Polymer composition with improved stress whitening resistance

A process for preparing a polymer composition of at least one electrically insulating layer of an electric cable the electric cable having

• at least one elongated electrically conducting element;
• and
• at least one electrically insulating layer obtained from a polymer composition having at least one polypropylene-based thermoplastic polymer material and a dielectric liquid,
• wherein the dielectric liquid comprises at least one compound corresponding to formula I) below:
• R1-A-R2 (I)
• in which R1 and R2, identical or different, are unsubstituted aryl groups and the element A represents a single bond or an alkylene group;
• and
• wherein the element A is an alkylene group of the formula —(CH2)n- with 1≤n≤10;
• a group —(CHR)n′- with 1≤n≤5 and R being an alkyl group;
• a statistical group —(CHR)p-(CH2)m-, with 1≤p+m≤9, and R being an alkyl group;
• or a statistical group —(CHR)p1-(CH2)m′—(CHR′)p2-, with 1≤p1+m′+p2≤8, and R and R′ being different alkyl groups,
• said process comprising at least one step i) of mixing a polypropylene-based thermoplastic polymer material with said dielectric liquid.