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:
May. 31, 1988
Filed:
Jan. 20, 1987
Yasushi Matsui, Yokohama, JP;
Toshinori Kamisaka, Yokohama, JP;
Takahiko Goto, Yokohama, JP;
Kenichi Okazaki, Kawasaki, JP;
Norio Koike, Tokyo, JP;
Showa Denko Kabushiki Kaisha, Tokyo, JP;
Abstract
Lepidocrocite suitable for obtaining excellent magnetic powders and magnetic recording media is manufactured by oxidizing an aqueous suspension of ferrous hydroxide obtained from a ferrous salt and an alkali by blowing an amount of an oxygen-containing gas into the suspension, in which the blowing amount of the oxygen-containing gas is appropriately controlled in three steps, according to three steps of the oxidation reaction of the ferrous hydroxide. In a preferred embodiment, average oxygen absorption rates in the three oxidization steps are defined and the blowing of the oxygen-containing gas is controlled thereby.