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:
Apr. 24, 1990
Filed:
May. 24, 1989
Applicant:
Inventors:
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01J / ; B05D / ;
U.S. Cl.
CPC ...
2041574 ; 20415751 ; 427 531 ; 427 541 ;
Abstract
A method for producing ferromagnetic powder comprising metal oxide magnetic powder particles and a magnetic metal layer of at least one metal selected from the group consisting of iron, cobalt and nickel which layer is formed on a surface of the powder particle and has a magnetic easy axis of magnetization in substantially the same direction as that of the powder particle, which has improved coercive force and saturation magnetization, comprising irradiating with light a liquid medium dispersion containing the metal oxide magnetic particles, a reducing agent, and at least one metal ion selected from the group consisting of iron ion, cobalt iron, and nickel iron.