Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

A process cartridge integrally supporting:

• an electrophotographic photosensitive member, and
• at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit, and
• the process cartridge being detachably attachable to a main body of an electrophotographic apparatus,
• wherein the electrophotographic photosensitive member comprises:
• a support,
• an undercoat layer, and
• a photosensitive layer, in this order,
• the undercoat layer comprises:
• a polyamide resin, and
• titanium oxide particles having been subjected to a surface treatment with an organic silicon compound,
• when an average primary particle size of the titanium oxide particles having been subjected to the surface treatment with the organic silicon compound is defined as “b” [μm], and a mass ratio of a Si element to TiO2 in the titanium oxide particles having been subjected to the surface treatment with the organic silicon compound is defined as “c” [mass %], “b” and “c” satisfy a relationship expressed by the following Expression (B),
• 0.025≤b×c≤0.050 (B), and
• the photosensitive layer is a monolayer type photosensitive layer comprising:
• a charge generating substance,
• a hole transporting substance, and
• an electron transporting substance.

An electrophotographic apparatus comprising:

• an electrophotographic photosensitive member,
• a charging unit,
• an exposing unit,
• a developing unit, and
• a transfer unit,
• wherein the electrophotographic photosensitive member comprises:
• a support,
• an undercoat layer, and
• a photosensitive layer, in this order,
• the undercoat layer comprises:
• a polyamide resin, and
• titanium oxide particles having been subjected to a surface treatment with an organic silicon compound,
• when an average primary particle size of the titanium oxide particles having been subjected to the surface treatment with the organic silicon compound is defined as “b” [μm], and a mass ratio of a Si element to TiO2 in the titanium oxide particles having been subjected to the surface treatment with the organic silicon compound is defined as “c” [mass %], “b” and “c” satisfy a relationship expressed by the following Expression (B),
• 0.025≤b×c≤0.050 (B), and
• the photosensitive layer is a monolayer type photosensitive layer comprising:
• a charge generating substance,
• a hole transporting substance, and
• an electron transporting substance.