JPH11116847A - Topcoat composition and method of forming coating film - Google Patents

Abstract

(57) [Problem] To provide an overcoating composition capable of forming an overcoating film having excellent appearance, weather resistance and stain resistance on an object to be coated, and forming the coating film. The organic coating composition has a weight average molecular weight of 75.
A topcoat composition comprising a hydrolytic condensate of a specific organosilicate compound having a contact angle of water of from 50,000 to 50,000 when applied on a basecoat applied on the surface of an object to be applied. To give a topcoat composition which gives a coating film having a thickness of 65 ° or less, and a coating film is formed using the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a top coating composition and a method for forming a coating film from the composition. More specifically, for example, cars, industrial machinery, steel furniture,
Suitable for interior and exterior of buildings, home appliances, plastics, etc., it has excellent appearance and curability, and has extremely excellent stain resistance. The present invention relates to a coating composition and a method for forming a coating film of the composition.

[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, household appliances, plastics, and the like. Have been. By using such a paint, a coating film having excellent appearance, weather resistance, and the like is formed on an object to be coated.

[0003] In the case of a top coat finish of an automobile, there are two types, a metallic color finish and a solid color finish.

[0004] In the case of a metallic color finish, a metallic base coat is applied, and then a clear paint such as an acrylic melamine resin paint, a fluororesin paint, an acrylic urethane resin paint is applied by a wet-on-wet method, In general, a method of heating and curing by a two-coat one-bake method or a method of two-coat two-bake method in which a base coat is applied and cured by heating, and then a top coat clear paint is applied and heated and cured.

On the other hand, in the case of solid color finishing, an alkyd melamine resin paint or the like is used, and a method of heating and curing by one coat and one bake method has been generally adopted, but recently, the finished appearance and weather resistance have been adopted. As the demands on various properties such as sex have become strict,
A method of applying 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, the resulting coating film has excellent appearance,
Despite exhibiting weather resistance and the like, attached dirt is difficult to remove, and is particularly remarkable in the case of light-colored paint. In view of the appearance of articles, the ease of cleaning, and the reduction in the number of times of cleaning, it is desired to improve the contamination resistance.

[0007] As a method for improving stain resistance, WO 94/106870 discloses a coating composition comprising an organic coating composition containing an organosilicate and a condensate thereof. The weight average molecular weight of the organosilicate compound used is at most about 500 at most, and sufficient contamination resistance is not necessarily obtained. In addition, a large amount of silicate compound is required for the development of stain resistance, and there is a disadvantage that appearance and impact resistance are reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and its objects are to improve the appearance,
Provided is a coating composition for forming a coating film having excellent weather resistance and impact resistance, as well as extremely excellent stain resistance on an object to be coated, and a method for forming a coating film from the composition. And a weight average molecular weight of 750 to 100 parts (parts by weight, hereinafter the same) of the organic coating composition.
General formula (I) which is 50,000:

[0009]

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(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
A monovalent hydrocarbon group selected from 10 alkyl groups, aryl groups and aralkyl groups, R ² is a monovalent hydrocarbon group selected from alkyl groups having 1 to 10 carbon atoms, aryl groups and aralkyl groups, a Represents 0 or 1), a partially hydrolyzed condensate of an organosilicate compound represented by the formula:
A top coat composition comprising 1 to 15 parts,
The contact angle between the surface of the coating film formed from this material and water is 65.
(4) The topcoat composition (claim 1), wherein the organic coating composition contains a reactive curable organic resin as a resin component. 2) The topcoat composition according to claim 1, wherein the organic coating composition contains an acrylic resin as a main component of the resin component, and the resin component contained in the organic coating composition is urethane. The top coating composition (Claim 4) according to claim 2, which is mainly composed of an acrylic resin capable of crosslinking, and the resin component contained in the organic coating composition is mainly composed of a modified silicone resin. The resin composition contained in the top coating composition (claim 5) and the organic coating composition is mainly composed of a fluororesin.
3. The top coating composition according to claim 2, wherein the resin component contained in the organic coating composition contains a melamine resin (claim 7), and the organic coating composition. 3. The overcoating coating composition according to claim 2, wherein the resin component contained in the composition is mainly an acrylic resin capable of crosslinking with an acid and an epoxy, and the organosilicate compound is methyl silicate. The top coating composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9 further comprising a curing catalyst. Forming a coating film from the top coating composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 by a two-coat one-bake method or a two-coat two-bake method. How to form a coating film characterized by (Claim 11), metallic powder and (or) coated article paint containing a color pigment is formed by coating on the coating surface, according to claim 1, 2, 3, 4,
A method for forming a coating film, characterized by applying the top coating composition according to 6, 7, 8, 9 or 10. (Claim 12)
About.

The "subject" in claim 3 etc.
The term "when" means 50% (% by weight, the same applies hereinafter) or more in the total amount of the resin components.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The top coating composition of the present invention has a general formula (I) having a weight average molecular weight of 750 to 50,000 in an organic coating composition.

[0013]

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(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
A monovalent hydrocarbon group selected from 10 alkyl groups, aryl groups and aralkyl groups, R ² is a monovalent hydrocarbon group selected from alkyl groups having 1 to 10 carbon atoms, aryl groups and aralkyl groups, a Is a top coat composition comprising a partially hydrolyzed condensate of an organosilicate compound represented by the formula:

The organic coating composition is not particularly limited as long as it is a coating composition mainly using an organic resin as a resin component (base resin component), and the reactive curable organic resin (A) is used as a resin component. It is preferable to contain it from the viewpoint of weather resistance, stain resistance and the like. In addition, it is preferable to contain a resin generally called an acrylic resin as a main component of the resin component from the viewpoint of appearance and weather resistance.

The reactive curable organic resin (A) contained as the resin component can be used as long as the resin itself can react and cure to form a crosslinked coating structure. The following is a specific example.

Further, the acrylic resin contained as a main component of the resin component may be contained in a non-curable organic resin which solidifies (forms a coating film) by scattering of an organic solvent.

Examples of the organic coating composition containing the reactive curable organic resin (A) as a resin component include the reactive curable organic resin (A) and, if necessary, a pigment, a leveling agent, and an ultraviolet absorber. And a curable resin composition containing a light stabilizer and the like dissolved or dispersed in an organic solvent.

As the organic solvent contained in the curable resin composition, those which are substantially inert to the curable resin composition and which can dissolve or disperse the curable resin composition are known in the art. What is necessary is just to select and use suitably from those. Specifically, hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as dioxane and ethylene glycol diethyl ether, butanol And alcohol solvents such as propanol, and aliphatic hydrocarbon solvents such as pentane, hexane and heptane.

The proportion of the curable resin composition in the organic coating composition comprising the curable resin composition and an organic solvent is as follows:
From the viewpoint of appearance and workability, 5 to 90%, further 10 to 8%
0%, preferably 15 to 75%, and the proportion of the organic solvent is 10 to 95%, more preferably 20 to 90%, particularly 2 to 90%.
5-85% is preferred.

When a non-curable organic resin of the above acrylic resins is used, acrylic resin, nitrified cotton lacquer, modified acrylic lacquer and the like may be used as necessary.

The proportion of the non-curable resin composition in the organic coating composition comprising the non-curable resin composition and the organic solvent is 10 to 60% from the viewpoint of workability and appearance, and more preferably 2 to 60%.
0-50% is preferable, and the ratio of the organic solvent is 40-9%.
It is preferably 0%, more preferably 50 to 80%, but is not limited thereto by the coating method or other conditions. As the organic solvent, those described above can be used.

Next, the reactive curable organic resin (A), the non-curable organic resin, and the partially hydrolyzed condensate of the organosilicate compound represented by the general formula (I) will be described.

[Reactive curable organic resin (A)] The reactive curable organic resin (A) has a number average molecular weight of, for example, 2,000 to 500,000, and more preferably 2,500 to 8,000.
A synthetic resin for a reactive curable paint of 0 is used, and a commercially available product can also be used. When the number average molecular weight is less than 2000, the weather resistance tends to be poor, and
If it exceeds 000, the appearance tends to decrease.

The reactive curable organic resin (A) may be of a solvent type or an aqueous type such as an emulsion type or a water-soluble type. In the case of the emulsion type, an emulsifier may be used, or a soap-free emulsifier may be used. In the case of an aqueous type, as a group for curing by a reaction (a group capable of undergoing a crosslinking reaction), a melamine crosslinking, a urethane crosslinking, a hydrazine group and a carbonyl group, an oxazoline group and a carboxyl group, and a crosslinking reaction with an alkoxysilyl group are performed. And those having a carboxylic acid group. Among them, the alkoxysilyl group is particularly preferable because it reacts with the partially hydrolyzed condensate (B) of the organosilicate compound represented by the general formula (I), and the durability increases.

Examples of the reactive curable organic resin (A) include a reactive curable acrylic resin capable of crosslinking with urethane, a reactive curable modified silicone resin, a reactive curable fluororesin, and a reactive curable melamine resin. And an acrylic resin that crosslinks with an acid and an epoxy.

In the process of forming a coating film, the reactive curable organic resin (A) is a reactive curable acrylic resin which forms a urethane and comprises a hydroxyl group-containing acrylic resin and a (block) polyisocyanate compound (crosslinking agent). In the case of the main resin component, an excellent and durable coating film is formed.

The hydroxyl group-containing acrylic resin can be obtained, for example, by copolymerizing a hydroxyl group-containing vinyl monomer (a) with another copolymerizable vinyl monomer (b).

The hydroxyl group-containing vinyl monomer (a) is not particularly restricted but includes, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxy Butyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, 4-hydroxystyrene, Alonix 5700 manufactured by Toa Gosei Chemical Industry Co., Ltd.
HE-10, HE-20 manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
HP-10 and HP-20 (all of which are acrylate oligomers having a hydroxyl group at a terminal), Blenmer PP series (polypropylene glycol methacrylate), Blenmer PE series (polyethylene glycol monomethacrylate), Blenmer, manufactured by NOF Corporation PEP series (polyethylene glycol polypropylene glycol methacrylate), Blemmer AP
-400 (polypropylene glycol monoacrylate), Blemmer AE-350 (polyethylene glycol monoacrylate), and Blemmer GLM (glycerol monomethacrylate), ε- obtained by the reaction of a hydroxyl group-containing vinyl compound with ε-caprolactone.
Caprolactone-modified hydroxyalkyl vinyl copolymerizable compound, polycarbonate-containing vinyl compound (for example, HEAC-1 (Daicel Chemical Industries, Ltd.)
Manufactured). These hydroxyl group-containing vinyl monomers may be used alone or in combination of two or more. Among them, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate,
-Hydroxybutyl (meth) acrylate is preferred because it can impart excellent acid resistance and water resistance to the coating film.

The other vinyl monomer (b) copolymerizable with the hydroxyl group-containing vinyl monomer (a) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) ) Acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, etc. (Meth) acrylic acid ester monomers; unsaturated polycarboxylic acids such as diesters or half esters of unsaturated polycarboxylic acids (maleic acid, fumaric acid, itaconic acid) and C1-C20 linear or branched alcohols Acid esters; aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrene sulfonic acid, vinyl toluene and sodium styrene sulfonate; unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, and fumaric acid Acids, salts thereof such as alkali metal salts, ammonium salts and amine salts; acid anhydrides of unsaturated carboxylic acids such as maleic anhydride, and salts thereof with linear or branched alcohols having 1 to 20 carbon atoms Esters of unsaturated carboxylic acids such as diesters or half esters; vinyl acetate, Vinyl esters and allyl compounds such as vinyl diallyl phthalate pionate; vinyl compounds containing nitrile groups such as (meth) acrylonitrile; vinyl compounds containing epoxy groups such as glycidyl (meth) acrylate; dimethylaminoethyl (meth) acrylate, dimethylaminoethyl ( Vinyl compounds containing a basic nitrogen atom such as (meth) acrylate, diethylaminoethyl (meth) acrylate, vinylpyridine and aminoethyl vinyl ether; (meth)
Acrylamide, itaconic diamide, α-ethyl (meth) acrylamide, crotonic amide, maleic diamide, fumaric diamide, N-vinylpyrrolidone, N
Amide group-containing vinyl compounds such as -butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, and acryloylmorpholine; photostable monomers (for example, 1,2,2,6,6-
Pentamethyl-4-piperidyl (meth) acrylate,
2,2,6,6-tetramethyl-4piperidyl (meth)
(Meth) acrylic acid alkyl ester-based polymers having a curability obtained by copolymerizing acrylates and the like, and ultraviolet-absorbing monomers (2-hydroxy-4-
((Meth) acryloyloxyethoxy) benzophenone, etc.), methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide, N-vinylimidazole, and other vinyl compounds such as vinylsulfonic acid And the like.

These may be used alone or in combination of two or more.

The hydroxyl group-containing acrylic resin preferably contains the hydroxyl group-containing vinyl monomer (a) in an amount of 10 to 80.
%, More preferably 20 to 60%, and the other copolymerizable vinyl monomer (b) is preferably 20 to 90%.
%, More preferably 40 to 80%. Hydroxyl-containing vinyl monomer (a)
If the amount is less than 10%, the curability tends to decrease.
%, The water resistance and weather resistance tend to decrease.

When the acrylic resin containing a hydroxyl group contains an n-butyl methacrylate unit as a copolymerization component, a phase with a partially hydrolyzed condensate (B) of an organosilicate compound represented by the following general formula (I) is used. Improved solubility. The preferable content ratio of the n-butyl methacrylate unit is 10 to 60%, and more preferably 15 to 50%.

The obtained hydroxyl-containing acrylic resin may contain less than 50% of a segment formed by a urethane bond or a siloxane bond in the main chain.

The hydroxyl-containing acrylic resin is preferably prepared by solution polymerization using a radical initiator.
In the solution polymerization, a chain transfer agent such as n-dodecyl mercaptan is used as needed to control the molecular weight.

As the solvent used in the solution polymerization, a non-reactive solvent is used, but the present invention is not limited by these.

The hydroxyl group-containing acrylic resin has a number average molecular weight of 1,000 to 25,000, more preferably 1,000 to 15,
000 is preferred. When the number average molecular weight is less than 1000, there is a case where weather resistance and water resistance are reduced,
Conversely, if it exceeds 25000, the compatibility of the blend may be reduced. Further, the hydroxyl value is preferably from 20 to 1,000, more preferably from 50 to 750. Hydroxyl value is 20
If it is less than 1,000, the durability and stain resistance of the coating film may decrease. If it exceeds 1,000, the durability and water resistance of the coating film may decrease.

The acrylic resin containing a hydroxyl group may be used alone or in combination of two or more.

The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule, and specific examples thereof include aliphatic compounds such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, and hydrogenated xylylene diisocyanate. Examples include alicyclic compounds such as isocyanate, isophorone diisocyanate and cyclohexane diisocyanate, and aromatic compounds such as tolylene diisocyanate and diphenylmethane diisocyanate.

As the above-mentioned blocked polyisocyanate compound, the above-mentioned polyisocyanate compound is, for example, ε
-Blocking agents such as lactam blocking agents such as caprolactam, alcohol blocking agents such as ethanol, propanol and butanol, and oxime blocking agents such as acetoxime.

The mixing ratio of the hydroxyl group-containing acrylic resin and the (block) polyisocyanate compound is such that the ratio of the isocyanate group of the (block) polyisocyanate compound to the hydroxyl group of the hydroxyl group-containing acrylic resin is 0.5 to 1.5.
It is preferable to make the equivalent amount, preferably 0.8 to 1.2 equivalent amount. If the compounding ratio is less than 0.5 equivalent, the stain resistance, weather resistance, water resistance, etc. of the coating film are reduced,
If the amount exceeds 1.5 equivalents, the stain resistance and weather resistance of the coating film tend to decrease.

When the reactive curable organic resin (A) is a reactive curable modified silicone resin, it has excellent weather resistance and acid resistance.

Specific examples of the reactive curable modified silicone resin include modified silicones having a siloxane skeleton in the resin, specifically, alkyd-modified silicone, epoxy-modified silicone, urethane-modified silicone, acryl-modified silicone, and polyester-modified silicone. And so on. These are usually used in the form of a modified silicone varnish. It may be a commercially available product or a synthesized product.

A resin obtained by copolymerizing an organopolysiloxane having a polymerizable double bond with another (meth) acrylic monomer can also be used.

As a method for synthesizing the above-mentioned organopolysiloxane having a polymerizable double bond, for example, glycidyl (meth) acrylate and amino group are reacted by reacting an isocyanate group-containing (meth) acrylate and a hydroxyl group-containing organopolysiloxane. A method of reacting with a group-containing organopolysiloxane is exemplified.

Specific examples of the organopolysiloxane having a polymerizable double bond include, for example,

[0047]

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And the like. Examples of the other (meth) acrylic monomer include, for example, the same monomers as the other vinyl monomer (b).

As the acrylic-modified silicone resin, there is also an acrylic silicone resin having an alkoxysilyl group as a crosslinking point and generating a siloxane bond by crosslinking. In addition, an alkoxysilyl group, an epoxy group,
There are also those using a hydroxyl group, those using an alkoxysilyl group, an epoxy group, a hydroxyl group, and a carboxyl group, and those using an acrylic resin having an amino group and a carboxyl group and being crosslinked by reaction with an epoxy compound or epoxysilane. Since the coating properties are improved by cross-linking after coating, the modified silicone resin has a reactive group such as a hydroxyl group, a type crosslinked by isocyanate or melamine and an epoxy group or a hydroxyl group, and a carboxyl group. Crosslinking types are preferred.

The modified silicone resin has a number average molecular weight of 2,000 to 20,000, more preferably 3,000 to 2,000.
Preferably it is 15,000. Number average molecular weight is 2,
When the molecular weight is less than 000, the curability and weather resistance tend to decrease, while when it exceeds 20,000, the appearance and workability tend to decrease.

The modified silicone resins may be used alone or in combination of two or more.

Other examples of the reactive curable organic resin (A) include a reactive curable polyester resin, a reactive curable fluororesin, an acid (a compound containing a carboxyl group and / or a resin, where the acid is vinyl ether). Acrylic resins which crosslink (cure) the epoxy (which may be blocked) with the epoxy, and the like, but are not limited thereto.

When the reactive curable fluororesin is used as a main component of the resin component, a topcoat composition having excellent weather resistance can be obtained.

Examples of the reactive curable fluororesin include those obtained by combining a hydroxyl group-containing fluororesin with a reactive curing agent such as an amino resin, a polyisocyanate compound or a blocked polyisocyanate compound.

Examples of the hydroxyl group-containing fluororesin include:
Examples of the resin include a resin obtained by copolymerizing the hydroxyl group-containing vinyl monomer (a), the fluoroolefin (c), and the other vinyl monomer (b) as needed.

The fluoroolefin (c) has the general formula:

[0057]

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Wherein R ³ , R ⁴ and R ⁵ each represent H, F or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different. sell. Specific examples include vinyl fluoride, vinylidene fluoride, ethylene trifluoride chloride, and ethylene tetrafluoride. Among these, from the point that a coating film excellent in durability and stain resistance is obtained, ethylene tetrafluoride,
Trifluoroethylene chloride is preferred.

Further, the hydroxyl group-containing fluororesin may have a carboxyl group. The carboxyl group is
For example, it can be introduced by subjecting a part of the hydroxyl groups in the hydroxyl group-containing fluororesin to an addition reaction with a polybasic anhydride (for example, itaconic anhydride, succinic anhydride, etc.).

The hydroxyl group-containing fluororesin preferably contains the hydroxyl group-containing vinyl monomer (a) in an amount of preferably 10 to 60%, more preferably 15 to 50%, and the fluoroolefin (c).
Is preferably 5 to 50%, more preferably 10 to 30%.
%, Other copolymerizable vinyl monomer (b) is preferably 20 to 80%, more preferably 30 to 70%.
Are copolymerized. If the amount of the hydroxyl group-containing vinyl monomer (a) is less than 10%, the curability tends to decrease, and if it exceeds 60%, the workability and water resistance tend to decrease. If the amount of the fluoroolefin (c) is less than 5%, high weather resistance tends not to be expected, and
If it exceeds 0%, the compatibility with the silicate compound tends to decrease.

Other than these, as the hydroxyl group-containing fluororesin, a monomer having a perfluoroalkyl group or a perfluoroalkenyl group at one end and an ethylenic double bond at the other end instead of the fluoroolefin (c) A polymer obtained by copolymerizing the compound (d) may also be used.

The monomer (d) having a perfluoroalkyl group or a perfluoroalkenyl group at one end and having an ethylenic double bond at the other end includes, for example, perfluorobutylethyl methacrylate, perfluorooctylethyl methacrylate, Perfluoroisononylethyl methacrylate, perfluorodecylethyl methacrylate and the like can be mentioned.

The hydroxyl group-containing fluororesin has a number average molecular weight of 2,000 to 100,000, more preferably 5,000 to 80,000.
000 is preferred. The number average molecular weight is 200
If it is less than 0, the durability of the coating film and the retention of stain resistance are reduced. On the other hand, if it exceeds 100,000, the compatibility with the curing agent and the partially hydrolyzed condensate (B) is reduced, and the paint is stored. There is a tendency for stability to decrease.

The hydroxyl group-containing fluororesin preferably has a hydroxyl value of about 20 to 200, more preferably about 50 to 150. When the hydroxyl value is less than about 20, the durability of the coating film and the retention of stain resistance are reduced.
If the ratio exceeds the above range, the durability, water resistance, and stain resistance of the coating film tend to decrease.

As the amino resin, melamine, urea,
Examples include methylolated amino resins obtained by reacting an aldehyde with an amino component such as benzoguanamine, acetoguanamine, steroganamin, spiroguanamine, dicyandiamide and the like. Aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. Further, those obtained by etherifying the methylolated amino resin with an appropriate alcohol can also be used. Examples of the alcohol used for the etherification include methyl alcohol, ethyl alcohol, and the like.
n-propyl alcohol, i-propyl alcohol, n
-Butyl alcohol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like.

The mixing ratio of the hydroxyl group-containing fluororesin and the amino resin is 90 to 40%, more preferably 80 to 50%, and the amino resin is 10 to 60%, and more preferably 20 to 40%, in terms of the total weight of both. 50% is preferred. Outside the above range, the stain resistance, water resistance, weather resistance and the like of the coating film are undesirably reduced.

The mixing ratio of the hydroxyl group-containing fluororesin to the (block) polyisocyanate compound is preferably about 0.6 to 1.5 equivalents of the isocyanate group of the (block) polyisocyanate compound to the hydroxyl groups of the hydroxyl group-containing fluororesin. Is preferably in the range of about 0.8 to 1.2 equivalents. When the mixing ratio is less than about 0.6 equivalent, the weather resistance of the coating film,
The stain resistance, weather resistance, water resistance, etc. are reduced, while about 1.
If the amount exceeds 5 equivalents, the stain resistance and weather resistance of the coating film tend to decrease, which is not preferable.

Cross-linking (curing) with the acid and epoxy
In the case of a resin component mainly composed of an acrylic resin, a top coating composition having excellent appearance and acid resistance can be obtained.

The reaction-curable organic resin (A) is a resin component mainly composed of an acrylic resin which forms an epoxy-epoxy crosslink composed of an epoxy group-containing resin and a carboxyl group-containing resin (or compound) in the process of forming a coating film. In this case, a coating film having excellent acid resistance and weather resistance is formed.

As the epoxy group-containing resin, for example, commercially available epoxy resins such as celloxite 2021, Eporide GT-400 (Daicel Chemical Co., Ltd.), and Epolite 100MF (Kyoeisha Oil & Fats Co., Ltd.) can be used. Is an epoxy group-containing vinyl monomer (e)
And an epoxy group-containing vinyl copolymer obtained by copolymerization with the above-mentioned other copolymerizable vinyl monomer (b).

The epoxy group-containing vinyl monomer (e)
There is no particular limitation, and for example, glycidyl methacrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, and the like are preferable because they can impart the curability and water resistance of the coating film. Further, the hydroxyl group-containing vinyl monomer (a) may be copolymerized.

The epoxy equivalent of the obtained epoxy group-containing resin is preferably 100 to 1,000, more preferably 2 to 1,000.
00 to 800. If the epoxy equivalent is more than 1000, the curability tends to be insufficient, and if it is less than 100, the coating becomes too hard and the coating film tends to become brittle.

The epoxy group-containing resin has a number average molecular weight of 2,000 to 20,000, more preferably 2,500 to 1
Preferably it is 5,000. Number average molecular weight is 2,0
If it is less than 00, the weather resistance and curability tend to decrease, and if it exceeds 20,000, the appearance tends to decrease.

Examples of the carboxyl group-containing resin (or compound) include a polycarboxylic acid compound obtained by reacting a polyol compound with an acid anhydride, and a carboxyl group-containing vinyl monomer and other copolymerizable vinyl monomers. A carboxyl group-containing resin obtained by copolymerization with (b), an acid anhydride group-containing resin obtained by copolymerization of an acid anhydride group-containing vinyl monomer with another copolymerizable vinyl monomer (b), and Examples thereof include a carboxyl group-containing resin obtained by a half esterification reaction with an alcohol (methanol, allyl alcohol, ethanol, etc.). Further, the hydroxyl group-containing vinyl monomer (a) may be copolymerized.

Examples of the carboxyl group-containing vinyl monomer include acrylic acid and methacrylic acid.

Examples of the acid anhydride group-containing vinyl monomer include maleic anhydride and itaconic anhydride.

The carboxyl group-containing resin is preferably a carboxyl group-containing vinyl monomer or an acid anhydride group-containing vinyl monomer in an amount of preferably 7 to 40%, more preferably 1 to 40%.
0 to 30%, and preferably 60 to 93%, more preferably 7%, of the other copolymerizable vinyl monomer (b).
It is obtained by copolymerizing 0 to 90%. If the ratio of the vinyl monomer having a carboxyl group or an acid anhydride group is less than 7%, curability tends to be insufficient, and
If it exceeds 0%, the obtained coating film tends to be too hard and brittle, and the weather resistance tends to decrease.

The carboxyl group-containing resin has a number average molecular weight of 1,500 to 20,000, more preferably 3,000 to 2,000.
Preferably it is 15,000. Number average molecular weight is 1,
If it is less than 500, the durability of the coating tends to decrease, and if it exceeds 20,000, the appearance and workability tend to decrease.

The mixing ratio of the epoxy group-containing resin and the carboxy group-containing resin (or compound) is such that the carboxyl group of the carboxyl group-containing resin (or compound) is 0.1 to 1 equivalent of the epoxy group of the epoxy group-containing resin. Two
It is preferred that the amount be 5 equivalents, preferably 0.3 to 3.0 equivalents. When the ratio of the carboxyl group is less than 0.2 equivalent, the curability tends to decrease, while when it exceeds 5 equivalents, the weather resistance and the water resistance tend to decrease.

The reactive curable organic resin (A) also includes a reactive curable amino resin as a main component of the resin component, so that a top coat composition having excellent heat curability and appearance can be obtained.

Specific examples of the reactive curable amino resin include a combination of a hydroxyl group-containing acrylic resin and an amino resin.

The mixing ratio of the hydroxyl group-containing acrylic resin and the amino resin is 90 to 40%, preferably 80 to 50%, and the amino resin is 10 to 60%, preferably 20 to 40% in total amount of both. 50% is good. Outside the above range, the stain resistance, water resistance, weather resistance and the like of the coating film are undesirably reduced.

[Non-Curable Organic Resin] As the solvent-based organic coating composition, a non-curable organic resin can be used in addition to the reactive curable organic resin. A coating composition using a non-curable organic resin is a solution-type or dispersion-type coating composition in which a solvent, for example, an organic solvent volatilizes at room temperature or under heating to form a coating film.

[Partially Hydrolyzed Condensate of Organosilicate Compound (B)] The general formula (I) used in the present invention:

[0085]

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The partially hydrolyzed condensate (B) of the organosilicate compound represented by the formula (B) is mixed with an organic coating composition, preferably an organic coating composition containing the reactive curable organic resin (A) as a resin component. It is a component that improves the stain resistance of the formed coating film.

In the general formula (I), R ¹ represents a hydrogen atom or a carbon atom having 6 to 10 carbon atoms, preferably 1 to 4 carbon atoms, preferably 1 to 4 carbon atoms, such as a phenyl group.
A monovalent hydrocarbon group selected from aralkyl groups having 7 to 9 carbon atoms such as an aryl group and an aralkyl group, preferably a benzyl group, wherein R ² has 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. A monovalent hydrocarbon group selected from an aryl group having 6 to 9 carbon atoms such as an phenyl group and an aralkyl group, preferably an aralkyl group having 7 to 9 carbon atoms such as a benzyl group; is there. Among the above R ^{1 and} R ² , an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms is preferable, since the obtained composition has excellent curability.

[0088] Further, a is 0 or 1, i.e. within the same in the molecule (R ¹ O) of the group are present three or four, three are present in the same molecule, or 4 (R ¹ O) groups Need not be the same. If a exceeds 1, the stain resistance decreases.

Specific examples of the above organosilicate compounds include, for example, tetramethyl silicate, tetraethyl silicate, tetra n-propyl silicate, tetra i-propyl silicate, tetra n-butyl silicate, tetra i-butyl silicate, tetra t-butyl silicate Alkyltrialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyltrisec-octyloxysilane, methyltriisopropoxysilane, and methyltributoxysilane;
Examples include aryltrialkoxysilanes such as phenyltrimethoxysilane and phenyltriethoxysilane, and trialkoxysilanes or triaryloxysilanes such as alkyltriaryloxysilanes such as methyltriphenoxysilane.

As the partially hydrolyzed condensate of the organosilicate compound, for example, water is added to an organosilicate compound such as a tetraalkylsilicate, trialkoxysilane, or triaryloxysilane by a usual method, and the resultant is partially hydrolyzed to condense. What was done is given.

The partial hydrolysis condensate (B) has a weight average molecular weight of 750 to 50,000,
000 is preferred. If the molecular weight is less than 750, the stain resistance is low, and if it exceeds 50,000, the finish and storage stability are poor.

Preferable specific examples of the partially hydrolyzed condensate (B) include partially hydrolyzed tetraalkyl silicates such as MS51, MS56 and MS56S (manufactured by Mitsubishi Chemical Corporation), MSI51 and ESI40 (manufactured by Colcoat Co., Ltd.). Decomposition condensates. Among them, a partially hydrolyzed condensate of the above tetraalkyl silicate is further preferably partially hydrolyzed and condensed to have a weight average molecular weight of about 750 to 50,000. These may be used alone.
More than one species may be used in combination. When the partially hydrolyzed condensate (B) is a partially hydrolyzed condensate of a tetraalkyl silicate, a resin component, preferably a reactive curable organic resin (A)
Compatibility with the composition, the curability of the resulting composition, and the high hardness of the coating film formed using the composition, which suppresses the fixation of contaminants. It is preferable from the viewpoint of removing contaminated substances by rainfall or the like. In the case where the partially hydrolyzed condensate of the tetraalkyl silicate is further partially hydrolyzed and condensed to have a weight average molecular weight of about 750 to 50,000, the present invention It is preferable because it is easy to synthesize a partially hydrolyzed condensate of an organosilicate compound having a weight average molecular weight to be used.

The amount (solid content) of the partially hydrolyzed condensate (B) is 0.1% based on the resin component in the organic coating composition, preferably 100 parts (solid content) of the reactive curable organic resin (A).
The amount is 1 to 15 parts, preferably 0.5 to 15 parts, more preferably 1.0 to 15 parts. Partial hydrolysis condensate (B)
If less than 0.1 part, the effect of stain resistance is not sufficient, and if it exceeds 15 parts, impact resistance and appearance deteriorate. Further, from the viewpoint of the stability of the obtained partially hydrolyzed condensate of an organosilicate compound, a methoxy-type organosilicate compound is preferred.

[Curing Catalyst (C)] The top coating composition of the present invention may optionally contain a curing catalyst (C).

Specific examples of the curing catalyst (C) include organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, and 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., Epicoat 828, Epicoat 100 manufactured by Yuka Shell Epoxy Co., Ltd.
Addition reaction product of epoxy compound such as 1 with phosphoric acid and / or monophosphate; organic titanate compound; organic aluminum compound; organic zinc compound; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid Carboxylic acid compounds (organic carboxylic acid compounds) such as succinic acid, phthalic acid, trimellitic acid, and pyromellitic acid, and their acid anhydrides; dodecylbenzenesulfonic acid, p-toluenesulfonic acid, 1-naphthalenesulfonic acid, Sulfonic acid compounds (organic sulfonic acid compounds) such as naphthalenesulfonic acid, and nitrogen-containing compounds containing the sulfonic acid compounds (eg, 1-amino-2-propanol, monoethanolamine, diethanolamine, 2- (methylamino) ethanol, Dimethylethanolamine, 2-A Roh-2-methyl-1-propanol, diisopropanolamine, 3-amino-propanol, 2-methylamino-2-methyl propanol,
Blocked with morpholine, oxazolidine, 4,4-dimethyloxazolidine, 3,4,4-trimethyloxazolidine, etc. (reacted product of acid and amine) (for example, King Industry (KING IND)
USTRIES) NACURE 5225, NAC
URE5543, NACURE 5925, etc.); hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine, dodecylamine, DABCO,
Amines such as DBU, morpholine and diisopropanolamine; reactants of these amines with acidic phosphate esters; and alkaline compounds such as sodium hydroxide and potassium hydroxide. The curing catalyst may be used alone or in combination of two or more. Among them, the use of a sulfonic acid compound blocked with an amine, a reaction product of an acidic phosphoric acid ester and an amine, and an organotin compound are preferable in terms of excellent curability and appearance.

When the curing catalyst (C) is used, the amount (solid content) of the resin component, preferably, the total solid content of the reactive curable organic resin (A) and the partially hydrolyzed condensate (B) is 100%. The amount is preferably 0.001 to 10 parts, more preferably 0.05 to 10 parts with respect to parts. If the amount of the curing catalyst (C) is less than 0.001 part, the effect of improving the curability by using the curing catalyst (C) cannot be sufficiently obtained,
If it exceeds 10 parts, the appearance of the coating film tends to decrease.

[Mechanism] The effect of imparting stain resistance by using the top coating composition of the present invention is considered to be exerted by the following mechanism.

That is, the cross-linking reaction of the partially hydrolyzed condensate (B) imparts high coating film surface hardness and high hydrophilicity. In particular, the partially hydrolyzed condensate (B) having a weight average molecular weight in the present invention imparts excellent hydrophilicity even in a small amount. Further, since the surface hardness of the coating film is increased, the coating film is hardly scratched or irregularities are hardly formed. As a result, the contaminants are hardly fixed on the coating film surface and are less likely to be contaminated. At the same time, since the coating film has high hydrophilicity, a cleaning effect against rain and the like is developed, and a coating film having more excellent stain resistance is formed.

[Other Ingredients] The weathering resistance can be further improved by adding a weathering resistance improver such as an ultraviolet absorber and a light stabilizer to the overcoat composition of the present invention. When these are used together,
Further, the weather resistance can be further improved.

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

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

When the ultraviolet absorber is used, the amount is usually 0.1 to 10 parts, preferably 1 to 5 parts, based on 100 parts of the resin solids in the topcoat composition. When the light stabilizer is used, the amount is usually 0.1 to 10 parts, more preferably 1 to 5 parts, based on 100 parts of the resin solid content in the top coating composition.

[Formation of Coating Film] Next, an example of a method for forming a coating film of the present invention will be described.

First, a paint containing a metallic powder and / or a coloring pigment is applied to the object to be coated, and then a topcoat clear paint mainly containing the topcoat composition of the present invention is applied to the applied surface.

The coating (base coat) containing the metallic powder and / or the coloring pigment is not particularly limited, and examples thereof include aminoalkyd resin coating, oil-free alkyd resin coating, thermosetting acrylic resin coating, and thermosetting urethane resin. Paint, nitrified cotton lacquer, modified acrylic lacquer, slate acrylic lacquer, cold-curable urethane resin paint, acrylic enamel resin paint, oxidation-curable alkyd resin paint, oxidation-curable modified (such as CAB) alkyd resin paint, normal-temperature or heat-curable Fluororesin paints, hydrolyzable silyl group-containing resin paints, and the like can be used.

The paint containing the metallic powder and / or the color pigment may be, for example, a solution paint using an organic solvent as a medium, a non-aqueous dispersion paint, a multi-pack paint, a powder paint, a slurry paint, or a water paint. Any type of paint may be used.

The metallic powder and coloring 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, mica powder,
Specific examples of the coloring pigment include, for example, organic pigments such as phthalocyanine blue, toluidine red, and benzidine yellow; and inorganic pigments such as titanium oxide, carbon black, and red iron oxide. These metallic powders and coloring pigments may be used alone or in combination of two or more.

When the above-mentioned ultraviolet absorber and light stabilizer are added to the base coat, the weather resistance of the coated product can be further improved.

Further, a silicone compound (for example, aminoethylaminopropyltrimethoxysilane, γ) may be added to a paint containing a metallic powder and / or a color pigment in order to improve the adhesion between the paint film and the top coat clear paint film. -Aminopropyltrimethoxysilane, γ-aminopropyldimethoxysilane, γ-aminopropyltriethoxysilane, aminosilane-based compounds such as γ-aminopropyldiethoxysilane, etc.).

Compounding amount (solid content) of the silicon compound
Is usually 20 parts or less with respect to 100 parts (solid content) of a paint containing a metallic powder and / or a color pigment.
Preferably it is 10 parts or less and 0.5 parts or more.

The coating film of the present invention is formed by applying a top coat clear paint to the surface to which the base coat has been applied. For example, the object to be coated contains the metallic powder and / or the coloring pigment. After applying paint and setting for a few minutes, wet on
Top coat clear paint is applied by applying a top coat clear paint by wet coating and heating and curing, or by applying a paint containing metallic powder and / or coloring pigment and heating and curing. It can be formed by a method such as a two-coat two-bake method of curing by heating.

The top coat clear paint can be applied by various methods conventionally used, such as dipping, spraying, brushing, and 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 specified unconditionally because it differs depending on the application, but the thickness of the coating film containing the metallic powder and / or the coloring pigment is preferably 10 to 30 μm in view of concealability and the like. Is preferable, and the thickness of the top coat clear coating film is preferably in the range of 20 to 50 μm from the viewpoint of durability and the like.

When the top coat composition of the present invention is applied on the base coat applied on the surface of the object to be applied as described above, the contact angle with water is 65 ° or less, and more preferably 6%.
A coating film of 0 ° or less can be obtained.

[0115]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

The curing catalyst (* 1) in the table is AP-8.
(Daihachi Chemical Co., Ltd., acid phosphate ester) / DBU
(1,8-diazabicyclo [5,4,0] -7-undecene) / isobutyl alcohol = 20 / 4.2 / 75.
A mixture of 8 (weight ratio) (solid content: 20%), a reaction product of aminosilane and epoxysilane (* 2) are A1122 (aminosilane manufactured by Nippon Unicar Co., Ltd.) and A187 (epoxysilane manufactured by Nippon Unicar Co., Ltd.) (Solid content 50%), Cymel 235 is a melamine resin (100% solid content) manufactured by Mitsui Cytec Co., Ltd., and Denacol EX-4.
12 (solid content 100%) is a diglycerol polyglycidyl ether manufactured by Nagase Sangyo Co., Ltd., A187 (solid content 10%).
0%) is Nippon Unicar Co., Ltd. epoxy silane, NA
CURE5225 is obtained by blocking dodecylbenzenesulfonic acid manufactured by King Industries Co., Ltd. with a solid content of 25% (solid content: 25%); Lumiflon LF-100-C (solid content: 50%) is a fluororesin manufactured by Asahi Glass Co., Ltd .; Nippon Polyurethane Co., Ltd.'s blocked isocyanate (solid content 75%) and Uban 20SE (solid content 60%) represent melamine resins manufactured by Mitsui Toatsu Chemicals, Inc.

The evaluation in Examples and Comparative Examples was performed by the following methods.

(Preparation of Coating Film (2 Coats 2 Bake)) (Examples 1 to 3 and Comparative Examples 1 and 2) An amide-based cationic electrodeposition primer for automobiles and an intermediate coating were applied to a steel plate which had been subjected to degreasing and phosphorylation Using a painted plate coated with a surfacer as a test piece, on top of which
An acrylic urethane resin paint (Hiart # 3000 White (paint containing a coloring pigment (titanium oxide)) manufactured by Isamu Paint Co., Ltd.) was applied and baked at 70 ° C. for 30 minutes. The dry film thickness of the obtained base coat was 15 μm.

Next, after cooling to room temperature,
The clear coating material for a top coat obtained in the comparative example was applied, set for 10 minutes, and 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 Coats 1 Bake)) (Examples 4 to 17 and Comparative Examples 3 to 7) An epoxyamide-based cationic electrodeposition primer for automobiles was applied to a steel plate which had been degreased and phosphorylated. A coated plate coated with a coated surfacer was used as a test piece, and an acrylic melamine resin paint (white (paint containing a color pigment)) was applied as a base coat on the surface thereof. After setting for 5 to 10 minutes, the clear paint for top coat obtained in Examples and Comparative Examples was wet-coated.
After painting on wet and setting for 10 minutes, 1
Baking was performed at 40 ° C. 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 to 40 μm for the top coat clear.
m.

(Appearance) Image clarity measuring device (ICM-1-DP type, manufactured by Suga Test Instruments Co., Ltd., slit width 0.5 m)
m) was used to measure the sharpness of the coating film.

The larger the numerical value of the sharpness, the better the appearance.

(Weather Resistance) A sunshine weatherometer-accelerated weather resistance test (manufactured by Suga Test Instruments Co., Ltd.) was performed at a black panel temperature of 63 ° C. for 2,000 hours, and the 60 ° gloss retention before and after the test was determined. .

(Contact angle to water) After the obtained coating film was allowed to stand at room temperature for 7 days, CA-S manufactured by Kyowa Interface Science Co., Ltd.
Using a Model 150, water droplets of about 0.03 ml of ion-exchanged water were dropped on the coating film surface, and the static contact angle after 3 minutes at 23 ° C. was measured.

(Stain resistance) The lightness represented by the L * a * b * color system at the initial stage of exposure was measured using a colorimeter (CR-3 manufactured by Minolta).
00), and an outdoor exposure of 30 ° on the south side was conducted for three months in Settsu City, Osaka Prefecture. L * a * b * after exposure was measured, and the difference in lightness (ΔL * value) before and after exposure 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).

(Impact Resistance) The test was conducted with a DuPont impact tester at a tip radius of 1/2 inch and a drop weight of 500 g. The maximum height at which the coated surface did not crack was shown at 5 cm intervals.

Synthesis Example 1 (Hydroxy group-containing acrylic resin (A-
Synthesis of 1)) A reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel was charged with 26 parts of Solvesso 100 (manufactured by Exxon Chemical Co., Ltd., petroleum aromatic solvent).
After heating to 110 ° C while introducing nitrogen gas, Table 1
Was dripped at a constant velocity over 5 hours from a dropping funnel.

[0129]

[Table 1]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 1 part of Solvesso 100
0 parts was dropped at a constant speed over 1 hour, polymerization was carried out for 2 hours, followed by cooling. Further, Solvesso 100 was added to adjust the resin solid content to 60%, and a hydroxyl group-containing acrylic resin (number average molecular weight 5,400).

Synthesis Example 2 (Hydroxy group-containing acrylic resin (A-
Synthesis of 2)) 26 parts of Solvesso 100 were charged into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel, and heated to 110 ° C. while introducing nitrogen gas. A mixture having the composition shown in Table 2 was dropped at a constant speed from the dropping funnel over 5 hours.

[0132]

[Table 2]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 1 part of Solvesso 100
0 parts was dropped at a constant speed over 1 hour, polymerization was carried out for 2 hours, followed by cooling. Further, Solvesso 100 was added to adjust the resin solid content to 60%, and a hydroxyl group-containing acrylic resin (number average molecular weight 5,200).

Synthesis Example 3 (Amino group-containing acrylic resin (A
Synthesis of -3)) 26 parts of Solvesso 100 were charged into a reactor equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel, and the temperature was raised to 110 ° C. while introducing nitrogen gas. After that, a mixture having the composition shown in Table 3 was dropped at a constant speed from the dropping funnel over 5 hours.

[0135]

[Table 3]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of xylene were added to 1 part of the mixture.
The mixture was dropped at a constant rate over a period of time, polymerized for 2 hours, cooled, and further added with Solvesso 100 to reduce the resin solid content to 60%.
% To obtain an amino group-containing acrylic resin (number average molecular weight 5,400).

Synthesis Example 4 (Synthesis of Hydrolyzable Silyl Group-Containing (Meth) acrylic Acid Alkyl Ester Polymer (A-4)) A stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel were used. After charging 26 parts of xylene into the reactor provided and heating to 110 ° C. while introducing nitrogen gas,
A mixture having the composition shown in Table 4 was dropped at a constant speed from the dropping funnel over 5 hours.

[0138]

[Table 4]

After the completion of the dropwise addition of the mixture, 0.25 part of 2,2'-azobisisobutyronitrile and 10 parts of toluene were mixed with 1 part.
The mixture was cooled at a constant rate over a period of time, polymerized for 2 hours, cooled, and then further adjusted with xylene so that the resin solid content became 60%, and a hydrolyzable silyl group-containing alkyl (meth) acrylate-based alkyl ester was used. Polymer (number average molecular weight 5,10
0).

Synthesis Example 5 (Synthesis of Hydrolyzable Silyl Group-Containing (meth) acrylic Acid Alkyl Ester Polymer (A-5)) A stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel were used. A reactor equipped with 26 parts of xylene,
After heating to 110 ° C. while introducing nitrogen gas, Table 5
Was dropped from the dropping funnel at a constant speed over 4 hours.

[0141]

[Table 5]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added to 3 parts of the mixture.
The mixture was dropped at a constant rate over 0 minutes, and polymerization was carried out for 1 hour and 30 minutes. After cooling, 4 parts of methyl orthoacetate and 4 parts of methanol were added.
The concentration was adjusted to 0% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,200).

Synthesis Example 6 (Synthesis of Hydrolyzable Silyl Group-Containing (Meth) acrylic Acid Alkyl Ester Polymer (A-6)) A stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel were used. A reactor equipped with 26 parts of xylene,
After heating to 110 ° C. while introducing nitrogen gas, Table 6
Was dripped at a constant rate over 4 hours from a dropping funnel.

[0144]

[Table 6]

After the addition of the mixture was completed, 0.25 part of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added to 30 parts of the mixture.
The mixture was cooled at a constant rate over 1 minute, polymerization was carried out for 1 hour and 30 minutes, and the mixture was cooled. 4 parts of methyl orthoacetate and 4 parts of methanol were added.
The concentration was adjusted to 0% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,100).

Synthesis Example 7 (Synthesis of Hydrolyzable Silyl Group-Containing (Meth) acrylic Acid Alkyl Ester Polymer (A-7)) A stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel were used. A reactor equipped with 26 parts of xylene,
After heating to 110 ° C. while introducing nitrogen gas, Table 7
Was dropped from the dropping funnel at a constant speed over 4 hours.

[0147]

[Table 7]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added to 3 parts of the mixture.
The mixture was dropped at a constant rate over 0 minutes, and polymerization was carried out for 1 hour and 30 minutes. After cooling, 4 parts of methyl orthoacetate and 4 parts of methanol were added.
The concentration was adjusted to 0% to obtain a hydrolyzable silyl group-containing vinyl polymer (number average molecular weight 5,400).

Synthesis Example 8 (Synthesis of Silicone-Modified Acrylic Resin (A-8)) 1,3,5,7 was added to a reactor equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel. Then, 42.4 parts of tetramethyl-3,5,7-tripropyl-1- (γ-hydroxypropyl) cyclotetrasiloxane and 6 parts of butyl acetate are added, and the mixture is maintained at 20 to 25 ° C., and methacryloyl isocyanate 11 is added to the solution. 1 part was dropped at a constant speed over 30 minutes, and the temperature was kept for 3 hours after dropping. Thereafter, the mixture was stirred for 1 hour under the conditions of a pressure of 5 mmHg and a temperature of 50 ° C., and butyl acetate was removed and concentrated to obtain a reaction product.

Solvesso 1 was placed in a reactor equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
, And charged with nitrogen gas.
After the temperature was raised to ° C., a mixture having the composition shown in Table 8 was dropped at a constant speed from the dropping funnel over 5 hours.

[0151]

[Table 8]

After the addition of the mixture was completed, 0.25 parts of 2,2'-azobisisobutyronitrile and 10 parts of toluene were added to 1 part of the mixture.
The mixture was dropped at a constant rate over a period of time, polymerized for 2 hours, cooled, and further added with Solvesso 100 to reduce the resin solid content to 60%.
% To obtain a silicone-modified acrylic resin (number average molecular weight 5,500).

Synthesis Example 9 (Synthesis of Epoxy Resin (A-9)) Solvent 17-17 was placed in a reactor equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
And 10 parts of n-butanol, the mixture was heated to 110 ° C. while introducing nitrogen gas, and then a mixture having the composition shown in Table 9 was dropped at a constant rate from the dropping funnel over 4 hours.

[0154]

[Table 9]

After the addition of the mixture was completed, 0.3 parts of Kayaester 0 and 10 parts of xylene were added dropwise at a constant speed over 30 minutes.
After performing polymerization for 1 hour and 30 minutes, the system was cooled, and Solvesso 1
Add 00 to adjust the resin solids to 60%,
An epoxy resin (number average molecular weight 5,400), which is an epoxy group-containing polymer, was obtained.

Synthesis Example 10 (Synthesis of Carboxyl Group-Containing Acrylic Resin (A-10)) Solvesso 100-26 was placed in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
After the temperature was raised to 110 ° C. while introducing nitrogen gas, a mixture having the composition shown in Table 10 was dropped at a constant speed from the dropping funnel over 4 hours.

[0157]

[Table 10]

After the addition of the mixture was completed, 0.3 parts of Kayaester 0 and 10 parts of xylene were added dropwise at a constant speed over 30 minutes.
After performing polymerization for 1 hour and 30 minutes, the system was cooled, and Solvesso 1
Add 00 to adjust the resin solids to 50%,
An acid anhydride group-containing polymer was obtained.

Further, 100 parts of an acid anhydride group-containing polymer obtained in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, 4 parts of methanol, 0.5 parts of triethylamine, 6 parts of a mixture consisting of 8 parts of butyl acetate
After reacting at 0 ° C for 6 hours, the infrared absorption spectrum was measured.
After confirming that the absorption of the acid anhydride group (1785 cm ^-1 ) had disappeared, a polymer containing a carboxyl group and a carboxylate group (number average molecular weight 5,400) was obtained.

Synthesis Example 11 (Preparation of Hydrolytic Condensate of Organosilicate Compound) (B-1) 100 parts of ethyl silicate 40, 100 parts of isopropyl alcohol, 10 parts of ion-exchanged water, 2%
The mixture consisting of 5 parts of hydrochloric acid was reacted with stirring with a stirrer for 1 hour to prepare a hydrolyzed condensate solution of ethyl silicate 40 (solid content: 46.5%) (weight average molecular weight: 38).
000).

(B-2) A mixture of 100 parts of MS56, 3 parts of cation exchange resin, 3 parts of ion-exchanged water, and 25 parts of methanol was reacted at 70 ° C. for 1 hour with stirring, and the hydrolysis condensate of MS56 was obtained. Solution (solid content 78.1)
%) (Weight-average molecular weight: 3680).

(B-3) A mixture comprising 100 parts of MSI51, 3 parts of ion-exchange resin and 25 parts of methanol was mixed with 7 parts of
The reaction was carried out with stirring at 0 ° C. for 2 hours to prepare a hydrolyzed condensate solution of MSI51 (solid content: 80%) (weight average molecular weight: 1980).

Examples 1 to 3 and Comparative Examples 1 and 2 The components shown in Table 11 were mixed in the proportions shown in Table 11, and the leveling agent was added to 100 parts of the solid content of the components (A) and (B). (Dispalon L-1984-50, manufactured by Kusumoto Kasei Co., Ltd.) 0.4 part, Tinuvin 3 as an ultraviolet absorber
84 (Ciba-Geigy) and 1 part of Tinuvin 292 (Ciba-Geigy) as a light stabilizer.

Thereafter, the mixture was diluted with xylene and adjusted so that the viscosity by Ford Cup # 4 was about 20 seconds to obtain a clear coating material for a top coat.

Using the obtained paint, a coating film was formed in accordance with the preparation of the coating film, and the coating film was evaluated. Table 11 shows the results.

[0166]

[Table 11]

Examples 4 to 17 and Comparative Examples 3 to 7 The components shown in Tables 12 to 14 were blended in the proportions shown in Tables 12 to 14, and the solid contents of the components (A) and (B) were further added. Leveling agent (Disparon L-19) to 100 parts
84-50, Kusumoto Kasei Co., Ltd.) (0.4 parts), Tinuvin 384 (Ciba Geigy) as an ultraviolet absorber, 2 parts, and Tinuvin 123 (Ciba Geigy) as a light stabilizer, 1 part.

After that, the mixture was diluted with Solvesso 100 and
o. The viscosity was adjusted to about 22 seconds with a 4 Ford cup to obtain a clear coating for the top coat.

Using the obtained paint, a coating film was formed in accordance with the preparation of the coating film, and the coating film was evaluated. The results are shown in Tables 12 to 14.

[0170]

[Table 12]

[0171]

[Table 13]

[0172]

[Table 14]

From the above results, it can be seen that the coating films formed using the coating materials obtained in Examples 1 to 16 are all excellent in appearance and weather resistance, have a small contact angle with water, and are resistant to contamination. It turns out that it is very excellent in sex.

[0174]

According to the present invention, when a coating film is formed by using the top coating composition of the present invention, for example, by the method for forming a coating film of the present invention, excellent appearance and weather resistance are exhibited, and the contact angle with water is reduced. A coating which is low and exhibits very good stain resistance is obtained.

The obtained coating film can be suitably used, for example, for automobiles, industrial machines, steel furniture, interior and exterior of buildings, home electric appliances, plastics, etc., especially for automotive top coats.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiro Nambu 7172-22-20 Tsutsujigaoka, Tarumizu-ku, Kobe-shi, Hyogo

Claims (12)

[Claims] 1. An organic coating composition based on 100 parts by weight,
General formula (I) having a weight average molecular weight of 750 to 50,000: (Wherein, R ¹ is a hydrogen atom or 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 an alkyl group having 1 to 10 carbon atoms, an aryl group and A monovalent hydrocarbon group selected from aralkyl groups, a represents 0 or 1), which is a topcoat paint composition comprising 0.1 to 15 parts by weight of a partially hydrolyzed condensate of an organosilicate compound represented by the formula: An overcoating composition, characterized in that the contact angle between the surface of the coating film formed from the composition and water is 65 ° or less. 2. The top coating composition according to claim 1, wherein the organic coating composition contains a reactive curable organic resin as a resin component. 3. The top coating composition according to claim 1, wherein the organic coating composition contains an acrylic resin as a main component of the resin component. 4. The top coating composition according to claim 2, wherein the resin component contained in the organic coating composition is mainly composed of an acrylic resin capable of performing urethane crosslinking. 5. The top coating composition according to claim 2, wherein the resin component contained in the organic coating composition mainly comprises a modified silicone resin. 6. The overcoat composition according to claim 2, wherein the resin component contained in the organic coating composition is mainly composed of a fluororesin. 7. The top coating composition according to claim 2, wherein the resin component contained in the organic coating composition contains a melamine resin. 8. The top coating composition according to claim 2, wherein the resin component contained in the organic coating composition is mainly composed of an acrylic resin capable of crosslinking with an acid and an epoxy. 9. The topcoat composition according to claim 1, wherein the organosilicate compound is methyl silicate. 10. The topcoat composition according to claim 1, further comprising a curing catalyst. 11. The method of claim 1, 2, 3, 4, 5, 6, 7,
11. A method for forming a coating film, wherein the formation of a coating film from the top coating composition according to 8, 9, or 10 is performed by a two-coat one-bake method or a two-coat two-bake method. 12. A coated article obtained by applying a coating material containing a metallic powder and / or a coloring pigment to an application surface, wherein the coating material is applied to a coating material. A method for forming a coating film, comprising applying the top coating composition according to any one of the preceding claims.