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:
Mar. 01, 2022
Filed:
Sep. 29, 2017
Dowa Electronics Materials Co., Ltd., Tokyo, JP;
Kazuhiro Yamaga, Tokyo, JP;
Tetsuya Kawahito, Tokyo, JP;
Toshihiko Ueyama, Tokyo, JP;
Kenji Sakane, Tokyo, JP;
DOWA ELECTRONICS MATERIALS CO., LTD., Tokyo, JP;
Abstract
An object of the present invention is to provide a magnetic powder having a narrow particle size distribution of epsilon-type iron oxide particles, and another object is to provide magnetic powder suitable for magnetic recording medium by improving particle size distribution, and provide epsilon-type iron oxide magnetic particles and related technologies in which a number average particle diameter of major diameters (D) is 10 to 20 nm, a 90% cumulative particle diameter (D) is 30 nm or less, and a geometric standard deviation (σ) of major diameters is 1.45 or less, which are obtained by TEM observation.