David A Lamb

US Patent:

62043862, Mar 20, 2001

Filed:

Nov 5, 1998

Appl. No.:

9/187104

Inventors:

David Anthony Schiraldi - Charlotte NC
James Seay Brown - Atlanta GA
Karen Chandler - Houston TX
Charles Alan Eckert - Atlanta GA
Jeffrey Scott Hurley - Bartlett TN
David Rene Lamb - Alpharetta GA
Heather Patrick Lesutis - Atlanta GA
Charles Leonard Liotta - Atlanta GA

Assignee:

Arteva North America S.A.R.L. - Zurich

International Classification:

C07D21372

US Classification:

546304

Abstract:

The esterification of a carboxylic or polycarboxylic acid, such as terephthalic acid, with ethylene oxide is conducted in the presence of a supercritical or near critical fluid with an esterification catalyst to form a monoester such as 2-hydroxyethylterephthalate (MHET). The monoester can be easily removed from the involatile terephthalic acid/catalyst bed by continuous extraction with supercritical fluid before subsequent reaction to the diester occurs. The esterification catalyst, such as quaternary ammonium salts, are at least substantially insoluble in the supercritical fluid and capable of withstanding prolonged exposure to elevated temperatures. The process is highly selective to formation of monoesters, and economical. The process can be modified for production of bis-esters or higher esters. The monoesters are polymerizable and can be used as monomers in the production of polyesters such as polyethylene terephthalate.