Durable hydrophilic coating for a porous hydrophobic substrate

Abstract

A coated porous substrate composed of a hydrophobic polymer which is substantially uniformly coated with a hydrophilic polymeric material. The substrate may be a sheet-like material, examples of which are foams, fibers, and fibrous webs. The fibrous webs desirably will be nonwoven webs. The coating on the substrate is durable to an aqueous medium at a temperature in a range of from about 10.degree. C. to about 50.degree. C. and does not significantly suppress the surface tension of an aqueous medium with which the coated substrate may come in contact. The hydrophobic polymer may be a polyolefin, such as polyethylene or polypropylene. The hydrophilic polymeric material with which the polymer fibers are coated may be a polysaccharide or a modified polysaccharide. Also provided is a method of preparing a coated porous substrate which involves providing a porous substrate composed of a hydrophobic polymer. At least a portion of the substrate then is exposed to a field of reactive species. At least a portion of the porous substrate, including the portion exposed to the reactive species, is treated with a mixture which includes water and a hydrophilic polymeric material under conditions sufficient to substantially uniformly coat the porous substrate with the hydrophilic polymeric material.

Dependencies are inferred from the claim text.