Method for converting perylen-3,4:9,10-tetracarboxylic acid diimides into a form suitable for use as a fluorescent dye

US7753967B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Peter Erk · Bischofswerda, DE
• Simone Schaefer · Kleinfischlingen, DE
• Arno Boehm · Mannheim, DE
• Peter Blaschka · Ludwigshafen, DE
• Harald Arms · Worms, DE
• Willi Helfer · Friedelsheim, DE

Key dates

• Filing date: Jun 6, 2003
• Grant date: Jul 13, 2010
• Expiry date: Dec 6, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B67/0025
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Novel crystalline forms of and a process for converting perylene-3,4:9,10-tetracarboximide of the general formula Ito a form used as a fluorescent dye. The process including: a) dissolving or suspending the perylene-3,4:9,10-tetracarboximide in a solvent to obtain a solution or suspension; and b1) cooling the solution obtained in step a) to a temperature at or below the crystallization temperature of the perylene-3,4:9,10-tetracarboximide and, if the solvent is organic, removing excess solvent until the first crystals form, otherwise, adding water or dilute aqueous solutions of the solvent until the first crystals form, and maintaining the solution at that temperature for further crystallization; or b2) cooling the suspension obtained in step a) to or below the crystallization temperature when the temperature in step a) was above the crystallization temperature, and maintaining the suspension at the temperature for further crystallization to form one or more solvate crystals.