Boron-containing iron oxide pigments and a process for their preparation

US5269843A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Herbert Kunstmann · Krefeld, DE
• Gunter Buxbaum · Krefeld, DE
• Horst Brunn · Meerbusch, DE

Key dates

• Filing date: Oct 19, 1992
• Grant date: Dec 14, 1993
• Expiry date: Oct 19, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/80
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Boron-containing iron-oxide pigments as disclosed which are prepared by a nitrobenzene reduction process. The boron is present in the pigments in a homogeneously doped form in amounts of 0.02 to 0.13% by weight, based on iron oxide. Preparation of the pigments is also described.