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. 18, 1979
Filed:
Dec. 21, 1977
Fuji Photo Film Co., Ltd., Minami-ashigara, JP;
Abstract
A magnetic Fe oxide containing Co, and optionally, a divalent metal, in which the oxidation degree indicated by the following formula ranges from about 30% to 80%; ##EQU1## wherein y is the amount of the Co, plus the divalent metal if present, in atomic % contained in the magnetic Fe oxide, and R is the ratio of the divalent Fe ion to the total Fe ions; and a process for producing a magnetic Fe oxide containing Co, and optionally, a divalent metal, and having an oxidizing degree of about 30 to 80%, which comprises dehydrating and reducing goethite containing Co, and optionally, the divalent metal, to obtain magnetic containing Co, and optionally, a divalent metal, and oxidizing gradually the magnetite at a relatively low temperature of lower than about 100.degree. C.