Cellular polymeric sheet material and method of making same

Claim 1

A SHEET MATERIAL HAVING A PEROEABLILITY VALUE OF AT LEAST 1000 AND COMPRISING A CELLULAR LAYER OF POLYMERIC MATERIAL IN ADHERENCE WITH A SURFACE OF A POROUS FIBROUS SHEET MATERIALS AT LEAST 50% OF THE VOLUME OF SAID LAYER BEING COMPOSED OF CONTIGUOUS ELONGATED CELLS HAVING (A) AN AVERAGE CROSS-SECTION DIAMETER OF ABOUT 20-200 MICRONS, (B) A SUBSTANTIALLY PERPENDICULAR ORIENTATION OF THEIR LONGEST DIMENSION IN RELATION TO THE PLANE OF THE SURFACE OF THE SHEET, AND (C) THIN MICROPOROUS CELL WALLS WHICH, BY VIRTUE OF THEIR MICROPOROSITY, RENDER THE CELLS INTERCOMMUNICATING; WHEREIN AT LEAST 51% BY WEIGHT OF SAID POLYMERIC MATERIAL CONSISTS OF A POLYURETHANE ELASTOMER AND UP TO 49% BY WEIGHT OF SAID POLYMER CONSISTS OF A VINYL CHLORIDE POLYMER AND WHEREIN THE POLYURETHANE ELASTOMER COMPRISES A CHAIN-EXTENDED POLYURETHANE POLYMER FORED BY THE REACTION OF AN EXCESS OF AN ORGANIC DIISOCYANATE AND AN ACTIVE HYDROGEN CONTAINING POLYMERIC MATERIAL SELECTED FROM THE GROUP CONSISTING OF POLYALKYLENEETHER GLYCOLS AND HYDROXYL-TERMINATED POLYESTERS WHICH PRODUCE AN ISOCYANATETERMINATED POLYURETHANE PREPOLYMER, SAID PREPOLYMER BEING CHAIN-EXTENED WITH A COMPOUND HAVING TWO ACTIVE HYDROGEN ATOMS EACH BONDED TO AN AMINO-NITROGEN ATOM.