Photoreceptor of electrophotographic system, process cartridge and image forming apparatus

1. A photoreceptor of an electrophotographic system, comprising:

a conductive substrate; and

a siloxane compound-containing layer located over the substrate and containing at least one of a cyclic siloxane compound and a derivative thereof, the cyclic siloxane compound having a cyclic structure represented by formula (7)

 wherein A 1 and A 2 , which may be the same or different, each represents a monovalent organic group, and n is an integer.

2. The photoreceptor claimed in claim 1 , wherein at least one of A 1 and A 2 in formula (1) has at least one of a fluorine atom and a cyclic substituent.

3. The photoreceptor claimed in claim 1 , wherein the siloxane containing-compound layer further contains a charge transport material.

4. The photoreceptor claimed in claim 1 , wherein the siloxane containing-compound layer further contains at least one of a resin and a resin precursor.

5. The photoreceptor as claimed in claim 4 , wherein the resin is a polycarbonate resin.

6. The photoreceptor as claimed in claim 1 , wherein the siloxane compound containing layer contains at least one of:

the cyclic siloxane compound;

a ring-opening polymer of the cyclic siloxane compound;

a complex of the cyclic siloxane compound and the charge transport material; and

a complex of the cyclic siloxane compound and the resin or the resin precursor.

7. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer contains at least one of polycarbonate, a methacrylic resin, an acrylic resin, and an organosilicon compound or its hydrolyzate or hydrolytic condensate.

8. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer contains at least one of an organosilicon compound and its hydrolyzate or hydrolytic condensate, the organosilicon compound being represented by formula (2) or (3):

SiQ 1 a R 1 3-a   (2)

wherein R 1 represents one selected from the group consisting of a hydrogen atom, an alkyl group, a fluoroalkyl group and a substituted or unsubstituted aryl group, Q 1 represents a hydrolyzable group, and a represents an integer from 1 to 3;

 B(—SiQ 2 b R 2 3-b ) 2   (3)

wherein R 2 represents one selected from the group consisting of a hydrogen atom, an alkyl group, a fluoroalkyl group and a substituted or unsubstituted aryl group, Q 2 represents a hydrolyzable group, B represents a divalent organic group, and b represents an integer from 1 to 3.

9. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer contains at least a charge transport material represented by formula (4) or (5):

F 1 (-D 1 -SiQ 3 c R 3 3-c ) d   (4)

wherein F 1 represents an organic group derived from a compound having a hole transportability, R 3 represents one selected from the group consisting of a hydrogen atom, an alkyl group, a fluoroalkyl group and a substituted or unsubstituted aryl group, D 1 represents a divalent group, Q 3 represents a hydrolyzable group, c represents an integer from 1 to 3, and d represents an integer from 1 to 4;

F 2 (-D 2 e -OH) f   (5)

wherein F 2 represents an organic group derived from a compound having a hole transportability, D 2 represents a divalent organic group, e represents 0 or 1, and f represents an integer from 1 to 4.

10. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer contains the charge transport material represented by formula (4), and organic group F 1 of the charge transport material is represented by formula (6):

wherein Ar 1 , Ar 2 , Ar 3 and Ar 4 , which may be the same or different, each represents a substituted or unsubstituted aryl group, Ar 5 represents a substituted or substituted aryl group or arylene group, and k represents 0 or 1, provided at least one of Ar 1 to Ar 5 has a bonding site with -D 1 -SiQ 3 c R 3 3-c in formula (4).

11. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer is cured.

12. The photoreceptor as claimed in claim 1 , wherein the siloxane compound-containing layer further contains at least one finely divided component.

13. A process cartridge comprising:

a photoreceptor of an electrophotographic system, comprising a conductive substrate and a siloxane compound-containing layer located over the substrate and containing at least one of a cyclic siloxane compound and a derivative thereof, the cyclic siloxane compound having a cyclic structure represented by formula (7)

 wherein A 1 and A 2 , which may be the same or different, each represents a monovalent organic group, and n represents an integer; and

at least one of a developing unit which develops an electrostatic latent image formed on the photoreceptor to form a toner image and a cleaning unit which removes a toner remaining on the photoreceptor after transferring the toner image.

14. The process cartridge as claimed in claim 13 , wherein the cleaning unit has a blade.

15. An image forming apparatus comprising

a photoreceptor of an electrophotographic system, comprising a conductive substrate and a siloxane compound-containing layer located over the substrate and containing at least one of a cyclic siloxane compound and a derivative thereof, the cyclic siloxane compound having a cyclic structure represented by formula (7)

 wherein A 1 and A 2 , which may be the same or different, each represents a monovalent organic group, and n represents an integer;

an electrification unit which electrifies the photoreceptor;

an exposure unit which exposes the electrified photoreceptor to form an electrostatic latent image;

a developing unit which develops the electrostatic latent image to form a toner image;

a transfer unit which transfers the toner image onto a transfer medium; and

a cleaning unit which removes a toner remaining on the photoreceptor after transferring the toner image.

16. The image forming apparatus as claimed in claim 15 , wherein the cleaning unit has a blade.