| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method capable of producing a methacrylic resin excellent in transparency, heat resistance, moldability, durability and mechanical strength with high production efficiency. <P>SOLUTION: The method for producing a methacrylic resin containing a polymer (a) having a weight average molecular weight of more than 50,000 and a polymer (b) having a weight average molecular weight of 20,000-50,000 in a mass ratio (a/b) of 60/40 to 90/10 comprises steps of: bulk-polymerizing a monomer mixture containing 50 mass% or more of methyl methacrylate and 50 mass% or less of a vinyl monomer copolymerizable therewith, in at least two systems of tank circulation type reaction apparatus until the polymerization conversion rates of the monomer mixture become 20-80 mass% at temperatures of 120 to 180°C; and mixing reaction solutions obtained in the respective systems. The molded article is composed of the methacrylic resin obtained by the method. <P>COPYRIGHT: (C)2013,JPO&INPIT |
