Method for coating outer surface of foundation concrete of house

Abstract

To provide a coating method suitable for enhancing the protective function of the outer surface of the foundation concrete of a house and imparting appearance having a high-grade feeling.SOLUTION: A step (1) of forming an undercoat coating film by applying an undercoat coating material (I) containing inorganic pigments (A1) and aqueous resins (B1) and drying the undercoat coating material (I), and a step (2) of forming a spot-patterned topcoat coating film by applying a topcoat coating material (II) containing colored coating material particles (A2) obtained by granulating a colored coating material and aqueous resins (B2) and drying the topcoat coating material (II), the amount of the inorganic pigments (A1) contained in the undercoat (I) is 100 parts by mass or more based on 100 parts by mass of the nonvolatile matter of the aqueous resins (B1), and the elongation at break at 23 °C of the coating film formed from the undercoat (I) is 100% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for painting the exterior surface of a concrete foundation for a house. [Background technology]

[0002] A home foundation is the foundation that supports a house and is usually made of reinforced concrete. Because this type of foundation, or concrete foundation, is located close to the ground, it is constantly exposed to moisture from rainwater and water from the ground, making it one of the harshest environments of all the components that make up a house. Furthermore, if the concrete cracks due to deterioration over time, moisture can seep into the foundation, causing rust in the rebar or carbonation of the concrete, leading to other problems. For these reasons, paints have recently been applied to concrete foundations to prevent deterioration over time.

[0003] For example, Patent Document 1 discloses a finishing method for coating concrete foundations for housing, in which a polymer cement-based surface preparation coating material is applied to the surface of the concrete foundation, and then a water vapor permeable finish coating film is laminated on top. This finishing method can provide the concrete foundation surface with a protective coating film that is less prone to swelling and peeling, but it requires trowel application to thickly apply the polymer cement-based surface preparation material as a base, which poses a problem in terms of painting workability.

[0004] In addition, Patent Document 2 discloses a coating method for coating a concrete surface of a house foundation with a water-based topcoat material containing a siloxane-modified resin emulsion as a binder, in which an acrylic resin derived from an alkyl ester of (meth)acrylic acid and a silicone resin derived from a cyclic siloxane compound are mixed in the particles. The coating method described in Patent Document 2 can protect the concrete surface of a house foundation for a long period of time, but there is a problem that cracks occur when the amount of water-based topcoat material applied is small.

[0005] In recent years, as user preferences have become more diverse, there has been a demand for homes to have an original exterior appearance. This has led to a need for paint specifications that can create a unique appearance even on the exterior surfaces of homes' foundations.

[0006] As a painting method for imparting design to the interior and exterior wall surfaces of buildings, the applicant has proposed a painting method using a multicolored pattern paint containing particles of multiple colors as a top coat in Patent Documents 3 and 4. However, when the painting methods described in Patent Documents 3 and 4 are applied directly to the concrete surface of a house foundation, the granular feel of the multicolored pattern is reduced, and swelling or cracks occur in the paint film over time, making it impossible to obtain a satisfactory appearance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-161625 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-12454 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-114112 [Patent Document 4] Japanese Patent Application Laid-Open No. 2008-155119 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0008] When a coating is applied to the concrete surface of a house foundation, rainwater that splashes off the ground comes into contact with the coating. Defects such as swelling and peeling can occur in the coating due to factors such as moisture absorbed from the ground and released from the surface of the concrete foundation of a house. In addition, concrete deteriorates over time and cracks can appear, so cracks can also appear in the coating applied to the surface of a concrete foundation of a house.

[0009] An object of the present invention is to propose a coating method suitable for enhancing the protective function of the outer surface of a concrete foundation of a house and for imparting a luxurious appearance to the surface. [Means for solving the problem]

[0010] The present inventors have conducted extensive research into paint compositions for application to the exterior surface of residential concrete foundations. As a result, they have discovered that by first applying a primer paint containing a specific range of inorganic pigment blending amount and coating film elongation at break, followed by a top coat paint containing colored paint particles formed by granulating a colored paint, and a binder resin, it is possible to easily obtain a luxurious appearance with a moderate amount of scattered spots without defects such as blisters or cracks.

[0011] That is, the present invention provides: Item 1 A process (1) of applying a primer coating (I) containing an inorganic pigment (A1) and an aqueous resin (B1) to the outer surface of a concrete foundation for a house and drying the coating to form a primer coating film; a step (2) of applying a topcoat paint (II) containing colored paint particles (A2) obtained by granulating a colored paint and an aqueous resin (B2) onto the undercoat paint film obtained in the step (1), and drying the topcoat paint to form a spotted topcoat paint film; the amount of inorganic pigment (A1) contained in the primer paint (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1), and the elongation at break of a coating film formed from the primer paint (I) is 100% or more at 23°C; How to paint the exterior surface of a house foundation concrete. Section 2 Item 2. The coating method according to Item 1, wherein the aqueous resin (B1) is an acrylic resin obtained by emulsion polymerization. Section 3 Item 3. The coating method according to Item 1 or 2, wherein the aqueous resin (B1) contains a carbonyl group. Section 4 4. The coating method according to any one of items 1 to 3, wherein the water-based resin (B1) has a glass transition temperature of 25° C. or lower. Section 5 5. The coating method according to any one of items 1 to 4, wherein the primer coating (I) is applied using a roller. Section 6 Item 6. The coating method according to any one of items 1 to 5, wherein the colored coating particles (A2) contained in the topcoat coating (II) are obtained by contacting a colored coating containing a colorant (a2-1), an aqueous resin (a2-2), and water, and an aqueous liquid composition containing a water-soluble polysaccharide, with an aqueous medium containing a metal compound, and stirring the mixture. Section 7 Item 7. The coating method according to Item 6, wherein the aqueous resin (a2-2) has a non-volatile acid value of 20 mg KOH / g or less. Section 8 8. The coating method according to any one of items 1 to 7, wherein the topcoat paint (II) contains an aqueous resin (B2) as a binder component, and the aqueous resin (B2) contains a carbonyl group. Section 9 9. The method according to any one of items 1 to 8, wherein the aqueous resin (B2) is a core-shell type dispersed particle. The painting method described below. Section 10 Item 10. The coating method according to any one of Items 1 to 9, wherein the viscosity of the top coat paint (II) is 100 KU or more at 25°C. Section 11 11. The coating method according to any one of items 1 to 10, wherein the topcoat paint (II) is applied using a roller. Section 12 12. The coating method according to any one of items 1 to 11, wherein a topcoat paint is further applied on the topcoat coating film formed in step (2). Section 13 A process (1) of applying a primer coating (I) containing an inorganic pigment (A1) and an aqueous resin (B1) to the outer surface of a concrete foundation for a house and drying the coating to form a primer coating film; a step (2) of applying a topcoat paint (II) containing colored paint particles (A2) obtained by granulating a colored paint and an aqueous resin (B2) onto the undercoat paint film obtained in the step (1), and drying the topcoat paint to form a spotted topcoat paint film; the amount of inorganic pigment (A1) contained in the primer paint (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1), and the elongation at break of a coating film formed from the primer paint (I) is 100% or more at 23°C; A method for producing painted exterior concrete surfaces for residential foundations. Regarding. [Effects of the Invention]

[0012] According to the coating method of the present invention, it is possible to protect the concrete foundation of a house for a long period of time and to give the exterior surface of the concrete foundation of a house a speckled, luxurious appearance. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Object to be coated> The substrate to which the coating method of the present invention is applied is a concrete foundation for a house. A concrete foundation for a house is typically formed by installing a formwork at the site where the house is to be built, placing rebar inside the formwork to increase strength, pouring ready-mixed concrete, curing the concrete, and then removing the formwork. The surface of the concrete foundation formed can be classified into an exterior surface and an interior surface, but the method of the present invention is applied to the exterior surface. The exterior surface of the concrete foundation for a house refers to the surface visible from the outside of the house, while the interior surface of the concrete foundation for a house refers to the surface that cannot be seen from the outside of the house, such as the concrete part of the foundation below the floor. The exterior surface of the concrete foundation for a house may be flat or may have a finely textured pattern for decorative purposes. Furthermore, the concrete foundation may be pre-treated with a sealer or primer to improve adhesion of the coating film formed by the primer paint (I) described below.

[0014] <Process (1)> In the coating method of the present invention, in step (1), a primer coating (I) containing an inorganic pigment (A1) and an aqueous resin (B1) is applied to the outer surface of the concrete foundation of the house, and then dried to form a primer coating film.

[0015] Inorganic pigments (A1): Examples of the inorganic pigment (A1) include titanium oxide, carbon black, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, red iron oxide, mica, talc, gypsum, clay, white carbon, diatomaceous earth, magnesium carbonate, alumina white, and gloss white.

[0016] In the present invention, it is important that the amount of inorganic pigment (A1) contained in the primer paint (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1) contained in the primer paint (I), and it is particularly suitable that the amount is in the range of 120 to 500 parts by mass.

[0017] In this specification, "non-volatile content" refers to the residue remaining after removing volatile components such as water and organic solvents, and is the component that will form the coating film. For example, the drying conditions for the sample when measuring the mass of non-volatile content include heating 1 gram of sample in a dryer at 110°C for 1 hour.

[0018] The amount of inorganic pigment (A1) contained in the primer paint (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1), which has the effect of suppressing defects such as swelling and whitening that occur over time in the multi-layer coating film applied to the outer surface of the concrete foundation of a house according to the present invention.

[0019] Water-based resin (B1): The aqueous resin (B1) used as the binder component of the primer (I) is a resin that is soluble or dispersible in water. There are no particular limitations on the type of resin, and specific examples include acrylic resins, polyolefin resins, silicone resins, polyurethane resins, epoxy resins, phenolic resins, polyester resins, alkyd resins, and polycarbonate resins. These resins can be used alone or in combination of two or more, and two or more of these resins may be modified or graft-polymerized. Furthermore, when the aqueous resin (B1) is in the form of dispersed particles, it may be either a single layer or a multilayer structure such as a core-shell structure.

[0020] The aqueous resin (B1) is preferably an acrylic resin from the viewpoint of the water resistance, crack resistance, weather resistance, etc. of the multi-layer coating film formed on the outer surface of the concrete foundation of a house. Preferably, 70 mass % or more of the aqueous resin (B1) is an acrylic resin.

[0021] Examples of the acrylic resin include resins obtained by copolymerizing polymerizable unsaturated monomers containing a (meth)acrylate compound as a main component. Examples of such polymerizable unsaturated monomers include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and isostearyl acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate; (Meth)acrylates having an isobornyl group, such as isobornyl (meth)acrylate; (meth)acrylates having an adamantyl group, such as adamantyl (meth)acrylate; vinyl aromatic compounds, such as styrene, α-methylstyrene, and vinyltoluene; Carboxyl group-containing polymerizable unsaturated monomers such as (meth)acrylic acid, maleic acid, crotonic acid, itaconic acid, and β-carboxyethyl acrylate; Polymerizable unsaturated monomers having an alkoxysilyl group, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, and γ-(meth)acryloyloxypropyltriethoxysilane; Perfluoroalkyl (meth)acrylates such as perfluorobutylethyl (meth)acrylate and perfluorooctylethyl (meth)acrylate; fluoroolefins, etc. Polymerizable unsaturated monomers having a fluorinated alkyl group; Monomers having a photopolymerizable functional group such as a maleimide group; nitrogen-containing polymerizable unsaturated monomers such as (meth)acrylonitrile, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylamide, and adducts of glycidyl (meth)acrylate with amines; hydroxyl group-containing polymerizable unsaturated monomers such as monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, ε-caprolactone-modified monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms, N-hydroxymethyl (meth)acrylamide, allyl alcohol, and (meth)acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular terminal; Epoxy group-containing polymerizable unsaturated monomers such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexylpropyl (meth)acrylate, and allyl glycidyl ether; (Meth)acrylate having a polyoxyethylene chain with an alkoxy group at the molecular terminal; sulfonic acid group-containing polymerizable unsaturated monomers such as 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, sodium styrenesulfonate, sulfoethyl methacrylate, and sodium or ammonium salts thereof; phosphoric acid group-containing polymerizable unsaturated monomers such as 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, and 2-methacryloyloxypropyl acid phosphate; carbonyl group-containing polymerizable unsaturated monomers such as acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formyl styrene, and vinyl alkyl ketones having 4 to 7 carbon atoms (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone); and combinations thereof.

[0022] In the present invention, the aqueous resin (B1) preferably contains a carbonyl group. By containing the aqueous resin (B1), a multi-layer coating film having excellent water resistance can be formed on the outer surface of the concrete foundation of a house, particularly when the aqueous resin (B2) contained in the topcoat paint (II) described below also contains a carbonyl group.

[0023] When a carbonyl group is introduced into the aqueous resin (B1), the amount of the carbonyl group-containing polymerizable unsaturated monomer used is preferably within the range of 5 to 35 mass %, particularly 10 to 30 mass %, of the total polymerizable unsaturated monomers used in the production of the aqueous resin (B1).

[0024] In addition, from the viewpoint of crack resistance of the multi-layer coating film formed on the outer surface of a concrete foundation of a house by the method of the present invention, the water-based resin (B1) preferably has a glass transition temperature of 25° C. or lower, particularly within the range of −30 to 15° C. In the present invention, the glass transition temperature of the resin is calculated as follows when the resin is an acrylic resin.

[0025] 1 / Tg(K)=W1 / T1+W2 / T2+ W n / T n Tg(℃)=Tg(K)-273 In the formula, W1, W2,...W nare the mass fractions of each monomer, and T1, T2, T n is the glass transition temperature Tg (K) of the homopolymer of each monomer. The glass transition temperatures of the homopolymers of each monomer are given in Polymer Handbook (Second Edition, J. Brandup·EH Immergut When the Tg of the homopolymer is not clear, the static glass transition temperature is taken as the value obtained when the homopolymer of the monomer is synthesized so as to have a weight-average molecular weight of about 50,000. The static glass transition temperature is used as the glass transition temperature of the homopolymer or resin other than the acrylic resin. The static glass transition temperature can be determined by using a differential scanning calorimeter "DSC-220U" (Seiko Instruments Inc.) to place a sample in a measuring cup, vacuum suction to completely remove the solvent, and then measuring the change in heat quantity in the range of -20°C to +200°C at a heating rate of 3°C / min, and reading the first change point in the baseline on the low temperature side.

[0026] The aqueous resin (B1) can be obtained by a conventional method, but emulsion polymerization is preferred from the viewpoint of the water resistance and weather resistance of the multi-layer coating film applied to the exterior surface of the concrete foundation of a house. In emulsion polymerization, a conventional ionic or nonionic emulsifier can be used.

[0027] Examples of the ionic emulsifier include alkyl diphenyl ether disulfonates such as diammonium dodecyl diphenyl ether disulfonate, sodium dodecyl diphenyl ether disulfonate, calcium dodecyl diphenyl ether disulfonate, and sodium alkyl diphenyl ether disulfonate; alkyl benzene sulfonates such as sodium dodecyl benzene sulfonate and ammonium dodecyl benzene sulfonate; alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate; aliphatic carboxylate salts such as sodium fatty acid and potassium oleate; and polyoxyalkylene unit-containing sulfate ester salts (e.g., sodium polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether sulfate). ammonium and the like; polyoxyethylene alkyl phenyl ether sulfate salts such as polyoxyethylene alkyl phenyl ether sodium sulfate and polyoxyethylene alkyl phenyl ether ammonium sulfate; polyoxyethylene polycyclic phenyl ether sulfate salts such as polyoxyethylene polycyclic phenyl ether sodium sulfate and polyoxyethylene polycyclic phenyl ether ammonium sulfate; naphthalenesulfonic acid formalin condensate salts such as sodium naphthalenesulfonic acid formalin condensate; alkyl succinate sulfonate salts such as sodium dialkyl sulfosuccinate and disodium monoalkyl succinate sulfonate; and combinations thereof.

[0028] Examples of nonionic emulsifiers include polyoxyalkylene unit-containing ether compounds (e.g., polyoxyalkylene alkyl ether compounds such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, and polyoxyethylene oleyl ether; polyoxyalkylene alkylphenyl ether compounds such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyalkylene polycyclic phenyl ether compounds such as polyoxyethylene polycyclic phenyl ether); polyoxyalkylene alkyl ester compounds such as polyoxyethylene monolaurate, polyoxyethylene monostearate, and polyoxyethylene monooleate; polyoxyalkylene alkylamine compounds such as polyoxyethylene alkylamine; sorbitan compounds such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan monooleate; and combinations thereof.

[0029] The emulsifier may be a reactive emulsifier containing both a polymerizable unsaturated group and an anionic or nonionic group in the molecule. The amount of the emulsifier used is usually 0.5 to 6% by mass, preferably 1 to 4% by mass, based on the total mass of the polymerizable unsaturated monomers. It can be within.

[0030] The aqueous resin (B1) is contained in the undercoat paint (I) in an amount of 5 to 50% by mass, more preferably 10 to 40% by mass, in terms of nonvolatile content.

[0031] Primer (I): The undercoat paint (I) may contain, as necessary, pigments other than the inorganic pigment (A1), aqueous resins other than the aqueous resin (B1), antifoaming agents, crosslinking agents, curing catalysts, pigment dispersants, emulsifiers, film-forming aids, thickeners, neutralizing agents, preservatives, and other paint additives.

[0032] In the present invention, the primer paint (I) forms a coating film having an elongation at break of 100% or more, preferably in the range of 150 to 400%, at 23° C. The use of a primer paint (I) having an elongation at break within the above range is effective in preventing cracks from occurring in the top coating film when the present invention is applied to the concrete foundation of a house.

[0033] In this specification, the elongation at break of a coating film is the percentage of elongation of a coating film when a 0.3 mm thick coating film is pulled to break at a rate of 20 mm / min. The drying conditions for the coating film for the tensile test are 23°C, 50% RH for 14 days, and the atmosphere for measuring the elongation is also 23°C, 50% RH.

[0034] Applying primer (I): In the coating method of the present invention, when the primer paint (I) is applied to the outer surface of the concrete foundation of a house, it can be applied using a coating means known per se, such as a roller, air spray, airless spray, lysine gun, all-purpose gun, brush, trowel, etc. It is particularly preferable to apply the primer paint (I) using a roller, which is a coating means that causes little paint to scatter around.

[0035] The amount of primer (I) applied is usually 100 to 2000 g / m 2 , preferably 200 to 1200 g / m 2 It is desirable to adjust it within the range of

[0036] The primer coating film can usually be dried at room temperature, but forced drying may be used if necessary. The drying time from the application of the primer coating (I) to the application of the top coating (II), which is the next step, is preferably 2 to 168 hours, and more preferably 4 to 72 hours.

[0037] <Process (2)> In the present invention, step (2) is a step of applying a topcoat paint (II) onto the primer coating film formed in step (1) and drying it to form a topcoat coating film having a spotted pattern (hereinafter referred to as a spotted topcoat coating film).

[0038] The topcoat paint (II) is a paint containing colored paint particles (A2) obtained by granulating a colored paint and an aqueous resin (B2).

[0039] Colored paint particles (A2): The colored coating particles (A2) in the present invention are obtained by granulating a colored coating. Examples of the colored coating material used to produce the colored coating particles (A2) include conventional liquid colored coating materials containing a colorant (a2-1), an aqueous resin (a2-2), water, and, if necessary, additives.

[0040] Examples of the colorant (a2-1) include color pigments and luster pigments. Among these, the color pigments include, for example, white pigments such as titanium dioxide; carbon black; Examples of suitable pigments include black pigments such as iron oxide yellow, titanium yellow, monoazo yellow, condensed azo yellow, azomethine yellow, bismuth vanadate, benzimidazolone, isoindolinone, isoindoline, quinophthalone, benzidine yellow, and permanent yellow; orange pigments such as permanent orange; red pigments such as red iron oxide, naphthol AS azo red, anthanthrone, anthraquinonyl red, perylene maroon, quinacridone red pigments, diketopyrrolopyrrole, watching red, and permanent red; purple pigments such as cobalt purple, quinacridone violet, and dioxazine violet; blue pigments such as cobalt blue, phthalocyanine blue, and threne blue; and green pigments such as phthalocyanine green. Examples of luster pigments include metallic pigments such as aluminum powder, bronze powder, copper powder, tin powder, iron phosphide, and zinc powder; and pearlescent pigments such as mica, metal oxide-coated mica powder, and mica-like iron oxide. The color pigments and luster pigments can be used alone or in combination of two or more.

[0041] The type and amount of the colorant (a2-1) used are adjusted appropriately depending on the type of colorant, and can generally be in the range of 0.01 to 500 mass %, preferably 0.05 to 400 mass %, based on the non-volatile mass of the aqueous resin (a2-2).

[0042] In the colored coating material, an extender pigment may be used together with the colorant (a2-1). Examples of the extender pigment include baryta powder, precipitated barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, white carbon, diatomaceous earth, talc, magnesium carbonate, alumina white, gloss white, and silica, and these may be used alone or in combination of two or more.

[0043] The aqueous resin (a2-2) can be any aqueous resin commonly used in the field of aqueous paints. Specific examples include the resins described above as the aqueous resin (B1) contained in the primer paint (I). The aqueous resin (a2-2) and the aqueous resin (B2) may be the same or different, but from the viewpoint of the water resistance of the multi-layer coating film, the same type is preferable, and an acrylic resin, particularly an acrylic resin containing a carbonyl group, is preferred. From the viewpoint of crack resistance on the outer surface of the concrete foundation of a house, the aqueous resin (a2-2) used to produce the colored paint particles (A2) preferably has a non-volatile acid value of 20 mg KOH / g or less, more preferably less than 20 mg KOH / g, and particularly preferably 10 mg KOH / g or less.

[0044] Examples of the additives include specific gravity adjusters such as balloon particles, antifoaming agents, crosslinking agents, catalysts, pigment dispersants, fragrances, deodorizers, antibacterial agents, neutralizing agents, surfactants, water repellents, dispersants, preservatives, mildew inhibitors, antifreeze agents, ultraviolet absorbers, light stabilizers, film-forming aids, and plasticizers.

[0045] The method for producing the colored coating particles (A2) is not particularly limited, but examples include a method in which an aqueous liquid composition containing the colored coating and a water-soluble polysaccharide is brought into contact with an aqueous medium containing a metal compound and stirred.

[0046] The water-soluble polysaccharide is a polysaccharide capable of changing into a water-insoluble or poorly soluble gel when it comes into contact with monovalent or polyvalent metal ions in an aqueous medium. Specific examples of the water-soluble polysaccharide include alginic acid or its alkali metal salts, gellan gum, carrageenan, and combinations thereof.

[0047] The metal compound is a compound capable of generating monovalent or polyvalent metal ions that can form water-insoluble or poorly soluble salts with the water-soluble polysaccharide in an aqueous medium, and the metal species in the metal compound is a Group 2 element of the periodic table, such as magnesium, calcium, strontium, or barium. Calcium is particularly preferred.

[0048] The metal compound is not particularly limited as long as it is a compound containing the above metal species, and examples thereof include metal salts of organic acids such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, oxalic acid, fumaric acid, succinic acid, phosphoric acid, citric acid, and gluconic acid; metal hydroxides, metal oxides; metal carbonates; and Combinations of these may be mentioned.

[0049] The metal compound can be at least partially dissolved in an aqueous medium such as water to prepare an aqueous medium containing metal ions. In this case, the metal compound does not need to be completely dissolved in the aqueous medium, and may be partially dissolved.

[0050] In the production of colored coating particles (A2), the stirring speed when contacting the aqueous liquid composition containing the above-mentioned colored coating and water-soluble polysaccharide with the aqueous medium containing the metal compound is, for example, in the range of 500 to 4000 rpm, preferably 700 to 3000 rpm.

[0051] The size of the colored coating particles (A2) obtained in this manner is generally within the range of 0.1 to 20 mm, preferably 0.2 to 10 mm. By having the size of the colored coating particles (A2) within this range, a clear spotted pattern can be created on the outer surface of the concrete foundation of a house, giving it a luxurious feel.

[0052] In this specification, the size of the colored paint particles (A2) is determined by randomly selecting 30 colored paint particles (A2) contained in the top coat paint (II), observing them under an optical microscope, and calculating the average value.

[0053] In the present invention, from the viewpoint of ease of painting and the texture of the outer surface of the concrete foundation of a house, it is preferable that the non-volatile content of the colored paint particles (A2) is in the range of 5 to 65 mass %, preferably 10 to 45 mass %, of the non-volatile content of the top coat paint (II).

[0054] Water-based resin (B2): In the present invention, the topcoat paint (II) is appropriately dotted with the colored paint particles (A2) and contains an aqueous resin (B2) as a binder component for protecting the outer surface of the concrete foundation of a house, which is the substrate. As the aqueous resin (B2), those generally used in the field of aqueous paints can be used. Specific examples include the resins described above as the aqueous resin (B1) contained in the primer paint (I).

[0055] In the present invention, the aqueous resin (B2) is preferably an acrylic resin, and particularly preferably a resin containing a carbonyl group.

[0056] The amount of the carbonyl group-containing polymerizable unsaturated monomer used to introduce a carbonyl group into the aqueous resin (B2) is preferably within a range of 5 to 35 mass %, particularly 10 to 30 mass %, based on the total amount of polymerizable unsaturated monomers used to produce the aqueous resin (B2).

[0057] The aqueous resin (B2) is preferably a core-shell type dispersed particle, which has the effect of providing the multilayer coating film formed by the coating method of the present invention with excellent alkali resistance, making it suitable for coating alkaline substrates such as residential foundation concrete.

[0058] In the present invention, when core-shell type dispersed particles are produced, for example, a mixture of monomer components forming the core part is emulsion-polymerized using a polymerization initiator in the presence of an emulsifier to obtain an aqueous dispersion of a copolymer, and then a mixture of monomer components forming the shell part is added to the aqueous dispersion. and then emulsion polymerization is carried out using a polymerization initiator.

[0059] The content of the aqueous resin (B2) in the nonvolatile content of the topcoat paint (II) is preferably in the range of 40 to 95 mass %, particularly 55 to 90 mass %.

[0060] Topcoat (II): In the present invention, the topcoat paint (II) preferably contains a crosslinking agent in addition to the colored paint particles (A2) and the aqueous resin (B2). By including a crosslinking agent in the topcoat paint (II), a multilayer coating film that is both crack-resistant and water-resistant can be obtained on the exterior surface of the concrete foundation of a house. The crosslinking agent is preferably a compound having a functional group capable of reacting with the functional group of the aqueous resin (B1) contained in the undercoat paint (I), the aqueous resin (B2) contained in the topcoat paint (II), and the aqueous resin (a2-2) used to produce the colored paint particles (A2). For example, when one or more of the aqueous resins (B1), (B2), and (a2-2) have a carbonyl group, it is preferable to use a hydrazide compound as the crosslinking agent. Examples of the hydrazide compounds include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, carbonic acid dihydrazide, phthalic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, pyromellitic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin, and combinations thereof.

[0061] The topcoat paint (II) may contain, as required, extender pigments, matting agents such as resin beads, luster pigments, and paint additives.

[0062] Examples of extender pigments that can be used in the matting agent include the same substances exemplified as extender pigments in the description of the colored paint particles (A2). On the other hand, examples of resin beads include acrylic resin beads, urethane resin beads, polyester resin beads, polyamide resin beads, polystyrene resin beads, polyethylene resin beads, melamine resin beads, urea resin beads, fluororesin beads, polyacrylonitrile resin beads, etc. By including a matting agent in the topcoat paint (II), the exterior surface of the concrete foundation of a house can be finished with a unique atmosphere that combines the luxurious feel of a speckled pattern with the depth of a matte finish.

[0063] When the topcoat paint (II) contains a matting agent, the content thereof is preferably adjusted to within a range of 0.5 to 30 parts by mass, particularly 5 to 20 parts by mass, based on 100 parts of the nonvolatile content of the aqueous resin (B2) contained in the topcoat paint (II), from the viewpoint of crack resistance on the outer surface of the concrete foundation of a house.

[0064] Examples of paint additives that can be contained in the topcoat paint (II) include neutralizing agents, viscosity adjusters, anti-settling agents, antibacterial agents, curing catalysts, pH adjusters, dispersants, antifoaming agents, preservatives, mildew inhibitors, antifreeze agents, ultraviolet absorbers, light stabilizers, film-forming aids, and plasticizers.

[0065] The viscosity of the top coat paint (II) obtained as described above is preferably 100 KU or more at 25°C, and preferably in the range of 110 to 150 KU. By having the viscosity of the top coat paint (II) within this range, a spotted pattern with little deviation can be obtained even on a surface with fine irregularities, such as the outer surface of a concrete foundation for a house. The viscosity of the top coat paint (II) is measured in accordance with the Stormer viscometer method of JIS K 5600-2-2.

[0066] Top coat (II) application: The topcoat paint (II) can be applied by a known application means, for example, a roller or an air spray. It can be done using painting tools such as an airless spray, a lysine gun, a universal gun, a brush, a trowel, etc. When the topcoat paint (II) is applied to the exterior surface of the concrete foundation of a house using a roller, which is a painting means that applies pressure to the applied surface during painting, individual spots are clear and a spotted pattern with little bias is obtained.

[0067] The amount of topcoat paint (II) applied is usually 50 to 1500 g / m per coat. 2 , preferably 100 to 1000 g / m 2 It is desirable to adjust it within the range of

[0068] The topcoat film formed can usually be dried at room temperature, but forced drying is also possible if necessary. The drying time should be at least 1 hour, and preferably at least 2 hours.

[0069] In the method of the present invention, a step of applying a top coat after applying and drying the top coat (II) may be provided as needed.

[0070] The topcoat paint for recoating is preferably a paint containing the same colored paint particles and aqueous resin as the topcoat paint (II), and a paint having the same composition as the above-mentioned topcoat paint (II) may be recoated, or a different topcoat paint having a different composition of colored paint particles may be applied to improve the texture of the finished appearance. The present invention includes a method for producing a painted exterior surface of a concrete foundation for a house using the above-mentioned painting method, or a method for producing a paint applied to the exterior surface of a concrete foundation for a house. [Example]

[0071] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, "parts" and "%" mean "parts by mass" and "% by mass," respectively.

[0072] Manufacture of water-based resin (B1) for manufacturing primer paint (I) Manufacturing Example 1 A 3-liter, four-necked flask was charged with 485 parts of deionized water and 1 part of "Newcol 707SF" (Note 1), and after purging with nitrogen, the flask was maintained at 85°C. 3% of a pre-emulsion with the following composition and 40 parts of 120 parts of an aqueous initiator solution made by mixing 3 parts of ammonium persulfate and 117 parts of deionized water were added to the flask, and after stirring for 20 minutes, the remaining pre-emulsion and aqueous initiator solution were added dropwise to the flask over 4 hours. Pre-emulsion 368 parts deionized water "New Call 707SF" (Note 1) 67 copies 150 parts styrene 300 parts methyl methacrylate n-Butyl acrylate 300 parts 2-Ethylhexyl acrylate 200 parts 2-Hydroxyethyl acrylate 15 parts Diacetone acrylamide 20 parts Acrylic acid 15 parts After the dropwise addition was completed, the mixture was stirred at 85° C. for a further 2 hours, and then cooled to 40 to 60° C. Next, the pH was adjusted with aqueous ammonia to obtain an aqueous resin (B1-1) in the form of dispersed particles with a nonvolatile content of 50%. (Note 1) "Newcol 707SF": Product name, manufactured by Nippon Nyukazai Co., Ltd., anionic emulsifier with polyoxyethylene chains, non-volatile content 30%.

[0073] Manufacturing Examples 2 and 3 Aqueous resins (B1-2) and (B1-3) were obtained in the same manner as in Production Example 1 above, except that the monomer compositions were as shown in Table 1.

[0074] [Table 1]

[0075] Manufacture of primer paint (I) Production Example 4 In a 1-liter stainless steel container, 115 parts of tap water, 200 parts of the aqueous resin (B1-1) synthesized in Production Example 1, 5 parts of "Nopcosant K" (Note 2), 100 parts of titanium oxide, and 150 parts of calcium carbonate were sequentially added with stirring, and the mixture was stirred until homogeneous. Then, 12 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 5 parts of "BYK-024" (Note 3), 10 parts of a 10% aqueous solution of adipic acid dihydrazide, and "PRIMAL ASE-60" (Note 4) 3 parts was added and stirred until homogeneous to obtain primer paint (I-1). (Note 2) "Nopco Santo K": Trade name, manufactured by San Nopco, sodium polycarboxylate dispersant, non-volatile content 33% (Note 3) "BYK-024": Product name, manufactured by BYK Chemie, silicone-based defoamer, non-volatile content 96% or more (Note 4) "PRIMAL ASE-60": Trade name, manufactured by Dow Chemical Company, anionic alkali swelling thickener, non-volatile content 28%

[0076] Manufacturing Examples 5-10 Primer coatings (I-2) to (I-7) were obtained in the same manner as in Production Example 4 above, except that the blending compositions were as shown in Table 2.

[0077] [Table 2]

[0078] Breaking elongation Each primer coating shown in Table 2 was applied to release paper to a dry film thickness of 0.3 mm and allowed to dry for 14 days in an atmosphere of 23°C and 50% RH. The coating was then peeled off the release paper carefully, and strips measuring 5 mm wide and 20 mm long were cut from the coating to obtain test specimens. These test specimens were mounted in a tensile testing machine (Shimadzu Autograph AG2000B) and subjected to a tensile test at 23°C with a chuck distance of 40 mm and a tensile speed of 20 mm / min. The elongation at break was used to evaluate the elongation.

[0079] Manufacture of water-based resin (a2-2) for manufacturing colored paint particles (A2) Manufacturing Example 11 A 3-liter, four-necked flask was charged with 485 parts of deionized water and 1 part of "Newcol 707SF" (Note 1), and after purging with nitrogen, the flask was maintained at 85°C. 3% of a pre-emulsion with the following composition and 40 parts of 120 parts of an aqueous initiator solution made by mixing 3 parts of ammonium persulfate and 117 parts of deionized water were added to the flask, and after stirring for 20 minutes, the remaining pre-emulsion and aqueous initiator solution were added dropwise to the flask over 4 hours. Pre-emulsion 368 parts deionized water Newcol 707SF (Note 1) 67 copies 150 parts styrene Methyl methacrylate 400 parts n-Butyl acrylate 200 parts 2-Ethylhexyl acrylate 200 parts 2-Hydroxyethyl acrylate 26 parts Diacetone acrylamide 20 parts Acrylic acid 4 parts After the dropwise addition was completed, the mixture was stirred at 85°C for a further 2 hours, and then cooled to 40 to 60°C. Next, the pH was adjusted with aqueous ammonia to obtain an aqueous resin (a-1) in the form of dispersed particles having a nonvolatile content of 50% and a nonvolatile acid value of 3.1 mgKOH / g.

[0080] Manufacturing Example 12 A 3-liter, four-necked flask was charged with 485 parts of deionized water and 1 part of "Newcol 707SF" (Note 1), and after purging with nitrogen, the flask was maintained at 85°C. 3% of a pre-emulsion with the following composition and 40 parts of 120 parts of an aqueous initiator solution made by mixing 3 parts of ammonium persulfate and 117 parts of deionized water were added to the flask, and after stirring for 20 minutes, the remaining pre-emulsion and aqueous initiator solution were added dropwise to the flask over 4 hours. Pre-emulsion 368 parts deionized water Newcol 707SF (Note 1) 67 copies 150 parts styrene Methyl methacrylate 400 parts n-Butyl acrylate 200 parts 2-Ethylhexyl acrylate 200 parts 2-Hydroxyethyl acrylate 18 parts Diacetone acrylamide 20 parts Acrylic acid 12 parts After the dropwise addition was completed, the mixture was stirred at 85°C for a further 2 hours, and then cooled to 40 to 60°C. Next, the pH was adjusted with aqueous ammonia to obtain an aqueous resin (a-2) in the form of dispersed particles having a nonvolatile content of 50% and a nonvolatile acid value of 9.4 mgKOH / g.

[0081] White paste production Manufacturing Example 13 The following ingredients were charged in order into a 1-liter stainless steel container, stirred and mixed for 30 minutes with a stirrer, and then filtered through a 100-mesh nylon cloth and discharged to produce a white paste. Water 300 parts Hydroxyethyl cellulose 2 parts "SN Deformer 777" (Note 5) 10 copies "DISPER BYK-190" (Note 6) 20 copies Titanium dioxide 600 parts (Note 5) "SN Deformer 777": Product name, antifoaming agent manufactured by San Nopco (Note 6) "DISPER BYK-190": Product name, pigment dispersant manufactured by BYK Chemie.

[0082] Black paste production Manufacturing Example 14 The following ingredients were charged in order into a 1-liter stainless steel container, stirred and mixed for 30 minutes with a stirrer, and then filtered through a 100-mesh nylon cloth and discharged to produce a black paste. Water 300 parts Hydroxyethyl cellulose 2 parts "SN Deformer 777" (Note 5) 10 copies "DISPER BYK-190" (Note 6) 20 copies Carbon black 30 parts

[0083] Production of aqueous liquid composition for producing colored coating particles (A2) Manufacturing Example 15 The following components were charged in order into a 1-liter stainless steel container and stirred and mixed with a stirrer until homogeneous, thereby obtaining an aqueous liquid composition (C-1) for colored coating particles. Water-based resin (a-1) 200 parts White paste 100 parts 10% aqueous solution of adipic acid dihydrazide 10 parts 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate 12 parts "BYK-024" (Note 3) 6 copies ADEKA NOL UH-420 (Note 8) 2 copies 370 parts of 2% sodium alginate solution

[0084] Manufacturing Examples 16-19 Aqueous liquid compositions (C-2) to (C-5) for producing colored coating particles were obtained in the same manner as in Production Example 15, except that the blending compositions were as shown in Table 3 below.

[0085] [Table 3]

[0086] (Note 7) Iriodin 103W2: Trade name, manufactured by Merck, titanium dioxide-coated mica pigment (Note 8) Adekanol UH420: Trade name, manufactured by Asahi Denka Co., Ltd., modified polyether urethane, viscosity adjuster.

[0087] Production of aqueous medium for producing colored paint particles (A2): Manufacturing Example 20 An aqueous medium was produced by adding 994 parts of deionized water to a 3-liter stainless steel container, then adding 3 parts of calcium hydroxide and 3 parts of "SN Deformer 777" (Note 5) and stirring for 3 minutes.

[0088] Preparation of colored paint particles (A2): Manufacturing Example 21 1000 parts of the aqueous medium obtained in Production Example 20 was attached to a stirrer with a stirring blade having a diameter of 75 mm, and then 450 parts of the aqueous liquid composition for colored coating particles (C-1) obtained in Production Example 15 was gradually added dropwise to the container while stirring at a rotation speed of 2000 rpm to produce colored coating particles. The liquid in the container was then stirred at the same rotation speed for an additional 5 minutes, and then filtered using an 80-mesh wire screen to obtain colored coating particles (A2-1) with a non-volatile content of 20%.

[0089] Manufacturing Examples 22-25 Colored coating particles (A2-2) to (A2-5) were produced in the same manner as in Production Example 21 above, except that the aqueous liquid compositions in Production Example 21 were as shown in Table 4.

[0090] [Table 4]

[0091] Preparation of water-based resin (B2) for topcoat paint (II): Manufacturing Example 26 A 3-liter, four-necked flask was charged with 485 parts of deionized water and 1 part of "Newcol 707SF" (Note 1), and after purging with nitrogen, the flask was maintained at 85°C. 3% of a pre-emulsion with the following composition and 40 parts of 120 parts of an aqueous initiator solution made by mixing 3 parts of ammonium persulfate and 117 parts of deionized water were added to the flask, and after stirring for 20 minutes, the remaining pre-emulsion and aqueous initiator solution were added dropwise to the flask over 4 hours. Pre-emulsion 368 parts deionized water Newcol 707SF (Note 1) 67 copies Methyl methacrylate 550 parts n-Butyl acrylate 200 parts 2-Ethylhexyl acrylate 200 parts 2-Hydroxyethyl acrylate 36 parts Diacetone acrylamide 10 parts Acrylic acid 4 parts After the dropwise addition was completed, the mixture was stirred at 85° C. for a further 2 hours, and then cooled to 40 to 60° C. Next, the pH was adjusted with aqueous ammonia to obtain an aqueous resin (B2-1) in the form of dispersed particles with a nonvolatile content of 50%.

[0092] Manufacturing Example 27 A 3-liter, four-necked flask was charged with 485 parts of deionized water and 1 part of "Newcol 707SF" (Note 1), and after purging with nitrogen, the flask was maintained at 85°C. 3% of the pre-emulsion (for core use) with the following composition and 40 parts of the 120 parts of an aqueous initiator solution made by mixing 3 parts of ammonium persulfate and 117 parts of deionized water were added to the flask, and after stirring for 20 minutes, the remaining pre-emulsion (for core use) and the aqueous initiator solution were added dropwise to the flask over 3 hours.

[0093] <Pre-emulsion composition (for core)> 300 parts deionized water 350 parts methyl methacrylate n-Butyl acrylate 230 parts 2-Ethylhexyl acrylate 100 parts 2-Hydroxyethyl acrylate 13 parts Vinyltriethoxysilane 6 parts 1 part acrylic acid "New Call 707SF" (Note 1) 46 copies After the dropwise addition, the mixture was further aged at 85° C. for 2 hours, and then a pre-emulsion (for shell) prepared by emulsifying the components shown below and 25% of the above aqueous ammonium persulfate solution were added dropwise over 2 hours.

[0094] <Pre-emulsion composition (for shell)> 200 parts deionized water 200 parts methyl methacrylate n-Butyl acrylate 41 parts 2-Ethylhexyl acrylate 15 parts Diacetone acrylamide 15 parts Hydroxyethyl acrylate 6 parts Vinyltriethoxysilane 2 parts Acrylic acid 4 parts "New Call 707SF" (Note 1) 20 copies After the dropwise addition, the mixture was kept at 85°C for another 2 hours and then cooled to 40-60°C. The pH was then adjusted with aqueous ammonia to obtain a core-shell emulsion (B2-2) with a non-volatile content of 50% and in the form of dispersed particles.

[0095] Manufacture of water-based clear paint for topcoat (II) manufacture Manufacturing Examples 28-30 Water-based clear paints (D-1) to (D-3) were produced with the blending compositions shown in Table 5 below to serve as binder components for the topcoat paint (II).

[0096] [Table 5]

[0097] (Note 9) Silysia 350: Product name, manufactured by Fuji Silysia Corporation, silica

[0098] Preparation of topcoat (II): Manufacturing Example 31 Put 200 parts of water-based clear paint (D-1), 65 parts of colored paint particles (A2-1), 20 parts of colored paint particles (A2-2), and 10 parts of colored paint particles (A2-3) into a container, and while stirring, add 1 part of "BYK-024" (Note 3), 2 parts of 10% adipic acid dihydrazide aqueous solution, and 2 parts of "PRIMAL ASE-60" (Note 4). Stir until the whole is uniform, and then apply the top coat. A paint (II-1) was prepared.

[0099] [Table 6]

[0100] Manufacturing Examples 32-37 Topcoat paints (II-2) to (II-7) were produced in the same manner as in Production Example 31 above, except that the blending compositions were as shown in Table 6.

[0101] coating Example 1 The concrete was poured, the formwork was removed, and the outer surface of the foundation concrete was coated with 600 g / m of primer paint (I-1). 2 The undercoat was then coated with a porous roller so that the thickness of the undercoat was 1 / 4 of the original thickness, and the coating was dried for 24 hours in an atmosphere of 23°C and 50% RH. Then, the topcoat (II-1) was applied to the undercoat film at a coating amount of 400 g / m 2 To ensure that the coating was uniform and to check the extent to which the spots had been crushed, the coating was applied in 10 passes over the same spot with a porous roller, and the coating was then dried for 7 days in an atmosphere of 23°C and 50% RH to prepare a test specimen.

[0102] Examples 2 to 7, 10 to 13 and Comparative Examples 1 to 3 Test specimens were prepared in the same manner as in Example 1 above, except that the paints used were as shown in Table 7 below. Comparative Example 3 is an example in which no primer paint (I) was applied.

[0103] Example 8 Example 8 is an example in which a top coat paint (II-1) was applied and dried, and then the same top coat paint (II-1) was reapplied in order to confirm the repairability of the top coat paint (II). The concrete was poured, the formwork was removed, and the outer surface of the foundation concrete was coated with 600 g / m of primer paint (I-1). 2 The coating was applied with a porous roller so that the coating amount was 400 g / m, and the coating was dried for 24 hours in an atmosphere of 23°C and 50% RH. Then, the topcoat paint (II-1) was applied to the undercoat film by moving the porous roller 10 times. 2 The coating was then dried for 7 days in an atmosphere of 23°C and 50% RH. Then, a topcoat paint (II-1) was applied to the topcoat coating film by rolling a porous roller 10 times to a coating amount of 400 g / m 2 The coating was repeated until the coating was uniform, and the coating was dried for 7 days in an atmosphere of 23°C and 50% RH to obtain a test specimen.

[0104] Example 9 Example 9 is an example in which a topcoat paint (II-1) was applied and dried, and then another topcoat paint (II-5) was applied over it in order to enhance the heavy feel in addition to the repairability of the topcoat paint (II). A test specimen was obtained in the same manner as in Example 8 above, except that the top coat paint (II-5) was used instead of the top coat paint (II-1) to be applied over it.

[0105] Evaluation Test The specimens obtained above were subjected to finish tests. Furthermore, for tests of water resistance, alkali resistance, crack resistance, and weather resistance, test panels were prepared using a flexible board (fiber-reinforced cement board), a material similar to concrete, as the base material, and were evaluated according to the following criteria. The results are also shown in Table 7.

[0106] (*1) Finish The appearance of the test specimen (uniformity of spots and degree of crushing) was evaluated visually. ⊚: There is no deviation in the speckled pattern due to minute irregularities, and the speckled pattern is clear. ◯: The spotted pattern is slightly uneven in the recessed areas, but the spotted pattern is clear. △: The spotted pattern is significantly biased towards the recessed areas and is somewhat unclear ×: The spot pattern is unclear and monotonous. (*2)Water resistance The surface of the flexible board was coated with each primer paint shown in Table 2 at a rate of 600 g / m 2 The surface was then dried for 24 hours in an atmosphere of 23°C and 50% RH. After that, each top coat shown in Table 6 was applied in an amount of 400 g / m 2 The test panels were then immersed in tap water at 23°C for 96 hours, after which their appearance was visually evaluated according to the following criteria: ⊚: No swelling or peeling, and no whitening of the coating film. ○: Slight whitening of the coating film is observed, but no swelling or peeling is observed. △: Part of the coating film is blistered or peeled off, or the coating film is whitened. ×: Blisters, peeling, and whitening of the coating film are observed over the entire surface. (*3) Alkali resistance The surface of the flexible board was coated with each primer paint shown in Table 2 at a rate of 600 g / m 2 The surface was then dried for 24 hours in an atmosphere of 23°C and 50% RH. After that, each top coat shown in Table 6 was applied in an amount of 400 g / m 2 The test panels were then immersed in a saturated aqueous calcium hydroxide solution at 23°C for 48 hours, and their appearance was visually evaluated according to the following criteria. ⊚: No swelling or peeling, and no whitening of the coating film. ○: Slight whitening of the coating film is observed, but no swelling or peeling is observed. △: Part of the coating film is blistered or peeled off, or the coating film is whitened. ×: Blisters, peeling, and whitening of the coating film are observed over the entire surface. (*4) Crack resistance A 1 mm wide, 3 mm deep groove was formed in the center of the back of a flexible plate. Each primer coating listed in Table 2 was applied to the surface of the plate to a dry film thickness of 0.5 mm and allowed to dry for 24 hours at 23°C and 50% RH. Each topcoat coating listed in Table 6 was then applied to a dry film thickness of 0.1 mm and allowed to dry for 14 days at 23°C and 50% RH. The groove in the center of the back of the flexible plate was then pressed with a finger without damaging the coating, and the flexible plate was split to form a test specimen. This test specimen was then mounted in a tensile tester (Shimadzu Corporation, product name: "Autograph AG2000B") and subjected to a tensile test at 23°C and a tensile speed of 1 mm / min. The test specimen was evaluated based on the elongation. ◎: 2.0mm or more. ○: Less than 1.0 to 2.0 mm. △: Less than 0.5 to 1.0 mm. ×: Less than 0.5. (*5) Accelerated weather resistance The surface of the flexible board was coated with each primer paint shown in Table 2 at a rate of 600 g / m 2The surface was then dried for 24 hours in an atmosphere of 23°C and 50% RH. After that, each top coat shown in Table 6 was applied in an amount of 400 g / m 2 The undercoat paint was then coated with a porous roller so that the coating was uniformly even, and the resulting coating was dried for 7 days in an atmosphere of 23°C and 50% RH to prepare a test panel. The resulting test panel was then subjected to a 2000-hour test in accordance with JIS K 5600-7-7 (xenon lamp method), and the appearance of the coating film after the test was visually evaluated according to the following criteria. ⊚: No loss of gloss, swelling, peeling or cracking is observed. ○: Slight loss of gloss is observed, but no swelling, peeling or cracking is observed. Δ: At least one of loss of gloss, swelling, peeling, and cracking is observed. x: Significant loss of gloss or at least one of swelling, peeling, or cracking over the entire coating film is observed.

[0107] [Table 7]

Claims

1. A step (1) of applying a primer coating (I) containing an inorganic pigment (A1) and an aqueous resin (B1) to the outer surface of a concrete foundation for a house and drying the coating to form a primer coating film; a step (2) of applying a topcoat paint (II) containing colored paint particles (A2) obtained by granulating a colored paint and an aqueous resin (B2) on the undercoat paint film obtained in the step (1), and drying the applied topcoat paint to form a topcoat paint film with a speckled pattern; the amount of inorganic pigment (A1) contained in the primer coating (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1), and the elongation at break of a coating film formed from the primer coating (I) is 100% or more at 23°C; How to paint the exterior surface of a house foundation concrete.

2. 2. The coating method according to claim 1, wherein the aqueous resin (B1) is an acrylic resin obtained by emulsion polymerization.

3. 3. The coating method according to claim 1, wherein the aqueous resin (B1) contains a carbonyl group.

4. The coating method according to any one of claims 1 to 3, wherein the water-based resin (B1) has a glass transition temperature of 25°C or lower.

5. The coating method according to any one of claims 1 to 4, wherein the primer coating (I) is applied using a roller.

6. The coating method according to any one of claims 1 to 5, wherein the colored coating particles (A2) contained in the topcoat coating (II) are obtained by contacting a colored coating containing a colorant (a2-1), an aqueous resin (a2-2), and water, and an aqueous liquid composition containing a water-soluble polysaccharide, with an aqueous medium containing a metal compound, and stirring the mixture.

7. 7. The coating method according to claim 6, wherein the aqueous resin (a2-2) has a non-volatile acid value of 20 mg KOH / g or less.

8. The coating method according to any one of claims 1 to 7, wherein the topcoat paint (II) contains an aqueous resin (B2) as a binder component, and the aqueous resin (B2) contains a carbonyl group.

9. The coating method according to any one of claims 1 to 8, wherein the aqueous resin (B2) is a core-shell type dispersed particle.

10. The coating method according to any one of claims 1 to 9, wherein the viscosity of the topcoat paint (II) is 100 KU or more at 25°C.

11. The coating method according to any one of claims 1 to 10, wherein the topcoat paint (II) is applied using a roller.

12. The coating method according to any one of claims 1 to 11, wherein a topcoat paint is further applied on the topcoat coating film formed in step (2).

13. A step (1) of applying a primer coating (I) containing an inorganic pigment (A1) and an aqueous resin (B1) to the outer surface of a concrete foundation for a house and drying the coating to form a primer coating film; a step (2) of applying a topcoat paint (II) containing colored paint particles (A2) obtained by granulating a colored paint and an aqueous resin (B2) on the undercoat paint film obtained in the step (1), and drying the applied topcoat paint to form a topcoat paint film with a speckled pattern; the amount of inorganic pigment (A1) contained in the primer coating (I) is 100 parts by mass or more per 100 parts by mass of the resin non-volatile content of the aqueous resin (B1), and the elongation at break of a coating film formed from the primer coating (I) is 100% or more at 23°C; A method for producing painted exterior concrete surfaces for residential foundations.

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