Carrier for developing electrostatic latent image, two-component developer, developer for replenishment, image forming device, process cartridge, and image forming method

Patent metadata

Field	Value
Publication number	US-10915035-B2
Application number	US-201716305196-A
Country	US
Kind code	B2
Filing date	May 26, 2017
Priority date	May 31, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.

First claim

The invention claimed is:

1. A carrier for developing an electrostatic latent image, the carrier comprising:
a core material particle and a resin layer covering a surface of the core material particle, wherein
the resin layer includes a resin and at least one kind of a fine particle;
the at least one kind of the fine particles includes a conductive fine particle and a chargeable fine particle;
the chargeable fine particle has a long diameter of 400 to 900 nm; and
the chargeable fine particle has a shape factor SF-1 of 160 to 250.

2. The carrier for developing an electrostatic latent image according to claim 1 , wherein the resin layer has a thickness of 0.2 to 2.0 μm.

3. A two-component developer comprising:
the carrier for developing an electrostatic latent image according to claim 1 ; and
a toner.

4. The two-component developer according to claim 3 , wherein the toner is a color toner.

5. An image forming device comprising:
an electrostatic latent image bearer;
a charging unit configured to charge the latent image bearer;
an exposure unit configured to form an electrostatic latent image on the latent image bearer;
a developing unit configured to develop the electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to claim 3 to form a toner image;
a transfer unit configured to transfer the toner image formed on the electrostatic latent image bearer to a recording medium; and
a fixing unit configured to fix the toner image transferred to the recording medium.

6. A process cartridge comprising:
an electrostatic latent image bearer;
a charging unit configured to charge a surface of the electrostatic latent image bearer;
a developing unit configured to develop an electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to claim 3 ; and
a cleaning unit configured to clean the electrostatic latent image bearer.

7. An image forming method comprising:
forming an electrostatic latent image on an electrostatic latent image bearer;
developing the electrostatic latent image formed on the electrostatic latent image bearer with the two-component developer according to claim 3 to form a toner image;
transferring the toner image formed on the electrostatic latent image bearer to a recording medium; and
fixing the toner image transferred to the recording medium.

8. The carrier of claim 3 , wherein the chargeable fine particle exhibits reverse chargeability with respect to the toner and imparts negative chargeability to the toner through friction with the toner.

9. A developer for replenishment comprising a carrier and a toner, wherein
the developer includes 2 to 50 parts by mass of the toner relative to 1 part by mass of the carrier, and
the carrier is the carrier for developing an electrostatic latent image according to claim 1 .

Assignees

• Murata Haruki
• Kishida Hiroyuki
• Tano Toyoaki
• Mashiko Kenichi
• Taikoji Masato
• Takii Mariko
• Murasawa Yoshihiro
• Ricoh Co Ltd

Inventors

• Murata Haruki
• Kishida Hiroyuki
• Tano Toyoaki
• Mashiko Kenichi
• Taikoji Masato
• Takii Mariko
• Murasawa Yoshihiro

Classifications

• G03G9/1131

  Coating methods; Structure of coatings · CPC title

• G03G9/1139 Primary

  Inorganic components of coatings · CPC title

• G03G15/08

  using a solid developer, e.g. powder developer · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G2215/0607

  two-component · CPC title