# US 8,541,155 B2 · Resin-coated carrier for electrophotographic developer, and electrophotographic developer

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- Number: US 8,541,155 B2
- Document ID: US8541155B2
- Status: Granted
- Kind: B2
- Application number: 13/432,360
- Filed: 2012-03-28
- Published: 2012-10-04
- Granted: 2013-09-24
- Earliest claimed: 2011-03-30
- Assignees: Powdertech Co., Ltd.
- Applicants: Tetsuya Uemura; Makoto Ishikawa
- Inventors: Tetsuya Uemura; Makoto Ishikawa
- Web page: https://patentgrep.com/patent/US8541155B2

## CPC

- G03G 9/113: having coatings applied thereto
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- G03G 9/1075: {Structural characteristics of the carrier particles, e.g. shape or crystallographic structure}
- G03G 9/1085: {with non-ferrous metal oxide, e.g. MgO-Fe2O3}
- G03G 9/1135: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds}
- G03G 9/1136: {containing silicon atoms}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

There are provided a resin-coated carrier for an electrophotographic developer, in which a magnetic particle is coated with a resin on its surface, and the coating resin contains a carbon nanotube having a carbon content of 75% by weight or more, and an electrophotographic developer using the resin-coated carrier.

## Claims

### Claim 1

A resin-coated carrier for an electrophotographic developer, wherein a magnetic particle is coated with a resin on its surface, and the coating resin comprises a carbon nanotube having a carbon content of 75% by weight or more,
wherein the carbon nanotube has a content of an iron element of 10 to 50% by weight with respect to a total amount of elements excluding carbon.

### Claim 2 (depends on 1)

The resin-coated carrier for an electrophotographic developer according to claim 1, wherein the carbon nanotube is contained in 0.1 to 25.0% by weight with respect to a solid content of the coating resin.

### Claim 3 (depends on 1)

The resin-coated carrier for an electrophotographic developer according to claim 1, wherein the carbon nanotube has a fiber length of 0.5 to 4.0 μm.

### Claim 4 (depends on 1)

An electrophotographic developer, comprising a resin-coated carrier according to claim 1, and a toner.

### Claim 5 (depends on 2)

An electrophotographic developer, comprising a resin-coated carrier according claim 2, and a toner.

### Claim 6 (depends on 3)

An electrophotographic developer, comprising a resin-coated carrier according claim 3, and a toner.