Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, and image forming device

An electrophotographic photoreceptor comprising:

• a conductive support;
• a photosensitive layer disposed on the conductive support;
• and
• an outermost layer disposed on the photosensitive layer, wherein
• the outermost layer comprises a polymer obtained by polymerizing a compound having a chain polymerizable functional group, and
• the photosensitive layer in contact with the outermost layer comprises a hole transport material satisfying the following formula (1) and an electron transport material satisfying the following formula (2),
• the electron transport material comprises a compound represented by the following formula (6),
• the compound represented by the following formula (6) comprises a compound represented by the following formula (7) or (8):
• 600≤a (1)
• 400≤b (2)
• in the formula (1), a represents a molecular weight of the hole transport material, and
• in the formula (2), b represents a molecular weight of the electron transport material,
• in the formula (6), R61 to R64 each independently represents a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms which may be substituted, or an alkenyl group having 2 or more and 20 or less carbon atoms which may be substituted, R61 and R62 or R63 and R64 may be bonded to each other to form a cyclic structure, and X represents an organic residue having a molecular weight of 120 or more and 250 or less;
• in the formula (7), R71 to R73 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms;
• in the formula (8), R81 to R84 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms.

An electrophotographic photoreceptor comprising:

• a conductive support;
• and
• a photosensitive layer and a protective layer disposed on the conductive support, wherein
• the protective layer comprises a polymer obtained by polymerizing a compound having a chain polymerizable functional group,
• the photosensitive layer in contact with the protective layer comprises a binder resin, a hole transport material, and an electron transport material, and
• the photosensitive layer in contact with the protective layer satisfies the following formula (5),
• 1.20≤(B/b)/(A/a)≤1.60 (5)
• in the formula (5), A represents a content (part by mass) of the hole transport material with respect to 100 of the binder resin content, a represents a molecular weight of the hole transport material, B represents a content (part by mass) of the electron transport material with respect to 100 of the binder resin content, and b represents a molecular weight of the electron transport material,
• the electron transport material comprises a compound represented by the following formula (6),
• the compound represented by the following formula (6) comprises a compound represented by the following formula (7) or (8):
• in the formula (6), R61 to R64 each independently represents a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms which may be substituted, or an alkenyl group having 2 or more and 20 or less carbon atoms which may be substituted, R61 and R62 or R63 and R64 may be bonded to each other to form a cyclic structure, and X represents an organic residue having a molecular weight of 120 or more and 250 or less;
• in the formula (7), R71 to R73 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms;
• in the formula (8), R81 to R84 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms.

An electrophotographic photoreceptor comprising:

• a conductive support;
• and
• a photosensitive layer and a protective layer disposed on the conductive support, wherein the protective layer comprises a polymer obtained by polymerizing a compound having a chain polymerizable functional group,
• the photosensitive layer in contact with the protective layer comprises a hole transport material and an electron transport material, and
• a ratio (a/b) of a molecular weight of the hole transport material a to a molecular weight of the electron transport material b is 1.40 or more and 1.90 or less,
• the electron transport material comprises a compound represented by the following formula (6),
• the compound represented by the following formula (6) comprises a compound represented by the following formula (7) or (8);
• in the formula (6), R61 to R64 each independently represents a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms which may be substituted, or an alkenyl group having 2 or more and 20 or less carbon atoms which may be substituted, R61 and R62 or R63 and R64 may be bonded to each other to form a cyclic structure, and X represents an organic residue having a molecular weight of 120 or more and 250 or less;
• in the formula (7), R71 to R73 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms;
• in the formula (8), R81 to R84 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms.