Patent ID: 8362157

Claim:
A polylactic acid composition, which is prepared from 75 to 25 weight parts of poly-L-lactic acid and 25 to 75 weight parts of poly-D-lactic acid (sum of poly-L-lactic acid and poly-D-lactic acid equals 100 weight parts), which is obtainable by melting and kneading poly-L-lactic acid and poly-D-lactic acid at a temperature in a range of 230 to 260° C. such that the weight average molecular weight of the aforementioned polylactic acid composition will be in a range of 0.3 to 0.6 times the value of the weight average molecular weight obtained by taking the weighted average of the weight average molecular weight of each of the poly-L-lactic acid and poly-D-lactic acid to be used, and characterized in that: (A) when measured by DSC, the cooling (10° C./minute) peak after 10 minutes at 250° C. is no less than 30 mJ/mg; or (B) when measured during the DSC second heating (cooling at a rate of 10° C./minute after 10 minutes at 250° C., and heating again from 0° C. at a rate of 10° C./minute), the peak ratio (peak 1 /peak 2 ) of the peak when Tm is between 150 and 180° C. (peak 1 ) and the peak when Tm is between 200 and 240° C. (peak 2 ) is 0.5 or less; or (C) when measured during the DSC second heating (cooling at a rate of 10° C./minute after 10 minutes at 250° C., and heating again from 0° C. at a rate of 10° C./minute), the peak when Tm is in a range of 200 to 240° C. (peak 2 ) is no less than 35 mJ/mg.