TRANSPARENT RESIN HAVING HIGH REFRACTIVE INDEX

PURPOSE:To obtain a transparent resin useful as optical lenses, especially as lens material for correcting glasses, having high refractive index and extremely large Abbe's number, by polymerizing a specific unsaturated diester alone or the diester with a polymerizable vinyl monomer. CONSTITUTION:One or more of unsaturated diesters (e.g. compounds shown by formulas II and III, etc.) shown by formula I (X is Cl, Br or I; R1 is alicyclic group or aliphatic group containing crosslinkable alicyclic group; R2 and R3 are H or CH3; m is 1-5; n is statistical number of 1-5) are polymerized alone or with one or more copolymerizable vinyl monomers [e.g. styrene, phenyl (meth)acrylate, etc.]. The polymerization reaction starts at 30-50 deg.C, temperature is gradually raised and preferably the polymerization ends at 110-130 deg.C. Prefer ably the blending ratio of the vinyl monomer is usually