Patent ID: 6210451
Filing Date: 2001-04-03
Classification: B01J,C10L

Abstract:
A stable organic sol comprising:particles of cerium dioxide (IV) in the form of agglomerates of crystallites, the d.sub.80 of the crystallites is no greater than 5 nanometers, and 90% of the agglomerates containing 1 to 5 crystallites;an amphiphilic acid system containing at least one acid whose total number of carbons is at least 10; andan organic diluent medium,wherein the sol is obtained by a process comprising of the following steps:(a) subjecting an aqueous phase of a cerium salt (IV) to a thermohydrolysis operation by heating this phase at a temperature ranging between 80.degree. C. and the critical temperature of the aqueous phase, so as to precipitate the cerium dioxide;(b) contacting the cerium dioxide aqueous suspension resulting from step (a) with the amphiphilic acid system and the organic diluent medium; and(c) recovering the organic sol.