Patent · US Expired

Hydrothermal process for producing dense iron oxide pigments

US4140539A · kind A · utility

8Cited by

2References

13Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Franz Hund · Krefeld, DE
Gunter Buxbaum · Krefeld, DE
Lutz Leitner · Krefeld, DE
Ingo Pflugmacher · Meerbusch, DE

Key dates

Filing date	Jul 18, 1977
Grant date	Feb 20, 1979
Priority date	—
Expiry date	Jul 18, 1997

Classification

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

Abstract

An acicular to prismatic ferrimagnetic iron oxide pigment with a porosity of less than about 10% by volume, and optionally containing up to about 15% by weight of other metal oxides such as Zn or especially Co, are produced by heating a suspension of iron(III)oxide hydroxide in an autoclave to a temperature above about 100.degree. C in the presence of at least one mono-, di- or tri-saccharide, at least one alkali metal or alkaline earth metal hydroxide or carbonate and excess water, and washing, filtering and drying the resulting pigments.

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