| 摘要 |
PURPOSE: To obtain an optical element which is made from a methacrylic resin compsn. which contains a copolymer contg. N-substd. maleimide units and cyclohexyl methacrylate units and exhibiting a high heat resistance, a low moisture absorption, and a low birefringence, is haredly contaminated by impurities in a long-time continuous molding, is not colored during molding, and gives an optical element not colored at a high temp. (about 100 deg.C). CONSTITUTION: This optical element is obtd. from a methacrylic resin compsn. which contains 100 pts.wt. copolymer formed from 10-70wt.% methyl methacrylate, 5-30wt.% N-substd. maleimide, and 15-85wt.% cyclohexyl methacrylate and 0.03-2.0 pts.wt. additives comprising 0.01-1 pt.wt. hindered amine light stabilizer, 0.01-1 pt.wt. hindered phenol antioxidant, and 0.01-1 pt.wt. phosphite antioxidant. |
