Patent · US Expired

Superparamagnetic oxidic particles, processes for their production and their use

US6746767B2 · kind B2 · utility

18Cited by

1References

20Claims

0Family size

Assignee

Degussa AG · DE

Inventors

Heiko Gottfried · Straubing, DE
Christian Janzen · Duisburg, DE
Markus Pridoehl · Großkrotzenburg, DE
Paul Roth · Cincinnati, US
Berthold Trageser · Alzenau, DE
Guido Zimmermann · Hanau, DE

Key dates

Filing date	Aug 16, 2002
Grant date	Jun 8, 2004
Priority date	—
Expiry date	Sep 26, 2022

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/2993
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

Pyrogenic, oxidic particles contain superparamagnetic metal oxide domains with a diameter of 3 to 20 nm in a non-magnetic metal or non-metal oxide matrix. The particles display a chloride content of 50 to 1000 ppm. The particles are produced by pyrogenic processes by mixing the precursor of the superparamagnetic domains and the precursor of the non-magnetic metal or non-metal oxide matrix in a flame with air and/or oxygen and fuel gas and reacting this mixture in a flame. The particles can be used as ferro fluids, for example.

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