Film formation method

Abstract

To provide a method capable of forming a film which exhibits rich and matte fine appearance, and is excellent in crack resistance, substrate followability and contamination resistance.SOLUTION: A film formation method coats an undercoat material, a decorative coating material, and a surface finish material onto a coated surface in this order, wherein the undercoat material contains a base coating material which contains resin emulsion and a coloring pigment and has an elongation rate of 30% or more, and a granule having a particle diameter of 45 μm or more, and enables formation of a film having 60-degree glossiness of 30 or less, the decorative coating material is obtained by dispersing liquid or gel color particles in an aqueous matte clear coating material, and the surface finish material contains silica having an average particle diameter of 1 to 200 nm and a resin component in a solid content mass ratio of 0.5:1 to 5:1.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel film-forming method.

Background Art

[0002] Conventionally, on the walls of buildings, civil engineering structures, etc., coating is performed with various decorative paints for the purposes of surface protection, improvement of aesthetics, etc. Among these, decorative paints in which liquid or gel-like color particles are dispersed in an aqueous medium are used in applications where high aesthetics are required because a colorful film can be formed. In the finish with such a decorative paint, a matte finish with suppressed gloss is often required.

[0003] Regarding a method for forming such a film, for example, Patent Document 1 (Japanese Patent Laid-Open No. 9-57186) describes that after applying a decorative paint containing enamel dispersed particles, a clear paint with a specific hiding power is applied, and that a matte type or a stain-resistant type clear paint can be used as the clear paint (Claim 1, Paragraphs 0038, 0040, etc.). In such a method, in order to obtain a stain-resistant matte finish, application of a specific clear paint is essential, but there is a risk of uneven gloss in the final finish appearance.

[0004] On the other hand, Patent Document 2 (Japanese Patent Laid-Open No. 2022-160152) describes that after applying an undercoat containing two kinds of extender pigments with a specific particle size, a paint in which liquid or gel-like color particles are suspended is applied as a decorative paint (Claim 1, Paragraph 0042, etc.), and that a decorative paint with a gloss value of 15 or less can be used as the decorative paint (Paragraph 0063). According to such a method, an appearance of a colorful matte finish can be obtained.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the above-mentioned Patent Document 2, the crack resistance, substrate followability, stain resistance, etc. of the coating film are not considered. Therefore, cracks and the like are likely to occur in the coating film, and the coating film may be contaminated, which may damage the original finish appearance.

[0007] The present invention has been made in view of such points, and an object thereof is to provide a method capable of forming a coating film that exhibits a colorful and matte aesthetic appearance and is excellent in crack resistance, substrate followability, stain resistance, etc.

Means for Solving the Problems

[0008] In order to solve such problems, as a result of intensive studies, the inventor of the present invention came up with a coating film forming method in which a specific undercoat material, a decorative coating material, and a surface finishing material are applied in this order, and the present invention was completed.

[0009] That is, the present invention has the following features. 1. A coating film forming method in which an undercoat material, a decorative coating material, and a surface finishing material are applied to a surface to be coated in this order, wherein the undercoat material contains a resin emulsion and a coloring pigment, is a base coating material having an elongation rate of 30% or more, and contains a granular material having a particle size of 45 μm or more, and forms a coating film having a 60-degree glossiness of 30 or less, the decorative coating material is formed by dispersing liquid or gel-like color particles in an aqueous matte clear coating material, the surface finishing material contains silica having an average particle size of 1 to 200 nm and a resin component in a solid content mass ratio of 0.5:1 to 5:1 and is characterized by being such.

Effects of the Invention

[0010] According to the present invention, it is possible to form a film that exhibits a rich and matte aesthetic appearance and is excellent in crack resistance, substrate followability, stain resistance, etc.

Embodiment for Carrying Out the Invention

[0011] Hereinafter, embodiments for carrying out the present invention will be described.

[0012] The present invention is a film-forming method in which a specific undercoat material and a decorative coating material are sequentially applied to a surface to be coated.

[0013] [Surface to be coated] Examples of the surface to be coated to be painted in the present invention include inner wall surfaces, outer wall surfaces, floor surfaces, ceiling surfaces, roof surfaces, etc. of buildings, civil engineering structures, etc. Examples of the base material constituting such a surface to be coated include various plate-like base materials such as concrete, mortar, or cement board, extruded board, slate board, PC board, ALC board, fiber-reinforced cement board, metal siding board, ceramic siding board, ceramic board, calcium silicate board, gypsum board, plastic board, hard wood chip cement board, PVC extruded siding board, plywood, etc. These may be those subjected to some surface treatment (filler treatment, putty treatment, surfacer treatment, sealer treatment, etc.), those on which a coating film has already been formed, those to which wallpaper has been attached, etc. Further, when the surface to be coated is composed of a plurality of plate-like base materials, joints between the plate-like base materials are preferably filled with joint materials (sealing materials, dry joints, etc.).

[0014] [Undercoat material] The undercoat material in the present invention contains a resin emulsion and a coloring pigment, and is a base coating material having an elongation rate of 30% or more, and contains powder particles having a particle size of 45 μm or more, and forms a film having a glossiness of 60 degrees or less of 30 or less. In the present invention, by using such an undercoat material, a matte undercoat film can be formed, and even if the undercoat film is visible from the gap of the decorative coating film, uneven gloss is less likely to occur, and a finished appearance excellent in aesthetic appearance can be obtained. Moreover, such an undercoat material can form a film excellent in crack resistance, substrate followability, etc. It is considered that such an effect is greatly contributed by powder particles having a relatively large particle size compared to general extender pigments, which make the film matte. The base coating material in the present invention is obtained by removing powder particles having a particle size of 45 μm or more from the undercoat material.

[0015] The base coating material forms a film having an elongation rate of 30% or more (preferably 70% or more, more preferably 100% or more, still more preferably 120% or more). By the elongation rate of the base coating material being within the above range, crack resistance, substrate followability, etc. can be enhanced. The upper limit of the elongation rate is preferably 800% or less, more preferably 500% or less, still more preferably 300% or less. By the upper limit of the elongation rate being within such a range, it is suitable in terms of suppressing cracks in the decorative coating film. The elongation rate of the base coating material can be appropriately set depending on, for example, the type of resin emulsion, glass transition temperature, mixing ratio of coloring pigment and powder particles, etc.

[0016] The elongation rate in the present invention is a value measured by the method of "elongation test at standard time" in JIS A6909 "7.26 elongation test" (elongation rate at standard time (air temperature 23 ° C, relative humidity 50%)). However, as the test piece, one having a dry film thickness of 0.3 mm is used.

[0017] The base coating material contains a resin emulsion and a coloring pigment as essential components. Among these, examples of the resin emulsion include an acrylic resin emulsion, a urethane resin emulsion, a vinyl acetate resin emulsion, an epoxy resin emulsion, a silicone resin emulsion, a fluororesin emulsion, an acrylic vinyl acetate resin emulsion, an acrylic urethane resin emulsion, an acrylic silicone resin emulsion, etc., and one or more of these can be used. Among these, an acrylic resin emulsion, an acrylic silicone resin emulsion, etc. are preferable. The glass transition temperature of the resin constituting such a resin emulsion is preferably -50°C to 50°C, more preferably -40°C to 40°C, and even more preferably -30 to 30°C. In the present invention, the glass transition temperature is a value obtained from the FOX calculation formula. "α to β" is synonymous with "α or more and β or less".

[0018] As coloring pigments in the base coating material, for example, colored pigments, white pigments, black pigments, etc. can be used. Among these, colored pigments are pigments that exhibit colors such as yellow, orange, red, green, blue, purple, etc. Such colored pigments include, for example, inorganic ones such as ferric oxide, hydrated ferric oxide, ultramarine, cobalt blue, cobalt green, etc., and organic ones such as azo-based, naphthol-based, pyrazolone-based, anthraquinone-based, perylene-based, quinacridone-based, disazo-based, isoindolinone-based, benzimidazole-based, phthalocyanine-based, quinophthalone-based, etc. On the other hand, white pigments are pigments that exhibit white, and examples include titanium oxide, zinc oxide, aluminum oxide, etc. Black pigments are pigments that exhibit black, and examples include inorganic ones such as iron black, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, etc., and others such as carbon black. As coloring pigments, pearl pigments, aluminum pigments, lustrous pigments, phosphorescent pigments, fluorescent pigments, etc. can also be used. These coloring pigments can be used singly or in combination of two or more. Also, these coloring pigments may have been subjected to some treatment on their surface. The average particle diameter of the coloring pigment is preferably less than 1 μm, more preferably 0.01 to 0.9 μm.

[0019] In the base coating material, the mixing ratio of the coloring pigment is preferably 3 to 300 parts by mass, more preferably 5 to 250 parts by mass with respect to 100 parts by mass of the solid content of the resin emulsion. If the coloring pigment is in such a mixing ratio, the undercoat material can be colored to a desired color, and the hiding power, aesthetic appearance, etc. can be enhanced, and it is also suitable in terms of crack resistance, substrate followability, etc.

[0020] In addition to the above-described components, the base coating material can contain various additives and the like. Examples of such additives include extender pigments, pigment dispersants, emulsifiers, thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, drying adjusters, antiseptics, antifungal agents, algicides, antibacterial agents, defoamers, adsorbents, deodorants, fibers, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, and the like. Further, as long as the effects of the present invention are not significantly inhibited, it can contain powdery particles having a particle size of less than 45 μm (for example, extender pigments having a particle size of less than 45 μm).

[0021] Since the base coating material contains a resin emulsion, it contains water as a medium. That is, the base coating material is an aqueous material. In addition to water, the medium may contain a water-soluble solvent or the like as necessary. Examples of the water-soluble solvent include alcohols, glycols, glycol ethers, and the like.

[0022] The undercoat material in the present invention contains powdery particles having a particle size of 45 μm or more (hereinafter also referred to as “component (F)”). In the present invention, by using such component (F), the undercoat film can be made to have a matte appearance, and further, physical properties such as crack resistance and substrate followability can be ensured. When the particle size of component (F) is less than the above lower limit value, it becomes difficult to obtain sufficient physical properties in terms of crack resistance, substrate followability, and the like.

[0023] The upper limit of the particle size of component (F) is preferably 1000 μm, more preferably 850 μm, and even more preferably 600 μm. By the particle size of component (F) being equal to or less than the above upper limit value, sufficient physical properties can be obtained in terms of the matte effect.

[0024] Examples of component (F) include gypsum spar, diatomaceous earth, silica sand, gravel, glass beads, resin beads, metal grains, or crushed products such as rocks, glass, ceramics, shells, sintered bodies, concrete, mortar, plastics, and rubber. These may be colored. These can be used alone or in combination of two or more.

[0025] As the component (F), a mode in which powdery particles having a particle size of 45 to 300 μm are contained in an amount of 50% by mass or more (more preferably 60% by mass or more, still more preferably 70 to 100% by mass) in the total amount of the component (F) is suitable. Such a mode is even more preferable in terms of improving the effects of the present invention. The particle size of the component (F) can be measured by sieving using a wire mesh sieve specified in JIS Z8801-1:2000.

[0026] The mixing ratio of the component (F) is preferably 50 to 500 parts by mass, more preferably 60 to 400 parts by mass, still more preferably 70 to 300 parts by mass with respect to 100 parts by mass of the solid content of the resin emulsion. If the component (F) has such a mixing ratio, an undercoat film having a sufficient matte appearance can be formed, and it is also suitable in terms of improving physical properties such as crack resistance and substrate followability.

[0027] The undercoat material of the present invention can contain an extender pigment (G) having a particle size of 1 μm or more and less than 45 μm (hereinafter referred to as "component (G)") as long as the effects of the present invention are not significantly inhibited. The mixing ratio of the component (G) is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 0 to 40 parts by mass with respect to 100 parts by mass of the solid content of the resin emulsion. The mass ratio of the component (F) to the component (G) ((F) component:(G) component) is preferably 100:0 to 80:20, more preferably 100:0 to 90:10.

[0028] The undercoat material in the present invention can be produced by uniformly mixing the above-described components by a conventional method.

[0029] Such an undercoat material forms a film having a matte appearance, and the 60-degree glossiness of the film is 30 or less, preferably 15 or less, more preferably 10 or less, still more preferably 1 to 5. The 60-degree glossiness of the undercoat material is the average value of the 60-degree specular glossiness measured using a gloss meter for a film obtained by spray-coating the undercoat material on a slate plate at an application rate of 0.2 kg / m 2 and drying it for 48 hours under standard conditions (temperature: 23°C, relative humidity: 50%).

[0030] [Decorative coating material] The decorative coating material in the present invention is formed by dispersing liquid or gel-like color particles in an aqueous matte clear coating material. Such liquid or gel-like color particles (hereinafter simply referred to as "color particles") in the decorative coating material contribute to the formation of a colorful film. On the other hand, the aqueous matte clear coating material serves as a medium for the color particles and is an essential component for making the formed film have a matte appearance.

[0031] The decorative coating material in the present invention can be used as a material defined in JIS K5667:2003 "Multicolor pattern paint". Such materials are classified into oil-in-water type (O / W type), water-in-water type (W / W type), etc. according to the combination of color particles and the medium (color particles / medium). The decorative coating material preferably has a water-in-water type (W / W type) aspect.

[0032] In the decorative coating material, the aqueous matte clear coating material can form a matte clear film and can contain a resin emulsion and a extender pigment as constituent components. Such an aqueous matte clear coating material may be any material that can form a transparent film in which the color particles can be visually recognized.

[0033] The resin emulsion (a) (hereinafter also referred to as "(a) component") in the aqueous matte clear coating material acts as a binder for the film and can form a clear film. Examples of the (a) component include acrylic resin emulsion, urethane resin emulsion, vinyl acetate resin emulsion, epoxy resin emulsion, silicone resin emulsion, fluororesin emulsion, acrylic vinyl acetate resin emulsion, acrylic urethane resin emulsion, acrylic silicone resin emulsion, etc., and one or more of these can be used. Among these, acrylic resin emulsion, acrylic urethane resin emulsion, acrylic silicone resin emulsion, fluororesin emulsion, etc. are preferred.

[0034] (a) The glass transition temperature of the resin constituting the component is preferably 30°C or lower, more preferably -10°C to 30°C. By having such a glass transition temperature for the (a) component, the crack resistance, substrate followability, etc. of the film can be further enhanced.

[0035] In the aqueous matte clear coating material, as the extender pigment, an extender pigment (b) having an average particle diameter of more than 15 μm (hereinafter also referred to as the “(b) component”) and an extender pigment (c) having an average particle diameter of 15 μm or less (hereinafter also referred to as the “(c) component”) can be used. In the present invention, by using the (b) component and the (c) component having different average particle diameters in combination as the extender pigment, while making the film have a matte appearance, the performance such as crack resistance and substrate followability can be further enhanced.

[0036] The materials of the (b) component and the (c) component are not particularly limited, and various extender pigments can be used. For example, heavy calcium carbonate, calcite, precipitated calcium carbonate, white carbon, talc, kaolin, clay, pottery clay, china clay, diatomaceous earth, barite powder, barium sulfate, precipitated barium sulfate, silica sand, silica powder, quartz powder, gravel, glass beads, resin beads, or crushed products of rocks, glass, shells, sintered bodies, plastics, rubber, etc. These may be those subjected to surface treatment or the like. These can be used alone or in combination of two or more.

[0037] From the viewpoint of the clarity of the film, it is desirable that the refractive index of the (b) component and the (c) component is 1.4 to 1.7. The refractive index can be measured using an Abbe refractometer.

[0038] (b) The average particle diameter of the component is preferably more than 15 μm, more preferably 16 to 100 μm, and still more preferably 18 to 60 μm. The average particle diameter of (c) component is preferably 15 μm or less, more preferably 0.1 to 14 μm, still more preferably 0.5 to 12 μm, and particularly preferably 1 to 10 μm. The average particle diameters of (b) component and (c) component are average values measured using a laser diffraction particle size distribution measuring device (measurement conditions: distribution standard: volume, refractive index: 1.60 - 0.10i, measurement temperature: 25 °C).

[0039] (b) The mixing ratio of the component is preferably 3 to 100 parts by mass, more preferably 5 to 90 parts by mass, and still more preferably 10 to 80 parts by mass with respect to 100 parts by mass of the solid content of (a) component. The mixing ratio of (c) component is preferably 0.5 to 80 parts by mass, more preferably 1 to 50 parts by mass, and still more preferably 2 to 30 parts by mass with respect to 100 parts by mass of the solid content of (a) component. Further, the mass ratio of (b) component to (c) component ((b) component : (c) component) is preferably 99:1 to 20:80, more preferably 98:2 to 50:50, and still more preferably 97:3 to 60:40. If (b) component and (c) component are in such mixing ratios, a clear film showing a sufficient matting appearance can be formed, which is also suitable in terms of improving physical properties such as crack resistance and substrate followability.

[0040] In the aqueous matting clear coating material, in addition to the above components, known additives can be appropriately mixed. Examples of such additives include dispersion stabilizers, pigment dispersants, emulsifiers, thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, drying adjusters, antiseptics, antifungal agents, anti-algal agents, antibacterial agents, defoaming agents, adsorbents, deodorants, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, solvents, water, etc. The ratio of water (including water as the medium such as (a) component) in the aqueous matting clear coating material is preferably 80 to 800 parts by mass, more preferably 100 to 600 parts by mass, and still more preferably 120 to 500 parts by mass with respect to 100 parts by mass of the solid content of (a) component.

[0041] In the case of an aqueous matte clear coating material, a dispersion stabilizer can be included in order to stably disperse the color particles described later. The dispersion stabilizer is a component that stabilizes the coloring material in a granular form, and can be selected according to the type of resin and coloring material that constitute the color particles. Specific examples of the dispersion stabilizer include, for example, magnesium salts, calcium salts, barium salts, aluminum salts, sodium salts, potassium salts, borate salts, silicate salts, phosphate salts, and the like. In addition, as the dispersion stabilizer, for example, water-soluble polymers, clays, etc. can also be used. Such a dispersion stabilizer can also be used as a gelling agent. The mixing ratio of the dispersion stabilizer is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the solid content of the component (a).

[0042] The aqueous matte clear coating material forms a film having a matte appearance, and the 60-degree glossiness of the film is preferably 30 or less, more preferably 15 or less, and even more preferably 8 or less. The 60-degree glossiness of the aqueous matte clear coating material is a value obtained by measuring the specular glossiness (measurement angle: 60 degrees) when a sample is applied to one side of a black acrylic plate using a film applicator with a gap of 150 μm, the coated surface is placed horizontally, and dried for 48 hours in a standard state (temperature 23°C, relative humidity 50%).

[0043] The color particles in the decorative coating material are those dispersed in the above-mentioned aqueous matte clear coating material. The decorative coating material can contain one or two or more kinds of color particles. When the decorative coating material contains two or more kinds of color particles of different colors, a color pattern formed by two or more kinds of color particles can be formed.

[0044] The color particles in the decorative coating material are granular substances in which a coloring material containing a resin, a coloring pigment, and various additives as required is dispersed in a liquid or gel state in the aqueous matte clear coating material. The resin contained in such a coloring material is preferably an aqueous resin. When the coloring material constituting the color particles contains an aqueous resin, the decorative coating material can be in the form of a water-in-water type (W / W type).

[0045] As the aqueous resin in the colorant, a resin emulsion and / or a water-soluble resin can be used. Among these, examples of the resin emulsion include an acrylic resin emulsion, a urethane resin emulsion, a vinyl acetate resin emulsion, a silicone resin emulsion, a fluororesin emulsion, an acrylic-vinyl acetate resin emulsion, an acrylic-urethane resin emulsion, an acrylic-silicone resin emulsion, etc., and one or more of these can be used. Among these, from the viewpoints of weather resistance, water resistance, etc., an acrylic resin emulsion, an acrylic-urethane resin emulsion, an acrylic-silicone resin emulsion, a fluororesin emulsion, etc. are preferable. The glass transition temperature of the resin emulsion in the colorant is not particularly limited, preferably -10 to 80°C, more preferably 10 to 60°C, and it can also be set to be equal to or higher than the glass transition temperature of the component (a).

[0046] Examples of the water-soluble resin include polyvinyl alcohol, poly(meth)acrylic acid, polyethylene oxide, water-soluble urethane, biogum, galactomannan derivative, alginic acid or its derivative, cellulose derivative, gelatin, casein, albumin, etc., or those chemically modified by oxidation, methylation, carboxymethylation, hydroxyethylation, hydroxypropylation, sulfation, phosphorylation, cationization, etc. These can be used singly or in combination of two or more. Such a water-soluble resin can contribute to the stabilization of the formation of color particles and can also be used as a gel former.

[0047] A mode in which the colorant contains a resin emulsion and a water-soluble resin is preferable. When the colorant contains both a resin emulsion and a water-soluble resin, color particles can be stably formed, and the weather resistance, water resistance, etc. of the film can also be improved. The ratio of the resin emulsion to the water-soluble resin in the colorant is the solid content mass ratio (solid content of the resin emulsion: solid content of the water-soluble resin), preferably 99.5:0.5 to 70:30, more preferably 99:1 to 80:20.

[0048] The coloring pigment in the colorant is a component that imparts color and the like to the color particles. Examples of the coloring pigment include inorganic colored pigments such as ferric oxide (red iron oxide), yellow iron oxide, ultramarine, cobalt blue, and cobalt green; organic colored pigments such as azo-based, naphthol-based, pyrazolone-based, anthraquinone-based, perylene-based, quinacridone-based, disazo-based, isoindolinone-based, benzimidazole-based, phthalocyanine-based, and quinophthalone-based pigments; black pigments such as carbon black, iron-manganese composite oxides, iron-copper-manganese composite oxides, iron-chromium-cobalt composite oxides, copper-chromium composite oxides, copper-manganese-chromium composite oxides, black iron oxide, iron-chromium composite oxides, manganese-bismuth composite oxides, and manganese-yttrium composite oxides; white pigments such as titanium oxide, zinc oxide, and alumina; and other pearl pigments, aluminum pigments, bright pigments, phosphorescent pigments, fluorescent pigments, and the like. These can be used alone or in combination of two or more. The average particle diameter of the coloring pigment is preferably less than 1 μm, more preferably 0.01 to 0.9 μm. The average particle diameter of the coloring pigment is an average value measured using a laser diffraction particle size distribution measuring device.

[0049] The mixing ratio of the coloring pigment in the colorant is preferably 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, based on 100 parts by mass of the solid content of the above resin.

[0050] As color particles in decorative coatings, particulate matter of coloring materials containing resins, coloring pigments, and extender pigments are suitable. That is, it is desirable for the coloring material to contain extender pigments. By the coloring material containing extender pigments, the prevention of uneven gloss of the formed film can be enhanced. Examples of extender pigments in the coloring material include heavy calcium carbonate, calcite, precipitated calcium carbonate, white carbon, talc, kaolin, clay, pottery clay, china clay, diatomaceous earth, barite powder, barium sulfate, precipitated barium sulfate, silica sand, silica powder, quartz powder, resin beads, and the like. These can be used alone or in combination of two or more. The refractive index of the extender pigment is preferably 1.4 to 1.7. The average particle diameter of the extender pigment is preferably less than 40 μm, more preferably 0.1 to 35 μm, still more preferably 0.5 to 25 μm, and particularly preferably 1 to 15 μm. The mixing ratio of the extender pigment in the coloring material is preferably 10 to 300 parts by mass, more preferably 20 to 200 parts by mass, still more preferably 30 to 150 parts by mass with respect to 100 parts by mass of the solid content of the above resin.

[0051] In addition to the above components, the coloring material can contain various additives. Examples of such additives include pigment dispersants, emulsifiers, thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, drying adjusters, preservatives, fungicides, algicides, antibacterial agents, defoaming agents, fibers, gel formers, adsorbents, deodorants, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, solvents, water, and the like. The ratio of water (including water as a medium such as aqueous resins) in the coloring material is preferably 80 to 800 parts by mass, more preferably 100 to 600 parts by mass with respect to 100 parts by mass of the solid content of the above resin.

[0052] The method of granulating the coloring material is not particularly limited, and known methods can be adopted. For example, a method according to the manufacturing method of the materials specified in JIS K5667:2003 "Multicolor Pattern Paint" can be adopted. Specifically, for example, a method of dispersing the coloring material in a medium (part or all of the components of the aqueous matte clear coating material) containing a dispersion stabilizer or the like can be adopted. The dispersion stabilizer is a component that stabilizes the coloring material in a granular form, and acts as a gelling agent for the coloring material, for example.

[0053] The particle size and shape of the color particles can be set as appropriate. Specifically, for example, the shape of the stirring blades during production, the size and position of the stirring blades relative to the stirring tank, the rotation speed of the stirring blades, the stirring time, the viscosity of the coloring material, the addition method and concentration of the dispersion stabilizer, the viscosity of the medium, etc. can be appropriately selected and adjusted. The average particle size of the color particles is preferably 0.05 to 20 mm (more preferably 0.1 to 18 mm). In the present invention, the average particle size of the color particles is a value obtained by drying the color particles on standard white paper for 48 hours under standard conditions and calculating the average value of the major axis (average value of 50 color particles).

[0054] In order to obtain a decorative coating material containing two or more kinds of color particles, for example, After respectively producing color particle dispersion liquids (color particle dispersion liquids containing one kind of color particles) in which one kind of coloring material is dispersed in a medium, these are mixed, or A method of adding and dispersing two or more kinds of coloring materials having different color tones, etc. to the medium simultaneously or in sequence to obtain a color particle dispersion liquid (color particle dispersion liquid containing two or more kinds of color particles), etc. can be adopted. In such a method, as the medium, part or all of the aqueous matte clear coating material can be used. When a color particle dispersion liquid is produced using a part of the components of the aqueous matte clear coating material as the medium, the remaining components of the aqueous matte clear coating material can be mixed with the color particle dispersion liquid.

[0055] In a decorative coating material, the mass ratio of the color particles to the aqueous matte clear coating material (color particles: aqueous matte clear coating material) is preferably 1:99 to 80:20 (more preferably 10:90 to 75:25, even more preferably 30:70 to 70:30).

[0056] [Surface finishing material] The surface finishing material contains silica with an average particle diameter of 1 to 200 nm and a resin component in a solid content mass ratio of 0.5:1 to 5:1. In the present invention, by applying such a surface finishing material, the silica particles are fixed on the surface of the coating film of the decorative coating material, and while maintaining performances such as a colorful matte aesthetic appearance, crack resistance, and substrate followability, the stain resistance can be enhanced.

[0057] The silica in the surface finishing material exhibits excellent stain resistance due to the high hardness of the particle itself and the large number of silanol groups on the particle surface. The average particle diameter of the silica is 1 to 200 nm, preferably 3 to 100 nm. Within this range, a plurality of silicas with different average particle diameters can also be used in combination. When the average particle diameter of the silica is larger than 200 nm, the specific surface area becomes smaller and the silanol groups also decrease, resulting in insufficient stain resistance. When the average particle diameter is smaller than 1 nm, the silica itself becomes unstable, which is not practical. The average particle diameter mentioned here is the average value measured using a dynamic light scattering method particle size distribution measuring device.

[0058] The silica in the surface finishing material is preferably derived from a silica sol, and more preferably derived from a water-dispersible silica sol having a pH of 5.0 or more and less than 9.5 (preferably 6.0 or more and 9.0 or less). Such a neutral type of water-dispersible silica sol can be produced using a silicate compound as a raw material. Examples of the silicate compound include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-sec-butoxysilane, tetra-t-butoxysilane, tetraphenoxysilane, or condensates thereof. In addition, alkoxysilane compounds other than the above silicate compounds, alcohols, glycols, glycol ethers, fluorinated alcohols, silane coupling agents, polyoxyalkylene group-containing compounds, etc. can also be used in combination.

[0059] The resin component in the surface finishing material plays a role in fixing the silica to the surface of the coating film of the decorative coating material, and various resins can be used. Specifically, for example, acrylic resin, urethane resin, vinyl acetate resin, silicone resin, fluororesin, acrylic vinyl acetate resin, acrylic urethane resin, acrylic silicone resin, etc. can be mentioned, and one or more of these can be used. As such a resin component, a water-soluble resin and / or a resin emulsion is preferable. The glass transition temperature of such a resin component is not particularly limited, and is preferably -10 to 60°C, more preferably 0 to 50°C.

[0060] The solid content mass ratio (silica: resin component) of the silica and the resin component in the surface finishing material is 0.5:1 to 5:1, preferably 0.8:1 to 4:1, more preferably 1:1 to 3:1. Such a ratio is preferable in terms of a matte finish appearance, stain resistance, etc., and it becomes possible to stably exhibit the effects of the present invention over a long period of time.

[0061] The solid content of the surface finishing material is preferably 0.1 to 20% by mass, more preferably 0.2 to 10% by mass. The solid content of the surface finishing material is the solid content during use, and it can be a high solid content during manufacturing, storage, and transportation, and can be appropriately diluted during use to obtain the above solid content. If the solid content concentration of the surface finishing material is set within the above range, it is suitable in terms of the finishability of the matte appearance and the like.

[0062] The surface finishing material may contain various components other than the above components as long as the effects of the present invention are not significantly impaired. Examples of such components include thickeners, film-forming aids, leveling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, preservatives, antifungal agents, algicides, antibacterial agents, dispersants, antifoaming agents, crosslinking agents, fugitive pigments, light stabilizers, ultraviolet absorbers, antioxidants, solvents, water, and the like.

[0063] [Film formation method] In the present invention, a primer, a decorative coating material, and a surface finishing material are sequentially applied (painted) to the surface to be coated.

[0064] Before applying the primer, surface treatment of the surface to be coated (substrate, existing film, sealing material, etc.) can be performed as necessary. Examples of the surface treatment include cleaning treatment, pickling treatment, filler treatment, putty treatment, surfacer treatment, sealer treatment, and the like. Such surface treatment can be appropriately performed in consideration of, for example, the type and state of the surface to be coated.

[0065] As the method of applying the primer, for example, spray painting, roller painting, trowel painting, brush painting, etc. can be adopted.

[0066] The primer can be applied one or more times. The number of coating times of the primer is preferably 1 or 2 times. The coating amount of the primer is preferably 0.05 to 1 kg / m 2 、more preferably 0.1 to 0.8 kg / m 2 per application. By applying the primer under such conditions, a primer film suitable for applying the decorative coating material can be formed, and the effects of the present invention can be easily obtained.

[0067] When applying the undercoat material, a diluent such as water can be mixed to appropriately adjust the viscosity. The dilution ratio is preferably 0 to 20% by mass. The viscosity of the undercoat material to be used for painting is preferably 3 to 30 Pa·s (more preferably 4 to 20 Pa·s), and the thixotropy index is preferably 2 to 9 (even more preferably 3 to 8). Here, the viscosity and thixotropy index mentioned refer to the values obtained using a BH-type viscometer as the measuring instrument (measurement temperature 23°C). The viscosity is the measured value when the rotation speed is 20 rpm. The thixotropy index is the value obtained by dividing the measured value at a rotation speed of 2 rpm by the measured value at a rotation speed of 20 rpm.

[0068] The drying of the undercoat material may preferably be carried out at normal temperature (0 to 40°C). When applying the undercoat material multiple times, it is desirable to apply the subsequent undercoat material after the film of the previous undercoat material has dried.

[0069] In the present invention, a decorative coating material is applied to the surface of the film of the above-mentioned undercoat material. The decorative coating material is preferably applied after the film of the undercoat material has dried.

[0070] As the method for applying the decorative coating material, for example, spray coating, roller coating, brush coating, etc. can be adopted. In roller coating, for example, a porous roller, a sponge roller, etc. can be used. The decorative coating material can be applied once or multiple times.

[0071] The application amount of the decorative coating material is preferably 0.1 kg / m per application 2 or more, more preferably 0.2 kg / m 2 or more. By setting the lower limit of the application amount of the decorative coating material to the above value, a film with a rich and colorful aesthetic appearance can be formed with a relatively small number of coating times (once or twice). The upper limit of the application amount of the decorative coating material is preferably 1.5 kg / m per application 2 or less, more preferably 1.2 kg / m 2The following is the case. By setting the upper limit of the coating amount of the decorative coating material to the above value, it is possible to sufficiently suppress the downward deviation of color particles during or after drying of the decorative coating material.

[0072] When applying the decorative coating material, a diluent such as water can be mixed to appropriately adjust the viscosity. The dilution ratio is preferably 0 to 10% by mass. The viscosity of the decorative coating material to be used for painting is preferably 1 to 30 Pa·s (more preferably 2 to 20 Pa·s), and the thixotropy index is preferably 2 to 9 (even more preferably 3 to 8).

[0073] The drying of the decorative coating material is preferably carried out at room temperature (0 to 40°C). When the decorative coating material is applied multiple times, it is desirable to apply the subsequent decorative coating material after the film of the previous decorative coating material has dried.

[0074] In the present invention, a surface finishing material is applied to the surface of the film of the above decorative coating material. It is desirable to apply the surface finishing material after the film of the decorative coating material has dried.

[0075] As a method for applying the surface finishing material, for example, spray painting, roller painting, brush painting, etc. can be adopted. The coating amount of the surface finishing material is preferably 0.005 to 0.5 kg / m 2 , more preferably 0.01 to 0.3 kg / m 2 . Within this range, multiple coats may be applied. By setting the lower limit of the coating amount of the surface finishing material to the above value, it is suitable in terms of stain resistance, etc. By setting the upper limit of the coating amount of the surface finishing material to the above value, it is possible to sufficiently ensure the performance such as the aesthetic appearance, crack resistance, and substrate followability of the finished appearance.

[0076] The drying of the surface finishing material is preferably carried out at room temperature (0 to 40°C). When the surface finishing material is applied multiple times, it is desirable to apply the subsequent surface finishing material after the previous surface finishing material has dried.

[0077] In the present invention, such painting can form a film exhibiting a colorful and matte aesthetic appearance.

Example

[0078] Examples and comparative examples are shown below to clarify the features of the present invention, but the present invention is not construed as being limited to these examples.

[0079] (Manufacture of primer) Using the parts by mass shown in Table 1, each raw material was mixed and stirred by a conventional method to produce a base coating material, and then the particulate matter was mixed and stirred into the base coating material to produce each primer. The following materials were used as raw materials. The elongation rate and 60-degree glossiness of the base coating material in each primer are as shown in Table 1.

[0080] ·Resin 1: Acrylic silicone resin emulsion (glass transition temperature 3°C, solid content 50% by mass) ·Resin 2: Acrylic resin emulsion (glass transition temperature 15°C, solid content 50% by mass) ·Resin 3: Acrylic resin emulsion (glass transition temperature 42°C, solid content 50% by mass) ·Coloring pigment 1: Light yellow-based coloring pigment mixture {mixed dispersion liquid of titanium oxide (average particle size 0.3 μm) · petal handle (average particle size 0.2 μm) · yellow iron oxide (average particle size 0.5 μm), solid content 60% by mass} ·Extender pigment 1: Heavy calcium carbonate (average particle size 6 μm, particle size 2 - 10 μm, ratio of particles with particle size 106 - 300 μm in total particulate matter 0% by mass, refractive index 1.6) ·Particulate matter 1: Silica sand (particle size: 45 - 425 μm, ratio of particles with particle size 45 - 300 μm in total particulate matter 96% by mass, refractive index 1.5) ·Particulate matter 2: Silica sand (particle size: 53 - 600 μm, ratio of particles with particle size 45 - 300 μm in total particulate matter 88% by mass, refractive index 1.5) ·Particulate matter 3: Silica sand (particle size: 150 - 600 μm, ratio of particles with particle size 45 - 300 μm in total particulate matter 42% by mass) ·Film-forming aid: Ester-based film-forming aid, ether-based film-forming aid ·Thickener: Urethane-based thickener ·Additive: Preservative, mildew-proof agent, algicide, light stabilizer · Defoaming agent: silicone-based defoaming agent

[0081]

Table 1

[0082] (Manufacture of Decorative Coating 1) To the a mixture of the water-based matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 1 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 1 was added to obtain a color particle dispersion liquid 1-1 in which yellow gel-like color particles with an average particle size of 1.5 mm were dispersed. On the other hand, to the a mixture of the water-based matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 2 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 1 was added to obtain a color particle dispersion liquid 1-2 in which brown gel-like color particles with an average particle size of 1.5 mm were dispersed. By mixing these color particle dispersion liquids 1-1 and 1-2 at a mass ratio of 80:20, Decorative Coating 1 was manufactured (Table 4).

[0083] In the manufacture of the decorative coating, the following were used as raw materials. · Resin 4: Acrylic silicone resin emulsion (glass transition temperature 20°C, solid content 40% by mass) · Resin 5: Acrylic silicone resin emulsion (glass transition temperature 38°C, solid content 40% by mass) · Resin 6: Acrylic resin emulsion (glass transition temperature 28°C, solid content 40% by mass) · Resin 7: Acrylic resin emulsion (glass transition temperature -5°C, solid content 40% by mass) · Resin 8: Water-soluble resin (aqueous solution of galactomannan derivative, solid content 3% by mass) · Dispersant: Anionic dispersant · Extender pigment 2: Resin beads (average particle diameter 38 μm, refractive index 1.5) · Extender pigment 3: Heavy calcium carbonate (average particle diameter 26 μm, refractive index 1.6) · Extender pigment 4: Silica powder (average particle diameter 58 μm, refractive index 1.6) · Extender pigment 5: Diatomaceous earth (average particle diameter 6 μm, refractive index 1.5) · Extender pigment 6: Heavy calcium carbonate (average particle size 4 μm, refractive index 1.6) · Extender pigment 7: Talc (average particle size 5 μm, refractive index 1.6) · Color pigment 2: Yellow color pigment mixture {mixed dispersion of titanium oxide (average particle size 0.3 μm) · bengal (average particle size 0.2 μm) · yellow iron oxide (average particle size 0.5 μm) · black iron oxide (average particle size 0.8 μm), solid content 60% by mass} · Color pigment 3: Brown color pigment mixture {mixed dispersion of bengal (average particle size 0.2 μm) · yellow iron oxide (average particle size 0.5 μm) · black iron oxide (average particle size 0.8 μm), solid content 60% by mass} · Film-forming aid: Ester-based film-forming aid, ether-based film-forming aid · Dispersion stabilizer: 5% by mass aqueous solution of gelling agent · Thickener: Urethane-based thickener · Additive: Preservative, mildew preventive, algicide, light stabilizer · Defoamer: Silicon-based defoamer

[0084] (Manufacture of decorative coating material 2) To the a mixture of the water-based matte clear 2 with the formulation shown in Table 2, 100 parts by mass of the colorant 1 with the formulation shown in Table 3 was added and stirred and dispersed, and then the b mixture of the water-based matte clear 2 was added to obtain a color particle dispersion liquid 2-1 in which yellow gel-like color particles with an average particle size of 1.3 mm were dispersed. On the other hand, to the a mixture of the water-based matte clear 2 with the formulation shown in Table 2, 100 parts by mass of the colorant 2 with the formulation shown in Table 3 was added and stirred and dispersed, and then the b mixture of the water-based matte clear 2 was added to obtain a color particle dispersion liquid 2-2 in which brown gel-like color particles with an average particle size of 1.5 mm were dispersed. By mixing these color particle dispersion liquids 2-1 and 2-2 at a mass ratio of 80:20, the decorative coating material 2 was manufactured (Table 4).

[0085] (Manufacture of decorative coating material 3) To the a mixture of the aqueous matte clear 3 with the formulation shown in Table 2, 100 parts by mass of the colorant 1 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the aqueous matte clear 3 was added, whereby a color particle dispersion liquid 3-1 in which yellow gel-like color particles with an average particle diameter of 1.6 mm were dispersed was obtained. On the other hand, to the a mixture of the aqueous matte clear 3 with the formulation shown in Table 2, 100 parts by mass of the colorant 2 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the aqueous matte clear 3 was added, whereby a color particle dispersion liquid 3-2 in which brown gel-like color particles with an average particle diameter of 1.4 mm were dispersed was obtained. By mixing these color particle dispersion liquids 3-1 and 3-2 at a mass ratio of 80:20, a decorative coating material 3 was produced (Table 4).

[0086] (Production of Decorative Coating Material 4) To the a mixture of the aqueous matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 3 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the aqueous matte clear 1 was added, whereby a color particle dispersion liquid 4-1 in which yellow gel-like color particles with an average particle diameter of 1.6 mm were dispersed was obtained. On the other hand, to the a mixture of the aqueous matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 4 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the aqueous matte clear 1 was added, whereby a color particle dispersion liquid 4-2 in which brown gel-like color particles with an average particle diameter of 1.5 mm were dispersed was obtained. By mixing these color particle dispersion liquids 4-1 and 4-2 at a mass ratio of 80:20, a decorative coating material 4 was produced (Table 4).

[0087] (Production of Decorative Coating Material 5) To the a mixture of the aqueous matte clear 4 with the formulation shown in Table 2, 100 parts by mass of the colorant 3 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the aqueous matte clear 4 was added, whereby A color particle dispersion liquid 5-1 in which yellow gel-like color particles with an average particle size of 1.8 mm were dispersed was obtained. On the other hand, 100 parts by mass of a colorant 4 having the formulation shown in Table 3 was added to an a mixture of an aqueous matte clear 4 having the formulation shown in Table 2, and the mixture was stirred and dispersed. Then, by adding a b mixture of the aqueous matte clear 4, a color particle dispersion liquid 5-2 in which brown gel-like color particles with an average particle size of 1.7 mm were dispersed was obtained. By mixing these color particle dispersion liquids 5-1 and 5-2 at a mass ratio of 80:20, a decorative coating material 5 was produced (Table 4).

[0088] (Production of Decorative Coating Material 6) To an a mixture of an aqueous matte clear 5 having the formulation shown in Table 2, 100 parts by mass of a colorant 3 having the formulation shown in Table 3 was added, and the mixture was stirred and dispersed. Then, by adding a b mixture of the aqueous matte clear 5, a color particle dispersion liquid 6-1 in which yellow gel-like color particles with an average particle size of 1.8 mm were dispersed was obtained. On the other hand, 100 parts by mass of a colorant 4 having the formulation shown in Table 3 was added to an a mixture of an aqueous matte clear 5 having the formulation shown in Table 2, and the mixture was stirred and dispersed. Then, by adding a b mixture of the aqueous matte clear 5, a color particle dispersion liquid 6-2 in which brown gel-like color particles with an average particle size of 1.6 mm were dispersed was obtained. By mixing these color particle dispersion liquids 6-1 and 6-2 at a mass ratio of 80:20, a decorative coating material 6 was produced (Table 4).

[0089] (Production of Decorative Coating Material 7) To an a mixture of an aqueous matte clear 6 having the formulation shown in Table 2, 100 parts by mass of a colorant 3 having the formulation shown in Table 3 was added, and the mixture was stirred and dispersed. Then, by adding a b mixture of the aqueous matte clear 6, a color particle dispersion liquid 7-1 in which yellow gel-like color particles with an average particle size of 1.7 mm were dispersed was obtained. On the other hand, 100 parts by mass of a colorant 4 having the formulation shown in Table 3 was added to an a mixture of an aqueous matte clear 6 having the formulation shown in Table 2, and the mixture was stirred and dispersed. Then, by adding a b mixture of the aqueous matte clear 6, a color particle dispersion liquid 7-2 in which brown gel-like color particles with an average particle size of 1.5 mm were dispersed was obtained. By mixing these color particle dispersion liquids 7-1 and 7-2 at a mass ratio of 80:20, a decorative coating material 7 was produced (Table 4).

[0090] (Manufacture of Decorative Coating Material 8) To the a mixture of the water-based matte clear 7 with the formulation shown in Table 2, 100 parts by mass of the colorant 3 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 7 was added. A color particle dispersion liquid 8-1 in which yellow gel-like color particles with an average particle size of 1.6 mm were dispersed was obtained. On the other hand, to the a mixture of the water-based matte clear 7 with the formulation shown in Table 2, 100 parts by mass of the colorant 4 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 7 was added. By doing so, a color particle dispersion liquid 8-2 in which brown gel-like color particles with an average particle size of 1.6 mm were dispersed was obtained. By mixing these color particle dispersion liquids 8-1 and 8-2 at a mass ratio of 80:20, the decorative coating material 8 was manufactured (Table 4).

[0091] (Manufacture of Decorative Coating Material 9) To the a mixture of the water-based matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 5 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 1 was added. A color particle dispersion liquid 9-1 in which yellow gel-like color particles with an average particle size of 1.5 mm were dispersed was obtained. On the other hand, to the a mixture of the water-based matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 6 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 1 was added. By doing so, a color particle dispersion liquid 9-2 in which brown gel-like color particles with an average particle size of 1.5 mm were dispersed was obtained. By mixing these color particle dispersion liquids 9-1 and 9-2 at a mass ratio of 80:20, the decorative coating material 9 was manufactured (Table 4).

[0092] (Manufacture of Decorative Coating Material 10) To the a mixture of the water-based matte clear 1 with the formulation shown in Table 2, 100 parts by mass of the colorant 7 with the formulation shown in Table 3 was added and stirred for dispersion, and then the b mixture of the water-based matte clear 1 was added. A color particle dispersion liquid 10-1 in which yellow gel-like color particles with an average particle size of 1.6 mm were dispersed was obtained. On the other hand, 100 parts by mass of a colorant 8 having the formulation shown in Table 3 was added to an a mixture of the aqueous matte clear 1 having the formulation shown in Table 2, and the mixture was stirred and dispersed. Then, by adding the b mixture of the aqueous matte clear 1, a color particle dispersion liquid 10-2 in which brown gel-like color particles with an average particle size of 1.2 mm were dispersed was obtained. By mixing these color particle dispersion liquids 10-1 and 10-2 at a mass ratio of 80:20, a decorative coating material 10 was produced (Table 4).

[0093] (Production of Decorative Coating Material 11) To an a mixture of the aqueous matte clear 8 having the formulation shown in Table 2, 100 parts by mass of a colorant 1 having the formulation shown in Table 3 was added, and the mixture was stirred and dispersed. Then, by adding the b mixture of the aqueous matte clear 8, a color particle dispersion liquid 11-1 in which yellow gel-like color particles with an average particle size of 1.5 mm were dispersed was obtained. On the other hand, to an a mixture of the aqueous matte clear 8 having the formulation shown in Table 2, 100 parts by mass of a colorant 2 having the formulation shown in Table 3 was added, and the mixture was stirred and dispersed. Then, by adding the b mixture of the aqueous matte clear 8, a color particle dispersion liquid 11-2 in which brown gel-like color particles with an average particle size of 1.6 mm were dispersed was obtained. By mixing these color particle dispersion liquids 11-1 and 11-2 at a mass ratio of 80:20, a decorative coating material 11 was produced (Table 4).

[0094]

Table 2

[0095]

Table 3

[0096]

Table 4

[0097] (Production of Surface Finishing Material 1) Silica sol 1 (aqueous dispersion silica sol, pH 7.6, solid content 20% by mass, average particle diameter 27 nm) and resin 7 (acrylic resin emulsion, glass transition temperature 18 °C, solid content 45% by mass) were mixed so that the solid content mass ratio was 1.2:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 1 with a solid content of 2% by mass.

[0098] (Production of surface finishing material 2) Silica sol 1 (same as above) and resin 7 (same as above) were mixed so that the solid content mass ratio was 2.0:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 2 with a solid content of 2% by mass.

[0099] (Production of surface finishing material 3) Silica sol 1 (same as above) and resin 7 (same as above) were mixed so that the solid content mass ratio was 2.8:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 3 with a solid content of 2% by mass.

[0100] (Production of surface finishing material 4) Silica sol 2 (aqueous dispersion silica sol, pH 7.8, solid content 12% by mass, average particle diameter 12 nm) and resin 7 (same as above) were mixed so that the solid content mass ratio was 2.0:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 4 with a solid content of 2% by mass.

[0101] (Production of surface finishing material 5) Silica sol 1 (same as above) and resin 8 (acrylic silicone resin emulsion, glass transition temperature 35 °C, solid content 45% by mass) were mixed so that the solid content mass ratio was 1.2:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 5 with a solid content of 2% by mass.

[0102] (Production of surface finishing material 6) Silica sol 1 (same as above) and resin 7 (same as above) were mixed so that the solid content mass ratio was 0.3:1, and a film-forming aid, thickener, antifoaming agent, and water were added thereto to produce a surface finishing material 6 with a solid content of 2% by mass.

[0103] (Test method) The tests were carried out and evaluated by the following methods. Note that all painting and drying were carried out under standard conditions (temperature 23°C, relative humidity 50%).

[0104] (1) Evaluation 1 On a slate board (900 mm × 900 mm × 3 mm) that had been pre-treated with a sealer, an undercoat was spray-painted at an application rate of 0.2 kg / m 2 and dried for 24 hours. Then, a decorative paint was spray-painted at an application rate of 0.6 kg / m 2 and dried for 24 hours. Next, a surface finish was spray-painted at an application rate of 0.1 kg / m 2 and dried and cured for 7 days. The appearance of the test panels obtained by the above method was visually observed. The evaluation was carried out in three grades (excellent: A > B > C: inferior), where those with no gloss unevenness and excellent finish appearance were rated "A", and those with gloss unevenness were rated "C".

[0105] (2) Evaluation 2 For the test panels cut out from the test panels obtained in Evaluation 1 to 100 mm × 300 mm, a thermal cycling test with a cycle of 18 hours of water immersion, 3 hours of standing at -20°C, and 3 hours of standing at 50°C was carried out for a total of 10 cycles. Then, the film appearance was confirmed and the state of crack occurrence was evaluated. The evaluation was carried out in three grades (excellent: A > B > C: inferior), where those with no crack occurrence were rated "A", and those with obvious crack occurrence were rated "C".

[0106] (3) Evaluation 3 Two slate boards of 100 mm × 300 mm × 6 mm were installed side by side, and a test substrate was made by filling a modified silicone-based sealing material into the connecting part (width 10 mm) between the boards. For the entire surface of this test substrate, an undercoat was spray-painted at an application rate of 0.2 kg / m 2 and dried for 24 hours. Then, a decorative paint was spray-painted at an application rate of 0.6 kg / m 2 and dried for 24 hours. Next, a surface finish was spray-painted at an application rate of 0.1 kg / m 2It was spray-painted and air-dried for 7 days. For the specimens obtained by the above method, a total of 10 cycles of temperature and cold repeated tests were performed, with 18 hours of water immersion, 3 hours of standing at -20°C, and 3 hours of standing at 50°C as one cycle. After that, the appearance of the coating was checked and the state of substrate followability was evaluated. The evaluation was carried out in three grades (excellent: A > B > C: poor), where those with no abnormality in the coating appearance and excellent substrate followability were rated as "A", and those with obvious abnormalities such as cracks were rated as "C".

[0107] (4) Evaluation 4 For the test panels cut out to 100 mm × 300 mm from the test panels obtained in the above Evaluation 1, they were exposed outdoors at a 45-degree angle southward for 4 months, and the contamination states before and after exposure were visually observed. The evaluation was carried out in three grades (excellent: A > B > C: poor), where those with no contamination were rated as "A", and those with obvious contamination were rated as "C".

[0108] (Test Results) The combinations of the undercoat materials, decorative coating materials, and surface treatment materials used, and their test results are shown in Tables 5 to 6. In the examples, good results were obtained in each test.

[0109]

Table 5

[0110]

Table 6

Claims

1. A coating method for coating a surface by applying an undercoat material, a decorative coating material, and a surface finishing material in that order, The undercoat material contains a base coating material containing a resin emulsion and a color pigment, and has an elongation rate of 30% or more, and a powder having a particle size of 45 μm or more, and forms a coating film with a 60 degree gloss of 30 or less; The decorative coating material is a coating material in which liquid or gel-like color particles are dispersed in a water-based matte clear coating material, The surface finishing material contains silica having an average particle size of 1 to 200 nm and a resin component in a solid content mass ratio of 0.5:1 to 5:

1. The coating forming method according to the present invention is characterized in that

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