JPH1180656A - Production of coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which is superior in storage stability, does not gel nor precipitate a pigment in storage and coating gives a coating of high weatherability, stain resistance and high gloss by mixing a dispersion obtained by dispersing a pigment in an organic solvent solution of a (meth) acrylic copolymer having a hydrolyzable silyl group with an organic solvent solution of a F-containing copolymer having a hydrolyzable silyl group. SOLUTION: A composition is obtained by mixing a dispersion obtained by dispersing a pigment in an organic solvent solution of a (meth)acrylic copolymer having a hydrolyzable silyl group which comprises, preferably, a 1-20C alkyl ester or a cycloalkyl ester of a (meth)acrylic acid and has a number average molecular weight, in accordance with PS conversion by GPC, of 3,000-200,000 with an organic solvent solution of a F-containing copolymer having a hydrolyzable silyl group which comprises, preferably, a fluoro-olefin, a methacrylate and an olefinic monomer having a hydrolyzable silyl group as essential components and has a number average molecular weight, in accordance with PS conversion by GPC, of 3,000-500,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coating composition, and more particularly to a method for forming a highly glossy coating film.
The present invention also relates to a method for producing a coating composition having excellent storage stability.

[0002]

2. Description of the Related Art Fluorine-containing paints provide coatings that do not deteriorate over a long period of time and are used as high-performance paints that do not require repainting.
Widely used in civil engineering and heavy duty anticorrosion fields. Generally, a fluorine-containing resin containing a hydroxyl group is used for a fluorine-containing paint, but a curing agent is required to form a tough coating film at room temperature, and it is used as a two-pack paint. recent years,
The toxicity of the isocyanate used as a curing agent is regarded as a problem, and the development of a one-pack type fluororesin that does not use an isocyanate is desired. In particular, a fluorine-containing resin containing a hydrolyzable silyl group can be converted into a one-package. It is being studied diligently (Japanese Patent Publication No. 1-14055). However, a coating composition based on a fluorine-containing resin containing a hydrolyzable silyl group has problems in storage stability, gloss of a coating film, and the like. For the purpose of improving this point, there has been proposed a coating composition comprising a fluororesin containing a hydrolyzable silyl group and a specific acrylic resin containing a hydrolyzable silyl group (JP-A-8-283649). Gazette). However, as a result of investigations by the present inventors, it has been found that the coating composition has problems that the gloss of the coating film is low, and that the storage stability of the coating material, particularly the stability at the time of dispersing the pigment, is poor. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to form a coating film having not only high weather resistance but also excellent gloss.
Another object of the present invention is to provide a method for producing a coating composition having excellent storage stability, particularly excellent stability during dispersion of a pigment.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, dispersed a pigment in an organic solvent solution of a (meth) acrylic copolymer having a hydrolyzable silyl group. Pigment dispersion liquid, a coating composition obtained by mixing an organic solvent solution of a fluorine-containing copolymer having a hydrolyzable silyl group, to form a coating film having not only high weather resistance but also excellent gloss, and The present inventors have found that the composition has excellent storage stability, and have completed the present invention. That is, the present invention
In a pigment dispersion obtained by dispersing a pigment in an organic solvent solution of a (meth) acrylic copolymer having a hydrolyzable silyl group,
A method for producing a coating composition, comprising mixing an organic solvent solution of a fluorine-containing copolymer having a hydrolyzable silyl group.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The (meth) acrylic copolymer having a hydrolyzable silyl group in the present invention is not particularly limited as long as it is dissolved in an organic solvent described below.
It is a copolymer containing an alkyl ester or a cycloalkyl ester of (meth) acrylic acid having 1 to 20 carbon atoms and containing no fluoroolefin. Examples of the alkyl ester or cycloalkyl ester of (meth) acrylic acid having 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, Butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, neopentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecynyl (meth) acrylate ,
Tetrahydrofurfuryl (meth) acrylate, (meth)
Methoxyethyl acrylate, dimethylaminoethyl (meth) acrylate, chloroethyl (meth) acrylate,
Trifluoroethyl (meth) acrylate and (meth)
Examples thereof include pentafluoropropyl acrylate, and the alkyl group may contain atoms such as oxygen, nitrogen, sulfur, fluorine, and chlorine.

[0006] As a method of including a hydrolyzable silyl group in the (meth) acrylic copolymer, a method of copolymerizing a monomer having a hydrolyzable silyl group, and After the production, reaction with a compound having a hydrolyzable silyl group may be mentioned. The monomer having a hydrolyzable silyl group is a compound represented by the following formula (1). _{R-SiX n Y 3-n} (1) ( wherein, R is a group having an olefinic unsaturated bond, X represents an alkyl group, Y is a hydrolyzable group having 1 to 20 carbon atoms, n represents 0, 1 or 2. In the case where there are a plurality of X or Y, they may be the same or different.) In the formula (1), R is a vinyl group, an allyl group,
Butenyl group, vinyloxy group, allyloxy group, acryloyl group, methacryloyl group, CH ₂ ＣＨCHO (CH ₂ )
_{3 -, CH 2 = CHCOO (} CH 2) 3 -, CH 2 = C
_{HOCO (CH 2) 3 -,} CH 2 = C (CH 3) COO
(CH ₂ ) ₃ — and CH ₂ ＣC (CH ₃ ) COO (C
H ₂ ) ₂ —O— (CH ₂ ) ₃ — and the like. X in the formula (1) includes a methyl group, an ethyl group, a propyl group, an octyl group and an octadecyl group. Examples of Y in the formula (1) include hydrolyzable groups such as an alkoxy group, an amino group, an acyloxy group, a phenoxy group, a mercapto group, and an iminooxy group, and among these, an alkoxy group is particularly preferable. Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and a methoxyethoxy group. Among the above, those in which R in the formula (1) is a (meth) acryloxypropyl group and Y is a methoxy group and an ethoxy group are particularly preferable.

Specific examples of the monomer having a hydrolyzable silyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane,
Vinyltris (β-methoxyethoxy) silane, trimethoxysilylethylvinylether, trimethoxysilylbutylvinylether, methyldimethoxysilylethylvinylether, trimethoxysilylpropylvinylether, vinyltriisopropenyloxysilane, vinylmethyldiisopropenyloxysilane, triiso Propenyloxysilylethyl vinyl ether, triisopropenyloxysilylpropyl vinyl ether, triisopropenyloxysilylbutyl vinyl ether, vinyltris (dimethyliminooxy) silane, vinyltris (methylethyliminooxy) silane, vinylmethylbis (dimethyliminooxy) silane, vinyl Dimethyl (dimethyliminooxy) silane, tris (dimethyliminooxy) silane Ethyl vinyl ether, methyl bis (dimethyliminooxy) silylethyl vinyl ether, tris (dimethyliminooxy) silylbutyl vinyl ether, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (Meth) acryloyloxypropylmethyldiethoxysilane and γ-
(Meth) acryloyloxypropyltriisopropenyloxysilane and the like.

On the other hand, after producing a copolymer having a functional group,
When reacting this with a compound having a hydrolyzable silyl group, a hydroxyl group and a carboxylic acid group are exemplified as the functional groups, and a monomer having these functional groups is copolymerized with a (meth) acrylate. Examples of monomers having these functional groups include hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and a polyethylene oxide macromonomer having a terminal hydroxyl group of (meth) acrylic acid. ,
Examples thereof include N-methylolated (meth) acrylamide, (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, and vinyl acetic acid. Examples of the compound having a hydrolyzable silyl group to be reacted with the copolymer having the above functional group include trimethoxysilylpropyl isocyanate, triethoxysilylpropyl isocyanate, γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyl. Triethoxysilane and the like are exemplified. In the reaction, a tin compound such as dibutyltin dilaurate and an organic acid such as p-toluenesulfonic acid may be used as a catalyst.

(Meth) having a hydrolyzable silyl group
The acrylic copolymer may be copolymerized with other monomers as long as the physical properties are not impaired.
Α-olefins such as ethylene, propylene and isobutylene, chloroethylenes such as vinyl chloride and vinylidene chloride, vinyl acetate, vinyl propionate, vinyl caproate, vinyl pivalate, Vova-9 [manufactured by Shell Chemical Co., Ltd.], Vinyl carboxylate such as vinyl cyclohexanecarboxylate, vinyl benzoate and vinyl laurate, (meth) acrylamides,
Styrene and α-methylstyrene are exemplified.

The number average molecular weight of the (meth) acrylic copolymer having a hydrolyzable silyl group in the present invention in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 3,000 to 200,000, more preferably 5,000. ~ 50,000. Further, the glass transition temperature (Tg) of the (meth) acrylic copolymer is preferably from -20 ° C to 60 ° C.
It is more preferable that the temperature is 50C.

(Meth) having a hydrolyzable silyl group
The acrylic copolymer can be produced by subjecting the monomer to radical copolymerization in the presence of a polymerization initiator.
As the polymerization method, a usual method such as solution polymerization in an organic solvent can be adopted. As the polymerization initiator, diisopropyl peroxydicarbonate, tert-butyl peroxypivalate, peroxides such as benzoyl peroxide and lauroyl peroxide, azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile And inorganic peroxides such as ammonium persulfate and potassium persulfate. These polymerization initiators are preferably used in an amount of 0.0001 to 10 parts by weight based on 100 parts by weight of the total monomers. Examples of the organic solvent used in the solution polymerization include cyclic ethers such as tetrahydrofuran and dioxane; n-hexane, cyclohexane, mineral spirit, industrial gasoline No. 4 volatile oil, and industrial gasoline No. 3 volatile oil;
Aliphatic hydrocarbons such as kerosene and turpentine; aromatic hydrocarbon compounds such as toluene and xylene; ethyl acetate;
Esters such as butyl acetate; ketones such as acetone, methyl ethyl ketone and cyclohexanone; and alcohols such as ethanol, isopropanol, n-butanol and n-butyl cellosolve. One or more of these may be used. it can. The organic solvent is preferably used in an amount of 20 to 200 parts by weight based on 100 parts by weight of all monomers. After the completion of the polymerization, it may be used as it is as a resin solution. In this case, the reaction solvent is used as it is as an organic solvent. Alternatively, the acrylic copolymer may be isolated and purified, and then redissolved in an organic solvent to prepare a resin solution. The polymerization conditions are not particularly limited, but preferably the polymerization temperature is 20 to 100 ° C., and the suitable pressure is 1 to 100 Kg / cm ² . The monomers to be used may be initially charged in batches at the beginning, or some of the monomers may be added sequentially as the polymerization proceeds. If necessary, potassium carbonate, sodium hydrogencarbonate, hydrotalsalt, anion exchange resin, inorganic ion exchanger and the like may be added as a pH adjuster.

Next, the composition of the fluorinated copolymer having a hydrolyzable silyl group in the present invention is not particularly limited as long as it is dissolved in an organic solvent, but preferably (a) a fluoroolefin, (b) (meth) It is a copolymer comprising an acrylate ester and (c) an olefinic monomer having a hydrolyzable silyl group. Examples of the (a) fluoroolefin include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, dichlorodifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, and the like. More preferred are tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and trifluoroethylene, and more preferred are chlorotrifluoroethylene and trifluoroethylene. Further, a plurality of the above monomers may be used in combination.

The (b) alkyl (meth) acrylate is preferably one having an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group and a halogen-containing alkyl group as an ester chain. As long as the physical properties are not impaired, the ester chain may contain atoms such as oxygen, nitrogen and sulfur. Specifically, the compounds described in the (meth) acrylic copolymer having a hydrolyzable silyl group can be used. Among them, acrylates are preferred from the viewpoint of polymerizability with a fluoroolefin and flexibility. These monomers can be used alone or in combination of several kinds.

The (c) olefinic monomer having a hydrolyzable silyl group includes the compounds described for the (meth) acrylic copolymer having a hydrolyzable silyl group.

The fluorine-containing copolymer having a hydrolyzable silyl group in the present invention may be copolymerized with other monomers as long as the physical properties are not impaired. , Olefins such as isobutylene, norbornene and norbornadiene, chloroethylenes such as vinyl chloride and vinylidene chloride, vinyl acetate, vinyl propionate, vinyl caproate, vinyl pivalate, Vova-9 [Shell Chemical Co., Ltd.
Carboxylic acid vinyl esters such as vinyl cyclohexanecarboxylate, vinyl benzoate and vinyl laurate, vinyl ethers such as ethyl vinyl ether and butyl vinyl ether, and allyl ethers such as ethyl allyl ether and cyclohexyl allyl ether.

Further, it is possible to copolymerize the fluorine-containing copolymer with a monomer having a functional group such as a hydroxyl group, an epoxy group and a carboxyl group. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, and 4-hydroxybutyl vinyl ether. , Allyl alcohol, cinnamon alcohol, N-methylol (meth) acrylamide, hydroxyl group-containing monomers such as 2-hydroxyethyl crotonate and 4-hydroxybutyl crotonate, and ε-caprolactam or Compounds obtained by ring-opening addition of ethylene oxide, and unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid and itaconic acid, and ethylene glycol, ethylene oxide, propylene glycol, propylene oxide, butylene Glycol, cyclohexanedimethanol, a monomer which is a reaction product of a polyhydric alcohol such as glycerine and trimethylol propane and the like. Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, allyl glycidyl ether, and glycidyl vinyl ether. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid,
Fumaric acid, itaconic acid, crotonic acid and the like. Of these, the amount of the hydroxyl group-containing monomer or carboxyl group-containing monomer used is preferably 5 mol% or less based on the total amount of all monomers.

The ratio of the above-mentioned fluorinated copolymer based on the total amount of the above-mentioned essential constituent monomers is as follows: (a) 10 to 70 mol% of fluoroolefin, (b) (meth) acrylic acid ester: 20 to 80 mol% and (c) an olefinic monomer having a hydrolyzable silyl group: 0.5 to 20 mol%
And more preferably (a): 20
Ｂ60 mol%, (b): 30-75% mol% and (c): 2-10 mol%. The other monomers can be used in the range of 0 to 30 mol%.

The number average molecular weight in terms of polystyrene of the fluorinated copolymer having a hydrolyzable silyl group in the present invention, as determined by GPC, is preferably from 3,000 to 500,000, more preferably from 5,000 to 30,000. Further, the glass transition temperature (Tg) of the fluorinated copolymer
Is preferably −20 ° C. to 60 ° C., and 0 to 50 ° C.
Is more preferable.

The fluorinated copolymer having a hydrolyzable silyl group can be produced in the same manner as the above-mentioned (meth) acrylic copolymer having a hydrolyzable silyl group.

The (meth) acrylic copolymer having a hydrolyzable silyl group and the fluorinated copolymer having a hydrolyzable silyl group obtained by the above method are again dissolved in an organic solvent to form a resin solution. In some cases, the organic solvent used in the solution polymerization may be used as the organic solvent, and the amount of the organic solvent used may be any of the copolymers.
The amount is preferably 20 to 200 parts by weight, more preferably 50 to 100 parts by weight, based on 0 parts by weight.

The production method of the present invention is directed to a pigment dispersion obtained by dispersing a pigment and, if necessary, other paint additives in an organic solvent solution of the (meth) acrylic copolymer having a hydrolyzable silyl group. An organic solvent solution of the fluorine-containing copolymer having a hydrolyzable silyl group is mixed, and as the pigment, titanium oxide, iron oxide, calcined pigment,
Inorganic pigments such as graphite and pearl pigments, phthalocyanine blue, phthalocyanine green, quinacridone red,
Examples thereof include organic pigments such as isoindolinone and carbon black, volume pigments such as calcium carbonate and barium sulfate, and metallic pigments such as aluminum flake and stainless flake. Further, as a matting agent which is a kind of pigment, polyethylene wax, polypropylene wax and silica-based matting agent can be added. These pigments may be used alone or in combination of two or three. The amount of the pigment used is 0.5 to 20 with respect to 100 parts by weight of the (meth) acrylic copolymer.
The amount is preferably 0 parts by weight, more preferably 1 to 100 parts by weight. Other paint additives include pigment dispersants,
A sedimentation inhibitor, a skin sticking inhibitor, a thickener, an antifoaming agent, a leveling agent, a slip agent, an ultraviolet absorber, and the like can be used. These paint additives are 100 parts by weight of the (meth) acrylic copolymer. Is preferably used in the range of 0.1 to 20 parts by weight. The method for dispersing the pigment and other paint additives is not particularly limited, and a paint shaker,
Conventional dispersion methods such as a ball mill, a sand mill, a roll mill and a disper are used.

Next, an organic solvent solution of a hydrolyzable silyl group-containing fluorinated copolymer is mixed with the pigment dispersion obtained above to obtain a viscosity, a pigment concentration and a resin concentration suitable for a coating composition. Adjust so that In the obtained coating composition, the ratio of the (meth) acrylic copolymer having a hydrolyzable silyl group to the fluorine-containing copolymer having a hydrolyzable silyl group is 10/90 to 90 / by weight.
It is preferably 10 and more preferably 20/8.
0 to 60/40.

The coating composition obtained by the above method may further contain, if necessary, a curing accelerator, an ultraviolet absorber, a light stabilizer, a flow regulator, a leveling agent, a silane coupling agent, an alkoxysilane. And an additive such as an ortho acid ester.

The silane coupling agent is added for the purpose of improving the adhesion of the coating composition. As the silane coupling agent, a compound having an epoxy group and a hydrolyzable silyl group in one molecule is preferable. Further, the partially hydrolyzed condensate of the alkoxysilane is added for the purpose of further improving the stain resistance of the coating film of the coating composition,
A self-condensate of an alkoxysilane having two or more hydrolyzable alkoxy groups in one molecule is used.

The coating composition of the present invention can be used by a method generally used in the field of coatings. In particular, it has excellent storage stability, does not gel during storage, does not precipitate pigments, and has high weather resistance. A coating film having high gloss and no color separation or blemishes, as well as having properties and stain resistance.

A specific description will be given below with reference to examples. (Sample Preparation Example) Xylene was added to a (meth) acrylic copolymer having the composition shown in Table 1 to adjust the solid content to 50% by weight.

[0027]

[Table 1] BMA: butyl methacrylate EMA: ethyl methacrylate CHA: cyclohexyl acrylate MTRIMS: γ-methacryloxypropyl trimethoxysilane

To the fluorine-containing copolymer having the composition shown in Table 2, butyl acetate was added to adjust the solid content to 50% by weight.

[Table 2] CTFE: chlorotrifluoroethylene CHA: cyclohexyl acrylate BA: butyl acrylate tBA: t-butyl acrylate VMS: vinyl trimethoxysilane

Example 1 22.7 g of A1 solution, Dis
perbyk165 (a pigment dispersant from BYK Chemie)
0.9 g, Nova Palm Red (6.7 g of red organic pigment manufactured by BASF), 12.9 g of xylene, 2.3 g of trimethyl orthoformate and steel beads were placed in a container, and the pigment was dispersed with a paint conditioner for 2 hours. Thereafter, 53.0 g of the F1 solution and 1.5 g of trimethyl orthoformate were added to the resulting dispersion and dispersed for 10 minutes, and then the beads were removed by filtration to obtain a coating composition. The weight ratio of the acrylic copolymer and the fluorine-containing copolymer in this composition was 3/7.

Example 2 28.1 g of A1 solution, Dis
1650.6 g of perbyk, 57.2 g of Perm Yellow 5G [Yellow of Kikuchi Color Co., Ltd.], 0.2 g of trimethyl orthoformate and steel beads were placed in a container, and the pigment was dispersed with a paint conditioner for 2 hours. Thereafter, 52.3 g of the F2 solution and 1.6 g of trimethyl orthoformate were added to the resulting dispersion and dispersed for 20 minutes, and then the beads were removed by filtration to obtain a coating composition. The weight ratio of the acrylic copolymer to the fluorine-containing copolymer in this composition was 35/65.

Example 3 21.9 g of A2 solution, Dis
perbyk 1650.6 g, rutile type titanium oxide 2
4.3 g, 0.2 g of trimethyl orthoformate and steel beads were put in a container, and the pigment was dispersed with a paint conditioner for 2 hours. Then, F is added to the obtained dispersion.
2 solution 51.2 g and trimethyl orthoformate 1.8 g
Was added and dispersed for 20 minutes, and then the beads were removed by filtration to obtain a coating composition. The weight ratio of the acrylic copolymer to the fluorine-containing copolymer in this composition was 30/70.

Comparative Example 1 A coating composition was obtained in the same manner as in Example 1 except that A1 and F1 were replaced. Comparative Example 2 A coating composition was obtained in the same manner as in Example 2 except that A1 and F2 were replaced.

Comparative Example 3 A coating composition was obtained in the same manner as in Example 1 except that a mixture of A2 and F2 in a weight ratio of 3/7 was used instead of A2 and F2.

(Test Example 1) Examples 1 to 3 and Comparative Example 1
The following tests were performed on the coating compositions obtained in Nos. 1 to 3, and the results are shown in Table 3. -Storage stability After the coating composition was placed in a bottle with a sealed stopper and stored at 50 ° C for one month, the appearance was observed. Gloss 1 g of dibutyltin dilaurate is added to 10.0 g of the coating composition.
A composition prepared by adding 1.5 g of a 10 wt% solution and 1.0 g of a 10 wt% solution of NUC silicon A187 [epoxy group-containing silane coupling agent of Nippon Unicar Co., Ltd.] was added to a glass composition with a doctor blade. Painted on board. After drying at room temperature for one week, the gloss value at 60 ° was measured. -Accelerated weather resistance The coating composition prepared in the above gloss test was applied to a galvanized plate coated with an epoxy primer. After drying at room temperature for one week and measuring the gloss, a 3000-hour test was performed using a sunshine weather meter, and the gloss after the test was measured to calculate the gloss retention.

[0035]

[Table 3]

Example 4 5.0 g of the composition of Example 1
A paint was prepared by mixing 45.0 g of the composition of Example 3 and 0.2 g of a 10% by weight xylene solution of BYK331 (a leveling agent from BYK Chemie).

Example 5 5.0 g of the composition of Example 2
A paint was prepared by mixing 45.0 g of the composition of Example 3 and 0.2 g of a 10% by weight xylene solution of BYK331 (a leveling agent from BYK Chemie).

(Comparative Example 4) 5.0 g of the composition of Comparative Example 1
A paint was prepared by mixing 45.0 g of the composition of Comparative Example 3 and 0.2 g of a 10% by weight xylene solution of BYK331 (a leveling agent from BYK Chemie).

(Test Example 2) Examples 4 to 5 and Comparative Example 4
The following tests were performed using the above paints, and the results are shown in Table 4.・ Different colors The above paint is diluted with xylene to the paint viscosity, 7 × 15c
m of a tin plate was spray-painted, and half of the painted surface was sprayed with paint. After drying at room temperature for 3 days, JIS
According to the method described in Z8730, the color difference between the spray-coated part and the flow-coated part was measured, and the ΔE value was calculated. -Storage stability The appearance after storage at 50 ° C for one month in a state where the paint was sealed in a bottle and sealed was observed. -Color separation after storage stability Using the paint after the storage stability test, coating was carried out in the same manner as in the item of the color separation, and the color difference between the spray part and the flow coating part was measured to calculate ΔE.

[0040]

[Table 4]

[0041]

The coating composition obtained by the production method of the present invention has excellent storage stability, does not gel or precipitate pigment during storage, and has high weather resistance and stain resistance. In addition to having a coating, it forms a coating film with high gloss and no color separation or spots, and its industrial use value as a paint is remarkably high.

Claims (4)

[Claims] 1. A pigment dispersion obtained by dispersing a pigment in an organic solvent solution of a (meth) acrylic copolymer having a hydrolyzable silyl group, and an organic solvent of a fluorine-containing copolymer having a hydrolyzable silyl group. A method for producing a coating composition, comprising mixing a solution. 2. The weight ratio of the (meth) acrylic copolymer having a hydrolyzable silyl group and the fluorinated copolymer having a hydrolyzable silyl group is in the range of 10/90 to 90/10. A method for producing the coating composition according to the above. 3. The (meth) acrylic copolymer having a hydrolyzable silyl group is a (meth) acrylic acid having 1 to 20 carbon atoms.
Having a number average molecular weight of 3 based on polystyrene by GPC.
The method for producing a coating composition according to claim 1, wherein the composition is from 000 to 200,000. 4. A fluorinated copolymer having a hydrolyzable silyl group contains a fluoroolefin, a (meth) acrylate ester and an olefinic monomer having a hydrolyzable silyl group as essential components, and is converted into polystyrene by GPC. The number average molecular weight is 3,000 to 500,000.
4. A method for producing the coating composition according to any one of the above items 3.