Patent · US Expired

Preparation of acicular ferromagnetic metal particles of substantially iron

US4933004A · kind A · utility

10Cited by

16References

4Claims

0Family size

Assignee

BASF SE

Inventors

Klaus-Dieter Hoppe · Monsheim, DE
Werner Steck · Ludwigshafen, DE
Jenoe Kovacs · Heßheim, DE
Rainer Feser · Havelsee, DE
Helmut Jakusch · Bischofswerda, DE

Key dates

Filing date	Feb 5, 1987
Grant date	Jun 12, 1990
Priority date	—
Expiry date	Feb 5, 2007

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01P2006/42
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

Ferromagnetic metal particles of substantially iron are prepared by starting from an acicular .alpha.-FeOOH, applying a shape-stabilizing finish to the particle surface, heating at 500.degree.-850.degree. C. and subsequently reducing with gaseous reducing agents at 200.degree.-500.degree. C. to the metal, and starting .alpha.-FeOOH being prepared in the presence of zinc and phosphate ions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.