Thermally-stabilized polyacetaldehyde elastomers, process for their preparation and mixtures of same with polycarbonamides

Claim 1

AN ELASTOMER CONSISTING ESSENTIALLY OF A MIXTURE OF AMORPHOSUS POLYACETALDEHYDE HAVING A NUMBER AVERAGE MOLECULAR WEIGHT BETWEEN ABOUT 1X10**5 AND 3X10**6, HAVING MOKLECULAR CHAINS CONSISTING OF A SUCCESSION OF ALTERNATE CARBON ATOMS AND OXYGEN ATOMS WHICH METHYL SIDE GROUPS ATTACHED TO THE CHAIN CARBON ATOMS IN RANDOM CONFIGURATION ALONG THE POLYMER CHAINS, AND SAID CARBOXYLIC ESTER GROUPS AS TERMINATING GRIYOS IB TGE EBDS OF THE POLYMER CHAINS, WITH FROM 0.1 TO 10% BY WEIGHT OF A SYNTHETIC LINEAR POLYMERIC CARBONAMIDE WHICH CONTAINS RECURRING CARBONAMIDE GROUPS AS AN INTEGRAL PART OF THE MAIN POLYMER CHAIN SEPARATED BY AT LEAST TWO CARBON ATOMS SAID POLYMERIC CARBONAMIDE HAVING A MELTING POINT BELOW 225*C. AND BEING SELECTED FROM THE GROUP CONSISTING OF MONOCARBOXYLIC ACID AMIDES, DICARBOXYLIC ACID DIAMIDES, AND FIBER-FORMING SYNTHETIC LINEAR POLYMERIC CARBONAMIDES WHICH CONTAIN RECURRING CARB ONAMIDE GROUPS AS AN INTEGRAL PART OF THE MAIN POLYMER CHAIN SEPARATED BY AT LEAST TWO CARBON ATOMS, SAID ELASTOMER HAVING A THERMAL DEGRADATION CONSTANT, K111*, OF LESS THAN 0.35% PER MINUTE AT 111*C.