PRODUCTION OF PLASTIC LENS

摘要

PROBLEM TO BE SOLVED: To improve moisture and shock resistances by applying heat energy to a polyurethane resin to melt the resin and curing the molten resin in a mold by the reaction of specified isocyanato groups with active hydrogen. SOLUTION: A uretdione group-contg. polyurethane resin having terminal active hydrogen groups obtd. by allowing a uretdione group-contg. polyisocyanate to react with an active hydrogen group-contg. compd. is poured into a mold, heated and cured. That is, heat energy is applied to the polyurethane resin to melt the resin and the molten resin is cured in the mold by the reaction of isocyanato groups formed by the dissociation of uretdione groups with active hydrogen groups remaining in the resin. The uretdione group-contg. polyisocyanate includes a modified body of a uretdione group-contg. org. diisocyanate and another isocyanate compd. Since the dissociation reaction of uretdione groups is utilized, one-pack forming and working of a plastic lens are enabled.