Electrophotographic roller, process cartridge, and electrophotographic image forming apparatus

A process cartridge configured to be detachably attached to a main body of an electrophotographic image forming apparatus, wherein

• the process cartridge has the electrophotographic roller,
• the electrophotographic roller has a conductive substrate and a resin layer on an outer peripheral surface of the substrate,
• a thickness of the resin layer is 2.0 to 30.0 μm,
• the resin layer comprises a binder resin and carbon black dispersed in the binder resin,
• an arithmetic mean value Rc of a circle-equivalent diameter of the carbon black in the resin layer is not more than 80 nm,
• an arithmetic mean value d of a distance between wall surfaces of the carbon black in the resin layer is 60 to 170 nm, and
• when an elastic modulus of the binder resin in a first region from an outer surface of the resin layer to a depth of 0.1 μm, measured in a cross section in a thickness direction of the resin layer, is defined as E1, E1 satisfies a following formula (1):
• E
• ⁢
• 1
• ≥
• 200
• ⁢
• MPa
• .
• (
• 1
• )

An electrophotographic image forming apparatus comprising:

• an image bearing member for bearing an electrostatic latent image;
• a charging roller for primarily charging the image bearing member;
• and a developing roller for developing the electrostatic latent image with toner to form a toner image, wherein
• either or both of the charging roller and the developing roller are an electrophotographic roller having a conductive substrate and a resin layer on an outer peripheral surface of the substrate,
• a thickness of the resin layer is 2.0 to 30.0 μm,
• the resin layer comprises a binder resin and carbon black dispersed in the binder resin,
• an arithmetic mean value Rc of a circle-equivalent diameter of the carbon black in the resin layer is not more than 80 nm,
• an arithmetic mean value d of a distance between wall surfaces of the carbon black in the resin layer is 60 to 170 nm, and
• when an elastic modulus of the binder resin in a first region from an outer surface of the resin layer to a depth of 0.1 μm, measured in a cross section in a thickness direction of the resin layer, is defined as E1, E1 satisfies a following formula (1):
• E
• ⁢
• 1
• ≥
• 200
• ⁢
• MPa
• .
• (
• 1
• )