Continuous production of cellular polyurethane plastics

Claim 1

A CONTINUOUS PROCESS FOR PREAPRING STABLE POLYURETHANE ELASTOMERS WHICH COMPRISES CONTINUOUSLY EXTRUDING AN ISOCYANATE-TERMINATED POLYURETHANE POLYMER INTO AN ATMOSPHERE CONTAINING WATER VAPOR, SAID POLYURETHANE POLYMER BEING PREPARED BY REACTING AN ORGANIC DIISOCYANATE WITH A POLYMER HAVING A MOLECULAR WEIGHT OF FROM ABOUT 750 TO 10,000 SAID POLYMER BEING SELECTED FROM THE GROUP CONSISTING OF POLYALKYLENEETHER GLYCOLS, POLYALKYLENEARYLENE ETHER GLYCOLS, POLYALKYLENE ETHERTHIOETHER GLYCOLS AND ALKYD RESINS CONTAINING TWO TERMINAL HYDROXYL GROUPS, IN A MOLAR RATIO OF SAID DIISOCYANATE TO SAID POLYMER OF BETWEEN 1.1:1.0 AND 12:10, SAID POLYURETHANE POLYMER BEING EXTRUDED AT A TEMPERATURE BELOW THE DEW POINT OF THE SAID ATMOSPHERE, MAINTAINING SAID POLYURETHANE POLYMER IN SAID ATMOSPHERE UNTIL AT LEAST 0.5 MOL OF WATER PER MOL OF ISOCYANATE-TERMINED POLYURETHANE POLYMER HAS BEEN TAKEN UP, CONTINUOUSLY CONVEYING THE RESULTANT MASS THROUGH A CHAMBER MAINTAINED AT ABOUT 50 TO 100*C. UNTIL A SELF-SUPPORTING, POROUS STRUCTURE IS FORMED, CONTINUOUSLY CONVEYING SAID POROUS STRUCTURE THROUGH A CHAMBER WHEREIN AIR AT A TEMPERATURE OF FROM ABOUT 60 TO 80C. IS DRAWN THROUGH SAID STRUCTURE, FOLLOWED BY DRAWING THE VAPOR OF A NITROGEN BASE HAVING ONLY ONE NITROGEN ATOM WITH HYDROGEN ATTACHED THERETO AND HAVING A BASIC IONIZATION CONSTANT GREATER THAN 1 X 10-12 THROUGH SAID POROUS STRUCTURE AT A TEMPERATURE OF FROM ABOUT 60 TO 80*C. TO STABILIZE IT, FOLLOWED BY DRAWING DRY AIR AT A TEMPERATURE OF FROM ABOUT 60 TO 150*C. THROUGH SAID POROUS STRUCTURE, AND RECOVERING THE RESULTANT STABLE POLYURETHANE ELASTOMER.