JP2003292876A - Sealer for inorganic building material, its applying method and coated inorganic building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration in external appearances and deterioration in weather resistance by elution of alkali caused by penetration of water due to a defect in a coating film of a coated inorganic building material, and to prevent a relatively large defect such as a hole in an organic building material. <P>SOLUTION: The sealer for an inorganic building material comprises an acrylic emulsion and, incorporated thereinto, a thermally expandable microcapsule. The method for applying the same is also provided. The coated inorganic building material has a coating film of the sealer for the inorganic building material formed thereon. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealer for inorganic building materials, a coating method therefor, and a painted inorganic building material.

[0002]

2. Description of the Related Art Conventionally, porous inorganic building materials, such as silica plate, pulp cement plate, asbestos slate plate, slag gypsum plate, magnesium carbonate plate, asbestos perlite plate, wood chip cement plate and ALC plate, are light and have heat insulating property. It is widely used as a building material because of its excellent sound insulation. Since such a building material is exposed outdoors, water will penetrate into the interior and cause deterioration of the material. Therefore, generally, a base coating material called a sealer or a primer is applied to the surface of the base material. In particular, in recent years, a water-based undercoating material has been widely used as the undercoating material in consideration of the environment. However, in such an undercoat coating composition, in order to obtain a continuous defect-free coating film on a porous substrate, the undercoat coating composition is applied at least three times or more, and the thickness of the coating film is set to a solvent system. Means have been taken to make it much thicker than the ones. However, even with respect to a base material having relatively large pores and defects during molding of the base material, sufficient waterproofing effect cannot be obtained even by these means.

[0003] In Japanese Patent Laid-Open No. 2001-205188, in a coating method in which the surface of an inorganic building material is coated with an aqueous undercoating material at least twice, an aqueous undercoating coating composition used in the second coating is disclosed. An undercoating method is described, characterized in that it comprises a pigment having a flat shape.

Further, Japanese Patent Application Laid-Open No. 11-207251 describes that a primer, an undercoat paint or a primer surfacer containing heat-expandable microcapsules is used for the base coating of an object having an uneven surface.

[0005]

Conventionally, due to coating film defects in inorganic coating building materials, water may permeate, and alkali elution may deteriorate the appearance of the top coating film and the weather resistance. Further, it has been required to prevent relatively large defects such as pores in the inorganic building material that may cause the above.

The present invention has been made in view of the above problems, and an object thereof is to effectively block holes and defective portions to suppress the amount of water permeation, as compared with the conventional method. It is possible to suppress the elution of alkaline components of inorganic building materials.

[0007]

In order to achieve the above-mentioned objects, the present invention is characterized by providing a sealer for an inorganic building material in which a water-based coating material is mixed with thermally expandable microcapsules.

More specifically, the present invention provides the following.

(1) A sealer for inorganic building materials, characterized in that an acrylic emulsion contains thermally expandable microcapsules.

(2) The sealer for inorganic building materials as described above, wherein 1 to 14 parts by mass of the heat-expandable microcapsule is mixed with 100 parts by mass of the solid content of the acrylic emulsion.

(3) The surface of the inorganic building material is coated with a sealer made of acrylic emulsion blended with heat-expandable microcapsules, and the surface is dried by a heating means for heating the coated surface to 80 ° C. or higher to expand the heat-expandable property. A method for coating a sealer for inorganic building materials, which comprises forming a sealer coating film containing microcapsules.

(4) The method for coating a sealer for inorganic building materials as described above, further comprising topcoating.

(5) A coated inorganic building material characterized in that a sealer coating film made of acrylic emulsion mixed with thermally expandable microcapsules is formed on the surface of the inorganic building material.

(6) The coated inorganic building material as described above, characterized in that an upper coating film is further formed on the sealer coating film.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an acrylic emulsion is used, and for example, a water-based paint containing an acrylic emulsion as a main component is used.

As the water-based paint containing an acrylic emulsion as a main component, for example, a product obtained by polymerizing a polymerizable monomer described below can be used. Such a polymerizable monomer includes a derivative of acrylic acid or methacrylic acid,
Those having at least one unsaturated bond such as a vinyl group in the molecule are preferable. For example, the cycloalkyl group-containing polymerizable monomer (a) may be contained, and in this case, the resulting coating film has excellent weather resistance, discoloration resistance, hydrolysis resistance, crack resistance, and water resistance. Properties, gloss and gloss retention, as well as excellent film forming properties, blocking resistance and temperature change resistance in cooperation with other components. Alternatively, the acrylic emulsion may consist of a copolymer of acrylic or methacrylic monomers with other ethylenically unsaturated monomers.

Examples of the cycloalkyl group-containing polymerizable monomer (a) include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate and hydroxy. Examples thereof include methylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, cyclodecyl (meth) acrylate, cyclododecyl (meth) acrylate and the like. These can be used alone or in combination of two or more. Of these, cyclohexyl (meth) acrylate and methylcyclohexyl (meth) acrylate are particularly preferable. In the present specification, (meth) acrylate refers to acrylate or methacrylate.

The cycloalkyl group-containing polymerizable monomer (a) is contained in the emulsion particles in an amount of 5 to 95 parts by weight. When the amount of the cycloalkyl group-containing polymerizable monomer (a) in the emulsion particles is less than 5 parts by weight, the weather resistance of the resulting coating film decreases, and when it exceeds 95 parts by weight, the coating film obtained is formed. Properties deteriorate and hot water resistance deteriorates. The amount is preferably 10 to 70 parts by weight, more preferably 20 to 55 parts by weight.

The emulsion particles further have 1 to 1 carbon atoms.
The alkoxysilyl group-containing polymerizable monomer (4) may be included. One to three alkoxyl groups having 1 to 14 carbon atoms can be bonded to the silicon atom constituting the alkoxysilyl group having 1 to 14 carbon atoms. The alkoxyl group is likely to be hydrolyzed to form a silanol group particularly in an acidic environment. Since the silanol group forms a siloxane bond by dehydration bonding to crosslink or increase the molecular weight, the film forming property of the obtained coating film, the blocking resistance and the temperature change resistance are significantly improved, and particularly,
Excellent weather resistance and hot water resistance can be obtained.

In the above-mentioned alkoxysilyl group-containing polymerizable monomer (b), at least one hydrocarbon group having a polymerizable unsaturated bond such as a vinyl group is attached to the silicon atom constituting the alkoxysilyl group. At least one bond is formed separately from the above alkoxyl group. Since it has the above unsaturated bond, the above-mentioned alkoxysilyl group-containing polymerizable monomer (b) can also contribute to the increase in the molecular weight by addition polymerization, and in addition to the effect due to the above siloxane bond, The film forming property, blocking resistance and temperature change resistance are remarkably improved.

The above-mentioned alkoxysilyl group-containing polymerizable monomer (b) is not particularly limited as long as it is a polymerizable monomer containing an alkoxysilyl group having 1 to 14 carbon atoms. For example, trimethoxysilylpropyl ( (Meth) acrylate, triethoxysilylpropyl (meth) acrylate, tributoxysilylpropyl (meth) acrylate, dimethoxymethylsilylpropyl (meth) acrylate, methoxydimethylsilylpropyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, Examples thereof include vinyldimethoxymethylsilane, vinylmethoxydimethylsilane, vinyltris (β-methoxyethoxy) silane and the like. These can be used alone or in combination of two or more. Of these, trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, vinyltrimethoxysilane, and vinyltriethoxysilane are particularly preferable.

The above-mentioned alkoxysilyl group-containing polymerizable monomer (b) is contained in the emulsion particles in an amount of 0.1 to 95 parts by weight. If the amount of the above-mentioned alkoxysilyl group-containing polymerizable monomer (b) in the emulsion particles is less than 0.1 part by weight, the crosslinking due to the siloxane bond and the increase in molecular weight will be insufficient, and the weather resistance of the resulting coating film will decrease. However, if it exceeds 95 parts by weight, stable production during polymerization becomes difficult. Preferably 0.
It is 5 to 70 parts by weight, and more preferably 1 to 50 parts by weight.

The emulsion particles may also contain other polymerizable monomer (c). The other polymerizable monomer (c) is not particularly limited as long as it is a monomer having at least one unsaturated bond in the molecule, and examples thereof include acrylic acid, methacrylic acid, maleic acid, itaconic acid and the like. Ethylenically unsaturated carboxylic acid monomer; ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate,
Ethylenically unsaturated carboxylic acid alkyl ester monomers such as n-butyl methacrylate and 2-ethylhexyl methacrylate; Monomers of ethylenically unsaturated dicarboxylic acids such as ethyl maleate, butyl maleate, ethyl itaconate and butyl itaconate Ester monomer: 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
4-hydroxybutyl methacrylate, 2-methacrylic acid
Hydroxyl group-containing ethylenically unsaturated carboxylic acid alkyl ester monomer such as reaction product of hydroxyethyl and ε-caprolactone; ethylenically unsaturated carboxylic acid aminoalkyl ester such as aminoethyl acrylate, dimethylaminoethyl acrylate, butylaminoethyl acrylate Monomers: Ethylenically unsaturated carboxylic acid aminoalkylamide monomers such as aminoethylacrylamide, dimethylaminomethylmethacrylamide, methylaminopropylmethacrylamide, etc. Acrylamide, methacrylamide, N-methylolacrylamide, methoxybutylacrylamide, diacetone Other amide group-containing ethylenically unsaturated carboxylic acid monomers such as acrylamide; unsaturated fatty acid glycols such as glycidyl acrylate and glycidyl methacrylate Zyl ester monomer; vinyl cyanide monomer such as (meth) acrylonitrile and α-chloroacrylonitrile; saturated aliphatic carboxylic acid vinyl ester monomer such as vinyl acetate and vinyl propionate; styrene and α-methylstyrene , Styrene-based monomers such as vinyltoluene, and the like. These can be used alone or in combination of two or more. Of these, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and styrene are preferable.

The average particle size of the emulsion particles, that is, the aqueous dispersion, is preferably 70 to 300 nm.
If the average particle diameter of the emulsion particles is less than 70 nm, the viscosity becomes too high, and the coating solid content concentration must be lowered. Further, the thermo-mechanical stability of the emulsion resin becomes low, and agglomerates are likely to occur when it is used as a paint or during coating. On the other hand, when the average particle size of the emulsion particles exceeds 300 nm, the dispersibility of the emulsion particles in the acrylic emulsion becomes poor. It is more preferably 80 to 250 nm, further preferably 80 to 250 nm.
It is 200 nm. Such an average particle diameter can be obtained by appropriately selecting the type and amount of the emulsifier.

The acrylic emulsion can be produced by appropriately selecting a usual emulsion polymerization method such as batch polymerization, monomer dropping polymerization and emulsion monomer dropping polymerization. In particular, the emulsion monomer dropping polymerization is suitable for ensuring stability during production. When carrying out emulsion polymerization, it is usual to use a water-soluble initiator as an initiator. Examples thereof include inorganic peroxide initiators such as hydrogen peroxide, ammonium persulfate, potassium persulfate, t-butyl hydroperoxide,
There are organic peroxide initiators such as t-amyl hydroperoxide, cumene hydroperoxide, tetralin hydroperoxide, diisopropyl hydroperoxide, and azo initiators such as 4,4′-azobis (4-cyanovaleric acid).

In the present invention, it is preferable that 1 to 14 parts by mass of the heat-expandable microcapsule is mixed with 100 parts by mass of the solid content of the acrylic emulsion,
It is more preferable that the compounding amount is 14 parts by mass. The softening point of the shell wall is typically 80 ° C. or higher, and depends on the type of microcapsule. The maximum expansion rate varies depending on the type, but for example, from 20 times,
There are up to 0 times. The heat-expandable capsule has, for example, a spherical shape.

As the heat-expandable microcapsules, for example, thermoplastics filled with a gas such as hydrocarbon are used. For example, known microcapsules in which a hydrocarbon or the like is included in the outer wall of a thermoplastic such as vinylidene chloride resin can be used.

Examples of physical methods for producing microcapsule particles include a coacervation method and a submerged drying method. The coacervation method is a method in which a dissolved polymer is phase-separated as a concentrated phase on the surface of a core substance due to a change in environment to form a capsule wall film. For example, in an aqueous medium, by mixing gum arabic and gelatin to adjust the pH of the solution, the dissolution or precipitation can be controlled and the formation of the capsule wall film can be controlled.

The in-liquid drying method is a method of dispersing a wall membrane substance solution in which a core substance is emulsified or dispersed in water or a non-aqueous medium,
After that, the solvent that dissolves the wall film substance is removed by stirring, heating, and / or depressurization to form a capsule wall film.

In order to impart water dispersibility to the microcapsule particles, it is preferable to use a hydrophilic polymer as the wall material of the microcapsule particles. When such a hydrophilic polymer wall material is formed by the coacervation method, it is formed by coacervating a concentrated solution phase of the polymer from an aqueous solution of the water-soluble polymer and crosslinking the water-soluble polymer with a curing agent. be able to.

In the case of producing microcapsule particles by the coacervation method, for example, a desired solution is first mixed with an aqueous solution of a water-soluble polymer to emulsify, and then pH is adjusted or diluted with water, or salt or alcohol is added. To induce coacervation, and then add a water-soluble polymer curing agent to crosslink the wall material of the microcapsule particles.

The water-soluble polymer that constitutes the wall material of the microcapsule particles is not particularly limited as long as it is a water-soluble polymer that can be made water-insoluble by a curing agent, but a gelatin-based polymer is particularly preferable. , A gelatin-arabic gum polymer, a gelatin-carboxymethyl cellulose polymer, and the like can be used. These polymers can be water-insolubilized with aldehydes such as glutaraldehyde, diketones, epoxides, acid anhydrides, acid chlorides, carbodiimides, and inorganic salts.

The average particle size of the microcapsule particles used in the present invention is preferably 50 μm or less, more preferably 30 μm or less. If the average particle size is too large, it becomes thicker than the thickness of the coating film, which is not preferable as a material to be blended in the coating material. The average particle diameter of the microcapsule particles is preferably 10 μm or more. If the average particle size is too small, a large coating amount is required to close the defective portion, which is not preferable.

The microcapsule particles are preferably dispersed and used in the presence of a dispersion medium such as glass beads. More preferably, in order to prevent re-aggregation, an emulsifier of 50 to 50 is used.
It can be present in the dispersion of microcapsules in the range of 2000 ppm. The emulsifier used here may be any of a cationic type, an anionic type and a nonionic type.

In the present invention, the thermal expansion microcapsules can be added by directly adding to the coating material, mixing and crushing. However, if there are aggregates of microcapsules,
Impairs the appearance of the coating film.

In the sealer for inorganic building materials of the present invention, other known additives such as a polymerization degree adjusting agent, a particle size adjusting agent, a thickening agent, a viscosity adjusting agent, a filler, a dispersant, and an ultraviolet absorber are added as necessary. Agents, light stabilizers, antioxidants, antifreeze agents, algae inhibitors,
Preservatives, defoamers, wetting agents and the like may be included. Examples of the defoaming agent include Nopco 8034 (manufactured by San Nopco) and SN Deformer 154 (manufactured by San Nopco). The wetting agent is used to disperse the pigment, for example, Yonerin (Yoneyama Chemical Co., Ltd.),
There are Poise 530 (manufactured by Kao), Emulgen 930 (manufactured by Kao) and the like.

The sealer for inorganic building materials according to the present invention comprises, in addition to the water-based paint and the heat-expandable microcapsules, if necessary, pigments, additives, film-forming aids, fungicides, light stabilizers, etc. Can be included.

Among the above pigments, examples of the coloring pigment include azo lake pigments, phthalocyanine pigments, indigo pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, metal complex pigments, etc. Inorganic pigments such as yellow lead, yellow iron oxide, red iron oxide, titanium dioxide, carbon black, and iron hydroxide. Further, various extender pigments can be used in combination. Further, if necessary, aluminum flake pigment, colored aluminum flake pigment, metal oxide coated alumina flake pigment, interference mica pigment, colored mica pigment, metal oxide coated glass flake, metal plated glass flake, metal oxide coated glass flake, Bright pigments such as metal oxide-coated silica flake pigments, metallic titanium flakes, graphite, stainless flakes, plate-shaped iron oxide, phthalocyanine flakes and hologram pigments can be contained. The total content (PWC) of the above-mentioned pigment as a whole is preferably less than 50% and 30%.
Less than is more preferable. If it exceeds 50%, the water permeability decreases. Furthermore, calcium carbonate, magnesium hydroxide,
An extender pigment such as aluminum hydroxide, barium sulfate or magnesium carbonate may be contained. Also, mica,
Clay, aluminum powder, talc, aluminum silicate can also be used.

The sealer for inorganic building materials of the present invention comprises, as the film forming aid, an organic solvent having a boiling point of 150 to 300 ° C. and an evaporation rate of 0.1 to 20 with butyl acetate as 100 1 to 100 parts by weight of particles
It is preferable to contain 20 parts by weight. Thereby, the film-forming property at low temperature or in a short time can be improved. More preferably, the organic solvent has a boiling point of 170 to 270.
And the evaporation rate is 0.5 with butyl acetate as 100.
~ 17. More preferably, the boiling point is 200 to 250.
And the evaporation rate is 1 to 1 with butyl acetate being 100.
It is 5.

The organic solvent is not particularly limited as long as it has the above-mentioned properties, and examples thereof include ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monobutyl ether. Examples thereof include acetate, ethylene glycol dibutyl ether, and 2,2,4-trimethylpentane-1,3-diol monoisobutyrate. These can be used alone or in combination of two or more. Of these, ethylene glycol monoethyl ether is particularly preferable.

The sealer for inorganic building materials of the present invention is provided in a form in which each of the above components is dispersed in an aqueous medium from the viewpoint of environmental friendliness. However, an appropriate amount of water-soluble organic solvent may be contained in the aqueous medium.

The base material to which the sealer for inorganic building materials of the present invention is applied is an inorganic material base material, particularly a wall surface or roof such as an inner wall or an outer wall of a building such as a house or a building, a building material for ceramics,
Concrete, ALC (autoclaved light weight conc
rete) and other inorganic building materials are preferred. For example, it can be applied to a slate plate or a calcium silicate plate. In particular, it can be suitably used as an inorganic exterior building material.

The above-mentioned base material may be surface-treated in order to improve the adhesion. Further, the base material may be coated with an undercoat paint (sealer), or an undercoat paint and an intermediate paint, and the back surface of the base material may be coated with a back surface paint. These can be appropriately selected according to the purpose of use.

The method for applying the sealer for inorganic building materials of the present invention is not particularly limited, and examples thereof include dipping, brush, roller,
Roll coater, air spray, airless spray,
Curtain flow coater, roller curtain coater,
A commonly used coating method such as a die coater can be used. These can be appropriately selected depending on the use of the base material.

Drying temperature of the sealer for inorganic building materials of the present invention,
The surface temperature of the sealer is preferably 80 ° C. or higher and 180 ° C. or lower. If it is lower than 80 ° C, it takes a long time to dry, which is not preferable. On the other hand, if the temperature is higher than 180 ° C., the sealer for inorganic building materials deteriorates or the base material loses water and is deformed. The drying time is, for example, 1 to 3.
0 minutes.

The sealer for inorganic building materials of the present invention can be usually coated on the above base material so that the dry film thickness is from 5 to 350 μm, and more preferably from 20 to 300.
μm, and more preferably 25 to 75 μm.

[0047]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Table 1 summarizes the paints, components, etc. used in the examples.

[0049]

[Table 1]

Examples 1 to 3 and Comparative Examples 1 and 2 Matsumoto Microsphere F30 (Matsumoto Yushi Co., Ltd.) was used as the thermal expansion microcapsules. Particle size is 1
The specific gravity is 1.13, the maximum expansion ratio is about 70 times, the flash point is 75 ° C, and the shell wall softening point is 80 to 85 ° C. In Examples 1 to 3 and Comparative Examples 1 and 2, the addition amount of the thermal expansion microcapsule aqueous dispersion was changed.

<Preparation of Sealer> First, a pigment dispersion paste is prepared. Pigment dispersant (“SMA1440H”, AR
CO Chemical Co., Ltd.) 4.34 g, Wetting Agent (“Yonerin”, 10% aqueous solution, Yoneyama Chemical Co., Ltd.) 2.17 g, Defoamer (“B940”, Asahi Denka Kogyo Co., Ltd.) 0.48 g, Talc (“ Talc PK ", manufactured by Maruo Calcium Co., Ltd.) 27.2
g, clay (“Clay FA80”, Sanyo Clay Co., Ltd.) 2
5.1 g, titanium dioxide (“CR50”, manufactured by Ishihara Sangyo Co., Ltd.) 2.0 g, and water (38.74 g) were mixed and dispersed in a sand mill together with glass beads (“GB503”, manufactured by Toshiba Ballotini), and glass beads were dispersed. It was separated by filtration to obtain a pigment dispersion paste.

Next, 90 parts by mass of this pigment-dispersed paste was added to a styrene acrylic emulsion ("Iodosol AD").
121 ", manufactured by Nippon NSC Co., Ltd.) 100 parts by mass were mixed and stirred at 1000 rpm for 5 minutes with a disper.
And, a further film-forming aid (“Kyowanol CS-1
2 ", manufactured by Kyowa Hakko Kogyo Co., Ltd.) 10 parts by mass are added with stirring, and then a thickener is added to give a viscosity of iwataNK'2.
The base sealer was adjusted using a cup to adjust to 30 ± 5 seconds. The solid content concentration of this sealer was 49% by mass.

On the other hand, for the thermal expansion microcapsules, 250 g of Matsumoto Microsphere F30 (manufactured by Matsumoto Yushi Co., Ltd.) was used, and 750 g of tap water and 200 g of glass beads (GB503) as a dispersion medium were attached to a stainless steel disk. 1000 rp with a homodisper
After stirring for 5 minutes, the glass beads were filtered off to prepare an aqueous dispersion having a concentration of 25% by mass. Then, this water dispersion was mixed in the above-mentioned base sealer at a ratio shown in Table 2 to obtain a sealer for inorganic building materials.

On the other hand, a large number of through holes were opened in a JIS A5430 6 mm thick slate plate with a 0.5 mm diameter drill at intervals of 10 mm in length and width. The composition of each of the examples and comparative examples was applied to this slate plate by air spraying to a coating amount of 50 g / m 2.
² was applied and dried at 100 ° C. for 10 minutes with a hot air dryer. After drying, the temperature of the slate plate was 85 ° C., taken out from the oven as it was, allowed to cool at room temperature, and evaluated the next day.

[Examples 4 to 6 and Comparative Examples 3 and 4] In Examples 4 to 6 and Comparative Examples 3 and 4, a top coat was further applied on top of the above base coat. That is, the coated inorganic building materials prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were preheated to 60 ° C., and audite 323 brown color (manufactured by Nippon Paint Co., Ltd.) as an acrylic emulsion paint was applied by air spray at an application amount of 50 g / m ^{2 was} applied and dried in a hot air drier at 80 ° C. for 10 minutes, and then allowed to cool overnight at room temperature, and the next day, water permeability, frost resistance, efflorescence, coating film appearance and adhesion were evaluated. The results are shown in Table 3.

[0056]

[Table 2]

[0057]

[Table 3]

In Tables 2 and 3, the addition amount is the weight part of the heat-expandable microcapsule aqueous dispersion with respect to 100 weight parts of the inorganic building material sealer, and the microcapsule content is the solid content of the heat-expandable microcapsule. It is converted into minutes.

In Tables 2 and 3, the water permeability is JIS A6910.
The test was based on the above, and a funnel having a diameter of 75 mm was fixed on a coated slate plate with a silicone sealing material so that water did not leak from the surroundings. Then, a 5 cc pipette was attached to the foot of the funnel, water was put into the funnel from the pipette, and the amount of water reduction after 24 hours was taken as the water permeation amount. The funnel has a size that covers about 30 through holes. In addition, from the area of the funnel, the amount of water reduced by the pipette 1 cc is 223 cc per square meter.

The efflorescence is also called efflorescence resistance, and means resistance to elution of an alkali component or an alkali metal component mainly composed of calcium hydroxide from the inorganic building material to the coating surface. "○" means that no red color was shown when the alcohol solution of phenolphthalein, which is a pH indicator, was applied to the coating film, and "x" means that the entire coating film was dyed red. "△" means that a part of the coating film was dyed red.

In Tables 2 and 3, frost damage is ASTM C6.
The results after 200 cycles are shown based on the 6B method. The coating appearance was visually determined.

The adhesion was measured by a 1 mm cross cut test method. The cross-cut test method is to use a cutter knife to form 100 squares with a width of 1 mm on the coating film, attach an adhesive tape, and then peel it off to count the number of squares on which the coating film remained. .

From the results of the above Examples and Comparative Examples, when the surface of the slate plate was coated using the sealer for inorganic building materials of the present invention, there was no risk of damage due to freezing and thawing, and there was no elution of alkali. Therefore, it is clear that there is no risk of coating film deterioration due to internal factors. Also, the coating film adhesion is good.

[0064]

The heat-expandable microcapsules are added to 100 parts by weight of the water-based coating composition containing an acrylic emulsion as a main component.
Since it is a sealer for inorganic building materials that is characterized by containing 10 to 10 parts by mass, compared with the conventional method, by closing defects such as pores, to suppress the amount of water permeation, elution of alkaline components of inorganic building materials Can be suppressed. Therefore, it is possible to prevent the deterioration of the appearance and the weather resistance of the inorganic building material due to the alkali elution. Further, it is possible to prevent relatively large defects such as holes in the inorganic building material.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 5/34 C09D 5/34 C09K 3/10 C09K 3/10 E E04F 13/14 102 E04F 13/14 102A (72) Inventor Katsuaki Yoshioka 4-1-115 Minami-Shinagawa, Shinagawa-ku, Tokyo Inside Nippon Paint Co., Ltd. (72) Yuji Yamaki 4-1-1, Minami-Shinagawa, Shinagawa-ku, Tokyo Japan Paint Co., Ltd. Tokyo, Japan business-house F-term (reference) 2E110 AA28 BB04 GB16X GB17X GB19X 4D075 AE16 BB24Y BB93Y CA03 CA13 CA32 CA38 CB04 DA06 DA25 DB12 DC01 EA06 EA13 EA39 EB14 EB20 EB22 EB43 EB56 EC24 EC41 EC54 4F100 AA01A AD00A AK25B BA02 BA03 BA07 BA10A BA10C CC00B DE04B EH46B EH46C GB07 JA02B JD05B JL09 JM01B 4H017 AA02 AA04 AA36 AB01 AC01 AD06 AE03 4J038 CC021 CC081 CG011 CG061 CG0 71 CG141 CG161 CG171 CH031 CH041 CH071 CH121 CH201 DL101 GA15 MA08 MA10 PB05 PC01 PC03 PC04

Claims (6)

[Claims] 1. A sealer for inorganic building materials, characterized in that a thermally expandable microcapsule is mixed in an acrylic emulsion. 2. A solid content of 10 of the acrylic emulsion
The amount of the heat-expandable microcapsule is 1 to 0 parts by mass.
14. The inorganic building material sealer according to claim 1, wherein 14 parts by mass of the sealant is mixed. 3. The thermally expansive microspheres which have been expanded by coating a sealer made of acrylic emulsion mixed with thermally expansive microcapsules on the surface of an inorganic building material, and drying by a heating means which makes the coated surface 80 ° C. or higher. A method for coating a sealer for inorganic building materials, which comprises forming a sealer coating film containing a capsule. 4. The method for coating a sealer for inorganic building materials according to claim 3, further comprising topcoating. 5. A coated inorganic building material, characterized in that a sealer coating film made of acrylic emulsion mixed with thermally expandable microcapsules is formed on the surface of the inorganic building material. 6. The coated inorganic building material according to claim 5, wherein a top coat film is further formed on the sealer coat film.