Patent ID: 8821984

Claim:
A method for imparting water repellency to a fabric substrate comprising (1) applying to a portion of the surface of said fabric substrate a treatment composition comprising an aqueous emulsion of a blend of (A) one or more fluorochemical esters and (B) one or more polycarbodiimides, and (2) drying said treatment composition at a temperature of about 50° C. to about 85° C. for about 45 to about 60 minutes; wherein said (A) fluorochemical ester is of the formula: R f —O—C(O)—R 1 wherein R f is selected from the group consisting of: (1) F(CF 2 ) x (CH 2 ) m wherein x is from 4 to 20 and m is from 0 to 6; and (2) F(CF 2 ) x SO 2 N(R 2 )R 3 wherein x is a positive integer from 4 to 20, R 2 is an alkyl radical of from 1 to 4 carbon atoms, and R 3 is an alkylene radical of from 1 to 12 carbon atoms; and R 1 is an aliphatic hydrocarbon having from 12 to 76 carbon atoms; wherein said treatment composition comprises from about 0.5 to about 2.5 parts by weight solids of said blend per 100 parts by weight and wherein the weight ratio of (A) to (B) is from about 25:75 to about 75:25.