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:
Dec. 29, 1987
Filed:
Jun. 11, 1985
Applicant:
Inventors:
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
428323 ; 427128 ; 428329 ; 428694 ; 428900 ; 428336 ;
Abstract
Magnetic recording medium having a magnetic layer in which magnetic powder of the magnetic layer includes iron oxide magnetic powder with more than 30 m.sup.2 /g specific surface area measured by BET method, chromium dioxide (CrO.sub.2) magnetic powder with more than 30 m.sup.2 /g specific surface area measured by BET method, and the rate of the chromium dioxide powder is within a range more than 3% to less than 20% by weight in the total amount of the magnetic powder in the magnetic powder. Said magnetic layer further includes carbon black.