| 摘要 |
PURPOSE:To obtain the titled copolymer useful for illumination covers, etc., having improved heat resistance, weather resistance, and transparency, by polymerizing methyl methacrylate with styrene and maleic anhydride by the use of a radical polymerization initiator having a specific temperature of half-life period under specified conditions. CONSTITUTION:A monomer mixture having a feed composition consisting of (A) 50-86wt% methyl methacrylate, (B) 7-25wt% styrene, and (C) 7-25wt% maleic anhydride, and a molar ratio of styrene to maleic anhydride of 0.5-2.0 is polymerized by the use of a radical polymerization initiator(e.g., lauroyl peroxide, etc.) having >=55 deg.C temperature of 10hr half-life period at a temperature >=5 deg.C higher than the temperature of 10hr half-life period in <=3hr exothermic peak at the temperature, to give the desired copolymer. |
