Method for the work-up of a surfactant-containing reaction mixture

US5912390A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Ortwin Wagner · Mayen, DE
• Reinhard Schomacker · Leverkusen, DE

Key dates

• Filing date: Dec 6, 1995
• Grant date: Jun 15, 1999
• Expiry date: Dec 6, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S516/925
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method for the work-up of a nonionic surfactant-containing microemulsion reaction mixture formed in the o-alkylation of phenols by an alkyl halide in the presence of sodium hydroxide. Said mixture has one reaction product present as an aqueous phase and a further reaction product present as a water immiscible phase and which the reaction mixture is obtained in microemulsion form. Said reaction mixture is worked up by: PA1 a) subjecting this microemulsion to a temperature decreased by 20 to 50K thereby forming an aqueous phase having a high surfactant content and a substantially surfactant-free organic phase, PA1 b) separating off the substantially surfactant-free organic phase formed and replacing said surfactant-free organic phase with an organic solution of the alkyl halide. After the replacement of the substantially surfactant-free phase, PA1 c) the reaction mixture thus treated is subjected to a temperature increase by 10 to 80K thereby forming a substantially surfactant-free aqueous phase and a high surfactant content organic phase, PA1 d) the substantially surfactant-free aqueous phase is separated off and replaced by additional aqueous solution of phenols. The mixture then…