Insulation coating for electric cable containing polyolefin and polymer with ester and epoxy groups

An electric cable comprising at least one conducting core (2) and at least one insulation coating (5) obtained by extruding onto said conducting core a polymeric composition comprising an effective amount of a peroxide cross-linking agent and subsequently cross-linking the composition via peroxide, said composition further comprising from 3 to 30% by weight of a terpolymer having a Melt Index of from 0.1 g/10′ to 40 g/10′ obtained by polymerizing ethylene with

• i) at least one acrylic ester of the formula:
• wherein R1 is H or CH3, R2 is an alkyl or aryl hydrocarbon group, linear or branched, preferably a phenyl, having 1 to 10 carbon atoms, and R3 is hydrogen or an alkyl or aryl hydrocarbon group, linear or branched, preferably a phenyl, having 1 to 10 carbon atoms;
• and
• ii) at least one glycidyl ester of the formula:
• wherein R3 and R5 are independently H, an alkyl or aryl hydrocarbon group, linear or branched, preferably a phenyl, having 1 to 10 carbon atoms;
• R1 is H or CH3, wherein the remainder of the polymeric composition is essentially constituted by a polyolefin polymeric base, wherein the polymeric composition includes, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups, said amounts of ester and epoxy groups, in combination, being such as to reduce the formation of water trees within the insulation coating (5) after electric ageing in water, and wherein said ester and epoxy groups are provided in the polymeric composition by said terpolymer.