comparative Example 4 (with a large amount of B-2). The appearance of the acrylic resin dispersions of Example 19 and Comparative Example 4 is milky white. Comparative Example 4 contains B-2 (KR-510, KR-515) different from B-2 (KR-500) of Comparative Example 3 in the liquid medium. In addition, the proportion of B-2 in the B component of Comparative Example 4 is about 31.3% by mass (= 100 × 125 parts by mass (B-2) / (225 parts by mass (B-1) + 125 parts by mass (B- 2) +50 parts by mass (B-3))). Thus, in Example 19, it is speculated that the curing properties of the acrylic resin dispersion were improved by including a small amount of B-2 in the liquid medium regardless of the type of the B component.

(Comparison between Example 19 and Comparative Example 5)
The curing and mechanical properties of Example 19 (with a small amount of B-2) were improved over Comparative Example 5 (with a large amount of B-2). The appearance of the acrylic resin dispersions of Example 19 and Comparative Example 5 is milky white. The proportion of B-2 in the B component of Example 19 is 12.5% by mass (= 100 × 50 parts by mass (B-2) / (300 parts by mass (B-1) + 50 parts by mass (B-2) + 50 Part by mass (B-3))). On the other hand, the proportion of B-2 in the B component of Comparative Example 5 is 75% by mass (= 100 × 300 parts by mass (B-2) / (300 parts by mass (B-2) + 100 parts by mass (B-3) )). Thus, in Example 19, unlike Comparative Example 5, the inclusion of a small amount of B-2 in the liquid medium is presumed to improve the curing properties and mechanical properties of the acrylic resin dispersion.

Here, FIG. 1(c) shows the cured products of Comparative Examples 3-5. In FIG. 1(c), the crushed stone on the bottom side of the hardened body has collapsed, and the crushed stone is scattered around the hardened body. On the other hand, the hardened body according to the present invention in FIG. 2 has a cylindrical shape, and no crushed stone is scattered around the hardened body. Thus, according to the present invention, it is possible to obtain a firm hardened body in which a series of crushed stones are firmly fixed from the surface layer to the bottom of the hardened body.

(Comparison between Example 19 and Comparative Example 6)
The curing and mechanical properties of Example 19 (with a small amount of B-2) were improved over Comparative Example 6 (with a large amount of B-2). The appearance of the acrylic resin dispersion of Example 19 is milky white. On the other hand, the appearance of the acrylic resin solution of Comparative Example 6 is transparent. The proportion of B-2 in the B component of Example 19 is 12.5% by mass (= 100 × 50 parts by mass (B-2) / (300 parts by mass (B-1) + 50 parts by mass (B-2) + 50 Part by mass (B-3))). On the other hand, the proportion of B-2 in the B component of Comparative Example 6 is about 75% by mass (= 100 × 300 parts by mass (B-2) / (300 parts by mass (B-2) + 100 parts by mass (B-3 ))). Thus, in Example 19, unlike Comparative Example 6, the acrylic resin particles were not compatible with the liquid medium by containing a small amount of B-2 in the liquid medium, so that the curing properties and mechanical properties were improved. It is speculated that

(Comparison between Example 18 and Comparative Example 7)
The curing properties and mechanical properties of Example 18 (without B-2) were better than Comparative Example 7 (with B-2). The appearance of the acrylic resin dispersion of Example 18 is milky white. On the other hand, the appearance of the acrylic resin solution of Comparative Example 7 is transparent. Example 18 and Comparative Example 7 each have 233 parts by weight of the B component. First, Example 18 and Comparative Example 7 each have EA and MMA as monomers constituting the acrylic resin particles (A). However, Example 18 has 200 parts by weight of B-1 component and 33.3 parts by weight of B-4 component in the B component. On the other hand, Comparative Example 7 has 200 parts by mass of B-2 component and 33.3 parts by mass of B-4 component in B component. Thus, in Example 18, unlike Comparative Example 7, since B-2 was not contained in the liquid medium as the B component, the acrylic resin particles were not compatible with the liquid medium, so that the curing properties and mechanical properties were improved. It is speculated that

Here, FIG. 1(b) shows the cured products of Comparative Examples 6 and 7. FIG. In FIG. 1(b), the hardened body has collapsed as a whole, and crushed stones are scattered around the hardened body. On the other hand, the hardened body according to the present invention in FIG. 2 has a cylindrical shape, and no crushed stone is scattered around the hardened body. Thus, according to the present invention, it is possible to obtain a firm hardened body in which a series of crushed stones are firmly fixed from the surface layer to the bottom of the hardened body.

As described above, the acrylic resin dispersion of the present invention has a remarkable effect that the ballast can be fixed uniformly without depending on the position of the ballast when the ballast is piled up.

The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the invention.

Claims (9)

An acrylic resin dispersion containing acrylic resin particles (A) containing at least a (meth)acrylic acid alkyl ester monomer as a structural unit, a liquid medium (B), and a curing catalyst (C),
The liquid medium (B) contains 50% by mass or more and 100% by mass or less of the polyether resin (B-1) whose terminal is modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B). , a liquid resin (B-2) having a crosslinkable silyl group in a side chain and a main chain consisting of repeating units of -Si-O- bonds at 0% by mass or more and 20% by mass or less ,
The acrylic resin dispersion has a viscosity of 3150 mPa s or more and 10400 mPa s or less.
Acrylic resin dispersion. An acrylic resin dispersion containing acrylic resin particles (A) containing at least a (meth)acrylic acid alkyl ester monomer as a structural unit, a liquid medium (B), and a curing catalyst (C),
The liquid medium (B) contains 50% by mass or more and 100% by mass or less of the polyether resin (B-1) whose terminal is modified with a crosslinkable silyl group with respect to 100% by mass of the liquid medium (B). , a liquid resin (B-2) having a crosslinkable silyl group in a side chain and a main chain consisting of repeating units of -Si-O- bonds at 0% by mass or more and 20% by mass or less ,
The acrylic resin dispersion has a depth curing index of 1.0 to 3.0 defined as 1/(lnV/Tc),
Here, V is the viscosity (mPa s) of the acrylic resin dispersion at 25 ° C., and Tc is the time (minutes) until the acrylic resin dispersion is cured to the touch in the curing test.
Acrylic resin dispersion. The liquid medium (B) has a crosslinkable silyl group in the side chain and a liquid resin (a main chain consisting of repeating units of -Si-O- bonds with respect to 100% by mass of the liquid medium (B). B-2) in an amount of 0% by mass or more and 15% by mass or less,
The acrylic resin dispersion according to claim 1 or 2 . The acrylic resin particles (A) further contain an ethylenically unsaturated monomer (A-1) having a crosslinkable silyl group as a structural unit,
The acrylic resin dispersion according to claim 1 or 2 . The acrylic resin particles (A) further include a monomer having two or more polymerizable unsaturated bonds as a structural unit,
The acrylic resin dispersion according to claim 1 or 2 . 5% by mass or more and 40% by mass or less of the acrylic resin particles (A) with respect to 100% by mass of the acrylic resin dispersion,
The acrylic resin dispersion according to claim 1 or 2 . The liquid medium (B) contains 0% by mass or more and 50% by mass or less of a liquid polyalkylene glycol (B-3) having no crosslinkable silyl group with respect to 100% by mass of the liquid medium (B).
The acrylic resin dispersion according to claim 1 or 2 . The liquid medium (B) contains 0% by mass or more and 40% by mass or less of a high boiling point plasticizer (B-4) having a boiling point of 180 ° C. or more with respect to 100% by mass of the liquid medium (B).
The acrylic resin dispersion according to claim 1 or 2 . for fixing gravel and/or aggregate;
The acrylic resin dispersion according to claim 1 or 2 .

Images