JPH09302286A - Method for forming coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method whereby a coating film excellent not only in appearance and weatherability but also in stain resistance can be formed on an object to be coated. SOLUTION: This coating method provides a coating film by applying a base coat and then a topcoat to an object to be coated. The base coat is a coating material contg. a metallic powder and/or a colored pigment, and the topcat is a coating material prepd. by incorporating 2-70 pts.wt. silicon compd. represented by the formula [wherein R<1> and R<2> are each a monovalent (1-10C)- alkyl, aryl, or aralkyl group; and b is 0 or 1] or its condensate of partial hydrolyzate into 100 pts.wt. acrylic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a coating film, and more specifically, a method for forming a coating film which is preferably used for automobiles, industrial machines, steel furniture, interior and exterior of buildings, household appliances, plastics and the like. More specifically, the present invention relates to a coating film forming method which exhibits excellent appearance properties, curability, and the like and extremely excellent stain resistance, and is particularly suitable for use as a top coating composition for automobiles.

[0002]

2. Description of the Related Art Conventionally, paints mainly containing acrylic melamine resin, fluororesin, acrylic urethane resin and the like have been used for coating automobiles, industrial machines, steel furniture, interior and exterior of buildings, home appliances, plastics and the like. Is coming. By using such a coating material, a coating film having excellent performance such as high appearance and high weather resistance is formed on the object to be coated.

By the way, generally, there are two types of finish coating for automobiles: metallic color finish and solid color finish.

Among them, in the case of metallic color finish, after applying a metallic base coat, a clear paint such as acrylic melamine resin paint, fluororesin paint, acrylic urethane resin paint, etc. is applied by a wet-on-wet method, and 2 Generally, a method of heating and curing by a coat 1 bake method, a method of coating a base coat and heating and curing, and then applying a top coat clear paint and heating and curing, a 2 coat and 2 bake method and the like are generally performed.

On the other hand, in the case of solid color finish,
Alkyd melamine resin paints and the like have been used, and the method of heating and curing by one coat and one bake method has been generally adopted, but recently, various characteristics such as finished appearance and weather resistance have become strict. Along with this, a method of coating a clear paint such as an acrylic melamine resin paint on a solid color finish has been proposed.

[0006]

However, in any of the above cases, although the obtained coating film has excellent appearance, weather resistance, etc., the adhered stain tends to be hard to be removed, and particularly the light-colored system is used. The tendency was remarkable in the case of the coating of. Improvements in stain resistance have been desired from the viewpoints of the appearance of articles, the ease of cleaning, the reduction in the number of cleanings, and the like.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object thereof is to provide a coating film which is excellent not only in appearance and weather resistance but also in stain resistance. It is an object of the present invention to provide a method capable of being formed on a coated article.

[0008]

According to the method for forming a coating film of the present invention, a top coat is applied on a base coat applied on the surface of an object to be coated to form a coating film having a contact angle with water of 65 ° or less. A method of forming a coating film, wherein the base coat comprises a paint containing a metallic powder and / or a coloring pigment, and the top coat comprises a silicon compound represented by the following general formula (1) and / or a partial hydrolysis thereof. It is characterized in that the decomposition condensate is composed of a coating material in which 2 to 70 parts are mixed with 100 parts by weight of the resin (hereinafter, simply referred to as "part").

[0009]

Embedded image (In the formula, R ¹ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group,
R ² is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and b is 0 or 1. )

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Component [Resin] As the resin used in the present invention, for example, a synthetic resin (A) for coating having a number average molecular weight of 2,000 to 500,000.
Is used. A commercial item can also be used as this resin (A).

The term "resin-based" as used in the claims
Means that the content of the resin is 50% by weight or more based on 100 parts by weight of the resin.

The resin (A) is, for example, an acrylic resin such as an acrylic resin (a homopolymer or a copolymer of an alkyl ester compound of (meth) acrylic acid) or a light-stable monomer (for example, 1, 2). , 2,6,6-Pentamethyl-4-piperidyl (meth) acrylate, 2,2,6
Acrylic resin obtained by copolymerizing 6-tetramethyl-4-piperidyl (meth) acrylate, etc., and an ultraviolet absorbing monomer (2-hydroxy-4-((meth) acryloyloxyethoxy) benzophenone, etc.) (copolymer) ) Polymerized acrylic resin, acrylic resin having a urethane bond, acrylic resin that cross-links urethane composed of acrylic polyol and isocyanate in the process of forming a coating film, and resin mainly composed of fluororesin.

By using an acrylic resin as the resin (A), an effect that a coating film having glossiness and durability can be easily formed can be obtained. Further, it is particularly preferable to use an acrylic resin having a urethane bond or an acrylic resin that is urethane-crosslinked, because it has further excellent durability.

This acrylic resin may be of a solvent type,
It may be an emulsion or an aqueous type such as water-soluble. The emulsion type may be one using an emulsifier or soap-free without using an emulsifier. Further, as an aqueous type, melamine cross-linking, urethane cross-linking, hydrazine group and carbonyl group,
Examples of the cross-linking type include an oxazoline group, a carboxylic acid group, and an alkoxysilyl group. Crosslinking with an alkoxysilyl group reacts with the silicon compound as the component (B),
It is particularly preferable because it has high durability.

By using a polymer containing an n-butyl methacrylate unit as the copolymerization component as the component (A), the effect of improving the compatibility with the component (B) can be obtained. A preferable content ratio of the n-butyl methacrylate unit is 10 to 60.

Examples of the silicone-modified resin include modified silicone varnish having a siloxane skeleton in the resin, specifically, alkyd silicone varnish, epoxy silicone varnish, urethane silicone varnish, acrylic silicone varnish, polyester silicone varnish and the like.
These modified silicone varnishes may be commercially available products or may be synthesized. Alternatively, a resin obtained by copolymerizing a polysiloxane having a polymerizable double bond with another (meth) acrylic monomer can also be used. By using the silicon-modified resin, it is possible to obtain the effect of excellent weather resistance and acid resistance.

As the method for synthesizing the polysiloxane having a polymerizable double bond, for example, a reaction between an isocyanate group-containing (meth) acrylic acid ester and a hydroxyl group-containing polysiloxane, a reaction between glycidyl methacrylate and an amine group-containing polysiloxane is performed. It can be obtained by reaction or the like. There is also an acrylic silicone resin which has an alkoxysilyl group at the cross-linking point and produces siloxane after cross-linking. There are also those using a silanol group, an epoxy group, and a hydroxyl group for crosslinking, and those having an amino group in an acrylic resin and crosslinking by a reaction with an epoxy compound or epoxysilane. Since the physical properties of the coating film are improved by crosslinking after coating, among the silicone-modified resins, those having a reactive group such as a hydroxyl group and capable of crosslinking with an isocyanate or melamine are preferable.

Other examples include epoxy resins such as polyester resins, fluorine resins, and epoxy resins that are crosslinked (cured) with an acid (the acid may be blocked with vinyl ether), but are not limited thereto. Not something. By using the fluorine-based resin, the effect of excellent weather resistance can be obtained. Further, by including an epoxy resin that is crosslinked (cured) with an acid, the effect of excellent appearance and acid resistance can be obtained. Specific examples of the epoxy resin that is crosslinked (cured) with an acid include an epoxy group-containing vinyl copolymer, and the content ratio thereof is 10 to 70.
It is preferable that the content is% by weight, but not limited to this.

Further, a melamine resin may be contained. By blending the melamine resin, the effect of heat-curability can be obtained. When the melamine resin is contained, its content is preferably 1 to 50% by weight, but not limited to this. Examples of the resin having a melamine resin include acrylic melamine resin, polyester melamine resin, and fluorine melamine resin.

Component (B) [silicon compound, partial addition thereof
Water Decomposition Condensate] The general formula (1) used in the present invention:

Embedded image The silicon compound represented by and / or its partial hydrolysis-condensation product (B) improves the stain resistance of the coating film formed from the curable coating composition obtained by blending this with the resin (A). .

In the general formula (1), R ¹ and R ²
Is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, preferably an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 9 carbon atoms and a carbon number. It is a monovalent hydrocarbon group selected from 7 to 9 aralkyl groups. Further, b is 0 or 1, ie in the same molecule ^(R 1 O) groups are present 4-3 pieces, present in the same molecule 4-3 amino required ^(R 1 O) groups are the same There is no.

1 to 1 carbon atoms in R ¹ or R ²
0, preferably a monovalent hydrocarbon group selected from an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 9 carbon atoms such as a phenyl group, and an aralkyl group having 7 to 9 carbon atoms such as a benzyl group. Of these, an alkyl group is preferable because the resulting composition has excellent curability.

Specific examples of the silicon compound include, for example, tetramethyl silicate, tetraethyl silicate, tetra n-propyl silicate, tetra i-propyl silicate, tetra n-butyl silicate and tetra i.
Tetraalkyl silicates (tetraalkoxysilanes) such as -butyl silicate and tetra t-butyl silicate; methyltrimethoxysilane, methyltriethoxysilane, octadecyltriethoxysilane, methyltrisec-octyloxysilane, methyltriisopropoxysilane, methyl Examples include alkyltrialkoxysilanes such as tributoxysilane, phenyltrimethoxysilane, aryltrialkoxysilanes such as phenyltriethoxysilane, and trialkoxysilanes or triaryloxysilanes such as alkyltriaryloxysilanes such as methyltriphenoxysilane. To be

As the partially hydrolyzed condensate of the silicon compound, for example, water is added to the tetraalkyl silicate, trialkoxysilane, triaryloxysilane or the like by a conventional method to cause partial hydrolysis and condensation. There are things.

The degree of condensation is not particularly limited, but is 2-5.
About 0 is preferable, and 2 to 20 is more preferable.

Specific examples of the partially hydrolyzed condensate of the silicon compound include, for example, MSI51, ESI40, H
AS-1, HAS-10 (above, Colcoat Co., Ltd. product)
Tetraalkyl silicate partial hydrolysis condensate such as,
Examples thereof include trialkoxysilane partially hydrolyzed condensates such as AFP-1 (manufactured by Shin-Etsu Chemical Co., Ltd.). For reference, the structural formulas of MSI51 and ESI40 are shown below.

[0027]

Embedded image The above-mentioned component (B) may be used alone or in combination of two or more kinds, but the compatibility with the component (A), the curability of the obtained composition and the composition is formed by using the composition. ESI40, MSI51, HAS-1, HAS-1 from the viewpoint of suppressing fixation of contaminants due to the high hardness of the coating film
A partially hydrolyzed condensate of tetraalkyl silicate such as 0 is preferable, and among them, tetraethyl silicate and a partially hydrolyzed condensate of tetraethyl silicate are particularly preferably used.

The amount of the component (B) used is the resin 1 of the component (A).
It is 2 to 70 parts, preferably 5 to 50 parts, and more preferably 10 to 50 parts, relative to 00 parts. If the amount of the component (B) is less than 2 parts, the effect of stain resistance is not sufficient, and if it exceeds 70 parts, the impact resistance decreases.

Component (C) A curing catalyst (C) may be added to the resin of the present invention, if desired.

Specific examples of the component (C) include organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, tin octylate; phosphoric acid, monomethyl phosphate, monoethyl. Phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate,
Phosphoric acid or phosphoric acid ester such as diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, Cardura E manufactured by Yuka Shell Epoxy Co., Ltd., and epoxy compounds such as Epicoat 828 and Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd. Addition reaction product with phosphoric acid and / or monophosphate ester; organic titanate compound; organoaluminum compound; organozinc compound; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, phthalic acid, Carboxylic acid compounds (organic carboxylic acid compounds) such as trimellitic acid and pyromellitic acid,
These acid anhydrides; dodecylbenzenesulfonic acid, paratoluenesulfonic acid, 1-naphthalenesulfonic acid, 2-
Sulfonic acid compounds such as naphthalenesulfonic acid (organic sulfonic acid compounds), and nitrogen compounds containing the sulfonic acid compounds (eg, 1-amino-2-propanol, monoethanolamine, diethanolamine, 2- (methylamino) ethanol, Dimethylethanolamine, 2-
Amino-2-methyl-1-propanol, diisopropanolamine, 3-aminopropanol, 2-methylamino-2-methylpropanol, morpholine, oxazolidine, 4,4-dimethyloxazolidine, 3,4,4
-A compound (a reaction product of an acid and an amine) blocked with trimethyloxazolidine (for example, N manufactured by KING INDUSTRIES)
ACURE5225, NACURE5543, NACU
RE5925); amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine, dodecylamine, DABCO, DBU, morpholine, diisopropanolamine; reaction products of these amines with acidic phosphate And alkaline compounds such as sodium hydroxide and potassium hydroxide. The curing catalyst may be used alone or in combination of two or more kinds.

Among them, it is preferable to use an amine-blocked sulfonic acid compound, a reaction product of an acidic phosphoric acid ester and an amine, or an organic tin compound in terms of excellent curability and appearance.

The amount of the component (C) used is 0.001 to 10 with respect to 100 parts by weight of the total solid content of the components (A) and (B).
Parts, preferably 0.05 to 10 parts. If the amount of the component (C) used is less than 0.001 part, the curability decreases, and
If it exceeds 0 parts, the appearance of the coating film deteriorates.

The effect of imparting stain resistance of the present invention is exhibited by the following mechanism. That is, the coating film surface hardness and hydrophilicity are imparted to the component (B) during the crosslinking reaction.
Since the surface hardness of the coating film becomes high, scratches are less likely to occur and irregularities are less likely to be formed, which makes it difficult for contaminants to settle on the surface of the coating film and prevents contamination. At the same time, since the coating film is hydrophilic, a cleaning effect against rain or the like is exhibited and a coating film having further excellent stain resistance is formed.

The topcoat of the present invention can be further improved in weather resistance by incorporating a weather resistance improver such as an ultraviolet absorber and a light stabilizer. In particular, by using these in combination, the weather resistance can be further improved.

Examples of the ultraviolet absorber include benzophenone type, triazole type, phenyl salicylate type, diphenyl acrylate type, acetophenone type and the like. These may be used alone or in combination of two or more.

Examples of the light stabilizer include bis (2,2
2,6-tetramethyl-4-piperidyl) sebacate,
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate 2,2,6,6-pentamethyl-4-piperidyl), tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1, 2,2,6,6-pentamethyl-4-piperidyl) -1,2,3-4-butanetetracarboxylate and the like can be mentioned. These may be used alone or in combination of two or more.

The amount of the ultraviolet absorber used is usually 0.1 to 10 parts with respect to 100 parts of the resin solid content of the curable composition,
It is preferably 1 to 5 parts, and the amount of the light stabilizer used is usually 0.1 to 10 parts, preferably 1 to 5 parts, relative to 100 parts of the resin solid content of the curable composition. Preferably there is.

Next, an example of the coating film forming method of the present invention will be described.

First, a coating material containing a metallic powder and / or a coloring pigment is applied to an object to be coated, and then a topcoat clear coating material containing the curable composition of the present invention as a main component is applied to the coated surface.

The paint (base coat) containing the metallic powder and / or the coloring pigment is not particularly limited, and examples thereof include aminoalkyd resin, oil-free alkyd resin,
Thermosetting acrylic resin, thermosetting urethane resin, nitrified cotton lacquer, modified acrylic lacquer, slate acrylic lacquer, room temperature curing urethane resin, acrylic enamel resin, oxidative curing alkyd resin, oxidative curing modified (CAB) alkyd resin, room temperature or heat curing Type fluororesin, hydrolyzable silyl group-containing resin and the like can be used.

The coating material containing the metallic powder and / or the color pigment is any one of a solution type coating material using an organic solvent as a medium, a non-aqueous disversion coating material, a multi-component type coating material, a powder coating material, a slurry coating material, an aqueous coating material and the like. Type of paint may be used.

The metallic powder and the color pigment are not particularly limited, and those conventionally used can be used. Specific examples of the metallic powder include, for example, aluminum powder, copper powder, and mica powder, and specific examples of the coloring pigment include organic pigments such as phthalocyanine blue, toluidine red, and benzidine yellow, titanium oxide, and carbon black. Inorganic pigments such as red iron oxide. These metallic powders and color pigments may be used alone or in combination of two or more.

If the base coat is blended with the above-mentioned UV absorber or light stabilizer, the weather resistance of the coated article can be further improved.

Further, a coating material containing metallic powder and / or a coloring pigment is blended with the above-mentioned silicon compound (aminosilane compound etc.) in order to improve the adhesion between the coating film and the top coat clear coating film. Good.

In this case, the compounding amount of the silicon compound is 100% by weight of the coating material 100 containing the metallic powder and / or the coloring pigment.
It is usually 20 parts or less, preferably 10 parts or less and 0.5 parts or more with respect to parts.

The coated article of the present invention is one in which a top coat clear coating composition is further coated on the coating surface coated with the base coat. For example, the coating material containing the metallic powder and / or the coloring pigment is coated on the coating object. After setting for a few minutes, apply the top coat clear paint by the wet-on-wet method and heat-cure the 2-coat 1-bake method, or apply the paint containing metallic powder and / or color pigment and heat-cure it. After that, it can be manufactured by a method such as a 2 coat 2 bake method in which a top coat clear paint is applied and cured by heating.

The top coat clear paint can be applied by various methods conventionally used such as dipping, spraying, brush coating, and a method using a roll coater or a flow coater. Then, it can be cured by heating to 30 ° C. or higher, preferably 55 to 350 ° C.

The thickness of the coating film of the coated product cannot be unconditionally specified because it depends on the application, but metallic powder and / or
Alternatively, the thickness of the coating film containing the color pigment is preferably in the range of 10 to 30 μm from the viewpoint of hiding property, and the thickness of the top coat clear coating film is 20 to 50 from the viewpoint of durability and the like.
The range of μm is preferred.

[0049]

According to the method of forming a coating film of the present invention, a coating film having excellent appearance, weather resistance and the like, a low contact angle with water and extremely excellent stain resistance can be obtained. This method can be used, for example, in automobiles, industrial machinery, steel furniture,
It can be suitably used as a top coat used for interior and exterior of buildings, home appliances, plastics, etc., particularly for automobiles.

[0050]

EXAMPLES Synthesis Example 1 (Synthesis of Acrylic Resin Containing Hydroxyl Group (A-1)) A reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel was fitted with Solvesso 100 (Exxon Chemical Co., Ltd. ), Petroleum-based aromatic solvent) (26 parts) and heated to 110 ° C. while introducing nitrogen gas, and then [Table 1] below.
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 5 hours.

[0051]

[Table 1] After the addition of the mixture was completed, 1 part of 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of Solvesso 100 were added.
After dripping at a constant rate over a period of time, polymerizing for 2 hours and then cooling,
Further, Solvesso 100 was added to adjust the resin solid content to 60% to obtain a hydroxyl group-containing acrylic resin (number average molecular weight 5,400).

Synthesis Example 2 (Synthesis of hydroxyl group-containing acrylic resin)
(A-2)) A reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction pipe and a dropping funnel was charged with 26 parts of Solvesso 100 (manufactured by Exxon Chemical Co., Ltd., petroleum aromatic solvent), After raising the temperature to 110 ° C. while introducing nitrogen gas, the following [Table 2]
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 5 hours.

[0053]

[Table 2] After the addition of the mixture was completed, 1 part of 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of Solvesso 100 were added.
After dripping at a constant rate over a period of time, polymerizing for 2 hours and then cooling,
Further, Solvesso 100 was added to adjust the resin solid content to be 60% to obtain a hydroxyl group-containing acrylic resin (number average molecular weight 5,200).

Synthesis Example 3 (Amino Group-Containing Acrylic Resin
(A-3)) A reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel was charged with 26 parts of Solvesso 100 (exxon chemical Co., Ltd., petroleum aromatic solvent). After heating to 110 ° C. while introducing nitrogen gas, the following [Table 3]
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 5 hours.

[0055]

[Table 3] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of xylene were added dropwise at a constant rate over 1 hour, polymerization was carried out for 2 hours, followed by cooling and then Solvesso 100. Acrylic resin containing amino groups (number average molecular weight 5,
400) was obtained.

Synthesis Example 4 (Vinyl containing hydrolyzable silyl group)
Synthesis of polymer (A-4)) 26 parts of xylene was charged into a reactor equipped with a stirrer, thermometer, reflux condenser, nitrogen gas introducing pipe and dropping funnel, and the temperature was raised to 110 ° C while introducing nitrogen gas. After heating, [Table 4] below
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 5 hours.

[0057]

[Table 4] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added dropwise at a constant rate over 1 hour, polymerization was carried out for 2 hours, and the mixture was cooled and xylene was further added. In addition, the resin solid content was adjusted to 60% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,100).

Synthesis Example 5 (Vinyl containing hydrolyzable silyl group)
Synthesis of polymer (A-5)) 26 parts of xylene was charged into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel, and the temperature was raised to 110 ° C while introducing nitrogen gas. After heating, [Table 5] below
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 4 hours.

[0059]

[Table 5] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added dropwise at a constant rate over 30 minutes, polymerization was carried out for 1 hour 30 minutes, and the mixture was cooled to an ortho Methyl acetate (4 parts) and methanol (4 parts) were added, and Solvesso 100 was further added to adjust the resin solid content to 60% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,200). Obtained.

Synthesis Example 6 (Vinyl containing hydrolyzable silyl group)
Synthesis of polymer (A-6)) 26 parts of xylene was charged into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel, and the temperature was raised to 110 ° C while introducing nitrogen gas. After heating, [Table 6] below
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 4 hours.

[0061]

[Table 6] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added dropwise at a constant rate over 30 minutes, polymerization was carried out for 1 hour and 30 minutes, and the mixture was cooled to obtain orthoacetic acid. Methyl 4 parts and methanol 4 parts were added, and Solvesso 100 was further added to adjust the resin solid content to 60% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,100). It was

Synthesis Example 7 (Hydrolysable silyl group-containing vinyl
Synthesis of polymer (A-7)) 26 parts of xylene was charged into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel, and the temperature was raised to 110 ° C while introducing nitrogen gas. After heating, [Table 7] below
The mixture having the composition described in 1) was added dropwise at a constant rate from the dropping funnel over 4 hours.

[0063]

[Table 7] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added dropwise at a constant rate over 30 minutes, polymerization was carried out for 1 hour 30 minutes, and the mixture was cooled to an ortho Methyl acetate (4 parts) and methanol (4 parts) were added, and Solvesso 100 was further added to adjust the resin solid content to 60% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,400). Obtained.

Synthesis Example 8 ( Compound of Silicon Modified Acrylic Resin)
(A-8)) 1,3,5,7-tetramethyl-3,5,7-tripropyl-in a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel. 42.4 parts of 1- (γ-hydroxypropyl) cyclotetrasiloxane and 6 parts of butyl acetate are added and kept at 20 to 25 ° C. 11.1 parts of methacryloyl isocyanate was added dropwise to this solution at a constant rate over 30 minutes, and the temperature was maintained for 3 hours after the addition. After that, the pressure is 5mm
The mixture was stirred for 1 hour under the conditions of Hg and a temperature of 50 ° C., butyl acetate was removed and the mixture was concentrated to obtain a reaction product.

Solvesso 100 is installed in a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel.
26 parts were charged, the temperature was raised to 110 ° C. while introducing nitrogen gas, and then the mixture having the composition shown in [Table 8] below was added dropwise at a constant rate over 5 hours from a dropping funnel.

[0066]

[Table 8] After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added dropwise at a constant rate over 1 hour, polymerization was carried out for 2 hours, followed by cooling and then Solvesso 100. Was added to adjust the resin solid content to be 60% to obtain a silicone-modified acrylic resin (number average molecular weight 5,500).

Synthesis Example 9 (Synthesis of Epoxy Group-Containing Polymer)
(A-9) ) 17 parts of Solvesso 100 (manufactured by Exxon Chemical Co., Ltd., petroleum-based aromatic solvent) in a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction pipe and a dropping funnel, n- After charging 10 parts of butanol and raising the temperature to 110 ° C. while introducing nitrogen gas, a mixture having the composition described in [Table 9] below was added dropwise at a constant rate from a dropping funnel over 4 hours.

[0068]

[Table 9] After the completion of dropping the mixture, 0.3 part of Kayaester 0 and 10 parts of xylene were dropped at a constant rate over 30 minutes, polymerization was carried out for 1 hour and 30 minutes, followed by cooling, and Solvesso 100 was added to obtain a resin solid content of 60. % To obtain an epoxy group-containing polymer (number average molecular weight 5,400).

Synthesis Example 10 (of carboxyl group-containing polymer
Synthesis (A-10) ) 26 parts of Solvesso 100 (Petroleum aromatic solvent manufactured by Exxon Chemical Co., Ltd.) was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction pipe and a dropping funnel. After introducing nitrogen gas and raising the temperature to 110 ° C., the following [Table 1
[0] was added dropwise at a constant rate from a dropping funnel over 4 hours.

[0070]

[Table 10] After the addition of the mixture was completed, 0.3 part of Kayaester 0 and 10 parts of xylene were added dropwise at a constant rate over 30 minutes, polymerization was carried out for 1 hour and 30 minutes, followed by cooling, and Solvesso 100 was added to obtain a resin solid content of 50. % To prepare an acid anhydride group-containing polymer.

Furthermore, 100 parts of the obtained acid anhydride group-containing polymer, 4 parts of methanol, 0.5 parts of triethylamine, acetic acid were placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube. A mixture of 8 parts of butyl was reacted at 60 ° C. for 6 hours to measure an infrared absorption spectrum, and it was confirmed that absorption of an acid anhydride group (1785 cm ⁻¹ ) disappeared, and a carboxyl group- and carboxylic acid ester group-containing polymer was obtained. (Number average molecular weight 5,400) was obtained.

Synthesis Example 11 (hydration of ethyl silicate 40)
Preparation of Decomposition Product (B-1)) 100 parts of ethyl silicate 40, 100 parts of isopropyl alcohol, 10 parts of ion-exchanged water, 5 parts of 2% hydrochloric acid were reacted with stirring with an agitator for 1 hour to obtain ethyl silicate. 40 hydrolysis solutions were prepared.

Examples 1 to 3 and Comparative Example 1 The components shown in [Table 11] were blended in the proportions shown in the same table, and the leveling agent was added to 100 parts of the solid contents of the components (A) and (B). (Disparon L-1984-5
0, 0.4 part of Kusumoto Kasei Co., Ltd., 2 parts of tinuvin 384 (manufactured by Ciba Geigy) as an ultraviolet absorber, and 1 part of tinuvin 292 (manufactured by Ciba Geigy) as a light stabilizer were added.

Then, it was diluted with xylene and adjusted to have a viscosity of about 20 seconds by Ford Cup # 4 to obtain a clear coating for top coat.

Examples 4 to 16 and Comparative Examples 2 to 7 The components shown in [Table 12] to [Table 14] were blended in the proportions shown in the table, and the solids of the component (A) and the component (B) were further added. Leveling agent (Disparon L-
1984-50, manufactured by Kusumoto Kasei Co., Ltd. 0.4 part, Tinuvin 384 (produced by Ciba-Geigy) as an ultraviolet absorber 2
Parts, and 1 part of TINUVIN 123 (manufactured by Ciba Geigy) as a light stabilizer.

After that, it was diluted with Solvesso 100, and the No. A clear paint for a top coat was obtained by adjusting the viscosity with a 4 Ford cup to be about 22 seconds.

Preparation of coating film [2 coat 2 bake] (implementation
Examples 1 to 3 and Comparative Example 1) A coated plate obtained by coating a degreased and phosphorylated steel sheet with an automobile amide-based cationic electrodeposition primer and an intermediate coating surfacer was used as a test piece, and an acrylic urethane resin coating was applied thereon. (High Art # 3 manufactured by Isamu Paint Co., Ltd.)
000 white (paint containing a coloring pigment (titanium oxide)) was applied and baked at 70 ° C. for 30 minutes.

Next, after cooling to room temperature, the clear paint for top coat obtained in the above Examples and Comparative Examples was applied, set for 10 minutes, and then baked at 70 ° C. for 30 minutes to form a coating film. The dry film thickness of the obtained top coat clear was about 30 to 40 μm.

Preparation of coating film [2 coat 1 bake] (implementation
Examples 4 to 16 and Comparative Examples 2 to 7) A coated plate prepared by coating a degreased and phosphorylated steel sheet with an automobile epoxy amide-based cationic electrodeposition primer and an intermediate coat surfacer was used as a test piece, and on its surface, Acrylic melamine resin paint (white (paint containing color pigment)) was applied as a base coat. 5-
After setting for 10 minutes, the clear paint for top coat obtained in the above Examples and Comparative Examples was wet-on.
Wet painting, setting for 10 minutes, 140 ℃
And baked for 30 minutes to form a coating film.

The dry film thickness of the obtained coating film was about 15 μm for the base coat and about 30-40 μ for the top coat clear.
m.

The appearance, weather resistance, contact angle to water, and stain resistance of the obtained coating film were evaluated according to the following methods. The results are shown in [Table 11] to [Table 14].

Appearance and image clarity measuring device (ICM-1-DP manufactured by Suga Test Instruments Co., Ltd.)
The image clarity of the coating film was measured using a mold and a slit width of 0.5 mm. It should be noted that the larger the value of the image clarity is, the more excellent the appearance is.

Weather resistance The sunshine weatherometer accelerated weather resistance test was conducted at a black panel temperature of 63 ° C. for 2,000 hours to determine the 60 ° gloss retention before and after the test.

Contact Angle to Water After leaving the obtained coating film at room temperature for 7 days, about 0.03 ml was applied to the surface of the coating film using Kyowa Interface Science CA-S150 type.
A water drop of ion-exchanged water was added and the static contact angle after 3 minutes at 23 ° C. was measured.

Contamination resistance The lightness represented by the L ^* a ^* b ^* color system at the early stage of exposure was measured with a color difference meter (CR-300 manufactured by Minolta), and the outdoor exposure at 30 ° on the south side was performed in Settsu City, Osaka Prefecture. It was carried out for 3 months. L ^* a ^* b ^* was measured after exposure, and the difference in brightness before and after exposure (ΔL ^* value)
Was used as a measure of contamination. In addition, a smaller value indicates that the sample is contaminated (a larger value indicates that the stain resistance is superior).

[0086]

[Table 11]

[Table 12]

[Table 13]

[Table 14] .

From the above results, the coating films formed by using the coating materials obtained in Examples 1 to 16 are all excellent in appearance and weather resistance, and at the same time, have a small contact angle to water and stain resistance. It can be seen that it is extremely excellent in sex.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C09D 201/00 PDC C09D 201/00 PDC

Claims (13)

[Claims] 1. A method for forming a coating film, comprising forming a coating film having a contact angle with water of 65 ° or less by applying a top coat on a base coat applied on the surface of an object to be coated, wherein the base coat comprises: The coating composition contains a metallic powder and / or a coloring pigment, and the top coat has a silicone compound represented by the following general formula (1) and / or a partial hydrolysis-condensation product thereof in an amount of 2 to 70 relative to 100 parts by weight of the resin.
A method for forming a coating film, characterized in that the coating film is formed by blending parts by weight. Embedded image (In the formula, R ¹ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group,
R ² is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and b is 0 or 1. ) 2. The method according to claim 1, wherein the resin is mainly an acrylic resin. 3. The method according to claim 1, wherein the resin is an acrylic resin, and is a resin having a urethane bond or a resin mainly subjected to urethane crosslinking. 4. The method according to claim 1, wherein the resin is mainly a silicone-modified resin. 5. The fluororesin-based resin as the main component.
The described method. 6. The method according to claim 1, wherein the resin contains a melamine resin. 7. The method according to claim 1, wherein the resin contains an acid-crosslinking epoxy resin. 8. The method according to claim 1, wherein the resin is a polymer containing an n-butyl methacrylate unit as a polymerization component. 9. The method according to claim 1, wherein two or more kinds of the silicon compound represented by the general formula (1) and / or its partial hydrolysis-condensation product are used in combination. 10. The partially hydrolyzed condensate of tetraalkyl silicate as claimed in claim 1.
9. The method according to any one of 9 above. . 11. The method according to claim 1, wherein the top coat further contains a curing catalyst. 12. The curing catalyst is at least one selected from the group consisting of an amine-blocked sulfonic acid compound, a reaction product of an acidic phosphoric acid ester and an amine, and an organotin compound. Method. 13. Two coat one bake system or two coat two
The method according to any one of claims 1 to 12, which is performed by a baking method.