| abstract |
PURPOSE:To produce the plastic lens having high surface accuracy and excellent weatherability by using the resin obtd. by reaction of sulfur-contg. aliphat. polyisocyanate and active hydrogen compd. having >=2 functional groups. CONSTITUTION:The resin, which is obtd. by the reaction of the sulfur-contg. aliphat. polyisocyanate and the active hydrogen compd. selected from a group consisting of polyol, polythiol in which the sulfur atom is only the mercapto group and polythiol contg. at least one sulfur atom except the mercapto group, has excellent optical properties. An internal release agent is added to the mixture composed of the polyisocyanate and the active hydrogen compd. and mixture is subjected to cast polymn. at the time of producing the lens by using this resin. The industrially extremely efficient production of the plastic lens having the high surface accuracy and excellent weatherability by using generally used glass molds is thus possible without executing the special release treatment of the mold surface. |