Highly light-scattering pigment mixture

US6648958B2 · kind B2 · utility

Assignee

• Merck Patentgesellschaft · DE

Inventors

• Ralf Anselmann · Munster, DE
• Martin Knapp · Dieburg, DE
• Uta Hillgärtner · Darmstadt, DE

Key dates

• Filing date: Nov 13, 2002
• Grant date: Nov 18, 2003
• Expiry date: Nov 13, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/66
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Highly light-scattering pigment mixture featuring(i) 70-99.9% by weight of a component A consisting of spherical silicon dioxide with a diameter of less than 50 &mgr;m, coated with titanium dioxide and optionally a further layer of SiO2, and(ii) 0.1-30% by weight of a component B consisting of spherical silicon dioxide with a diameter of less than 50 &mgr;m, coated with titanium dioxide as a first layer and iron(III) oxide as a second, outer layer, the refractive index of the pigment being adjusted to a value of between 1.45 and 1.65.