Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

A process cartridge integrally supporting an electrophotographic photosensitive member and comprising:

• at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit and a cleaning unit, the process cartridge being detachably attachable to a main body of an electrophotographic apparatus;
• the electrophotographic photosensitive member comprising a support, an undercoat layer, a charge generation layer and a charge transport layer in this order;
• the charge transport layer containing a charge transport material;
• the undercoat layer comprising a polyamide resin and a titanium oxide fine particle;
• and
• the charge generation layer comprising a hydroxygallium phthalocyanine pigment, wherein
• Ra≤50 and 0.1≤Ra/Rsm≤0.5 when on the surface of the undercoat layer, Ra (nm) is an arithmetic mean roughness and Rsm (nm) is an average length of a roughness curve element according to JIS B0601:2001
• the hydroxygallium phthalocyanine pigment comprises crystal particles having a crystal form that exhibits peaks at 7.4°±0.3° and 28.2°±0.3° at Bragg angles 2θ in a spectrum of X-ray diffraction using a CuKα ray, and
• a peak having a half-value width of 50 nm or smaller exists in a range of 20 to 50 nm in a size distribution of the crystal particles measured using small-angle X-ray scattering.

An electrophotographic apparatus, comprising:

• an electrophotographic photosensitive member;
• a charging unit;
• an exposure unit;
• a developing unit;
• and
• a transfer unit;
• the electrophotographic photosensitive member comprising a support, an undercoat layer, a charge generation layer and a charge transport layer in this order;
• the charge transport layer containing a charge transport material;
• the undercoat layer comprising a polyamide resin and a titanium oxide fine particle;
• and
• the charge generation layer comprising a hydroxygallium phthalocyanine pigment, wherein
• Ra≤50 and 0.1≤Ra/Rsm≤0.5 when on the surface of the undercoat layer, Ra (nm) is an arithmetic mean roughness and Rsm (nm) is an average length of a roughness curve element according to JIS B0601:2001
• the hydroxygallium phthalocyanine pigment comprises crystal particles having a crystal form that exhibits peaks at 7.4°±0.3° and 28.2°±0.3° at Bragg angles 2θ in a spectrum of X-ray diffraction using a CuKα ray, and
• a peak having a half-value width of 50 nm or smaller exists in a range of 20 to 50 nm in a size distribution of the crystal particles, which is measured using small-angle X-ray scattering.