Patent ID: 7842624

Claim:
A process for producing a vapor-pervious, water-impervious textile substrate, comprising a) treating a substrate with a liquid comprising at least one adhesion promoter to form a liquid treated substrate which, after drying, has fibers coated with a first coating consisting of a hydrolyzed tetraethoxysilane obtained by reacting tetraethoxysilane with an aqueous solution of hydrochloric acid, and at least one first adhesion promoter, wherein the first coating is in direct contact with the fibers and is at least circumferentially continuous; and b) treating the liquid treated substrate from a) with a mixture comprising hydrophobic particles, a solvent, and at least one adhesion promoter to form the vapor-pervious, water-impervious textile substrate having, on the first coating, a second coating comprising the hydrophobic particles having an average particle size in the range from 0.02 to 100 μm, a hydrolyzed tetraethoxysilane obtained by reacting tetraethoxysilane with an aqueous solution of hydrochloric acid, and at least one second adhesion promoter, where the second coating is at least circumferentially continuous; wherein the liquid treated substrate of a) is dried before being treated in b); wherein the mixture treated substrate of b) is dried; and wherein the at least one adhesion promoter in a) and b) may be the same or different.