| abstract |
This invention provides an optical copolymer, which has good balance among high transmittance, high heat resistance, low birefringence, and mechanical strength, and an optical molded product comprising the optical copolymer. The optical copolymer comprises 50 to 80% by mass of methyl methacrylate units, 10 to 20% by mass of units derived from a lactone compound represented by general formula (1), and 10 to 30% by mass of trifluoroethyl methacrylate units. The mass ratio of the trifluoroethyl methacrylate units is in the range of 0.5 to 2.0 when the mass of the units derived from the specific lactone compound is presumed to be 1, and the glass transition temperature is 120°C or above. The optical copolymer is suitable for objective lenses, prisms, condensing lenses, diffraction gratings, collimator lenses, and sensor lenses. |