Heat-stable zinc ferrite colour pigments, process for preparing them and their use

US7294192B2 · kind B2 · utility

Assignee

• LANXESS Deutschland GmbH · DE

Inventors

• Carsten Rosenhahn · Kempen, DE
• Horst Brunn · Meerbusch, DE
• Wolfgang Oehlert · Wheeling, US

Key dates

• Filing date: Oct 21, 2004
• Grant date: Nov 13, 2007
• Expiry date: Apr 4, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2235/3284
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to zinc ferrite colour pigments, including a process for preparing and using them and, more particularly, the present invention relates to light-coloured zinc ferrite colour pigments having enhanced thermal stability, a magnesium content of from 0.01%-0.4% by weight, a color difference ΔE* according to DIN 53 772 at 260° C. of <3.0, a color difference ΔE* according to DIN 53 772 at 300° C. of <5.0, and a lightness of L*, measured in PE-HD full shade according to DIN 55 772 of >52.5.