JP2001089141A - Coating agent for forming inorganic film, method of producing the same and method of forming the same inorganic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating agent for forming an inorganic film capable of providing a titanium oxide film excellent in photoactivity, antimicrobial properties, hydrophilicity, fouling resistance, antifogging properties, gas decomposing properties, deodorizing properties, water treating properties, energy conversion properties, decoloring properties, etc. SOLUTION: This coating agent for forming an inorganic film is obtained by reacting a titanium monomer containing a group capable of hydrolyzing and providing hydroxyl group in the presence of a titanium oxide sol and/or its low condensate with aqueous hydrogen peroxide. The titanium monomer containing the group capable of hydrolyzing and providing the hydroxyl group is represented by the general formula Ti(OR)4 (Rs are each same or different and denote each a 1-5C alkyl group). The degree of condensation of the low condensate is 2-30. The mixing ratio of the titanium monomer containing the group capable of hydrolyzing and providing the hydroxyl group and/or its low condensate to the aqueous hydrogen peroxide is within the range of 0.1-100 pts.wt. of the aqueous hydrogen peroxide expressed in terms of hydrogen peroxide based on 10 pts.wt. of the titanium monomer and/or its low condensate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photoactive, antibacterial, hydrophilic, stain resistant, antifogging, gas decomposable, deodorant,
The present invention relates to a coating material for forming an inorganic film, a method for producing a coating material for forming an inorganic film, and a method for forming an inorganic film, which provide a titanium oxide film having excellent water treatment properties, energy conversion properties, and decolorization properties.

[0002]

2. Description of the Related Art Conventionally, methods for forming a titanium oxide film include (1) a method in which a titanium oxide sol is applied to a substrate and then sintering, and (2) an aqueous solution of titanium chloride or titanium sulfate. (3) Plasma spraying method in which solid particles are melted in plasma generated in the atmosphere and beat on the substrate surface, (4) Sputtering of oxide target in vacuum (5) CVD method for evaporating organometallic compounds and decomposing in an electric furnace to form a film on the substrate, (6) CVD method for forming a film on the substrate
The sol obtained by hydrolysis of a metal alkoxide is applied to a substrate, and then sintering is performed.

However, in the above method,
(1) When the film thickness is 0.1 μm or more, cracking and peeling occur, resulting in inferior film-forming properties. Further, sintering must be performed at a temperature of several hundred degrees or more, which is troublesome. (3) the inability to form a dense film, poor adhesion to the substrate, (4) and (5) In the case of (1), a good film cannot be obtained unless the pressure is reduced, and a reaction vessel capable of evacuating is required. Generally, the film forming speed is low, and in order to obtain a dense film, the substrate must be heated to several hundred degrees or more. That is, the acid, alkali or organic substance is added to the sol of (6), and there is a problem of corrosion of the material to be coated.
℃ or more).

[0004] Further, as a method not including the high-temperature sintering step, which is the above-mentioned disadvantage, (7) forming a titanium oxide film from an aqueous solution of titanium oxide fluoride and boric acid, (8) an aqueous solution of titanium chloride or titanium sulfate. Titanium hydroxide gel is precipitated from an alkaline solution such as ammonia and caustic soda, and then separated by decantation to obtain a titanium hydroxide gel. Etc. are known. However, (7) requires a long time to form a film, the handling of fluoride is troublesome, (8) the process is complicated, and removal of alkali salts is troublesome. There are drawbacks such as difficulty in obtaining a high-purity product due to the incorporation of other metals, difficulty in controlling PH, and variations in the product obtained due to the fluctuation.

An object of the present invention is to provide a coating agent for forming an inorganic film, which solves the above problems, a method for producing the same, and a method for forming an inorganic film.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above-mentioned object, and as a result, in particular, a titanium monomer containing a group which becomes a hydroxyl group by hydrolysis in the presence of a titanium oxide sol; The present invention has found that an inorganic film-forming coating agent obtained by reacting a low-condensate thereof with aqueous hydrogen peroxide and an inorganic film-forming coating agent obtained by heating and denaturing the inorganic film eliminate all of the conventional disadvantages. Was completed. That is, the present invention relates to an inorganic material obtained by reacting a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis and / or a low-condensate thereof with hydrogen peroxide in the presence of a titanium oxide sol. An inorganic material characterized by reacting a coating agent for forming a film, a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis and / or a low condensate thereof with a hydrogen peroxide solution at a reaction temperature of 1 to 70 ° C. A method for producing a film-forming coating material, an inorganic film-forming coating material obtained by heat-modifying the inorganic film-forming coating material, and a substrate coated or impregnated with the inorganic film-forming coating material, followed by drying or heat treatment. The present invention relates to a method for forming an inorganic film, which is obtained by being formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The coating agent for forming an inorganic film according to the present invention comprises a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis in the presence of a titanium oxide sol, and / or a low-condensation product thereof. And obtained by reacting

In the titanium oxide sol used in the present invention, fine particles of amorphous titania or anatase titania are contained in water (if necessary, for example, may contain an aqueous organic solvent such as an alcoholic or alcoholic ether). It is a dispersed sol.

As the above-mentioned titanium oxide sol, a conventionally known one can be used. Examples of the titanium oxide sol include (1) those obtained by hydrolyzing a titanium-containing solution such as titanium sulfate or titanyl sulfate;
Titanium oxide aggregates such as those obtained by hydrolyzing an organic titanium compound such as titanium alkoxide and (3) those obtained by hydrolyzing or neutralizing a titanium halide solution such as titanium tetrachloride are dispersed in water. Amorphous titania sol or anatase type titanium fine particles obtained by firing the titanium oxide aggregates and dispersing them in water can be used. Amorphous titania can be converted to anatase-type titania by firing at a temperature at least equal to or higher than the crystallization temperature of anatase, for example, at a temperature of 400 to 500 ° C. or higher. As an aqueous sol of the titanium oxide, for example, TKS-201 (manufactured by Teica Corporation,
Trade name, anatase type crystal form, average particle diameter 6nm), T
A-15 (manufactured by Nissan Chemical Industries, Ltd., trade name, anatase type crystal form), STS-11 (manufactured by Ishihara Sangyo Co., Ltd., trade name, anatase type crystal form) and the like.

The weight ratio of the titanium oxide sol to the titanium hydrogen peroxide reactant when used for reacting the titanium monomer or its condensate with aqueous hydrogen peroxide is from 1/99 to
99/1, preferably in the range of about 10/90 to 90/10. When the weight ratio is less than 1/99, the effect of adding titanium oxide sol such as stability and photoreactivity is not seen, and 99/99
If it exceeds 1, the film-forming property is inferior, which is not preferable.

As the titanium monomer containing a group that becomes a hydroxyl group by hydrolysis, particularly, a titanium monomer represented by the general formula: Ti (OR) ₄
(Wherein R is the same or different and represents an alkyl group having 1 to 5 carbon atoms).
Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,
n-butyl group, iso-butyl group, sec-butyl group,
and a tert-butyl group.

The low-condensation product of a titanium monomer containing a group which becomes a hydroxyl group by hydrolysis is, in particular, a condensation degree of 2 obtained by subjecting the above-mentioned Ti (OR) ₄ to a condensation reaction with each other.
Compounds having a condensation degree of 2 to 30 can be used, and those having a condensation degree of 2 to 10 are particularly preferable. The mixing ratio between a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis and / or a low condensate thereof (hereinafter, these are simply referred to as “hydrolysable titanium”) and a hydrogen peroxide solution, 0.1 to 10 parts by weight of titanium oxide
100 parts by weight, preferably in the range of 1 to 20 parts by weight. If the amount is less than 0.1 part by weight in terms of hydrogen peroxide, chelate formation is not sufficient and cloudy precipitation occurs. On the other hand, 100
Exceeding the weight part is not preferable because unreacted hydrogen peroxide tends to remain and releases dangerous active oxygen during storage.

The concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is not particularly limited, but is preferably in the range of 3 to 30% by weight in view of the ease of handling and the solid content of the product liquid related to coating workability. The coating material for forming an inorganic film of the present invention can be produced by reacting hydrolyzable titanium with aqueous hydrogen peroxide at a reaction temperature of 1 to 70 ° C for 10 minutes to 20 hours.

In the coating material for forming an inorganic film of the present invention, the hydrolyzable titanium is reacted with aqueous hydrogen peroxide, whereby the hydrolyzable titanium is hydrolyzed with water to form a hydroxyl-containing titanium compound. It is presumed that hydrogen oxide is coordinated to the generated hydroxyl-containing titanium compound, and the hydrolysis reaction and the coordination by hydrogen peroxide occur at the same time, resulting in extremely stable stability at room temperature. Produces a chelating solution that is highly resistant to long-term storage. The titanium hydroxide gel used in the conventional production method is partially three-dimensionalized by Ti-O-Ti bonds, and is essentially different in composition and stability from a product obtained by reacting this gel with a hydrogen peroxide solution. Further, if titanium oxide sol is added in advance, it is possible to prevent a partial condensation reaction from taking place during the synthesis to increase the viscosity. It is considered that the reason for this is that the condensation reaction product is adsorbed on the surface of the titanium oxide sol, thereby preventing polymerization in a solution state. A dense titanium oxide film having excellent adhesion can be formed by applying the inorganic film-forming coating agent of the present invention on a substrate and drying or heating at a low temperature. Although a titanium oxide film can be formed even at a low temperature, a processing temperature of 200 ° C. or more is preferable for improving the adhesion. In addition, a film having excellent adhesion can be formed without peeling a titanium oxide film having a thickness of 1 μm or more by one coating, but the film thickness is usually
The range is preferably from 0.001 to 10 μm, particularly preferably from 0.1 to 1 μm. The coating material for forming an inorganic film of the present invention forms a film containing amorphous titanium oxide slightly containing a hydroxyl group at a temperature lower than 200 ° C., but forms a crystalline dense titanium oxide film at a temperature of 200 ° C. or higher. .

When the amount of the titanium oxide sol is large, a crystalline titanium oxide film can be formed only by coating, so that it is useful as a coating material of a material that cannot be subjected to heat treatment. In such a method, a material having a relatively high density and good adhesion at a low temperature can be used for the above-mentioned various applications. The film that has just been dried is water-resistant, but also impregnating.By impregnating with another compound solution and then heat-treating, a complex is formed in which the titanium oxide film carries or disperses other substances. It is also possible. As other substances, for example, other metal compounds can be used.

It is also possible to add and disperse other pigments or sols to the above-mentioned coating material for forming an inorganic film later. Examples of the additive include commercially available titanium oxide sol and titanium oxide powder.

As the substrate that can be used in the present invention, for example, any material that can withstand heat treatment according to the intended use, such as metal, ceramics, plastics, fiber, glass, concrete, etc., can be applied. Surface treatment of the inside of the porous body and the powder can also be performed. Many of the titanium oxide films obtained according to the present invention are activated by light irradiation. For example, nitrogen oxides or the like can be oxidized and changed to nitric acid. Further, the titanium oxide film obtained by the present invention can form a film having excellent heat resistance and corrosion resistance in addition to the property of photoactivity, and thus can be used as a heat and corrosion protection coating.

Utilizing the photoactive properties of titanium oxide as described above, for example, decomposing and removing environmental pollutants of air and water, hydrophilizing treatment, antibacterial treatment, deodorizing, antifogging, water treatment, energy It can be used in fields such as conversion.

[0019]

EXAMPLES Next, the present invention will be described in detail with reference to examples. The present invention is not limited to the embodiments described below. In addition, "part" and "%" described in Examples and Comparative Examples
Is based on weight. Example 1 A mixture of 10 parts of tetra-iso-propoxytitanium and 10 parts of iso-propanol was mixed with TKS-201 (Taika Co., Ltd.).
10% in a mixture of 5 parts (solid content), 10 parts of 30% hydrogen peroxide solution and 100 parts of deionized water.
For 1 hour with stirring. Thereafter, the mixture was aged at 10 ° C. for 24 hours to obtain a yellow transparent and slightly viscous coating material for forming an inorganic film.

Example 2 A coating agent for forming an inorganic film was obtained under the same conditions as in Preparation Example 1 except that tetra-n-butoxytitanium was used instead of tetra-iso-propoxytitanium.

Example 3 A coating solution for forming an inorganic film was obtained under the same production conditions as in Example 1 except that the tetraiso-propoxytitanium trimer was used instead of the tetraiso-propoxytitanium trimer.

Example 4 The same procedure as in Example 1 was carried out except that the amount of hydrogen peroxide was
The mixture was added dropwise over a period of time, and then aged at 10 ° C. for 30 hours to obtain a coating agent for forming an inorganic film.

COMPARATIVE EXAMPLE 1 A mixture of 10 parts of tetra-iso-propoxytitanium and 10 parts of iso-propanol was mixed with 10 parts of 30% hydrogen peroxide solution,
The mixture was added dropwise to a mixture of 100 parts of deionized water at 10 ° C. over 1 hour with stirring. Thereafter, the mixture was aged at 10 ° C. for 24 hours to obtain a yellow transparent and slightly viscous coating material for forming an inorganic film.
When the coating liquids for forming an inorganic film of Examples 1 to 4 and Comparative Example 1 were concentrated to 5% in titanium oxide concentration, Comparative Example 1 was solidified in a glue state, whereas Production Examples 1 to 4 were liquids having fluidity. Was.

The coating film was formed by the following method. The dry film thickness of the coating material for forming an inorganic film of Examples 1 to 4 and the coating material for forming an inorganic film of Comparative Example 1 was reduced to 0.3 with a bar coater.
It was coated to a thickness of μm and baked at 100 ° C. for 30 minutes. Storage stability of the inorganic film-forming coating materials of Examples 1 to 4 and the inorganic film-forming coating material of Comparative Example 1 (1) and the state of the coating film (2) using the coated plate formed under the above conditions, adhesion Tests (3), pencil hardness (4), water resistance (5), and water wettability (water contact angle) (6) were performed. The results are shown in Table 1.

[0025]

[Table 1]

(1) Storage stability: Changes in viscosity, sedimentation, and the like after storage at 50 ° C. for 100 hours were examined (compared with the initial ones). (2) State of coating film: The presence or absence of coating film abnormality such as smoothness, transparency, and film forming property (such as cracking) of the coating film was observed. (3) Adhesion: JIS K-5400 8.5.2 (1
990) According to the grid-tape method, 100 squares of 1 mm x 1 mm were formed, and the number of squares remaining when the tape was adhered to the surface and peeled was examined. (4) Pencil hardness: JIS K-5400 8.4.2
A pencil scratch test specified in (1990) was performed, and evaluation was performed by scratching. (5) Water resistance: After dipping in water at 20 ° C. for 7 days, the appearance of the coating film was visually observed. (6) Water wettability: The water contact angle on the coating film surface was measured. 4K
After irradiation with a W high-pressure mercury lamp at a distance of 30 cm from the coating film surface for 10 minutes, the water contact angle was measured. At a water contact angle of 20 ° C., a water droplet of 0.03 cc of deionized water was formed on the test coated plate, and the contact angle of the water droplet was adjusted by Kyowa Chemical Co., Ltd.
It was measured with a DCCA model.

[0027]

Effect of the Invention In the production method of the present invention, a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis in the presence of a titanium oxide sol and / or a low condensate thereof is reacted with a hydrogen peroxide solution, The components of the titanium monomer and / or its low-condensate are adsorbed on the titanium oxide sol particles of the titanium oxide sol, and the adsorbed titanium monomer and / or its low-condensate condense on the particle surface to react with hydroxyl groups on the particle surface. In addition to chemically bonding to the titanium monomer and / or its low-condensate, the titanium monomer and / or its low-condensate itself also undergoes a condensation reaction on the particle surface and is polymerized, so that there is no gelation or thickening, and it is stable. In addition, a coating agent (titanium sol liquid) having excellent coating film performance can be manufactured without manufacturing variation. Naturally, titanium oxide sol alone is inferior in film-forming properties,
Even if a titanium hydrogen peroxide complex is added later, the compatibility is low and the film forming property is not so improved. Further, in the production method of the present invention, only the titanium hydrogen peroxide complex formed by the reaction of the titanium monomer and / or its low-condensate with the aqueous hydrogen peroxide forms only amorphous titanium oxide when the coating film is dried at a low temperature. However, when anatase-type titanium oxide sol is used as the sol, it functions as a photocatalyst even when the coating film is dried at a low temperature. This can be used in fields such as anticorrosion properties and in fields utilizing the photocatalytic activity of the titanium oxide film.

Claims (16)

[Claims] 1. An inorganic film obtained by reacting a titanium monomer containing a group that becomes a hydroxyl group by hydrolysis and / or a low-condensate thereof with hydrogen peroxide in the presence of a titanium oxide sol. Forming coating agent. 2. The titanium monomer containing a group that becomes a hydroxyl group by hydrolysis is represented by the general formula Ti (OR) ₄ (wherein R is the same or different and represents an alkyl group having 1 to 5 carbon atoms). The coating agent for forming an inorganic film according to claim 1, wherein 3. The coating material for forming an inorganic film according to claim 1, wherein the low-condensate has a degree of condensation of 2 to 30. 4. A mixing ratio of a titanium monomer containing a group which becomes a hydroxyl group by hydrolysis and / or a low condensate thereof to an aqueous hydrogen peroxide is based on 10 parts by weight of the titanium monomer and / or a low condensate thereof. 0.1-100 in terms of hydrogen peroxide
4. The method according to claim 1, wherein the amount is within a range of parts by weight.
The coating material for forming an inorganic film according to any one of the above. 5. A method for producing a coating agent for forming an inorganic film, comprising adding a titanium monomer having a group which becomes a hydroxyl group by hydrolysis in a hydrogen peroxide solution and / or a low condensate thereof. 6. A method for forming an inorganic film, which is obtained by applying or impregnating a coating material for forming an inorganic film according to claim 1 onto a substrate, followed by drying or heat treatment. 7. When the titanium oxide sol according to claim 1 is an anatase type, it is active against light obtained by applying or impregnating a coating material for forming an inorganic film on a base material, and drying or heat-treating the coating material. A method for forming an inorganic film, characterized in that the film is a simple film. 8. When the titanium oxide sol according to claim 1 is an anatase type, it has excellent antibacterial properties obtained by coating or impregnating a coating material for forming an inorganic film on a substrate, and drying or heating to form the coating material. A method for forming an inorganic film, which is a film. 9. When the titanium oxide sol according to claim 1 is an anatase type, it has excellent hydrophilicity obtained by coating or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film, which is a film. 10. When the titanium oxide sol according to claim 1 is of an anatase type, the inorganic film-forming coating agent is coated or impregnated on a substrate and dried or heated to form an excellent stain resistance. A method for forming an inorganic film, comprising: 11. When the titanium oxide sol according to claim 1 is of an anatase type, the inorganic film-forming coating agent is excellent in anti-fogging property obtained by coating or impregnating the substrate with a coating or impregnating the coating and drying or heating. A method for forming an inorganic film, comprising: 12. When the titanium oxide sol of claim 1 is of an anatase type, a gas-decomposable film obtained by applying or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film, the method comprising: 13. When the titanium oxide sol according to claim 1 is of an anatase type, it is excellent in deodorization obtained by applying or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film, which is a film. 14. When the titanium oxide sol according to claim 1 is of an anatase type, it is excellent in water treatment obtained by applying or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film, which is a film. 15. When the titanium oxide sol of claim 1 is an anatase type, it is an energy conversion film obtained by applying or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film. 16. When the titanium oxide sol according to claim 1 is an anatase type, it has excellent decoloring properties obtained by applying or impregnating a coating material for forming an inorganic film on a base material and drying or heating to form the coating material. A method for forming an inorganic film, which is a film.