Process for the production of an electrically conducting polymer composite material

Process for the production of an electrically conducting carbon nanotube polymer composite material, in which carbon nanotubes and thermoplastic polymer are mixed in a twin-shaft screw extruder or a ring extruder or a planetary roller extruder or a co-kneader with non-conical shafts rotating in the same direction and having a main feed (2), a solids conveying zone (12, 13), and a heated melting zone (14, 15), and are then extruded, wherein

• a) the carbon nanotubes together with the polymer or polymers and optionally additives, in the solid phase, are fed to the main feed (2) of the screw extruder (1), the carbon nanotubes are pre-dispersed in the solids conveying zone (12,13) of the extruder by frictional forces between the solids, with the formation of a solids mixture, the solids mixture is then conveyed to the melting zone where the polymer is heated to a temperature above its melting point or glass transition temperature, to form a melt, and the solids are further dispersed in the polymer melt in the melting zone (14, 15), predominantly due to hydrodynamic forces, and
• b) the resulting mixture is further post-dispersed in at least one further zone (16, 17, 18, 19) of the screw extruder (1) the carbon nanotubes thereby being homogeneously distributed in the polymer melt.