| abstract |
The invention relates to a process for the preparation of polyalcohols comprising the following stages: (a) reaction of an alcanal or ketone with formaldehyde in an aqueous solution in the presence of a tertiary amine; (b) separation of water, excess tertiary amine, excess formaldehyde; (c) heating of the remaining mixture of (b) separating further formaldehyde and tertiary amine and formation of polyalcohol formates; (d) conveying of tertiary amine separated from stage (b) and/ or stage (c) into the synthesis stage (a) and/or into the following transesterification stage (e); (e) transesterification of the polyalcohol formates obtained from stage (c) with an alcohol of the formula ROH in the presence of a transesterification catalyst to form polyalcohols and formates of the formula (I), R being a hydrocarbon radical, preferably an alkyl radical with 1-6, in particular preferably 1-2 C-atoms; (f) retrieval of polyalcohols. |