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:
Jan. 20, 1987
Filed:
Oct. 22, 1984
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
4284259 ; 360134 ; 360135 ; 360136 ; 427128 ; 427131 ; 428694 ; 428900 ;
Abstract
A magnetic recording medium comprised of a non-magnetic substrate and a magnetic layer formed on one surface of the substrate and consisting essentially of a binder and magnetic powders. As the binder, a thermoplastic polyurethane-urea resin is employed, in which hydrophilic polar groups are introduced. The thermoplastic polyurethane-urea resin contains urethane and urea bonds in the molecule thereof and may be synthesized from a long-chain diol with a molecular weight of about 500 to 5000, a short-chain diol with a molecular weight of about 50 to 500, an organic diisocyanate and an organic diamine. Examples of the thus introduced hydrophilic polar groups are: ##STR1##