JPH0940909A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating compsn. which can form a coating film excellent in resistances to stain, water, alkalis, and acids. SOLUTION: This coating compsn. is prepd. by compounding an org.- solvent-base coating compsn. with a silicone compd. obtd. by the partial hydrolysis and cocondensation of a silane mixture of 100 pts.wt. alkoxysilane compd. having at least one kind of an org. functional. group selected from among (meth)acryloyl, vinyl, haloalkyl, and amino groups and 20-2,000 pts.wt. tetraalkoxysilane compd.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to crack resistance, flexibility, stain resistance, water resistance, alkali resistance, acid resistance, etc., which are applied to outdoor structures or structures for the purpose of decoration or protection. The present invention relates to a coating composition that forms an excellent coating film.

[0002]

2. Description of the Related Art Conventionally, an outdoor paint having excellent weather resistance has been developed as a paint to be applied to outdoor structures and the like. In particular, acrylic silicone resin paints, fluororesin paints, and the like have been considered to be suitable as outdoor paints because of little deterioration of the paint film due to sunlight, rain, and the like. However, these paints are said to have a bad appearance when exposed to contaminants on the surface of the coating film due to the effects of atmospheric dust, sand, iron powder and acid rain, which has become a problem in recent years. There was a flaw.

As a technique for preventing the adhesion of dust in the atmosphere, various antistatic agents that lower the surface resistivity of the coating film to prevent electrostatic adhesion of dust or the like, such as the electrostripper TS-2B (Kao). Known is a method of adding Colaccoat R (made by Co., Ltd., a surfactant type), Colcoat R (Colcoat Co., Ltd., a brand name, alkyl silicate type) to a coating material, or applying this to the coating film surface for treatment. ing.
However, in these methods, since the water resistance of the substance to be added is essentially inferior, it is difficult to maintain the effect, and it is not suitable for outdoor use.

Further, as an organic coating composition excellent in acid rain resistance, a coating composition to which a condensation reaction product of an alkyl silicate oligomer and a silane coupling agent (hydrolyzate of epoxy functional silane) is added has been proposed. (Japanese Patent Laid-Open No. 6-306328). The condensation reaction product prepared by this method becomes a mixture of an alkyl silicate oligomer, a silane coupling agent oligomer, and a block condensate of both, and since the epoxy group is not uniformly introduced into the condensation reaction product, the existing alkyl silicate is present. There is a drawback that the oligomer is eluted by water, and as a result, the water resistance, especially the alkali resistance of the coating film is lowered. In addition, the coating film has drawbacks that cracks are likely to occur during the formation of the coating film and the flexibility is not sufficient.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems, and as a result, have found that the water contact angle of the coating film surface and the contaminants on the coating film surface during outdoor exposure to the coating film surface. The adhesion has a close relationship such that the smaller the water contact angle is, the less the adhesion of pollutants is, and the substance that reduces the water contact angle is at least selected from (meth) acryloyl group, vinyl group, haloalkyl group, and amino group. A specific compound obtained by partially co-hydrolyzing and condensing a mixture of an alkoxysilane containing one kind of organic functional group and a tetraalkoxysilane, which contains the above various organic functional groups and an alkoxy group uniformly in one molecule. It was found that a coating composition containing a silicone compound can provide a coating film excellent in stain resistance, water resistance, alkali resistance, acid resistance, etc. This has led to the.

The present invention relates to an organic solvent-based coating composition,
(1) 100 parts by weight of an alkoxysilane compound containing at least one organic functional group selected from a (meth) acryloyl group, a vinyl group, a haloalkyl group and an amino group,
(2) To provide a coating composition containing a silicone compound obtained by partially cohydrolyzing and condensing a silane mixture with 20 to 2000 parts by weight of a tetraalkoxysilane compound.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that a coating film having a small water contact angle is less likely to be contaminated with contaminants such as dust in the atmosphere in outdoor exposure than a coating film having a large water contact angle. It was found that the stain resistance was excellent. At the same time, the coating film with hydrophilicity reduces the surface resistivity of the coating film and prevents the electrostatic adhesion of contaminants such as dust. It is easily washed away by the action of etc.

A method for forming a coating film surface having hydrophilicity is, for example, by adding a hydrophilic substance (antistatic agent,
It becomes possible by adding a condensation reaction product of an alkyl silicate oligomer and a pre-hydrolyzed compound of a silane coupling agent), but the performance such as water resistance and alkali resistance of the coating film is also deteriorated at the same time, so that it is suitable for outdoor applications. Not suitable.

According to the present invention, the alkoxysilane compound having an organic functional group and the tetraalkoxysilane compound are partially cohydrolyzed and condensed, so that these components are uniformly introduced into the silicone compound. It is possible to form a coating film whose performance such as alkalinity does not deteriorate.

As the organic solvent-based coating composition used in the present invention, known uncrosslinked and crosslinked coating compositions which have been conventionally used for the outdoors can be used. The uncrosslinked and crosslinked coating compositions are composed of a resin solution prepared by dissolving or dispersing an uncrosslinked or crosslinked organic resin in an organic solvent, and the uncrosslinked or crosslinked coating composition is applied at room temperature or by heating. A film is formed.

Examples of the uncrosslinked coating composition include nitrification cotton lacquer, acrylic lacquer coating, vinyl resin coating, fluororesin coating and the like.

As the crosslinkable coating composition, those which can be crosslinked at room temperature or by heating can be preferably used. Specifically, for example, oxidative cross-linking paints such as unsaturated fatty acid-modified alkyd resin paints, polyester melamine resin paints, acrylic melamine resin paints, melamine cross-linking paints such as fluoromelamine resin paints; (block) polyisocyanate acrylic resin paints , (Block) polyisocyanate polyester resin paints, (block) polyisocyanate fluororesin paints and other isocyanate crosslinkable resin paints; alkoxysilane group-containing acrylic resin paints and other moisture crosslinkable resin paints; epoxy group-containing acrylic resin paints and other epoxies Examples include cross-linking resin paints.

Any organic solvent can be used without particular limitation as long as it dissolves or disperses the resin and does not substantially react with the functional groups and hydrolyzable groups of the silicone compound. Specifically, for example, acetic acid esters (ethyl acetate, propyl acetate, etc.), ketones (methyl isobutyl ketone, etc.), aromatic hydrocarbons (xylene, toluene, etc.), aliphatic hydrocarbons (heptane, etc.), Examples thereof include alcohols (propyl alcohol etc.), ethers (ethyl cellosolve, butyl cellosolve etc.) and the like. These organic solvents can be used alone or in combination of two or more.

The organic solvent-based coating composition used in the present invention may contain, for example, a colorant, a filler, a curing catalyst, an anti-sagging agent, an anti-cissing agent, an ultraviolet absorber, an ultraviolet stabilizer and the like, if necessary. Can be used.

The silicone compound used in the present invention is
(Meth) acryloyl group, vinyl group, haloalkyl group,
And an alkoxysilane compound containing at least one organic functional group selected from amino groups (hereinafter, this is abbreviated as “organic functional group-containing alkoxysilane compound”).
And a mixture of a tetraalkoxysilane compound and a partial cohydrolytic condensation.

The organic functional group-containing alkoxysilane compound used as a starting material may have an organic functional group directly bonded to a silicon atom, or may have a silicon atom through a divalent hydrocarbon group having 1 to 10 carbon atoms. It may be attached to an atom. As the compound, conventionally known compounds can be used, and specifically, the following compounds can be exemplified.

Γ-methacryloxypropyltrimethoxysilane γ-methacryloxypropyltriethoxysilane γ-methacryloxypropyltributoxysilane γ-methacryloxypropylmethyldimethoxysilane γ-methacryloxypropylmethyldiethoxysilane γ-acryloxypropyltri Methoxysilane γ-acryloxypropyltriethoxysilane γ-acryloxypropylmethyldimethoxysilane γ-methacryloxymethyltrimethoxysilane γ-acryloxymethyltrimethoxysilane vinyltrimethoxysilane vinyltriethoxysilane vinyltributoxysilane vinylmethyldimethoxysilane 5-Hexenyltrimethoxysilane 9-decenyltrimethoxysilane Styryltrimethoxysilane γ-chloropropyltri Methoxysilane γ-Bromopropyltrimethoxysilane Trifluoropropyltrimethoxysilane Nonafluorohexyltrimethoxysilane γ-Aminopropyltrimethoxysilane γ-Aminopropyltriethoxysilane γ-Aminopropyltributoxysilane γ-Aminopropylmethyldimethoxysilane γ -Aminopropylmethyldiethoxysilane N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane N- (β-aminoethyl) -γ-aminopropyltriethoxysilane N- (β-aminoethyl) -γ- Aminopropyltributoxysilane N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane N-phenyl-γ-aminopropyltrimethoxysilane

These organic functional group-containing alkoxysilane compounds may be used alone or in combination of two or more. Among these compounds, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropyltriethylsilane and the like have excellent coating properties such as stain resistance and durability. Methoxysilane, trifluoropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl)-
It is preferred to use γ-aminopropyltrimethoxysilane.

The above-mentioned organic functional group forms a chemical bond with the organic resin of the coating material by a chemical reaction, forms a hydrogen bond due to a polar structure, or interacts based on affinity, etc. to form a coating film of a silicone compound. It functions to prevent detachment from the body.

Specific examples of the tetraalkoxysilane compound which is the other starting material include the following. Tetramethoxysilane Tetraethoxysilane Tetraisopropoxysilane Tetrabutoxysilane These compounds can be used alone or in combination of two or more. Among these, it is particularly preferable to use tetramethoxysilane and tetraethoxysilane because the alkoxysilane group easily hydrolyzes to form a silanol group and forms a coating film excellent in stain resistance.

The mixing ratio of the organic functional group-containing alkoxysilane compound and the tetraalkoxysilane compound is such that the tetraalkoxysilane is in the range of 20 to 2000 parts by weight based on 100 parts by weight of the organic functional group-containing alkoxysilane compound. Preference is given to using. If it is less than 20 parts by weight, the hydrophilicity of the co-hydrolysis condensate is lowered, and as a result, the desired stain resistance, acid resistance and the like are deteriorated, which is not preferable.
On the other hand, if it exceeds 2000 parts by weight, the affinity and reactivity with the organic resin will be poor, the ability to fix the silicone compound in the coating film will be insufficient, and it will easily fall off from the coating film after hydrolysis, which is not preferable. . Further, it is particularly preferable to satisfy the range of 50 to 1000 parts by weight.

The silicone compound used in the present invention preferably has an average degree of polymerization of 3 to 100. If the degree of polymerization is less than 3, volatilization is not possible, sufficient hydrophilicity cannot be imparted to the surface of the coating film, or elution from the coating film is likely to occur, such being undesirable. On the other hand, when the degree of polymerization exceeds 100, the silicone compound is not well dispersed in the coating film and it is difficult to form a uniform coating film, which is not preferable. Further, the degree of polymerization is preferably in the range of 5 to 80.

The method for producing the silicone compound is based on a conventionally known method, for example, in the presence of a hydrolysis catalyst, water is added to the mixture of the above-mentioned organic functional group-containing alkoxysilane compound and tetraalkoxysilane compound to carry out partial co-hydrolysis. It can be obtained by carrying out a decomposition condensation reaction.

In the partial cohydrolysis condensation, the degree of partial cohydrolysis is, for example, an average degree of polymerization of 0 when not hydrolyzed at all, and an excessive degree of polymerization when 100% hydrolyzed to cause gelation. As described above, the polymerization degree is closely related to the polymerization degree, and in the silicone compound used in the present invention, the average polymerization degree is adjusted to 3 to 100.

As the hydrolysis-condensation catalyst used, various conventionally known catalysts can be used. Specific examples include organic acids such as acetic acid, butyric acid, maleic acid and citric acid, inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid and sulfuric acid; basic compounds such as triethylamine; tetrabutyl titanate and dibutyltin dilaurate. Examples thereof include F-containing compounds such as KF and NH ₄ F. The above catalysts may be used alone or in combination of two or more. The amount of catalyst used is
The range of 0.0001 to 1 mol% is preferable. Among these catalysts, the F-containing compound is excellent in the function of promoting the condensation of silanol groups, which are rich in reaction activity, and is therefore suitable for synthesizing those containing a small amount of silanol groups, which makes the storage stability of paints stable. It is particularly preferable to use this because it has good properties.

When carrying out the partial cohydrolysis condensation reaction, an organic solvent may be used if necessary. Examples of usable organic solvents include alcohols such as methanol, ethanol, isopropanol and t-butanol; ketones such as acetone and methyl isobutyl ketone; ethers such as dibutyl ether; esters such as ethyl acetate; toluene and the like. The aromatics and the like can be exemplified. Particularly, organic solvents such as methanol, ethanol, and acetone are preferable.

The amount of water used in the partial cohydrolytic condensation reaction is determined by the desired degree of polymerization. Excessive addition destroys the alkoxy group and eventually leads to gelation, so it must be determined strictly. In particular, when an F-containing compound is used as a catalyst, the F-containing compound has the ability to completely proceed with hydrolysis and condensation, so that the degree of polymerization can be determined by the amount of water added and an arbitrary molecular weight can be set, which is preferable. . That is, in order to prepare a target product having an average degree of polymerization M,
(M-1) mol of water may be used with respect to M mol of the alkoxysilane compound. In the case of other catalysts, it is necessary to slightly increase the amount.

The partial cohydrolysis condensation reaction is carried out at room temperature or 1
It can be performed in a temperature range of 50 ° C. or lower. If the temperature is lower than room temperature, the reaction proceeds slowly and is not practical.
When the temperature exceeds 0 ° C, thermal decomposition of organic substituents such as organic functional groups occurs, which is not preferable.

The blending ratio of the silicone compound is 0.1 to 50 parts by weight, preferably 1.0 to 20 parts by weight, per 100 parts by weight of the organic resin solid content of the organic solvent-based coating composition. If the blending ratio is less than 0.1 part by weight, the stain resistance of the coating film cannot be sufficiently obtained, while if it exceeds 50 parts by weight, the water resistance, acid resistance, alkali resistance and the like of the coating film are deteriorated. Absent.

When the coating film formed by the coating composition of the present invention is exposed to the outdoors, the water contact angle gradually decreases due to the action of rain or the like, but the surface of the coating film before the exposure is treated with an acid (2 Predicted the final water contact angle of the exposed coating film by measuring the water contact angle after immersion in 0.5 wt% sulfuric acid water at 20 ° C. for 24 hours, and then washing the adhered sulfuric acid water with water and drying) You can do it.

In the coating composition of the present invention, the surface of the formed coating film is acid-treated (immersed in 2.5% by weight sulfuric acid water at 20 ° C. for 24 hours, and then the adhered sulfuric acid water is washed with water and dried. However, it is preferable that the surface of the coating film has a contact angle with water of 70 degrees or less, preferably 10 to 60. If the contact angle is more than 70 degrees, the stain resistance decreases, which is not preferable. If the contact angle is less than 10 degrees, the water resistance, acid resistance, alkali resistance, and the like of the coating film decrease, which is not preferable.

The coating composition of the present invention can be formed into a coating film by coating the above coating composition on a substrate and drying at room temperature or by heating. Examples of the base material include inorganic base materials such as slate and concrete; metallic base materials such as steel, aluminum, zinc, and stainless steel, which are surface-treated with chromic acid, zinc phosphate, etc .; polyvinyl chloride. Examples include plastic base materials such as polyethylene terephthalate and polyethylene. Further, a base material obtained by coating a known primer, an intermediate coating material, a top coating material, or the like on these base materials, if necessary, can also be used.

As a coating method, for example, brush coating, spray coating, roller coating, dip coating and the like can be used. The coating amount is generally in the range of 1 to 100 μm, preferably 10 to 60 μm.

The conditions for drying the coating film may be selected depending on the kind of the coating material, but generally, it is 1 hour to
About 1 week, heat drying at 60-300 ° C for 30 seconds-1
I think time is enough.

[0035]

EXAMPLES Fluorine resin coatings (Examples 1 to 6 and Comparative Examples 1 to 5), polyisocyanate urethane resin coatings (Examples 7 to 12 and Comparative Examples 6 to 10), unsaturated fatty acid-modified alkyd resin coatings ( The present invention will be described in detail with reference to Examples and Comparative Examples using Examples 13 to 18 and Comparative Examples 11 to 15). “Parts” and “%” in the examples are on a weight basis.

Preparation of Methacryloyl Group- and Alkoxy Group-Containing Silicone Compound: Preparation Example of Silicone Compound A 2000 ml equipped with a thermometer, nitrogen inlet tube and dropping funnel
In a reaction vessel of No. 2, 248 g (1.00 mol) of γ-methacryloxypropyltrimethoxysilane, 152 g (1.00 mol) of tetramethoxysilane, and 320 of methanol.
g (10 mol) and NH ₄ F 0.04 g (0.001 m
28.8 g (1.60 m) of water at room temperature with stirring.
ol) was slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and then heated and stirred under methanol reflux for 2 hours. Thereafter, low-boiling components were distilled off under reduced pressure and filtered to obtain 266 g of a colorless transparent liquid. As a result of GPC measurement of the thus obtained substance, the average degree of polymerization was 5.3 (set degree of polymerization = 5.
0), which was almost as set. When the amount of alkoxy groups was quantified by the alkali cracking method, it was 35.7% by weight (setting value 36.1% by weight), and it was confirmed that the alkoxy groups remained as set. In addition, ¹ H
From the measurement result of NMR (integral ratio of methoxy group and methacryloxypropyl group), the structure of the obtained substance was the following structure as set. Average composition formula:

[0037]

Embedded image

The silicone compound thus obtained is referred to as Compound A.

Compounds B to E and comparative compound F. G
Preparation Example of Compound B having the set structure as shown in Table 1 in the same manner as described below by changing the type and the set amount of the organic functional group-containing alkoxysilane, tetraalkoxysilane and contact to be used.
-E, and the compounds F and G for comparative examples were prepared. In Table 1,
The compounding amounts of A to G are expressed in molar units.

Further, instead of the partial cohydrolysis condensation method (hereinafter, Production method I) in the present invention, the following production method was also examined. Production Method II An organofunctional alkoxysilane and a tetraalkoxysilane oligomer are subjected to a condensation reaction. Manufacturing Method III The alkoxysilane containing an organic functional group is hydrolyzed in advance and then subjected to a condensation reaction with an oligomer of tetraalkoxysilane.

Examples 1 to 6 and Comparative Examples 1 to 5 The coating materials of Examples 1 to 6 and Comparative Examples 1 to 5 were prepared with the formulations (unit: parts by weight) shown in Table 2. Fukkaron White Enamel: Trademark name, Kansai Paint Co., Ltd.
Made, non-crosslinked fluororesin top coating, resin solid content =
35% zinc phosphate treated zinc steel sheet (zinc weight: 130 on one side)
g / m ² , 1.2 mm thickness) with Fukkalon FR primer (trade name, un-crosslinked fluororesin base coat made by Kansai Paint Co., Ltd.) by air spray coating to a dry film thickness of about 10 μm went. After standing at 20 ° C. for 10 minutes, the coating materials of Examples 1 to 6 and Comparative Examples 1 to 5 were air-spray coated so that the dry film thickness was about 25 μm.
A test plate was prepared by drying at 235 ° C for 15 minutes. The coating film performance test results are shown in Table 2.

Examples 7 to 12 and Comparative Examples 6 to 10 Paints of Examples 7 to 12 and Comparative Examples 6 to 10 were prepared with the formulations shown in Table 3. Retan PAQ White Enamel: Trademark name, Kansai Paint Co., Ltd.
Made, polyisocyanate acrylic resin-based top coating, resin solid content = 36% zinc phosphate treated zinc steel sheet (zinc weight: 130 on one side)
(g / m ² , 1.2 mm thickness) Retan CW primer (trademark, Kansai Paint Co., Ltd., epoxy resin-based undercoat paint) was air-spray coated to a dry film thickness of about 30 μm, A substrate was prepared by drying at 30 ° C. for 30 minutes. Next, Examples 7-1 were added to the obtained base material.
2. After air-spraying the paints of Comparative Examples 6 to 10 so that the dry film thickness is about 30 μm, the paints are dried at 80 ° C. for 30 minutes.
A test plate was prepared by drying for one minute. The coating film performance test results are shown in Table 3.

Examples 13 to 18 and Comparative Examples 11 to 15 Using the formulations (unit: parts by weight) shown in Table 4, Examples 13 to 1
8, the coating materials of Comparative Examples 11 to 15 were prepared. Neophthalit white enamel: Trade name, Kansai Paint Co., Ltd., unsaturated fatty acid-modified alkyd resin-based top coating, resin solid content = 32% # 320 Sandpaper treated polished mild steel plate (SPC)
C, 0.8 mm) was coated with Rustite NC (trademark, manufactured by Kansai Paint Co., Ltd., unsaturated fatty acid-modified alkyd resin undercoat paint) by air spray coating so that the dry film thickness was about 30 μm. After standing at 20 ° C. for 10 minutes, the coating materials of Examples 13 to 18 and Comparative Examples 11 to 15 were subjected to air spray coating so that the dry film thickness was about 30 μm.
A test plate was prepared by drying at 20 ° C. for 7 days. The coating film performance test results are shown in Table 4.

* 1 to * 8 in Tables 2, 3 and 4 have the following meanings. ^{* 1} ; Trade name, low-condensation product of tetramethyl silicate, manufactured by Colcoat Co., Ltd. ^{* 2} ; Trade name, manufactured by Shin-Etsu Chemical Co., Ltd., γ-glycidoxypropyltrimethoxysilane ^{* 3} ; Water contact angle: test The plate is immersed in 2.5% by weight sulfuric acid water at 20 ° C. for 24 hours, then the adhered sulfuric acid water is washed with water and dried, and then a contact tangle meter DCAA type manufactured by Kyowa Chemical Co., Ltd. Deionized water 0.03c
A value measured after dropping a water droplet of c and 3 minutes at 20 ° C. ^{* 4} : Water resistance: The appearance of the coating film was visually evaluated after the test plate was immersed in warm water at 40 ° C. for 24 hours. ⊚: No change in appearance with respect to the coated plate before the test. ◯ = Very slight change in appearance is observed with respect to the coated plate before the test. ○ ^- = A slight change in appearance was observed with respect to the coated plate before the test. Δ: A change in appearance is recognized with respect to the coated plate before the test. X = Significant change in appearance is observed on the coated plate before the test. The appearance change means stain, color change, swelling, cracking, blurring, peeling, softening, etc. of the coated surface. ^{* 5} ； Alkali resistance A: 2% test plate in 1% caustic soda water
The appearance of the coating film after being immersed at 0 ° C. for 3 days was visually observed.
The evaluation was performed by the same method as ^{* 4} . ^{* 6} ； Alkali resistance B: Test plate in 3% sodium carbonate water 2
The appearance of the coating film after being immersed at 0 ° C. for 3 days was visually observed.
The evaluation was performed by the same method as ^{* 4} . ^{* 7} : Outdoor exposure test: Tokyo Plant, Kansai Paint Co., Ltd. A test plate was installed at an angle of 30 degrees on the south side. 3 months each
The coating properties of the test plates exposed for 6 months and 12 months were evaluated without adjusting the sample such as washing with water. Appearance (dirt): The degree of dirt on the coated surface was evaluated in the same manner as ^{* 4} . Water contact angle: Measured by the same method as ^{* 4} without adjusting the sample (immersing in sulfuric acid, washing with water, etc.). Lightness difference (ΔL ^* ): The difference in lightness (L value) before and after exposure was defined as ΔL ^* . For the measurement of the L value, a color difference meter CR-300 manufactured by Minolta Co., Ltd. was used. The brightness difference ΔL ^* is
The smaller the number, the less the stain. ^{* 8} : Trade name, HMDI urethane curing agent, manufactured by Kansai Paint Co., Ltd.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

EFFECTS OF THE INVENTION The cured coating film obtained from the coating composition of the present invention does not stain even when exposed outdoors, and has good water resistance, acid resistance, alkali resistance and the like. Regarding the surface properties of the coating film after exposure, the contact angle with water is remarkably reduced as compared with that before exposure, and the coating film exhibits hydrophilicity. This is because moisture and rain (especially acid rain) in the exposed environment act on the silicone compound in the coating film, and the silanol groups generated by hydrolysis reduce the water contact angle on the coating surface and make it hydrophilic. It The hydrophilized coating weakens the adhesion of organic substances such as oil, which is one of the pollutants in the atmosphere, and even if it adheres to the coated surface, it is easily washed away by rain. , Surface resistivity (hydrophilization)
Therefore, it is possible to prevent static electricity from adhering dust particles such as sand dust that are dirt components in the air, and to form a coating film having excellent dirt resistance. The coating film formed from the coating composition of the present invention has a low water contact angle at an early stage due to outdoor exposure, and almost reaches equilibrium after 3 to 6 months. The water contact angle when this equilibrium is reached is
The water contact angle after immersion of the coating film before exposure in 2.5% by weight sulfuric acid for 24 hours is almost equal. That is, the state of stain after exposure can be estimated by measuring the water contact angle when the cured coating film before exposure is immersed in 2.5 wt% sulfuric acid water for 24 hours. In addition, the organic functional group derived from the silicone compound acts so as to strongly bond with the polymer in the coating material, and since the silicone compound has a very small amount of a component containing no organic functional group in the molecule, , Elution and hydrolysis in environments such as water, acidic solutions, and alkaline solutions are suppressed, and the performance of stain resistance and water resistance, acid resistance, alkali resistance, etc. imparted to the coating film is made extremely durable. You can do it.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Onishi 4-17-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai Paint Co., Ltd. (72) Inventor Masaaki Yamatani 1 Hitomi, Daiji, Matsuida-cho, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicon Silicon Electronic Materials Research Laboratory (72) Inventor Masahiro Yoshizawa 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Industrial Silicone Electronic Materials Research Laboratory

Claims (3)

[Claims] 1. An organic solvent-based coating composition containing 100 parts by weight of (1) an alkoxysilane compound containing at least one organic functional group selected from a (meth) acryloyl group, a vinyl group, a haloalkyl group and an amino group, And (2) tetraalkoxysilane compound 20-2000
A coating composition comprising a silicone compound which is a partial co-hydrolyzed condensate of a silane mixture in parts by weight. 2. The silicone compound has an average degree of polymerization of 3 to 10.
The coating composition according to claim 1, wherein the coating composition is 0. 3. The coating composition according to claim 1, wherein the silicone compound is 0.1 to 50 parts by weight with respect to 100 parts by weight of the resin solid content of the coating composition.