JP2003105266A - Powder coating material and method for forming coated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a powder coating material excellent in stainproofness against exposure of the coated film, excellent in finished appearance of the coated film without occurrence of defects such as a pitting surface, and excellent in workability at the application and in storage stability as well, and to provide a method for forming the coated film. SOLUTION: This powder coating material comprises (A) a silicate compound having a specified structure, (B) a resin composition and (C1) a high boiling point solvent whose boiling point at the normal pressure is 150 to 300 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a new and useful powder coating material and a method for forming a coating film. More specifically, the powder coating and the powder which can provide a coating having particularly excellent resistance to contamination by exposure, flowability of the powder coating, workability of electrostatic coating, and finished appearance of the coating. The present invention relates to a coating film forming method using body paint.

[0002]

2. Description of the Related Art Powder coatings are widely used for metal coatings in general as environmentally friendly coatings that do not volatilize organic solvents into the atmosphere during coating, especially on roads such as gates, fences and guardrails. The use for outdoor applications such as materials is increasing.

With the increasing use in these outdoor applications, the long-term outdoor exposure of the coating film causes
There is a big problem of exposure and pollution, in which the surface of the coating film is contaminated by being wet with rain containing dust in the air and exhaust gas of automobiles. It is known that a method of making the coating film surface hydrophilic is effective for this problem. For example,
Japanese Patent Laid-Open No. 2001-003006 discloses an antifouling powder coating composition in which a silicate compound is added to the powder coating to improve the hydrophilicity of the coating film and improve the exposure stain resistance. ing.

However, when the antifouling powder coating composition is used, a large amount of lower alcohol, which is a by-product of the curing reaction, is volatilized from the silicate compound during curing of the coating film, so that the surface of the coating film is not affected. There is a problem in that coating film defects such as Benzoin is widely and commonly used as an anti-arming agent for powder coatings, but it is difficult to prevent the occurrence of coating film defects resulting from the use of these silicate compounds only by adding benzoin. Further, if the amount of benzoin added is increased too much, not only adversely affects other coating performance such as weather resistance and recoatability, but also benzoin is expensive, which leads to an increase in raw material cost of the powder coating. Also becomes.

Further, most of the silicate compounds are liquid at room temperature, and it is difficult to sufficiently mix them with other raw materials by the melt-kneading method which is generally used as a method for producing powder coatings. Therefore, there are problems that it is necessary to use many silicate compounds in order to obtain the effect of improving the exposure stain resistance, and the storage stability decreases.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies to solve the above-mentioned various problems in the prior art and to obtain a highly practical powder coating material and coating film forming method. The problem to be solved by the present invention is particularly excellent in the exposure stain resistance of the coating film, the workability during coating, the storage stability is excellent, and the coating film has a finished appearance without the occurrence of coating film abnormalities such as armpits. Another object is to provide an excellent powder coating material and a coating film forming method thereof.

[0007]

Means for Solving the Problems The inventors of the present invention have earnestly studied to solve the above-mentioned problems, and as a result, the silicate compound (A), the resin composition (B), and the boiling point of 1
A powder coating material containing a high boiling point solvent (C1) having a temperature of 50 to 300 ° C. has excellent storage stability, and a coating film formed using the powder coating material has particularly excellent exposure stain resistance. Moreover, they have found that the appearance of the coating film is excellent, and have completed the present invention.

That is, the present invention comprises a silicate compound (A) represented by the following general formula (I), a resin composition (B), and a high-boiling solvent (C1) having a boiling point of 150 to 300 ° C. under normal pressure. A powder coating material is provided.

[0009]

[Chemical 3]

(In the formula, n is an integer of ₁ to 20, R _{1 to} R ₄
Are each independently an alkyl group having 1 to 9 carbon atoms)

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. First, the silicate compound (A) used in the present invention will be described. The silicate compound (A) is very effective for preventing exposure pollution. The term "exposure pollution" as used in the present invention refers to a phenomenon in which a coating film is contaminated over time due to the adherence of contaminants in the atmosphere to the coating film by exposing the coating film to the outdoors. This phenomenon is remarkable in urban areas where the proportion of lipophilic pollutants in the atmosphere is high, resulting in a large loss of the aesthetic appearance of the coated article.

The silicate compound (A) used in the present invention is represented by the following general formula (I).

[0013]

[Chemical 4]

(In the formula, n is an integer of ₁ to 20, R _{1 to} R ₄
Are each independently an alkyl group having 1 to 9 carbon atoms)

Of the above silicate compounds (A), those having an alkyl group of a methyl group and / or an ethyl group are preferably used because the coating film is particularly excellent in exposure stain resistance. Among them, those in which all the alkyl groups are methyl groups have a high effect of improving the exposure stain resistance of the coating film, and are particularly preferably used. In the general formula (1), the range of the value of n is 3 to 25, preferably 3 to 20. When the value of n is within the above range, it is possible to obtain a coating film in which the effect of improving the exposure stain resistance is maintained for a long period of time.

As typical examples of the silicate compound (A), tetramethyl silicate, tetraalkyl silicate, tetra-n-propyl silicate, tetra-i-propyl silicate and tetra-n-butyl silicate are given. Such as a tetraalkyl silicate;

"MS51", "MS56", "MS5"
7 "," MS56S "(both are condensation products of tetramethyl silicate manufactured by Mitsubishi Chemical Corporation)," Ethyl silicate 40 "," Ethyl silicate 48 "(all are tetraethyl silicate condensation manufactured by Colcoat Co., Ltd.) Product), "BTS" (condensation product of tetrabutyl silicate manufactured by Mitsubishi Chemical Corporation), "MS58B15", "MS"
58B30 ”(all are manufactured by Mitsubishi Chemical Corporation, tetraalkyl silicate condensates having a methyl group and a butyl group), such as a partial condensate obtained by hydrolyzing a tetraalkyl silicate.

The addition amount of the silicate compound is 1 relative to the resin composition (B) from the viewpoint that the effect of improving the exposure stain resistance can be sufficiently exhibited and the storage stability of the coating is excellent. -30 wt% is preferable, and 3-20 wt% is more preferable.

Further, a silicate compound condensation catalyst may be used. As a typical condensation catalyst,
Butylamine, dibutylamine, hexylamine, te
various basic compounds such as rt-butylamine, ethylenediamine, triethylamine, isophoronediamine, imidazole, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate;

Various types such as tetraisopropyl titanate, tetrabutyl titanate, tin octylate, zinc octylate, calcium octylate, lead naphthenate, cobalt naphthenate, di-n-butyltin dilaurate and di-n-butyltin malate. A metal-containing compound of

Alternatively, there are various acidic compounds such as p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, phosphoric acid monoalkyl ester, phosphoric acid dialkyl ester and phosphoric acid trialkyl ester.

Among these, it is preferable to use a metal-containing compound because it has a high condensation promoting effect on the silicate compound.

Next, the resin composition (B) will be described. The resin composition (B) used in the present invention is the main component of the formed coating film, and either a thermoplastic resin composition or a thermosetting resin composition can be used, but the mechanical properties of the coating film It is preferable to use a thermosetting resin composition composed of a combination of a thermosetting resin (D) and a curing agent (E) because it has excellent physical properties. The type of resin used for the resin composition (B) is not particularly limited, and any resin used for powder coating can be used. As such a resin,
Examples thereof include acrylic resins, polyester resins, epoxy resins, urethane resins, fluororesins, and the like. Among these, acrylic resins, polyester resins, and fluororesins are particularly preferable because of their excellent coating film appearance.

First, when the thermosetting resin (D) is a thermosetting acrylic resin, a known and commonly used method can be applied to prepare the thermosetting acrylic resin, but it has a curing reactive group. The simplest method is to use vinyl monomers and, if necessary, other copolymerizable vinyl monomers, and radically polymerize each of these monomers in an organic solvent. Recommended as it exists. As the radical polymerization initiator and the organic solvent used at that time, known and conventional ones can be used as they are.

Examples of the curing-reactive group of the thermosetting acrylic resin include an epoxy group, a carboxyl group, a hydroxyl group, an amide group, an amino group, an acid anhydride group, and a (block) isocyanate group. Therefore, at least one selected from the group consisting of epoxy groups, carboxyl groups and hydroxyl groups is desirable. Above all, it is more preferable that at least one of the curing reactive groups is an epoxy group because of excellent storage stability and appearance of the coating film.

Typical examples of vinyl monomers having a curing reactive group are as follows. First, when the curing reactive group is an epoxy group, for example, glycidyl (meth) acrylate, β-methylglycidyl ( (Meth) acrylate,
Various epoxy group-containing monomers such as glycidyl vinyl ether and allyl glycidyl ether; (2-oxo-1,3-oxolane) group such as (2-oxo-1,3-oxolane) methyl (meth) acrylate Containing vinyl monomers; 3,4-epoxycyclohexyl (meth)
There are various alicyclic epoxy group-containing vinyl monomers such as acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and 3,4-epoxycyclohexylethyl (meth) acrylate.

When the curing reactive group is a carboxyl group, various carboxyl group-containing monomers such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid; monomethyl fumarate; Monoethyl fumarate, monobutyl fumarate, monoisobutyl fumarate,
Monotert-butyl fumarate, monohexyl fumarate, monooctyl fumarate, mono-2-ethylhexyl fumarate, monomethyl maleate, monoethyl maleate, monobutyl maleate, monoisobutyl maleate, monotert-butyl maleate, monohexyl maleate. , Monooctyl maleate, mono 2 maleate
-Monoesters of various α, β-unsaturated dicarboxylic acids such as ethylhexyl and monohydric alcohols having 1 to 18 carbon atoms; monomethyl itaconate, monoethyl itaconate, monobutyl itaconate, monoisobutyl itaconate, There are monoalkyl esters of itaconic acid, such as monohexyl itaconic acid, monooctyl itaconic acid and mono-2-ethylhexyl itaconic acid.

When the curing-reactive group is a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate. , 3-hydroxybutyl (meth)
Various hydroxyl group-containing (meth) acrylates such as acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate;
Addition reaction products of various (meth) acrylates and ε-caprolactone as listed above;

2-hydroxyethyl vinyl ether, 3
-Hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-
Hydroxy-2-methylpropyl vinyl ether, 5-
Various hydroxyl group-containing vinyl ethers such as hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; various vinyl ethers as listed above,
addition reaction product with ε-caprolactone;

2-hydroxyethyl (meth) allyl ether, 3-hydroxypropyl (meth) allyl ether, 2-hydroxypropyl (meth) allyl ether,
4-hydroxybutyl (meth) allyl ether, 3-hydroxybutyl (meth) allyl ether, 2-hydroxy-2-methylpropyl (meth) allyl ether, 5-
Various hydroxyl group-containing allyl ethers such as hydroxypentyl (meth) allyl ether and 6-hydroxyhexyl (meth) allyl ether; addition reaction products of various allyl ethers listed above with ε-caprolactone .

Further, other copolymerizable vinyl monomers can also be used if necessary, but if representative examples of such other copolymerizable monomers are given, ( Methyl (meth) acrylate, ethyl (meth) acrylate,
N-Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ter (meth) acrylate
t-butyl or n-hexyl (meth) acrylate,

Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate,
2-Methyl acrylate (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate or stearyl (meth) acrylate, such as alkyl (meth) acrylate,

Benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate or tetrahydrofurfuryl (meth) acrylate,

Alternatively, various alkyl carbitol (meth) s such as ethyl carbitol (meth) acrylate
In addition to acrylates, various (meth) acryl such as isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate or dicyclopentenyloxyethyl (meth) acrylate. Acid esters;

Various α-olefins such as ethylene, propylene and butene-1; Various halogenated olefins (halo olefins) other than fluoroolefins such as vinyl chloride and vinylidene chloride; styrene and α
Various aromatic vinyl monomers such as methylstyrene, vinyltoluene;

Dimethyl fumarate, diethyl fumarate, dibutyl fumarate, dioctyl fumarate, dimethyl maleate, diethyl maleate, dibutyl maleate, dioctyl maleate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, dioctyl itaconate. Such as various unsaturated dicarboxylic acids with 1 to 18 carbon atoms
Diesters with monohydric alcohols;

Various amino group-containing amides such as N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide and N-diethylaminopropyl (meth) acrylamide Unsaturated monomers; various dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate;

Tert-Butylaminoethyl (meth) acrylate, tert-butylaminopropyl (meth)
Various amino group-containing monomers such as acrylate, aziridinylethyl (meth) acrylate, pyrrolidinylethyl (meth) acrylate, piperidinylethyl (meth) acrylate; maleic anhydride, itaconic anhydride,
Various acid anhydride group-containing monomers such as citraconic anhydride, anhydrous (meth) acrylic acid, and tetrahydrophthalic anhydride;

Diethyl-2- (meth) acryloyloxyethyl phosphate, dibutyl-2- (meth) acryloyloxybutyl phosphate, dioctyl-2
-(Phosphorus ester group-containing monomers such as meacryloyloxyethyl phosphate and diphenyl-2- (meth) acryloyloxyethyl phosphate);
Various hydrolyzable silyl group-containing monomers such as γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane and γ- (meth) acryloyloxypropylmethyldimethoxysilane;

Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, branched (branched) aliphatic vinyl carboxylate having 9 carbon atoms. ,
Various aliphatic vinyl carboxylates such as branched aliphatic vinyl carboxylates having 10 carbon atoms, branched aliphatic vinyl carboxylates having 11 carbon atoms, and vinyl stearate;

Vinyl cyclohexanecarboxylate, vinyl methylcyclohexanecarboxylate, vinyl benzoate, p
There are various vinyl esters of carboxylic acids having a cyclic structure such as -tert-butyl vinyl benzoate.

The amount of various curing reactive group-containing vinyl monomers as exemplified above is preferably in the range of 10 to 70% by weight based on the total amount of vinyl monomers used. When the amount of the curing-reactive group-containing vinyl monomer used is within the above range, a coating film having excellent mechanical properties and flexibility can be obtained.

As the organic solvent used for preparing the thermosetting acrylic resin, known and commonly used organic solvents can be used.

As typical examples of such organic solvents, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol and n-butanol are given.
Alkyl alcohols such as pentanol and isopentanol;

Methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether,
Glycol ethers such as propylene glycol monopropyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; Exxon aromatic naphtha No. 2 (manufactured by Exxon, USA), such as mixed hydrocarbons containing aromatic hydrocarbons; n-pentane, n
-Aliphatic hydrocarbons such as hexane and n-octane;
Isopar C, Isopar E, Exor DSP100
/ 140, Exol D30 (all manufactured by Exxon, USA), IP Solvent 1016 (manufactured by Idemitsu Petrochemical Co., Ltd.), mixed hydrocarbons containing aliphatic hydrocarbons; cyclopentane, cyclohexane, methylcyclohexane,
Alicyclic hydrocarbons such as ethylcyclohexane;

Ethers such as tetrahydrofuran, dioxane, diisopropyl ether, di-n-butyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, acetic acid n -Butyl, isobutyl acetate, n-amyl acetate, isoamyl acetate, hexyl acetate, ethyl propionate, butyl propionate, and other esters.

As the radical polymerization initiator used in the preparation of the thermosetting acrylic resin, various known and commonly used compounds can be used.

Of these, only typical ones are exemplified by 2,2'-azobisisobutyronitrile, 2,2'-azobis-methylbutyronitrile and 2,2'-. Azobis-2,4-dimethylvaleronitrile, 1,1'-azobis-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, 2,2 '-
Azobis- (2-amidinopropene) dihydrochloride, 2-t
ert-butylazo-2-cyanopropane, 2,2'-
Azobis (2-methyl-propionamide) dihydrate,
2,2'-azobis [2- (2-imidazolin-2-yl) propene] or 2,2'-azobis (2,2,4
Various azo compounds such as -trimethylpentane);

Alternatively, benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, potassium persulfate, tert-butyl peroxy neodecanoate, tert-butyl peroxypivalate, tert-butyl peroxy-2-ethylhexano Ate, tert-butyl peroxyisobutyrate, 1,1-bis-tert-butyl peroxy-
3,3,5-trimethylcyclohexane or tert
-Butyl peroxy laurate,

Tert-butyl peroxyisophthalate, tert-butyl peroxyacetate, tert
Various ketone peroxides such as -butyl peroxybenzoate, dicumyl peroxide or di-tert-butyl peroxide; peroxy ketals; hydroperoxides; dialkyl peroxides; diacyl peroxides; peroxy Esters; peroxydicarbonates; or hydrogen peroxide.

The number average molecular weight of the thermosetting acrylic resin is preferably in the range of 1,000 to 20,000, and more preferably in the range of 1,500 to 15,000. . When the number average molecular weight of the thermosetting acrylic resin is within the above range, a coating film having excellent smoothness and mechanical properties can be obtained.

The preparation method for obtaining the thermosetting polyester resin used as the thermosetting resin (D) is not particularly limited, and it is a known and commonly used method prepared by condensing a polyhydric alcohol and a polybasic acid. Various methods are available. As the curing-reactive group, a carboxyl group and / or a hydroxyl group is preferably adopted because of easy preparation.

As the polyhydric alcohol and polybasic acid which can be used as a raw material for the thermosetting polyester resin, various known and commonly used compounds can be used. By adjusting the amounts of these polyhydric alcohol and polybasic acid to be used. A thermosetting polyester resin having a carboxyl group and / or a hydroxyl group can be obtained.

First, only the typical polyhydric alcohols are ethylene glycol,
Diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-
Butanediol, 1,5-pentanediol, 1,6-
Hexanediol, neopentyl glycol, triethylene glycol, bis-hydroxyethyl terephthalate, cyclohexanedimethanol, octanediol,
Diethyl propane diol, butyl ethyl propane diol, 2-methyl-1,3-propane diol, 2,
2,4-trimethylpentanediol, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of hydrogenated bisphenol A, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, trishydroxyethylisocyanate Examples include nurate and hydroxypivalyl hydroxypivalate.

On the other hand, only typical ones of the above-mentioned polybasic acids are given as examples: terephthalic acid, isophthalic acid, phthalic acid, methylterephthalic acid, trimellitic acid,
Pyromellitic acid or their anhydrides; succinic acid, adipic acid, azelaic acid, sebacic acid or their anhydrides; maleic acid, itaconic acid or their anhydrides; fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexa Hydrophthalic acid, methylhexahydrophthalic acid or their anhydrides; cyclohexanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and the like.

Further, as a raw material of the thermosetting polyester resin, a compound having both a carboxyl group and a hydroxyl group in one molecule, such as dimethanolpropionic acid and hydroxypivalate; "Cadura E10" (manufactured by Shell in the Netherlands) (Trade name of glycidyl ester of branched aliphatic carboxylic acid); various monohydric alcohols such as methanol, propanol, butanol and benzyl alcohol; benzoic acid, p-tert.
Various monovalent basic acids such as -butylbenzoic acid; various fatty acids such as castor oil fatty acid, coconut oil fatty acid and soybean oil fatty acid can also be used.

As the polyester resin obtained by using various polyhydric alcohols, polybasic acids and other raw materials as mentioned above, the total of the acid value and the hydroxyl value is 10
To 250 (mgKOH / g; the same applies below),
In addition, it is desirable to use a resin having a number average molecular weight in the range of 500 to 10,000.

When the sum of the acid value and the hydroxyl value is within the above range, a coating film having excellent smoothness and mechanical properties can be obtained. Further, when the number average molecular weight is within the above range, not only a coating film having excellent smoothness and mechanical properties can be obtained, but also a coating having excellent storage stability can be obtained.

The structure of the thermosetting polyester resin is
It is not particularly limited as long as it is within the range of various characteristic values of the resin as described above, and may have a branched structure or a linear structure.

The epoxy resin which can be used as the thermosetting resin (D) is not particularly limited, but examples thereof include an epoxy resin such as polyglycidyl ether of bisphenol-A.

The thermosetting fluororesin usable as the thermosetting resin (D) refers to a polymer compound having a fluorine atom in the molecule, specifically, polytetrafluoroethylene or polyvinylidene fluoride. And a (tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride) copolymer obtained by (co) polymerizing one or more fluorine-containing vinyl monomers (d-1), (Per) Fluoroalkyl polyether, (Per)
Fluoroalkyl polycarbonate and the like,
In particular, a fluorine-containing vinyl monomer (d-1), a vinyl ether (d-2) and / or a carboxylic acid vinyl ester (d-3) are further co-used with other vinyl monomers, if necessary. A thermosetting fluororesin obtained by polymerization is excellent in coating properties such as weather resistance and mechanical properties, and also excellent in solubility in an organic solvent, and therefore can be preferably used.

To prepare these heat-curable fluororesins, known and conventional methods can be applied. For example, fluorine-containing vinyl monomer (d-1) and vinyl ether (d-).
2) and / or carboxylic acid vinyl ester (d-3)
Is used together with other vinyl monomers, if necessary, and each of these monomers is polymerized in an organic solvent, which is recommended because it is the simplest method.

The above-mentioned fluorine-containing vinyl monomer (d-1) used in that case has a fluorine atom in the molecule,
Moreover, it refers to a compound having a form such that it also has a polymerizable unsaturated double bond (hereinafter, also referred to as an unsaturated double bond), and preferably such fluorine-containing vinyl monomers In the case of polymerization of
I)

[0065]

[Chemical 5]

[However, W, X, Y and Z in the formula are
Each of them represents a hydrogen atom, a halogen atom, an alkyl group or a halogenated alkyl group, which may be the same or different, and W, X, Y
Alternatively, at least one of Z is a fluorine atom. ] The fluoroolefin structural unit represented by] is referred to as a compound capable of being introduced into the main chain.

Of these, only typical ones are exemplified by vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene,
Various fluorine-containing α-olefins such as chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene, hexafluoropropylene;
Such as trifluoromethyl trifluorovinyl ether, pentafluoroethyl trifluorovinyl ether, heptafluoropropyl trifluorovinyl ether,
Examples include various perfluoroalkyl-perfluorovinyl ethers; various (per) fluoroalkyl vinyl ethers (provided that the alkyl group has 1 to 18 carbon atoms).

These fluorine-containing vinyl monomers (d-1)
May be used alone or in combination of two or more,
Since a copolymer having excellent weather resistance can be obtained, vinyl fluoride, vinylidene fluoride, trifluoroethylene,
It is desirable to use at least one fluorine-containing vinyl monomer selected from the group consisting of tetrafluoroethylene and chlorotrifluoroethylene.

Furthermore, it is desirable to use the above-mentioned vinyl ether (d-2) and / or carboxylic acid vinyl ester (d-3) for the thermosetting fluororesin. These vinyl ethers (d-2) and / or carboxylic acid vinyl esters (d-3) are excellent in copolymerizability with the fluorine-containing vinyl monomer (d-1), and therefore, in the thermosetting fluororesin. It can be said that fluorine atoms can be introduced efficiently.

As typical examples of the vinyl ether (d-2), methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether,
Isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether and the like, and further, 2-ethylhexyl vinyl ether, chloromethyl vinyl ether, chloroethyl vinyl ether, benzyl vinyl ether, phenethyl ethyl vinyl ether and the like. , Various (substituted) alkyl vinyl ethers or aralkyl vinyl ethers; various cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether, and methyl cyclohexyl vinyl ether.

On the other hand, carboxylic acid vinyl ester (d-
3) Particularly representative are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl stearate; a branch having 9 carbon atoms. A branched (branched) aliphatic vinyl carboxylate, a branched (branched) aliphatic vinyl carboxylate having 10 carbon atoms, a branched (branched) aliphatic vinyl carboxylate having 11 carbon atoms, Various aliphatic carboxylic acid vinyl esters; various carboxylic acid vinyl esters having a cyclic structure, such as vinyl cyclohexanecarboxylate, vinyl methylcyclohexanecarboxylate, vinyl benzoate and vinyl p-tert-butylbenzoate. is there.

In addition to the compounds listed above, other vinyl monomers such as those mentioned for the thermosetting acrylic resin can be used if necessary.

As a method of introducing a curing reactive group into a thermosetting fluororesin, a method of copolymerizing monomers having a curing reactive group with the above-mentioned monomers is easy. It is recommended that a curing reactive group can be introduced into the thermosetting fluororesin. From the viewpoint of storage stability of the powder coating material produced using the thermosetting fluororesin and excellent coating film properties, the curing reactive group is at least one of a hydroxyl group, a carboxyl group, and an epoxy group. Is desirable.

As typical examples of such curing reactive group-containing monomers, the hydroxyl group-containing vinyl monomers include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, and 4-hydroxyethyl vinyl ether. Various hydroxyl group-containing vinyl ethers such as hydroxybutyl vinyl ether; addition reaction products of these hydroxyl group-containing vinyl ethers and ε-caprolactone; 2-hydroxyethyl (meth) allyl ether, 3-hydroxypropyl (meth) allyl ether, Various hydroxyl group-containing allyl ethers such as 4-hydroxybutyl (meth) allyl ether;

This hydroxyl group-containing allyl ether and ε-
Addition reaction product with caprolactone; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate G, 3-hydroxybutyl (meth) acrylate
Group, a hydroxyl group-containing (meth) acrylate compound such as 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate; Examples thereof include addition reaction products of (meth) acrylate and ε-caprolactone.

Examples of the carboxyl group-containing monomers include (meth) acrylic acid, crotonic acid, itaconic acid,
Various carboxyl group-containing monomers such as maleic acid and fumaric acid; monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monoisobutyl fumarate, monotert-butyl fumarate, monohexyl fumarate,
Monooctyl fumarate, mono-2-ethylhexyl fumarate, monomethyl maleate, monoethyl maleate, monobutyl maleate, monoisobutyl maleate, monotert-butyl maleate, monohexyl maleate, monooctyl maleate, mono-2-maleate. Monoesters of various α, β-unsaturated dicarboxylic acids such as ethylhexyl and monohydric alcohols having 1 to 18 carbon atoms; monomethyl itaconate, monoethyl itaconate,
There are monoalkyl esters of itaconate such as monobutyl itaconate, monoisobutyl itaconate, monohexyl itaconate, monooctyl itaconate and mono-2-ethylhexyl itaconate.

Examples of the epoxy group-containing monomers include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, (3,4-epoxy-butyl) methacrylate, and (2-oxo-1,3-). Epoxy group-containing (meth) acrylates such as oxolane) methyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate; (2-oxo-
1,3-oxolane) vinyl methanecarboxylate, 3,4
-Epoxy group-containing carboxylic acid vinyl esters such as epoxycyclohexanecarboxylic acid vinyl ester; glycidyl vinyl ether, epoxy group-containing vinyl ethers such as 3,4-epoxycyclohexyl vinyl ether; epoxy group-containing allyl ethers such as allyl glycidyl ether and so on.

In addition to the above-mentioned curing reactive group-containing monomers, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; N-dimethylaminoethyl (meth) acrylamide, N Various amino group-containing amide unsaturated monomers such as diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, N-diethylaminopropyl (meth) acrylamide; dimethylaminoethyl (meth) acrylate , Various dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate; tert-butylaminoethyl (meth) acrylate, tert-butylaminopropyl (meth) acrylate, aziridinylethyl (meth) acrylate,
Various amino group-containing monomers such as pyrrolidinylethyl (meth) acrylate and piperidinylethyl (meth) acrylate;

Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldiethoxysilane, vinyltris (β-methoxyethoxy) silane, allyltrimethoxysilane, trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ether, Methyldimethoxysilylethyl vinyl ether, trimethoxysilylpropyl vinyl ether, triethoxysilylpropyl vinyl ether,
Methyldiethoxysilylpropyl vinyl ether, γ-
Various monomers having a hydrolyzable silyl group such as (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane or γ- (meth) acryloyloxypropylmethyldimethoxysilane Also, it can be used as a monomer having a curing reactive group.

To prepare the thermosetting fluororesin by the solution polymerization method, all the monomers, the polymerization initiator and the solvent are charged all at once into the reactor for polymerization, or the fluorine-containing vinyl monomer (d- 1) and a reactor charged with a solvent, the monomer other than the fluorine-containing vinyl monomer (d-1) and a polymerization initiator are added continuously or in a divided manner to polymerize, Furthermore, it is possible to apply a method in which all the monomers and the polymerization initiator are added to the reactor charged with only the solvent continuously or in a divided manner to perform polymerization. As the polymerization initiator and solvent used at that time, known and conventional ones can be used as they are.

The fluorine content of the thermosetting fluororesin is 1
It is desirable to be 5% by weight or more. Fluorine content is 1
If it is 5% by weight or more, sufficient weather resistance can be imparted to the coating film formed using the thermosetting fluororesin.

The softening point of the thermosetting fluororesin is 80 to 1
It is desirable that the temperature is in the range of 50 ° C. When the softening point is within the above range, it is possible to obtain a powder coating excellent in both appearance of the coating film and storage stability.

Further, the number average molecular weight of the thermosetting fluororesin is preferably in the range of 500 to 50,000, and more preferably in the range of 1,000 to 10,000. If the number average molecular weight is within the above range,
A coating film having excellent weather resistance, mechanical properties and smoothness can be obtained.

Next, the curing agent (E) will be described. The curing agent (E) used in the present invention is appropriately selected from those generally used for powder coatings depending on the type of the curing reactive group of the thermosetting resin (D). Used.

As the curing agent (E), when the curing-reactive group of the thermosetting resin (D) is an epoxy group, succinic acid, glutaric acid, Adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid,
Maleic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, trimellitic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexene-1,2-dicarboxylic acid, trimellitic acid, pyromellitic acid, or There are such acid anhydrides and urethane modified products, and among them, since the coating film physical properties and storage stability are excellent, an aliphatic dibasic acid is preferable, and particularly since the coating film physical properties are excellent, dodecanedioic acid is particularly preferable. .

When the curing-reactive group of the thermosetting resin (D) is a carboxyl group, only typical examples of the curing agent (E) are listed, and the polyglycidyl ether of bisphenol A is Such as various epoxy resins; glycidyl group-containing acrylic resins, epoxy group-containing acrylic resins, polyglycidyl ethers of various polyhydric alcohols such as 1,6-hexanediol, trimethylolpropane and trimethylolethane; phthalates Acid, terephthalic acid, isophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, trimellitic acid, pyromellitic acid, polyglycidyl esters of various polycarboxylic acids; bis (3,4-epoxycyclohexyl) Various alicyclic epoxy group-containing compounds such as methyl adipate; Triglycidyl isocyanurate, β-
Examples thereof include hydroxyamides such as hydroxyalkylamides.

When the curing-reactive group of the thermosetting resin (D) is a hydroxyl group, a polyblock isocyanate compound, aminoplast, etc. are particularly preferable as the curing agent (E).

Typical examples of the polyblock polyisocyanate compound are various aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; various cyclic aliphatic compounds such as xylylene diisocyanate and isophorone diisocyanate. Diisocyanates; organic diisocyanates such as various aromatic diisocyanates such as tolylene diisocyanate and 4,4′-diphenylmethane diisocyanate, or these organic diisocyanates and polyhydric alcohols, low molecular weight polyester resins (polyester polyols) or water There are additional items such as

Furthermore, the above-mentioned polymers of organic diisocyanates (including isocyanurate type polyisocyanate compounds) and various polyisocyanate compounds such as isocyanate biuret compounds are formed into known and commonly used blocks. Examples thereof include those obtained by blocking with an agent, so-called self-blocked polyisocyanate compounds having a uretdione bond as a structural unit, and the like.

On the other hand, examples of aminoplasts include melamine, urea, acetoguanamine, benzoguanamine,
Various amino group-containing compounds such as steroganamin and spiroguanamine, and formaldehyde, paraformaldehyde, acetaldehyde and glyoxal,
Condensates in the form obtained by reacting various aldehyde compound components with various conventionally known methods, or compounds in the form obtained by etherifying these condensates with alcohols and so on.

As only specific examples of such aminoplasts, hexamethoxymethylolmelamine, hexabutyletherified methylolmelamine, methylbutyl mixed etherified methylolmelamine, methyletherified methylolmelamine and n-butyletherified methylol are given. Melamine, isobutyl etherified methylol melamine, or their condensates; various bicyclic compounds such as hexamethoxyglycoluril, hexabutoxyglycoluril, tetramethoxymethylglycoluril; aliphatic dibasic acids and diethanolamine, etc. Various acid amides in the form of being obtained by condensation reaction with various alkanolamines; Polymerizable monomers such as butyl ether of N-methylolacrylamide Alone, or other such as obtained by copolymerizing possible Naru monomers and copolymerization reaction, and the like various polymer compounds.

The above-mentioned hexamethoxymethylol melamine is referred to as "Cymel 300, 301 or 303" (manufactured by Mitsui Cyanamid Co.); methylbutyl mixed etherified methylol melamine is referred to as "Cymel 238, 2".
32 or 266 "(manufactured by Mitsui Cyanamid); n-butyl etherified methylol melamine as" Super Beckamine L-164 "(manufactured by Dainippon Ink and Chemicals, Inc.); tetramethoxymethylglycoluril as" Powder Link " (POWDERLIN
K) 1174 ”(product of American Cyanamid Co., USA); acid amides are“ PRIMID (PRIMI)
D) XL-552 "," Primid (PRIMID)
QM-1260 "(manufactured by EMS), which is commercially available.

The above curing agent (E) may be used alone or in combination of two or more kinds. The compounding amount of the curing reactive group of the thermosetting resin (D) and the curing agent (E) is such that the equivalent ratio of the curing reactive group of the thermosetting resin (D) to the equivalent amount of the curing agent (E) is 2. It is preferably between 0 and 0.5.

Next, the high boiling point solvent (C1) having a boiling point of 150 to 300 ° C. at atmospheric pressure used in the present invention will be described. High boiling point solvent (C
1) is used to prepare a high boiling solvent (C
By allowing 1) to remain, it is possible to obtain a powder coating material that forms a coating film that does not cause coating film defects such as armpits and pinholes, and improve the smoothness of the coating film. The high boiling point solvent (C1) may be a single component or a mixture of a plurality of components.

As the boiling point of the high boiling point solvent (C1) at normal pressure, a boiling point of 170 to 250 ° C. is more preferably used. Furthermore, the boiling point at normal pressure is +15 to +1 with respect to the temperature when baking and curing the powder coating material of the present invention.
Those at 50 ° C. are particularly preferable.

The high boiling point solvent (C1) is at 25 ° C.,
The solubility in water and toluene is preferably 50% by weight or more. Within this range, the occurrence of cracking and cissing at the time of forming the coating film is effectively suppressed, and a good finished appearance of the coating film can be obtained. From this viewpoint, the solubility in methanol and ethanol is 1
More preferably, it is at least 00% by weight. Where 2
The fact that the solubility in water at 5 ° C. is 50% by weight or more means that 50 g or more dissolves in 100 g of water at 25 ° C. in water.

The amount of the high boiling point solvent (C1) used is preferably 0.005 to 3 parts, more preferably 0.01 to 2 parts, and 0.0
It is even more preferably 5 to 1 part.

When the boiling point of the high boiling point solvent (C1) at normal pressure and the amount used are in the above-mentioned ranges, the silicate compound (when the coating material is applied on the object to be coated and then baked and cured to form a coating film ( It is possible to prevent the generation of coating film defects such as cracks and pinholes derived from alcohol and the like generated by the reaction of A).

Specific examples of such high boiling point solvents (C1) include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol; Butyl cellosolve, isoamyl cellosolve, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol monobutyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, methyl carbitol, ethyl carbitol, butyl carbitol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether , Diethylene glycol dipropyl ether, diethyl Glycol dibutyl ether,
Glycol ethers such as triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether tripropylene glycol monomethyl ether;

N-hexanol, n-octanol, 2
-Alcohols such as ethylhexanol, cyclohexanol, benzyl alcohol; propylbenzene,
Aromatic hydrocarbons such as butylbenzene, pentylbenzene, diethylbenzene, dipropylbenzene, dipentylbenzene, dodecylbenzene, cyclohexylbenzene; aromatic carbons such as Solvesso 100, Solvesso 150, Solvesso 200 (all manufactured by Exxon USA) Mixed hydrocarbons containing hydrogen; Exxon naphtha No. 3, Exxon naphtha No. 5, Exxon Naphtha N
o. 6, Exxon Solvent No. 7, Isopar G,
Isopar H, Isopar L, Isopar M, Exol D40, Exol D90, Exol D110 (all manufactured by US Exxon Corporation), IP Solvent 1620,
Mixed hydrocarbons containing aliphatic hydrocarbons such as IP Solvent 2028 (manufactured by Idemitsu Petrochemical Co., Ltd.), Merbeil 20, Merbeil 30, Merbeil 40 (manufactured by Showa Shell Sekiyu KK), and mineral spirits;

Glycerin alkyl ether, glycerin alkyl ester; ketones such as diisobutyl ketone, methyl amyl ketone, cyclohexanone and isophorone; cyclohexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, isoamyl propionate, butyric acid alkyl ester Esters such as, stearic acid alkyl ester, benzoic acid alkyl ester, adipic acid dialkyl ester, phthalic acid dialkyl ester;

Examples thereof include N-methylpyrrolidone, dimethylformamide, dimethylacetamide and ethylene carbonate.

Among the high boiling point solvents (C1) mentioned above,
Since the effect of preventing the occurrence of coating film defects of the obtained coating film is high, it is preferable to use glycol ethers, and at least one selected from the group consisting of methyl carbitol, ethyl carbitol, and butyl carbitol is used. Particularly preferred.

The method of adding the high boiling point solvent (C1) to the powder coating material is not particularly limited. In the case of producing powder coating material by the melt-kneading method, it is sufficient to mix it with other raw materials when blending the coating material, and in the case of producing powder coating material by the spray drying method, powder coating material A method of mixing and dissolving with other raw materials when preparing a solution, and a method of adding and mixing the powder coating raw material solution immediately before spray drying are recommended because they are simple and convenient. Resin composition (B)
When is obtained by solution polymerization, a method of adding it as a part of the polymerization solvent for the polymerization or a method of adding it after the completion of the polymerization can be adopted.

The method for preparing the powder coating material of the present invention is not particularly limited, and either a melt-kneading method which is usually adopted as a method for producing a powder coating material or another manufacturing method such as a freeze-drying method is used. The method of can also be adopted. Above all,
A powder coating material obtained by spray-drying a powder coating material solution obtained by dissolving or dispersing a silicate compound (A), a resin composition (B), and a high boiling point solvent (C1) in an organic solvent (C) is stored. It is particularly preferable because it has excellent stability and the resulting coating film has excellent smoothness and image clarity.

When the resin composition (B) used in the powder coating composition of the present invention comprises the thermosetting resin (D) and the curing agent (E), the silicate compound (A) and the thermosetting resin are used. (D) or curing agent (E) and high boiling point solvent (C1)
A silicate compound (A) and a thermosetting resin (D) or a curing agent (E) and a high boiling point solvent (C) obtained by spray-drying an organic solvent solution prepared by dissolving the above in an organic solvent (C).
The mixture of 1) may be used together with other raw materials to produce a powder coating material by a melt-kneading method or the like, but with the silicate compound (A), the thermosetting resin (D) and the curing agent (E). The powder coating material obtained by spray-drying the powder coating material solution obtained by dissolving the high boiling point solvent (C1) in the organic solvent (C) has the above-mentioned characteristics, that is, storage of the powder coating material. It is more preferable because it is excellent in stability and exposure stain resistance of the coating film, and particularly excellent in smoothness and sharpness of the coating film.

Next, the organic solvent (C) will be described. As the organic solvent (C), a known and commonly used solvent that dissolves the silicate compound (A) and / or the resin composition (B) can be used, and one kind or a combination of two or more kinds of solvents may be used. When the composition (B) is obtained by solution polymerization,
The solvent used at the time of polymerization can be used as it is as a part or all of the organic solvent (C).

Even if the organic solvent does not dissolve the silicate compound (A) and / or the resin composition (B), the organic solvent (as long as the storage stability of the powder coating material solution is not impaired) It can be used as a part of C).

As the organic solvent (C), any of the organic solvents described in the description of the thermosetting acrylic resin can be used.

From the standpoint of improving the drying property of the paint particles during spray drying, 65 to 100% by weight of the organic solvent (C) has a boiling point of 100 ° C. or less at normal pressure.
It is preferable to occupy

When the resin composition (B) comprises a thermosetting resin (D) and a curing agent (E) and the curing agent (E) is an aliphatic dibasic acid, the solubility of the curing agent is increased. In addition, the organic solvent contains at least one alcohol having 4 or less carbon atoms, and the amount of the alcohol having 4 or less carbon atoms is
The weight ratio of the aliphatic dibasic acid contained in the powder coating material solution is preferably 4 times or more.

Next, the powder coating material solution will be described.
The powder coating material raw material solution of the present invention is an organic solvent solution containing a coating film forming component, and the powder coating material of the present invention is obtained by spray drying the powder coating material raw material solution.

The method for preparing the powder coating material raw material solution is not particularly limited. For example, the silicate compound (A) and the resin composition (B) are added to the organic solvent (C) and mixed by stirring at room temperature. Then, it can be prepared by dissolving the silicate compound (A) and the resin composition (B).

The powder coating material solution used in the present invention is
At a temperature lower than the temperature when spraying, for example, at room temperature,
It is preferable that the silicate compound (A) and the resin composition (B) are completely dissolved in the organic solvent (C).
When completely dissolved, the silicate compound (A) and the resin composition (B) are more uniformly mixed, as compared with the mixing by melt kneading which is performed in the conventional manufacturing method,
This is because it is possible to obtain a powder coating material in which the appearance of the coating film, particularly the sharpness of the coating film is significantly improved.

Further, if necessary, pigments, other resins, curing catalysts, additives and the like may be added to the powder coating material solution and dissolved or dispersed to form a coating material. As typical examples of pigments, titanium oxide, red iron oxide, chromium titanium yellow, yellow iron oxide, various inorganic pigments of carbon black, phthalocyanine blue,
Phthalocyanine series such as phthalocyanine green, anthraquinone series such as induslen blue, dianthraquinonyl red, quinacridone series, lake red, fast yellow, disazo yellow, azo series such as permanent red, nitro series such as naphthol yellow, pigment green B, Various conventionally known organic pigments such as naphtho green such as naphthol green, various commonly used extender pigments, and various conventionally known bright (metallic) pigments such as aluminum flakes and mica flakes. Etc. are used.

A colored powder coating material can be prepared by dispersing the above pigment in a powder coating material solution and then spray drying. As a method for dispersing the pigment in the powder coating material solution, a known and commonly used method such as a sand mill can be used. Further, a colored powder coating material may be manufactured by mixing a plurality of colored powder coating material solutions to adjust the color, preparing a colored powder coating material solution having a desired color, and spray-drying.

As the other resins, only representative ones will be exemplified. Acrylic resin, polyester resin, fluororesin, silicone resin, chlorinated polyethylene, chlorinated polypropylene, petroleum resin, epoxy resin, chlorinated resin, etc. Various resins such as rubber and resins other than the resin composition (B) can be mentioned.

The resin composition (B) is a thermosetting resin (D)
In the case of comprising a curing agent (E) and a curing agent (E), known curing agents can be used as they are depending on the combination of the thermosetting resin (D) and the curing agent (E). Examples of the additives include flow regulators, color separation inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, and other known and commonly used additives.

Further, if necessary, nitrocellulose,
Various fibrin derivatives such as cellulose acetate butyrate may be used.

Next, spray drying will be described. The apparatus used for spray drying may be one capable of removing the organic solvent from the sprayed powder coating material solution, for example, by contacting the sprayed powder coating material solution with a heat source gas to volatilize the organic solvent. A spray drying device or the like can be used. Since the organic solvent is volatilized, it is desirable that the device be explosion proof. Further, from the viewpoint of keeping the vapor content of the solvent in the heat source gas low, which is used for drying the sprayed powder coating material raw material solution, it is desirable to provide a solvent recovery device.

In the case of using the above-mentioned spray dryer for contacting the sprayed powder coating material solution with the heat source gas to volatilize the organic solvent, the method of contacting the powder coating material solution and the heat source gas is not particularly limited. Instead, any method such as a co-current type, a counter-current type, a co-current / counter-current mixed type, which is commonly used, may be used. The pressure in the device may be normal pressure, reduced pressure or increased pressure, and is not particularly limited.

Regarding the spraying method of the powder coating material solution,
Any of known and conventional types such as a rotating disk type, a two-fluid nozzle type, and a pressure nozzle type can be used. Factors for controlling the particle size during spraying include the rotation speed of the disk in the rotary disk system, the discharge speed from the nozzle in the two-fluid nozzle system, and the compression used by mixing with the raw material solution. The mixing ratio of air and the raw material solution, and the pressure nozzle type include the discharge pressure and the like, but these values may be appropriately determined according to the target particle size.

The supply rate of the raw material solution and the flow rate of the heat source gas may be appropriately determined according to the target particle size. However, if the supply rate of the raw material solution or the flow rate of the heat source gas changes during spray drying, Since the particle size, particle size distribution and non-volatile content of the obtained particles also change, it is desirable to keep it constant during spray drying.

The non-volatile content concentration of the powder coating material solution at the time of spray drying may be appropriately determined according to the specifications of the spray dryer and the spray drying conditions.

Usually, the heat source gas containing particles obtained by spray drying is continuously introduced into a classifying device represented by a cyclone, and particles are collected and classified. In order to adjust the particle size distribution of the powder coating material of the present invention, when it is necessary to perform classification for removing coarse particles and fine particles, a commercially available general classifier can be used.

An inert gas is desirable as the heat source gas. Above all, it is preferable to use nitrogen gas in terms of cost and the like. The temperature of the heat source gas is a temperature at which the thermosetting resin and the curing agent of the powder coating material solution do not substantially cause a curing reaction, that is, the coating material of the powder coating obtained even if a partial curing reaction occurs. The temperature may be appropriately determined within a temperature range in which the performance as is not substantially impaired. The lower limit of the temperature of the heat source gas is not particularly limited, but in order to evaporate the solvent efficiently, it is preferably 20 ° C. or higher, and more preferably 30 ° C. or higher. Usually, the temperature of the heat source gas is 20 to 160 ° C, preferably 30 to 13 ° C.
It is appropriately determined within the range of 0 ° C.

Further, in order to evaporate the solvent more efficiently, the powder coating material solution may be preheated before spray drying. At this time, the temperature for preheating is preferably 70 ° C. or lower in order to prevent gelation of the powder coating material raw material solution, and spray drying is preferably performed as soon as possible after preheating.

The powder coating material thus obtained can be used as it is, but if necessary, it may be secondarily dried by another drying method such as vacuum drying, aeration drying and fluidized bed drying. . At that time, in order to prevent gelation of the powder coating material or heat fusion of the coating particles, secondary drying is performed at about 7
It is desirable to carry out at a temperature of 0 ° C. or lower.

The obtained powder coating material may be further adjusted in particle size by a pulverizing step or a granulating step before use.

The powder coating material of the present invention has an average particle diameter of 5 to 5.
It is preferably 50 μm. Considering the smoothness of the thin film, the thickness is more preferably 10 to 30 μm. The above average particle diameter means a volume average median diameter, and for example, a laser diffraction particle size analyzer (SALD-2 manufactured by Shimadzu Corporation).
000).

The powder coating material of the present invention preferably has an average circularity of 0.9 or more. By using a spherical powder paint, the paint fluidity and repaintability are improved.
From this viewpoint, it is preferable that the particles having a circularity of 0.9 or more have a frequency of 50% or more, and more preferably 70% or more.

The powder coating material of the present invention is spray-dried with a powder coating material solution in which the silicate compound (A), the resin composition (B) and the high boiling point solvent (C1) are dissolved in the organic solvent (C). When produced, the resulting powder coating is essentially spherical and is a particularly preferred production method.

The circularity and the average circularity referred to here are one of the particle shape indexes representing the unevenness of the particle surface,
It is expressed as the following equation.

Circularity = (perimeter of circle having the same area as the projected area of particle) / (perimeter of projected image of particle)

Therefore, the circularity becomes 1 if the particle image is a perfect circle, and becomes smaller as the particle image deviates from the perfect circle and becomes elongated or uneven. The average circularity is calculated by dividing the sum of the circularity of each particle by the total number of particles. The shape and average circularity of the above powder coating material are determined by a flow type particle image analyzer (FPIA-
1000, manufactured by Toa Medical Electronics Co., Ltd. The shape of the powder coating material can also be confirmed by a scanning electron microscope.

Regarding the coating method of the powder coating material of the present invention,
The base material to be coated is coated by various known and conventional methods such as an electrostatic spraying method or a triboelectrification coating method, fluidized dipping, etc. Usually, the thus-obtained coated material is coated with about 120
It suffices to perform baking at a temperature of about 250 ° C., and in this way a powder coated product can be obtained.

The powder coating material of the present invention can be suitably used as an undercoat coating material or a topcoat coating material in a coating film forming method for forming a single-layer or multi-layer coating film on an object to be coated.

Here, the article to be coated refers to a base material to which the coating material is applied, and more specifically, it is an unpainted metal material such as an unpainted steel plate or an untreated or chemically treated aluminum base material. Examples include base materials used for road vehicles such as automobile bodies and motorcycle bodies, base materials used for automobile parts such as aluminum wheels, and base materials used for beverage cans. Also included are base materials used for road vehicles such as automobile bodies that have been subjected to electrodeposition coating. Furthermore, base materials used for home appliances, vending machines, steel furniture, etc., such as electrogalvanized steel sheets, hot-dip galvanized steel sheets, roof tiles; glasses; or various inorganic building materials; gates or fences Examples include various building materials, such as a class; various building interior and exterior materials, such as an aluminum sash.

These base materials may be processed into a shape according to their final use, or may be in a form to which a PCM (pre-coat metal) coating method is applied, that is, a roughly flat plate-like base material. However, after the coating film is formed by the method of the present invention, the coating film may be bent into a predetermined shape according to the purpose, or may be completely post-processed such as coil coating. It may be a base material used in a coating system.

The powder coating material obtained by the production method of the present invention is applied to the various substrates to be coated as described above by a conventional method, and then baked and dried by a conventional method. It is possible to provide a coating film having excellent curability, appearance, weather resistance and mechanical properties, among others.

[0141]

EXAMPLES Next, the present invention will be described more specifically by reference examples, examples and comparative examples, but it goes without saying that the present invention is not limited to these examples.
In the following, all "parts" mean "parts by weight" unless otherwise specified.

Reference Example 1 [Preparation of Thermosetting Acrylic Resin (D)] 1800 parts of methyl ethyl ketone was charged into a stainless steel autoclave whose internal air was replaced with nitrogen gas.
The temperature was raised to 135 ° C. 600 parts of styrene, 900 parts of methyl methacrylate, 600 parts of n-butyl methacrylate, 900 parts of glycidyl methacrylate, ter
A mixture of 230 parts of t-butyl peroxyoctoate and 600 parts of methyl ethyl ketone was added dropwise over 6 hours. After completion of the dropping, the temperature is kept at the same temperature for 5 hours to complete the polymerization reaction, whereby the thermosetting acrylic resin having an epoxy equivalent of 520 (g / equivalent) and a number average molecular weight of 2,300 (D-1 ) Solution (D'-1)
(Nonvolatile matter 57.5%) was obtained. Property values are shown in Table 1 (1)
Shown in.

[0143]

[Table 1]

[0144] << Footnotes in Table 1 >> TBPO: tert-butyl peroxyoctoate MEK ... Methyl ethyl ketone

Reference Example 2 [Preparation of thermosetting polyester resin (D)] In a reaction vessel equipped with a stirrer, a thermometer, a rectification column and a nitrogen gas inlet, 180 parts of ethylene glycol, 876 parts of neopentyl glycol and Charge 135 parts of hydrogenated bisphenol A, and keep stirring under nitrogen atmosphere at 150 ° C.
Then, 1500 parts of terephthalic acid, 300 parts of hexahydrophthalic anhydride, 9 parts of trimethylolpropane and 2 parts of dibutyltin oxide were charged, and the temperature was raised to 240 ° C. while continuing stirring.

Further, at the same temperature, the resin has a hydroxyl value of 35.
By continuing the dehydration condensation reaction until it became (mgKOH / g), a thermosetting polyester resin (D-2) having a number average molecular weight of 3,200 was obtained. Property value is first
It shows in Table (2).

Reference Example 3 (same as above) A reaction vessel equipped with a stirrer, a thermometer, a rectification column and a nitrogen gas inlet was charged with 891 parts of neopentyl glycol and 265 parts of cyclohexanedimethanol and stirred under a nitrogen atmosphere. While continuing to raise to 150 ℃, then,
835 parts of isophthalic acid, 1000 parts of terephthalic acid, 9 parts of trimethylolpropane and 2 parts of dibutyltin oxide were charged, and the temperature was raised to 240 ° C. while continuing stirring.

Further, at the same temperature, the acid value of the resin is 31 (mg
The thermosetting polyester resin (D-3) having a number average molecular weight of 3,700 was obtained by continuing the dehydration condensation reaction until it reached KOH / g). Property values are shown in Table 1 (2).

[0149]

[Table 2]

Reference Example 4 [Preparation of thermosetting fluororesin (D)] 1800 parts of ortho-xylene and bis (1,2,2,2) were placed in a stainless steel autoclave having an internal volume of 3000 ml.
6,6-pentamethylpiperidinyl) sebacate 30
A portion was charged and nitrogen gas was blown into the autoclave to replace the air in the autoclave. Next, this autoclave is heated to 75 ° C.
To 1500 parts of chlorotrifluoroethylene,
390 parts of ethyl vinyl ether, 210 parts of 2-hydroxyethyl vinyl ether, 600 parts of "Veova-9" (vinyl ester of branched aliphatic carboxylic acid having 9 carbon atoms manufactured by Shell Co., Netherlands), p-tert-butylbenzoic acid. 300 parts vinyl, 600 parts orthoxylene, te
A mixture of 240 parts of rt-butyl peroxypivalate was added dropwise over 8 hours. Then, the temperature was maintained for 1 hour, and tert-butyl peroxypivalate
After adding 5 parts and continuing the reaction at the same temperature for 8 hours to complete the polymerization reaction, the hydroxyl value was 40 (mg
KOH / g) to obtain a solution (D'-4) (nonvolatile content: 54.5%) of a thermosetting fluororesin (D-4) having a number average molecular weight of 5,800. Property values are shown in Table 1 (3).

[0151]

[Table 3]

[0152] << Footnotes in Table 1 >> CTFE ・ ・ ・ ・ ・ ・ Chlorotrifluoroethylene Eve: Ethyl vinyl ether HEVE ... 2-hydroxyethyl vinyl ether "Veova-9" --- C9 branched aliphatic vinyl carboxylate made by Shell in the Netherlands Luster VTB: p-tert-butyl vinyl benzoate TBPV ... tert-Butyl peroxypivalate o-Xy ... Orthoxylene

Reference Example 5 (Preparation Example of Powder Coating Raw Material Solution) A thermosetting acrylic resin (D-) obtained in Reference Example 1 was placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet. 1430 parts of the solution (D'-1) of 1), 660 parts of methyl ethyl ketone, and 60 parts of isopropyl alcohol.
0 parts were charged, 70 parts of "MS51" (condensation product of tetramethyl silicate manufactured by Mitsubishi Chemical Corporation) as a silicate compound (A), 175 parts of dodecanedioic acid as a curing agent (E), and a high boiling point while stirring. As a solvent (C1) 4 parts of butyl carbitol, 5 parts of benzoin, "acronal"
4F "(flow control agent manufactured by BASF, Germany) was added, until the raw materials were uniformly dissolved and the solution became transparent,
The powder coating material solution (S-1) was prepared by sufficiently stirring and mixing. The obtained powder coating material solution (S
The property values of -1) are shown in Table 4 (1).

Reference Example 6 (Preparation example of powder coating material solution in which pigment is dispersed) Thermosetting acrylic resin solution (D'-) obtained in Reference Example 1
1) In 1430 parts, as a pigment, "Taipec CR-9
0 "(Rutile titanium oxide manufactured by Ishihara Sangyo Co., Ltd.) 43
A white pigment-dispersed resin solution was prepared by adding 0 part and dispersing with a sand mill.

Then, the prepared white pigment-dispersed resin solution, 1200 parts of methyl ethyl ketone and 700 parts of isopropanol were charged into a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet, and the silicate compound ( As A), "MS51" (Mitsubishi Chemical Corporation)
85 parts of a condensate of tetramethyl silicate), 175 parts of dodecanedioic acid as a curing agent (B), 5 parts of butyl carbitol as a high boiling point solvent (C1), 5 parts of benzoin and "Acronal 4F" (Germany). 5 parts of a flow control agent manufactured by BASF Japan) was added and further stirred sufficiently to obtain a colored powder coating material raw material solution (S-2). Property values of this solution (S-2) are shown in Table 2 (1).

Reference Example 7 (Preparation of Powder Coating Raw Material Solution in which Pigment is Dispersed) Thermosetting polyester resin (D-
2) 854 parts were crushed and dissolved in 1000 parts of ethyl acetate. Next, as a pigment, "Taipec CR-9
430 parts of "0" was added and the pigment was dispersed with a sand mill to prepare a white pigment dispersion solution.

Further, to this solution, the kind and amount of the silicate compound (A), the curing agent (E), the high boiling point solvent (C1) and various additives shown in Table 2 (2) and ethyl acetate 170 were added.
A colored powder coating material solution (S-3) was obtained by adding 0 part and stirring sufficiently. Property values are shown in Table 2 (2).

Reference Example 8 (same as above) Thermosetting polyester resin (D), silicate compound (A), curing agent (E), high boiling point solvent (C1), and various additives and organic solvent (C) A colored powder coating material solution (S-4) was obtained in the same manner as in Reference Example 7 except that the changes were made as shown in Table (2). Property values are shown in Table 2 (2).

Reference Example 9 (same as above) Thermosetting fluororesin solution (D'-) obtained in Reference Example 4
4) "Taipec CR-90" 430 on 1540 copies
Parts were added and dispersed by a sand mill to prepare a pigment-dispersed resin solution.

Next, in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet, 1460 parts of the pigment dispersion resin solution prepared, methyl ethyl ketone, and high-boiling solvent (C1), dipropylene glycol monoethyl ether. 5 parts and 1 part of "Solvesso 150" (manufactured by Exxon Corporation, aromatic hydrocarbon-containing mixed hydrocarbon solvent) were charged, and the temperature was raised to 30 ° C. As a silicate compound (A) with stirring, "MS56" (manufactured by Mitsubishi Chemical Corporation,
Condensation product of tetramethyl silicate) 80 parts, as curing agent (E) "Vestagon B1530" (block isocyanate compound manufactured by Huls in Germany) 160
Parts, 5 parts of benzoin and 5 parts of "Modaflow" (flow control agent manufactured by Monsanto, USA) were added and further stirred for 30 minutes to obtain a powder coating material solution (S-5). Property values of this solution (S-5) are also shown in Table 2 (3).
Shown in.

Reference Example 10 (Preparation Example of Organic Solvent Solution in which Thermosetting Resin (D) and Silicate Compound (A) are Dissolved) Thermosetting polyester resin (D-
3) 1140 parts were crushed and this was dissolved in 2400 parts ethyl acetate. Next, 120 parts of "ethyl silicate 40" (a tetraethyl silicate condensate having a property of Colcoat (corporation)) as the silicate compound (A) and 6 parts of dipropylene glycol monoethyl ether as the high boiling point solvent (C1) were added sufficiently. The organic solvent solution (M) was obtained by stirring. Property values are shown in Table 2 (4).

[0162]

[Table 4]

[0163]

[Table 5]

[0164]

[Table 6]

[0165]

[Table 7]

<< Footnotes in Table 2 >>"MS51" ... Tetramethyl silicate condensate "40" manufactured by Mitsubishi Chemical Co., Ltd. Tetraethyl silicate condensate "Ethyl silicate 40 manufactured by Colcoat Co., Ltd.""MS56S" ... Tetramethyl silicate condensate manufactured by Mitsubishi Chemical Co., Ltd. "MS56" ... Tetramethyl silicate condensate manufactured by Mitsubishi Chemical Co., Ltd. "B1530" ... Made by Huls in Germany "VESTA
GON B1530 "(blocked isocyanate compound in the form of a nurate of isophorone diisocyanate blocked with ε-caprolactam)

"BF1540" ... "VESTAGON BF1540" manufactured by Huls in Germany (blocked isocyanate compound in the form of self-blocking isophorone diisocyanate with uretdione bond) "XL-552" ... Switzerland Acid amide compound “PRIMID XL-552” manufactured by MUS

DPGME: dipropylene glycol monoethyl ether "CR-90": rutile type titanium oxide "Taipec CR-90" manufactured by Ishihara Sangyo Co., Ltd. "Acronal 4F" ... manufactured by BASF, Germany , A flow control agent "Modaflow" ... manufactured by Monsanto, USA Flow control agent "Solvesso 150" ... mixed hydrocarbon solvent containing aromatic hydrocarbons manufactured by Exxon, USA

Example 1 (Production of Powder Coating Material of the Present Invention by Spray Drying Method) An explosion-proof vertical descending cocurrent spray drying apparatus equipped with a solvent recovery apparatus was used, and powder was produced using a two-fluid nozzle method as the spraying method. Body paint was produced. The atomizing gas pressure was set to 0.3 MPa, nitrogen gas was used as the heat source gas, and the raw material solution and the heat source gas were brought into contact with each other in a vertically descending cocurrent manner. The temperature of the heat source gas was set to 45 ° C. Powder coating raw material solution (S
-1) was sprayed into the spray drying device at a supply rate of 1 kg / hr, and the particles of the powder coating material dried in the device were collected by a cyclone to obtain a powder coating material having an average particle diameter of 17 μm. Most of the particles had a spherical shape. The nonvolatile content of the obtained powder coating material was 99.4%, and the content of butyl carbitol, which is a high boiling point solvent (C1), was measured and found to be 0.35% by weight.

Examples 2 to 5 (same as above) Powder coating raw material solutions (S-2) to (S-5) were used in place of the powder coating raw material solution (S-1), and a preliminary powder coating raw material solution was prepared. The heating temperature and the temperature of the heat source gas are shown in Table 3 (1),
Powder coatings (P-2) to (P-5) were obtained in the same manner as in Example 1 except that the changes were made as shown in (2). Property values of the obtained powder coating material are also shown in Table 3 (1) and (2).

[0171]

[Table 8]

[0172]

[Table 9]

Example 6 (Production Example of Powder Coating Material of the Present Invention by Melt Kneading Method) Thermosetting polyester resin (D-
2) 854 parts were crushed and "MS51" (Mitsubishi Chemical Corporation)
100 parts of tetramethyl silicate condensate manufactured by
"Vestagon B1530" (block isocyanate compound manufactured by Huls in Germany) 103 parts, "Vestagon BF1540" (block isocyanate compound manufactured by Huls in Germany) 43 parts, "Taipec C"
R-90 "(rutile titanium oxide manufactured by Ishihara Sangyo Co., Ltd.) 430 parts, benzoin 5 parts," Acronal 4 "
"F" (flow control agent manufactured by BASF, Germany) and 5 parts of butyl carbitol as a high boiling point solvent (C1) were added, and then a "Henschel mixer" (driving blender manufactured by Mitsui Miike Kakoki Co., Ltd.) was used. , After mixing, "MP-2
015 ”(a twin-screw extruder kneader manufactured by APV Chemical Machinery, USA). By crushing and classifying the obtained kneaded product, an average particle size of 2
A powder coating (P-6) of 3 μm was obtained. High boiling point solvent (C1)
When the content of butyl carbitol which is
It was 0.31% by weight.

Example 7 (same as above) The organic solvent solution (M) obtained in Reference Example 10 was used in Example 4
By spray drying in the same manner as above, particles of a mixture of the base polyester resin (D-3) and the silicate compound (A) were obtained. 1055 parts of particles of the obtained mixture, 50 parts of "Primid XL-552" (an acid amide compound manufactured by Ems in Switzerland), "Taipec CR-90" 43
After mixing 0 parts, 5 parts of benzoin, and "Acronal 4F" (fluidity regulator manufactured by BASF, Germany) with a "Henschel mixer" (Dry blender manufactured by Mitsui Miike Kakoki Co., Ltd.) , "MP-2015" (a twin-screw extruder kneader manufactured by APV Chemical Machinery, USA). The obtained kneaded product,
By pulverizing and classifying, a powder coating material (P-7) having an average particle diameter of 21 μm was obtained. The content of dipropylene glycol monoethyl ether, which is a high boiling point solvent (C1), was measured and found to be 0.30% by weight.

Comparative Reference Example 1 (Production Example of Powder Coating by Mechanical Grinding Method) Thermosetting polyester resin (D-
2) Crush 854 parts of "ethyl silicate 40"
(Tetraethyl silicate condensate manufactured by Colcoat Co., Ltd.) 100 parts, "Vestagon B1530" (blocked isocyanate compound manufactured by Huls, Germany) 1
03 parts, "Vestagon BF1540" (block isocyanate compound manufactured by Hüls, Germany) 43 parts,
"Taipeque CR-90" (Rutile titanium oxide manufactured by Ishihara Sangyo Co., Ltd.) 430 parts, benzoin 5 parts, "Acronal 4F" (flow control agent manufactured by BASF Germany) was added, and "Henschel mixer" was added. After mixing with (Drybender made by Mitsui Miike Kakoki Co., Ltd.),
The mixture was heated and kneaded by "MP-2015" (a twin-screw extruder kneader manufactured by APV Chemical Machinery, USA). By crushing and classifying the obtained kneaded product,
A powder coating material (P-8) having an average particle diameter of 25 μm was obtained.

Example 8 (Properties of cured coating film of powder coating material of the present invention) White alkyd melamine solvent-based coating material was spray-coated to a thickness of 30 μm on a 0.8 mm thick zinc phosphate-treated steel sheet. After baking and curing at 160 ° C for 20 minutes,
On top of that, 60 parts of the powder coating material (P-1) obtained in Example 1 was added.
Electrostatic coating was performed so that the film thickness was μm. A coated plate was obtained by baking and curing the coated test plate at 160 ° C. for 20 minutes. The evaluation results of the powder coating and the obtained cured coating film are shown in Table 4 (1).

Example 9 (same as above) The powder coating material (P-2) obtained in Example 2 was electrostatically coated on a 0.8 mm thick zinc phosphate-treated steel plate to a film thickness of 60 μm. A coated plate was obtained by baking and curing the coated test plate at 160 ° C. for 20 minutes. The properties of the obtained cured coating film are shown in Table 4 (1).

Examples 10 to 14 (same as above) The powder coating materials used and the baking and curing temperature are shown in Table 4 (1).
A coated plate was obtained in the same manner as in Example 7 except that the changes were made as shown in (3) to (3). The properties of the obtained cured coating film are shown in Table 4 (1) to (3).

Comparative Example 1 A coated plate was obtained in the same manner as in Example 9 except that the powder coating material used was the powder coating material (P-8) obtained in Comparative Reference Example 1. The evaluation results of the powder coating material and the obtained cured coating film are shown in Table 4 (3).

[0180]

[Table 10]

[0181]

[Table 11]

[0182]

[Table 12]

<< Footnote in Table 4 >>

Smoothness: The smoothness of the coating film was visually evaluated. Evaluation 5: Evaluation of smooth and smooth coating surface 4: Evaluation of small rounds 3: Evaluation of large rounds 2: Evaluation of large rounds with many fine dust skin Evaluation 1: Large rounds When there is a large amount of fine dusty skin and the appearance of the coating film is greatly impaired

Vividness ... A coating plate was placed under the light of a fluorescent lamp, and the image quality of the fluorescent lamp reflected on the surface of the coating film was judged. Evaluation 5: The border of the image is clear and there is no line bleeding 4: The border is slightly blurred 3: The border is blurred 2: The border is difficult to discriminate 1: The border is indistinguishable

Presence / absence of coating film defects ...
Number of coating defects such as dents and pinholes (Coating plate 1
(Per 00 square cm). Evaluation ◎: 0 evaluation ○: 1-2 evaluation Δ: 3-10 evaluation ×:> 10

Coating film gloss: Measured from the specular gloss of JIS-K5400.

Applicability for thick coating: Presence or absence of coating film defects when a coating film is formed by electrostatic coating so that the film thickness is 120 μm, the presence of cracks, dents, pinholes, etc. on the coating surface The number of coating film defects (per 100 square cm of coated plate) was determined. Evaluation ◎: 0 evaluation ○: 1-2 evaluation Δ: 3-10 evaluation ×:> 10

· Contamination ····· 1 liter of water, JIS
5g of 12 kinds of mixed dust [product of Japan Powder Industrial Technology Association] for the pollution test specified in Z-8901
Each test plate was immersed in suspension water consisting of 10 minutes, then pulled up, and then shower-washed for 2 minutes as one cycle, and a repeated test was performed for a predetermined number of cycles. Was dried, and the color difference (ΔE) from the untested test plate was measured. The larger the ΔE value, the greater the degree of contamination.

· Storage stability ······················· produced paint was left in a thermostat at 30 ° C. for 2 weeks, and then judged again by coating workability when the paint was sprayed. Evaluation ◯: No problem evaluated Δ: Difficulty in spraying due to the formation of some aggregates ×: Impossible to spray

[0191]

【The invention's effect】

As is clear from the detailed description above, the powder coating material according to the present invention is particularly excellent in the exposure stain resistance of the coating film and, in addition, is excellent in the appearance of the coating film. The manifestation of various effects aimed at by the present invention is recognized.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 183/02 C09D 183/02 F term (reference) 4J038 CD091 CD101 CD111 CD121 CD131 CE051 CG001 CH031 CH041 CH071 CH141 CJ011 CJ021 CJ061 CJ101 CJ131 DA132 DB001 DB002 DD001 DD051 DG001 DG262 DL021 GA03 GA06 GA07 GA08 GA11 GA12 GA15 KA03 KA06 MA02 NA01 NA05 NA23 PA02 PB05 PC02

Claims (7)

[Claims] 1. A silicate compound (A) represented by the following general formula (I), a resin composition (B), and a high boiling point solvent (C1) having a boiling point of 150 to 300 ° C. under normal pressure. , Powder coatings. [Chemical 1] (In the formula, n is an integer of ₁ to 20, R _{1 to} R ₄ are each independently an alkyl group having 1 to 9 carbon atoms) 2. An organic solvent containing a silicate compound (A) represented by the following general formula (I), a resin composition (B), and a high boiling point solvent (C1) having a boiling point of 150 to 300 ° C. under normal pressure. Obtained by spray-drying a powder coating material solution containing (C) as an essential component, and having an average particle size of 5 to 50 μm.
m, a powder coating having an average circularity of 0.9 or more. [Chemical 2] (In the formula, n is an integer of ₁ to 20, R _{1 to} R ₄ are each independently an alkyl group having 1 to 9 carbon atoms) 3. The powder coating composition according to claim 1, wherein the high boiling point solvent (C1) has a solubility in water and toluene at 25 ° C. of 50% by weight or more. 4. The powder according to claim 1, wherein the resin composition (B) is a thermosetting resin composition comprising a thermosetting resin (D) and a curing agent (E). paint. 5. The thermosetting resin (D) is an acrylic resin,
The powder coating material according to any one of claims 1 to 4, which is at least one selected from the group consisting of polyester resins and fluororesins. 6. A coating film forming method for forming a single-layer or multi-layer coating film on an object to be coated, characterized in that the powder coating material according to any one of claims 1 to 5 is used. , Coating film forming method. 7. A coated article having a coating film formed by the method for forming a coating film according to claim 6.