JP6929701B2 - Water-based compositions, water-based paints, coatings, and painted products - Google Patents

Description

The present invention relates to aqueous compositions, aqueous coatings, coatings, and coated products.

The surface of outdoor structures such as building exteriors, bridges, and tanks is painted with paint, etc., but the surface of the paint film is dust, soot, sand, etc. in the air, and dirt components eluted from the sealant. , Contaminated by pollutants discharged from the outlet of the building. Such contamination of the coating is usually dark and significantly spoils the aesthetics of buildings and outdoor structures.

Conventionally, as an aqueous topcoat coating composition for suppressing contamination of a coating film as described above, an aqueous composition containing a polymer particle dispersion and inorganic oxide particles, which is a component contained in the polymer particle dispersion. The specified aqueous composition has been proposed (see, for example, Patent Document 1).
Further, a technique for reducing the surface tension of a coating material by adding a composition additive containing a specific amount of a hydrocarbon surfactant and a specific amount of a fluorocarbon surfactant is disclosed (see, for example, Patent Document 2). ..

Japanese Unexamined Patent Publication No. 2014-114425 Japanese Unexamined Patent Publication No. 2012-219215

The technique described in Patent Document 1 is an excellent technique in which sufficient stain resistance and weather resistance can be obtained, but it is a requirement required when the paint is circulated and used as in line painting in a factory. There is a problem that foaming property, which is one of the performances, is not considered.
Further, in the technique described in Patent Document 2, the foaming property when the paint is shaken in a short time is improved, but the circulating foaming property when the paint is circulated for a long time is suppressed and the coating is applied. There is a problem that an aqueous composition having both properties and weather resistance has not been obtained.

Therefore, in view of the above-mentioned problems of the prior art, the present invention provides an aqueous composition capable of forming a coating film capable of suppressing circulating foaming property of a coating material and maintaining good coating property and weather resistance. The purpose.

As a result of diligent studies, the present inventors have found inorganic oxide particles (B) having no catalytic activity, a specific surfactant (C), water as a solvent, and a monohydric alcohol (D). It has been found that the above-mentioned problems of the prior art can be solved by the aqueous composition contained and having a specific solid content, and the present invention has been completed.
That is, the present invention is as follows.

[1]
Inorganic oxide particles (B) having no catalytic activity and
Silicone-based surfactant (C) and
Water as a solvent and
Monohydric alcohol (D) and
Defoamers containing hydrophobic silica and mineral oil,
, Contains
An aqueous composition having a solid content of 0.5 to 5% by mass.
[2]
The aqueous composition according to the above [1], which has a solid content of 0.5 to 4.5% by mass.
[3]
The aqueous composition according to the above [1] or [2] , which further contains an aqueous dispersion (AD) of the polymer (A).
[4]
The polymer (A)
The aqueous composition according to the above [3] , which is a polymer obtained by polymerizing a vinyl monomer and a hydrolyzable silicon compound in the presence of water and an emulsifier.
[5]
The inorganic oxide particles (B) having no catalytic activity are silicon dioxide, as described in [1] to [1] to
The aqueous composition according to any one of [4].
[6]
The static surface tension at an alcohol concentration of 15% by mass in the aqueous composition is 20 to 40 mN /
The aqueous composition according to any one of the above [1] to [5], which is m.
[7]
The aqueous composition according to any one of [1] to [6] above, further containing an inorganic oxide (E) having photocatalytic activity.
[8]
A water-based coating material containing the water-based composition according to any one of the above [1] to [7].
[9]
A coating film obtained from the water-based paint according to the above [8].
[10]
A coated product comprising a base material and the coating film according to the above [9] formed on at least a part of the surface of the base material.

According to the present invention, it is possible to provide an aqueous composition capable of forming a coating film capable of suppressing the circulating foaming property of a coating material and maintaining good coating property and weather resistance.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.

[Aqueous composition]
The aqueous composition of this embodiment is
Inorganic oxide particles (B) having no catalytic activity and
Silicone-based surfactant (C) and
Water as a solvent and
Monohydric alcohol (D) and
, And the solid content is 0.5 to 5% by mass.

(Ingredients of aqueous composition)
<Aqueous dispersion (AD) of polymer (A)>
From the viewpoint of weather resistance and stain resistance, the aqueous composition of the present embodiment is added to the inorganic oxide particles (B), silicone-based surfactant (C), water, and monovalent alcohol (D). Further, it is preferable to contain an aqueous dispersion (AD) of the polymer (A).
In the present specification, the polymer (A) may be referred to as the component (A).

As the polymer (A), a polymer obtained by a method such as emulsion polymerization can be used.
Specific examples thereof include a polymer obtained by carrying out any polymerization reaction of radical polymerization, anionic polymerization, or cationic polymerization in an aqueous medium.
The component (A) is not limited to the following, but is, for example, a poly (meth) acrylate-based polymer, a polyvinyl acetate-based polymer, a vinyl acetate- (meth) acrylic-based polymer, or an ethylene vinyl acetate-based polymer. Combined, silicone-based polymer, fluorine-based polymer, polybutadiene-based polymer, styrene-butadiene-based polymer, NBR-based polymer, polyvinyl chloride-based polymer, chlorinated polypropylene-based polymer, polyethylene-based polymer, polystyrene-based weight Homopolymers or copolymers typified by coalesced vinylidene chloride-based polymers, polystyrene- (meth) acrylate-based polymers, styrene-maleic anhydride-based polymers, etc .; silicone-modified (meth) acrylic-based polymers, fluorine Examples thereof include modified copolymers typified by- (meth) acrylic polymers, (meth) acrylic-silicone polymers, and epoxy- (meth) acrylic polymers.
Only one of these may be used alone, or two or more thereof may be used in combination.
In addition, "(meth) acrylate" means "acrylate" and the corresponding "methacrylate", and "(meth) acrylic" means "acrylic" and the corresponding "methacryl".

Various homopolymers, copolymers, modified copolymers and the like (hereinafter, these may be collectively referred to as "polymers") which are the polymers (A) are obtained in the state of an aqueous dispersion. Is preferable.
Preferable embodiments of these polymers include emulsions, such as acrylic emulsions and acrylic silicone emulsions. These can be obtained, for example, by emulsion polymerization of a monomer such as (meth) acrylic acid ester or a hydrolyzable silicon compound described later.

The component (A) preferably contains a functional group capable of interacting with the inorganic oxide (B) having no catalytic activity, which will be described later. The interaction referred to here may be a chemical interaction, and examples thereof include hydrogen bonds, covalent bonds, ionic bonds, and van der Waals forces.
Examples of the hydrogen bond include a hydrogen bond between a hydroxyl group of a metal oxide particle or the like and a functional group of a polymer particle (for example, a hydroxyl group, an amino group, an amide group, etc.).
Examples of the covalent bond include a covalent bond generated by a condensation reaction (dehydration condensation reaction) between a hydroxyl group of a metal oxide particle or the like and a hydroxyl group of a polymer particle.
Examples of the ionic bond include an ionic bond between a hydroxyl group of metal oxide particles and the like and a cationic group (for example, an amino group, an imino group, etc.) in the polymer particles.

The functional group capable of interacting with the inorganic oxide (B) having no catalytic activity is not limited to the following, but for example, an amide group, a hydroxyl group, a carboxyl group, a carbonyl group, a silanol group, and the like. Examples thereof include a thiol group, an amino group, an imino group and a ureido group.
These functional groups may contain only one type, or may contain two or more types.

In addition to the component (A), the aqueous composition of the present embodiment may further contain a compound having a functional group that reacts with the functional group contained in the polymer (A).
Such compounds include, but are not limited to, for example, (poly) isocyanate compounds, (poly) epoxy compounds, amino compounds, (poly) carboxy compounds, (poly) hydroxy compounds, glycol compounds, silanols. Examples thereof include compounds, silyl compounds, alkoxy compounds, and (meth) acrylate compounds.
Only one of these may be used alone, or two or more thereof may be used in combination.

The component (A) preferably contains a polymer obtained by polymerizing a vinyl monomer described later and a hydrolyzable silicon compound in the presence of water and an emulsifier.
As a result, the effect of improving the weather resistance of the coating film can be obtained.

When the component (A) is a polymer obtained by emulsion polymerization, it is obtained as a solvent dispersion of the polymer, and the number average particle size of the polymer is preferably 10 to 300 nm, more preferably. It is 50 to 200 nm, more preferably 80 to 150 nm.
When the number average particle size of the component (A) is in the above range, the weather resistance of the obtained coating film is further improved. Further, when the number average particle size is 10 nm or more, the stain resistance of the coating film is further improved, and when the number average particle size is 300 nm or less, the transparency of the coating film is further improved.
The number average particle size referred to here can be measured using a wet particle size analyzer.

The vinyl monomer that can be used for producing the component (A) is not limited to the following, but includes, for example, a (meth) acrylic acid ester, an aromatic vinyl compound, a vinyl cyanide compound, and a carboxyl group. Examples thereof include vinyl compounds, hydroxyl group-containing vinyl compounds, glycidyl group-containing vinyl compounds, vinyl compounds having secondary and / or tertiary amide groups, vinyl monomers containing functional groups such as anionic vinyl compounds, and the like.

The (meth) acrylic acid ester is not limited to the following, but for example, a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 50 carbon atoms and an ethylene oxide group having 1 to 100 carbon atoms (. Examples thereof include poly) oxyethylene di (meth) acrylate. Specific examples of these are not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic. Examples thereof include methylcyclohexyl acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, and dodecyl (meth) acrylate.
The (poly) oxyethylene di (meth) acrylate is not limited to the following, but is, for example, di (meth) acrylate ethylene glycol, di (meth) acrylate diethylene glycol, methoxy (meth) acrylate diethylene glycol, and the like. Examples thereof include tetraethylene glycol di (meth) acrylate.
Examples of the aromatic vinyl compound include, but are not limited to, styrene, α-methylstyrene, p-tert-butylstyrene, chlorostyrene, vinyltoluene and the like.
The vinyl cyanide compound is not limited to the following, and examples thereof include (meth) acrylonitrile and α-chloroacrylonitrile.
The carboxyl group-containing vinyl compound is not limited to the following, but is, for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, or itaconic acid, maleic acid, fumaric acid. Examples thereof include half esters of dibasic acids such as acids. By using a vinyl monomer containing a carboxyl group, a carboxyl group can be introduced into the component (A). It is presumed that this makes it possible to further improve the stability of the emulsion and impart a high resistance to the dispersion-destroying action from the outside to the coating film (however, the action of the present embodiment is not limited to these). Part or all of the carboxyl group to be introduced can be neutralized with amines such as ammonia, triethylamine and dimethylethanolamine, and bases such as NaOH and KOH. The amount of the carboxyl group-containing vinyl monomer used in the total amount of the above-mentioned vinyl monomers is preferably 0 to 50% by mass from the viewpoint of water resistance, but is not limited thereto.

The hydroxyl group-containing vinyl compound is not limited to the following, and is, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl. Hydroxyalkyl esters of (meth) acrylic acids such as (meth) acrylates, 3-hydroxybutyl (meth) acrylates, 4-hydroxybutyl (meth) acrylates; di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl mono Butyl fumarate, allyl alcohol, (poly) oxyethylene mono (meth) acrylate having 1 to 100 number of ethylene oxide groups; (poly) oxypropylene mono (meth) acrylate having 1 to 100 propylene oxide groups, Further, "Plaxel FM, FA monomer" (trade name of caprolactone-added monomer manufactured by Daicel Chemical Co., Ltd.) and other hydroxyalkyl esters of α, β-ethylene unsaturated carboxylic acid can be mentioned.
The (poly) oxyethylene mono (meth) acrylate is not limited to the following, and includes, for example, (meth) ethylene glycol (meth) acrylate, methoxy (meth) ethylene glycol acrylate, (meth) diethylene glycol (meth) acrylate, and methoxy. Examples thereof include diethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, and tetraethylene glycol methoxy (meth) acrylate.
The (poly) oxypropylene mono (meth) acrylate is not limited to the following, but is, for example, propylene glycol (meth) acrylate, propylene glycol methoxy (meth) acrylate, dipropylene glycol (meth) acrylate. , Dipropylene glycol methoxy (meth) acrylate, tetrapropylene glycol (meth) acrylate, tetrapropylene glycol methoxy (meth) acrylate and the like.
The ratio of the hydroxyl group-containing vinyl monomer to the total amount of the above-mentioned vinyl monomer is not limited to the following, but is preferably 0 to 80% by mass, more preferably from the viewpoint of water resistance of the coating film. Is 0.1 to 50% by mass.

Examples of the glycidyl group-containing vinyl compound include, but are not limited to, glycidyl (meth) acrylate, allyl glycidyl ether, and allyl dimethyl glycidyl ether.
Among the above-mentioned vinyl monomers, when a glycidyl group-containing vinyl monomer is used, the reactivity of the component (A) is further improved. Therefore, by cross-linking with a hydrazine derivative, a carboxylic acid derivative, an isocyanate derivative, or the like, a coating film having further excellent solvent resistance and the like can be obtained. From this point of view, the total amount of the glycidyl group-containing vinyl monomer used in the total amount of the vinyl monomers described above is preferably 0 to 50% by mass.

The vinyl compound having a secondary and / or tertiary amide group is not limited to the following, and examples thereof include N-alkyl-substituted (meth) acrylamide and N-alkylene-substituted (meth) acrylamide.
The N-alkyl substituted (meth) acrylamide is not limited to the following, but is not limited to, for example, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and N. , N-diethylacrylamide, N-methyl-N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-methyl-N-n-propyl (meth) acrylamide, N-Methyl-N-isopropyl (meth) acrylamide, N- (meth) acryloylpyrrolidine, N- (meth) acryloylpiperidin, N-acryloylhexahydroazepine, N- (meth) acryloylmorpholin, N-vinylpyrrolidone, N- Examples thereof include vinyl caprolactam, N, N'-methylenebis (meth) acrylamide, N-vinylacetamide, diacetone (meth) acrylamide, N-methylol (meth) acrylamide and the like.

Vinyl monomers other than the above are not limited to the following, but are, for example, olefins such as (meth) acrylamide, ethylene, propylene and isobutylene; dienes such as butadiene; vinyl chloride and vinylidene fluoride fluoride. Haloolefins such as vinyl, tetrafluoroethylene, chlorotrifluoroethylene; vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl benzoate, p-tert-vinyl benzoate, vinyl pivalate, 2-ethylhexanoic acid Vinyl acid vinyl esters such as vinyl, vinyl versaticate, vinyl laurate; carboxylic acid isopropenyl esters such as isopropenyl acetate and isopropenyl propionate; vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether and cyclohexyl vinyl ether; styrene, vinyl Aromatic vinyl compounds such as toluene; allyl esters such as allyl acetate and allyl benzoate; allyl ethers such as allyl ethyl ether and allyl phenyl ether; 4- (meth) acryloyloxy-2,2,6,6-tetra Methylpiperidin, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidin, perfluoromethyl (meth) acrylate, perfluoropropyl (meth) acrylate, perfluoropropylmethyl (meth) acrylate, Examples thereof include vinylpyrrolidone, trimethylpropantri (meth) acrylate, and allyl (meth) acrylate.
Only one of these may be used alone, or two or more thereof may be used in combination.

When the component (A) is produced by a polymerization reaction, a chain transfer agent may be used for the purpose of controlling the molecular weight of the polymerization product of the vinyl monomer used.
The chain transfer agent is not limited to, for example, alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan, and tert-dodecyl mercaptan; aromatic mercaptans such as benzyl mercaptan and dodecyl benzyl mercaptan. Thiolous acids such as thioapple acid or salts thereof or alkyl esters thereof; Polythiols; Diisopropylxanthogen disulfides, disulfides such as di (methylenetrimethylolpropane) xanthogen disulfides; Dimers such as thioglycols and α-methylstyrenes. Examples include allyl compounds.
Only one of these may be used alone, or two or more thereof may be used in combination.
The amount of the chain transfer agent used with respect to the total amount of the vinyl monomer described above is not particularly limited, but is preferably 0.001 to 30% by mass, and more preferably 0.05 to 10% by mass.

When the polymer (A) is produced by a polymerization reaction of a vinyl monomer and a hydrolyzable silicon compound, the hydrolyzable silicon compound used for producing the polymer (A) is limited to the following. Although not, for example, a compound represented by the following formula (1), a silane coupling agent, and a condensate thereof are mentioned as preferable ones.
SiWxRy ・ ・ ・ (1)
In the formula (1), W is an alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, an acetoxy group having 1 to 20 carbon atoms, a halogen atom, a hydrogen atom, an oxime group having 1 to 20 carbon atoms, an enoxy group, and an aminoxy group. And at least one selected from the group consisting of amide groups.
R is a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and 6 to 20 carbon atoms substituted with halogen atoms. Represents at least one group selected from the group consisting of aryl groups of.
x is an integer of 1 or more and 4 or less, y is an integer of 0 or more and 3 or less, and satisfies the relationship of x + y = 4.
When there are a plurality of Ws or a plurality of Rs, the respective Ws and Rs may be the same or different from each other.

The compound represented by the formula (1) is not limited to the following, and examples thereof include silicon alkoxide represented by the formula (1).
As the silicon alkoxide, a tetrafunctional silicon alkoxide is preferable from the viewpoint of the hydrolysis rate.

Examples of the silane coupling agent include hydrolyzable groups (for example, alkoxy groups having 1 to 20 carbon atoms, hydroxyl groups, acetoxy groups having 1 to 20 carbon atoms, halogen atoms, hydrogen atoms, oxime groups having 1 to 20 carbon atoms, and enoxy. A functional group (for example, a vinyl polymerizable group, an epoxy group, an amino group, a methacryl group, a thiol group) having a reactivity with another compound (for example, at least one selected from the group consisting of a group, an aminoxy group and an amide group) and another compound. , A hydrolyzable silicon compound (silane coupling agent) having an isocyanate group, etc.).
By using such a silane coupling agent as a hydrolyzable silicon compound, a polycondensate product of the hydrolyzable silicon compound and a vinyl monomer can be chemically bonded to each other. As a result, the compatibility is further improved, and the transparency of the coating film is further improved.
Among the above, a silane coupling agent having at least a vinyl polymerizable group and / or a thiol group is preferable, and a silane coupling agent having at least a vinyl polymerizable group is more preferable.

Since the vinyl polymerizable group and the thiol group have high reactivity with the vinyl monomer described above, a chemical bond can be efficiently formed by a copolymerization reaction or a chain transfer reaction with the vinyl monomer. Therefore, by using a silane coupling agent having a vinyl polymerizable group or a thiol group, it is possible to efficiently combine with other components (for example, vinyl monomer or the like) constituting the component (A). By using the component (A) in which such a hydrolyzable silicon compound (or a polymerization product thereof) and / or a vinyl monomer (or a polymerization product thereof) is compounded by a chemical bond, weather resistance is used. It is possible to obtain a coating film having further improved strength and the like (however, the action of the present embodiment is not limited to these).

The silane coupling agent having a vinyl polymerizable group is not limited to the following, but for example, 3- (meth) acrylicoxypropyltrimethoxysilane, 3- (meth) acrylicoxypropyltriethoxysilane, 3 -(Meta) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropyltri n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltri Preferable examples include methoxysilane and 2-trimethoxysilylethyl vinyl ether.

The silane coupling agent having a thiol group is not limited to the following, and examples thereof include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

The hydrolyzable silicon compound and silane coupling agent represented by the formula (1) are not limited to the following, but are, for example, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetra. Tetraalkoxysilanes such as isopropoxysilane, tetra-n-buxisilane; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, Isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptiltlimethoxysilane, n-octyltrimethoxysilane Silane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltri Ethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltri Methoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane , 3-Mercaptopropyltriethoxysilane, 3-Isocyanatopropyltrimethoxysilane, 3-Isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-( 3,4-Epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acrylicoxypropyltrimethoxysilane, 3- (meth) acrylicoxypropyltriethoxysilane , 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropylto Trialkoxysilanes such as lyisopropoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyl Dimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n- Pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n -Dialkoxysilanes such as octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane; Examples thereof include monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane.
Among these, tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes are preferable, and tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, 3- (meth) acrylicoxypropyltrimethoxysilane, and dimethyldimethoxysilane. Is more preferable, and tetramethoxysilane and tetraethoxysilane, which are tetrafunctional silicon alkoxides, are further preferable from the viewpoint of high hydrolysis rate.

When the compound represented by the formula (1) or the condensate of the silane coupling agent is applied as a hydrolyzable silicon compound used for producing the polymer (A), it is represented by the formula (1). The polystyrene-equivalent weight average molecular weight of the compound or the condensate of the silane coupling agent is not particularly limited, but is preferably 200 to 5000, and more preferably 300 to 1000. By using the compound of the formula (1) having the weight average molecular weight in the above range or the condensate, the polymerization stability is further improved.

As the silicon alkoxide or silane coupling agent represented by the above formula (1), only one type may be used alone, or two or more types may be used in combination. Among these, from the viewpoint of improving the performance of the aqueous composition of the present embodiment and the coating film obtained from the aqueous composition, the silicon alkoxide represented by the above formula (1) and the silane coupling agent can be used in combination. It is preferable to use at least one selected from the group consisting of tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane and dimethyldimethoxysilane in combination with 3- (meth) acrylicoxypropyltrimethoxysilane.

The total amount of the silane coupling agent having at least a vinyl polymerizable group and / or a thiol group in 100 parts by mass of the component (A) is preferably 0.01 to 20 parts by mass from the viewpoint of polymerization stability. More preferably, it is 0.1 to 10 parts by mass.

In the aqueous composition of the present embodiment, a cyclic siloxane oligomer can be used in combination with the above-mentioned hydrolyzable silicon compound used for producing the above-mentioned polymer (A).
By using the cyclic siloxane oligomer in combination, a coating film having even better flexibility can be obtained.
The cyclic siloxane oligomer is not limited to the following, and examples thereof include compounds represented by the following formula (2).
_{(R '2 SiO) m ···} (2)
In the above formula (2), R'is independently a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and 1 to 20 carbon atoms. Represents at least one selected from the group consisting of an alkoxy group of the above and an aryl group having 6 to 20 carbon atoms substituted with a halogen atom. m is an integer of 2 or more and 20 or less.
Among the cyclic siloxane oligomers, cyclic dimethylsiloxane oligomers such as octamethylcyclotetrasiloxane are preferable from the viewpoint of reactivity and the like.

When producing the component (A), titanium alkoxide, zirconium alkoxide, a condensation product thereof, or a chelated product thereof can be used in combination with the hydrolyzable silicon compound. By using these compounds in combination, a coating film having more excellent water resistance and the like can be obtained.

The titanium alkoxide is not limited to the following, but is, for example, tetramethoxy titanium, tetraethoxy titanium, tetra-i-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-sec-. Butoxytitanium, tetra-tert-butoxytitanium and the like can be mentioned.
When a condensation product of titanium alkoxide is used, its polystyrene-equivalent weight average molecular weight is not particularly limited, but is preferably 200 to 5000, and more preferably 300 to 1000.

The zirconium alkoxide is not limited to the following, but is, for example, tetramethoxyzirconium, tetraethoxyzirconium, tetra-i-propoxyzirconium, tetra-n-propoxyzirconium, tetra-n-butoxyzirconium, tetra-sec-. Examples thereof include butoxyzirconium and tetra-tert-butoxyzirconium.
When the zirconium alkoxide is used as the condensation product, the polystyrene-equivalent weight average molecular weight of the condensation product is not particularly limited, but is preferably 200 to 5000, more preferably 300 to 1000.

The mass ratio of the hydrolyzable silicon compound to the vinyl monomer used when polymerizing the polymer (A) (hydrolyzable silicon compound / vinyl monomer) is preferably 0.5 / 99.5-99. It is 5 / 0.5, more preferably 0.5 / 99.5 to 15/85.

When producing the component (A), a chelating agent that coordinates with the free metal ion of the metal compound to form a chelated product can also be used in combination.
Preferred chelating agents include, but are not limited to, alkanolamines such as diethanolamine and triethanolamine; glycols such as ethylene glycol, diethylene glycol and propylene glycol; acetylacetone; ethyl acetoacetate and the like. Be done.
The molecular weight of the chelating agent is not limited to the following, but is preferably 10,000 or less.
By using these chelating agents, the polymerization rate of the hydrolyzable silicon compound and the like can be controlled, and the polymerization stability in the presence of water and an emulsifier is further improved.
The amount of the chelating agent to be blended is not particularly limited, but is preferably 0.1 mol to 2 mol per 1 mol of free metal ions to be coordinated.

The emulsifier that can be used for producing the component (A) is not limited to the following, but is, for example, alkylbenzene sulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylenealkylsulfate, polyoxyethylenealkylaryl. Acidic emulsifiers such as sulfuric acid and polyoxyethylene distyrylphenyl ether sulfonic acid; alkali metal (Li, Na, K, etc.) salts of the acidic emulsifiers, ammonium salts of the acidic emulsifiers; anionic surfactants such as fatty acid soaps; For example, quaternary ammonium salts such as alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, pyridinium salt, imidazolinium salt type cationic surfactant; polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan fatty acid. Nonionic surfactants such as esters, polyoxyethylene oxypropylene block copolymers and polyoxyethylene distyrylphenyl ethers; reactive emulsifiers having a radically polymerizable double bond and the like.
Among these emulsifiers, a reactive emulsifier having a radically polymerizable double bond (reactive emulsifier) is preferable. By using such a reactive emulsifier, the water dispersion stability of the polymer (A) becomes very good, and the water resistance of the obtained coating film is further improved.

Examples of the anionic reactive emulsifier include, but are not limited to, a sulfonic acid group, a sulfonate group, a sulfate ester group, an ethylenically unsaturated monomer having a salt thereof, and the like. A compound having an acid group or a group which is an ammonium salt or an alkali metal salt thereof (ammonium sulfonate group or alkali metal sulfonate group) is preferable.
For example, but not limited to, alkylallyl sulfosuccinate (for example, Sanyo Kasei Co., Ltd., "Ereminol (trademark) JS-20", for example, Kao Co., Ltd., "Latemuru (trademark) S-120"". , "Latemuru S-180A", "Latemuru S-180", etc.), for example, polyoxyethylene alkylpropenylphenyl ether sulfate (for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Aqualon ™ HS-" 10 ”etc.), For example, α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-polyoxyethylene sulfate ester salt (for example, manufactured by ADEKA,“ Adecaria ”. Soap ™ SE-10N ”etc.), For example, ammonium-α-sulfonato-ω-1- (allyloxymethyl) alkyloxypolyoxyethylene (eg, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.,“ Aqualon KH ”. -1025 ”and the like), for example, styrene sulfonate (for example,“ Spinomer ™ NaSS ”, manufactured by Toso Organic Chemical Co., Ltd., etc.), for example, α-[2-[(allyloxy)- 1- (alkyloxymethyl) ethyl] -ω-polyoxyethylene sulfate ester salt (for example, "Adecaria Soap ™ SR-1025" manufactured by ADEKA), for example, polyoxyethylene polyoxy. Examples thereof include a sulfate ester salt of butylene (3-methyl-3-butenyl) ether (for example, "Latemul ™ PD-104" manufactured by Kao Co., Ltd.) and the like.
Among these, ammonium-α-sulfonato-ω-1- (allyloxymethyl) alkyloxypolyoxyethylene, α- [2-[(allyloxy) -1- (alkyloxymethyl) ethyl] -ω-polyoxyethylene Sulfate ester salts are preferred.

The nonionic reactive emulsifier is not limited to the following, but is, for example, α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene. (For example, (Adeka Corporation, "ADEKA CORPORATION NE-20", "ADEKAIA SOLP NE-30", "ADEKAIA SOLP NE-40", etc. may be mentioned.), For example, polyoxyethylene alkylpropenylphenyl ether. (For example, "Aqualon RN-10", "Aqualon RN-20", "Aqualon RN-30", "Aqualon RN-50", etc. manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), for example, α- [2. -[(Allyloxy) -1- (alkyloxymethyl) ethyl] -ω-hydroxypolyoxyethylene (for example, ADEKA Corporation, "ADEKA CORPORATION ER-10" and the like), for example, poly. Examples thereof include oxyethylene polyoxybutylene (3-methyl-3-butenyl) ether (for example, "Latemuru ™ PD-420" manufactured by Kao Corporation) and the like.

The amount of the emulsifier used is preferably 10 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the hydrolyzable silicon compound and the vinyl monomer which are the raw materials of the component (A) which is the polymer. 0.001 to 5 parts by mass. By setting the amount of the emulsifier used in the above range, the polymerization stability is further improved and the water resistance of the coating film is further improved.

The polymerization of the vinyl monomer and the hydrolyzable silicon compound is preferably carried out in the presence of a polymerization catalyst.
The polymerization catalyst of the vinyl monomer is not particularly limited, but a radical polymerization catalyst that causes addition polymerization of the vinyl monomer by radically decomposing itself by heat, a reducing substance, or the like is preferable.
Examples of such a radical polymerization catalyst include, but are not limited to, persulfates, peroxides, and azobis compounds. These may be water-soluble or oil-soluble.
Specific examples of the radical polymerization catalyst include potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, tert-butyl hydroperoxide, tert-butyl peroxybenzoate, and 2,2-azobisisobutyronitrile. , 2,2-Azobis (2-diaminopropane) hydrogen peroxide, 2,2-azobis (2,4-dimethylvaleronitrile) and the like.
The amount of the radical polymerization catalyst to be blended is not particularly limited, but is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of the vinyl monomer.
When it is desired to accelerate the polymerization rate and efficiently polymerize at a low temperature (for example, 70 ° C. or lower), for example, a reducing agent such as sodium bisulfite, ferrous chloride, ascorbic acid salt, or longalite is used as a radical polymerization catalyst. It is preferable to use in combination with.

The polymerization catalyst of the hydrolyzable silicon compound is not limited to the following, but for example, hydrogen halides such as hydrochloric acid and hydrofluoric acid; carboxylic acids such as acetic acid, trichloroacetic acid, trifluoroacetic acid and lactic acid; sulfuric acid. , P-Toluene sulfonic acid and other sulfonic acids; alkylbenzene sulfonic acid, alkyl sulfonic acid, alkyl sulfosuccinic acid, polyoxyethylene alkyl sulfate, polyoxyethylene alkylaryl sulfate, polyoxyethylene distyrylphenyl ether sulfonic acid and other acidic emulsifiers Acidic or weakly acidic inorganic salts; Acidic compounds such as phthalic acid, phosphoric acid, nitrate; sodium hydroxide, potassium hydroxide, sodium methylate, sodium acetate, tetramethylammonium chloride, tetramethylammonium hydroxide, tributylamine , Diazabicycloundecene, ethylenediamine, diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane and other basic compounds; dibutyltin octylate, dibutyltin Examples include tin compounds such as dilaurate.
Among these, as the polymerization catalyst of the hydrolyzable silicon compound, acidic emulsifiers are preferable from the viewpoint of having a function as an emulsifier as well as a polymerization catalyst. As the acidic emulsifiers, alkylbenzene sulfonic acid having 5 to 30 carbon atoms (for example, dodecylbenzene sulfonic acid) is more preferable.

The polymerization of the vinyl monomer and the hydrolyzable silicon compound can be carried out separately, but it is preferable to carry out the polymerization at the same time because the compounding can be efficiently achieved.

A suitable method for obtaining the component (A) is, for example, so-called emulsion polymerization in which a vinyl monomer and a hydrolyzable silicon compound are polymerized in the presence of an amount of water sufficient for the emulsifier to form micelles. Can be mentioned.
The specific method of emulsion polymerization is not particularly limited, and for example, the vinyl monomer and the hydrolyzable silicon compound are dropped into the reaction vessel as they are or in an emulsified state in a batch, in a divided manner, or continuously. However, a method of polymerizing at a reaction temperature of about 30 to 150 ° C. in the presence of a polymerization catalyst, preferably under a pressure of atmospheric pressure to 10 MPa can be mentioned.
The reaction temperature and reaction pressure are not limited to the above-mentioned conditions depending on the reaction conditions and the like, and any conditions can be appropriately selected.
The solid content in the emulsion obtained by emulsion polymerization is not particularly limited, but is preferably 0.1 to 70% by mass, more preferably 1 to 55% by mass, and further preferably 5 to 30% by mass. be.
When it is desired to control the particle size more precisely during emulsion polymerization, it is preferable to adopt a seed polymerization method in which emulsion particles are present in the aqueous phase in advance and polymerized. The pH of the polymerization system in this case is not particularly limited, but is preferably 1.0 to 10.0, and more preferably 1.0 to 6.0. This pH can be adjusted by using a pH buffer such as disodium phosphate, sodium tetraborate (Borax or the like), sodium hydrogen carbonate, ammonia or the like.

As a method for producing the component (A), a hydrolyzable silicon compound and a vinyl monomer are polymerized in the presence of water and an emulsifier, if necessary, in the presence of a solvent, and then water is added until the polymerization product becomes an emulsion. Further addition methods can also be adopted. However, emulsion polymerization is preferable from the viewpoint that the particle size of the obtained component (A) can be easily controlled.

The component (A) preferably has a core / shell structure in which the polymer particles have a core and one or more shell layers.
Having a core / shell structure is preferable because the mechanical properties (balance between strength and flexibility, etc.) of the obtained coating film are further improved. The core / shell structure of the component (A) can be confirmed, for example, by morphological observation with a transmission electron microscope or analysis by viscoelasticity measurement.
The method for producing the component (A) having a core / shell structure is not particularly limited, but multi-stage emulsion polymerization can be mentioned as a preferable method.
The multi-stage emulsion polymerization referred to here is a method of preparing two or more kinds of reaction solutions having different compositions containing a vinyl monomer and a hydrolyzable silicon compound, and polymerizing them in separate steps.
As an example of multi-stage emulsion polymerization, a method for synthesizing component (A) having a core / shell structure by two-stage emulsion polymerization will be mainly described.
The two-stage emulsion polymerization includes, for example, a step of polymerizing a vinyl monomer and / or a hydrolyzable silicon compound in the presence of water and an emulsifier to obtain seed particles (first stage), and the obtained seed particles. A method having a step (second step) of polymerizing a hydrolyzable silicon compound and a vinyl monomer in the presence of the above can be mentioned.
The production of the component (A) by the two-stage emulsion polymerization is carried out following the first-stage polymerization in which the first series (vinyl monomer and / or hydrolyzable silicon compound) is supplied and emulsion-polymerized, and the first stage. It is carried out by a two-step polymerization step consisting of a second-step polymerization in which a second series (vinyl monomer and / or a hydrolyzable silicon compound) is supplied and further emulsion-polymerized in an aqueous medium. At this time, the mass ratio ((M1) / (M2)) of the solid content (M1) in the first series to the solid content (M2) in the second series is not particularly limited, but is preferably 9 / 1-1. It is / 9, more preferably 8/2 to 2/8.
By performing such multi-stage emulsion polymerization, polymer particles having a more uniform particle size can be obtained. As a method of adding the raw material in the multi-stage emulsion polymerization, a method of preparing seed particles (core) in the first-stage polymerization and then adding another monomer or the like is preferable. As a result, the particle size of the polymer particles obtained in the second stage polymerization is increased without changing the volume average particle size / number average particle size ratio of the seed particles (core) obtained in the first stage polymerization. It is also possible to do.
When performing multi-stage emulsion polymerization of three or more stages, the number of stages of polymerization may be increased in the same manner as in two-stage polymerization.

The content of the component (A) in the aqueous composition of the present embodiment is not particularly limited, but is preferably 0 to 4.0% by mass, more preferably 0.025 to 4.0% by mass. More preferably, it is 0.1 to 3.75% by mass.
By setting the content of the component (A) in the aqueous composition within the above range, a coating film having further excellent weather resistance and stain resistance can be obtained.
The content of the component (A) in the coating film obtained from the aqueous composition of the present embodiment is not particularly limited, but is preferably 0.0 to 80.0% by mass, more preferably 5.0. It is ~ 80.0% by mass, more preferably 20.0 to 75.0% by mass. By setting the content of the component (A) in the coating film to the lower limit value or more, the weather resistance of the coating film is further improved, and by setting the content to the upper limit value or less, the stain resistance of the coating film is further improved. ..

<Inorganic oxide particles (B) having no catalytic activity>
The aqueous composition of the present embodiment contains inorganic oxide particles (B) having no catalytic activity (may be referred to as component (B) in the present specification).
The inorganic oxide particles (B) having no catalytic activity are particles of an inorganic oxide having no photocatalytic activity.
The term "not having photocatalytic activity" as used herein means that neither an oxidation reaction nor a reduction reaction occurs due to light irradiation.
The component (B) is not limited to the following, but includes, for example, silicon dioxide (silica), aluminum oxide (alumina), calcium silicate, magnesium oxide, antimony oxide, zirconium oxide and composite oxides thereof. Can be mentioned. Among these, silicon dioxide, aluminum oxide, antimony oxide, and composite oxides thereof are preferable, and silicon dioxide is more preferable, from the viewpoint of having a large number of surface hydroxyl groups.

The inorganic oxide particles used as the component (B) preferably exist as colloidal particles such as hydrates. That is, the inorganic oxide colloidal particles enable further compounding with other components such as the component (A) and the component (E) described later, and the stability of the aqueous composition of the present embodiment. Is further improved.

The silicon dioxide as the component (B) is preferably colloidal silica. Examples of colloidal silica include colloidal silica which is a dispersion of water or a water-soluble solvent of silica having silicon dioxide as a basic unit.
The method for producing colloidal silica is not particularly limited, and for example, it can be prepared by a sol-gel method. When prepared by the sol-gel method, Werner Stober et al .; Journal of Colloid And Interface Science, vol. 26, pp. 62-69 (1968) and Rickey D. Badley et al .; Langmuir 6, 792 -801 (1990), "Journal of the Japan Society of Color Material", 61 [9] 488-493 (1988) and the like can be referred to.

The number average particle size of the component (B) is not particularly limited, but is preferably 1 to 400 nm, and more preferably 1 to 100 nm. By setting the number average particle size of the component (B) to 1 nm or more, the storage stability of the aqueous composition of the present embodiment is further improved. By setting the number average particle size of the component (B) to 400 nm or less, the transparency of the obtained coating film is further improved. The number average particle size can be measured using a wet particle size analyzer.

The colloidal silica as the component (B) may be either acidic or basic in the state of an aqueous dispersion.
As the acidic colloidal silica using water as a dispersion medium, a commercially available product can also be used. Examples of such commercially available products include "Snowtex (trademark) -OXS", "Snowtex-OS", "Snowtex-O", "Snowtex-O-40", and "Snowtex-O-40" manufactured by Nissan Chemical Industries, Ltd. Examples include "Snowtex-OL" and "Snowtex-OYL", "Adelite (trademark) AT-20Q" manufactured by Asahi Denka Kogyo Co., Ltd., "Klebozol (trademark) 20H12" and "Klebozol 30CAL25" manufactured by Clariant Japan. ..
Examples of the basic colloidal silica include colloidal silica stabilized by the addition of alkali metal ions, ammonium ions, amines and the like. Commercially available products can also be used for these. Examples of such commercially available products include "Snowtex-XS", "Snowtex-S", "Snowtex-30", "Snowtex-50", and "Snowtex-20L" manufactured by Nissan Chemical Industries, Ltd. , "Snowtex-XL", "Snowtex-YL", "Snowtex-ZL", "Snowtex-NXS", "Snowtex-NS", "Snowtex-N", "Snowtex-N40", "Snowtex-CXS", "Snowtex-C", "Snowtex-CM", "Snowtex-PS-S" and "Snowtex PS-M";"AdeliteAT-20" manufactured by Asahi Denka Kogyo Co., Ltd. , "Adelite AT-30", "Adelite AT-20N", "Adelite AT-30N", "Adelite AT-20A", "Adelite AT-30A", "Adelite AT-40", and "Adelite AT-50""ClariantJapan's" Crevosol 30R9 "," Crevosol 30R50 "," Crevosol 50R50 ", DuPont's" Ludox ™ HS-40 "," Ludox HS-30 "," Ludox LS ", and" Ludox SM-30 ”and the like.

As the colloidal silica using a water-soluble solvent as a dispersion medium, a commercially available product can also be used. Examples of such commercially available products include "MA-ST-M (methanol dispersion type having a particle size of 20 to 25 nm)" and "IPAST (isopropyl alcohol dispersion type having a particle size of 10 to 15 nm)" manufactured by Nissan Chemical Industry Co., Ltd. , "EG-ST (ethylene glycol dispersion type with particle size 10 to 15 nm)", "EG-ST-ZL (ethylene glycol dispersion type with particle size 70 to 100 nm)", "NPC-ST (particle size 10 to 15 nm) Ethylene glycol monopropyl ether dispersion type) ”and the like.

The colloidal silica may be used alone or in combination of two or more.
Further, alumina, sodium aluminate and the like may be contained as a small amount component.
Further, colloidal silica may contain an inorganic base (sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, etc.) or an organic base (tetramethylammonium, etc.) as a stabilizer.

The content of the component (B) in the aqueous composition of the present embodiment is not particularly limited, but is preferably 0.025 to 4.995% by mass, more preferably 0.025 to 4.0% by mass. Yes, more preferably 0.05 to 3.0% by mass. By setting the content of the component (B) in the aqueous composition within the above range, a coating film having further excellent weather resistance and stain resistance can be obtained.
The content of the component (B) in the coating film obtained from the aqueous composition of the present embodiment is not particularly limited, but is preferably 5.0 to 99.9% by mass, and more preferably 5.0 to 80%. It is 0.0% by mass, more preferably 10.0 to 60.0% by mass. By setting the content of the component (B) in the coating film to the lower limit value or more, the stain resistance of the coating film is further improved, and by setting the content to the upper limit value or less, the weather resistance of the coating film is further improved. ..

<Silicone-based surfactant (C)>
The aqueous composition of the present embodiment contains a silicone-based surfactant (C) (which may be referred to as component (C) in the present specification). As a result, when painting with the water-based composition of the present embodiment or the water-based paint containing the same, the wettability to the organic base material or the like is improved, appearance troubles such as repelling are suppressed, and the coating film is coated. The uniformity is further improved, and the circulating foaming property can be suppressed to a certain level or less.

As the silicone-based surfactant (C), a silicone-based surfactant, a modified silicone surfactant, or the like can be used. The modified silicone surfactant may be, for example, a modified silicone surfactant modified with a polyether, or may be a modified silicone surfactant obtained by adding, for example, a polyether surfactant to the silicone surfactant. ..

As the silicone-based surfactant (C), for example, a conventionally known commercially available product can also be used. Such commercially available products are not limited to the following, but for example, "BYK-302", "BYK-307", "BYK-331", "BYK-333" manufactured by Big Chemie Japan Co., Ltd., "BYK-342", "BYK-345", "BYK-346", "BYK-347", "BYK-348", "BYK-349", "BYK-378", "BYK-3455"; San Nopco Ltd. "SN Wet 125", "SN Wet 126", "SN Leveler S-906-10" and the like.
Only one of these may be used alone, or two or more thereof may be used in combination.

The content of the component (C) in the aqueous composition of the present embodiment is not particularly limited, but is preferably 0.0005 to 1.0% by mass, more preferably 0.0025 to 0.75% by mass. Yes, more preferably 0.005 to 0.5% by mass. By setting the content of the component (C) to the above lower limit value or more, the uniformity of the obtained coating film is further improved. By setting the content of the component (C) to the above upper limit value or less, the circulating foaming property and the shaking foaming property are suppressed to a certain level or less, and the weather resistance of the obtained coating film is further improved.
The content of the component (C) in the coating film obtained from the aqueous composition of the present embodiment is not particularly limited, but is preferably 0.1 to 20.0% by mass, more preferably 0.5. It is ~ 15.0% by mass, more preferably 1.0 to 10.0% by mass. By setting the content of the component (C) to the lower limit value or more, the uniformity of the coating film is further improved, and by setting the content to the upper limit value or less, the weather resistance of the coating film is further improved.

<Monohydric alcohol (D)>
The aqueous composition of the present embodiment contains a monohydric alcohol (D) (which may be referred to as component (D) in the present specification).
The monohydric alcohol (D) is not particularly limited, and examples thereof include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, hexane alcohol, heptane alcohol, octane alcohol, diethyl hexane alcohol and the like. Be done. Among them, ethyl alcohol, propyl alcohol and isopropyl alcohol are preferable from the viewpoint of volatility, odor, wettability and safety.
Only one of these monohydric alcohols may be used alone, or two or more of these monohydric alcohols may be used in combination.
The content of the monohydric alcohol in the aqueous composition of the present embodiment is not particularly limited, but is preferably 1.0 to 50.0% by mass, more preferably 5.0 to 40.0% by mass. More preferably, it is 10.0 to 35.0% by mass.
By setting the content of the component (D) to the above lower limit or more, the coating property and the drying property are further improved. By setting the content of the component (D) to the above upper limit value or less, the safety and the storage stability of the paint are further improved.

<Inorganic oxide particles (E) having photocatalytic activity>
The aqueous composition of the present embodiment preferably further contains inorganic oxide particles (E) having photocatalytic activity (may be referred to as component (E) in the present specification). As a result, photocatalytic activity and hydrophilicity can be exhibited by irradiating the coating film with light.

The type of the inorganic oxide particles (E) having photocatalytic activity is not particularly limited.
As the component (E) include, but are not limited to, for _{example, TiO 2, ZnO, SrTiO 3} , BaTiO 3, BaTiO 4, BaTi 4 O 9, K 2 NbO 3, Nb 2 O 5, Fe 2 O ₃ , Ta ₂ O ₅ , K ₃ Ta ₃ Si ₂ O ₃ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , BiVO ₄ , NiO, Cu ₂ O, RuO ₂ , CeO ₂ ;, Ti, Nb, Ta, Layered oxides having at least one element selected from the group consisting of and V (for example, JP-A-62-074452, JP-A-02-172535, JP-A-07-024329, JP-A08- 089799, Japanese Patent Application Laid-Open No. 08-0898800, Japanese Patent Application Laid-Open No. 08-089804, Japanese Patent Application Laid-Open No. 08-198061, Japanese Patent Application Laid-Open No. 09-248465, Japanese Patent Application Laid-Open No. 10-099694, Japanese Patent Application Laid-Open No. 10-244165 Gazette, etc.).

_{The component (E) is preferably TIO 2} (titanium oxide) from the viewpoints of chemical stability, toxicity, environmental aspects and the like. The titanium oxide may have an anatase-type, rutile-type, or brookite-type crystal structure.

The component (E) is preferably an inorganic oxide having photocatalytic activity and is a metal compound whose particle surface has been modified. By the modification treatment, the _{amount of active oxygen species such as H 2} O ₂ and · OH can be suppressed, and the damage to the underlying coating film can be further suppressed. The substance to be modified is not particularly limited, and examples thereof include silica, aluminum, copper oxide, and iron oxide. Among these, silica is preferable. The same effect can be obtained by modifying with a metal such as Fe, Cu, Al or Pt, or a complex such as chloroplatinic acid.

The method of modifying the surface of the component (E) will be described by taking silica as an example. The method for modifying the surface of silica is not particularly limited, and examples thereof include a method of adding a silicon compound to a titanium oxide slurry and precipitating a hydrous oxide of silicon through a step such as a neutralization treatment. ..
The silicon compound is not particularly limited, and for example, a water-soluble alkali metal silicate such as sodium silicate can be used. Among these, sodium silicate is preferable from the viewpoint of being colorless and not coloring the titanium oxide sol.
The treatment amount of the hydroxide-containing material of silicon is preferably 3 to 25% by mass, more preferably 5 to 20% by mass, based on the oxide, with respect to titanium oxide. When the treatment amount is at least the above lower limit value, an increase in the amount of active oxygen species can be suppressed, so that damage to the underlying coating film can be prevented. Further, when the treatment amount is not more than the above upper limit value, the aggregation of titanium oxide can be suppressed and the viscosity increase of the sol can be suppressed, so that the dispersibility and transparency are further improved.

The content of the component (E) in the aqueous composition of the present embodiment is not particularly limited, but is preferably 0.015 to 2.00% by mass, more preferably 0.015 to 1.50% by mass. Yes, more preferably 0.025 to 1.25% by mass. By setting the content of the component (E) in the aqueous composition within the above range, a coating film having further excellent stain resistance and transparency can be obtained.
The content of the component (E) in the coating film obtained from the aqueous composition of the present embodiment is not particularly limited, but is preferably 3.0 to 40.0% by mass, more preferably 3.0. It is ~ 30.0% by mass, more preferably 5.0 to 25.0% by mass. When the content of the component (E) in the coating film is at least the above lower limit value, the stain resistance of the coating film is further improved, and when it is at least the above upper limit value, the transparency of the coating film is further improved. ..

<Amount of solids in aqueous composition>
The solid content (solid content) in the aqueous composition of the present embodiment is 0.5 to 5.0% by mass. It is preferably 0.7 to 5.0% by mass, and more preferably 1.2 to 4.5% by mass.
By setting the content of the solid content in the aqueous composition to the above lower limit value or more, the uniformity and stain resistance of the coating film are further improved. By setting the content of the solid content in the aqueous composition to the above upper limit value or less, the transparency and weather resistance are further improved.
The solid content referred to here can be determined by the method described in Examples described later.
Further, depending on the use of the coating film, it may be required that the film thickness of the coating film is thin. Even in such a case, since the solid content in the aqueous composition is not more than the above upper limit value, it is possible to obtain a coating film having excellent physical properties such as weather resistance and stain resistance while having a thin film thickness. can. By setting the amount of solid content in the aqueous composition to the lower limit value or more, the drying time required for forming the coating film can be shortened, and the work efficiency can be further improved.
The content of the solid content in the aqueous composition of the present embodiment can be controlled within the above numerical range by the amount of water added as a solvent and a monohydric alcohol.

<Other ingredients>
The aqueous composition of the present embodiment may further contain other components other than the above, if necessary, within the range in which the effect can be obtained.
Such other components include, but are not limited to, defoaming agents, fading dyes, freeze stabilizers, matting agents, cross-linking reaction catalysts, pigments, curing catalysts, cross-linking agents, fillings. Agents, anti-skin agents, dispersants, wetting agents, light stabilizers, antioxidants, UV absorbers, film-forming aids, rust inhibitors, plasticizers, lubricants, reducing agents, preservatives, fungicides, Examples thereof include deodorants, anti-yellowing agents, anti-static agents and anti-static agents.
Only one of these may be used alone, or two or more thereof may be used in combination.

(Physical characteristics of aqueous composition)
From the viewpoint of circulating foaming property and coating property of the coating material, the aqueous composition of the present embodiment preferably has a static surface tension of 20 to 40 mN / m at an alcohol concentration of 15% by mass.
More preferably, it is 20 to 35 mN / m, and even more preferably, it is 22 to 32 mN / m.
The static surface tension at an alcohol concentration of 15% by mass can be measured by the method described in Examples described later.
The static surface tension of the aqueous composition can be controlled within the above numerical range by the silicone surfactant (C).

[Water-based paint]
The water-based coating material of the present embodiment contains the above-mentioned water-based composition of the present embodiment.
As the water-based coating material of the present embodiment, the water-based composition of the present embodiment may be used alone, or any other additive or solvent may be blended.
The water-based paint can be appropriately applied by a suitable method depending on the intended use, the material to be applied, and the like.
The coating method is not limited to the following, but is, for example, a manual spraying method, an automatic spraying method on a line, a flow coating method, a roll coating method, a brush coating method, a dip coating method, and a spin coating. Examples include the method, screen printing method, casting method, gravure printing method, and flexographic printing method.

A coating film is obtained by applying the water-based paint of the present embodiment and then drying to remove volatile components. Drying may be performed at room temperature, or heat treatment may be performed at a temperature of about 40 to 120 ° C. Further, ultraviolet irradiation treatment or the like may be performed.

[Coating film]
As described above, a coating film can be obtained by the water-based coating material containing the water-based composition of the present embodiment.
This coating film is obtained from an aqueous composition. For example, the above-mentioned aqueous composition may be applied to the surface of various substrates and dried to obtain a coating film formed on the substrate. can.

[Painted products]
The coated product of the present embodiment includes a base material and the coating film formed on at least a part of the surface of the base material.
The base material is not particularly limited as long as a coating film can be formed on the surface thereof, and may be either an organic base material or an inorganic base material, but an organic base material is preferable.
The material of the base material is not limited to the following, and examples thereof include synthetic resin, natural resin, metal, ceramics, glass, stone, cement, concrete, and ceramic siding.
Only one of these may be used alone, or two or more thereof may be used in combination.

Examples of the synthetic resin include, but are not limited to, a thermoplastic resin and a curable resin (thermosetting resin, photocurable resin, moisture curable resin, etc.).
Specifically, silicone resin, acrylic resin, methacrylic resin, fluororesin, alkyd resin, aminoalkyd resin, vinyl resin, polyester resin, styrene-butadiene resin, polyolefin resin, polystyrene resin, polyketone resin, polyamide resin, polycarbonate resin, Polyacetal resin, polyether ether ketone resin, polyphenylene oxide resin, polysulphon resin, polyphenylene sulfone resin, polyether resin, polyvinyl chloride resin, polyvinylidene chloride resin, urea resin, phenol resin, melamine resin, epoxy resin, urethane resin, Examples include silicone-acrylic resin.
Examples of the natural resin include, but are not limited to, cellulose-based resins, isoprene-based resins such as natural rubber, and protein-based resins such as casein.
When the base material is a resin base material using the above-mentioned synthetic resin, natural resin, or the like, surface treatment such as corona discharge treatment, frame treatment, plasma treatment, or the like may be performed, if necessary.

The coated product of the present embodiment includes a base material and a coating film formed on the base material, and the coating film is also useful as a coating film or the like.

Since the coating film obtained by the present embodiment can maintain its appearance and antifouling property at a high level for a long period of time, it can be suitably used in an environment where it has been difficult to use in the past. From this point of view, the painted product of the present embodiment is not limited to the following, but for example, building materials, building exteriors, building interiors, window frames, windowpanes, various lenses, structural members, building equipment such as houses, etc. Vehicle lighting covers and windowpanes, exteriors of mechanical devices and articles, dustproof covers and paints, display devices, their covers, traffic signs, various display devices, display objects such as advertising towers, sound insulation walls for roads and railways, etc. , Bridges, guard rail exteriors and paints, tunnel interiors and paints, glass, solar cell covers, solar water heater heat collector covers, etc. Exteriors of electronic and electrical equipment used outside, especially transparent members, vinyl houses, greenhouses, etc. Can be mentioned.

As a method for producing a coated product of the present embodiment, for example, a coating film is coated by applying the above-mentioned aqueous composition of the present embodiment to at least a part of the surface of a base material and drying it if necessary. However, the method is not limited to this. For example, after applying the coating film of the present embodiment on a base material, the coating film may be peeled off from the base material and adhered to another base material. Alternatively, the coating film of the present embodiment may be applied onto a base material and then adhered to another base material in a state of being in close contact with the base material.

The aqueous composition of the present embodiment may be blended with various aqueous paints. Such a water-based paint can form a coating film having excellent appearance, stain resistance, transparency, weather resistance, and the like. As described above, the coating film of the present embodiment is excellent in appearance, stain resistance, transparency, weather resistance, etc., and can be used for a wide range of applications including exterior paints for buildings.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
In Examples and Comparative Examples, various physical properties were measured by the following methods.

〔Base material〕
Exterior wall material (ceramic siding; clear layer applied on a single color coating; water contact angle 82 °; dark color (brown): lightness L * = 31; light color (beige): L * = 68)

[Content of each component and solid content]
2 g of the sample was placed in an aluminum dish and heated at 130 ° C. for 1 hour. The mass of the sample before and after heating was measured, and the solid content (mass%) was calculated from the difference.
[Amount of solids in aqueous composition]
2 g of the sample was placed in an aluminum dish and heated at 130 ° C. for 1 hour. The mass of the sample before and after heating was measured, and the solid content (mass%) was calculated from the difference.
[Composition in Aqueous Composition and Composition of Coating Film]
The solid content of each component was measured according to [content of each component and solid content]. The composition in the aqueous composition and the composition of the coating film were calculated from the blending amount and the solid content amount described in the examples.

[Number average particle size]
A wet particle size analyzer (manufactured by Nikkiso Co., Ltd., " It was measured using Microtrack UPA-9230 ").
The measurement conditions are shown below.
-Loading index: 1.5 to 3.0
・ Measurement time: 60 seconds ・ Number of measurements: 3 times

[Static surface tension at alcohol concentration of 15% by mass]
The static surface tension of the aqueous compositions obtained in Examples and Comparative Examples at an alcohol concentration of 15% by mass was measured by using an automatic surface tensiometer "CBVP-Z" manufactured by Kyowa Interface Science Co., Ltd. to measure a platinum plate (Wilhelmy). Method), the measurement was carried out under the measurement conditions of a liquid temperature of 23 ° C.

[Physical characteristics]
(Circulation foaming property)
As the circulating foaming property, the foaming ratio of the aqueous composition 30 minutes after circulation was determined as follows.
It was evaluated that the smaller the foaming ratio, the better the circulating foaming property.
The aqueous composition (300 mL) is placed in a graduated stainless steel container (capacity 2 L) having a diameter of 13.5 cm and a height of 15 cm, and the liquid is dropped from a height of 20 cm above the liquid surface with a circulation pump at a discharge rate of 230 g / min. It circulated.
Circulation foaming property = (volume of aqueous composition containing generated foam after 30 minutes circulation / volume of aqueous composition before circulation (300 mL))
2x: Foaming magnification is 2x or more and less than 3x 3x: Foaming magnification is 3x or more and less than 4x 4x: Foaming magnification is 4x or more and less than 5x 5x: Foaming magnification is 5x or more and less than 6x 6x Above: Foaming magnification is 6 times or more

(Shaking foaming property)
The foaming ratio of the aqueous composition was determined as follows for the shaking foaming property.
It was evaluated that the smaller the foaming multiple, the better the shaking foaming property.
Operation A: The aqueous composition (30 mL) obtained in Examples and Comparative Examples was placed in a 250 mL graduated cylinder, sealed, and turned upside down, and the process was repeated 10 times.
Foaming multiple = (Volume of aqueous composition containing generated bubbles after operation A / Volume of aqueous composition before operation A (30 mL))
Less than 2 times: Foaming multiple is less than 2 times 2 times: Foaming multiple is 2 times or more and less than 3 times 3 times: Foaming multiple is 3 times or more and less than 4 times 4 times: Foaming multiple is 4 times or more and less than 5 times 5 times: Foaming Multiples are 5 times or more

(Covering property)
The surface of the coating film obtained by using the light-colored substrate in Examples and Comparative Examples was subjected to a reflected electron stereoscopic image (acceleration voltage 10 kV, magnification 500 times) of a scanning electron microscope (manufactured by JEOL; JSM-6390LV). I took a picture.
The obtained image was subjected to image analysis dedicated software (manufactured by Asahi Kasei Engineering Co., Ltd .; "A image-kun"), and there was no coating film obtained from the aqueous composition and the portion covered with the coating film obtained from the aqueous composition. The area ratio of the portion covered with the coating film obtained from the aqueous composition was determined by binarizing the portion.
The larger the area ratio value, the better the coverage.
The degree of coverage was evaluated according to the following criteria.
◎: Area ratio 90% or more ○: Area ratio 75% or more △: Area ratio 60% or more ×: Area ratio less than 60%

(Color difference before and after painting)
JIS K5600 Paint General Test Method Using a spray on the black background (L * value 7) of the concealment rate test paper (manufactured by Nippon Test Panel Co., Ltd.) so that the amount of the aqueous composition applied is 33 g / m ^2. I painted it.
The coated test paper was kept horizontal and allowed to stand at a temperature of 23 ° C., a relative humidity of 50%, and an illuminance of 20000 lux for 48 hours to prepare a test plate.
The color difference before and after painting was measured using a "color guide" manufactured by BYK Gardner.
If the color difference is 3.0 or less, it means that there is little change in the color difference on the dark background and it is good.
It is preferably less than 2.0.
Further, it was visually confirmed whether or not the test plate had local white unevenness.
It is preferable that there is no local white unevenness.
As described above, the results of color difference and visual confirmation were evaluated according to the following criteria.
⊚: The color difference was less than 2.0, and there was no local white unevenness.
◯: The color difference was 2.0 or more and 3.0 or less, and there was no local white unevenness.
◯ to Δ: The color difference was 2.0 or more and 3.0 or less, and some white unevenness was locally observed.
Δ: The color difference was 2.0 or more and 3.0 or less, and local white unevenness was observed.
×: Color difference over 3.0

(Dryness)
The dark-colored substrate was preheated to 80 ° C. and coated with a spray so that the ^{amount of the aqueous composition applied was 33 g / m 2.}
The coated base material was kept horizontal, and the dryness of the surface 30 seconds after coating was visually observed and evaluated according to the following criteria.
<Evaluation criteria>
◯: It was almost dry.
Δ: There was some uneven drying.
X: There was an undried part that caused dripping.

(Weather resistance test: Gloss retention after 2500 hours)
Exposure test (black panel temperature 63 ° C, rainfall 18 minutes / 2 hours) using "Sunshine Weather Meter" manufactured by Suga Test Instruments Co., Ltd. on the coating film obtained using the light-colored substrate in Examples and Comparative Examples. Was done.
The 60 ° glossiness after 2500 hours of exposure was measured using a gloss meter (“Microtrigloss μ” manufactured by BYK Gardner).
Then, the gloss retention rate was calculated based on the following formula.
The result of evaluation using only the base material shows that the gloss retention rate is 80% after 2500 hours of exposure, and when the gloss retention rate is larger than these values, the weather resistance is good.
Gloss retention (%) = 60 ° gloss after exposure test / 60 ° gloss before exposure test x 100

(Stain resistance)
The coating film obtained by using the light-colored base material in Examples and Comparative Examples is attached to a fence facing a general road (truck traffic of about 500 to 1000 vehicles / day) and left to stand for 6 months or 1 year. bottom.
The degree of contamination of the test plate after standing was visually evaluated according to the following criteria.
The result of evaluation using only the base material was "Δ" for 6 months and "x" for 1 year.
◯: Almost no dirt was confirmed.
Δ: Some dirt was confirmed.
X: A large amount of dirt was confirmed.

[Manufacturing Example 1]
<Synthesis of aqueous dispersion (AD-1) of polymer (A-1)>
After charging 850 g of ion-exchanged water and 5.6 g of a 10 mass% dodecylbenzene sulfonic acid aqueous solution into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer, the temperature in the reactor is raised to 80 under stirring. It was heated to ° C.
A mixed solution consisting of 93.9 g of dimethyldimethoxysilane, 73.0 g of phenyltrimethoxysilane, and 29.4 g of methyltrimethoxysilane was placed in this reactor for about 2 hours while the temperature in the reactor was maintained at 80 ° C. Dropped over. Then, the temperature in the reactor was maintained at 80 ° C. and stirring was continued for 30 minutes.
Next, after adding 5.6 g of a 10 mass% dodecylbenzene sulfonic acid aqueous solution, the temperature in the reactor was maintained at 80 ° C. and stirring was continued for 4 hours. After adding 6.6 g of a 2 mass% ammonium persulfate aqueous solution, 22.5 g of methyl methacrylate, 11.2 g of n-butyl acrylate, 12.3 g of phenyltrimethoxysilane, 28.6 g of tetraethoxysilane, 3 -A mixed solution consisting of 1.1 g of metharoxypropyltrimethoxysilane, 0.9 g of acrylic acid, and 1.2 g of a reactive emulsifier ("Adecaria Soap SR-1025" manufactured by ADEKA; 25% by mass aqueous solution of solid content), A mixed solution consisting of 1.2 g of a reactive emulsifier (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Aqualon KH-1025"; 25% by mass aqueous solution of solid content), 30 g of a 2.0% by mass aqueous solution of ammonium persulfate, and 286.4 g of ion-exchanged water. Was simultaneously added dropwise over about 2 hours while maintaining the temperature in the reactor at 80 ° C.
Further, the temperature in the reactor was maintained at 80 ° C. and stirring was continued for about 1 hour, then cooled to room temperature, and a 25% aqueous ammonia solution was added to the reaction solution to adjust the pH to 8, and then 100 mesh. It was filtered with a wire mesh. The solid content was adjusted to 10.0% by mass with ion-exchanged water to obtain an aqueous dispersion (AD-1) of polymer particles (A-1) having a number average particle diameter of 148 nm.

[Manufacturing Example 2]
<Synthesis of aqueous dispersion (AD-2) of polymer (A-2)>
After charging 560 g of ion-exchanged water and 15.0 g of a 10 mass% dodecylbenzene sulfonic acid aqueous solution into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer, the temperature in the reactor is raised to 80 under stirring. It was heated to ° C. A mixed solution consisting of 125.9 g of dimethyldimethoxysilane and 39.4 g of methyltrimethoxysilane was added dropwise to the reactor over about 2 hours while maintaining the temperature in the reactor at 80 ° C. Then, the temperature in the reactor was maintained at 80 ° C. and stirring was continued for 30 minutes.
Next, 16.8 g of a 10 mass% dodecylbenzene sulfonic acid aqueous solution was added, and then the temperature in the reactor was maintained at 80 ° C. and stirring was continued for 2 hours.
A mixed solution consisting of 36.8 g of phenyltrimethoxysilane, 28.6 g of tetraethoxysilane, and 1.1 g of 3-methacryloxypropyltrimethoxysilane, 0.9 g of acrylic acid, and a reactive emulsifier (made by ADEKA, "Adecaria Soap". SR-1025 "; solid content 25% by mass aqueous solution) 1.5 g, reactive emulsifier (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.," Aqualon KH-1025 "; solid content 25% by mass aqueous solution) 3.0 g, ammonium persulfate 0. A mixed solution consisting of 146.4 g of a 5 mass% aqueous solution and 256.4 g of ion-exchanged water was simultaneously added dropwise over about 2 hours while maintaining the temperature in the reactor at 80 ° C.
Even after the completion of the dropping, the temperature in the reactor was maintained at 80 ° C., and stirring was continued for about 1 hour.
After cooling to room temperature, the hydrogen ion concentration of the reaction solution in the reactor was measured and found to be pH 1.9. A 25% aqueous ammonia solution was added to the reaction solution to adjust the pH of the solution to 8, and then the reaction solution was filtered through a 100-mesh wire mesh.
Further, the solid content was adjusted to 10.0% by mass with ion-exchanged water to obtain an aqueous dispersion (AD-2) of a polymer (A-2) having a number average particle size of 100 nm.

[Manufacturing Example 3]
<Synthesis of inorganic oxide (E-1) with photocatalytic activity>
Titanium tetrachloride aqueous solution 700mL of a concentration of 200 g / L as the silica modified rutile-type titanium oxide TiO _2, an aqueous sodium hydroxide solution having a concentration of 100 g / L as Na ₂ O, while maintaining the pH of the reaction solution to 5-9 , Added.
Then, after adjusting the pH of the reaction solution to 7, it was filtered and washed until the conductivity of the filtrate became 100 μS / cm to obtain titanium oxide wet cake 1 having a solid content of 28.3% by mass.
The titanium oxide wet cake 1 contained fine particles having a rutile-type structure, and the number average particle diameter of the primary particles was 8 nm.
The obtained titanium oxide wet cake 1 was diluted with pure water to prepare a 1 mol / L slurry.
1 L of this slurry is placed in a 3 L flask, 1 specified nitric acid is further added so that the molar ratio of titanium oxide / nitric acid becomes 1/1, and the mixture is heated to a temperature of 95 ° C. and maintained at this temperature for 2 hours. The acid heat treatment was carried out. The slurry after the acid heat treatment was cooled to room temperature, neutralized to pH 6.7 with 28% aqueous ammonia, and filtered. Then, the filtrate was washed until the conductivity became 100 μS / cm to obtain a titanium oxide wet cake 2 having a solid content of 25% by mass.
To the obtained titanium oxide wet cake 2, a 10% aqueous solution of sodium hydroxide was added to repulp, and then dispersed in an ultrasonic cleaner for 3 hours to make the cake alkaline with a pH of 10.5 and a solid content of 10% by mass. A titanium oxide sol was obtained. 2 L of this alkaline titanium oxide sol was placed in a 3 L flask, the temperature was raised to 70 ° C., 69.4 mL of a sodium silicate aqueous solution having a concentration of 432 g / L was added as _{SiO 2, and then the temperature was raised to 90 ° C. 1} After maintaining for a long time, 10% sulfuric acid was added to adjust the pH to 6, and a titanium oxide sol whose surface of titanium oxide was surface-treated with a hydroxide containing silicon was obtained.
The obtained titanium oxide sol was cooled to room temperature, 5.4 L of pure water was added, impurities were removed and concentrated using a desalting concentrator, pH 7.3, solid content 29% by mass, conductivity. A neutral rutile-type titanium oxide sol of 1.18 mS / cm was obtained. The neutral rutile titanium oxide sol contained 15 mass% of silicon hydrous oxide of SiO ₂ basis relative to TiO _2. The number average particle size of the primary particles of titanium oxide in this sol was 9 nm.

[Manufacturing Example 4]
<Synthesis of inorganic oxide (E-2) with photocatalytic activity>
Aggregated metatitanic acid produced by heating and hydrolyzing a titanium sulfate solution obtained by reacting silica-modified anatase-type titanium oxide titanium ore with sulfuric acid was used as _{an aqueous slurry having a TiO 2} equivalent of 30% by mass.
Ammonia water was added to this aqueous slurry to neutralize it to pH 7, and then sulfate ions were removed by filtration and washing to obtain a dehydrated cake.
The obtained dehydrated cake was defibrated by adding nitric acid to obtain an acidic titanium oxide sol having a pH of 1.5 composed of titanium oxide fine particles having an anatase-type crystal structure (number average particle diameter of primary particles was 7 nm).
The obtained acidic titanium oxide sol is diluted with pure water to obtain _{600 mL of titanium oxide sol having a TiO 2} conversion concentration of 200 g / L, then heated to 70 ° C. and _{sodium silicate having a SiO 2} conversion concentration of 432 g / L. 20.8 mL of aqueous solution was added at the same time as 20% sulfuric acid.
Then, it was aged for 30 minutes. Then, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 8, and then a 2% aqueous sulfuric acid solution was used to adjust the pH to 6, and the cake was filtered and washed to obtain a wet cake. This wet cake was repulped in pure water and then ultrasonically dispersed to obtain an anatase-type titanium oxide sol (solid content 20% by mass, pH 7.5) stable in the neutral region.
In this sample, aggregated silica was adhered to the surface of the titanium oxide fine particles in a porous state, and the content thereof was 7 parts by mass in terms of _{SiO 2 with} respect to 100 parts by mass of _{TiO 2.}

[Example 1]
Water-dispersed colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; solid content 20% by mass), 25.0 g, and a silicone-based surfactant (C-1) ( Sannopco, "SN Wet 126"; 5.0 g of ethanol diluted in advance to 10.0% by mass), 70.5 g of ethanol, and antifoaming agent (Sannopco, "SN Deformer 323"; water in advance (Diluted to 1.0% by mass) and 394.5 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-1) having a solid content of 1.1% by mass.
The surface tension of this aqueous composition (G-1) was 24 mN / m.
Next, the aqueous composition (G-1) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-1) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-1), the coating film and the test plate (H-1).

[Example 2]
Water-dispersed colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; solid content 20% by mass) 75.0 g, and a silicone-based surfactant (C-2) ( "BYK-348" manufactured by Big Chemie Japan Co., Ltd .; 1.0 g of ethanol diluted to 10.0% by mass in advance), 74.1 g of ethanol, and an antifoaming agent (manufactured by Sannopco Co., Ltd., "SN Deformer 323"); An aqueous composition (G-2) having a solid content of 3.0% by mass is obtained by mixing 5.0 g of (preliminarily diluted to 1.0% by mass with water) and 344.9 g of ion-exchanged water and stirring. rice field.
The surface tension of this aqueous composition (G-2) was 40 mN / m.
Next, the aqueous composition (G-2) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-2) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-2), the coating film and the test plate (H-2).

[Example 3]
110.0 g of an aqueous dispersion (AD-1) of the polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; Solid content 20% by mass) 20.0g and silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol) 5.0g. Mix 70.5 g of ethanol, 5.0 g of antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; diluted to 1.0% by mass with water in advance), and 289.5 g of ion-exchanged water, and stir. To obtain an aqueous composition (G-3) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-1) was 30 mN / m.
Next, the aqueous composition (G-3) was applied to a dark-colored and light-colored substrate of 15 cm × 15 cm, which had been preheated to a plate temperature of 80 ° C., using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-3) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-3), the coating film and the test plate (H-3).

[Example 4]
110.0 g of an aqueous dispersion (AD-1) of the polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; 20.0 g of solid content (20% by mass) and 20.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). Mix 57.0 g of ethanol, 5.0 g of antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; diluted to 1.0% by mass with water in advance), and 288.0 g of ion-exchanged water, and stir. To obtain an aqueous composition (G-4) having a solid content of 3.4% by mass.
The surface tension of this aqueous composition (G-4) was 28 mN / m.
Next, the aqueous composition (G-4) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-4) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-4), the coating film and the test plate (H-4).

[Example 5]
107.25 g of an aqueous dispersion (AD-1) of polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; 10.15 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 70.5 g of ethanol, 7.75 g of inorganic oxide (E-1) having photocatalytic activity (solid content 29% by mass), antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; 1.0 in advance with water 5.0 g of (diluted to mass%) and 294.35 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-5) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-5) was 30 mN / m.
Next, the aqueous composition (G-5) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-5) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-5), the coating film and the test plate (H-5).

[Example 6]
107.25 g of an aqueous dispersion (AD-1) of the polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; 12.65 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 7.0.5 g of isopropyl alcohol, 5.15 g of an inorganic oxide (E-1) having photocatalytic activity (solid content 29% by mass), and an antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; in advance with water. 5.0 g of (diluted to 0% by mass) and 294.45 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-6) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-6) was 30 mN / m.
Next, the aqueous composition (G-6) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-6) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-6), the coating film and the test plate (H-6).

[Example 7]
111.75 g of an aqueous dispersion (AD-1) of polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; 11.65 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 70.5 g of ethanol, 5.15 g of inorganic oxide (E-1) having photocatalytic activity (solid content 29% by mass), antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; 1.0 in advance with water 5.0 g of (diluted to mass%) and 290.95 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-7) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-7) was 30 mN / m.
Next, the aqueous composition (G-7) was applied to a dark-colored and light-colored substrate of 15 cm × 15 cm, which had been preheated to a plate temperature of 80 ° C., using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-7) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-7), the coating film and the test plate (H-7).

[Example 8]
90.0 g of an aqueous dispersion (AD-1) of polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; 18.75 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 70.5 g of ethanol, 7.75 g of inorganic oxide (E-1) having photocatalytic activity (solid content 29% by mass), antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; 1.0 in advance with water 5.0 g of (diluted to mass%) and 303.0 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-8) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-8) was 31 mN / m.
Next, the aqueous composition (G-8) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-8) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-8), the coating film and the test plate (H-8).

[Example 9]
35.5 g of an aqueous dispersion (AD-2) of the polymer particles (A-2) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; 39.0 g of solid content (20% by mass), 4.5 g of zirconia aqueous sol (B-2) (manufactured by Nissan Chemical Industries, Ltd .; "Nanouse ZR-30BS"; solid content of 30%), and silicone-based surfactant (C) -1) ("SN Wet 126" manufactured by Sannopco Co., Ltd .; pre-diluted to 10.0% by mass with ethanol) 5.0 g, 70.5 g of ethanol, and an inorganic oxide having photocatalytic activity (E-1) 7.95 g (solid content 29% by mass), 5.0 g of defoamer (manufactured by Sannopco, "SN Deformer 323"; pre-diluted to 1.0% by mass with water), and 332.55 g of ion-exchanged water. Was mixed and stirred to obtain an aqueous composition (G-9) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-9) was 30 mN / m.
Next, the aqueous composition (G-9) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-9) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-9), the coating film and the test plate (H-9).

[Example 10]
67.0 g of an aqueous dispersion (AD-1) of polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; 7.0 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 145.5 g of ethanol, 3.1 g of inorganic oxide (E-1) having photocatalytic activity (solid content 29% by mass), antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; 1.0 in advance with water 5.0 g of (diluted to mass%) and 267.4 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-10) having a solid content of 1.9% by mass.
Of this aqueous composition (G-10), the surface tension of the aqueous composition (G-10') prepared by replacing 75.0 g of ethanol with 75.0 g of ion-exchanged water was 30 mN / m.
Next, the aqueous composition (G-10) was applied to a dark-colored and light-colored substrate of 15 cm × 15 cm, which had been preheated to a plate temperature of 80 ° C., using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-10) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-10), (G-10'), the coating film and the test plate (H-10).

[Example 11]
107.25 g of an aqueous dispersion (AD-1) of polymer particles (A-1) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; 10.15 g of solid content (20% by mass) and 5.0 g of silicone-based surfactant (C-1) (manufactured by Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ethanol). 70.5 g of ethanol, 7.75 g of inorganic oxide (E-2) having photocatalytic activity (solid content 29% by mass), antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; 1.0 in advance with water 5.0 g of (diluted to mass%) and 294.35 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-11) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-11) was 30 mN / m.
Next, the aqueous composition (G-11) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-11) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-11), the coating film and the test plate (H-11).

[Comparative Example 1]
Water-dispersed colloidal silica (B-1) with a number average particle size of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; solid content 20% by mass) 5.0 g, and a silicone-based surfactant (C-1) ( Sannopco, "SN Wet 126"; 2.5 g of ethanol diluted to 10.0% by mass in advance), 72.75 g of ethanol, and antifoaming agent (Sannopco, "SN Deformer 323"; water in advance (Diluted to 1.0% by mass) and 414.75 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-12) having a solid content of 0.3% by mass.
The surface tension of this aqueous composition (G-12) was 24 mN / m.
Next, the aqueous composition (G-12) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-12) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-12), the coating film and the test plate (H-12).

[Comparative Example 2]
Water-dispersed colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; solid content 20% by mass), 150.0 g, and a silicone-based surfactant (C-1) ( Sannopco, "SN Wet 126"; 5.0 g of ethanol diluted in advance to 10.0% by mass), 70.5 g of ethanol, and antifoaming agent (Sannopco, "SN Deformer 323"; water in advance (Diluted to 1.0% by mass) and 269.5 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-13) having a solid content of 6.1% by mass.
The surface tension of this aqueous composition (G-13) was 24 mN / m.
Next, the aqueous composition (G-13) was applied to a dark-colored and light-colored substrate of 15 cm × 15 cm, which had been preheated to a plate temperature of 80 ° C., using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-13) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-13), the coating film and the test plate (H-13).

[Comparative Example 3]
Water-dispersed colloidal silica (B-1) with a number average particle size of 8 nm (Nissan Chemical Industries, Ltd., "Snowtex OS"; solid content 20% by mass) 75.0 g, ethanol 75.0 g, and defoamer (San Nopco) "SN Deformer 323" manufactured by San Nopco Ltd.; (preliminarily diluted to 1.0% by mass with water) 5.0 g and 345.0 g of ion-exchanged water are mixed and stirred to create an aqueous solution having a solid content of 3.0% by mass. The composition (G-14) was obtained.
The surface tension of this aqueous composition (G-14) was 41 mN / m.
Next, the aqueous composition (G-14) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-14) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-14), the coating film and the test plate (H-14).

[Comparative Example 4]
Water-dispersed colloidal silica (B-1) with a number average particle size of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; solid content 20% by mass) and 75.0 g, and a fluorocarbon surfactant (manufactured by AGC Seimi Chemical Co., Ltd., "Surflon S-232"; 1.0 g of solid content 30% by mass), 75.0 g of ethanol, and antifoaming agent ("SN Deformer 323" manufactured by Sannopco Co., Ltd .; pre-diluted to 1.0% by mass with water ) 5.0 g and 344.0 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-15) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-15) was 16 mN / m.
Next, the aqueous composition (G-15) was applied to a dark-colored and light-colored substrate of 15 cm × 15 cm, which had been preheated to a plate temperature of 80 ° C., using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-15) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-15), the coating film and the test plate (H-15).

[Comparative Example 5]
Water-dispersed colloidal silica (B-1) with a number average particle size of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; solid content 20% by mass) 75.0 g, and a hydrocarbon-based surfactant (Lion Specialty) "Lypon LH-200" manufactured by Chemicals Co., Ltd .; 5.0 g of "Lypon LH-200" diluted with ion-exchanged water in advance to 10.0% by mass), 75.0 g of ethanol, and an antifoaming agent (manufactured by Sannopco Co., Ltd., "SN Deformer 323") An aqueous composition (G-16) having a solid content of 3.1% by mass was obtained by mixing 5.0 g of (preliminarily diluted to 1.0% by mass with water) and 340.0 g of ion-exchanged water and stirring. Obtained.
The surface tension of this aqueous composition (G-16) was 38 mN / m.
Next, the aqueous composition (G-16) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-16) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-16), the coating film and the test plate (H-16).

[Comparative Example 6]
Water-dispersed colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., "Snowtex OS"; solid content 20% by mass) 75.0 g, and a silicone-based surfactant (C-1) ( Sannopco, "SN Wet 126"; pre-diluted to 10.0% by mass with ion-exchanged water) 5.0 g and defoamer (Sannopco, "SN Deformer 323"; pre-water 1.0 5.0 g of (diluted to mass%) and 415.0 g of ion-exchanged water were mixed and stirred to obtain an aqueous composition (G-17) having a solid content of 3.1% by mass.
The surface tension of this aqueous composition (G-17) was 24 mN / m.
Next, the aqueous composition (G-17) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-17) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-17), the coating film and the test plate (H-17).

[Comparative Example 7]
35.5 g of an aqueous dispersion (AD-2) of the polymer particles (A-2) and an aqueous dispersion colloidal silica (B-1) having a number average particle diameter of 8 nm (manufactured by Nissan Chemical Industries, Ltd., “Snowtex OS”; Solid content 20% by mass) 39.0 g, zirconia aqueous sol (B-2) (manufactured by Nissan Chemical Industries, Ltd .; "Nanouse ZR-30BS"; solid content 30%) 4.5 g, fluorocarbon surfactant (AGC Seimi) "Surflon S-232" manufactured by Chemical Co., Ltd .; 1.0 g of solid content (30% by mass), 75.0 g of ethanol, and 7.95 g of inorganic oxide (E-1) having photocatalytic activity (29% by mass of solid content). , 5.0 g of antifoaming agent (manufactured by Sannopco, "SN Deformer 323"; diluted to 1.0% by mass with water in advance) and 332.05 g of ion-exchanged water are mixed and stirred to obtain a solid content. A 3.1% by mass aqueous composition (G-18) was obtained.
The surface tension of this aqueous composition (G-18) was 18 mN / m.
Next, the aqueous composition (G-18) was applied to a dark-colored and light-colored base material of 15 cm × 15 cm previously heated to a plate temperature of 80 ° C. using a spray so as to ^{have an application amount of 33 g / m 2.}
The coated substrate was kept horizontal and allowed to stand at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours to obtain a test plate (H-18) having a coating film formed on the substrate.
Table 1 shows various physical characteristics and evaluation results of the aqueous composition (G-18), the coating film and the test plate (H-18).

It was confirmed that all of the aqueous compositions of the examples of the present invention can form a coating film capable of suppressing the circulating foaming property of the paint and maintaining good coating property and weather resistance at a high level. ..

The water-based composition, water-based paint, coating film, and coated product of the present invention have industrial applicability as various members such as building exterior applications, exterior display applications, automobile parts, and optical parts such as displays and lenses. have.

Claims (10)

Inorganic oxide particles (B) having no catalytic activity and
Silicone-based surfactant (C) and
Water as a solvent and
Monohydric alcohol (D) and
Defoamers containing hydrophobic silica and mineral oil,
, Contains
An aqueous composition having a solid content of 0.5 to 5% by mass. The aqueous composition according to claim 1, wherein the solid content is 0.5 to 4.5% by mass. The aqueous composition according to claim 1 or 2 , further comprising an aqueous dispersion (AD) of the polymer (A). The polymer (A)
The aqueous composition according to claim 3 , which is a polymer obtained by polymerizing a vinyl monomer and a hydrolyzable silicon compound in the presence of water and an emulsifier. Claims 1 to 4 , wherein the inorganic oxide particles (B) having no catalytic activity are silicon dioxide.
The aqueous composition according to any one of the above. The static surface tension at an alcohol concentration of 15% by mass in the aqueous composition is 20 to 40 mN /
The aqueous composition according to any one of claims 1 to 5 , which is m. The aqueous composition according to any one of claims 1 to 6 , further containing an inorganic oxide (E) having photocatalytic activity. A water-based coating material containing the water-based composition according to any one of claims 1 to 7. A coating film obtained from the water-based paint according to claim 8. A coated product comprising a base material and the coating film according to claim 9 formed on at least a part of the surface of the base material.