JPH08105178A - Tile with photocatalytic function - Google Patents

Abstract

PURPOSE: To promote light catalytic activity by coating diatom earth or burning pearl rock with aluminum oxide through wet treatment, and coating titanium oxide to obtain oxidizing titanium coating porous powder. CONSTITUTION: Porous powder constituted of diatom earth, burning pearl rock, etc., is dispersed into water, sulfate band is added thereto and is neutralized by means of urea, and aluminum hydroxide is settled to obtain alumina coating porous powder. The alumina coating porous powder is dispersed into water again, titanate is added and dissolved to made hydrolysis, titanium hydroxide is settled, and the porous powder coating titanium hydroxide having light catalytic function is obtained and is fixed to the surface of a tile. Accordingly, the tile having light catalytic function can be molded.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tile having a photocatalytic function. More specifically, the present invention relates to a tile in which a photocatalytic activity per unit area is increased by fixing on a tile a porous powder or granular material whose surface is coated with an inorganic oxide having a photocatalytic function.

[0002]

2. Description of the Related Art Titanium oxide or a substance in which a platinum group metal such as platinum or palladium is carried has photocatalytic activity. Substances having these photocatalytic activity used by utilizing the properties, tap water, drinking water, sterilization or disinfection of such waste water, the decomposition of the mixed organic, also the oxidation and deodorization of the NO _X or SO _X in the atmosphere (Japanese Patent Laid-Open No. 1-262944, etc.).

[0003]

When titanium oxide or the like is directly used as the substance having photocatalytic activity, the particle size must be set to about 0.005 to 0.007 μm or the photocatalytic activity will not be sufficiently exhibited. However, handling becomes very difficult to use monodispersely.

For this reason, it has been proposed that the above-mentioned substance having photocatalytic activity is adhered to the surface of an article having a specific shape such as tile or gypsum board (Japanese Patent Laid-Open No. 60-60).
118236, etc.). In this case, the higher the photocatalytic activity per unit surface area of the article, the higher the efficiency of sterilization,
Although sterilization and deodorization can be performed, a large photocatalytic activity cannot be expected because the area is limited only by coating the surface of the article.

In order to solve the above problems, for example, in Japanese Patent Laid-Open No. 63-97234, particles of a material transparent to light necessary for catalyst activation are coated with a thin film of a substance having photocatalytic activity. By doing so, we aim to improve the photocatalytic activity. Further, JP-A-63-248443 discloses a photooxidation reaction catalyst comprising a porous glass film having titanium oxide and platinum group metal supported in the pores.

[0006]

The present invention provides a porous powder obtained by coating the surface of a porous granular material such as diatomaceous earth with an inorganic oxide having a photocatalytic function such as titanium oxide by a wet reaction. By further fixing the particles on a plate-like article such as a tile, the photocatalytic activity per unit area of the article surface is increased.

Since the surface of the porous granular material is coated with an inorganic oxide having a photocatalytic function by a wet reaction, the photocatalytic activity per unit volume becomes large as compared with the case of coating with ordinary material particles. , The porous powder,
Since it is fixed on the surface of the plate-like article, the photocatalytic activity per unit surface area is larger than that of a porous glass film or the like.

The present invention will be described in more detail below. Specific examples of the porous granular material according to the present invention include diatomaceous earth, calcined pearlite (pearlite), CORAL, vermiculite, and zeolite. The preferred particle size varies depending on the purpose of use, but is generally 0.01 to 1
It is in the range of 0 mm.

The inorganic oxide having a photocatalytic function in the present invention is specifically titanium oxide or titanium oxide on which a platinum group metal such as platinum, palladium, rhodium or ruthenium is carried.

Regarding the method of coating the surface of the porous granular material with an inorganic oxide having a photocatalytic function by a wet reaction,
If the photocatalytic activity per unit volume is substantially increased,
The coating may be performed using any wet reaction, but as a specific example, the hydrolysis method when the inorganic oxide is titanium oxide will be mainly described.

First, the porous powdery particles are dispersed in water, and 1 to 20% by weight of the porous powdery particles is converted into alumina.
By adding a sulfuric acid band corresponding to this, neutralizing with urea to deposit aluminum hydroxide, filtering, washing with water, drying and baking at 400 to 800 ° C., the titanium compound is easily deposited in the next step. To obtain an alumina-coated porous powdery granule. This alumina-coated porous granular material is again dispersed in water, and this time, titanates such as titanium chloride, titanium sulfate, and alcooxytitanium are added and dissolved in the porous granular material in an amount of 1 to 50%. Then, hydrolysis is performed by a neutralization method or a heating method to deposit titanium hydroxide, which is filtered, washed with water, dried, and then baked at 300 to 900 ° C.

The porous granular material coated with titanium oxide as an inorganic oxide having a photocatalytic function, obtained as described above, can be dispersed in, for example, tap water, drinking water, waste water, etc. Then, by irradiating ultraviolet rays from a natural light, a fluorescent lamp, a mercury lamp, etc., the functions of sterilization, sterilization and decomposition of organic substances are exhibited. Although it is difficult to handle, it can be recovered by a method such as sedimentation and centrifugation after a certain period of time and reused.

The above-mentioned inorganic oxide-coated porous powdery or granular material having a photocatalytic function can be further fixed to the surface of a plate-like article such as a tile with a glaze or the like for use. The plate-like article here means concrete boards, gypsum boards, plastic plates, plastic sheets, etc. in addition to tiles. In particular, by using a plate-like article such as a tile, the practical use is expanded. For example, for sterilization or sterilization of tap water, drinking water, or for decomposition of organic matter such as wastewater from industry, life, or agriculture, as a wall material in a tank, for deodorizing purposes, as a building interior material, atmospheric NO _x , The plate-shaped article can be provided as a highway side wall material for the purpose of oxidizing SO _X.

[0014]

EXAMPLES The present invention will be further described with reference to examples. In addition, all the various amounts such as the compounding amount are based on the weight.

Example 1 720 ml of water was placed in a container having an internal volume of 1 liter, and diatomaceous earth (manufactured by Showa Chemical Industry Co., Ltd., trade name:
Radiolite R- # 900, average particle size 30 μm) 9
0.0 g was added and dispersed. Further, after adding 26.5 g of aluminum sulfate (containing 17% in terms of Al ₂ O ₃ and 5% with respect to diatomaceous earth), 16.5 g of urea was added and heated to boil to heat and hydrate the aluminum sulfate. Decomposition was performed and boiling was continued until the pH of the reaction solution reached 6.3. Then, filtration and water washing were performed, and the obtained filter cake was dried and calcined at 600 ° C. for 2 hours to obtain an alumina-coated diatomaceous earth.

Next, 5 water was placed in a container having an internal volume of 1 liter.
Into 81 ml, 85 g of the above alumina-coated diatomaceous earth was added and dispersed while stirring. Further, by adding 72.9 ml of an aqueous solution of titanyl sulfate (concentration of TiO ₂ : 233.2 g / liter, 20% based on TiO ₂ with respect to diatomaceous earth coated with alumina), the temperature was raised and the mixture was boiled for 3 hours to give titanyl sulfate. Was hydrolyzed by heating. Then, the mixture was filtered and washed with water, and the obtained filter cake was placed in a 2 liter beaker containing 900 ml of water and dispersed by stirring. After adjusting the liquid temperature to 60 ° C., the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and stirring was continued for 30 minutes. Then, filtration and washing with water, the obtained filter cake is dried,
It was calcined at 600 ° C. for 2 hours to obtain a titanium oxide-coated diatomaceous earth.

The titanium oxide-coated diatomaceous earth thus obtained was analyzed and found to contain 16.3% of TiO ₂ . Moreover, as a result of observing the particle surface with an electron microscope, it was confirmed that the diatomaceous earth particle surface was covered with TiO ₂ . Furthermore, it was found by X-ray diffraction that the crystal form of titanium oxide coated on diatomaceous earth was anatase form. The titanium oxide-coated diatomaceous earth was further fixed on the tile surface to obtain a tile having a photocatalytic function.

Example 2 Instead of the diatomaceous earth used in Example 1, pearlite (trade name: Nippon Perlite T-2, manufactured by Showa Chemical Industry Co., Ltd., average particle size 1 mm) was used to perform the same treatment, and titanium oxide was used. A coated pearlite was obtained.

As a result of analyzing the obtained titanium oxide-coated pearlite, it was found to contain 14.8% of TiO ₂ . Moreover, as a result of observing the particle surface with an electron microscope, it was confirmed that the particle surface was covered with TiO ₂ .
Furthermore, it was found by X-ray diffraction that the crystal form of titanium oxide coating the pearlite was anatase form. The titanium oxide-coated pearlite was further fixed on the tile surface to obtain a tile having a photocatalytic function.

Claims (1)

[Claims] 1. A titanium oxide-coated porous powder or granular material having a photocatalytic function is obtained by coating diatomaceous earth or calcined pearlite with aluminum oxide by a wet treatment, and then coating titanium oxide. A tile having a photocatalytic function, which is fixed on the surface of a tile.