Preparation of cellular polyurethane resins

Claim 1

THE PROCESS OF MAKING FOAM STRUCTURES WHICH COMPRISES REACTING AN ALKYD RESIN WHICH IS THE REACTION PRODUCT OF A DICARBOXYLIC ACID AND AN ALCOHOL CONTAINING ONLY CARBON, HYDROGEN, AND OXYGEN ATOMS SELECTED FROM THE GROUP CONSISTING OF DIHYDRIC AND TRIHYDRIC ALCOHOLS, SAID ALKYD RESIN HAVING AN ACID NUMBER IN A RANGE BETWEEN APPROXIMATELY 26 TO 110 AND A HYDROZYL NUMBER IN THE RANGE BETWEEN APPROXIMATELY 228 TO 505, WITH AN ORGANIC POLYISOYANATE SELECTED FROM THE GROUP CONSISTING OF A 2,4-TOLUENE DIISOCYANATE, A 2,6-TOLUENE DIISOCYANATE, AND A 1,6-HEXAMETHYLENE DISOCYNATE IN APROPORTION OF FROM APPROXIMATELY 59 TO APPROXIMATELY 92 PARTS BY WEIGHT OF THE ORGANIC POLYISOCYANATE TO 100 PARTS OF THE RESIN, MIXING PULVERIZED SOLID CARBON DIOXIDE INTO THE POLYISOCYANATE-RESIN LIQUID CONDENSATE IN SUFFICIENT AMOUNT TO MAINTAIN SAID CONDENSATE AT SUBSTANTIALLY CONSTANT TEMPERATURE IN A RANGE BETWEEN ABOUT 70* TO 73* F, TO CONSERVE EXOTHERMIC HEAT OF REACTION WHILE CONTINUALLY STIRRING UNTIL HOMOGENEOUS SINGLE PHASE COMPATIBILITY IS OBTAINED, FURTHER MIXING INTO THE CONDENSATE ADDITIONAL PULVERIZED SOLID CARBON DIOXIDE IN AMOUNT SUFFICIENT TO MAINTAIN SAID CONDENSATE AT A RELATIVELY CONSTANT PRESELECTED TEMPERATURE IN A RANGE BETWEEN ABOUT 40* TO 70*F. AFTER ATTAINING SINGLE PHASE COMPATIBILITY WHILE CONTINUING MIXING AT COMPARATIVELY CONSTANT VISCOSITY UNTIL AN ABRUPT INCREASE IN VISCOSITY OCCURS, ALLOWING THE CONDENSATE TO PRECEED UNINHIBITED ON ITS OWN EXOTHERM WHILE CONTINUING MIXING UNTIL A MINUMUM POUR POINT VISCOSITY IS REACTED FOR POURING INTO MOLDS, AND MAINTAINING SAID CONDENSATE AT A FOAMABLE TEMPERATURE AFTER POURING INTO MOLDS UNTIL THE EVOLUTION OF GAS IS COMPLETED AND THE FOAM STRUCTURE IS SET.