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:
Apr. 23, 1996

Filed:

Dec. 21, 1992
Applicant:
Inventors:

Kenichi Masuyama, Kanagawa, JP;

Kazuo Kato, Kanagawa, JP;

Hiroaki Araki, Kanagawa, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ; G11B / ;
U.S. Cl.
CPC ...
428323 ; 428328 ; 428329 ; 428331 ; 4284231 ; 428447 ; 4284735 ; 4284744 ; 428480 ; 428500 ; 428515 ; 428522 ; 428532 ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 428900 ;
Abstract

A magnetic recording medium having two or more magnetic layers is disclosed, comprising a first magnetic layer and a second magnetic layer which-have been provided in this order on a surface of a nonmagnetic support, and which contain ferromagnetic particles and a binder, wherein said second magnetic layer (outermost layer) contains nonmagnetic particles having a pH of less than 7, and a Mohs' hardness of 6 or more, in an amount of from 1 to 20 parts by weight, per 100 parts by weight of the ferromagnetic particles in the second magnetic layer, and said first magnetic layer contains nonmagnetic particles having a pH of 7 or more, and a Mohs' hardness of 6 or more, in an amount of from 5 to 50 parts by weight, per 100 parts by weight of the ferromagnetic particles in the first magnetic layer.


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