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:
Oct. 17, 1989
Filed:
Jul. 07, 1987
Applicant:
Inventors:
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428403 ; 428404 ; 428694 ; 428900 ;
Abstract
Magnetic powder at least a part of particles of which have surface-adjacent layers comprising an aluminium-containing oxide of the corundum structure has high hardness so that a magnetic recording medium comprising a magnetic layer containing such magnetic powder has improved durability.