The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1999
Filed:
Nov. 17, 1997
Jean-Claude Descorps, Paris, FR;
Francois Metz, Irigny, FR;
Rhone-Poulenc Agrochimie Department Propriete Industrielle, Lyon Cedex, FR;
Abstract
Process for the phosgenation of monocarboxylic acids and/or anhydrides, characterized in that the acid and/or the anhydride is treated, in the presence or absence of solvent, with a molar excess of phosgene, preferably 2 to 15 times as much phosgene as acid, at temperatures between 80 and 200.degree. C. and at pressures between 2 and 60 bar, with or without catalyst, preferably in the absence of any catalyst. Process furthermore characterized in that pressure is used to facilitate the separation of the hydrochloric acid, the carbon dioxide and the phosgene, in a column which is external to the reactor.