Process for isolating H acid and K acid

US4426334A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Horst Behre · Odenthal, DE
• Heinz U. Blank · Odenthal, DE
• Otto Lindner · Bensberg, DE
• Willi Schossler · Cologne, DE

Key dates

• Filing date: Apr 14, 1982
• Grant date: Jan 17, 1984
• Expiry date: Apr 14, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C303/44
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for isolating H acid and K acid in the form of their monoalkali metal salts from acid aqueous solutions which contain these two acids and alkali metal ions and may contain other aminonaphtholdisulphonic acids, in which process H acid monoalkali metal salts are precipitated at elevated temperatures from solutions which contain not only sodium ions but also potassium ions and then precipitating K acid monoalkali metal salts by cooling down the filtrate obtained after separating off the H acid monoalkali metal salts.