US 12,405,550 B2
Developing device, process cartridge, and electrophotographic image forming apparatus
Takashi Koyanagi, Shizuoka (JP); Kineo Takeno, Shizuoka (JP); and Takuho Sato, Shizuoka (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Mar. 4, 2022, as Appl. No. 17/687,146.
Claims priority of application No. 2021-038262 (JP), filed on Mar. 10, 2021.
Prior Publication US 2022/0291607 A1, Sep. 15, 2022
Int. Cl. G03G 15/08 (2006.01); G03G 5/10 (2006.01); G03G 9/083 (2006.01); G03G 15/10 (2006.01)
CPC G03G 15/0818 (2013.01) [G03G 5/105 (2013.01); G03G 9/083 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A developing device comprising:
a developer; and
a developing member configured to carry the developer on a surface thereof,
the developing member including an electro-conductive substrate and a single-layer elastic layer serving as a surface layer on the substrate,
the surface layer comprising a binder resin, and the binder resin containing a crosslinked urethane resin and a crosslinked acrylic resin,
the crosslinked urethane resin and the crosslinked acrylic resin forming an interpenetrating polymer network structure in a first region from an outer surface of the surface layer to a position at a depth of 0.1 μm from the outer surface of the surface layer,
wherein the developer contains developer particles each containing at least a binder resin and a magnetic substance,
the crosslinked urethane resin is a polycarbonate-modified urethane resin having, in its soft segment, a structure having a side-chain methyl group, and
the binder resin incorporated into the surface layer (1) of the developing member has a volume resistivity of 1.0×1010 Ω·cm or more and 1.0×1018 Ω·cm or less.