Patent ID: 8298659

Claim:
A polysiloxane coating composition comprising (a) about 5 to about 50 wt % of solids comprising about 2 to about 30 wt % of a silica, about 0.25 to about 9 wt % of a partial condensate of an aminosilane, and about 2 to about 90 wt % of a partial condensate of a tri-functional silane having a formula RSi(OR′) 3 , wherein R is selected from the group consisting of alkyl, vinyl, and aryl radicals and R′ is selected from the group consisting of H., alkyl radicals having 1 to 4 carbons, and alkylcarbonyl radicals having 1 to 4 carbons; and (b) about 50 to 95 wt % of a solvent comprising about 10 to about 90 wt % of a lower aliphatic alcohol and about 10 to about 90 wt % of water; and wherein the coating composition is prepared by; (i) dispersing and mixing the tri-functional silane into a water-based solution of polysilicic acid or a colloidal suspension of silica, which has a pH level of about 2 to about 6, to form a bath A; (ii) dispersing and mixing the aminosilane into water, which is acidified to a pH level of about 2 to about 6, to form formation a bath B; and (iii) diluting the baths A and B with a mixture of the lower aliphatic alcohol and water and combining the diluted baths A and B to form the coating composition; wherein the sum of the weight percentages of the silica and the partial condensates in (a) is 100%, wherein the aminosilane is γ-aminopropyltrimethoxysilane.