Method for preventing undesired polymerization in a mixture of substances containing ethylenically unsaturated compounds

US6835288B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Heinz Friedrich Sutoris · Bischofswerda, DE
• Konrad Mitulla · Ludwigshafen, DE

Key dates

• Filing date: Dec 11, 2001
• Grant date: Dec 28, 2004
• Expiry date: Feb 5, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/19
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for preventing undesired polymerization is conducted by maintaining an effective concentration of a stabilizer which comprises N-oxyl radicals in a mixture containing ethylenically unsaturated compounds, wherein(i) an electronic signal which correlates with the concentration of the N-oxyl radicals in the mixture is obtained periodically or continuously,(ii) the electronic signal is compared with a reference value, and(iii) addition of a stabilizer to the mixture is controlled according to the comparison (ii).The signal is preferably obtained by ESR measurement. The process permits efficient use of the stabilizer.