Patent ID: 8425806

Claim:
A semiconductive polymer composition, comprising: (a) from 30 to 90 wt % of a polymer component; (b) from 10 to 60 wt % of carbon black; and (c) from 0 to 8 wt % additives, based on the total semiconductive polymer composition, and wherein the composition comprises, when measured in accordance with the Surface Smoothness Analysis (SSA) method using a tape sample prepared by extrusion of said semiconductive polymer composition using a single screw extruder (20 mm), a screw speed of 50 rpm and extruder die opening of 30 mm×1 mm, the tape sample having a thickness of 500±20 μm and a width of 18 mm, in which method a measurement area of 1 m 2 of the tape surface is scanned with a camera while the tape moves with a speed of 50 mm/s, less than 23 particles per m 2 having a width of larger than 150 μm at the half height of said particle protruding from the surface of the tape sample, and less than 10 particles, per m 2 having a width of larger than 200 μm at the half height of said particle protruding from the surface of the tape sample.