| 摘要 |
PURPOSE:To enhance transparency, refractive index, heat resistance, and workability by using a plastic lens made of a copolymer obtained by copolymerizing a mixture composed essentially of a specific (meth)acrylate monomer and a specified radically polymerizable polyfunctional monomer. CONSTITUTION:The copolymer to be used is obtained by copolymerizing a mixture composed essentially of a useful radically-polymerizable polyfunctional monomer, such as divinylbenzene, ethylene glycol dimethacrylate, or their mixture, and a (meth)acrylate monomer represented by formula I (X is halogen except F; R is H or methyl; Y is one of groups of formula II-VI; l is 0 or 1; m is an integer of 1-5, n is an integer of 0-4, and m+n<=5), such as 3-(2,3,4,5,6-pentbromophenoxy)-2-hydroxypropyl acrylate, and their mixture. Said (meth)acrylate monomer is used in the amt. of 40-90wt% of the total weight, and the polyfunctional monomer is used in the amt. of 10-60wt%, thus permitting refractive index to the extremely enhanced, heat resistance to be made excellent, and cuttability and grindability to be improved. |
