Colloidal sol, fine powder of crystalline zirconia and preparation thereof

Abstract

Abstract PURPOSE:To prepare a colloidal sol and fine powder of crystalline zirconia consisting of uniform ultrafine secondary aggregated particles, by adding a suitable amount of hydrogen peroxide as a reaction accelerator to an aqueous solution of a zirconium salt, and heat-treating the resultant mixture solution. CONSTITUTION:Hydrogen peroxide in a molar amount of about (1/2) or more of the zirconium in an aqueous solution of a zirconium salt, e.g. zirconyl chloride, in 0.05-2.0mol/l concentration, is added to the aqueous solution, and the resultant mixture solution is then heat-treated at 80-300 deg.C to produce the aimed ultrafine colloidal sol of ultrafine crystalline zirconia particles in a relatively short time. The reaction may be accelerated by adding a base, e.g. ammonia, together with the addition of the hydrogen peroxide, or by treating the aqueous solution with an ion exchange resin, etc. to increase the pH thereof. Most of the zirconia contained in the colloidal sol is monoclinic crystals consisting of crystallites having 30-100Angstrom diameter. The average diameter of the secondary aggregated particles is <=500Angstrom , and the suspended particles are filtered and dried to give the fine powder.

Inventors

• 👤 Etsuro Kato
• 👤 加藤　悦朗

Bibliographic Details