| 摘要 |
PURPOSE:To obtain the subject copolymer having excellent heat-resistance, transparency and strength in high efficiency using a suspension polymerization process by using a styrenic monomer and a methacrylic acid monomer at a specific ratio and adding the monomers to a polymerization system in divided state under a specific condition. CONSTITUTION:(A) A styrenic monomer and (B) methacrylic acid monomer are used at a ratio of 75-95wt.% of the component A and 5-25wt.% of the component B (the sum is 100wt.%) and a suspension polymerization is started in the presence of a part of the component A accounting for 75-99% of the total component A and a part of the component B accounting for 20-80% of the total component B. In the course of polymerization, the remaining monomers, i.e., the component A accounting for 1-25% of the total component A and the component B accounting for 20-80% of the total component B, are added to the polymerization system and the copolymerization is continued to obtain the objective copolymer. The addition of the monomers during the polymerization is preferably carried out immediately after the start of polymerization and before the polymerization ratio reaches 80%. |
