JP2011132626A - Textile product supporting photocatalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a textile product supporting a photocatalyst exhibiting a high photocatalyst activity. <P>SOLUTION: There is provided the textile product supporting the photocatalyst, wherein the photocatalyst is supported on a textile fabric. The textile product supporting the photocatalyst is obtained by supporting the photocatalyst having an average particle diameter of 0.2-2.5 μm on the textile fabric having at least one surface subjected to a raising treatment, and having 250-500 g/m<SP>2</SP>weight. The photocatalyst is at least one in titanium oxide and tungsten oxide. The textile product supporting the photocatalyst is obtained from a photocatalyst dispersion containing the photocatalyst and an inorganic thickener. Furthermore, the inorganic thickener is a smectitic clay mineral. A woven fabric, knitted fabric or nonwoven fabric is used as the textile fabric. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fiber product carrying a photocatalyst, and more particularly to a fiber product carrying a photocatalyst having a specific average particle diameter on a fiber fabric having a brushed surface at least on one side.

  When a semiconductor is irradiated with light having energy greater than or equal to the band gap, electrons in the valence band are excited by the conductor and holes are generated in the valence band. The holes generated in this manner have a strong oxidizing power, and the excited electrons have a strong reducing power, so that the material in contact with the semiconductor has a redox action. This redox action is called a photocatalytic action, and a semiconductor that can exhibit such a photocatalytic action is called a photocatalyst. As such a photocatalyst, titanium oxide or tungsten oxide is known.

  It is known that a photocatalyst-supported fiber product in which a photocatalyst is supported on a fiber fabric exhibits a deodorizing action, an antibacterial action, and the like. The photocatalyst is activated on the light-receiving surface of the fiber because the photocatalyst is activated by light reception. For example, in Patent Document 1, the photocatalyst is obtained by applying the photocatalyst to the tip of the fluff with the fibers fluffed. An efficient method is disclosed. However, in such a brushed fiber fabric, when a photocatalyst having a small average particle diameter is supported, the photocatalyst is buried in the brushed fiber fabric or attached to the base of the hair, so that it is difficult for light to reach. For this reason, there is a problem that the ratio of the photocatalyst that receives light is lowered and the photocatalytic activity is lowered.

JP 2007-332121 A

  Then, this invention makes it a subject to provide the photocatalyst body carrying | support fiber product which shows high photocatalytic activity.

  As a result of intensive studies to solve the above problems, the present inventors have developed a photocatalyst exhibiting excellent photocatalytic activity by supporting a photocatalyst having a specific average particle diameter on a fiber fabric having a brushed surface on at least one side. The present inventors have found that a body-supporting fiber product can be obtained and completed the present invention.

That is, the photocatalyst-supporting fiber product of the present invention is a photocatalyst-supporting fiber product in which a photocatalyst is supported on a fiber fabric, and the photocatalyst having an average particle diameter of 0.2 to 2.5 μm is at least on one side. It is supported on the fiber fabric having a basis weight of 250 to 500 g / m ² subjected to raising treatment.
The photocatalyst of the present invention preferably contains at least one of titanium oxide and tungsten oxide.
The photocatalyst is preferably obtained by using a photocatalyst dispersion containing titanium oxide and / or tungsten oxide and an inorganic thickener.
Examples of the inorganic thickener include smectite clay minerals.
Examples of the fiber fabric of the present invention include woven fabric, knitted fabric and non-woven fabric.

  According to the present invention, a photocatalyst having a specific average particle diameter is supported on a fiber fabric having a specific basis weight at least on one side, thereby preventing the photocatalyst from being buried in the fiber fabric, As a result, a photocatalyst-supported fiber product that exhibits an excellent photocatalytic action can be produced.

(Photocatalyst)
The photocatalyst of the present invention is, for example, a semiconductor that exhibits a photocatalytic action by irradiation with ultraviolet rays or visible light, and examples thereof include a compound of a metal element having a specific crystal structure and oxygen, nitrogen, sulfur, and fluorine. Examples of metal elements include Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, and Cu. , Ag, Au, Zn, Cd, Ga, In, Tl, Ge, Sn, Pb, Bi, La, and Ce. Examples of the compound include one or more oxides, nitrides, sulfides, oxynitrides, oxysulfides, nitrofluorides, oxyfluorides, and oxynitrofluorides of these metals. Of these, oxides of Ti, W, and Nb are preferable, and metatitanic acid, titanium oxide, tungsten oxide, and the like are particularly preferable. In addition, a photocatalyst body may be used independently and may use 2 or more types together.

(Metatitanic acid)
Metatitanic acid (H ₂ TiO ₃ , TiO (OH) ₂ , β-titanium hydroxide) can be obtained, for example, by heating and hydrolyzing an aqueous solution of titanyl sulfate.
BET specific surface area of the metatitanic acid is not particularly limited, from the viewpoint of photocatalytic activity, usually 100 to 500 m ² / g, preferably from 300~400m ² / g.

(Titanium oxide)
Titanium oxide (TiO ₂ ) is obtained, for example, by (i) a method in which a precipitate is obtained by adding a base to this without heating an aqueous solution of titanyl sulfate or titanium chloride, and (ii) titanium is fired. It can be obtained by adding water, acidic aqueous solution, basic aqueous solution or the like to the alkoxide to obtain a precipitate, and baking this precipitate, or (iii) baking metatitanic acid. The titanium oxide obtained by these methods can be made into a desired crystal type such as anatase type, brookite type, rutile type, etc. by adjusting the baking temperature and baking time at the time of baking.
In addition to the above, as titanium oxide, JP 2001-72419 A, JP 2001-190953 A, JP 2001-316116 A, JP 2001-322816 A, and JP 2002-29749 A. Publication, JP 2002-97019, WO 01/10552 pamphlet, JP 2001-212457, JP 2002-239395, WO 03/080244 pamphlet, WO 02/053501 pamphlet, JP 2007-69093, Chemistry. Letters, Vol. 32, NO. 2, P.196-197 (2003), Chemistry Letters, Vol.32, NO. 4, P.364-365 (2003), Chemistry Letters, Vol.32, NO. 8, P. 772-773 (2003), Chem. Mater., 17, P. 1548-1552 (2005) and the like may be used. JP 2001-278625 A, JP 2001-278626 A, JP 2001-278627 A, JP 2001-302241 A, JP 2001-335321 A, JP 2001-354422 A, It can also be obtained by the methods described in JP 2002-29750 A, JP 2002-47012 A, JP 2002-60221 A, JP 2002-193618 A, JP 2002-249319 A, and the like.

BET specific surface area of the titanium oxide is not particularly limited, from the viewpoint of photocatalytic activity, usually 100 to 500 m ² / g, preferably from 300~400m ² / g.

(Tungsten oxide)
Tungsten oxide (WO ₃ ) includes, for example, (i) a method of adding tungstic acid as a precipitate by adding an acid to an aqueous solution of tungstate, and firing this tungstic acid, (ii) ammonium metatungstate, para It can be obtained by a method of thermally decomposing by heating ammonium tungstate.

BET specific surface area of the tungsten oxide is not particularly limited, from the viewpoint of photocatalytic activity, typically 5 to 100 m ² / g, preferably from 20 to 50 m ² / g.

  The average particle size of the photocatalyst of the present invention is 0.2 to 2.5 μm, preferably 0.5 to 2.0 μm, more preferably 0.5 to 1.8 μm. When the average particle diameter is less than 0.2 μm, the photocatalyst is partially buried between the fibers, so that the amount of the photocatalyst that receives light is reduced and the photocatalytic activity is lowered. On the other hand, when the particle diameter is larger than 2.5 μm, the texture of the fiber fabric is impaired.

(Photocatalyst dispersion medium)
In order to uniformly and efficiently support the photocatalyst of the present invention on the light receiving surface of the fiber fabric, it is preferable to use the photocatalyst as a photocatalyst dispersion in which the photocatalyst is dispersed in a dispersion medium. There is no particular limitation as long as the body can be dispersed, and an aqueous solvent mainly containing water is usually used. Specifically, water alone or a mixed solvent of water and a water-soluble organic solvent may be used. When a mixed medium of water and a water-soluble organic solvent is used, the content of water is preferably 50% by mass or more. Examples of the water-soluble organic solvent include water-soluble alcohols such as methanol, ethanol, propanol, and butanol, acetone, and methyl ethyl ketone. In addition, a water-soluble organic solvent may be used independently and may use 2 or more types together. The dispersion medium is usually contained in an amount of 5 to 200 times by mass, preferably 10 to 100 times by mass with respect to the photocatalyst. Furthermore, the dispersion medium may contain a known dispersant for the purpose of improving the dispersion stability of the photocatalyst in the dispersion.

(Electron-withdrawing substance or its precursor)
The photocatalyst dispersion liquid may contain an electron-withdrawing substance or a precursor of the electron-withdrawing substance in order to enhance the photocatalytic action. The electron-withdrawing substance is a compound that can be carried on the surface of the photocatalyst and can exhibit electron-withdrawing substance, and the precursor of the electron-withdrawing substance is a compound that can transition to the electron-withdrawing substance on the surface of the photocatalyst. (For example, a compound that can be reduced to an electron-withdrawing substance by light irradiation). When an electron-withdrawing substance is supported on the surface of the photocatalyst, recombination of electrons excited by the conductor with light irradiation and holes generated in the valence band is suppressed, and the photocatalytic action is further enhanced. it can.

When the precursor of the electron-withdrawing substance is added, it is preferable that the photocatalyst dispersion liquid is irradiated with light after the addition. The light to be irradiated is not particularly limited as long as the light has energy higher than the band gap of the photocatalyst. By irradiating with light, the precursor is reduced by the electrons generated by photoexcitation to become an electron-withdrawing substance and is carried on the surface of the photocatalyst. In addition, although light irradiation may be performed with respect to a photocatalyst body dispersion liquid, you may perform after formation of a photocatalyst layer. More preferably, when a plurality of photocatalysts are mixed, it is preferably performed before mixing.
Furthermore, methanol, ethanol, oxalic acid, or the like can be added as a sacrificial agent before irradiation with light for the purpose of more efficiently supporting the electron-withdrawing substance.

  The electron-withdrawing substance or its precursor contains one or more metal atoms selected from the group consisting of Cu, Pt, Au, Pd, Ag, Fe, Nb, Ru, Ir, Rh and Co. It is preferable that More preferably, it contains one or more metal atoms of Cu, Pt, Au and Pd. For example, the electron-withdrawing substance may be a metal made of the metal atom, or an oxide or hydroxide of these metals, and the precursor of the electron-withdrawing substance may be a metal made of the metal atom. Nitrates, sulfates, halides, organic acid salts, carbonates, phosphates, and the like.

Preferable specific examples of the electron-withdrawing substance include Cu, Pt, Au, and Pd metals. Moreover, as a preferable specific example of the precursor of an electron withdrawing substance, as a precursor containing Cu, copper nitrate [Cu (NO ₃ ) ₂ ], copper sulfate [CuSO ₄ ], copper chloride [CuCl ₂ , CuCl], Copper bromide [CuBr ₂ , CuBr], copper iodide [CuI], copper iodate [CuI ₂ O ₆ ], ammonium chloride [Cu (NH ₄ ) ₂ Cl ₄ ], copper oxychloride [Cu ₂ Cl (OH) ) ₃ ], copper acetate [CH ₃ COOCu, (CH ₃ COO) ₂ Cu], copper formate [(HCOO) ₂ Cu], copper carbonate [CuCO ₃ ], copper oxalate [CuC ₂ O ₄ ], copper citrate [ Cu ₂ C ₆ H ₄ O ₇ ], copper phosphate [CuPO ₄ ]; as a precursor containing Pt, platinum chloride [PtCl ₂ , PtCl ₄ ], platinum bromide [PtBr ₂ , PtBr ₄ ], platinum iodide [PtI _2, PtI _4], potassium platinum chloride [K ₂ (PtCl _4)], hexa Rollo chloroplatinic acid [H ₂ PtCl _6], platinum sulfite _{[H 3 Pt (SO 3) 2} OH ], platinum oxide [PtO _2], tetraammine platinum chloride [Pt (NH _{3) 4} Cl _2], bicarbonate tetraammineplatinum [ C ₂ H ₁₄ N ₄ O ₆ Pt], tetraammineplatinum hydrogen phosphate [Pt (NH ₃ ) ₄ HPO ₄ ], tetraammineplatinum platinum [Pt (NH ₃ ) ₄ (OH) ₂ ], tetraammineplatinum nitrate [Pt ( NO ₃ ) ₂ (NH ₃ ) ₄ ], tetraammine platinum tetrachloro platinum [(Pt (NH ₃ ) ₄ ) (PtCl ₄ )], dinitrodiamine platinum [(Pt (NO ₂ ) ₂ (NH ₃ ) ₂ )] As a precursor containing Au, gold chloride [AuCl], gold bromide [AuBr], gold iodide [AuI], gold hydroxide [Au (OH) ₂ ], tetrachloroauric acid [HAuCl ₄ ], tetrachloro; Potassium goldate [KAuCl ₄ ], tetrabromoauric acid For example, palladium [KAHBr ₄ ], gold oxide [Au ₂ O ₃ ]; Pd-containing precursors such as palladium acetate [(CH ₃ COO) ₂ Pd], palladium chloride [PdCl ₂ ], palladium bromide [PdBr ₂ ] ], Palladium iodide [PdI ₂ ], palladium hydroxide [Pd (OH) ₂ ], palladium nitrate [Pd (NO ₃ ) ₂ ], palladium oxide [PdO], palladium sulfate [PdSO ₄ ], potassium tetrachloropalladate [K ₂ (PdCl ₄ )], potassium tetrabromopalladate [K ₂ (PdBr ₄ )], tetraammine palladium chloride [Pd (NH ₃ ) ₄ Cl ₂ ], tetraammine palladium bromide [Pd (NH ₃ ) ₄ Br ₂ ], Tetraammine palladium nitrate [Pd (NH ₃ ) ₄ (NO ₃ ) ₂ ], tetraammine palladium tetraammine palladium acid Tetraamminepalladium chloride [(Pd (NH ₃ ) ₄ ) (PdCl ₄ )], ammonium tetrachloropalladate [(NH ₄ ) ₂ PdCl ₄ ]; In addition, an electron withdrawing substance or its precursor may each be used independently, and may use 2 or more types together. Needless to say, one or more electron-withdrawing substances and one or more precursors may be used in combination.

  When the electron-withdrawing substance or its precursor is also contained, the content is usually 0.005 to 0.6 parts by mass, preferably 100 to parts by mass in terms of the total amount of photocatalyst particles, in terms of metal atoms. Is 0.01 to 0.4 parts by mass. If the electron withdrawing substance or its precursor is less than 0.005 parts by mass with respect to the total amount of 100 parts by mass, the effect of improving the photocatalytic activity by the electron withdrawing substance may not be sufficiently obtained, If it exceeds 0.6 parts by mass relative to 100 parts by mass of the total amount, the photocatalytic action may be lowered.

(Additive)
The photocatalyst dispersion liquid may contain an additive for the purpose of improving the photocatalytic action. Specific examples of additives include silicon compounds such as amorphous silica, silica sol, water glass, and organopolysiloxane; aluminum compounds such as amorphous alumina, alumina sol, and aluminum hydroxide; zeolite; magnesium oxide, calcium oxide , Strontium oxide, barium oxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide and other alkaline earth metal oxides or alkalinity metal hydroxides; calcium phosphate, molecular sieve, activated carbon, organic polysiloxane compounds Polycondensates, phosphates, fluoropolymers, silicone polymers, acrylic resins, polyester resins, melamine resins, urethane resins, alkyd resins, and the like.
Further, as the additive, a binder or the like can be used in order to hold the photocatalyst body more firmly on the fiber surface (for example, JP 2008-237793 A, JP 2008-80237 A, JP 2008). No.-50707, JP-A-2005-194625, JP-A-2005-97773, JP-A-2008-163480, JP-A-2008-307528, JP-A-2008-223175, JP-A-2006-28688. (See the official gazette, etc.)
Each additive may be used alone or in combination of two or more.

  Moreover, when sedimentation is observed when the photocatalyst dispersion liquid is allowed to stand, by adding a thickener, sedimentation is suppressed and handling becomes easy. The thickener is not particularly limited, but an inorganic thickener is preferable to an organic thickener in that it hardly inhibits photocatalytic activity. Examples of inorganic thickeners include smectite clay minerals (montmorillonite, piderite, nontronite, saponite, hectorite, soconite, pentonite, etc.), aluminosilicates (zeolite, mordenite, etc.), and synthetic silicates. In particular, it is preferable to use a smectite clay mineral. An inorganic type thickener is 0.01-100 mass parts with respect to 100 mass parts of photocatalyst body dispersion liquid, Preferably, it is good to add 0.1-10 mass parts. When the amount of the inorganic thickener is less than 0.01 parts by mass with respect to 100 parts by mass of the photocatalyst dispersion, the thickening effect cannot be obtained and the photocatalyst is precipitated. Since the system thickener covers the photocatalyst, the photocatalytic activity decreases.

(Preparation of photocatalyst dispersion)
The photocatalyst dispersion liquid can be obtained by adding and dispersing the photocatalyst body to the photocatalyst dispersion medium. The dispersion treatment can be performed, for example, by an ordinary method using a medium stirring type disperser.

(Application and drying of photocatalyst)
The photocatalyst dispersion liquid thus obtained is applied to a fiber fabric such as a woven fabric, a knitted fabric, or a non-woven fabric, and the fiber fabric is dried, whereby the photocatalyst is supported on the surface of the fiber fabric. As a coating method, a photocatalyst dispersion diluted with water is impregnated into a fiber fabric, and after removing moisture from the fiber fabric with a roller press, drying is generally performed. Screen printing processing may be used. The drying condition after processing may be performed within a range not impairing the function of the fiber, and is usually 100 to 200 ° C., and the drying time is usually 1 to 60 minutes.

  Examples of the material of the fiber fabric used in the present invention include, for example, polyester, polyacrylonitrile, polyethylene, polypropylene, polyamide, polyvinyl chloride, polyvinylidene chloride, nylon, cellulose, acetate, protein fibers such as promix, vinylon, rayon, Examples include cupra, polynosic, cotton, hemp, silk, wool and cashmere.

Basis weight of the fiber cloth used in the present invention ^{is, 250g / m 2 ~500g / m} 2, preferably from ^{280g / m 2 ~400g / m 2} . When the basis weight is 250 g / m ² or less, the strength as a fiber product is lowered, and problems such as easy breakage occur. In addition, the fiber fabric needs to be brushed at least on one side. As a raising method, any of Emery raising, needle cloth raising, and thistle raising may be used, and the fiber fabric can be raised with a commercially available raising machine.

  The photocatalyst-supported fiber product of the present invention is not only outdoors but also has a high catalyst by irradiation with light even in an indoor environment receiving only light from a visible light source such as a fluorescent lamp, an incandescent lamp, a halogen lamp, and a sodium lamp. Shows the effect. Therefore, the photocatalyst dispersion liquid of the present invention can be used, for example, for curtains, carpets, futon covers, sheets, clothing, automobile interior materials (automobile seats using fiber products as surface materials, automobile ceiling materials, automobile floor carpets, etc. ), Masks, wall materials (limited to those using fiber products as surface materials), etc., and dried, they are exposed to formaldehyde, acetaldehyde, aroma contained in the gas phase by irradiation with light from indoor lighting. Reduces the concentration of volatile organic compounds such as aromatic compounds, mercaptans, ammonia and other malodorous substances, nitrogen oxides, and Staphylococcus aureus, Escherichia coli, Bacillus anthracis, tuberculosis, cholera, diphtheria, tetanus, and plague Eradicates pathogenic bacteria such as Shigella, Clostridium botulinum, Legionella, and viruses such as influenza virus and norovirus Decomposition, can be removed.

  Examples of the volatile aromatic compound include benzene, toluene, xylene, methylbenzene, trimethylbenzene, ethylbenzene, styrene, chlorobenzene, dichlorobenzene, trichlorobenzene, cresol, aniline, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

  In addition, about the measurement of each physical property in an Example and a comparative example, and the evaluation of the photocatalytic activity, it performed with the following method.

<Crystal type>
An X-ray diffraction spectrum was measured using an X-ray diffractometer (“RINT2000 / PC” manufactured by Rigaku Corporation), and a crystal type was determined from the spectrum.

<BET specific surface area>
It measured by the nitrogen adsorption method using the specific surface area measuring apparatus ("Monosorb" by Yuasa Ionics Co., Ltd.).

<Average dispersed particle size>
The average particle size was measured using a submicron particle size distribution measuring device (“N4Plus” manufactured by Coulter) or a particle size distribution measuring device (“MICROTRAC HRA model 9320-X100” manufactured by Nikkiso). In the former, after the sample was dispersed in water and measured, the result obtained by automatically performing the monodisperse mode analysis with the software attached to the apparatus was taken as the average dispersed particle size (nm). In the latter, the sample was dispersed in a 0.2% by mass aqueous solution of sodium hexametaphosphate (manufactured by Wako Pure Chemical Industries, Ltd.) and then measured for 50 volume% diameter, which was taken as the average particle diameter.

<Photocatalytic activity evaluation>
The fiber fabric carrying the photocatalyst was irradiated with black light (ultraviolet intensity ² mW / cm ² ) for 16 hours, then placed in a gas bag with an internal volume of 1 L, sealed, and then the inside was evacuated. Next, 600 mL of a mixed gas of oxygen and nitrogen (volume ratio 1: 4) is sealed in this gas bag, and 0.6 mL of nitrogen gas containing toluene (concentration 0.5% by volume) is sealed, and in the dark for 1 hour. After holding, the light from the white fluorescent lamp was irradiated so that the illuminance immediately before the measurement sample was 6000 lux. A UV light intensity meter [“UD-36”] manufactured by Topcon Corporation was attached to a UV intensity meter [“UVR-2”] manufactured by Topcon Corporation, and the UV intensity of the measurement sample at this time was measured to find 40 μW / cm ^2. Met. After 22 hours of light irradiation, the components in the gas bag were sampled, and the concentration of toluene was measured by a gas chromatograph apparatus [“GC-14A” manufactured by Shimadzu Corporation]. The decomposition rate of toluene is calculated from the following formula, and the higher the decomposition rate, the higher the resolution of toluene.
Decomposition rate of toluene = (C ₀ -C ₂₂ ) / C ₀
(C ₀ : toluene concentration at 0 hours of light irradiation, C ₂₂ : toluene concentration at 22 hours of light irradiation)

(Production Example 1-Preparation of platinum-supported tungsten oxide particle dispersion)
4146 g of tungsten oxide (WO ₃ , manufactured by Nippon Inorganic Chemical Co., Ltd.) was charged in an alumina sheath having a side of 190 mm, placed in a high-speed heating furnace (manufactured by Motoyama), and heat-treated at 700 ° C. for 2 hours. Next, the heat-treated tungsten oxide was subjected to jet mill pulverization using STJ-200 (manufactured by Seishin Enterprise). The indentation pressure and pulverization pressure during jet mill pulverization were both 0.68 MPa, and the feed rate of the raw material (tungsten trioxide powder) was 3 kg / h. The average particle diameter of the pulverized tungsten oxide was measured by “MICROTRAC HRA model 9320-X100” and found to be 0.45 μm.

50 g of the obtained tungsten oxide was dispersed in 445 g of water, and an aqueous hexachloroplatinic acid solution (H ₂ PtCl ₆ ) was added so that Pt was 0.12 parts by mass with respect to 100 parts by mass of the tungsten oxide particles, while stirring. A high pressure mercury lamp (100 W, manufactured by USHIO) was irradiated for 1 hour. Thereafter, 5 g of methanol was added to the tungsten oxide particle dispersion, followed by irradiation with a high-pressure mercury lamp for 2 hours in the same manner as described above, to obtain a platinum-supported tungsten oxide particle dispersion.

(Production Example 2-Preparation of titanium oxide particle dispersion)
20.7 g of ammonium dihydrogen phosphate (Wako Special Grade Reagent) was dissolved in 5.39 kg of water. To this aqueous solution of ammonium dihydrogen phosphate, 1.49 kg of a metatitanic acid solid (cake) (solid content concentration of 46.2% by mass as TiO ₂ ) obtained by hydrolyzing titanyl sulfate with heating was mixed. At this time, the aqueous solution was an aqueous solution containing 0.02 mol of ammonium dihydrogen phosphate with respect to 1 mol of metatitanic acid. The obtained mixture was subjected to a dispersion treatment under the following conditions using a medium stirring type disperser (“Ultra Apex Mill UAM-1” manufactured by Kotobuki Giken Co., Ltd.) to obtain a titanium oxide particle dispersion.
Dispersion medium: 1.85 kg of zirconia beads having a diameter of 0.05 mm
Stirring speed: peripheral speed 8.1 m / sec Flow rate: 0.25 L / min Processing time: about 76 minutes

  The average particle diameter of the titanium oxide particles in the obtained titanium oxide particle dispersion was 96 nm when measured by the above-mentioned “N4Plus”. A part of the mixture before the dispersion treatment and a part of the titanium oxide particle dispersion after the dispersion treatment were vacuum-dried to obtain a solid content, and the X-ray diffraction spectrum of each solid content was measured and compared. The crystal type was anatase type, and no change in crystal type due to dispersion treatment was observed.

(Production Example 3-Preparation of platinum-supported tungsten oxide particle dispersion)
1 kg of particulate tungsten oxide powder (manufactured by Nippon Inorganic Chemical Co., Ltd.) was added to 4 kg of ion-exchanged water and mixed to obtain a mixture. This mixture was subjected to dispersion treatment under the following conditions using a medium agitating disperser (“Ultra Apex Mill UAM-1” manufactured by Kotobuki Giken Co., Ltd.) to obtain a tungsten oxide particle dispersion.
Dispersion medium: 1.85 kg of zirconia beads having a diameter of 0.05 mm
Stirring speed: peripheral speed 12.6 m / sec Flow rate: 0.25 L / min Processing time: about 50 minutes

The average particle diameter of the tungsten oxide particles in the obtained tungsten oxide particle dispersion was 118 nm as measured by the above-mentioned “N4Plus”. Moreover, when a part of this dispersion was vacuum-dried to obtain a solid content, the BET specific surface area of the obtained solid content was 40 m ² / g. The mixture before the dispersion treatment is similarly vacuum dried to obtain a solid content, and the X-ray diffraction spectrum is obtained for the solid content of the mixture before the dispersion treatment and the solid content of the tungsten oxide particle dispersion after the dispersion treatment. As a result of measurement and comparison, the crystal form of both was WO ₃ , and no change in crystal form due to dispersion treatment was observed.

Next, water was added to the obtained tungsten oxide particle dispersion (corresponding to 50 g of tungsten oxide) to make a total amount of 495 g. Thereto, a hexachloroplatinic acid aqueous solution (H ₂ PtCl ₆ ) was added so that Pt was 0.12 parts by mass with respect to 100 parts by mass of tungsten oxide particles to obtain a hexachloroplatinic acid-containing tungsten oxide particle dispersion. The solid content (amount of tungsten oxide particles) contained in 100 parts by mass of this dispersion was 10 parts by mass (solid content concentration 10% by mass). Next, a high pressure mercury lamp (100 W, manufactured by USHIO) was irradiated for 1 hour while stirring the hexachloroplatinic acid-containing tungsten oxide particle dispersion. Thereafter, 5 g of methanol was added to the above tungsten oxide mixed solution, and irradiation with a high-pressure mercury lamp was performed for 2 hours in the same manner as described above with continuous stirring to obtain a platinum-supported tungsten oxide dispersion.

(Example)
The platinum-supported tungsten oxide particle dispersion obtained in Production Example 1 and the aqueous solution of titanyl sulfate were hydrolyzed and filtered to obtain a metatitanic acid cake (containing 45 mass% of titanium component in terms of TiO ₂ ). When mixed so as to be 1: 1 (mass ratio), the content of platinum in the dispersion is about 0.1 parts by mass with respect to 100 parts by mass of the total amount of titanium oxide particles and tungsten oxide particles in terms of platinum atoms. The amount was 06 parts by mass. This dispersion was further diluted with water to obtain a photocatalyst particle dispersion. The solid content (total amount of titanium oxide particles and tungsten oxide particles) contained in 100 parts by mass of this photocatalyst particle dispersion was 11 parts by mass (solid content concentration 11% by mass). The average particle size of the photocatalyst in the photocatalyst dispersion was measured by “MICROTRAC HRA model 9320-X100” and found to be 1.3 μm.

The photocatalyst particle dispersion obtained above is diluted with water to 2.67% by mass, impregnated in a woven fabric (made of polyester) having a basis weight of 322 g / m ² , and then roller press The moisture of the woven fabric was removed by heating at 120 ° C. for 2 minutes and then at 180 ° C. for 1 minute. Finally, the supported amount of the photocatalyst was 1 g / m ² with respect to the fiber fabric. Moreover, when the photocatalytic activity of this fiber fabric was measured, the toluene decomposition rate was 58%.

(Comparative example)
In the titanium oxide particle dispersion obtained in Production Example 2 and the platinum-supported tungsten oxide particle dispersion obtained in Production Example 3, the ratio of titanium oxide particles to tungsten oxide particles is 1: 1 (mass ratio). By mixing, a photocatalyst particle dispersion was obtained. Moreover, the solid content (total amount of titanium oxide and tungsten oxide) contained in 100 parts by mass of the photocatalyst particle dispersion was 5 parts by mass (solid content concentration of 5% by mass). The average particle size of the photocatalyst in the photocatalyst particle dispersion was measured by the above-mentioned “N4Plus” and found to be 147 nm.

The photocatalyst particle dispersion obtained above was impregnated into a woven fabric (made of polyester) with a raised basis weight of 322 g / m ² , and then the moisture of the woven fabric was removed with a roller press at 120 ° C. for 2 minutes. Subsequently, heat treatment was performed at 180 ° C. for 1 minute. Finally, the supported amount of photocatalyst particles was 1 g / m ² with respect to the woven fabric. Further, when the photocatalytic activity of the photocatalyst particle-supporting woven fabric was measured, the toluene decomposition rate was 23%.

(Reference example)
By adding 2.8 parts by mass of smecton SA (Saponite: manufactured by Kunimine Industries) to 100 parts by mass of the photocatalyst dispersion obtained in the examples, the sedimentation of the photocatalyst can be suppressed. it can.

Claims (5)

A photocatalyst-supported fiber product in which a photocatalyst is supported on a fiber fabric, wherein the photocatalyst having an average particle size of 0.2 to 2.5 μm is subjected to raising treatment on at least one side, and has a basis weight of 250 to 500 g / m ^2. A photocatalyst-supporting fiber product, which is supported on the fiber fabric.   The photocatalyst-supporting fiber product according to claim 1, wherein the photocatalyst is titanium oxide and / or tungsten oxide.   The photocatalyst-supported fiber product according to claim 1, wherein the photocatalyst is obtained from a photocatalyst dispersion containing titanium oxide and / or tungsten oxide and an inorganic thickener.   The photocatalyst-supported fiber product according to claim 1 or 3, wherein the inorganic thickener is a smectite clay mineral.   The photocatalyst-supported fiber product according to any one of claims 1 to 4, wherein the fiber fabric is a woven fabric, a knitted fabric, or a nonwoven fabric.