Method of coating of non-crystal titanium peroxide

Coating method of amorphous titanium peroxide

[Detailed Description of the Invention]

The present invention relates to a coating method for a substrate of amorphous titanium peroxide, in particular to a coating method for a viscous amorphous titanium peroxide substrate with excellent adhesion even if the surface has a water-repellent substrate , And, a substrate with a thin layer of photocatalyst semiconductor or dielectric or conductive ceramic using the viscous amorphous titanium peroxide as a binder.

In the method of coating a photocatalyst semiconductor or dielectric or conductive ceramic material on a substrate, the conventional techniques include sputtering, vapor deposition, and high-temperature sintering by transfer printing film.

In the method of fixing photocatalyst semiconductors, it is known to add various organic binders or silica gels to perform thermal processing (Japanese Patent Laid-Open No. 7-171408). In addition, the binder uses glaze, inorganic glass, and thermoplastic Resin, soldering rod, etc. are also known (Japanese Patent Application Publication No. 7-232080), SnO₂A method of fixing to a substrate for use as a coagulating material is also known (Japanese Patent Laid-Open No. 7-155598).

However, the sputtering method or the evaporation method has a very high cost of coating equipment. The transfer printing method must consider the thermal stress imposed on the substrate according to the thermal processing conditions, and the selection of materials is limited.

In addition, in the method of fixing by using a photocatalyst semiconductor, a dielectric or a conductive ceramic material as a binder, when the surface has a water-repellent matrix, the surface of the matrix must be pretreated with a surfactant or caustic solution. Furthermore, it is difficult for particles of these photocatalyst semiconductors, dielectrics, and conductive ceramics to be coated with various binders to sufficiently exert redox effects, or dielectric and conductive effects.

In addition, in JP 7-286114 A, titanium peroxide has described a coating liquid for forming a film composed of a polymer of titanic acid peroxide, namely, polytitanic acid peroxide. This peroxide polytitanic acid is added with hydrogen peroxide in the gel, sol or mixed dispersion of titanium oxide hydrate, and heated at room temperature or below 90°C (Example 1 is heated at 80°C for 1 hour ) The getter.

In addition, viscous liquids or even jelly-like ones in which an aqueous solution of titanium hydrogen peroxide is condensed are also known (Japanese Patent Laid-Open No. 62-252319). This is to add hydrogen peroxide aqueous solution to the fine powder of titanium hydroxide to obtain a yellow titanium peroxide aqueous solution, which is placed at room temperature, the evaporation of water and the condensation of the solute slowly progress, and a yellow film can be obtained.

However, the peroxypolytitanic acid described in the above-mentioned Japanese Patent Application Publication No. 7-286114 is a gel, sol or mixed dispersion of titanium oxide hydrate with hydrogen peroxide added and heated at room temperature or below 90°C. In addition, compared with the "Viscous Amorphous Titanium Peroxide" obtained by adding hydrogen peroxide to titanium oxide hydrate and reacting at 15°C or less, not only its manufacturing method is different, but also its physical properties are different. Especially the viscosity is very different, the function of the adhesive is poor, and the formation of the thin layer of the photocatalyst semiconductor or the dielectric and the conductive ceramic material is difficult.

In addition, a viscous liquid or even a jelly-like solution obtained by condensing the aqueous solution of titanium hydrogen peroxide described in JP-A 62-252319 is to add an aqueous solution of hydrogen peroxide to the fine powder of titanium hydride, and borrow from the yellow aqueous solution of titanium peroxide. A yellow film can be obtained by evaporation of water. In addition, it is compared with the "viscous amorphous titanium peroxide" in this case where hydrogen peroxide is added to titanium oxide hydrate and reacted below 15°C to produce a viscous jelly-like substance. Not only the manufacturing method is different, but also the physical properties are different. As described in the aforementioned JP 7-286114 (column 2), it is stable only at extremely thin concentrations and does not exist in a stable state for a long period of time. The film formed on the substrate is prone to cracks and peeling, and when it is fired at a high temperature, the film after firing will become porous.

<p>The subject of the present invention is to provide a coating material, even if the surface has a water-repellent matrix or a matrix with thermoplasticity, it does not need to be treated with a surfactant or the like for hydrophilicity, and the thermoplasticity of the matrix is unlimited; in addition, it provides a film forming In this way, the formation and thickness management of thin layers of photocatalyst semiconductors, dielectrics, and conductive ceramic materials are easy, and the photocatalyst semiconductors, etc. are not covered by adhesives.</p>

<p>In order to solve the above-mentioned problems, the inventors of the present invention, as a result of their deliberate research, fixed viscous amorphous titanium peroxide on the substrate as an adhesive layer, and made the photocatalyst semiconductor and dielectric The fine particles of ceramics or conductive ceramics adhere to the amorphous titanium peroxide layer in a uniformly dispersed state in the gas; in addition, the viscous amorphous titanium peroxide is fixed to the substrate and heated and fired to form a photocatalyst The titanium oxide layer has finally completed the present invention.</p><p>That is, the present invention relates to a method of fixing an amorphous titanium peroxide layer to a substrate or a substrate having an amorphous titanium peroxide layer prepared by this method, characterized in that: the amorphous titanium peroxide is coated Sol, or do not perform hydrophilic treatment on the surface of the substrate with a surfactant or the like, but coat viscous amorphous titanium peroxide, and then dry and sinter at room temperature to 250°C or less.</p><p>In addition, regarding a method of fixing a titanium oxide layer to a substrate, or a substrate having a titanium peroxide layer prepared by this method, it is characterized in that it is coated with an amorphous titanium peroxide sol, or is not interface-active The surface of the substrate is treated with a hydrophilic agent and the like is coated with viscous amorphous titanium peroxide, and then dried and fired at a temperature of 250°C or higher.</p><p>Furthermore, regarding a method for fixing a thin layer of photocatalyst semiconductor, dielectric ceramic or conductive ceramic, it is characterized in that: the substrate is coated with amorphous titanium peroxide sol, or the surface of the substrate is not hydrophilic with surfactants. Treatment, and coating viscous amorphous titanium peroxide to form an amorphous titanium peroxide layer. When the amorphous titanium peroxide layer has adhesion, make the photocatalyst semiconductor, dielectric ceramic or conductive ceramic The fine particles are attached to the amorphous titanium peroxide layer in a uniformly dispersed state in the gas; or in relation to an amorphous titanium peroxide layer formed on the substrate by this method, and the amorphous titanium peroxide layer formed on the substrate. A substrate composed of a thin layer of photocatalyst semiconductor, dielectric ceramic or conductive ceramic on the titanium oxide layer.</p><p>It further relates to a manufacturing method of viscous amorphous titanium peroxide, which is characterized in that: after the titanium tetrachloride solution and the ammonium hydroxide solution are reacted in the acidic region of pH 2~6, the light blue and white of the precipitate is washed Orth-titanic acid is then diluted or concentrated to adjust the solid content concentration to 0.2~0.6% by weight of the aqueous solution, adding hydrogen peroxide water, at low temperature, preferably below 15°C, more preferably about 5°C~8°C The reaction is carried out while stirring on the next side, and then the cultivation is carried out at room temperature; and regarding a viscous amorphous titanium peroxide produced by this method.</p>

The "amorphous titanium peroxide sol" in the present invention can be manufactured as follows. Yuru Titanium Tetrachloride TiCl₄Add alkali hydroxides such as ammonia or sodium hydroxide to the titanium salt aqueous solution, and react at pH 6~7. The light blue-white, amorphous titanium hydroxide Ti(OH)₄(Also known as orthotitanate H₄TiO₄) After washing and separation, it is treated with an aqueous hydrogen peroxide solution to obtain an amorphous titanium peroxide sol.

The thus-obtained "amorphous titanium peroxide sol" of the present invention has a particle diameter of 8-20 nm at pH 6-7, and its appearance is a yellow transparent liquid, and it is stable even if stored for a long period of time at room temperature. In addition, the concentration of the sol is usually adjusted to 1.4~1.6% by weight, but the concentration can be adjusted as needed. When using at a low concentration, dilute it with distilled water or the like.

In addition, this amorphous titanium peroxide sol is in an amorphous state at room temperature and has not yet been crystallized into conicite-type titanium oxide, and can be made into a thin film with excellent adhesion, high film formation, and uniform flatness, and, The dry film is insoluble in water.

In addition, if the amorphous titanium peroxide sol is heated above 100°C for several hours, it will form a cone-type titanium oxide sol. After the amorphous titanium peroxide sol is coated on the substrate, it is dried and fixed at 250°C. Heating at ~940°C can form conical titanium oxide.

The "viscous amorphous titanium peroxide" in the present invention can be produced, for example, as follows. Yuru Titanium Tetrachloride TiCl₄In the titanium salt aqueous solution 0.3 to 1.5% by weight, 1.0 to 5.0% by weight of alkali hydroxides such as ammonia or sodium hydroxide are added, and the reaction is at pH 2 to 6, especially pH 2 in an acidic pH region. The precipitated light blue-white, amorphous titanium hydroxide Ti(OH)₄(Also known as orthotitanate H₄TiO₄) After washing and separating, treat with aqueous hydrogen peroxide solution at a low temperature, preferably below 15°C, particularly preferably at 5~8°C while stirring and reacting, then incubate at room temperature for 7~10 days. By.

The thus obtained "viscous amorphous titanium peroxide" of the present invention has a particle diameter of 8-20 nm at pH 2 to 4, and its appearance is a yellow, transparent, slightly viscous sol ~ semi-jelly-like, that is, it has It has a variety of stickiness, and has strong adhesion, and it is stable even if it is stored for a long period of time at room temperature. In addition, the solid content concentration is usually adjusted to 0.2 to 0.6% by weight, preferably to 0.3% by weight, but the concentration can be adjusted as required.

In the present invention, the "viscous amorphous titanium peroxide" is used in its manufacturing process, such as titanium tetrachloride TiCl₄The pH of the titanium salt aqueous solution and alkali hydroxides such as ammonia or sodium hydroxide is changed in the acidic region, preferably within the range of pH 2~6, and the solid content concentration is 0.2~0.6% by weight For those with various viscosities, various applications can be considered according to their viscosities. However, for the purpose of forming a so-called uniform film thickness, it is preferable to have a uniform semi-jelly-like viscosity.

Then, if the pH of the above reaction exceeds 6, an amorphous titanium peroxide sol with less viscosity will be formed. When it is coated on the surface of a substrate such as metal and plastic with strong water repellency, it must be treated with a surface active agent for hydrophilicity. , If the pH is below 2, the precipitation of orthotitanic acid will be extremely low.

In addition, if the solid content concentration exceeds 0.6% by weight, it will become an inhomogeneous semi-jelly shape, causing difficulty in the formation of a uniform film thickness. In addition, if it is less than 0.2% by weight, it must be interfacially active when coated on the surface of the substrate. Agents, etc. are subjected to hydrophilic treatment.

In this way, the viscous amorphous titanium peroxide of the present invention is a novel yellow, transparent, and viscous substance. It is in an amorphous state at room temperature and has not been crystallized into ocherite-type titanium oxide. Its adhesion and adhesion It is excellent in all kinds of substrates with water-repellent substrates. In addition, it can be easily formed into a uniform and flat film with high film-forming properties, and the dry film has the property of being insoluble in water.

Then, the viscous amorphous titanium peroxide is coated on the substrate and dried and fired at room temperature to 250°C to form an amorphous titanium peroxide layer with strong adhesion. In addition, if it is heated and dried and fired at 250°C to 940°C, a conicite-type titanium oxide layer will be formed, and if heated above 940°C, a rutile-type titanium oxide layer will be formed, and the function of the photocatalyst will be greatly reduced.

In the present invention, the "substrate" can use inorganic materials such as ceramics and glass, organic materials such as plastic, rubber, wood, paper, and metal materials such as aluminum and steel. Among these, it is especially suitable for organic polymer resins such as acrylonitrile resin, vinyl chloride resin, polycarbonate resin, methyl methacrylate resin (acrylic resin), polyester resin, polyurethane resin, etc. The material can exert excellent effects.

In addition, the size or shape is not limited, and it may be in the form of a film, honeycomb, fiber, filter plate, bead, foam, or the like. Furthermore, if it is a substrate that passes ultraviolet rays, it can be applied to its inner surface, and it can also be applied to coated articles.

When coating amorphous titanium peroxide sol or viscous amorphous titanium peroxide on the substrate, known methods such as dipping and spraying can be used.

After coating or spraying as described above, it is dried and fired at 250°C or lower to cure it, and a substrate with the amorphous titanium peroxide layer of the present invention can be manufactured.

In addition, after immersion, sintering is carried out at about 250°C to 400°C, and a solidified substrate supporting the conicite-type titanium oxide layer can also be manufactured. Since such a substrate has a photocatalyst function, it uses organic polymer resins that are easily decomposed by photocatalysts, high-performance engineering plastics such as polytetrafluoroethylene (PTFE), or super heat-resistant engineering plastics such as polyamide imine (PAI) or When polyimide (PI) is used as a substrate, the photocatalyst function of titanium oxide is reduced by sodium ions, pre-coated, and the surface of the resin is cleaned with a substance containing sodium ions such as sodium hydroxide solution, etc. The existence of the source is beneficial.

A coating composition composed of amorphous titanium peroxide sol or viscous amorphous titanium peroxide has a characteristic system that can be applied to a predetermined thickness once. Then, the thickness of the titanium peroxide layer formed by coating or the thickness of the titanium oxide layer obtained by heating and firing at 250°C or higher can also be adjusted by viscous amorphous titanium peroxide, etc. The concentration of titanium oxide (weight%), viscosity and coating thickness before drying can be adjusted.

In addition, if necessary, the coating material may be overlapped and applied.

The substrate with the above-mentioned amorphous titanium peroxide layer has excellent weather resistance and can protect the substrate composed of polymer organic materials from ultraviolet rays and the like. Moreover, when a photocatalyst semiconductor layer is provided on the substrate, It can protect the matrix of organic polymer materials that are easily decomposed by the light energy of the photocatalyst.

In the present invention, "photocatalyst semiconductor" can be exemplified by TiO₂, ZnO, SrTiO₃, CdS, CdO, CaP, InP, In₂O₃, CaAs, BaTiO₃, K₂NbO₃, Fe₂O₃, Ta₂O₅, WO₃, SaO₂, Bi₂O₃, NiO, Cu₂O, SiC, SiO₂, MoS₂, MoS₃, InPb, RuO₂, CeO₂And so on, but among these are titanium oxide TiO₂Preferably, the photocatalyst semiconductor is in the form of fine particles or fine powder with a diameter of about 0.001 μm to 20 μm.

In addition, Pt, Ag, Rh, RuO can also be used to supplement the photocatalyst function₂, Nb, Cu, Sn, NiO, etc. as additives.

In the present invention, the material of "dielectric ceramic" can be exemplified by SiO₂, Ta₂O₅, TiO₂, SrTiO₃, BaTiO₃, Pb is the Peloguskaite compound.

In addition, the "conductive ceramic" materials may be light metal alloys such as copper, nickel, chromium, titanium, and aluminum.

These ceramic materials are in the form of fine particles or fine powders with a diameter of about 0.001 μm to 20 μm. Such fine powder can float in a uniform and dispersed state in the gas.

In the present invention, if the "method for fixing a thin layer of photocatalyst semiconductor, dielectric ceramic or conductor ceramic" is described according to FIG. 1, the following method can be exemplified: on the substrate 3 which is treated with a surface active agent and the like. Coated with amorphous titanium peroxide sol, or without hydrophilic treatment, and directly coated with viscous amorphous titanium peroxide on the substrate to form an amorphous titanium peroxide layer 2. When the titanium peroxide layer has adhesion properties (usually, after coating, within 1-10 minutes at room temperature), use a closed, atmospheric pressure container to make the above-mentioned photocatalyst semiconductor, dielectric ceramic or conductor ceramic particles 1 in the gas It forms a uniform and scattered state, and adheres to the amorphous titanium peroxide layer by natural adhesion or air pressure adhesion to remove excess fine particles. In addition, after fixing a thin layer of photocatalyst semiconductor, dielectric ceramic or conductive ceramic to the amorphous titanium peroxide layer, the adhesion between the layers is significantly improved by applying pressure. In this way, a homogeneous film can be produced.

By forming such a thin layer of photocatalyst semiconductor, dielectric ceramic, or conductive ceramic, it is possible to achieve small size, light weight, or small capacity of electronic devices, etc. In addition, the photocatalyst functional substrate is a laminated thin film of a photocatalyst semiconductor, and has no effect of reducing the function due to the interference of particles on the surface of particles caused by the movement of electrons during the oxidation and reduction of the photocatalyst semiconductor, or the film thickness causes economic loss.

[Example]

Hereinafter, the present invention will be explained more specifically by giving examples, but the scope of the present invention is not limited to these examples.

Reference example 1 (manufacturing of amorphous titanium peroxide sol)

Titanium Tetrachloride TiCl₄50% solution (Sumitomo<img file="TW349981B_D0002.tif" />Co., Ltd.) 100 ml diluted 70 times with distilled water, and ammonium hydroxide NH₄The 25% OH solution (Takasugi Pharmaceutical Co., Ltd.) was diluted 10 times with distilled water, adjusted to pH 6.5~6.8, and reacted. After the reaction, after leaving it temporarily, discard the supernatant liquid. Add residual Ti(OH)₄The amount of gel is about 4 times the distilled water, stir well and place. Repeated water washing until the conductivity measured with a conductivity meter is 2~10μS, and finally the top solution is discarded and only the sediment is left. Depending on the situation, the thickener can be used for concentration. Here is the pale blue and white Ti(OH)₄3600 Add 210 ml of 35% hydrogen peroxide aqueous solution to ml twice every 30 minutes and stir overnight at about 5°C to obtain about 3800 ml of yellow transparent amorphous titanium peroxide sol.

In addition, in the above steps, if heat generation is not suppressed, substances that may be insoluble in water such as metatitanic acid may be precipitated. Therefore, it is preferable to suppress heat generation in all steps.

Example 1 (manufacturing of viscous amorphous titanium peroxide)

Titanium Tetrachloride TiCl₄50% solution (Sumitomo<img file="TW349981B_D0003.tif" />Co., Ltd.) 100 ml diluted to 70 times with distilled water, and ammonium hydroxide NH₄25% OH solution (Takasugi Pharmaceutical Co., Ltd.) diluted to 10 times with distilled water, mixed, adjusted to pH 2.0, and reacted. After the reaction, after leaving it temporarily, discard the supernatant liquid. Add residual titanate Ti(OH)₄The amount of gel is about 4 times the distilled water, stir well and place. Repeatedly wash with water until the conductivity measured by a conductivity meter is 2~10μS, and finally, discard the supernatant liquid and leave only the sediment. Depending on the situation, the thickener can be used for concentration. Here, light blue and white titanic acid Ti(OH)₄Add 200 ml of 35% hydrogen peroxide aqueous solution twice every 30 minutes to 2550 ml of aqueous solution. After stirring for one night at about 5°C, incubate at room temperature for 7 to 10 days to obtain a yellow, transparent jelly that is viscous and amorphous. Type titanium peroxide is about 2800 ml.

Example 2 (Preparation method of viscous amorphous titanium peroxide with various viscosities)

In Example 1, except that the pH during the reaction was 3, 4, and 5, the rest were the same as in Example 1. As the pH increased, a viscous amorphous titanium peroxide that was higher than that obtained in Example 1 could be obtained. For those who are still hard jelly, the solids concentration gradually increases.

Example 3

Acrylic resin plates, methacrylic resin plates, and methyl methacrylate resin plates are used as substrates. After washing the surface of these resin plates with water, they were dried, and these resin plates were dip-coated with 0.3% by weight of the viscous titanium peroxide prepared in Example 1 once. When the coated surface is in a wet state, in a container, the conicite-type titanium oxide powder ST-01 (manufactured by Ishihara Sangyo Co., Ltd.) is attached in a uniformly floating state, dried at 50°C, and then heated at 200°C under pressure. It is heated and then cleaned to make a photocatalyst semiconductor substrate.

The photocatalyst layer of these substrates is a thin film. Compared with the conventional thick film, there is no risk of peeling off. In addition, the decomposition performance of organic compounds will not change at all, which is very excellent.

Example 4

A half-magnet glazed tile (made by INAX Co., Ltd.: 100x100x5 mm), a ceramic-coated stainless steel plate (210x296x0.8 mm), and a Keramite plate (glazed type: 157x223x4 mm) were used as the substrate. After washing these surfaces and drying them at room temperature, 0.3% by weight of the viscous titanium peroxide produced in Example 1 was applied to the compaction plate, 0.1-0.2 g/piece of semi-magnet glazed tiles, and ceramic coating. Stainless steel plate 2.0~2.3 g/piece, Keramite plate 1.5~1.8 g/piece. When the coated surface is in a wet state, the conicite-type titanium oxide powder ST~01 (Ishihara Sangyo Co., Ltd.) is attached in a uniform gas floating state in a container for 1 minute, and then the conicite-type titanium oxide powder adheres to the half. Ceramic glazed tile 0.01~0.02 g/piece, ceramic coated stainless steel plate 0.1~0.2 g/piece, Keramete plate 0.1 g/piece, then dried at 50°C, and fired at 500°C for 30 minutes to make a photocatalyst semiconductor Substrate.

The photocatalyst function of these substrates is very excellent in terms of cosmetic properties or adhesion.

Example 5

Use polyester non-woven fabric (300x300 mm) as the substrate. After washing the non-woven fabric with water, it was dried, and 0.3% by weight of the viscous titanium peroxide produced in Example 1 was adhered by immersion. Then, the conicite type titanium oxide powder ST~01 (manufactured by Ishihara Sangyo Co., Ltd.) was uniformly floated in a gas State adhered, dried and fixed at 50°C. Of course, this dried product is pressurized with an iron at 120~150°C to further improve the adhesion between the layers.

This substrate is not only excellent in cosmetic properties or adhesion, but also excellent in decomposition performance.

Example 6

The decomposition test of organic substances is carried out as follows. The base system uses Para glass of 210x296 mm in vertical and horizontal (<img file="TW349981B_D0004.tif" />Co., Ltd. methacrylic resin). 0.3% by weight of the viscous titanium peroxide produced in Example 1 was adhered to this substrate by immersion, and then conicite-type titanium oxide powder ST-01 (manufactured by Ishihara Sangyo Co., Ltd.) was adhered in a gas uniformly floating state. Dry and fix at 50°C. Then, the dried product is pressurized with an iron at 120~150°C to further improve the adhesion between the layers. Obtained the photocatalyst media supporting the photocatalyst. Put the light touch media for the test into the test container, and then pour the coloring solution of the decomposed organic substance into the container to a depth of 1 cm. This coloring solution is an aqueous dispersion of mono-azo red (red liquid), namely Polukru Red PM-R (Sumitomo Chemical<img file="TW349981B_D0005.tif" />-Co., Ltd.) diluted to 30 times. Secondly, in order to prevent the coloring solution in the container from evaporating, the container is covered with float glass (wavelength below 300 nm). 5 cm above the test container and 9.5 cm away from the substrate, two ultraviolet emitters (20 W blue fluorescent tubes) are set 13 cm apart from each other, and irradiate them on the above-mentioned photo-contact medium. At the point when the color of the coloring solution disappears, The decomposition of organic matter is terminated. As a result, the color completely disappeared after 2 days from the start of the test, indicating that it has an excellent photocatalyst function.

(Effects of the invention)

Using the viscous amorphous titanium peroxide of the present invention, it is not necessary to apply a hydrophilic treatment to all substrates with surfactants, etc., and an amorphous titanium peroxide layer can be formed, thanks to its excellent adhesion. Fixing the thin layer of photocatalyst semiconductor, dielectric ceramic or conductive ceramic can achieve the miniaturization, weight reduction, or miniaturization of the electronic equipment using them. The photocatalyst functional substrate can eliminate the following effects by the laminated film of the photocatalyst semiconductor: the reduction of function due to the interference of the particle surface caused by the movement of electrons during the oxidation and reduction of the photocatalyst semiconductor or the economic loss caused by the film thickness.

<p>1Particles of photocatalyst semiconductors, dielectric ceramics or conductive ceramics</p><p>2Amorphous titanium peroxide layer</p><p>3Matrix</p>

Figure 1 shows the method of fixing a thin layer of photocatalyst semiconductor, dielectric ceramic or conductive ceramic.