| 摘要 |
Disclosed is a magnetic recording medium having a magnetic layer directly formed on at least one surface of a base film that comprises, as the essential ingredient, an aromatic polyamide, in which the number of protrusions having a height of at least 10 nm on the surface of the magnetic layer, Na(10) (/mm<2>), the number of protrusions having a height of at least 50 nm thereon, Na(50) (/mm<2>), and the number of protrusions having a height of at least 10 nm on the surface of the base film coated with the magnetic layer, Na(10)' (/mm<2>), all satisfy the following formulae: <DF>2 x 10<4> ≤ Na(10) ≤ 2 x 10<7>, </DF> <DF>0 ≤ Na(50) ≤ 5 x 10<4>, </DF> <DF>-0.9 ≤ (Na(10) - Na(10)')/Na(10)' ≤ 0. </DF> The medium has, as the non-magnetic substrate (base film), a highly-tough, aromatic polyamide film, and the surface profile of its magnetic layer and that of its base film are specifically controlled. Therefore, its overall thickness can be reduced without lowering its recording capacity. Such high-capacity, thin tapes of the medium have good running durability, and the reliability for data recording and reading thereon is high. The medium is favorable to computer data recording thereon. |
