Electrophotographic photoreceptor, process cartridge, and image forming apparatus

1. An electrophotographic photoreceptor comprising:

an electroconductive substrate;

an undercoat layer that is provided on the electroconductive substrate, contains a binder resin, metal oxide particles and an electron accepting compound having an acidic group and has an AC impedance of from 1×10 5 Ω to 1×10 8 Ω under the measurement condition in which a temperature is 22° C., a humidity is 50% RH, an AC voltage is ±1 V, and a frequency is 1 Hz and an AC impedance of from 1×10 3 Ω to 1×10 8 Ω under the measurement condition in which a temperature is 22° C., a humidity is 50% RH, an AC voltage is ±1 V, and a frequency is 100 Hz; and

a photosensitive layer that is provided on the undercoat layer.

2. The electrophotographic photoreceptor according to claim 1 ,

wherein the AC impedance under the measurement condition in which a temperature is 22° C., a humidity is 50% RH, an AC voltage is ±1 V, and a frequency is 1 Hz is from 1×10 4 Ω to 1×10 7 Ω.

3. The electrophotographic photoreceptor according to claim 1 ,

wherein the AC impedance under the measurement condition in which a temperature is 22° C., a humidity is 50% RH, an AC voltage is ±1 V, and a frequency is 100 Hz is from 5×10 3 Ω to 1×10 7 Ω.

4. The electrophotographic photoreceptor according to claim 1 ,

wherein the AC impedance under the measurement condition in which a temperature is 22° C., a humidity is 50% RH, an AC voltage is ±1 V, and a frequency is from 1 Hz to 100 Hz is from 1×10 3 Ω to 1×10 8 Ω.

5. The electrophotographic photoreceptor according to claim 1 ,

wherein the electron accepting compound is an anthraquinone derivative.

6. The electrophotographic photoreceptor according to claim 5 ,

wherein the anthraquinone derivative is the compound represented by the following Formula (1):

wherein in Formula (1), n1 and n2 each independently represent an integer of from 0 to 3, provided that at least one of n1 and n2 represents an integer of from 1 to 3; m1 and m2 each independently represent an integer of 0 or 1; and R 1 and R 2 each independently represent an alkyl group having from 1 to 10 carbon atoms or an alkoxy group having from 1 to 10 carbon atoms.

7. The electrophotographic photoreceptor according to claim 1 ,

wherein the metal oxide particles are at least one selected from the group consisting of zinc oxide, titanium oxide and tin oxide.

8. The electrophotographic photoreceptor according to claim 1 ,

wherein the metal oxide particles are zinc oxide.

9. A process cartridge detachable from an image forming apparatus, the process cartridge comprising the electrophotographic photoreceptor according to claim 1 .

10. The process cartridge according to claim 9 , further comprising a contact type charging unit that charges a surface of the electrophotographic photoreceptor.

11. An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 1 ;

a charging unit that charges a surface of the electrophotographic photoreceptor;

an electrostatic latent image forming unit that forms an electrostatic latent image on the surface of a charged electrophotographic photoreceptor;

a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor using toner to form a toner image; and

a transfer unit that transfers the toner image formed on the surface of the electrophotographic photoreceptor onto a recording medium.

12. The image forming apparatus according to claim 11 ,

wherein the charging unit is a contact type charging unit.