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:
Oct. 13, 1987
Filed:
Mar. 26, 1985
Applicant:
Inventors:
Hirotaka Yokoyama, Yokosuka, JP;
Tadashi Ido, Ebina, JP;
Tatsumi Maeda, Yokohama, JP;
Shunji Kurisu, Yokohama, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01F / ; C01G / ; C04B / ;
U.S. Cl.
CPC ...
423138 ; 252 6263 ; 423155 ; 428402 ; 428694 ; 428900 ;
Abstract
A matnetic recording powder comprising a hexagonal barium ferrite substituted with a coercive force control element. This magnetic powder is preliminarily treated with sulfate ion-containing water so as to convert any free barium ions in the magnetic powder to a water insoluble compound such as BaSO.sub.4 or BaS.sub.2 O.sub.7. There is also proposed a magnetic recording medium having a magnetic layer containing such a magnetic powder as mentioned above.