| 摘要 |
1302146 Purification of carboxylic acid esters MELLE-BEZONS 30 June 1971 [24 July 1970] 30760/71 Heading C2C A process for the purification of a high boiling carboxylic acid ester produced by catalytic esterification of an alcohol and an acid or anhydride thereof, using an excess of alcohol, neutralization of the reaction mixture, waterwashing of the neutralized product and separation of the excess alcohol, water and impurities using a technique involving steam distillation or stripping carried out in successive distillation columns the last two of which are operated under vacuum, the final column being operated under a higher vacuum than the preceding column which process comprises continuously injecting the vapours of the head products of the final column, together with steam, into the bottom portion of the preceding column. The invention is described with reference to a flow diagram in the purification of di-(2-ethylhexyl)- phthalate. |
