Mixtures of tin, lead and zinc naphthenates and octoates as catalysts for polyurethane foams

Claim 1

IN THE METHOD OF PRODUCING A POLYURETHANE FOAM BY REACTING A POLYHYDROXY COMPOUND SELECTED FROM THE GROUP CONSISTING OF A POLYESTER CONTAINING AT LEAST TWO HYDROXYL GROUPS PREPARED BY THE ESTERIFICATION OF A DICARBOXYLIC ACID WITH A POLYHYDRIC ALCOHOL AND A POLYETHER HAVING A MOLECULAR WEIGHT FROM ABOUT 500 TO ABOUT 5000 WITH AN ORGANIC POLYISOCYANATE SELECTED FROM THE GROUP CONSISTING OF ALKYLENE AND ARYLENE POLYISOCYANATES, WATER, AND A CATALYST, THE IMPROVEMENT CONSISTING OF THE STEP OF INCLUDING IN SAID REACTION IN SYNERGISTIC RELATIONSHIP TIN, LEAD AND ZINC SALTS, SAID SALTS BEING SELECTED FROM THE GROUP CONSISTING OF THE RESPECTIVE NAPHTHENATES AND OCTOATES IN AMOUNTS TO CONTRIBUTE: (A) FROM ABOUT 0.006 PART TO ABOUT 0.085 PART TIN CATION PER 100 PARTS POLYHYDROXY COMPOUND, (B) LEAD AND ZINC CATIONS IN A RATIO OF FROM ABOUT 1.5:1 TO ABOUT 4.5:1 LEAD TO ZINC, SAID COMBINED LEAD AND ZINC CATIONS PRESENT IN AN AMOUNT EQUIVALENT TO FROM ABOUT 66% TO ABOUT 250% OF SAID TIN CATION.