JP2002138250A - Water-based coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based coating material composition capable of forming coating films which have high surface gloss and excel in stain resistance and its durability. SOLUTION: The water-based coating material composition comprises 100 pts. synthetic resin (e.g. a fluorine-containing monomer/alkyl vinyl ether copolymer), 0.1-50 pts. alkoxysilane containing a monovalent organic group having a fluorine-containing group and a hydrophilic group and/or its condensate (e.g. a trimethoxy-silane having a perfluroalkyl group and a polyoxyethylene chain), and 0-50 pts. another alkoxysilanes and/or its condenstate (e.g. a 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, the stain resistance to rain streaks
It is called rain streak stain resistance. ) Requires a large amount of addition, and the water in the coating causes hydrolysis and condensation of tetraalkoxysilane or a condensate thereof to proceed to polymerize, thereby decreasing the dispersibility and causing an organic coating composition. Is insufficient in storage stability. JP-A-8-337754 discloses that
A method of adding a fluorinated alkoxysilane or a condensate thereof to a water-based coating composition is described. 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. H10-110078 describes a method of adding a mixed product of tetraalkoxysilane and alkyltrialkoxysilane to an aqueous fluororesin paint. However, the dispersion stability is insufficient, and a large amount of the mixed product cannot be added, so that 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), and 100 parts of a synthetic resin (A), and A composition for an aqueous coating material, comprising 0 to 50 parts of an alkoxysilane represented by Formula 2 and / or a condensate (C) thereof. (R ¹ ) _a Si (OR ² ) _4-a Formula 1 (R ³ ) _b Si (OR ⁴ ) _4-b Formula 2 In Formula 1, a is an integer of 0 to 3, and 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 fluorine-containing group and a hydrophilic group. In the formula 2, b is an integer of 0 to 3, R ³ is a monovalent organic group, and R ⁴ is 1
It represents a valent organic group or a hydrogen atom, and R ³ and R ⁴ are not monovalent organic groups having a fluorinated group and 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 other monomer 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, and monomers having a hydrolyzable silyl group. And monomers.

Examples of monomers having a hydroxyl group include 2-
Examples include hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 1-vinyloxymethyl-4-hydroxymethylcyclohexane, 4-hydroxybutyl allyl ether, and 2-hydroxyethyl acrylate.

Examples of the monomer 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 molecules of ethylene oxide to 4-hydroxybutyl vinyl ether.

The 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 fluorine-containing monomer and another monomer, if the copolymerization ratio of the fluorine-containing monomer is too small, the durability is reduced. Therefore, the copolymerization ratio of the fluorine-containing monomer is 30 to 90 mol%, particularly 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 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 having a fluorine-containing group and a hydrophilic group. Organic group. When at least ^one of R ¹ is a monovalent organic group having a fluorine-containing group and a hydrophilic group, the durability of the stain resistance is further improved. When (B) is a condensate of an alkoxysilane, it is preferably a partial condensate.

The monovalent organic group having a fluorine-containing group and a hydrophilic group is more preferably a monovalent organic group represented by the formula (3). ^Rf -XYZ-Formula 3 Here, ^Rf represents a fluorine-containing group, Y represents a hydrophilic group, and X and Z represent a bonding group or a single bond.

In the formula 3, R ^f is preferably a monovalent organic group having a polyfluoroalkyl group, and Y is preferably a divalent organic group having a nonionic group, a cationic group, or an anionic group. More preferred. The carbon number of R ^f is preferably 1 to 20 in order to improve the stain resistance.

Specific examples of R ^f include CF ₃ —, H (CF
_{2) 2 -, CF 3 CF} 2 -, CF 3 (CF 2) 2 -, H (C
_{F 2) 4 -, (CF} 3) 2 CF-, CF 3 (CF 2) 3 -, H
_{(CF 2) 6 -, CF} 3 (CF 2) 4 -, CF 3 (CF 2)
_{6 -, CF 3 (CF 2} ) 2 OCF (CF 3) CF 2 -, CF 3
_{(CF 2) 5 -, H} (CF 2) 8 -, CF 3 (CF 2) 7 -,
_{CF 3 (CF 2) 8 -} , (CF 3) 2 CF (CF 2) 6 -, C
F ₃ (CF ₂ ) ₉ −, CF ₃ (CF ₂ ) ₁₁ −, CF ₃ (C
F ₂ ) _13- , CF ₃ (CF ₂ ) _15- and the like.

As the divalent organic group having a nonionic group, a divalent organic group having a polyoxyalkylene (hereinafter, referred to as POA) chain is preferable. In order to improve dispersibility in an aqueous medium, polyoxyethylene (hereinafter referred to as P
OE. ) Chains, polyoxypropylene chains, polyoxybutylene chains are preferred, and POE chains are most preferred. When the POA chain is composed of two or more alkylene oxide copolymer chains 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 of 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 POA chain is more preferably from 2 to 30.

The divalent organic group having a cationic group is preferably a divalent organic group having a base neutralized with an acid.
Specific examples include a divalent organic group having a primary amino group, a divalent organic group having a secondary amino group, and a divalent organic group having a tertiary amino group neutralized with an acid. Most preferred is a group consisting of a neutralized tertiary amino group.

Examples of the acid used for neutralizing the base include carboxylic acids, organic sulfonic acids, and inorganic acids.
Inorganic acids are more preferred. The divalent organic group having a cationic group preferably has 2 to 20 carbon atoms.

The divalent organic group having an anionic group is preferably a divalent organic group having an acidic group neutralized with a base. Specific examples include a divalent organic group having a carboxy group, a divalent organic group having a phosphate group, a divalent organic group having an acidic phosphate group, and a divalent group having a phosphite group neutralized with a base. Examples thereof include an organic group, a divalent organic group having a sulfo group, and a divalent organic group having a sulfi group. A divalent organic group having a carboxy group neutralized with a base is more preferable.

The base used for neutralization of the acidic group includes
Examples thereof include organic amines, ammonia, quaternary ammonium hydroxide, and inorganic bases. Organic amines and ammonia are most preferred. The bivalent organic group having an anionic group preferably has 2 to 20 carbon atoms.

X is a single bond, 2-20 carbon atoms.
Valent organic group, and a hetero atom., -CH ₂ -, - C
_{H 2 CH 2 -, - CH} 2 CH 2 CH 2 -, - CH (CH 3) C
H ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ —, —CH (CH ₃ ) C
_{H 2 CH 2 -, - CH} 2 (CH 2) 3 CH 2 -, - CH 2 CH
(CH ₃ ) CH ₂ CH ₂ —, —COO—, —SO ₂ N
(R ⁵⁾ - (provided that, R ⁵ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms or less the same..), - CON (R 5)
_{-, - CH 2 COO -,} - CH 2 OCOO -, - CH 2 O
_{CONH (CH 2) 6 NHCOO -} , - CH 2 CH 2 S
_{i (CH 3) 2 O -} , - O- , and the like. Particularly, a divalent organic group having 1 to 20 carbon atoms is preferable.

As Z, a divalent organic group having 1 to 20 carbon atoms is preferable, and —CH ₂ —, —CH ₂ CH ₂ —, —CH ₂ CH
_{2 CH 2 -, - CH (} CH 3) CH 2 -, - CH 2 CH 2 CH
₂ CH ₂ —, —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ (C
_{H 2) 3 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 -,
_{-CONHCH 2 CH 2 CH 2 -,} - COCH 2 CH 2 CH 2
—, —COOCH ₂ CH ₂ CH ₂ — and the like.

It is particularly preferred that the fluorinated group is a monovalent polyfluoroalkyl group and the hydrophilic group is a polyoxyalkylene chain, and that the monovalent organic group having such a fluorinated group and a hydrophilic group is used. Specific examples include the following. However, C ₄ F ₉ , C ₆ F ₁₃ , C ₈ F ₁₇ , C
₁₀ F ₂₁ , C ₂ H ₄ and C ₄ H ₈ have a linear structure, and C ₃ H ₆ has CH ₂
Represents the branched chain structure of CH (CH ₃ ).

C_FourF₉(CH_Two)_TwoO (C_TwoH_FourO)₈CON
H (CH_Two)_Three-, C₆F₁₃(CH_Two)_TwoO (C_TwoH_FourO)_Ten
CONH (CH_Two)_Three-, C₆F₁₃(CH_Two)_TwoO (C_ThreeH₆
O)_Five(CH_Two)_Three-, CF_Three(CF_Two)_TwoOCF (CF_Three)
CF_TwoCH_TwoO (C_TwoH_FourO)_TenCONH (CH _Two)_Three-, C
₇F_FifteenCH_TwoO (C_TwoH_FourO)_TenCONH (CH_Two)_Three-, C
₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)₁₃CONH (CH_Two)_Three
-, C₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)₁₃(CH_Two)
_Three-, C₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)₁₃CO (C
H_Two)_Two-, C₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)₂₀CON
H (CH_Two)_Three-, C₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)_{twenty five}
(CH_Two)_Three-, C₈F₁₇(CH_Two)_TwoO (C_TwoH_FourO)₈(C
_ThreeH₆O)_FourCONH (CH_Two)_Three-, C₈F₁₇(CH_Two)_TwoO
(C_TwoH_FourO)_Ten(C_FourH₈O)_Three(CH_Two)_Three-, C₈F
₁₇(CH_Two)_ThreeO (C_ThreeH₆O)_TenCONH (CH_Two)_Three−,
C₈F₁₇(CH_Two)_ThreeO (C_TwoH_FourO)₈(C_ThreeH₆O)_FourCO
NH (CH_Two)_Three-, C₈F₁₇(CH_Two)_ThreeO (C_TwoH_FourO)
₁₃CONH (CH_Two)_Three-, C₈F₁₇(CH_Two)_FourO (C_ThreeH
₆O)_TenCONH (CH_Two)_Three-, C₈F₁₇(CH_Two)_FourO
(C_TwoH_FourO)₁₃CONH (CH_Two)_Three-, C₈F₁₇(C
H_Two)_FourO (C_TwoH_FourO)_Ten(C_ThreeH₆O)_ThreeCONH (C
H_Two)_Three-, C₈F₁₇CON (CH_Three) (C_TwoH_FourO)₁₃CO
NH (CH_Two)_Three-, C₈F₁₇SO_TwoN (CH_Three) (C_TwoH_Four
O)₁₃CONH (CH_Two)_Three-, C₈F₁₇(CH_Two)_TwoOC
ONH (CH_Two)₆NHCOO (C_TwoH_FourO)₂₀(CH_Two) _Three
-, C₈F₁₇(CH_Two)_ThreeOCONH (CH_Two)₆NHCO
O (C_TwoH_FourO)₂₀(CH_Two) _Three-, C_TenF_{twenty one}(CH_Two)_TwoO
(C_TwoH_FourO)₂₀CONH (CH_Two)_Three-, C_TenF_{twenty one}(CH
_Two)_TwoO (C_TwoH_FourO)_Fifteen(C_ThreeH₆O)_FiveCONH (CH_Two)
_Three-.

R ¹ having a fluorine-containing group and a hydrophilic group
When it is not a valent organic group, R ¹ is preferably a monovalent organic group having 1 to 20 carbon atoms. From the viewpoint of improving the compatibility with the synthetic resin (A) and the 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, and a chlorine atom are contained in the monovalent organic group. May be included. However, 1
A valent organic group is directly bonded to a silicon atom via a carbon atom. When two or more R ¹ are contained in the molecule,
R ¹ may be the same or different.

[0038] 1 in which R ² and a fluorine-containing group and a hydrophilic group
When it is not a valent organic group, R ² is preferably a monovalent organic group having 1 to 10 carbon atoms. As R ² , an alkyl group or an alkoxyalkyl group is preferable, and in particular, a group having 1 carbon atom such as methyl group, ethyl group, propyl group,
A monovalent alkyl group having 1 to 6 carbon atoms and an alkoxyalkyl group having 1 to 6 carbon atoms such as a 2-methoxyethyl group are more preferable.
Further, when two or more R ² are contained in the molecule, R ² 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.

(C) in the present invention is an alkoxysilane represented by the formula (2) and / or a condensate thereof. In Formula 2, b represents an integer of 0 to 3. b is preferably 0 or 1, and most preferably 0.

R ³ is a monovalent organic group which is not a monovalent organic group and has a fluorine-containing group and a hydrophilic group. As R ³ ,
It is preferably a monovalent organic group having 1 to 20 carbon atoms. From the viewpoint of improving the compatibility with the synthetic resin (A) and the 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, and a chlorine atom are contained in the monovalent organic group. May be included. However, a monovalent organic group is directly bonded to a silicon atom via a carbon atom. Further, when two or more R ³ are contained in the molecule, R ³ may be the same or different. R ⁴ in ° C 2 represents a monovalent organic group which is not a monovalent organic group having a fluorine-containing group and a hydrophilic group, or a hydrogen atom. As the monovalent organic group, an alkyl group, an alkoxyalkyl group or a fluorinated alkyl group is preferable, and particularly a monovalent organic group having 1 carbon atom such as a methyl group, an ethyl group, a propyl group or a butyl group.
To 6 monovalent alkyl groups, alkoxyalkyl groups having 1 to 6 carbon atoms such as 2-methoxyethyl group, 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 - fluorinated alkyl group having 1 to 6 carbon atoms such as are more preferred. When two or more R ⁴ are included in the molecule, R ⁴ may be the same or different. When (C) is a condensate of an alkoxysilane, it is preferably a partial condensate.

Specific examples of (C) 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, and tetraethoxysilane in which a part of the ethyl group is substituted with a 4,4,5,5,5-pentafluoropentyl group Tetraethoxysilane, tetrakis (2,
2,2-trifluoroethoxy) silane, tetrakis (2,2,3,3,3-pentafluoropropoxy) silane, methyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-chloro Propyltrimethoxysilane, 3
-Mercaptopropyltrimethoxysilane and the like, and condensates thereof.

The compounding amount of (C) is 100 parts of synthetic resin (A).
0 to 50 parts per part. (C) is an optional component and may or may not be contained, but if the amount is too 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 each of (B) and (C) is a condensate, their number average molecular weight is preferably from 200 to 100,000, more preferably from 200 to 20 000.
000 is more preferred. If the number average molecular weight is too large, it is difficult to transfer (B) and (C) to the surface of the coating film, and the stain resistance to rain streaks decreases.

The aqueous coating composition of the present invention contains (C) as necessary together with (B). When (C) is contained, (B) and (C) Is preferably mixed in advance. After the mixing treatment, it is also preferable to mix with the synthetic resin (A) to produce the aqueous coating composition of the present invention.

It is also preferable to add an alkoxysilane condensation catalyst to be described later during the mixing treatment and to mix by stirring. When the condensation catalyst is added and stirred and mixed, it is presumed that a cocondensate is also formed between (B) and (C). Therefore,
In the aqueous coating composition of the present invention, (B) and (C)
In addition to the above, containing a co-condensate of (B) and (C) can be considered as one of the preferred embodiments of the present invention.

When a co-condensate is contained, if the content of the co-condensate is too small, it becomes difficult to exhibit rain streak stain resistance, while if it is too large, the water resistance and weather resistance of the coating film are not sufficient, and Streaks are less likely to be exhibited. The number-average molecular weight of the co-condensate is 200 to 1 with a good transfer to the coating film surface.
00000, more preferably 200 to 20,000.

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.

[0049]

[Table 1]

Here, A1 to A4 represent the following copolymers, respectively, and B1 to B4 and C1 to C2 represent the following alkoxysilanes, respectively. A1: Copolymer of tetrafluoroethylene, alkyl vinyl ether and monomer having POE chain, A2: Copolymer of chlorotrifluoroethylene, alkyl vinyl ether, monomer having POE chain and monomer having 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
Is a monovalent organic group containing nC ₈ F ₁₇ — and a POE chain, and R ² is an alkoxysilane having a methyl group and / or an ethyl group. B2: In the formula 1, a is 1, R ¹ Is CF ₃ (CF
₂ ) an alkoxysilane in which a monovalent organic group containing ₂ OCF (CF ₃ ) CF ₂ — and a POE chain, and R ² is a methyl group or an ethyl group; B3: In the formula 1, a is 0; One of R ² is n-
An alkoxysilane in which a monovalent organic group containing C ₈ F ₁₇ — and a POE chain and the other R ² is a methyl group or an ethyl group; B4: in the formula 1, a is 1 and R ¹ is methyl One of R ² is a group comprising n—C ₈ F ₁₇ — and a POE chain.
An alkoxysilane having a valence organic group and another R ² being a methyl group or an ethyl group;

C1: In the formula 2, b is 0 and R ⁴
Is an alkoxysilane in which is a methyl group and / or an ethyl group; C2: an alkoxysilane in which b is 1, R ³ is a methyl group, and R ⁴ is a methyl group and / or an ethyl group in Formula 2.

The aqueous coating composition of the present invention may contain an alkoxysilane condensation catalyst. The content of the condensation catalyst is selected from the group consisting of (B)
And 10 parts or less for 100 parts of the total of (C) and (C).

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 development of stain resistance and high gloss provided by the aqueous coating composition of the present invention is not necessarily clear,
It is considered as follows. (B) has a fluorinated group, and since the fluorinated organic group has a low surface energy,
It is considered that (B) easily migrates to the coating film surface, and that a small amount of (B) can exhibit stain resistance. further,
It is considered that (B) has a hydrophilic group, so that the dispersibility of the alkoxysilane is improved, (B) and (C) are finely dispersed in the coating film, and high gloss is exhibited. Further, it is considered that the hydrophilic group exerts an effect of removing dirt attached to the coating film, and develops rain streak stain resistance. In particular, by using a monovalent organic group having a fluorine-containing group and a hydrophilic group having the structure of Formula 3, the transferability and dispersibility of the alkoxysilane to the surface are improved, and the surface is resistant to contamination and dirt. It is considered that a coating film having excellent effects and the like and excellent stain resistance to rain streaks can be formed.

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.

As the polybasic acid anhydride, phthalic anhydride,
Aromatic polycarboxylic anhydrides such as pyromellitic anhydride,
Examples thereof include aliphatic polycarboxylic anhydrides such as maleic anhydride and succinic anhydride.

Examples of the coloring agent include dyes, organic pigments, inorganic pigments, and metallic pigments such as aluminum paste. 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 a coating method, a commonly used coating method such as coating using 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 employed without any particular limitation. Drying of the coating film may be performed at room temperature or may be performed at a higher temperature.

The paint containing the obtained aqueous paint composition is as follows:
The coating may be applied to a newly-installed base material / article before installation, or may be applied after the base material / 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 the 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 painted include vehicles such as automobiles and trains, aircrafts, building members such as exterior panels, doors, windows and gates, road medians such as road dividers, guardrails, bridge members, and steel towers. , Tanks, pipes, communication equipment, electrical and electronic components, and the like.

[0067]

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 Coating] Base white coating 1: a polymerization unit based on a monomer obtained by adding an average of 10 molecules of ethylene oxide to chlorotrifluoroethylene / ethyl vinyl ether / cyclohexyl vinyl ether / 4-hydroxybutyl vinyl ether / 4-hydroxybutyl vinyl ether, An aqueous dispersion of the fluororesin 1 containing 50/15/33 / 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.

[0074] 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): CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₃ O (CH ₂ ) was placed in a glass flask having an internal volume of 300 mL.
183 g of CH ₂ O) _n H (average molecular weight 955) and 0.18 g of dibutyltin dilaurate were charged. At 50 ° C., isocyanate group-containing silane OCNCH ₂ CH ₂ CH ₂ S
i (OCH ₃ ) ₃ (KBE9007, Shin-Etsu Chemical Co., Ltd.)
Was dropped over 3 hours. The reaction was further performed at 50 ° C. for 4 hours to obtain alkoxysilane B-1 having a fluorine-containing group and a POE chain. The number average molecular weight of the alkoxysilane B-1 was 1200.

Synthesis Example 2 (Mixed product 1): Internal volume 300
In a mL glass flask, 143.6 g of a condensate of tetraethoxysilane (average degree of condensation: about 5, silica content: 40% by mass, trade name: ethyl silicate 40 (hereinafter, referred to as ES40), manufactured by Colcoat Co., Ltd.), alkoxysilane B-1
57.9 g of dibutyltin dilaurate 0.10
g and 3.5 g of ion-exchanged water were charged and reacted at 80 ° C. for 4 hours to obtain a mixed product 1. Mixed product 1
Had a number average molecular weight of 4,300.

Synthesis Example 3 (Mixed product 2): Internal volume 300
143.6 g of ES40 and 0.11 g of triethylamine were charged into a 3-mL three-necked flask. Then 100 ° C
And the above-mentioned CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₃ O (CH ₂
92.2 g of CH ₂ O) _n H was added dropwise over 10 minutes.
The mixture was stirred at 5 ° C. for 5 hours to remove volatile components to obtain a mixed product 2. The number average molecular weight of the mixed product 2 was 3,000.

Synthesis Example 4 (Mixed product 3): Internal volume 300
160 g of ES40 and PO in a mL glass flask
E-chain containing alkoxysilane CH ₃ O (CH ₂ CH ₂ O) _m S
36.3 g of i (OCH ₂ CH ₃ ) ₃ (m is about 10, A-1230, manufactured by Nippon Unicar), 0.13 g of dibutyltin dilaurate, and 3.9 g of ion-exchanged water were charged.
The mixture was reacted at 80 ° C. for 4 hours to obtain a mixed product 3. The number average molecular weight of the mixed product 3 was 3,800.

Synthesis Example 5 (Mixed product 4): Internal volume 300
A 50 mL three-necked flask was charged with 50 g of ES40 and 0.11 g of triethylamine. Next, the mixture was heated to 100 ° C., and 220 g of 4,4,5,5,5-pentafluoropentyl alcohol (manufactured by Asahi Glass Co., Ltd.) was added dropwise over 10 minutes.
The mixture was stirred at 00 ° C. for 5 hours to remove volatile components, thereby obtaining a mixed product 4. The number average molecular weight of the mixed product 4 was 1,000.

Examples 1 to 11 The mixed products 1 to 4 obtained in Synthesis Examples 2 to 5 were added to the base white paint 1 or 2 at the mixing ratios shown in Tables 2 and 3 to obtain paints. The paint is 200 × 95
An aluminum plate having a size of × 8 mm 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 5 are Examples, and Examples 6 to 11 are Comparative Examples. Table 4 shows the composition ratios of (B) and (C) in the mixed products 1 to 4 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: A specular gloss of 60 degrees was measured according to JIS Z8741.

Accelerated stain resistance: Painted plate at 50 ° C., 95% R
After curing for 1 day under H, 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. The lightness (L ^* value) before and after the test was measured, and the difference (ΔL ^* ) was calculated.
It is 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 board (size: 200 x 95 x 8m)
m) at a position of 100 mm (that is, the center in the longitudinal direction)
And the exposed surface was exposed outside in summer in Kawasaki City, Kanagawa Prefecture, with the painted surface outside so that the upper portion was at an angle of 30 degrees from the horizontal plane and the lower portion was vertical. 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: With respect to the outdoor exposure plate evaluated for slope stain, the state of vertical streak stain was evaluated. 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. 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. 80% gloss retention
The above was described as ○, and the gloss retention of less than 80% was described as ×.

[0084]

[Table 2]

[0085]

[Table 3]

[0086]

[Table 4]

[0087]

As described above, the 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, stain washability, stain removal effect and the like, and also excellent in weather resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CB021 CB091 CB131 CD091 CD111 CD121 CE051 CF021 CF091 CG141 DA161 DB001 DD001 DG031 DL022 DL031 DL032 DL072 DL082 DL092 DL152 GA02 GA03 GA06 GA07 GA12 GA15 KA04 MA08 MA10 MA18 PB07 PB09 PC02 PC03 PC04 PC08

Claims (7)

[Claims] 1. An alkoxysilane represented by the formula 1 and / or a condensate thereof (B) based on 100 parts of the synthetic resin (A).
And 0.1 to 50 parts of an alkoxysilane represented by the formula 2 and / or a condensate (C) thereof of 0 to 50 parts. (R ¹ ) _a Si (OR ² ) _4-a Formula 1 (R ³ ) _b Si (OR ⁴ ) _4-b Formula 2 In Formula 1, a is an integer of 0 to 3, and 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 fluorine-containing group and a hydrophilic group. In the formula 2, b is an integer of 0 to 3, R ³ is a monovalent organic group, and R ⁴ is 1
It represents a valent organic group or a hydrogen atom, and R ³ and R ⁴ are not monovalent organic groups having a fluorinated group and a hydrophilic group. 2. The aqueous coating composition according to claim 1, wherein the components (B) and (C) are previously mixed. 3. The water-based coating composition according to claim 1, wherein the monovalent organic group having a fluorinated group and a hydrophilic group in (B) is a monovalent organic group represented by Formula 3. Composition. R ^f -X-Y-Z- formula 3 wherein R ^f is a fluorine-containing group, Y is a hydrophilic group,
X and Z represent a bonding group or a single bond. 4. The aqueous coating composition according to claim 1, wherein the fluorine-containing group in (B) is a polyfluoroalkyl group, and the hydrophilic group is a polyoxyalkylene chain. 5. A paint comprising the aqueous paint composition according to claim 1. 6. A coating method comprising applying the paint according to claim 5 to an object to be coated. 7. A coated article having a coating film formed from the paint according to claim 5.