Electrophotographic apparatus, process cartridge and cartridge set

A process cartridge that is detachably attachable to a main body of an electrophotographic apparatus,

• the process cartridge comprising:
• a charging device for charging a surface of an electrophotographic photosensitive member;
• and
• a developing device for developing an electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a toner to form a toner image on the surface of the electrophotographic photosensitive member, wherein
• the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member,
• the conductive member comprises a support having a conductive outer surface, and a conductive layer provided on the outer surface of the support,
• the conductive layer comprises a matrix and a plurality of domains dispersed in the matrix,
• the matrix contains a first rubber,
• each of the domains contains a second rubber and an electronic conductive agent,
• at least some of the domains are exposed at the outer surface of the conductive member,
• the outer surface of the conductive member is composed of at least the matrix and the domains exposed at the outer surface of the conductive member,
• the matrix has a volume resistivity R1 of larger than 1.00×1012 Ω·cm,
• the volume resistivity R1 of the matrix is 1.0×105 times or more a volume resistivity R2 of the domains,
• the developing device comprises the toner,
• the toner comprises a toner particle containing a binder resin, and a silica fine particle on a surface of the toner particle, and
• a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.

A cartridge set that is detachably attachable to a main body of an electrophotographic apparatus and comprises a first cartridge and a second cartridge, wherein

• the first cartridge comprises
• a charging device for charging a surface of an electrophotographic photosensitive member, and
• a first frame for supporting the charging device,
• the second cartridge comprises
• a toner container that accommodates a toner for developing an electrostatic latent image formed on the surface of the electrophotographic photosensitive member to form a toner image on the surface of the electrophotographic photosensitive member,
• the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member;
• the conductive member comprises a support having a conductive outer surface, and a conductive layer provided on the outer surface of the support,
• the conductive layer comprises a matrix and a plurality of domains dispersed in the matrix,
• the matrix contains a first rubber;
• each of the domains contains a second rubber and an electronic conductive agent,
• at least some of the domains are exposed at the outer surface of the conductive member,
• the outer surface of the conductive member is composed of at least the matrix and the domains exposed at the outer surface of the conductive member,
• the matrix has a volume resistivity R1 of larger than 1.00×1012 Ω·cm,
• the volume resistivity R1 of the matrix is 1.0×105 times or more a volume resistivity R2 of the domains,
• the toner comprises a toner particle containing a binder resin, and a silica fine particle on a surface of the toner particle, and
• a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.