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:
Nov. 06, 2007
Filed:
Feb. 21, 2003
Sadamu Kuse, Minoo, JP;
Tsugihiro Doi, Ibaraki, JP;
Tetsutaro Inoue, Ikeda, JP;
Mikio Kishimoto, Moriya, JP;
Yuji Sasaki, Kyoto-fu, JP;
Hideaki Watanabe, Kyoto-fu, JP;
Sadamu Kuse, Minoo, JP;
Tsugihiro Doi, Ibaraki, JP;
Tetsutaro Inoue, Ikeda, JP;
Mikio Kishimoto, Moriya, JP;
Yuji Sasaki, Kyoto-fu, JP;
Hideaki Watanabe, Kyoto-fu, JP;
Hitachi Maxell, Ltd., Ibaraki-shi, JP;
Abstract
A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 μm. This magnetic recording medium can achieve an excellent block error rate, which cannot be realized with magnetic recording media comprising conventional acicular magnetic powders.