Magnetic recording medium
AssigneeSony Corporation
InventorsSatoshi Sato, Shinichi Matsumura, Yuichi Arisaka
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Abstract
The present invention provides a metal thin film type magnetic recording medium including a non-magnetic substrate made from a polyamide film whose surface configuration is controlled so as to obtain an optimal fine configuration of a magnetic layer surface, enabling to simultaneously obtain a preferable electro-magnetic conversion characteristic and preferable running characteristic. The non-magnetic substrate is made from an aromatic polyamide film formed in such a manner that fine protrusions having an average height of 5 to 50 nm are formed in a range of 103 to 105 thousand pieces/mm2 on a surface where a ferromagnetic metal thin film is to be formed.
Claims5
A magnetic recording medium having a ferromagnetic metal thin film formed on a non-magnetic substrate made from an aromatic polyamide film having 103 to 105 thousand pieces/mm2 of fine protrusions having an average height of 5 to 50 nm on a surface where said ferromagnetic metal thin film is to be formed,
- wherein, if it is assumed that m is the height of the bottom of the deepest indentation defined by the fine protrusions, n is the height of the tip of the highest fine protrusions, and s is a distance between the m and n, i.e., s=m−n, then the number of fine protrusions having a height exceeding ¾×s+m is in a range from 103 to 5×103 thousand/mm 2 and the total of their cross sectional areas at the height of ¾×s+m is 0.1 to 0.5% of a cross sectional area of the non-magnetic substrate at the height m.
Dependencies are inferred from the claim text.