Patent ID: 6669873
Filing Date: 2003-12-30
Classification: C08G,G02B

Abstract:
A polymerizable organic composition comprising:(a) a radically polymerizable prepolymer of, (i) at least one first polymerizable monomer having at least two radically polymerizable ethylenically unsaturated groups, and (ii) at least one first polythiol monomer having at least two thiol groups, the molar equivalent ratio of ethylenically unsaturated groups of (a)(i) to thiol groups of (a)(ii) is no greater than 1:1, and the percent consumption of ethylenically unsaturated groups of (a)(i) is selected such that said prepolymer is a substantially gel-free liquid at 25Â° C.; and(b) at least one second polymerizable monomer having at least two radically polymerizable ethylenically unsaturated groups, wherein a polymerizate of said polymerizable organic composition has a refractive index of at least 1.57, an Abbe number of at least 33, said polymerizable organic composition having a percent shrinkage less than that of a corresponding polymerizable composition containing substantially no prepolymer, said first and second radically polymerizable monomers each being substantially free of norbornene groups.