Electrophotographic photoreceptor
View Patent ↗An electrophotographic photoreceptor including an electroconductive substrate and a photosensitive layer formed thereon, the photosensitive layer containing a polyester resin which is a copolymerized polyester resin having at least two different types of repeating ester structure (A) each comprising a bivalent phenol residue represented by invention formula (1) and an aromatic dicarboxylic acid residue represented by invention formula (3), and a repeating ester structure (B) comprising a bivalent phenol residue represented by invention formula (2) and an aromatic dicarboxylic acid residue represented by invention formula (3):
1. An electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein in the photosensitive layer comprises a polyester resin which is a copolymerized polyester resin having at least two different types of repeating ester structure (A) each comprising a bivalent phenol residue represented by the following formula (1) and an aromatic dicarboxylic acid residue represented by the following formula (3), and a repeating ester structure (B) comprising a bivalent phenol residue represented by the following formula (2) and an aromatic dicarboxylic acid residue represented by the formula (3):
wherein 0.1<x/(x+y)<0.9, wherein x represents the molar ratio of the repeating ester structure comprising a residue represented by the formula (2) and a residue represented by the formula (3) and y represents the molar ratio of the repeating ester structure comprising a residue represented by the formula (1) and a residue represented by the formula (3).
2. The electrophotographic photoreceptor according to claim 1 , wherein the bivalent phenol residue represented by the formula (1) is one selected from bivalent phenol residues represented by the following formulae (4) to (6):
3. The electrophotographic photoreceptor according to claim 1 , wherein the aromatic dicarboxylic acid residue represented by the formula (3) is a terephthaloyl group.
4. The electrophotographic photoreceptor according to claim 2 , wherein the repeating ester structure (A) has at least a repeating ester structure comprising a bivalent phenol residue represented by the formula (4).
5. The electrophotographic photoreceptor according to claim 1 , wherein the viscosity average molecular weight of the polyester resin is from 15,000 to 100,000.
6. The electrophotographic photoreceptor according to claim 1 , which further comprises at least one compound represented by the following formula (7), as a charge transport material:
in the formula (7), each of Ar 1 to Ar 4 which are independent of one another, represents an arylene group which may have a substituent, or a bivalent heterocyclic group which may have a substituent, each of m 1 and m 2 which are independent of each other, represents 0 or 1, each of Ar 5 when m 1 =0 and Ar 6 when m 2 =0 represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent, each of Ar 5 when m 1 =1 and Ar 6 when m 2 =1 represents an alkylene group which may have a substituent, an arylene group which may have a substituent, or a bivalent heterocyclic group which may have a substituent, Q represents a direct bond or a bivalent residue, each of R 1 to R 8 which are independent of one another, represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent, each of n 1 to n 4 which are independent of one another, represents an integer of from 0 to 4, provided that Ar 1 to Ar 6 may be mutually bonded to form a cyclic structure.
7. The electrophotographic photoreceptor according to claim 1 , wherein 0.1≦x/(x+y)≦0.7.
8. An electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein the photosensitive layer comprises a polyester resin of the formula:
9. An electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein the photosensitive layer comprises a polyester resin of the formula:
10. An electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein the photosensitive layer comprises a polyester resin of the formula:
11. The electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein the photosensitive layer comprises a polyester resin of the formula:
12. An electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, wherein the photosensitive layer comprises a polyester resin of the formula: