| abstract |
PROBLEM TO BE SOLVED: To provide a method for producing a methacrylic polymer having excellent thermal decomposition resistance and excellent moldability with good productivity. In a method for producing a polymer by a step including a continuous bulk polymerization step, (a) 0.01 to 1.0 mol% of a mercaptan, and (b) a compound represented by the formula (1) a) 1.3 ≦ A · (B −2/5 ) × 10 5 , Expression (2) A ≦ 0.5 × 10 −4 and formula (3a) 0.01 ≦ B ≦ 0.3 (Where A is the number of moles of the radical polymerization initiator per mole of the supplied monomer, and B is the half-life (hr) at the polymerization temperature of the radical polymerization initiator). The monomer containing is continuously supplied to the reaction zone, and polymerization is carried out at a polymerization temperature of 110 ° C. or higher and lower than 150 ° C. so that the polymerization rate (% by weight) φ satisfies the expression (4) 40 ≦ φ ≦ 65. The reaction mixture is continuously removed from the reaction zone. |