JP3493393B2 - Photocatalytic powder for environmental purification, powder-containing polymer composition and molded article thereof, and methods for producing them - Google Patents

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 offensive odors, decomposing and removing harmful substances or dirt in the air, drainage treatment, water purification treatment, or water sterilization or algae killing. , An environment-cleaning photocatalyst powder suitable for use in a form added by kneading or embedding in, for example, 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 Heretofore, a method of absorbing or absorbing an odor such as an acid or an alkali or an adsorbent has been often used as a method of preventing or removing a bad odor or a method of removing a harmful substance in the air. May cause secondary pollution due to problems with the treatment of waste liquid and used adsorbent. There is also a method of masking offensive odors by using a fragrance, but it has a drawback such that the odor of the fragrance may be transferred to food and damage may be caused by the odor of the fragrance itself (for example, Konosuke Nishida, Heibonsha "Large Encyclopedia," Vol. 1, p. 136 (19)
84)).

When titanium oxide is irradiated with light, electrons having a strong reducing action and holes having a strong oxidizing action are generated, and the molecular species coming into contact with each other are decomposed by the redox action. By utilizing such an action of titanium oxide, that is, a photocatalytic action, it is possible to decompose and remove organic solvents dissolved in water, environmental pollutants such as pesticides and surfactants, harmful substances in the air and bad odors. You can This method can be used repeatedly only by utilizing titanium oxide and light. The reaction product is harmless carbon dioxide gas, etc., and there are less restrictions on reaction conditions such as temperature, pH, gas atmosphere, toxicity, etc. compared to biological treatment methods using microorganisms, and moreover, it is difficult to treat by biological treatment methods. It has the advantage that even halogen compounds and organic phosphorus compounds can be easily decomposed and removed.

[0004]

However, in the researches on decomposition and removal of organic substances by titanium dioxide photocatalyst conducted so far, titanium dioxide powder was used as it is as a photocatalyst (for example, A. L. Pruden and D. F. Oris, Journal of Cata (ALPruden and DFOllis, Journal of Cata)
lysis) Vol. 82 404 (1983); H. Hidaka, H. Joe, Kay Nohara, Jay. Zao. Chemosphere (H.Hi
daka, H.Jou, K.Nohara, J.Zhao, Chemosphere) 25 volumes 1589
(1992); Teruaki Kubo, Kenji Harada, Keiichi Tanaka, Industrial Water, No. 3
79, 12 (1990)). Therefore, it is difficult to handle and use the photocatalyst after use, and it is difficult to put the photocatalyst into practical use. Therefore, it was attempted to use the titanium dioxide photocatalyst by kneading it into a medium such as fiber or plastic that is easy to handle, but its strong photocatalytic action decomposes not only harmful organic substances and environmental pollutants but also fiber and plastic itself. Since it is extremely susceptible to deterioration, it was difficult to use it in the form of kneading it into fiber or plastic.

Japanese Unexamined Patent Publication (Kokai) No. 9-239277 proposes a photocatalyst carrier in which a surface of titanium dioxide is loaded with a photoinactive compound such as aluminum, silicon or zirconium in an island shape. However, such a supporting method, that is, a method of supporting the surface of titanium dioxide by treating it with a photo-inactive compound such as aluminum, silicon or zirconium, originally greatly reduces the catalytic activity of titanium dioxide in the field of cosmetics or pigments. However, there is a contradiction that the action as a photocatalyst is significantly reduced when the reaction between titanium oxide and fiber or plastic is suppressed. In addition, when such surface-treated titanium dioxide is used as a photocatalyst and as an antibacterial and antifungal material, it is difficult for the bacteria to adhere to the photocatalyst under running water, so the photocatalytic effect is difficult to exert, the efficiency is poor, and the durability is poor. There was a problem.

[0006]

In view of the problems of the prior art as described above, an object of the present invention is to remove a bad odor, to decompose and remove harmful substances or dirt in the air, to treat wastewater or to purify, It can effectively and economically and safely purify the environment such as antibacterial and antifungal, especially when it is kneaded into an organic polymer medium such as organic fiber or plastic and used by being supported by embedding. Another object of the present invention is to provide a powder for environmental purification which exhibits excellent photocatalytic action from the viewpoint of durability without causing deterioration of

Another object of the present invention is to provide a method for producing such a photocatalyst powder for environmental purification. Still another object of the present invention is to provide an organic polymer composition containing such a photocatalyst powder for environmental purification. 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 extensive studies in order to achieve the above object. As a result, titanium dioxide fine particles are dispersed in an aqueous slurry containing an anionic surfactant in advance, and then the titanium dioxide fine particles are dispersed. By forming a coating of calcium phosphate on the entire surface or a part of the surface, a durable calcium phosphate coating is obtained, and since this coating has the property of adsorbing various bacteria and is porous, titanium dioxide is The present invention has been completed by finding that the durability of the medium can be dramatically improved when the medium is used while being supported on a medium such as an organic polymer without impairing its photocatalytic function.

Thus, according to the present invention, it comprises a powder having a porous calcium phosphate coating layer formed on at least a part of the surface of titanium dioxide fine particles, and at least the porous calcium phosphate coating layer and the titanium dioxide fine particles are present. Provided is a photocatalyst powder for environmental purification, which is characterized in that an anionic surfactant is present at the 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. Provided is a method for producing a photocatalyst powder for environmental purification, which is characterized by being 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 above photocatalytic powder for environmental purification.
Further, according to the present invention, there is provided a polymer molded article having an environmental purification function, which is formed by molding the above polymer composition. Further, according to the present invention, there is provided a method for producing a polymer molded article having an environmental purifying function, which comprises kneading the above polymer composition in an extruder and extruding from the extruder.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The photocatalyst powder for environmental purification of the present invention comprises an anionic surfactant at least at the interface between titanium dioxide fine particles and a coating layer of porous calcium phosphate 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 the porous calcium phosphate formed on the surface thereof, but also in the coating layer of the porous calcium phosphate. .

The titanium dioxide fine particles used for producing such a photocatalyst powder for environmental purification are preferably those having a crystal form of anatase as a main component in terms of high performance as a photocatalyst. The titanium dioxide fine particles used in the present invention preferably have an average primary particle diameter of 0.001 to 0.2 micron. If the average particle size is less than 0.001 micron, it is difficult to produce efficiently and not practical. On the contrary, if the average particle size exceeds 0.2 micron, the performance as a photocatalyst is significantly reduced. A more preferable average particle diameter of the primary particles is 0.005 to 0.1 micron.

The titanium dioxide used in the present invention is not particularly limited as long as it has a photocatalytic ability, but the titanium halide is excellent in primary particle dispersibility. The primary dispersed particles produced by the gas phase reaction, that is, the gas phase oxidation and / or the gas phase hydrolysis reaction, are preferable. The term “primary dispersed particles” as used herein refers to a state in which particles are less aggregated when the particles are observed using a transmission electron microscope, for example.

In order to produce 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 particles are preliminarily prepared in an aqueous slurry containing an anionic surfactant in advance. Perform distributed processing. The term "anionic surfactant" as used herein indicates remarkable surface activity at a relatively low concentration, and among those used for controlling interfacial phenomena, the anionic surfactant is the main anionic agent that is ionized in an aqueous solution. Refers to

Specific examples of the anionic surfactant include:
Sodium fatty acid 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 Sulfates such as sodium dodecylbenzene sulfonate, sodium alkylnaphthalene sulfonate, sodium alkyl diphenyl ether disulphonate, sodium alkane sulfonate, sodium sulfonate of aromatic sulfonic acid formalin condensate, alkyl phosphonate potassium salt ,
Examples thereof include sodium hexametaphosphate and dialkylsulfosuccinic acid. These may be used alone,
Alternatively, a plurality of them may be used in combination.

By pretreatment with a slurry containing an anionic surfactant, the precipitation reaction rate of calcium phosphate is improved in the step of forming the coating layer of porous calcium phosphate, and the precipitation is completed in a short time. Also,
By the presence of 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 titanium dioxide 10
0 to 20 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 part by weight, the effect as a surfactant is hard to appear, and the adhesive force of the porous calcium phosphate and eventually the durability are lowered. On the other hand, if it exceeds 20 parts by weight, the effect depending on the added amount is not obtained and it becomes economically impractical.

After performing 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 fine particles of titanium dioxide to deposit calcium phosphate on the surfaces of the fine particles.

The simulated body fluid used herein is a working fluid that gives calcium phosphate compounds represented by various rational formulas such as tricalcium phosphate Ca ₃ (PO ₄ ) ₂ and is, 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 in water. In addition, HCl and (CH ₂ OH) ₃ CN
It is preferable to adjust the pH to 7 to 8, especially 7.4 with 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
It is preferably 0 mM. If the concentration of Ca ²⁺ ion and phosphate ion is dilute, the precipitation of calcium phosphate will take time. On the contrary, if the concentration is higher than this, generation will occur too rapidly, and the control of porosity and film thickness will occur. Becomes difficult.

The porous calcium phosphate produced may be any porous calcium phosphate composed of 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
Etc. are included. Among these, hydroxyapatite is preferable, and amorphous hydroxyapatite is particularly preferable. 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 titanium dioxide fine particles is preferably about 0.01 to 50% by weight based on the weight of titanium dioxide. If the amount of porous calcium phosphate is too small, the amount of adsorption of harmful substances, malodorous substances, etc. by the porous calcium phosphate will decrease, so the decomposition and removal efficiency of those substances will decrease,
Further, the carrier of the photocatalyst powder is deteriorated, and the sustainability of the photocatalytic function is reduced. Further, if the amount is too large, the photocatalytic function of titanium dioxide is difficult to sufficiently develop. Finally, the titanium dioxide slurry that has been coated with the porous calcium phosphate is dried to obtain a photocatalyst powder for environmental purification.

The photocatalyst powder for environmental purification according to the present invention may have fine particles carrying a metal such as platinum, rhodium, ruthenium, palladium, silver, copper, iron or zinc on the surface thereof. In such a case, the rate of oxidative decomposition of the chemical substance is further increased, and the bactericidal and algicidal actions are also increased. Further, the metal may be supported on the raw material 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 an exposed portion where the surface of titanium dioxide is not covered in the pores. Under irradiation, titanium dioxide can act as a catalyst for environmental purification. That is, by the redox action of electrons and holes generated by the photocatalyst powder under irradiation of light, an organic substance which is a malodor source adsorbed by calcium phosphate, a harmful substance in the air, or an organic solvent dissolved in water Organic compounds that pollute the environment such as agricultural chemicals and pesticides 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 photocatalytic powder for environmental purification is applied to an organic polymer medium such as organic fiber or plastic. Even when it is added by kneading or the like, the fiber or the plastic itself is less likely to undergo deterioration such as decomposition and the photocatalytic effect can be maintained for a long time.

Further, since the porous calcium phosphate membrane has a property of adsorbing bacteria, proteins, amino acids, bacteria in water and air, viruses, organic substances as a source of malodor, nitrogen oxides, etc., adsorbed bacteria etc. The strong oxidizing power generated in titanium dioxide by irradiation of light can surely and efficiently kill or decompose it. Light sources for light irradiation include fluorescent lamps, incandescent lamps, black lights, and UV.
It is possible to use artificial light from a lamp, a mercury lamp, a xenon lamp, a halogen lamp, a metal halide lamp, or sunlight. Then, due to the redox action of electrons and holes generated in titanium dioxide by irradiation of light,
It is possible to rapidly and continuously decompose and remove proteins, amino acids, bacteria, viruses, etc. adsorbed on the porous calcium phosphate membrane.

In particular, when the above-mentioned photocatalyst powder for environmental purification is kneaded or embedded in an organic polymer medium such as an organic fiber or a plastic, the organic fiber or the plastic is not decomposed and a foul odor or NO _x is generated. Adsorbs environmentally polluting organic compounds such as toxic substances in the air or organic solvents and pesticides dissolved in water, fluorescent lamps, incandescent lamps, black lights, UV lamps, mercury lamps, xenon lamps, halogens 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 from a lamp or a metal halide lamp or sunlight. Moreover, since such an effect can be obtained simply by irradiating light, low cost,
It is energy saving and maintenance free.

Platinum on its surface as titanium dioxide particles,
When a metal carrying a metal such as rhodium, ruthenium, palladium, silver, copper, iron, zinc is used, the catalytic action further enhances the effect of decomposing and removing organic compounds and the effect of environmental purification such as sterilization and antifungal effect. 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 and poly. Acetate, ABS resin, epoxy resin, vinyl acetate resin, cellulose, cellulose derivative, polyamide, polyurethane, polycarbonate,
It is applicable to organic fibers and plastic molded products made of all kinds of organic polymers such as polystyrene, urea resin, fluororesin, polyvinylidene fluoride, phenolic resin, celluloid, chitin and starch sheet. By molding a composition composed of a polymer, a polymer molded article having an environmental purification function can be obtained. Generally, a photocatalyst powder is kneaded and carried by a means such as embedding in the manufacturing process of an organic fiber or a plastic molded product. In particular, it is preferable to obtain a polymer molded product having an environmental purification function by kneading the organic polymer and the photocatalyst powder using an extruder and extrusion molding. The concentration of the photocatalyst powder in the polymer composition composed of 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.

The photocatalyst powder for environmental purification of the present invention will be specifically described below with reference to examples. In each Example and Comparative Example, photoactivity was measured by the following method.
Research by Kato et al. (Industrial Chemistry, 63, 5, 748-75
0 (1960)), 20 mL of tetralin and 0.02 g of titanium dioxide are sealed in a sealed 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, it was irradiated with ultraviolet rays and the oxygen absorption rate by the liquid phase oxidation reaction of tetralin was determined. 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 taken as the oxygen absorption rate, which was used as a measure of photoactivity.

[0030]

Example 1 To 250 L of pure water, 600 g of a commercially available polycarboxylic acid type polymer surfactant (Poise 530 manufactured by Kao Corporation) was added, and titanium dioxide ultrafine particles (Showa Titanium Co., Ltd.) were added thereto. ) F4, average particle size of primary particles 0.03 micron)
12 kg was added to carry out dispersion treatment. Separately, in pure water, 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 ⁻
Was prepared at a concentration of 144 mM and HPO ₄ ⁻ was 1.1 mM to prepare 350 L of a simulated body fluid. 250 L of titanium dioxide slurry obtained by the above method and 350 of simulated body fluid
L was mixed, and the temperature was kept at 40 ° C. and kept for 24 hours. When the amount of calcium phosphate deposited was analyzed after 4 hours, it was confirmed that about 90% by weight of the finally deposited amount was deposited. Then, the slurry was dried to obtain 10 kg of photocatalyst powder for environmental purification.
When this precipitate was analyzed, it was calcium phosphate containing hydroxyapatite.

The photocatalyst powder for environmental purification thus obtained was used to measure the photoactivity utilizing the oxidation reaction of tetralin. It was found that the photocatalytic activity was as high as 10.0 (mmH ₂ O / min). Next, a compound having a titanium dioxide concentration of 40% by weight was produced from 1 kg of this powder and a polyethylene terephthalate resin using a commercially available twin-screw kneading extruder (KZW15-30MG manufactured by Technobel Co., Ltd.). The obtained compound was neither colored nor resin deterioration 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 (Perex 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 a polyethylene terephthalate resin. The photoactivity of the obtained powder was 10.3. Further, no coloring was observed in the compound as in Example 1.

Example 3 Example 1 was repeated except that sodium hexametaphosphate (special grade reagent manufactured by Junsei Chemical Co., Ltd.) was used as the anionic surfactant.
A photocatalyst powder for environmental purification was obtained by the same method as above, and a compound having a titanium dioxide concentration of 20% by weight was prepared from the powder and the polyester resin. The photoactivity of the obtained powder was 10.9 (mmH ₂ O / min). Also, the compound was not similarly colored.

Example 4 As titanium dioxide fine particles, the average primary particle size was 0.0
A photocatalyst powder for environmental purification was obtained in the same manner as in Example 1 except that the one having a size of 6 microns (F2 manufactured by Showa Titanium Co., Ltd.) was used. The photoactivity of the obtained powder was 9.8 (mmH ₂
O / min). Further, 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 procedure of Example 1 was repeated except that the composition of the simulated body fluid was adjusted so that Ca ²⁺ was 0.9 mM and HPO ₄ ⁻ was 9.6 mM after mixing the titanium dioxide slurry and the simulated body fluid. A photocatalyst powder for environmental purification was obtained by the same procedure as in Example 1, and the titanium dioxide concentration was 25% by weight from the powder and the polyester resin.
The compound of The photoactivity of the obtained powder was 11.1 (mmH ₂ O / min). Similarly, no coloring was observed in the compound.

Comparative Example 1 Titanium dioxide is used as a main component in the same manner as in Example 1 except that lauryltrimethylammonium chloride (Kotamin 24P, Kao Corporation), which is a cationic surfactant, is used. 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 2 250 L of titanium dioxide slurry was prepared without adding a surfactant in Example 1. Then, 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
It heat-processed 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 containing titanium dioxide as a main component. The photoactivity of this powder is 11.5 (mmH ₂ O /
Minutes). Next, an attempt was made to make a compound from the powder and a polyethylene terephthalate resin in the same manner as in Example 1, but coloration and deterioration of the resin were observed.

Comparative Example 3 12 kg of titanium dioxide ultrafine particles (F4 manufactured by Showa Titanium Co., Ltd., average particle size of primary particles: 0.03 micron) was put into 600 L of pure water, and after stirring, an aqueous solution of sodium aluminate ( 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 treatment was carried out so that the pH value became 7.5. Then, 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 coloration was observed.

[0039]

Industrial Applicability According to the photocatalyst powder for environmental purification of the present invention, various bacteria, proteins, amino acids, bacteria in water and air, viruses, organic substances as a source of malodor, nitrogen oxides, etc. are excellent by the porous calcium phosphate. The bacteria and the like that are adsorbed on and adsorbed on the can be securely and efficiently killed or decomposed by the strong oxidizing power generated in titanium dioxide by irradiation of light. Therefore, it is possible to efficiently and economically and safely purify the environment, such as removing offensive odors, decomposing and removing harmful substances or stains in the air, drainage treatment, purification treatment, antibacterial treatment and fungi prevention. In particular, when used by being kneaded or embedded in an organic polymer molded product such as an organic fiber or a plastic molded product, the photocatalytic action excellent in durability is exhibited without causing deterioration of the polymer medium.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI B01J 33/00 B01J 33/00 Z 37/03 37/03 Z C01B 25/32 C01B 25/32 B C01G 23/04 C01G 23 / 04 Z 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 (73) Patent holder 597039869 Nonami Toru 3-9-6 Kibogaoka, Chikusa-ku, Nagoya-shi, Aichi (74) The above three agents 100070792 Patent attorney Yukio Uchida (72) Inventor Hiroshi Amada, Heiwagaoka, Meito-ku, Nagoya, Aichi 70 Address 4 Inokoishi Housing No. 301 (72) Inventor Toru Nonami 1-70 Heiwagaoka, Meito-ku, Nagoya City, Aichi Prefecture No. 302 Inoshikoishi Housing No. 302 (72) Inventor Katsura Ito Soga, Nagano Prefecture 1 Showa Denko Stock market Shiojiri Laboratory, Research Institute (72) Hiroyuki Hagiwara, Inoue, Shiojiri City, Nagano 1 Suga, Showa Denko Co., Ltd. Research Institute, Shiojiri Laboratory (56) Reference JP-A-8-322923 (JP, A) JP 9 -52052 (JP, A) JP-A-62-101496 (JP, A) JP-A-9-299809 (JP, A) JP-A-7-69691 (JP, A) JP-A-9-262481 (JP, A) ) JP-A-10-193500 (JP, A) JP-A-4-308513 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B01J 21/00 -38/74 B01J 2 / 00,2 / 20 C01B 25/32 C01G 23/07 C02F 1 / 32,1 / 72 D01F 1/10 JISST file (JOIS)

Claims (13)

(57) [Claims] 1. A powder comprising a coating layer of porous calcium phosphate formed on at least a part of the surface of titanium dioxide fine particles, wherein the coating layer of the porous calcium phosphate and titanium dioxide fine particles are at least at the interface. 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 or 2, 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 photocatalytic powder for environmental purification according to claim 1, wherein the amount of porous calcium phosphate is 0.01 to 50% by weight based on the weight of titanium dioxide fine particles. 5. Titanium dioxide fine particles are dispersed in an aqueous slurry containing an anionic surfactant, and then a porous calcium phosphate coating is formed on at least a part of the surface of the titanium dioxide fine particles. Method for producing photocatalyst powder for environmental purification. 6. The environmental purifying agent according to claim 5, wherein the aqueous slurry used for the dispersion treatment of 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. Method for producing photocatalyst powder. 7. The titanium dioxide fine particles have an average primary particle diameter of 0.001 to 0.2 micron.
Alternatively, the method for producing a photocatalyst powder for environmental purification according to claim 6. 8. The photocatalyst for environmental purification according to claim 5, wherein the fine particles of titanium dioxide are powders of primary dispersed particles produced by a gas phase reaction using titanium halide as a raw material. Powder manufacturing method. 9. A method in which a pseudo-body fluid containing at least calcium ions and phosphate ions is contacted with titanium dioxide fine particles to precipitate porous calcium phosphate on at least a part of the surface of the titanium dioxide fine particles to form a coating thereof. Item 9. A method for producing a photocatalyst powder for environmental purification according to any one of items 5 to 8. 10. The calcium ion concentration in the simulated body fluid is 0.1 to 50 mM, and the phosphate ion concentration is 0.1 to 20 m.
The method for producing a photocatalyst powder for environmental purification according to claim 9, wherein M 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 product having an environmental purification function, which is obtained by molding the polymer composition according to claim 11. 13. A method for producing a polymer molded article having an environmental purification function, which comprises kneading the polymer composition according to claim 11 in an extruder and extrusion-molding from the extruder.