Abstract: A ceramics dispersion liquid is provided. The dispersion liquid may form an applied film easily recovering hydrophilic properties with light irradiation even when contaminated by lipophilic materials. The ceramics dispersion liquid comprises a ceramics, a dispersion medium, and at least one compound selected from a carboxylic acid, an ammonium carboxylate, a salt of carboxylic acid with metal selected from Ia group, IIa group, IIIa group, Va group, VIa group, VIIa group, VIII group, Ib group, IIb group, IIIb group, IVb group and lanthanoid group, and a salt of oxalic acid with metal selected from IVa group.

Abstract: A titanium oxide showing sufficiently high photocatalytic activities by irradiation of visible light is provided. Using the titanium oxide, an excellent photocatalyst and photocatalyst coating composition are also provided. The titanium oxide has a selected ion chromatogram in which an evolution gas having 28 of a ratio of mass number to electric charge quantity exhibits at least one peak at about 600° C. or higher, the selected ion chromatogram being measured in a thermogravimetry-mass-spectroscopy.

Abstract: A titanium oxide dispersion composition is provides, the composition comprising a solvent and a titanium oxide with an average secondary particle diameter of 100 nm or smaller, the dispersion composition having a maximum intensity within the range of from 435 nm to 700 nm of a primary differential spectrum of a transmittance spectrum, wherein the transmittance spectrum is measured using an ultraviolet-visible spectrophotometer after adjusting a solid content of the dispersion composition to be about 2% by weight. The composition provides a film having a high hydrophilicity under the irradiation of a visible light.

Abstract: The present invention provides a method for producing a ceramic dispersion composition, the method comprising the step of heating a mixture of a ceramic powder having a photocatalytic activity, a dispersant and a solvent at a temperature of about 70° C. or higher without substantially letting the solvent out of the reaction system. The ceramic dispersion composition can be used for providing a film showing a high hydrophilicity by light irradiation.

Abstract: A titanium oxide showing sufficiently high photocatalytic activities by irradiation of visible light is provided. Using the titanium oxide, an excellent photocatalyst and photocatalyst coating composition is also provided. The titanium oxide has (i) three or more peaks within the range of from 1.930 to 2.030 in g value of electron spin resonance spectrum of the titanium oxide, wherein the largest one of the peaks is within the range of from 1.990 to 2.020 in the g value and/or (ii) a spin concentration X of 1.50×1016 spins/g or more, which is determined from electron spin resonance spectrum of the titanium oxide measured after irradiation of visible light.

Abstract: A process for producing a titanium oxide is provided which comprises (i) a step of calcining a titanium compound in the presence of ammonia gas or (ii) steps of treating a titanium compound with heat in the presence of ammonia gas and calcining the heat-treated titanium compound. The titanium oxide obtained in the present invention exhibits a sufficiently high photocatalytic activity by irradiation of visible light.

Abstract: A catalyst, a method for producing the same, and a method for treating an exhaust gas are described. The catalyst comprises an oxide containing titanium, vanadium, phosphorus and oxygen.

Abstract: A metal oxide powder except &agr;-alumina, comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: A process for producing a titanium oxide is provided which comprises the steps of (i) reacting a titanium compound with ammonia in an amount exceeding the stoichiometric amount necessary to convert the titanium compound to a titanium hydroxide or reacting a titanium compound with a base at pH of from about 2 to about 7, to obtain a reaction product and (ii) calcining the obtained product. The titanium oxide exhibits a high photocatalytic activity by visible light radiation.

Abstract: A titanium oxide particle showing high photocatalytic activity with a small particle size can be efficiently produced in a method which comprises the steps of (1) mixing together or sequentially a titanium compound, a base and a foaming agent, wherein the hydroxyl group provided by the base is in a molar amount of about 2.1 times to about 3 times of the titanium atom in the titanium compound; and (2) calcining a solid resulting from said mixing together or sequentially of said titanium compound, said base and said foaming agent.

Abstract: A process for producing a titanium oxide is provided which comprises (i) a step of calcining a titanium compound in the presence of ammonia gas or (ii) steps of treating a titanium compound with heat in the presence of ammonia gas and calcining the heat-treated titanium compound. The titanium oxide obtained in the present invention exhibits a sufficiently high photocatalytic activity by irradiation of visible light.

Abstract: A titanium hydroxide is provided which can be utilized for producing a photocatalyst exhibiting a superior photocatalytic activity by irradiation of visible light. The titanium hydroxide has a primary differential spectrum (of radial structure function in connection with titanium K absorption edge) having maximal intensities (U1 and U2) and minimal intensities (L1 and L2) at interatomic distances in the range of from 1.4 Å to 2.8 Å, the maximal intensities being at an interatomic distance of from 1.4 Å to 1.7 Å and of from 2.2 Å to 2.5 Å and the minimal intensities being at an interatomic distance of from 1.9 Å to 2.2 Å and of from 2.5 Å to 2.8 Å; and index X calculated by the equation X=(U2−L2)/(U1−L1) of about 0.06 or more.

Abstract: A titanium oxide dispersion composition is provides, the composition comprising a solvent and a titanium oxide with an average secondary particle diameter of 100 nm or smaller, the dispersion composition having a maximum intensity within the range of from 435 nm to 700 nm of a primary differential spectrum of a transmittance spectrum, wherein the transmittance spectrum is measured using an ultraviolet-visible spectrophotometer after adjusting a solid content of the dispersion composition to be about 2% by weight. The composition provides a film having a high hydrophilicity under the irradiation of a visible light.

Abstract: The present invention provides a method for producing a ceramic dispersion composition, the method comprising the step of heating a mixture of a ceramic powder having a photocatalytic activity, a dispersant and a solvent at a temperature of about 70° C. or higher without substantially letting the solvent out of the reaction system. The ceramic dispersion composition can be used for providing a film showing a high hydrophilicity by light irradiation.

Abstract: There is provided a titanium hydroxide having a nitrogen content of 2.3% by weight or more in terms of nitrogen atom based on the titanium hydroxide and/or having a nitrogen content of about 3.3% by weight or more in terms of nitrogen atom based on the titanium oxide obtained after calcining the titanium hydroxide in air at about 400° C. The titanium hydroxide may be utilized as a raw material for producing a photocatalyst which exhibits a superior photocatalytic activity by irradiation of visible light.

Abstract: Titanium oxide exhibiting a superior photocatalytic activity through irradiation of a visible light as well as an ultraviolet light, and a photocatalyst and a photocatalytic coating agent including said titanium oxide, wherein said titanium oxide has a value of an index X1 calculated by the following equation (I) of not more than about 0.90, and a value of an index Y1 calculated by the following equation (II) of not less than 0.

Abstract: A process for producing a titanium oxide is provided which comprises the steps of (i) reacting a titanium compound with ammonia in an amount exceeding the stoichiometric amount necessary to convert the titanium compound to a titanium hydroxide or reacting a titanium compound with a base at pH of from about 2 to about 7, to obtain a reaction product and (ii) calcining the obtained product. The titanium oxide exhibits a high photocatalytic activity by visible light radiation.

Abstract: A ceramics dispersion liquid is provided. The dispersion liquid may form an applied film easily recovering hydrophilic properties with light irradiation even when contaminated by lipophilic materials. The ceramics dispersion liquid comprises a ceramics, a dispersion medium, and at least one compound selected from a carboxylic acid, an ammonium carboxylate, a salt of carboxylic acid with metal selected from Ia group, IIa group, IIIa group, Va group, VIa group, VIIa group, VIII group, Ib group, IIb group, IIIb group, IVb group and lanthanoid group, and a salt of oxalic acid with metal selected from IVa group.

Abstract: There are provided: (i) an acid resistant catalyst sheet comprising: a catalyst component-containing titania fiber; a glass fiber; and at least one resin selected from the group consisting of an epoxy resin, a phenolic resin, a melamine resin, a furan resin, a polyimide resin, a silicone resin, a fluororesin, a polyphenylene sulfide resin and a polyether ether ketone resin; and (ii) a process for producing an acid resistant catalyst sheet, which comprises the step of making paper from a mixture containing: a catalyst component-containing titania fiber; a glass fiber; and at least one resin selected from the group consisting of an epoxy resin, a phenolic resin, a melamine resin, a furan resin, a polyimide resin, a silicone resin, a fluororesin, a polyphenylene sulfide resin and a polyether ether ketone resin.

Abstract: There are provided (i) a heat resistant catalyst sheet having an aramid fiber and a catalyst component-containing titania fiber; and (ii) a process for producing a heat resistant catalyst sheet, which has the step of making paper from a mixture of an aramid fiber and a catalyst component-containing titania fiber.