Process of making cellular material

Claim 1

THE PROCESS OF PRODUCING A LIGHTWEIGHT, CLOSED-CELL CELLULAR MATERIAL IN A DEFINITE DESIRED SHAPE WHICH COMPRISED FORMING A PLASTIC, SHAPABLE MIXTURE COMPRISING FROM 10 TO 66% BY WEIGHT OF THERMOPLASTIC VINYL RESIN, FROM 10 TO 60% OF A PLASTICIZER THEREFOR, AND FROM 16 TO 80% OF A RUBBERY BUTADIENE-ACRYLONITRILE COPOLYMER, SAID PECENTAGES TOTALLY 100%, A CHEMICAL BLOWING AGENT HAVING A DECOMPOSITION TEMPERATURE OF AT LEAST 300*F., WHICH TEMPERATURE IS ABOVE THE TEMPEATURE USED IN THE HEREINAFTER-MENTIONED SHAPING STEP, AND VULCANIZING INGREDIENTS FOR SAID RUBBERY COPOLYMER, SAID VULCANIZING INGREDIENTS COMPRISING FROM 2 TO 5 PARTS OF ULTRA-ACCELERATOR PER 100 PARTS OF SAID COPOLYMER, SAHPING THIS MIXTURE IN THE FORM OF A MININATURE OF THE SAID FINALLY DESIRED SHAPE AT A TEMPERATURE SUBSTANTIALLY BEELOW 300*F., SAID TEMPERATURE BEING BELOW THAT AT WHICH SUBSTANTIAL DECOMPOSITION OF THE BLOWING AGENT OR VULCANIZATION OF THE COPOLYMER, OCCUR, THEREBY EFFECTING CONSOLIDATION OF THE MIXTURE AND KNITTING TOGETHER OF TH ECOMPONENTS OF THE MIXTURE INTO A UNITARY, SELF-SUPPORTING, SHAPE-RETAINING, UNVULCANIZED MASS WHICH IS A MINIATURE OF THE DESIRED SHAPE AND WHICH STILL CONTAINS THE BLOWING AGENT IN AN UNDECOMPOSED STATE, AND THEREAFTER HEATING THE RESULTING MINIATURE AT A VULZANIZING TEMPERATURE OF 300*F. UNDER CONDITIONS OF FREE EXPANSION TO DECOMPOSE SAID BLOWING AGENT AND VULCANIZE SAID COPOLYMER IN A SINGLE HEATING STEP, WHEREBY THERE IS FORMED AN EXPANDED CLOSEDECELL VULCANIZED MASS HAVING THE SAID FINALLY DESIRED SHAPE.