Magnetic recording medium comprising a backcoat layer having specific protrusions
US6645648B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2001 |
| Grant date | Nov 11, 2003 |
| Priority date | — |
| Expiry date | Jul 24, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/733
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Provided is a magnetic recording medium having good electromagnetic characteristics, particularly both improved high-density recording characteristics and good durability, and particularly a C/N ratio that is markedly improved in the high-density recording region. A magnetic recording medium comprising a nonmagnetic lower layer and a magnetic layer provided in this order on a support wherein said magnetic layer comprises a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder and a binder and has a coercive force equal to or higher than 143 kA/m. Said magnetic recording medium is a medium for recording signals having a surface recording density ranging from 0.2 to 2 Gbit/inch2; said support has a thickness equal to or less than 5.5 &mgr;m and a Young's modulus in the MD direction equal to or higher than 11,000 Mpa; and said support has on the reverse surface from said magnetic layer a backcoat layer, said backcoat layer having not fewer than 200 and not more than 1,000 protrusions having a height equal to or higher than 50 nm per 10,000 &mgr;m2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.