PROCESS FOR THE PREPARATION OF POLYOLS

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 aledhyde 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 is 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.