Title:
Mg系フェライト材料、該フェライト材料を含む電子写真現像用キャリア、及び該キャリアを含む現像剤
Document Type and Number:
Japanese Patent JP4540668
Kind Code:
B2
Abstract:
This invention provides an Mg-based ferrite carrier composed of an environment-friendly material meeting environmental regulations, and an electrophotographic developer comprising the carrier. The carrier and the developer of this invention realize high image quality and improved gradation properties. This invention also provides a method for producing the Mg-based ferrite material having a saturation magnetization of from 30 to 80 emu/g and a dielectric breakdown voltage of from 1.0 to 5.0 kV, and having the composition of the formula (1). The above properties are obtained by controlling conditions of sintering and heating treatments. CaaMgbFecOd (1) wherein a, b, and c satisfy 0.10 b/(b+c/2) 0.85 and 0 R(Ca) 0.10; R(Ca) is expressed as R(Ca)=a~Fw(CaO)/(a~Fw(CaO)+b~Fw(MgO)+(c/2)~Fw(Fc2O3)) (Fw(A): formula weight of A j; and d is determined by oxidation numbers of Ca, Mg and Fe.
Inventors:
Hidehiko Iinuma
Kenkichi Hara
Hayashi Masatomo
Kenkichi Hara
Hayashi Masatomo
Application Number:
JP2006507694A
Publication Date:
September 08, 2010
Filing Date:
March 26, 2004
Export Citation:
Assignee:
Kanto Denka Kogyo Co., Ltd.
International Classes:
C04B35/26; G03G9/107; G03G9/113; H01F1/11; H01F1/34; H01F1/36; H01F1/37
Domestic Patent References:
| JP2001154414A | ||||
| JP2001154416A |
Attorney, Agent or Firm:
Kazuo Shamoto
Tadashi Masui
Yasushi Kobayashi
Akio Chiba
Hiroyuki Tomita
Shinya Hosokawa
Tadashi Masui
Yasushi Kobayashi
Akio Chiba
Hiroyuki Tomita
Shinya Hosokawa