Abstract: Electro-conductive fibers comprise synthetic fibers and an electro-conductive layer containing carbon nanotubes and covering a surface of the synthetic fibers, and the coverage of the electro-conductive layer relative to the whole surface of the synthetic fibers is not less than 60% (particularly not less than 90%). The electric resistance value of the electro-conductive fibers ranges from 1×10?2 to 1×1010 ?/cm, and the standard deviation of the logarithm of the electric resistance value is less than 1.0. The thickness of the electro-conductive layer ranges from 0.1 to 5 ?m, and the ratio of the carbon nanotubes may be 0.1 to 50 parts by mass relative to 100 parts by mass of the synthetic fibers. The electro-conductive layer may further contain a binder. The electro-conductive fibers may be produced by immersing the synthetic fibers in a dispersion with vibrating the synthetic fibers to form the electro-conductive layer adhered to the surface of the synthetic fibers.

Abstract: An electro-conductive multifilament yarn for an electro-conductive brush that includes an electro-conductive fiber containing a synthetic fiber and a carbon nanotube covering a surface of the fiber. The synthetic fiber may have a single-filament fineness of not more than 30 dtex. The synthetic fiber may have 3 to 6 elongated recesses or grooves extending in a longitudinal direction thereof and have a multi-leaves or cross-section.

Abstract: An electro-conductive multifilament yarn for forming an electro-conductive brush comprises an electro-conductive fiber containing a synthetic fiber and a carbon nanotube covering a surface of the fiber. The synthetic fiber may have a single-filament fineness of not more than 30 dtex. The synthetic fiber may have 3 to 6 elongated recesses or grooves extending in a longitudinal direction thereof and have a multi-leaves or star-shaped cross-section. The electro-conductive multifilament yarn of the present invention has a high electro-conductivity and may have an electric resistance value of 1×106 to 1×1011 ?/cm at 20° C. Further, the electro-conductivity has a high uniformity; the standard deviation of a logarithm of the electric resistance value may be not more than 1.0.