Method of manufacturing a magnetic recording medium
US4332834A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1981 |
| Grant date | Jun 1, 1982 |
| Priority date | — |
| Expiry date | Feb 18, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/845
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Improved orientation method is disclosed which is used in manufacturing magnetic recording medium. The method comprises the steps of, applying magnetic paint composed mainly of acicular magnetic powder, binder and solvent on a non-magnetic substrate to form a magnetic coating layer, passing the magnetic coating layer through a magnetic field to apply an orientation magnetic field to align the magnetic powder along a predetermined direction while the coating layer is still wet and the powder is still movable in the paint, and drying the magnetic coating layer, wherein the magnetic coating layer is applied with the orientation magnetic field composed of a plurality of pulse magnetic field along one direction each is stronger than coercive force of the magnetic powder and subsequently applied with a D.C. magnetic field along the same direction and the same polarity as the last pulse magnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.