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:
Apr. 27, 1993
Filed:
Nov. 19, 1990
Mark O Scates, Pearland, TX (US);
Russell K Gibbs, Jr, Houston, TX (US);
G Paull Torrence, Corpus Christi, TX (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
Esters such as methyl acetate which contain carbonyl impurities including aldehydes are purified by adding to the esters an amino compound which reacts with the carbonyls to form water soluble nitrogenous derivatives, separating an organic ester phase from an aqueous derivative phase, and distilling the ester phase to further remove heavier impurities. The formation of nitrile from the nitrogenous derivative is minimized by adding water to the distillation column or washing the aqueous bottoms from distillation with water to further remove the derivatives from any ester contained in the bottoms. The organic phase recovered from the bottoms can be recycled to the distillation to recover ester.