Coating Formation Method

Abstract

This invention provides a coating film formation method that enables the creation of a novel, highly decorative coating film, unlike anything seen before, using a topcoat material in which liquid or gel-like color particles are dispersed in an aqueous medium. [Solution] The present invention relates to a method for forming a coating film by sequentially applying a main material and a topcoat to a surface to be coated, wherein the main material contains a resin component and granular material, and forms a main material coating film having an uneven pattern, and the topcoat is a liquid or gel-like color particle containing granular material with an average particle size of 1 μm or more dispersed in an aqueous medium, and after applying the topcoat, the color particle is stretched using a pressing tool while the coating film of the topcoat is still wet.

Description

[Technical Field]

[0001] This invention relates to a novel method for forming a coating film. [Background technology]

[0002] Traditionally, the walls of buildings and civil engineering structures have been coated with various topcoats for purposes such as surface protection and aesthetic enhancement. Among these, topcoats in which liquid or gel-like color particles are dispersed in an aqueous medium are used in applications where high aesthetic appeal is required, as they can form a richly colored coating.

[0003] As a method for forming such a coating film, for example, Patent Document 1 (Japanese Patent Application Publication No. 2013-99725) describes a coating film formation method in which two types of intermediate coating paints are applied to form a blurred pattern coating film, and then a coating paint containing colored paint particles is applied. The purpose of this coating film formation method is to form original multi-colored patterns that are three-dimensional and have a sense of depth. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-99725 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in the above-mentioned patent document, the patterns formed by paint containing colored paint particles are limited to spotted patterns in which colored paint particles (color granules) are scattered.

[0006] The present invention has been made in view of these points, and aims to provide a coating film forming method that can form a novel, highly decorative coating film unlike any other, using a topcoat material in which liquid or gel-like color particles are dispersed in an aqueous medium. [Means for solving the problem]

[0007] To solve these problems, the inventors, after diligent research, conceived a method for forming a coating film using specific main materials and topcoat materials, and thus completed the present invention.

[0008] In other words, the present invention has the following features. 1. A method for forming a coating film by sequentially applying a main material and a topcoat material to a surface to be coated, The above main material contains resin components and powders and granules, and forms a main material coating film having an uneven pattern. The above topcoat material consists of liquid or gel-like color particles containing powders with an average particle size of 1 μm or more, dispersed in an aqueous medium. After applying the above topcoat material, while the coating film of the above topcoat material is still wet, the above color particles are spread out using a pressing tool. A method for forming a coating film, characterized by the features described above. 2. The above-mentioned granular material with an average particle diameter of 1 μm or more includes granular material with an average particle diameter of 1 μm or more and less than 50 μm, and / or granular material with an average particle diameter of 50 μm or more. The coating film forming method according to 1., characterized by the features described above. [Effects of the Invention]

[0009] According to the present invention, a novel, highly decorative coating film, unlike anything seen before, can be formed using a topcoat material in which liquid or gel-like color particles are dispersed in an aqueous medium. [Modes for carrying out the invention]

[0010] The following describes embodiments for carrying out the present invention.

[0011] The present invention relates to a method for forming a coating film, wherein a main material and a topcoat material are applied sequentially to a surface to be coated, the main material comprising a resin component and granular material, forming a main material coating film having an uneven pattern, the topcoat material comprising liquid or gel-like color particles (hereinafter also simply referred to as "color particles") containing granular material with an average particle diameter of 1 μm or more, dispersed in an aqueous medium, and the method is characterized by applying the topcoat material and, while the coating film of the topcoat material is still wet, stretching the color particles using a pressing tool.

[0012] In this invention, a highly aesthetic finish can be obtained by combining the main coating film and the topcoat coating film, and a new, highly decorative coating film unlike any other can be formed. Specifically, in this invention, by stretching the color particles, a flow pattern (streaky pattern) is formed, which is different from a simple granular pattern. Moreover, since the color particles are stretched on the main coating film which has an uneven surface, the degree of stretching differs depending on the position of the color particles, etc., resulting in a natural-looking pattern in which flow patterns of various shapes are mixed together. Furthermore, because the color particles of the topcoat contain specific granular materials, the flow pattern created by the color particles blends easily with the main coating film, resulting in a finish with excellent texture.

[0013] <Surface to be coated> Examples of surfaces to be painted in this invention include interior and exterior surfaces of buildings, civil engineering structures, etc. (e.g., exterior walls, interior walls, ceilings, roofs, etc.). Examples of substrates constituting such surfaces to be painted include concrete, mortar, and plate-shaped substrates. Among these, examples of plate-shaped substrates include cement boards, extruded boards, slate boards, PC boards, ALC boards, fiber-reinforced cement boards, metal siding boards, ceramic siding boards, ceramic boards, calcium silicate boards, plastic boards, hard wood chip cement boards, PVC extruded siding boards, and plywood. When the surface to be painted is composed of multiple plate-shaped substrates, the joints between the plate-shaped substrates may be filled with jointing materials such as sealants and dry jointing materials.

[0014] The surface to be coated may have an existing coating film. Such an existing coating film is formed by, for example, one or more coating agents. As the coating agent, various types such as colored or uncolored, opaque or transparent can be used. For example, those containing one or more resins selected from vinyl acetate resin, alkyd resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, silicone resin, fluororesin, etc. can be mentioned. The existing coating film is a single-layer or multi-layer coating film, and can be, for example, of any type such as an elastic type or a hard type.

[0015] <Main material> The main material of the present invention can be directly applied to the above-mentioned surface to be coated, or can be applied after treating the surface to be coated by applying an undercoat material, a substrate conditioning coating material, etc. (for example, sealer, primer, surfacer, filler, putty, etc.).

[0016] The main material in the present invention contains a resin component and powder particles, and forms a main material coating film having an uneven pattern. As the main material, as long as an uneven pattern can be formed, it is not particularly limited and can be used. Such an uneven pattern is a surface pattern having a height difference of generally about 0.2 to 5 mm. In the present invention, "α to β" is synonymous with "α or more and β or less".

[0017] The resin component is not particularly limited, but one or more selected from water-soluble resins and water-dispersible resins (resin emulsions) are preferred. Examples of the type of resin include vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc., or composite systems thereof. These can be used singly or in combination of two or more. In the present invention, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc. are preferred. These resin components may have crosslinking reactivity.

[0018] As the powder or granular material, for example, aggregates, pigments, etc. can be used. Among these, as the aggregate, preferably, an aggregate with an average particle size of 50 μm or more, more preferably 53 μm to 5 mm can be used. Such aggregates include, for example, marble, shadow stone, serpentine, granite, fluorite, gypsum, feldspar, limestone, silica, silica sand, crushed stone, mica, siliceous shale, and pulverized products thereof, pulverized ceramic products, pulverized ceramic materials, pulverized glass materials, glass beads, pulverized resin products, resin beads, rubber particles, metal particles, etc. Also, pulverized products such as shells, corals, wood, charcoal, activated carbon, waste glass, etc. can be used. Further, those obtained by surface treatment of these surfaces with pigments, dyes, glazes, etc. to form a colored coating (colored aggregates) can also be used. Note that the average particle size of the aggregate is the value of D50 and is obtained by sieving using a metal mesh sieve specified in JIS Z8801-1:2019. This average particle size D50 is the 50% cumulative particle size and refers to the particle size at which the cumulative amount from the fine particle side reaches 50 mass% (average value of the mass distribution).

[0019] As the pigment, for example, coloring pigments, extender pigments, etc. can be used. Specifically, as the coloring pigment, for example, titanium oxide, zinc oxide, alumina, carbon black, graphite, black iron oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, copper-magnesium composite oxide, bismuth-manganese composite oxide, ferric oxide (valve handle), molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chromium green, cobalt green, phthalocyanine green, ultramarine, navy blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigment, pearl pigment, etc. can be mentioned. These can be used singly or in combination of two or more. The average particle size of the coloring pigment is preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 0.01 to 0.9 μm.

[0020] Examples of extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, pottery clay, china clay, diatomaceous earth, hydrated fine silica, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, aluminum hydroxide, resin beads, and resin powder. These can be used individually or in combination of two or more. The average particle size of the extender pigment is preferably less than 50 μm, more preferably 0.5 to 48 μm, and even more preferably 1 to 45 μm. In this invention, the average particle size of the pigment is the D50 value, i.e., the value of the 50% cumulative particle size based on volume (cumulative from the fine particle side), and can be measured using a laser diffraction particle size distribution analyzer.

[0021] Specific examples of main materials include, for instance, stone-like finishing coatings, and coatings such as thin-layer and thick-layer finishing coatings specified in JIS A6909.

[0022] Stone-like finish coatings are coatings capable of forming a coating film that exhibits color due to the color development of aggregates, and are coatings that have resin components and colored aggregates as essential components. With stone-like finish coatings, various colors can be imparted to the main coating film by using one or more types of colored aggregates in appropriate combinations, and fine irregularities can also be given to the coating film surface. The finish can also be improved by using transparent aggregates. The mixing ratio of aggregates is preferably 100 to 4000 parts by mass, more preferably 150 to 3000 parts by mass, and even more preferably 200 to 2000 parts by mass, per 100 parts by mass of solid content of the resin component.

[0023] Stone-like finish coatings may contain other components besides those listed above. Examples of such components include coloring pigments, extender pigments, fibers, film-forming aids, plasticizers, antifreeze agents, preservatives, fungicides, antibacterial agents, defoaming agents, pigment dispersants, thickeners, leveling agents, coupling agents, wetting agents, pH adjusters, matting agents, UV absorbers, antioxidants, catalysts, and crosslinking agents.

[0024] Thin-coat and thick-coat finish coatings specified in JIS A6909 can be obtained by uniformly mixing resin components, coloring pigments, extender pigments, aggregates, and other admixtures (dispersants, thickeners, defoamers, preservatives, etc.). With such coatings, the desired color can be imparted to the coating film by using one or more coloring pigments in combination. The mixing ratio of the coloring pigments is preferably 1 to 300 parts by mass, more preferably 2 to 200 parts by mass, per 100 parts by mass of the solid content of the resin component.

[0025] Extender pigments primarily act as bulking agents and are components that effectively contribute to the formation of thick coating films. The mixing ratio of extender pigments is preferably 10 to 1000 parts by mass, more preferably 20 to 500 parts by mass, per 100 parts by mass of solid content of the resin component.

[0026] The aggregate plays a role in creating fine irregularities on the surface of the coating film. The mixing ratio of the aggregate is preferably 10 to 2000 parts by mass, more preferably 30 to 1500 parts by mass, per 100 parts by mass of the solid content of the resin component.

[0027] When applying such coatings, various textured patterns can be formed by appropriately selecting the type of coating tool and its usage method. These patterns include sand-like, orange peel-like, fibrous-like, ripple-like, stucco-like, uneven, moon-like, comb-like, and insect-eaten patterns. Suitable coating tools include sprays, rollers, trowels, and brushes. Furthermore, various textured patterns can be formed by treating the surface with a design roller, trowel, brush, comb, or spatula before the coating dries. It is also possible to create multi-colored patterns by combining two or more coatings of different colors.

[0028] The amount of coating material applied depends on the type of pattern to be formed, but is preferably 0.5 to 10 kg / m². 2 More preferably 1-8 kg / m 2 More preferably 1.5 to 6 kg / m 2The viscosity of the coating material can be adjusted as needed by mixing in a diluent such as water during painting. The dilution ratio is preferably 0 to 10% by mass. Drying can be carried out at room temperature (preferably 0 to 50°C, more preferably 5 to 45°C).

[0029] <Top coat material> The topcoat material of the present invention comprises liquid or gel-like color particles containing powders with an average particle size of 1 μm or more, dispersed in an aqueous medium.

[0030] Such topcoat materials can be used as materials specified in JIS K5667:2003 "Multicolor Pattern Paints". Such materials are classified into oil-in-water (O / W) type, water-in-water (W / W) type, etc., depending on the combination of color particles and medium (color particles / medium). The topcoat material of the present invention can preferably be of the water-in-water (W / W) type.

[0031] Liquid or gel-like color particles in the topcoat contribute to the formation of a highly decorative coating film. These color particles are liquid or gel-like color particles containing powder (f) with an average particle size of 1 μm or more. In this invention, because the color particles in the topcoat contain powder (f) with an average particle size of 1 μm or more, the flowing pattern created by the color particles blends easily with the main coating film, resulting in a finish with excellent texture. Specifically, the edges of the stretched color particles become slightly blurred, which helps them blend easily with the main coating film and enhances the natural appearance.

[0032] As the powdery material (f) (hereinafter also referred to as "component (f)") with an average particle diameter of 1 μm or more in the color particles, for example, extender pigments, aggregates, etc., can be used. Among these, examples of extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, pottery clay, china clay, diatomaceous earth, hydrated fine silica, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, aluminum hydroxide, resin beads, resin powder, etc. These can be used individually or in combination of two or more. The average particle diameter of the extender pigment contained in the color particles is preferably 1 μm or more and less than 50 μm, more preferably 2 to 48 μm. The average particle diameter of the extender pigment is the D50 value measured using a laser diffraction particle size distribution analyzer, as described above.

[0033] Preferably, aggregates with an average particle size of 50 μm or more, more preferably 53 to 1000 μm, even more preferably 63 to 600 μm, and particularly preferably 75 to 300 μm can be used. Examples of such aggregates include marble, granite, serpentinite, fluorite, feldspar, limestone, silica, silica sand, crushed stone, mica, siliceous shale, and their crushed products, crushed ceramics, crushed glass, glass beads, crushed resin, resin beads, rubber granules, metal granules, shirasu balloons, glass balloons, perlite, pumice, hollow balloons, etc. Crushed seashells, coral, wood, charcoal, activated carbon, waste glass, etc., can also be used. Furthermore, aggregates whose surfaces have been colored by surface treatment with pigments, dyes, glazes, etc., can also be used. The average particle size of the aggregate is the D50 value, which is determined by sieving using a metal mesh sieve as specified in JIS Z8801-1:2019. This average particle size D50 is the 50% cumulative particle size, and refers to the particle size that, after sieving, accumulates to 50% by mass (average value of mass distribution) from the finer particles.

[0034] The color particles preferably contain powders with an average particle size of 1 μm or more and less than 50 μm (f1), and / or powders with an average particle size of 50 μm or more (f2). In the present invention, it is preferable that the color particles contain either one of these powders, and more preferably both. In this configuration, the ends of the stretched color particles become more naturally faded, which is advantageous in terms of improving aesthetic appeal. Furthermore, it is possible to improve the ability to prevent uneven gloss of the formed coating film. For example, the above-mentioned extender pigment can be used as the powders with an average particle size of 1 μm or more and less than 50 μm (f1), and the above-mentioned aggregate can be used as the powders with an average particle size of 50 μm or more (f2).

[0035] It is desirable that the powder particles (f) with an average particle diameter of 1 μm or more are included in the colored particles in a ratio of preferably 2 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 8 to 30% by mass. Furthermore, the mass ratio {(f1 component):(f2 component)} of powder particles with an average particle diameter of 1 μm or more and less than 50 μm (f1) to powder particles with an average particle diameter of 50 μm or more (f2) is preferably 90:10 to 10:90, more preferably 80:20 to 20:80. When the powder particles are included in such a ratio, the above effects can be enhanced and it is more preferable.

[0036] In topcoat materials, the water-based medium serves as a medium for color particles. However, if the water-based medium contains resin components, it can also play a role in fixing the color particles in the formed coating film. Hereafter, water-based mediums containing resin components will be referred to as water-based clear coating materials.

[0037] A suitable water-based clear coating material for use as an aqueous medium in a topcoat is one that can form a clear coating film and may contain a resin emulsion (a1) as a component. The water-based clear coating material only needs to be capable of forming a transparent coating film in which color particles are visually recognizable.

[0038] The resin emulsion (a1) (hereinafter also referred to as "component (a1)") acts as a binder for the coating film, enabling the formation of a clear coating film. Examples of component (a1) 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 and acrylic silicone resin emulsion are particularly preferred.

[0039] The glass transition temperature (Tg) of component (a1) is preferably 30°C or lower, and more preferably -10°C to 30°C. Having such a glass transition temperature for component (a1) makes it possible to form a coating film with excellent crack resistance, substrate conformability, etc. If the glass transition temperature of component (a1) is above the lower limit mentioned above, stain resistance, etc. can be improved, and the aesthetic appearance of the coating film can be sufficiently maintained over a long period of time. The glass transition temperature can be calculated using Fox's formula.

[0040] (a1) The solid content of component (a1) is preferably 5 to 50% by mass, and more preferably 15 to 45% by mass, in the aqueous clear coating material.

[0041] The water-based clear coating material may contain, in addition to the above-mentioned component (a1), granular particles (g) with an average particle size of 1 μm or more. By including granular particles (g) with an average particle size of 1 μm or more in the water-based clear coating material, the workability when spreading the color particles can be improved, and it is also preferable in terms of improving the finish.

[0042] Examples of powders and granules (g) with an average particle size of 1 μm or more in a water-based clear coating material (hereinafter also referred to as "(g) component") include heavy calcium carbonate, crushed stone, light calcium carbonate, white carbon, talc, kaolin, clay, earthenware clay, china clay, diatomaceous earth, barite powder, barium sulfate, precipitated barium sulfate, silica sand, silica powder, quartz powder, gravel, glass beads, resin beads, mica, sericite, plate-like kaolin, barium sulfate flakes, glass flakes, alumina flakes, shell fragments, metal fragments and other inorganic fragments, or rubber fragments, plastic fragments, wood fragments, etc., or crushed materials such as rocks, glass, shells, sintered bodies, plastics, rubber, waste glass, etc. These may be surface-treated. These can be used individually or in combination of two or more types. The mixing ratio of powders (g) with an average particle size of 1 μm or more is preferably 3 to 200 parts by mass, more preferably 5 to 150 parts by mass, and even more preferably 10 to 120 parts by mass, per 100 parts by mass of the solid content of component (a1).

[0043] In water-based clear coatings, powders with an average particle size of 1 μm or more and less than 50 μm (g1) (hereinafter also referred to as "(g1) component") can be used as the (g) component (g) with an average particle size of 1 μm or more. By using the (g1) component as the (g) component in water-based clear coatings, in addition to the above effects, the gloss of the topcoat film can be reduced and the finish can be improved. From the viewpoint of the clarity of the coating film, it is desirable that the refractive index of the (g1) component be 1.4 to 1.7. The refractive index can be measured using an Abbe refractometer. The average particle size of the (g1) component is the D50 value measured using a laser diffraction particle size distribution analyzer, as described above.

[0044] Furthermore, in water-based clear coatings, the (g1) component can be either a powder or granular material with an average particle size of 1 μm or more and less than 15 μm (g11) (hereinafter also referred to as "(g11) component") or a powder or granular material with an average particle size of 15 μm or more and less than 50 μm (g12) (hereinafter also referred to as "(g12) component"). By using a combination of (g11) component and (g12) component with different average particle sizes as the (g) component in a water-based clear coating, in addition to the effects mentioned above, it is possible to enhance performance such as matte finish, crack resistance, and substrate conformability.

[0045] The average particle size of component (g11) is 1 μm or more and less than 15 μm, preferably 1 to 14 μm, more preferably 2 to 12 μm. The average particle size of component (g12) is 15 μm or more and less than 50 μm, preferably 16 to 48 μm, more preferably 18 to 45 μm.

[0046] The mixing ratio of component (g11) is preferably 0.5 to 80 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 2 to 30 parts by mass, per 100 parts by mass of the solid content of component (a1). The mixing ratio of component (g12) is preferably 3 to 100 parts by mass, more preferably 5 to 90 parts by mass, and even more preferably 10 to 80 parts by mass, per 100 parts by mass of the solid content of component (a1). Furthermore, the mass ratio of component (g11) to component (g12) {(g11):(g12)} is preferably 1:99 to 80:20, more preferably 2:98 to 50:50, and even more preferably 3:97 to 40:60. With such mixing ratios of component (g11) and component (g12), in addition to the above effects, performance such as matte finish, crack resistance, and substrate conformability can be sufficiently enhanced.

[0047] In water-based clear coatings, powders with an average particle size of 50 μm or more (g2) (hereinafter also referred to as "(g2) component") can be used as the powder (g) component with an average particle size of 1 μm or more. By using powders (g2) with an average particle size of 50 μm or more as the (g) component in water-based clear coatings, the workability when spreading the color particles can be further improved, and it is also preferable in terms of improving the finish.

[0048] The average particle size of component (g2) is 50 μm or more, preferably 150 to 4000 μm, more preferably 300 to 2800 μm, and particularly preferably 500 to 2000 μm. The average particle size of component (g2) is the D50 value, which is determined by sieving using a metal mesh sieve as specified in JIS Z8801-1:2019. This average particle size D50 is the 50% cumulative particle size, which is the particle size that, when sieved, accumulates to 50% by mass (average value of mass distribution) from the finer particles.

[0049] The mixing ratio of component (g2) is preferably 0.5 to 80 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 2 to 30 parts by mass, per 100 parts by mass of the solid content of component (a1). With such a mixing ratio of component (g2), the workability when stretching the color granules and the finish after stretching the color granules can be further improved.

[0050] The (g) component in the water-based clear coating material may include particles with a flaky shape (hereinafter referred to as "flaky powder"). The inclusion of flaky powder in the water-based clear coating material further improves the workability when spreading the color particles, and is also preferable in terms of improving the finish. This is particularly effective when the color particles contain the (f2) component.

[0051] Examples of such flake-like powders include mica, sericite, clay, talc, plate-like kaolin, barium sulfate flakes, glass flakes, alumina flakes, shell fragments, metal fragments, and other inorganic materials, as well as rubber fragments, plastic fragments, and wood fragments. Other examples include substrate particles that have been surface-treated (for example, by coating (or adsorbing) colorants containing pigments or dyes onto the substrate particles, or by applying calcination treatments to the substrate particles). These can be used individually or in combination of two or more types.

[0052] The flake-like granular material is not particularly limited as long as its shape is flake-like (thin flake-like), but its aspect ratio (ratio of "short diameter / thickness") is preferably 1.5 to 2000, more preferably 2 to 500, and even more preferably 3 to 100. The ratio of the short diameter to the long diameter (short diameter / long diameter) is preferably 0.3 to 1, more preferably 0.4 to 1, and even more preferably 0.5 to 1. The "short diameter," "long diameter," and "thickness" referred to here are calculated by observing the flake-like particles stably on a horizontal surface using a microscope from above, with the shortest part being the "short diameter," the longest part being the "long diameter," and the maximum height from the bottom surface being the "thickness."

[0053] The average particle size of such flake-like granules can be 50 μm or more, preferably 150 to 4000 μm, more preferably 300 to 2800 μm, and particularly preferably 500 to 2000 μm. In the present invention, flake-like granules can be used as component (g2).

[0054] The mixing ratio of the flake-like powder is preferably 0.5 to 80 parts by mass, more preferably 1 to 50 parts by mass, and even more preferably 2 to 30 parts by mass, per 100 parts by mass of the solid content of component (a1). With such a mixing ratio of flake-like powder, the workability when stretching the colored granules and the finish after stretching the colored granules can be further improved.

[0055] When using flake-shaped granules as component (g2), component (g1) can be used in combination. This configuration is advantageous for improving workability when stretching the color granules and the finish after stretching the color granules. In this case, the above effect can be further enhanced by using a material with a perfectly spherical particle shape (hereinafter referred to as "perfectly spherical granules") as component (g1). As for the perfectly spherical granules, those with a ratio of major axis to minor axis (major axis / minor axis) of 0.8 to 1.2 (preferably 0.9 to 1.1, more preferably 0.95 to 1.05) are preferred. Various materials can be used for the perfectly spherical granules, regardless of whether they are organic or inorganic. Examples include glass beads, resin beads, hollow glass beads, hollow resin beads, etc. These can be used one or more of each type. The mass ratio of flaky granules to spherical granules (flaky granules:spherical granules) is preferably 5:95 to 80:20, and more preferably 10:90 to 50:50.

[0056] In water-based clear coatings, known additives can be appropriately mixed in addition to the components described above. Examples of such additives include dispersion stabilizers, water-soluble resins, pigment dispersants, emulsifiers, thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, drying adjusters, preservatives, antifungal agents, antialgal agents, antibacterial agents, defoaming agents, adsorbents, deodorizers, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, solvents, and water. Resin emulsions other than component (a1) can also be mixed in, as long as they do not significantly impair the effects of the present invention.

[0057] The ratio of water (including water that is a medium such as component (a1)) in the aqueous clear coating material is preferably 80 to 800 parts by mass, more preferably 100 to 600 parts by mass, and even more preferably 120 to 500 parts by mass, per 100 parts by mass of the solid content of component (a1).

[0058] In water-based clear coatings, a dispersion stabilizer may be included to stably disperse the color particles. The dispersion stabilizer can be selected according to the type of resin and colorant that make up the color particles. Specific examples of dispersion stabilizers include magnesium salts, calcium salts, barium salts, aluminum salts, sodium salts, potassium salts, borates, silicates, phosphates, etc. In addition, water-soluble polymers, clays, etc. can also be used as dispersion stabilizers. Such dispersion stabilizers can also be used as gelling agents. 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, per 100 parts by mass of the solid content of component (a1).

[0059] Color particles in the topcoat material can be obtained, for example, by dispersing a coloring material containing an aqueous resin, a coloring pigment, the above-mentioned powder (f), and various additives as needed, in an aqueous medium in a liquid or gel state. By including an aqueous resin in the coloring material constituting the color particles, the topcoat material can be made into a water-in-water (W / W) type. As the aqueous resin, a resin emulsion and / or a water-soluble resin can be used.

[0060] In the present invention, a resin emulsion (a2) can be used as the aqueous resin in the coloring agent. Examples of resin emulsions (a2) (hereinafter also referred to as "component (a2)") include acrylic resin emulsion, urethane resin emulsion, vinyl acetate 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 and acrylic silicone resin emulsion are particularly preferred.

[0061] The glass transition temperature (Tg) of component (a2) is preferably -10 to 80°C, more preferably 10 to 60°C, and can also be set to a temperature higher than the glass transition temperature of component (a1).

[0062] (a2) The solid content of component (a2) is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass, in the coloring agent.

[0063] The coloring agent constituting the color particles preferably comprises a water-soluble resin component (a2) and a water-soluble resin. Examples of water-soluble resins include polyvinyl alcohol, poly(meth)acrylic acid, polyethylene oxide, water-soluble urethane, biogum, galactomannan derivatives, alginic acid or its derivatives, cellulose derivatives, gelatin, casein, albumin, etc., or chemically modified versions thereof obtained by oxidation, methylation, carboxymethylation, hydroxyethylation, hydroxypropylation, sulfation, phosphorylation, cationization, etc. These can be used individually or in combination of two or more. Such water-soluble resins can contribute to the stabilization of color particle formation and can also be used as gel-forming agents. In the present invention, by including both of these in the coloring agent, color particles can be stably formed, and the weather resistance, water resistance, etc. of the coating film can be improved.

[0064] The ratio of component (a2) to water-soluble resin in the coloring agent is preferably 99.8:0.2 to 70:30, and more preferably 99.5:0.5 to 90:10, in terms of solid content mass ratio (solid content of component (a2): solid content of water-soluble resin).

[0065] In colorants, coloring pigments are components that impart color to color particles. Examples of coloring pigments include inorganic chromatic pigments such as ferric oxide (red iron oxide), yellow iron oxide, ultramarine, cobalt blue, and cobalt green; organic chromatic pigments such as azo, naphthol, pyrazolone, anthraquinone, perylene, quinacridone, disazo, isoindolinone, benzimidazole, phthalocyanine, and quinophthalone; black pigments such as carbon black, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, black iron oxide, iron-chromium composite oxide, manganese-bismuth composite oxide, and manganese-yttrium composite oxide; white pigments such as titanium dioxide, zinc oxide, and alumina; and other pigments such as pearl pigments, aluminum pigments, luminescent pigments, phosphorescent pigments, and fluorescent pigments. These can be used individually or in combination of two or more. The average particle size of the coloring pigment is preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 0.01 to 0.9 μm. The average particle size of the coloring pigment is the D50 value measured using a laser diffraction particle size distribution analyzer, as described above.

[0066] The mixing ratio of the coloring pigment in the coloring material is preferably 1 to 100 parts by mass, more preferably 2 to 80 parts by mass, per 100 parts by mass of the solid content of component (a2).

[0067] The mixing ratio of powders (f) with an average particle size of 1 μm or more in the coloring agent is preferably 10 to 500 parts by mass, more preferably 30 to 400 parts by mass, and even more preferably 50 to 300 parts by mass, per 100 parts by mass of the solid content of component (a2). Furthermore, the mass ratio {(f1 component):(f2 component)} of powders (f1) with an average particle size of 1 μm or more and less than 50 μm to powders (f2) with an average particle size of 50 μm or more is preferably 90:10 to 10:90, and more preferably 80:20 to 20:80. When the powders are included in such a ratio, the above effects can be enhanced and it is more preferable.

[0068] In addition to the components mentioned above, the coloring agent may contain various additives. Examples of such additives include pigment dispersants, emulsifiers, thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, drying adjusters, preservatives, antifungal agents, antialgal agents, antibacterial agents, defoaming agents, fibers, gel-forming agents, adsorbents, deodorizers, UV absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, solvents, and water. It is also possible to mix in resin emulsions other than component (a2) as long as they do not significantly impair the effects of the present invention.

[0069] The ratio of water (including water used as a medium such as aqueous resin) in the coloring agent is preferably 80 to 800 parts by mass, more preferably 100 to 600 parts by mass, per 100 parts by mass of the solid content of component (a2).

[0070] The method for granulating the coloring agent is not particularly limited, and known methods can be used. For example, a method similar to the manufacturing method of materials specified in JIS K5667:2003 "Multicolor Pattern Paints" can be used. Specifically, for example, a method can be used in which the coloring agent is dispersed in a medium containing a dispersion stabilizer (some or all of the components of the aqueous clear coating material). The dispersion stabilizer is a component that stabilizes the coloring agent into granules, and acts as a gelling agent for the coloring agent, for example.

[0071] The particle size and shape of the color particles can be set as appropriate. Specifically, for example, the shape of the stirring blades during manufacturing, 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 agent, the method and concentration of adding 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 0.5 to 20 mm (more preferably 1 to 18 mm, and even more preferably 1.2 to 15 mm). In this invention, the average particle size of the color particles is obtained by drying the color particles on a standard white paper for 48 hours under standard conditions (temperature 23°C, relative humidity 50%; the same applies hereinafter) and calculating the average value of their major axis (average value of 50 color particles).

[0072] To obtain a topcoat material containing two or more types (two or more colors) of colored particles, for example, After producing a colorant dispersion liquid (a colorant dispersion liquid containing one type of colorant particles) in which one type of colorant is dispersed in a medium respectively, these are mixed, or a method of obtaining a colorant dispersion liquid (a colorant dispersion liquid containing two or more types of colorant particles) by adding two or more types of colorants having different color tones etc. to a medium simultaneously or successively and dispersing them, methods such as the like can be adopted. In such a method, as the medium, a part or the whole of an aqueous clear coating material can be used. When producing a colorant dispersion liquid using a part of the components of an aqueous clear coating material as the medium, the remaining components of the aqueous clear coating material may be mixed with the said colorant dispersion liquid.

[0073] In the topcoat material, the mass ratio (colorant particles:aqueous clear coating material) of the colorant particles and the aqueous clear coating material is preferably 1:99 to 80:20 (more preferably 10:90 to 75:25, still more preferably 30:70 to 70:30).

[0074] The topcoat material of the present invention contains colorant particles containing a powder particle (f) having an average particle diameter of 1 μm or more as an essential component, but can contain other colorant particles (colorant particles not containing a powder particle having an average particle diameter of 1 μm or more), transparent gel particles, etc. as long as the effects of the present invention are not significantly impaired. The ratio of the colorant particles containing a powder particle having an average particle diameter of 1 μm or more in all the colorant particles in the topcoat material is preferably 50 mass% or more, more preferably 70 mass% or more, still more preferably 90 to 100 mass%.

[0075] As a coating method of the topcoat material of the present invention, for example, spray coating, roller coating, brush coating, etc. can be adopted. The coating amount of the topcoat material is preferably 2 0.6 kg / m or less, more preferably 2 0.1 to 0.5 kg / m, 2 still more preferably [[ID=??]] 2 0.2 to 0.4 kg / m. 2 The coating amount (in terms of solid content) of the topcoat material is preferably 2 0.3 kg / m or less, more preferably 2 0.05 to 0.2 kg / m, 2 It should be noted that there seems to be an error in the original text where the unit for the coating amount in line 17 is incomplete. It should be something like "0.6 kg / m²" etc. The above translation is based on the provided text as accurately as possible.By applying the topcoat under these conditions, it is possible to fully impart a highly decorative pattern that combines the uneven texture of the main coating film with patterns created by color particles. The application and drying of the topcoat may preferably be carried out at room temperature.

[0076] When applying the topcoat, the viscosity can be adjusted as needed by mixing in a diluent such as water. The dilution ratio is preferably 0 to 10% by mass. The viscosity of the topcoat to be applied 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).

[0077] <Stretching process> In this invention, after applying the topcoat material, the color particles are stretched using a pressing tool while the topcoat film is still wet (stretching step). In this invention, this stretching step forms a flow pattern on the main material film, resulting in a highly aesthetic finish through the composite of the main material film and the topcoat film, and enabling the formation of a new, highly decorative coating film unlike any other.

[0078] In the stretching process, a pressing tool is brought into contact with the color particles, and the shape of the color particles is deformed and stretched by dragging while pressing, thereby forming a flowing pattern. Examples of pressing tools that can be used in the stretching process include trowels, spatulas, brushes, brooms, etc. The stretching of the color particles can be performed while the topcoat material is still wet, preferably within 20 minutes after application of the topcoat material (more preferably within 10 minutes, and even more preferably within 5 minutes).

[0079] The degree of load on the pressing tool can be appropriately set within the range in which the color particles are crushed and can be stretched. By adjusting the load on the pressing tool, the length, width, thickness, etc. of the formed pattern can also be changed. The direction in which the color particles are stretched by the pressing tool can be set according to the desired pattern. For example, to form a linear pattern, the particles should be stretched straight in a certain direction. To form an arc-shaped pattern, the particles should be stretched in a semicircle. Random stretching is also possible. When the surface to be coated is a vertical surface such as a wall, it is desirable to stretch the particles horizontally. This method is preferable because it can suppress the falling of color particles, improve work efficiency, and enhance the finished design.

[0080] After spreading the color particles, allow the topcoat film to dry. Drying should preferably be done at room temperature.

[0081] In this invention, a highly decorative coating can be formed by performing the above steps in order. Furthermore, the application and stretching of the topcoat material may be repeated as long as it does not hinder the effects of this invention. In this invention, after the topcoat material coating has dried, a clear coating or the like may be applied as needed. [Examples]

[0082] Examples and comparative examples are shown below to further clarify the features of the present invention, but the present invention is not limited to these examples.

[0083] (Manufacturing of main material 1) To 200 parts by mass of acrylic silicone resin emulsion (glass transition temperature 22°C, solid content 50% by mass), 700 parts by mass of aggregate (a mixture of white colored silica sand, light gray colored silica sand, light yellow colored silica sand, and transparent glass pulverized material, particle size 0.08-0.2 mm), 16 parts by mass of film-forming aid, 1 part by mass of thickener, and 2 parts by mass of defoamer were mixed and uniformly stirred by a conventional method to produce a light gray main material 1.

[0084] (Manufacturing of main material 2) To 200 parts by mass of acrylic resin emulsion (glass transition temperature 18°C, solids content: 50% by mass), 120 parts by mass of extender pigment (heavy calcium carbonate, average particle size 20 μm), 18 parts by mass of film-forming aid, 1 part by mass of thickener, 2 parts by mass of defoamer, 30 parts by mass of coloring pigment (mixed dispersion of titanium dioxide, yellow iron oxide, and carbon black), and 500 parts by mass of aggregate (colonite, particle size 0.1-0.4 mm) were mixed and uniformly stirred by conventional methods to produce a light gray main material 2.

[0085] (Manufacturing of topcoat material 1) (1) In the colorant 1 with the formulation shown in Table 2, the coloring pigment is: Coloring pigment 1: Coloring pigment 3: Coloring pigment 4: Coloring pigment 5 A white coloring agent was prepared using a ratio of 1.960:0.004:0.004:0.032 (total 2 parts by mass). This white coloring agent (100 parts by mass) was added to mixture a of aqueous clear coating material 1 with the formulation shown in Table 1 and stirred to disperse. Then, mixture b of aqueous clear coating material 1 was added to obtain a white color particle dispersion liquid containing gel-like color particles (white) with an average particle size of approximately 3 mm. (2) In the colorant 1 with the formulation shown in Table 2, the coloring pigment is: Coloring pigment 1: Coloring pigment 2: Coloring pigment 3: Coloring pigment 4 A gray coloring agent was prepared using a ratio of 1.508:0.400:0.084:0.008 (total 2 parts by mass). This gray coloring agent (100 parts by mass) was added to mixture a of aqueous clear coating material 1 with the formulation shown in Table 1 and stirred to disperse. Then, mixture b of aqueous clear coating material 1 was added to obtain a gray color particle dispersion liquid containing gel-like color particles (gray) with an average particle size of approximately 3 mm. (3) In the colorant 1 with the formulation shown in Table 2, the coloring pigment is: Coloring pigment 1: Coloring pigment 2: Coloring pigment 3: Coloring pigment 4 A purple coloring agent was prepared using the ratio =1.000:0.764:0.016:0.220 (total 2 parts by mass). This purple coloring agent (100 parts by mass) was added to mixture a of aqueous clear coating material 1 with the formulation shown in Table 1 and stirred to disperse. Then, mixture b of aqueous clear coating material 1 was added to obtain a purple color particle dispersion liquid containing gel-like color particles (purple) with an average particle size of approximately 3 mm. (4) Topcoat material 1 was manufactured by mixing the white granular dispersion, gray granular dispersion, and purple granular dispersion in a mass ratio of 55:40:5.

[0086] The following raw materials were used in the manufacture of the topcoat material. • Resin 1: Acrylic silicone resin emulsion (glass transition temperature 20°C, solids content 40% by mass) • Resin 2: Acrylic silicone resin emulsion (glass transition temperature 38°C, solids content 40% by mass) • Resin 3: Acrylic resin emulsion (glass transition temperature 20°C, solids content 40% by mass) • Resin 4: Water-soluble resin (galactomannan derivative aqueous solution, solid content 3% by mass) • Dispersant: Anionic dispersant • Powder / Granule 1: Diatomaceous earth (average particle size 6 μm, refractive index 1.5) • Powder / Granule 2: Heavy calcium carbonate (average particle size 4 μm, refractive index 1.6) • Powder / Granule 3: Talc (average particle size 5 μm, refractive index 1.6) • Powder / granular material 4: Resin beads (average particle size 38 μm, refractive index 1.5) • Powder / Granule 5: Perlite (average particle size 125-150 μm) ·Powder 6: Silica sand (average particle size 150~180μm) • Powder / Granule 7: Mica (average particle size 1000-1180 μm) • Coloring pigment 1: White pigment dispersion {Aqueous dispersion of titanium dioxide (average particle size 0.3 μm), solid content 60% by mass} • Coloring Pigment 2: Black Pigment Dispersion {Aqueous dispersion of black iron oxide (average particle size 0.8 μm), solid content 60% by mass} • Coloring Pigment 3: Yellow Pigment Dispersion {Aqueous dispersion of yellow iron oxide (average particle size 0.5 μm), solid content 50% by mass} • Coloring pigment 4: Red pigment dispersion {Aqueous dispersion of reddish-brown pigment (average particle size 0.2 μm), solid content 60% by mass} • Coloring Pigment 5: Blue Pigment Dispersion {Aqueous dispersion of cobalt blue (average particle size 0.4 μm), solid content 50% by mass} • Film-forming aids: Ester-based film-forming aids, ether-based film-forming aids • Dispersion stabilizer: 5% by mass aqueous solution of gelling agent • Thickener: Urethane-based thickener • Additives: Preservatives, fungicides, algaecides, light stabilizers • Defoaming agent: Silicone-based defoaming agent

[0087] [Table 1]

[0088] [Table 2]

[0089] (Manufacturing of topcoat materials 2-13) Instead of colorant 1 and water-based clear coating material 1, white granular dispersion, gray granular dispersion, and purple granular dispersion were prepared using the combinations of colorant and water-based clear coating materials shown in Tables 3 and 4, respectively. These were then mixed in a mass ratio of 55:40:5 to produce topcoat materials 2 to 13.

[0090] (Test method) The tests were conducted using the following method, and evaluations 1-3 were performed. Painting and drying were all carried out under standard conditions (temperature 23°C, relative humidity 50%).

[0091] Slate boards (900mm x 900mm x 3mm) that had been pre-treated with a sealer were installed vertically. The main material was then applied to these slate boards using a spray gun at a rate of 3kg / m². 2 After painting, a pattern was immediately applied using a trowel, and the surface was dried for 24 hours to form a main coating film with an uneven surface. Next, the application amount of the main coating film, calculated based on solid content, was 0.13 kg / m². 2 After spray-painting the topcoat material in this manner, the pressing tool was immediately brought into contact with the color particles, and the material was stretched horizontally while applying constant pressure, and then allowed to dry and cure for 7 days. A test board was obtained using the above method. The main material, topcoat material, and film formation conditions used in the test are shown in Tables 3 and 4.

[0092] (Rating 1) Evaluation 1 assessed the workability when stretching the color particles. Of the methods described above, those where the color particles were stretched a relatively long distance were rated "AA", and those where the stretched distance was relatively short were rated "C", on a four-point scale (Excellent: AA > A > B > C: Poor).

[0093] (Rating 2) In Evaluation 2, the aesthetic appeal of the flow pattern formed by the stretching process was evaluated. The appearance of the test panels obtained by the above method was visually observed, and those with a blurred edge to the flow pattern and a texture that blended well with the main coating were rated "AA," while those with a straight edge to the flow pattern and a large difference in texture from the main coating were rated "C." This was evaluated on a four-point scale (Excellent: AA > A > B > C: Poor).

[0094] (Rating 3) In Evaluation 3, the state of gloss unevenness was evaluated. With light shining from the right side of the test plate obtained using the method described above, the appearance of the test plate was visually observed from the left front. At this time, a three-level evaluation (Excellent: A > B > C: Poor) was used, with "A" indicating suppressed gloss unevenness and "C" indicating gloss unevenness.

[0095] Next, for Examples 1-13, which received favorable evaluations 1-3, evaluation 4 was performed.

[0096] (Rating 4) The test plates obtained using the above method were cut to 100 mm x 300 mm and subjected to a total of 10 cycles of repeated hot and cold tests, each consisting of 18 hours of water immersion, 3 hours of standing at -20°C, and 3 hours of standing at 50°C. After these cycles, the appearance of the coating was checked and the state of crack formation was evaluated. The evaluation was performed on a three-tiered scale (Excellent: A > B > C: Poor), with "A" indicating no crack formation and "C" indicating clear crack formation.

[0097] (Test results) The test results are shown in Tables 3 and 4. In Examples 1 to 13, favorable results were obtained in each evaluation.

[0098] Table 3

[0099] Table 4

Claims

1. A method for forming a coating film by sequentially applying a main material and a topcoat material to a surface to be coated, The above main material contains resin components and powders and granules, and forms a main material coating film having an uneven pattern. The above topcoat material consists of liquid or gel-like color particles containing powders with an average particle size of 1 μm or more, dispersed in an aqueous medium. After applying the topcoat material, while the coating of the topcoat material is still wet, the color particles are spread out using a pressing tool. A method for forming a coating film, characterized by the features described above.

2. The above-mentioned granular material with an average particle diameter of 1 μm or more includes granular material with an average particle diameter of 1 μm or more and less than 50 μm, and / or granular material with an average particle diameter of 50 μm or more. The coating film forming method according to feature 1.

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