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:
Dec. 14, 1982
Filed:
Sep. 26, 1980
Applicant:
Inventors:
Shinji Umeki, Tokyo, JP;
Kazuo Takada, Tokyo, JP;
Assignee:
TDK Electronics Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B05D / ;
U.S. Cl.
CPC ...
427127 ; 427128 ; 427130 ; 427214 ; 427215 ; 427343 ; 427380 ;
Abstract
A magnetic iron oxide powder which has high coercive force and stable magnetic characteristics is produced by forming a surface layer of the magnetic iron oxide powder which comprises a cobalt compound as a main component. The magnetic iron oxide powder is treated with an aqueous solution of a cobalt ion for two times or more to form at least two surfaces comprising the cobalt compound.