| 摘要 |
HIGH-PURITY ALDITOL DIACETALS, FREE FROM ORGANIC SOLVENT TRACES AND PROCESSES FOR PREPARING SAME. The invention is concerned with diacetals resulting of the dehydrocondensation of an alditol comprising or 6 carbon atoms and a benzoic aldehyde such as in particular DBS, BEBS, BMBS or DBX, featuring a purity of at least 95% and being free of organic solvent traces, and a process for preparing the same in aqueous medium, in the presence of an acid catalyst, according to which acetalization is carried out by mixing the reactants under stirring, the reaction mixture is then neutralized by a base, then the solid phase is separated from the liquid phase and washed with warm water, wherein: the initial molar ratio of the benzoic aldehyde to the alditol is lower than 2/1, the acid catalyst is an arylsulfonic acid, the initial molar ratio of the arylsulfonic acid to the benzoic aldehyde is higher than 0.6, and the reaction temperature is lower than about 45.degree.C. Application specially to the clarification and stabilization of polyolefins. (no drawing) |
