Electrophotographic photoreceptor and image forming apparatus

Patent metadata

Field	Value
Publication number	US-10025208-B2
Application number	US-201715450094-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Apr 5, 2016
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

An electrophotographic photoreceptor includes: a conductive support; and a photosensitive layer which contains an electric charge generating material and an electric charge transport material, wherein a layer configuring a surface of the electrophotographic photoreceptor contains a resin binder, and conductive particles A and B dispersed in the resin binder, the conductive particles A have a single peak and volume resistance ρ1, the conductive particles B have a single peak and volume resistance ρ2, when a particle diameter of the conductive particles A is set to d1, and a particle diameter of the conductive particles B is set to d2, Expression (1) is satisfied, and when the volume resistance of the conductive particles A is set to ρ1, and the volume resistance of the conductive particles B is set to ρ2, Expression (2) is satisfied:

4× d 2≤ d 1≤20× d 2  (1)

10×ρ1<ρ2  (2).

First claim

What is claimed is:

1. An electrophotographic photoreceptor comprising:
a conductive support;
a photosensitive layer which is disposed on the conductive support and contains an electric charge generating material and an electric charge transport material; and
a surface layer of the electrophotographic photoreceptor containing a resin binder, conductive particles A dispersed in the resin binder, and conductive particles B dispersed in the resin binder,
the conductive particles A have a single peak in a range of 80 nm to 200 nm in a particle size distribution based on the number of particles and volume resistance ρ1 in a range of 10 1 Ωcm≤ρ1<10 4 Ωcm,
the conductive particles B have a single peak in a range of 10 nm to 30 nm in a particle size distribution based on the number of particles and volume resistance ρ2 in a range of 4.3×10 5 Ωcm≤ρ2≤10 9 Ωcm,
when a particle diameter of the conductive particles A at the peak is set to d1, and a particle diameter of the conductive particles B at the peak is set to d2, Expression (1) described below is satisfied, and
when the volume resistance of the conductive particles A is set to ρ1, and the volume resistance of the conductive particles B is set to ρ2, Expression (2) described below is satisfied:
4× d 2≤ d 1≤20× d 2  (1)

10×ρ1<ρ2  (2).

2. The electrophotographic photoreceptor according to claim 1 ,
wherein a number density of the conductive particles A in the layer is in a range of 1 item/μm 3 to 150 items/μm 3 , and
a number density of the conductive particles B in the layer is in a range of 100 items/μm 3 to 70000 items/μm 3 .

3. The electrophotographic photoreceptor according to claim 1 ,
wherein both of the conductive particles A and the conductive particles B are SnO 2 .

4. The electrophotographic photoreceptor according to claim 1 ,
wherein a total formulation amount of the conductive particles A and the conductive particles B is in a range of 50 parts by mass to 250 parts by mass with respect to 100 parts by mass of the resin binder.

5. The electrophotographic photoreceptor according to claim 1 ,
wherein the resin binder has a structure in which a polymerizable cured material is polymerized.

6. The electrophotographic photoreceptor according to claim 1 ,
wherein the conductive particles A and the conductive particles B have a surface layer which comprises a residue of a surfactant having a crosslinkable reactive group.

7. The electrophotographic photoreceptor according to claim 1 ,
wherein a thickness of the layer is in a range of 1.5 μm to 5.0 μm.

8. An image forming apparatus comprising:
the electrophotographic photoreceptor according to claim 1 ;
a charging device for charging the surface of the electrophotographic photoreceptor;
an exposing device for forming an electrostatic latent image by irradiating the charged surface of the electrophotographic photoreceptor with light;
a developing device for forming a toner image by supplying a toner onto the electrophotographic photoreceptor on which the electrostatic latent image is formed; and
a transfer device for transferring the toner image on the surface of the electrophotographic photoreceptor onto a recording medium,
wherein the charging device is a contact type charging device for applying a charged voltage by being in contact with the surface of the electrophotographic photoreceptor.

Assignees

• Konica Minolta Inc

Inventors

• Maeda Seisuke
• Kuramochi Kazuhiro

Classifications

• G03G5/087

  and being incorporated in an organic bonding material · CPC title

• G03G5/0592

  Macromolecular compounds characterised by their structure or by their chemical properties, e.g. block polymers, reticulated polymers, molecular weight, acidity · CPC title

• G03G5/05

  Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers · CPC title

• G03G2215/00957

  Compositions · CPC title

• G03G5/043 Primary

  Photoconductive layers characterised by having two or more layers or characterised by their composite structure · CPC title