Crystal polymorphs of a yellow disazo colorant, and their preparation

US6504045B2 · kind B2 · utility

Assignee

• Clariant Corporation · DE

Inventors

• Ruediger Jung · Kelkheim, DE
• Hans Joachim Metz · Darmstadt, DE
• Joachim Weber · Frankfurt am Main, DE
• Martin Schmidt · Frankfurt am Main, DE
• Olaf Schupp · Frankfurt am Main, DE
• Andreas Wacker · Plochingen, DE

Key dates

• Filing date: Sep 13, 2001
• Grant date: Jan 7, 2003
• Expiry date: Sep 13, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B67/0015
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to six new crystal polymorphs, &agr; (alpha), &bgr; (beta), &ggr; (gamma), &dgr; (delta), &zgr; (zeta), and &eegr; (eta), of the disazo colorant of the formula I, having characteristic reflections in the X-ray diffraction spectrum. The novel crystal polymorphs are prepared by treatment in organic solvents.