Silica gel comprising guanidine carbonate

摘要

A process of preparing a silica sol is described. The process involves reacting a fresh sol with guanidine carbonate. The reaction may be conducted in the presence of a base (e.g., sodium water glass), and at a pH of from 8 to 12. The process of the present invention may also include concentrating steps. The silica sol prepared by the method of the present invention has a BET surface area of greater than or equal to 100 m2/g, and contains from 0.05 to 15% by weight of gaunidinium ions, based on the total weight of the silica gel.