Polymerizable compositions based on thio(meth)acrylate monomers, polymers with a low yellow index obtained from such compositions, and corresponding ophthalmic lenses

摘要

Transparent polymer compsn. comprises: Component A consisting of: at least 10 wt.% monomer or mixt. of monomers R(SC(=O)-(R1)C=CH2)n (I) contg. at least 1 thioacrylate or thiomethacrylate gp.; and 0-90 wt.% one or more radically copolymerisable monomers (II) pref. mono- or poly-functional vinyl, acrylic or methacrylic; and Component B comprising, with regard to weights of A: 0.1-15 wt.% one or several monomers (III) comprising an alkene with an alpha -carbon atom carrying a free hydroxyl gp. and which is close to at least 1 hydrogen atom. Also claimed are: (i) formulae for monomers (I) and (III); (ii) prepn. process for polymer compsn. involving making component A in presence of initiator or polymerisation catalyst and mixing with component B for photochemical polymerisation.