PURPOSE: To obtain a silica particle having high purity and excellent fine pore property by emulsifying an acidic silica water sol heat-treated in a basic environment in an organic medium and after gelating and heat-treating, post-treating under a basic environment.
CONSTITUTION: The objective silica particle is obtained by (a) producing the acidic silica water sol ≤100ppm in an alkali metal content and ≤3nm in particle dimension, (b) heat-treating the sol under the basic environment basing on ammonium or amine to grow the sol particle equivalent to 50-500m2/g specific surface area, (c) emulsifying the sol in the organic medium immiscible or having restricted miscibility or solubility to water in the presence of a surfactant if necessary after concentrating, (d) dehydrating the formed sol liquid drop under a condition of a controlled temp. and pH to gelate, (e) heat-treating the resultant gel particle to remove an organic material and (f) post-treating the gel particle under the basic environment basing on ammonium or amine.
HAAMAN UORUFUGANGU
RARUSON BAANTO
| JPS5654220A | 1981-05-14 |