PURPOSE: To obtain a plastic lens having a high refractive index by using a copolymer which consists essentially of monomers of specific two components and is obtd. in the presence of a radical polymn. initiator.
CONSTITUTION: The two components expressed by the formula I (X is halogen except F, (a) is 0W4) and the formula II (R1 is H or an alkyl group, (b) is 0W4, n is 1W4) are used as an essential component and are copolymerized in the presence of a radical polymn. initiator. The copolymer obtd. by incorporating the compd. expressed by the formula I in a 10W90wt% range therein and incorporating the compd. expressed by the foumula II in a 10W50wt% range therein has ≥1.57 refractive index. The monomer mixture contg. the above-mentioned radical polymn. initiator is polymerized by using, for example, molds for forming a lens, etc. The polymer obtd. in the above-mentioned way has not only a high refractive index but also excellent mechanical properties, workability, dyeability, formability, chemical resistance, etc. and is usable preferably in the same applications as for inorg. glass, i.e., for a lens of a camera, spectacles, etc. or for a prism, etc.
FUTAKI KOUJI
TAKAMIZAWA MORIO
FUJISAWA TAKAO
