Polyurethane foam and method for making same

Claim 1

IN A PROCESS FOR MANUFACTURING A RIGID POLYURETHANE CLOSED CELL HEAT INSULATION HAVING THE CELLS SUBSTANTIALLY FILLED WITH RETAINED TRICHLOROMONOFLUORAMETHANE, THE STEPS COMPRISING; INTRODUCING INTO A MIXING CHAMBER A FIRST SUBSTANTIALLY ANHYDROUS LIQUID COMPONENT CONSISTING OF AN ORGANIC POLYISOYANATE, INTRODUCING INTO SIAD MIXING CHAMBER A PORTION ONLY OF A SECOND ANHYDROUS LIQUID COMPONENT COMPRISING A POLYMERIC MATERIAL HAVING A PLURALITY OF REACTIVE HYDROGEN GROUPS AND A NEGLIGIBLE ACID NUMBER NOT SUBSTANTIALLY GREATER THAN 1.5 AND A HIGH HYDROXYL NUMBER OF ABOUT 420 TO 440 AND CONSISTING OF A POLYESTER WHICH IS A REACTION PRODUCT OF A POLYCARBOXYLIC ACID AND A POLYHYDRIC ALCOHOL AND BEING CAPABLE OF REACTING WITH THE FIRST MENTIONED COMPONENT TO FORM A LIQUID ISOCYANATE-MODIFIED POLYMER, REACTING SAID TWO COMPONENTS WITHIN SAID CHAMBER, THEN INTRODUCING INTO SAID CHAMBER THE REMAINDER OF SAID POLYMERIC MATERIAL TOGETHER WITH TRICHLOROMONOFLUOROMETHANE IN LIQUID FORM, MIXING THROUGHLY ALL SIAD LIQUID COMPONENTS, VAPORIZING SAID TRICHLOROMONOFLUOROMETHANE BY HEAT GENERATED DUE TO THE EXOTHERMIC REACTION BETWEEN THE ISOCYANATE-MODIFIED POLYMER AND THE REMAINDER OF SAID POLYMERIC MATERIAL, INITIATING THE FORMATION OF CELLS IN SAID LIQUID MIXTURE SOLELY BY THE VAPORIZATION OF SAID TRICHLOROMONOFLUOREMETHANE, AND SUBSEQUENTLY POURING THE RESULTING MIXTURE INTO A MOLD WHEREIN CONTINUING POLYMERIZATION TAKES PLACE TO FORM A RIGID CLOSED CELL STRUCTURE CONTAINING THE TRICHLOROMONOFLUOREMETHANE IN THE CELLS THEREOF.