Iron oxide-based anti-corrosion pigments

US4211565A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Franz Hund · Krefeld, DE
• Gunter Linde · Krefeld, DE
• Peter Kresse · Krefeld, DE

Key dates

• Filing date: Jul 10, 1978
• Grant date: Jul 8, 1980
• Expiry date: Jul 10, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/12
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

An anti-corrosion pigment comprising about 30 to 70 mole % of an oxide of at least one metal selected from the group consisting of magnesium, calcium and zinc, about 70 to 30 mole % of Fe.sub.2 O.sub.3, and up to about 20 mole % of Cr.sub.2 O.sub.3, the pigment having a specific surface of about 1 to 30 m.sup.2 /g and exhibiting a weight loss of less than about 0.05% per gram of pigment by the Thomson corrosion test, is produced by calcining the corresponding metal oxides. The temperature is about 200.degree. to 650.degree. C. in the absence of chromium and about 200.degree. to 900.degree. C. when chromium is present.