Production of ultrafine suspensions of bisphenol, sodium hydroxide and water

US5275758A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Claus Wulff · Krefeld, DE
• Reinhard Schomacker · Leverkusen, DE
• Jurgen Kadelka · Krefeld, DE
• Jürgen Heuser · Krefeld, DE
• Gunther Weymans · Leverkusen, DE
• Konrad Hable · Leverkusen, DE

Key dates

• Filing date: Sep 1, 1992
• Grant date: Jan 4, 1994
• Expiry date: Sep 1, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S516/926
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to ultrafine suspensions of bisphenol, sodium hydroxide and water for the production of polycarbonates by the two-phase interfacial process. According to the invention, these suspensions are prepared by cooling bisphenolate concentrations near the solubility limit in aqueous sodium hydroxide with intensive mixing at relatively high temperatures and precipitating bisphenolate or more bisphenolate in the form of fine droplets during the cooling process. The ultrafine suspensions provide for a high volume/time yield in the interfacial reaction.