| 摘要 |
PURPOSE: To obtain a copolymer excellent in hydrolyzability by mixing anα-hydroxy carboxylic acid polymer with an alkyl (meth)acrylate polymer in a specified ratio. CONSTITUTION: This copolymer comprises 10-60wt.%α-hydroxy carboxylic acid polymer and 90-40wt.% (the total being 100wt.%) alkyl (meth)acrylate polymer. It is desirable that the weight-average molecular weight of this copolymer is 55000-600000. The alkyl (meth)acrylate polymer is a (co)polymer comprising structural units derived from at least one monomer selected from among methyl acrylate, ethyl acrylate, n-propyl acrylate, n-pulyl acrylate, cyanoethyl acrylate, cyanobutyl acrylate, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, etc.
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