method for separating catalysts from raw weichmacherestern

摘要

A Sn, Ti or Zr catalyst used in the esterification of phthalic anhydride or adipic acid with 6-13C alcohols is removed by (1) treatment of the crude ester with aq. alkali at is not 100 degrees C and (2) decanting the aq. hydrolysed catalyst contg. phase. In (I) the neutral or weakly acidic crude ester is treated for =3 mins. with 5-20 pt. wt. per 100 pt. wt. crude ester of a 0.1-5 wt.% aq. alkali soln. so that an emulsion is formed. The size of the drops in the organic phase is 0.5-10 (0.5-3) mm. Esters of purity 99% are obtd. They are used as plasticisers.