Plasticiser esters

摘要

Esters produced by the catalyzed reaction of alcohols and acids or anhydrides are neutralized by treatment with an aqueous alkaline alkali metal salt solution in an amount that provides less than a stoichiometric amount of alkali metal salt in relation to the acidity of the crude ester and the amount of water present during the treatment is from 0.8 to 1.4 wt % of water based on the weight of crude ester. When using titanium as the esterification catalyst, the ester resulting from this process contains less than 0.01 ppm by weight of titanium residue, so that it is storage stable when stored in the presence of an antioxidant.

主权项

1. A process for the purification of a crude ester produced by the reaction of an acid or anhydride and an alcohol having from 6-15 carbon atoms in the presence of at most 0.039% wt of a titanium esterification catalyst, relative to the amount of acid or anhydride reagent, which process comprises treating the crude ester with an alkaline aqueous alkali metal salt solution wherein less than a stoichiometric amount of alkali metal in relation to the acidity of the crude ester is employed and the amount of water present during the treatment is from 0.8 to 1.4 wt % based on the weight of crude ester;
wherein said treatment is performed under an elevated pressure, sufficient to prevent water vaporization; wherein said ester is a C7-C11 phthalate; and wherein said process is operated in a continuous or semi-continuous mode.