Electric cable with polyethylene type insulation - and outer conductive layer contg. release agents e.g. silicone or polyethylene glycol! cpds.

摘要

An electric cable comprises an insulation of opt. cross-linked polyethylene or ethylene co- or terpolymer and an outer conductive layer co-extruded and opt. co-vulcanised with the insulating layer. The conductive layer is of polyethylene, chloroprene rubber, chlorinated polyethylene, SB and/or natural rubber contg. conductive lamp black. The improvement consists in incorporating release agents in the conductive layer comprising silicones, polyols, ethers, aldehydes, waxy aliphatic hydrocarbon and/or higher liq. aromatic hydrocarbons. Good adhesion between the layers is ensured and, therefore, good electrical rigidity, while, on the other hand, the external conductive layer can be easily removed from the insulation without damaging the latter. The silicones are pref. silicone oil, grease, resin or rubber. The polyols have mol. wt. =500 and are pref. polyethylene-glycols. The ethers have b.pts. =200 degrees C and are pref. dibenzylethers and/or their derivs. The aldehydes influence the peroxidic crosslinking speed and are pref. tetra hydrobenzaldehyde. The waxy aliphatic hydrocarbons are paraffin oil, wax or polyethylene wax.