Method of producing highly pure trimethylolpropane

摘要

A method of producing a highly pure trimethylolpropane from a crude trimethylolpropane obtained by a reaction of n-butyl aldehyde and formaldehyde in the presence of a basic catalyst in a two-stage process of an aldol condensation and a crossed Cannizzaro reaction. Since a high-boiling component and an inorganic salt are removed in advance from the crude trimethylolpropane, hardly removable impurities such as condensation products in the crude trimethylolpropane are changed in the subsequent heat treatment under acidic conditions to components easily removable by distillation. By distilling the heat-treated crude trimethylolpropane, a highly pure trimethylolpropane with a low content of remaining formaldehyde and a low coloring degree is easily obtained.