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Abstract

An insulating composition for an electric power cable, and an electric power cable comprising a conductor surrounded by an inner semiconducting layer, an insulating layer, and an outer semiconducting layer, where the insulating layer consists of said insulating composition, are disclosed. The insulating composition comprises a crosslinkable multimodal ethylene copolymer obtained by coordinating catalysed polymerization of ethylene and at least one alpha-olefin, and has a density of 0.890-0.940 g/cm.sup.3 and an MFR.sub.2 of 0.1-10 g/10 min. The insulating composition is characterized in that the ethylene copolymer has an MWD of 3-12, a melting temperature of at most 125.degree. C., and a viscosity of 2500-7000 Pa.s at 135.degree. C. and a shear rate of 10 s.sup.-1, 1000-1800 Pa.s at 135.degree. C. and a shear rate of 100 s.sup.-1, and 250-400 Pa.s at 135.degree. C. and a shear rate of 1000 s.sup.-1, and that the multimodal ethylene copolymer includes an ethylene copolymer fraction selected from (a) a low molecular weight ethylene copolymer having a density of 0.900-0.950 g/cm.sup.3 and an MFR.sub.2 of 25-300 g/10 min and (b) a high molecular weight ethylene copolymer having a density of 0.870-0.940 g/cm.sup.3 and an MFR.sub.2 of 0.01-3 g/10 min.

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