Magnitic recording medium

Abstract

Abstract PURPOSE:To obtain a magnetic recording medium having superior durability by specifying the surface roughness CLA of both sides of a substrate and the coefft. of kinematic friction and by restricting the thickness of recording layers to <=1.5mum so as to increase output during reproduction in high density recording. CONSTITUTION:A biaxially stretched polyethylene terephthalate film is used as a substrate, and recording layers each having a two-layered structure consisting of an Ni-Fe-Mo film as a soft-magnetic layer and a Co-Cr film as a vertically magnetizable layer are formed on both front and rear sides of the substrate to manufacture a vertical magnetic recording medium. At this time, the surface roughness CLA of both sides of the substrate is regulated to 0.005-0.015mum, and the coefft. muk of kinematic friction to <=0.30. The thickness of the recording layers is restrictd to <=1.5mum. The number of projections of >0.27-0.54mum height on both sides of the substrate is <=10 per 1mm.<2>, and that of projection of >0.54mum height is <=0.2 per 1mm.<2>.

Inventors

• 👤 Masato Sugiyama
• 👤 杉山　征人
• 👤 Takashi Tomie
• 👤 崇 冨江
• 👤 Yoshio Itakura
• 👤 義雄 板倉
• 👤 Hiroshi Noda
• 👤 能田　豁

Bibliographic Details