JP2020033390A - Coloring coating agent - Google Patents

Abstract

To provide a coloring coating agent which exhibits stable overcoating suitability and enables coloring finishing excellent in appearance.SOLUTION: A coloring coating agent is a coloring coating agent which contains an oxidation curable type resin (A), a pigment (B), an organic metallic compound (C) and an aliphatic hydrocarbon-containing non-aqueous agent (D), in which the oxidation curable type resin (A) has an acid value and contains surface-treated rutile-type titanium oxide (B-1) and a coloring pigment (B-2) other than (B-1) as the pigment (B), and the total oil absorption amount of the pigment (B) based on 100 g of a solid content of the oxidation curable type resin (A) is 60 g or less.SELECTED DRAWING: None

Description

  The present invention relates to a novel colored coating agent.

  2. Description of the Related Art Conventionally, in buildings, civil engineering structures, and the like, colored finishes with various coating agents have been performed for the purpose of protecting base materials and improving aesthetics. In recent years, in the field of such coating agents, the use of aromatic hydrocarbon solvents such as toluene and xylene has been suppressed in consideration of safety at the time of painting, work hygiene, and influence on air pollution. Movement is growing. In order to cope with such a movement, various environmentally friendly coating agents using an aliphatic hydrocarbon-based solvent have been proposed.

  As such an environment-friendly coating agent, a coating agent using an oxidation-curable resin is known. For example, Japanese Patent Application Laid-Open No. 2004-352764 (Patent Document 1) describes a coating agent containing a resin component derived from an unsaturated fatty acid, a metal dryer, a specific titanium oxide, and the like. The coating agent described in this publication causes a cross-linking reaction by oxidation of reactive double bonds contained in unsaturated fatty acids, and a metal dryer is used as a curing catalyst therefor.

JP-A-2004-352768

  In the coating agent as described above, various colors can be imparted by mixing various chromatic or black coloring pigments in addition to the white pigment. When performing a coloring finish with such a coloring coating agent, the concealing property or the like is likely to be insufficient with a single application, so that the coating may be finished by applying the coating two or more times. However, there is a possibility that the finish may be hindered. In addition, if the formed colored finish film is stained or damaged, repair may be performed by over-coating, and the same problem may occur at this time.

  The present invention has been made in view of the above points, and has as its object to provide a colored coating agent which exhibits stable recoatability and is capable of performing a colored finish with excellent aesthetics.

  In order to solve such problems, the present inventors have conducted intensive studies and, as a result, to suppress the occurrence of the above-described problems during recoating and to develop stable recoatability, a resin component and a pigment component. It has been found that it is effective to control the configuration of the present invention, and the present invention has been completed.

  That is, the present invention has the following features.

1. A color coating agent comprising an oxidation-curable resin (A), a pigment (B), an organometallic compound (C), and a non-aqueous solvent containing an aliphatic hydrocarbon (D),
The oxidation-curable resin (A) has an acid value,
The pigment (B) includes a surface-treated rutile-type titanium oxide (B-1), and a coloring pigment (B-2) other than the (B-1),
A colored coating agent, wherein the pigment (B) has a total oil absorption of 60 g or less based on 100 g of the solid content of the oxidation-curable resin (A).
2. The surface-treated rutile-type titanium oxide (B-1) has an oil absorption of 30 g / 100 g or less. The colored coating agent according to the above.

  ADVANTAGE OF THE INVENTION According to this invention, the coloring coating agent which shows stable recoatability and which can perform the coloring finish excellent in aesthetics is obtained.

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

  The colored coating agent of the present invention contains an oxidation-curable resin (A), a pigment (B), an organometallic compound (C), and a non-aqueous solvent containing an aliphatic hydrocarbon (D).

  In the colored coating agent of the present invention, an oxidation-curable resin (A) (hereinafter also referred to as “component (A)”) is used as a resin component. The component (A) in the present invention is one which is air-oxidized and cured and dried by an oxidatively polymerizable double bond (oxidatively polymerizable group). The component (A) has an oxidatively polymerizable group, and specifically, the following resins can be used.

1) A resin obtained by copolymerizing a vinyl monomer having an oxidatively polymerizable group with another vinyl monomer copolymerizable with the monomer.
2) After copolymerizing an epoxy group-containing vinyl monomer and another vinyl monomer copolymerizable with the monomer, an unsaturated fatty acid is added to the epoxy group-containing vinyl monomer. The obtained resin.
3) A resin obtained by copolymerizing and / or graft-polymerizing a vinyl monomer having an oxidatively polymerizable group and / or another vinyl monomer copolymerizable with this monomer to an alkyd resin.

  Examples of the vinyl monomer having an oxidatively polymerizable group in the above 1) and 3) include, for example, a vinyl monomer obtained by adding an unsaturated fatty acid to an epoxy group-containing vinyl monomer. This vinyl monomer is obtained by reacting an epoxy group with a carboxyl group in an unsaturated fatty acid. The resin of the above 2) is obtained by an addition reaction of an unsaturated fatty acid to an epoxy group in the resin. When the epoxy group is reacted with the unsaturated fatty acid, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used.

  Specific examples of the epoxy group-containing vinyl monomer include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-oxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether. These can be used alone or in combination of two or more.

  Examples of unsaturated fatty acids include linseed oil fatty acids, tung oil fatty acids, fish oil fatty acids, dehydrated castor oil fatty acids, soybean oil fatty acids, sesame oil fatty acids, poppy oil fatty acids, eno oil fatty acids, safflower oil fatty acids, hemp seed oil fatty acids, and grape kernel oil. Fatty acids, tall oil fatty acids, sunflower oil fatty acids, cottonseed oil fatty acids, corn oil fatty acids, walnut oil fatty acids, and the like. These can be used alone or in combination of two or more. The component ratio of the unsaturated fatty acid in the component (A) is preferably from 0.5 to 30% by weight, more preferably from 1 to 25% by weight, from the viewpoint of curability, suitability for recoating and the like. In the present invention, “ab” is synonymous with “a or more and b or less”.

  Examples of the vinyl monomer having an oxidatively polymerizable group in the above 1) and 3) include, for example, a vinyl monomer containing a dicyclopentadieneoxyalkyl group such as dicyclopentadieneoxyalkyl (meth) acrylate, and allyl (meth) acrylate And allyl group-containing vinyl monomers. These can be used alone or in combination of two or more.

  As the alkyd resin in the above 3), a resin obtained by polycondensing a polyhydric alcohol and a polycarboxylic acid and modifying the polycondensation with a drying oil, unsaturated fatty acid or the like can be used. Among them, polyhydric alcohols include, for example, ethylene glycol, glycerin, pentaerythritol and the like, and polyhydric carboxylic acids include, for example, phthalic anhydride and maleic anhydride. Examples of the drying oil include linseed oil, paulownia oil, deer oil, safflower oil and the like.

  Examples of other vinyl monomers in the above 1) to 3) include alkyl (meth) acrylates and aromatic monomers. Among them, specific examples of the alkyl (meth) acrylate include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n -Amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) A) acrylate, cyclohexyl (meth) acrylate and the like. Specific examples of the aromatic monomer include, for example, styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, and the like. These can be used alone or in combination of two or more. As such a vinyl monomer, for example, a carboxyl group-containing vinyl monomer, an amino group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer and the like can also be used. As the component (A), other monomers such as those obtained by copolymerizing at least an alkyl (meth) acrylate, those obtained by copolymerizing an alkyl (meth) acrylate and an aromatic monomer, and the like can be used. It is suitable.

  The oxidation-curable resin (A) in the present invention has an acid value. In the present invention, by using the component (A) having such an acid value, curability can be improved and suitability for recoating can be improved. Further, it is possible to improve the pigment miscibility and the like, which is also advantageous in terms of finishability and the like. The acid value of the component (A) is preferably 0.1 to 50 mgKOH / g, more preferably 0.3 to 30 mgKOH / g, and still more preferably 0.5 to 20 mgKOH / g. The acid value is a value represented by the number of mg of potassium hydroxide in an equimolar amount to the acid group contained in 1 g of the solid content of the component (A). In order to impart an acid value to the component (A), for example, a carboxyl group-containing vinyl monomer may be used as the other vinyl monomer in the above 1) to 3). As the carboxyl group-containing vinyl monomer, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid or its monoalkyl ester, itaconic acid or its monoalkyl ester, fumaric acid or its monoalkyl ester, ω-carboxy-poly Butyrolactone mono (meth) acrylate, ω-carboxy-polyvalerolactone mono (meth) acrylate, ω-carboxy-polycaprolactone mono (meth) acrylate, ω-carboxy-polycaprylolactone mono (meth) acrylate, ω-carboxy- Polylauryl lactone mono (meth) acrylate, (meth) acrylic acid dimer, (meth) acrylic acid trimer, (meth) acrylic acid tetramer, (meth) acrylic acid heptamer, (meth) acrylic acid hexamer and the like. You. These can be used alone or in combination of two or more.

  As the component (A) in the present invention, a resin obtained by modifying the above resin with, for example, an isocyanate compound, a urethane compound, a silicone compound, an alkoxysilane compound, or the like can be used.

  The form of the component (A) may be any of a solvent-soluble form and a non-aqueous dispersion form. In the present invention, both types of resins can be used in combination.

  The weight average molecular weight of the component (A) is preferably 10,000 to 500,000, and more preferably 20,000 to 300,000. The glass transition point of the component (A) is preferably -5C to 70C, more preferably 10C to 60C.

  The pigment (B) (hereinafter also referred to as “component (B)”) is a component that imparts various colors to the colored coating agent of the present invention and further imparts opacity and the like.

  In the present invention, as the pigment (B), at least a surface-treated rutile-type titanium oxide (B-1) (hereinafter, also referred to as a “(B-1) component”) and a coloring pigment (B) other than the (B-1) -2) (hereinafter also referred to as “component (B-2)”). The total oil absorption of the pigment (B) (based on the solid content of the oxidation-curable resin (A) of 100 g) is set to be 60 g or less. In the present invention, when the pigment (B) satisfies such a condition, stable suitability for recoating is developed, and a colored finish excellent in aesthetic appearance can be obtained.

  The reason for such an effect is not limited to the following theory, but titanium oxide has a property of generating a radical, and the radical is an oxidatively polymerizable group of the oxidation-curable resin (A). And may inhibit the curing by the organometallic compound (C). On the other hand, if the total oil absorption of the pigment (B) is too large, the organometallic compound (C) tends to be adsorbed on the pigment (B), and hardening by the organometallic compound (C) does not easily proceed.

  On the other hand, in the present invention, the pigment (B) satisfies the above conditions, that is, by using the specific titanium oxide (B-1) and controlling the total oil absorption of the pigment (B). The curing of the oxidation-curable resin (A) by the organometallic compound (C) proceeds stably. Further, the curing action of the organometallic compound (C) is sufficiently exerted by the acid group of the oxidation-curable resin (A). Thereby, it is considered that lifting or the like at the time of re-coating is suppressed, the re-coating suitability is improved, and a colored finish state excellent in aesthetic appearance is obtained.

The surface-treated rutile-type titanium oxide (B-1) plays a role as a white pigment and contributes to suitability for recoating and the like. In untreated rutile-type titanium oxide and anatase-type titanium oxide, radicals are easily generated, and the radicals inhibit curing by the organometallic compound (C), promote lifting, and adversely affect recoatability. Become. In the present invention, the titanium oxide may be one containing substantially TiO ₂ as a main component, and some impurities (for example, antimony oxide, niobium oxide, potassium oxide, phosphorus oxide, sulfur oxide, etc.) May be included.

  As the component (B-1), those in which the surface of rutile-type titanium oxide particles is surface-treated with at least an inorganic compound can be used. Examples of the inorganic compound used for the surface treatment include silica, alumina, zirconia, titania, tin oxide, antimony oxide, zinc oxide and the like. Among them, one kind selected from the group consisting of silica, alumina, and zirconia Alternatively, an embodiment including two or more types is preferable. In addition, as the inorganic compound, for example, a compound containing phosphorus, calcium, magnesium, strontium, barium, or the like may be included. The surface treatment with such an inorganic compound can be performed by a known method. For example, an aqueous solution of a salt such as Si, Al, Zr, Ti, Sn, Sb, Zn, or the like is added to a slurry containing titanium oxide, and After adding a hydrated alkali or acid to generate a hydrated oxide on the surface of the titanium oxide particles, a method of performing steps such as filtration, drying, and pulverization can be employed.

  Further, the component (B-1) may be surface-treated with an organic compound in addition to the inorganic compound. Examples of the organic compound used for the surface treatment include, for example, a fatty acid, a fatty acid ester, a surfactant, a metal soap, a silicone resin, a fluororesin, an acrylic resin, a polyester resin, a silane coupling agent, a titanium coupling agent, and a wax. Can be These can be used alone or in combination of two or more. Such a surface treatment with an organic compound can be performed by a known method. For example, a method of adding and mixing an organic compound before or after drying in the surface treatment method with an inorganic compound can be employed.

  The oil absorption of the component (B-1) is preferably 30 g / 100 g or less. With such an oil absorption, the surface of the titanium oxide particles is likely to be in a state where the surface is densely treated with the inorganic compound or the like, which is advantageous for suppressing the generation of radicals and for suppressing the adsorption of the organometallic compound (C). Is also advantageous, and is preferable in terms of improving the effects of the present invention. The lower limit of the oil absorption of the component (B-1) is not particularly limited, but is preferably 5 g / 100 g or more. If the lower limit of the oil absorption is such a value, it is preferable in terms of viscosity imparting, coating workability, finishability, and the like. In addition, the oil absorption is a value measured by the method of JIS K5101-13-2: 2004.

(B-1) TiO ₂ content of the component is preferably 95% or less, more preferably 90% or less, more preferably from 80 to 89%. When the TiO ₂ content of the component (B-1) is within such a range, the surface treatment is likely to be in a thick state, which is advantageous in suppressing the generation of radicals, and is suitable in terms of improving the effects of the present invention. is there. The TiO ₂ content is a value (mass fraction) measured according to JIS K5116: 2004 7.2.

  In the present invention, various colors can be expressed by including the coloring pigment (B-2). As the component (B-2), chromatic pigments, black pigments and the like can be used. Among them, the chromatic pigment is a pigment that exhibits a chromatic color such as yellow, orange, red, green, blue, and purple. Examples of such chromatic pigments include, for example, ferric oxide, ferric hydrated oxide, ultramarine, cobalt blue, inorganic substances such as cobalt green, azo-based, naphthol-based, pyrazolone-based, anthraquinone-based, perylene-based, and the like. Organic materials such as quinacridone, disazo, isoindolinone, benzimidazole, phthalocyanine, and quinophthalone are exemplified. On the other hand, the black pigment is a pigment that exhibits black, for example, iron black, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, Inorganic substances such as copper-manganese-chromium composite oxides, and other carbon blacks may be mentioned. In addition, as the component (B-2), for example, white pigments such as zinc oxide and aluminum oxide can be used. These can be used alone or in combination of two or more.

  In the present invention, extender pigment (B-3) (hereinafter, also referred to as “component (B-3)”) may be mixed as component (B). Examples of the component (B-3) include heavy calcium carbonate, light calcium carbonate, kaolin, clay, porcelain clay, china clay, diatomaceous earth, hydrous fine silica, talc, barite powder, barium sulfate, precipitated barium sulfate, and carbonic acid. Examples include barium, magnesium carbonate, silica powder, and aluminum hydroxide. These can be used alone or in combination of two or more. The component (B-3) can be used, for example, for the purpose of adjusting the solid content, adjusting the viscosity, adjusting the gloss (reducing the gloss, etc.).

  In the present invention, the total oil absorption of the component (B) based on 100 g of the solid content of the component (A) (hereinafter also simply referred to as “total oil absorption”) is 60 g or less, and preferably 55 g or less. Since the upper limit of the total oil absorption of the component (B) is such a value, the curing of the oxidation-curable resin (A) by the organometallic compound (C) proceeds stably, and lifting and the like at the time of recoating are prevented. Suppression is suppressed, suitability for recoating is improved, and a colored finish excellent in aesthetic appearance can be obtained. The lower limit of the total oil absorption of the component (B) is not particularly limited, but is preferably 3 g or more, more preferably 5 g or more. When the lower limit of the total oil absorption is such a value, it is preferable in terms of viscosity imparting, coating workability, finishability, and the like. The total oil absorption of the component (B) can be set, for example, by adjusting the oil absorption, the mixing ratio, and the like of each component (B) used.

In the present invention, the total oil absorption of the component (B) is the amount (g) of the boiled linseed oil absorbed by the component (B) based on 100 g of the solid content of the component (A). Specifically, when m kinds (m is an integer) represented by (B ₁ ), (B ₂ ),... (B _m ) are used as the component (B), the total oil absorption of the component (B) Is calculated by the following equation.
(B) Total oil absorption of component =
[{Oil absorption of (B ₁ )} × {g of (B ₁ ) based on 100 g of solid content of component (A)} / 100] +
[{Oil absorption of (B ₂ )} × {g of (B ₂ ) based on 100 g of solids of component (A)} / 100] +.
[{Oil absorption of (B _m )} × {g of (B _m ) based on 100 g of solids of component (A)} / 100]

  The mixing ratio of the component (B) in the colored coating agent of the present invention may be set within a range in which the total oil absorption satisfies the above range, but the component (B-1) has a solid content of the component (A) of 100% by weight. The amount is preferably from 5 to 150 parts by weight, more preferably from 10 to 120 parts by weight, per part by weight. The component (B-2) is preferably 0.1 to 100 parts by weight, more preferably 0.3 to 90 parts by weight, based on 100 parts by weight of the solid content of the component (A). When the component (B-3) is used, the component (B-3) is preferably 50 parts by weight or less, and more preferably 1 to 40 parts by weight, based on 100 parts by weight of the solid content of the component (A). Is more preferred.

  The organometallic compound (C) (hereinafter also referred to as “component (C)”) is a component that functions as a curing catalyst or a curing accelerator for the oxidation-curable resin (A). As the component (C), for example, organometallic compounds including metals such as cobalt, manganese, vanadium, cerium, iron, tin, zirconium, bismuth, aluminum, strontium, titanium, zinc, barium, copper, calcium, lead, and nickel (For example, metal organic acid salt compounds, metal chelate compounds, metal alkoxide compounds, metal acylate compounds, etc.) can be used. Specifically, the component (C) includes, for example, cobalt octylate, cobalt naphthenate, manganese octylate, manganese naphthenate, iron octylate, iron naphthenate, tin octylate, tin naphthenate, dibutyltin diacetate, dibutyltin dilaurate , Dibutyltin dioctiate, zirconium octylate, zirconium naphthenate, zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate), zirconium ethoxide, zirconium n-propoxide, zirconium n-butoxide, aluminum Monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum ethylacetoacetate diisopropylate, aluminum Methylate, aluminum isopropylate, aluminum sec-butyrate, titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), titanium ethoxide, titanium isopropoxide, titanium n-butoxide, zinc octylate, naphthene Zinc acid, barium octylate, barium naphthenate, copper octylate, copper naphthenate, calcium octylate, calcium naphthenate, and the like. These can be used alone or in combination of two or more.

  In the present invention, as the component (C), an organometallic compound (C-1) containing at least one metal selected from the group consisting of cobalt, manganese, vanadium, cerium, and iron (hereinafter referred to as “(C-1) component ") And an organometallic compound (C-2) containing at least one metal selected from the group consisting of zirconium, bismuth, aluminum, strontium, titanium, zinc, barium, copper, and calcium (hereinafter referred to as" (C -2) also referred to as “component”). The case where such a component (C-1) and a component (C-2) are contained is preferable in terms of improving effects such as curability, lifting resistance, suitability for recoating and the like. The weight ratio of the component (C-1) to the component (C-2) {(C-1) :( C-2)} is preferably 1:99 to 50:50, more preferably metal conversion. 2:98 to 40:60.

  The mixing ratio of the component (C) is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 3 parts by weight, in terms of metal, based on 100 parts by weight of the solid content of the component (A). If the component (C) has such a mixing ratio, it is preferable in terms of curability, lifting resistance, suitability for recoating, and the like.

  The coloring coating agent of the present invention is a so-called weak solvent type material containing a non-aqueous solvent containing an aliphatic hydrocarbon (D) (hereinafter also referred to as “component (D)”) as a medium. Such a component (D) is a non-aqueous solvent having lower toxicity, higher safety in operation, and less influence on air pollution than toluene, xylene and the like. Examples of the aliphatic hydrocarbon include n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane and the like. These can be used alone or in combination of two or more. In the present invention, an aliphatic hydrocarbon can be introduced by using a mixed solvent such as mineral spirits. The aliphatic hydrocarbon is preferably contained in an amount of at least 5% by weight, more preferably from 10 to 80% by weight, based on the total amount of the component (D).

  The component (D) may contain a solvent that can be mixed with the aliphatic hydrocarbon. Examples of such a solvent include petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha, as well as ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. Suitable solvents include, for example, mixed aniline And petroleum solvents having an aniline point of 12 to 70 ° C. (petroleum mixed solvents containing aromatic hydrocarbons). The mixed aniline point or the aniline point is a value measured by the method of JIS K2256: 2013.

  The mixing ratio of the component (D) is preferably from 100 to 300 parts by weight, more preferably from 120 to 250 parts by weight, based on 100 parts by weight of the solid content of the component (A), from the viewpoints of workability at the time of recoating and finishability. Parts by weight. The component (D) also includes a solvent used as a medium for each component.

  The colored coating agent of the present invention may contain various components in addition to the components described above to such an extent that the effects of the present invention are not affected. Such components include, for example, plasticizers, preservatives, fungicides, anti-algal agents, defoamers, leveling agents, pigment dispersants, thickeners, anti-skinning agents, dehydrating agents, matting agents, Examples include an ultraviolet absorber, a light stabilizer, an antioxidant, and a catalyst. Further, it may contain a resin component other than the component (A). The colored coating agent of the present invention can be produced by uniformly stirring and mixing the above components (A) to (D) and, if necessary, such components according to a conventional method.

  The colored coating agent of the present invention can be mainly applied to buildings, civil engineering structures and the like. Examples of the base material constituting such a site include concrete, mortar, siding board, extruded board, gypsum board, perlite board, wood board, plastic board, metal board and the like. These substrates may be those that have been subjected to some kind of surface treatment (filler treatment, putty treatment, surfacer treatment, sealer treatment, etc.) or those on which a coating film has already been formed. The colored coating agent of the present invention is particularly suitable under conditions where titanium oxide is liable to generate radicals, for example, for outdoor use, which is susceptible to sunlight. Further, the colored coating agent of the present invention is desirably used in a one-pack type.

  The colored coating agent of the present invention can be diluted at the time of painting. The diluent is preferably the above-mentioned component (D), and it is desirable to dilute the diluent within a range where the total amount of the diluted component (D) satisfies the above-mentioned mixing ratio.

As the coating method, for example, various methods such as brush coating, roller coating, spray coating and the like can be adopted. Dabs amount during painting, once per coating, preferably 30 to 250 g / ^{m 2,} more preferably 50 to 200 g / ^{m 2.} In the present invention, once coating is performed, and after the coating film is dried, the next coating (overcoating) may be performed. The drying temperature is preferably from -10 to 50C, more preferably from -5 to 40C. The number of coatings is preferably two or more.

  Hereinafter, examples and comparative examples are shown to further clarify the features of the present invention.

(Manufacture of colored coating agents)
Each component was uniformly mixed at a weight ratio shown in Table 1 by an ordinary method to produce each colored coating agent. The components used are as follows.

-Resin 1: Oxidation-curable resin (resin component: alkyl methacrylate, alkyl acrylate, styrene, glycidyl methacrylate, acrylic acid copolymer modified with soybean oil, non-aqueous dispersion resin with mineral spirit as medium) , Unsaturated fatty acid composition ratio: 10% by weight, acid value: 2 mg KOH / g, solid content: 50% by weight)
-Resin 2: Oxidation-curable resin (resin component: alkyl methacrylate, alkyl acrylate, styrene, glycidyl methacrylate, acrylic acid copolymer modified with soybean oil fatty acid, non-aqueous dispersion resin with mineral spirit as medium , Unsaturated fatty acid constituent ratio: 10% by weight, acid value: 0.2 mg KOH / g, solid content: 50% by weight)
-Resin 3: Oxidation-curable resin (resin component: alkyl methacrylate, alkyl acrylate, styrene-glycidyl methacrylate copolymer, soybean oil fatty acid modified product, non-aqueous dispersion resin using mineral spirit as medium, unsaturated resin Fatty acid composition ratio: 10% by weight, acid value: 0 g KOH / g, solid content: 50% by weight)
Titanium oxide 1: surface treatment rutile titanium oxide (oil absorption: 24 g / 100 g, TiO ₂ content: 93%, the surface treatment compounds: silica, alumina, zirconia)
Titanium oxide 2: surface treated rutile titanium oxide (oil absorption: 22 g / 100 g, TiO ₂ content: 87%, the surface treatment compounds: silica, alumina, zirconia, organic compounds)
・ Titanium oxide 3: Surface-treated rutile-type titanium oxide (oil absorption: 33 g / 100 g, TiO ₂ content: 88%, surface treatment compound: silica, alumina)
Titanium oxide 4: untreated rutile titanium oxide (oil absorption: 17 g / 100 g, TiO ₂ content: 99%)
・ Titanium oxide 5: anatase type titanium oxide (oil absorption: 23 g / 100 g, TiO ₂ content: 99%)
Coloring pigment 1: black pigment (carbon black, oil absorption: 98 g / 100 g)
Coloring pigment 2: yellow pigment (containing ferric hydroxide, oil absorption: 30 g / 100 g)
Coloring pigment 3: red pigment (ferric oxide, oil absorption: 25 g / 100 g)
Coloring pigment 4: Blue pigment (copper phthalocyanine blue, oil absorption: 35 g / 100 g)
-Body pigment 1: Body pigment (hydrous finely divided silica, oil absorption: 250 g / 100 g)
-Organometallic compound 1: Mineral spirit solution of cobalt naphthenate-Organometallic compound 2: Mineral spirit solution of zirconium naphthenate-Organometallic compound 3: Aluminum monoacetylacetonate bis (ethylacetoacetate)
・ Dispersant: Acrylic dispersant ・ Thickener: Amide wax-based thickener ・ Defoamer: Mineral oil-based defoamer ・ Solvent: Non-aqueous solvent containing aliphatic hydrocarbon (including mineral spirit and aromatic hydrocarbon) Mixture of petroleum mixed solvents, aliphatic hydrocarbon content: 65% by weight)

(Test method)
The following tests were performed for each colored coating agent.

・ Overcoating suitability 1
A slate plate previously coated with an epoxy resin undercoat material was spray-coated with a coloring coating agent at a coating amount of 100 g / m ² . During the day, after drying and curing for a predetermined time (48 hours, 72 hours) in a room receiving sunlight, the same colored coating agent was partially overcoated with a brush at an application amount of 100 g / m ² . Observing the surface condition of the coating film at this time, "a" indicates that no lifting phenomenon was observed, "b" indicates that a very slight lifting phenomenon was observed, and "b" indicates that a slight lifting phenomenon was observed. The evaluation was performed in four steps (a>b>c> d, practical levels a to c), where "c" and those in which the lifting phenomenon was clearly recognized were "d". Table 1 shows the results.

・ Overcoating suitability 2
A slate plate previously coated with an epoxy resin undercoat material was spray-coated with a coloring coating agent at a coating amount of 100 g / m ² . After drying and curing for 48 hours in a room receiving sunlight during the day, the same colored coating agent was partially applied again at a coating amount of 100 g / m ² using a brush. After the test specimen was left for 48 hours, the color difference (ΔE) between the spray-coated area and the brush-coated area was measured with a colorimeter. The evaluation criteria were “a” when ΔE was less than 0.5, “b” when ΔE was 0.5 or more and less than 1.0, “c” when ΔE was 1.0 or more and less than 1.5, and ΔE1. .5 or more were designated as "d" (practical levels are ac). Table 1 shows the results. In addition, about Comparative Examples 1-4, since it was inferior to the above-mentioned recoatability 1, the evaluation was not performed.

(Test results)
In Examples 1 to 9 (especially Examples 2 to 6), good results were obtained in recoatability 1 and 2.

Claims (2)

A color coating agent comprising an oxidation-curable resin (A), a pigment (B), an organometallic compound (C), and a non-aqueous solvent containing an aliphatic hydrocarbon (D),
The oxidation-curable resin (A) has an acid value,
The pigment (B) includes a surface-treated rutile-type titanium oxide (B-1), and a coloring pigment (B-2) other than the (B-1),
A colored coating agent, wherein the pigment (B) has a total oil absorption of 60 g or less based on 100 g of the solid content of the oxidation-curable resin (A). The colored coating agent according to claim 1, wherein the surface-treated rutile-type titanium oxide (B-1) has an oil absorption of 30 g / 100 g or less.