Patent · US Expired

Magnetic iron oxides with improved orientability and a process for their production

US3931025A · kind A · utility

31Cited by

3References

7Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Peter Woditsch · Krefeld, DE
Gunter Buxbaum · Krefeld, DE
Franz Hund · Krefeld, DE
Volker Hahnkamm · Krefeld, DE

Key dates

Filing date	Aug 29, 1974
Grant date	Jan 6, 1976
Priority date	—
Expiry date	Aug 29, 1994

Classification

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

Abstract

An acicular, magnetic iron oxide pigment containing about 0.1 to 2 percent by weight of zinc and phosphate ions is produced by growing seeds and subsequently reducing and optionally reoxidizing acicular FeOOH. Said seeds were formed by precipitation from an iron (II) salt solution in the presence of about 0.1 to 4 percent by weight of zinc ions and about 0.1 to 2 percent by weight of phosphate ions based on the formed seeds.

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