Patent ID: 7307031

Claim:
A moisture vapor permeable, substantially liquid impermeable composite sheet material comprising a fibrous substrate and a moisture vapor permeable thermoplastic film layer; said fibrous substrate comprised of synthetic fibers, said synthetic fibers being comprised of at least 50% by weight polyolefin polymer, said substrate having opposite first and second planar sides; said moisture vapor permeable film layer comprised of at least about 50% by weight of polymer selected from the group of block copolyether esters, block copolyether amides, polyurethanes, and combinations thereof, said film layer being melt bonded directly to the first side of said substrate in the absence of an adhesive between the film layer and the substrate; and said composite sheet exhibiting a peel strength of at least 0.1 N/cm, a dynamic fluid transmission of less than about 0.75 g/m 2 when subjected to an impact energy of about 2400 joules/m 2 , and having a moisture vapor transmission rate, according to the desiccant method, of at least 1500 g/m 2 /24 hr.