PROCESS FOR THE PREPARATION OF POLYOLS

摘要

The invention relates to a process for the preparation of polyols having 3 or 4 hydroxyl groups, from an aldehyde and formaldehyde in the presence of water, followed by hydrogenation of the aldolisation product in the presence of a hydrogenation catalyst at an elevated temperature. The aldehyde is obtained by an aldolisation reaction of an aldehyde having at least two alpha -hydrogen atoms and a formula according to R1CH2CHO, wherein R1 is selected from a group comprising hydrogen, alkyl groups having 1 - 7 carbon atoms which can have cycloalkyl substituents, cycloalkyl groups, aryl groups and aralkyl groups with 1 - 7 carbon atoms in the alkyl chain, with formaldehyde in the presence of water in an amount of 20 - 70 wt.%, preferably 40 - 60 wt.% and in the presence of an anion exchange resin. The hydrogenation is preferably carried out in the presence of water.