JPH11172200A - Inorganic-organic composite type aqueous coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of exhibiting excellent storage stability and forming coating films having excellent weather resistance and stain resistance and useful for coating outer wall materials such as hydraulic plate materials or the like by compounding a specific hydrolyzable silyl group-containing copolymer aqueous dispersion. SOLUTION: This inorganic-organic composite type aqueous coating composition comprises (A) a water-soluble or dispersible alkoxysilane condensate for example, a product obtained by condensing a compound of formula I [R<1> is a 1-6C alkyl or phenyl; R<2> is a 1-4C alkyl; (a) is 1 or 2] or a compound of formula II [R<3> is R<1> or a group of the formula: OR<2> ; (n) is 1-10]}, (B) a hydrolyzable silyl group-containing fluorocopolymer aqueous dispersion or a hydrolyzable silyl group-containing acrylic copolymer aqueous dispersion, (C) an organic solvent and (D) water. The composition preferably comprises the components A, B, C and D so as to contain the components A and B in and A:B solid weight ratio of 90:10 to 15:85 and in a total amount of <=55 wt.% and contain the components C and D in amounts of 10-35 wt.% and 10-35 wt.% respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic / organic composite water-based coating composition, and more particularly, to an inorganic / organic composite water-based coating composition capable of forming a film having excellent storage stability and excellent weather resistance and stain resistance. -It relates to an organic composite type aqueous coating composition.

[0002]

2. Description of the Related Art Conventionally, an organic solvent solution of an alkoxysilane condensate or a mixture of an alkoxysilane condensate and a hydrolyzable silyl group-containing acrylic copolymer exhibits weather resistance and stain resistance. It is widely known that the material is a useful material capable of forming a coating film. However, since these coating materials are used after being diluted with an organic solvent, the range of use and the mode of use of the coating materials are naturally limited due to the toxicity and flammability of the organic solvent. For example, it is necessary to take measures such as performing ventilation during the painting operation to maintain the health environment of the worker, or making the painting line an exposure-resistant type.

[0003]

In order to solve the above problems, it is ideal that the above coating composition is made into an aqueous solution or an aqueous dispersion. It is known that it is extremely difficult to keep such a composition stable in water for a long period of time since the alkoxysilyl group present in water has a high hydrolyzability in water and the condensation reaction proceeds.

[0004] Further, when an organic solvent solution of an alkoxysilane condensate is used alone to form a film, there is also a disadvantage that a hard and brittle film is formed. As a means for improving the disadvantages of this coating film, an organic solvent solution of an alkoxysilane condensate is mixed with a hydrolyzable silyl group-containing acrylic resin diluted with an organic solvent to alter or modify the properties. Even with a hydrolyzable silyl group-containing acrylic resin, it has been extremely difficult to keep the hydrolyzable silyl groups present in the molecule stable in water for a long period of time. An object of the present invention is to provide an inorganic / organic hybrid aqueous coating composition which is rich in storage stability and can form a film having excellent weather resistance and stain resistance.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a film having excellent storage stability and excellent weather resistance and stain resistance is formed. The present inventors have found an inorganic / organic hybrid aqueous coating composition which can be obtained, and have reached the present invention.

That is, the inorganic / organic composite aqueous coating composition of the present invention comprises (a) a water-soluble or water-dispersible alkoxysilane condensate, and (b) a hydrolyzable silyl group-containing fluorine-containing copolymer aqueous dispersion. At least one selected from the group consisting of a product and a hydrolyzable silyl group-containing acrylic copolymer aqueous dispersion,
(C) an organic solvent; and (d) water.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic / organic hybrid water-based coating composition of the present invention will be specifically described below in detail. Typical examples of the water-soluble or water-dispersible alkoxysilane condensate used in the present invention include the following three types.

(1) Chemical formula (I) (R ¹ ) _a -Si (OR ² ) _4-a (I) (where a is an integer of 1 or 2, and R ¹ is C ₁ -C ₆
R ² is a C ₁ -C ₄
Or an alkoxysilane compound represented by the formula (II):

[0009]

Embedded image (Wherein, n is an integer of 1 to 10, and R ¹ is C _{1 to} C ₆
R ² is a C ₁ -C ₄
Wherein R ³ is an R ¹ group or an OR ² group) in the presence of a surfactant in water or a mixture of water and a hydrophilic solvent. (X) obtained by the above method.

(2) In the presence of a trialkoxysilane or dialkoxysilane having a glycidoxy group in the molecule,
An alkoxysilane compound represented by the chemical formula (I) or an alkoxysilane precondensate represented by the chemical formula (II):
A condensate (Y) obtained by condensing in water or a mixture of water and a hydrophilic solvent. (3) After reacting a primary amine and / or a secondary amine with an alkoxysilane compound having a glycidoxy group in the molecule, neutralize with an acid, and further dilute with water to obtain a solution having the chemical formula A condensate (Z) obtained by condensing an alkoxysilane compound represented by (I) or an alkoxysilane initial condensate represented by chemical formula (II).

As specific examples of the alkoxysilane compound represented by the above formula (I), methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane Ethoxy silane, diphenyl diethoxy silane, methyl tripropoxy silane, dimethyl dipropoxy silane, phenyl tripropoxy silane, diphenyl dipropoxy silane, methyl tributoxy silane, dimethyl dibutoxy silane, phenyl tributoxy silane, diphenyl dibutoxy silane, etc. Can be

The substituent R ¹ in the chemical formula (I) is preferably a methyl group or a phenyl group from the viewpoint of the recoating property of the film. As for the substituent OR ² (alkoxy group), methoxy group, ethoxy group, propoxy group, and butoxy group are improved in the order of stability in water, but the reactivity at the time of film formation is in the opposite order. . Therefore, an ethoxy group is particularly preferred from the viewpoint of satisfying both the stability of the condensate and the reaction at the time of forming the film.

The alkoxysilane initial condensate represented by the above formula (II) is obtained by condensing one kind of the alkoxysilane compound of the above formula (I) or a mixture of two or more kinds. And the basic unit

Embedded image Of dimers to 11-mers. In the present invention, the alkoxysilane initial condensate represented by the chemical formula (II) can be used in combination with the alkoxysilane compound represented by the chemical formula (I) for the purpose of improving the flexibility and weather resistance of the coating film. is there.

Examples of the surfactant (hereinafter referred to as an emulsifier) used for the production of the above-mentioned condensate (X) include anionic surfactants such as sodium lauryl sulfate and sodium polyoxyethylene alkylphenol ether sulfate; Non-ionic surfactants such as ethylene alcohol, ethoxylated nonylphenol, dialkylphenol ethoxylate, block copolymers of ethylene oxide and propylene oxide, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are listed as typical examples. Sorbitan fatty acid esters having an HLB value in the range of 4.3 to 8.6 and polyoxyethylene sorbitan fatty acid esters having an HLB value in the range of 9.6 to 11.4 are included. These emulsifiers can be used alone or in combination of two or more.

The concentration of the emulsifier used for producing the above-mentioned condensate (X) is generally the same as the concentration of the alkoxysilane compound represented by the chemical formula (I) or the alkoxysilane compound represented by the chemical formula (II). 1 to 30 based on the weight of the condensate
%, Preferably in the range of 3 to 20% by weight. The silane condensate produced by appropriately selecting the type and concentration of these preferable emulsifiers can be maintained as a stable emulsion for two months or more.

Examples of the alkoxysilane compound having a glycidoxy group used for producing the above-mentioned condensates (Y) and (Z) include, for example, γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane. , Γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, and γ-glycidoxypropyldimethylethoxysilane.

Further, the concentration of the glycidoxy group-containing alkoxysilane compound used in the production of the above-mentioned condensate (Y) is determined based on the content of only the oxirane ring portion based on the weight of the total solid content of the alkoxysilane condensate. Amount is 4.0
Preferably, the amount is in the range of １12.0% by weight.
When the content of only the oxirane ring portion is less than 4.0% by weight, the water solubility or water dispersibility of the alkoxysilane condensate is not sufficient, and the storage stability tends to deteriorate, which is not preferable. Conversely, the content of only the oxirane ring portion is 1
If it exceeds 2.0% by weight, the water resistance tends to decrease, which is not preferable.

The primary or secondary amine used in producing the above-mentioned condensate (Z) includes, for example, n-
Propylamine, isopropylamine, n-butylamine, monoethanolamine, aniline, benzylamine, octylamine, oleylamine, stearylamine, γ-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, organosiloxane-modified primary amine, -Fluoroaniline, 2,2-bis [(4
-Aminophenyl) hexafluoropropane], any primary amine such as 4-aminobenzotrifluoride,
Any secondary amine such as diethylamine, di- (n-propyl) amine, diamylamine, diethanolamine, or a mixture thereof can be used. However, considering the water resistance and weather resistance of the coating, the hydrophobicity of the organic group is considered. A strong one is desirable.

In producing the above-mentioned condensate (Z),
An alkoxysilane compound having a glycidoxy group and a primary or secondary amine are prepared such that the primary or secondary amine is present in an amount of 0.1 to 2 mol per 1 mol of the epoxy group of the alkoxysilane compound having a glycidoxy group. Mix in the amount
Seal and heat with stirring at 60-100 ° C. for 2-8 hours to synthesize the silicon-containing amine, which is then mixed with an equimolar amount of the above mixed and primary or secondary amine molar amount. An aqueous solution of an acid is added and neutralized to obtain an aqueous organosilicon compound having a relatively low molecular weight.

In this case, in the presence of the compound obtained under the condition that the mixing amount of the primary or secondary amine is less than 0.1 mol, the alkoxysilane compound represented by the chemical formula (I) or the chemical formula ( Condensation of the alkoxysilane initial condensate represented by II) is not preferred because the resulting aqueous solution or aqueous dispersion tends to have poor storage stability. Conversely, if condensation occurs in the presence of the compound obtained under the condition that the mixing amount of the primary or secondary amine exceeds 2 mol, the water resistance of the finally obtained coating tends to decrease, which is not preferable.

Further, when the alkoxysilane compound represented by the chemical formula (I) or the alkoxysilane initial condensate represented by the chemical formula (II) is condensed in the solution after the neutralization, the unneutralized When the generated amine compound remains,
Since the reaction with the alkoxy group in the system becomes unstable and may cause precipitation or gelation, it must be accurately neutralized by adding an appropriate amount of acid.

As the acid used for neutralization, any acid can be used as long as it reacts with an amine formed by a reaction with a primary or secondary amine to form an ammonium salt. . For example, inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid,
Organic acids such as acetic acid, propionic acid and benzoic acid; chlorosilanes such as trimethylchlorosilane, dimethylchlorosilane and silicon tetrachloride; titanium tetrachloride; zirconium tetrachloride; At this time, the amount of water added together with the acid depends on the amount of the silane component after the addition of the alkoxysilane compound represented by the chemical formula (I) or the alkoxysilane initial condensate represented by the chemical formula (II). 10-50% by weight
Is desirable. When the amount is less than 10% by weight, the solid content concentration of the obtained silane condensate dispersion tends to be low, and the ability to form a film tends to be poor. It tends to decrease significantly.

The above condensates (X), (Y) and (Z)
The conditions for the condensation of the alkoxysilane compound represented by the chemical formula (I) or the alkoxysilane initial condensate represented by the chemical formula (II) in water or a mixture of water and a hydrophilic solvent in the production of PH is 4.0-8.
Suitably, it is in the range of zero. When the pH is close to 4.0, the stability of the condensate is good, and the stability tends to deteriorate as the pH approaches 8.0. In consideration of the compatibility with the hydrolyzable silyl group-containing fluorinated copolymer and the hydrolyzable silyl group-containing acrylic copolymer, storage stability, and the like, the pH is in the range of 5.5 to 7.0. More preferably, there is. The reaction temperature is in the range of 30 to 80 ° C, and the reaction time is in the range of 2 to 10 hours. In the present invention, the water-soluble or water-dispersible alkoxysilane condensate, for example, the above condensates (X), (Y) or (Z) can be used alone or in combination of two or more. is there.

The aqueous dispersion of the hydrolyzable silyl group-containing fluorine-containing copolymer used in the present invention has at least one compound per molecule.
These are fluorine-containing copolymers having various kinds of hydrolyzable silyl groups, which are dispersed in an aqueous medium. The fluorinated copolymer has an effect of imparting flexibility while maintaining the weather resistance of the alkoxysilane condensate by mixing with the water-soluble or water-dispersible alkoxysilane condensate.

The above fluorine-containing copolymer has a structural unit of 10 to 70 mol% based on the fluoroolefin (i) and a structural unit 0 based on the organosilicon compound (ii) having both an olefinically unsaturated bond and an alkoxysilyl group. 1 to 20 mol%, and 30 to 85 mol% of the structural unit based on the other copolymerizable compound (iii), wherein the total of (i), (ii) and (iii) is 100 mol%. It is obtained by subjecting the monomer composition to emulsion polymerization in an aqueous medium.

The fluoroolefin (i) in the above-mentioned fluorine-containing copolymer is a component necessary for imparting weather resistance to the polymer, and is a polymerizable polymer containing at least one fluorine atom in the molecule. It is a compound having a bond.
For example, chlorotrifluoroethylene, vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, hexafluoroisobutene and the like have 2 carbon atoms.
About 6 to 6 fluoroolefins are mentioned, and chlorotrifluoroethylene is the most preferred. Even if only one kind of fluoroolefin is used, 2
More than one kind may be used in combination, and when two or more kinds are used in combination, it is preferable that chlorotrifluoroethylene is included as one of them.

When the aqueous dispersion of the hydrolyzable silyl group-containing fluorocopolymer used in the present invention is produced, the mixing ratio of the fluoroolefin (i) preferably accounts for 10 to 70 mol% of all monomers. More preferably, it accounts for 30 to 60 mol%. When the compounding ratio is less than 10 mol%, the weather resistance of the obtained fluorinated copolymer tends to be insufficient, and when it exceeds 70 mol%, the film forming property tends to deteriorate. Not preferred.

The organosilicon compound (ii) having both an olefinically unsaturated bond and an alkoxysilyl group in the above fluorinated copolymer ensures compatibility with the water-soluble or water-dispersible alkoxysilane condensate. And a component that becomes a cross-linking site at the time of film formation. That is, while the state of the alkoxysilyl group is stable in the emulsion, the alkoxysilyl group undergoes a hydrolysis reaction to form a silanol group during the formation of the coating film, and the alkoxysilyl group reacts with the water-soluble or water-dispersible alkoxysilane condensate. It is presumed to contribute to the cross-linking reaction or between the fluorine-containing copolymers, or to the cross-linking reaction with the silyl group-containing acrylic copolymer described below, for example, the alkoxysilyl group is hydrolyzed to become a silanol group, and then It is considered that the silanol groups are condensed to form an intermolecular cross-link by a siloxane bond. It is presumed that the water resistance, stain resistance, and solvent resistance of the coating film obtained due to the crosslinked structure are improved.

In the above-mentioned organosilicon compound (ii), the group having an olefinically unsaturated bond is not particularly limited, and examples thereof include a vinyl group, an allyl group, an acryloyl group and a methacryloyl group. The alkoxysilyl group is not particularly limited, but at least one methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, n-butoxy group, Butoxy group, t
tert-butoxy group bonded thereto.

The above organosilicon compounds (ii) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (n-propoxy) silane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltris (methoxyethoxy) silane, vinyl Methyldiethoxysilane, vinylmethyldiisopropoxysilane,
Vinylmethyldi-n-propoxysilane, vinylmethoxydiethoxysilane, vinylmethoxydiisopropoxysilane, vinylmethoxydi-n-propoxysilane, vinylethoxydimethoxysilane, vinylethoxydiisopropoxysilane, vinylethoxydi-n-propoxysilane, Vinyl-n-propoxydimethoxysilane, vinyl-n-propoxydiethoxysilane, vinyl-n-
Propoxydiisopropoxysilane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N-allyl-N-methacryloyl) aminopropyltrimethoxysilane, N, N-bis [3- (tri Methoxysilyl) propyl] methacrylamide, N, N-
Bis [3- (methyldimethoxysilyl) propyl] methacrylamide, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltris (trimethylsiloxy) silane and the like can be exemplified.

These may be used alone or in combination of two or more. Further, among the vinyltrialkoxysilanes exemplified above, vinyltrialkoxysilanes having an alkoxy group having 1 to 4 carbon atoms are particularly preferred because of their excellent copolymerizability with other monomers. It is also desirable to include them when used together.

In preparing the aqueous dispersion of the hydrolyzable silyl group-containing fluorocopolymer used in the present invention, the compounding ratio of the above-mentioned organosilicon compound (ii) is 0.1 to 20 of the total monomers.
It preferably occupies 0.3% to 10% by mole, more preferably 0.3% to 10% by mole. When the compounding ratio is less than 0.1 mol%, the finally obtained coating film is not sufficiently crosslinked, and the water resistance and stain resistance of the coating film tend to be inferior. And the storage stability of the dispersion tends to be inferior.

Examples of the other copolymerizable compound (iii) in the above fluorine-containing copolymer include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl pivalate, vinyl caproate, vinyl caprylate, and lauric acid. Vinyl, vinyl cyclohexanecarboxylate, vinyl vivalate, vinyl versatate, (Veova 9, Veova 1
0) or a branched or cyclic alkyl having 1 to 6 carbon atoms such as fatty acid vinyl esters, ethyl vinyl ether, propyl vinyl ether, cyclohexyl vinyl ether, etc. Alkyl vinyl ethers having a group, allyl acetate, allyl propionate, allyl butyrate, allyl isobutyrate, allyl caproate, allyl caprylate, allyl laurate, allyl carboxylate such as allyl cyclohexanecarboxylate, methyl allyl ether, ethyl Allyl ethers such as allyl ether and butyl allyl ether, hydroxybutyl allyl ether, ethylene glycol monoallyl ether, propylene glycol monoallyl ether, triethylene glycol monoallyl ether, Hydroxyl group-containing allyl ethers such as phosphorus monoallyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, hydroxyl group-containing vinyl ethers such as hydroxymethyl vinyl ether, ethylene, propylene, 1-butene, and 1-octene α
-Olefins, polyethylene oxides, unsaturated esters having a hydrophilic side chain such as a polypropylene oxide chain or unsaturated ethers, halogenated olefins such as vinyl chloride and vinylidene chloride, styrene, α-methylstyrene, vinyltoluene Aromatic vinyl compounds such as, (meth) acryloyl compounds such as ethyl (meth) acrylate, unsaturated carboxylic anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride or derivatives thereof, Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, vinyl acetic acid, and maleic acid, and dicarboxylic acids; or chemical formula (III): CH ₂ ＣＨCH— (CH ₂ ) n —COOH (III) Is an integer of 3 to 15).
Hexenoic acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecylenic acid, 11-
Examples thereof include unsaturated carboxylic acids such as dodecylenic acid and 17-octadecylenic acid, and further include those obtained by neutralizing an unsaturated carboxylic acid such as sodium 10-undecylenate with an alkali substance, and a sulfonic acid-containing monomer.

Among these, unsaturated carboxylic acids represented by the above chemical formula (III) are components that play a role in the stability of the silyl group-containing fluorocopolymer aqueous dispersion and the catalytic action for the crosslinking reaction of alkoxysilyl groups. is there. The stabilizing action means that the unsaturated carboxylic acid acts in the same manner as the emulsifier, that is, acts as a reactive emulsifier, so that the amount of the non-reactive emulsifier can be reduced.

In general, the non-reactive emulsifier bleeds from the coating film and precipitates on the surface when the compatibility with the resin is poor,
There is a tendency to absorb water and contaminants, and even if it has good compatibility with the resin, it tends to give water absorption to the resin itself and deteriorate the water resistance of the coating film. is there. Therefore, it is presumed that the use of the unsaturated carboxylic acids as described above results in the effect of improving the water resistance and stain resistance of the coating film.

On the other hand, with regard to the catalytic action on the crosslinking reaction, the carboxyl groups introduced by the unsaturated carboxylic acids are present on the surface of the emulsion particles in the form of an aqueous dispersion, so that the carboxyl groups are present on the alkoxysilyl groups inside. It has no effect, but it is considered that it diffuses uniformly and forms a catalytic action on the alkoxysilyl group at the time of coating formation by water volatilization. Therefore, the long-term storage stability of the dispersion is sufficiently ensured, and furthermore, the water vaporization accompanying the film formation promptly exerts a catalytic action on the crosslinking reaction, so that the film has excellent initial water resistance and stain resistance. It is presumed.

The proportion of the unsaturated carboxylic acids preferably accounts for 0.1 to 5 mol% of all monomers.
More preferably, it accounts for 0.1 to 2 mol%. If the compounding ratio is less than 0.1 mol%, the effect of stabilizing the dispersion tends to be insufficient, and if the amount of the non-reactive emulsifier used is increased to compensate for this, the water resistance of the coating film is increased. It is not preferable because the property is lowered. The compounding ratio is 5 mol%
If it exceeds, the alkali resistance of the coating film tends to decrease, such being undesirable. In addition, two or more of these unsaturated carboxylic acids can be used in combination.

When the unsaturated carboxylic acid represented by the chemical formula (III) has an n of less than 3, it is difficult to improve the stability of the dispersion during the production of the dispersion because the water solubility of the monomer is high. There is a tendency that it does not contribute much, and when it exceeds 15, there is a tendency that problems such as poor polymerization reactivity occur. Among the unsaturated carboxylic acids represented by the chemical formula (III), 10-undecylenic acid is preferred because it has particularly good polymerizability at the time of producing a dispersion and storage stability of the produced dispersion.

Among the copolymerizable compounds other than the unsaturated carboxylic acids, fatty acid vinyl esters and alkyl vinyl ethers are particularly excellent in polymerizability and film forming property when forming a coating film from a dispersion. Can be cited as preferred. The mixing ratio of the above-mentioned other copolymerizable compound (iii) in producing the hydrolyzable silyl group-containing fluorocopolymer aqueous dispersion used in the present invention occupies 30 to 85 mol% of all monomers. And more preferably accounts for 35 to 70 mol%. If the compounding ratio is less than 30 mol%, the film-forming properties tend to be poor, and if it exceeds 85 mol%, the weather resistance tends to be poor, which is not preferred.

As described above, the aqueous dispersion of the hydrolyzable silyl group-containing fluorine-containing copolymer used in the present invention is a fluoroolefin (i), an organosilicon compound having both an olefinically unsaturated bond and an alkoxysilyl group. (Ii) and other copolymerizable compound (iii) by emulsion polymerization. As the medium at this time, an aqueous medium, that is, water, or a mixed solution of water and an organic solvent can be used. Here, examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, n-butanol, isobutanol, tert-butanol and sec-butanol, dihydric alcohols such as ethylene glycol and diethylene glycol, methyl cellosolve, ethyl cellosolve and isopropyl. Examples thereof include ether alcohols such as cellosolve, aromatic or aliphatic hydrocarbons such as xylene, and esters such as butyl acetate and ethyl acetate. These organic solvents can be used alone or as a mixture of two or more. When used as a mixed solution of water and an organic solvent, the compounding amount of the organic solvent is preferably 10% by weight or less of the total solvent, and it is preferable that the medium becomes a uniform medium.

In order to ensure that the unsaturated carboxylic acid in the fluorine-containing copolymer aqueous dispersion functions as a reactive emulsifier, the storage stability of the alkoxysilyl group in the dispersion is further improved. For this purpose, the pH of the medium and the pH of the resulting dispersion at the time of production of the aqueous fluorocopolymer dispersion are preferably 5 to 9, and more preferably 6 to 9, respectively. Therefore, in the production of the fluorocopolymer aqueous dispersion, it is preferable to use various pH adjusters for the purpose of adjusting pH. Examples of the pH adjusting agent that can be used include inorganic salts such as sodium carbonate, potassium carbonate, sodium hydrogen orthophosphate, sodium thiosulfate, and sodium tetraborate; and organic bases such as triethylamine, triethanolamine, ammonia, and dimethylethanolamine. You. The amount of the pH adjuster is usually 0.05 to 5 per 100 parts by weight of the emulsion polymerization medium.
It is about parts by weight. Even if the pH adjuster is added during polymerization,
It may be added after the polymerization, or a combination thereof is also possible.

The initiation of emulsion polymerization is carried out by adding a polymerization initiator. As such a polymerization initiator, a water-soluble initiator is preferably employed in view of polymerization stability and workability. Examples of the polymerization initiator that can be used include potassium persulfate, persulfates such as ammonium persulfate, hydrogen peroxide,
Alternatively, a redox initiator comprising a combination of these with a reducing agent such as sodium sulfite may be used. The polymerization initiator was added in an amount of 0.000 parts by weight per 100 parts by weight of the total monomers.
It is 1 to 5 parts by weight, preferably 0.001 to 3 parts by weight. The emulsion polymerization initiation temperature is optimally selected mainly depending on the type of polymerization initiator, but from the viewpoint of workability and polymerization reaction stability, it is 0 to 100 ° C, preferably 30 to 70 ° C.
° C is adopted.

In the preparation of the aqueous dispersion of the hydrolyzable silyl group-containing fluorocopolymer, various dispersion stabilizers can be used for the purpose of improving the stability of the emulsified state during the polymerization. Examples of such a dispersion stabilizer include known surfactants such as anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and water-soluble polymers such as polyvinyl alcohol and methyl cellulose. They can be used, and nonionic surfactants are particularly preferred because of their excellent compatibility with the polymer.
More preferably, HLB showing a balance between hydrophilicity and hydrophobicity
The nonionic surfactant has a value of 10 to 18. These dispersion stabilizers may be used alone or in combination of two or more. Also, these dispersion stabilizers are apt to be added in an amount of 10 parts by weight or less with respect to 100 parts by weight of the total monomer, since the water resistance and weather resistance of the coating film tend to be inferior when the added amount is large. More preferably, it is added in an amount of 5 parts by weight or less.

The aqueous dispersion of the hydrolyzable silyl group-containing acrylic copolymer used in the present invention has at least one aqueous dispersion per molecule.
This is an acrylic copolymer having one hydrolyzable silyl group and dispersed in an aqueous medium. By mixing the acrylic copolymer with the alkoxysilane condensate, the acrylic copolymer has the effect of imparting flexibility while maintaining the weather resistance of the alkoxysilane condensate.

Although various acrylic copolymers can be mentioned, those which can meet the purpose of the present invention include, particularly, structural units 35 to 97 based on alkyl (meth) acrylate (i). 0.3% by weight of a structural unit based on an organosilicon compound (ii) having both at least one polymerizable unsaturated double bond (hereinafter, abbreviated as an unsaturated bond) and an alkoxysilyl group in a molecule. (I), (ii) consisting of 0.5 to 60% by weight of a structural unit based on 15% by weight and another copolymerizable compound (iii)
It is desirable to use an emulsion copolymer (copolymer emulsion) obtained by emulsion-copolymerizing a monomer composition in which the sum of (iii) and (iii) is 100% by weight.

Particularly typical examples of the above-mentioned alkyl (meth) acrylate (i) include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylate.
Examples thereof include n-butyl acrylate, isobutyl (meth) acrylate, -tert-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. The alkyl (meth) acrylate is 1
35 to 97 of all monomers by using only one kind or in combination of two or more kinds
It is used in an amount which will be% by weight. Further, cyclohexyl (meth) acrylate and the like can be used in the same manner.

Particularly typical examples of the organosilicon compound (ii) include divinyldimethoxysilane, divinyldi-β-methoxyethoxysilane, vinyltriethoxysilane, vinyltris-β-methoxyethoxysilane, and γ-methacryloyl. Oxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane and the like can be mentioned. These may be used alone or in combination of two or more, and may be used in an amount of 0.3 to 15
It is used in an amount which will be% by weight.

The above-mentioned organosilicon compound (ii) is an essential component for ensuring compatibility with the water-soluble or water-dispersible alkoxysilane condensate and for forming a cross-linking site in the polymer. If the ratio is less than 0.3% by weight,
Inevitably, the effect of improving or expressing the performance cannot be exhibited. On the other hand, if the compounding ratio exceeds 15% by weight, the effect is saturated, so that it is economical. Not preferred.

The other copolymerizable monomers (i)
Illustrative examples of ii) include various hydroxy compounds such as β-hydroxyethyl (meth) acrylate and β-hydroxypropyl (meth) acrylate;
Various vinyl cyanides such as (meth) acrylonitrile, maleic dinitrile or vinylidene cyanide;
Various glycidyl compounds such as glycidyl (meth) acrylate or allyl glycidyl ether; various amide compounds such as (meth) acrylamide, N-methylol (meth) acrylamide or dimethylol methanoic acid amide or alkoxy compounds thereof; alkylamino (meth) acrylate , N-alkylaminoalkyl (meth) acrylate or various amino group-containing compounds such as N-alkylaminoalkyl (meth) acrylamide; styrene, α-methylstyrene, p-tert-
Styrene such as butylstyrene or vinyltoluene or a derivative thereof; or various reactive polar group-containing monomers such as N-vinylpyrrolidone, or divinylbenzene, ethylene glycol di (meth) acrylate or glycerin tri (meth) acrylate; Crosslinkable monomer having two or more unsaturated bonds in one molecule, (meth) acrylic acid, maleic acid or its half-esterified product, fumaric acid or its half-esterified product, itaconic acid or its half-esterified product, or crotonic acid And the like.

The above other copolymerizable monomers (iii)
Among them, particularly useful monomers are α, β-monoethylenically unsaturated carboxylic acids, and the monomer has a miscibility with an alkoxysilane condensate which is another component of the present invention. It is necessary to improve the content, and the compounding ratio is suitably in the range of 0.5 to 5% by weight. When the blending ratio is less than 0.5% by weight, the effect of improving the performance tends not to be exhibited, while when the blending ratio exceeds 5% by weight, the obtained emulsion copolymer is inevitably obtained. In any case, the alkali resistance tends to be inferior.

An emulsion copolymer obtained by emulsion copolymerization using the above-mentioned alkyl (meth) acrylate (i), organosilicon compound (ii) and other copolymerizable compound (iii) is produced. The emulsifier used at this time may be a known and commonly used emulsifier. Among them, particularly typical ones are various anionic emulsifiers such as alkylbenzene sulfonate, alkyl sulfate or alkylaryl polyether sulfate; Various nonionic emulsifiers such as oxyethylene alkyl ether, polyoxyethylene alkylaryl ether or polyoxyethylene-polyoxypropylene block copolymer; or various cationic emulsifiers such as alkyltrimethylammonium salt or dialkyldimethylammonium salt Can be mentioned Although et materials are selected appropriately,
In particular, anionic or nonionic emulsifiers are preferable from the viewpoint of the mixing stability of the alkoxysilane condensate and the like.

In addition to these emulsifiers, various protective colloids such as water-soluble oligomers and water-soluble polymer compounds such as polyvinyl alcohol and hydroxyethyl cellulose can be used as dispersion stabilizers. If a large amount of such an emulsifier and protective colloid is used, the water resistance of the film of the obtained resin composition will be deteriorated. Conversely, if the amount is too small, cissing and choking will easily occur during film formation. Not preferred.
From such a meaning, it is appropriate that the amount of the emulsifier and the protective colloid used is in the range of 1 to 10% by weight, preferably 2 to 8% by weight based on the total amount of the monomers.

Further, particularly representative polymerization initiators used for emulsion-copolymerizing (meth) acrylic acid alkyl ester (i), organosilicon compound (ii) and other copolymerizable compound (iii). For example, various water-soluble radical generators such as hydrogen peroxide or persulfate; and / or 2,2'-azobisisobutyronitrile, benzoyl peroxide (benzoyl peroxide), cumene hydroperoxide ( Cumene hydroperoxide) or tert-
Various oil-soluble radical generators such as butyl hydroperoxide can be mentioned, and further, a so-called redox-based initiator obtained by combining these polymerization initiators with a known and commonly used reducing agent is appropriately selected and used. Can also.

Further, in order to adjust the molecular weight of the emulsion copolymer, various known chain transfer agents such as alcohols (catechols) and thiols may be used.
The reaction temperature for the emulsion copolymerization of the alkyl (meth) acrylate (i), the organosilicon compound (ii) and the other copolymerizable compound (iii) is generally about 3
The temperature is preferably about 0 to 90 ° C., and the copolymerization reaction at that time is preferably performed in an inert gas such as nitrogen gas.

The inorganic / organic composite water-based coating composition of the present invention comprises (a) a water-soluble or water-dispersible alkoxysilane condensate described above, and (b) a hydrolyzable silyl group-containing fluorocopolymer. It is composed of at least one selected from the group consisting of an aqueous dispersion and an aqueous dispersion of a hydrolyzable silyl group-containing acrylic copolymer, (c) an organic solvent, and (d) water, preferably (a) )) And the component (b) are mixed at a solid content ratio of (a) :( b) = 90: 10 to 15: 8.
5, more preferably (a) :( b) = 70: 30
４０40: 60. If the mixing ratio of the component (a) is less than 15% by weight, the hardness and stain resistance tend to be inferior, which is not preferable. Conversely, the mixing ratio of component (a) is 90
When the amount is more than 10% by weight, the flexibility of a film formed using the obtained composition is not sufficient, and when exposed outdoors, a tendency to crack in a short period is observed, which is not preferable.

As a method of mixing the components (a) and (b), the components (a) and (b) may be mixed in advance before coating, or Become (a)
Although the component and the component (b) may be used as a mixture, it is preferable to use a premixed one in consideration of workability. In the inorganic / organic composite coating composition of the present invention, the total solid content of the components (a) and (b) is preferably 55% by weight or less, more preferably 50% by weight or less. If the total solid content exceeds 55% by weight, the storage stability tends to be significantly deteriorated, which is not preferable.

In the inorganic / organic composite coating composition of the present invention, the amount of component (c) is preferably 10% by weight or less, more preferably 7% by weight or less. The component (c) in the inorganic / organic composite coating composition of the present invention is by-produced during the production of the water-soluble or water-dispersible alkoxysilane condensate of the component (a), and the number of carbon atoms contained in the system. Also included are lower alcohols of 1 to 4 and those contained in the system as a film-forming auxiliary for the fluorine-containing copolymer or acrylic copolymer of the component (b). When the amount of the component (c) exceeds 10% by weight, it is far from the category of the water-based coating composition of the present invention, and it is necessary to perform ventilation during the coating work in consideration of flammability and hygiene. There is.

Further, in the inorganic / organic composite coating composition of the present invention, the water as the component (d) is preferably at least 35% by weight from the viewpoint of ensuring the storage stability of the coating composition of the present invention. It is preferably at least 40% by weight. The inorganic / organic hybrid aqueous coating composition of the present invention obtained as described above may be used as a clear coating film forming agent, or may be blended with various pigments and the like to form a translucent to opaque colored coating. It is also possible to use as a film forming agent. Further, if necessary, various known and commonly used additive components such as an antifoaming agent, a thickener, and a surface conditioner can, of course, be appropriately selected and blended as long as the object of the present invention is not impaired. .

Although the inorganic / organic composite coating composition of the present invention is basically used in a one-pack type, it can be used by mixing a curing catalyst immediately before coating, if necessary. . Typical examples of these curing catalysts include, as listed below, organometallic compounds of metals such as Sn, Zn, B, Ti, and Al, and alkoxysilane compounds having an amino group. They can be used together.

The inorganic / organic composite water-based coating composition of the present invention is mainly applied to an outer wall material such as a hydraulic plate material (eg, gypsum slag perlite plate), and an acrylic material is previously applied on the substrate. After forming a lower layer coating with a base paint, urethane-based paint, epoxy-based paint, acrylic silicone-based paint, etc., it is applied to form a top-coated film, and exhibits excellent stain resistance and weather resistance. The reason why such excellent physical properties are exhibited is that the silyl group-containing fluorine-containing compounded in addition to the stain resistance and ultraviolet ray deterioration resistance inherently possessed by the water-soluble or water-dispersible alkoxysilane condensate. It is thought that by partially condensation-crosslinking with the copolymer or the silyl group-containing acrylic copolymer, the flexibility is improved and the weather resistance is assured.

[0061]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, "part" and "%"
All are by weight unless otherwise specified. The components used in the following Examples and Comparative Examples are the following commercially available products or products manufactured by the following methods.

-Alkoxysilane condensate A X-51-714B [trade name, manufactured by Shin-Etsu Chemical Co., Ltd.] Appearance: milky white liquid Active ingredient: 18.0% Composition: methyltrimethoxysilane condensate 10% methanol containing non-ion -Combined use of an anionic emulsifier pH: 6.0 to 7.0

-Alkoxysilane condensate B APZ-6613 [trade name, manufactured by Nippon Unicar Co., Ltd.] Appearance: slightly white transparent liquid Active ingredient: 35% Composition: γ-glycidoxypropyl trialkoxysilane methanol 2%, ethanol 6% content pH: 3.5-4.0

The alkoxysilane condensate C 26.8 g (0.1 mol) of oleylamine and 23.6 g (0.1 mol) of γ-glycidoxypropyltrimethoxysilane
Mol) and heated in a sealed vessel at 75 ° C for 6 hours. Then, after returning to room temperature and stirring, 0.25
400 ml of a prescribed hydrochloric acid was gradually added to obtain an aqueous solution of a quaternary ammonium salt-containing organosilicon compound. 40 g of the obtained aqueous solution was immediately diluted with 40 g of water, and 20 g of methyltrimethoxysilane was gradually added thereto while stirring at a high speed of about 10,000 rpm using a homomixer to obtain a white aqueous emulsion.

Alkoxysilane condensate D Nonionic emulsifier Polyoxyethylene (20) 2 g of sorbitan trioleate was diluted with 78 g of water, and 20 g of methyltrimethoxysilane was stirred at a high speed of about 10,000 rpm using a homomixer. A white aqueous emulsion was obtained by slow addition.

Aqueous dispersion of fluorine-containing copolymer E (containing a hydrolyzable silyl group) In a 2-liter autoclave with a stainless steel stirrer, 125.7 parts of vinyl butyrate and Vova 9 (vinyl manufactured by Shell Chemical Co., Ltd.) Ester) 81.2 parts, vinyl bivalate 39.5 parts, vinyltriethoxysilane 25.1 parts, undecylenic acid 40.6 parts, ion-exchanged water 570 parts, ammonium persulfate 2.58 parts, sodium carbonate decahydrate 1.14 parts and 11.4 parts of Nowco 1504 (Nonion emulsifier manufactured by Nippon Emulsifier Co.) were charged. Then, the autoclave was cooled with ice water, the autoclave was pressurized with nitrogen gas to 5 kg / cm ² , and then deaerated to remove dissolved air. Furthermore, after introducing 257.0 parts of chlorotrifluoroethylene into the autoclave,
The reaction was carried out for an hour to obtain a fluororesin aqueous dispersion having a solid content of 48.6%.

Aqueous fluorinated copolymer dispersion F (does not contain hydrolyzable silyl groups) 125.7 parts of vinyl butyrate used in the above process for producing a fluorinated copolymer aqueous dispersion E was used in an amount of 150.8 parts. Parts, except that 25.1 parts of vinyltriethoxysilane were not blended.
A fluororesin aqueous dispersion was obtained in the same manner as in the method for producing the fluorocopolymer aqueous dispersion E described above. Acrylic copolymer aqueous dispersion G (containing a hydrolyzable silyl group) Polydurex X1248-15TH (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.) Appearance: milky white liquid Heating residue: 42 ± 1% Viscosity: 320 ± 20 mPa · s pH: 8.5 to 9.0

Acrylic copolymer water dispersion H (containing a hydrolyzable silyl group) In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel, 40 parts of deionized water, 1 part of oxyethylene nonyl phenyl ether sulfate, 1 part of polyoxyethylene nonyl phenyl ether, 0.5 part of ammonium acetate, 0.3 part of Rongalite, and 0.1 part of t-butyl hydroperoxide were charged, and nitrogen gas was introduced. While the temperature was raised to 50 ° C. Butyl methacrylate 60
A mixture 158 parts, 2 parts of methacrylic acid ester (MA50), 5 parts of γ-methacryloxypropyltriethoxysilane, 1 part of polyoxyethylene nonyl phenyl ether, 1 part of polyoxyethylene nonyl phenyl ether sulfate, and 56 parts of deionized water 20 parts of these parts were dropped using a dropping funnel over 30 minutes to carry out initial polymerization. One hour after the end of the dropwise addition, the remaining 138 of the mixture (158 parts)
And 0.1 part of t-butyl hydroperoxide were dropped at a constant rate over 3 hours by a dropping funnel. After this, 1
Polymerization is carried out for a period of time, and deionized water is added to reduce the resin solid content to 5
A 0% by weight emulsion was obtained.

Acrylic copolymer water dispersion I (containing no hydrolyzable silyl group) The butyl methacrylate 60 parts used in the method for producing the acrylic copolymer water dispersion H was changed to 65 parts, An emulsion was obtained in the same manner as in the method for producing the acrylic copolymer water dispersion H, except that 5 parts of γ-methacryloxypropyltriethoxysilane was not blended.

Example 1 Adeca UH thickener was added to 34 parts of an aqueous dispersion of a fluorocopolymer E34.
420S 0.1 part was stirred and mixed, and then 54 parts of alkoxysilane condensate A and alkoxysilane condensate B10
Parts, and 2 parts of butyl carbitol acetate were uniformly mixed to obtain a clear coating. Example 2 An alkoxysilane condensate A54 parts, an alkoxysilane condensate B10 parts and an acrylic copolymer aqueous dispersion G36 parts were uniformly mixed to obtain a water-dilutable clear coating material.

Example 3 Adeca UH, a thickener, was added to 34 parts of an aqueous dispersion of a fluorocopolymer E34.
420S 0.1 part was stirred and mixed, and then 64 parts of alkoxysilane condensate C, butyl carbitol acetate 2
The parts were uniformly mixed to obtain an aqueous clear paint. Example 4 54 parts of an alkoxysilane condensate A, 10 parts of an alkoxysilane condensate B, 10 parts of a fluorinated copolymer aqueous dispersion E, 25 parts of an acrylic copolymer aqueous dispersion H, and 1 part of butyl carbitol acetate were uniformly mixed. An aqueous clear paint was obtained.

Example 5 In 5 parts of ion-exchanged water, 0.1 part of thickener Adeka UH420S was dissolved, and 0.2 part of Neugen 140 and 15 parts of titanium white CR97 were mixed. An aqueous coating composition was prepared by mixing 100 parts of the clear paint. Example 6 To 100 parts of the clear paint of Example 2, N-
One part of phenyl-γ-aminopropyltrimethoxysilane was uniformly mixed to prepare a clear coating.

Comparative Example 1 65 parts of an alkoxysilane condensate D and 35 parts of an acrylic copolymer aqueous dispersion I were uniformly mixed to prepare a water-dilutable clear coating material. Comparative Example 2 Aqueous dispersion of fluorine-containing copolymer F34 parts, thickener Adeka UH
0.1 parts of 420S are mixed with stirring, and further, 54 parts of alkoxysilane condensate A, 10 parts of alkoxysilane condensate B,
Two parts of butyl carbitol acetate were mixed. Comparative Example 3 Thickening agent Adeka UH was added to 94 parts of the fluorine-containing copolymer aqueous dispersion F.
A clear coating was prepared by uniformly mixing 0.1 part of 420S and further 6 parts of butyl carbitol acetate.

Performance Evaluation Test The storage stability of the coating compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated by the following method. -6 and the coating composition obtained in Comparative Example 3 was applied to a gypsum slag perlite plate at an application amount of 90 g / m.
² (wet coating amount), dried at 120 ° C. for 20 minutes, stored at room temperature for 7 days, and then subjected to the following test. The test results were as shown in Table 1.

Evaluation of Storage Stability of Paint The dispersion state of the water-based paint was evaluated by visual observation after being stored at 50 ° C. for 4 weeks. ○: No aggregation ×: Generation of aggregates

Evaluation of Initial Water Resistance of Coating Film After the coating film was immersed in water at room temperature for 96 hours, changes in appearance such as swelling were evaluated by visual observation. ：: No change in appearance such as swelling △: Partial change in appearance such as swelling ×: Change in appearance such as swelling

Evaluation of stain resistance of coating film A 10% dispersion of carbon / water was dropped on the coating film,
After drying at a saturated vapor pressure for 1 day and at 40 ° C. for 2 days, the degree of remaining carbon after wiping the dripping portion using gauze was evaluated by visual observation. ○: Almost no trace of carbon remains-thin residual ×: Deep trace of carbon remains-cannot be wiped off

Evaluation of Weather Resistance of Coating Film The gloss of the coating film was evaluated by visual observation both in the untreated state and after the treatment with a sunshine weatherometer for 2000 hours. ：: No crack and no decrease in gloss △: No crack but slight decrease in gloss ×: Cracked and marked decrease in gloss

[0079]

[Table 1]

The compositions of the present invention of Examples 1 to 6 were all good in the evaluation tests. However, the paint of Comparative Example 1 in which the aqueous acrylic copolymer dispersion I containing no hydrolyzable silyl group was mixed showed two-layer separation in the evaluation of storage stability and was poor as a paint. Further, the paint of Comparative Example 2 in which the water-dispersible fluorine-containing copolymer F containing no hydrolyzable silyl group was blended was not compatible with each other and was poor as a paint. In the paint of Comparative Example 3 containing no alkoxysilane condensate, traces of carbon remained thick in the evaluation of the stain resistance of the paint, and were poor.

[0081]

Industrial Applicability The inorganic / organic hybrid aqueous coating composition of the present invention has excellent storage stability, and exhibits excellent stain resistance and weather resistance when the composition is applied as a top coat.

Claims (2)

[Claims] 1. A water-soluble or water-dispersible alkoxysilane condensate, (b) an aqueous dispersion of a hydrolyzable silyl group-containing fluorinated copolymer and an aqueous dispersion of a hydrolyzable silyl group-containing acrylic copolymer. And (c) an organic solvent, and (d) water. 2. The mixing ratio of the component (a) and the component (b) is (a) :( b) = 90: 10 to 15:85 in terms of solid content ratio.
And the total solid content of component (a) and component (b) is 5
The inorganic / organic hybrid water-based coating according to claim 1, wherein the amount of the component (c) is at most 10% by weight and the amount of the component (d) is at least 35% by weight. Composition.