| 摘要 |
PURPOSE:To obtain the titled copolymer having improved thermal decomposition properties, causing a few silver streaking, by polymerizing a methacrylic acid alkyl ester, etc., by the use of an azo compound, etc. as a radically polymerization initiator and a polyfunctional mercaptan as a chain transfer agent. CONSTITUTION:(A) 80-95wt% methacrylic acid alkyl ester is polymerized with (B) 0.5-5wt% acrylonitrile, and (C) 2-15wt% methacrylonitrile in the presence of (D) 0.01-2wt% (based on monomers) of a peroxide (e.g., lauroyl peroxide, etc.) or an azo compound (e.g., azobisisobutyronitrile, etc.) as a polymerization initiator and (E) 0.02-3wt% (based on monomer) of a polyfunctional mercaptan (e.g., thioglycolic ester of pentaerythritol, etc.) as a chain transfer agent preferably by suspension polymerization at 60-95 deg.C, to give the aimed copolymer. |
