PRODUCTION OF DIPENTAERYTHRITOL

摘要

PURPOSE:To obtain a reaction solution at an increased concentration of the title substance by lowering the temperature of the reaction solution and crystallizing part of the raw material before the conversion rate attains a specific value or above in producing the title substance according to dehydration condensing reaction of pentaerythritol using an acid catalyst. CONSTITUTION:Pentaerythritol (PE) in a liquid-phase state is subjected to dehydration condensing reaction using an acid catalyst (e.g. phosphoric acid or a metallic phosphate) to produce the title substance. In the process, the temperature of the reaction solution is lowered the presence of a polar solvent (e.g. water or sulfolane) before the conversion rate of the PE attains >=25% to crystallize part of the PE. Thereby, the reaction solution at an increased concentration of the objective substance is taken out. The title substance can be efficiently and mainly produced according to the aforementioned method and the readily purifiable objective substance of high quality is obtained at a low concentration of impurities such as tripentaerythritol.