METHOD OF PRODUCING POLYTHIOL COMPOUND FOR THIOEPOXY BASED OPTICAL MATERIAL, AND COPOLYMERIZABLE COMPOSITION FOR THIOEPOXY BASED OPTICAL MATERIAL COMPRISING THE POLYTHIOL COMPOUND

摘要

PURPOSE: A manufacturing method of a polythiol compound is provided to manufacture a polythiol compound with low discoloration by controlling the calcium content in a thiourea which is for the synthesis of a polythiol compound for a thioepoxy-based optical material. CONSTITUTION: A manufacturing method of a bis(2-mercaptoethyl)sulfide for a thioepoxy-based optical material includes a step of obtaining a bis(2-hydroxyethyl)sulfide by the reaction of 2-chloroethanol and 2-mercaptoethanol; a step of obtaining a thiouronium by the reaction of a thiourea and the bis(2-hydroxyethyl)sulfide; and a step of obtaining a bis(2-mercaptoetyhl)sulfide by hydrolyzing the thiouronium. The calcium content in the thiourea is 1 wt% or less.