Compositions of matter and electric cables

摘要

A composition of matter useful for strippable shields for electric power cables comprises: a base polymer which is a copolymer of ethylene with a mono-unsaturated ester; conductive carbon black in an amount to give the composition an electrical resistivity below 500 OMEGA m; and as adhesion-controlling additive, a copolymer of ethylene with a mono-unsaturated ester containing from 0.5 to 2% by weight of side-chains each of which comprises an inflexible ring structure bonded to a backbone carbon atom of the copolymer with at most five atoms interposed between them. The compositions have the advantage of being less rubbery than current strippable-screen compositions and can be made successfully with copolymers of lower ester content.