Patent ID: 8729203

Claim:
A monomer for a polymerizable composition, the monomer being selected from the group consisting of compounds having formula (I) and compounds having formula (Ia): wherein D is: and R 1 is hydrogen or a methyl group; Z is O or N—R 4 , where R 4 is hydrogen or C 1-10 alkyl; m is an integer from 1 to 3; n is an integer from 0 to 6; R 2 and R 3 are independently selected from C 1-10 alkyl, C 3-10 cycloalkyl, C 6-37 aryl ether, an optionally substituted C 4-36 heterocyclyl, C 1-7 alkoxy, C 5-36 aryloxy, and C 2-11 alkyl ether; X is sulphur; Ar is an optionally substituted C 5-36 aryl group; wherein the optional substituents for when Ar is an optionally substituted C 5-36 aryl group are independently selected from halogen atom, C 1-10 alkyl, C 3-10 cycloalkyl, C 5-36 aryl, C 5-37 aryl ether, C 1-7 alkoxy, C 6-37 aryl thioether, an optionally substituted C 4-36 heterocyclyl, C 2-11 alkyl ether, C 2-11 alkyl thioether, C 5-36 aryloxy, C 5-36 arylsulfide, C 6-38 arylalkyl and an optionally substituted C 5-38 heterocyclyl-alkyl group.