Titanate-containing pearlescent pigments

US5972098A · kind A · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Stefanie Andes · Maintal, DE
• Sabine Hock · Schaafheim, DE
• Gunter Brenner · Griesheim, DE
• Dieter Bruckner · Darmstadt, DE
• Andrea Heyland · Ober-Kainsbach, DE
• Matthias Kuntz · Seeheim-Jugenheim, DE
• Karl Osterried · Dieburg, DE
• Gerhard Pfaff · Mainburg, DE
• Michael Schmelz · Griesheim, DE

Key dates

• Filing date: Jan 9, 1998
• Grant date: Oct 26, 1999
• Expiry date: Jan 9, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2993
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Single-layer or multilayer titanate-containing pearlescent pigments comprising iron titanate and, if appropriate, titanium oxide and/or iron oxide, which is obtainable by solidification of an aqueous solution of a thermally hydrolysable titanium compound on a continuous belt, detachment of the layer formed, coating of the resulting titanium dioxide platelets, after or without intermediate drying, with iron oxide in a wet process, and drying and calcining of the resulting material in an oxidizing or reducing gas atmosphere at not less than 500.degree. C., the layer thicknesses of the titanium dioxide layer and iron dioxide layer being adjusted such that either the stoichiometric ratio between iron oxide and titanium dioxide necessary for the formation of pseudo-brookite or ilmenite is obtained or an excess of iron oxide or titanium dioxide is present.