Electrophotographic photoconductor, image forming apparatus, and process cartridge

Patent metadata

Field	Value
Publication number	US-9671706-B2
Application number	US-201514669115-A
Country	US
Kind code	B2
Filing date	Mar 26, 2015
Priority date	Apr 25, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

An electrophotographic photoconductor including a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer is provided. The undercoat layer includes zinc oxide particles and a binder resin. The undercoat layer has a voltage (V)-current (I) characteristics such that, when S1 is a value obtained by integrating current (I [A]) in terms of voltage (V [V]) from 0 to a distribution voltage V UL [V] distributed to the undercoat layer, and S2 is a value obtained by integrating a line connecting two points at a voltage (V [V]) of 0 and the distribution voltage V UL [V] in terms of voltage (V [V]) from 0 to the distribution voltage V UL [V], S1 is within a range of from 1.0×10 −4 to 1.0×10 −2 and a ratio (S1/S2) of S1 to S2 is 0.50 or less.

First claim

What is claimed is:

1. An electrophotographic photoconductor, comprising:
a conductive support having a volume resistivity of 1×10 10 Ω·cm or less;
an undercoat layer overlying the support, the undercoat layer having an average thickness of not less than 0.5 μm and less than 15 μm and comprising:
zinc oxide particles having an average particle diameter of from 20 to 200 nm; and
a binder resin, wherein a mass ratio (F/R) of the zinc oxide particles (F) to the binder resin (R) is from 1/1 to 6/1; and

a photosensitive layer comprising at least one of a phthalocyanine pigment and an azo pigment overlying the undercoat layer,
wherein the undercoat layer has a voltage (V)-current (I) characteristics such that S1 is within a range of from 1.0×10 −4 to 1.0×10 −2 and a ratio (S1/S2) of S1 to S2 is 0.50 or less, where
S1 is a value obtained by integrating current (I [A]) in terms of voltage (V [V]) from 0 to a distribution voltage V UL [V] distributed to the undercoat layer, and
S2 is a value obtained by integrating a line connecting two points at a voltage (V [V]) of 0 and the distribution voltage V UL [V] in terms of voltage (V [V]) from 0 to the distribution voltage V UL [V].

2. The electrophotographic photoconductor according to claim 1 , wherein the distribution voltage V UL [V] distributed to the undercoat layer is from 50 to 150 V.

3. The electrophotographic photoconductor according to claim 1 , wherein the zinc oxide particles include surface-treated zinc oxide particles.

4. The electrophotographic photoconductor according to claim 1 , wherein the zinc oxide particles have an average particle diameter of from 50 to 150 nm.

5. The electrophotographic photoconductor according to claim 1 , wherein a mass ratio (F/R) of the zinc oxide particles (F) to the binder resin (R) is from 3/1 to 5/1.

6. An image forming apparatus, comprising:
the electrophotographic photoconductor according to claim 1 ;
a charger to charge a surface of the electrophotographic photoconductor;
an irradiator to irradiate the charged surface of the electrophotographic photoconductor with light to form an electrostatic latent image thereon;
a developing device to develop the electrostatic latent image into a visible image with toner; and
a transfer device to transfer the visible image onto a recording medium.

7. A process cartridge detachably mountable on image forming apparatus, comprising:
the electrophotographic photoconductor according to claim 1 ; and
at least one of a charger to charge a surface of the electrophotographic photoconductor, an irradiator to irradiate the charged surface of the electrophotographic photoconductor with light to form an electrostatic latent image thereon, a developing device to develop the electrostatic latent image into a visible image with toner, and a transfer device to transfer the visible image onto a recording medium.

8. The electrophotographic photoconductor according to claim 1 , wherein the zinc oxide particles have a volume resistivity of from 10 2 to 10 13 Ω·m.

9. The electrophotographic photoconductor according to claim 1 , wherein the binder resin comprises at least one of a water-soluble resin, an alcohol-soluble resin, and a curable resin.

10. The electrophotographic photoconductor according to claim 1 , wherein the photosensitive layer comprises a charge generation layer and a charge transport layer.

11. The electrophotographic photoconductor according to claim 1 , wherein S1 is within a range of from 5.5×10 −4 to 9.0×10 −3 .

12. The electrophotographic photoconductor according to claim 1 , wherein the ratio (S1/S2) of S1 to S2 is 0.45 or less.

13. The electrophotographic photoconductor according to claim 11 , wherein the ratio (S1/S2) of S1 to S2 is 0.45 or less.

14. The electrophotographic photoconductor according to claim 1 , wherein, the undercoat layer has an average thickness of not less than 0.5 μm and less than 14 μm.

15. The electrophotographic photoconductor according to claim 1 , wherein, the undercoat layer has an average thickness of not less than 0.5 μm and less than 13 μm.

Assignees

• Nii Daisuke
• Kurimoto Eiji
• Suzuki Tetsuro
• Asano Tomoharu
• Ishida Toshihiro
• Ricoh Co Ltd

Inventors

• Nii Daisuke
• Kurimoto Eiji
• Suzuki Tetsuro
• Asano Tomoharu
• Ishida Toshihiro

Classifications

• G03G5/142

  Inert intermediate layers · CPC title

• G03G5/144 Primary

  comprising inorganic material · CPC title