PREPARATION METHOD OF POLYOL

摘要

PURPOSE: A method for preparing a polyol is provided, to obtain a high purity polyols in high production yield and to suppress the production of by-products comprising acetal compounds and aldol compounds. CONSTITUTION: A polyol is prepared by reacting an aliphatic aldehyde represented by the formula (i) with formaldehyde in the presence of a basic catalyst, wherein the method comprises the steps of removing water and the unreacted formaldehyde from a reaction mixture by distillation to concentrate it; extracting the polyol from the concentrated reaction mixture with an extracting agent; and washing the extract with water and separating the washed extract into an oil layer containing the polyol and an aqueous layer. In the formula (i), R1 and R2 are H or an aliphatic alkyl group of C1-C6. The extracting agent is a specific aliphatic aldehyde represented by the formula (ii), wherein R3 is H or an aliphatic alkyl group of C1-C2 and R4 is an aliphatic alkyl group of C1-C5. The extracting agent is recovered from the oil layer containing the polyol after adjusting the pH of the oil layer.