Resin molded article for optical product and light transmitting plate comprising the same
AssigneeSumitomo Chemical Company, Limited
InventorsIkuo Morisada, Kenji Manabe
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Abstract
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.
Claims6
A resin molded article
- containing about 150 or less of foreign bodies per volume having a length of 210 mm, a width of 210 mm and a thickness of 3 mm as visually examined under a strain meter and determined by optical microscopy;
- having an average light transmittance of about 83% or higher at light wavelengths of from 380 nm to 780 nm when the light transmittance is measured in the condition that the light travels through the resin molded article in a distance of 200 mm;
- and
- comprising a copolymer which is obtained by a process comprising the steps of:
- (i) feeding a solution comprising a methyl methacrylate and a styrenic monomer through a filter with a pore size of about 0.1 μm to about 10 μm into a reaction vessel, and
- (ii) polymerizing the solution with bulk polymerization in the condition that the vessel is filled up with the solution leaving substantially no gas phase in the vessel, and that the vessel is maintained in a thermally insulated state allowing substantially no exchange of heat with the external environment, to obtain a methacrylate polymer.
Dependencies are inferred from the claim text.