Abstract: A polymeric composition comprises a polymerised propylene sequence and a propylene/ethylene copolymer sequence, has a melt index (230.degree.C; 2.16 kgms) of 0.01 to 0.5, preferably 0.025 to 0.25 and an ethylene content in the range 10-30% by weight, preferably at least 15% by weight. The polymer can accept a high carbon loading, for example in excess of 25% by weight. The invention also includes an electric conductor insulated with the polymer and also the use of the carbon filled polymer as a dielectric screen material.

Abstract: There is disclosed a thermoplastic, film-forming composition comprising a blend ofA. a propylene-ethylene copolymer, the propylene content of the copolymer being from 95 to 99.75% by weight of the copolymer, andB. a polymer of an alpha-olefin of 4 to 10 carbon atoms copolymerized with from 0 to 10% by weight of the copolymer of an alpha-olefin of 2 to 10 carbon atoms,The alpha-olefin polymer constituting from 41 to 90% by weight of the composition.The propylene-ethylene copolymer preferably contains from 2 to 4% by weight of ethylene, and preferably, in granular form, exhibits a Melt Flow Index of from 10 to 200 g/10 minutes, measured according to ASTM/D1238-65T (Condition N).The alpha-olefin component of the blend is suitably a polymer, preferably a homo-polymer, of butene-1, and suitably has a Melt Flow Index, by the aforementioned test, of less than 50 g/10 minutes, preferably between 5 and 40 g/10 minutes.