Vulcanized elastomers and methods of making the same

Claim 1

TRANSPARENT, SATURATED ELASTOMERS HAVING A DENSITY BELOW 1.0 KG./DM.3 AND CONSISTING ESSENTIALLY OF THE PRODUCT OBTAINED BY HEATING, AT A TEMPERATURE BETWEEN 100* C. AND 250*C., FOR FROM 20 MINUTES TO ONE HOUR AND UNDER PRESSURE, A MIXTURE CONSISTING ESSENTIALLY OF (1) A PRE-FORMED AMORPHOUS, LINEAR COPOLYMER OF PROPYLENE WITH ETHYLENE CONTAINING FROM 20% TO 80% BY WEIGHT OF ETHYLENE IN THE COPOLYMER MACROMOLECULE; (2) AN ORGANIC PEROXY COMPOUND AS A RADICAL INITIATOR; AND (3) A POLYMERIZABLE MONOMERIC HYDROCARBON THE POLYMERIZATION OF WHICH IS INITIATED BY FREE RADICAL MECHANISM AND WHICH IS SELECTED FROM THE GROUP CONSISTING OF DIVINYL BENZENE AND STYRENE, THE AMOUNT OF (3) IN THE MIXING BEING FROM 5 PARTS TO 40 PARTS PER 100 PARTS OF THE PRE-FORMED COPOLYMER (1) AND THE MIXING OF (1), (2) AND (3) BEING CARRIED OUT AT A TEMPERATURE BETWEEN 30*C. AND 70*C.; SAID ELASTOMERS BEING CHARACTERIZED IN THAT THE CHAINS OF THE COPOLYMER PRESENT THEREIN ARE CROSS-LINKED BY SHORT CHAINS CONSISTING OF UNITS OF THE POLYMERIZABLE MONOMER (3); AND IN HAVING A RELATIVELY LOW INTIAL ELASTIC MODULUS, A HIGH ULTIMATE TENSILE STRENGTH AND A STRESS-ELONGATION CURVE CHARACTERISTIC OF PRODUCTS THAT CRYSTALLIZE UNDER STRETCH.