# US 2013/0157181 A1 · Electrophotographic photoconductor, electrophotographic apparatus and process cartridge

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- Number: US 2013/0157181 A1
- Document ID: US20130157181A1
- Status: Published application
- Kind: A1
- Application number: 13/715,322
- Filed: 2012-12-14
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Ricoh Company, Ltd.
- Inventors: Eiji Kurimoto; Tadayoshi Uchida; Hideki Nakamura
- Web page: https://patentgrep.com/patent/US20130157181A1

## CPC

- G03G 5/047: characterised by the charge-generation layers or charge transport layers {(G03G5/0433 and G03G5/0436 take precedence)}
- G03G 5/061443: {benzidine}
- G03G 5/06147: {alkenylarylamine}
- G03G 5/061473: {plural alkenyl groups linked directly to the same aryl group}
- G03G 5/0668: {containing only one methine or polymethine group}
- G03G 5/0672: {containing two or more methine or polymethine groups}
- G03G 5/144: {comprising inorganic material}
- G03G 21/18: using a processing cartridge {, whereby the process cartridge comprises at least two image processing means in a single unit}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An electrophotographic photoconductor including: an electroconductive substrate; an intermediate layer; and a photoconductive layer, the intermediate layer and the photoconductive layer being on the electroconductive substrate, wherein the intermediate layer includes an inorganic pigment and a binder resin, wherein a volume ratio of the inorganic pigment in the intermediate layer is 30% by volume to 50% by volume, wherein the inorganic pigment comprises titanium oxide and a content of the titanium oxide in the inorganic pigment is 70% by mass to 90% by mass, wherein the inorganic pigment has a specific surface area of 70 m2/g to 140 m2/g, and wherein the intermediate layer has a volume resistivity at an electrical field intensity of 2.5×105 V/cm of 5×1011 Ω·cm to 1×1013 Ω·cm.

## Claims

### Claim 1

An electrophotographic photoconductor comprising:
an electroconductive substrate;
an intermediate layer; and
a photoconductive layer,
the intermediate layer and the photoconductive layer being on the electroconductive substrate,
wherein the intermediate layer comprises an inorganic pigment and a binder resin,
wherein a volume ratio of the inorganic pigment in the intermediate layer is 30% by volume to 50% by volume,
wherein the inorganic pigment comprises titanium oxide and a content of the titanium oxide in the inorganic pigment is 70% by mass to 90% by mass,
wherein the inorganic pigment has a specific surface area of 70 m2/g to 140 m2/g, and
wherein the intermediate layer has a volume resistivity at an electrical field intensity of 2.5×105 V/cm of 5×1011 Ω·cm to 1×1013 Ω·cm.

### Claim 2 (depends on 1)

The electrophotographic photoconductor according to claim 1,
wherein the titanium oxide in the inorganic pigment is treated with aluminum hydroxide, and the other ingredients in the inorganic pigment than the titanium oxide are derived from the treatment with aluminum hydroxide.

### Claim 3 (depends on 1)

The electrophotographic photoconductor according to claim 1,
wherein the binder resin is a polyamide copolymer resin.

### Claim 4 (depends on 1)

The electrophotographic photoconductor according to claim 1,
wherein the photoconductive layer comprises a charge generation layer and a charge transport layer, and
wherein the charge transport layer comprises a charge transporting material represented by the following General Formula (1):
where R1 to R4 each independently represent hydrogen, a C1-C6 alkyl group which may have a substituent, or a C1-C6 alkoxy group which may have a substituent.

### Claim 5 (depends on 4)

The electrophotographic photoconductor according to claim 4,
wherein the charge transporting material represented by the General Formula (1) is a charge transporting material expressed by the following Formula (1-1):

### Claim 6 (depends on 1)

The electrophotographic photoconductor according to claim 1,
wherein the photoconductive layer comprises a charge generation layer and a charge transport layer, and
wherein the charge transport layer comprises a charge transporting material represented by the following General Formula (2):
where R5 to R9 each independently represent hydrogen, a C1-C6 alkyl group which may have a substituent, or a C1-C6 alkoxy group which may have a substituent.

### Claim 7 (depends on 6)

The electrophotographic photoconductor according to claim 6,
wherein the charge transporting material represented by the General Formula (2) is a charge transporting material expressed by the following Formula (2-1):

### Claim 8

An electrophotographic apparatus comprising:
an electrophotographic photoconductor;
a charging unit;
an exposing unit;
a developing unit;
a cleaning unit; and
a transfer unit,
wherein the electrophotographic photoconductor is an electrophotographic photoconductor comprising:
an electroconductive substrate;
an intermediate layer; and
a photoconductive layer,
the intermediate layer and the photoconductive layer being on the electroconductive substrate,
wherein the intermediate layer comprises an inorganic pigment and a binder resin,
wherein a volume ratio of the inorganic pigment in the intermediate layer is 30% by volume to 50% by volume,
wherein the inorganic pigment comprises titanium oxide and a content of the titanium oxide in the inorganic pigment is 70% by mass to 90% by mass,
wherein the inorganic pigment has a specific surface area of 70 m2/g to 140 m2/g, and
wherein the intermediate layer has a volume resistivity at an electrical field intensity of 2.5×105 V/cm of 5×1011Ω·cm to 1×1013Ω·cm.

### Claim 9 (depends on 8)

The electrophotographic apparatus according to claim 8,
wherein the exposing unit is a LED light source, and
wherein the developing unit is a developing unit configured to perform development with a one-component developer.

### Claim 10

A process cartridge comprising:
an electrophotographic photoconductor; and
a charging unit, an exposing unit, a developing unit, a cleaning unit or a transfer unit, or any combination thereof,
wherein the electrophotographic photoconductor is an electrophotographic photoconductor comprising:
an electroconductive substrate;
an intermediate layer; and
a photoconductive layer,
the intermediate layer and the photoconductive layer being on the electroconductive substrate,
wherein the intermediate layer comprises an inorganic pigment and a binder resin,
wherein a volume ratio of the inorganic pigment in the intermediate layer is 30% by volume to 50% by volume,
wherein the inorganic pigment comprises titanium oxide and a content of the titanium oxide in the inorganic pigment is 70% by mass to 90% by mass,
wherein the inorganic pigment has a specific surface area of 70 m2/g to 140 m2/g, and
wherein the intermediate layer has a volume resistivity at an electrical field intensity of 2.5×105V/cm of 5×1011 Ω·cm to 1×1013Ω·cm.