Multilayer interference pigments

US7169222B2 · kind B2 · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Hans-Dieter Bruckner · Darmstadt, DE
• Andrea Heyland · Ober-Kainsbach, DE
• Christoph Schmidt · Kriftel, DE
• Christina Schank · Mühltal, DE
• Claudia Seibel · Otzberg, DE

Key dates

• Filing date: Jul 11, 2005
• Grant date: Jan 30, 2007
• Expiry date: Jul 11, 2025

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A40/25
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Multilayer interference pigment consisting of a transparent carrier material coated with alternating layers of metal oxides of low and high refractive index, the difference in the refractive indices being at least 0.1, which is obtainable by alternate coating of the transparent carrier material with a metal oxide of high refractive index and with a metal oxide of low refractive index in a wet process by hydrolysis of the corresponding water-soluble metal compounds, separation, drying and, if desired, calcination of the resulting pigment.