OPTICAL MOLDING MATERIAL AND OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To obtain a stable molding material having a low rate of change of an optical characteristic (retardation) in a wide wavelength range and suitable for optical use and to obtain an optical disk capable of reading and writing with plural lasers because of good optical characteristics in a wide wavelength range. SOLUTION: The optical molding material is a cyclic polyolefin resin and the width of change of the retardation of the resin when the wavelength of light is varied from 400 nm to 830 nm is <±10% of the retardation at 590 nm wavelength. The optical disk is obtained by molding the resin.