JP2001348529A - Water-based coating composition, water vapor permeable film and method for forming water vapor permeable film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a water-based coating composition capable of forming a film excellent in water vapor permeability and water permeation preventing properties in the initial stage and for a long period and a water vapor permeable film obtained therefrom. SOLUTION: This water-based coating composition is characterized as comprising 100 pts.wt. of the solid content composed of (a) 15-47 pts.wt. of an aqueous dispersion of an alkylalkoxysilane, (b) 8-24 pts.wt. of a fluorine emulsion, (c) 9-27 pts.wt. of a fluorine-pendant acrylic polymer and (d) 1-35 pts.wt. of a pigment in the water-based coating composition. The water vapor permeable film is characterized in that the film is obtained by coating the above water- based coating composition and has 30-40 g/m2 amount of water vapor permeation based on 24 h at 23 deg.C and 50% humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous coating composition, and more particularly to an aqueous coating composition capable of forming a coating film having excellent moisture permeability and a moisture-permeable coating film obtained therefrom.

[0002]

2. Description of the Related Art In recent years, the durability of concrete buildings has been improved by forming a stretchable elastic coating film having crack tracing properties and carbon dioxide gas barrier properties on the surface thereof. On the other hand, while this stretch type elastic coating film is excellent in preventing water permeation,
It was known that it had poor moisture permeability. In particular, when this stretchable elastic coating is formed on the concrete of the base part which is the foundation of the house, the moisture in the base part cannot escape to the outside efficiently, so that not only the concrete of the base deteriorates, The house built on the base itself may be deteriorated due to dew condensation or mold.

[0003] Commercially available water repellents have high moisture permeability immediately after formation and a small amount of water permeation, but their performance is significantly deteriorated due to weather resistance. A repainting was necessary.

To solve such a problem, Japanese Patent Laid-Open Publication No.
No. 9270 discloses a highly moisture-permeable aqueous coating composition in which the weight ratio of a water-dispersed acrylic resin emulsion to hydrophilic microparticles is specified. The coating film obtained from this coating composition had moisture permeability because a moisture passage was formed in the coating film despite being a stretchable elastic coating film having a dry film thickness of about 1 mm. .

[0005] However, when the coating film becomes thin with the passage of time, there is a possibility that the passage of the moisture is blocked and the moisture permeability is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention provides a water-based coating composition capable of forming a coating film having excellent initial and long-term moisture permeability and excellent water-permeability, and a moisture-permeable coating film obtained therefrom. It is intended to do so.

[0007]

According to the present invention, 100 parts by weight of a solid content in an aqueous coating composition is 15 to 47 parts by weight of an aqueous dispersion of an alkylalkoxysilane (a), and 8 to 24 parts by weight of a fluorine emulsion (b). An aqueous coating composition comprising: 9 parts to 27 parts by weight of a fluorine pendant acrylic polymer (c) and 1 to 35 parts by weight of a pigment (d). Further, the composition preferably contains 0.1 to 2 parts by weight of a biological inactive agent, and preferably contains a total of 3 to 10% by weight of a polar organic solvent and / or a thickener.

[0008] The present invention also relates to a coating film obtained by applying the above aqueous coating composition to a substrate, wherein the coating film has a temperature of 23 ° C and a humidity of 50 ° C.
% Is 30 to 40 g / m per 24 hours.
² is a moisture-permeable coating film. here,
The water permeability of the coating is preferably less than 0.5 ml / 24 hours, and the water contact angle is preferably 100 degrees or more. Furthermore, the dry film thickness of the coating film may be 15 to 120 μm.

Further, the present invention is a method for forming a moisture-permeable coating film, characterized by obtaining a moisture-permeable coating film by applying the above aqueous coating composition to a porous substrate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Aqueous coating composition The aqueous coating composition of the present invention has a solid content of 100 parts by weight of an alkyl alkoxysilane aqueous dispersion (a) 15 to
47 parts by weight, a fluorine emulsion (b) 8 to 24 parts by weight, a fluorine pendant acrylic polymer (c) 9 to 27
Parts by weight, and 1 to 35 parts by weight of the pigment (d).

It is considered that the aqueous dispersion (a) of the alkylalkoxysilane contained in the aqueous coating composition of the present invention penetrates the base material to form a water-permeable coating when the coating material is applied to the base material. Specific examples of the aqueous dispersion (a) of the alkylalkoxysilane include an alkylalkoxysilane dispersed in water with an emulsifier. Here, the alkylalkoxysilane in the present invention means alkylalkoxysilane and its condensate.

Specific examples of the above alkylalkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyl Triethoxysilane, pentyltrimethoxysilane,
Pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, Decyltriethoxysilane,
Undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxy Silane, pentadecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, heptadecyltrimethoxysilane,
Heptadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, nonadecyltrimethoxysilane, nonadecyltriethoxysilane, eicosyltrimethoxysilane, alkyltrialkoxysilanes such as eicosyltriethoxysilane, dimethyldimethoxysilane, Examples thereof include dialkyl dialkoxysilanes such as octylmethyldimethoxysilane and octadecylmethyldimethoxysilane.

The emulsifiers used for dispersion include:
Specific examples include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, and amphoteric emulsifiers.

Examples of such aqueous dispersions (a) of alkoxysilanes which are commercially available include tight silane series manufactured by Toyo Ink Mfg. Co., Ltd. and Aquaproof manufactured by Toa Gosei Co., Ltd.

The aqueous coating composition of the present invention has a solid content of 10%.
When the solid content of the aqueous dispersion of the alkylalkoxysilane (a) is less than 15 parts by weight in 0 part by weight, the effect of the water permeation preventing coating becomes insufficient, and when it exceeds 47 parts by weight, Not only is it not economical, but also the coating composition tends to separate.

The solid content of the aqueous dispersion (a) of alkoxysilane in the present invention means an active ingredient, not a heating residue.

The fluorine emulsion (b) contained in the aqueous coating composition of the present invention is a so-called binder component, and when the coating is applied to a base material, the emulsion particles fuse together to form a film, and the above-mentioned alkylalkoxy is formed. It is considered that the anti-water-permeable coating obtained by the aqueous dispersion (a) of silane functions to protect and sustain sunlight-rays and rain.

The fluoroemulsion (b) is obtained by copolymerizing a fluoroolefin with a particle of a fluoropolymer obtained by polymerizing a fluoroolefin or a monomer copolymerizable with the fluoroolefin. It is preferably a fluorinated seed polymer obtained by seed-polymerizing a monomer having a reactive α, β-unsaturated group in the presence of fluoropolymer particles.

The fluorinated polymer in the fluorine emulsion (b) is obtained by copolymerizing a monomer containing 70 to 95 mol% of vinylidene fluoride and 5 to 30 mol% of chlorotrifluoroethylene. More preferably, it is a fluorinated seed polymer obtained by seed polymerization of an acrylate ester and / or a methacrylate ester in the presence of the fluoropolymer particles to be obtained.

Examples of the monomer having a reactive α, β-unsaturated group include acrylates such as methyl acrylate, butyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate, methyl methacrylate, and methacrylic acid. Methacrylates such as butyl acrylate and polyoxyethylene methacrylate, organosilicon compounds having a reactive α, β-unsaturated group such as γ-methacryloyloxypropyl-trimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, styrene And vinyl esters such as vinyl acetate, vinyl benzoate (vinyl ester manufactured by Shell Co., trade name: Beova), and the like, such as film-forming property and weather resistance. Acrylic ester, methacrylic from the point Esters, reactive alpha, beta-
Organic silicon compounds having an unsaturated group, vinyl esters are preferred, butyl acrylate, methyl methacrylate,
Polyoxyethylene methacrylate and γ-methacryloyloxypropyl-trimethoxysilane are more preferred.

The average particle size of such a fluorine emulsion (b) is, for example, 50 to 250 nm, and 8
It is preferably from 0 to 200 nm. When the average particle diameter is less than 50 nm, the viscosity of the emulsion increases, a high-concentration emulsion cannot be obtained, and the solid content concentration of the obtained paint may decrease. The particles may settle and solidify.

Examples of commercially available products include Ziffle series manufactured by Daikin Industries, and Lumiflon series manufactured by Asahi Glass.

The aqueous coating composition of the present invention has a solid content of 10%.
If the solids content of the fluorine emulsion (b) is less than 8 parts by weight at 0 parts by weight, the durability of the water-permeation-preventing coating will be insufficient. The wetness decreases.

It is considered that the fluorinated pendant acrylic polymer (c) contained in the aqueous coating composition of the present invention imparts a water-repellent effect to the surface and the inside of the coating film when formed.
Such a fluorine pendant acrylic polymer (c)
Is preferably a copolymer of a perfluoroalkyl group-containing ethylenically unsaturated monomer alone or with another monomer. Examples of the perfluoroalkyl group-containing ethylenically unsaturated monomer include, for example, compounds represented by the following chemical formula.

[0025]

Embedded image

In the formula, R _f represents an alkyl group having 4 to 2 carbon atoms.
Represents a 0 perfluoroalkyl group. R ¹ represents hydrogen or an alkyl group having 1 to 10 carbon atoms. R ² has 1 to 1 carbon atoms
Represents 10 alkylene groups. The R ³ represents a hydrogen or a methyl group. R ⁴ represents an alkyl group having 1 to 17 carbon atoms.
n represents an integer of 1 to 10, and m represents an integer of 0 to 10.

Examples of other monomers copolymerizable with the above-mentioned perfluoroalkyl group-containing ethylenically unsaturated monomer include (meth) alkyl having 1 to 20 carbon atoms in the alkyl group.
Alkyl acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol di (meth) acrylate,
N-methylolacrylamide, styrene, α-methylstyrene, p-methylstyrene, a vinyl alkyl ether having an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl vinyl ether having an alkyl group having 1 to 20 carbon atoms,
Vinyl alkyl ketone having an alkyl group of 1 to 20 carbon atoms, maleic anhydride, butadiene, isoprene, chloroprene; silyl group-containing vinyl monomer such as vinyltriethoxysilane, γ- (methacryloxypropyl) trimethoxysilane Can be mentioned.

Such a product is dissolved or dispersed in an organic solvent or an aqueous medium, and commercially available products include Unidyne TG-652 and Unidyne TG-66.
4, Unidyne TG-410 (all manufactured by Daikin Industries, Ltd.) and the like.

The solid content of the aqueous coating composition of the present invention is 10%.
When the solid content of the fluorine pendant acrylic polymer (c) at 0 parts by weight is less than 9 parts by weight, the water repellency of the coating film becomes insufficient. It becomes difficult to form the same type or different types of coating films one upon another.

The pigment (d) contained in the aqueous coating composition of the present invention imparts high moisture permeability to the entire coating film obtained. Specific examples of such a pigment (d) include extender pigments and color pigments. When the obtained aqueous coating composition is used as a top coat, it is preferably a color pigment from the viewpoint of aesthetic appearance. .

Examples of the extender include calcium carbonate, barium sulfate, clay, and talc.

Examples of the coloring pigment include, for example, organic pigments such as azo chelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, and the like.
Perinone pigments, perylene pigments, dioxane pigments,
Examples thereof include quinacridone-based pigments, isoindolinone-based pigments, metal complex pigments, and the like, and inorganic-based pigments include yellow lead, yellow iron oxide, red iron oxide, carbon black, and titanium dioxide.

The aqueous coating composition of the present invention has a solid content of 10%.
If the solids content of the pigment (d) in 0 parts by weight is less than 1 part by weight, the resulting coating film has insufficient moisture permeability, and if it exceeds 35 parts by weight, the resulting coating film has water repellency. Decrease.

Further, the aqueous coating composition of the present invention contains 0.1% of a biologically inactive agent per 100 parts by weight of the solid content of the coating composition.
To 2 parts by weight. The biological inactivator,
The purpose of the present invention is to improve the effect of suppressing the occurrence of mold and the like on the surface of a coating film obtained by the aqueous coating composition of the present invention. Examples of the biological inactivator include, for example, an antialgal agent, an antifungal agent,
The well-known thing used for aqueous paints, such as a preservative, can be illustrated.

When the aqueous coating composition of the present invention contains the above-mentioned biologically inactive agent, if the amount of the biologically inactive agent is less than 0.1 part by weight, the inactive effect may be insufficient.
When the amount is more than the weight part, the effect corresponding thereto cannot be obtained, and there is a possibility that it is not economical.

The aqueous coating composition of the present invention may contain a polar organic solvent and / or a thickener in a total amount of 3 to 10% by weight based on the whole coating composition.

The above-mentioned polar organic solvent and / or thickener is for facilitating recoating with the aqueous coating composition of the present invention.

As the polar organic solvent, alcohols having 6 or less carbon atoms are preferable. For example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, i-butanol, t-butyl alcohol, ethylene glycol, propylene Glycol,
Examples thereof include butyl diglycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol. Ethanol,
Examples thereof include isopropyl alcohol, n-butanol and butyl diglycol, and isopropyl alcohol, ethylene glycol and butyl diglycol from the viewpoint of less generation of odor. As described above, it is preferable that the polar organic solvent is used by variously selecting and mixing these organic solvents according to the purpose.

When the aqueous coating composition of the present invention contains the above-mentioned polar organic solvent, when the content of the polar organic solvent is less than 3% by weight with respect to the above-mentioned aqueous coating composition, the effect corresponding to the improvement is small. If it exceeds 10% by weight, odor may be generated.

Examples of the above thickener include cellulose thickeners such as viscose, methylcellulose, ethylcellulose and hydroxyethylcellulose, and alkali thickeners such as sodium polyacrylate, polyvinyl alcohol and carboxymethylcellulose. Polyvinyl alcohol, associative thickeners such as polyethylene oxide, clay-based thickeners such as montmorillonite, and the like, from the viewpoint of storage stability, cellulose-based,
An alkali thickening type is preferable, and a cellulosic type is most preferable. Tylose MH and Tylose H (both manufactured by Hoechst) and the like are commercially available as the above-mentioned celluloses. Primal ASE-60 and Primal ASE are commercially available as alkali-thickened types. Examples thereof include TT-615, Primal RM-5 (both manufactured by Rohm & Haas), Euker Polyforb (manufactured by Union Carbite), and the like. These are preferably used by selecting and mixing the above-mentioned thickeners variously according to the purpose.

When the water-based coating composition of the present invention contains the above-mentioned thickener, the thickener for the water-based coating composition is 3
If the amount is less than 10% by weight, the effect corresponding to the improvement is small. If the amount exceeds 10% by weight, the water repellency of the obtained coating film may be reduced.

When the aqueous coating composition of the present invention contains both the polar organic solvent and the thickener, the total amount is preferably 3 to 10% by weight based on the coating composition. .

Further, the aqueous coating composition of the present invention can contain various additives well known by those skilled in the art, such as a film-forming aid, an ultraviolet ray inhibitor, and a light stabilizer, in addition to the above components. .

The aqueous coating composition of the present invention can be obtained by stirring and mixing the above components using a stirrer such as a disper well known to those skilled in the art.

The moisture-permeable coating film of the present invention is a coating film obtained by applying the above-mentioned water-based coating composition, and is obtained at 23 ° C. and 50% humidity.
The moisture permeation amount per 4 hours is 30 to 40 g / m ² .

The moisture permeability can be determined in accordance with ASTM-E96-66. For example, a sponge is put into a 100 cc polycup filled with an appropriate amount of water to sufficiently absorb water, and a test plate having a coating film formed thereon so that the sponge is in contact with the coating film is placed over the polycup, and the temperature is set at 23 ° C. and a humidity of 50%.
% By measuring the amount of weight loss at regular time intervals by setting the chamber in a chamber maintained at%. The moisture permeability is 30 g / m ²
If less than, when this coating is formed on the building wall,
There is no place for moisture in the building to escape, and the members in the building are degraded. If it exceeds 40 g / m ² , the water permeability described later increases.

The water permeability of the moisture-permeable coating film of the present invention is
It is preferably less than 0.5 ml / 24 hours.
More preferably, it is less than 3 ml / 24 hours. The water permeability can be determined by a method based on JIS-A-6910. When the above water permeability is 0.5 ml or more / 24 hours, the waterproofness becomes insufficient, water that has entered the base material cannot be stopped by the coating film, water leaks out to the coating film surface, and There is a risk of causing deterioration and generation of mold and the like.

Further, the water-permeable coating film of the present invention preferably has a water contact angle of 100 ° or more on its surface, preferably 10 ° or more.
More preferably, it is 0 to 125 degrees.

The water contact angle is determined by, for example, using a contact angle meter CA-Z manufactured by Kyowa Interface Chemical Co., at 23 ° C. and room temperature, dropping about 1 cc of water onto the coating film, It can be determined by a method well known by those skilled in the art, such as a method of measuring a contact angle with water. When the water contact angle is less than 100 degrees, the water repellency of the coating film is low. Therefore, when this coating film is formed on a building wall, rain stains and dirt streaks are conspicuous, and 125 degrees. If it exceeds, the water repellency of the coating film is too high, so that it may be difficult to further apply the same or different coating material on the coating film.

Method for forming a moisture-permeable coating film The method for forming a moisture-permeable coating film of the present invention is characterized in that a moisture-permeable coating film is obtained by applying the above aqueous coating composition to a porous substrate. It is.

Examples of the porous substrate include concrete, mortar, slate plate and the like. In addition, as an application method, for example, a brush, a roller, a spray, an airless spray, or the like can be used.

The coating conditions are not particularly limited.
It is preferably from 150 to 600 g / m ² . After coating, a coating film can be obtained by drying at room temperature. Drying time varies depending on environmental conditions, etc.
Preferably, it is three days. The film thickness of the dried coating film thus obtained is, for example, 15 to 120 μm.

[0053]

EXAMPLES Production Example 1 Production of white pigment-dispersed paste Deionized water 17.0 parts by weight Water-soluble styrene-acrylic resin 1.5 parts by weight (manufactured by Nippon Paint Co., Ltd., resin solid content acid value 190, number average molecular weight 7,000, Resin solid content 30% by weight) Aqueous acrylic dispersant 2.9 parts by weight 25% aqueous ammonia 0.2 parts by weight Taipaque CR-95 69.0 parts by weight (Titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.) The above raw materials were charged in a vessel. Then, after stirring and mixing with a disper, an appropriate amount of glass beads was added and dispersed with a sand grind mill to obtain a white pigment-dispersed paste.

Production Example 2 Production of Ocher Color Pigment Dispersion Paste 18.0 parts by weight of deionized water 22.0 parts by weight of water-soluble acrylic resin (Nippon Paint Co., Ltd., resin solid content acid value 75, number average molecular weight 4000, resin solid content 30% by weight) Aqueous silicone antifoaming agent 0.6 parts by weight TAROX LL-XLO 40.0 parts by weight (synthetic iron oxide manufactured by Titanium Industry Co., Ltd.) Calcium carbonate 8.0 parts by weight S-517 10.0 parts by weight ( After the above raw materials were charged into a vessel and stirred and mixed with a disper, an appropriate amount of glass beads were added, and the mixture was dispersed with a sand grind mill. An ocher color pigment dispersion paste was obtained.

Production Example 3 Production of black pigment-dispersed paste 20.0 parts by weight of deionized water 50.0 parts by weight of a water-soluble acrylic resin (manufactured by Nippon Paint Co., Ltd., resin solid content acid value 75, number average molecular weight 4000, resin solid content) 30% by weight) Aqueous silicone antifoaming agent 0.7 parts by weight MA-100 19.0 parts by weight (carbon black manufactured by Mitsubishi Chemical Corporation) 8.0 parts by weight of calcium carbonate After charging the above raw materials in a vessel, stirring with a disper. After mixing, an appropriate amount of glass beads was added and dispersed by a sand grind mill to obtain a black pigment-dispersed paste.

Production Example 4 Production of Indian Red Pigment Dispersion Paste 11.0 parts by weight of deionized water 28.0 parts by weight of water-soluble acrylic resin (Nippon Paint Co., Ltd., resin solid content acid value 75, number average molecular weight 4000, resin Solid content 30% by weight) Aqueous silicone defoamer 0.6 parts by weight Bengala CM-25P 50.0 parts by weight (iron oxide manufactured by Nippon Bengala) S-517 10.0 parts by weight (Nippon Paint Co., Ltd. cellulose-based increase) After mixing the above raw materials in a vessel, stirring and mixing with a disperser, adding an appropriate amount of glass beads and dispersing with a sand grind mill, an Indian red pigment dispersion paste is obtained. Obtained.

Example 1 S-517 varnish (cellulose thickener manufactured by Nippon Paint Co., Ltd., solid content: 2.5% by weight) in 32.0 parts by weight of deionized water
Was added and stirred, and 23.5 parts by weight of Tight Silane Super Z (aqueous dispersion of alkoxysilane manufactured by Toyo Ink Mfg. Co., Ltd., 60% by weight) was added thereto, and Zeffle SE-405 (Daikin Industries, Ltd.) Company-made fluorine emulsion,
Solid content 50% by weight) 12.0 parts by weight, diethyl adipate (film-forming aid) 2.7 parts by weight, Unidyne TG-410
(Fluorine pendant acrylic polymer manufactured by Daikin Industries, solid content 18% by weight) 13.5 parts by weight, diethylene glycol monobutyl ether 3.0 parts by weight, isopropyl alcohol 1.0 part by weight, SYLGARD-309
(Toray Dow Corning silicone additive) 0.1
By weight, 0.05 parts by weight of Primal TT-615 (alkali thickening type thickener manufactured by Rohm & Haas Co.) was added while stirring was continued to obtain a clear liquid. After adding 0.05 parts by weight of 25% ammonia water to the obtained clear liquid and stirring, 8.7 parts by weight of the white pigment paste obtained in Production Example 1 and the ocher color obtained in Production Example 2 were further added. 0.9 parts by weight of the pigment paste, 0.3 parts by weight of the black pigment paste obtained in Production Example 3 and 0.1 parts by weight of the Indian pigment dispersion paste were added, and the mixture was stirred. An aqueous coating composition 1 was obtained.

Example 2 S-517 varnish (cellulose thickener manufactured by Nippon Paint Co., 2.5% by weight solid content) in 22.9 parts by weight of deionized water
Was added and stirred, and 23.5 parts by weight of Tight Silane Super Z (aqueous dispersion of alkoxysilane manufactured by Toyo Ink Mfg. Co., Ltd., 60% by weight) was added thereto, and Zeffle SE-405 (Daikin Industries, Ltd.) Company-made fluorine emulsion,
12.0 parts by weight, 2.7 parts by weight of diethyl adipate, Unidyne TG-410 (fluorine pendant acrylic polymer manufactured by Daikin Industries, solid content 18)
13.5 parts by weight) and 3.0 parts by weight of diethylene glycol monobutyl ether were added while stirring was continued to obtain a clear liquid. After adding 0.05 parts by weight of 25% aqueous ammonia to the obtained clear liquid and stirring, 8.0 parts by weight of the white pigment paste obtained in Production Example 1 and the ocher color obtained in Production Example 2 were further added. 1. Pigment paste
5 parts by weight of the black pigment paste obtained in Production Example 3 was added to 0.1 part by weight.
6 parts by weight, 0.1 part by weight of an Indian color pigment-dispersed paste, 8% osmos N aqueous solution (clay thickener manufactured by Shiraishi Industry Co., Ltd.) and Silcarite NP (clay manufactured by Takehara Chemical Co., Ltd.) 2
0.0 parts by weight was added and stirred to obtain an aqueous coating composition 2 having a heating residue of 28% by weight.

Example 3 The same procedure as in Example 2 was repeated except that 0.3 part by weight of Monicide WG (a biological inactivator manufactured by Takeda Pharmaceutical Company, solid content: 28% by weight) was added. % By weight of the aqueous coating composition 3 was obtained.

Comparative Example 1 S-517 varnish (cellulose thickener manufactured by Nippon Paint Co., 2.5% by weight solid content) in 50.0 parts by weight of deionized water
Was added and stirred, and 23.5 parts by weight of Tight Silane Super Z (aqueous dispersion of alkoxysilane, manufactured by Toyo Ink Mfg. Co., Ltd., 60% by weight) was added thereto.
E-405 (Daikin Industries, Ltd., fluorine emulsion, solid content 50% by weight) 12.0 parts by weight, 2.7 parts by weight of diethyl adipate (film-forming aid), Unidyne TG-410
(Fluorine pendant acrylic polymer manufactured by Daikin Industries, solid content 18% by weight) 13.5 parts by weight, 3.0 parts by weight of diethylene glycol monobutyl ether, 1.0 part by weight of isopropyl alcohol, and SYLGARD-30
9 (silicone-based additive manufactured by Toray Dow Corning) 0.
1 part by weight and 0.05 part by weight of Primal TT-615 (alkali thickener manufactured by Rohm & Haas Co.) were added while stirring was continued to obtain a clear liquid. To the obtained clear liquid, 0.05 parts by weight of 25% aqueous ammonia was added and stirred to obtain an aqueous coating composition 4 having a heating residue of 8% by weight.

Evaluation Test Each of the aqueous coating compositions of Examples 1 to 3 and Comparative Example 1 was applied on a slate plate as a base material using a roller.
After coating at a rate of 00 g / m ² ,
After drying for a time, two types of test pieces each having a coating film formed on a substrate were obtained. Further, a commercially available water-based water-absorbing agent commercially available as a comparative example was added with a roller at 300 g /
It was painted in such a way as to provide m ^2. Table 1 shows the obtained results.
It was shown to.

<Initial and Long-term Moisture Permeability> A sponge was placed in a 100 cc polycup filled with an appropriate amount of water and water was sufficiently absorbed, and a test piece was placed on the polycup so that the sponge was in contact with the surface of the coating film. It is installed in a chamber maintained at a humidity of 50%, and the amount of weight loss is measured at regular time intervals, and the initial moisture permeability per 24 hours is calculated.
g / m ² was accepted. Furthermore, after treating this test plate with a sunshine weatherometer for 1000 hours,
The weight loss was measured again, and the long-term moisture permeability was calculated. The initial moisture permeability of the used slate plate in an unpainted state is 2
It was 46 g / m ² per 4 hours.

<Water Permeability Prevention Property>
The amount of water permeation was measured according to the water permeation test method specified in ISK 5400 8-16. Less than 0.5 ml / 24 hours was accepted.

<Initial and Long-Term Water Repellency> For each of the above test pieces, the water contact angle of the coating film was measured to evaluate the initial water repellency. Furthermore, after treating this test plate with a sunshine weatherometer for 3000 hours, the water contact angle of the coating film was measured again to evaluate long-term water repellency. The water contact angle is a value measured using a contact angle meter CA-Z manufactured by Kyowa Interface Chemical Co., Ltd., and the water repellency was 100 to 125 degrees. The measurement was performed 5 seconds after the contact of the water droplet with the surface of the coating film.

[0065]

[Table 1]

As apparent from Table 1, the aqueous coating composition containing a predetermined amount of the aqueous dispersion (a) of the alkylalkoxysilane, the fluorine emulsion (b), the fluorine pendant acrylic polymer (c), and the pigment (d). The coating film obtained from the product is not only excellent in moisture permeability and water permeability prevention for a long period immediately after the coating film formation, but also excellent in water repellency.

However, although the clear coating film of Comparative Example 1 was excellent in water permeability prevention, it was inferior in moisture permeability, and a film made of a commercially available water-based water absorption inhibitor was excellent in moisture permeability.
It is inferior in water permeation prevention properties and has a long-term water repellency.

[0068]

The aqueous coating composition of the present invention contains predetermined amounts of an aqueous dispersion of an alkylalkoxysilane (a), a fluorine emulsion (b), a fluorine pendant acrylic polymer (c) and a pigment (d). Therefore, the obtained coating film has high moisture permeability and water repellency without being impaired for an initial period and for a long period of time. The moisture permeability is such that when the aqueous coating composition of the present invention is applied to a substrate, a water-permeation preventing coating formed by an aqueous dispersion (a) of an alkylalkoxysilane, a fluorine emulsion (b), a fluorine pendant acrylic polymer (c) It is considered that this is because the film formed by the pigment (d) does not pass through large water molecules such as water droplets, but forms pores that pass only small water molecules such as moisture and water vapor. The high water repellency is considered to be due to the fact that the fluorine pendant acrylic polymer (c) prevents water permeation from the coating film surface.

Therefore, when the water-based coating composition of the present invention is applied to the foundation of a foundation portion of a house made of concrete or cement-based material, moisture generated from the soil inside the foundation is transferred from the entire foundation portion to the outside. Since it can be released, it is effective not only for preventing deterioration of the base and the house itself, but also for preventing generation of mold and dew condensation in the room.

The water-borne coating composition of the present invention can realize the above-mentioned performance of the coating film, which can be obtained only by forming a thick film of about 1 mm in the past, with a thin film of 15 to 120 μm. Is economical.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C09D 133/16 C09D 133/16 F term (reference) 4D075 BB92Z CA36 CA38 CA40 CA45 DA25 DB12 DC05 EA06 EA10 EA13 EB14 EB16 EB19 EB20 EB22 EB43 EB47 EB56 EC11 EC30 EC33 EC54 EC60 4J038 BA022 BA092 CA021 CA081 CC021 CC071 CD111 CE022 CE051 CG081 CG112 CG141 CG171 CH031 CH041 CH071 CH081 CH201 CH251 CJ251 CL001 GA02 HA05 GA01 GA01 GA01 GA02 JA26 KA06 KA07 KA08 MA08 MA10 NA06 NA08

Claims (8)

[Claims] 1. An aqueous dispersion of an alkylalkoxysilane (a) having a solid content of 100 parts by weight in an aqueous coating composition.
To 47 parts by weight, a fluorine emulsion (b) 8 to 24 parts by weight, a fluorine pendant acrylic polymer (c) 9 to 27
An aqueous coating composition comprising: parts by weight and 1 to 35 parts by weight of a pigment (d). 2. The aqueous coating composition according to claim 1, further comprising 0.1 to 2 parts by weight of a biologically inactive agent. 3. The method according to claim 1, further comprising a total of 3 to 10% by weight of a polar organic solvent and / or a thickener.
2. The aqueous coating composition according to item 1. 4. A coating film obtained by applying the aqueous coating composition according to any one of claims 1 to 3, wherein the moisture permeability per 24 hours at 23 ° C. and 50% humidity. Is 30 to 40 g / m ² . 5. The method according to claim 1, wherein the water permeability of the coating is less than 0.5 ml / 24.
The moisture permeable coating film according to claim 4, which is time. 6. The moisture-permeable coating film according to claim 4, wherein the water contact angle of the coating film is 100 degrees or more. 7. The moisture-permeable coating film according to claim 4, wherein a dry film thickness of the coating film is 15 to 120 μm. 8. A moisture-permeable coating characterized by obtaining a moisture-permeable coating by applying the aqueous coating composition according to any one of claims 1 to 3 to a porous substrate. Method of forming a film.