Plastic lenses having a high-refractive index, process for the

Abstract

One aspect of the present invention relates to a process for preparing plastic lenses having a high-refractive index comprising forming a mixture containing one or more polyisocyanate compounds; one or more active hydrogen compounds selected from the group consisting of a polyol compound having no sulfur atom, a polyol compound having at least one sulfur atom, and a polythiol compound having at least one sulfur atom in addition to the sulfur atom contained in mercapto group and at least one internal releasing agent and then casting and polymerizing the mixture. A second aspect of the present invention relates to a process for preparing a sulfur-containing urethane resin lens is here disclosed which comprises mixing polyisocyanate having two or more isocyanato groups, polythiol having two or more thiol groups and one or more surface active agent selected from the group consisting of fluorine-containing nonionic surface active agents, silicone-containing nonionic surface active agents, alkyl quaternary ammonium salts and acid phosphoric esters and then cast polymerizing the mixture in a mold made of a glass or a metal. Lenses prepared by the processes are also disclosed.