Multilayer interference pigments

US6689205B1 · kind B1 · utility

Assignee

• Merck Patentgesellschaft · 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: Oct 24, 2000
• Grant date: Feb 10, 2004
• Expiry date: Oct 24, 2020

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.