Patent ID: 7169882

Claim:
A molding resin formed from a block copolymer comprising polyhydroxycarboxylic acid structural units (I), and polyester structural units (II) derived from a dicarboxylic acid and a diol, wherein a weight ratio (I)/(II) between said polyhydroxycarboxylic acid structural units (I) and said polyester structural units (II) is within a range from 95/5 to 10/90, said molding resin has a microphase separated structure in which one of either said polyhydroxycarboxylic acid structural units (I) or said polyester structural units (II) forms domains within a matrix formed by said other structural units, an average domain size of said domains is within a range from 0.08 to 5.0 μm, a weight average molecular weight of said molding resin is within a range from 10,000 to 400,000, and wherein when said molding resin is tested using a rotational rheometer, under measurement conditions including a frequency of 1 Hz and a temperature within a range from a melting point of said molding resin through to said melting point +50° C., then when a strain of said molding resin is varied from 1 through to 60%, a storage elastic modulus G′(M%) at a strain of M% (1<M≦60) is within a range from 90 to 100% of a value of a storage elastic modulus G′(1%) at a strain of 1%.