| 摘要 |
Esters of solid polyhydric aliphatic alcohols and carboxylic acids which have been prepared by a transesterification reaction between the polyhydric alcohol and a mixture of an ester of aliphatic alcohols, glycols, glycerine and other polyols and monocarboxylic acids (8-32 C) and di- and poly-carboxylic acids (8-60 C), and another ester, over 50% of the mixture being mono-esterified polyhydric alcohol ester, are purified after de-activation of the catalyst by distillation by having at least 1% of a fluxing agent present in the mixture. The fluxing agent is a polar organic compound (2-12C) with at least two polar groups hydroxyl carboxyl, carboxy ester and/or ketone carbonyl groups, and with oxygen in the ratio of 1 atom/3 atoms of carbon. The agents specified are (1) an aliphatic diol (2-6 C) or ester thereof with fatty acid (2-4 C), (2) aliphatic triol (2-6 C) or similar ester thereof, (3) ester of aliphatic dicarboxylic acid (4-6 C) or ester of malic with monohydric p- or sec.-aliphatic alcohol (1-4 C), (d) methyl and ethyl esters of aconitic, tartaric, or citric acids, (e) p- or sec.-aliphatic monohydric alcohol (3-6 C) ester of lactic acid or an aliphatic diol (2-6 C) hemi-ester of lactic acid, (f) an ester of acetoacetic and levulinic acid with a p- or sec.-aliphatic monohydric alcohol (1-5 C) or aliphatic diol (2-5 C) in which only one hydroxyl of the diol is esterified, (g) a mixture of two or more of the above. The ester product after distillation may be further purified by extraction or recrystallization with a further solvent. The polyhydric alcohols used are aliphatic and contain at least 4 unesterified hydroxyl groups and 4 to 18 carbon atoms and a M.P. of at least 85 DEG C., e.g. sucrose, raffinose, sorbitol, mannitol, methyl glucoside and ethyl glucoside or mixtures thereof, and many esters are listed. Examples describe the purification of sucrose monopalmitate, monotallowate, and monolaurate, sorbitol monopalmitate, monolaurate, and monooleate, mannitol monocaprate, raffinose monotallowate and monolaurate, and methyl glucoside monolaurate. |
