| abstract |
Problems of birefringence can be avoided in an optical element including an optical resin composition consisting essentially of certain polycarbonates having a melt flow rate of more than or equal to 5.0 g/10 min. as measured based on ISO R-1133 Standard at 230°C and 5 kgf., and having a glass transition point of more than or equal to 100°C. The polycarbonates preferably include major repeating units having the formula (I) or (II). Formula (I)n Formula (II)n wherein Ar 1 and Ar 2 each represent an arylene group or a cycloalkylene group; R represents an alkylene group, a cycloalkylene group, -0-, -O-Ar 3 -O-, -S-, -SO-, -S0 2 -, -SO 2 -Ar 3 -SO 2 -, -R 1 -Ar 4 -R 1 -, -O-R 1 -O-.n -CONH-R 1 -NHCO-, or -Ar 5 -R 1 -; Ar 3 and Ar4 each represent a phenylene group or a bisphenylene group; R 1 represents an alkylene group; R 2 represents an alkyl group; Ar s represents a cycloalkylene group, -R 1 -Ar 4 -R 1 -. -R 1 -Ar 5 -R 1 -, -R 1 -O-Ar 4 -O-R 1 -, or -R 1 -O-Ar 4 -X--Ar 4 -O-R 1 ; and X represents -S0 2 -, -CO-, an alkylene group, or -R 1 -Ar 4 -R 1 -. |