CONDUCTIVE RUBBER MATERIAL

摘要

PURPOSE: To obtain a material having stable electric resistance against the change in temp. and humidity by adding a specified amt. of amorphous metakaolin clay to a rubber having a low resistance. CONSTITUTION: An amorphous kaolin is compounded by 20-80 pts.wt. to 100 pts.wt. of rubber having a low electric resistance. The rubber having low resistance means such a rubber having about 10<4> to 10<12>Ωresistance, and epichlorohydrin rubber is preferably used. The amorphous kaolin is prepared by firing a clay essentially comprising kaolinite at 600 deg.C to remove the water of crystallization. The amorphous kaoline may be treated with a silane coupling agent to improve dispersibility and reinforcing property in the rubber. Since the amorphous kaolin has an excellent effect to decrease the surface free energy of the rubber, influences of temp. or humidity on the electric resistance of the rubber can be decreased by compounding the kaolin into the rubber.