JPH0539402A - Curable composition - Google Patents

Abstract

(57) [Abstract] [Purpose] Improving the sag performance (performance capable of forming a thick film without sagging with a single coating) of a curable composition used for painting requiring durability and aesthetics. . [Structure] Acrylic copolymer containing alkoxysilyl group or acrylic resin (A) having the copolymer and hydroxyl group
, The curable catalyst (B) and the organic solvent (C),
The specific crosslinked polymer fine particles (D) which were insoluble and stably dispersed in the component (A), the component (B) and the component (C) were blended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is applicable to various coatings such as building exteriors, automobiles, industrial machines, steel furniture, home appliances, plastics, etc. It relates to a composition.

[0002]

2. Description of the Related Art Durability and aesthetics are required for exterior coating materials, heavy-duty anticorrosive applications, top coatings for automobiles and the like. Thick film coating is used as a means to improve aesthetics, but conventional coating compositions have poor sagging performance and at most 30μ per coating.
Only a coating film with a thickness of m is obtained, and two coatings are necessary to secure a film thickness of 50 μm or more.

For this reason, a method of adding fine particles of a crosslinked polymer for the purpose of improving the sag of an acrylic melamine paint (Japanese Patent Publication No. 2629/1990, Japanese Patent Publication No. 58906/1983, Japanese Patent Publication No. 97026/1983). Has been reported. However, with this method, the effect of improving the sag of the acrylic melamine paint is recognized, but the effect is not sufficient, and the effect of improving the sag of the alkoxysilyl group-containing acrylic copolymer paint is hardly recognized.

As described above, it is desired to form a thick film by one-time coating not only for labor saving but also for resource saving. However, the conventional method cannot sufficiently thicken the film. It is not satisfactory, and there is a demand for a technique capable of forming a thick film for an acrylic copolymer coating containing an alkoxysilyl group.

[0005]

The inventors of the present invention have found that an alkoxysilyl group-containing acrylic copolymer or a mixture of an alkoxysilyl group-containing acrylic copolymer and an acrylic resin having a hydroxyl group has durability and chemical resistance. , Has found that the coating film has excellent appearance and solvent resistance, and has already applied for a patent, but as a result of further studies on thickening the film,
Addition of crosslinked polymer fine particles obtained by polymerization in the presence of a polymer having a glass transition temperature of 10 ° C. or less makes it possible to significantly increase the alkoxysilyl group-containing acrylic copolymer paint unpredictably by conventional methods. The inventors have found that the sagging performance and appearance are improved, and have completed the present invention.

That is, the present invention relates to the general formula (A) (a1):

[0007]

[Chemical 2]

(Wherein R ¹ is an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
Alkoxysilyl group-containing acrylic copolymer having a group represented by a monovalent hydrocarbon group selected from the group consisting of an aryl group and an aralkyl group, a is 0, 1 or 2, or (a2) the alkoxysilyl Group-containing acrylic copolymer and hydroxyl group-containing acrylic resin, (B) curing catalyst, (C) organic solvent and (D) (A) component, (B) component and (C) component insoluble and composition Crosslinked polymer fine particles which can be stably dispersed in the system in the case of the above, and are 50 parts by weight or more of at least one alkyl acrylate ester having an alkyl group having 2 to 8 carbon atoms (parts by weight; Of 0.05 to 5 parts of other monomers, 0 to 49.95 parts of other (meth) acrylic monomers, and 0 other monomers copolymerizable therewith
To at least 20 parts, in the presence of a polymer (stem polymer) having a glass transition temperature of 10 ° C. or lower, at least one alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms
Crosslinked polymer fine particles obtained by polymerizing a monomer mixture of 40 parts or more, 0 to 60 parts of another (meth) acrylic acid ester, and 0 to 60 parts of another monomer copolymerizable therewith. It relates to a curable composition.

[0009]

EXAMPLE The composition of the present invention has the following formula (a1) as the component (A):

[0010]

[Chemical 3]

An alkoxysilyl group-containing acrylic copolymer having a group represented by or (a2) the alkoxysilyl group-containing acrylic copolymer and an acrylic resin having a hydroxyl group are used.

Since the above-mentioned alkoxysilyl group-containing acrylic copolymer has the alkoxysilyl group represented by the above formula, it undergoes a hydrolysis reaction and a silanol condensation reaction with water to crosslink.

In the above formula, R ¹ is an alkyl group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. When the number of carbon atoms exceeds 10, the reactivity of the alkoxysilyl group decreases, and when R ¹ is other than an alkyl group, for example, a phenyl group or a benzyl group, the reactivity also decreases. Specific examples of R ¹ include, for example, methyl group, ethyl group, n-propyl group, iso-propyl group, n-
Examples thereof include a butyl group and an iso-butyl group.

In the above formula, R ² is a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms, an aryl group and an aralkyl group.

Specific examples of the alkyl group having 1 to 10 carbon atoms which is one kind of R ² include the same groups as R ^1, and specific examples of the aryl group include, for example, phenyl group, Specific examples of the aralkyl group include benzyl group and the like.

In the above formula, a represents 0, 1 or 2.

Specific examples of the alkoxysilyl group represented by the above general formula include groups contained in the alkoxysilyl group-containing monomer described later.

The number of alkoxysilyl groups in the molecule of the alkoxysilyl group-containing acrylic copolymer is at least 1, preferably 2 or more. If the number is less than 1, the coating obtained from the composition of the present invention will be used. The solvent resistance of the film tends to decrease. The alkoxysilyl group may be at the terminal of the polymer, may be at the side chain, or may be at the terminal and side chain.

Since the main chain of the alkoxysilyl group-containing acrylic copolymer is substantially composed of the acrylic copolymer chain, the weather resistance, chemical resistance and water resistance of the cured product are improved. Further, since the alkoxysilyl group is bonded to a carbon atom, the water resistance, alkali resistance, acid resistance and the like of the cured product are improved.

The number average molecular weight of the alkoxysilyl group-containing acrylic copolymer is preferably 1,000 to 30,000, from the viewpoint of physical properties such as durability of the coating film obtained from the composition of the present invention.
More preferably, it is 3,000 to 25,000.

The alkoxysilyl group-containing acrylic copolymer can be obtained, for example, by copolymerizing acrylic acid, methacrylic acid, or a derivative thereof with an alkoxysilyl group-containing monomer.

The derivative of acrylic acid or methacrylic acid is not limited, and specific examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (Meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-methylol (meth) acrylamide, Aronix M-5700 manufactured by Toagosei Chemical Industry Co., Ltd. AS-6 is a macromer of Toagosei Chemical Industry (Ltd.), AN-6, AA-6, AB-6,
AK-5, Placcel FA-1, Plac manufactured by Daicel Chemical Industries, Ltd.
α, β- such as cel FA-4, Placcel FM-1, Placcel FM-4, hydroxyalkyl esters of (meth) acrylic acid
Examples thereof include phosphoric acid ester group-containing vinyl compounds, which are condensation products of hydroxyalkyl esters of ethylenically unsaturated carboxylic acids and phosphoric acid or phosphoric acid esters, and (meth) acrylates containing a urethane bond or a siloxane bond. When the hydroxyl group-containing monomer is used, it is preferably used in a small amount (for example, 5% (% by weight in the copolymer, the same applies hereinafter) or less).

The alkoxysilyl group-containing monomer is not particularly limited except that it is a monomer having a polymerizable unsaturated double bond and an alkoxysilyl group, and specific examples thereof include

[0024]

[Chemical 4]

Etc.

[0026]

[Chemical 5]

(In the formula, n represents an integer of 0 to 20) and the like, and (meth) acrylate having an alkoxysilyl group at the terminal via a urethane bond or a siloxane bond can be mentioned. These alkoxysilyl group-containing monomers are 1
The seeds may be used, or two or more kinds may be used in combination.

The proportion of the units derived from these alkoxysilyl group-containing monomers in the alkoxysilyl group-containing acrylic copolymer is preferably 2 to 90% from the viewpoint of the curability of the composition and the durability of the coating film. ˜70% is more preferred.

The copolymer may contain a unit formed by a urethane bond or a siloxane bond in the main chain within a range of not more than 50%, and is derived from a monomer other than the (meth) acrylic acid derivative. The unit may be included.
The monomer is not limited, and specific examples thereof include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene and vinyltoluene; maleic acid, fumaric acid, Unsaturated carboxylic acids such as itaconic acid, their salts (alkali metal salts, ammonium salts, amine salts, etc.),
Esters of unsaturated carboxylic acids such as their acid anhydrides (maleic anhydride, etc.) or their diesters or half esters with linear or branched alcohols having 1 to 20 carbon atoms; vinyl acetate, vinyl propionate, diallyl Vinyl ester and allyl compounds such as phthalates; amino group-containing vinyl compounds such as vinyl pyridine and aminoethyl vinyl ether; amide group-containing vinyl compounds such as itaconic acid diamide, crotonamide, maleic acid diamide, fumaric acid diamide and N-vinylpyrrolidone; 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene,
Other vinyl compounds such as isoprene, fluoroolefin, maleimide, N-vinylimidazole, vinylsulfonic acid and the like can be mentioned.

The alkoxysilyl group-containing acrylic copolymer can be produced, for example, by the method disclosed in JP-A-54-36395, but from the viewpoint of ease of synthesis, azobisisobutyronitrile and the like. Most preferably, it is produced by a solution polymerization method using the azo radical initiator.

In the solution polymerization, if necessary, n-
Dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane,
γ-mercaptopropylmethyldiethoxysilane,

[0032]

[Chemical 6]

The molecular weight can be adjusted by using a chain transfer agent such as. Particularly, by using a chain transfer agent having an alkoxysilyl group in the molecule, for example, γ-mercaptopropyltrimethoxysilane, the alkoxysilyl group can be introduced at the terminal of the alkoxysilyl group-containing acrylic copolymer.

The polymerization solvent used for the solution polymerization is hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.), acetic acid esters (ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, etc.). n-butanol, etc.), ethers (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol,
There is no particular limitation as long as it is a non-reactive solvent such as methyl isobutyl ketone and acetone.

Such an alkoxysilyl group-containing acrylic copolymer may be used alone or in combination of two or more.

As the component (A) used in the present invention, an acrylic resin having a hydroxyl group is used together with the above-mentioned alkoxysilyl group-containing acrylic copolymer in order to further improve coating properties such as hardness immediately after baking and solvent resistance. You may.
Since the main chain of the acrylic resin having a hydroxyl group is substantially composed of an acrylic copolymer chain, weather resistance, chemical resistance, water resistance and the like of the cured product are improved.

There is no particular limitation on the molecular weight of the acrylic resin having a hydroxyl group, and any conventionally used one can be used, but the physical properties of the coating film such as durability (the coating formed from the composition of the present invention can be used. The number average molecular weight is
It is preferably from 1,500 to 40,000, more preferably from 3,000 to 25,000, and preferably has a hydroxyl group that can be sufficiently crosslinked, and has a hydroxyl value from the viewpoint of coating film physical properties such as strength and durability. It is preferably 10 to 300 mg KOH / g, more preferably 30 to 150 mg KOH / g.

The hydroxyl group-containing acrylic resin can be obtained, for example, by copolymerizing a hydroxyl group-containing vinyl monomer with acrylic acid, methacrylic acid, or a derivative thereof.

Examples of the hydroxyl group-containing vinyl monomer include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether and N-methylol (meth).
Acrylamide, Aronix 5700, 4-hydroxystyrene manufactured by Toagosei Chemical Industry Co., Ltd., HE-10, HE-20, HP-10 and HP-20 manufactured by Nippon Shokubai Chemical Co., Ltd. Acrylic ester oligomers), NOF CORPORATION, BLEMMER PP series (polypropylene glycol methacrylate), BLEMMER PE
Series (Polyethylene glycol monomethacrylate), Bremmer PEP series (Polyethylene glycol polypropylene glycol methacrylate), Bremmer AP-400 (Polypropylene glycol monoacrylate), Bremmer AE-350 (Polyethylene glycol monoacrylate), Bremmer NKH-5050 (Polypropylene glycol polytri) Methylene monoacrylate) and Blemmer GLM (glycerol monomethacrylate),
Examples thereof include ε-caprolactone-modified hydroxyalkylvinyl-based monomers obtained by the reaction of a hydroxyl group-containing vinyl compound and ε-caprolactone.

Typical examples of the above-mentioned ε-caprolactone-modified hydroxyalkylvinyl-based monomer include those represented by the formula:

[0041]

[Chemical 7]

Placcel FA-1 (R = H, n = 1) manufactured by Daicel Chemical Industries, Ltd. having a structure represented by the formula (wherein R is H or CH ₃ , and n is an integer of 1 or more). , Placcel FA-4 (R
= H, n = 4), Placcel FM-1 (R = CH ₃ , n = 1) and Placcel
FM-4 (R = CH ₃ , n = 4), UCC Co., Ltd.TONE M-100 (R = H,
n = 2), TONE M201 (R = CH ₃ , n = 1) and the like. By using ε-caprolactone-modified hydroxyalkylvinyl-based monomer as the hydroxyl group-containing vinyl-based monomer, impact resistance and flexibility of the coating film can be improved.

These hydroxyl group-containing vinyl monomers are 1
The seeds may be used, or two or more kinds may be used in combination.

The acrylic acid or methacrylic acid derivative copolymerizable with the hydroxyl group-containing vinyl monomer is not particularly limited, and specific examples thereof include methyl (meth).
Acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoro Propyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth ) Acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, N-methylol (meth Acrylamide, AS-6, AN-6 is a macromer made of Toagosei Chemical Industry (Ltd.), AA-
6, AB-6, AK-5, Condensation products of hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as hydroxyalkyl esters of (meth) acrylic acid with phosphoric acid or phosphoric acid esters Examples thereof include a vinyl compound containing a phosphoric acid ester group and a (meth) acrylate containing a urethane bond or a siloxane bond.

The copolymer may contain a unit formed by a urethane bond or a siloxane bond in the main chain within a range not exceeding 50%, and is derived from a monomer other than the (meth) acrylic acid derivative. The unit may be included.
The monomer is not limited, and specific examples thereof include styrene, α-methylstyrene, chlorostyrene,
Aromatic hydrocarbon vinyl compounds such as styrenesulfonic acid and vinyltoluene; unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid, their salts (alkali metal salts, ammonium salts, amine salts, etc.), those Acid anhydrides (maleic anhydride, etc.), or esters of unsaturated carboxylic acids such as diesters or half esters of them with linear or branched alcohols having 1 to 20 carbon atoms; vinyl acetate, vinyl propionate, diallyl phthalate Vinyl esters and allyl compounds; vinylpyridine, amino group-containing vinyl compounds such as aminoethyl vinyl ether; itaconic acid diamide, crotonamide,
Amide group-containing vinyl compounds such as maleic acid diamide, fumaric acid diamide and N-vinylpyrrolidone; methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide,
Other vinyl compounds such as N-vinyl imidazole and vinyl sulfonic acid are listed.

The acrylic resin having a hydroxyl group is preferably produced by a solution polymerization method using an azo radical initiator such as azobisisobutyronitrile for ease of synthesis.

In solution polymerization, a chain transfer agent such as n-dodecyl mercaptan, t-dodecyl mercaptan or n-butyl mercaptan can be used to adjust the molecular weight, if necessary. The polymerization solvent is not particularly limited as long as it is a non-reactive solvent. Further, the acrylic resin having a hydroxyl group may be a non-aqueous dispersion type in which insoluble polymer particles are dispersed in a non-polar organic solvent such as heptane or pentane.

One kind of such acrylic resin having a hydroxyl group may be used, or two or more kinds thereof may be used in combination.

When an acrylic resin having a hydroxyl group is used as the component (A), the proportion of the acrylic resin having a hydroxyl group and the alkoxysilyl group-containing acrylic copolymer used is not particularly limited, but the weight ratio is from 9/1 to 1 / 9 is preferable, 8/2
More preferably, it is 2/8. If the proportion of the acrylic resin having a hydroxyl group exceeds 9/1, the water resistance of the coating film obtained from the composition of the present invention tends to decrease, and if it is less than 1/9, the characteristic of blending an acrylic resin having a hydroxyl group is It tends to be difficult to obtain.

Specific examples of the curing catalyst which is the component (B) used in the present invention include, for example, dibutyltin dilaurate,
Dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, polymers of dioctyltin maleate, organotin compounds such as tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, mono Decyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate,
Phosphoric acid or phosphate such as dioctyl phosphate and didecyl phosphate; propylene oxide,
Butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane,

[0051]

[Chemical 8]

Addition reaction product of epoxy compounds such as Cardura E manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 828 and Epicoat 1001 manufactured by Yuka Shell Epoxy Co., and phosphoric acid and / or mono-acidic phosphate ester Organic titanate compounds; organoaluminum compounds such as tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum; tetrabutylzirconate, tetrakis (acetylacetonato) zirconium, tetraisobutylzirconate, butoxytris (acetylacetonate) ) Organozirconium compounds such as zirconium; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid,
Acidic compounds such as phthalic acid, trimellitic acid, pyromellitic acid, their acid anhydrides and paratoluenesulfonic acid;
Amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine and dodecylamine; Mixtures or reaction products of these amines and acidic phosphates; Alkaline compounds such as sodium hydroxide and potassium hydroxide And so on.

Of these curing catalysts, organotin compounds,
Acidic phosphoric acid ester, mixture or reaction product of acidic phosphoric acid ester and amine, saturated or unsaturated polyvalent carboxylic acid or acid anhydride thereof, reactive silicon compound, organic titanate compound, organic aluminum compound, organic zirconium compound or these The mixture of is also preferable because of high activity.

Such a curing catalyst may be used alone or in combination of two or more kinds.

The amount of the curing catalyst used is not particularly limited, but is usually 0.1 to 20 relative to 100 parts of the solid content of the component (A).
Parts, preferably 0.1-10 parts. The amount of curing catalyst used
If it is less than 0.1 part, the curability tends to decrease, and if it exceeds 20 parts, the appearance of the coating film tends to deteriorate.

As the organic solvent which is the component (C), any non-reactive solvent can be used.

Specific examples of such an organic solvent include, for example, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols and ketones used in general paints and coating agents. , Esters, ethers, alcohol esters, ketone alcohols,
Examples thereof include ether alcohols, ketone ethers, ketone esters, ester ethers and the like.

In particular, it is preferable to use an alkyl alcohol or a hydrolyzable ester compound having a dehydrating effect as the solvent because the storage stability is improved.

The alkyl alcohol is preferably an alcohol having an alkyl group having 1 to 10 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol. , Te
rt-Butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, cellosolve and the like are used.

The amount of the solvent used varies depending on the molecular weight or composition of the component (A), and is adjusted according to the solid content concentration or viscosity required for practical use. The amount of the organic solvent used such as the alkyl alcohol is not particularly limited, but is usually 100 parts or less, preferably 0. 0, based on 100 parts of the solid content of the component (A).
5 to 50 copies.

When an alcohol, particularly an alkyl alcohol, is used in combination with a dehydrating agent, when the component (A) and the component (B) of the composition of the present invention are mixed and stored, the storage stability thereof is significantly improved.

Specific examples of the dehydrating agent include methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, and γ.
-Methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methyl silicate, ethyl silicate and the like hydrolyzable ester compounds.

The amount of the dehydrating agent used is not particularly limited,
It is usually 100 parts or less, preferably 50 parts or less, based on 100 parts of the solid content of the component (A).

The component (D) used in the present invention is insoluble in the above-mentioned components (A), (B) and (C), and can be stably dispersed in the system when formed into a composition. Is a crosslinked polymer fine particle. The crosslinked polymer fine particles are the above-mentioned component (A),
It is insoluble in the component (B) and the component (C) and can be stably dispersed in the system when it is made into a composition, and therefore imparts thixotropic properties to the composition. The term "stable dispersion" as used herein means that the crosslinked polymer fine particles may be in a state where they do not aggregate with each other until they are coated and cured after being mixed.

As the specific crosslinked polymer fine particles, for example, the fine particles described in US Pat. No. 3,678,133 are used. That is, 50 parts or more of at least one alkyl acrylate having an alkyl group having 2 to 8 carbon atoms, 0.05 to 5 parts of a crosslinkable monomer, 0 to 49.95 parts of another (meth) acrylic monomer and copolymerization with these. Other possible monomers 0
To 20 parts of a polymer having a glass transition temperature of 10 ° C. or less (stem polymer) (total amount of monomers of the stem polymer is 100 parts), and at least having an alkyl group having 1 to 4 carbon atoms. 1
A monomer mixture consisting of 40 parts or more of a particular type of methacrylic acid alkyl ester, 0 to 60 parts of another (meth) acrylic acid ester, and 0 to 60 parts of another monomer copolymerizable therewith (hereinafter referred to as a graft monomer). ) (100 parts by weight of the total amount of graft monomers) are fine particles of a cross-linked polymer.

The proportion of the trunk polymer in the crosslinked polymer fine particles is preferably 10 to 95%, more preferably 25 to 75%.
It is (as polymer solid content), and the trunk polymer used in the production of the crosslinked polymer fine particles is preferably in the state of an aqueous dispersion.

The average particle diameter of the crosslinked polymer fine particles insoluble in the components (A) to (C) is preferably 0.01 to 10 μm, more preferably 0.02 to 5 μm. If the average particle size is outside this range, the anti-sagging effect will be reduced. The crosslinked polymer fine particles have an average particle size of 10 μm or less and have a particle size that does not hinder coating film formation, and if desired, can be easily made fine by mechanical means.

The cross-linked polymer fine particles may be obtained by copolymerization in the presence of a stabilizer in a non-aqueous organic solvent in which emulsion polymerization method fine particles and aliphatic hydrocarbon monomers are dissolved but the polymer is not dissolved. Examples thereof include fine particles (hereinafter, referred to as NAD method fine particles) and the like, and the emulsion polymerization method is preferable from the viewpoint that a coating film with less deterioration in gloss can be easily formed. In the NAD method, the arm part needs to have a composition with a solubility parameter close to that of the solubility parameter of the non-aqueous organic solvent, and the core part needs to have a composition having a considerably different solubility parameter. Therefore, the composition of the cross-linked polymer synthesized is limited, and thus fine particles obtained by an emulsion polymerization method are preferable.

The acrylic acid alkyl ester for producing the trunk polymer used in producing the crosslinked polymer fine particles has a straight or branched chain alkyl group having an alkyl group having 2 to 8 carbon atoms. Acrylic acid ester having, for example, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, etc. can give. These monomers can be used alone or in combination. An acrylic acid alkyl ester having an alkyl group having 1 or 9 or more carbon atoms is not preferable because it has a high glass transition temperature.

The proportion of alkyl acrylate used for producing the trunk polymer is preferably 50 parts or more, and more preferably 70 parts or more.

Examples of the crosslinkable monomer include monomers having two or more radically polymerizable ethylenically unsaturated bonds in the molecule. Specific examples thereof include ethylene glycol diacrylate and diethylene glycol diacrylate. , Mono- or polyethylene glycol diacrylates such as triethylene glycol diacrylate, tetraethylene glycol diacrylate,
Mono- or polyethylene glycol dimethacrylate such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, divinyl benzene, diallyl phthalate, diallyl sebacate, triallyl triazine and other di or triallyl compounds Allyl compounds such as allyl methacrylate, allyl acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol Lutri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, glycerol allyloxydi (meth) acrylate, 1,1,1-trishydroxymethylethanedi (meth) acrylate, 1,1, 1-
Trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane di (meth) acrylate
Acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl cyanurate,
Examples thereof include triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, and allyl (meth) acrylate. These crosslinkable monomers may be used alone or in combination of two or more kinds. Particularly, it is preferable to use dimethacrylates or diacrylates of mono- or polyethylene glycol in order to enhance the swelling property of the monomer during the graft polymerization and improve the compatibility between the rubber and the resin. The amount of these crosslinkable monomers used is in the range of 0.05 to 5 parts, and if it exceeds 5 parts, the impact resistance will decrease.
By copolymerizing the crosslinkable monomer, the alkyl acrylate increases the gel content and reduces the swelling degree in the organic solvent.

Specific examples of the other (meth) acrylic monomers include, for example, methyl acrylate, alkyl acrylate having an alkyl group having 9 or more carbon atoms,
Acrylic acid aromatic esters such as phenyl acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid esters such as benzyl methacrylate, unsaturated nitriles such as acrylonitrile and methacrylonitrile, 2-ethylhexyl Methacrylate, stearyl (meth) acrylate,
Cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate , (Meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate, N-methylol (meth) acrylamide, Aronix M-5700 manufactured by Toagosei Co., Ltd., Toagosei Co., Ltd.
Macromers made by AS-6, AN-6, AA-6, AB-6, AK-5,
Placcel FA-1 and Placcel FA manufactured by Daicel Chemical Industries, Ltd.
-4, Placcel FM-1, Placcel FM-4, hydroxyalkyl esters of (meth) acrylic acid such as hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids with phosphoric acid or phosphoric acid esters Examples thereof include a phosphoric acid ester group-containing vinyl compound as a condensation product or (meth) acrylic acid esters such as (meth) acrylate having a urethane bond or a siloxane bond; and (meth) acrylic acid. However, the use of conjugated dienes in which a double bond is introduced into the main chain of the polymer reduces weather resistance and is not preferred. The glass transition temperature of the trunk polymer is 10 ° C.
Below, it is preferable to select a polymer or copolymer that can maintain a temperature of −10 ° C. or lower.

Specific examples of the other copolymerizable monomers include aromatic vinyl such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, bromostyrene, vinylcarbazole and its derivatives, methyl vinyl ether, Butyl vinyl ether, octyl vinyl ether, stearyl vinyl ether and other vinyl ethers, vinyl formate, vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl stearate, vinyl halides such as vinyl chloride and vinyl bromide, vinylidene chloride such as vinylidene chloride, vinylidene bromide and vinylidene fluoride, styrene sulfonic acid, 4-hydroxystyrene, aromatics such as vinyltoluene. Group hydrocarbon vinyl compounds; unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid, their salts (alkali metal salts, ammonium salts, amine salts, etc.), their acid anhydrides (maleic anhydride, etc.), Alternatively, unsaturated carboxylic acid esters such as diesters or half esters of them with linear or branched alcohols having 1 to 20 carbon atoms; vinyl group-containing vinyl compounds such as vinylpyridine and aminoethyl vinyl ether; itaconic acid diamide, croton Amide, maleic acid diamide, huma Amide group-containing vinyl compounds such as acid diamide and N-vinylpyrrolidone; 2-hydroxyethyl vinyl ether, cyclohexyl vinyl ether,
Other vinyl compounds such as chloroprene, propylene, isoprene, fluoroolefin, maleimide, N-vinylimidazole, vinylsulfonic acid and the like can be mentioned. However, the use of conjugated dienes in which a double bond is introduced into the main chain of the polymer reduces weather resistance and is not preferred. Further, it is preferable to select a polymer or copolymer that can maintain the glass transition temperature of the trunk polymer at 10 ° C or lower, preferably -10 ° C or lower.

To obtain an aqueous dispersion of the trunk polymer, a usual emulsion polymerization method is preferred. As the emulsifier, a usual anionic surfactant, nonionic surfactant or cationic surfactant can be used. As the initiator, known water-soluble peroxides, redox catalysts and the like can be used, and further, a polymerization degree regulator, a builder and the like can be added if necessary. The polymerization temperature can be selected from ordinary emulsion polymerization conditions, and 20 to 95 ° C is selected. However, if the polymerization temperature is too high, the molecular weight is lowered and the gel content is reduced, which is not preferable. Therefore, the preferred range is 30-70.
℃. Polymerization may be carried out at a constant polymerization temperature, or the temperature may be raised or lowered stepwise during the polymerization. The acrylic acid alkyl ester and the monomer copolymerizable therewith may be initially charged in the total amount, or the whole or a part thereof may be added to proceed the polymerization. Since the control of the polymerization temperature considerably affects the quality, it is preferable to carry out the polymerization while adding a part thereof.

The glass transition temperature of the trunk polymer is 10 ° C. or lower, preferably −10 ° C. or lower, from the viewpoint of impact resistance and cracking of the coating film.

In order to obtain the graft copolymer used in the present invention, 40 parts by weight or more of at least one methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, preferably, in the presence of the above-mentioned trunk polymer, preferably Over 60 copies, other (meta)
Acrylic ester 0-60 parts, preferably 0-50 parts, and a monomer mixture which can be copolymerized with these monomers 0-60 parts, preferably 0-50 parts (graft monomer) Polymerize.

The glass transition temperature of the graft layer in the graft copolymer is preferably 20 ° C. or higher from the viewpoint of hardness of the coating film and solvent resistance.

The proportion of the trunk polymer in the graft copolymer is not particularly limited, but if there is a large amount of the trunk polymer, it is not possible to cover the trunk polymer with the graft component and the particles tend to aggregate. However, it is not preferable because the surface property of the coated article after coating is not uniform, and as described above, preferably 10 to 95% in the graft copolymer, preferably 25 to
75%.

The number of carbon atoms of the alkyl group of the methacrylic acid alkyl ester is 1 to 4 from the viewpoint of glass transition temperature, and the alkyl group may be linear or branched. Methyl methacrylate is a typical example, ethyl methacrylate,
Examples thereof include propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and tert-butyl methacrylate. These monomers may be used alone or in combination of two or more.

Other (meth) used during graft polymerization
As the acrylic ester, those other than the methacrylic ester having an alkyl group having 1 to 4 carbon atoms used in the graft polymerization are used, and specific examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl. (Meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, glycidyl (meth ) Acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate Relate, Toagosei Chemical Industry Co., Ltd. of Aronikusu M-5700, AS-6 is a macromer of Toagosei Chemical Industry (Ltd.), AN-6, AA-6, AB-6,
AK-5, Placcel FA-1, Plac manufactured by Daicel Chemical Industries, Ltd.
α, β- such as cel FA-4, Placcel FM-1, Placcel FM-4, hydroxyalkyl esters of (meth) acrylic acid
Phosphate ester group-containing vinyl compound, which is a condensation product of hydroxyalkyl esters of ethylenically unsaturated carboxylic acid and phosphoric acid or phosphoric acid esters, or (meth) acryl such as (meth) acrylate containing urethane bond or siloxane bond Examples thereof include acid esters.

Specific examples of other copolymerizable monomers used in the graft polymerization include (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N. -Dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, N-methylol (meth) acrylamide, (meth) acrylonitrile, (meth) acrylic acid, styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, Aromatic hydrocarbon vinyl compounds such as vinyltoluene; unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid, salts thereof (alkali metal salts, ammonium salts, amine salts, etc.),
Those acid anhydrides (maleic anhydride, etc.), or esters of unsaturated carboxylic acids such as diesters or half esters of them with linear or branched alcohols having 1 to 20 carbon atoms; vinyl acetate, vinyl propionate, etc. Vinyl ester; amino group-containing vinyl compounds such as vinyl pyridine and aminoethyl vinyl ether; amide group-containing vinyl compounds such as itaconic acid diamide, crotonamide, maleic acid diamide, fumaric acid diamide and N-vinylpyrrolidone; 2-hydroxyethyl vinyl ether , Methyl vinyl ether, cyclohexyl vinyl ether,
Other vinyl compounds such as vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin, maleimide, N-vinylimidazole, vinylsulfonic acid and the like can be mentioned.

The total amount of the monomers for the graft polymerization may be added at once, or the total amount or a part thereof may be added continuously or intermittently to proceed the graft polymerization. Further, all the monomers may be used in a mixture, and may be polymerized while changing the composition as long as the properties of the obtained composition are not deteriorated.

The graft polymerization may be carried out subsequently after the production of the trunk polymer, or may be carried out again in another reactor. The trunk polymer is preferably used in the state of an aqueous dispersion, and may be polymerized with or without addition of an initiator, an emulsifier, a polymerization degree modifier and the like. Further, when it is added, it may be the same as or different from the drug used for producing the trunk polymer. Other conditions such as polymerization temperature may be the same or different, and may be changed during the process.

From the aqueous dispersion of the copolymer thus obtained, the polymer may be recovered by spray drying, or may be recovered by salting out and coagulating, filtering and washing with water, and then drying.

The amount of the crosslinked polymer fine particles to be blended is not particularly limited, but is usually 0.01 per 100 parts of the solid content of the component (A).
-40 parts, preferably 0.1-20 parts. If the compounding amount is too small, the composition tends to sag when coated, and if it is too large, the smoothness of the coating film is deteriorated and a product having a good finished appearance is difficult to obtain.

The composition of the present invention may contain a pigment. Specific examples of pigments include inorganic pigments such as titanium oxide, ultramarine blue, navy blue, zinc yellow, red iron oxide, yellow lead, lead white, carbon black, transparent iron oxide, aluminum powder; azo type, triphenylmethane type, quinoline type pigments. , Anthraquinone-based, phthalocyanine-based organic pigments, and the like.

The composition of the present invention may further contain additives such as a diluent, an ultraviolet absorber, a light stabilizer, an anti-settling agent, a leveling agent, etc. depending on the application; a fibrin such as nitrocellulose, cellulose acetate butyrate; Resins such as epoxy resin, melamine resin, vinyl chloride resin, chlorinated polypropylene, chlorinated rubber, polyvinyl butyral and polysiloxane may be added.

The composition of the present invention is applied to an object to be coated by a conventional method such as dipping, spraying, brush coating, etc., and if it does not contain a hydroxyl group-containing acrylic resin, it is normally dried to 180 ° C.
And those containing an acrylic resin having a hydroxyl group are usually
It can be cured at 30 ° C. or higher, preferably 55 to 350 ° C. Since the composition of the present invention has good sag performance, a coating film having a thickness of 50 μm or more can be formed by one coating, and the obtained coating film has excellent appearance. .

Next, the composition of the present invention was prepared based on Examples.
A more specific description will be given.

Production Example 1 (Synthesis of Alkoxy Copolymer Containing Alkoxysilyl Group) 45.9 parts of xylene was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing tube and a dropping funnel, and nitrogen was added. After the temperature was raised to 110 ° C. while introducing gas, the mixture (A-1) or (A-2) having the composition shown in Table 1 was added dropwise at a constant rate over 5 hours with a dropping funnel.

After the dropping of the mixture was completed, 0.5 parts of 2,2'-azobisisobutyronitrile and 5 parts of toluene were added dropwise at a constant rate over 1 hour. After completion of the dropping, the mixture was aged at 110 ° C. for 2 hours and then cooled, and xylene was added to the resin solution to adjust the solid content concentration to 60%. Obtained resin solution (A-1)
And the number average molecular weight of (A-2) is shown in Table 1.

[0092]

[Table 1]

Production Example 2 (Synthesis of Acrylic Resin Having Hydroxyl Group) In place of 45.9 parts of xylene in Production Example 1, butyl acetate was used.
31.3 parts and xylene 9.5 parts were charged, and the mixture (A-3) having the composition shown in Table 2 was added dropwise at a constant rate over 5 hours in the same manner as in Production Example 1.

[0094]

[Table 2]

After the addition of the mixture was completed, 0.2 parts of 2,2'-azobisisobutyronitrile and 3.8 parts of toluene were added dropwise over 1 hour. After the completion of dropping, react at 110 ° C for 2 hours, cool, and add xylene to the resin solution to adjust the solid content concentration.
Adjusted to be 60%. The obtained resin solution (A-3) has a hydroxyl value (mgKOH / g.solid) of 72 and a number average molecular weight of 6,000.
Met.

Production Example 3 (Production of fine particles of cross-linked polymer) Production of the trunk polymer: In order to obtain the trunk polymer (d-1 to 4), a stirrer, a thermometer, a reflux condenser and a nitrogen gas introducing pipe were used. The glass reactor provided was charged with the one shown in Table 3.

[0097]

[Table 3]

Then, while stirring in a nitrogen stream, the temperature was 55 ° C.
When heated to 50 ° C., the temperature inside the reactor increased after 45 minutes, so the reaction was continued for 8 hours while cooling and maintaining the temperature at 55 ° C. The yields of the obtained polymers (trunk polymers) were 98% for all three types. The particle diameter calculated from the turbidity of 546 mμ of this aqueous dispersion was 0.15 μ in all cases.

The aqueous dispersion was salted out and coagulated with calcium chloride, washed with water and methanol, and then dried with a vacuum dryer. The dried polymer was sampled in a 100-mesh stainless steel wire net and immersed in a toluene solvent for 48 hours in the dark. After that, the attached toluene was wiped off, the weight was measured, and the weight was measured again by drying with a vacuum dryer, and the swelling degree and the gel content were calculated by the following formulas.

[0100]

[Equation 1]

As a result, the swelling degree of this polymer was 10.1 and the gel content was 93%.

The glass transition temperature of the trunk polymer is (d-
1) is -54 ° C, (d-2) is -39 ° C, (d-3) is -66 ° C, (d-4)
Is 20 ° C.

Production of graft polymer: The equipment used for production of the trunk polymer was equipped with a monomer addition device, and the components shown in Table 4 (however, the trunk polymer aqueous dispersion was prepared using the stem weight shown in Table 6). Aqueous dispersion of the coalescence) was added, and the mixture of monomers (d'-1) or (d'-2) shown in Table 5 containing 0.2 part of kyumen hydroperoxide at 60 ° C with stirring in a nitrogen stream was prepared. Part of the solution was added dropwise over 4 hours for polymerization, and then maintained for 1 hour to complete the polymerization. The conversion rate was 95% in all cases.
To the obtained aqueous dispersion, 1 part of 2,6-ditertiarybutyl-p-cresol was added, and a calcium chloride solution was added to salt out and coagulate, followed by heating to granulate, dehydration, washing and drying. The crosslinked polymer fine particles (D-1) to (D-5) shown in 6 were obtained.

[0104]

[Table 4]

[0105]

[Table 5]

[0106]

[Table 6]

Production Example 4 (Production of Crosslinked Polymer Fine Particles) Stirrer, nitrogen introducing tube, temperature control device, condenser,
2 l Kolben equipped with a decanter, 134 parts of bishydroxyethyl taurine, 130 parts of neopentyl glycol,
236 parts of azelaic acid, 186 parts of phthalic anhydride and 27 parts of xylene were charged and the temperature was raised. Water generated by the reaction was removed by azeotropic distillation with xylene.

It takes about 2 hours from the start of reflux to bring the temperature to 190
The temperature was raised to 140 ° C., and stirring and dehydration were continued until the acid value corresponding to the carboxylic acid became 145, and then cooled to 140 ° C. Then, the temperature was maintained at 140 ° C., 314 parts of Cardura E10 (glycidyl ester of versatic acid manufactured by Shell Co.) was added dropwise over 30 minutes, and then stirring was continued for 2 hours to terminate the reaction.

The polyester resin thus obtained had an acid value of 59 and a hydroxyl value of 90.

10 parts of the obtained polyester resin and 0.75 part of dimethylethanolamine were charged, and the temperature was adjusted to 80 with stirring.
Dissolve it while maintaining it at ℃, and add 4.5 parts of azobiscyanovaleric acid to 45 parts of deionized water and dimethylethanolamine.
A solution dissolved in 4.3 parts was added. Then, a mixed solution consisting of 70.7 parts of methyl methacrylate, 94.2 parts of n-butyl acrylate, 70.7 parts of styrene, 30 parts of 2-hydroxyethyl acrylate and 4.5 parts of ethylene glycol dimethacrylate was added dropwise over 60 minutes. After dripping, 1.5 parts of azobiscyanovaleric acid was further dissolved in 15 parts of deionized water and 1.4 parts of dimethylethanolamine and added at 60 ° C at 80 ° C.
When stirring was continued for a minute, the nonvolatile content was 45%, pH 7.2, and viscosity.
An emulsion of 92 cps (25 ° C) was obtained. This emulsion was spray dried to give particles with a particle size of 0.8 μ (D-6).
.

Examples 1 to 6 and Comparative Examples 1 to 6 24 g of the resin solution (A-3), 24 g of CR-90 (titanium oxide manufactured by Ishihara Sangyo Co., Ltd.), 16 g of xylene and 20 g of glass beads were mixed with a paint shaker 3 times. Resin solution (A-1) after dispersion for a time
After adding 30 g and further dispersing for 1 hour, white enamel (white enamel (1)) having a solid content concentration of 60% was obtained.

Further, the resin solution (A-2) 60 g, CR-90 24 g,
16 g of xylene and 20 g of glass beads were dispersed with a paint shaker for 3 hours to obtain white enamel (white enamel (2)) having a solid content concentration of 60%.

The white enamel, crosslinked polymer fine particles, dioctyltin maleate and xylene were mixed in the proportions shown in Table 7 to prepare a coating material, and the dispersion stability coating film of the crosslinked polymer fine particles was prepared as follows. Appearance and sauce level,
The thickness and gloss of the dried coating was examined. The results are shown in Table 7. In addition, the effects of addition or non-addition of crosslinked polymer particles to the acrylic melamine coatings marketed in Comparative Examples 5 and 6 were examined. The results are shown in Table 7.

(Dispersion Stability of Crosslinked Polymer Fine Particles) White enamel in which crosslinked polymer fine particles are dispersed is stored at 50 ° C. for 1 minute.
After a month, visually check for the presence of aggregation. If there is no agglomeration, it is indicated as ○.

(Appearance) After paint was applied on an aluminum plate by flow coating, it was visually observed and judged according to the following criteria.

○: glossy (60 ° gloss 80 or more) ×: luster (60 ° gloss 60 or less) (sag tester sag level) Paint with a sag tester on a glass plate and stand immediately vertically. Evaluated by the sagging film thickness. 125μm with sag tester is 30μm of dry film thickness
Corresponding to a degree, 200 μm or more corresponds to 50 μm or more.

(Dry coating thickness) Minitest 2000 (Germany,
The thickness of the coating film on the aluminum plate was measured with Electro-Fijik Cologne Co., Ltd.).

(Dry coating gloss) The coating surface was painted on an aluminum plate and baked at 140 ° C. for 30 minutes, and the gloss value of the coating surface was measured according to JIS K 5400 manufactured by Murakami Color Research Laboratory Co., Ltd. It was measured using a GMX-202 color difference meter (60 ° gloss).

[0119]

[Table 7]

From the results shown in Table 7, in the composition of the present invention, by adding specific crosslinked polymer fine particles obtained by polymerization in the presence of a polymer having a glass transition temperature of 10 ° C. or lower, It can be seen that the level of sagging of the alkoxy silyl group-containing acrylic copolymer paint is significantly improved in an unexpectedly large manner in the case of the acrylic melamine paint.
As a result, it is possible to apply thick film coating that could not be performed conventionally.
You can see that it can be done by recoating.

[0121]

When the curable composition of the present invention is used, a coating film having a thickness of 50 μm or more can be formed by one coating without dripping, and it has excellent appearance, durability and chemical resistance. It is possible to obtain a coating film having excellent properties and solvent resistance.

Claims (6)

[Claims] 1. A general formula of (A) (a1): (In the formula, R ¹ is an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, a represents 0, 1 or 2) or an alkoxysilyl group-containing acrylic copolymer having a group represented by (a2) the alkoxysilyl group-containing acrylic copolymer and a hydroxyl group-containing acrylic resin, (B) a curing catalyst, Insoluble in (C) organic solvent and (D) (A) component, (B) component and (C) component,
And, it is a crosslinked polymer fine particle which can be stably dispersed in the system when it is made into a composition, and is 50 parts by weight or more of at least one alkyl acrylate ester having an alkyl group having 2 to 8 carbon atoms, and a crosslinkable monomer. Of 0.05 to 5 parts by weight, 0 to 49.95 parts by weight of another (meth) acrylic monomer and 0 to 20 parts by weight of another monomer copolymerizable with these, and having a glass transition temperature of 10 ° C. or less. In the presence, 40 parts by weight or more of at least one methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, 0 to 60 parts by weight of another (meth) acrylic acid ester, and another monomer copolymerizable therewith A curable composition comprising crosslinked polymer fine particles obtained by polymerizing a monomer mixture comprising 0 to 60 parts by weight of a monomer. 2. The alkoxysilyl group-containing acrylic copolymer of the component (A) has 2 to 10 units from an alkoxysilyl group-containing monomer having a polymerizable unsaturated double bond and an alkoxysilyl group in the molecule. The curable composition according to claim 1, which is a polymer containing 90% by weight. 3. The acrylic resin having a hydroxyl group in the component (A) has a hydroxyl value of 10 to 300 mgKOH / g and a number average molecular weight.
The curable composition according to claim 1, which is an acrylic resin of 1,500 to 40,000. 4. The component (B), which is a curing catalyst, is an organic tin compound, an acidic phosphoric acid ester, a mixture or reaction product of an acidic phosphoric acid ester and an amine, a saturated or unsaturated polyvalent carboxylic acid, a saturated or unsaturated polycarboxylic acid. Acid anhydrides of polycarboxylic acids, reactive silicon compounds, organic titanate compounds,
The curable composition according to claim 1, which is an organoaluminum compound, an organozirconium compound, or a mixture thereof. 5. The curable composition according to claim 1, wherein the average particle size of the crosslinked polymer fine particles as the component (D) is 0.01 to 10 μm. 6. The curable composition according to claim 1, which contains a pigment.