Process for producing acicular .gamma.-FeOOH particles
US5531977A · kind A · utility
0Cited by
6References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 6, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Acicular .gamma.-FeOOH particles useful as precursors for magnetic particles suitable for magnetic recording are produced advantageously in industry. In a reaction of the growth of .gamma.-FeOOH nuclei by oxidizing a suspension containing .gamma.-FeOOH nuclei in a ferrous salt solution while neutralizing with alkali, a phosphorus compound is added to the reaction mixture at the time before the end of said reaction and when the ratio of Fe.sup.++ /total Fe in the reaction mixture is 0.15 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.