JP2001347136A - Inorganic coating material capable of forming photocatalytically activated coating film and method of coating with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material capable of forming a coating film excellent in coating film characteristics such as oxidation resistance, weatherablity, impact resistance, coating material adhesion property and having photocatalytic activity and capable of drying at a relatively low temperature. SOLUTION: The inorganic coating material contains (1) a condensation reaction product of a mixture containing (A) 100 pts.wt. alkylarylpolysiloxane having a weight average molecular weight of 500-6,000 and 0-30 wt.% alkoxyl group content, (B) 0-200 pts.wt. alkyl trialkoxy silane or the condensation product, (C) 0.1-200 pts.wt. mono- and/or di-alkoxy silane and further (D) 0.1-200 pts.wt. epoxy group-containing silane based on 100 pts.wt. in total of (A), (B) and (C) component and (2) photocatalyst-active titanium oxide, and is capable of forming the photocatalytically activated coating film. Further, the method for forming the photocatalytically activated coating film by applying the inorganic coating material on a material to be coated is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic paint capable of forming a photocatalytically active coating film and a method for forming a photocatalytically active coating film using the inorganic paint.

[0002]

2. Description of the Related Art In recent years,
As part of the purification of living environment, to decompose pollutants such as nitrogen oxides and sulfur oxides in the air due to exhaust gas around the motorway, and to improve the exposure pollution resistance by making the coating film surface hydrophilic. It has also been proposed to apply a photocatalytically active paint for the purpose of imparting antibacterial and antifungal properties to the coating film.

As a coating material having photocatalytic activity, for example, a coating material in which a powder such as titanium dioxide or zinc oxide having photocatalytic activity is blended into a fluororesin-based coating material or an inorganic coating material has been proposed (for example, Japanese Patent Application Laid-Open No. H10-163,878). 10-19533
No. 3, JP-A-10-265713). Titanium dioxide and zinc oxide having photocatalytic activity are optical semiconductors and have a band gap around 3 eV.
It is easily excited by irradiation of sunlight or artificial illumination light, generates holes and OH radicals, exhibits strong oxidizing action, and has an antibacterial property due to the oxidizing action.

[0004] The oxidizing action can decompose pollutants in the air. For example, it has the action of oxidizing nitrogen oxides in the air and eventually converting it into nitric acid, or decomposing it into nitrogen and water. When the surface of the coating film is hydrophilized to improve the resistance to exposure contamination, a powder having photocatalytic activity and, if necessary, an alkyl silicate or a condensate thereof are blended with the resin having an alkoxysilyl group. In addition, the surface of the coating film is made hydrophilic by changing an alkoxysilyl group into a silanol group by an acid generated by the oxidizing action.

[0005] However, the organic resin-based coatings having photocatalytic activity such as the above-mentioned fluororesin-based coatings are liable to be oxidized, and the resulting coating film has poor weather resistance and is easily decomposed and deteriorated. It could not stand and was not practical.

[0006] Further, conventional inorganic coatings having photocatalytic activity have the problems that the coating film properties such as impact resistance and coating film adhesion of the obtained coating film are not sufficient, and the dispersibility of the pigment is not sufficient. there were.

An object of the present invention is to provide a coating film having good oxidation resistance, weather resistance, impact resistance, coating adhesion, etc., without being deteriorated by the oxidizing action of the powder having photocatalytic activity, and being suitable for long-term use. It can withstand, can form a coating film with excellent decomposability of pollutants such as nitrogen oxides in the air, exposure pollution resistance, antibacterial property, and can be dried at room temperature or relatively low temperature, pigment dispersibility It is to provide a good paint.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a specific alkylarylalkoxypolysiloxane as a binder component is combined with an alkyltrialkoxysilane and / or a condensation product thereof. Product, a mono- and / or di-alkoxysilane, and a condensation reaction product of an epoxy group-containing alkoxysilane,
It has been found that the above object can be achieved by an inorganic coating material in which the binder component and the photocatalytically active titanium oxide are combined, and the present invention has been completed.

[0009] The present invention, [I] (A) the following rational formula ^{_{R 1 a R 2 b (R}} 3 O) c SiO in _{(4-abc) / 2} Formula, R ¹ is 1 to 8 carbon atoms An alkyl group, R ² represents an aryl group, R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, a is 0.1 ≦ a ≦ 2.0, and b is 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
And the weight average molecular weight is in the range of 500 to 6,000, and the alkoxyl group content is in the range of 0 to 30% by weight based on the polysiloxane. 100 parts by weight of an alkylaryl polysiloxane and (B) in the following formula R ⁴ Si (OR ⁵ ) ₃ , wherein R ⁴ and R ⁵ are the same or different and represent an alkyl group having 1 to 8 carbon atoms. In the alkyltrialkoxysilane and / or 0 to 200 parts by weight of the condensate of the alkyltrialkoxysilane, (C) in the following general formula R ⁶ _d Si (OR ⁷ ) _(4-d) , R ⁶ is the same or Differently represents an alkyl group or aryl having 1 to 8 carbon atoms, R ⁷ is the same or different and represents an alkyl group having 1 to 8 carbon atoms, and d represents 2 or 3, mono- and / or Or di-alkoxy A run 0.1 to 200 parts by weight, the alkyl aryl polysiloxane (A) and the alkyl trialkoxy silane and /
Alternatively, based on a total of 100 parts by weight of the condensate (B) of the alkyltrialkoxysilane and the mono- and / or di-alkoxysilane (C), (D) the following general formula: R ⁸ R ⁹ _n Si (OR ¹⁰ ) In the formula _(3-n) , R ⁸ is a monovalent organic group containing an epoxy group, n R ⁹ are the same or different, and are an alkyl group having 1 to 8 carbon atoms;
R ¹⁰ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 0 to 2;
Which comprises a condensation reaction product with 0.1 to 200 parts by weight of an epoxy group-containing silane represented by formula (1) and [II] a photocatalytically active titanium oxide; It is.

[0010] The present invention also provides a method for forming a photocatalytically active coating film, which comprises applying an inorganic paint capable of forming the above-mentioned photocatalytically active coating film on an object to be coated.

Further, the present invention provides an inorganic paint capable of forming an inorganic undercoating film containing no photocatalytically active titanium oxide on a substrate to be coated, and forming the photocatalytically active coating film on the inorganic undercoating film. And a method of forming a photocatalytically active coating film, characterized by coating

Further, the present invention provides a method for forming a colored organic coating film on an object to be coated, and forming an inorganic coating film containing no photocatalytically active titanium oxide on the colored organic coating film. A method for forming a photocatalytically active coating film, characterized by applying an inorganic paint capable of forming the above-mentioned photocatalytically active coating film thereon.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the inorganic paint of the present invention will be described in detail.

The inorganic coating composition of the present invention comprises [I] an alkylarylpolysiloxane (A) and an alkyltrialkoxysilane and / or a condensate (B) of the alkyltrialkoxysilane and a mono- or di-alkoxysilane ( This is a paint capable of forming a photocatalytically active coating film containing a condensation reaction product of C) and an epoxy group-containing silane (D) and [II] photocatalytically active titanium oxide.

Alkylarylpolysiloxane (A) An alkylarylpolysiloxane which is a component (A) for producing the condensation reaction product [I] in the paint of the present invention [hereinafter referred to as "polysiloxane (A)". is there]
Is a polysiloxane containing alkyl group and an aryl group and an alkoxy group or a hydroxyl group, ⁽³ O R) _c SiO in _{(4-abc) / 2} Equation following rational formula _{^{R 1 a R 2 b, R}} 1 is An alkyl group having 1 to 8 carbon atoms, R ² represents an aryl group, R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, a is 0.1 ≦ a ≦ 2.0, and b is 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
Is a polysiloxane represented by the following formula:

Since the polysiloxane (A) has an aryl group in the above-mentioned quantitative range, it is excellent in film-forming properties. The polysiloxane (A) has a weight average molecular weight (in terms of polystyrene) of 500 to 6,000, particularly 700 to 6,000.
It is preferred that the content be in the range of 4,000 and the content of the alkoxyl group be in the range of 0 to 30% by weight, particularly in the range of 0 to 25.

Commercial products of polysiloxane (A) include:
For example, SH-6018, DC3074, DC303
7, SR2402 (all, products of Toray Dow Corning Co., Ltd.); KR9218, X-40-9220 (all, products of Shin-Etsu Chemical Co., Ltd.), TSR165, X
Examples thereof include R-31B1763 and XR-31B1410 (both are products of Toshiba Silicone Co., Ltd.).

Alkyl trialkoxysilane and / or
The condensate of the alkyl trialkoxysilane (B) The component (B) for producing the condensation reactant [I] in the paint of the present invention is the following alkyltrialkoxysilane and / or a condensate of the alkyltrialkoxysilane. , Alkyltrialkoxysilanes, condensates thereof, and mixtures of alkyltrialkoxysilanes and condensates thereof.

The alkyltrialkoxysilane which can be the component (B) is a compound represented by the following general formula R ⁴ Si (OR ⁵ ) _{3 wherein} R ⁴ and R ⁵ are the same or different and have 1 to 1 carbon atoms.
8, preferably 1 to 4 alkyl groups.

Specific examples of the above alkyltrialkoxysilane include, for example, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane,
Butyltrimethoxysilane, hexyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, methyltripropoxysilane, propyltripropoxysilane, methyltributoxysilane, etc. . These alkyl trialkoxysilanes can be used alone or in combination of two or more.

The condensate of the alkyltrialkoxysilane which can be the component (B) is a condensate of the above-mentioned alkyltrialkoxysilane, and has a weight average molecular weight of 300 to 3,000, particularly 500 to 2,000. It is preferable that the content of the alkoxyl group is 20% by weight or more, preferably 25 to 50% by weight based on the condensate. In producing the condensate, the alkyl trialkoxysilane can be condensed by using alone or in combination of two or more.

Mono- and / or dialkoxysilane
(C) The mono- and / or di-alkoxysilane as the component (C) for producing the condensation reaction product [I] in the paint of the present invention is represented by the following general formula: R ⁶ _d Si (OR ⁷ ) _{(4-d )} wherein, R ⁶ are the same or different, 1 to 8 carbon atoms, preferably represents from 1 to 4 alkyl or aryl, R ⁷ are the same or different, 1 to 8 carbon atoms, preferably 1 to 4 And d represents 2 or 3.

Specific examples of the above mono- or di-alkoxysilane include, for example, methoxytrimethylsilane, methoxytriethylsilane, methoxymethyldiethylsilane, ethoxytrimethylsilane, ethoxytriethylsilane, ethoxytriphenylsilane, propoxytrimethylsilane, propoxy Monoalkoxysilanes such as tripropylsilane and butoxytributylsilane; dimethoxydimethylsilane, dimethoxydiethylsilane, dimethoxydiphenylsilane, diethoxydimethylsilane,
Diethoxydiethylsilane, diethoxydiphenylsilane, dipropoxydimethylsilane, dipropoxydiethylsilane, dipropoxydipropylsilane, dipropoxydiphenylsilane, dibutoxydimethylsilane, dibutoxydiethylsilane, dibutoxydibutylsilane, dibutoxydiphenylsilane And the like. These mono- or di-alkoxysilanes can be used alone or in combination of two or more.

The above-mentioned mono- and / or di-alkoxysilane has the effect of imparting flexibility to the coating film and improving the crack resistance of the coating film.

Epoxy group-containing silane (D) Epoxy group-containing silane which is the component (D)
May be abbreviated as "epoxysilane (C)"]
The following general formula _{^{R 8 R 9 n Si (OR}} 10) in _(3-n) wherein the monovalent organic group R ⁸ is containing an epoxy radical, n pieces of R ⁹ may be the same or different, 1 to carbon atoms 8, preferably 1 to 4 alkyl groups, R ¹⁰ being the same or different,
A hydrogen atom or an alkyl group having 1 to 8 carbon atoms, preferably 1
Represents an alkyl group of from 4 to 4, and n represents an integer of from 0 to 2.

Specific examples of the epoxysilane (D) include, for example, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, and γ-glycidoxyethyltriethoxysilane.
Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl (methyl) dimethoxysilane, γ-glycidoxypropyl (dimethyl) methoxysilane, γ-glycidoxypropyl (ethyl ) Dimethoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. These epoxy group-containing alkoxysilanes can be used alone or in combination of two or more.

The above-mentioned polysiloxane (A), alkyltrialkoxysilane and / or condensate thereof (B), mono- and / or di-alkoxysilane (C) and epoxysilane (D) are subjected to a condensation reaction. Thereby, a condensation reaction product can be produced.

The above-mentioned condensation reaction product is, for example, the above-mentioned polysiloxane (A), alkyltrialkoxysilane and / or its condensate (B), mono- and / or di-alkoxysilane (C) and epoxysilane (D) Is heated in the presence of a reaction catalyst and water without removing the alcohol from the reaction system to convert a part of the alkoxy group bonded to Si into a hydroxyl group (silanol group) bonded to Si and partially condense After forming a siloxane bond, that is, after hydrolysis and partial condensation, the product can be produced by heating to cause a condensation reaction while removing the alcohol outside the system.

The condensation reaction product is, for example, a polysiloxane (A) and an alkyl trialkoxysilane and / or
Alternatively, a mixture of the condensate (B) and the mono- and / or di-alkoxysilane (C) is heated in advance in the presence of a reaction catalyst and water without removing the alcohol from the reaction system, thereby obtaining (A) After converting a part of the alkoxyl group bonded to Si in the components (B) and (C) into a hydroxyl group (silanol group) bonded to Si and partially condensing to form a siloxane bond, After decomposition and partial condensation, the product can also be produced by adding epoxysilane (D) to the product and subjecting it to a condensation reaction while heating to remove distillates such as alcohol from the system.

In the above reaction, the reaction conditions are not particularly limited, but the reaction is carried out without removing the alcohol from the reaction system in the presence of a reaction catalyst and water without removing the alcohols (A), (B) and (C). ) And, if necessary, converting a part of the alkoxy group bonded to Si in the component (D) into a hydroxyl group (silanol group) bonded to Si and partially condensing to form a siloxane bond, ie, hydrolysis. In the case of partial condensation, the mixture is usually stirred at room temperature to 100 ° C. for 5 minutes to 24 hours, particularly at 40 to 80 ° C. for 10 minutes to 12 hours without removing the alcohol.
1 hour to 24 hours while removing alcohol and the like generated by the reaction at 0 to 300 ° C. (preferably 80 ° C. to 250 ° C.).
It is preferable to carry out the condensation reaction for a time.

In producing the above condensation reaction product, the above polysiloxane (A), alkyl trialkoxysilane and / or its condensate (B), mono- and / or di-alkoxysilane (C) and epoxy silane (D )) Are as follows. The amount of the alkyl trialkoxysilane and / or the condensate thereof (B) is 0 to 100 parts by weight of the polysiloxane (A).
It is preferably 200 parts by weight, particularly from 0 to 100 parts by weight, from the viewpoint of room temperature curability, adhesion of the obtained coating film, and coating film hardness. The amount of the mono- and / or di-alkoxysilane (C) is 0.1 to 200 parts by weight, particularly 1.0 to 1 part by weight, based on 100 parts by weight of the polysiloxane (A).
The amount within the range of 00 parts by weight is preferable from the viewpoints of room temperature curability, adhesion of the obtained coating film, cracking resistance, and coating film hardness.

The compounding amount of the epoxysilane (D) is as follows:
Based on a total of 100 parts by weight of polysiloxane (A), alkyl trialkoxysilane and / or condensate (B) thereof, and mono- and / or di-alkoxysilane (C),
It is preferably from 0.1 to 200 parts by weight, particularly from 1 to 100 parts by weight, from the viewpoint of room temperature curability, pot life and adhesion of the coating film.

As a reaction catalyst in the above condensation reaction,
Metal alkoxide compounds, metal chelate compounds, metal ester compounds, inorganic acids, organic acids, basic compounds and the like are used.

Examples of the metal alkoxide compound include aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, and aluminum tri-n-oxide.
Butoxide, aluminum triisobutoxide, aluminum trisec-butoxide, aluminum tritert-
Aluminum alkoxides such as butoxide; tetramethyl titanate, tetraethyl titanate, tetra-n-
Propyl titanate, tetraisopropyl titanate,
Titanium alkoxide such as tetra n-butyl titanate, tetraisobutyl titanate, tetra tert-butyl titanate, tetra n-hexyl titanate, tetraisooctyl titanate, tetra n-lauryl titanate; tetraethyl zirconate, tetra n-propyl zirconate, tetraisopropyl Zirconate, tetra n-butyl zirconate, tetra sec-butyl zirconate, tetra tert-butyl zirconate, tetra n-pentyl zirconate, tetra tert-pentyl zirconate, tetra tert-hexyl zirconate, tetra n-heptyl zirconate Zirconium alkoxides such as tert., Tetra n-octyl zirconate and tetra n-stearyl zirconate; dibutyltin dibutoxide; and the like. For example, tris (ethylacetoacetate) aluminum, tris (n-propylacetoacetate) aluminum, tris (isopropylacetoacetate) aluminum, tris (n)
-Butylacetoacetate) aluminum, isopropoxybis (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, tris (proponylacetonato) aluminum, diisopropoxypropionylacetonatoaluminum, acetylacetonatobis (propionylacetone) Nato) aluminum,
Monoethyl acetoacetate bis (acetylacetonato) aluminum, acetylacetonatoaluminum
Aluminum chelate compounds such as di-sec-butylate, methyl acetoacetate aluminum di-tert-butylate, bis (acetylacetonato) aluminum mono-sec butyrate, di (methyl acetoacetate) aluminum mono-tert-butylate; diisopropoxy bis (Ethyl acetoacetate) titanate, diisopropoxy bis (acetylacetonato) titanate,
Titanium chelate compounds such as di-n-butoxybis (acetylacetonato) titanate; zirconium chelate compounds such as tetrakis (acetylacetonato) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; dibutyl Examples of the metal ester compound include dibutyltin diacetate, dibutyltin di (2-ethylhexylate), dibenzyltin di (2-ethylhexylate), and dibutyltin. Tin ester compounds such as tin dilaurate and dibutyltin diisooctyl maleate;

Examples of the inorganic acid include nitric acid, hydrochloric acid, phosphoric acid, and halogenated silane, and examples of the organic acid include acetic acid,
Examples include formic acid, propionic acid, maleic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, glutaric acid, glycolic acid, maleic acid, toluenesulfonic acid, oxalic acid, and the like. As the basic compound, ammonia, methylamine, ethylamine, propylamine,
Butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine and the like.

These reaction catalysts can be used alone or in combination of two or more.

The amount of the reaction catalyst used is (A), (B),
It is usually preferred that the amount be in the range of 0.0001 to 5 parts by weight based on 100 parts by weight of the total of the components (C) and (D). The amount of water is usually in the range of 0.02 to 1.0 mol based on 1 equivalent of the alkoxysilyl group in the total of the components (A), (B), (C) and (D). It is preferred that there be.

The above condensation reaction product has an epoxy equivalent of 300
5,000, especially 500-4,000, and a weight average molecular weight (polystyrene conversion) of 1,000-400,
000, especially in the range of 2,000 to 200,000, and in the infrared absorption spectrum, the absorbance ratio of [absorption based on silanol group (around 3400 cm ⁻¹ ) / absorption based on siloxane (around 1080 cm ⁻¹ )] 0.05
Hereinafter, desirably 0.03 or less is preferable from the viewpoint of pigment dispersion stability.

Photocatalytically active titanium oxide [II] The photocatalytically active titanium oxide contained in the inorganic coating composition of the present invention can be used without particular limitation as long as it has photocatalytic activity. Titanium dioxide can be mentioned. Suitable commercial products of anatase-type titanium dioxide include, for example, ST-01, ST-21, ST-31, manufactured by Ishihara Techno Co., Ltd.
AMT600 and the like can be mentioned.

The photocatalytically active titanium oxide is excited by absorbing ultraviolet light such as sunlight or artificial illumination light, for example, ultraviolet light having a wavelength of 400 nm or less, preferably light having a wavelength of 285 nm to 380 nm. It generates OH radicals, which have a strong oxidizing effect, and also have antibacterial properties due to this oxidizing effect.

By this strong oxidizing action, pollutants in the air can be decomposed. For example, nitrogen oxides in the air can be oxidized to be converted to nitric acid, or chemically converted to nitrogen or water. Also, sulfur oxides in the air can be oxidized and changed to sulfuric acid. Further, the alkoxysilyl group based on the condensation reaction product [I] and the alkyl silicate to be blended as necessary and the alkoxysilyl group of the condensate are changed to silanol groups to hydrophilize the coating film surface to thereby prevent exposure contamination resistance. Can be improved.

In the paint of the present invention, the blending amount of the above-mentioned photocatalytically active titanium oxide is 100% of the total solid content of the inorganic paint of the present invention.
It is preferably 5 to 90 parts by weight, and more preferably 30 to 30 parts by weight.
More preferably, it is in the range of 80 parts by weight.

The inorganic coating composition of the present invention contains the condensation reaction product [I] as a binder component, and usually further contains a curing agent. Typical examples of the curing agent include amino group-containing alkoxysilanes. Specific examples thereof include N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and
Examples thereof include N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. These compounds can be used alone or in combination of two or more.

In the inorganic coating composition of the present invention, the mixing ratio of the curing agent is not particularly limited, but when an amino group-containing alkoxysilane is used as the curing agent, the condensation reaction product [I] and the amino group The ratio of the number of equivalents of the active hydrogen of the amino group / the number of equivalents of the epoxy group in the dealcoholization condensation reaction product [I] is 0.1 to 3.0, particularly 0.3. It is preferable that the ratio be in the range of from 2.0 to 2.0 in terms of the curability of the obtained paint and the pot life.

In addition to the condensation reaction product [I], the photocatalytically active titanium oxide, and the curing agent optionally added, the inorganic coating material of the present invention further comprises, if necessary, a curing catalyst; iron oxide, titanium oxide. Pigments such as carbon black, cyanine blue, cyanine green and quinacridone red; extender pigments such as calcium carbonate, talc, clay, silica, barium sulfate and mica; organic solvents; fluidity regulators used in the paint industry; Other additives can be contained.

The curing catalyst promotes a curing reaction between the dealcoholization condensation product [I] and a curing agent such as an amino group-containing alkoxysilane. Specific examples of the curing catalyst include sodium hydroxide. Alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid; organic acids such as acetic acid and paratoluenesulfonic acid; tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide Ammonium salts such as dibutylamine-2-hexoate, dimethylamine acetate and ethanolamine acetate; quaternary ammonium salts of carboxylic acids such as tetramethylammonium acetate; butylamine, octylamine, triethylenediamine , T-butylamid Alkoxides, aluminum chelates; organic titanium compounds such as tetraisopropyl titanate, tetrabutyl titanate, titanium tetraacetylacetonate; organic acid tin ester compounds such as dibutyltin diacetate and dibutyltin dilaurate Imidazole derivatives such as imidazole, 1-methylimidazole, 2-methylimidazole and 4-methylimidazole; piperidine, piperazine, pyrrolidine and the like; and potassium fluoride, sodium fluoride, tetrabutylammonium fluoride, benzyltrimethylammonium fluoride Ride can be mentioned. These curing catalysts can be used alone or in combination of two or more.

When the curing catalyst is blended, the amount of the curing catalyst is usually 0.0001 to 5 based on 100 parts by weight of the total of the dealcoholization condensation reaction product [I] and the curing agent.
It is preferably in the range of parts by weight.

Next, a method for forming a photocatalytically active coating film of the present invention will be described. The method for forming the photocatalytically active coating film of the present invention includes the following three embodiments. (1) As a first embodiment, a photocatalyst for coating an inorganic paint capable of forming the photocatalytically active coating film of the present invention on an object to be coated (hereinafter, may be abbreviated as “photocatalytically active inorganic paint”). A method for forming an active coating. (2) As a second embodiment, an inorganic lower layer coating film containing no photocatalytically active titanium oxide is formed on the object to be coated, and the above-mentioned photocatalytically active inorganic coating material of the present invention is coated on the inorganic lower layer coating film. Of forming a photocatalytically active coating film. (3) As a third embodiment, a colored organic coating film is formed on an object to be coated, and an inorganic coating film containing no photocatalytically active titanium oxide is formed on the colored organic coating film. A method for forming a photocatalytically active coating film on which the above-mentioned photocatalytically active inorganic coating material of the present invention is applied.

In the first, second and third aspects,
Metal substrates such as iron, aluminum, stainless steel, galvanized steel sheet, zinc alloy-plated steel sheet (steel plated with an alloy such as iron-zinc, nickel-zinc, and aluminum-zinc), and tin plate; Plastic substrate;
Inorganic ceramic substrates such as glass, cement, slate, mortar, concrete, and tile; and the like; paper; and coated substrates obtained by coating these substrates with a coating film.

In the first embodiment, the object to be coated is
Since the photocatalytically active inorganic paint of the present invention is applied directly, the object to be coated is hardly deteriorated by the oxidizing action of the photocatalytically active titanium oxide, for example, concrete, an inorganic base material such as mortar, or photocatalytically active. It is preferable that the inorganic paint contains a coloring pigment in an amount sufficient for hiding, so that ultraviolet rays do not reach the vicinity of the object to be coated.

In any of the first, second and third embodiments, the method of applying the photocatalytically active inorganic coating material of the present invention is not particularly limited. The coating can be performed using an air spray coating, an airless spray coating, a roll coater, a flow coater, or the like, and the coating film thickness is not particularly limited, but is usually 5 to 60 μm (dry film thickness). Within the range is desirable. The photocatalytically active inorganic paint of the present invention,
Although it can be cured at room temperature, it may be forcibly dried or cured by heating.

In the second embodiment, an inorganic lower-layer coating film containing no photocatalytically active titanium oxide is formed on an object to be coated. By forming the inorganic lower layer coating film, it is possible to suppress or block the adverse effect on the object due to the oxidizing action of the photocatalytically active titanium oxide in the inorganic coating material of the present invention applied on the coating film.

As the coating for forming the inorganic lower layer coating film, known inorganic coatings, such as alkyl silicate condensate and silicone resin coating, can be used. Examples of the inorganic paint include a condensation reaction product [I] in the inorganic paint and, if necessary, a curing agent. These may be colored paints containing a color pigment or clear paints containing no color pigment. The thickness of the inorganic lower coating film is not particularly limited, but is usually 3 to
It is desirable to be within the range of 30 μm (dry film thickness). The photocatalytically active inorganic coating material of the present invention is applied on the inorganic lower coating film.

In the third embodiment, the colored organic coating film formed on the object to be coated is for the purpose of sealing the surface of the object to be coated, making the surface uniform, improving the aesthetics by coloring, and the like. As a paint for forming the colored organic coating film (hereinafter, may be abbreviated as “colored organic resin paint”), a paint containing a conventionally known organic resin-based paint resin and a color pigment as essential components is used. be able to. As the above-mentioned colored organic resin paint, an epoxy resin paint and an acrylic silicone paint are particularly preferable.

Examples of the epoxy resin-based paint include epoxy resin-based paints known per se as sealers and primers, and typical examples thereof include epoxy-amine resin-based paints and epoxy urethane resin-based paints. And the like.

As the acrylic silicone paint, (1)
Polymer of a monomer mixture comprising an alkoxysilyl group-containing polymerizable unsaturated monomer or polysiloxane macromonomer such as γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, and other polymerizable unsaturated monomers ;
(2) A paint containing, as a resin component, a condensation polymer obtained by subjecting an alkoxysilyl group-containing organopolysiloxane and a hydroxyl group-containing acrylic resin to a dealcoholization reaction. The acrylic silicone-based paint may contain, for example, a curing agent such as a polyisocyanate compound.

The above-mentioned colored organic resin paint contains, in addition to the binder component and the colored pigment, organic solvents, extenders, pigments such as rust-preventive pigments, curing catalysts, paint additives such as coating surface adjusters and anti-sagging agents. Can be contained.

The above organic solvent can be used without any particular limitation as long as it can dissolve or disperse the resin in the colored organic resin coating material. It is necessary that when the colored organic resin paint is applied over the old coating film, lifting of the old coating film does not occur, and therefore, an aliphatic hydrocarbon solvent and a boiling point of 150 ° C. or more are required. It is preferable that the solvent contains at least 95% by weight of a hydrocarbon solvent selected from high-boiling aromatic hydrocarbon solvents, based on the total amount of the organic solvent in the undercoat paint.

Specific examples of the above-mentioned aliphatic hydrocarbon solvents and high-boiling aromatic hydrocarbon solvents include, for example, VM & P
Naphtha, Mineral Spirit, Solvent Kerosene, Aromatic Naphtha, Solvent Naphtha, Solvesso 100, Solvesso 150, Solvesso 200 [“Solvesso” is a registered trademark of Esso Oil Co., Ltd.], Swazol 310, Swazol 1000, Swazol 1500 [“Swazol” is Cosmo Aliphatic or aromatic hydrocarbons having a relatively low dissolving power, such as n-butane, n-hexane, n-heptane, n-octane, isononane, n-decane, n-dodecane And aliphatic hydrocarbons such as cyclopentane, cyclohexane and cyclobutane. In this case, the organic solvent in the colored organic resin paint is most preferably all aliphatic hydrocarbon solvents or high-boiling aromatic hydrocarbon solvents, but among the organic solvents, aliphatic hydrocarbon solvents and It may contain 5% or less, preferably 3% or less of other organic solvents other than the high-boiling aromatic hydrocarbon solvent. When the amount of the other organic solvent increases, lifting of the old coating film easily occurs at the time of recoating.

The above-mentioned colored organic resin paint is dried after application to form a colored organic coating film. The coating film thickness is not particularly limited, but is usually preferably in the range of 20 to 100 μm (dry film thickness), and the drying conditions are appropriately determined according to the type of the paint and the like. It can be set, and can be cured by drying at room temperature, drying by heating, light curing and the like.

In the third embodiment, an inorganic coating film containing no photocatalytically active titanium oxide is formed on the colored organic coating film formed on the substrate. By forming the inorganic coating film, it is possible to suppress or block the adverse effects on the colored organic coating film due to the oxidizing action of the photocatalytically active titanium oxide in the inorganic coating material of the present invention applied on the coating film.

As the inorganic coating material for forming the inorganic coating film, the same coating material as the coating material for forming the inorganic lower coating film used in the second embodiment can be used. The thickness of the inorganic coating film is not particularly limited, but is usually preferably in the range of 3 to 30 μm (dry film thickness). In the third embodiment, the photocatalytically active inorganic paint of the present invention is applied on the inorganic paint film.

According to the method of the present invention, it is possible to form a coating film having excellent photocatalytic activity and excellent coating film appearance, coating film properties, weather resistance, etc. on the substrate.

[0064]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments. In the following, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively, unless otherwise specified.

Production Example 1 Production of Condensation Reaction Product Liquid (a) "DC3074" (manufactured by Dow Corning Toray Silicone Co., Ltd., alkylarylalkoxysilane) was placed in a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a distilling tube. Oligomer, phenyl group content (about 1 equivalent of organic group, the same applies hereinafter) about 50 equivalent%, methoxy group content about 17%,
(Weight average molecular weight about 1600) 100 parts, "XR31B-
1410 "(manufactured by Toshiba Silicone Co., Ltd., partial condensate of alkyl trialkoxysilane, methoxy group content of about 45 to 45)
50 parts by weight, weight average molecular weight of about 500), 40 parts of trimethylmethoxysilane, 20 parts of γ-glycidoxypropylmethyldimethoxysilane, 0.2 parts of diisopropoxybisacetylacetonato titanium, and 10 parts of methyl alcohol. After the temperature was raised to 60 ° C., a mixture of 10 parts of water and 0.8 part of a dimethylamine solution was added dropwise, and the mixture was stirred at 60 ° C. for 2 hours. Thereafter, the mixture was heated to 130 ° C. while removing the distilling solvent, and stirring was continued at the same temperature for 6 hours to produce a condensation reaction liquid (a). The condensation reaction liquid (a) has a nonvolatile content of 9
1%, the weight average molecular weight was about 12,000, and the epoxy equivalent was 2,200. In addition, the infrared absorption spectrum (I
In R), the ratio of the absorbance of the absorption of silanol (absorption at 3400 cm ^-1 ) / the absorption of siloxane (absorption at 1080 cm ^-1 ) was 0.01.

Production Example 2 Production of Condensation Reaction Liquid (b) In a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a distilling tube, 100 parts of “DC3074” (described above) and “XR3
1B1410 "(described above), 20 parts of methyltrimethoxysilane, 50 parts of dimethyldimethoxysilane, 50 parts of γ-glycidoxypropylmethyldimethoxysilane, 0.2 parts of diisopropoxybisacetylacetonato titanium,
After 10 parts of isopropyl alcohol was charged and the temperature was raised to 50 ° C., a mixture of 8 parts of water and 0.8 part of a dimethylamine solution was added dropwise, and the mixture was stirred at 60 ° C. for 2 hours. Thereafter, the mixture was heated to 120 ° C. while removing the distilling solvent, and stirring was continued at the same temperature for 3 hours to produce a condensation reaction liquid (b). The condensation reaction liquid (b) has a nonvolatile content of 89% and a weight average molecular weight of about 6,7.
00, the epoxy equivalent was 1200. In addition, in the infrared absorption spectrum (IR), the absorption of silanol (34
Absorbance of siloxane / absorbance (10 cm- ¹ )
The absorbance ratio (absorption at 80 cm ^-1 ) was 0.02.

Production Example 3 Production of Condensation Reaction Liquid (c) In a reaction vessel equipped with a thermometer, thermostat, stirrer, and rectification tube, 100 parts of “DC3074” (described above), 30 parts of xylene, and “SH6018” ( 15 parts of a silanol group-containing alkylarylpolysiloxane (manufactured by Dow Corning Toray Silicone Co., Ltd.) and stirred at 50 ° C.
6018 ", 30 parts of γ-glycidoxypropylmethyldimethoxysilane, dimethyldimethoxysilane 1
5 parts, 10 parts of methyl alcohol, 0.3 part of diisopropoxybisacetylacetonato titanium and 5.5 parts of water were charged, and stirring was continued at 70 ° C. for 6 hours. Thereafter, the temperature was raised to about 150 ° C. while removing the distilling solvent, and the temperature was gradually raised and heating was continued so that the solvent vapor temperature of the rectification tube was maintained at 60 ° C. to 70 ° C. When the solvent distilled at 70 ° C. or less disappeared, heating was stopped to produce a condensation reaction liquid (c). The condensation reaction product liquid (c) has a nonvolatile content of 82%, a weight average molecular weight of about 28,000, an epoxy equivalent of 1,100, and absorbance of silanol (absorption of 3400 cm ^-1 ) / absorbance of siloxane (absorption of siloxane). The absorbance ratio (at 1080 cm ^-1 ) was 0.01.

Production Example 4 Production of Inorganic White Paint (A) 109.9 parts of the condensation reaction liquid (a) having a nonvolatile content of 91% obtained in Production Example 1 was added to "Taipek CR-93" (manufactured by Ishihara Sangyo Co., Ltd.). , Brand name, titanium white) 100 parts and toluene 2
0 parts were added and mixed, and pigment was dispersed using a paint shaker to obtain a paint base (A-1). Separately, 3.0 parts of γ-aminopropyltriethoxysilane and 0.1 part of dibutyltin diacetate were mixed to obtain a coating curing agent (C). Immediately before painting, the paint base (A
-1) 229.9 parts and 3.1 parts of the above-mentioned curing agent for paint (C) were mixed to prepare an inorganic white paint (A), which was used for coating. The inorganic white paint (A) had good coloring properties.

Production Example 5 Production of Inorganic Clear Paint (B) 209.9 parts of toluene was added to 109.9 parts of the alcohol-free condensation reaction liquid (a) having a non-volatile content of 91% obtained in Production Example 1 above, and mixed. A paint base (B) was obtained. Immediately before coating, 129.9 parts of the clear paint base (B) and 3.1 parts of the paint curing agent (C) obtained in Production Example 1 were mixed to obtain an inorganic clear paint (B).

Example 1 Photocatalytically active inorganic paint (D)
AMT600 (trade name, manufactured by Teica Co., Ltd., anatase-type titanium oxide having photocatalytic activity) was added to 109.9 parts of the alcohol-free condensation reaction liquid (a) having a nonvolatile content of 92% obtained in Production Example 1 above. 500 parts and 5,000 parts of toluene were added and mixed, and pigment was dispersed using a paint shaker to obtain a base (D-1) for a photocatalytically active paint. Immediately before coating, the base for photocatalytically active paint (D-1) 5,60
9.9 parts and 3.1 parts of the curing agent (C) obtained in Production Example 1 were mixed to obtain a photocatalytically active inorganic paint (D).

Example 2 Photocatalytically active inorganic paint (E)
Production of "AMT600" 500 in 112.4 parts of the dealcoholation condensation reaction liquid (b) having a nonvolatile content of 89% obtained in Production Example 2 above
Parts and 5,000 parts of toluene were added and mixed, and pigment was dispersed using a paint shaker to obtain a base (E-1) for a photocatalytically active paint. Immediately before coating, 5,612.4 parts of the base for photocatalytically active paint (E-1) and 3.1 parts of the curing agent (C) obtained in Production Example 1 were mixed to prepare a photocatalytically active inorganic paint (E). I got

Example 3 Production of Photocatalytically Active Inorganic Topcoat (F) 109.9 parts of a dealcoholization condensation reaction liquid (a) having a non-volatile content of 91% obtained in Production Example 1 was added to "Taipek CR-9".
3 "100 parts," AMT600 "50 parts and toluene 3
0 parts were added and mixed, and the pigment was dispersed using a paint shaker to obtain a base (F-1) for a photocatalytically active paint.
Immediately before coating, the base (F-
1) 289.9 parts of curing agent (C) obtained in Production Example 1 3.1
And the resulting mixture were mixed to obtain a photocatalytically active inorganic topcoat paint (F).

Example 4 Preparation of Photocatalytically Active Inorganic Topcoat (G) 112.4 parts of the alcohol-free condensation reaction liquid (b) having a non-volatile content of 89% obtained in Preparation Example 2 was added to “Taipec CR-9”.
3 "100 parts," AMT600 "50 parts and toluene 3
0 parts were added and mixed, and pigment was dispersed using a paint shaker to obtain a base (G-1) for a photocatalytically active paint.
Immediately before coating, the photocatalytically active topcoat base (G-
1) 292.4 parts and curing agent (C) 3.1 obtained in Production Example 1
And the resulting mixture were mixed to obtain a photocatalytically active inorganic top coat (G).

Example 5 Production of Photocatalytically Active Inorganic Topcoat (H) 122.0 parts of a dealcoholization-condensation reaction liquid (c) having a nonvolatile content of 82% obtained in Production Example 3 was added to “Taipek CR-9”.
3 "100 parts," AMT600 "50 parts and toluene 3
0 parts were added and mixed, and the pigment was dispersed using a paint shaker to obtain a base (H-1) for a photocatalytically active paint.
Immediately before coating, the base for photocatalytically active topcoat paint (H-
1) 302.0 parts of curing agent (C) obtained in Production Example 1 3.1
And the resulting mixture were mixed to obtain a photocatalytically active inorganic topcoat paint (H).

Comparative Example 1 Production of fluororesin-based photocatalytically active topcoat (I) (for comparison) "Lumiflon LF-200" (trade name, Asahi Glass Co., Ltd.)
Fluorine resin solution, solid content 60%) 100 parts of "Typek CR-93" and "AMT600" in 166.7 parts
50 parts and 30 parts of toluene were added and mixed, and pigment was dispersed using a paint shaker to obtain a fluororesin-based photocatalytically active topcoat paint (I). Immediately before coating, 346.7 parts of the fluororesin-based photocatalytically active topcoat paint base (I-1) and a curing agent "Duranate TPA-100" (trade name, manufactured by Asahi Kasei Corporation, isocyanurate of hexamethylene diisocyanate) 30 parts) to obtain a fluororesin-based photocatalytically active topcoat paint (I).

Example 6 Newly-installed specification A multi-tile concrete primer EPO (trade name, manufactured by Kansai Paint Co., trade name, epoxy-amine resin base coat) was coated on a mortar board having a size of 150 × 70 × 20 mm at a rate of 120 g / m ² , and brushed in a room at a temperature of 20 ° C. and a humidity of 65% RH.
After drying in the sun, the inorganic white paint (A) obtained in Production Example 4 above
Was applied to give a coating amount (paint weight) of 100 g / m ² , dried in a room at a temperature of 20 ° C. and a humidity of 65% RH for 1 day, and then the photocatalytically active inorganic paint obtained in Example 1 was obtained. (D) was applied in a room at a temperature of 20 ° C. and a relative humidity of 65% RH with a brush so as to give a coating amount (paint weight) of 10 g / m ^2.
After drying for days, a coated plate was obtained.

Example 7 New specification The procedure of Example 6 was repeated, except that the photocatalytically active inorganic paint (E) obtained in Example 2 was used instead of the photocatalytically active inorganic paint (D). A painted plate was obtained.

Example 8 Newly installed specification 120 g of “multi-tile concrete primer EPO” was placed on a mortar board having a size of 150 × 70 × 20 mm.
/ M ^{2 with} a coating amount (paint weight),
After drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for 1 day, “Alesletan” (manufactured by Kansai Paint Co., Ltd., trade name, acrylic urethane resin paint, white) was applied, and the temperature was 20 ° C.
It was dried for 1 day in a room having a humidity of 65% RH. Then, on this, 40 g of the inorganic clear paint (B) obtained in Production Example 5 was added.
/ M ^{2 with} a coating amount (paint weight),
After drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for one day, the photocatalytically active inorganic paint (D) obtained in Example 1 was 10 g / m ^2.
Brushing temperature 20 so that the coating amount (paint weight)
The coated plate was dried in a room at a temperature of 65 ° C. and a relative humidity of 65% for 10 days.

Example 9 Newly installed specifications 120 g of “multi-tile concrete primer EPO” was placed on a mortar board having a size of 150 × 70 × 20 mm.
/ M ^{2 with} a coating amount (paint weight),
After drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for one day, 100 g of the photocatalytically active inorganic top coat (F) obtained in Example 3 was obtained.
/ M ^{2 with} a coating amount (paint weight),
The coated plate was dried for 10 days in a room at a temperature of 20 ° C. and a humidity of 65% RH.

Example 10 Newly established specification Same as Example 9 except that the photocatalytically active inorganic top coat (G) obtained in Example 4 was used instead of the photocatalytically active inorganic top coat (F). And a coated plate was obtained.

Example 11 New specification Same as Example 9 except that the photocatalytically active inorganic top coat (H) obtained in Example 5 was used instead of the photocatalytically active inorganic top coat (F). And a coated plate was obtained.

Example 12 Coating on Old Coating Film As a top coating, “Alesflon” (manufactured by Kansai Paint Co., Ltd.)
A coated plate having a surface coated with a coating film (trade name, fluororesin-based overcoating material) was baked for one year at a bakery field in Okinoerabu, Okinawa. The inorganic clear paint (B) was brushed to a coating amount (paint weight) of 40 g / m ² , dried in a room at a temperature of 20 ° C. and a humidity of 65% RH for 1 day, and obtained in Example 1. The photocatalytically active inorganic paint (D) was brushed to a coating amount (paint weight) of 10 g / m ² at a temperature of 20 ° C. and a humidity of 65%.
The coated plate was dried by drying in a room of RH for 10 days.

Example 13 Repainting Specifications As a topcoat, "Alesletan" (manufactured by Kansai Paint Co., Ltd.)
Product name, acrylic urethane resin-based top coating) is coated on the surface of a coated plate that has been baked for three years at a bakery in Okinoerabu, Okinawa Prefecture. Primer EPO 12
After brushing to a coating amount (paint weight) of 0 g / m ² and drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for one day,
100 g of the inorganic white paint (A) obtained in Production Example 4
/ M ^{2 with} a coating amount (paint weight),
After drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for one day, the photocatalytically active inorganic paint (D) obtained in Example 1 was dried for 10 days.
It was brush-coated so as to have a coating amount (paint weight) of g / m ² and dried in a room at a temperature of 20 ° C. and a humidity of 65% RH for 10 days to obtain a coated plate.

Example 14 Recoating Specifications A coating film of “SD Super Marine Topcoat” (manufactured by Kansai Paint Co., Ltd., trade name, long-oil phthalic acid resin-based topcoat, JIS K5516 type 2 compatible product) was applied to the surface as a topcoat. Escomild NB (manufactured by Kansai Paint Co., Ltd., trade name, weak solvent type epoxy resin) system coating) the coating with the amount of 120 g / m ² (brushed so that paint weight), the temperature 20 ° C., after 1 day drying at room RH 65% humidity, inorganic based white obtained in preparation example 4 The paint (A) was applied with a brush so as to give a coating amount (paint weight) of 100 g / m ² , and the temperature was 20 ° C. and the humidity was 6
After drying in a room at 5% RH for 1 day, the photocatalytically active inorganic paint (D) obtained in Example 1 was brushed to a coating amount (paint weight) of 10 g / m ² at a temperature of 20 ° C. and humidity. 65% R
H was dried in a room for 10 days to obtain a coated plate.

Comparative Example 2 In Example 6, without applying the photocatalytically active inorganic paint (D) obtained in Example 1, the inorganic white paint (A) obtained in Production Example 4 was applied, and then the temperature was increased to 20 ° C. A coated plate was obtained in the same manner as in Example 6, except that drying was performed in a room at a temperature of 65 ° C and a relative humidity of 65% for 10 days. .

Comparative Example 3 The fluororesin-based photocatalytically active topcoat (I) obtained in Comparative Example 1 was applied in place of the photocatalytically active inorganic topcoat (F) in Example 9, and the temperature was 20 ° C. and the humidity was 65% RH. A coated plate was obtained in the same manner as in Example 9 except that drying was performed in the room for 10 days.

In Examples 6, 7, 9, 10 and 11, and Comparative Examples 2 and 3, 150 × 70 × 20 m
A test plate for a NOx oxidation test was prepared in the same manner except that an aluminum plate of 150 × 35 × 0.8 mm was used instead of the mortar plate of m.

The coated plates obtained in the above Examples 6 to 14 and Comparative Examples 2 to 3 were subjected to a test of a coated surface state, initial adhesion and weather resistance according to the following test methods. Further, an NOx oxidation test was performed on the test plate for NOx oxidation test. The results of these tests are shown in Table 1 below.

Test Method Painted surface condition: The coated surface of the coated plate was visually observed, and the
Evaluations were made for abnormalities such as cracks, peeling, discoloration, and chalking.

Adhesion: JIS K5400 8.5.
2 (1990), according to the grid-tape method,
Six parallel and vertical knife wounds reaching the substrate were made on the coating surface of the coated plate, and 25 squares of 2 mm x 2 mm were created. A cellophane pressure-sensitive adhesive tape was adhered to the grid, and was instantaneously peeled off, and the ratio of the number of cells remaining without peeling out of the 25 cells was described.

Weather resistance: The coated plate was subjected to an outdoor backwash test for 3 months at an outdoor backpack shop at the Kansai Paint Co., Ltd. Tokyo office located in Ota-ku, Tokyo. With respect to the coating film after the backwash test, the coated surface condition, the adhesion, and the lightness difference ΔL between the coating film before the backwash test and the coating film after the backwash test were determined. Regarding the state of the coated surface and the adhesion, a test was conducted in the same manner as in the case of the initial coating film of the coated plate. Further, regarding the lightness difference ΔL,
3 using "CR-300" (Minolta, colorimeter)
The locations were measured and their average values were taken.

NOx Oxidation Test: Two NOx oxidation test plates (coating area 105 cm ² ) were set in a closed container having a capacity of 6.8 liters, and the NOx concentration (initial concentration) was 3%.
ppm after filling with NOx-containing air.
The coating surface of the test plate for x oxidation test was irradiated with black light (UV intensity 200 μW) for 60 minutes. The gas in the container was circulated at a rate of 3 liters / minute, and the gas in the container was sampled a total of six times every 10 minutes after the start of black light irradiation to measure the NOx concentration. The measured values were plotted to determine a reaction rate constant k of the following formula. As the test plate for the NOx oxidation test, an initial test plate and a test plate three months after the backlash subjected to the weather resistance test were used.

C = C ₀ exp (−kst) In the above equation, C: NOx concentration (mol / liter) C ₀ : NOx initial concentration (mol / liter) k: reaction rate constant (liter / m ² · min) s : Area of coating part of test plate (m ² ) t: Time (minute)

[0094]

[Table 1]

[0095]

The inorganic paint capable of forming the photocatalytically active coating film of the present invention does not deteriorate due to the oxidizing action of the photocatalytically active titanium oxide, and has oxidation resistance, weather resistance, impact resistance, and coating adhesion. The coating film performance is good and can withstand long-term use, and the decomposability of pollutants such as nitrogen oxides in the air,
It is a paint that can form a coating film having excellent exposure stain resistance and antibacterial properties, can be dried at room temperature or relatively low temperature, and has good pigment dispersibility.

Further, the photocatalytically active coating film is formed on the object to be coated by the method for forming a photocatalytically active film (first embodiment) in which the above-mentioned inorganic paint capable of forming the photocatalytically active film is formed on the object to be coated. can do.

Further, a photocatalyst in which an inorganic lower coating film containing no photocatalytically active titanium oxide is formed on an object to be coated, and an inorganic coating material capable of forming the photocatalytically active coating film is coated on the inorganic lower coating film. According to the method for forming the active coating film (second embodiment), even when the object to be coated is easily degraded by the oxidizing action of the photocatalytically active titanium oxide, there is no problem of deterioration by the photocatalytically active titanium oxide, photocatalytic activity, coating appearance, A coated article having excellent coating film performance can be obtained.

Further, a colored organic coating film is formed on the object to be coated,
A photocatalytically active coating that forms an inorganic coating containing no photocatalytically active titanium oxide on the colored organic coating, and coats the inorganic coating capable of forming the photocatalytically active coating on the inorganic coating. The photocatalytically active, arbitrarily colored coating has no problem of deterioration by the photocatalytically active titanium oxide even when the object to be coated is easily degraded by the oxidizing action of the photocatalytically active titanium oxide by the method of forming (third embodiment). A coated article excellent in appearance and coating film performance can be obtained. In the forming method of the third aspect of the present invention, by using a weak solvent type epoxy resin-based paint or acrylic silicone-based paint as the colored organic film-forming paint, it is applied on the deteriorated old paint film. Also, there is no abnormality such as shrinkage at the time of coating, and an inorganic overcoating film having excellent coating surface appearance and coating film performance can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 183/04 C09D 183/06 183/06 B01D 53/36 J F-term (Reference) 4D048 AA06 AB01 AB03 BA07X BA41X BB03 CA06 CC40 CC41 CD10 EA01 4D075 CA45 DA06 DB01 DC02 DC05 EA02 EA05 EA06 EB42 EC02 4G069 AA03 BA04A BA04B BA48A CA01 CA03 CA07 CA10 CA12 CA13 EA07 FA03 FB23 FC05 4J038 DL031 GA07 GA09 GA08 KA03 KA03 PC03 PC04 PC08 PC10

Claims (7)

[Claims] 1. A [I] (A) the following rational formula ^{_{R 1 a R 2 b (R}} 3 O) c SiO (4-abc) / ₂ wherein, R ¹ represents an alkyl group having 1 to 8 carbon atoms, R ² represents an aryl group, R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, a is 0.1 ≦ a ≦ 2.0, and b is 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
And the weight average molecular weight is in the range of 500 to 6,000, and the alkoxyl group content is in the range of 0 to 30% by weight based on the polysiloxane. and alkylaryl polysiloxane 100 parts by weight, (B) the following general formula R ⁴ Si (oR ⁵⁾ ₃ wherein, R ⁴ and R ⁵ are the same or different, represents an alkyl group having 1 to 8 carbon atoms, in illustrated condensates 0-200 parts by weight of alkyltrialkoxysilane and / or the alkyltrialkoxysilane and, (C) the following general formula R ⁶ _d Si (oR ⁷⁾ in _(4-d) formula is, R ⁶ are the same or Differently represents an alkyl group or aryl having 1 to 8 carbon atoms, R ⁷ is the same or different and represents an alkyl group having 1 to 8 carbon atoms, and d represents 2 or 3, mono- and / or Or di-alkoxy 0.1 to 200 parts by weight of silane, the alkylarylpolysiloxane (A), the alkyltrialkoxysilane and / or
Alternatively, based on a total of 100 parts by weight of the condensate (B) of the alkyltrialkoxysilane and the mono- and / or di-alkoxysilane (C), (D) the following general formula: R ⁸ R ⁹ _n Si (OR ¹⁰ ) In the formula _(3-n) , R ⁸ is a monovalent organic group containing an epoxy group, n R ⁹ are the same or different, and are an alkyl group having 1 to 8 carbon atoms;
R ¹⁰ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 0 to 2;
An inorganic paint capable of forming a photocatalytically active coating film, comprising: a condensation reaction product with 0.1 to 200 parts by weight of an epoxy group-containing silane represented by the formula: and [II] a photocatalytically active titanium oxide. 2. The inorganic paint contains an amino group-containing alkoxysilane with respect to 1 equivalent of epoxy group of the condensation reaction product in such an amount that the active hydrogen of the amino group is 0.1 to 3.0 equivalent. The inorganic paint according to claim 1, wherein the paint is an inorganic paint. 3. The inorganic paint according to claim 1, further comprising a color pigment. 4. A method for forming a photocatalytically active coating film, comprising applying the inorganic coating material capable of forming the photocatalytically active coating film according to claim 1 on an object to be coated. 5. The photocatalytic activity according to any one of claims 1 to 3, wherein an inorganic lower layer coating containing no photocatalytically active titanium oxide is formed on the substrate, and the inorganic lower layer coating is formed on the inorganic lower layer coating. A method for forming a photocatalytically active coating film, comprising applying an inorganic paint capable of forming a coating film. 6. A colored organic coating film is formed on an object to be coated, an inorganic coating film containing no photocatalytically active titanium oxide is formed on the colored organic coating film, and a colored organic coating film is formed on the inorganic coating film. Item 1
4. A method for forming a photocatalytically active coating film, comprising applying the inorganic paint capable of forming the photocatalytically active coating film according to any one of 3. 7. The method for forming a photocatalytically active coating film according to claim 6, wherein the colored organic coating film is an epoxy resin-based coating film or an acrylic silicone resin-based coating film containing a color pigment.