Interference pigments

US6596070B1 · kind B1 · utility

Assignee

• Merck Patentgesellschaft · DE

Inventors

• Christoph Schmidt · Kriftel, DE
• Gerhard Pfaff · Mainburg, DE
• Christina Schank · Mühltal, DE
• Sabine Schoen · Darmstadt, DE

Key dates

• Filing date: Apr 17, 2000
• Grant date: Jul 22, 2003
• Expiry date: Apr 17, 2020

Classification

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

Abstract

The present invention relates to interference pigments on the basis of multiply coated, platelet-shaped substrates which comprise at least one layer sequence comprising(A) a coating having a refractive index n≧2.0,(B) a colorless coating having a refractive index n≦1.8, and(C) a nonabsorbing coating of high refractive index,and, if desired,(D) an external protective layer.