Agency of Industrial Science and Technology

Japan As Represented by Director General of Agency of Industrial Science

National Institute of Advanced Industrial Science and Technology

Co-op Chemical Co., Ltd.

Kunio Kimura

Hiroshi Tateyama

Hiroyuki Nakamura

Junichi Kimoto

Hiromi Okada

Yukiyoshi Tamoto

Kazuhiko Jinnai

Eiji Tani

Hideharu Hirosue

Kinue Tsunematsu

Dae-Yong Shin

Takashi Furusawa

A visible-light-responsive three-dimensional fine cell-structured photocatalytic filter in accordance with the present invention includes a sponge-like porous structure (B) containing an anatase-type titanium oxide coating formed on a surface of a sponge-like porous structural body (A) which has a porosity of 85 vol % or more. The sponge-like porous structural body (A) is composed of one material selected from the group consisting of one metal selected from the group consisting of (a) to (e): (a) carbon and either or both of silicon and a silicon alloy; (b) silicon carbide and at least one material selected from the group consisting of silicon, a silicon alloy, and carbon; (c) silicon nitride and at least one material selected from the group consisting of silicon, a silicon alloy, carbon, and silicon carbide; (d) carbon; and (e) carbon and one metal selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, platinum, and gold.

Visible-light-responsive three-dimensional fine cell-structured photocatalytic filter, its manufacturing method and purifier device

Disclosed is a method for the preparation of fine hollow glass spheres coated with titanium dioxide from particles of a volcanic vitreous deposit sand occurring in nature. The method comprises the steps of: (a) dispersing the starting particles in an aqueous medium containing hydrogen chloride (or sulfuric acid) and titanium chloride (or titanium sulfate); (b) admixing the aqueous dispersion of the particles with an aqueous alkaline solution such as a solution of ammonium hydrogencarbonate to effect hydrolysis of the titanium chloride (or sulfate) into hydrous titanium oxide forming a coating layer on the particles; and (c) subjecting the particles coated with hydrous titanium oxide to a heat treatment for expansion of the vitreous particles into hollow glass spheres with simultaneous conversion of the hydrous titanium oxide into titanium dioxide forming a coating layer on the hollow glass spheres.

Method for the preparation of fine hollow glass spheres coated with

Provided is a method for the efficient preparation of fine hollow spherical glassy bodies having a high strength and excellent whiteness from a volcanic vitreous deposit as the starting material. The fine hollow spherical glassy bodies as desired can be prepared by dispersing 100 parts by weight of a powder of a volcanic vitreous deposit in an aqueous solution containing 1 to 10 parts by weight of aluminum sulfate, adding an aqueous alkaline solution to this liquid suspension to cause deposition of an alumina hydrate onto the surface of the particles of said powder and washing and drying of the solid material followed by a heat treatment for 1 second to 1 minute at a temperature of 900.degree. to 1100.degree. C.

Method for the preparation of vitreous hollow microspheres

Proposed is an efficient method for the preparation of vitreous hollow microspheres from particles of a vitreous volcanic deposit by a heat treatment to effect expansion of the particles by foaming. The inventive method comprises a step, prior to the heat treatment for expansion of the particles, in which the starting particles are dispersed in an aqueous medium containing aluminum sulfate and urea each in a specified concentration followed by a heating treatment of the dispersion so as to deposit a coating layer of aluminum hydroxide on the particle surface so that the efficiency of foaming can be greatly improved without the disadvantage of particle agglomeration.

The present invention is a method for producing swellable or nonswellable fluorine mica at a relatively lower temperature by heating a powdery mixture comprising 10 to 35% by weight of an alkali silicofluoride as the main component optionally together with an alkali fluoride and the balance of talc. This fluorine mica is used for pigments, etc.

Method for producing fluorine mica

Ultra-fine hollow glass spheres suitable as a filler in light-weight composite materials for building use and the like can be prepared from a fine powder of volcanic glass even when the starting powder has a particle size as fine as 20 .mu.m or smaller. The inventive method comprises an acid-leaching treatment of the starting powder using hydrochloric or sulfuric acid under hydrothermal conditions at 150.degree.-200.degree. C. to modify the chemical composition in the surface layer of the particles and a subsequent heat treatment of the acid-treated particles at a specified high temperature to effect expansion by the water vapor produced from the structural water in the softened particles. By virtue of the modified composition in the surface layer and in contrast to the prior art method without the acid treatment, a good balance can be obtained between the rate of water vapor release and softening of the particles even when the particle size is extremely small to facilitate expansion of the particles.

Growing community of inventors

Tosu, Japan

Kunio Kimura