| 摘要 |
PURPOSE:To obtain the titled resin having excellent heat resistance and impact resistance and high alpha-methylstyrene content, by adding a specific amount of comonomer to alpha-methylstyrene, completely emulsifying the mixture, and carrying out the polymerization of the mixture keeping the ratio of the monomer to the polymer in the system at a specific level by the addition of additional comonomer. CONSTITUTION:The polymerizer is first charged with >=50pts.wt. of alpha-methylstyrene and <=10wt% acrylonitrile, methyl methacrylate and a vinyl monomer based on the alpha-methylstyrene, and the mixture is completely emulsified. The polymerizer is then charged with <=50pts.wt. of acrylonitrile, methyl methacrylate and a vinyl monomer, and the emulsion polymerization of the mixture is carried out by keeping the weight ratio of the alpha-methylstyrene monomer to the other monomers always at >=90/10 until the polymerization conversion exceeds 30%. The copolymer obtained by this process contains >=30pts.wt. of the component containing >=70wt% alpha-methylstyrene and composed of 50-90pts.wt. of alpha-methylstyrene, 5-30pts.wt. of methyl methacrylate, 5-30pts.wt. of acrylonitrile and 0-5pts.wt. of other vinyl monomers. |
