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:
Aug. 17, 2004
Filed:
Mar. 27, 2003
TDK Corporation, Tokyo, JP;
Abstract
The present invention provides a high recording density magnetic recording medium with improved dropout and excellent surface smoothness and electromagnetic conversion characteristics, as well as a process for producing such a medium. A magnetic recording medium comprising a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on one surface of a non-magnetic support, an upper magnetic layer containing at least a ferromagnetic powder and a binder resin on said lower non-magnetic layer, and a back coat layer on an opposite surface of said non-magnetic support, wherein said lower non-magnetic layer contains an acicular powder of hydrated iron oxide as the non-magnetic powder, said ferromagnetic powder has an average long axial length of 0.1 &mgr;m or less, and said upper magnetic layer has a surface roughness (center line average roughness: Ra) of 2.4 nm or less. After curing the lower non-magnetic layer, the magnetic layer is applied and formed.