Patent ID: 6313251
Filing Date: 2001-11-06
Classification: C08F,G02B

Abstract:
A cross-linkable polymeric casting composition that comprises:A: an acrylic or methacrylic monomer that is selected from an acrylate or a methacrylate derivative of a cycloolefin which provides high rigidity and low colour dispersion and is characterized by an Abbe number of at least 35 in the final product;B. a di- or polythiol compound;C. a di- or polyvinyl monomer; optionallyD. a polymerisable comonomer;wherein component C is a rigid cyclic vinyl monomer of the formula ##STR36##whereinX is selected from one or more of the following: ##STR37##Sp is a spacer group selected from one or more of the following: ##STR38##Y is hydrogen or halogenn=0, 1 or 2m=2-6p=1-4.