Wenderoth, Lind & Ponack
Halogen-containing lens material
 A lens material having a refractive index n.sub.D.sup.20 of at least 1.57 or more and an Abbe's number .nu. of at least 30, comprising: a copolymer comprising (I) 10 to 85% by weight of a halogen-containing monomer represented by the following formula (1), (II) 15 to 90% by weight of a halogen-containing monomer represented by the following formula (2), and (III) 0 to 20% by weight of a monomer copolymerizable with the above mentioned monomers, the composition of the copolymer being based on the total quantity of the monomers (I), (II), and (III): ##STR1## wherein: D represents ##STR2## in which n represents an integer selected from the group consisting of 0, 1, and 2; each R.sup.1 represents hydrogen or a methyl group; Y represents CHOH; and r represents 0 or 1; each of X.sup.1 and X.sup.2 represents, independently from each other, a methyl group in which one through three of the hydrogen atoms are substituted by a member selected from the group consisting of bromine, iodine and a hydroxyl group (OH group), with the proviso that the number of substitution of the OH group is only one; X.sup.3 represents a methyl group in which one through three of the hydrogen atoms are substituted by a member selected from the group consisting of bromine, iodine and D, with the proviso that the number of substitution of D is only one; wherein at least one of X.sup.1, X.sup.2, and X.sup.3 contains at least one bromine or iodine; ##STR3## wherein: each R.sup.2 represents hydrogen or a methyl group; p represents an integer selected from the group consisting of 0, 1, 2, and 3; X.sup.4 represents bromine or iodine; and q represents an integer selected from the group consisting of 1, 2, 3, 4, and 5. An example of the copolymer is 1-methacryloxy-2,2-di(bromomethyl)-3-bromopropane/methacryloxypolyethyoxy- 2,4,6-tribromobenzene/styrene/divinylbenzene having a n.sub.D.sup.20 of 1.596 and a .nu. of 35.3. 
Kureha Kagaku Kogyo Kabushiki Kaisha
C C G
C08F C08F G02B
inventional inventional inventional
Naohiro Yasufumi Teruo
Murayama Fujii Sakagami