Electrophotographic photoreceptor and image-forming apparatus
View Patent ↗To provide an electrophotographic photoreceptor having a high sensitivity, a good balance of various electric properties such as chargeability and residual potential, a good stability of the coating solution, and an excellent light resistance. An electrophotographic photoreceptor comprising an electroconductive support having thereon a photosensitive layer, wherein the photosensitive layer contains a compound represented by the following formula (1): (wherein R 1 represents a group having a chiral center, R 2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, R 3 and R 4 each independently represents an alkylene group which may have a substituent, or an arylene group which may have a substituent, and R 5 , R 6 , R 7 and R 8 each independently represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, and at least one member of R 5 to R 8 is an aryl group having a substituent).
1. An electrophotographic photoreceptor comprising an electroconductive support having thereon a photosensitive layer, wherein said photosensitive layer comprises:
a compound represented by the following formula (1):
wherein
R 1 is a group represented by the following formula (2) with a chiral center being the carbon atom designated with a notation “*”:
wherein R 9 , R 10 and R 11 are groups different from each other and each represents a hydrogen atom, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent,
R 2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent,
R 3 and R 4 each independently represents an alkylene group which may have a substituent, or an arylene group which may have a substituent, and
R 5 , R 6 , R 7 and R 8 each independently represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, with the proviso that at least one of R 5 to R 8 is an aryl group having a substituent; and
an azo pigment represented by the following formula (3):
wherein R 12 represents an alkyl group having a total carbon number of 4 to 20 and having a cycloalkyl group which may have an alkyl substituent, and Z represents
provided that the ring X may have a substituent.
2. The electrophotographic photoreceptor as claimed in claim 1 , wherein two out of R 9 , R 10 and R 11 in formula (2) are an alkyl group which may have a substituent, and one is a hydrogen atom.
3. The electrophotographic photoreceptor as claimed in claim 1 or claim 2 , wherein in formula (1), R 3 and R 4 each is a phenylene group and R 5 , R 6 , R 7 and R 8 each is a tolyl group or a xylyl group.
4. The electrophotographic photoreceptor as claimed in claim 1 , wherein said azo pigment is a compound represented by the following formula (3):
wherein R 12 represents an alkyl group having a total carbon number of 4 to 20 and having a cycloalkyl group which may have an alkyl substituent, and Z represents
provided that the ring X may have a substituent.
5. The electrophotographic photoreceptor as claimed in claim 1 , wherein said azo pigment is a compound represented by the following formula (3):
wherein R 12 represents an alkyl group having a total carbon number of 4 to 20 and having a cycloalkyl group which may have an alkyl substituent, and Z represents
provided that the ring X may have a substituent.
6. The electrophotographic photoreceptor as claimed in claim 1 , wherein said photosensitive layer further comprises a phthalocyanine pigment.
7. The electrophotographic photoreceptor as claimed in claim 6 , wherein said phthalocyanine pigment is oxytitanium phthalocyanine.
8. The electrophotographic photoreceptor as claimed in claim 4 , wherein said photosensitive layer further comprises a phthalocyanine pigment.
9. The electrophotographic photoreceptor as claimed in claim 5 , wherein said photosensitive layer further comprises a phthalocyanine pigment.
10. The electrophotographic photoreceptor as claimed in claim 8 , wherein said phthalocyanine pigment is oxytitanium phthalocyanine.
11. The electrophotographic photoreceptor as claimed in claim 9 , wherein said phthalocyanine pigment is oxytitanium phthalocyanine.
12. An image forming apparatus mounting the electrophotographic photoreceptor claimed in claim 1 , wherein an image is formed by exposing said electrophotographic photoreceptor with monochromatic light at a wavelength of 380 to 500 nm.
13. An image forming apparatus mounting the electrophotographic photoreceptor claimed in claim 4 , wherein an image is formed by exposing said electrophotographic photoreceptor with monochromatic light at a wavelength of 380 to 500 nm.
14. An image forming apparatus mounting the electrophotographic photoreceptor claimed in claim 5 , wherein an image is formed by exposing said electrophotographic photoreceptor with monochromatic light at a wavelength of 380 to 500 nm.
15. An image forming apparatus mounting the electrophotographic photoreceptor claimed in claim 6 , wherein an image is formed by exposing said electrophotographic photoreceptor with monochromatic light at a wavelength of 380 to 500 nm.