Abstract: A method of manufacturing polylactic acid having excellent heat resistance and strength without using a harmful solvent and a method of manufacturing a film thereof. An aqueous emulsion of polylactic acid which is suitable for the manufacture of polylactic acid and does not contain a harmful solvent, and a coating agent containing the same. The method of manufacturing polylactic acid includes the steps of: (1) preparing an aqueous emulsion of poly-L-lactic acid and an aqueous emulsion of poly-D-lactic acid; (2) mixing them together to prepare a mixed emulsion; and (3) drying the mixed emulsion.

Abstract: It is an object of the present invention to provide polylactic acid containing a stereocomplex crystal and having excellent moldability, a high molecular weight, high crystallinity and a high melting point and a process for manufacturing the same. It is another object of the present invention to provide a composition comprising the polylactic acid and a molded product of the polylactic acid. The present invention is characterized from polylactic acid having a weight average molecular weight of 80,000 to 500,000 and a melting peak at 195° C. or higher which accounts for 80% or more of the total of melting peaks in the temperature elevation step when measured by a differential scanning calorimeter (DSC) and a process for manufacturing the same.