| abstract |
PROBLEM TO BE SOLVED: To provide a continuous solution polymerization method excellent in productivity and production stability of a methacrylic polymer excellent in optical transparency, weather resistance and thermal decomposition resistance. SOLUTION: A mixture of 95.0 to 99.9% by weight of a specific ratio of a methyl methacrylate monomer and an alkyl acrylate monomer having an alkyl group having 1 to 8 carbon atoms and a non-polymerizable solvent 5 0.010.0% by weight, a feed solution comprising a specific free radical generator and a chain transfer agent is brought into countercurrent contact with gaseous nitrogen to reduce the dissolved oxygen content to 1 ppm or less, After passing through a filter having a diameter of 2 μm or less, the mixture is supplied to the reactor, and the temperature is set to 130 to 170. ° C, the average residence time is 0.5 to 1.9 hours, and the ratio of the half-life of the free radical generator to the average residence time in the reactor is 5.0 × 10 5 -4 to 2.50, and continuously polymerized under the conditions of a polymer concentration (weight fraction) ratio of 0.5 × 10 −6 to 6.0 × 10 −6 mol · g −1 in the reactor. A method for producing a methacrylic polymer, characterized by reacting. |