Patent ID: 6777522
Filing Date: 2004-08-17
Classification: C07F,C08G,C08L,C09D,G02B

Abstract:
A prepolymer comprising: wherein the V groups may be the same or different unsaturated photo or thermal polymerizable substituents of the general structure R3CH&boxH;C(R4)(CH2)p(W)q(Z)q(Ar)qR5; the R groups may be the same or different saturated C1-10 hydrocarbon substituents; the R1 groups may be the same or different C1-10 alkyl substituents; the R2 groups may be the same or different selected from the group consisting of C1-10 alkyl substituents, C1-10 fluoroalkyl substituents, C2-20 alkyl-fluoroalkyl substituents and C6-30 aromatic substituents; the L groups, which may or may not be present in the subject prepolymers, may be the same or different urethane, urea or ester linkages; y is a natural number greater than 4 representing the sum of siloxane moieties with randomly differing R2 groups as defined above so as to have a molar ratio of aromatic substituents to alkyl substituents no less than 1:4; x is a natural number such that the prepolymer molecular weight is at least approximately 1000 and refractive index is at least approximately 1.45; R3 is selected from the group consisting of hydrogen, C1-10 alkyl and â€”COâ€”U; R4 is selected from the group consisting of hydrogen and methyl; R5 is a C1-10 divalent alkylene radical; the W group is selected from the group consisting of â€”COâ€” and â€”OCOâ€”; the Z group is selected from the group consisting of â€”Oâ€” and â€”NHâ€”; the Ar groups may be the same or different C6-30 aromatic radicals; p is a non-negative integer less than 7; q is either 0 or 1; and U is selected from the group consisting of â€”OC1-12 alkyl radical, â€”SC1-12 alkyl radical and â€”NHC1-12 alkyl radical.