Fibrous electrically-conductive filler and process for producing the same

Abstract

A fibrous electrically-conductive filler comprises fibrous aluminum borate as a core material and a layer of a electrically-conductive substance which covers the core material or comprises fibrous aluminum borate as a core material, a layer of titanium oxide which covers the fibrous aluminum borate and a layer of a electrically-conductive substance which covers the titanium oxide layer. The fibrous electrically-conductive filler can be prepared by a process comprising the step of directly forming a layer of a electrically-conductive substance doped with antimony or fluorine on the surface of fibrous aluminum borate, or the steps of forming, on the surface of the fibrous aluminum borate, an intermediate layer of titanium oxide in an amount ranging from 2 to 50% by weight on the basis of the weight of the fibrous aluminum borate and then forming a layer of a electrically-conductive substance doped with antimony or fluorine on the surface of fibrous aluminum borate. The filler has a low volume specific resistivity and is substantially excellent in electrical conductivity-imparting effect per unit weight thereof when it is added to a basic material such as a resin. The electrically-conductive substance coated on the filler surface is not peeled off and hence the filler does not cause loss of the electrical conductivity when it is incorporated into a basic material such as paper, a plastic, a rubber, a resin or a paint. The filler per se is white or transparent and, therefore, the color tone of such a basic material may be arbitrarily changed by the addition of a coloring agent.