PURPOSE: To obtain the title molding low in a double refraction to an oblique incident light and excellent in heat resistance, mechanical strengths, dimensional stability and adhesion to recording media, by mixing a specified copolymer with a polyphenylene ether.
CONSTITUTION: 80W99wt.% aromatic vinyl monomer (e.g., styrene) and 20W1wt.% carboxylated vinyl monomer (e.g., methacrylic acid) are bulk- polymerized or suspension-polymerized in the presence of a radical initiator to obtain a copolymer of a melt flow rate (at 230°C under a load of 3.8kg) of 0.5W200. 30W70wt.% this copolymer is mixed with 70W30wt.% polyphenylene ether of the formula (wherein R1W4 are each H, halogen or hydrocarbon group), having an intrinsic viscosity of 0.1W1.0 until these polymers are dispersed in the form of particles of 1μ or below, and mixture is injection-molded to obtain an optical resin molding having a transmittance (wavelength of 800nm, thickness of 1.2mm) ≥75%.
NIWANO MASAHIRO
MANABE KENJI
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