Dicarboxylic acid esters prodn - esp as plasticisers prepd from excess alcohol and dicarboxylic acids anhydrides or monoesters

摘要

The alcohol is added to reaction in high excess, esp. 90-600 (280) mol. % excess, and is partly supplied to end zone of distilling column via a thin layer evaporator connected with the distn. pt. of the reaction zone and admitting the reaction prod., and partly also to a concentrating column pt. of the reaction zones. An entrainer is added for water formed. Largest amount alcohol supplied to the 3 posns. of reaction zones is led in as vapour to distn. part, and also acts as entrainer. Pref. 5-25 (10)% excess liq. alcohol is supplied with dicarboxylic acid, 80-500 (250)% vapour excess is led to distn. pt. and 10-100 (20)% liquid is charged to concentrating column. Pref. process is prdon. of di-(2-ethylexyl)-phthalate using a weak acid catalyst at 180-250 degrees C.