ZIRCONIA SPHERICAL PARTICLE AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain the subject zirconia spherical particles excellent in monodispersion properties with economical advantage by hydrolyzing a reaction product between ammonium zirconyl carbonate and a chelating agent and growing the resultant zirconia sol particles. CONSTITUTION:Ammonium zirconyl carbonate is reacted with a chelating agent (e.g. an oxyacid such as citric acid or a beta-diketone such as acetylacetone) and the resultant product is hydrolyzed to prepare a zirconia sol. The obtained zirconia sol is mixed with a water-insoluble (sparlingly soluble) organic solvent in the presence of a surfactant to form a W/O type emulsion. By heating the resultant emulsion for azeotropic distillation, water in the spherical sol is removed to the outside of the system together with the organic solvent and the sol is converted to a gel at the same time. The gel is calcined to remove organic components in the surfactant, thus obtaining the objective zirconia spherical particles having 0.05-50/mum average particle size, 1-1.5 standard deviation thereof and 5-200m<2>/g specific surface area.