BIODEGRADABLE POLYESTER RESIN COMPOSITION WITH IMPROVED MECHANICAL STRENGTH, TEAR STRENGTH AND FLEXIBILITY, COMPRISING POLYLACTIC ACID AND STARCH

PURPOSE: Provided is a biodegradable polyester resin composition, which has improved mechanical strength, tear strength and flexibility and thus can form various films via conventional film molding machines. CONSTITUTION: The biodegradable polyester resin composition comprises a mixture of 30-70 parts by weight of a polylactic acid and 70-30 parts by weight of an aromatic-aliphatic polyester, and 1-30 parts by weight of starch, based on 100 parts by weight of the mixture. Particularly, in the aromatic-aliphatic polyester, the aromatic component is contained in the range of 10-30 mol% and is at least one selected from a dicarboxylic acid of ROOC-Ar-COOR', or a derivative thereof, and the aliphatic component is at least one selected from a dicarboxylic acid of ROOC(CH2)nCOOR' or a derivative thereof. The polylactic acid comprises L-, D- or L,D-lactic acid having a molecular weight of 10,000 or more. The starch is a corn starch, a potato starch, a rice starch, an acid-treated starch, an ester starch, a cationic starch or a mixture thereof.