KR100609824B1 - A process for preparing of yellow soil balls coated with photocatalyst - Google Patents

Abstract

The present invention relates to a method for producing a photocatalyst coated ocher ball, and more particularly, a tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst is coated on the ocher ball to have photoactivity in the ultraviolet light region as well as in the visible light region. The present invention also relates to a method for producing a photocatalyst-coated ocher ball, which contains an alkoxysilane-based or inorganic silane-based binder in the photocatalyst coating film, which is excellent in strength and adhesion of the coating film.

Tungsten Oxide-Titanium Dioxide, Photocatalyst, Ocher Ball

Description

A process for preparing of yellow soil balls coated with photocatalyst}

1 is a graph showing an organic gas decomposition test result in a visible light region,

Figure 2 is a graph showing the organic resolution deodorization test results.

The present invention relates to a method for producing a photocatalyst coated ocher ball, and more particularly, a tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst is coated on the ocher ball to have photoactivity in the ultraviolet light region as well as in the visible light region. The present invention also relates to a method for producing a photocatalyst-coated ocher ball, which contains an alkoxysilane-based or inorganic silane-based binder in the photocatalyst coating film, which is excellent in strength and adhesion of the coating film.

Photocatalysts are catalysts that receive light and catalyze chemical reactions. Photocatalysts include semiconductors and pigments, and chlorophyll and titanium oxide (TiO ₂ ), which perform photosynthesis of plants, are one type of photocatalyst. Photocatalysts have several useful functions in industry. For example, titanium oxide has a function of oxidatively decomposing toxic substances, that is, environmental purification, deodorization, antibacterial and anti-fouling action on the air, water quality, soil, etc., and have a superhydrophilic property on the surface of an object. It is applied to various products such as glass, tiles, cleaners, air cleaners, refrigerators, pavement blocks, curtains, wallpaper, underwear, and artificial houseplants that have self-cleaning effects.

Ocher is a soil component covering about 10% of the earth's surface and contains a large amount of calcium carbonate (CaCO ₃ ). Due to the calcium carbonate component, loess has a viscosity that is not easily broken, and when water is added, it turns into clay. In addition to calcium carbonate, ocher is composed of silica (SiO ₂ ), alumina (Al ₂ O ₃ ), iron, magnesium (Mg), sodium (Na), and kali.

The structure of the ocher is a honeycomb structure with a very large surface area and forms a multi-layer structure with numerous spaces. In these sponge-like holes, far-infrared rays are absorbed and stored in large quantities, and when heated, they emit far-infrared rays necessary for the growth of plants and animals, stimulating molecular activity of other objects. In addition, about a hundred million microorganisms live in one spoon of ocher, and various enzymes cause circulation. The enzyme component of loess includes catalase, diphenol oxidase, saccharase, protease and the like. Each of these enzymes plays a role in detoxification, degradability, fertilizer elements, and purification. Thus, ocher has been called living organisms since ancient times, and has been used in a variety of disease-free soils for providing various useful functions to the human body.

In particular, in recent years, the so-called well-being (development) industry has developed a variety of living products using the functional characteristics of the loess is one of the ocher ball. Ocher ball is a product shaped like a bead with a uniform diameter by using the viscosity of ocher. It has the far-infrared effect inherent in ocher, weakens the bacteria causing various diseases in the human body, and promotes blood circulation by expanding capillaries. As well as the effect of promoting the generation of cellular tissues, it is used in a variety of purposes, such as deodorization, antibacterial, moisture-proof, purification in the home, work, sauna facilities, swimming pools, automobiles, and the like.

On the other hand, to enhance the function of the ocher ball has been developed a technology for coating a photocatalyst on the ocher ball. For example, Korean Laid-open Patent Publication No. 2003-46159 evenly mixes ocher powder and water to form and dry an ocher ball having a diameter of 1 to 10 mm, and then coats the titanium oxide (TiO ₂ ) photocatalyst on the ocher ball. Disclosed is a method for sintering at least 12 hours at a temperature of at least ℃. When the photocatalyst is coated on the ocher ball, the function of the photocatalyst is added to the inherent far-infrared effect of the ocher ball, and thus industrially useful performance is obtained.

However, since the titanium oxide used as a photocatalyst in the above-mentioned Patent Publication No. 2003-46159 exhibits photodegradation only in an ultraviolet region having a wavelength region of 385 nm or less, there is a limit in which illumination is insufficient or shows little function in a dark place. In addition, in order to bond the photocatalyst coating coated on the surface of the ocher ball with sufficient strength, there was a need to sinter the titanium oxide coated ocher ball at a temperature of 600 ° C. or more for 12 hours or more, and nevertheless, the strength of the titanium oxide film There remains a technical need to improve the system even more strongly.

Accordingly, an object of the present invention is that in an ocher ball coated with a photocatalyst, the photocatalyst coated on the ocher ball exhibits photodegradation not only in the ultraviolet region but also in visible light having a wavelength of 440 nm or less. It is to provide a method for producing a photocatalyst coated ocher ball to have a sufficient strength and bonding force for the ball.

The present invention is 10 to 50 parts by weight of an alkoxysilane-based binder, or inorganic silane-based binders 3 to 20 parts by weight of tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst on the surface of the ocher ball having a diameter of 3 to 20 mm. The photocatalyst composition containing 30 parts by weight is a photocatalyst coated ocher ball, characterized in that coated with a thickness of 0.1 ~ 10 ㎛.

In the method for preparing a photocatalyst coated ocher ball according to the present invention, 3 to 7 parts by weight of tungsten oxide-titanium dioxide photocatalyst powder is added to 100 parts by weight of a mixed solution of ethanol and water in a 4: 1 ratio, and an alkoxysilane-based binder is added thereto. Is added to 10 to 50% by weight of the photocatalyst powder, and then the photocatalyst sol (sol) solution is impregnated with ocher ball, or the photocatalyst sol (sol) solution is spray-coated on the surface of the ocher ball to have a thickness of 0.1 to 10 μm. Forming a phosphorous film, it is characterized in that the heat treatment for 1 to 3 hours at a temperature of 200 ~ 500 ℃.

Another method for producing a photocatalyst coated ocher ball according to the present invention is to add 3 to 7 parts by weight of tungsten oxide-titanium dioxide photocatalyst powder to 100 parts by weight of distilled shoe, and an inorganic silane binder having a solid content of 20 to 40% by weight. 5 to 30% by weight based on the photocatalyst powder, and then impregnated ocher ball in the photocatalyst sol (Sol) solution, or spray coating the photocatalyst sol solution on the surface of the ocher ball thickness of 0.1 ~ 10 ㎛ To form, it is characterized in that it is dried at room temperature.

Hereinafter, the present invention will be described in more detail.

The photocatalyst coated ocher ball of the present invention is coated with a tungsten oxide-titanium dioxide photocatalyst film. Tungsten oxide-titanium dioxide photocatalyst is a doping of tungsten oxide on titanium dioxide which is the most widely used photocatalyst, and its lighting is somewhat insufficient because it shows the photo resolution not only in the ultraviolet region but also in the visible region having a wavelength of 440 nm or less. There is a feature that can perform the function of the photocatalyst in a dark or dark place.

Tungsten oxide-titanium dioxide photocatalyst can be manufactured by a well-known method. For example, dispersing titanium dioxide in water, adding tungsten oxide to dissolve it, and then evaporating and drying water in the mixed solution to prepare a tungsten oxide-titanium dioxide photocatalyst.

The tungsten oxide-titanium dioxide film according to the present invention contains 10 to 50 parts by weight of an alkoxysilane-based binder, or 5 to 30 parts by weight of an inorganic silane-based binder, based on 100 parts by weight of the photocatalyst component. The binder serves to firmly fix the photocatalyst film to the ocher ball. At this time, when the content of the alkoxy silane-based binder is 10 parts by weight or less or the content of the inorganic silane-based binder is 5 parts by weight or less, the adhesive strength of the photocatalytic coating cannot obtain the desired strength, and conversely, the content of the alkoxy silane-based binder is 50 parts by weight or more. When the content of the inorganic silane-based binder is 30 parts by weight or more, there is a problem that the function of the photocatalyst is deteriorated or the physical properties of the film are deteriorated.

The alkoxysilane-based binders used in the present invention are, for example, tetraethyl autosilicate [Si (OEt) ₄ ], tetramethyl autosilicate [Si (OMe) ₄ ], 3-glycidoxypropyl dimethoxymethylsilane [OCH ₂ CHCH ₂ O (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ] can be used.

The photocatalyst coated ocher balls of the present invention may be prepared by thermal curing or room temperature curing. In the thermosetting method, 3 to 7 parts by weight of tungsten oxide-titanium dioxide photocatalyst powder is added to 100 parts by weight of a mixed solution of ethanol and water in a 4: 1 ratio. At this time, when the content of the photocatalyst powder is 3 parts by weight or less, the photocatalyst of the photocatalyst is weakened. On the contrary, when the content of the photocatalytic powder is 7 parts by weight or more, the viscosity of the photocatalyst sol solution becomes too high, and the workability during coating is poor. Subsequently, 10 to 50% by weight of the alkoxysilane-based binder is added to the mixed solution with respect to the photocatalyst powder, and the photocatalyst sol (Sol) solution is impregnated with ocher balls, or the photocatalyst sol (Sol) solution is added to the surface of the ocher ball. Spray it on. At this time, the thickness of the photocatalyst coating is most preferably 0.1 to 10 탆, preferably 1 탆.

Because ocher balls themselves are porous materials, if the photocatalyst solution is absorbed and coated on the ocher balls too much, the drying time may be long, or the appearance of the ocher balls may become cloudy and damage the original appearance of the ocher balls. In addition, since the photocatalytic reaction is a surface reaction, it is advantageous in terms of productivity that the photocatalyst is coated on the surface rather than absorbed into the ocher ball. Therefore, the photocatalyst sol solution is repeatedly applied two or three times by impregnation or spray coating so that only the surface of the ocher ball is coated.

After the photocatalyst solution is coated, it is heat-treated at a temperature of 200 to 500 ° C. for 1 to 3 hours. At this time, if the heat treatment temperature is too high, a rutile may occur, in which the photodegradation of the photocatalyst may be deteriorated.

Next, in the room temperature curing method, 3 to 7 parts by weight of tungsten oxide-titanium dioxide photocatalyst powder is added to 100 parts by weight of distilled shoe. Then, an inorganic silane binder having a solid content of 20 to 40% by weight is added to 5 to 30% by weight based on the photocatalyst powder, and the photocatalyst sol solution is impregnated with ocher ball, or the photocatalyst sol solution is applied to the surface of the ocher ball. Spray coating is performed to form a film having a thickness of 0.1 to 10 μm, and then cured at room temperature. At this time, in order to increase the strength of the photocatalyst coating film may be further aged for 2 hours at a temperature of 70 ~ 90 ℃.

The technical problem that is most problematic in coating a photocatalyst on a conventional material is how to maintain the function of the photocatalyst by semi-permanently immobilizing the photocatalyst without damaging the material. In fact, many researches have been conducted on the function and action of photocatalysts, but there are still many difficulties in the technique of firmly fixing the coating film. However, in the present invention, an alkoxysilane-based binder or an inorganic silane-based binder was used to significantly improve the strength of the tungsten oxide-titanium dioxide coating layer on the ocher ball. In fact, while the conventional titanium dioxide coating film exhibits a strength of 2H as a pencil hardness, the tungsten oxide-titanium dioxide coating film of the present invention has a strength of about 5 to 6H at room temperature curing, and about 8H at heat treatment or aging.

Hereinafter, examples of the present invention will be described.

Example  One

5 g of tungsten oxide-titanium dioxide powder is added to 100 ml of a mixed solution of ethanol and water in a 4: 1 ratio, and 1 g of tetraethyl autosilicate [Si (OEt) ₄ ] powder is added to the photocatalyst sol ( Sol) solution was prepared.

Subsequently, the photocatalyst sol solution was impregnated twice with a previously prepared ocher ball (diameter 8 mm) to form a film having a thickness of 1 μm on the surface of the ocher ball, and then heat-treated at a temperature of 350 ° C. for 2 hours and 30 minutes. The photocatalyst coated ocher ball of the invention was prepared.

Example  2

5 g of tungsten oxide-titanium dioxide photocatalyst powder was added to 100 ml of distilled water, and 1 g of a silica sol binder having a solid content of 30 wt% was added thereto to prepare a photocatalyst sol (Sol) solution.

Subsequently, the previously prepared ocher balls (diameter 8 mm) are laid on a plate, and the coating is spray-coated with the photocatalyst sol solution using a high pressure injector while shaking the plate to form a film having a thickness of 1 μm on the surface of the ocher balls. It was dried at room temperature. On the other hand, with respect to some of the samples finished drying at room temperature, further aged at 80 ℃ temperature for 2 hours.

Various physical properties of the photocatalyst coated ocher ball of the present invention prepared according to Examples 1 and 2 were measured and the results were compared with those of the conventional titanium dioxide coating film.

1) physical strength of the photocatalyst coating film; Example 1 showed a strength of pencil strength 8H, in the case of Example 6H at room temperature drying, 8H when aged. However, in the case of the conventional titanium dioxide photocatalyst coating film, the pencil strength was only 2H.

2) decomposition test of organic gas (formaldehyde, methanol) in the visible region; 1 is a graph showing the amount of CO ₂ released, the amount of methanol remaining, and the amount of formaldehyde remaining, respectively, with respect to visible light irradiation time. In the case of the tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst used in the present invention, the removal rate of the organic gas is improved by about 25 to 50% compared to the conventional titanium dioxide photocatalyst, indicating that the residual amount of organic gas remains much smaller. .

3) test for resolution of organic compounds; When the photocatalyst adsorbs the organic compound and the organic matter is decomposed, H ₂ O and CO ₂ gases are generated. At this time, the ability of the photocatalytic activity of the photocatalyst can be confirmed by confirming the amount of CO ₂ generated. Figure 2 shows the test results for the resolution of the organic compound, the tungsten oxide-titanium dioxide photocatalyst used in the present invention, compared to the conventional titanium dioxide photocatalyst, about 5 times the C2 _O at 1 hour light irradiation results It can be seen that the gas concentration is increased.

The photocatalyst coated ocher ball of the present invention has excellent photoactivity in the dark or poor lighting because the tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst coated on the ocher ball has photoactivity in the visible region as well as in the ultraviolet region. In particular, since an alkoxysilane-based or inorganic silane-based binder is included, the coating film has a very good strength and adhesion. The photocatalyst coated ocher ball of the present invention can be used in various ways such as foot pressing pressure yellow clay, ocher mat, ocher warmer, water treatment material of fish tank, potting cover material and the like.

Claims (5)

delete delete 3 to 7 parts by weight of tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst powder is added to 100 parts by weight of a mixed solution of ethanol and water in a 4: 1 ratio, and an alkoxysilane-based binder is added to the photocatalyst powder. 10 to 50% by weight is added, and the photocatalyst sol (Sol) solution is impregnated with ocher balls, or the photocatalyst sol (Sol) solution is applied to the surface of the ocher balls by forming a film having a thickness of 0.1 to 10 μm. Method for producing a photocatalyst coated ocher ball, characterized in that the heat treatment for 1 to 3 hours at a temperature of 200 ~ 500 ℃ 3 to 7 parts by weight of tungsten oxide-titanium dioxide (WO ₃ -TiO ₂ ) photocatalyst powder is added to 100 parts by weight of distilled shoe, and an inorganic silane binder having a solid content of 20 to 40% by weight is added to the photocatalyst powder. 5 to 30% by weight is added, and the photocatalyst sol (Sol) solution is impregnated with ocher balls, or the photocatalyst sol (Sol) solution is spray-coated on the surface of the ocher balls to form a film having a thickness of 0.1 to 10 μm. , The method for producing a photocatalyst coated ocher ball, which is dried at room temperature. 5. The method of claim 4, wherein the ocher balls dried at room temperature are further aged for 2 hours at a temperature of 70 to 90 ° C. 6.

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