PHOTOCATALYST POWDER, PRODUCTION OF TITANIUM DIOXIDE FINE PARTICLES, COATING AND BUILDING MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain titanium dioxide, coating and building material high in photocatalic activity suitable for removing a harmful substance in environment and purifying environment. SOLUTION: A building material 10 is obtained by forming a coating film 2 containing titanium oxide fine particles on the surfaces of the recessed and projected parts 11b of an ALC panel 1. This coating film 2 is formed from a silicone resin soln. having titanium dioxide fine particles dispersed therein in a mixed state. The content of titanium dioxide particles is set to 50-75% by wt. of the total solid of coating. The titanium dioxide fine particles has a crystal size of 6-below 20nm and a specific surface area of 130-350m<2> /g. These titanium dioxide fine particles are obtained by setting the heat treatment temp. of hydrous titanium oxide to 100-400 deg.C when titanium dioxide is obtained by a sulfuric acid method.