# US 8,273,509 B2 · Electrophotographic photoreceptor, and image forming device and electrophotographic photoreceptor cartridge using the same member cartridge

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- Number: US 8,273,509 B2
- Document ID: US8273509B2
- Status: Granted
- Kind: B2
- Application number: 12/160,052
- Filed: 2007-01-09
- Published: 2009-09-17
- Granted: 2012-09-25
- Earliest claimed: 2006-01-06
- Assignees: Mitsubishi Chemical Corporation
- Inventors: Yuka Nagao; Tadashi Mizushima; Masami Tsurumori; Tomoko Nakagawa; Hiroaki Takamura; Shunichirou Kurihara; Tooru Uenaka; Masayuki Hiroi
- Web page: https://patentgrep.com/patent/US8273509B2

## CPC

- G03G 5/056: {Polyesters}
- G03G 5/0564: {Polycarbonates}
- G03G 5/0616: {Hydrazines; Hydrazones}
- G03G 5/0764: {triarylamine}
- G03G 5/0765: {alkenylarylamine}
- G03G 5/0766: {benzidine}
- G03G 5/0767: {comprising hydrazone moiety}
- G03G 5/14752: {Polyesters}
- G03G 5/14769: {Other polycondensates comprising nitrogen atoms with or without oxygen atoms in the main chain}
- G03G 9/0804: {whereby the components are brought together in a liquid dispersing medium}
- G03G 9/0806: {whereby chemical synthesis of at least one of the toner components takes place}
- G03G 9/0827: {characterised by their shape, e.g. degree of sphericity}
- G03G 9/08755: {Polyesters}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

To realize an electrophotographic photoreceptor excellent in abrasion resistance, the photosensitive layer of the photoreceptor comprises a polyester resin containing a repeating structural unit represented by the formula (1) and a hydrazone compound. (In the formula (1), Ar1 to Ar4 each represents, independently of each other, an arylene group which may have a substituent. X1 represents a bivalent group (including a single bond) and X2 represents a bivalent group (including a single bond) with 3 or less atoms.)

## Claims

### Claim 1

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein
said photosensitive layer comprises a polyester resin comprising a hydrazone compound and having a repeating structural unit represented by the formula (1):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 2

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein
said photosensitive layer comprises a layer including a polyester resin comprising a repeating structural unit represented by the formula (1) and a charge transport material, and
said charge transport material comprises only a charge transport material containing substantially no unsaturated bond other than in an aromatic ring:
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 3

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein
said photosensitive layer comprises a polyester resin comprising a repeating structural unit represented by the formula (1) and a diamine compound represented by the formula (2):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted , X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms; and
wherein Ar5 to Ar8 each represents, independently of each other, an aryl group which may have a substituent with 8 or less carbon atoms, and Ar9 and Ar10 each represents, independently of each other, an arylene group which may be substituted.

### Claim 4

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein
said photosensitive layer comprises a polyester resin containing an antioxidant and having a repeating structural unit represented by the formula (1):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 5 (depends on 4)

The electrophotographic photoreceptor according to claim 4, wherein said antioxidant is a phenolic antioxidant.

### Claim 6

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein
said photosensitive layer comprises a polyester resin as a first resin comprising a repeating structural unit represented by the formula (1) and at least another resin as a second resin selected from the group consisting of a polyester resin having a different structure from said first resin and a polycarbonate resin, wherein
at least either said first resin or said second resin comprises a repeating structural unit represented by the formula (3):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substitute , X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms; and
wherein R1 and R2 each represents, independently of each other, a hydrogen atom or an alkyl group, R3 and R4 each represents, independently of each other, an alkyl group, and m and n each represents, independently of each other, an integer selected from 1 to 4.

### Claim 7 (depends on 6)

The electrophotographic photoreceptor according to claim 6, wherein said second resin is a polycarbonate resin.

### Claim 8 (depends on 6)

The electrophotographic photoreceptor according to claim 6, wherein the repeating structural unit represented by the formula (3) is a repeating structural unit represented by the formula (3′):

### Claim 9 (depends on 8)

The electrophotographic photoreceptor according to claim 8, wherein the weight ratio of the repeating structural unit represented by the formula (3′) in the total weight of said first resin and said second resin is from 1 weight % to 45 weight %.

### Claim 10 (depends on 8)

The electrophotographic photoreceptor according to claim 8, wherein said second resin is a polycarbonate resin.

### Claim 11 (depends on 10)

The electrophotographic photoreceptor according to claim 10, wherein the second resin comprises repeating structural unit of the formula (3″), and the weight ratio of the repeating structural unit represented by the formula (3″) contained in said polycarbonate resin is 70 weight % or more of said polycarbonate resin:

### Claim 12

An electrophotographic photoreceptor of a positive charge type comprising a monolayer type photosensitive layer on an electroconductive support, wherein said monolayer type photosensitive layer comprises a polyester resin comprising a repeating structural unit represented by the formula (1):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 13 (depends on 1)

An electrophotographic photoreceptor cartridge comprising:
the electrophoto graphic photoreceptor according to claim 1 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and a means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 14 (depends on 2)

An electrophotographic photoreceptor cartridge comprising:
the electrophotographic photoreceptor according to claim 2 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 15 (depends on 3)

An electrophotographic photoreceptor cartridge comprising:
the electrophotographic photoreceptor according to claim 3 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 16 (depends on 4)

An electrophotographic photoreceptor cartridge comprising:
the electrophotographic photoreceptor according to claim 4 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 17 (depends on 6)

An electrophotographic photoreceptor cartridge comprising:
the electrophotographic photoreceptor according to claim 6 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 18 (depends on 12)

An electrophotographic photoreceptor cartridge comprising:
the electrophotographic photoreceptor according to claim 12 and
at least one means selected from the group consisting of means for charging said electrophotographic photoreceptor, means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon, and means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 19 (depends on 1)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 1,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 20 (depends on 2)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 2,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 21 (depends on 3)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 3,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 22 (depends on 4)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 4,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 23 (depends on 6)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 6,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 24 (depends on 12)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 12,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor to form an electrostatic latent image thereon,
means for developing the electrostatic latent image with toner, and
means for transferring the toner to a transfer target.

### Claim 25

An image forming device comprising at least an electrophotographic photoreceptor and a toner, wherein
the photosensitive layer of said electrophotographic photoreceptor comprises a polyester resin containing a repeating structural unit represented by formula (1) below, and
the average degree of circularity of said toner, measured by a flow particle image analyzer, is 0.940 or larger and 1.000 or smaller:
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may have a substituent, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 26 (depends on 25)

An image forming device according to claim 25, wherein said toner is produced in an aqueous medium.

### Claim 27 (depends on 25)

An image forming device according to claim 25, wherein said toner has a resin-coating layer.

### Claim 28 (depends on 27)

An image forming device according to claim 27, wherein said toner contains polysiloxane wax in said resin-coating layer.

### Claim 29 (depends on 25)

An image forming device according to claim 25, wherein said toner contains a paraffin wax.

### Claim 30

An electrophotographic photoreceptor for an image forming device of which an exposure part for forming an electrostatic latent image emits a monochromatic light having an exposure wavelength of 380 nm to 500 nm,
the photoreceptor comprising at least a photosensitive layer which comprises a polyester resin comprising a repeating structural unit represented by the formula (1):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 31

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, said photosensitive layer comprises a charge transport layer,
wherein said charge transport layer has a transmittance of 70% or larger in the wavelength region of 400 nm to 500 nm, and
said charge transport layer comprises a polyester resin, said polyester resin comprises a repeating structural unit represented by the formula (1):
wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substitued, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

### Claim 32 (depends on 30)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 30,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor with a monochromatic light having an exposure wavelength of 380 nm to 500 nm to form an electrostatic latent image thereon, and
means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.

### Claim 33 (depends on 31)

An image forming device comprising:
the electrophotographic photoreceptor according to claim 31,
means for charging said electrophotographic photoreceptor,
means for exposing said charged electrophotographic photoreceptor with a monochromatic light having an exposure wavelength of 380 nm to 500 nm to form an electrostatic latent image thereon, and
means for developing the electrostatic latent image formed on said electrophotographic photoreceptor.