Repair method

Abstract

To provide a repair method having high aesthetic appearance on an aggregate-containing decorative surface.SOLUTION: A repair method of an aggregate-containing decorative surface includes a step of applying a clear coat material having a thixotropic index value (TI value) of 1.5 or more to the decorative surface and forming a design layer, wherein a 60-degree specular gloss of the design layer is 25 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for renovating an aggregate-containing decorative surface. [Background technology]

[0002] Conventionally, decorative layers with various patterns have been applied to wall surfaces of buildings, civil engineering structures, etc. Examples of such decorative layers include decorative surfaces such as coatings and sheets containing aggregate, and their patterns (designs) vary widely, including stone, earthen wall, and wood grain. Such decorative surfaces contain synthetic resin and aggregate, and may develop uneven color and gloss due to deterioration over time, impairing their aesthetic appearance.

[0003] As a method for repairing such decorative surfaces, for example, Patent Document 1 describes a repair method in which a water-based paint is applied to an uneven coating film base containing aggregate. However, when water-based paint is applied as in Patent Document 1, uneven absorption occurs on the decorative surface containing aggregate, which may impair the aesthetic appearance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-104856 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above problems, and has as its object to provide a repair method that provides a highly aesthetic appearance to aggregate-containing decorative surfaces. [Means for solving the problem]

[0006] In order to solve these problems, the present inventors have conducted extensive research and have come up with a repair method for forming a specific design layer on an aggregate-containing decorative surface, thereby completing the present invention.

[0007] That is, the present invention has the following features.

[0008] 1. In terms of solid content, the resin is 1 part by weight or more and 50 parts by weight or less per 100 parts by weight of the total amount of aggregate. A method for repairing aggregate-containing decorative surfaces, comprising the step of applying a clear coat material having a thixotropic index (TI value) of 1.5 or more to form a design layer, wherein the 60-degree specular gloss of the design layer is 25 or less. 2. The repair method according to 1., wherein the clear coat material contains an inorganic thickener. 3. The repair method according to 1., characterized in that the clear coat material contains color pigments and / or aggregates. 4. 1. to 1. characterized in that the concealment rate of the design layer is 85% or less. 3. Either The repair method described. [Effects of the Invention]

[0009] According to the present invention, uneven color tone and uneven gloss can be suppressed in an aggregate-containing decorative surface, and a decorative surface with excellent aesthetics can be formed. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described.

[0011] The present invention is a method for repairing an aggregate-containing decorative surface, which includes a step of forming a specific design layer. The present invention is a repair method suitable for cases where the aggregate-containing decorative surface has deteriorated over time or has suffered some kind of damage.

[0012] <Aggregate-containing decorative surface> Examples of aggregate-containing decorative surfaces (hereinafter also referred to as "decorative surfaces" or "renovated surfaces") that are the target of the renovation method of the present invention include decorative surfaces obtained by applying a composition containing synthetic resin and aggregate (paint, coating material, finishing material), or decorative surfaces to which a building material formed from a composition containing synthetic resin and aggregate in the form of a sheet or plate has been attached. Furthermore, the surface may have some kind of protective layer.

[0013] The synthetic resin that constitutes the aggregate-containing decorative surface is not particularly limited, and any commonly available resin can be used. Examples of the resin form include solvent-soluble resins, non-aqueous dispersion resins, solventless resins, aqueous dispersion resins, and water-soluble resins. Examples of resin types include ethylene resins, vinyl acetate resins, polyester resins, alkyd resins, vinyl chloride resins, epoxy resins, acrylic resins, urethane resins, phenolic resins, melamine resins, amino resins, polycarbonate resins, acrylic silicone resins, acrylic vinyl acetate resins, acrylic urethane resins, silicone resins, and fluororesins. One or more of these resins can be used.

[0014] The aggregate is recognized as granular, and at least one selected from natural aggregates such as natural stone and crushed natural stone, and artificial aggregates such as colored aggregates can be suitably used. Specific examples include marble, granite, serpentine, granite, fluorite, kansui stone, feldspar, silica stone, silica sand, and crushed products thereof, crushed porcelain, crushed ceramic, crushed glass, glass beads, crushed resin, resin beads, metal particles, and those with colored coatings on their surfaces. These can be used alone or in combination of two or more.

[0015] The particle size of the aggregate is set depending on the pattern of the decorative surface, etc., and is preferably less than 5.6 mm (more preferably more than 20 μm and less than 4.75 mm, even more preferably more than 25 μm and less than 2 mm, and even more preferably more than 38 μm and less than 850 μm). The particle size of the aggregate is measured by sieving using a metal mesh sieve specified in JIS Z8801-1:2019.

[0016] The mixing ratio of the resin to the aggregate is preferably 1 to 50 parts by weight (more preferably 2 to 30 parts by weight, and even more preferably 3 to 25 parts by weight) of resin per 100 parts by weight of the total amount of aggregate, calculated as solid content. With such a ratio, an aggregated pattern (for example, a stone-like pattern) having fine irregularities derived from the aggregate can be obtained.

[0017] The aggregate-containing decorative surface may also contain other components (additives) as needed, as long as they do not significantly impair the effects of the present invention. Examples of such components include plasticizers, anti-algae agents, antibacterial agents, deodorizers, adsorbents, flame retardants, thickeners, antifoaming agents, crosslinking agents, coloring pigments, extender pigments, lustrous pigments, phosphorescent pigments, fluorescent pigments, fibers, ultraviolet absorbers, light stabilizers, antioxidants, and catalysts.

[0018] Furthermore, the aggregate-containing decorative surface of the present invention may have a textured pattern such as a stone-like pattern, a wood-grain pattern, or a joint pattern on its surface. The repair method of the present invention can repair these textured patterns while preserving them. When the height difference of the textured pattern is preferably within the range of 0.2 to 6 mm or less (more preferably 0.3 to 5.5 mm or less), the effects of the present invention can be fully exhibited. In the present invention, "a to b" is synonymous with "a or more and b or less."

[0019] <Design layer> The clear coat material of the present invention is characterized by a thixotropic index (TI value) of 1.5 or more (preferably 1.6 to 8.0, more preferably 1.8 to 6.0). In the present invention, by setting the viscosity characteristics of the clear coat material to such conditions, it is possible to suppress uneven absorption into the aggregate-containing decorative surface, thereby forming a uniform design layer and achieving a finish with excellent aesthetics.

[0020] The TI value in the present invention is a value determined by the following formula (1) using a BH type rotational viscometer. (Equation 1) TI value = η1 / η2 however, η1: Viscosity at 2 rpm (Pa·s: guideline value at second rotation, measurement temperature: 23°C) η2: Viscosity at 20 rpm (Pa·s: guideline value at 4th rotation, measurement temperature: 23°C)

[0021] The viscosity of the clear coat material of the present invention is preferably 0.3 to 10 Pa·s (more preferably 0.5 to 8 Pa·s). The viscosity in the present invention is a value determined by measuring the viscosity at 20 rpm (the indicator value at the fourth rotation) using a BH-type viscometer (measurement temperature: 23°C).

[0022] The design layer of the present invention is also characterized by a 60-degree specular gloss (hereinafter simply referred to as "gloss") of 25 or less (preferably 3 to 20, more preferably 5 to 15). In the present invention, when the gloss of the clear coat material satisfies these conditions, a matte decorative surface can be formed. In particular, by forming the design layer using a clear coat material that satisfies the above viscosity characteristics, color unevenness and gloss unevenness can be further suppressed, and a decorative surface with excellent aesthetics and little difference in gloss depending on the viewing angle can be formed.

[0023] The gloss level in the present invention is a value measured in accordance with JIS K5600-4-7 "Specular Gloss Level." Specifically, the gloss level is a value obtained by applying a clear coat material to one side of a glass plate using a film applicator with a gap of 150 μm, placing the coated surface horizontally, and allowing it to dry for 48 hours under standard conditions, and then measuring the specular gloss level (measurement angle: 60 degrees).

[0024] The clear coat material can contain a synthetic resin and, if necessary, a matting agent. The gloss of the clear coat material (design layer) can be set, for example, by adjusting the type and ratio of the resin components. The gloss can also be adjusted by combining two or more resins. If the second clear coat material contains a matting agent, the gloss can be set by adjusting the type and ratio of the matting agent.

[0025] As the synthetic resin, a resin having a transparent coating can be used. Examples of the form of such a resin include solvent-soluble resins, non-aqueous dispersion resins, solventless resins, aqueous dispersion resins, and water-soluble resins, among which aqueous dispersion resins (resin emulsions) are preferred. Examples of the resin include acrylic resins, urethane resins, epoxy resins, vinyl chloride resins, vinyl acetate resins, acrylic silicone resins, fluororesins, silicone resins, and the like, as well as composites thereof. These resins can be used alone or in combination of two or more. Such resins may have the property of undergoing a crosslinking reaction.

[0026] As the matting agent, known organic matting agents and inorganic matting agents can be used. As the organic matting agent, for example, organic resin particles can be used, such as polyethylene, polypropylene, nylon, polycarbonate, polyamide, polyamideimide, polyether ether ketone, polytetrafluoroethylene, acrylic resin, spherical crosslinked acrylic resin particles, crosslinked urethane resin particles, etc. These can be used alone or in combination of two or more. The average particle size of the organic resin particles is preferably less than 50 μm (preferably 0.5 μm to 30 μm). Examples of inorganic matting agents that can be used include extender pigments, such as heavy calcium carbonate, light calcium carbonate, kaolin, clay, calcined clay, china clay, diatomaceous earth, hydrous silicic acid, talc, baryte powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, and aluminum hydroxide. These can be used alone or in combination. The particle size of the extender pigment is preferably less than 50 μm (preferably 0.5 μm to 30 μm). In the present invention, it is preferable to include an inorganic matting agent. This can further enhance the effects of the present invention.

[0027] The mixing ratio of the matting agent is preferably 0.1 to 50 parts by weight (more preferably 0.3 to 45 parts by weight, and even more preferably 0.5 to 40 parts by weight) relative to 100 parts by weight of the synthetic resin, calculated as solid content. Within this range, the gloss of the design layer is set within the above range, enabling uniform gloss adjustment (gloss reduction), and the effects of the present invention can be fully exerted.

[0028] The clear coat material forming the design layer of the present invention may further contain color pigments and / or aggregates. Color pigments are used to impart various colors, and aggregates are used to enhance various colors and textures.

[0029] Examples of color pigments include titanium oxide, zinc oxide, carbon black, lamp black, bone black, graphite, black iron oxide, copper chromium black, cobalt black, copper manganese iron black, red iron oxide, molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine blue, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigments, pearl pigments, and luster pigments. One or more of these color pigments can be used. The average particle size of the color pigment is preferably 5 μm or less (more preferably 2 μm or less).

[0030] The mixing ratio of the color pigment is preferably 0.1 to 10 parts by weight (more preferably 0.3 to 8 parts by weight, and even more preferably 0.5 to 5 parts by weight) relative to 100 parts by weight of synthetic resin, calculated as solid content. Within this range, the design (pattern, etc.) of the aggregate-containing decorative surface is not impaired, and the design layer is combined to provide a finish with excellent aesthetics. When the pigment is mixed with the synthetic resin, it can be mixed in the form of a dispersion of each pigment.

[0031] The aggregate may be at least one selected from the aggregates described in the aggregate-containing decorative surface. In the clear coat material, the particle size of the aggregate is preferably less than 212 μm (more preferably, greater than 20 μm and less than 180 μm, and more preferably, greater than 53 μm and less than 150 μm). The particle size of the aggregate is measured by the above-mentioned sieving method, and the content of aggregates satisfying the above range among the aggregates blended into the clear coat material is preferably 70% by weight or more (more preferably, 80% by weight or more). By using aggregates satisfying such particle size, the texture of the aggregate-containing decorative surface can be improved without impairing the textured pattern. Furthermore, it is preferable to use colored aggregates (not colorless and transparent), and it is particularly preferable to use colored aggregates with a colored coating on the surface (e.g., colored silica sand). This allows the desired color and texture to be simultaneously imparted.

[0032] The mixing ratio of the aggregate is preferably 5 to 200 parts by weight (more preferably 10 to 180 parts by weight) relative to 100 parts by weight of synthetic resin, calculated as solid content.Within this range, the effects of the present invention can be fully exhibited.

[0033] Methods for setting the TI value of the clear coat material within the above range include adjusting the type and ratio of the matting agent, and adding a thickener. The clear coat material of the present invention preferably contains a thickener. Examples of thickeners include organic thickeners and inorganic thickeners. In the present invention, it is preferable to contain an inorganic thickener.

[0034] Examples of organic thickeners include hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, alkali swelling thickeners, hydrophobically modified alkali swelling thickeners, urethane associative thickeners, etc. These can be used alone or in combination of two or more.

[0035] Examples of inorganic thickeners that can be used include inorganic layered compounds, silica aerosil, and fumed silica. In the present invention, it is preferable to use an inorganic layered compound. Examples of inorganic layered compounds include natural or synthetic smectite clay minerals such as bentonite, montmorillonite, hectorite, saponite, sauconite, beidellite, and nontronite; magnesium aluminum silicate; and derivatives thereof modified with organic polymers such as carboxyvinyl polymers, xanthan gum, and guar gum. These compounds can be used alone or in combination of two or more.

[0036] The inorganic thickener of the present invention preferably has a transmittance of 90% or more in a 1% aqueous dispersion. Furthermore, the particle size of the inorganic layered compound contained in the inorganic thickener is preferably 5 to 50 nm, and the thickness thereof is preferably 0.5 to 2 nm. In this case, the transparency of the design layer formed by the clear coat material is not impaired, and the effects of the present invention can be fully achieved.

[0037] Another method for setting the TI value of the clear coat material within the above range is to add, for example, volatile alcohols (methanol, ethanol, isopropyl alcohol, etc.).

[0038] Furthermore, the clear coat material may contain, as needed, for example, anti-algae agents, antibacterial agents, deodorizers, adsorbents, flame retardants, antifoaming agents, film-forming aids, antifreezing agents, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, etc.

[0039] The design layer formed by the above clear coat material preferably has a hiding rate of 85% or less (more preferably 0 to 83%, and even more preferably 1 to 80%). When the hiding rate is in this range, the aggregate-containing decorative surface and the design layer work together to produce a finish with excellent aesthetics. The method for measuring the hiding rate is to use a test specimen coated on a hiding rate test paper to a thickness of 150 μm when the clear coat material does not contain aggregate, or 250 μm when it does contain aggregate, and use a color difference meter "CR-300" (manufactured by Minolta Co., Ltd.) to determine the value using the following (Equation 2). (Formula 2) Concealment rate (%) = (Y value measured on the black background of the opacity test paper / Y value measured on the white background of the opacity test paper) × 100

[0040] Furthermore, it is preferable that the hue of the design layer be similar (approximate, similar, or congruent) to the hue (tone) of the aggregate-containing decorative surface. In such cases, the design (tone, pattern, etc.) of the aggregate-containing decorative surface is not concealed, and the hue of the aggregate-containing decorative surface and the design layer combine to produce a more aesthetically pleasing finish. Furthermore, if the design layer contains aggregate, by including aggregate of a similar color (approximate, similar, or congruent) to the hue (tone) of the aggregate-containing decorative surface, a unified design can be imparted, and if aggregate of a different color is included, an accent design can be imparted.

[0041] The clear coat material can be applied using known tools such as a sprayer, roller, etc. The clear coat material can be diluted with various solvents when applied, and the solid content at the time of application is preferably 10 to 80% by weight (more preferably 15 to 60% by weight), and the amount applied per unit area is preferably 10 to 500 g / m. 2 (More preferably 20 to 300 g / m 2 In such a case, the effects of the present invention can be fully exerted. The clear coat material may be cured by natural drying or may be forcibly cured by applying heat or the like.

[0042] In the present invention, the design layer may be a laminated coating formed by applying two or more clear coat materials. For example, a clear coat material containing a synthetic resin and a pigment may be applied first, and then a clear coat material containing a synthetic resin and an aggregate may be applied.

[0043] In the repair method of the present invention, after forming the design layer, a clear coat material can be applied to the outermost surface to provide a colorless, transparent clear layer for purposes such as surface protection, improved weather resistance, stain resistance, etc., as long as the effects of the present invention are not impaired. Such a clear layer may be glossy or matte (including 70% gloss, 50% gloss, 30% gloss, etc.). [Example]

[0044] The following examples will clarify the features of the present invention.

[0045] <Aggregate-containing decorative surface> The following decorative surfaces were used, which had been deteriorated by outdoor exposure. Cosmetic surface 1 A decorative surface (sandstone pattern, uneven height difference (maximum): 3.0 mm, color: brown) formed on a base material (slate board) using an aggregate-containing finishing material containing 100 parts by weight of aggregate (grain size: 200 μm to 400 μm) and 20 parts by weight of acrylic resin. Cosmetic surface 2 A decorative surface (wood grain pattern, maximum height difference of the uneven surface: 0.5 mm, color tone: brown) in which a building material made from a composition containing 20 parts by weight of acrylic resin and 100 parts by weight of aggregate (particle size: 200 μm to 400 μm) is attached to a base material (slate board) in the form of a sheet. <Clear coat material> (1-1) 200 parts by weight of acrylic resin emulsion (solid content: 50% by weight), 10 parts by weight of matting agent [polyethylene wax emulsion, average particle size: 5 μm, solid content: 40% by weight], 0.06 parts by weight of thickener (hydroxyethyl cellulose), clear coat material containing additives (film-forming aids, etc.) (TI value: 1.5, 60-degree specular gloss: 16, hiding power: 65%) (1-2) A clear coat material (TI value: 2.2, 60-degree specular gloss: 16, hiding power: 70%) containing 100 parts by weight of the above clear coat material (1-1) and 10 parts by weight of isopropyl alcohol (1-3) A clear coat material (TI value: 3.5, 60-degree specular gloss: 16, hiding power: 70%) containing 0.15 parts by weight of a thickener (synthetic smectite clay mineral) in 100 parts by weight of the above clear coat material (1-1). (1-4) A clear coat material containing 100 parts by weight of the above clear coat material (1-1) and 10 parts by weight of water (TI value: 1.0, 60-degree specular gloss: 16, hiding power: 70%) (1-5) 200 parts by weight of acrylic resin emulsion (solid content 50% by weight), 15 parts by weight of extender pigment [heavy calcium carbonate: calcined clay: diatomaceous earth (weight ratio) = 2:5:1, average particle size: 3-12 μm], 0.06 parts by weight of thickener (hydroxyethyl cellulose), and additives (film-forming aids, etc.) containing clear coat material (TI value: 2.2, 60-degree specular gloss: 8.0, hiding power: 70%) (1-6) Clear coat material (TI value: 1.7, 60-degree specular gloss: 13, hiding power: 65%) containing 200 parts by weight of acrylic resin emulsion (solid content 50% by weight), 3 parts by weight of extender pigment [heavy calcium carbonate, average particle size: 1.5 μm], 0.06 parts by weight of thickener (hydroxyethyl cellulose), and additives (film-forming aids, etc.). (1-7) 200 parts by weight of acrylic resin emulsion (solid content 50% by weight), 15 parts by weight of extender pigment [heavy calcium carbonate: calcined clay: diatomaceous earth (weight ratio) = 2:5:1, average particle size: 3-12 μm], 0.06 parts by weight of thickener 1 (hydroxyethyl cellulose), 0.15 parts by weight of thickener 2 (synthetic smectite clay mineral), and additives (film-forming aids, etc.). Clear coat material (TI value: 3.0, 60-degree specular gloss: 8.0, hiding power: 70%). (1-8) 200 parts by weight of acrylic resin emulsion (solid content 50% by weight), 15 parts by weight of extender pigment [heavy calcium carbonate: calcined clay: diatomaceous earth (weight ratio) = 2:5:1, average particle size: 3-12 μm], 0.06 parts by weight of thickener (hydroxyethyl cellulose), 3 parts by weight of coloring pigment (titanium oxide, yellow iron oxide, carbon black, red iron oxide), clear coat material (TI value: 2.4, 60-degree specular gloss: 7.5, hiding power: 72%) containing additives (film-forming aids, etc.) (1-9) Acrylic resin emulsion (solid content 50% by weight) 200 parts by weight, extender pigment [heavy calcium carbonate: calcined clay: diatomaceous earth (weight ratio) = 2:5:1, average particle size: 3-12 μm] 15 parts by weight, color pigment (titanium oxide, yellow iron oxide, carbon black, red iron oxide) 3 parts by weight, thickener 1 (hydroxyethyl cellulose) 0.06 parts by weight, thickener 2 (synthetic smectite clay mineral) 0.15 parts by weight, including additives (film-forming aids, etc.) Brown clear coat material (TI value: 4.0, 60-degree specular gloss: 7.5, hiding power: 72%) (1-10) 200 parts by weight of acrylic resin emulsion (solid content 50% by weight), 15 parts by weight of extender pigment [heavy calcium carbonate: calcined clay: diatomaceous earth (weight ratio) = 2:5:1, average particle size: 3-12 μm], 90 parts by weight of colored silica sand (particle size: over 45 μm and less than 150 μm, brownish), 0.06 parts by weight of thickener 1 (hydroxyethyl cellulose), 0.15 parts by weight of thickener 2 (synthetic smectite clay mineral), and additives (film-forming agents, etc.). Clear coat material containing brown aggregate (TI value: 4.0, 60-degree specular gloss: 8.5, hiding power: 70%).

[0046] (Examples 1 to 13, Comparative Example 1) The clear coat material was applied to the decorative surface in the combination shown in Table 1 (weight per unit area: 80 g / m 2 ) and hardened (at 23°C for 3 hours) to form a design layer, thereby improving the decorative surface. The decorative surface after renovation was visually inspected and rated on a five-point scale (excellent: AA>A>B>C>D: poor), with "AA" being given to those with excellent aesthetics with no uneven color or gloss, and "D" being given to those with uneven color or gloss.

[0047] [Table 1]

Claims

1. A method for repairing an aggregate-containing decorative surface in which, in terms of solid content, the resin is 1 part by weight or more and 50 parts by weight or less per 100 parts by weight of total aggregate, the method comprising the step of applying a clear coat material having a thixotropic index value (TI value) of 1.5 or more to form a design layer, wherein the 60-degree specular gloss of the design layer is 25 or less.

2. The repair method described in claim 1, characterized in that the clear coat material contains an inorganic thickener.

3. A renovation method as described in claim 1, characterized in that the clear coat material contains coloring pigments and / or aggregates.

4. The repair method according to any one of claims 1 to 3, characterized in that the concealment rate of the design layer is 85% or less.

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