WATER VAPOR PERMEABLE, AIR IMPERMEABLE FILM AND COMPOSITE COATINGS AND LAMINATES

摘要

The water vapor transmission rate (WVTR) of a nonporous polymeric film can be increased by incorporating into it hydrophilic absorbent particles. Compositions are provided for controlled increase in WVTR of a non-porous polymer film or of composites containing it, which can be used in articles of protective clothing and medical dressing with balanced properties of protection and comfort to the user. The material of the invention can be in the form of a waterproof, air permeable, water vapor permeable non-porous polymer film or sheet made of a polymer resin and hydrophilic absorbent particles having absorptive capacity greater than 1 gram of water per gram of dry (water-free) particles. The amount of the particles is such that the WVTR of the film or sheet is higher than that of a comparable film of the polymer resin above. The film or sheet can be substantially planar in nature or can be in the form of a three-dimensional shaped article.