Process for preparing cellular polyurethanes from mixture of two prepolymers and resulting product

Claim 1

IN A PROCESS FOR THE PREPARATION OF A CELLULAR POLYURETHANE PLASTIC BY A PROCESS WHICH COMPRISES REACTING AN EXCESS OF AN ORGANIC POLYISOCYANATE WITH A POLYHYDRIC AN EXCESS OF AN ORGANIC POLYISOCYANATE WITH A POLYHYDRIC TIONS IN A FIRST STEP TO PREPARE AN ISOCYANATO TERMINATED PREPOLYMER AND SUBSEQUENTLY REACTING SAID PREPOLYMER WITH WATER AND ADDITIONAL ORGANIC POLYISOCYANATE TO GENERATE CARBIN DIOXIDE AND PREPARE A CELLULAR POLYURETHANE PLASTIC, THE IMPROVEMENT WHICH COMPRISES REACTING A MIXTURE OF AT LEAST TWO SEPARATE, DISTINCT PREPOLYMERS (A) AND (B) WITH WATER AND ADDITIONAL ORGANIC POLYISOCYANATE AND (B) WITH WATER AND ADDITIONAL ORGANIC POLYISOCYANATE PREPOLYMER (A) IS THE REACTION PRODUCT OF AN EXCESS OF AN ORGANIC POLYISOCYANATE WITH A POLYALKYLENE ETHER GLYCOL HAVING A MOLECULAR WEIGHT OF AT LEAST ABOUT 100 UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 30* CC. TO ABOUT 150*C. TO PREPARE A PREPOLYMER CONTAINING ALLOPHANATE GROUPS, PREPOLYMER (B) IS THE REACTION PRODUCT OF AN ORGANIC POLYISOCYANTE WITH A MIXTURE OF A POLYALKYLENE ETHER GLYCOL HAVING A MOLECULAR WEIGHT OF AT LEAST ABOUT 500 AND A POLYHYDRIC POLYALKYLENE ETHER CONTAINING MORE THAM TWO HYDROXYL GROUPS AND HAVING A MOLECULAR WEIGHT OF AT LEAST ABOUT 1000 UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 30*C. TO ABOUT 150*C. TO PREPARE A PREPOLYMER CONTAINING ALLOPHANATE GROUPS, THE RELATIVE AMOUNTS OF (A) AND (B) BEING WITHIN THE RANGE OF ABOUT 50 TO ABOUT 95 PERCENT BY WEIGHT OF ONE TO ABOUT 50 TO ABOUT 5 PERCENT BY WEIGHT OF THE OTHER.