Interference pigments for preparing forgeryproof documents

US5573584A · kind A · utility

Assignee

• BASF SE

Inventors

• Werner Ostertag · Havelsee, DE
• Helmut Schmidt · Riegelsberg, DE

Key dates

• Filing date: Apr 21, 1995
• Grant date: Nov 12, 1996
• Expiry date: Apr 21, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09C2220/10
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Interference pigments based on multiply coated plateletlike silicatic substrates comprising PA1 A) a first layer comprising a colorless or selectively absorbing metal oxide with a high refractive index, PA1 B) a second, non-selectively absorbing, semitransparent layer consisting essentially of carbon, a metal or a metal oxide, and optionally PA1 C) a third layer comprising a colorless or selectively absorbing metal oxide in combination with scattering color pigments which are complementary in color to the reflection color of the interference pigments are useful for preparing valuable documents that are forgeryproof.