Abstract: The present invention provides particulate titanium oxide and a production process thereof. The particulate titanium oxide comprises mixed crystal titanium oxide containing rutile crystal produced by a vapor phase process, wherein the titanium oxide has a property represented by the following general formula R?1300×B?0.95 wherein R represents a rutile content (%) and B represents a BET specific surface area (m2/g). The titanium oxide is particulate high-rutile-content titanium oxide with very low aggregation and having a high dispersibility.

Abstract: Alumina particles obtained from aluminum chloride by a gas phase method, the alumina having an amorphous form or a crystalline form of transition alumina, with primary particles thereof having an average particle diameter of approximately 5 to 100 nm, and secondary particles, resulting from the aggregation of the primary particles, having an average particle diameter of approximately 150 to 800 nm and wherein the particles having a secondary particle diameter larger than 45 ?m are contained in an amount of about 0.05% by mass or less.

Abstract: A process for producing alumina particles, comprising vaporizing aluminum chloride to form an aluminum chloride vaporized gas, which optionally contains an inert gas, and oxidizing the vaporized aluminum chloride with an oxidizing gas to produce alumina particles, wherein the aluminum chloride vaporized gas and the oxidizing gas are introduced into a reactor each at an ejecting flow velocity of about 10 m/sec or more, the ratio of the flow velocity of oxidizing gas to the flow velocity of the aluminum chloride vaporized gas is approximately from 0.2 to less than 10, and the amount of oxidizing gas is about 1 or more times the amount of oxidizing gas necessary for stoichiometrically oxidizing aluminum chloride.

Abstract: The present invention provides particulate titanium oxide and a production process thereof. The particulate titanium oxide comprises mixed crystal titanium oxide containing rutile crystal produced by a vapor phase process, wherein the titanium oxide has a property represented by the following general formula R≧1300×B−0.95 (In the formula, R represents a rutile content (%) and B represents a BET specific surface area (m2/g)).

Abstract: Alumina particles obtained from aluminum chloride by a gas phase method, the particles being amorphous or transition alumina particles and having an amorphous, &ggr;-, &dgr;- or &thgr;-crystalline form or a mixed form thereof, with primary particles thereof having an average particle diameter of 5 to 100 nm, and secondary particles, resulting from the aggregation of primary particles, having an average particle diameter of 50 to 800 nm.

Abstract: The present invention provides particulate titanium oxide and a production process thereof.

Abstract: The present invention provides particulate titanium oxide and a production process thereof.

Abstract: Ultrafine particulates of highly white zinc oxide having a reduced average particle diameter of about 15 nm to about 55 nm as measured by the BET-one point method and that has an L value of about 90 or more as measured by a Hunter-type color-difference meter. Also, a process for producing ultrafine particulates of highly white zinc oxide, comprising oxidizing zinc vapor with an oxidizing gas in a reactor, wherein a zinc vapor-containing gas has a temperature of about 950° C. or more at a nozzle of the reactor for discharging the zinc vapor-containing gas and the oxidizing gas has a temperature of about 900° C. or more at a nozzle of the reactor for discharging the oxidizing gas is disclosed.

Abstract: An ultrafine particulate zinc oxide where the ultrafine particulate zinc oxide has a specific surface area determined by the single-point BET technique of from about 10 to about 200 m2/g and a substantially isotropic primary particle shape, wherein the specific volume determined by a tapping machine is from about 4 to about 40 ml/g, and additionally a process for producing the ultrafine particulate zinc oxide, a silica-coated ultrafine particulate zinc oxide powder and a cosmetic material using the zinc oxide powder.

Abstract: Alumina particles obtained from aluminum chloride by a gas phase method, the particles being amorphous or transition alumina particles and having an amorphous, &ggr;-, &dgr;- or &thgr;-crystalline form or a mixed form thereof, with primary particles thereof having an average particle diameter of 5 to 100 nm, and secondary particles, resulting from the aggregation of primary particles, having an average particle diameter of 50 to 800 nm.