JP2012082270A - Coating composition and kit for the coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use an environmentally friendly solvent in the formation of a cured coating film having low fouling properties, to ensure good solubility of a silicon-containing compound in the solvent, and to form a cured coating film excellent in low fouling properties.SOLUTION: A coating composition is provided containing ethyl silicate having an SiOcontent of 45-50 mass%, a fluorine-containing copolymer having a crosslinkable group, a curing agent and a weak solvent. There is also provided a kit for the coating composition for preparing the coating composition.

Description

  The present invention relates to a coating composition and a coating composition kit.

  A roof or wall of a building or the like is formed with a coating film that imparts low contamination for the purpose of suppressing dirt due to dust or rain in the atmosphere. For example, as a coating composition for forming a low-fouling cured coating film, a silicon-containing compound such as methyl silicate, phenyl silicate, tetraphenylethyl silicate, and a fluorine-containing copolymer having a hydroxyl group are mixed with xylene, butyl acetate. A coating composition dissolved in an organic solvent such as the above is known (Patent Document 1).

  On the other hand, in recent years, various coating compositions used in various fields are weak solvents that are environmentally friendly due to the impact on the base (old paint film) during repair and the problem of burden on the global environment. Switching to paint compositions that use is being promoted.

JP-A-10-72569

  However, when a silicon-containing compound described in Patent Document 1 and a weak solvent are combined to form a coating composition, the silicon-containing compound may not be sufficiently dissolved in the weak solvent, making it difficult to form a uniform coating film. . Moreover, the low contamination property of the formed coating film may not be obtained sufficiently.

  The present invention relates to a coating composition that can form a uniform cured coating film that has a low environmental burden due to the use of a weak solvent, has good solubility of the silicon-containing compound in the weak solvent, and is excellent in low contamination. An object of the present invention is to provide a coating composition kit for preparing a coating composition.

The present invention employs the following configuration in order to solve the above problems.
[1] A silicon-containing compound (A) represented by the following formula (1), a fluorine-containing copolymer (B) having a crosslinkable group, a curing agent (C) and a weak solvent (D),
Coating composition SiO ₂ minutes is 45 to 50 wt% of the silicon-containing compound (A).

(However, n is an integer of 1 to 100.)
[2] The ratio of the silicon-containing compound (A) to the total amount of 100 parts by mass of the fluorine-containing copolymer (B) and the curing agent (C) is 1.5 to 90 parts by mass. Composition for paint.
[3] The coating composition according to [1] or [2], wherein the content of the weak solvent (D) is 10 to 90% by mass with respect to the total amount (100% by mass) of the coating composition.
[4] The copolymer contained in the coating composition, wherein the crosslinkable group in the fluorine-containing copolymer (B) is a hydroxyl group, the curing agent (C) is a polyisocyanate curing agent. The coating composition according to any one of [1] to [3], wherein the molar ratio (OH / NCO) of the hydroxyl group having and the isocyanate group of the curing agent (C) is 0.3 to 2.0.
[5] The coating composition according to any one of [1] to [4], wherein the curing agent (C) is the following curing agent (C1).
Curing agent (C1): Allophanate group (All) and isocyanate obtained by reacting one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates with monoalcohols having 1 to 20 carbon atoms. A polyisocyanate curing agent having a molar ratio (All / Iso) of nurate groups (Iso) of 81/19 to 90/10.
[6] The coating composition according to any one of [1] to [5], wherein the weak solvent (D) is mineral spirit.
[7] A kit for preparing a coating composition according to any one of [1] to [6],
Curing containing the main component containing a part of the fluorine-containing copolymer (B) and the weak solvent (D), and the silicon-containing compound (A), the curing agent (C), and the remainder of the weak solvent (D). A coating composition kit comprising the above composition.

The coating composition of the present invention can form a uniform cured coating film that has a low environmental load due to the use of a weak solvent, has good solubility of the silicon-containing compound in the weak solvent, and is excellent in low contamination.
In addition, the coating composition kit of the present invention forms a uniform cured coating film that has a low environmental impact due to the use of a weak solvent, has good solubility of the silicon-containing compound in the weak solvent, and is excellent in low contamination. A paint composition that can be prepared can be prepared.

  In the present specification, a repeating unit obtained directly by polymerization and a repeating unit obtained by reacting another compound with the repeating unit obtained by polymerization are collectively referred to as “unit”. Moreover, in this specification, the compound represented by Formula (1) is described as a compound (1). The same applies to compounds represented by other formulas. Moreover, in this specification, (meth) acrylic acid shows either acrylic acid or methacrylic acid.

<Coating composition>
The coating composition of the present invention contains a silicon-containing compound (A), a fluorine-containing copolymer (B), a curing agent (C), and a weak solvent (D) described later.

[Silicon-containing compound (A)]
The silicon-containing compound (A) is the following compound (1).

  However, n is an integer of 1-100. n is an integer of 1 or more, but an integer of 2 or more is preferable. N is an integer of 100 or less, preferably an integer of 70 or less, and more preferably an integer of 50 or less. If n is within this range, low contamination of the cured coating film formed from the coating composition, solubility of the silicon-containing compound (A) in the weak solvent (D), and storage stability of the coating composition Property is improved.

The SiO ₂ content in the silicon-containing compound (A) (100% by mass) is 45 to 50% by mass, and more preferably 47 to 49% by mass. When the SiO ₂ content in the silicon-containing compound (A) is within this range, the solubility of the silicon-containing compound (A) in the weak solvent (D) and the storage stability of the coating composition are improved, and The low contamination property of the cured coating film formed from the coating composition is excellent.
“SiO ₂ min” is a value indicating the content of silica in terms of SiO ₂ when the total mass of the silicon-containing compound (A) is 100% by mass.

Examples of the silicon-containing compound (A) include a trade name “ethyl silicate 48” (SiO ₂ min: 48 mass%) manufactured by Colcoat Co., Ltd.

  The ratio of the silicon-containing compound (A) in the coating composition of the present invention is 1.5 to 90 parts by mass with respect to 100 parts by mass of the total amount of the fluorine-containing copolymer (B) and the curing agent (C). Is preferable, and 3-30 mass parts is more preferable. If the ratio of a silicon-containing compound (A) is more than the lower limit of the said range, the low pollution property of the cured coating film formed will improve. If the ratio of a silicon-containing compound (A) is below the upper limit of the said range, the solubility of the silicon-containing compound (A) with respect to a weak solvent (D) will improve, and it will be easy to form a uniform cured coating film.

[Fluorine-containing copolymer (B)]
The fluorine-containing copolymer (B) is a fluorine-containing copolymer having a crosslinkable group. That is, the fluorine-containing copolymer (B) is a copolymer having a fluorine atom and a crosslinkable group. The fluorine-containing copolymer (B) includes a resinous polymer having a clear melting point, an elastomeric polymer exhibiting rubber elasticity, and an intermediate thermoplastic elastomeric polymer.
The crosslinkable group is a functional group that forms a chemical bond (crosslink) by reacting with each other or with a curing agent.
As the fluorine-containing copolymer (B), a fluorine-containing copolymer (B1) having a unit having a fluorine atom (β1) and a unit having a crosslinkable group (β2) is preferable.

(Unit (β1))
The unit (β1) is formed by polymerizing a monomer having a fluorine atom (hereinafter referred to as “monomer (b1)”).
As the monomer (b1), a monomer having a fluorine atom which is usually used as a raw material for a fluororesin can be used. Specifically, fluoroolefins such as tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), vinylidene fluoride (VdF), and vinyl fluoride (VF); fluoroalkyl groups Examples thereof include olefins and fluorovinyl ethers such as perfluoro (alkyl vinyl ether) (PAVE). Among these, fluoroolefins are preferable, TFE, HFP, CTFE, VdF, and VF are more preferable, TFE, CTFE, and VdF are more preferable, TFE and CTFE are particularly preferable, and weather resistance, chemical resistance, and permeability of the cured coating film are preferable. From the point of wetness, CTFE is most preferable.
A monomer (b1) may be used individually by 1 type, and may use 2 or more types together.

(Unit (β2))
The unit (β2) can be formed by polymerizing a monomer having a crosslinkable group (hereinafter referred to as “monomer (b2)”). The monomer (b2) may be any monomer having a crosslinkable group and a polymerizable unsaturated group copolymerizable with the monomer (b1). A monomer (b2) may be used individually by 1 type, and may use 2 or more types together.
Examples of the crosslinkable group in the monomer (b2) include a hydroxyl group, a carboxyl group, an amino group, an epoxy group, and a hydrolyzable silyl group. Of these, a hydroxyl group, a carboxyl group, and an epoxy group are preferred, and a hydroxyl group is particularly preferred from the viewpoints of crosslinking reactivity, availability, and ease of introduction into the copolymer.

The monomer having a hydroxyl group (hereinafter referred to as “monomer (b21)”) is a monomer having a hydroxyl group and a polymerizable unsaturated group.
Examples of the monomer (b21) include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxy-2. -Vinyl ethers having a hydroxyl group such as methylbutyl vinyl ether and 5-hydroxypentyl vinyl ether-10-hydroxyhexyl vinyl ether; Allyl ethers having a hydroxyl group such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether and glycerol monoallyl ether A hydroxyalkyl ester of (meth) acrylic acid such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate; Of these, vinyl ethers having a hydroxyl group are preferred, and 4-hydroxybutyl vinyl ether and 2-hydroxyethyl vinyl ether are more preferred from the viewpoints of availability, polymerization reactivity, and hydroxyl crosslinking.
A monomer (b21) may be used individually by 1 type, and may use 2 or more types together.

A monomer having a carboxyl group (hereinafter referred to as “monomer (b22)”) is a monomer having a carboxyl group and a polymerizable unsaturated group, and can be easily converted to a monomer having a carboxyl group. Also included are anhydrides of unsaturated dicarboxylic acids.
Examples of the monomer (b22) include acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, cinnamic acid, undecylenic acid, 3-allyloxypropionic acid, 3- (2-allyloxyethoxycarbonyl) propionic acid, and phthalate. Unsaturated monocarboxylic acids such as vinyl acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid; unsaturated dicarboxylic acid monoesters such as itaconic acid monoester, maleic acid monoester and fumaric acid monoester; Examples thereof include anhydrides of unsaturated dicarboxylic acids such as acid anhydrides. In addition to these, vinyl ethers or allyl ethers of polyvalent carboxylic acids such as vinyl pyromellitic acid are listed. Of these, crotonic acid, undecylenic acid, maleic acid, and itaconic acid are preferred from the viewpoints of availability, polymerization reactivity, and crosslinkability.
A monomer (b22) may be used individually by 1 type, and may use 2 or more types together.

The monomer having an epoxy group (hereinafter referred to as “monomer (b23)”) is a monomer having an epoxy group and a polymerizable unsaturated group. The epoxy group in the monomer (b23) is preferably a glycidyl group.
As the monomer (b23), glycidyl vinyl ether, glycidyl allyl ether, and (meth) acrylic acid glycidyl ester are preferable.
A monomer (b23) may be used individually by 1 type, and may use 2 or more types together.

The unit (β2) is preferably a unit formed by polymerizing the monomer (b2). However, the unit (β2) is not limited to a unit formed by polymerizing the monomer (b2). For example, when a carboxyl group is introduced as the crosslinkable group of the unit (β2), a method of copolymerizing the monomer (b21) and reacting an acid anhydride with a hydroxyl group introduced into the obtained copolymer Can introduce a carboxyl group.
Examples of the acid anhydride include succinic anhydride, hexahydrophthalic anhydride, methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid anhydride, bicyclo [2.2.1] heptane-2,3- Examples thereof include dicarboxylic acid anhydride and 4-methylhexahydrophthalic anhydride.

The fluorine-containing copolymer (B1) may contain, in addition to the unit (β1) and the unit (β2), other monomers (hereinafter referred to as “monomer (b1)” and “monomer (b2)” as necessary. And a unit (β3) based on “monomer (b3)”.
Examples of the monomer (b3) include olefins, alkyl vinyl ethers in which an alkyl group and a polymerizable unsaturated group are linked by an ether bond, or a carboxylic acid in which an alkyl group and a polymerizable unsaturated group are linked by an ester bond. Acid vinyl esters are preferred.

Examples of olefins include isobutylene.
Examples of the alkyl vinyl ethers include ethyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether and the like.
Examples of the carboxylic acid vinyl esters include vinyl versatate.

The ratio of the unit (β1) to the total unit (100 mol%) of the fluorinated copolymer (B1) is preferably 35 to 65 mol%, and more preferably 40 to 60 mol%. When the proportion of the unit (β1) is within the above range, it is easy to achieve both the weather resistance of the formed cured coating film and the solubility in the weak solvent (D).
The ratio of the unit (β2) to the total unit (100 mol%) of the fluorinated copolymer (B1) is preferably 6 to 50 mol%, more preferably 7 to 40 mol%. If the ratio of the unit (β2) is not less than the lower limit of the above range, the degree of cross-linking of the formed cured coating film is increased and the hardness and the like are improved. If the ratio of the unit (β2) is not more than the upper limit of the above range, gelation hardly occurs in the coating composition of the present invention.
The ratio of the unit (β3) to the total unit (100 mol%) of the fluorinated copolymer (B1) is preferably 45 mol% or less, and more preferably 35 mol% or less.

  For the production of the fluorinated copolymer (B), a known polymerization method can be employed. Specifically, a polymerization method such as solution polymerization, emulsion polymerization, suspension polymerization or the like can be employed.

  The number average molecular weight (Mn) of the fluorinated copolymer (B) is preferably from 5,000 to 20,000. If Mn of a fluorine-containing copolymer (B) is 5,000 or more, the weather resistance of the cured coating film formed will improve. Moreover, if Mn of a fluorine-containing copolymer (B) is 20,000 or less, the viscosity of a coating composition will become moderate and handleability will improve. Mn of the fluorinated copolymer (B) is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

  The fluorine content in the fluorine-containing copolymer (B) is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 25% by mass or more from the viewpoint of improving the weather resistance. On the other hand, the fluorine content of the fluorine-containing copolymer (B) is preferably 35% by mass or less from the viewpoint of the solubility of the fluorine-containing copolymer (B) in the weak solvent (D). The fluorine content of the fluorine-containing copolymer (B) is the total mass ratio of fluorine atoms of the fluorine-containing copolymer (B) to the mass of the fluorine-containing copolymer (B).

  5-55 mass% is preferable and, as for content of the fluorine-containing copolymer (B) in the composition for coating materials (100 mass%) of this invention, 10-45 mass% is more preferable. When the fluorinated copolymer (B) is at least the lower limit of the above range, the weather resistance is improved. When the fluorinated copolymer (B) is not more than the upper limit of the above range, the coating workability is improved.

The coating composition of the present invention may contain a copolymer other than the fluorine-containing copolymer (B). Other copolymers include alkyd resin, amino alkyd resin, polyester resin, epoxy resin, urethane resin, epoxy polyester resin, polyvinyl acetate resin, acrylic resin, vinyl chloride resin, phenol resin, silicone modified polyester resin, acrylic silicone Examples thereof include resins and silicone resins. Among these, an acrylic resin is preferable.
Further, the other copolymer preferably has the crosslinkable group, more preferably has a hydroxyl group, and an acrylic resin having a hydroxyl group is particularly preferable from the viewpoint of weather resistance.

[Curing agent (C)]
The curing agent (C) undergoes a crosslinking reaction with the fluorine-containing copolymer (B) and another copolymer having a crosslinkable group to be used as necessary. A hardening | curing agent (C) is suitably selected according to the kind of crosslinkable group which the copolymer contained in the composition for coatings has. In the coating composition of the present invention, it is preferable that the crosslinkable group of the fluorine-containing copolymer (B) and the other copolymer is a hydroxyl group and the curing agent (C) is a polyisocyanate curing agent. .

As the polyisocyanate curing agent, the following curing agent (C1) is preferable from the viewpoint of excellent solubility in the weak solvent (D). However, the polyisocyanate curing agent is not limited to the following curing agent (C1), and a general polyisocyanate curing agent may be used.
Curing agent (C1): Allophanate group (All) and isocyanate obtained by reacting one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates with monoalcohols having 1 to 20 carbon atoms. A polyisocyanate curing agent having a molar ratio (All / Iso) of nurate groups (Iso) of 81/19 to 90/10.
An aliphatic diisocyanate is a diisocyanate compound having an aliphatic group in the molecule. On the other hand, alicyclic diisocyanate is a diisocyanate compound having a cyclic aliphatic group in the molecule.

Examples of the aliphatic diisocyanate include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane (HDI), 1,6-diisocyanato-2,2,4- Examples include trimethylhexane and methyl 2,6-diisocyanatohexanoate (lysine diisocyanate). Of these, HDI is preferred from the viewpoint of industrial availability.
Examples of the alicyclic diisocyanate include 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (also known as isophorone diisocyanate) and 1,3-bis (isocyanatomethyl) cyclohexane (also known as hydrogenated). Xylylene diisocyanate), bis (4-isocyanatocyclohexyl) methane (also known as hydrogenated diphenylmethane diisocyanate), 1,4-diisocyanatocyclohexane and the like. Of these, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate are preferred from the viewpoint of industrial availability.
As the diisocyanate, an aliphatic diisocyanate is preferable to an alicyclic diisocyanate from the viewpoint that the curing agent (C1) has a low viscosity, and HDI is particularly preferable from the viewpoint of the weather resistance and flexibility of the formed cured coating film. preferable.

  The lower limit of the carbon number of the monoalcohol is 1 from the viewpoint of solubility in the weak solvent (D), 2 is preferable, 3 is more preferable, 4 is more preferable, and 6 is particularly preferable. The upper limit of the carbon number of the monoalcohol is 20 from the viewpoint of the hardness of the cured coating film to be formed, 16 is preferable, 12 is more preferable, and 9 is more preferable.

The monoalcohol is preferably composed only of a saturated hydrocarbon group and a hydroxyl group. Moreover, it is preferable that the monoalcohol has a branch.
Examples of the monoalcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol, isoamyl alcohol, 1-hexanol, and 2-hexanol. 1-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 1,3,5-trimethylcyclohexanol, 3,3,5-trimethyl-1-hexanol, tridecanol, pentadecanol, pal Examples include methyl alcohol, stearyl alcohol, cyclopentanol, cyclohexanol, methylcyclohexanol, trimethylcyclohexanol, and the like.

In terms of solubility in the weak solvent (D), monoalcohol is isobutanol, 1-butanol, isoamyl alcohol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-octanol, 2- Ethyl-1-hexanol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, 1,3,5-trimethylcyclohexanol, 3,3,5-trimethyl-1-hexanol are preferred, isobutanol, 2-hexanol, 2-octanol, 2-ethyl-1-hexanol, and 3,3,5-trimethyl-1-hexanol are more preferable.
In addition, monoalcohol has a lower viscosity such as 1-propanol, isobutanol, 1-butanol, isoamyl alcohol, 1-pentanol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2 -Octanol, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1-hexanol are preferred.
The monoalcohol is not limited to those described above, and may be a monoalcohol having an ether group, an ester group, or a carbonyl group in the molecule.
Monoalcohol may use only 1 type and may use 2 or more types together.

The molar ratio (All / Iso) of allophanate groups (All) and isocyanurate groups (Iso) in the curing agent (C1) is 81/19 to 90/10. When the molar ratio (All / Iso) is within the above range, curability and solubility in the weak solvent (D) are excellent. The lower limit of the molar ratio (All / Iso) is preferably 83/17. The upper limit of the molar ratio (All / Iso) is preferably 88/12, more preferably 86/14.
The molar ratio (All / Iso) is determined by ¹ H-NMR (see International Publication No. 2008/047761).

  The isocyanate group content (hereinafter referred to as “NCO content”) in the curing agent (C1) (100 mass%) is 10 to 22 mass from the viewpoint of solubility in the weak solvent (D) and crosslinkability. % Is preferable, 13 to 21% by mass is more preferable, and 16 to 20% by mass is further preferable.

  The lower limit of the viscosity of the curing agent (C1) is preferably 50 mPa · s, more preferably 75 mPa · s, further preferably 100 mPa · s, and 120 mPa · s from the viewpoint of crosslinkability. s is particularly preferred. The upper limit of the viscosity of the curing agent (C1) is preferably 500 mPa · s, more preferably 450 mPa · s, further preferably 400 mPa · s, and particularly preferably 350 mPa · s from the viewpoint of reducing the volatile organic compound (VOC). 300 mPa · s is most preferable.

The average number of isocyanate groups in the curing agent (C1) is preferably 2.10 to 2.50, more preferably 2.15 to 2.40, in view of curability and solubility in the weak solvent (D). 2.20 to 2.35 are more preferable.
The average number of the isocyanate groups is determined by the following formula.
(Average number of isocyanate groups) = (Number average molecular weight) × (NCO content) / 4200
The number average molecular weight of the curing agent (C1) can be measured by GPC.

  When a polyisocyanate curing agent is used as the curing agent (C), it may be a blocked polyisocyanate curing agent in which the isocyanate group is protected, and a non-blocking polyisocyanate curing agent in which the isocyanate group is not protected. It may be. When a non-blocked polyisocyanate curing agent is used as the curing agent (C), the curing agent is blended immediately before the coating composition is applied. On the other hand, when a blocked polyisocyanate curing agent is used as the curing agent (C), the blending time of the curing agent is not particularly limited.

When the crosslinkable group of the fluorinated copolymer (B) and the other copolymer is a hydroxyl group and the curing agent (C) is a polyisocyanate curing agent, the copolymer contained in the coating composition The molar ratio (OH / NCO) of the hydroxyl groups possessed by the coalescence, that is, the total hydroxyl groups possessed by the fluorine-containing copolymer (B) and the other copolymer, and the isocyanate group of the curing agent (C) is 0.3 to 2.0 is preferable, and 0.7 to 1.3 is more preferable. When the molar ratio (OH / NCO) is not less than the lower limit, the solvent resistance is improved. When the molar ratio (OH / NCO) is equal to or less than the upper limit, weather resistance is improved, and it is easy to suppress the occurrence of poor curing (remaining tack).
A polyisocyanate type hardening | curing agent may be used individually by 1 type, and may use 2 or more types together.

What is necessary is just to select suitably the hardening | curing agent (C) in case the crosslinkable group which the copolymer contained in the composition for coating has other than a hydroxyl group according to the kind of this crosslinkable group.
When the crosslinkable group of the copolymer contained in the coating composition is a carboxyl group, examples of the curing agent (C) include known amino curing agents and epoxy curing agents.
When the crosslinkable group of the copolymer contained in the coating composition is an amino group, as the curing agent (C), known curing agents having a carbonyl group, epoxy curing agents, and acid anhydride curings. Agents and the like.
When the crosslinkable group of the copolymer contained in the coating composition is an epoxy group, the curing agent (C) includes a known carboxyl group-containing curing agent, acid anhydride curing agent, amino curing. Agents and the like.
A hardening | curing agent (C) may be used individually by 1 type, and may use 2 or more types together.

[Weak solvent (D)]
The weak solvent (D) is an organic solvent classified as a third type organic solvent in the classification of organic solvents according to the Industrial Safety and Health Act. By using the weak solvent (D), it is possible to reduce the influence on the base (old paint film) during repair and the burden on the global environment.
Examples of the weak solvent (D) include gasoline, coal tar naphtha, solvent naphtha, petroleum ether, petroleum naphtha, petroleum benzine, turpentine oil, mineral spirit, mineral thinner, petroleum spirit, white spirit, mineral turpentine and the like.

  The weak solvent (D) is preferably a weak solvent having an aniline point of 30 to 70 ° C, and more preferably a weak solvent having an aniline point of 40 to 60 ° C. If the aniline point of the weak solvent (D) is not less than the lower limit of the above range, it is easy to suppress erosion of the old coating film during repair. If the aniline point of a weak solvent (D) is below the upper limit of the said range, the solubility of a silicon containing compound (A) and a fluorine-containing copolymer (B) will improve. The aniline point of the weak solvent (D) is measured according to the aniline point test method described in JIS K 2256.

As the weak solvent (D), mineral spirit is preferable because the flash point is room temperature or higher.
Examples of weak solvents marketed as mineral spirits include HAWS (manufactured by Shell Japan, aniline point 17 ° C.), Essonaphtha No. 6 (ExxonMobil Chemical Co., aniline point 43 ° C), LAWS (Shell Japan Co., aniline point 44 ° C), Pegasol 3040 (ExxonMobil Chemical Co., aniline point 55 ° C), A Solvent (Shin Nippon Petrochemical Co., Ltd.) Manufactured by Nippon Petrochemical Co., Ltd., aniline point 64 ° C.), mineral spirit A (manufactured by Nippon Petrochemical Co., Ltd., aniline point 43 ° C.), Hyalom 2S (manufactured by Nippon Petrochemical Co., Ltd., Aniline point 44 ° C), Hyalom 2S (manufactured by Nippon Petrochemical Co., Ltd., aniline point 44 ° C), linearene 10, linearene 12 (manufactured by Idemitsu Petrochemical Co., Ltd., α-olefinic hydrocarbon, aniline point is 44 ° C, 54 ° C in this order) Exol D30 (manufactured by ExxonMobil, naphthenic solvent, aniline point 63 ° C.), Ricasolve 900, 910B, 1000 New Japan Chemical Co., Ltd., hydrogenated C9 solvent, aniline point in turn 53 ° C., 40 ° C., include 55 ° C.) and the like.
A weak solvent (D) may be used individually by 1 type, and may use 2 or more types together.

  The content of the weak solvent (D) in the coating composition of the present invention takes into account the solubility of the silicon-containing compound (A) and the fluorine-containing copolymer (B), the optimum viscosity according to the coating method, and the like. As appropriate. 10-90 mass% is preferable with respect to the total amount (100 mass%) of the composition for coating materials, and, as for content of a weak solvent (D), 20-70 mass% is more preferable.

[Other ingredients]
The coating composition of the present invention is a curing catalyst, pigment, light stabilizer, UV absorber, delustering agent, surfactant, leveling agent, antifoaming agent, dispersion, as long as the effects of the present invention are not impaired. Other components such as an agent may be included.

  Examples of the curing catalyst include dibutyltin dilaurate when a polyisocyanate curing agent is used as the curing agent (C).

  Examples of the pigment include inorganic pigments such as carbon black and titanium oxide, and organic pigments such as phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, and isoindolinone-based yellow. Thermal barrier pigments can also be used. The titanium oxide is preferably a surface-coated titanium oxide, and the titanium oxide can be obtained under the trade name “PFC-105” manufactured by Ishihara Sangyo Co., Ltd .;

  Examples of the light stabilizer include hindered amine light stabilizers. Examples of the hindered amine light stabilizer include trade names “MARX LA62” and “MARX LA67” manufactured by Adeka Argus Chemical Co., Ltd .; trade names “Tinubin 292”, “Tinubin 144”, “Tinuvin” manufactured by Ciba Specialty Chemicals, Inc. -123 "," Tinuvin 440 "and the like.

  Examples of ultraviolet absorbers include benzophenone compounds, benzotriazole compounds, triazine compounds, and cyanoacrylate compounds. Specifically, “Viosorb 130”, “Viosorb 582”, “Viosorb 583” (manufactured by Kyodo Pharmaceutical Co., Ltd., trade name), “Tinuvin 320”, “Tinuvin 384-2”, “Tinuvin 982”, “Tinuvin 1130”, “Tinubin 400” (trade name, manufactured by Ciba Specialty Chemicals, Inc.) and the like.

  Examples of matting agents include ultra fine powder synthetic silica. When a matting agent is used, it is possible to form a cured film with an elegant semi-glossy and matte finish.

  The surfactant may be any of nonionic type, cationic type, anionic type, ROLEX ASE (Daiichi Kogyo Co., Ltd., trade name), Fluorosurfactant "Surflon" (Asahi Glass Co., Ltd., trade name) In addition, “Modaflow” (trade name) manufactured by Monsanto Co., Ltd., “Leo Fat” series (trade name, manufactured by Kao Corporation), and the like are available.

  If a leveling agent is mix | blended, the uniformity of the thickness of the cured coating film to form will improve. As the leveling agent, BYK-300 (manufactured by BYK-Chemie, trade name), Floren No. 3 (manufactured by Kyoeisha Chemical Co., Ltd., trade name), Disparon LF 1985 (trade name, manufactured by Enomoto Kasei Co., Ltd.) and the like.

  Since the coating composition of the present invention described above uses a weak solvent (D), the environmental load is small, and the solubility of the silicic acid-containing compound (A) in the weak solvent (D) is good. Therefore, a uniform cured coating film can be formed, and the low contamination property of the formed cured coating film is excellent.

<Coating composition kit>
The coating composition kit of the present invention is a two-component curing type kit for preparing the above-described coating composition of the present invention. The coating composition kit of the present invention comprises a main component containing a part of a fluorine-containing copolymer (B) and a weak solvent (D), a silicon-containing compound (A), a curing agent (C) and a weak solvent ( And a curing composition containing the remainder of D). When the other copolymer other than the fluorine-containing copolymer (B) is used, the other copolymer is contained in the main agent.
When the coating composition of the present invention is prepared using the coating composition kit of the present invention, the curing agent (C) is preferably a non-blocked polyisocyanate curing agent that is not protected by a protective group.

The composition of the main agent and the curing composition in the coating composition kit of the present invention may be any composition that becomes the above-described coating composition of the present invention when they are mixed.
The weak solvent (D) in the main agent in the coating composition kit of the present invention is 10 to 90 parts by mass with respect to a total of 100 parts by mass of the fluorine-containing copolymer (B) and the other copolymer. preferable.
As for the weak solvent (D) in the composition for hardening in the kit for coating compositions of this invention, 10-90 mass parts is preferable with respect to 100 mass parts of a silicon containing compound (A).

  The material of the article to be painted is not particularly limited, and inorganic materials such as concrete, natural stone and glass; metals such as iron, stainless steel, aluminum, copper, brass and titanium; organic materials such as plastic, rubber, adhesive and wood Can be mentioned. Moreover, as a material of articles | goods, FRP which is an organic inorganic composite material, resin reinforced concrete, fiber reinforced concrete, etc. are mentioned.

  The coating composition and the coating composition kit of the present invention are transport equipment such as automobiles, trains, and aircraft; civil engineering members such as bridge members and steel towers; industrial equipment such as waterproof sheets, tanks and pipes; , Doors, window gate members, monuments, poles and other building materials; road median strips, guardrails, soundproof walls, road members such as polycarbonate, acrylic, etc .; communication equipment; electrical and electronic parts; Can be used for coating sheets, solar cell surface protective paints, etc

  The coated article of the present invention described above has a cured coating film formed from the coating composition of the present invention having a small environmental load, and has excellent low contamination.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.
<Evaluation of solubility>
[Example 1]
28.3 g of A2400-100 (Asahi Kasei Chemicals Co., Ltd., polyisocyanate type curing agent) as a curing agent (C), and 18.3 g of Mineral Spirit A (Shin Nippon Petrochemical Co., Ltd.) as a weak solvent (D). Then, 10.8 g of ethyl silicate 48 (manufactured by Colcoat Co., SiO ₂ min. 48 mass%), which is a silicon-containing compound (A), was added and mixed to obtain a curing composition 1.

[Example 2]
A curable composition 2 was obtained in the same manner as in Example 1 except that ethyl silicate 40 (manufactured by Colcoat Co., SiO ₂ min. 40% by mass) was used instead of ethyl silicate 48.

[Example 3]
A curable composition 3 was obtained in the same manner as in Example 1 except that methyl silicate 51 (manufactured by Colcoat Co., SiO ₂ minute 51 mass%) was used instead of ethyl silicate 48.

[Example 4]
A curable composition 4 was obtained in the same manner as in Example 1 except that methyl silicate 53A (manufactured by Colcoat Co., SiO ₂ min. 53 mass%) was used instead of ethyl silicate 48.

[Example 5]
A curable composition 5 was obtained in the same manner as in Example 1 except that MKC silicate MS56S (Methyl silicate, manufactured by Mitsubishi Chemical Corporation, SiO ₂ min 56 mass%) was used instead of ethyl silicate 48.

[Example 6]
A curable composition 6 was obtained in the same manner as in Example 1 except that n-butyl silicate (manufactured by Colcoat Co., SiO ₂ min 19% by mass) was used in place of ethyl silicate 48.

[Example 7]
A curable composition 7 was obtained in the same manner as in Example 1 except that n-propyl silicate (manufactured by Colcoat Co., SiO ₂ min 23 mass%) was used instead of ethyl silicate 48.

[Example 8]
A curable composition 8 was prepared in the same manner as in Example 1 except that MCS-18 (Si (OCH ₂ CH ₂ OCH ₃ ) ₄ , Colcoat Co., SiO ₂ min. 18% by mass) was used instead of ethyl silicate 48. Got.

[Evaluation methods]
About the hardening compositions 1-8 of Examples 1-8, the initial solubility in 5 degreeC or 23 degreeC and the solubility after storing for 6 months at 23 degreeC were confirmed visually, and the following references | standards evaluated .
“◯”: colorless and transparent with no cloudiness.
"△": There was cloudiness.
"X": The cloudiness was remarkable.
The solubility evaluation results are shown in Table 1.

In the curing compositions of Examples 4 and 5 using methyl silicate having a SiO ₂ content of 53 mass% and 56 mass%, the solubility of methyl silicate in the weak solvent (D) was poor, whereas SiO ₂ In the curing composition of Example 1 using the silicon-containing compound (A) having a content of 45 to 50% by mass, the solubility of the silicon-containing compound (A) in the weak solvent (D) was good.

<Evaluation of low contamination of cured coating film>
Hereinafter, Example 9 is an example, and Examples 10 to 15 are comparative examples.
[Example 9]
In Example 1, 70 g of the main ingredient prepared by dissolving 45 g of LS-800S (manufactured by Asahi Glass Co.), which is a fluorine-containing copolymer (B), in 25 g of mineral spirit A, which is a weak solvent (D), was obtained. A coating composition was prepared by mixing 10 g of the curable composition 1.
Bon Epo Coat Light Gray (epoxy paint, manufactured by AGC Cortec Co., Ltd.) is primed on the surface of the base material (vertical 20 cm x horizontal 9 cm x thickness 0.1 cm, material aluminum plate) (application amount 0.27 kg / m ² ) In addition, after Bonflon Light intermediate coating white color (fluorine resin paint, manufactured by AGC Co., Ltd.) is applied (coating amount 0.13 kg / m ² ), the coating composition is made to have a film thickness of 30 μm by a spray gun. And cured for 14 days under conditions of 23 ° C. and a relative humidity of 60% or less to form a cured coating film to obtain a test specimen.

[Examples 10 to 14]
A test specimen was obtained in the same manner as in Example 9 except that the curable composition shown in Table 2 was used instead of the curable composition 1.

[Example 15]
A curing composition 9 was obtained by adding 29.1 g of mineral spirit A as a weak solvent (D) to 20.9 g of A2400-100 as a curing agent (C) and mixing them. Then, the test body was obtained like Example 9 except having used the composition 9 for hardening instead of the composition 1 for hardening.

[Bend exposure (rain exposure) test]
The test specimen of 20 cm in length having a cured coating film obtained in each example was bent 60 ° in the middle so that the region from the lower end to 10 cm had a vertical surface and the region from 10 cm to the lower end had an inclined surface. It was. The cured coating film was on the upper side of the inclined surface. The test specimen bent in this way was exposed to the outdoors, and the degree of occurrence of rain stripes on the inclined surface and the vertical surface was visually confirmed, and the low contamination was evaluated according to the following criteria.
“◎”: There was no dirt on the slope or dirt on the rain lines.
“◯”: Soil dirt and rain stains were hardly seen.
“△”: There was dirt on the slope and dirt on the rain stripes.
“×”: Soil on the slope and dirt on the rain lines were noticeable.
Table 2 shows the evaluation of low contamination of the specimens of Examples 9 to 15.

The test body of Example 9 using a silicon-containing compound (A) having a SiO ₂ content of 45 to 50% by mass shows little occurrence of rain stripes even after exposure for 3 months, and the test of Example 15 using no silicon-containing compound Compared to the body, the low contamination was excellent. Moreover, the test body of Example 9 was obtained by using Example 10 in which ethyl silicate having a SiO ₂ content of 40% by mass, methyl silicate, n-butyl silicate, n-propyl silicate, and Si (OCH ₂ CH ₂ OCH ₃ ) ₄ were used. Even when compared with the specimens of Examples 11 to 14 used, the low contamination property was excellent.

Claims (7)

Containing a silicon-containing compound (A) represented by the following formula (1), a fluorine-containing copolymer (B) having a crosslinkable group, a curing agent (C) and a weak solvent (D),
Coating composition SiO ₂ minutes is 45 to 50 wt% of the silicon-containing compound (A).

(However, n is an integer of 1 to 100.)   The composition for paint according to claim 1, wherein a ratio of the silicon-containing compound (A) to 100 parts by mass of the total amount of the fluorinated copolymer (B) and the curing agent (C) is 1.5 to 90 parts by mass. object.   The coating composition according to claim 1 or 2, wherein the content of the weak solvent (D) is 10 to 90 mass% with respect to the total amount (100 mass%) of the coating composition.   The crosslinkable group in the fluorine-containing copolymer (B) is a hydroxyl group, the curing agent (C) is a polyisocyanate-based curing agent, and the hydroxyl group contained in the copolymer contained in the coating composition The coating composition according to any one of claims 1 to 3, wherein a molar ratio (OH / NCO) of isocyanate groups of the curing agent (C) is 0.3 to 2.0. The said hardening | curing agent (C) is the following hardening | curing agent (C1), The composition for coating materials as described in any one of Claims 1-4.
Curing agent (C1): Allophanate group (All) and isocyanate obtained by reacting one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates with monoalcohols having 1 to 20 carbon atoms. A polyisocyanate curing agent having a molar ratio (All / Iso) of nurate groups (Iso) of 81/19 to 90/10.   The said weak solvent (D) is a mineral spirit, The composition for coating materials as described in any one of Claims 1-5. A kit for preparing a coating composition according to any one of claims 1 to 6,
Curing containing the main component containing a part of the fluorine-containing copolymer (B) and the weak solvent (D), and the silicon-containing compound (A), the curing agent (C), and the remainder of the weak solvent (D). A coating composition kit comprising the above composition.