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:
Aug. 23, 1977
Filed:
Mar. 17, 1976
Applicant:
Inventors:
Masahiro Amemiya, Hino, JA;
Seiichi Asada, Hachioji, JA;
Assignees:
Hitachi, Ltd., BOTH OF, JA;
Hitachi Maxell, Ltd., BOTH OF, JA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F / ; C22C / ; B22F / ;
U.S. Cl.
CPC ...
148105 ; 75 / ; 75 / ; 252 6255 ; 252 6256 ; 252 6258 ; 252 6259 ;
Abstract
A method of producing ferromagnetic iron powder comprises the steps of dipping iron compound powder in a solution in which silicone oil is dissolved, removing solvent from the iron compound powder, reducing the iron compound powder in a reducing atmosphere at an elevated temperature and forming oxide layers on whole surfaces of the individual particles of the iron compound powder. Ferromagnetic iron powder produced according to this method has both a high coercive force and a high remanence ratio.