Method for reducing the toxicity of spent liquors and novel cationic dyes

US5869731A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Henry Giera · Wittlich, DE
• Felix Reichel · Bensberg, DE
• Horst Berneth · Leverkusen, DE

Key dates

• Filing date: Sep 25, 1997
• Grant date: Feb 9, 1999
• Expiry date: Sep 25, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S8/927
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

There has been found PA1 1) a method for reducing the toxicity of spent liquors from dyeing with cationic dyes or mixtures thereof, characterized by the step of dyeing with cationic dyes having a computed electrostatic shielding energy (idealized hydration energy) of .gtoreq.50 kcal/mol, PA1 2) cationic, generally low toxicity dyes, their preparation and use for dyeing.