JP4509587B2 - Aqueous resin dispersion for cement mortar and composition thereof - Google Patents

Description

The present invention relates to an aqueous resin dispersion for cement mortar used in the field of civil engineering and architecture, and a composition thereof, such as a building repair material, a flooring material, a waterproof material, a protective material, an anticorrosive material, a finishing material, It is used for thin coating materials, adhesives, molding materials and the like.
Specifically, in a resin cement mortar composition containing an aqueous resin dispersion, cement, and filler, it gives good blending stability into cement mortar and simulability (resin cement mortar composition has a long simulative time). The present invention relates to an aqueous resin dispersion in which the strength of compression / bending of a cured cement mortar exhibits superior strength as compared with an unmixed cement mortar composition. Furthermore, since the cement mortar composition using the aqueous resin dispersion of the present invention has no hardening delay of cement, the above-described strength development is equal to or higher than that of the aqueous resin dispersion-free cement mortar composition. .

  Conventionally, emulsion / latex which is an aqueous resin dispersion has been blended for the purpose of improving the physical properties of cement mortar. By blending emulsion / latex, the bending strength of the cured product is improved, the adhesion to the ground concrete is improved, the water resistance and chemical resistance of the cured cement mortar is improved, neutralization prevention, and abrasion resistance Improvement of the nature has been attempted. Emulsion / latex used in cement mortar includes ethylene-vinyl acetate emulsion, styrene-butadiene latex, styrene- (meth) acrylate emulsion, (meth) acrylate emulsion, etc. . Among them, in applications that require durability, environmental resistance, chemical resistance, water resistance, weather resistance, etc., styrene- (meth) acrylate emulsions and (meth) acrylate emulsions are used as emulsions and latexes. Is particularly used.

In recent years, weight reduction of the cured cement mortar has been demanded, and the thickness of the cured cement mortar has been reduced. As a result, there is a strong demand for improvement in the bending and compressive strength of the cured cement mortar, and there is a strong demand for improvement in the aqueous resin dispersion blended therein. However, conventional styrene- (meth) acrylic ester emulsions and (meth) acrylic ester emulsions have improved bending and compressive strength compared to cement mortar without water resin dispersion, but currently required performance. Is not enough.
On the other hand, Patent Document 1 discloses an aqueous emulsion made by emulsion polymerization of two or more stages, in which an unsaturated monomer having one kind of ethylene oxide group is copolymerized in the outermost layer. is there. Although improvements to the water resistance and bending / compressive strength of the cured cement mortar are described, the presently required bending / compressive strength of the cured cement mortar is not sufficient.

Furthermore, in Patent Document 2, an unsaturated monomer having a carboxyl group and an unsaturated monomer selected from an acrylic ester and a methacrylic ester, and having a glass transition temperature of 220 to 270 K, are mixed with an ethylenically unsaturated monomer. There is a disclosure of a technology of a polymer emulsion obtained by emulsion polymerization using an emulsifier containing a molecule having a saturated bond and a polyoxyalkylene group. Even in the disclosed technique, the miscibility with cement and the adhesion to concrete are improved, but the improvement in bending and compressive strength is not sufficient.
JP-A-8-217513 JP-A-10-251313

  In the resin mortar composition containing cement and filler, the present invention has good blending stability, the cement hardens without delay, and the cured product has good bending and compressive strength and is good. It is an object of the present invention to provide a water-based resin dispersion that provides excellent environmental resistance and water resistance, and to provide a resin cement mortar composition containing the water-based resin dispersion.

  The present inventor uses multi-stage emulsion polymerization, specifies the monomer composition, and an aqueous resin dispersion in which the ratio of the ethylenically unsaturated carboxylic acid in the first stage and the last stage is in a specific range It is. Furthermore, it came to solve the said subject because the aqueous resin dispersion contains a specific alkali component. Furthermore, it has been found that by using the aqueous resin dispersion of the present invention in combination with a cement and a filler, it is effective to solve the above-mentioned problems in the cement mortar composition, and the present invention has been made.

That is, the present invention is as described below.
1. And one or more monomers selected from an ethylenically unsaturated carboxylic acid monomer (a), an aromatic vinyl monomer (b) and / or a (meth) acrylic acid ester monomer (c). An aqueous resin dispersion (1) obtained by emulsion polymerization of a monomer composition, wherein the aqueous resin dispersion (1) is obtained by emulsion polymerization of two or more stages and used in the first stage Ratio (a-final) / (a-1) of the ethylenically unsaturated carboxylic acid monomer (a-1) to be used and the ethylenically unsaturated carboxylic acid monomer (a-final) used in the final stage There 4-8 der is, and aqueous resin dispersion (1) of cement mortar aqueous resin dispersion which is characterized that you have to contain a basic alkali metal compound.
2. The aqueous resin dispersion for cement mortar according to (1) above, wherein the pH of the aqueous resin dispersion (1) is 5 to 12.
3. The aqueous resin dispersion (1) is obtained by two-stage emulsion polymerization, and the mass ratio of the first-stage and second-stage monomer compositions is 3/7 to 7/3 (1) ) Or the aqueous resin dispersion for cement mortar according to (2).
4. Monomer composition of the first stage is ethylenically unsaturated carboxylic acid monomer (a) 0.2-1.0 mass%, aromatic vinyl monomer (b) 0-80.0 mass% (Meth) acrylic acid ester monomer (c) 0 to 99.8% by mass, other monomers 0 to 50.0% by mass, and the second stage monomer composition is ethylenically unsaturated Carboxylic acid monomer (a) 1.0-5.0 mass%, aromatic vinyl monomer (b) 0-80.0 mass%, (meth) acrylic acid ester monomer (c) 0-99 The aqueous resin dispersion for cement mortar according to (3), which is 0.0% by mass and 0 to 50.0% by mass of other monomers.
5 . The filler (3) is 5 to 600 parts by mass with respect to 100 parts by mass of the cement (2), and the aqueous resin dispersion (1) 0.5 to 100 according to any one of the above (1) to (4). Resin cement mortar composition containing parts by mass (solid content) .

  The aqueous resin dispersion of the present invention has good blendability into cement mortar, has no delay in cement curing, and has an excellent effect in bending and compressive strength of the cured product.

The present invention will be specifically described below.
The aqueous resin dispersion of the present invention is 1 selected from an ethylenically unsaturated carboxylic acid monomer (a), an aromatic vinyl monomer (b) and / or a (meth) acrylic acid ester monomer (c). An aqueous resin dispersion (1) obtained by emulsion polymerization of a monomer composition containing at least one kind of monomer, and the aqueous resin dispersion (1) obtained by emulsion polymerization in two or more stages The mass ratio of the ethylenically unsaturated carboxylic acid monomer (a-1) used in the first stage to the ethylenically unsaturated carboxylic acid monomer (a-final) used in the last stage (a -Final) / (a-1) is 4-8.
By using the ethylenically unsaturated carboxylic acid monomer (a) in the aqueous resin dispersion (1) of the present invention, there is no problem in blendability with cement mortar and bending / compressive strength of the cured cement mortar.

Examples of the ethylenically unsaturated carboxylic acid monomer (a) used in the aqueous resin dispersion (1) of the present invention include acrylic acid, methacrylic acid, maleic acid monoester, fumaric acid monoester, and itaconic acid. Examples include ethylenically unsaturated monocarboxylic acids such as monoesters, and ethylenically unsaturated dicarboxylic acids such as itaconic acid, fumaric acid and maleic acid. One or more ethylenically unsaturated carboxylic acids selected from acrylic acid, methacrylic acid and itaconic acid are preferred.
Examples of the aromatic vinyl monomer (b) used in the aqueous resin dispersion (1) of the present invention include styrene, vinyl toluene, α-methyl styrene and the like. Styrene is preferred.

  Examples of the (meth) acrylic acid ester monomer (c) include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, Lauryl acrylate, benzyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl acrylate, butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, phenyl methacrylate, etc. Can be mentioned. Preferred are butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate.

  In addition to the above monomers, monomer components other than those described above can also be used in order to improve various qualities and physical properties required for the aqueous resin dispersion of the present invention. These monomers include (a) an amide group-containing vinyl monomer, (b) a hydroxyl group-containing vinyl monomer, (c) an epoxy group-containing vinyl monomer, and (d) a methylol group-containing vinyl monomer. (E) an alkoxymethyl group-containing vinyl monomer, (f) a cyano group-containing vinyl monomer, (to) a vinyl monomer having two or more radical polymerizable double bonds, H) Vinyl monomers having a hydrolyzable silyl group.

(I) Examples of the amide group-containing vinyl monomer include acrylamide, methacrylamide, N, N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic acid amide, maleimide and the like. Preferred are acrylamide and methacrylamide.

  (B) Examples of the hydroxyl group-containing vinyl monomer include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, polyethylene glycol acrylate, and polyethylene glycol methacrylate. Preferred are hydroxyethyl acrylate and hydroxyethyl methacrylate.

  (C) Examples of the epoxy group-containing vinyl monomer include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, methyl glycidyl acrylate, and methyl glycidyl methacrylate. Glycidyl methacrylate is preferred.

(D) Examples of the methylol group-containing vinyl monomer include N-methylolacrylamide, N-methylolmethacrylamide, dimethylolacrylamide, dimethylolmethacrylamide and the like.
(E) Examples of the alkoxymethyl group-containing vinyl monomer include N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-butoxymethylacrylamide, and N-butoxymethylmethacrylamide.
(F) Examples of the cyano group-containing vinyl monomer include acrylonitrile and methacrylonitrile.

  (G) Examples of vinyl monomers having two or more radical polymerizable double bonds include divinylbenzene, polyoxyethylene diacrylate, polyoxyethylene dimethacrylate, polyoxypropylene diacrylate, poly Oxypropylene dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, etc. Can be mentioned.

(H) Examples of vinyl monomers having hydrolyzable silyl groups include vinyl silane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- And methacryloxypropyltriethoxysilane.
Other vinyl monomers (Li) can also be used. For example, various vinyl monomers having a functional group such as amino group, sulfonic acid group, and phosphoric acid group, as well as vinyl acetate, vinyl propionate, vinyl versatate, vinyl pyrrolidone, methyl vinyl ketone, butadiene, ethylene, Propylene, vinyl chloride, vinylidene chloride and the like can be used as desired.

The aqueous resin dispersion (1) of the present invention is obtained by a usual emulsion polymerization method. There is no restriction | limiting in particular regarding the method of emulsion polymerization, A conventionally well-known method can be used. That is, in a dispersion system containing a monomer composition, a surfactant, a radical polymerization initiator and other additive components such as a chain transfer agent used as necessary in an aqueous medium, A method for polymerizing a body composition. In the emulsion polymerization, the composition of the monomer composition to be supplied is preferably two or more. By using two or more steps, there is no problem in the bending and compressive strength of the cement mortar cured product.
The supply of the monomer composition in two stages or more means that the first stage of the monomer composition is polymerized, and then the monomer composition is further supplied to perform the second stage polymerization. And repeat this. The supply of the monomer composition in the present invention is preferably two or three stages, more preferably two stages.

The mass ratio between the first-stage monomer composition (m-1) and the second-stage monomer composition (m-2) is not particularly limited, but (m-1) / (m-2) ) = 3/7 to 7/3 is preferable. When (m-1) / (m-2) = 3/7 or more, there is no delay in hardening of the cement mortar, and when it is 7/3 or less, there is no problem in the stability of cement mortar.
In the present invention, the mass ratio of the ethylenically unsaturated carboxylic acid monomer (a-1) used in the first stage to the ethylenically unsaturated carboxylic acid monomer (a-final) used in the last stage (a -Final) / (a-1) is preferably 4-8. When the mass ratio of (a-final) / (a-1) is 4 or more, there is no problem in the mixing stability of cement mortar, and when it is 8 or less, there is no delay in cement hardening. The mass ratio of (a-final) / (a-1) is preferably 5 to 7, and the final stage is more preferably the second stage.

  In the present invention, the preferred first-stage monomer composition is that the ethylenically unsaturated carboxylic acid (a-1) is 0.2 to 1.0% by mass, and the aromatic vinyl monomer (b-1). 0 to 80.0 mass%, (meth) acrylic acid ester monomer (c-1) is 0 to 99.8 mass%, and other monomers are 0 to 50.0 mass%. Further, the preferred second-stage monomer composition is 1.0 to 5.0% by mass of ethylenically unsaturated carboxylic acid (a-2) and 0% of aromatic vinyl monomer (b-2). -80 mass%, (meth) acrylic acid ester monomer (c-2) is 0-99.0 mass%, and other monomers are 0-50.0 mass%.

  In the first-stage monomer composition, when the ethylenically unsaturated carboxylic acid (a-1) is 0.2% by mass or more, there is no problem in the mixing stability of the cement mortar, and 1.0% by mass or less of the cement mortar is cured. There is no delay. More preferably, it is 0.2-0.8 mass%. When the aromatic vinyl monomer (b-1) is 80.0% by mass or less, there is no problem in durability of the cured cement mortar. When the (meth) acrylic acid ester monomer (c-1) is 99.8% by mass or less, there is no problem in the durability of the cured cement mortar.

  In the second-stage monomer composition, when the ethylenically unsaturated carboxylic acid (a-2) is 1.0% by mass or more, there is no problem in the mixing stability of the cement mortar, and 5.0% by mass or less of the cement mortar is cured. There is no delay. More preferably, it is 1.5-4.5 mass%. When the aromatic vinyl monomer (b-2) is 80.0% by mass or less, there is no problem in the durability of the cured cement mortar. When the (meth) acrylic acid ester monomer (c-2) is 99.0% by mass or less, there is no problem in durability of the cured cement mortar.

  The radical polymerization initiator used in the present invention is one that initiates addition polymerization of a monomer by radical decomposition with heat or a reducing substance, and any of inorganic initiators and organic initiators can be used. As such, water-soluble and oil-soluble polymerization initiators can be used. Examples of water-soluble polymerization initiators include peroxodisulfates, peroxides, water-soluble azobis compounds, peroxide-reducing agent redox systems, and the like. Peroxodisulfates include, for example, potassium peroxodisulfate ( KPS), sodium peroxodisulfate (NPS), ammonium peroxodisulfate (APS) and the like. Examples of peroxides include hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxymaleic acid, and succinic acid peroxide. Examples of water-soluble azobis compounds include 2,2-azobis (N-hydroxyethylisobutyramide), 2,2-azobis (2-amidinopropane) dihydrochloride, 4,4- And azobis (4-cyanopentanoic acid) and the like. For example, sodium sulfooxylate formaldehyde, sodium bisulfite, sodium thiosulfate, sodium hydroxymethanesulfinate, L-ascorbic acid, and salts thereof, cuprous salts, ferrous salts, etc. These reducing agents can also be used in combination with a polymerization initiator.

As a quantity of a radical polymerization initiator, 0.05-1 mass part of radical polymerization initiators can be used with respect to 100 mass parts of monomer compositions.
The surfactant used in the present invention refers to a compound having at least one hydrophilic group and one or more lipophilic groups in one molecule. Examples of the surfactant include an anionic surfactant and a nonionic surfactant. Examples of the anionic surfactant include non-reactive alkyl sulfate, polyoxyethylene alkyl ether sulfate, alkylbenzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfosuccinate, alkyl diphenyl ether disulfonate, and naphthalene. Examples include sulfonic acid formalin condensate, polyoxyethylene polycyclic phenyl ether sulfate, polyoxyethylene distyrenated phenyl ether sulfate, fatty acid salt, alkyl phosphate, polyoxyethylene alkylphenyl ether sulfate. . Examples of nonionic surfactants include non-reactive polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyethylene distyrenated phenyl ether, sorbitan fatty acid ester, polyoxyethylene. Examples include sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, alkylalkanolamide, polyoxyethylene alkylphenyl ether, and the like.

  In addition to these, a so-called reactive surfactant in which an ethylenic double bond is introduced into the chemical structural formula of a surfactant having a hydrophilic group and a lipophilic group may be used. Among the reactive surfactants, the anionic surfactant is, for example, an ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group or a sulfate ester group and a salt thereof, a sulfonic acid group, or an ammonium thereof. A compound having a group (ammonium sulfonate group or alkali metal sulfonate group) which is a salt or an alkali metal salt is preferable. For example, alkylallylsulfosuccinate (for example, Sanyo Kasei Co., Ltd., Eleminol (trademark) JS-2, JS-5, for example, Laumul (trademark) S-120, S-180A, S-180 manufactured by Kao Corporation), etc. ), For example, polyoxyethylene alkylpropenyl phenyl ether sulfate ester salt (for example, Aqualon (trademark) HS-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), for example, α- [1-[(allyloxy) methyl] -2 -(Nonylphenoxy) ethyl] -ω-polyoxyethylene sulfate ester salt (for example, Adekaria Soap (trademark) SE-1025N manufactured by Asahi Denka Kogyo Co., Ltd.), for example, ammonium = α-sulfonato-ω-1 -(Allyloxymethyl) alkyloxypolyoxyethylene (for example, Aqualon KH-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Etc., and styrene sulfonate.

Examples of reactive surfactants and nonionic surfactants include α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene (for example, Asahi Denka Kogyo Co., Ltd.). Adekaria soap NE-20, NE-30, NE-40, etc.), for example, polyoxyethylene alkylpropenyl phenyl ether (for example, Aqualon RN-10, RN-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) RN-30, RN-50, etc.).
As an amount of the surfactant, 0.1 to 3 parts by mass of an anionic surfactant and 0.1 to 30 parts by mass of a nonionic surfactant can be used with respect to 100 parts by mass of the monomer composition.

The surfactant may be added either during the polymerization or after the polymerization.
Examples of chain transfer agents include mercaptans such as n-butyl mercaptan, t-butyl mercaptan, n-octyl mercaptan, n-lauryl mercaptan, n-dodecyl mercaptan, disulfides such as tetramethylthuradium disulfide, carbon tetrachloride and the like. Halogenated derivatives, α-methylstyrene dimers and the like can be mentioned, and these can be used alone or in combination of two or more. N-dodecyl mercaptan is preferred.
As a quantity of a chain transfer agent, 0-1 mass part of chain transfer agents can be used with respect to 100 mass parts of monomer compositions.

In the present invention, the glass transition temperature in each stage of the copolymer in the aqueous resin dispersion (1) is preferably 0 to 40 ° C. When the glass transition temperature is 0 ° C. or higher, there is no problem with the stability of blending with cement mortar, and when it is 40 ° C. or lower, there is no problem with the bending / compression strength of the cured cement mortar. More preferably, the glass transition temperature of the copolymer is 5 to 35 ° C.
In the present invention, for example, when the aqueous resin dispersion (1) has two stages, the glass transition temperature of the copolymer can include the following. The glass transition temperature of the first stage copolymer has a lower limit of −10 ° C. and an upper limit of 40 ° C. Preferably, the lower limit is 0 ° C and the upper limit is 30 ° C. The glass transition temperature of the second stage copolymer has a lower limit of 0 ° C. and an upper limit of 60 ° C. Preferably, the lower limit is 20 ° C and the upper limit is 40 ° C.

The glass transition temperature of the copolymer referred to here can be estimated from the following equation from the glass transition temperature of the monomer homopolymer and the copolymerization ratio of the monomer.
1 / Tg = W1 / Tg1 + W2 / Tg2 +
Tg: Glass transition temperature (° K) of a copolymer comprising monomers 1, 2...
W1, W2 ···: Monomer 1, monomer 2, ··· mass fraction W1 + W2 + ··· = 1
Tg1, Tg2, ...: Glass transition temperature (° K) of homopolymer of monomer 1, monomer 2, ...
Homopolymers of the monomers used in the calculation Tg (° K) is described, for example, Polymer Handbook (J oh n Willey & Sons) . The numerical value used in this application is illustrated. The value in parentheses indicates the Tg of the homopolymer. Polystyrene (373 ° K), polymethyl methacrylate (378 ° K), polybutyl acrylate (219 ° K), polyethyl acrylate 2-ethylhexyl (205 ° K), polyacrylic acid (379 ° K), polymethacryl Acid (403 ° K), polyacrylonitrile (373 ° K), 2-hydroxyethyl polyacrylate (258 ° K), poly 2-hydroxyethyl methacrylate (328 ° K).

The polymerization temperature in this emulsion polymerization is usually selected in the range of 60 to 100 ° C., but the polymerization may be carried out at a lower temperature, for example, 20 to 40 ° C. by a redox polymerization method or the like.
The particle diameter of the aqueous resin dispersion (1) of the present invention is not particularly limited. The particle size control method can be adjusted by, for example, seed latex, surfactant use ratio, etc. In general, the higher the use ratio, the smaller the average particle size of the aqueous resin dispersion produced, and vice versa. The average particle size tends to increase. The seed latex may be polymerized in the same reaction vessel prior to the polymerization of the aqueous resin dispersion of the present invention, or seed latex polymerized in a different reaction vessel may be used. A preferable particle diameter is 50 to 400 nm, and more preferably 100 to 200 nm.

  The aqueous resin dispersion (1) of the present invention preferably contains a basic alkali metal compound. By containing a basic alkali metal compound, there is no problem in the bending / compressive strength of the cement mortar cured product. Content of a basic alkali metal compound is adjusting pH of the aqueous resin dispersion to the range of 5-12. A more preferred basic alkali metal content is one in which the pH of the aqueous resin dispersion is adjusted to 7-10.

  Examples of the basic alkali metal compound include alkali metal hydroxides, hydrogen carbonates, carbonates, and organic carboxylates. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. Examples of the bicarbonate and carbonate include sodium bicarbonate, sodium carbonate, potassium bicarbonate, and potassium carbonate. Examples of alkali metal organic carboxylates include sodium acetate, sodium oxalate, and sodium benzoate. Alkali metal hydroxides are preferable, and one or more alkali metal hydroxides selected from sodium hydroxide and potassium hydroxide are more preferable.

In addition to the basic alkali metal compound, other basic compounds may be added to the aqueous resin dispersion (1) of the present invention in order to maintain long-term dispersion stability. For example, amines such as ammonia and dimethylaminoethanol may be used.
Moreover, as solid content of an aqueous resin dispersion (1), it is preferable that it is 30-70 mass%.

  In order to improve the performance, the following materials may be blended in the aqueous resin dispersion (1) of the present invention. For example, water-soluble resins, solvents, plasticizers, antifoaming agents, thickeners, leveling agents, dispersants, coupling agents, colorants, water resistance agents, lubricants, pH adjusters, preservatives, inorganic pigments, organic Examples include pigments, surfactants, and crosslinking agents such as epoxy compounds, polyvalent metal compounds, and isocyanate compounds. In addition, water reducing agents and fluidizing agents (polycarboxylic acid, melamine sulfonic acid, naphthalene sulfonic acid, lignin sulfonic acid, etc.), shrinkage reducing agents (glycol ether, polyether, etc.), cold resistance (calcium chloride) , Silicates, etc.), waterproofing agents (stearic acid, silicones, etc.), rust inhibitors (phosphates, nitrites, etc.), viscosity modifiers (methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, etc.), setting modifiers (phosphoric acid) Salt, etc.) may be blended.

  Examples of the cement (2) used in the present invention include ordinary Portland cement and early strength specified in JIS R5210 (Portland cement), R5211 (blast furnace cement), R5212 (silica cement), R5213 (fly ash cement), for example. Portland cement, ultra-high strength Portland cement, moderately hot Portland cement, sulfate-resistant Portland cement, blast furnace cement, silica cement, fly ash cement can be used, and the Japan Cement Association has a common sense of cement (issued in March 1994) Special cement, white Portland cement, cement-based solidified material, alumina cement, super-hard cement, colloid cement, yui cement, geothermal well cement, expanded cement, and other special cements The instrument can be used.

  As the filler (3) used in the present invention, sand, quartz sand, cold water sand, natural and artificial lightweight aggregates and the like generally used for cement mortar can be used, and inorganic or organic pigments can also be used. Examples of inorganic pigments include various metal oxides such as magnesium, calcium, zinc, barium, titanium, aluminum, antimony, and lead, hydroxides, sulfides, carbonates, sulfates, and silicate compounds. Specific examples include calcium carbonate, kaolin, talc, titanium dioxide, aluminum hydroxide, silica, gypsum, barite powder, alumina white, and satin white. Examples of organic pigments include solid polymer fine powders such as polystyrene, polyethylene, and polyvinyl chloride.

The amount used in the present invention is 5 to 600 parts by mass of the filler (3) with respect to 100 parts by mass of the cement (2), 0.5 to 100 parts by mass (solid content) of the aqueous resin dispersion (1) of the present invention. It is. When the filler is 5 parts by mass or more, there is no problem in bending and compressive strength. On the other hand, at 600 parts by mass or less, there is no problem in water resistance of the cured cement mortar. Preferably it is the range of 50-500 mass parts.
Further, when the aqueous resin dispersion (1) of the present invention is 0.5 parts by mass or more, there is no problem in the bending and compressive strength of the cement cured product, and when it is 100 parts by mass or less, there is no problem in the mixing stability in cement mortar. Preferably it is the range of 1-80 mass parts. More preferably, it is the range of 2-50 mass parts.
The blending method of the resin cement mortar composition of the present invention is not particularly limited. The aqueous resin dispersion, cement, and filler may be mixed together or sequentially.

The molding method of the resin cement mortar composition of the present invention is not particularly limited. For example, the resin cement mortar composition may be put into a frame made of a wooden frame or the like.
The resin cement mortar composition of the present invention is not limited to the above components, and any other components may be added. For example, water reducing agents and fluidizing agents (polycarboxylic acid type, melamine sulfonic acid type, naphthalene sulfonic acid type, lignin sulfonic acid type, etc.) listed above, shrinkage reducing agents (glycol ether type, polyether type, etc.), cold resistance Agent (calcium chloride, silicate, etc.), waterproofing agent (stearic acid, silicone, etc.), rust inhibitor (phosphate, nitrite, etc.), viscosity modifier (methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, etc.), setting adjustment Agents (phosphates, etc.), expansion agents (etringite, lime, etc.), colorants (iron oxide, chromium oxide, etc.), antifoaming agents (silicon, mineral oils, etc.), reinforcing materials (steel fibers, glass, etc.) Fibers, synthetic fibers, etc.), surfactants (anions, nonions, cationics, etc.), thickeners, leveling agents, film forming aids, solvents, plasticizers, dispersants, water resistance agents, lubrication Etc. The.

  Moreover, you may mix | blend emulsion / latex other than the aqueous resin dispersion of this invention with the resin cement mortar composition of this invention. Examples thereof include vinyl acetate emulsion, ethylene-vinyl acetate emulsion, urethane emulsion, styrene-butadiene latex, acrylonitrile-butadiene latex and the like. Further, a re-emulsification type powder resin may be blended.

The present invention will be described based on examples. The embodiment of the present invention is not limited by these. Note that. The number of parts in the examples is the number of parts as they are (that is, the aqueous resin dispersion contains water itself). “Part” means “part by mass” unless otherwise specified.
Each characteristic was calculated | required as follows.
(1) Workability of resin cement mortar JIS A 1171-2000 (Test method for polymer cement mortar) Resin cement mortar was prepared in accordance with the method of adjusting the polymer cement mortar by hand-kneading. 20-30 parts by mass of water was added so that the flow value of the resin mortar composition was 170 ± 5 mm.
After adjusting the resin cement mortar shown in Table 3 and Table 4, it was left as it was at 20 degreeC, and the case where it could stir for 2 hours or more was set as pass. In addition, this evaluation shows the mixing | blending stability and simplicity to mortar.

(2) Bending / compressive strength of cured resin cement mortar The measurement was performed according to the 7.2 bending strength compressive strength test of JIS A 1171-2000 (test method for polymer cement mortar).
However, the curing condition was set to 14 days after the underwater curing.

(3) Durability of cured resin cement mortar JIS A6909 (finishing coating material for construction) 7.11 The cured resin cement mortar was left under the repeated test conditions of warm and cool, and 40 cycles of warm and cool cycles were performed. Thereafter, the bending strength was measured. This evaluation shows the environmental resistance of the mortar cured product.
An aqueous resin dispersion was obtained using the monomer compositions shown in Tables 1 and 2. The specific method is as follows.
In the first-stage monomer composition shown in Tables 1 and 2, 50 parts by mass of 20% aqueous solution of Emulgen 150 (manufactured by Kao Corporation, polyoxyethylene alkyl ether), Emar D-3-D (Kao Corporation) 20 parts by weight of 25% aqueous solution of sodium polyoxyethylene alkyl ether sulfate), 1.2 parts by weight of ammonium peroxodisulfate, and 300 parts by weight of water were added and stirred with a homomixer to prepare a pre-emulsion solution.

  Moreover, the pre-emulsion liquid of the 2nd step | paragraph monomer composition was produced similarly to the 1st step | paragraph monomer composition.

Separately, a polymerization vessel equipped with a stirrer and a temperature control jacket was charged with 10 parts by weight of 25% aqueous solution of Emar D-3-D and 480 parts by weight of water, the internal temperature was raised to 80 ° C., and then ammonium peroxodisulfate An aqueous solution in which 0.25 part by mass was dissolved in 30 parts by mass of water was added. Five minutes after the addition of the aqueous ammonium peroxodisulfate solution, the first-stage pre-emulsion was added at a constant flow rate over 2 hours. Polymerization was continued for 0.5 hour at the same temperature. Next, the second stage pre-emulsion was added at a constant flow rate over 2 hours. Polymerization was continued at the same temperature for 1.0 hour.
Then, it cooled and added 10% concentration sodium hydroxide aqueous solution, and adjusted to pH8. Next, filtration was performed using a 200-mesh wire mesh, water was blended so that the solid content was 45%, and an aqueous resin dispersion was obtained.

[Examples 1 to 8]
Adjusting the resin cement mortar compositions described in Table 3 and Table 4, a. Workability, b. The bending strength and compressive strength of the cured product, c. The durability of the cured product was evaluated. The evaluation results are shown in Tables 3 and 4.
The raw materials used are as follows.
Cement: Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
Filler: Standard sand described in JIS R 5201 10.2.

[Comparative Examples 1-3]
Adjusting the resin cement mortar composition described in Table 5; a. Workability, b. The bending strength and compressive strength of the cured product, c. The durability of the cured product was evaluated in the same manner as in the examples. The evaluation results are shown in Table 5.
As can be seen from Table 5, the durability in Comparative Examples 1 and 2 was poor, and the workability and durability in Comparative Example 3 were poor.

  The use of the resin cement mortar composition of the present invention is not particularly limited. For example, building waterproofing materials, repair materials, nursing materials, finishing materials, foundation conditioning materials, tile bonding, rust prevention, grout, putty, self-leveling floors, wear-resistant floors, foundation concrete parts It can be suitably used in fields such as coating materials, deck coverings, elastic mortars, cement moldings, paints, and anticorrosion.

Claims (5)

And one or more monomers selected from an ethylenically unsaturated carboxylic acid monomer (a), an aromatic vinyl monomer (b) and / or a (meth) acrylic acid ester monomer (c). An aqueous resin dispersion (1) obtained by emulsion polymerization of a monomer composition, wherein the aqueous resin dispersion (1) is obtained by emulsion polymerization of two or more stages and used in the first stage Ratio (a-final) / (a-1) of the ethylenically unsaturated carboxylic acid monomer (a-1) to be used and the ethylenically unsaturated carboxylic acid monomer (a-final) used in the final stage There 4-8 der is, and aqueous resin dispersion (1) of cement mortar aqueous resin dispersion which is characterized that you have to contain a basic alkali metal compound.   The aqueous resin dispersion for cement mortar according to claim 1, wherein the pH of the aqueous resin dispersion (1) is 5 to 12.   The aqueous resin dispersion (1) is obtained by two-stage emulsion polymerization, and the mass ratio of the first-stage and second-stage monomer compositions is 3/7 to 7/3. Or the aqueous resin dispersion for cement mortar according to 2.   The first-stage monomer composition is an ethylenically unsaturated carboxylic acid monomer (a) 0.2 to 1.0 mass%, an aromatic vinyl monomer (b) 0 to 80.0 mass%, ( (Meth) acrylic acid ester monomer (c) 0 to 99.8% by mass, other monomers 0 to 50.0% by mass, and the second-stage monomer composition is an ethylenically unsaturated carboxylic acid Monomer (a) 1.0-5.0 mass%, aromatic vinyl monomer (b) 0-80.0 mass%, (meth) acrylic acid ester monomer (c) 0-99.0 The aqueous resin dispersion for cement mortar according to claim 3, wherein the content is 0% by mass and 0 to 50.0% by mass of other monomers. The filler (3) is 5 to 600 parts by mass with respect to 100 parts by mass of the cement (2), and 0.5 to 100 parts by mass of the aqueous resin dispersion (1) according to any one of claims 1 to 4. A resin cement mortar composition containing a solid content).