Iron oxide coated perlescent pigments

US4744832A · kind A · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Klaus-Dieter Franz · Kelkheim, DE
• Klaus Ambrosius · Frankfurt, DE

Key dates

• Filing date: Aug 7, 1986
• Grant date: May 17, 1988
• Expiry date: Aug 7, 2006

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/251
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

The application relates to a pearlescent pigments based on platelet-like substrates, such as mica, which are coated with metal oxides, the metal oxide layer containing titanium and also iron, wherein the pigment has a multi-layer structure in which a first layer of TiO.sub.2 in the rutile form is followed by a layer of pseudobrookite and an iron oxide layer.