| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical lens made of a polycarbonate resin, which has excellent transparency and color tone stability and exhibits excellent optical characteristics by low birefringence. SOLUTION: The optical lens is obtained by molding a polycarbonate resin composition (E) comprising 100 pts.wt. of a resin component comprising 97-99.95 wt.% of a polycarbonate resin (A) and 0.05-3 wt.% of a polystyrene resin (B) having a weight average molecular weight of 1,000-18,000, and 0.02-2 pts.wt. of a phosphoric antioxidant (C) and/or a phenolic antioxidant (D). The optical lens has total light transmittance of≥89.0% and the reduction rate of birefringence of the optical lens calculated by expression: reduction rate (%) of birefringence=(σPC-σ)×100/σPC is≥5%, whereinσrepresents a birefringence measured by using a test piece of 1 mm thickness obtained from the polycarbonate resin composition (E); andσPC represents a birefringence measured by using a test piece of 1 mm thickness obtained from the same polycarbonate resin (A) as that used as a constituent of the polycarbonate resin composition (E). Since the optical lens is excellent in transparency, mechanical properties, heat resistance and hue stability, even in molding of the lens, a hue change and degradation of the resin itself are avoided, and the optical lens of very high industrial utility value is acquired. COPYRIGHT: (C)2011,JPO&INPIT |
