POLYLACTIC ACID COMPOSITION

摘要

A polylactic acid composition comprising (A) a polylactic acid-series resin and (B) an acrylic triblock copolymer is prepared. The composition fulfills the following requirements: (1) the acrylic triblock copolymer (B) is a triblock polymer comprising (B1) a polymer block having a glass-transition temperature of not higher than 25°C, (B2a) a polymer block which has a glass-transition temperature of not lower than 60°C and is bound to a terminal of the polymer block(B1), and (B2b) a polymer block which has a glass-transition temperature of not lower than 60°C and is bound to another terminal thereof; (2) the polymer block (B1) comprises a main structural unit derived from an acrylate, and the polymer block (B2a) and the polymer block (B2b) independently comprise a main structural unit derived from a methacrylate; and (3) both of the weight-average molecular weights of the polymer block (B2a) and polymer block (B2b) are smaller than the weight-average molecular weight of the polymer block (B1). The polylactic acid-series resin (A) and the acrylic triblock copolymer (B) may form a phase separation structure.