Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoreceptor comprising:

• a conductive support;
• and
• an undercoat layer and a photosensitive layer stacked on the conductive support,
• wherein the undercoat layer contains crystalline electron transport compound particles, and
• the electron transport compound particles have an average aspect ratio of 4.5 or less, and
• wherein the electron transport compound particles are particles of a compound represented by one of formulae (P1) to (P8) below:
• in formula (P1), R11, R12, R13, R14, R15, R16, R17, and R18 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom, R11 and R12 taken together may form a ring and so may R12 and R13, and R13 and R14, and R15 and R16 taken together may form a ring and so may R16 and R17, and R17 and R18,
• in formula (P2), R21, R22, R23, R24, R25, R26, R27, and R28 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom, R21 and R22 taken together may form a ring and so may R22 and R23, and R23 and R24, and R25 and R26 taken together may form a ring and so may R26 and R27, and R27 and R28,
• in formula (P3), R31, R32, R33, R34, R35, and R36 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an alkoxycarbonyl group, or a halogen atom,
• in formula (P4), R41, R42, R43, R44, R45, R46, R47, R48, R49, and R50 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an alkoxycarbonyl group, or a halogen atom,
• in formula (P5), R51, R52, R53, R54, R55, R56, R57, and R58 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an alkoxycarbonyl group, or a halogen atom,
• in formula (P6), R61, R62, R63, and R64 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an alkoxycarbonyl group, or a halogen atom,
• in formula (P7), R71, R72, R73, R74, R75, R76, R77, and R78 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, or a halogen atom, and Z represents an oxygen atom or a dicyanomethylene group (═C(CN)2), and
• in formula (P8), R81, R82, R83, R84, R85, R86, and R87 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, or a halogen atom, and Z represents an oxygen atom or a dicyanomethylene group (═C(CN)2).