Process for producing organophilic silica

摘要

In a silica organosol consisting of silica dispersed in a water-miscible organic solvent, a process for treating the silica with a trialkoxysilane to make the silica more organophilic while minimizing the self condensation of the trialkoxy silane, which process comprises: (a) admixing water and a catalytic amount of acid to the silica organosol; and (b) gradually adding a trialkoxysilane to the admixture under reactive conditions; and (c) removing substantially all of the water; wherein the trialkoxy silane is present at a level up to about 30% by weight based upon the weight of the silica and the water is added at an amount up to about 30% by weight based upon the weight of the water-miscible organic solvent.