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.

Date of Patent:
Nov. 05, 1985

Filed:

Jul. 12, 1983
Applicant:
Inventors:

Ichiro Honma, Moriyama, JP;

Arata Koyama, Moriyama, JP;

Masatoshi Amano, Moriyama, JP;

Nobusuke Takumi, Kusatsu, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01G / ;
U.S. Cl.
CPC ...
423594 ; 252 6256 ;
Abstract

An aqueous slurry of a magnetic iron oxide powder is mixed with a suspension prepared by neutralizing an aqueous ferrous salt solution with an alkali to form ferrous hydroxide and then adding an aqueous cobalt salt solution thereto, and the excess OH concentration of the mixed slurry is adjusted to 0.05 to 3 mol/l, thereby obtaining a cobalt-and ferrous iron-containing ferromagnetic iron oxide. The cobalt-and ferrous iron-containing ferromagnetic iron oxide is excellent in coercivity, distribution of coercivity and other magnetic properties, and the magnetic tape produced by using such iron oxide is also excellent in coercivity and switching field distribution.


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