| abstract |
MICROPOROUS POLYMERIC SHEET MATERIALS AND LEATHER SUBSTITUTES FORMED FROM POLYURETHANE OR POLYURETHANE-UREA POLYMERS WHICH ARE CROSSLINKED BY MEANS OF URETHANE OR UREA LINKAGES, AND A METHOD OF FORMING SUCH MATERIALS WHICH INCLUDES MIXING THE ACTIVE COMPONENTS INCLUDING AN ORGANIC-POLYISOCYANATE, A POLYOL, USUALLY A POLYAMINE, AND CATALYST TOGETHER IN A SOLVENT, CARRYING OUT THE REACTION IN THE SOLVENT WITH AGITATION UNTIL A DISPERSION OF PARTICLES INSOLUBLE IN THE SOLVENT IS FORMED, FORMING THE DISPERSION INTO A LAYER AND COMPLETING THE REACTION BEFORE REMOVAL OF THE LIQUID VEHICLE, THUS FORMING A CROSSLINKED MICROPOROUS LAYER. |