JP2023068707A - Repair method - Google Patents

Abstract

To provide a repair method having excellent aesthetic appearance in an aggregate-containing decorative surface.SOLUTION: A repair method of an aggregate-containing decorative surface includes the step of: applying a clear coat material which contains a synthetic resin, a pigment and/or an aggregate and has a thixotropic index value (TI value) of 1.5 or more to an aggregate-containing decorative surface, and forming a design layer.SELECTED DRAWING: None

Description

The present invention relates to a method for refurbishing an aggregate-containing decorative surface.

2. Description of the Related Art Conventionally, decorative layers having various patterns are applied to walls of buildings, civil engineering structures, and the like. An example of such a decorative layer is a coated surface containing aggregate or a decorative surface such as a sheet, and the pattern (design) is diverse, such as stone tone, clay wall tone, and wood grain tone. Such decorative surfaces contain synthetic resins and aggregates, and deterioration over time may cause unevenness in color tone and luster, impairing aesthetics.

As such a decorative surface refurbishing method, for example, Patent Document 1 describes a refurbishing method of removing only the deteriorated surface layer of an existing aggregate-containing finishing layer. On the other hand, Patent Literature 2 describes a refurbishing method of applying a water-based paint to an uneven coating base containing aggregates. However, in Patent Document 1, since the surface layer of the existing aggregate-containing finishing layer is removed, there is a possibility that texture such as unevenness may be impaired in some cases. In addition, as in Patent Document 2, when a water-based paint is applied, uneven absorption occurs on the decorative surface containing the aggregate, which may impair the aesthetic appearance.

JP 2012-144896 A JP 2019-104856 A

The present invention has been made in view of such problems, and an object of the present invention is to provide a highly aesthetically pleasing method for repairing aggregate-containing decorative surfaces.

In order to solve such a problem, the present inventors have made intensive studies, and as a result, have conceived of a modification method for forming a specific design layer on the aggregate-containing decorative surface, and have completed the present invention.

That is, the present invention has the following features.

1. A method for repairing an aggregate-containing decorative surface, comprising:
A step of forming a design layer by applying a clear coating material containing a synthetic resin and a pigment and/or aggregate and having a thixotropic index value (TI value) of 1.5 or more;
A refurbishment method comprising:
2. 1. The design layer has a hiding rate of 85% or less. Repair method described in.

Effect of the Invention According to the present invention, it is possible to suppress color tone unevenness, gloss unevenness, and the like in an aggregate-containing decorative surface, and form a decorative surface excellent in aesthetics.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated.

The present invention is a method for refurbishing an aggregate-containing decorative surface, characterized by including a step of forming a specific design layer. INDUSTRIAL APPLICABILITY The present invention is a repair method suitable for cases such as when the aggregate-containing decorative surface has deteriorated over time or has some defects.

<Decorative surface containing aggregate>
The aggregate-containing decorative surface (hereinafter also referred to as "decorative surface" or "refurbished surface") to be subjected to the refurbishment method of the present invention includes, for example, a paint (coating material, finishing material) containing synthetic resin and aggregate. A decorative surface obtained by painting, or a decorative surface to which a building material obtained by molding a composition containing a synthetic resin and an aggregate into a sheet or plate is pasted. Moreover, it may have some kind of protective layer on its surface.

The synthetic resin that constitutes the aggregate-containing decorative surface is not particularly limited, and any commonly available resin can be used. Examples of forms of such resins include solvent-soluble resins, non-water-dispersible resins, solvent-free resins, water-dispersible resins, and water-soluble resins. Examples of resin types include ethylene resin, vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, phenol resin, melamine resin, amino resin, polycarbonate resin, acrylic silicon resin, Acrylic vinyl acetate resins, acrylic urethane resins, silicone resins, fluorine resins, etc., may be mentioned, and one or more of these may be used.

The aggregate is recognized to be granular, and for example, at least one selected from natural aggregate such as natural stone, pulverized natural stone, and artificial aggregate such as colored aggregate is preferably used. be able to. Specifically, for example, marble, granite, serpentinite, granite, fluorite, cold water stone, feldspar, silica, silica sand, pulverized products thereof, pulverized ceramics, pulverized ceramics, pulverized glass, glass beads, resins Examples include pulverized materials, resin beads, metal particles, and the like, and those whose surfaces are colored and coated. These can be used singly or in combination of two or more.

The particle size of the aggregate is set according to the pattern of the decorative surface, etc., preferably less than 5.6 mm (more preferably more than 20 μm and less than 4.75 mm, more preferably more than 25 μm and less than 2 mm, still more preferably more than 38 μm 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.

The mixing ratio of the resin and the aggregate is preferably 1 part by weight or more and 50 parts by weight or less (more preferably 2 parts by weight or more and 30 parts by weight) with respect to the total amount of 100 parts by weight of the aggregate in terms of solid content. below, more preferably 3 parts by weight or more and 25 parts by weight or less). With such a ratio, it is possible to obtain an aggregated pattern (for example, a stone texture pattern, etc.) having fine uneven shapes derived from the aggregate.

In addition, the aggregate-containing decorative surface may contain components (additives) other than those described above, if necessary, as long as the effects of the present invention are not significantly impaired. Examples of such components include plasticizers, anti-algae agents, antibacterial agents, deodorants, adsorbents, flame retardants, thickeners, antifoaming agents, cross-linking agents, coloring pigments, extender pigments, glitter pigments, Phosphorescent pigments, fluorescent pigments, fibers, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, and the like.

Furthermore, the aggregate-containing decorative surface of the present invention may have an uneven pattern such as a stone-like pattern, a wood-grain pattern, or a joint pattern on its surface. In the repairing method of the present invention, repairing can be performed while making use of these uneven patterns. The effect of the present invention can be sufficiently exhibited when the height difference of the unevenness is preferably within the range of 0.2 to 6 mm or less (more preferably 0.3 to 5.5 mm or less). In the present invention, "a to b" is synonymous with "a or more and b or less".

<Design layer>
The clear coat material forming the design layer of the present invention is characterized by containing a synthetic resin, a pigment and/or an aggregate.

As the synthetic resin, those having a transparent film can be used. Examples of the form of such resins include solvent-soluble resins, non-water-dispersible resins, solvent-free resins, water-dispersible resins, water-soluble resins, etc. Among them, water-dispersible resins (resin emulsions ) is preferred. Examples of resin types include acrylic resins, urethane resins, epoxy resins, vinyl chloride resins, vinyl acetate resins, acrylic silicon resins, fluorine resins, silicon resins, and composites thereof. These can be used singly or in combination of two or more. Such a resin may have the property of causing a cross-linking reaction.

Pigments include coloring pigments and extender pigments. Coloring pigments are used for the purpose of imparting various colors, and extender pigments are used for the purposes of, for example, solid content adjustment, viscosity adjustment, and gloss adjustment (gloss reduction, etc.). . In the present invention, it is preferable to use at least a coloring pigment as the pigment.

Coloring pigments include, for example, titanium oxide, zinc oxide, carbon black, lamp black, bone black, graphite, black iron oxide, copper chrome 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, luster pigments, and the like. 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).

Extender pigments include, for example, heavy calcium carbonate, light calcium carbonate, kaolin, clay, china clay, china clay, diatomaceous earth, hydrated finely divided silicic acid, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, and magnesium carbonate. , silica powder, and aluminum hydroxide. These can be used singly or in combination of two or more. The particle size of the extender is preferably less than 50 µm (preferably 0.5 µm or more and 30 µm or less).

The mixing ratio of the pigment is preferably 0.1 to 50 parts by weight (more preferably 0.3 to 45 parts by weight, still more preferably 0.5 to 40 parts by weight) per 100 parts by weight of the synthetic resin in terms of solid content. part). Within such a range, the effects of the present invention can be sufficiently exhibited. When the pigment is mixed with the synthetic resin, the pigment can be mixed in the form of a dispersion liquid.

As the aggregate, at least one or more selected from the aggregates described in the above-mentioned aggregate-containing decorative surface can be used. For clearcoat materials, the aggregate particle size is preferably less than 212 μm (more preferably greater than 20 μm and less than 180 μm, more preferably greater than 53 μm and less than 150 μm). In addition, the particle size of the aggregate is measured by the above-described sieving, and the content of the aggregate satisfying the above range is preferably 70% by weight or more (more preferably is 80% by weight or more). By using an aggregate that satisfies such a particle size, texture can be enhanced without impairing the uneven pattern of the aggregate-containing decorative surface. Further, it is preferable to use a colored aggregate (not colorless and transparent) as the aggregate, and it is particularly preferable to use a colored aggregate whose surface is coated with a color (for example, colored silica sand). Thereby, the desired color and texture can be imparted at the same time.

The mixing ratio of the aggregate is preferably 5 to 200 parts by weight (more preferably 10 to 180 parts by weight) per 100 parts by weight of the synthetic resin in terms of solid content. Within such a range, the effects of the present invention can be sufficiently exhibited.

The clear coating material of the present invention 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, more preferably 2.3 to 5.5, particularly preferably 2.5 to 5.0). In the present invention, by setting the viscosity characteristics of the clear coat material to such conditions, uneven absorption into the aggregate-containing decorative surface can be suppressed. excellent finish can be obtained.

In addition, the TI value in the present invention is a value obtained by the following (Equation 1) using a BH type rotational viscometer.
(Formula 1) TI value = η1/η2
however,
η1: Viscosity at 2 rpm (Pa s: guideline value for second rotation, measurement temperature: 23°C)
η2: Viscosity at 20 rpm (Pa s: guideline value at 4th rotation, measurement temperature: 23°C)

Further, the viscosity of the clear coating 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 obtained by measuring the viscosity (guideline value at the 4th rotation) at 20 rpm with a BH type viscometer (measurement temperature: 23°C).

As a method for setting the TI value of the clear coat material within the above range, it is preferable to add a thickening agent. Examples of thickeners include organic thickeners and inorganic thickeners. In the present invention, it is preferred that an inorganic thickener is included.

Examples of organic thickeners include hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, alkali swelling thickeners, hydrophobic modified alkali swelling thickeners. Viscous agents, urethane associative thickeners and the like are included. These can be used singly or in combination of two or more.

Examples of inorganic thickeners that can be used include inorganic layered compounds, silica aerosil, and fumed silica. In the present invention, it is preferable that an inorganic layered compound is included. 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; derivatives modified from organic polymers such as These can be used singly or in combination of two or more.

Further, the inorganic thickener of the present invention preferably has a transmittance of 90% or more in a 1% dispersed aqueous solution. Furthermore, the particle size of the inorganic layered compound contained in the inorganic thickener is preferably 5 to 50 nm, and the thickness is preferably 0.5 nm to 2 nm. In such a case, the effect of the present invention can be fully exhibited without impairing the transparency of the design layer formed by the clear coat material.

As another method for setting the TI value of the clear coat material within the above range, for example, volatile alcohols (methanol, ethanol, isopropyl alcohol, etc.) may be added.

Furthermore, the clear coating material may include, as required, for example, anti-algae agents, antibacterial agents, deodorants, adsorbents, flame retardants, antifoaming agents, film-forming aids, antifreezing agents, ultraviolet absorbers, light stabilizers, agents, antioxidants, catalysts and the like can be added.

The design layer formed of the clear coat material preferably has a hiding rate of 85% or less (more preferably 0 to 83%, still more preferably 1 to 80%). When the concealing ratio is within such a range, the aggregate-containing decorative surface and the design layer are combined to obtain a finish excellent in aesthetics.
In addition, as a method for measuring the hiding rate, a test was applied on the hiding rate test paper so that the coating thickness was 150 μm when the clear coat material did not contain aggregates, and 250 μm when it contained aggregates. It is a value obtained by the following (Equation 2) using a body and using a color difference meter "CR-300" (manufactured by Minolta Co., Ltd.).
(Formula 2) Concealment rate (%) = (Y value measured at the black background portion of the concealment test paper/Y value measured at the white background portion of the concealment test paper) × 100

Furthermore, it is preferable that the hue of the design layer is the same color (approximate color, similar color, co-color) as the hue (color) of the aggregate-containing decorative surface. In such a case, the hue of the aggregate-containing decorative surface and the hue of the design layer are combined, and a finish with even more excellent aesthetics can be obtained. In addition, when aggregate is included in the design layer, by including aggregate of the same color (approximate color, similar color, co-color) as the hue (color) of the above-mentioned aggregate-containing decorative surface, design with a sense of unity can be given, and if aggregates other than similar colors are included, an accent design can be given.

As a method for applying the clear coat material, known instruments such as sprays and rollers can be used. In addition, the clear coating material can be diluted with various solvents at the time of application, 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 unit area The coating amount per unit 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 exhibited. The clear coat material may be hardened by natural drying, or may be forcibly hardened by applying heat or the like.

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

In the repair method of the present invention, after forming the design layer, a clear coat material is applied to the outermost surface for the purpose of surface protection, weather resistance improvement, stain resistance, etc., as long as the effects of the present invention are not hindered. A colorless and transparent clear layer can also be provided. Such a clear layer may be glossy or matte (including 70% gloss, 50% gloss, 30% gloss, etc.).

Examples are shown below to further clarify the features of the present invention.

<Decorative surface containing aggregate>
The following decorative surface was used after being deteriorated by exposure to the outdoors.
・Cosmetic surface 1
A decorative surface (sandstone pattern, uneven pattern) formed on a base material (slate plate) by a finishing material containing 20 parts by weight of acrylic resin per 100 parts by weight of aggregate (particle size: 200 μm to 400 μm). Height difference (maximum value): 3.0 mm, color tone: brown).
・Cosmetic surface 2
On a base material (slate plate), a decorative surface (wood grain pattern) in which a composition containing 20 parts by weight of an acrylic resin with respect to 100 parts by weight of an aggregate (particle size: 200 μm to 400 μm) is formed into a sheet. , uneven height difference (maximum value): 0.5 mm, color tone: brown).
<Clear coat material>
・(1-1)
Acrylic resin emulsion (solid content 50% by weight) 200 parts by weight Coloring pigments (titanium oxide, yellow iron oxide, carbon black, red iron oxide) 3 parts by weight Thickener (hydroxyethyl cellulose) 0.06 parts by weight Additives Brown color clear coat material (TI value: 2.2, hiding rate: 70%)
・(1-2)
A brown color clear coating material containing 10 parts by weight of isopropyl alcohol in 100 parts by weight of the brown color clear coating material (1-1) (TI value: 2.4, hiding rate: 70%)
・(1-3)
A clear coating material containing 0.15 parts by weight of a thickening agent (synthetic smectite clay mineral) in 100 parts by weight of the above brown color clear coating material (1-1) (TI value: 2.6, hiding rate: 70%)
・(1-4)
A clear coating material containing 10 parts by weight of water in 100 parts by weight of the brown color clear coating material (1-1) (TI value: 1.0, hiding rate: 70%)
・(1-5)
Acrylic resin emulsion (solid content 50% by weight) 200 parts by weight, colored silica sand (particle size: more than 45 μm and less than 150 μm, brown type) 90 parts by weight, thickener 1 (hydroxyethyl cellulose) 0.06 parts by weight, thickener 2 ( Synthetic smectite clay mineral) containing 0.15 parts by weight, tea-based aggregate-containing Kakurya coating material containing additives (film-forming aids, etc.) (TI value: 3.3, hiding rate: 70%)
・(1-6)
Color pigment ((titanium oxide, yellow iron oxide, carbon black, red iron oxide) containing 3 parts by weight of brown aggregate-containing color clear coating material ( TI value: 3.4, concealment rate: 72%)

(Examples 1 to 8, Comparative Example 1)
Using the combination shown in Table 1, a clear coating material was applied to the decorative surface (weight per unit area: 80 g/m ² ) and cured (at 23°C for 3 hours) to form a design layer. Refurbished.
Visually observe the cosmetic surface after the repair, 4 levels of "A" for those with excellent aesthetics without uneven color and uneven gloss, and "D" for those with uneven color and uneven gloss (excellent: A) >B>C>D: inferior).

Claims (2)

A method for repairing an aggregate-containing decorative surface, comprising:
A step of forming a design layer by applying a clear coating material containing a synthetic resin and a pigment and/or aggregate and having a thixotropic index value (TI value) of 1.5 or more;
A refurbishment method comprising: 2. The repair method according to claim 1, wherein the design layer has a concealment rate of 85% or less.