苯酐渣制备邻苯二甲酸二异丁酯增塑剂

苯酐渣系萘氧化或邻二甲苯氧化的副产物。在杂多酸催化下 ,与异丁醇直接酯化再经减压蒸馏制得合格的邻苯二甲酸二异丁酯 (DIBP)增塑剂 ,苯酐回收利用率可达 95 %以上。在 30 0t/aDIBP工业生产装置上 ,考察了催化剂用量、原料配比、反应温度和时间、搅拌及蒸馏压力等因素对制备产品的影响。其最佳工艺条件为 :(1)酯化反应 :催化剂用量为反应物总质量的1 0 % ,n(异丁醇 )∶n(苯酐 ) =1 2∶1 0 ,温度 12 0～ 16 0℃ ,时间 4h ,反应在搅拌下进行 ;(2 )减压蒸馏 :蒸馏压力≤ 5 0kPa。

Preparation of DIBP Plasticizer from Phthalic Anhydride Residue

Phthalic anhydride residue is the by product from oxidation of naphthalene or o xylene.The title process giving qualified diisobutyl phthalate(DIBP) plasticizer involves direct esterification of the residue with isobutanol catalyzed by heteropoly acid and distillation of the ester under reduced pressure. Rate of recovery of phthalic anhydride can exceed 95%. Factors such as the ratio of catalyst and feedings,reaction temperature and time ,agitation and the distilling pressure were studied in a production equipment of 300 t/a DIBP.The optimal technological conditions are as follows.(1) For esterification, amount of catalyst is 1 0% of the total mass of reactants, n (C 4H 10 O)∶ n (C 8H 4O 3)=1 2∶1 0,and the reaction is carried out at 120-160 ℃ for 4 h with agitation.(2) The ester is distilled under reduced pressure≤5 0 KPa .