Method for producing phthalic anhylic anhydride according to specifications

US6570026B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Werner Peschel · Lohr am Main, DE
• Bernd Bessling · Grünstadt, DE
• Peter Reuter · Bad Dürkheim, DE
• Peter Michael Lorz · Mannheim, DE
• Bernhard Ulrich · Port Aransas, US
• Jean Werner Knab · Schifferstadt, DE
• Matthias Kummer · Schaffhausen, CH
• Thomas Ruhl · Bischofswerda, DE

Key dates

• Filing date: Feb 19, 2002
• Grant date: May 27, 2003
• Expiry date: Feb 19, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D307/89
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

On-spec phthalic anhydride is prepared by distillative purification of crude phthalic anhydride by a process in which crude phthalic anhydride is fed to a distillation column which is operated at reduced pressure, the low boilers are removed at the top or in the vicinity of the top of the distillation column and the on-spec phthalic anhydride is removed from the column via a side take-off.