Production of gas-expanded organic plastics

Claim 1

A METHOD OF MAKING A GAS-EXPANDED ORGANOPLASTIC MATERIAL WHICH COMPRISES MIXING A BLOWING AGENT SELECTED FROM THE GROUP CONSISTING OF PHYSICAL MIXTURES AND SOLID SOLUTIONS OF UREA AND OXALIC ACID IN PROPORTIONS CORRESPONDING TO FORM 1 TO 5 MOLS OF UREA PER MOL OF OXALIC ACID AND UREA OXALATE WITH AN EXPANDABLE ORGANOPLASTIC MATERIAL WHICH IS CAPABLE OF SETTING TO A NORMALLY SOLID STATE AND HAVING SUFFICIENT CONSISTENCY AND TENSILE STRENGTH UNDER THE CONDITIONS OF THE DECOMPOSING STEP TO RETAIN THE EVOLVED EXPANDING GAS AND THE RESULTING EXPANDED STRUCTURE, THE AMOUNT OF SAID BLOWING AGENT RANGING FROM 1 TO 40 PARTS PER 100 PARTS OF SAID ORGANOPLASTIC MATERIAL, SUBSEQUENTLY DECOMPOSING SAID BLOWING AGENT BY HEAT TO EVOLVE GAS, CAUSING SAID EVOLVED GAS TO BE RETAINED IN AND TO EXPAND SAID ORGANOPLASTIC MATERIAL, AND CAUSING SAID ORGANOPLASTIC MATERIAL TO SET AND RETAIN ITS EXPANDED CONDITION.