Electrophotographic photoreceptor, and electrophotographic cartridge and image forming apparatus including same

An electrophotographic photoreceptor comprising:

• a conductive support;
• and at least a photosensitive layer on the conductive support,
• wherein the photosensitive layer contains a polyester resin,
• the polyester resin contains at least one structure α selected from the group consisting of a structure represented by the following Formula (1), a structure represented by the following Formula (2), and a structure represented by the following Formula (3), the structure α having a number average molecular weight of 15,000 or less, and
• the polyester resin contains a divalent phenol residue and a divalent carboxylic acid residue:
• wherein in the Formula (1), R1 represents an alkylene group which may have a substituent or a divalent group represented by the following Formula (5), and n1 represents an integer of 1 to 100,
• wherein in the Formula (2), R1 represents an alkylene group which may have a substituent or a divalent group represented by the following Formula (5), R3 represents a divalent group, and n3 represents an integer of 1 to 100,
• wherein in the Formula (3), R1 represents an alkylene group which may have a substituent or a divalent group represented by the following Formula (5), R3 represents a divalent group, and n4 and n5 each independently represents an integer of 1 to 100, and
• R2—On2R2— (5)
• wherein in the Formula (5), R2 represents an alkylene group which may have a substituent, and n2 represents an integer of 1 to 10.