Small Particle Size Silica Sol and Method of Preparing same

Abstract

Abstract 1,181,296. Silica sol. NALCO CHEMICAL CO. 20 July, 1967 [18 Oct., 1966], No. 33525/67. Heading C1A. An aqueous silica sol contains discrete dense amorphous particles of silica having a particle diameter of from 5 to 10 mÁ, the silica being present in an amount ranging from 5+3D weight per cent to 15+3D weight per cent, where D is the particle diameter, and the sol has a salt content of from 0À05% to 0À15% by weight. An aqueous silica sol is made by mixing alkali metal silicate and an acid sol having a concn. of 4-8% by wt. of silica as SiO2, in such proportions that the final silica sol has a ratio of silica to alkali metal, calculated as SiO2/M2O of (10Œ6)D, where D is as defined above and ranges from 5 to 10, and evaporating under a reduced pressure of from 10 to 25 inches of Hg, while simultaneously adding sufficient additional acid sol to maintain a constant volume of the mixture, for sufficient time to form a concentration of silica ranging from 5 + 3D to 15 + 3D wt. per cent.

Inventors

No inventors recorded.

Bibliographic Details