Magnetic recording medium
US4302510A · kind A · utility
4Cited by
3References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1980 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Apr 25, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium having more than 550 Oersted of a coercive force, less than 1.8 of a ratio of a coercive force at -196.degree. C. to a coercive force at 25.degree. C., less than 1.0 wt. % of a content of Fe.sup.2+ is prepared by incorporating a magnetic powder obtained by dispersing acicular .gamma.-Fe.sub.2 O.sub.3 in an aqueous solution of a cobalt salt and reducing it with a reducing agent to deposit a cobalt compound on the acicular .gamma.-Fe.sub.2 O.sub.3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.