Interference pigments with great color strength

US6599355B1 · kind B1 · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Christoph Schmidt · Kriftel, DE
• Klaus Bernhardt · Groß-Umstadt, DE
• Sabine Schoen · Darmstadt, DE
• Dieter Heinz · Heppenheim, DE

Key dates

• Filing date: Apr 26, 2002
• Grant date: Jul 29, 2003
• Expiry date: Apr 26, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09C2200/303
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to interference pigments with a great color strength that are based on multicoated platelet-shaped substrates that have at least one series of layers from (A) a highly refractive coating that consists of a mixture of TiO2 and Fe2O3 in ratio of 1:0.1 to 1:5 and optionally one or more metal oxides in amounts of ≦20% by weight based on layer (A), (B) a colorless coating with a refractive index n≦1.8, (C) a colorless coating with a refractive index of n 1.8, (D) an absorptive coating with a refractive index of n 1.8, and optionally (E) an outer protective layer.