JP2000212509A - Method for forming coating film and cured product obtained therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating film forming method capable of preventing deterioration of a base material due to a photocatalyst and obtaining an antifouling coating material excellent in long-term durability adhesion, and a cured product obtained by the method. SOLUTION: An undercoating coating composition comprising an aqueous dispersion containing a polyorganosiloxane and a vinyl-based polymer is applied on a substrate, and a topcoat is formed by adding a photocatalyst to the aqueous dispersion. Provided are a method for forming a coating film, which is characterized by applying a composition, and a cured product obtained by the method.

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 capable of preventing deterioration of a substrate due to a photocatalyst and obtaining an antifouling coating material having excellent long-term durability, and a cured product obtained by the method.

[0002]

2. Description of the Related Art Conventionally, various treatments have been performed on coating materials in order to improve the stain resistance and waterproofness of the coating film surface. However, with the conventional surface treatment method, it is difficult to obtain a coating film having high adhesion, weather resistance, heat resistance, moisture resistance, stain resistance, antibacterial property, antifungal property, deodorant function, etc., and high hardness. there were. In particular, in the case of an outdoor structure, it has been recognized that it is better to make the coating film surface hydrophilic in order to improve the stain resistance. For example, a method of adding a hydrophilic substance or a water-soluble substance has been proposed. However, in such a method, it is difficult to maintain the hydrophilicity of the coating film surface at a sufficient level for a long period of time because the hydrophilic substance and the water-soluble substance gradually deteriorate with light or are washed away with water. there were. In addition, conventional photocatalyst inorganic fine particle dispersions have poor stretchability, require high-temperature sintering, are difficult to thicken, have poor adhesion to the substrate, and are limited in applications, and have very long-term durability. There were problems such as scarcity. Furthermore, the conventional coating materials used for the formation of coating films are all solvent type, and from the viewpoints of low pollution, resource saving, safety and health in recent years,
There was a strong demand for solvent removal. Thus, the present inventors have found a photocatalyst-dispersed coating material using a silicon-based aqueous dispersion.However, the photocatalyst-dispersed coating material deteriorates the surface of the base material due to its photocatalytic activity, and the base material and the coating material are not dispersed. Had a problem that the long-term adhesion was poor.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to prevent deterioration of a base material due to a photocatalyst and to provide an excellent long-term durability adhesion. An object of the present invention is to provide a method for forming a coating film from which a soil coating material is obtained and a cured product obtained by the method.

[0004]

According to the present invention, a coating film comprising the following (I) undercoating composition is formed on a substrate, and the following (II) overcoating composition is formed thereon: Characterized by forming a coating film consisting of A polymer containing (I) (A) (a) a polyorganosiloxane and (b) a vinyl polymer (hereinafter also referred to as “specific polymer (A)”) is dispersed in an aqueous medium. Undercoating coating composition containing an aqueous dispersion (hereinafter, referred to as
"(I) Composition"). (II) An aqueous dispersion in which the specific polymer (A) and (B) inorganic fine particles and / or sol having photocatalytic ability (hereinafter also referred to as “photocatalytic component (B)”) are dispersed in an aqueous medium. An overcoating coating composition containing a body (hereinafter, also referred to as “(II) composition”). Further, the present invention provides a cured product obtained by the method for forming a coating film. Hereinafter, the composition used in the present invention will be specifically described.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

(I) Undercoat Coating Composition The (I) composition used in the present invention is a specific polymer (A)
Contains, as a main component, an aqueous dispersion dispersed in an aqueous medium. Specific Polymer (A) The specific polymer (A) is a polymer containing (a) a polyorganosiloxane and (b) a vinyl polymer. Here, "containing (a) a polyorganosiloxane and (b) a vinyl polymer" means that the two components are present separately from each other, or the two components are chemically bonded to each other. It means that they are chemically bonded. Hereinafter, (a) the polyorganosiloxane and (b) the vinyl polymer in the specific polymer (A) will be sequentially described.

(A) Polyorganosiloxane The polyorganosiloxane (a) which is one component of the specific polymer (A) includes an organosilane (hereinafter referred to as “organosilane (a1)” represented by the following general formula (1). ) ") Is preferred. (R ¹ ) _n Si (OR ² ) _4-n (1) (wherein, R ¹ is an organic group having 1 to 8 carbon atoms, and R ² is an organic group having 1 carbon atom.
Represents an alkyl group having from 5 to 5 or an acyl group having from 2 to 4 carbon atoms, and n is an integer from 0 to 2. In the general formula (1), examples of the organic group having 1 to 8 carbon atoms for R ¹ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, s
ec-butyl group, t-butyl group, n-pentyl group, n-
Alkyl groups such as hexyl group, n-heptyl group and n-octyl group; acyl groups such as acetyl group, propionyl group and butyryl group; γ-chloropropyl group, γ-bromopropyl group and 3,3,3-trifluoro Propyl group, γ-glycidoxypropyl group, γ- (meth) acryloxypropyl group, γ-mercaptopropyl group, γ-aminopropyl group, γ-dimethylaminopropyl group, 2- (3,4-epoxycyclohexyl) Examples include an ethyl group, a vinyl group, and a phenyl group. Examples of the alkyl group having 1 to 5 carbon atoms of R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group. -Butyl group, n-pentyl group and the like. Examples of the acyl group having 2 to 4 carbon atoms include an acetyl group, a propionyl group and a butyryl group.

Specific examples of such organosilane (a1) include tetramethoxysilane, tetraethoxysilane, methylsilicate, ethylsilicate, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane. , N-
Propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane,
3,3,3-trifluoropropyltrimethoxysilane,
3,3,3-trifluoropropyltriethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyl Triethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, ureidopropyltrimethoxy Silane, mercaptopropyltrimethoxysilane, aminopropyltrimethoxysilane, ether-modified alkyltrimethoxysilane, aminoethylaminopropyltrimeth Sisilane, aminopropylmethyldimethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di- n-
Alkoxysilanes such as propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxysilane, divinyldimethoxysilane, divinyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane; tetraacetoxysilane, methyl Examples include acyloxysilanes such as triacetoxysilane, ethyltriacetoxysilane, dimethyldiacetoxysilane, and diethyldiacetoxysilane, and preferred are methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane. .

These organosilanes (a1) can be used alone or in combination of two or more. In the present invention, the organosilane (a1) is used as it is or as a hydrolyzate and / or condensate. Here, the hydrolyzate of the organosilane (a1) is
It is not necessary that all the OR ² groups contained in the organosilane (a1) are hydrolyzed, and only one is hydrolyzed, two or more are hydrolyzed, or a mixture thereof. You may. In addition, the condensate of the organosilane (a1) is an organosilane (a1)
The silanol group of the hydrolyzate is condensed to form Si-O-Si
Although a bond is formed, in the present invention, it is not necessary that all silanol groups are condensed, and the present invention also includes those in which a small amount of silanol groups are condensed and those in which the degree of condensation is different. It is a concept that was. In this case, when the specific polymer is produced, a polycondensation reaction of the organosilane (a1) forms a polyorganosiloxane chain, and a condensation reaction between the organosilane (a1) and a vinyl polymer described later occurs. The polyorganosiloxane chain can be chemically bonded to the vinyl polymer. The polystyrene-equivalent weight average molecular weight (hereinafter, referred to as “Mw”) of the condensate of organosilane (a1) is preferably 800 to 100,000, and more preferably 1,0.
00 to 50,000.

(B) Vinyl Polymer The vinyl polymer as the other component of the specific polymer (A) is preferably a vinyl polymer having a hydrophilic functional group. Its structure is such that the main chain is composed of a vinyl polymer, and a hydrolyzable silyl group and / or a hydroxysilyl group (hereinafter, these groups are collectively referred to as "terminals and / or side chains" of the polymer molecular chain). A polymer having at least one, preferably two or more, and at least one, preferably two or more hydrophilic functional groups (hereinafter, referred to as “hydrolyzable silyl group”). b
1) ". Is preferred. Vinyl polymer (b
The hydrolyzable silyl group and the like in 1) are generally represented by the following general formula (2).

[0010]

(Wherein X is a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group, a thioalkoxy group,
Amino group, hydrolyzable group or hydroxyl group such as acetoxy group, R ³ represents a hydrogen atom, an alkyl group or aralkyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms, m is an integer of 1 to 3. )

One or more hydrolyzable silyl groups may be present in the vinyl polymer (b1). Further, as the hydrophilic functional group in the vinyl polymer (b1),
For example, a carboxyl group, a carboxylic anhydride group, a hydroxyl group, an amino group, an amide group, an amine imide group, a glycidyl group and the like can be mentioned. One or more of these hydrophilic functional groups can be present in the vinyl polymer (II). For example, any two or more of a carboxyl group, a hydroxyl group, an amide group, an amine imide group and a glycidyl group coexist. Is preferred. The vinyl polymer (b1) is, for example,
(A) A hydrolyzable silyl group is added to the carbon-carbon double bond of a vinyl polymer having a carbon-carbon double bond and a hydrophilic functional group (hereinafter referred to as “functional unsaturated polymer”). A method of performing an addition reaction with a hydrosilane compound having
(B) It can be produced by a method of copolymerizing a vinyl monomer having a hydrolyzable silyl group or the like and a vinyl monomer having a hydrophilic functional group.

The functional unsaturated polymer used in the above method (a) can be produced, for example, as follows. That is, (a-1) a vinyl monomer having a hydrophilic functional group is (co) polymerized with another vinyl monomer in some cases to synthesize a precursor (co) polymer. A suitable functional group (hereinafter referred to as “complementary functional group (α)”) in the (co) polymer is replaced with a functional group capable of reacting with the complementary functional group (α) (hereinafter, “complementary functional group (α)”). β) ”) and an unsaturated compound having a carbon-carbon double bond to form a carbon-carbon on the side chain of the polymer molecular chain.
A functional unsaturated polymer having a carbon double bond can be produced. Further, (a-2) a radical polymerization initiator having a complementary functional group (α) (for example, 4,4-azobis-4
A compound having a functional group (α) complementary to both the radical polymerization initiator and the chain transfer agent (for example, 4,4-azobis-4-cyanovaleric acid and dithioglycolic acid, etc.) ), And (co) polymerizing a vinyl monomer having a hydrophilic functional group together with another vinyl monomer in some cases, to form a radical polymerization initiator at one or both terminals of the polymer molecular chain. After synthesizing a precursor (co) polymer having a complementary functional group (α) derived from the chain transfer agent, the complementary functional group (α) in the precursor (co) polymer is
By reacting a complementary functional group (β) with an unsaturated compound having a carbon-carbon double bond, a functional unsaturated polymer having a carbon-carbon double bond at one end or both ends of a polymer molecular chain is obtained. Coalescence can be manufactured. further,
(A-3) A functional unsaturated polymer can also be produced by a combination of the above (A-1) and (A-2).
Examples of the reaction between the complementary functional group (α) and the complementary functional group (β) in the methods (A-1) and (A-2) include:
Esterification reaction between carboxyl group and hydroxyl group, ring-opening esterification reaction between carboxylic anhydride group and hydroxyl group, esterification reaction between carboxyl group and epoxy group, amidation reaction between carboxyl group and amino group, carboxylic acid anhydride Ring-opening amidation reaction between a substance group and an amino group, ring-opening addition reaction between an epoxy group and an amino group, urethanization reaction between a hydroxyl group and an isocyanate group, and the like.

Examples of the vinyl monomer having a hydrophilic functional group include (meth) acrylic acid, crotonic acid,
Carboxyl group-containing unsaturated acids such as cinnamic acid, maleic acid, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, monomethyl itaconate, monoethyl itaconate, mono-2- (meth) acryloyloxyethyl hexahydrophthalate Compounds; unsaturated carboxylic anhydrides such as maleic anhydride and itaconic anhydride; 2-hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl ( (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-
Hydroxybutyl (meth) acrylate, 5-hydroxyamyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, neopentyl glycol mono (meth) acrylate, 3-chloro-2-hydroxy Propyl (meth) acrylate, 3-amino-2-hydroxypropyl (meth) acrylate, mono- or di- (meth) acrylate of glycerin, mono- or di- (meth) acrylate of trimethylolpropane, mono- of pentaerythritol Or di- (meth) acrylate, N-methylol (meth) acrylamide, N, N
Hydroxyl-containing vinyl monomers such as dimethylol (meth) acrylamide, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether and 3-hydroxypropyl vinyl ether; 2-aminoethyl (meth) acrylate, 2-aminopropyl (meth) Acrylate, 3-aminopropyl (meth) acrylate, 2
-Dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 2-aminoethyl vinyl ether, N, N-dimethylamino Amino group-containing vinyl monomers such as (meth) acrylamide and N, N-diethylamino (meth) acrylamide; acrylamide, diacetone acrylamide, maleic diamide, fumaric diamide, itaconic diamide, α-ethylacrylamide, N- Vinyl monomers containing an amide group such as butoxymethyl (meth) acrylamide; 1,1,1
-Trimethylamine (meth) acrylimide, 1-methyl-1-ethylamine (meth) acrylimide, 1,1
-Dimethyl-1- (2-hydroxypropyl) amine (meth) acrylimide, 1,1-dimethyl-1-
(2′-phenyl-2′-hydroxyethyl) amine (meth) acrylimide, 1,1-dimethyl-1-
Amine-containing vinyl monomers such as (2'-hydroxy-2'-phenoxypropyl) amine (meth) acrylimide; containing glycidyl groups such as allyl glycidyl ether, glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate Vinyl monomers; epoxy group-containing vinyl monomers such as epoxidized cyclohexyl (meth) acrylate; and vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl versatate. These vinyl monomers can be used alone or in combination of two or more.

Among the above-mentioned vinyl monomers having a hydrophilic functional group, in the group of unsaturated carboxylic acids and unsaturated carboxylic anhydrides, (meth) acrylic acid is particularly preferred. Is particularly preferably 2-hydroxyethyl (meth) acrylate, and in the group of the vinyl monomer containing an amino group and the vinyl monomer containing an amine imide, 1,1-dimethyl-1- (2-hydroxypropyl) is particularly preferable. Amine (meth) acrylimide, 1,1-
Dimethyl-1- (2'-phenyl-2'-hydroxyethyl) amine (meth) acrylimide, 1,1-dimethyl-1- (2'-hydroxy-2'-phenoxypropyl) amine (meth) acrylimide, etc. (Meth) acrylic amide imide having a hydroxyl group is preferred.

Other vinyl monomers to be copolymerized with a vinyl monomer having a hydrophilic functional group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
N-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate,
(Meth) acrylates such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate; (meth) acrolein, crotonaldehyde, formylstyrene, and formyl-α -Methylstyrene, diacetone acrylamide, (meth) acrylamide pivalinaldehyde, 3-
(Meth) acrylamidomethyl-anisaldehyde, β
-(Meth) acryloxy-α, α-dimethylpropanal (ie, β- (meth) acryloxypivalinaldehyde), β- (meth) acryloxy-α, α-diethylpropanal, β- (meth) acryloxy-α , Α-dipropylpropanal, β- (meth) acryloxy-α-
Methyl-α-butylpropanal, β- (meth) acryloxy-α, α, β-trimethylpropanal, diacetone (meth) acrylamide, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, Vinyl ethyl ketone, vinyl-n-propyl ketone, vinyl-i-propyl ketone, vinyl-n-butyl ketone, vinyl-i-butyl ketone, vinyl-t-butyl ketone, etc.), vinyl phenyl ketone, vinyl benzyl ketone, divinyl ketone, diacetone (Meth) acrylate, acetonitrile (meth) acrylate, 2-hydroxypropyl (meth) acrylate-acetyl acetate, 3-hydroxypropyl (meth) acrylate-
Acetyl acetate, 2-hydroxybutyl (meth) acrylate-acetyl acetate, 3-hydroxybutyl (meth) acrylate-acetyl acetate, 4-hydroxybutyl (meth) acrylate-acetyl acetate, butanediol-1,4- (meth) acrylate A vinyl monomer having a carbonyl group such as acetyl acetate; (meth) acrylonitrile, styrene, α
-Methylstyrene, vinyl chloride, vinyl acetate, vinyl propionate and the like. These vinyl monomers can be used alone or in combination of two or more. The vinyl monomer having a carbonyl group reacts with the component (G) described below to form a network structure. In this case, the specific polymer (A) preferably contains the carbonyl group-containing vinyl monomer in an amount of 0.5 to 30 parts by weight. Examples of the unsaturated compound having a complementary unsaturated group (β) and a carbon-carbon double bond include, for example, unsaturated carboxylic acids and unsaturated carboxylic acids of the above vinyl monomers having a hydrophilic functional group. In addition to anhydrides, hydroxyl group-containing vinyl monomers or amino group-containing vinyl monomers, for example, epoxy group-containing unsaturated compounds such as glycidyl (meth) acrylate and allyl glycidyl ether;
Examples of the isocyanate group-containing unsaturated compound obtained by reacting the hydroxyl group-containing vinyl monomer and the diisocyanate compound in an equimolar amount.

The hydrosilane compound having a hydrolyzable group used in the method (a) includes, for example,
Halogenated silanes such as methyldichlorosilane, phenyldichlorosilane and trichlorosilane; alkoxysilanes such as methyldimethoxysilane, methyldiethoxysilane, phenyldimethoxysilane, trimethoxysilane and triethoxysilane; methyldiacetoxysilane; Acyloxysilanes such as phenyldiacetoxysilane and triacetoxysilane; aminoxysilanes such as dimethylaminoxysilane, methyldiaminooxysilane and triaminoxysilane; phenoxysilanes such as methyldiphenoxysilane and triphenoxysilane Thioalkoxysilanes such as methyldi (thiomethoxy) silane and tri (thiomethoxy) silane; and aminosilanes such as methyldiaminosilane and triaminosilane. These hydrosilane compounds can be used alone or in combination of two or more. Next, the vinyl monomer having a hydrolyzable silyl group or the like used in the above method (b) is represented by the following general formula (3).

[0018]

(In the formula, X, R ³ and m have the same meanings as in formula (2), and R ⁴ represents an organic group having a polymerizable carbon-carbon double bond.)

Specific examples of such a vinyl monomer having a hydrolyzable silyl group include CH ₂ ＣＨCHSi
(CH ₃ ) (OCH ₃ ) ₂ , CH ₂ ＣＨCHSi (OCH ₃ )
₃ , CH ₂ ＣＨCHSi (CH ₃ ) Cl ₂ , CH ₂ ＣＨCHS
iCl ₃ , CH ₂ ＣＨCHCOO (CH ₂ ) ₂ Si (CH ₃ )
(OCH ₃ ) ₂ , CH ₂ ＣＨCHCOO (CH ₂ ) ₂ Si (O
_{CH 3) 3, CH 2 =} CHCOO (CH 2) 3 Si (CH 3)
(OCH ₃ ) ₂ , CH ₂ ＣＨCHCOO (CH ₂ ) ₃ Si (O
CH ₃ ) ₃ , CH ₂ ＣＨCHCOO (CH ₂ ) ₂ Si (CH ₃ )
Cl ₂ , CH ₂ ＣＨCHCOO (CH ₂ ) ₂ SiCl ₃ , C
H ₂ ＣＨCHCOO (CH ₂ ) ₃ Si (CH ₃ ) Cl ₂ , CH
₂ ＣＨCHCOO (CH ₂ ) ₃ SiCl ₃ , CH ₂ ＣC (C
H ₃ ) COO (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , CH
₂ ＣC (CH ₃ ) COO (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , C
H ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) (OC
H ₃ ) ₂ , CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₃ Si (O
CH ₃ ) ₃ , CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₂ Si
(CH ₃ ) Cl ₂ , CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₂
SiCl ₃ , CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₃ Si
(CH ₃ ) Cl ₂ , CH ₂ ＣC (CH ₃ ) COO (CH ₂ ) ₃
SiCl ₃ ,

[0021]

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[0022]

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[0023]

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[0024]

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And the like. These vinyl monomers having a hydrolyzable silyl group or the like can be used alone or in combination of two or more. Examples of the vinyl monomer having a hydrophilic functional group used in the method (b) include, for example, the same vinyl monomer having a hydrophilic functional group exemplified in the method (a) above. One or more can be used. Further, in the method (b), one or more other vinyl monomers exemplified for the method (a) may be copolymerized.

In the present invention, the particularly preferred content of the vinyl monomer having a hydrophilic functional group in the vinyl polymer (b1) varies depending on the type of the vinyl monomer. That is, the total content of (a) the unsaturated carboxylic acid and / or the unsaturated carboxylic acid anhydride is particularly preferably from 0.5 to
10% by weight is preferred, and the content of (b) the hydroxyl group-containing vinyl monomer is particularly preferably 5 to 30% by weight, and (c)
The total content of the amino group-containing vinyl monomer and / or the amine imide group-containing vinyl monomer is particularly 0.05%.
~ 3% by weight is preferred. In the present invention, by setting the content of the vinyl monomer having a hydrophilic functional group in the above range, the storage stability of the obtained aqueous dispersion becomes particularly excellent. Further, in the present invention, the above (a),
It is preferable to use any two or more of the vinyl monomers shown in (b) and (c) in combination.
It is preferable to use one or more of the vinyl monomers shown in (b) and (c) in combination.

The vinyl polymer (b1) obtained as described above has a polystyrene reduced number average molecular weight (hereinafter referred to as "M
n ") is preferably from 2,000 to 100,00
0, and more preferably 4,000 to 50,000. In the present invention, the vinyl polymer (b1) can be used alone or as a mixture of two or more. The amount of the vinyl polymer (b1) used in the present invention is usually 2 parts by weight based on 100 parts by weight of the polyorganosiloxane (a1).
９００900 parts by weight, preferably 10-400 parts by weight, more preferably 20-200 parts by weight. In this case, if the amount of the vinyl polymer (b1) used is less than 2 parts by weight, the alkali resistance of the coating film formed from the aqueous dispersion tends to decrease. The weather resistance tends to decrease.

Synthesis of Specific Polymer (A) The aqueous dispersion used in the present invention is obtained by dispersing a specific polymer (A) comprising a polyorganosiloxane (a) and a vinyl polymer (b1) in an aqueous medium. Is what it is. In this case, the specific polymer (A) is, for example, dispersed in the form of a particle or an aqueous sol, and the average particle diameter of the specific polymer in the form of a particle is usually 0.001 to 100 μm, preferably,
It is 0.001-10 micrometers. The aqueous medium in the aqueous dispersion is essentially composed of water, but may contain an organic solvent such as an alcohol up to about several weight% in some cases.

The aqueous dispersion used in the present invention is preferably (C) an organic solvent (a1) and a vinyl polymer (b1) in the presence of an organic metal compound (C) and water, which will be described later, in an organic solvent. After hydrolysis and / or partial condensation in the reaction solution, the reaction solution is dispersed in an aqueous medium, and then the organic solvent can be removed. In the above method (c), the amount of water present at the time of hydrolysis and / or partial condensation depends on the amount of the organosilane (a
1) It is usually about 0.5 to 3.0 mol, preferably about 0.7 to 2.0 mol, per 1 mol. When the reaction product is dispersed in the aqueous medium in the method (c), an emulsifier, a pH adjuster, and the like can be used. Examples of the emulsifier include alkyl sulfates,
Anionic surfactants such as alkylaryl sulfates, alkylphosphates, and fatty acid salts; cationic surfactants such as alkylamine salts and alkylquaternary amine salts; polyoxyethylene alkyl ethers and polyoxyethylene alkylaryls Nonionic surfactants such as ether and block type polyether; and amphoteric surfactants such as carboxylic acid type (for example, amino acid type and betaine type) and sulfonic acid type can be used. These emulsifiers can be used alone or in combination of two or more. As the organic solvent used in the method (c), for example, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are suitable. Some of these organic solvents can be removed before dispersing the reaction solution in an aqueous medium. Regarding the reaction conditions at the time of hydrolysis and / or partial condensation in the above method (c), the temperature is usually 40 to 70 ° C, and the reaction time is
Usually 1 to 8 hours.

In the above method (c), when the vinyl polymer (b1) has an acidic group such as a carboxyl group or a carboxylic anhydride group, at least one kind of basic group is obtained after hydrolysis and / or partial condensation. It is preferable to adjust the pH by adding a compound, and the vinyl polymer (b1)
Has a basic group such as an amino group or an amine imide group, after hydrolysis and / or partial condensation,
It is preferable to adjust the pH by adding a kind of acidic compound, and further, when the vinyl polymer (b1) has the acidic group and the basic group, after the hydrolysis and / or partial condensation, By adding at least one basic compound or acidic compound according to the ratio of the groups and adjusting the pH, the hydrophilicity of the obtained specific polymer is increased, and the emulsification and dispersibility of the specific polymer is increased. Can be improved. Examples of the basic compound include ammonia,
Examples of amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, and dimethylaminoethanol: alkali metal hydroxides such as caustic potash and caustic soda; , Hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid and other inorganic acids; formic acid, acetic acid, propionic acid, lactic acid, oxalic acid,
Organic acids such as citric acid, adipic acid, (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid.
The pH value at the time of the pH adjustment is usually 6 to 10, preferably 7 to 8.

The composition (I) used in the present invention is excellent in weather resistance and oxidation resistance and contains a large amount of silanol groups, so that the effect of increasing the adhesion between the overcoat layer and the substrate can be obtained. Things.

(II) Coating composition for overcoating The (II) composition used in the present invention is obtained by further mixing a photocatalyst component (B) with the specific polymer (A) and dispersing them in an aqueous medium. The main component is an aqueous dispersion. Photocatalyst component (B) The photocatalyst component (B) in the present invention comprises inorganic fine particles and / or sol having photocatalytic ability, and is used for the purpose of imparting antibacterial and antifungal properties and stain resistance. As the photocatalyst component (B), for example, TiO ₂ , TiO ₃ , SrT
iO ₃ , FeTiO ₃ , WO ₃ , SnO ₂ , Bi ₂ O
₃ , In ₂ O ₃ , ZnO, Fe ₂ O ₃ , RuO ₂ , Cd
O, CdS, CdSe, GaP, GaAs, CdFeO
₃ , MoS ₂ , LaRhO _{3 and the} like, and preferably TiO ₂ and ZnO. Particularly preferred is TiO ₂ of the anatase type. These can be used alone or in combination of two or more.

Before the photocatalyst component (B) is dispersed in the aqueous medium, it may be in the form of particulate powder, an aqueous sol in which fine particles are dispersed in water, or a polar solvent such as methanol or isopropyl alcohol. There are three types of solvent sols dispersed in non-polar solvents such as toluene. For solvent-based sols,
Depending on the dispersibility of the semiconductor fine particles, the fine particles may be further diluted with water or a solvent. The average particle diameter of the semiconductor fine particles in these existing forms is usually 1 μm or less, preferably 0.5 μm or less, and particularly preferably 0.3 μm or less in order to obtain a transparent coating film. In the case of an aqueous sol and a solvent sol, a surface treatment may be previously performed with a surfactant, a dispersant, and an organometallic compound in order to improve the stability and dispersibility of the fine particles.

As a method for dispersing the photocatalyst component (B) in the aqueous dispersion, the photocatalyst component (B) may be added after the aqueous dispersion is prepared, or may be added during the preparation of the aqueous dispersion to prepare the photocatalyst component (B). In the presence, organosilane (a1), vinyl polymer (b1) and the like can be hydrolyzed and partially condensed. The amount of the photocatalyst component (B) used in the present invention is generally 1 to 500 parts by weight, preferably 1 to 500 parts by weight, based on 100 parts by weight of the polyorganosiloxane (a).
0 to 400 parts by weight.

(II) The composition has a structure which is hardly chemically bonded and physically adsorbed to contaminants. Further, since the surface of the obtained coating film is hydrophilic and has a property of being further hydrophilized by weak light due to a photocatalytic reaction, the attached contaminants can be easily washed.

Further, the following components (C) to (H) may be added to the composition (I) and the composition (II) (hereinafter, also simply referred to as “aqueous dispersion”) used in the present invention. Can be. Organometallic Compound (C) In the aqueous dispersion used in the present invention, a chelate compound of a metal selected from the group consisting of zirconium, titanium and aluminum (hereinafter, referred to as “metallic compound”).
Also referred to as “organic metal compound (C)”. ) Is preferred. The organometallic compound (C) promotes the hydrolysis and / or partial condensation reaction between the polyorganosiloxane (a) and the vinyl polymer (b), and promotes the formation of a co-condensate of both components. It is considered something to do. Examples of such an organometallic compound (C) include those represented by the general formula

Zr (OR ⁵ ) _p (R ⁶ COCHCOR ⁷ )
_{^{q, Ti (OR 5) r}} (R 6 COCHCOR 7) s or _{^{Al (OR 5) t (R}} 6 COCHCOR 7) u

Or partially hydrolyzed products of these compounds. R ⁵ and R ⁶ in the organometallic compound (C) are each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, specifically, an ethyl group,
n-propyl group, i-propyl group, n-butyl group, se
a c-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, a phenyl group or the like;
⁷ is a monovalent hydrocarbon group having 1 to 6 carbon atoms similar to R ⁵ and R ^6, and an alkoxy group having 1 to 16 carbon atoms, specifically, a methoxy group, an ethoxy group, and an n-propoxy group. ,
and i-propoxy, n-butoxy, sec-butoxy, t-butoxy, lauryloxy, stearyloxy and the like. P, q, r and s are numbers from 0 to 4, t and u are numbers from 0 to 3, and (p + q), (r
+ S) and (t + u) are the valences of zirconium, titanium and aluminum, respectively.

Specific examples of the organometallic compound (C) include zirconium tri-n-butoxyethylacetoacetate, zirconium di-n-butoxybis (ethylacetoacetate), and n-butoxytris (ethyl). Zirconium compounds such as zirconium acetoacetate, zirconium tetrakis (n-propylacetoacetate), zirconium tetrakis (acetylacetoacetate), zirconium tetrakis (ethylacetoacetate), and tetrabutoxyzirconium; di-i-propoxybis (ethylacetoacetate) ) Titanium, di-i-propoxybis (acetylacetate) titanium, di-i-propoxybis (acetylacetone) titanium, tetraisopropyl titanate, tetra-n-butyl Ruchitaneto, titanium compounds such as tetra-styryl titanate; di -i- propoxy ethylacetoacetate aluminum, di -i- propoxy acetylacetonate aluminum, i- propoxy bis (ethylacetoacetate) aluminum, i-
Propoxy bis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum,
Tris (acetylacetonate) aluminum, monoacetylacetonate bis (ethylacetoacetate)
Aluminum, aluminum-i-propionate, monosec-butoxyaluminum diisopropylate,
Aluminum compounds such as aluminum-sec-butylate and aluminum ethylate are exemplified. Among these compounds, tri-n-butoxyethylacetoacetate zirconium, di-i-propoxybis (acetylacetonato) titanium, di-i-propoxyethylacetoacetate aluminum, and tris (ethylacetoacetate) aluminum are preferable. These organometallic compounds (C) can be used alone or in combination of two or more. Organometallic compound (C)
Is preferably used after being dissolved in an organic solvent. As the organic solvent in this case, for example, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are suitable.

The amount of the organometallic compound (C) used in the present invention is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 50 parts by weight, based on 100 parts by weight of the polyorganosiloxane (a). It is. In this case, if the amount of the organometallic compound (C) exceeds 50 parts by weight, the storage stability of the aqueous dispersion may be reduced, or cracks may be easily generated in the coating film.

Β-keto compound (D) In order to further improve the storage stability, the aqueous dispersion used in the present invention may contain, for example, a compound represented by the general formula R ⁶ COCH ₂ COR ⁷ (wherein R ⁶ and R ⁷ Have the same meanings as R ⁶ and R ⁷ in the above general formula representing the organometallic compound (C).)
At least one ketoester (hereinafter, these compounds are collectively referred to as “β-keto compound (D)”);
Seeds can be blended. It is particularly preferable that the aqueous dispersion contains the organometallic compound (C), and the β-keto compound (D) is further added. Such β
-Specific examples of the keto compound (D) include acetylacetone, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, i-propyl acetoacetate, n-acetoacetate
-Butyl, acetoacetate sec-butyl, acetoacetate t-
Butyl, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,4-octanedione, 2,4-nonanedione, and 5-methyl-2,4-hexanedione. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. Β-keto compound (D) in the present invention
Is usually 2 mol or more, preferably 3 to 20 mol, per 1 mol of the organometallic compound (C). In this case, when the amount of the β-keto compound (D) used is less than 2 mol, the effect of improving the storage stability of the obtained aqueous dispersion tends to decrease.

Filler (E) The aqueous dispersion used in the present invention is used to develop various properties such as coloring, thickening of the cured product, prevention of ultraviolet transmission to the substrate, corrosion resistance and heat resistance. In addition, a filler other than the photocatalyst component (B) can be added and dispersed.

Added to further increase the hardness of the cured product
Filler (hereinafter also referred to as “filler (E1)”)
And particles of an inorganic compound other than the photocatalyst component (B)
And / or sols or colloids. The above inorganic
Specific examples of the compound include SiO_Two , Al_Two O_Three , Al
(OH)_Three , Sb_Two O_Five , Si_Three N_Four , Sn-In_Two O
_Three , Sb-In_Two O_Three , MgF, CeF_Three , CeO_Two ,
3Al_Two O_Three ・ 2SiO_Two , BeO, SiC, AlN,
Fe, Fe_Two O_Three , Co, Co-FeO_X , CrO_Two ,
Fe_Four N, Ba ferrite, SmCO_Five , YCO_Five , C
eCO_Five , PrCO_Five , Sm_Two CO₁₇, ZrO_Two , Nd
_Two Fe₁₄B, Al_Four O_Three And the like. this
These inorganic compounds may be used alone or as a mixture of two or more.
Can be used.

Before the filler (E1) is mixed with the aqueous dispersion, the filler may be in the form of a particulate powder, an aqueous sol or colloid in which fine particles are dispersed in water, or a polar solvent such as isopropyl alcohol. Solvent-based sols or colloids dispersed in non-polar solvents such as toluene and toluene. In the case of a solvent-based sol or colloid, it may be further diluted with water or a solvent depending on the dispersibility of the semiconductor fine particles.
When the filler (E1) is an aqueous sol or colloid and a solvent sol or colloid, the solid content concentration is preferably 40% by weight or less. Among the fillers (E1), colloidal silica is, for example, snowtex, methanol silica sol, isopropanol silica sol (all manufactured by Nissan Chemical Industries, Ltd.); Cataloid SN, Oscar (all manufactured by Catalyst Chemical Industry Co., Ltd.) Ludex (Dupont, USA); Syton (Monsanto, USA);
Under the trade name of Nalcoag (Nalco Chemical Co., USA), the above-mentioned colloidal alumina is, for example, alumina sol-100, alumina sol-200, alumina sol-
520 (both manufactured by Nissan Chemical Industries, Ltd.), alumina clear sol, alumina sol 10, and alumina sol 132 (both manufactured by Kawaken Fine Chemical Co., Ltd.) are commercially available.

As a method of blending the filler (E1) into the aqueous dispersion used in the present invention, the filler may be added after the preparation of the aqueous dispersion, or may be added during the preparation of the aqueous dispersion, ) Component in the presence of the organosilane (a
1) Hydrolysis and partial condensation of the vinyl polymer (b1) and the like can also be performed. The amount of the filler (E1) used in the present invention is generally 0 to 500 parts by weight, preferably 0.1 to 400 parts by weight, as solids, based on 100 parts by weight of the polyorganosiloxane (a).

Examples of the filler (hereinafter, also referred to as “filler (E2)”) for imparting coloring, design properties, or thickening of the coating film and further improving corrosion resistance, weather resistance, and the like include, for example, Metals and alloys; compounds such as metal oxides, hydroxides, carbides, nitrides, and sulfides; and water-insoluble pigments such as organic pigments and inorganic pigments. These components are used in the form of particles, fibers, whiskers or scales. Specific examples of the filler (E2) include iron, nickel, aluminum, zinc, copper, silver, carbon black, graphite, stainless steel, ferric oxide, ferrite, cobalt oxide, manganese oxide, chromium oxide, and oxides for pigments. Zirconium, pigment (rutile type) titanium oxide, zirconium oxide, silicon dioxide, lead oxide, aluminum oxide,
Zinc oxide, cuprous oxide, ferric hydroxide, aluminum hydroxide, slaked lime, barium carbonate, calcium carbonate, magnesium carbonate, lead sulfate, basic lead sulfate, barium sulfate, gypsum, molybdenum disulfide, lead sulfide, copper sulfide , Lead silicate, calcium leadate, copper borate, potassium titanate, silicon carbide,
Silicon nitride, boron nitride, lead phthalate, synthetic mullite, clay, diatomaceous earth, talc, bentonite, mica, green earth, cobalt green, manganese green, biryan, guinea green, cobalt chrome green, schule green, green earth, chrome green, Zinc green, pigment green, ultramarine, rock ultramarine, navy blue, cobalt blue,
Cerulean Blue, Molybdenum Blue, Cobalt Purple, Mars Purple, Manganese Purple, Pigment Violet, Zinc Yellow, Chrome Yellow, Cadmium Yellow, Strontium Yellow, Titanium Yellow, Lisage, Pigment Yellow, Loess, Cadmium Red, Selenium Red, Chrome Vermillion, Bengala , Lead zinc white, bunchison white, manganese white, bone black, diamond black, thermatomic black, vegetable black and the like. These fillers (E2) can be used alone or in combination of two or more.

The amount of the filler (E2) used in the present invention is 100% of the total solid content of the aqueous dispersion used in the present invention.
It is usually 300 parts by weight or less based on parts by weight. If the amount of the filler (E2) exceeds 300 parts by weight, the adhesion of the coating film may decrease.

Curing accelerator (F) In order to further increase the curing speed of the aqueous dispersion used in the present invention, a curing accelerator other than the above-mentioned organometallic compound (C) may be used depending on the curing conditions. (Also referred to as "curing accelerator (F)"), which is particularly effective when cured at a relatively low temperature. Examples of the curing accelerator (F) include alkali metal salts such as naphthenic acid, octylic acid, nitrous acid, sulfurous acid, aluminate, and carbonic acid;
Methanesulfonic acid, etc .; ethylenediamine, hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, piperidine, piperazine, metaphenylenediamine, ethanolamine, triethylamine, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) Amine compounds such as -aminopropyltrimethoxysilane, 3- (2-aminoethyl) -aminopropylmethyldimethoxysilane, 3-anilinopropyltrimethoxysilane, and various modified amines used as curing agents for epoxy resins; C ₄ H ₉ )
₂ Sn (OCOC ₁₁ H ₂₃ ) ₂ , (C ₄ H ₉ ) ₂ Sn (OCO
CH = CHCOOCH ₃ ) ₂ , (C ₄ H ₉ ) ₂ Sn (OCO
CH = CHCOO (C ₄ H ₉ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (O
COC ₁₁ H ₂₃ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH = CH
COOCH ₃ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH = CH
COO (C ₄ H ₉ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH =
Carboxylic acid type organotin compounds such as CHCOOC ₈ H ₁₇ ) ₂ and Sn (OCOC ₈ H ₁₇ ) ₂ ; (C ₄ H ₉ ) ₂ Sn (SCH
₂ COOC ₈ H ₁₇ ) ₂ , (C ₄ H ₉ ) ₂ Sn (SCH ₂ CH
₂ COOC ₈ H ₁₇ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (SCH ₂ CO
OC ₈ H ₁₇ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (SCH ₂ CH ₂ CO
OC ₈ H ₁₇ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOC _{12
H 25) 2, (C 8} H 17) 2 Sn (SCH 2 CH 2 COOC 12
H ₂₅₎ mercaptide type organotin compounds such as _{2; (C 4 H 9)} 2
_{Sn = S, (C 8 H} 17) sulfide type organic tin compounds such as _{2 Sn = S; (C 4} H 9) 2 SnO, (C 8 H 17) 2 and organotin oxide SnO etc. These organic tin Examples of the reaction product include a reaction product of an oxide and an ester compound such as an alkyl silicate, dimethyl maleate, diethyl maleate, and dioctyl phthalate. These curing accelerators (F) can be used alone or in combination of two or more. As a method for adding the curing accelerator (F) to the aqueous dispersion, a method in which the curing accelerator (F) is diluted with an alcohol solvent in advance and added, or an emulsifier is added to the curing accelerator (F) and then added to water And a method of emulsifying and dispersing the mixture into a mixture. In the present invention, the amount of the curing accelerator (F) used is determined based on the amount of the polyorganosiloxane (a) 10
0 to 100 parts by weight, preferably 0.1 to 80 parts by weight, more preferably 0.5 to 50 parts by weight, based on 0 parts by weight.
Parts by weight.

The polyfunctional hydrazine derivative (G)
The aqueous dispersion used in the present invention includes a polyfunctional hydrazine derivative having two or more hydrazino groups in a molecule (hereinafter, referred to as a “hydrazine”).
"A polyfunctional hydrazine derivative (G)") may be contained. The polyfunctional hydrazine derivative (G)
Is a vinyl polymer (b) constituting the specific polymer (A)
It is preferable to mix when 1) contains a carbonyl group. In the drying process after the application of the aqueous dispersion, the polyfunctional hydrazine derivative reacts with the carbonyl group contained in the specific polymer (A) to form a network structure and crosslinks the coating film. It has the function of causing
Examples of the polyfunctional hydrazine derivative (G) include oxalic acid dihydrazide, malonic acid dihydrazide,
Total number of carbons such as succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, phthalic dihydrazide, isophthalic dihydrazide, terephthalic dihydrazide, maleic dihydrazide, fumaric dihydrazide, and itaconic dihydrazide. Dicarboxylic acid dihydrazides having 4 to 6 carbon atoms; 3 such as trihydrazide citrate, trihydrazide nitriloacetate, trihydrazide cyclohexanetricarboxylate, and tetrahydrazide ethylenediaminetetraacetate;
Functional or higher hydrazides; ethylene-1,2-dihydrazine, propylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1,2-dihydrazine, butylene-1,3-dihydrazine , Butylene-
Water-soluble dihydrazines such as aliphatic dihydrazines having a total of 2 to 4 carbon atoms such as 1,4-dihydrazine and butylene-2,3-dihydrazine are preferred. Further, at least a part of the hydrazino group of these water-soluble dihydrazines is converted to acetaldehyde, propionaldehyde, butyraldehyde, acetone, methyl ethyl ketone, diethyl ketone,
Compounds blocked by reacting with carbonyl compounds such as methyl propyl ketone, methyl butyl ketone and diacetone alcohol (hereinafter referred to as "blocked polyfunctional hydrazine derivatives"), for example, adipic acid dihydrazide monoacetone hydrazone, adipic acid Dihydrazide diacetone hydrazone and the like can also be used. By using such a blocked polyfunctional hydrazine derivative, the progress of the cross-linking reaction of the aqueous dispersion can be moderately suppressed, so that redispersibility, which is particularly important as a printing ink, can be further improved. Among these polyfunctional hydrazine derivatives, adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide diacetone hydrazone and the like are preferable. The above polyfunctional hydrazine derivatives can be used alone or in combination of two or more.

The amount of the polyfunctional hydrazine derivative (G) used in the present invention is such that the equivalent ratio of the carbonyl group to the hydrazino group in the specific polymer (A) is usually 1: 0.1 to 5,
Preferably 1: 0.5 to 1.5, more preferably 1:
The amount is in the range of 0.7 to 1.2. In this case, if the amount of the hydrazino group is less than 0.1 equivalent relative to 1 equivalent of the carbonyl group, the solvent resistance, damage resistance, etc. of the coating film tends to decrease. Tends to decrease in water resistance and transparency. However, when the blocked polyfunctional hydrazine derivative is used as the polyfunctional hydrazine derivative, the above equivalent ratio is based on the equivalent ratio of the carbonyl group to the hydrazino group in the polyfunctional hydrazine derivative before blocking. . The polyfunctional hydrazine derivative (G) can be blended in an appropriate step of preparing the aqueous dispersion used in the present invention. However, the formation of a coagulated product during the production of the specific polymer (A) is suppressed, and the polymerization is stabilized. In order to maintain the property, it is desirable to blend the entire amount of the polyfunctional hydrazine derivative (G) after the production of the specific polymer (A).

Oxazoline Derivative (H) Further, the aqueous dispersion used in the present invention includes an oxazoline derivative having one or more oxazoline groups (dihydrooxazolyl groups) in the molecule (hereinafter referred to as “oxazoline derivative (H)”). ) May be contained. The oxazoline derivative (H) is such that the vinyl polymer (b1) constituting the specific polymer (A) has a carboxyl group, a thiol group,
Hydroxyl group, epoxy group, amino group, sulfine group (hereinafter, referred to as
These organic groups are preferably added when they contain a “reactive functional group”, and particularly preferably when they contain a carboxyl group. The oxazoline derivative is
In the drying process after the application of the aqueous dispersion, the oxazoline group reacts with the functional group contained in the specific polymer (A) to form a network structure, and has an effect of crosslinking the coating film. . The oxazoline derivative (H) is synthesized by an emulsion polymerization method or a suspension polymerization method of a copolymerizable oxazoline such as 2-isopropenyl-2-oxazoline and another copolymerizable vinyl resin. Commercial products include Epocross K-1000, K-1020E, and K-1030 manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
E, K-2010E, K-2020E, K-2030
E, WS-500 and the like.

Oxazoline derivative (H) in the present invention
Is used, the equivalent ratio of the reactive functional group to the oxazoline group in the specific polymer (A) is usually 1: 0.1 to 5,
Preferably 1: 0.5 to 1.5, more preferably 1:
The amount is in the range of 0.7 to 1.2. In this case, the oxazoline group is added in an amount of 0.1 equivalent to 1 equivalent of the reactive functional group.
If the amount is less than the equivalent, the solvent resistance and the damage resistance of the coating film tend to decrease, while if it exceeds 5 equivalents, the water resistance and the transparency of the coating film tend to decrease. The oxazoline derivative (H) can be blended in an appropriate step of preparing the aqueous dispersion used in the present invention, but suppresses the generation of coagulated products during the production of the specific polymer (A) and maintains the polymerization stability. In order to do so, it is desirable to mix the entire amount of the oxazoline derivative (H) after the production of the specific polymer (A).

Other Additives The aqueous dispersion used in the present invention may contain a resinous additive. Examples of the resinous additive include, for example, water-soluble polyester resins, water-soluble or water-dispersible epoxy resins, water-soluble or water-dispersible acrylic resins, styrene-maleic acid copolymers and the like which are usually used in water-based paints. Examples thereof include a carboxyl group-containing aromatic vinyl resin and a urethane resin. These resinous additives can be used alone or in combination of two or more. The amount of the resinous additive used in the present invention is usually 50 parts by weight or less based on 100 parts by weight of the total solid content of the aqueous dispersion.
Preferably it is 30 parts by weight or less.

The aqueous dispersion used in the present invention may contain an organic solvent for the purpose of improving film formability and wettability. Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, i-
Alcohols such as propyl alcohol, n-butyl alcohol, i-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether;
Ethylene glycol mono-i-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-i-propyl ether, ethylene glycol monomethyl ether acetate, ethylene Glycol monoethyl ether acetate, tributoxymethyl phosphate and the like can be mentioned. These organic solvents can be used alone or
A mixture of more than one species can be used. The amount of the organic solvent used in the present invention is usually 50% by weight or less, preferably 20% by weight or less of the total aqueous dispersion. further,
The aqueous dispersion used in the present invention, if necessary, a pigment,
Thickeners, dispersants, silane coupling agents, titanium coupling agents, leveling agents, dyes, antifungal agents, preservatives, antioxidants, antioxidants, adhesives, antifoggants, flame retardants, etc. Additives can also be included.

The total solid content of the composition (I) used in the present invention is usually 50% by weight or less, preferably 20 to 4% by weight.
It is 0% by weight, and is appropriately adjusted according to the purpose of use, the type of the substrate, the coating method, the coating film thickness, and the added components. The total solid content of the composition (II) used in the present invention is preferably 50% by weight or less, and is appropriately adjusted depending on the purpose of use. For example, when the purpose is to impregnate the thin film forming substrate, it is usually 5 to 30% by weight, and when it is used for the purpose of forming a thick film, it is usually 20 to 50% by weight, preferably, 30 to 45% by weight. If the total solid content of the composition (I) and / or the composition (II) exceeds 50% by weight, the storage stability may decrease.

Cured Product The composition of the cured product of the present invention includes a substrate / (I) composition /
It consists of (II) a composition, or a substrate / primer / (I) composition / (II) composition. When applying the composition of the present invention to a substrate, in the case of any composition, a brush,
A roll coater, a flow coater, a centrifugal coater, an ultrasonic coater, or the like, a dip coat, a flow coat, a spray, a screen process, an electrodeposition, a vapor deposition and the like can be mentioned.

In the case of undercoating, the dry film thickness is 1
The second coating can form a coating film having a thickness of about 0.05 to 20 μm and the second coating can have a thickness of about 0.1 to 40 μm. Then, dry at room temperature, or 30 ~ 20
By heating and drying at a temperature of about 0 ° C. for about 1 to 60 minutes, a coating film can be formed on various substrates. In the case of overcoating, the dry film thickness is 1
The second coating can form a coating film having a thickness of about 0.05 to 20 μm and the second coating can have a thickness of about 0.1 to 40 μm. Then, dry at room temperature, or 30 ~ 20
By heating and drying at a temperature of about 0 ° C. for about 1 to 60 minutes, a coating film can be formed on the undercoat layer. The total film thickness of the undercoat and the top coat is a dry film thickness, usually 0.1 to 80 μm, preferably 0.2 to 80 μm.
It is about 60 μm.

Substrates Substrates used for the cured product of the present invention include, for example, metals such as iron, aluminum and stainless steel; inorganic ceramics such as cement, concrete, ALC, flexible boards, mortar, slate, gypsum, ceramics, and bricks. System material: phenolic resin, epoxy resin, polyester, polycarbonate, polyethylene, polypropylene, AB
Plastic molded products such as S resin (acrylonitrile-butadiene-styrene resin); polyethylene, polypropylene, polyvinyl alcohol, polycarbonate,
Examples include plastic films such as polyethylene terephthalate, polyurethane, and polyimide, wood, paper, and glass. The composition of the present invention is also useful for repainting a deteriorated coating film.

These substrates may be subjected to a surface treatment in advance for the purpose of adjusting the base, improving the adhesion, filling the porous substrate, smoothing, and patterning. Examples of the surface treatment for the metal-based substrate include polishing, degreasing, plating, chromate treatment, flame treatment, and coupling treatment. Examples of the surface treatment for the plastic-based substrate include blasting, Chemical treatment,
Degreasing, flame treatment, oxidation treatment, steam treatment, corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, ion treatment and the like can be mentioned. As the surface treatment for the inorganic ceramics-based substrate, for example, polishing, filling, patterning The surface treatment for the wood substrate, for example, polishing, filling, insect repellent treatment and the like,
As the surface treatment for the paper base material, for example,
Insect repellent treatment and the like can be mentioned, and as the surface treatment for the deteriorated coating film, for example, kerosene and the like can be mentioned.

The coating operation in the present invention differs depending on the type and state of the substrate and the coating method. For example, in the case of a metal-based substrate, if it is necessary to prevent rust, a primer is used in addition to the undercoating coating composition of the present invention. In the case of an inorganic ceramic-based substrate, the properties of the substrate (surface roughness, impregnation, Alkaline, etc.)
Since the opacity of the coating film differs depending on the type, a primer may be used in some cases. In the case of repainting of a deteriorated coating film, a primer is used when the old coating film is significantly deteriorated. In the case of other substrates, for example, plastic, wood, paper, glass and the like, a primer may or may not be used other than the undercoating coating composition depending on the application.

The type of the primer is not particularly limited as long as it has an effect of improving the adhesion between the substrate and the composition, and is selected according to the type of the substrate and the purpose of use. The primers can be used alone or in combination of two or more, and may be an enamel containing a coloring component such as a pigment or a clear containing no coloring component.

As the type of the primer, for example, a solvent-based resin such as an alkyd resin, an amino alkyd resin, an epoxy resin, a polyester, an acrylic resin, a urethane resin, a fluororesin, and an acrylic silicone resin can be used. And aqueous emulsions such as epoxy resin emulsions, polyurethane emulsions and polyester emulsions. In addition, these primers can be provided with various functional groups when adhesion between the substrate and the coating film under severe conditions is required. Examples of such a functional group include a hydroxyl group, a carboxyl group, a carbonyl group, an amide group, an amine group, a glycidyl group, an alkoxysilyl group, an ether bond, and an ester bond.

[0063]

EXAMPLES Hereinafter, embodiments of the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. In the examples, parts and%
Are by weight unless otherwise specified.

The measurement and evaluation in Examples and Comparative Examples were performed as follows.

Appearance of the coating film The appearance of the coating film was observed visually and by a stereoscopic microscope (100 times magnification).
And the gloss of the coating film was measured and evaluated according to the following criteria. ○: Gloss retention of 90% or more △: gloss retention of 50% or more less than 90% ×: Gloss retention rate was based on pencil hardness in less than 50% Hardness JIS K5400.

Adhesion test A grid test (JIS 1005) according to JIS K5400
), The tape peeling test was performed three times, and evaluated by the average number of the remaining grids. According to JIS K5400, an irradiation test was performed for 3,000 hours using a sunshine weather meter, and the appearance (crack, peeling, etc.) of the coating film was visually observed. After 2 cc of isopropyl alcohol was dropped on the chemically resistant coating film and wiped off with a cloth after 5 minutes, the state of the coating film was visually observed.

A test piece using the warm water- resistant inorganic substrate was immersed in warm water at 60 ° C. for 14 days, and the state of the coating film was visually observed. The hydrophilic coating film was irradiated with a 1 mW / cm ² black light fluorescent lamp, and the time until the contact angle of water became 10 ° or less was measured.

Reference Examples 1 to 3 <Production of vinyl polymer (b1)> In a reactor equipped with a reflux condenser and a stirrer, 40 parts of methyl methacrylate and 2-ethylhexyl acrylate 18 were added.
Part, 5 parts of acrylic acid, 10 parts of 2-hydroxyethyl methacrylate, 15 parts of γ-methacryloxypropyltrimethoxysilane, 4- (meth) acryloyloxy-2,
2,6,6-tetramethylpiperidine 5 parts, diacetone acrylamide 6 parts, 1,1,1-trimethylamine methacrylimide 1 part and i-propyl alcohol 13
After adding and mixing 5 parts, the mixture was heated to 80 ° C. while stirring, and a solution prepared by dissolving 4 parts of azobisisovaleronitrile in 15 parts of xylene was added dropwise to the mixture over 30 minutes. The vinyl polymer (b1) having a solid content concentration of 40% (hereinafter referred to as “vinyl polymer (b)
-1) "). Hereinafter, vinyl polymers (b-2) and (b-3) having the compositions shown in Table 1 were obtained.

[0069]

[Table 1]

Preparation Example 1 <Preparation of (I) Composition> In a reactor equipped with a stirrer and a reflux condenser, 70 parts of methyltrimethoxysilane and 30 parts of dimethyldimethoxysilane as an organosilane (a1) were prepared. As the copolymer (b), the vinyl polymer (b-
1) 50 parts and a solution obtained by dissolving 5 parts of di-i-propoxyethyl acetoacetate aluminum in 180 parts of an i-propyl alcohol solution as the organometallic compound (C) were mixed, and then 13 parts of ion-exchanged water was added. , 60 ° C
For 4 hours. Next, the reaction product is cooled to room temperature, and 5 parts of acetylacetone and 130 parts of i-propyl alcohol are added as a β-keto compound (D) to give a specific polymer having a total solid content of 20% (hereinafter, referred to as “ Polymer (1) "). This polymer (1)
To 100 parts of the solution at 30 ° C. or lower, an alkyl sulfate salt as an emulsifier and 10% aqueous ammonia were added.
The mixture was mixed well and adjusted to pH 7.5. Next, the mixture was diluted with 50 parts of i-propyl alcohol, and the resulting solution was gradually added to 250 parts of ion-exchanged water over 2 hours to form an emulsion. To this emulsion, 2 parts of adipic dihydrazide as a polyfunctional hydrazine derivative (G) is added, and then the i-propyl alcohol and water are removed from the emulsion under reduced pressure at a temperature of 50 ° C. or less, and the total solid content is reduced to 20%. % Of the composition (I),
"(I-1)").

Preparation Examples 2 to 14 <Preparation of (I) Composition> In the same manner as in Preparation Example 1 except that the compositions described in Tables 2 and 3 were used, the (I) composition having a total solid content of 20% was used. Object (I-
2) to (I-14) were obtained.

[0072]

[Table 2]

[0073]

[Table 3]

In Tables 2 and 3, the organic UV absorbers
-Hydroxyphenylbenzotriazine and organic UV absorbers represent 2- (2'-hydroxy-5'-methylphenyl) benzotriazole.

Preparation Example 15 <Preparation of (I) Composition (Enamel)> To 100 parts of the solution of the polymer (1) obtained in Preparation Example 1 (total solid content concentration: 20%) was added a cellulose-based thickening agent. .5 parts and stirrer at 2,000 rpm for 30
After stirring for 2 minutes, 26 parts of rutile-type titanium oxide was added little by little as a filler (E2), and the mixture was stirred. After confirming that the pigment was dispersed with a particle gauge, the composition (I) (enamel) ( Hereinafter, “(I-15)” was obtained.

Preparation Example 16 <Preparation of (II) Composition> In a reactor equipped with a stirrer and a reflux condenser, titanium oxide sol (anatase type titanium oxide 20% (solid content), nitric acid 80 %), 70 parts of methyltrimethoxysilane and 30 parts of dimethyldimethoxysilane as the organosilane (a1), and the vinyl polymer (b-1) obtained in Reference Example 1 as the vinyl polymer (b). ) 50 parts, and i-propyl alcohol 1
After stirring while dropping 80 parts, 5 parts of di-i-propoxyethyl acetoacetate aluminum was added as the organometallic compound (C), and the mixture was reacted at 60 ° C. for 4 hours. Next, 5 parts of acetylacetone was added as the β-keto compound (D) to obtain a solution of a titanium oxide-dispersed specific polymer (hereinafter, also referred to as “polymer (i)”) having a total solid content of 20%. To 100 parts of this polymer (i) solution, 30 parts
At a temperature of not more than 0 ° C., an alkyl sulfate ester salt as an emulsifier and 10% aqueous ammonia are added, mixed well, and pH 7.5
Was adjusted to Next, the mixture was diluted with 50 parts of i-propyl alcohol, and the resulting solution was gradually added to 250 parts of ion-exchanged water over 2 hours to form an emulsion. To this emulsion, 2 parts of adipic dihydrazide as a polyfunctional hydrazine derivative (G) is added, and then the i-propyl alcohol and water are removed from the emulsion under reduced pressure at a temperature of 50 ° C. or less, and the total solid content is reduced to 20%. % To obtain a composition (II) (hereinafter also referred to as "(II-1)").

Preparation Examples 17 to 21 <Preparation of (II) Composition> Polymers (ii) to (vi) were prepared in the same manner as in Preparation Example 16 with the formulation shown in Table 4. Then, the polymer (i
(II-2) to (II-6) were obtained in the same manner as in Preparation Example 14 except for using i) to (vi).

[0078]

[Table 4]

Preparation Example 22 <Preparation of (II) Composition> 100 parts of the solution of the polymer (1) obtained in Preparation Example 3
At a temperature of 0 ° C. or lower, an alkyl sulfate ester salt as an emulsifier and 10% aqueous ammonia are added and mixed well to obtain a pH of 7.0.
Adjusted to 5. Then, i-propyl alcohol 100
The resulting solution was gradually added to 200 parts of ion-exchanged water over 2 hours to form an emulsion. To this emulsion was added 4 parts of adipic dihydrazide as a polyfunctional hydrazine derivative (G). Then, i-propyl alcohol and water were removed from the emulsion under reduced pressure at a temperature of 50 ° C. or less, and the total solid content was reduced to 20%. %. To 100 parts of this emulsion, as a photocatalyst component (B), a titanium oxide sol whose pH was adjusted to 7 (anatase type titanium oxide 20% (solid content), water 80
%) Was added dropwise, and the mixture was stirred well to obtain a total solid content of 2 parts.
0% of the (II) composition (hereinafter also referred to as "(II-7)")
I got

Preparation Example 23 <Preparation of (II) Composition> In Preparation Example 22, as a photocatalyst component (B), a titanium oxide sol whose pH was adjusted to 7 (anatase type titanium oxide 20% (solid content), water 80 %) In the same manner as in Preparation Example 20 except that 25 parts of (II) having a total solid concentration of 20% was used.
A composition (hereinafter, also referred to as “(II-8)”) was obtained.

Preparation Example 24 <Preparation of (II) Composition> In Preparation Example 22, as a photocatalyst component (B), a titanium oxide sol whose pH was adjusted to 7 (anatase type titanium oxide 20% (solid content), water 80 %) In the same manner as in Preparation Example 20 except that 400 parts of (I) was used.
I) A composition (hereinafter, also referred to as “(II-9)”) was obtained.

Preparation Example 25 <Preparation of (II) Composition (Enamel)> To 100 parts of (II-9) obtained in Preparation Example 24, 0.5 part of a cellulosic thickener was added, and a stirrer was used. After stirring at a rotation speed of 2,000 rpm for 30 minutes, the filler (E
As 2), the mixture was stirred while adding 26 parts of rutile-type titanium oxide little by little, and it was confirmed that the pigment was dispersed by a particle gauge, and then the composition (II) (enamel) (hereinafter referred to as “(II-1)
0) ").

Preparation Example 26 <Preparation of (II) Composition> To 100 parts of (I-1) obtained in Preparation Example 1, 0.5 part of a cellulosic thickener was added, and the number of revolutions was 2 using a stirrer. After stirring at 2,000 rpm for 30 minutes, anatase-type titanium oxide particles (particle size: 1 μm) were used as the photocatalytic component (B).
m) The mixture was stirred while 20 parts were added little by little, and it was confirmed that the particles were dispersed by a particle gauge. Thus, a composition (II) (hereinafter, also referred to as “(II-11)”) was obtained.

Examples 1 to 20 and Comparative Examples 100 parts of each of the composition (I) and the composition (II) obtained in the preparation examples were prepared by adding 15% of dibutyltin dimaleate
5 parts of an isobutyl alcohol solution were added. 50μ thickness
The composition (I) was applied to the surface of a PET film in a combination as shown in Tables 5 to 7 so that the dry film thickness was 1 μm, and dried at 120 ° C. for 10 minutes. A coating was formed. Thereafter, the composition (II) was applied to the surface of the coating film so that the dry film thickness became 0.2 μm,
It dried at 10 degreeC for 10 minutes, and formed the coating film. About the obtained coating film, coating film appearance, hardness, adhesion, weather resistance, chemical resistance,
Warm water resistance and hydrophilicity were evaluated. Evaluation results
The results are shown in Tables 5 to 7.

[0085]

[Table 5]

[0086]

[Table 6]

[0087]

[Table 7]

Examples 21 to 45 Each coating composition for undercoating was applied to each substrate described in Tables 8 to 9 and dried, and then each coating composition for overcoating was applied and dried to obtain a cured product of the present invention. And The obtained cured product was evaluated for adhesion and weather resistance.
The results are shown in Tables 8 and 9. In the examples using two to three types of undercoat coating compositions, the composition was not mixed, and two to three undercoat layers were provided on the substrate to regulate the overall film thickness.

[0089]

[Table 8]

[0090]

[Table 9]

[0091]

According to the method for forming a coating film of the present invention, deterioration of a substrate due to a photocatalyst can be prevented, and a cured product excellent in weather resistance and adhesion can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 Z 143/04 143/04 F term (Reference) 4D075 AE03 CA13 CA34 EA06 EB19 EB43 EC37 4G069 AA03 BA04B BA37 BA48A EA02X EA02Y EB19 ED02 4J038 CL001 CL002 DL031 DL032 KA04 KA20 MA08 MA10 PA07

Claims (2)

[Claims] 1. A coating film comprising the following coating composition for undercoating (I) is formed on a substrate, and a coating film comprising the coating composition for undercoating below (II) is formed thereon. A method for forming a coating film, characterized in that: A coating composition for undercoating comprising an aqueous dispersion obtained by dispersing a polymer containing (I) (A) (a) a polyorganosiloxane and (b) a vinyl polymer in an aqueous medium. (II) A polymer containing (A) (a) a polyorganosiloxane and (b) a vinyl polymer, and (B) inorganic fine particles and / or sol having photocatalytic ability are dispersed in an aqueous medium. A coating composition for overcoating comprising an aqueous dispersion. 2. A cured product obtained by the method for forming a coating film according to claim 1.