Method of making sponge rubber with the aid of amines

Claim 1

IN A METHOD OF PRODUCING A CELLULAR RUBBERLIKE MATERIAL WHEREIN A HYDROCARBON RUBBERY POLYMER OF A CONJUGATED BUTADIENE WHICH POLYMER IS IN A PLASTIC FORM, IS MIXED WITH A BLOWING AGENT AND A CURING AGENT, AND CURED IN A MOLD WITH THE AID OF HEAT UNDER CONDITIONS IMPARTING AN INCREASE IN VOLUME, THE STEPS WHICH COMPRISE DISPERSING THROUGH THE PLASTIC RUBBERY POLYMER PRIOR TO CURING A MEMBER OF THE GROUP CONSISTING OF AMINES HAVING AN ALIPHATIC GROUP CONNECTED DIRECTLY TO THE AMINE NITROGEN AND WHICH ARE HIGHLY SOLUBLE IN HYDROCARBON OILS, AND MIXTURES OF CARBON DIOXIDE PRODUCING MATERIALS AND SUCH AMINES, SAID AMINE GROUP MEMBERS BEING PRESENT IN TOTAL AMOUNTS GREATER THAN 2% AND NOT EXCEEDING 15% BY WEIGHT OF THE RUBBERY POLYMER, AND SAID GROUP MEMBERS CONTAINING A CARBON-TO-CARBON CHAIN OF AT LEAST FIVE CARBON ATOMS EXCLUSIVE OF THAT DIRECTLY CARRYING THE AMINE NITROGEN PER HYDROPHILIC GROUP, AND THEREAFTER HEATING THE MIXTURE THUS FORMED TO SUFFICIENT TEMPERATURE TO RELEASE GAS THEREIN AND CAUSE EXPANSION OF SAID MIXTURE, AND VULCANIZING SAID MIXTURE IN EXPANED FORM.