Abstract: Provided is a conductive roll for an electrophotographic machine. The conductive roll is a charging roll and includes a shaft body, and an elastic body layer formed on an outer periphery of the shaft body. The elastic body layer is a crosslinked body of a composition containing a diene-based polymer (a), a sulfur or peroxide crosslinking agent (b), carbon black (c), and a coupling agent (d). (c) has a specific surface area of 40 to 300 m2/g. (d) is a coupling agent having a NHR1 group and a SSO3H group, or a coupling agent having a NHR1 group and an ene structure (where R1 is H or a hydrocarbon group having 1 to 8 carbon atoms). The contents of (c) and (d) in the composition are respectively 10 to 45 parts by mass and 0.5 to 20 parts by mass with respect to 100 parts by mass of (a).

Abstract: An elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black. The elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber; in the range of a 5 ?m×5 ?m square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase is within a range of 10 to 90%. The resistance value of the elastic body layer is within a range of 1.0×103 to 1.0×106?. A surface layer contains an electronic conductive agent and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of ?10 to ?70° C.

Abstract: An elastic body layer is composed of a conductive rubber composition containing an isoprene rubber, a rubber other than the isoprene rubber, and carbon black. The elastic body layer is phase-separated into a first rubber phase containing the isoprene rubber and a second rubber phase containing the rubber other than the isoprene rubber; in the range of a 5 ?m×5 ?m square of an arbitrary cross section of the elastic body layer, the area ratio of the first rubber phase is within a range of 10 to 90%. The resistance value of the elastic body layer is within a range of 1.0×103 to 1.0×106?. A surface layer contains an electronic conductive agent and a crosslinked body of at least one polyurethane resin of an ether polyurethane resin and a carbonate polyurethane resin, and the glass transition point of the surface layer is within a range of ?10 to ?70° C.

Abstract: Provided is a conductive roll for an electrophotographic machine. The conductive roll is a charging roll and includes a shaft body, and an elastic body layer formed on an outer periphery of the shaft body. The elastic body layer is a crosslinked body of a composition containing a diene-based polymer (a), a sulfur or peroxide crosslinking agent (b), carbon black (c), and a coupling agent (d). (c) has a specific surface area of 40 to 300 m2/g. (d) is a coupling agent having a NHR1 group and a SSO3H group, or a coupling agent having a NHR1 group and an ene structure (where R1 is H or a hydrocarbon group having 1 to 8 carbon atoms). The contents of (c) and (d) in the composition are respectively 10 to 45 parts by mass and 0.5 to 20 parts by mass with respect to 100 parts by mass of (a).