Silica gel comprising guanidine carbonate
AssigneeAkzo Nobel Chemicals International B.V.
InventorsLothar Puppe, Dietrich Pantke
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Abstract
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.
Claims13
A process for the preparation of a silica sol comprising reacting a fresh sol with guanidine carbonate, wherein the fresh sol comprises an aqueous system having an SiO2 content of 4 to 8% by weight and a pH of 2 to 4, wherein the prepared silica sol has a BET surface area of 100 to 1200 m2/g, comprises from 0.05 to 15% by weight of guanidinium ions, based on the total weight of the prepared silica sol, and wherein the prepared silica sol is free of amine.
Dependencies are inferred from the claim text.