Patent ID: 6605682
Filing Date: 2003-08-12
Classification: G01M

Abstract:
A resin molded articlecontaining 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 &mgr;m to about 10 &mgr;m 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.