| 摘要 |
PURPOSE:To obtain a plastic lens having a high refractive index, especially high shock resistance and superior physical and chemical characteristics by copolymerizing a mixture contg. two kinds of monomers in a specified ratio in the presence of a radical polymn. initiator. CONSTITUTION:The suitable amount of the 1st monomer represented by formula I (where X is halogen except fluorine, and a is an integer of 0-4) is 50- 90wt%. In case of >90wt%, the solvent resistance and heat resistance of the resulting copolymer are improved, yet satisfactory shock resistance and moldability and not always provided. In case of <50wt%, the heat resistance and solvent resistance are especially deteriorated. The suitable amount of the 2nd monomer represented by formula II (where X is halogen except fluorine, and b is an integer of 0-5) is 10-50wt%. In case of >50wt%, the shock resistance is improved, yet the solvent resistance, heat resistance and workability are reduced. In case of <10wt%, the shock resistance is reduced. |
