| 摘要 |
PURPOSE:To obtain an acrylic copolymer excellent in transparency, impact resistance, etc., by feeding methyl methacrylate and an alkyl (meth)acrylate to a polymerization system in a specified manner and emulsion-polymerizing the monomers. CONSTITUTION:50-90pts.wt. methyl methacrylate (A) containing, optionally, 10wt% or below ethylenically monounsaturated monomer and 50-10pts.wt. ester of a 1-8C monoalcohol with methacrylic acid (except for component A) are fed to a polymerization system while the composition ratio of components A and B is being varied, and the monomers are emulsion-copolymerized. Namely, the purpose copolymer is obtained in such a manner that at the start of feeding, components A and B in an amount corresponding to 8-35wt% of the entire monomers are simultaneously fed to the system and the amount of component B Added per unit time is continuously decreased with the progress of feeding and is zero at the end of feeding and at the same time that the addition of component B has been completed within a period of feeding of component A.
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