Electrophotographic photoreceptor, process cartridge, and image forming apparatus

• US 8,524,428 B2
• Filed: 09/03/2010
• Issued: 09/03/2013
• Est. Priority Date: 01/22/2010
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Nakamura, Hirofumi
• Primary Examiner(s): RODEE, CHRISTOPHER D
• Application Number:
  US12/875,626
• Publication Number:
  US 20110183242A1
• Time in Patent Office: 1,096 Days
• Field of Search: 430/58.7, 430/58.8, 430/58.85, 430/66, 430/58.5, 399/159
• US Class Current: 430/58.7
• CPC Class Codes: G03G 15/75 Details relating to xerographic drum, band or plate, e.g. replacing, testing electrographic recording members per se G03G5/00
• CPC Class Codes: G03G 5/064 containing three hetero atoms
• CPC Class Codes: G03G 5/14708 comprising organic material
• CPC Class Codes: G03G 5/14786 Macromolecular compounds characterised by specific side-chain substituents or end groups
• CPC Class Codes: G03G 5/14791 Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity

Abstract

An electrophotographic photoreceptor includes: a conductive substrate; a photosensitive layer including a charge-generating layer containing a charge-generating material and a charge-transporting layer containing a charge-transporting material, the charge-transporting layer having a hole mobility of about 5.0×10⁻⁶ (cm²/V·sec) or less at an electric field of 2 V/cm; and an overcoat layer that is provided on the photosensitive layer and contains a cured material of a charge-transporting material, wherein relational expression (1) Ip(OCL)>Ip(CTL)>Ip(CGL) is satisfied wherein Ip(CGL) represents an ionization potential (eV) of the charge-generating material contained in the charge-generating layer; Ip(CTL) represents an ionization potential (eV) of the charge-transporting material contained in the charge-transporting layer; and Ip(OCL) represents an ionization potential (eV) of the charge-transporting material contained in the overcoat layer.

Claims

1. An electrophotographic photoreceptor comprising:

a conductive substrate;

a photosensitive layer including a charge-generating layer containing a charge-generating material and a charge-transporting layer containing a first charge-transporting material, the charge-transporting layer having a hole mobility of 5.0×

10<sup>−

6</sup> (cm²/V·

sec) or less at an electric field of 2 V/cm; and

an overcoat layer that is provided on the photosensitive layer and contains a cured material of at least one compound and at least one second charge-transporting material, the at least one compound being selected from a group consisting of guanamine compounds and melamine compounds, the at least one second charge-transporting material having at least one substituent selected from a group consisting of —

OH, —

OCH₃, —

NH₂, —

SH, and —

COOH, a content of the at least one compound in the overcoat layer being in a range from 0.1% by weight to 5% by weight, and a content of the at least one second charge-transporting material in the overcoat layer being in a range from 90% by weight to less than 99.9% by weight;

wherein the following relational expression (1) is satisfied

Ip(OCL)>

Ip(CTL)>

Ip(CGL) 

 

(1)

wherein Ip(CGL) represents an ionization potential (eV) of the charge-generating material;

Ip(CTL) represents an ionization potential (eV) of the first charge-transporting material; and

Ip(OCL) represents an ionization potential (eV) of the at least one second charge-transporting material.

2. The electrophotographic photoreceptor according to claim 1, wherein the following relational expressions (2) and (3) are satisfied

|Ip(OCL)−

Ip(CTL)≦

|≦

0.4 (eV) 

 

(2)

|Ip(CTL)−

Ip(CGL)|≦

0.3 (eV) 

 

(3).

3. The electrophotographic photoreceptor according to claim 1, wherein the content of the at least one compound in the overcoat layer is in a range from 1% by weight to 3% by weight.

4. The electrophotographic photoreceptor according to claim 1, wherein the at least one compound includes a guanamine compound, and the guanamine compound is a compound represented by the following formula (A) or an oligomer thereof

5. The electrophotographic photoreceptor according to claim 1, wherein the at least one compound includes a melamine compound, and the melamine compound is a compound represented by the following formula (B) or an oligomer thereof

6. The electrophotographic photoreceptor according to claim 1, wherein the at least one second charge-transporting material includes a compound represented by the following formula (I)

F(—

(R¹⁵—

X)_n1—

(R¹⁶)_n2—

Y)_n3 

 

(I)

wherein F represents an organic group derived from a compound having a hole transporting ability;

R¹⁵ and R¹⁶ each independently represent a linear or branched alkylene group having from 1 to 5 carbon atoms;

n1 represents 0 or 1;

n2 represents 0 or 1;

n3 represents an integer from 1 to 4;

X represents an oxygen atom, NH, or a sulfur atom; and

Y represents —

OH, —

OCH₃, —

NH₂, —

SH, or —

COOH.

7. A process cartridge comprising the electrophotographic photoreceptor according to claim 1, wherein the process cartridge is attachable to and detachable from an image forming apparatus for forming an image on a recording medium.

8. The process cartridge according to claim 7, wherein the following relational expressions (2) and (3) are satisfied in the electrophotographic photoreceptor

|Ip(OCL)−

Ip(CTL)|≦

0.4 (eV) 

 

(2)

|Ip(CTL)−

Ip(CGL)|≦

0.3 (eV). 

 

(3)

9. The process cartridge according to claim 7, wherein the content of the at least one compound in the overcoat layer is in a range from 1% by weight to 3% by weight.

10. An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 1;

a charging unit that charges the electrophotographic photoreceptor;

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

a development unit that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a 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.

11. The image forming apparatus according to claim 10, wherein the following relational expressions (2) and (3) are satisfied in the electrophotographic photoreceptor

|Ip(OCL)−

Ip(CTL)|≦

0.4 (eV) 

 

(2)

|Ip(CTL)−

Ip(CGL)|≦

0.3 (eV). 

 

(3)

12. The image forming apparatus according to claim 10, wherein the content of the at least one compound in the overcoat layer is in a range from 1% by weight to 3% by weight.