Autophobic water repellent surface treatment

A method of producing a non-wetting surface on a substrate comprising the steps of:

• preparing a solution of a perfluoroalkylalkyl silane selected from compounds having the general formula R.sub.m R'.sub.n SiX.sub.4-m-n, wherein R is a perfluoroalkylalkyl radical, R' is an alkyl or vinyl radical, m is 1, n is 0 or 1, and X is selected from the group consisting of halogen, alkoxy and acyloxy radicals wherein the perfluoroalkyl moiety of the perfluoroalkylalkyl radical is selected from CF.sub.3 to C.sub.30 F.sub.61 in a solvent said solvent consisting essentially of an aprotic solvent having a surface tension at least 5 dynes per centimeter higher than the surface free energy of the substrate, a boiling point sufficiently high to prevent complete evaporation of the solvent during application and selected from the group consisting of toluene, naptha, chlorobenzene, ethers, ketones, perfluorinated organic compounds and mixtures thereof;
• contacting a surface of the substrate with the solution wherein the boiling point of the solvent prevents complete evaporation of the solvent during application of the solution to the surface of the substrate.

A composition for producing a nonwetting surface on a substrate comprising a perfluoroalkylalkyl silane, the perfluoroalkylalkyl silane is selected from compounds having the general formula R.sub.m R'.sub.n SiX.sub.4-m-n, wherein R is a perfluoroalkylalkyl radical, R' is an alkyl or vinyl radical, m is 1, n is 0 or 1 and m+n is not greater than 3, and X is selected from the group consisting of halogen, alkoxy and acyloxy radicals wherein the perfluoroalkyl moiety of the perfluoroalkylalkyl radical is selected from CF.sub.3 to C.sub.30 F.sub.61 in a solvent said solvent consisting essentially of an aprotic solvent having a surface tension at least 5 dynes per centimeter higher than the surface free energy of the substrate, a boiling point sufficiently high to prevent evaporation of the solvent during application of the composition to the surface of the substrate and selected from the group consisting of hexanes, heptanes, methylene chloride, naphtha, toluene acetone, perfluorocarbons and mixtures thereof.

A method of producing a non-wetting surface on a substrate comprising the steps of:

• preparing a solution of a perfluoroalkylalkyl silane selected from compounds having the general formula R.sub.m R'.sub.n SiX.sub.4-m-n, wherein R is a perfluoroalkylalkyl radical, R' is an alkyl or vinyl radical, m is 1, n is 0 or 1 and m+n is not greater than 3, and X is selected from the group consisting of halogen, alkoxy and acyloxy radicals wherein the perfluoroalkyl moiety of the perfluoroalkylalkyl radical is selected CF.sub.3 to C.sub.30 F.sub.61 and in a solvent, said solvent consisting essentially of an aprotic solvent having a surface tension at least 5 dynes per centimeter higher than the surface free energy of the substrate, a boiling point sufficiently high to prevent complete evaporation of the solvent during application of the solution and selected from the group consisting of hexanes, heptanes, methylene chloride, naphtha, toluene, acetone. perfluorocarbons and mixtures thereof;
• contacting a surface of the substrate with the solution wherein the boiling point of the solvent prevents complete evaporation of the solvent during application to the substrate surface.