Repair method

Abstract

To provide a method for repairing an aggregate-containing decorative surface with high appearance.SOLUTION: The method for repairing an aggregate-containing decorative surface includes a step of forming an adjustment layer by applying a first clear coating material having a thixotropic index value (TI value) of 1.5 or more, and a step of forming a design layer by applying a second clear coating material containing a synthetic resin, a pigment and / or an aggregate.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] For example, Patent Document 1 describes a repair method for such decorative surfaces, in which only the deteriorated surface layer of an existing aggregate-containing finish layer is removed. Meanwhile, Patent Document 2 describes a repair method in which a water-based paint is applied to an uneven coating base containing aggregate. However, since Patent Document 1 removes the surface layer of the existing aggregate-containing finish layer, there is a risk that the texture, such as the uneven feel, may be impaired in some cases. Furthermore, when a water-based paint is applied, as in Patent Document 2, uneven absorption may occur on the aggregate-containing decorative surface, which may impair the aesthetic appearance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-144896 [Patent Document 2] 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 inventors have conducted extensive research and have come up with a repair method for forming a specific adjustment layer and 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. A method for repairing an aggregate-containing decorative surface in which 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, calculated as solid content, a step of applying a first clear coat material having a thixotropic index (TI value) of 1.5 or more, containing an extender pigment but not containing a coloring pigment, to form an adjustment layer; The method includes a step of applying a second clear coat material containing a synthetic resin, a pigment and / or an aggregate to form a design layer. fruit, The concealment rate of the above adjustment layer is 1 to 80%; The concealment rate of the above design layer is 1 to 80%; is A renovation method characterized by: 2. The repair method according to 1., wherein the first clear coat material contains an inorganic thickener. 3. The repair method described in 2. is characterized in that the inorganic thickener is an inorganic layered compound consisting of natural or synthetic smectite clay minerals, aluminum magnesium silicate, and / or organic polymer-modified derivatives thereof. 4. The repair method described in 1., characterized in that the hue of the design layer is similar to the hue of the aggregate-containing decorative surface. 5. The repair method described in 1., wherein the second clear coat material contains aggregate of a color similar to the hue of the aggregate-containing decorative surface. [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 the steps of forming an adjustment layer and a 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 paint (coating material, finishing material) containing synthetic resin and aggregate, or decorative surfaces to which a building material formed into a sheet or plate from a composition containing synthetic resin and aggregate is 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] <Adjustment layer> The present invention is characterized in that a first clear coat material is applied to form an adjustment layer. The first clear coat material of the present invention is characterized in that it has a thixotropic index value (TI value) of 1.5 or more (preferably 1.8 to 8.0, more preferably 2.0 to 6.0, and even more preferably 2.3 to 5.0). In the present invention, by setting the viscosity characteristics of the first clear coat material to such conditions, it is possible to suppress uneven absorption into the aggregate-containing decorative surface, and it is possible to adjust the surface condition of the aggregate-containing decorative surface to a normal (homogeneous) state. This allows a uniform design layer to be formed in the next process, resulting in 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 first 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] Furthermore, the adjusting layer formed by the first clear coat material preferably has a hiding rate of 85% or less (more preferably 0 to 83%, and even more preferably 1 to 80%). By keeping the hiding rate within this range, it is possible to take advantage of the aggregate-containing decorative surface and carry out repairs that enhance the aesthetic appearance. The above-mentioned hiding rate is a value calculated by the following formula (2) using a test piece in which the first clear coat material is applied to a hiding rate test paper to a thickness of 150 μm and a color difference meter "CR-300" (manufactured by Minolta Co., Ltd.). (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

[0023] The first clear coat material of the present invention may be any material that contains a synthetic resin and, if necessary, other components, and is capable of forming a coating that satisfies the above conditions.

[0024] 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.

[0025] A preferred method for setting the TI value of the first clear coat material within the above range is to add a thickener. Examples of thickeners include organic thickeners and inorganic thickeners. In the present invention, it is preferable to include an inorganic thickener.

[0026] 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.

[0027] 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.

[0028] 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 adjustment layer formed by the first clear coat material is not impaired, and the effects of the present invention can be fully achieved.

[0029] Another method for setting the TI value of the first clear coat material within the above range is to add, for example, volatile alcohols (methanol, ethanol, isopropyl alcohol, etc.).

[0030] Furthermore, the first clear coat material may contain, as needed, for example, color pigments, extender pigments, matting agents, anti-algae agents, antibacterial agents, deodorizers, adsorbents, flame retardants, antifoaming agents, film-forming aids, antifreeze agents, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, etc. Note that an embodiment in which the first clear coat material does not contain a color pigment is also suitable.

[0031] The first clear coat material can be applied using known tools such as a sprayer, roller, etc. The first 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 / m2 In such a case, the effects of the present invention can be fully exerted. The first clear coat material may be cured by natural drying, or may be forcibly cured by applying heat or the like.

[0032] <Design layer> The present invention is characterized in that a design layer is formed after the adjustment layer is formed.The second clear coat material of the present invention is characterized in that it contains a synthetic resin, a pigment and / or an aggregate.

[0033] As the synthetic resin, at least one selected from the synthetic resins described above as the first clear coat material can be used.

[0034] Examples of pigments include color pigments and extender pigments. Color pigments are used for the purpose of imparting various colors, while extender pigments are used for the purpose of, for example, adjusting solid content, viscosity, and gloss (reducing gloss, etc.). In the present invention, it is preferable to use at least a color pigment as the pigment.

[0035] 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).

[0036] Examples of extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, china clay, diatomaceous earth, hydrous finely powdered 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 of two or more. The particle size of the extender pigment is preferably less than 50 μm (preferably 0.5 μm to 30 μm).

[0037] The mixing ratio of the pigment 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 such a range, the effects of the present invention can be fully exhibited. When the pigment is mixed with the synthetic resin, it can be mixed in the form of a dispersion of each pigment.

[0038] The aggregate may be at least one selected from the aggregates described in the aggregate-containing decorative surface. In the second clear coat material, the particle size of the aggregate is preferably less than 212 μm (more preferably, more than 20 μm and less than 180 μm, more preferably, more than 38 μm and less than 150 μm). The particle size of the aggregate is measured by the above-mentioned sieving, and the content of aggregate satisfying the above range among the aggregates blended into the second clear coat material is preferably 70 wt % or more (more preferably, 80 wt % or more). By using aggregate satisfying such particle size, the texture can be improved without impairing the uneven pattern of the aggregate-containing decorative surface. Furthermore, it is preferable to use colored aggregate (not colorless and transparent), and it is particularly preferable to use colored aggregate with a colored surface coating (e.g., colored silica sand). This allows the desired color and texture to be simultaneously imparted.

[0039] 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.

[0040] Furthermore, the second clear coat material may contain, as needed, for example, anti-algae agents, antibacterial agents, deodorizers, adsorbents, flame retardants, antifoaming agents, film-forming aids, antifreeze agents, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, etc.

[0041] The hiding rate of the design layer formed by the second clear coat material is preferably 85% or less (more preferably 0 to 83%, even more preferably 1 to 80%). The hiding rate of the laminate of the adjustment layer and the design layer is preferably 85% or less (more preferably 0 to 83%, even more preferably 1 to 80%). When the hiding rate is in this range, the aggregate-containing decorative surface and the design layer combine to produce a finish with excellent aesthetics. The hiding rate can be measured using the same method as for the adjustment layer. However, the hiding rate of the design layer is measured using a test specimen in which the second clear coat material is applied to a hiding rate test paper to a thickness of 150 μm if the second clear coat material does not contain aggregate, or 250 μm if the second clear coat material does contain aggregate. The hiding rate of the laminate of the adjustment layer and the design layer is measured using a test specimen in which the first clear coat material is applied to a thickness of 150 μm, dried (3 hours, 23°C), and then the second clear coat material is applied to a thickness of 250 μm.

[0042] 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 hue of the aggregate-containing decorative surface and the hue of the design layer combine to produce a finish with even greater aesthetic appeal. Also, 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 color other than the similar color is included, an accent design can be imparted.

[0043] The second clear coat material can be applied using known tools such as a sprayer, roller, etc. The second 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 second clear coat material may be cured by natural drying, or may be forcibly cured by applying heat or the like.

[0044] In the present invention, the design layer can also be a laminated coating in which two or more second clear coat materials are applied. For example, a clear coat material containing a synthetic resin and a pigment may be applied as the second clear coat material, and then a clear coat material containing a synthetic resin and an aggregate may be applied.

[0045] 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]

[0046] The following examples will clarify the features of the present invention.

[0047] <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. <First clear coat material> (1-1) Clear coat material (TI value: 1.5, hiding power: 65%) containing 200 parts by weight of acrylic resin emulsion (solid content: 50% by weight), 0.06 parts by weight of thickener (hydroxyethyl cellulose), and additives (film-forming aids, etc.). (1-2) A clear coat material (TI value: 2.2, hiding rate: 65%) 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, hiding power: 65%) containing 0.15 parts by weight of synthetic smectite clay mineral as a thickener in 100 parts by weight of the above clear coat material (1-1). (1-4) A clear coat material (TI value: 1.0, hiding rate: 65%) containing 100 parts by weight of the above clear coat material (1-1) and 10 parts by weight of water. <Second clear coat material> (2-1) A brown-colored clear coat material (hiding rate: 70%) containing 200 parts by weight of acrylic resin emulsion (solid content: 50% by weight) and 3 parts by weight of coloring pigments (titanium oxide, yellow iron oxide, carbon black, red iron oxide). (2-2) An aggregate-containing clear coat material (concealment rate: 60%) containing 200 parts by weight of acrylic resin emulsion (solid content: 50% by weight) and 90 parts by weight of colored silica sand (particle size: over 45 μm and less than 150 μm, brown).

[0048] (Examples 1 to 6, Comparative Example 1) The first 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 harden (at 23°C for 3 hours) to form an adjustment layer, then apply the second clear coat material (weight per unit area 80g / 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 four-point scale (A>B>C>D: poor) with "A" being an excellent appearance with no uneven color or gloss, and "D" being an appearance with uneven color or gloss.

[0049] [Table 1]

Claims

1. A method for repairing an aggregate-containing decorative surface, in which 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, calculated as solid content, a step of applying a first clear coat material having a thixotropic index (TI value) of 1.5 or more, containing an extender pigment but not containing a coloring pigment, to form an adjustment layer; A step of applying a second clear coat material containing a synthetic resin, a pigment and / or an aggregate to form a design layer, The hiding rate of the adjustment layer is 1 to 80%; The concealment rate of the design layer is 1 to 80%; A repair method characterized by:

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

3. The repair method described in Claim 2, characterized in that the inorganic thickener is an inorganic layered compound consisting of natural or synthetic smectite clay minerals, magnesium aluminum silicate, and / or organic polymer-modified derivatives thereof.

4. A renovation method as described in claim 1, characterized in that the hue of the design layer is similar to the hue of the aggregate-containing decorative surface.

5. A renovation method as described in claim 1, characterized in that the second clear coat material contains aggregate of a color similar to the hue of the aggregate-containing decorative surface.

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