Electrophotographic photosensitive member, process cartridge, and image forming apparatus

1. An electrophotographic photosensitive member comprising:

a conductive support;

a charge generation layer disposed on the conductive support, the charge generation layer including:

a charge generating material; and

a vinyl copolymer, the vinyl copolymer including:

a structural unit including a chlorine atom,

a structural unit including an acyloxy group, and

a structural unit including an aromatic polycarboxylic acid structure,

a proportion of the structural unit including a chlorine atom to all the structural units constituting the vinyl copolymer being 80% by mass or more, a proportion of the structural unit including an aromatic polycarboxylic acid structure to all the structural units constituting the vinyl copolymer being 0.5% by mass or more; and

a charge transport layer disposed on the charge generation layer, the charge transport layer including:

a charge transporting material; and

a binder resin.

2. The electrophotographic photosensitive member according to claim 1 ,

wherein the proportion of the structural unit including a chlorine atom to all the structural units constituting the vinyl copolymer is 80% by mass or more and 88% by mass or less.

3. The electrophotographic photosensitive member according to claim 2 ,

wherein the proportion of the structural unit including a chlorine atom to all the structural units constituting the vinyl copolymer is 80% by mass or more and 87% by mass or less.

4. The electrophotographic photosensitive member according to claim 1 ,

wherein, when the proportion of the structural unit including an aromatic polycarboxylic acid structure to all the structural units constituting the vinyl copolymer is defined as A [mass %] and a content of the charge generating material relative to the vinyl copolymer is defined as C [mass %], a ratio A/C is 3.00×10 −3 or more and 1.40×10 −2 or less.

5. The electrophotographic photosensitive member according to claim 2 ,

wherein, when the proportion of the structural unit including an aromatic polycarboxylic acid structure to all the structural units constituting the vinyl copolymer is defined as A [mass %] and a content of the charge generating material relative to the vinyl copolymer is defined as C [mass %], a ratio A/C is 3.00×10 −3 or more and 1.40×10 −2 or less.

6. The electrophotographic photosensitive member according to claim 3 ,

wherein, when the proportion of the structural unit including an aromatic polycarboxylic acid structure to all the structural units constituting the vinyl copolymer is defined as A [mass %] and a content of the charge generating material relative to the vinyl copolymer is defined as C [mass %], a ratio A/C is 3.00×10 −3 or more and 1.40×10 −2 or less.

7. The electrophotographic photosensitive member according to claim 1 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

8. The electrophotographic photosensitive member according to claim 2 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

9. The electrophotographic photosensitive member according to claim 3 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

10. The electrophotographic photosensitive member according to claim 4 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

11. The electrophotographic photosensitive member according to claim 5 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

12. The electrophotographic photosensitive member according to claim 6 ,

wherein the structural unit including a chlorine atom is represented by General Formula (1), and the structural unit including an acyloxy group is represented by General Formula (2),

where, in General Formula (1), R 11 to R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and, in General Formula (2), R 21 to R 23 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 24 represents an alkyl group having 1 to 5 carbon atoms.

13. The electrophotographic photosensitive member according to claim 7 ,

wherein, in General Formula (1), all of R 11 to R 13 represent a hydrogen atom; and, in General Formula (2), all of R 21 to R 23 represent a hydrogen atom, and R 24 represents a methyl group.

14. The electrophotographic photosensitive member according to claim 1 ,

wherein the structural unit including an aromatic polycarboxylic acid structure is a structural unit including a phthalic acid structure.

15. A process cartridge detachably attachable to an image forming apparatus, the process cartridge comprising:

the electrophotographic photosensitive member according to claim 1 .

16. An image forming apparatus comprising:

the electrophotographic photosensitive member according to claim 1 ;

a charging unit that charges a surface of the electrophotographic photosensitive member;

an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the electrophotographic photosensitive member;

a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer including a toner in order to form a toner image; and

a transfer unit that transfers the toner image onto a surface of a recording medium.