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:
Mar. 10, 1992
Filed:
Dec. 18, 1990
Applicant:
Inventors:
Kunitsuna Sasaki, Hino, JP;
Kiyoshi Sawada, Hino, JP;
Ryosuke Isobe, Hino, JP;
Takahiro Mori, Hino, JP;
Yuki Ando, Hino, JP;
Assignee:
Konica Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
4284259 ; 4284246 ; 428694 ; 428900 ;
Abstract
A magnetic recording medium is disclosed which has a magnetic layer comprising a ferromagnetic powder and a specific polyurethane resin as a binder. The polyurethane resin has a weight average molecular weight of not more than 30,000, a glass transition point of not higher than 0.degree. C. and a -SO.sub.3 M group, wherein M is a hydrogen atom or an alkali metal atom, in an amount of not less than 0.35% by weight in terms of sulfur atom. The recording medium is excellent in the dispersibility of the magnetic powder in the binder and has high running stability.