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:
Sep. 17, 1996
Filed:
Aug. 04, 1995
Applicant:
Inventors:
Masachika Hashiuchi, Tamano, JP;
Takeshi Miyazono, Tamano, JP;
Hiroyuki Watanabe, Tamano, JP;
Tadashi Yamanishi, Tamano, JP;
Assignee:
Mitsui Mining & Smelting Co., Ltd., Okayama, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F / ; H01F / ;
U.S. Cl.
CPC ...
252 6256 ; 252 6259 ; 252 6262 ; 106456 ; 106457 ; 106459 ; 428403 ;
Abstract
There are provided magnetite particles characterized in that they have surfaces each covered with a thin film or iron-zinc oxides or further covered thereon with a thin film of iron-silicon oxides and have a saturation magnetization of at least 79 emu/g, a degree of blackness (L) of at most 19.5 as measured with a differential colorimeter, and an absorption of at least 30 ml/100 g as measured according to JIS K 5101. There is also provided a process for preparing magnetite particles as described above.