Patent · US Expired

Manufacture of acicular ferromagnetic iron particles

US4295879A · kind A · utility

8Cited by

8References

2Claims

0Family size

Assignee

BASF SE

Inventors

Werner Steck · Ludwigshafen, DE
Wilhelm Sarnecki · Schifferstadt, DE
Laszlo Marosi · Ludwigshafen, DE
Manfred Ohlinger · Bischofswerda, DE
Horst Autzen · Freinsheim, DE

Key dates

Filing date	Jul 31, 1980
Grant date	Oct 20, 1981
Priority date	—
Expiry date	Jul 31, 2000

Classification

Technology area (CPC H)Electricity
CPC primaryH01F1/065
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A process for the manufacture of acicular ferromagnetic iron particles by reducing an iron(III) oxide which carries a shape-stabilizing surface coating and has been produced by heating acicular iron(III) oxide hydroxide at 250.degree.-390.degree. C. in an atmosphere containing water vapor at a partial pressure of not less than 30 mbar, with hydrogen at 275.degree.-425.degree. C.

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