KR20040085080A - Coating composition and coated articles - Google Patents

Abstract

PURPOSE: Provided are a paint composition which is improved in weather resistance, is free from the pollution of rainwater and does not damage an already-formed coat, and a coated product obtained by coating the paint composition. CONSTITUTION: The paint composition comprises 100 parts by weight of a fluoroolefin-based polymer which has a reaction curing region and whose fluorine content is 5 wt% or more; 1-100 parts by weight of a polyisocyanate-based curing agent which contains 1.5 or more of an isocyanate group in molecule on the average; a medium which contains 30 wt% of a paraffin-based solvent and/or a naphthene-based solvent; and 0.1-100 parts by weight of a four functional hydrolyzable silane compound oligomer. The fluoroolefin-based polymer and the polyisocyanate-based curing agent can be soluble or dispersible in the medium. Preferably the four functional hydrolyzable silane compound oligomer is an oligomer of tetraalkoxysilane.

Description

Paint compositions and paints {COATING COMPOSITION AND COATED ARTICLES}

The present invention relates to paint compositions and painted articles.

Fluorine-containing resins for paints have excellent weather resistance, endure long-term use, and excellent protection functions for building and civil engineering structures, which can significantly reduce maintenance such as cleaning and repainting, contributing to the improvement of residential environment, and new clearness. Color is preserved in the long term, free color design is possible. As such a coating composition, a two-component coating composition comprising a polymer containing an isocyanate group and a fluoroalkyl group and a hydroxyl group-containing fluorine polymer has been proposed (see, for example, Japanese Patent Laid-Open No. 62-022862).

In the two-component type coating composition containing a curing agent as in this proposal, it is common to use a large amount of a strong solvent such as an aromatic compound such as toluene or an ester compound such as butyl acetate.

However, when the coating composition using such a strong solvent is apply | coated to the surface of an existing coating film in order to repair an existing coating film, there existed a problem of damaging an existing coating film.

In solving the above problems, in a coating composition containing a fluorine-containing resin, a one-component type containing no curing agent containing a so-called relatively low solvent such as a paraffinic solvent or a naphthenic solvent as a solvent is used. Coating compositions have also been proposed (see, for example, Japanese Patent Laid-Open No. 63-199770).

However, since this one-component type coating composition does not form a three-dimensional network structure even when cured, the coating film after film formation has no solvent resistance, and also has disadvantages of poor fouling resistance and chemical resistance.

Accordingly, a two-component fluorine resin-containing coating composition which is soluble or dispersible in a medicinal solvent such as a paraffinic solvent or a naphthenic solvent and further contains a curing agent has been developed (for example, Japanese Patent Application Laid-Open No. 8-302281). Reference).

However, the coating film formed using the fluorine resin-containing coating composition described in Japanese Patent Application Laid-Open No. Hei 8-302281 can be used as a high-performance product to the same extent as in the case of other synthetic resin coating materials having antifouling properties on the surface. The improvement of the antifouling property is calculated | required.

The present invention is to solve the above-described problems, provides a coating composition that is excellent in weather resistance, does not cause rain pollution, and does not damage the existing coating film even when applied to the surface of the existing coating film.

The coating composition of the present invention,

(a) a fluoroolefin polymer having a reaction curable site and having a fluorine content of 5% by mass or more;

(b) a polyisocyanate curing agent containing 1.5 or more on average of isocyanate groups in the molecule,

(c) a medium containing at least 30% by mass of a paraffinic solvent and / or a naphthenic solvent in total,

(d) contains a multimer of tetrafunctional hydrolyzable silane compounds,

The said (a) component and (b) component are soluble or dispersible in (c) component, the ratio of (b) component is 1-100 mass parts with respect to 100 mass parts of (a) component, (d) component It is characterized by the ratio of 0.1-100 mass parts with respect to 100 mass parts of (a) component.

The coated article of the present invention is characterized by coating the article with the composition for coating.

Embodiment of the invention

(a) Ingredients:

The component (a) is soluble or dispersible in a medium containing 30% by mass or more of paraffinic and / or naphthenic solvents, has a reaction curable site, and has a fluorine content of 5% by mass or more with respect to the entire polymer. It is a fluoroolefin type polymer (henceforth a fluororesin). In the present invention, a polymer means a homopolymer and / or a copolymer. The fluoroolefin polymer having the above reaction curable portion and having a fluorine content of 5% by mass or more is a polymer obtained by polymerization using a fluoroolefin as the fluorine monomer of the polymerization raw material. Examples of such fluoroolefins include fluoroolefins having 2 to 3 carbon atoms, such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride. Rhoethylene and trifluoroethylene are preferable. As a fluoroolefin, 1 type may be used or 2 or more types may be used.

When a fluoroolefin type polymer is a copolymer of a fluorine-type monomer and copolymerization monomers other than a fluorine type, a vinyl monomer is preferable as a copolymerization monomer. As this vinyl type monomer, vinyl ether, allyl ether, carboxylic acid vinyl ester, carboxylic acid allyl ester, olefin, etc. are illustrated, for example, vinyl ether, carboxylic acid vinyl ester, etc. are preferable.

As vinyl ether, alkyl vinyl ethers, such as cycloalkyl vinyl ether, nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, n-butyl vinyl ether, tert- butyl vinyl ether, are mentioned. .

In particular, in order to be able to dissolve or disperse | distribute in the medium containing a paraffinic solvent and / or a naphthenic solvent in a high ratio, the linear or branched vinyl ether which has a C1-C18 alkyl group is preferable.

As allyl ether, alkyl allyl ether, such as ethyl allyl ether and hexyl allyl ether, is mentioned.

Examples of the carboxylic acid vinyl ester and the carboxylic acid allyl ester include vinyl or allyl esters of carboxylic acids such as acetic acid, butyric acid, pivalic acid, crotonic acid, benzoic acid and maleic acid. Moreover, you may use the commercially available beoba-9 and beoba-10 (all are the Shell Chemicals make, brand names) etc. as a branched vinyl ester.

Ethylene, isobutylene, etc. are mentioned as olefins.

The said copolymer monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

The reaction curable site in (a) component should just react with a hardening | curing agent, and form crosslinking. Although this reaction curable site | part can be suitably selected by combination with a hardening | curing agent, a hydroxyl group, a carboxyl group, a hydrolyzable silyl group, glycidyl group, an epoxy group, an amino group, etc. are mentioned. As a reaction curable site | part, it is preferable that it is an active hydrogen containing group because it is excellent in reactivity with a hardening | curing agent. As this active hydrogen containing group, a hydroxyl group, a carboxyl group, and an amino group are preferable.

As a method of introducing a reaction curable site | part into a polymer, there exists a method of copolymerizing the monomer which has a reaction curable site | part, and the method of introducing a reaction curable site | part after superposition | polymerization.

As a monomer which has this reaction curable site | part in the former, For example, hydroxyalkyl vinyl ether, such as hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, cyclohexanediol monovinyl ether; Hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether; Monomers having hydroxyl groups such as hydroxyl group-containing vinyl carboxylates such as hydroxyalkyl crotonate or allyl esters; Monomers having carboxylic acid groups such as crotonic acid vinyl ester; Monomers having hydrolyzable silyl groups such as triethoxy vinylsilane, monomers having epoxy groups such as glycidyl vinyl ether, glycidyl allylethyl and β-methyl glycidyl ether, aminopropyl vinyl ether, aminopropyl vinyl ether, and the like. The monomer etc. which have an amino group of these are mentioned.

As the latter method, for example, a method of introducing a hydroxyl group by saponifying a polymer copolymerized with a carboxylic acid vinyl ester, a method of introducing a carboxyl group by reacting a polyvalent carboxylic acid or an anhydride thereof with a polymer having a hydroxyl group, isocyanate And a method of introducing a hydrolyzable silyl group by reacting an alkoxysilane, a method of introducing a isocyanate group by reacting a polyvalent silyl isocyanate compound, and the like.

The number of the reaction curable moieties in the fluoroolefin-based polymer is 1 to 150 mg / g in terms of chemical reaction equivalents of potassium hydroxide relative to the resin solid content, soluble in paraffin solvents and / or naphthenic solvents. Is preferred, with 10 to 70 mg / g being particularly preferred.

The fluorine content of the fluoroolefin polymer used in the present invention is 5 to 100% by mass, preferably 10 to 70% by mass, particularly preferably 20 to 35% by mass, based on the total amount of the fluoroolefin polymer. A fluoroolefin type polymer may be used individually by 1 type, and may be used in combination of 2 or more type.

In the composition for coatings of this invention, you may contain other resin other than (a) component. Examples of other resins include acrylic resins, polyester resins, acrylic polyol resins, polyester polyol resins, urethane resins, and fluorine resins other than the component (a). The other resin may have a reaction curable site. Examples of the fluorine resin other than the component (a) include Kyna 500, Kyna SL, Kyna ADS (above, manufactured by Atopina, trade name), and Florene (manufactured by Nippon Synthetic Rubber, trade name). Another resin may be used individually by 1 type, and may be used in combination of 2 or more type. The compounding quantity of another resin can be suitably selected in the range which does not impair the effect of this invention, and 1-200 mass parts is preferable normally with respect to 100 mass parts of (a) component.

(a) As a component, Lumipron LF200, Lumipron LF400, Lumipron LF500, Lumipron LF544, etc. (above, Asahi Glass Co., Ltd. brand name), a fluorate (made by Dainippon Ink & Chemicals Co., Ltd., brand name), Sepral coat (Central) Only resin components of commercially available products such as Ralgaras Co., Ltd., Zaffron 200, Zaffron 300 (manufactured by Doa Synthetic Chemical Co., Ltd., Trademark), and Jetple GK510 (manufactured by Daiseng Co., Ltd., trade name) are taken out to obtain a paraffin solvent and / or What melt | dissolved or disperse | distributed to the medium containing 30 mass% or more of naphthenic solvents can also be used.

In addition, the polymer of component (a) is polymerized in a paraffinic solvent and / or naphthenic solvent, or after the polymerization, a part or all of the solvent or dispersion medium is replaced with a paraffinic solvent and / or naphthenic solvent to form a varnish of a weak solvent type. Can be.

(b) ingredients

The component (b) is a polyisocyanate curing agent containing 1.5 or more on average of isocyanate groups in the molecule, soluble or dispersible in a medium containing 30 mass% or more of a paraffinic solvent and / or a naphthenic solvent. Although the upper limit of the isocyanate group contained in a molecule | numerator is not specifically limited, On average, 3 or less are preferable.

As the component (b), ethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 4,4-methylene-bis (phenyl isocyanate), 4 And polyisocyanates such as 4-diisocyanate diethyl xylene, 4,4-methylene-bis (cyclohexyl isocyanate), and triphenylmethane triisocyanate. In addition, polyisocyanates obtained by reacting these isocyanates with polyols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, polyisocyanates having biuret structure, polyisocyanates having allophanate structure, iso Polyisocyanate etc. which have a cyanurate structure are mentioned. Moreover, in order to improve the dilution property of polyisocyanate, the hydrocarbon chain was introduce | transduced by reacting with alcohol and mercaptans.

Examples of the component (b) include those in which an isocyanate group is blocked with caprolactam, isophorone, β-diketone, or the like.

(b) A component can also be used in combination of multiple types. The compounding ratio in the composition of (b) component is 1-100 mass parts with respect to 100 mass parts of (a) component, and 1-50 mass parts is preferable. If this ratio is 1 mass part or more, solvent resistance and hardness will become enough, and if it is 100 mass parts or less, since it is excellent in workability and impact resistance, it is preferable.

When (a) component in the composition of this invention is hydroxyl-containing fluororesin, it is preferable that the ratio of (b) component is 0.8 mol or more of isocyanate groups with respect to 1 mol of hydroxyl groups of hydroxyl-containing fluororesin. It is preferable that an isocyanate group is 0.8 mol or more because curing of the coating composition is sufficient, and solvent resistance and the like are excellent. Particularly, if the isocyanate group is 1.1 mol or more, it is preferable because the effect of preventing occurrence of rain pollution increases. Although the upper limit of content of an isocyanate group is not specifically limited, Since unreacted isocyanate group which remains in a coating film does not affect light resistance or other performance, it is preferable that it is 2.0 mol or less. The ratio of more preferable isocyanate groups is 1.2-1.6 mol.

(c) Ingredients:

The component (c) is a medium containing 30% by mass or more of a paraffinic solvent and / or a naphthenic solvent.

As the paraffin solvent, n-pentane, isopentane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, n-heptane, 2-methylhexane, 3-ethylpentane, 2,2- Dimethylpentane, 2,3-dimethylpentane, n-octane, 2-methylheptane, n-nonane, 2-methyloctane, 2,3,4-trimethylpentane, n-decane, 2-methylnonane, 2-methyldecane Etc. can be mentioned.

Examples of naphthenic solvents include cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, 1,3-dimethylcyclohexane, 1,4-dimethylcyclohexane, cycloheptane, methylcycloheptane, cyclooctane and methyl Cyclooctane, cyclononane, cyclodecane, etc. are mentioned.

A paraffinic solvent and a naphthenic solvent may be used independently and may use 2 or more types together.

As a paraffinic solvent and a naphthenic solvent, mineral spirit, mineral tapene, etc. are preferable.

As (c) component, there are many commercial items, Mineral spirit A, A solvent, Hyalom 2S made from Shin-Nippon Petroleum Corporation; Shell Chemicals, Inc. LAWS, HAWS; Pegasol 3040, AN45 by Exxon Mobil Corporation; The so-called "painter thinner" generally used in paints and the coating industry is mentioned.

As (c) component, Aromatic hydrocarbons, such as toluene and xylene; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Esters such as ethyl acetate and butyl acetate; Alcohol, such as n-butanol and isobutanol, etc. are mentioned.

The compounding quantity of the paraffinic solvent and / or naphthenic solvent in (c) component is 30 mass% or more, Preferably it is 50 mass% or more, Especially preferably, it is 70 mass% or more. It is preferable that the aniline point of (c) component is 10-55 degreeC. This aniline point is one of the measures indicating the dissolving power of the medicinal solvent, and indicates that the lower the temperature, the higher the dissolving power. This aniline point is the minimum temperature at which an equal amount of aniline and a medicinal solvent can exist as a uniform solution, and are obtained by JIS-K2256 and ASTM D611.

The ratio of (c) component in the coating composition of this invention is not restrict | limited, What is necessary is just to select suitably according to the viscosity of the coating composition, and to 100 mass parts of the total amount of (a) component and (b) component 80-600 mass parts is preferable, and 100-250 mass parts is especially preferable.

(d) component

The component (d) is a multimer of a tetrafunctional hydrolyzable silane compound. The tetrafunctional hydrolyzable silane compound is a compound in which four hydrolyzable groups are directly bonded to silicon atoms, and the component (d) is a compound in which the compound is multiplied by condensation.

Examples of the hydrolyzable group include an alkoxy group, an alkoxyalkyl group, an acyloxy group, an aryloxy group, an aminooxy group, an amide group, a ketooxime group, an isocyanate group and a halogen atom. Preferably it is group remove | excluding the hydrogen atom from the hydroxyl group of monohydric alcohol, such as an alkoxy group and an alkoxyalkyl group. Especially, an alkoxy group is preferable, The carbon number of this alkoxy group is 4 or less preferable, and 1 or 2 is especially preferable.

The degree of multimerization of the multimer of the tetrafunctional hydrolyzable silane compound is preferably such that the composition does not produce a gelled product. The degree of multimerization means the number of condensation molecules of the tetrafunctional hydrolyzable silane compound.

As the component (d), a multimer of tetraalkoxysilane is preferable. As the tetraalkoxysilane of linear structure, the compound represented by following formula (1) is preferable.

RO (Si (OR) ₂ O) _n R Equation 1

(In Formula 1, n represents the multimerization degree of a multimer, R represents the C1-C4 alkyl group. N R in a multimer may be same or different.)

Normally available multimers are mixtures of multimers with different n's, and the degree of multimerization thereof is represented by an average of n.

In Formula 1, R has a methyl group, an ethyl group, a propyl group, and a butyl group, and a methyl group and an ethyl group are preferable. As (d) component, the multimer of tetramethoxysilane and the multimer of tetraethoxysilane are more preferable, and the multimer of tetraethoxysilane is the most preferable.

The degree of multimerization of tetrafunctional hydrolyzable silane compounds such as tetraalkoxysilane or its multimers may be represented by "silica powder". "Silica powder" is obtained by measuring the amount of silica produced by sintering the compound stably and calcining the compound in a mass ratio of silica (SiO ₂ ) produced from the compound. In addition, "silica powder" shows the ratio of the silica produced | generated with respect to 1 molecule of the compound, and is a value calculated by a following formula.

Silica fraction (mass ratio) = multimerization degree x molecular weight of SiO ₂ / molecular weight of the compound

When the tetrafunctional hydrolyzable silane compound is a multimer of tetraalkoxysilane, the silica powder is made 40 parts by mass or more, and when the tetrafunctional hydrolyzable silane compound is a multimer of compounds other than tetraalkoxysilane, the silica powder is 35 By setting it as mass part or more, the composition for coatings containing this multimer can prevent generation | occurrence | production of rain-soil contamination over a long term.

As a (d) component, you may use a commercial item, MKC silicate MS51 and MS56 by Mitsubishi Chemical Corporation; Methyl silicate 51 (multimer of tetramethoxysilane), ethyl silicate 40, 40T, and 48 (all of multimers of tetraethoxysilane) manufactured by Colcot Co., Ltd .; Orgastics SI series from Matsumoto Gausho; Ethyl silicate 40 and 45 (all are multimers of tetraethoxysilane) by Tama Chemical Co., Ltd. are mentioned. Among these, it is preferable that the silica powder of tetraethoxysilane is 45 mass% or more, and ethyl silicate 48 and ethyl silicate 45 are especially preferable.

When (d) component is a multimer of tetramethoxysilane or a multimer of tetraethoxysilane, it is preferable that the content rate in a composition is 5-50 mass parts with respect to 100 mass parts of (a) component. By setting the content ratio to 5 parts by mass or more, the effect of preventing rain pollution is increased, and by setting it to 50 parts by mass or less, a favorable coating film without curing failure of the coating film can be obtained.

As for the ratio of (d) component in a composition, it is more preferable that the amount more than incompatible point with respect to (a) component is mix | blended. This incompatible point means that the solution obtained by dissolving the component (a) and the component (d) in the component (c) is coated on the surface of the glass plate, and confirmed by the presence or absence of turbidity of the coating film when dried at 20 ° C. The mass of the minimum (d) component which is not turbid with respect to the mass of the component).

When (d) component is mix | blended more than incompatibility point, generation | occurrence | production of rain-strip shape can be prevented more effectively. Although the mechanism is not clear, after coating, the components (a) and (d) undergo phase separation, and the component (d) is hydrolyzed near the surface of the coating film of the composition formed on the surface of the outdoor article, and the surface becomes hydrophilic, thereby making it comb. It is assumed that this is because the occurrence of shape contamination can be prevented more effectively. This incompatible point becomes a value different according to the kind of (a) component, the kind of (d) component, and the degree of multiplication.

It is assumed that the surface of the coating film is hydrophilic and oil-repellent because it is possible to prevent the occurrence of rain pollution in the coating film formed by using the coating composition of the present invention.

If the surface of the coating film is hydrophobic, oily contamination in the rainwater adheres to the surface of the coating film along the flow of the rainwater, and it can be considered that it remains as stem-shaped contamination by drying. On the other hand, if the coating film is hydrophilic and oil-repellent, oil contamination does not spread on the surface of the coating film, and the contact area between the coating film surface and oily contamination becomes small. Therefore, it is thought that oil adhesion is low on the coating film surface, and it is easy to flow with the flow of rain water.

The degree of hydrophobicity-hydrophilicity of the surface can be seen by measuring the octane contact angle in water. The larger the octane contact angle in water, the more hydrophilic and oil repellent the surface is. In order to sufficiently prevent the occurrence of rain pollution, the contact angle of octane in water is preferably 102 ° or more.

The octane contact angle in the water of the coating film formed by the coating composition of this invention is 102 degrees or more.

It was also found that there was a correlation between the forward tension of the coating film surface and the ease of occurrence of rain pollution.

The forward tension on the surface refers to the tension per unit circumferential length at the point of contact of the sample with water when the sample having the thin film is immersed in distilled water. It is distinguished from the antibody tension, which is the tension per unit perimeter length when the sample falls from the water surface when the sample is pulled out of distilled water.

This forward tension can be measured using a dynamic contact angle measuring device. Since the forward tension is difficult to measure directly, the mass change of the sample is measured until the mass change amount dyn is constant while the sample is immersed in distilled water at 25 ° C. at a constant speed, and the straight line of the change amount is the surface of the water. It extrapolates to the point of contact to the surface, and obtains the mass change amount at the point of time when the sample contacts the water surface and divides it by the unit circumferential length (cm) of the sample. As an immersion speed in the measurement of this forward tension, 20 mm / min can be employ | adopted.

That is, it was found that rain pollution is unlikely to occur when the forward tension of the surface is 0 dyn / cm (0 N / m) or more.

Although this action is not necessarily clear, if the forward tension of the coating film surface is less than 0 dyn / cm, the rain water tends to gather when the rain water falls, and since the rain water flows in the shape of a stem, the stem-like contamination after the rain water flows. It can be thought of as occurring. On the other hand, when the forward tension on the surface of the thin film is 0 dyn / cm or more, since there is less tendency to gather when rain water flows down, it is considered that contamination of the rain-like shape is unlikely to occur.

Therefore, in order to prevent the occurrence of rain pollution on the surface of the painted outdoor article, the forward tension of the coating film surface is preferably 0 dyn / cm or more.

The coating composition of the present invention may further contain a curing catalyst for curing the composition at the time of coating film formation, if necessary. When tetraethoxysilane is used especially as (d) component, it is preferable to use a curing catalyst together in order to accelerate hardening.

As this hardening catalyst, what is generally used as a hardening catalyst of paint can be used, Dibutyltin dilaurate etc. are mentioned. The use of the (e) zirconium compound as the curing catalyst is preferable because it is a port life equivalent to dibutyltin dilaurate and the dryness of the coating film is faster than that of dibutyltin dilaurate, thereby making it possible to shorten the time for the dry contact of the coating film. .

Zirconium chelate etc. are mentioned as said (e) zirconium compound. Moreover, as a commercial item of a zirconium compound, "K-KAT XC-4205" (made by Kusumoto Chemical Co., Ltd.), etc. are mentioned.

(e) 0.000001-10 mass parts is preferable with respect to 100 mass parts of (a) component, and, as for the ratio in the composition of a zirconium compound, 0.001-1 mass part is more preferable.

When the coating composition of the present invention is applied to the surface of an outdoor article to form a coating film, since the component (d) is considered to cause hydrolysis near the surface of the coating film, the composition may contain a catalyst for promoting hydrolysis. It may be. Examples of the catalyst include metal compound catalysts such as metal chelates, metal esters, and metal alkoxides, and examples of the metal include aluminum, titanium, silicon, tin, and zinc. Examples of the metal compound catalyst include aluminum monoacetylacetonate bis (ethylacetate acetate), aluminum tris (acetylacetonate), and the like. 0.1-20 mass parts is preferable with respect to 100 mass parts of (d) component, and, as for the ratio in the composition of this catalyst, 1-10 mass parts is more preferable.

You may mix | blend a coloring pigment or dye, the silane coupling agent for improving the adhesiveness of a coating film with the coating composition of this invention.

Examples of the color pigments include inorganic pigments such as carbon black and titanium oxide having good weather resistance, organic pigments such as phthalocyanine blue, phthalocyanine green, knacridon red, indanthren orange and isoindolinone-based yellow.

You may add a light stabilizer, a ultraviolet absorber, a gloss remover, etc. suitably to the coating composition of this invention further as needed. Moreover, when hardening | curing agent is amino resin, you may use together acidic catalysts, such as paratoluenesulfonic acid. As a light stabilizer, a hindered amine light stabilizer etc. are mentioned, For example, MARX LA62, MARX LA67 (above, Adekagas Chemicals make, brand name), Tinuvin 292, Tinuvin 144, Tinuvin 123, Tinuvin 440 ( Ciba, Specialty Chemicals Co., Ltd. brand name, etc. are mentioned above.

As a ultraviolet absorber, a benzophenone type compound, a benzotriazole type compound, a triazine type compound, a cyanoacrylate type compound, etc. are mentioned. Examples of this compound include Viosorb 130, Viosorb 582, Viosorb 583 (above, Kyodo Pharmaceutical Co., Ltd., brand name), tinuvin 320, tinubin 982, tinubin 1130, tinubin 400 (above, manufactured by Chiba Specialty Chemicals Co., Ltd.) Etc. can be mentioned.

Examples of the gloss removing agent include ultra-fine synthetic silica. When a gloss remover is used, an elegant semi gloss and gloss finish coating film can be formed.

You may mix surfactant in the coating composition of this invention. Since surfactants can control the surface tension, they are useful for adjusting the surface concentration to specific components. As this surfactant, any of nonionic, cationic, and anionic type may be sufficient, and "Lepron" (made by Daiichi Kogyo Co., Ltd., brand name), "Saffron" (Asahi Glass Co., Ltd. brand name) of an fluorine-type surfactant, acrylic type "Mother Pro" (the Monsanto company brand name), a "leo part" series (the Kao Corporation brand name), etc. are mentioned.

Preparation of the coating composition of this invention can be performed by mixing the said essential component and the various additives added as needed. The mixing order and the addition order are not particularly limited.

The coating method using the coating composition of the present invention may be applied to any method such as spray coating, brush coating, dipping, roll coater, flow coater, and the like.

The material of the article to be painted is not particularly limited, and examples include inorganic materials such as concrete, natural stone and glass, organic materials such as metals such as iron, stainless steel, aluminum, copper, brass, and titanium, plastics, rubber, adhesives, and wood. . In addition, FRP, resin-reinforced concrete, and fiber-reinforced concrete, which are organic inorganic composites, may be mentioned.

The coating composition of the present invention is particularly suitable for painting on the surface of a coating film already formed.

The articles to be painted include industrial materials such as automobiles, trams, aircrafts, transportation equipment, bridge members, civil engineering members such as steel towers, waterproofing sheets, tanks, and pipes; Building members such as building exteriors, doors, window members, memorial buildings and poles; Road members such as floodlights such as median dividers, road rails, soundproof walls, polycarbonates, and acrylics; Communication base materials, electrical and electronic components, and the like.

EXAMPLE

Although this invention is demonstrated in more detail based on an Example, this invention is not limited by these.

About the paint obtained by each of the following Examples (Examples 1-3) and Comparative Examples (Examples 4-6), the following evaluation is performed and a result is shown in Table 1.

(Rain pollution)

The surface of the coating film 1 year after outdoor exposure in Kanagawa-Kawasaki-shi was visually observed and evaluated by the following evaluation criteria.

(Circle): Rain pollution does not generate | occur | produce on the coating film surface.

X: Rainwater contamination was observed on the coating film surface.

(Weather resistance)

Glossiness before and after application to the shunt shine weather tester for 3000 hours was measured using PG-1M (gloss system: manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated according to the following evaluation criteria.

○: gloss support 80% or more

×: less than 80% gloss support

(Tag feeling)

After 8 hours of coating, the texture when the surface of the coating film was touched with a finger was evaluated based on the following criteria.

(Circle): A fingertip slips without a trouble.

(Triangle | delta): There exists a feeling caught on a fingertip.

X: There is adhesiveness in a fingertip.

(Solvent resistance)

The coating state cured for 1 week was rubbed 20 times with gauze-containing gauze, and the coating state at this time was evaluated based on the following criteria.

○: no dissolution of the coating

×: There is melting of the coating film

(Workability)

The finishing state of the coating film after 1 day of coating was visually evaluated.

○: no problem

×: There is a slight problem

(Example 1)

Chlorotrichlorethylene / ethyl vinyl ether / hydroxybutyl vinyl ether / cyclohexyl vinyl ether = 50/2/8/40 mol% of copolymer (hydroxyl value: 40 mg / g, fluorine content: 22 mass%) 13 mass parts of 100 mass parts and mineral spirit A (made by Shin-Nippon Petroleum company, aromatic hydrocarbon content: 30 mass%, aniline point 43 degreeC) were mixed uniformly, and the resin solution was obtained.

17.5 mass parts of D-918 (manufactured by Sakai Chemical Co., Ltd., titanium oxide) and 4.68 mass of Takeate D-178N (made by Mitsuda Chemical Co., Ltd., polylysocyanate composition, NCO content 18.9%) in 82.5 mass parts of the obtained resin solution. Parts, 0.01 parts by mass of K-KAT XC4205 (manufactured by Kusumoto Chemical Co., Ltd., zirconium compound curing catalyst), 3.5 parts by mass of ethyl silicate 48 (manufactured by Kolkote, tetraethoxysilane), and hyalom 2S (new) Nippon Petroleum Co., Ltd., aromatic hydrocarbon content: 50 mass%, aniline point 44 degreeC) 6 mass parts was mixed, and the coating composition (A) was obtained.

The obtained composition (A) was coated on the iron member after curing for 10 years of coating of the vinyl chloride paint, and the above evaluation was performed.

(Example 2)

Chlorotrifluoroethylene / 2-ethylhexylvinylether / hydroxybutylvinylether / cyclohexylvinylether = 50/20/10/20 mol% as a copolymer (hydroxy group value: 40 mg / g, fluorine content) : The coating composition (B) was obtained like Example 1 except having used the copolymer of: 22 mass%), and coating and evaluation were performed similarly to Example 1.

(Example 3)

Coating composition (C) was obtained like Example 1 except having mix | blended 0.00025 mass part of dibutyltin dilaurate as a hardening catalyst. Coating and evaluation were performed similarly to Example 1.

(Example 4)

A coating composition (D) was obtained in the same manner as in Example 1 except that ethylene silicate 48 and hyalum 2S were not blended. Coating and evaluation were performed similarly to Example 1.

(Example 5)

Coating composition (E) was obtained like Example 1 except having used 135.7 mass parts of xylene instead of mineral spirit A. Coating and evaluation were performed similarly to Example 1.

(Example 6)

Coating composition (F) was obtained like Example 1 except not having mix | blended Takeate D-178N and K-KAT XC4205. Coating and evaluation were performed similarly to Example 1.

Rain pollution Weather resistance Tack Solvent resistance Machinability Example 1 ○ ○ ○ ○ ○ Example 2 ○ ○ ○ ○ ○ Example 3 ○ ○ △ ○ ○ Example 4 × ○ ○ ○ ○ Example 5 ○ ○ ○ ○ X not lift Example 6 × ○ × × ○

From Table 1, the coating composition (D) of Example 4 which does not contain the component (d) has insufficient anti-soil contamination ability, and Example 5 using xylene instead of the paraffinic solvent and / or naphthenic solvent of the component (c) The paint composition (E) of the coating material (E) was damaged due to damage to the paint of the base material. Enactment was also insufficient. The coating compositions (A) to (C) of the present invention have weather resistance peculiar to the fluororesin and also do not cause rain pollution, so that they do not damage the appearance of the coating film, and are excellent in solvent resistance, workability and good feel. . In particular, when a zirconium compound is used as the curing catalyst, the feeling of tack is more favorable.

The coating composition of the present invention is excellent in weather resistance and does not cause rain pollution, and has a feature that does not damage the existing coating film even when applied to the surface of the existing coating film.

Claims (5)

(a) a fluoroolefin polymer having a reaction curable site and having a fluorine content of 5% by mass or more, (b) a polyisocyanate curing agent containing 1.5 or more on average of isocyanate groups in the molecule, (c) a medium containing at least 30% by mass of a paraffinic solvent and / or a naphthenic solvent in total, (d) contains a multimer of tetrafunctional hydrolyzable silane compounds, The said (a) component and (b) component are soluble or dispersible in (c) component, the ratio of (b) component is 1-100 mass parts with respect to 100 mass parts of (a) component, (d) component The composition for coating materials whose ratio is 0.1-100 mass parts with respect to 100 mass parts of (a) component. The coating composition according to claim 1, wherein the reaction curable moiety is at least one group selected from hydroxyl, carboxyl and amino groups. The coating composition according to claim 1 or 2, wherein the multimer of the (d) tetrafunctional hydrolyzable silane compound is a multimer of tetraalkoxysilane. The coating composition according to claim 1, further comprising (e) a zirconium compound, wherein the proportion of the component (e) is 0.000001 to 10 parts by mass with respect to 100 parts by mass of the component (a). The coated article formed by coating the article with the coating composition of Claims 1-4.