| 摘要 |
PROBLEM TO BE SOLVED: To produce a methacrylate resin sheet substantially free from appearance defects such as polymerization foaming and voids with good productivity by effectively reducing the concentration of dissolved oxygen in monomers. SOLUTION: A method for producing a methacrylate resin sheet comprises the steps of supplying a raw material comprising solely methyl methacrylate or a monomer mixture of 60 mass% or more of methyl methacrylate and 40 mass% or less of an acrylic ester into a polymerization vessel in which oxygen concentration is reduced to 3 mass% or less by supplying gaseous nitrogen beforehand, obtaining a methacrylate syrup by polymerizing part of the raw material with a dissolved oxygen concentration of 0.5 ppm or less in the polymerization vessel in the presence of a radical initiator such that the content of the polymer is from 10 mass% to 35 mass%, and polymerizing the methacrylate syrup obtained in the polymerization vessel by pouring the same into a mold. COPYRIGHT: (C)2004,JPO&NCIPI
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