Abstract: The present invention relates to an electrically insulating composition that withstands high temperature T, the composition comprising a first component constituted by an organic polymer having a decomposition temperature lower than said temperature T, a second component constituted by a fusible ceramic filler having a melting temperature lower than said temperature T, and a third component constituted by a refractory filler having a melting temperature higher than said temperature T. According to the invention, the fusible ceramic filler content is less than or equal to 50 parts by weight per 100 parts by weight of polymer.

Abstract: A semiconducting mixture which is curable with the aid of silanes includs the following parts by weight:a) 70 to 80 parts of a first copolymer of ethylene, or of ethylene and another olefin, with an ester taken from the group constituted by ethyl acrylate, vinyl acetate, and butyl acetate, with only a fraction lying in the range 60% to 75% of the copolymer being grafted with the aid of silanes;b) 30 to 40 parts of a second copolymer of acrylonitrile and butadiene having about 40% by weight of acrylonitrile;c) 40 to 60 parts of conducting carbon black of the quality satisfying the standard ASTM D 2515-68;d) 15 to 20 parts of monocrystaline wax; ande) 1 part of a phenolic antioxidant.