Patent · US Expired

Preparation of ferromagnetic chromium dioxide

US4670177A · kind A · utility

7Cited by

7References

8Claims

0Family size

Assignee

BASF SE

Inventors

Manfred Ohlinger · Bischofswerda, DE
Norbert Mueller · Ostseebad Nienhagen, DE
Peter Rudolf · Ludwigshafen, DE
Eugen Wettstein · Germersheim, DE

Key dates

Filing date	Aug 7, 1985
Grant date	Jun 2, 1987
Priority date	—
Expiry date	Aug 7, 2005

Classification

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

Abstract

Ferromagnetic chromium dioxide is prepared by converting oxides of trivalent and hexavalent chromium under superatmospheric pressure and at elevated temperatures in the presence of water and with the addition of an antimony compound as a modifier and, if required, further additives in an amount of not more than 15% by weight, by a method in which the antimony compound is present in the form of a water-soluble salt whose anion contains one or more organic molecular moieties which are oxidized in concentrated chromic acid.

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