Patent ID: 8063167

Claim:
A composition for producing an optical casting polyurethane resin, the composition consisting of: a polyisocyanate component comprising at least one cyclic polyisocyanate selected from the group consisting of alicyclic polyisocyanates, and aralkyl polyisocyanates; and a polyol component, wherein the polyol component comprises a combination of a crosslinking polyol having an average hydroxyl value of 150 to 1300 mg KOH/g and an average functionality of 2.5 or more and 5 or less, and a polytetramethylene ether glycol having an average hydroxyl value of 70 to 500 mg KOH/g; wherein the optical casting polyurethane resin obtained by a reaction of the polyisocyanate component and the polyol component has an average molecular weight between crosslinking points in a range of 150 to 400.