Polysiloxane coatings doped with aminosilanes
AssigneeE. I. Du Pont de Nemours and Company
InventorJerrel C. Anderson
Life of this patent
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Abstract
A polysiloxane coating composition comprises (a) about 5 to about 50 wt % of solids complementally comprising about 2 to about 30 wt % of a silica; about 0.25 to about 7 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 the 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 about 95 wt % of solvent comprising about 10 to about 90 wt % of a lower aliphatic alcohol and about 10 to about 90 wt % of water. The coating composition has a pH level in the range of about 2 to about 6.
Claims23
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.
Dependencies are inferred from the claim text.