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:
Jul. 22, 1997
Filed:
Dec. 19, 1994
Applicant:
Inventors:
Jean A Lown, St. Paul, MN (US);
Gerald G Endres, Hastings, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ;
U.S. Cl.
CPC ...
423632 ; 423633 ;
Abstract
Spindle-shaped goethite particles are produced by oxidizing a ferrous carbonate intermediate in the presence of a growth modifier, or alternatively by changing the flowrate of oxidizing gas during oxidation. The goethite particles thus produced have a narrow size distribution, high aspect ratio and are substantially dendrite-free. These properties make the inventive goethite particles suitable for use in preparation of high density magnetic recording media.