Method for inserting carbon particles into a polyurethane surface layer

Introducing electrically conductive particles into a polyurethane comprising surface layer, comprises: providing a solution of non-aggregated carbon particles with an average particle diameter of 0.3-3000 nm in a solvent; contacting the polyurethane comprising surface layer with the solution of the carbon particles; influencing the solution of the carbon particles on the polyurethane comprising surface layer for a period, which is not sufficient to convert the polyurethane in the solution; and terminating the influence of the solution of the carbon particles. Introducing electrically conductive particles into a polyurethane comprising surface layer, comprises: (a) providing a solution of non-aggregated carbon particles with an average particle diameter of 0.3-3000 nm in a solvent, which can cause the swelling of the polyurethane comprising surface layer; (b) contacting the polyurethane comprising surface layer with the solution of the carbon particles; (c) influencing the solution of the carbon particles on the polyurethane comprising surface layer for a period, which is not sufficient to convert the polyurethane in the solution; and (d) terminating the influence of the solution of the carbon particles on the polyurethane comprising surface layer. Independent claims are also included for: (1) a polyurethane layer comprising electrically conductive carbon particles and obtained by the above method. The external surface of the polyurethane layer comprises elevations and depressions, where the average height of the elevations is 50-500 nm and the average distance between the adjacent elevations is 0.5-1.5 mu m; and (2) a polyurethane article obtainable by the above method, comprising electrically conductive carbon particles containing surface layer, where the carbon particles in the polyurethane are present upto a depth of = 1 mu m, arranged below the surface.