申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0707024A2
公开(公告)日:1996-04-17
The invention relates to a purification process for polyhydroxycarboxylic acids which comprises dissolving a polyhydroxycarboxylic acid in an water-immiscible phenol or an organic solvent containing said water-immiscible phenol, successively bringing the resulting solution into contact with water which contains an acidic material, separating the organic layer from an aqueous layer, and isolating polyhydroxycarboxylic acid from the organic layer; and the process of the invention can efficiently remove a catalyst contained in polyhydroxycarbo xylic acid prepared in the presence of the catalyst, not always requires to take out polyhydroxycarboxylic acid in the form of a solid, and can treat polyhydroxycarboxylic acid in a higher concentration as compared with the case using chlorinated hydrocarbon as a solvent.
Polyhydroxycarboxylic acid obtained by the purification process of the invention can be used for slow release drugs with safety. Polyhydroxycarboxylic acid of the invention has also excellent mechanical properties, heat resistance and weatherability, and thus is stable in a thermoforming stage, can be molded or processed with ease, and can be used for the material of various kinds of films and workpieces.
本发明涉及一种多羟基羧酸的纯化工艺,该工艺包括将多羟基羧酸溶解在水不混溶苯酚或含有上述水不混溶苯酚的有机溶剂中,先后将所得溶液与含有酸性物质的水接触,从水层中分离出有机层,并从有机层中分离出多羟基羧酸;本发明的工艺可以有效地除去在催化剂存在下制备的聚羟基羧酸中所含的催化剂,不一定需要以固体形式取出聚羟基羧酸,而且与使用氯化烃作为溶剂的情况相比,可以处理更高浓度的聚羟基羧酸。
通过本发明的纯化工艺获得的聚羟基羧酸可安全地用于缓释药物。本发明的聚羟基羧酸还具有优异的机械性能、耐热性和耐候性,因此在热成型阶段稳定,可轻松成型或加工,并可用于各种薄膜和工件的材料。