Flexible urethane foams and a process for producing same

Claim 1

A FLEXIBLE URETHANE FOAM PRODUCED BY MIXING A POLYESTER PREPOLYMER WITH WATER AND AN ACTIVATOR THEREFOR IN THE PRESENCE OF FROM ABOUT 0.1% TO ABOUT 3.0% BASED UPON THE WEIGHT OF SAID PREPOLYMER, OF AT LEAST ONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF TRIALKY PHOSPHATES, TRIALKYL BORATES, AND TRIALKYL PHOSPHITES IN WHICH SaID ALKYL SUBSTITUTENT CONTAINS FROM ABOUT 2 TO 12 CARBON ATOMS, SAID POLYMESTER PREPOLYMER BEING THE REACTION PRODUCT OF AN ORGANIC POLYISOCYANATE AND A POLYESTER WHICH IS THE REACTION PRODUCT OF A MIXTURE OF AT LEAST ONE DIHYDRIC ALCOHOL, AT LEAST ONE DICARBOXYLIC ACID AND UP TO MINOR QUANTITIES OF AT LEAST ONE POLYHYDRIC ALCOHOL CONTAINING AT LEAST THREE HYDROXYL GROUPS, SAID POLYESTER HAVING A HYDROXYL NUMBER BETWEEN ABOUT 40 TO 80 AND A RELATIVELY LOW ACID NUMBER, SaID POLYISOCYANATE AND POLYESTER BEING PRESENT IN SUCH QUANTITIES TO PROVIDE THE POLYISOCYANATE-POLYESTER REACTION PRODUCT WITH A RATIO OF ISOCYANATE GROUPS TO HYDROXYL GROUPS OF 1,05 (NCO):1(OH) TO 6 (NCO):1(OH).