AMORPHOUS SILICA-ALUMINA SPHERICAL PARTICLES AND PROCESS FOR PREPARATION THEREOF

摘要

Disclosed are amorphous silica-alumina spherical particles having a notched surface. The particles have a small specific surface area and a highly controlled hygroscopic property. The spherical particles are obtained by exchanging at least a part of an alkali metal ion of a P-type zeolite as the starting material with a divalent metal and firing the ion-exchanged zeolite. Since the pH value is shifted to a weakly alkaline level by the ion exchange treatment, the particles are effective as a filler for stabilizing a resin or the like when incorporated therein, and the refractive index of the particles can be made close to that of a resin in which the particles are to be incorporated.