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:
Feb. 18, 1992
Filed:
Jan. 30, 1991
Applicant:
Inventor:
Donald C Paul, Landenberg, PA (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549274 ;
Abstract
Process for preparing high purity solvent-free cyclic esters from alpha hydroxycarboxylic acids via an intermediate oligomer wherein a fluorocarbon or a mixture of fluorocarbons is employed to strip the ester from the oligomer as well as a refrigerant to quench lactide from a gaseous reaction stream comprising, besides cyclic ester, unconverted alpha-hydroxycarboxylic acid and water.