Patent ID: 6465642
Filing Date: 2002-10-15
Classification: C07H,Y02P

Abstract:
An esterification and separation process for synthesizing polyol fatty acid polyesters, which process minimizes degradation reaction products in unreacted lower alkyl esters during synthesis of the polyol fatty acid polyesters, the process comprising the steps of:(a) reacting lower alkyl ester with polyol, partially esterified polyol, or mixtures thereof to esterify hydroxyl groups thereof and form polyol fatty acid polyester, said polyol fatty acid polyester comprising partially esterified polyol, fully esterified polyol, or mixtures thereof, the polyol fatty acid polyester being in admixture with unreacted lower alkyl ester to obtain a product mixture, wherein the reaction of said lower alkyl ester, said partially esterified polyol, or said mixtures thereof occurs in the presence of from about 0.001 moles to about 0.7 moles of soap per mole of polyol; (b) removing residual soap from the product mixture of step (a); (c) water-washing and drying the product mixture to remove impurities; wherein the water-washing temperature is less than about 85Â° C., and the unreacted lower alkyl ester has a contact time with water of less than about 15 minutes; (d) bleaching the product mixture for refinement; (e) separating at least a portion of the unreacted lower alkyl ester from the polyol fatty acid polyester in the product mixture, wherein the separated unreacted lower alkyl ester is free of degradation reaction products; (f) recycling the separated unreacted lower alkyl ester directly back to step (a) for further reaction with polyol, partially esterified polyol, or mixtures thereof; and wherein said process is solvent-free.