Curable casting compositions having a high refractive index and high impact resistance

A high refractive index composition consisting essentially of:

• (a) a core resin mixture consisting essentially of
• (i) at least 40 parts by weight of a first compound and/or a mixture thereof based on the total parts by weight of the core resin equaling 100, having the formula (I):
• wherein the average value of n and n′ independently are 0-30, R1-R4 independently represent H or C1-C6 alkyl, X is O, S, SO2, CO2, CH2, CH═CH, C(CH3)2 or a single bond, and y1-y8 independently represent H, OH, halogen, mercaptan and derivatives thereof or C1-C4 alkyl,
• (ii) 5 to 30 parts by weight of a second compound of a poly(ethylene glycol) di(meth)acrylate and/or a mixture thereof, based on the total parts by weight of the core resin equaling 100, having the formula (II):
• wherein the average value of m is 1 or more, R5-R7 independently represent H or C1-C6 alkyl, and
• (iii) up to 30 parts by weight of a reactive diluent comprising, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, isobornyl (meth)acrylate, 2-phenoxyethyl(meth)acrylate, vinyl benzoate, vinyl 4-t-butyl benzoate, styrene, divinyl benzene or a mixture thereof,
• (b) up to 2 parts by weight of an ultraviolet absorber per 100 parts by weight of the core resin;
• and
• (c) up to a combined total of 3 parts by weight of an additive per 100 parts by weight of the core resin.

A high refractive index composition consisting essentially of:

• a core resin mixture consisting essentially of
• (i) a first compound and/or a mixture thereof having the formula (I):
• wherein the average value of n and n′ independently are 0-30, R1-R4 independently represent H or C1-C6 alkyl, X is O, S, SO2, CO2, CH2, CH═CH, C(CH3)2 or a single bond, and y1-y8 independently represent H, OH, halogen, mercaptan and derivatives thereof or C1-C4 alkyl,
• (ii) a second compound is a poly(ethylene glycol) di(meth)acrylate and/or a mixture thereof, having the formula (II):
• wherein the average value of m is 1 or more, R5-R7 independently represent H or C1-C6 alkyl, and
• (iii) a reactive diluent comprising, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, isobornyl (meth)acrylate, 2-phenoxyethyl(meth)acrylate, vinyl benzoate, vinyl 4-t-butyl benzoate, styrene, divinyl benzene or a mixture thereof;
• the mixture having at least 40 parts by weight of the composition of component (i), 5 to 30 parts by weight of the composition of component (ii) and up to 30 parts by weight of the composition of component (iii), based on the total parts by weight of the combined components (i), (ii) and (iii) equaling 100.