Purification of N-vinylpyrrolidone by crystallization

US5710284A · kind A · utility

Assignee

• BASF SE

Inventors

• Martin Schmidt-Radde · Beindersheim, DE
• Herbert Helfert · Bischofswerda, DE
• Bernd Eck · Viernheim, DE
• Bernhard Maltry · Obrigheim, DE

Key dates

• Filing date: Sep 9, 1996
• Grant date: Jan 20, 1998
• Expiry date: Sep 9, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D207/267
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

In a process for purifying N-vinylpyrrolidone by crystallization in a crystallizer, those surfaces of the crystallizer from which crystals grow during the crystallization are covered with an N-vinylpyrrolidone seed layer before the crystallization.