PROCESS FOR THE PREPARATION OF LOW MOLECULAR WEIGHT POLYHYDROXYL COMPOUNDS

摘要

A process is disclosed for preparing mixtures of low molecular weight polyhydroxyl compounds and optionally hydroxyaldehydes and ketones by condensing formaldehyde hydrate with itself in the presence of(A) soluble or insoluble lead(II) salts or of divalent lead attached to a high molecular weight carrier, and(B) a co-catalyst, comprising a mixture of hydroxyaldehydes and hydroxyketones obtainable by condensation of formaldehyde, which mixture contains at least 75%, by weight, of C3 to C6 compounds and is characterized by the following molar ratios: Compounds having 3 carbon atoms/compounds having 4 carbon atoms from 0.5:1 to 2.0:1; Compounds having 4 carbon atoms/compounds having 5 carbon atoms from 0.2:1 to 2.0:1; Compounds having 5 carbon atoms/compounds having 6 carbon atoms from 0.5:1 to 5.0:1; The pH of the reaction mixture is held at from 6.0 to 7.0 until from 10 to 60% conversion has occurred and is then lowered to between 4.0 to 6.0 until 90-100% conversion has occurred. The reaction is then stopped by inactivating the catalyst.