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. 08, 1990
Filed:
Sep. 19, 1988
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428458 ; 427129 ; 428460 ; 4284735 ; 4284744 ;
Abstract
There are disclosed a perpendicular magnetic recording medium comprising a substrate of a polymer film containing 0.7% by weight or less of a residual solvent and a ferromagnetic alloy layer formed on the substrate and a method for preparing the same comprising the steps of heating a substrate composed of a polymer film containing a residual solvent in order to regulate a content of the solvent existing in the substrate to 0.7% by weight or less; and afterward forming a magnetic layer composed of a ferromagnetic alloy on the substrate. The perpendicular magnetic recording medium of the present invention has a prolonged durability and heightened reliability.