Process for the production of cobalt-containing magnetic iron oxide powder
US4501774A · kind A · utility
4Cited by
3References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Feb 26, 1985 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A process is provided for coating the particle surfaces of a phosphor-containing magnetic iron oxide powder with a cobalt compound after subjecting said powder to an activation treatment with an aqueous alkaline and/or acidic medium. The cobalt-containing magnetic iron oxide powder obtained according to this process has excellent coercivity and thermal stability, and the magnetic tape produced by using said powder has not only high coercivity but also excellent squareness, orientability and remanent induction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.