PROCESS FOR PRODUCING MODIFIED ZIRCONIA FINE PARTICLES, COATING LIQUID FOR FORMING TRANSPARENT FILM CONTAINING MODIFIED ZIRCONIA FINE PARTICLES AND SUBSTRATE WITH TRANSPARENT FILM

摘要

PROBLEM TO BE SOLVED: To provide a process for producing modified zirconia fine particles having a high refractive index and being excellent in dispersibility and stability, to provide a coating liquid for forming a transparent film containing the modified zirconia fine particles and to provide a substrate with a transparent film. SOLUTION: The modified zirconia fine particles are produced through steps (a)-(f): (a) a step of calcining a zirconia fine powder; (b) a step of pulverizing the calcined zirconia fine powder in the presence of an alkali including an alkali metal; (c) a step of washing the pulverized fine powder; (d) a step of removing an alkali by treating an aqueous dispersion having the washed fine powder dispersed therein with an ion exchange resin; (e) a step of replacing a solvent of the aqueous dispersion by an alcohol; and (f) a step of surface-treating with an organosilicon compound represented by formula (1): Rn-SiX4-n(wherein each of R is a 1-10C, unsubstituted or substituted hydrocarbon group, which may be the same or different from each other; X is a 1-4C alkoxy group, a hydroxyl group, halogen or hydrogen; and n is an integer of 1-3) and the thus-produced modified zirconia fine particles are used in the coating liquid for forming a film. COPYRIGHT: (C)2009,JPO&INPIT