Interference pigments

US6579355B1 · kind B1 · utility

Assignee

• MERCK PATENT GESELLSCHAFT MIT BESHRANK TER HAFTUNG · DE

Inventors

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

Key dates

• Filing date: Feb 15, 2000
• Grant date: Jun 17, 2003
• Expiry date: Feb 15, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D17/00
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to an interference pigment based on multiply-coated platelet-shaped substrates, comprising at least one layer sequence of(A) a high refractive index coating comprising a mixture of TiO2 and Fe2O3 in a ratio of about 10:1 to about 3:1 and optionally one or more metal oxides in amounts of ≲ about 20% by weight based on the layer (A),(B) a colorless coating having a refractive index n ≲ about 1.8, and optionally(C) an outer protective layer.