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. 20, 1990
Filed:
Aug. 08, 1988
Applicant:
Inventors:
Hiroshi Mitake, Neyagawa, JP;
Takashi Wakabayashi, Ibaraki, JP;
Hiroshi Suzuki, Kadoma, JP;
Nozomu Ueshiba, Hirakata, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
4284259 ; 252 6254 ; 428694 ; 428900 ;
Abstract
S/N characteristic and durability of recording medium e.g. video tape or magnetic disket are improved by using as bonding resin used in the magnetic paint to make the magnetic layer a polyester-based polyurethane having a number average molecular weight of 5,000-100,000 and containing at least two hydroxyl group and at least one sulfone bond therein, through improvement of dispersibility of fine magnetic powder in the magnetic paint.