Multilayer nacreous pigment

US6648957B1 · kind B1 · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Stephanie Andes · Hanau, DE
• Gerald Fuchs-Pohl · Weiterstadt, DE
• Gerhard Pfaff · Mainburg, DE

Key dates

• Filing date: Dec 4, 2001
• Grant date: Nov 18, 2003
• Expiry date: Dec 4, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09C2220/20
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Multilayer pearl lustre pigment on the basis of a platelet-shaped substrate comprising a material of low refractive index in the range from 1.35 to 1.8, which comprises at least(i) one first layer comprising a material having a refractive index of more than 1.8,(ii) optionally, a second layer comprising a material of low refractive index in the range from 1.35 to 1.8,(iii) a semitransparent metal layer which is applied to the substrate or to the layers (i) or (ii), and(iv) if desired, an aftercoating, the substrate being platelet-shaped silicon dioxide, aluminium oxide, boron oxide or magnesium fluoride.