| abstract |
An optical material composed essentially of a hydrogenation product of a polymer of an alkenyl aromatic hydrocarbon compound or a copolymer of an alkenyl aromatic hydrocarbon compound with a copolymerizable monomer, wherein at least 30% of the aromatic hydrocarbon ring has been hydrogenated. This material has a low index of birefringence, high transparency and excellent moldability, and accordingly is very useful as a material for optical recording disk and optical lenes. |