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. 28, 1998
Filed:
Nov. 13, 1996
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
4284259 ; 4286 / ; 428900 ;
Abstract
A magnetic recording medium wherein a magnetic metal film has been formed on one surface of a non-magnetic substrate, and a back coat resulting from a non-magnetic pigment dispersed among a binder has been formed on the other, or reverse to the side upon which the magnetic film has been formed, characterized by that each of the chloride and sulfate ion contents of the back coat, according to the analysis by ion chromatography of its pure water extract, is not more than 5 ppm, and that the binder acting as a constituent of the back coat contains at least polycarbonate urethane.