JP2002129110A - Water-based coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide water-based coating compositions capable of forming coating films which have high surface gloss and excel in stain resistance and its durability. SOLUTION: The water-based coating compositions comprise 100 pts. synthetic resin (e.g. a fluorine-containing monomer/alkyl vinyl ether copolymer), 0.1-50 pts. alkoxysilane having a hydrophilic organic group and/or its condensate (e.g. a trimethoxysilane having a polyoxyethylene chain), 0.01-20 pts.wt. alkoxysilane having a fluorine-containing organic group and/or its condenstate (e.g. perfluorooctylethyltri-methoxysilane), and 0-50 pts. other alkoxysilane and/or its condenstate (e.g. partial condensate of tetraethoxysilane).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for water-based paint, a paint, a coating method and a coated article.

[0002]

2. Description of the Related Art Conventionally, products such as inorganic substances, plastics, wood, paper, leather, and fibers have been subjected to surface coating for the purpose of protecting the surface, imparting design and function, and the like. Paints have been developed.

[0003] In particular, fluororesin paints have been used in various applications as coating materials having excellent weather resistance. Fluororesin paints have significantly better weather resistance than other synthetic resin paints, but do not show much superiority in stain resistance, and improvement is required.

[0004] When a base material such as a building material is coated at a factory, a solvent-based paint or a solvent-based surface treatment agent containing an organic solvent can be used. Use of a water-based paint is required for reasons such as stability and environmental preservation.

[0005] Various techniques have been studied for improving the synthetic resin paint and improving the stain resistance of the coating film surface. WO94 / 0
No. 6870 describes a method of adding tetraalkoxysilane or a condensate thereof to an organic coating composition. In this method, a large amount of addition is required to develop stain resistance to rain streak stains (hereinafter referred to as rain streak stain resistance), and hydrolysis of tetraalkoxysilane or a condensate thereof due to moisture in the paint. In addition, since the condensation reaction proceeds to polymerize, the dispersibility decreases, and the storage stability of the organic coating composition is insufficient. JP-A-8-337754 describes a method of adding a fluorinated alkoxysilane or a condensate thereof to an aqueous coating composition. Although the dispersibility of the fluorine-containing alkoxysilane or its condensate and the stain resistance of the coating film are improved, the pot life of the water-based coating composition is short, and the stain resistance is not sufficiently long.

[0006] Japanese Patent Application Laid-Open No. 10-110078 describes a method of adding a mixed product of a tetraalkoxysilane and an alkyltrialkoxysilane to an aqueous fluororesin paint. However, the dispersion stability is insufficient,
Since a large amount of the mixed product cannot be added, the stain resistance is insufficient. JP-A-2000-44836 describes a method of adding a condensate of an alkoxysilane modified with polyoxyethylene glycol to an aqueous coating of a synthetic resin. In this method, the initial gloss of the coating film is high, but the stain resistance is insufficient.

[0007]

SUMMARY OF THE INVENTION In order to improve the prior art described above, the present invention provides a water-based paint composition, a paint, and a paint capable of forming a coating film having a high surface gloss and having excellent stain resistance and durability. The aim is to provide methods and painted articles.

[0008]

According to the present invention, 0.1 to 50 parts of an alkoxysilane represented by the formula 1 and / or a condensate thereof (B) is added to 100 parts of the synthetic resin (A). 0.01 to 20 parts of the alkoxysilane represented by Formula 2 and / or its condensate (C), and 0 to 50 parts of the alkoxysilane represented by Formula 3 and / or its condensate (D). An aqueous coating composition is provided. (R ¹ ) _a Si (OR ² ) _4-a Formula 1 (R ³ ) _b Si (OR ⁴ ) _4-b Formula 2 (R ⁵ ) _c Si (OR ⁶ ) _4-c Formula 3 , A is an integer of 0 to 3, R ¹ is 1
Valence organic group, R ² represents a monovalent organic group or a hydrogen atom, R ¹
And one or more selected from the group consisting of R ² is a monovalent organic group having a hydrophilic group. In Formula 2, b represents an integer of 1 to ³ , R ³ represents a monovalent organic group, R ⁴ represents a monovalent organic group or a hydrogen atom, and at least one of R ³ is a fluorine-containing monovalent organic group. R ³ and R ⁴ are not monovalent organic groups having a hydrophilic group. In the formula 3, c is an integer of 0 to 3, R ⁵ is a monovalent organic group, R ⁶ is a monovalent organic group or a hydrogen atom, R ⁵ is not a fluorine-containing monovalent organic group, and R ⁵ and R ⁶ is not a monovalent organic group having a hydrophilic group.

The present invention also has a paint containing the composition for water-based paint, a coating method characterized in that the paint is applied to an object to be coated, and a coating film formed from the paint. A coated article characterized by the above feature.

[0010] In this specification, "parts" means "parts by mass". In addition, acrylic acid and methacrylic acid are collectively referred to as (meth) acrylic acid, and the same applies to (meth) acrylate and the like.

The synthetic resin (A) in the present invention includes:
Various known synthetic resins are used without any particular limitation. Specific examples include fluorine resin, acrylic resin, silicon-modified acrylic resin, urethane resin, melamine resin, silicone resin, epoxy resin, polyester resin, and the like. Synthetic resins may be used alone or in combination of two or more. In particular, it is preferable to use a fluororesin having excellent weather resistance and chemical resistance alone or as a main component.

As the fluororesin, a polymer of a fluorine-containing monomer or a copolymer with another monomer is used. One kind of the fluorinated monomer may be used alone,
Two or more kinds may be used in combination. Other monomers may be used alone or in combination of two or more.

Specific examples of the fluorine-containing monomer include fluoroolefins such as tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, and hexafluoropropylene, (meth) acrylates of a fluorine-containing alkyl alcohol, and fluorine-containing alkylene. Oxides and the like. In particular, fluoroolefins are preferred because of their excellent durability.

Other monomers include hydrocarbon olefins, alkyl vinyl ethers, alkyl isopropenyl ethers, alkyl allyl ethers, vinyl carboxylate, allyl carboxylate, (meth) acrylate and the like. Is mentioned.

Examples of the hydrocarbon olefins include ethylene, propylene, isobutylene and the like. Alkyl vinyl ethers include methyl vinyl ether,
Ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether and the like can be mentioned. Examples of the alkyl isopropenyl ethers include methyl isopropenyl ether, ethyl isopropenyl ether, propyl isopropenyl ether, and butyl isopropenyl ether. As alkyl allyl ethers,
Examples include ethyl allyl ether and cyclohexyl allyl ether.

Examples of the vinyl carboxylate include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl octanoate, vinyl versatate, and vinyl octadecanoate. Examples of the allyl carboxylate include allyl acetate and allyl propionate. Examples of (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and fluorine-containing alkyl (meth) acrylate.

The above-mentioned other monomers may include a monomer having a functional group. Examples of the monomer having a functional group include monomers having a hydroxyl group, monomers having a carboxy group or a salt thereof, monomers having a polyoxyalkylene chain, monomers having an epoxy group,
Examples include monomers having a hydrolyzable silyl group. Examples of monomers having a hydroxyl group include 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 1-vinyloxymethyl-4-hydroxymethylcyclohexane, 4-hydroxybutyl allyl ether, and 2-hydroxyethyl acrylate. Examples of monomers having a carboxy group or a salt thereof include (meth) acrylic acid, crotonic acid, and salts thereof.

Examples of monomers having a polyoxyalkylene chain include monomers obtained by adding an average of 10 ethylene oxide molecules to 4-hydroxybutyl vinyl ether. Examples of monomers having an epoxy group include glycidyl vinyl ether, glycidyl allyl ether,
Glycidyl methacrylate and the like can be mentioned. Examples of monomers having a hydrolyzable silyl group include vinyltrimethoxysilane, 3-vinyloxypropyltrimethoxysilane, and the like.

In a copolymer of a fluorinated monomer and another monomer, if the copolymerization ratio of the fluorinated monomer is too small, the durability is reduced. Therefore, the copolymerization ratio of the fluorinated monomer is from 30 to 90 mol%, especially 40-80 mol% is preferred. When the monomer having a functional group is not copolymerized, the copolymerization ratio of other monomers (excluding the monomer having a functional group) is preferably from 10 to 70 mol%, particularly preferably from 20 to 60 mol%. When a monomer having a functional group is copolymerized, the copolymerization ratio of other monomers (excluding the monomer having a functional group) is preferably 9 to 69 mol%, particularly preferably 18 to 58 mol%, The copolymerization ratio of the monomer having a functional group is 1 to 2
0 mol%, especially 2 to 15 mol%, is preferred.

The copolymerization of other monomers is preferred because the dispersion stability of the aqueous coating composition, the transparency of the coating film, the adhesion to the substrate and the like are improved. Further, copolymerization of a monomer having a functional group is preferable because the mechanical strength, hardness, adhesion, durability, and the like of the coating film are further improved.

(B) in the present invention is an alkoxysilane represented by the formula 1 and / or a condensate thereof. In Formula 1, a represents an integer of 0 to 3. a is preferably 0 or 1. R ¹ represents a monovalent organic group, R ² represents a monovalent organic group or a hydrogen atom, and at least one selected from the group consisting of R ¹ and R ² is a monovalent organic group having a hydrophilic group. When the molecule has two or more hydrophilic groups, they may be the same or different. When (B) is a condensate of an alkoxysilane, it is preferably a partial condensate. Examples of the hydrophilic group include a nonionic, cationic or anionic hydrophilic group.

As the nonionic hydrophilic group, a polyoxyalkylene (hereinafter referred to as POA) chain is preferable.
In order to improve dispersibility in an aqueous medium, a polyoxyethylene (hereinafter, referred to as POE) chain, a polyoxypropylene chain, and a polyoxybutylene chain are preferable. POA
As the chain, a POE chain is most preferred. Further, when the POA chain is composed of a copolymer chain of two or more monomers such as an ethylene oxide / propylene oxide copolymer chain, it may be a random copolymer chain or a block copolymer chain.

The degree of polymerization of the oxyalkylene unit in the POA chain is preferably from 1 to 100. In the case of a POE chain, if the degree of polymerization is low, the hydrophilicity is insufficient, and if the degree of polymerization is high, the coating film is softened and stains are easily attached. The degree of polymerization of the POE chain is more preferably from 2 to 30.

As the cationic hydrophilic group, a base neutralized with an acid is preferable. Specific examples include a neutralized primary amino group, a secondary amino group, and a tertiary amino group.
Neutralized tertiary amino groups are most preferred. Examples of the acid used for neutralizing the base include carboxylic acids, organic sulfonic acids, and inorganic acids, and inorganic acids are more preferable. The number of carbon atoms of the cationic hydrophilic group is preferably 2 to 20.

As the anionic hydrophilic group, an acidic group neutralized with a base is preferred. Specific examples include a carboxy group neutralized with a base, a phosphate group, an acidic phosphate group,
Examples thereof include a phosphite group, a sulfo group and a sulfi group. A carboxy group neutralized with a base is more preferred. Bases used for neutralization of acidic groups include organic amines, ammonia,
Examples thereof include a quaternary ammonium hydroxide and an inorganic base, and an organic amine or ammonia is more preferable. The number of carbon atoms of the anionic hydrophilic group is preferably 2 to 20.

When R ¹ is not a monovalent organic group having a hydrophilic group, it is preferably a monovalent organic group having 1 to 20 carbon atoms. From the viewpoint of improving compatibility with the synthetic resin (A) and stain resistance,
A monovalent organic group having 10 or less carbon atoms is more preferable, and the monovalent organic group may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a chlorine atom. However, a monovalent organic group is directly bonded to a silicon atom via a carbon atom. When two or more molecules are contained in a molecule, they may be the same or different.

When R ² is not a monovalent organic group having a hydrophilic group, it is preferably a monovalent organic group or a hydrogen atom. As the monovalent organic group, an alkyl group or an alkoxyalkyl group is preferable, and a monovalent alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a butyl group is more preferable. When two or more molecules are contained in a molecule, they may be the same or different.

The compounding amount of (B) is 100 parts of synthetic resin (A).
0.1 to 50 parts per part. If the amount is too small, the gloss decreases, and if it is too large, the stain resistance decreases. Preferably 0.2 to 20 parts, more preferably 0.5 to 10
Department.

In the present invention, (C) is an alkoxysilane represented by the formula (2) and / or a condensate thereof. In Formula 2, b represents an integer of 1 to 3. b is preferably 1.
R ³ represents a monovalent organic group. In Formula 2, one or more of R ³ is a fluorinated monovalent organic group, and R ³ and R ⁴ are not monovalent organic groups having a hydrophilic group. Further, when two or more R ³ are contained in the molecule, R ³ may be the same or different. When (C) is a condensate of an alkoxysilane, it is preferably a partial condensate.

In the fluorine-containing monovalent organic group, an oxygen atom,
It may contain an atom such as a sulfur atom and a chlorine atom. However, the fluorine-containing monovalent organic group is directly bonded to a silicon atom via a carbon atom. The carbon number of R ³ is preferably 1 to 20.

As the fluorine-containing monovalent organic group, R ^f1 —, R
^{f1 OCONHR 7 -, R f1 SCONHR} 7 -, R f2 CON
_{^{HR 7 -, R f2 SO 2}} N (R 8) R 7 - , and the like. However, R ^f1 represents a fluorine-containing alkyl group having 2 to 18 carbon atoms,
R ^f2 represents a C 1-18 perfluoroalkyl group. R ^f1 and R ^f2 may contain an etheric oxygen atom. R ⁷ represents a divalent organic group having 1 to 10 carbon atoms, and R ⁸ represents a monovalent organic group having 1 to 10 carbon atoms.

Specific examples of R ^f1 include CF ₃ CH ₂ —, C
_{F 3 CH 2 CH 2 -,} H (CF 2) 2 CH 2 -, CF 3 CF 2 C
H ₂ —, CF ₃ CF ₂ CH ₂ CH ₂ —, CF ₃ (CF ₂ ) ₂ CH
_{2 CH 2 -, H (CF} 2) 4 CH 2 -, (CF 3) 2 CFCH 2
CH ₂ —, CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ —, H (CF ₂ ) ₆
CH ₂ —, CF ₃ (CF ₂ ) ₄ CH ₂ CH ₂ —, CF ₃ (C
_{F 2) 6 CH 2 -,} CF 3 (CF 2) 2 OCF (CF 3) CH 2
—, CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ —, H (CF ₂ ) ₈ CH ₂
—, CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ —, CF ₃ (CF ₂ ) ₈ C
_{H 2 CH 2 -, (CF} 3) 2 CF (CF 2) 6 CH 2 CH 2 -,
CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ —, CF ₃ (CF ₂ ) ₁₁ CH ₂
CH ₂ —, CF ₃ (CF ₂ ) ₁₃ CH ₂ CH ₂ —, CF ₃ (CF
₂ ) ₁₅ CH ₂ CH ₂ — and the like.

Specific examples of R ^f2 include CF ₃ —, CF ₃ C
_{F 2 -, CF 3 CF 2} CF 2 -, CF 3 (CF 2) 4 -, CF 3
(CF ₂ ) _5- , CF ₃ (CF ₂ ) _6- , CF ₃ (CF ₂ ) ₂ O
_{CF (CF 3) CF 2 -} , CF 3 (CF 2) 7 -, CF 3 (C
_{F 2) 8 -, (CF} 3) 2 CF (CF 2) 6 -, CF 3 (C
_{F 2) 9 -, CF 3} (CF 2) 11 -, CF 3 (CF 2) 13 -,
CF ₃ (CF ₂ ) ₁₅ — and the like.

Specific examples of R ⁷ include —CH ₂ CH ₂ —,
_{-CH 2 CH 2 CH 2 -,} - CH 2 CH 2 CH 2 CH 2 -, -
_{CH 2 CH (CH 3) CH} 2 -, - CH 2 (CH 2) 3 CH 2
-And the like. Specific examples of R ⁸ include CH ₃ —, C
_{H 3 CH 2 -, CH 3} CH 2 CH 2 -, CH 3 CH 2 CH 2 CH
_2- and the like.

R in equation (2)^FourIs a monovalent organic group or hydrogen
Represents an atom. Monovalent organic groups include alkyl groups and alkoxy.
A silalkyl group or the aforementioned R^f1Is preferable, and especially CH_Three−,
CH_ThreeCH_Two-, CH_ThreeCH_TwoCH_Two-, CH_ThreeCH_TwoCH_TwoC
H_TwoAn alkyl group having 1 to 6 carbon atoms such as -CH_ThreeOCH_TwoC
H_TwoAn alkoxyalkyl group having 1 to 4 carbon atoms, such as_Three
CH_Two-, CF_ThreeCH_TwoCH_Two−, H (CF_Two)_TwoCH_Two−,
CF_ThreeCF_TwoCH_Two-, CF _ThreeCF_TwoCH_TwoCH_Two-, CF_ThreeC
F_TwoCH_TwoCH_TwoCH_TwoR having 1 to 6 carbon atoms such as-^f1Is better
Good. In addition, R^FourWhen two or more are included
Is R^FourMay be the same or different.

The compounding amount of (C) is 100 parts of synthetic resin (A).
The amount is 0.01 to 20 parts per part. If the amount is too small or too large, the stain resistance decreases. Preferably 0.
01 to 10 parts, more preferably 0.01 to 5 parts.

(D) in the present invention is an alkoxysilane represented by Formula 3 and / or a condensate thereof. In Formula 3, c represents an integer of 0 to 3. c is preferably 0 or 1, and most preferably 0.

R ⁵ is not a fluorinated monovalent organic group but a monovalent organic group which is not a monovalent organic group having a hydrophilic group.
R ⁵ is preferably a monovalent organic group having 1 to 20 carbon atoms. Further, from the viewpoint of improving compatibility with the synthetic resin (A) and stain resistance, a monovalent organic group having 10 or less carbon atoms is more preferable, and an oxygen atom, a sulfur atom, a nitrogen atom,
It may contain a chlorine atom. However, a monovalent organic group is directly bonded to a silicon atom via a carbon atom. In particular, CH _{3
-, CH 3 CH 2 -,} CH 3 CH 2 CH 2 -, CH 3 CH 2 C
An alkyl group having 1 to 6 carbon atoms such as H ₂ CH ₂ — and a monovalent organic group having 2 to 8 carbon atoms including a functional group are preferable. When two or more R ⁵ are contained, R ⁵ may be the same or different. When (D) is a condensate of an alkoxysilane, it is preferably a partial condensate.

R ⁶ in the formula 3 is 1 having a hydrophilic group.
It represents a monovalent organic group that is not a valent organic group or a hydrogen atom. As the monovalent organic group, an alkyl group, an alkoxyalkyl group or the aforementioned R ^f1 is preferable, and in particular, CH ₃ —, CH ₃ CH ₂ —,
An alkyl group having 1 to 6 carbon atoms such as CH ₃ CH ₂ CH ₂ — and CH ₃ CH ₂ CH ₂ CH ₂ —, an alkoxyalkyl group having 1 to 4 carbon atoms such as CH ₃ OCH ₂ CH ₂ —, CF ₃ CH _2- , CF
_{3 CH 2 CH 2 -, H} (CF 2) 2 CH 2 -, CF 3 CF 2 CH
_{2 -, CF 3 CF 2 CH} 2 CH 2 - of 1 to 4 carbon atoms, such as R ^f1
Is more preferred. If R ⁶ is 2 or more or are in the molecule R ⁶ may be the same or different.

Specific examples of (D) include tetraethoxysilane, tetramethoxysilane in which a part of a methyl group is substituted by an ethyl group, and tetramethoxysilane in which a part of a methyl group is substituted by a propyl group and / or a butyl group. Tetramethoxysilane, tetraethoxysilane in which a part of the ethyl group is substituted with a propyl group and / or a butyl group, tetrakis (2,2,2-trifluoroethoxy) silane, tetrakis (2,2,3,3 , 3-pentafluoropropoxy) silane, tetrakis (4,4,5,5,5-pentafluoropentyloxy) silane, methyltrimethoxysilane, vinyltrimethoxysilane, (3-methacryloyloxypropyl) trimethoxysilane, 3 -Chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like, and These condensation products thereof.

The compounding amount of (D) is 100 parts of synthetic resin (A).
0 to 50 parts per part. (D) is an optional component, and may or may not be contained, but if the amount is small, the stain resistance may not be sufficient. If the amount is too large, the gloss and stain resistance deteriorate. Preferably 0.1 to 30
Parts, more preferably 1 to 20 parts.

In the present invention, when (B), (C) and (D) are condensates, the number average molecular weight thereof is preferably in the range of 200 to 100,000,
The range of 200 to 20,000 is more preferable. If the number average molecular weight is too large, it is difficult to transfer (B), (C) and (D) to the surface of the coating film, and the stain resistance to rain streak decreases.

The aqueous coating composition of the present invention contains (D) as required, together with (B) and (C), and is a group consisting of (B), (C) and (D). It is also preferable that two or more kinds selected from are mixed in advance. The mixing treatment refers to stirring and mixing different alkoxysilanes and / or condensates thereof. It is also preferable to produce the aqueous coating composition of the present invention by mixing and then mixing with the synthetic resin (A). It is also preferable to add the below-described alkoxysilane condensation catalyst during the mixing treatment and mix by stirring.

When the alkoxysilane condensation catalyst is added and mixed with stirring, it is presumed that a cocondensate is also formed between different alkoxysilanes and / or condensates thereof.
Therefore, in the aqueous coating composition of the present invention,
(B) In addition to (C) and (D), a cocondensate of (B) and (C), a cocondensate of (B) and (D), and (C) and (D)
Or a co-condensate of (B), (C) and (D) can also be considered as one of the preferred embodiments of the present invention.

When the co-condensate is contained, if the content of the co-condensate is too small, it becomes difficult to exhibit the stain resistance to rain streaks. If the amount is too large, the water resistance and weather resistance of the coating film are not sufficient, and the stain resistance to rain streaks is hardly exhibited. Also,
The number average molecular weight of the co-condensate is preferably in the range of 200 to 100,000 where migration to the coating film surface is favorable, and 200 to 20
000 is more preferred.

In the present invention, examples of preferred combinations of the respective components are shown in Table 1.好 ま し く is preferred, and ◎ is more preferred.

[0047]

[Table 1]

Here, A1 to A4 represent the following copolymers, respectively, and B1 to B3, C1, D1, and D2 represent the following alkoxysilanes, respectively. A1: a copolymer of tetrafluoroethylene, alkyl vinyl ether, and a monomer having a POA chain, A2: a copolymer of chlorotrifluoroethylene, an alkyl vinyl ether, a monomer having a POA chain, and a monomer having a hydroxyl group, A3: tetrafluoro A4: a copolymer of ethylene and a hydrocarbon olefin, A4: a blend of a copolymer of tetrafluoroethylene and a hydrocarbon olefin and a (meth) acrylate copolymer.

B1: In the formula 1, a is 1 and R ¹
There is a hydrophilic group containing a POE chain, an alkoxysilane R ² is a methyl group, B2: In Formula 1, a is 1, a hydrophilic group R ¹ contains a POE chain, 1 R ² One is an alkoxysilane having a hydrophilic group containing a POE chain and the other is a methyl group and / or an ethyl group. B3: In the formula 1, a is 0, and one of R ² is PO ²
An alkoxysilane having a hydrophilic group containing an E chain and the other being a methyl group and / or an ethyl group.

C1: In the formula 2, b is 1 and R ³
Is R ^f (CH ₂ ) ₂ —, and R ⁴ is a methyl group and / or an ethyl group, alkoxysilane. C2: In the formula 2, b is 1 and R ³ is R ^f OCON
An alkoxysilane wherein H (CH ₂ ) ₃ — and R ⁴ is a methyl group and / or an ethyl group.

D1: In the formula 3, c is 0 and R ⁶
Is a methyl group and / or an ethyl group, D2: In the formula 3, c is 0, R ⁶ is a methyl group,
At least one alkoxysilane selected from the group consisting of an ethyl group and a 4,4,5,5,5-pentafluoropentyl group.

The aqueous coating composition of the present invention may contain an alkoxysilane condensation catalyst. As the content of the condensation catalyst, to prevent the coloring of the coating film, a decrease in gloss, and the like,
1 for 100 parts of the total of (B), (C) and (D)
0 parts or less are preferable.

Examples of the condensation catalyst include metal compound catalysts such as metal chelates, metal esters and metal alkoxides, phosphate esters, amines, acid anhydrides, organic sulfonic acids and the like. The condensation catalyst may be used alone or in combination of two or more.

As the metal compound catalyst, aluminum,
Examples include compounds of metals such as titanium, zirconium, tin, and zinc. Specifically, aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetonate), tetrabutyl titanate, tetraisopropyl titanate, tetrakis (2-aminoethyl) titanate , Diisopropoxytitanium bis (ethylacetoacetate), zirconium tetrakis (acetylacetonate), dibutyltin dilaurate, dibutyltin di (maleic acid monoester), dioctyltin dilaurate, dioctyltindi (maleic acid monoester), dibutyltin diacetate, etc. No.

Although the mechanism of the stain resistance and high gloss exhibited by the water-based coating composition of the present invention is not necessarily clear,
It is considered as follows. Since the fluorine-containing monovalent organic group has oil repellency and mud stain resistance, contamination resistance is exhibited by containing (C). Further, since the surface energy of the fluorine-containing monovalent organic group is low, (C) easily migrates to the surface of the coating film, and it is considered that contamination resistance can be exhibited by containing a small amount of (C). Moreover, since the fluorine-containing monovalent organic group is bonded to the silicon atom via the carbon atom in (C), it is considered that the stain resistance is maintained for a long time. (B)
Is thought to exhibit an effect of removing stains adhered to the coating film and to exhibit rain streak stain resistance. Therefore, it is considered that the water-based coating composition of the present invention can form a coating film excellent in stain resistance, particularly in rain streak stain resistance, by a synergistic effect of these components.

Further, (B) is excellent in dispersibility and the dispersibility of (C) and (D) can be improved, so that (B), (C) and (D) are finely dispersed in the coating film. And high gloss.

The aqueous coating composition of the present invention may contain, if necessary, a curing agent, a coloring agent, a film-forming aid, a thickener, a plasticizer, an antifoaming agent, an ultraviolet absorber, a leveling agent, and an anti-cissing agent. Additives used in ordinary aqueous paints, such as anti-skinning agents and pigment dispersants, may be mixed.

As the curing agent, polyisocyanates,
Aminoplast, polybasic anhydride, hydrazide derivative,
Carbodiimide derivatives, aziridine derivatives, oxazoline derivatives, and the like.

Examples of the polyisocyanates include polyisocyanate compounds such as hexamethylene diisocyanate and isophorone diisocyanate; silyl isocyanate compounds such as methylsilyl triisocyanate; and / or condensates and polymers thereof; And the like. Particularly, a non-yellowing type is preferable.

As aminoplast, melamine resin,
Examples thereof include a guanamine resin and a urea resin. In particular, methylol melamine which is at least partially etherified with one or more lower alcohols such as methanol, ethanol, propanol and butanol is preferable. Examples of the polybasic acid anhydride include aromatic polycarboxylic anhydrides such as phthalic anhydride and pyromellitic anhydride, and aliphatic polycarboxylic anhydrides such as maleic anhydride and succinic anhydride.

Examples of the coloring agent include dyes, organic pigments, inorganic pigments, metallic pigments such as aluminum paste and the like. The use of inorganic pigments is preferred because of excellent weather resistance. Organic solvents that do not impair the stability of the dispersion can be used as the film-forming auxiliary. Polyhydric alcohol monoalkyl ethers such as dipropylene glycol mono n-butyl ether, tripropylene glycol mono n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc., and polyhydric alcohol monoalkyl Examples thereof include organic acid esters of ethers and 3-ethoxypropionic acid esters. Examples of the plasticizer include plasticizers such as dioctyl phthalate, and high molecular weight plasticizers such as a vinyl polymer plasticizer and a polyester plasticizer.

As the coating method, any commonly used coating method such as coating with a brush and a roller brush, air spray coating, airless spray coating, coating with a curtain flow coater, and coating with a roll coater can be used without any particular limitation. Drying of the coating film may be performed at room temperature,
It may be carried out at a higher temperature.

The paint containing the obtained aqueous paint composition is as follows:
The coating may be applied to a newly provided base material or article before installation, or may be applied after the base material or article is installed. In addition, it is also suitable for repair painting for painting on already painted substrates and articles. In particular, it is suitable for coating of substrates and articles used outdoors.

As a substrate to be coated, concrete,
Examples thereof include inorganic materials such as natural stone and glass, metals such as iron, stainless steel, aluminum, copper, brass, and titanium, and composite materials such as fiber-reinforced plastics, resin-reinforced concrete, and fiber-reinforced concrete.

Examples of articles to be coated include vehicles such as automobiles and trains, aircrafts, building members such as exterior panels, doors, windows, and gates, road dividers, road members such as guardrails, bridge members, and steel towers. , Tanks, pipes, communication equipment, electrical and electronic components, and the like.

[0066]

EXAMPLES The present invention will be described below with reference to Synthesis Examples and Examples, but the present invention is not limited thereto. The number average molecular weight is a value measured by gel permeation chromatography using polystyrene as a standard substance.

[Preparation of base paint] Base white paint 1: chlorotrifluoroethylene / ethyl vinyl ether / cyclohexyl vinyl ether / 4-
A polymerization unit based on a monomer obtained by adding an average of 10 molecules of ethylene oxide to hydroxybutyl vinyl ether / 4-hydroxybutyl vinyl ether is 50/15/33.
An aqueous dispersion of the fluororesin 1 containing a ratio of /1.5/1.5 (mol%) was prepared. The solid content concentration was 50% by mass, and the average particle size of the dispersed fine particles was 140 nm.

The aqueous dispersion of the fluorine-containing resin 1
Parts, 3.6 parts of a film-forming assistant (Cs-12, manufactured by Chisso Corporation)
0.3 of thickener (Leobis CR, manufactured by Hoechst Gosei)
Part, titanium oxide (CR-97, manufactured by Ishihara Sangyo Co., Ltd.)
4 parts, 0.8 part of a pigment dispersant (Nopcosperse 44-C, manufactured by San Nopco), an antifoaming agent (FS Antifoam 9)
0, manufactured by Dow Corning Co., Ltd.) and 10.3 parts of ion-exchanged water to obtain Base White Paint 1. The concentration of the fluororesin 1 in the base white paint 1 is 34.8% by mass.
Met.

Base white paint 2: 1100 g of ion-exchanged water, a fluorine-based anionic emulsifier (FC-14)
3: 4.75 g of Sumitomo 3M, 2.2 parts of a nonionic emulsifier (N-1110; manufactured by Nippon Emulsifier) and 47 g of tert-butyl alcohol were charged, degassed by a vacuum pump, and nitrogen gas was used. Pressing was repeated.
Next, 72 g of tetrafluoroethylene, 1.1 g of propylene, and 1.4 g of ethylene were charged.

When the temperature in the autoclave reached 70 ° C., the pressure showed 1.34 MPa. 2 mL of a 25% by mass aqueous solution of ammonium persulfate was added to initiate polymerization. As the pressure decreases, tetrafluoroethylene /
A propylene / ethylene 50/25/25 (mol%) mixed gas was charged and the pressure was maintained. Further, 30 mL of a 25% by mass aqueous solution of ammonium persulfate was continuously added. After 8 hours, the supply of the mixed gas was stopped, and the autoclave was cooled to room temperature with water, and then the unreacted monomer was purged.
An aqueous dispersion of fluorinated resin 2 was obtained. The post-charge amount of the mixed gas was 861.5 g in total. The solid concentration of the aqueous dispersion was 43.1% by mass.

A part of the aqueous dispersion of the fluorine-containing resin 2 was settled by a centrifugal separator, then filtered with a glass filter, and after removing water under reduced pressure for 5 hours, pulverized with a hammer mill. A powder of fluorinated resin 2 was obtained. As a result of composition analysis by ¹³ C-NMR spectrum, fluorinated resin 2 contained polymerized units based on tetrafluoroethylene / propylene / ethylene at a ratio of 52/28/20 (mol%). The melting point was 96.2 ° C.

In a glass flask having an internal volume of 200 mL,
104 g of the aqueous dispersion of the fluororesin 2 was charged,
Warmed until the temperature reached 70 ° C. 1.2 g of methyl methacrylate, te
6.2 g of rt-butyl, 0.6 g of methacrylic acid ester of alcohol having POE chain (Blenmer PE200, manufactured by NOF Corporation), 0.04 g of N-1110, 0.02 g of sodium lauryl sulfate, and ion exchange A pre-emulsion emulsified by stirring 10 g of water was added dropwise over 1 hour. After further stirring for 1 hour, 1 mL of a 0.5% by mass aqueous solution of ammonium persulfate was added to initiate polymerization. After 4.5 hours, an aqueous dispersion containing the fluororesin 2 and the methacrylate copolymer 1 in a mass ratio of 85:15 was obtained. The solid concentration of the aqueous dispersion was 42.9% by mass.

71 parts of the obtained aqueous dispersion, Cs-12
3.6 parts of Reobis CR, 0.3 part of CR-97
5.4 parts, 0.8 parts of Nopcosperse 44-C, 0.6 parts of FS Antifoam 90, and 1 part of ion-exchanged water
The base white paint 2 was obtained by mixing 0.3 parts. The concentration of the resin component in the base white paint 2 was 29.9% by mass.

[Synthesis of Alkoxysilanes] Synthesis Example 1 (Alkoxysilane B-1): 300 m in internal volume
In a glass flask of L, add polyoxy with an average molecular weight of 200.
Cyethylene glycol (polyoxyethylene glycol
200 g, manufactured by Tokyo Chemical Industry Co., Ltd.)
0.18 g of urate was charged. Then, at 50 ° C,
Isocyanate group-containing silane OCNCH _TwoCH_TwoCH_TwoS
i (OCH_Three)_Three(KBE9007, Shin-Etsu Chemical Co., Ltd.)
Was added dropwise over 3 hours. Reaction for another 2 hours
To obtain an alkoxysilane B-1 having a POE chain.
Was. The number average molecular weight of the alkoxysilane B-1 is 1000
Met.

Synthesis Example 2 (Alkoxysilane B-2): Except that 80 g of polyoxyethylene glycol having an average molecular weight of 600 (polyoxyethylene glycol 600, manufactured by Tokyo Chemical Industry Co., Ltd.) was used in place of 80 g of polyoxyethylene glycol 200. Is POE in the same manner as in Synthesis Example 1.
A chain-containing alkoxysilane B-2 was obtained. The number average molecular weight of alkoxysilane B-2 was 1,400.

Synthesis Example 3 (Alkoxysilane C-1): 4,4,5,
70 g of 5,5-pentafluoropentyl alcohol (manufactured by Asahi Glass Co., Ltd.) and 0.18 of dibutyltin dilaurate
g. Then, at 50 ° C, 1 of KBE9007
00 g was added dropwise over 3 hours. The reaction was further performed for 4 hours to obtain an alkoxysilane C-1 having a 4,4,5,5,5-pentafluoropentyloxy group. The number average molecular weight of alkoxysilane C-1 was 520.

Synthesis Example 4 (Mixed product 1): Internal volume 300
In a mL glass flask, a condensate of tetraethoxysilane (average degree of condensation: about 5, silica content: 40% by mass, trade name: ethyl silicate 40, manufactured by Colcoat Co., Ltd.) (hereinafter referred to as ES4
It is called 0. ) Of 100 g of the alkoxysilane B-1
7.7 g, alkoxysilane having a perfluoroalkyl group CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ )
₃ (TSL8233, manufactured by Toshiba Silicone Co., Ltd.)
g, 0.13 g of dibutyltin dilaurate, and 2.5 g of ion-exchanged water were charged and reacted at 80 ° C. for 4 hours to obtain a mixed product 1.

Synthesis Example 5 (Mixed product 2): In place of 27.7 g of alkoxysilane B-1, alkoxysilane B
Except for using 47.1 g of -2, a mixed product 2 was obtained in the same manner as in Synthesis Example 4.

Synthesis Example 6 (Mixed product 3): An alkoxysilane having a POE chain instead of 27.7 g of alkoxysilane B-1 CH ₃ O (CH ₂ CH ₂ O) _m Si (OC
A mixed product 3 was obtained in the same manner as in Synthesis Example 4, except that 22.7 g of H ₂ CH ₃ ) ₃ (m was about 10, A-1230; manufactured by Nippon Unicar) was used.

Synthesis Example 7 (Mixed product 4): TSL823
0.3 g of alkoxysilane C-1 instead of 1.0 g of 0.3.
A mixed product 4 was obtained in the same manner as in Synthesis Example 4 except that 70 g was used.

Synthesis Example 8 (Mixed product 5): TSL823
A mixed product 5 was obtained in the same manner as in Synthesis Example 4 except that No. 3 was not used.

Synthesis Example 9 (Mixed product 6): TSL823
A mixed product 6 was obtained in the same manner as in Synthesis Example 4, except that 27.4 g of Compound 3 was used instead of 1.0 g, and alkoxysilane B-1 was not used.

Synthesis Example 10 (Mixed product 7): Internal volume 30
In a 0 mL three-necked flask, a condensate of tetramethoxysilane (silica content: 56% by mass, trade name: methyl silicate 5)
6, manufactured by Mitsubishi Chemical Corporation) and 0.11 g of triethylamine. Heat to 100 ° C,
22, of 5,5,5-pentafluoropentyl alcohol
0 g was added dropwise over 10 minutes, and volatile components were removed at 100 ° C. over 5 hours. ¹ H-NMR of the product (yield 73 g)
As a result of measuring the spectrum, CF ₃ CF ₂ CH ₂ CH ₂ CH
₂ O / CH ₃ O = 0.25 / 1 (molar ratio). This product was transferred to a glass flask having an internal volume of 300 mL, and further charged with 20.2 g of alkoxysilane C-1, 0.13 g of dibutyltin dilaurate, and 2.5 g of ion-exchanged water, and reacted at 80 ° C. for 4 hours. As a result, a mixed product 7 was obtained.

Examples 1 to 13 The mixed products 1 to 7 obtained in Synthesis Examples 4 to 10 were added to the base white paint in the mixing ratios shown in Tables 2 and 3 to obtain paints. The paint is 200 × 95 × 8m
An aluminum plate having a size of m was coated using an applicator so that the dry film thickness became 20 μm. Then, it was dried at 20 ° C. and 65% RH for one week to obtain a coated plate. Tables 2 and 3 show the evaluation results of the paint and the coated plate. Examples 1 to 6 are Examples, and Examples 7 to 13 are Comparative Examples. Table 4 shows the composition ratios of (B), (C) and (D) in the mixed products 1 to 7 and ES40 used.

Compatibility: After mixing the base white paint and the mixture, the mixture was allowed to stand at 20 ° C. and 65% RH for 1 hour, and the presence or absence of liquid separation was visually checked. The sample without liquid separation was indicated by "O", and the sample with liquid separation was indicated by "X". Stability of paint: After mixing the base white paint with the mixed product, 5
It was stored at 0 ° C. for one week, and the stability was visually evaluated. A sample having no abnormality was indicated by ○, and a gelled one was indicated by ×.

Gloss: 60 according to JIS Z8741
The degree of specular gloss was measured. Accelerated stain resistance: 1% at 50 ° C and 95% RH
After curing on a day, a 5% by weight aqueous dispersion of hydrophobic carbon black was applied to the coated surface and dried at 60 ° C. for 1 hour. Then, it was washed with gauze. Lightness before and after the test (L
^* Value) was measured, and the difference (ΔL ^* ) was calculated and described as an absolute value. The L ^* value was measured using SQ2000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS Z8730.

Slope resistance: Painted plate (size: 200 ×
95 x 8mm) is bent at 100mm (i.e., the center in the longitudinal direction), the upper surface is at an angle of 30 degrees from the horizontal plane, the lower surface is vertical, and the painted surface is outside. In summer in Kawasaki City, Kanagawa Prefecture, Outdoor exposure. The L ^* value of the 30-degree slope was measured three months after the exposure of the coated plate. The difference ΔL ^* between the L ^* values before and after the test was calculated and described as an absolute value. Rain streak stain resistance: The state of rain streak stain on a vertical surface was evaluated for an outdoor exposure plate evaluated for slope stains. When the stain on the rain streak was not conspicuous, the result was indicated by ○, when the test was slightly conspicuous, and when notable, the test was indicated by x.

Stain resistance persistence: JIS K5400
After performing the carbon arc lamp accelerated weathering test described in 9.8.1 for 360 hours, a 5% by mass aqueous dispersion of hydrophobic carbon black was applied to the coated surface, and dried at 60 ° C. for 1 hour. Then, the plate was washed with gauze and the L ^* value of the washed portion was measured. The difference ΔL ^* between this measured value and the measured value before applying the aqueous dispersion of hydrophobic carbon black was calculated and described as an absolute value. Accelerated weathering resistance: The gloss retention after the carbon arc lamp accelerated weathering test described in JIS K5400 9.8.1 was performed for 4000 hours was measured. Gloss retention 80
% Or more, and the gloss retention of less than 80% was indicated by x.

[0089]

[Table 2]

[0090]

[Table 3]

[0091]

[Table 4]

[0092]

The composition for aqueous coating composition of the present invention can form a highly glossy coating film on a painted surface. Further, it is possible to form a coating film which is excellent in stain resistance, rain streak stain resistance, mud stain resistance, dirt washability, dirt release effect, and the like, and is excellent in persistence of these properties. Further, a coating film having excellent weather resistance can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C09D 183/08 C09D 183/08 F term (Reference) 4D075 CA32 CA34 CB04 DB02 DB04 DB06 DB07 DB12 DB13 DB14 DB61 DC01 DC05 DC08 DC11 DC18 DC21 EB16 EB22 EB32 EB33 EB35 EB38 EB42 EB43 EB45 EB56 EC07 EC54 4J038 CB001 CD111 CD121 CD131 CE051 CF011 CF021 CG031 CG141 CH031 CH041 CH071 CH121 CH171 CH25 DL12 DL06 GA05 HA156 MA08 MA10 NA01 NA03 NA05

Claims (6)

[Claims] 1. An alkoxysilane represented by the formula 1 and / or a condensate thereof (B) based on 100 parts of the synthetic resin (A).
0.1 to 50 parts of the alkoxysilane represented by the formula 2 and / or its condensate (C) 0.01 to 20 parts, the alkoxysilane represented by the formula 3 and / or its condensate (D)
The composition for water-based paints, comprising 0 to 50 parts of (R ¹ ) _a Si (OR ² ) _4-a Formula 1 (R ³ ) _b Si (OR ⁴ ) _4-b Formula 2 (R ⁵ ) _c Si (OR ⁶ ) _4-c Formula 3 , A is an integer of 0 to 3, R ¹ is 1
Valence organic group, R ² represents a monovalent organic group or a hydrogen atom, R ¹
And one or more selected from the group consisting of R ² is a monovalent organic group having a hydrophilic group. In Formula 2, b represents an integer of 1 to ³ , R ³ represents a monovalent organic group, R ⁴ represents a monovalent organic group or a hydrogen atom, and at least one of R ³ is a fluorine-containing monovalent organic group. R ³ and R ⁴ are not monovalent organic groups having a hydrophilic group. In the formula 3, c is an integer of 0 to 3, R ⁵ is a monovalent organic group, R ⁶ is a monovalent organic group or a hydrogen atom, R ⁵ is not a fluorine-containing monovalent organic group, and R ⁵ and R ⁶ is not a monovalent organic group having a hydrophilic group. 2. The aqueous paint composition according to claim 1, wherein two or more kinds selected from the group consisting of (B), (C) and (D) are mixed and treated in advance. 3. The aqueous coating composition according to claim 1, wherein the hydrophilic group in (B) is a polyoxyalkylene chain. 4. A paint comprising the aqueous paint composition according to claim 1, 2 or 3. 5. A coating method comprising applying the coating material according to claim 4 to an object to be coated. 6. A coated article comprising a coating film formed from the coating composition according to claim 4.