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:
Jun. 19, 2001
Filed:
Mar. 08, 2000
Robert Lin, Kingsport, TN (US);
Robert Thomas Hembre, Johnson City, TN (US);
Edwin Franklin Holcombe, III, Morristown, TN (US);
Mark Robert Shelton, Kingsport, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
Disclosed is process for the production of symmetrical fluoro-substituted anhydrides from mixed or unsymmetrical anhydrides, i.e., wherein the two carboxylic acid acyl groups of the anhydrides are different, by subjecting an unsymmetrical anhydrides to reactive distillation to produce a lower boiling product comprising a symmetrical fluorocarboxylic acid anhydride and a higher boiling product comprising a second symmetrical anhydride. The process is particularly useful for the coproduction of trifluoroacetic anhydride (TFAA) and acetic anhydride (Ac,O) from ketene and trifluoroacetic acid wherein ketene and trifluoroacetic acid (TFA) are reacted to produce a mixed anhydride, acetyl trifluoroacetate (Ac-TFA), which then is subjected to reactive distillation to produce a vapor product comprising TFAA and a liquid product comprising Ac,O.