Process for producing magnetizable particles
US4457955A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1982 |
| Grant date | Jul 3, 1984 |
| Priority date | — |
| Expiry date | Dec 29, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing cobalt-modified iron oxide particles, which comprises the steps of: PA1 (1) adding to magnetic iron oxide particles PA2 (a) a cobalt compound, PA2 (b) an iron component which is either (b.sub.1) a ferric compound at an atomic ratio to the cobalt compound in the range of 0.68 to 2 or (b.sub.2) a combination of a ferrous compound and a ferric compound, and PA2 (c) an alkali at a concentration enough to cause the cobalt and iron to precipitate as hydroxides; and PA1 (2) heating the mixture at a temperature of at least 50.degree. C. and not higher than the reflux temperature thereof in a non-oxidizing atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.