Process for the recovery of methyl trimethylolpropane methane or ethyl trimethylolpropane methane

摘要

Methyltrimethylolmethane or ethyltrimethylolmethane is recovered from a mixture containing also an alkali or alkaline earth formate and organic impurities by adding an organic liquid boiling above 180 DEG C., stable at 200 DEG C., substantially immiscible with water and which does not dissolve alkali or alkaline earth formates and does not dissolve the trimethylol compounds to an appreciable extent at ordinary temperatures; heating the mixture to evaporate off any water and other volatile materials, separating the organic liquid together with the trimethylol compound from residual impurities (e.g. by distillation, preferably at a pressure such that distillation occurs at 150-200 DEG C.; or by heating with sufficient organic liquid to dissolve all the trimethylol compound, and filtering or decanting), and separating the trimethylol compound from the organic liquid. Specified organic liquids are diphenyl, diphenyl oxide, tetrahydronaphthalene, decahydronaphthalene and their mixtures. Suitable starting mixtures are those obtained by reacting formaldehyde with propionaldehyde or n-butyraldehyde in a solution containing an alkali or alkaline earth hydroxide.