JPH11267519A - Photocatalyst powder for purifying environment, polymer composition containing the powder and its molding, and production of these - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a photocatalyst powder for purifying environment to be added into organic fibers and others by kneading and others, by making an anionic surfactant exist on an interface between a titanium dioxide fine particle and a porous calcium phosphate coating layer formed on a part of its surface. SOLUTION: In the photocatalyst powder for purifying environment which can purify environment effectively, economically, and safely, a powder, in which a porous calcium phosphate coating layer is formed on a part of the surface of a titanium dioxide fine particle, is prepared, an anionic surfactant is made to exist on the interface between the coating layer and the particle. When the photocatalyst powder is supported on an organic polymer medium such as organic fibers by kneading, embedding, and other means and used, the durability is made able to be improved without deteriorating the medium. The titanium dioxide fine particles to be used are preferably a substance the average particle diameter of the primary particles of which is 0.001-0.2 micron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as an environmental purification material for removing odors, decomposing and removing harmful substances or dirt in the air, draining and purifying water, or sterilizing and algae-killing water. In particular, a photocatalyst powder for environmental purification suitable for use in a form added by kneading or embedding into organic fibers or plastics, and a method for producing the same; a polymer composition containing the powder; The present invention relates to a molded article of a polymer composition and a method for producing the molded article.

[0002]

2. Description of the Related Art Conventionally, as a method of preventing or removing a bad smell or a method of removing harmful substances in the air, a method of absorbing an odorant in an absorbent such as an acid or an alkali or an adsorbent is often used. There is a risk of secondary pollution due to problems in the treatment of waste liquid and used adsorbent. There is also a method of masking a bad smell by using a fragrance, but it has a drawback such that the odor of the fragrance may be transferred to food and the fragrance itself may be damaged (for example, Konosuke Nishida, Heibonsha "Encyclopedia of Encyclopedia", Volume 1, p.136 (19
84)).

When light is applied to titanium oxide, electrons having a strong reducing action and holes having a strong oxidizing action are generated, and the contacting molecular species are decomposed by the redox action. Decomposition and removal of organic solvents dissolved in water, environmental pollutants such as pesticides and surfactants, harmful substances and odors in the air, etc. by utilizing such action of titanium oxide, that is, photocatalysis. Can be. This method can be repeatedly used only by utilizing titanium oxide and light. The reaction product is a harmless carbon dioxide gas, and is less restricted in reaction conditions such as temperature, pH, gas atmosphere, toxicity, and the like, and is more difficult to treat by a biological treatment method than a biological treatment method using microorganisms. It has the advantage that even compounds such as halogen compounds and organic phosphorus compounds can be easily decomposed and removed.

[0004]

However, in the studies on the decomposition and removal of organic substances using a titanium dioxide photocatalyst, a powder of titanium dioxide has been used as a photocatalyst as it is (for example, A. Pruden and D. F. Oris, Journal of Catalysis (ALPruden and DFOllis, Journal of Cata
lysis) 82 vol. 404 (1983); H. Hidaka, H. J., K. Nohara, J. Zao. Chemosphere (H.Hi
daka, H. Jou, K. Nohara, J. Zhao, Chemosphere) Volume 25 1589
(1992); Teruaki Kubo, Kenji Harada, Keiichi Tanaka, Industrial Water, No. 3
No. 79, 12 (1990)). Therefore, it is difficult to handle and use the photocatalyst, for example, it is difficult to recover the used photocatalyst, and it has been difficult to put the photocatalyst to practical use. Attempts were made to knead the titanium dioxide photocatalyst into a medium such as easy-to-handle fibers or plastics, but the strong photocatalytic action decomposed not only harmful organic substances and environmental pollutants but also fibers and plastics themselves. Since it is extremely susceptible to deterioration, it has been difficult to use it in a form kneaded with fiber or plastic.

Japanese Patent Application Laid-Open No. 9-239277 proposes a photocatalyst carrier in which a photoinactive compound such as aluminum, silicon, zirconium or the like is supported in the form of islands on the surface of titanium dioxide. However, such a loading method, that is, a method in which the surface of titanium dioxide is treated with a photoinactive compound such as aluminum, silicon, and zirconium to be loaded, significantly reduces the catalytic activity of titanium dioxide in the field of cosmetics or pigments. Although this method has been developed for the purpose, there is a contradiction that when the reaction between titanium oxide and fibers or plastics is suppressed, the function as a photocatalyst is also greatly reduced. In addition, when such surface-treated titanium dioxide is used as a photocatalyst and used as an antibacterial and antifungal material, bacteria hardly adhere to the photocatalyst under running water, etc., so that the photocatalytic effect is hardly exhibited, the efficiency is poor, and the durability is poor. There was a problem.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to remove odors, decompose and remove harmful substances or dirt in the air, and treat wastewater and purify. It can effectively, economically and safely purify the environment, such as antibacterial and fungicide, especially when it is kneaded into an organic polymer medium such as organic fiber or plastic and used by being supported by embedding. It is an object of the present invention to provide an environmental purification powder exhibiting an excellent photocatalytic action from the viewpoint of durability without causing deterioration of the powder.

Another object of the present invention is to provide a method for producing such an environmental purification photocatalyst powder. Still another object of the present invention is to provide an organic polymer composition containing such an environmental purification photocatalyst powder. Still another object of the present invention is to provide a molded article molded from the organic polymer composition and a method for producing the molded article.

The present inventor has conducted intensive studies to achieve the above object. As a result, the titanium dioxide fine particles were dispersed in an aqueous slurry containing an anionic surfactant in advance, and then the titanium dioxide fine particles were dispersed. By forming a coating of calcium phosphate on the entire surface or a part of the surface, a durable calcium phosphate coating can be obtained, and since the coating has a property of adsorbing various bacteria and is porous, titanium dioxide is used. The present inventors have found that the durability of the medium can be drastically improved when used while being supported on a medium such as an organic polymer without impairing the photocatalytic function of the medium, and the present invention has been completed.

[0009] Thus, according to the present invention, it is composed of a powder in which a porous calcium phosphate coating layer is formed on at least a part of the surface of the titanium dioxide fine particles. Provided is a photocatalyst powder for environmental purification, wherein an anionic surfactant is present at an interface.

Further, according to the present invention, titanium dioxide fine particles are dispersed in an aqueous slurry containing an anionic surfactant, and then a coating layer of porous calcium phosphate is formed on at least a part of the surface of the titanium dioxide fine particles. The present invention provides a method for producing an environmental purification photocatalyst powder, which is formed.

Further, according to the present invention, there is provided a polymer composition comprising an organic polymer and 0.01 to 80% by weight based on the total weight of the composition of the photocatalyst powder for environmental purification.
Further, according to the present invention, there is provided a polymer molded article having an environmental purification function obtained by molding the polymer composition. Further, according to the present invention, there is provided a method for producing a polymer molded article having an environmental purification function, comprising kneading the above polymer composition in an extruder and extruding the mixture from the extruder.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The photocatalytic powder for environmental purification according to the present invention comprises an anionic surfactant at least at an interface between titanium dioxide fine particles and a porous calcium phosphate coating layer formed on at least a part of the surface thereof. Is characterized by the existence of The anionic surfactant is usually present not only at the interface between the titanium dioxide fine particles and the coating layer of porous calcium phosphate formed on the surface thereof, but also in the coating layer of porous calcium phosphate. .

The titanium dioxide fine particles used in the production of such an environmental purification photocatalyst powder preferably have an anatase crystal form as a main component in terms of high performance as a photocatalyst. The average particle size of the primary particles of the titanium dioxide fine particles used in the present invention is preferably 0.001 to 0.2 μm. If the average particle size is less than 0.001 micron, it is difficult to produce efficiently and it is not practical. Conversely, if the average particle size exceeds 0.2 microns, the performance as a photocatalyst is greatly reduced. The more preferred average particle size of the primary particles is 0.005 to 0.1 micron.

The production method of the titanium dioxide used in the present invention is not particularly limited as long as the titanium dioxide basically has photocatalytic activity. Are preferably used as primary dispersion particles produced by a gas phase reaction, that is, a gas phase oxidation and / or a gas phase hydrolysis reaction. The term “primary dispersed particles” as used herein refers to a state in which particles are less aggregated when the particles are observed using, for example, a transmission electron microscope.

In order to manufacture the photocatalyst powder for environmental purification of the present invention, prior to the step of coating the titanium dioxide fine particles with porous calcium phosphate, the titanium dioxide fine particles are previously dissolved in an aqueous slurry containing an anionic surfactant. Perform distributed processing. The term "anionic surfactant" as used herein refers to a substance that exhibits remarkable surface activity at a relatively low concentration, and is particularly used for controlling interfacial phenomena. Refers to

Specific examples of the anionic surfactant include:
Fatty acid soda soap, potassium oleate soap, carboxylate such as alkyl ether carboxylate, sodium lauryl sulfate, higher alcohol sodium sulfate, triethanolamine lauryl sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate Sulfonates such as sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium alkyldiphenylether disulfonate, sodium alkanesulfonate, and sodium salts of aromatic sulfonate formalin condensates; potassium alkylphosphates ,
Sodium hexametaphosphate, dialkyl sulfosuccinic acid and the like can be mentioned. These may be used alone,
Alternatively, a plurality of them may be used in combination.

By pre-treating with a slurry containing an anionic surfactant, in the step of forming a coating layer of porous calcium phosphate, the deposition reaction rate of calcium phosphate is improved, and the deposition is completed in a short time. Also,
By the presence of an anionic surfactant at the interface,
The adhesion of the calcium phosphate coating layer to the titanium dioxide fine particles is improved. The amount of the surfactant in the aqueous slurry containing the anionic surfactant is 10% by weight of titanium dioxide.
0 parts by weight, preferably 0.02 to 20 parts by weight,
More preferably, 1 to 10 parts by weight is used. When the relative amount of the anionic surfactant is less than 0.02 parts by weight, the effect as the surfactant is hardly exhibited, and the adhesion of the porous calcium phosphate and the durability are reduced. On the other hand, if it exceeds 20 parts by weight, the effect corresponding to the added amount cannot be obtained, and it is not economically practical.

After dispersion treatment in an aqueous slurry containing an anionic surfactant, a coating of porous calcium phosphate is formed on at least a part of the surface of the titanium dioxide fine particles. In order to form a coating of porous calcium phosphate, a method is usually employed in which a pseudo body fluid containing at least calcium ions and phosphate ions is brought into contact with titanium dioxide fine particles to precipitate calcium phosphate on the surface of the fine particles.

The simulated body fluid used herein is a processing fluid that gives a calcium phosphate compound represented by various descriptive formulas such as tricalcium phosphate Ca ₃ (PO ₄ ) ₂ , for example, NaCl, NaHCO ₃ , KCl, K ₂ HPO
_{4 · 3H 2 O, MgCl 2} · 6H 2 O, CaCl 2 and Na ₂ S
This working fluid is prepared by dissolving O ₄ or NaF or the like in water. HCl or (CH ₂ OH) ₃ CN
It is preferable to adjust the pH to 7 to 8, particularly 7.4 by using H ₂ or the like. The simulated body fluid used here has a Ca ²⁺ ion concentration of 0.1 to 50 mM, and a phosphate ion concentration of 0.1 to 2 mM.
Desirably, it is 0 mM. If the concentration of Ca ²⁺ ions and phosphate ions is low, the precipitation of calcium phosphate takes a long time. Conversely, if the concentration is higher than this, the generation will occur too rapidly, and the control of porosity and film thickness Becomes difficult.

The produced porous calcium phosphate may be any porous calcium phosphate comprising phosphate ions and calcium ions. These are Ca ₉
A compound having (PO ₄ ) ₆ as a basic unit, and specific examples thereof include tricalcium phosphate Ca ₃ (PO ₄ ) ₂ ,
Hydroxyapatite _{Ca 10 (PO 4) 6 (} OH) 2, dicalcium phosphate-dihydrate CaHPO ₄ · 2H ₂ O, octacalcium phosphate _{Ca 8 H 7 (PO 4)} 6 · 5H
₂ O, tetracalcium phosphate Ca ₄ O (PO ₄ ) ₂
And so on. Among these, hydroxyapatite is preferred, and amorphous hydroxyapatite is particularly preferred. The coating form is not particularly limited, but it is preferable to coat the titanium dioxide surface as uniformly as possible.

The amount of porous calcium phosphate deposited on the surface of the titanium dioxide fine particles is preferably about 0.01 to 50% by weight based on the weight of titanium dioxide. If the amount of the porous calcium phosphate is too small, the adsorption amount of harmful substances and malodorous substances by the porous calcium phosphate decreases, so that the decomposition and removal efficiency of those substances decreases,
Further, the photocatalyst powder carrying medium is deteriorated, and the durability of the photocatalytic function is reduced. If the amount is too large, the photocatalytic function of titanium dioxide is hardly sufficiently exhibited. Finally, the titanium dioxide slurry which has been coated with the porous calcium phosphate is dried to obtain an environmental purification photocatalyst powder.

The photocatalyst powder for environmental purification of the present invention may be one in which a metal such as platinum, rhodium, ruthenium, palladium, silver, copper, iron, zinc or the like is carried on the surface of the fine particles. In such a case, the oxidative decomposition rate of the chemical substance is further increased, and the bactericidal and algicidal actions are also increased. The metal may be carried on the raw titanium dioxide fine particles before the coating treatment.

In the photocatalyst powder for environmental purification of the present invention, since the calcium phosphate film covering the surface of the fine particles is porous, there is a portion where the surface of titanium dioxide is uncovered and exposed in the pores. An environmental purification catalytic action by titanium dioxide under irradiation can be caused. That is, due to the redox action of the electrons and holes generated by the photocatalyst powder under light irradiation, organic substances serving as odor sources adsorbed by calcium phosphate, harmful substances in the air, or organic solvents dissolved in water Organic compounds that pollute the environment, such as food and agricultural chemicals, are easily decomposed and removed.

Further, since the durable porous calcium phosphate film obtained by the above method prevents direct contact between titanium dioxide and the medium, the photocatalyst for environmental purification is converted to an organic polymer medium such as organic fiber or plastic. Even when added and used by kneading or the like, the fiber or plastic itself is unlikely to be degraded by decomposition or the like, and the photocatalytic effect can be maintained for a long time.

Furthermore, since the porous calcium phosphate membrane has a property of adsorbing various bacteria, proteins, amino acids, bacteria and viruses in water and air, organic substances serving as odor sources, nitrogen oxides, etc. Titanium dioxide can be reliably and efficiently killed or decomposed by the strong oxidizing power generated in the titanium dioxide by light irradiation. Light sources for light irradiation include fluorescent light, incandescent light, black light, UV
Artificial light or sunlight from lamps, mercury lamps, xenon lamps, halogen lamps, metal halide lamps and the like can be used. And, by the redox action of the electrons and holes generated in titanium dioxide by light irradiation,
Proteins, amino acids, bacteria, viruses, and the like adsorbed by the porous calcium phosphate membrane can be rapidly and continuously decomposed and removed.

[0026] particularly when the environmental purification photocatalytic powder is used in dough crowded by or embedded in an organic polymer medium such as organic fibers or plastic, without causing the decomposition of the organic fiber or plastic, bad smell and NO _X, etc. Adsorbs harmful substances in the air, or organic compounds that pollute the environment, such as organic solvents and pesticides dissolved in water, and emits fluorescent, incandescent, black, UV, mercury, xenon, and halogen lamps. It can be rapidly and continuously decomposed and removed by the redox effect of electrons and holes generated in titanium dioxide by irradiation of artificial light or sunlight from a lamp, a metal halide lamp, or the like. In addition, such effects can be obtained simply by irradiating light,
Energy saving and maintenance free.

Platinum on the surface as titanium dioxide particles,
When a metal carrying rhodium, ruthenium, palladium, silver, copper, iron, zinc, etc. is used, its catalytic action further enhances the environmental purification effects such as decomposition and removal of organic compounds, sterilization, and antifungal effects. Increase.

The photocatalyst powder for environmental purification of the present invention comprises polyethylene, nylon, polyvinyl chloride, polyvinylidene chloride, polyester, polypropylene, polyethylene oxide, polyethylene glycol, polyethylene terephthalate, silicone resin, polyvinyl alcohol, vinyl acetal resin, Acetate, ABS resin, epoxy resin, vinyl acetate resin, cellulose, cellulose derivative, polyamide, polyurethane, polycarbonate,
Polystyrene, urea resin, fluororesin, polyvinylidene fluoride, phenolic resin, celluloid, chitin, applicable to organic fiber and plastic molded products made of all kinds of organic polymers such as starch sheet, the above photocatalyst powder and organic By molding a composition comprising a polymer, a polymer molded article having an environmental purification function can be obtained. Generally, a photocatalyst powder is kneaded in a manufacturing process of an organic fiber or a plastic molded product, and is supported by means such as embedding. In particular, it is preferable to knead the organic polymer and the photocatalyst powder using an extruder and extrude to obtain a polymer molded product having an environmental purification function. The concentration of the photocatalyst powder in the polymer composition comprising the photocatalyst powder and the organic polymer is usually 0.0% based on the weight of the polymer composition.
It is 1 to 80% by weight, preferably 1 to 50% by weight.

Hereinafter, the photocatalyst powder for environmental purification of the present invention will be described in detail with reference to examples. In each of Examples and Comparative Examples, the photoactivity was measured by the following method.
Research by Kato et al. (Industrial Chemistry Magazine, 63, 5, 748-75)
0 (1960)), 20 mL of tetralin and 0.02 g of titanium dioxide are sealed in a closed heat-resistant glass reaction vessel having a capacity of about 100 mL, and the reaction temperature is kept constant (40.1 ° C.) under an O ₂ atmosphere. Then, ultraviolet irradiation was performed to determine the oxygen absorption rate by the liquid phase oxidation reaction of tetralin. That is, the pressure in the reactor at every predetermined time was read by a differential pressure gauge, and the pressure change (unit: mmH ₂ O / min) was defined as the oxygen absorption rate and used as a measure of photoactivity.

[0030]

Example 1 600 g of a commercially available polycarboxylic acid type polymer surfactant (Poise 530 manufactured by Kao Corporation) was added to 250 L of pure water, and ultrafine titanium dioxide particles (Showa Titanium Co., Ltd.) were added thereto. ) F4, average primary particle size 0.03 micron)
12 kg was charged and dispersion treatment was performed. Separately, NaCl, NaHPO ₄ , KH ₂ PO ₄ , KCl, MgC
l ₂ · 6H ₂ O, was added CaCl _2, the Na ⁺ after mixing with titanium dioxide slurry 139 mm, K ⁺ is 2.8m
M, Ca ²⁺ 1.8 mM, Mg ²⁺ 0.5 mM, Cl ⁻
However, 350 L of a simulated body fluid prepared such that 144 mM and HPO ₄ ^- were 1.1 mM were prepared. 250 L of titanium dioxide slurry obtained by the above method and simulated body fluid 350
And the mixture was maintained at 40 ° C. for 24 hours. When the amount of precipitated calcium phosphate was analyzed after 4 hours, it was confirmed that about 90% by weight of the finally precipitated amount was precipitated. Thereafter, the slurry was dried to obtain 10 kg of an environmental purification photocatalyst powder.
When this precipitate was analyzed, it was found to be calcium phosphate containing hydroxyapatite.

The obtained photocatalytic powder for environmental purification was measured for photoactivity using the oxidation reaction of tetralin, and found to have a high photocatalytic activity of 10.0 (mmH ₂ O / min). Next, a compound having a titanium dioxide concentration of 40% by weight was produced from 1 kg of the powder and the polyethylene terephthalate resin using a commercially available twin-screw kneading extruder (KZW15-30MG manufactured by Technobel Co., Ltd.). The obtained compound was not colored and no deterioration of the resin was observed.

Example 2 A photocatalyst powder for environmental purification was obtained in the same manner as in Example 1 except that sodium alkylnaphthalene sulfonate (Perox NB-L, Kao Corporation) was used as the anionic surfactant. Further, a compound having a titanium dioxide concentration of 20% by weight was prepared from the powder and the polyethylene terephthalate resin. The photoactivity of the obtained powder was 10.3. In addition, no coloring was observed in the compound as in Example 1.

Example 3 Example 1 except that sodium hexametaphosphate (special grade reagent manufactured by Junsei Chemical Co., Ltd.) was used as the anionic surfactant.
An environmental purification photocatalyst powder was obtained in the same manner as in Example 1, and a compound having a titanium dioxide concentration of 20% by weight was produced from the powder and a polyester resin. The photoactivity of the obtained powder was 10.9 (mmH ₂ O / min). No coloring was observed in the compound.

Example 4 The average particle size of the primary particles as the titanium dioxide fine particles was 0.0
An environmental purification photocatalyst powder was obtained in the same manner as in Example 1 except that a 6-micron particle (F2 manufactured by Showa Titanium Co., Ltd.) was used. The photoactivity of the obtained powder was 9.8 (mmH ₂
O / min). A compound having a titanium dioxide concentration of 30% by weight was prepared from the powder and the polyethylene terephthalate resin in the same manner as in Example 1, but no coloring was observed.

Example 5 The same procedure as in Example 1 was carried out except that the composition of the simulated body fluid was adjusted so that the Ca ²⁺ was 0.9 mM and the HPO ₄ ⁻ was 9.6 mM after mixing the titanium dioxide slurry and the simulated body fluid. An environmental purification photocatalyst powder was obtained in the same procedure as in Example 1, and a titanium dioxide concentration of 25% by weight was obtained from the powder and the polyester resin.
Was prepared. The photoactivity of the obtained powder was 11.1 (mmH ₂ O / min). No coloration was observed in the compound.

Comparative Example 1 Titanium dioxide was used as a main component in the same manner as in Example 1 except that lauryltrimethylammonium chloride (Kaomin 24P, Kao Corporation) was used as the cationic surfactant. A powder was obtained. The photoactivity of this powder was 10.2 (mmH ₂ O / min). However, when a compound similar to that of Example 1 was prepared using this, coloring was observed.

Comparative Example 2 In Example 1, 250 L of a titanium dioxide slurry was prepared without adding a surfactant. Thereafter, a simulated body fluid was prepared to have the same ion concentration as described in Example 1, and mixed with the titanium dioxide slurry. 40 ° C
For 24 hours. Even after heating for 24 hours, the precipitation of calcium phosphate was not completely completed. The product was dried to obtain a powder mainly composed of titanium dioxide. The photoactivity of this powder was 11.5 (mmH ₂ O /
Min). Next, as in Example 1, an attempt was made to prepare a compound from the powder and the polyethylene terephthalate resin.

Comparative Example 3 12 kg of ultrafine titanium dioxide particles (F4 manufactured by Showa Titanium Co., Ltd., average particle size of primary particles: 0.03 μm) were put into 600 L of pure water, and stirred. Showa Denko KK SA2019) 1800
g was added, and 0.3 M sulfuric acid was added dropwise while maintaining the temperature at 40 ° C., and the mixture was treated so that the pH value became 7.5. Next, this slurry was dried to obtain a powder containing titanium dioxide as a main component and coated with aluminum oxide. The photoactivity of this powder was as low as 8.5 (mmH ₂ O / min). A compound similar to that of Example 1 was obtained using this powder, but coloring was observed.

[0039]

According to the photocatalyst powder for environmental purification of the present invention, various bacteria, proteins, amino acids, bacteria and viruses in water and in the air, organic substances serving as odor sources, nitrogen oxides, etc. can be improved by porous calcium phosphate. The germs and the like adsorbed on the surface can be reliably and efficiently killed or decomposed by the strong oxidizing power generated in the titanium dioxide by light irradiation. Therefore, it is possible to efficiently, economically, and safely perform environmental purification such as removal of offensive odors, decomposition and removal of harmful substances or dirt in the air, wastewater treatment and purification treatment, antibacterial and antifungal treatment. In particular, when kneaded into an organic polymer molded article such as an organic fiber or a plastic molded article, or used by being supported by embedding or the like, it exhibits a photocatalytic action having excellent durability without causing deterioration of the polymer medium.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01J 33/00 B01J 33/00 Z 37/03 37/03 Z C01B 25/32 C01B 25/32 B C01G 23/07 C01G 23/07 C02F 1 / 32 C02F 1/32 1/72 101 1/72 101 D01F 1/10 D01F 1/10 // A61L 9/01 A61L 9/01 B 9/16 9/16 D (71) Applicant 597039869 Toru Nonami Aichi 3-9-6 Kibogaoka, Chikusa-ku, Nagoya-shi, Japan (74) The above three agents Patent Attorney Yukio Uchida (72) Inventor Hiroshi Taota 1-70, Heiwagaoka, Meito-ku, Nagoya-shi, Aichi Prefecture 4 Inokoishi Houses No. 301 (72) Inventor Toru Nonami 1-70, Heiwagaoka, Meito-ku, Nagoya-shi, Aichi No. 302 Inokoishi House No. 302 (72) Inventor Katsura Ito 1 Soka, Oji, Shiojiri-shi, Nagano Prefecture Showa Denko Corporation Research Laboratory Shiojiri Laboratory (72) Inventor Hiroyuki Hagiwara Shiojiri Laboratory, Shiojiri City, Nagano Prefecture 1 Shiojiri Laboratory, Showa Denko KK

Claims (13)

[Claims] A powder comprising a porous calcium phosphate coating layer formed on at least a part of the surface of titanium dioxide fine particles, and at least an interface between the porous calcium phosphate coating layer and the titanium dioxide fine particles is at least at the interface. A photocatalyst powder for environmental purification, characterized by the presence of an ionic surfactant. 2. The photocatalyst powder for environmental purification according to claim 1, wherein the titanium dioxide fine particles have an average primary particle diameter of 0.001 to 0.2 μm. 3. The photocatalytic powder for environmental purification according to claim 1, wherein the titanium dioxide fine particles are powders composed of primary dispersed particles produced by a gas phase reaction using titanium halide as a raw material. 4. The photocatalyst powder for environmental purification according to claim 1, wherein the amount of the porous calcium phosphate is 0.01 to 50% by weight based on the weight of the titanium dioxide fine particles. 5. A process for dispersing titanium dioxide fine particles in an aqueous slurry containing an anionic surfactant, and then forming a porous calcium phosphate coating on at least a part of the surface of the titanium dioxide fine particles. Of producing a photocatalyst powder for environmental purification. 6. The environmental purification according to claim 5, wherein the aqueous slurry used for the dispersion treatment of the titanium dioxide fine particles contains 0.02 to 20 parts by weight of an anionic surfactant with respect to 100 parts by weight of titanium dioxide. A method for producing a photocatalyst powder. 7. The titanium dioxide fine particles have an average primary particle size of 0.001 to 0.2 μm.
A method for producing the photocatalyst powder for environmental purification according to claim 6. 8. The photocatalyst for environmental purification according to claim 5, wherein the titanium dioxide fine particles are powders composed of primary dispersed particles produced by a gas phase reaction using titanium halide as a raw material. Powder manufacturing method. 9. A method of forming a coating by depositing porous calcium phosphate on at least a part of the surface of titanium dioxide fine particles by bringing a pseudo body fluid containing at least calcium ions and phosphate ions into contact with titanium dioxide fine particles. A method for producing a photocatalyst powder for environmental purification according to any one of claims 5 to 8. 10. The simulated body fluid has a calcium ion concentration of 0.1 to 50 mM and a phosphate ion concentration of 0.1 to 20 mM.
The method for producing a photocatalyst powder for environmental purification according to claim 9, which is M. 11. A polymer composition comprising an organic polymer and 0.01 to 80% by weight based on the total weight of the composition of the photocatalyst powder for environmental purification according to claim 1. 12. A polymer molded article having an environmental purification function obtained by molding the polymer composition according to claim 11. 13. A method for producing a polymer molded article having an environmental purification function, comprising kneading the polymer composition according to claim 11 in an extruder and extruding the mixture from the extruder.