申请人:IDEMITSU PETROCHEMICAL CO., LTD.
公开号:EP1008608A1
公开(公告)日:2000-06-14
A branched polycarbonate resin which is prepared by using a tetrahydric phenol having a specific structure as the branching agent, has a branching agent content [branching agent /(dihydric phenol + terminating agent + branching agent) x 100] of 0.05 to 0.5 mole % and satisfies the relationship: y ≥ 11x + 0.5 (wherein x is the branching agent content of the resin; and y is the melt tension (g) thereof at 280°C); and a process for preparing a branched polycarbonate from a dihydric phenol, phosgene or a carbonic acid ester, a branching agent and an terminating agent, characterized by preparing an oligocarbonate, particularly one having chloroformate groups without the addition of the terminating agent, and then reacting the oligocarbonate with the dihydric phenol and the terminating agent. This process can provide a branched polycarbonate which is lowered in the branching agent content, exhibits a high melt tension and good melt characteristics, and can be stably molded through blow molding, extrusion, vacuum forming and so on.
一种用具有特定结构的四氢苯酚作为支化剂制备的支化聚碳酸酯树脂,其支化剂含量[支化剂/(二氢苯酚+终止剂+支化剂)×100]为 0.05 至 0.5 摩尔%,并满足以下关系式:y ≥ 11x + 0.5(其中 x 为树脂中的支化剂含量;y 为 280℃时的熔体张力(g));以及一种用二元酚、光气或碳酸酯、支化剂和终止剂制备支化聚碳酸酯的工艺,其特征在于制备低碳酸酯,特别是不添加终止剂的具有氯甲酸酯基团的低碳酸酯,然后使低碳酸酯与二元酚和终止剂反应。该工艺可提供一种支化聚碳酸酯,其支化剂含量较低,具有较高的熔体张力和良好的熔体特性,可通过吹塑、挤出、真空成型等方式稳定成型。