Electrophotographic photoreceptor
View Patent ↗Disclosed is an electrophotographic photoreceptor which is excellent in wear resistance and electrical characteristics. Specifically disclosed is an electrophotographic photoreceptor containing a polyester resin in a photosensitive layer provided on an electroconductive substrate. The polyester resin is composed of a copolymer represented by the general formula 1 below, which has a viscosity average molecular weight (Mv) of 10,000-300,000 and contains a diphenyl ether 4,4′-dicarboxylic acid component and a bivalent phenol component. In the general formula 1, A represents a diphenyl ether 4,4′-dicarboxylic acid residue represented by the formula A below, and B represents a bivalent phenol residue represented by the formula B below. In the formula A, each of Ra 1 and Ra 2 independently represents a hydrogen atom or a monovalent substituent which may have a substituent, and each of n and m is independently an integer from 0 to 4. In the formula B, each of R 1 and R 2 independently represents one selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, a halogen group, and an alkoxy group.
1. An electrophotographic photoreceptor comprising:
an electroconductive substrate; and
a photosensitive layer provided on the electroconductive substrate,
wherein
the photosensitive layer comprises an organic pigment and a polyester resin containing at least one of the repeating units represented by the following formulae 1 and 2:
wherein n is a positive integer and
A is a compound having a structure represented by the following formula (A)
wherein
each of Ra 1 and Ra 2 independently represents a hydrogen atom or a monovalent substituent which may have a substituent, and
each of n and m is independently an integer from 0 to 4,
B is a compound having a structure represented by the following formula (B)
wherein each of R 1 and R 2 independently represents an alkyl group,
C is a compound having a structure represented by the following formula (C)
wherein
each of R 3 and R 4 independently represents an alkyl group.
2. The electrophotographic photoreceptor according to claim 1 , wherein
A is derived from a diphenyl ether dicarboxylic acid.
3. The electrophotographic photoreceptor according to claim 1 , wherein
A is one derived from the group consisting of a diphenyl ether 2,2′-dicarboxylic acid, a diphenyl ether 2,4′-dicarboxylic acid, and a diphenyl ether 4,4′-dicarboxylic acid.
4. The electrophotographic photoreceptor according to claim 1 , wherein
A is derived from a diphenyl ether 4,4′-dicarboxylic acid.
5. The electrophotographic photoreceptor according to claim 1 , wherein
B is derived from the group consisting of bis(4-hydroxy-3-methylphenyl)methane, and bis(4-hydroxy-3-ethylphenyl)methane.
6. The electrophotographic photoreceptor according to claim 1 , wherein
B is derived from bis(4-hydroxy-3-methylphenyl)methane.
7. The electrophotographic photoreceptor according to claim 1 , wherein
C is derived from the group consisting of 1,1-bis(4-hydroxy-3-methylphenyl)ethane, and 1,1-bis(4-hydroxy-3-ethylphenyl)ethane.
8. The electrophotographic photoreceptor according to claim 1 , wherein
C is derived from 1,1-bis(4-hydroxy-3-methylphenyl)ethane.
9. The electrophotographic photoreceptor according to claim 1 , wherein
the polyester resin has the repeating units represented by the general formula 2.
10. The electrophotographic photoreceptor according to claim 1 , wherein
the photosensitive layer further comprises a compound represented by the following formula (6)
wherein
each of Ar 1 to Ar 6 independently represents one selected from the group consisting of an arylene group which may have a substituent, and a bivalent heterocyclic group which may have a substituent;
each of m 1 and m 2 independently represents 0 or 1;
Q represents one selected from the group consisting of a direct bond and a bivalent residue;
each of R 9 to R 16 independently represents one selected from the group consisting of a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, and a heterocyclic group which may a substituent; each of n 1 to n 4 represents independently an integer from 0 to 4; and
Ar 1 to Ar 6 may bond with each other to form a cyclic structure.
11. The electrophotographic photoreceptor according to claim 1 , wherein
the polyester resin has a viscosity-average molecular weight (Mv) of 10,000 to 300,000.
12. A photoreceptor cartridge to be attached to an image forming device, the photoreceptor cartridge comprising:
the electrophotographic photoreceptor as set forth in claim 1 ; and
at least one device selected from the group consisting of a charging device for charging the electrophotographic photoreceptor at a predetermined potential, a developing device for supplying toner on a surface of the electrophotographic photoreceptor, and a cleaning device for scraping off and collecting residual toner adhered on the surface of the electrophotographic photoreceptor.
13. An image forming device comprising:
the electrophotographic photoreceptor as set forth in claim 1 ;
a charging device for charging the electrophotographic photoreceptor;
an exposing device for forming an electrostatic latent image on a photosensitive surface of the electrophotographic photoreceptor;
a developing device for supplying toner on a surface of the electrophotographic photoreceptor;
a transporting device for transferring a toner image formed on the electrophotographic photoreceptor onto a sheet of recording paper; and
a fixing device for fixing the toner image transferred onto the recording paper.
14. The electrophotographic photoreceptor according to claim 1 , wherein the organic pigment is at least one selected from the group consisting of a phthalocyanine pigment, an azo pigment, a quinacridone pigment, an indigo pigment, a perylene pigment, a polycyclic quinine pigment, an anthraquinone pigment and a benzimidazole pigment.
15. The electrophotographic photoreceptor according to claim 14 , wherein the organic pigment is a phthalocyanine or an azo pigment.