Prepn. and purificn. of carboxylic ester - useful as plasticiser and prepd. in presence of tetra:alkyl titanate

摘要

The prepn. of an ester, useful as a plasticiser, involves the reaction of a carboxylic acid or anhydride and an alcohol in the liq. phase, in the presence of a catalytic amt. of >=1 tetraalkyl titanate. The ester obtd. is purified by (a) cooling the reaction mixt. to 50-150 degrees C under atmospheric pressure; then (b) adding 0.05-5 pref. 0.5-2 wt. % H2O (wrt ester wt.); (c) sepg. the hydrolysed catalyst by filtration; (d) sweeping the remaining reaction mixt. with steam under vacuum to separate the excess alcohol, then (e) drying the ester obtd. The process, which can be discontinuous, semi-continuous, or continuous, gives high yields (>=99.97%) of an ester which has a low acidity index, and which does not need a further bleaching treatment.