CATALYST FOR DIRECT CONVERSION OF LACTIC ACID ESTER TO LACTIDE AND METHOD FOR PRODUCING LACTIDE BY USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a catalyst for direct production of a lactide which is a cyclic ester usable as a monomer of a polylactide from a lactic acid ester, and a method for producing the lactide by using the catalyst. SOLUTION: The method for producing the lactide includes a step to perform a transesterification reaction of a lactic acid ester in itself as a starting substance or a lactic acid ester mixture containing small amounts of lactic acid and a lactic acid oligomer in the presence of a titanium-based catalyst or a catalyst mixture containing the titanium-based catalyst in an inert atmosphere to produce the lactide and simultaneously remove alcohols produced as by-products. The lactide production method is a new method of producing the lactide directly from the lactic acid ester and, accordingly, having decreased energy consumption compared with known commercialized methods and producing the lactide with a simple procedure. Since the lactide is producible in high yield while maintaining optical characteristics (D- or L-optical isomer), the method has extremely high industrial utility. COPYRIGHT: (C)2011,JPO&INPIT