Manufacture of cellular polyurethane plastics

Claim 1

IN THE PREPARATION OF PLASTIC FOAMS FROM A FLUID POLYURETHANE PRODUCTS, SAID PRODUCT BEING SELECTED FROM THE GROUP CONSISTING OF (A) A REACTION PRODUCT OF AN ARYLENE DIISOCYANATE AND AN ALKYD RESIN CONTAINING A PLURALITY OF HYDROXYL GROUPS, (B) A REACTION PRODUCT OF AN ARYLENE DIISOCYANATE AND A FATTY ACID TRIGLYCERIDE HAVING A HYDROXYL NUMBER OF AT LEAST 49, (C) A REACTION PRODUCT OF AN ARYLENE DISSOCYANATE, AN EPOXY RESIN AND CASTOR OIL, AND (D) A REACTION PRODUCT OF AN ARYLENE DIISOCYANATE AND A POLYALKYLENE ETHER GLYCOL, SAID PRODUCT CONTAINING FREE ISOCYANATE GROUPS, SAID GROUPS COMPRISING FROM ABOUT 10 TO 20% OF THE ENTIRE WEIGHT OF SAID PRODUCT, AND SAID PRODUCT YIELDING A PLASTIC FOAM UPON REACTION WITH A SUFFICIENT AMOUNT OF WATER TO PROVIDE ABOUT 0.5 MOLE OF WATER FOR EACH ISOCYANATE GROUP IN SAID POLYURETHANE PRODUCT, THE METHOD OF PREPARING A PLASTIC FOAM OF HIGHER DENSITY WHICH COMPRISES REACTING THE SID POLYURETHANE PRODUCT WITH A MIXTURE OF WATER AND AN ORGANIC COMPOUND HAVING A PLURALITY OF GROUPS CONTAINING ACTIVE HYDROGEN, SAID GROUPS BEING SELECTED FROM THE CLASS CONSISTING OF AMINO GROUPS AND HYDROXYL GROUPS, THE COMBINED AMOUNT OF WATER AND COMPOUND CONTAINING ACTIVE HYDROGEN BEING SUFFICIENT TO REACT WITH ALL FREE ISOCYANATE GROUPS IN THE POLYURETHANE; THERE BEING USED FOR EVERY 100 PARTS BY WEIGHT OF SAID FLUID POLYURETHANE PRODUCT FROM ABOUT 0.2 TO 4.0 PARTS BY WEIGHT OF WATER AND NO MORE THAN ABOUT 48 PARTS BY WEIGHT OF COMPOUND CONTAINING ACIVE HYDROGEN SO AS TO PRODUCE A PLASTIC FOAM RANGING IN DENSITY FROM MORE THAN 1.48 TO ABOUT 47.0 POUNDS PER CUBIC FOOT