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:
May. 19, 1987
Filed:
Sep. 16, 1985
Applicant:
Inventors:
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
428323 ; 427131 ; 428402 ; 428408 ; 428694 ; 428695 ; 428900 ;
Abstract
A magnetic disc comprising a non-magnetic substrate, an undercoat coated on the surfaces of the substrate and a magnetic layer containing magnetic powder dispersed in a binder coated on the undercoat, characterized in that the undercoat has a thickness of from 0.5 to 10.0 .mu.m and such a porosity that a lubricant is contained therein in an amount of from 30 to 200 mg/cm.sup.3, which provides good surface lubricity and improved durability.