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.

Date of Patent:
Jun. 01, 1999

Filed:

Dec. 26, 1996
Applicant:
Inventors:

Yuichiro Murayama, Odawara, JP;

Masaki Satake, Odawara, JP;

Hiroshi Hashimoto, Odawara, JP;

Tsutomu Okita, Odawara, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428323 ; 428336 ; 4284259 ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 428900 ;
Abstract

The present invention provides a magnetic recording medium having high durability and excellent electromagnetic transfer characteristics and having a lower coating layer, which contains a binder and has high dispersion property and durability. The magnetic recording medium comprises a lower coating layer where non-magnetic powder or ferromagnetic power is dispersed in a binder and an upper magnetic layer where ferromagnetic powder is dispersed in a binder, said two layers being placed on a non-magnetic support member, whereby the binder of the lower coating layer comprises polyurethane resin, which is a reaction product using diol and organic diisocyanate as major materials, the polyurethane resin contains short-chain diol having cyclic structure by 17 to 40 weight %, and the polyurethane resin contains long-chain diol, containing ether groups by 1.0 to 5.0 mmol/g to the entire polyurethane resin, by 10 to 50 weight %.


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