The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 2015
Filed:
Mar. 02, 2012
Takeshi Kawauchi, Okayama, JP;
Tomohide Iida, Okayama, JP;
Takeshi Kawauchi, Okayama, JP;
Tomohide Iida, Okayama, JP;
DOWA ELECTRONICS MATERIALS CO., LTD., Tokyo, JP;
DOWA IP CREATION CO., LTD., Okayama, JP;
Abstract
A method for manufacturing carrier core particles for electrophotographic developer including a slurrying step (A) of making an iron-containing raw material and a strontium-containing raw material into slurry, a granulation step (B) of granulating the slurry mixture obtained in the slurrying step, and a firing step (C) of firing a powdery material, which is obtained by granulating the slurry mixture in the granulation step, at a predetermined temperature to form a magnetic phase. The slurrying step makes the iron-containing raw material into the slurry containing the iron-containing raw material having a volume diameter Dof 1.0 to 4.0 μm and a volume diameter Dof 2.5 to 7.0 μm, and makes the strontium-containing raw material into the slurry so that the carrier core particles for electrophotographic developer contain 0<y≦5000 ppm, where y denotes the content of the strontium in the carrier core particles.