| 摘要 |
<p>A composition of matter for use as dielectric shield in an electric power cable having insulation of XLPE, EPR or EPDM 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 Am; and as an adhesion-adjusting additive, 1-20 % by weight of the base polymer of a copolymer which consists essentially of ethylene and a comonomer having in its molecule at least one carbon-oxygen dipole, said copolymer having a molecular weight less than 20,000 Daltons but a melting point higher than 30 °C. This new class of additive permits use of EVA's with lower vinyl acetate content than prior art additives and so enables the composition to have less rubbery physical properties.</p> |
