| abstract |
The present invention provides a conductive rubber composition with a low hardness and low distortion, and exhibiting less variations in volume specific resistance value and less dependence on environment, a manufacturing method thereof, and further, a conductive rubber member using the same. The conductive rubber composition of the present invention contains a particulate polymer (A1, crosslinked particulate polymer, and the like), an uncrosslinked polymer (A2), and a conductivity imparting agent (B). The particulate polymer (A1) is a nonpolar polymer (SBR, and the like), the uncrosslinked (A2) is a polar polymer (NBR, and the like), and the more conductivity imparting agent (B) exists in the uncrosslinked polymer than in the crosslinked particulate polymer. This composition can be obtained by starting the kneading of the above-described respective compounds at such a temperature (T C.) that the Mooney viscosity of the uncrosslinked polymer is equal or less than the Mooney viscosity of particulate polymer. The particulate polymer (A1) preferably has an average particle diameter of 25 mm or less, and a Duro A hardness of 45 to 80. The conductive rubber member, according to the present invention, can be obtained by molding the above-described conductive rubber composition and then vulcanizing it. |