TWO-COMPONENT DEVELOPER

• US 20130244159A1
• Filed: 11/24/2011
• Published: 09/19/2013
• Est. Priority Date: 11/30/2010
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Baba, Yoshinobu, Ishigami, Koh, Komatsu, Nozomu, Kamae, Kentaro
• Application Number:
  US13/988,867
• Publication Number:
  US 20130244159A1
• Time in Patent Office: Days
• US Class Current: 430/106.2
• CPC Class Codes: G03G 9/0827 characterised by their shape, e.g. degree of sphericity
• CPC Class Codes: G03G 9/0832 Metals
• CPC Class Codes: G03G 9/1075 Structural characteristics of the carrier particles, e.g. shape or crystallographic structure
• CPC Class Codes: G03G 9/1131 Coating methods; Structure of coatings
• CPC Class Codes: G03G 9/1136 containing silicon atoms

Abstract

Provided is a two-component developer having excellent developing performance and little change in image concentration, and achieving long-term suppression of image defects such as transfer failure and fogging.

Provided is a two-component developer containing a magnetic carrier and a toner, wherein the magnetic carrier has magnetic carrier particles comprising a silicone resin B coated on the surfaces of filled core particles in which pores of porous magnetic core particles are filled with a silicone resin A, the silicone resin A is a silicone resin cured in the presence of a non-metal catalyst or without a catalyst, while the silicone resin B is a silicone resin cured in the presence of a metal catalyst having titanium or zirconium, and the toner contains a binder resin, a release agent and a colorant, and has an average circularity of 0.940 or more.

Claims

1. A two-component developer containing a magnetic carrier and a toner,

wherein the magnetic carrier comprises magnetic carrier particles each of which comprises a filled core particle and a silicone resin B, the surface of the filled core particle being coated with the silicone resin B,

wherein the filled core particle comprises a porous magnetic core particle and a silicone resin A, pores of the porous magnetic core particle being filled with a silicone resin A,

wherein the silicone resin A is a silicone resin cured in the presence of a non-metal catalyst or without a catalyst, while the silicone resin B is a silicone resin cured in the presence of a metal catalyst having titanium or zirconium,

and wherein the toner contains a binder resin, a release agent and a colorant, and has an average circularity of 0.940 or more.

2. The two-component developer according to claim 1, wherein the metal catalyst has one or more titanium catalysts selected from the group consisting of a titanium alkoxide catalyst and a titanium chelate catalyst.

3. The two-component developer according to claim 1, wherein in a pore diameter distribution of the porous magnetic core particles as measured by a mercury intrusion method,

the pore diameter at which a log differential pore volume is maximum within a range of pore diameter ranging from 0.10 μ

m to 3.00 μ

m, is in a range from 0.70 μ

m to 1.30 μ

m, and

a cumulative pore volume of pores within a range of pore diameter ranging from 0.10 μ

m to 3.00 μ

m, is in a range from 0.03 ml/g to 0.12 ml/g.