Monoalkali metal salts of perylene-3,4,9,10-tetracarboxylic acid monoanhydride and process for their manufacturing

US4501906A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Ernst Spietschka · Idstein, DE
• Helmut Troster · Königstein, DE

Key dates

• Filing date: Feb 10, 1983
• Grant date: Feb 26, 1985
• Expiry date: Feb 10, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B3/18
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Perylene-3,4,9,10-tetracarboxylic acid monoanhydride mono-sodium or mono-potassium salts are obtained from neutral salts of perylene-3,4,9,10-tetracarboxylic acid, if necessary in the presence of at least one molar equivalent of sodium or potassium ions, at 20.degree. to 100.degree. C. by adding three molar equivalents of a sufficiently strong acid. The products are dye precursors, especially for asymmetric N-substituted perylenetetracarboxylic acid diimide pigments.