Process for thermally cracking carbamic acid esters

US5731458A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Jurgen Dahmer · Krefeld, DE
• Dieter Schleenstein · Odenthal, DE
• Heinrich Steude · Leverkusen, DE
• Oswald Wilmes · Recklinghausen, DE
• Christian Rasp · Cologne, DE
• Georg Ronge · Mülheim an der Ruhr, DE
• Klaus Nachtkamp · Cologne, DE
• Wilfried Litz · Neunburg vorm Wald, DE
• Stephan Kabelac · Langenfeld, DE

Key dates

• Filing date: Mar 6, 1997
• Grant date: Mar 24, 1998
• Expiry date: Mar 6, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/582
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

This present invention relates to a process for thermally cracking carbamic acid esters into the corresponding isocyanate and hydroxyl compounds in the liquid phase, wherein the reaction proceeds as a reactive rectification in the stripping zone of a column and in an inert, high-boiling solvent, which acts as a buffer to keep the reaction away from the evaporator region of the column.