Sumitomo Chemical Company, Limited

Ikuo Morisada

Kenji Manabe

Osamu Moriya

Koji Yano

The invention provides a resin molded article for optical products comprising a copolymer predominantly composed of methyl methacrylate and a styrenic monomer, wherein the number of foreign bodies contained in the resin molded article having a length of 210 mm, a width of 210 mm and a thickness of 3 mm as visually examined using a strain meter is about 150 or less, which is useful for a light transmitting plate employed in a liquid crystal display device because the possibility that the display screen looks whitely turbid due to the warp of the light transmitting plate, is reduced.

Resin molded article for optical product and light transmitting plate comprising the same

The present invention provides a method for producing a methyl methacrylate polymer, wherein monomers containing methyl methacrylate as a main component are bulk-polymerized or solution-polymerized in the presence of a polymerization initiator and mercaptan compound as a chain transfer agent to form a liquid polymer composition containing unreacted monomers and then a volatile content is separated from the liquid polymer composition, the method comprising the steps of: distilling the volatile content to recover unreacted monomers, (1) subjecting the residue to a contact treatment with hydrazine compound or (2) subjecting the residue to an azeotropic distillation with water to remove impurities, distilling the resultant to recover the mercaptan compound and reusing the mercaptan compound as the chain transfer agent of raw materials.

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Niihama, Japan

Ikuo Morisada