摘要 |
The invention relates to a method for isolating poly- or monomethyl alkanoic acids of the general formula (I), wherein R is the same or different and represents a substituted or unsubstituted hydrocarbon or a methylol group that is produced from the corresponding polymethylol alkanals or monomethylol alkanals of the general formula (II), wherein R has the meaning indicated above, by oxidation with an aqueous solution of hydrogen peroxide. The method further comprises the following steps: a) crystallization, followed by solid/liquid separation (B), thereby obtaining the acid as the first crystallized product (2a) and a mother liquor (3), b) producing in the mother liquor (3) another crystallized product (2b), and removing the resulting mother liquor (3) in another solid/liquid separation (C) from the crystallized product (2b), and c) disposing of the resulting acid-depleted mother liquor (3).
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