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:
Nov. 03, 1998
Filed:
May. 05, 1997
Applicant:
Inventors:
Takahiro Miyazaki, Miyagi, JP;
Koji Inomata, Miyagi, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428141 ; 428323 ; 428328 ; 428332 ; 428340 ; 4286 / ; 4283 / ; 4286 / ; 4286 / ; 4286 / ; 428900 ;
Abstract
A magnetic recording medium comprising a substrate made of non-magnetic material, and a magnetic layer formed on the substrate, the magnetic layer being composed primarily of a ferromagnetic powder and a binder, wherein an amount of a sulfuric ion extracted when the magnetic recording medium is immersed in a pure water having a temperature of 30.degree. C. for one hour, is 100 .mu.g or less per one square meter of the magnetic recording medium.