Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

A process cartridge, comprising:

• electrophotographic photosensitive member;
• and
• at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit,
• the process cartridge integrally supporting the electrophotographic photosensitive member and the at least one unit, and being removably mounted onto a main body of an electrophotographic apparatus, wherein
• the electrophotographic photosensitive member includes a support bearing a charge-generating layer and a charge-transporting layer,
• a surface layer of the electrophotographic photosensitive member contains inorganic particles (α) having an average particle diameter (Lα) of primary particles of 5 to 50 nm and resin particles (β) having an average particle diameter (Lβ) of primary particles of 0.1 to 5.0 μm,
• (Smα)/(Sα)≥0.3 in any cross-section of the surface layer, where a region within (Lβ/2) from a surface of each of the resin particles (β) is defined as a region (M), a sum of cross-sectional areas of the inorganic particles (α) that are present in the cross-section is represented by (Sα), and a sum of cross-sectional areas of the inorganic particles (α) that are included in the region (M) is represented by (Smα),
• inorganic particles (α) are selected from the group consisting of silica particles and alumina particles,
• the inorganic particles in the surface layer each have a surface treated with a silicone oil or at least one compound selected from compounds represented by formulae (1) and (2)
• where R1 to R3 independently represent an alkoxy group or an alkyl group provided that at least two of R1 to R3 represent an alkoxy group, R4 represents a vinyl group, a 1-methylvinyl group, an acryloyloxy group or a methacryloyloxy group, R5 represents an acryloyloxy group or a methacryloyloxy group, and n represents an integer of 1 to 6, and
• the average particle diameter (Lβ) of primary particles is 0.1 to 1.5 μm.

Ari electrophotographic apparatus, comprising:

• an electrophotographic photosensitive member;
• and
• at least one unit selected from the group consisting of a charging unit, an exposing unit, a developing unit, and a transferring unit, wherein
• the electrophotographic photosensitive member includes a support bearing a charge-generating layer and a charge-transporting layer,
• a surface layer of the electrophotographic photosensitive member contains inorganic particles (α) having an average particle diameter (Lα) of primary particles of 5 to 50 nm and resin particles (β) having an average particle diameter (Lβ) of primary particles of 0.1 to 5.0 μm,
• (Smα)/(Sα)≥0.3 in any cross-section of the surface layer, where a region within (Lβ/2) from a surface of each of the resin particles (β) is defined as a region (M), a sum of cross-sectional areas of the inorganic particles (α) that are present in the cross-section is represented by (Sα), and a SUM across-sectional areas of the inorganic particles (α) that are included in the region (M) is represented by (Smα),
• inorganic particles (α) are selected from the group consisting of silica particles and alumina particles,
• the inorganic particles (α) in the surface layer each have a surface treated with a silicone oil or at least one compound selected from compounds represented by formulae (1) and (2)
• where R1 to R3 independently represent an alkoxy group or an alkyl group provided that at least two of R1 to R3 represent an alkoxy group R4 represents a vinyl group, a 1-methylvinyl group, an acryloyloxy group or a methacryloyloxy group, R5 represents an acryloyloxy group or a methacryloyloxy group, and n represents an integer of 1 to 6, and
• the average particle diameter (Lβ) of primary particles is 0.1 to 1.5 μm.