Ferrite carrier for electrophotographic developer and method for preparing the same, and electrophotographic developer using the same
AssigneePowdertech Co., Ltd.
InventorsHiromichi Kobayashi, Kanao Kayamoto, Tadashi Harayama, Issei Shinmura, Toshio Honjo
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Abstract
A ferrite carrier for the electrophotographic developer containing 40 to 500 ppm of zirconium; a method for preparing a ferrite carrier for the electrophotographic developer, comprising the steps for weighing, mixing, and pulverizing ferrite raw materials, and for granulating, drying, and firing the obtained slurry; wherein a zirconium raw material is added so that the zirconium content after firing becomes 40 to 500 ppm; and an electrophotographic developer using the ferrite carrier.
Claims4
A ferrite carrier for an electrophotographic developer wherein the ferrite carrier is represented by formula (1)
- (MnO)x(MgO)y(Fe2O3)z (1);
- wherein x=35-45 mol %, y=5-15 mol %, z=40-60 mol %, and x+y+z=100 mol %;
- and
- wherein a part of MnO and/or MgO is replaced by an oxide of strontium and wherein the ferrite carrier contains a content of 40 ppm to 500 ppm of zirconium.
Dependencies are inferred from the claim text.