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:
Jul. 16, 1996

Filed:

Mar. 29, 1995
Applicant:
Inventors:

Atsushi Kato, Miyagi, JP;

Yuji Kato, Miyagi, JP;

Haruo Ishizaki, Miyagi, JP;

Takahiro Takayama, Miyagi, JP;

Assignee:

Sony Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428323 ; 428336 ; 4284259 ; 428522 ; 4286 / ; 4286 / ; 4286 / ; 428900 ;
Abstract

Disclosed is a magnetic recording medium having a first magnetic layer 2 and a second magnetic layer 4 laminated on a non-magnetic support in this order, wherein the binder in the lower first magnetic layer 2 comprises only polyurethane resin(s) having tertiary amines as polar groups or only said polyurethane resin(s) and a curing agent or comprises a mixed system composed of polyurethane resin(s) having tertiary amines as polar groups and amine-modified vinyl chloride-based resin(s) or of these resins and a curing agent. The first magnetic layer 2 may contain carbon black having a specifically-defined mean particle size. The coatability of the magnetic coating compositions is improved. The electromagnetic conversion characteristics (especially, video S/N, chroma output power, chroma S/N) of the medium are improved. Since the crosslinking of the components constituting the lower magnetic layer is improved, the dropout of the medium is not increased even after stored. This invention provides a magnetic recording medium capable of being subjected to long-sustained, high-quality recording and reproduction in severe conditions. The medium has high electric resistance, high light transmittance and good running durability, even though not having a back coat layer.


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