Electrophotographic photoreceptor, image forming apparatus, and process cartridge

1. An electrophotographic photoreceptor comprising:

a support;

an undercoat layer which is provided on the support and contains at least a binder resin, metal oxide particles, and an electron-accepting compound having an anthraquinone structure, in which a content of the electron-accepting compound is from 0.5% by weight to 1.5% by weight with respect to the metal oxide particles and a contact angle of the metal oxide particles with respect to water is from 7° to 12°; and

a photosensitive layer which is provided on the undercoat layer,

wherein

surfaces of the metal oxide particles are treated with a surface treating agent, and

an amount of the surface treating agent is from 0.5% by weight to 1.0% by weight with respect to the metal oxide particles.

2. The electrophotographic photoreceptor according to claim 1 , wherein the contact angle of the metal oxide particles with respect to water is from 9° to 11°.

3. The electrophotographic photoreceptor according to claim 1 , wherein the content of the electron-accepting compound is from 0.75% by weight to 1.25% by weight with respect to the metal oxide particles.

4. The electrophotographic photoreceptor according to claim 1 , wherein the content of the electron-accepting compound is from 0.75% by weight to 1.0% by weight with respect to the metal oxide particles.

5. The electrophotographic photoreceptor according to claim 1 , wherein the electron-accepting compound includes a hydroxyl group.

6. The electrophotographic photoreceptor according to claim 1 , wherein the surface treating agent is a silane coupling agent.

7. The electrophotographic photoreceptor according to claim 1 , wherein the surface treating agent is a silane coupling agent having an amino group.

8. The electrophotographic photoreceptor according to claim 1 , wherein a thickness of the undercoat layer is from 20 μm to 50 μm.

9. The electrophotographic photoreceptor according to claim 1 , wherein a thickness of the undercoat layer is from 20 μm to 40 μm.

10. The electrophotographic photoreceptor according to claim 1 , wherein a thickness of the undercoat layer is from 23 μm to 33 μm.

11. The electrophotographic photoreceptor according to claim 1 , wherein the undercoat layer has a resistance value of from 1×10 8 Ω to 1×10 10 Ω in AC impedance measurement.

12. The electrophotographic photoreceptor according to claim 1 , wherein

the photosensitive layer includes a charge generation layer and a charge transport layer, and

a charge mobility of the charge transport layer at a field intensity of 30 V/μm is greater than or equal to 1×10 −5 cm 2 /Vs.

13. The electrophotographic photoreceptor according to claim 1 , wherein

the photosensitive layer includes a charge generation layer and a charge transport layer, and

a charge mobility of the charge transport layer at a field intensity of 30 V/μm is greater than or equal to 1.5×10 −5 cm 2 /Vs.

14. An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 1 ;

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

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

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

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

15. A process cartridge, which is detachable from an image forming apparatus, comprising:

the electrophotographic photoreceptor according to claim 1 .