Preparation method for polythiol having improved storage stability

Abstract

According to one embodiment, in producing polythiols in a manner similar to a conventional method, a polythiol having improved storage stability may be produced in a convenient manner by adjusting reaction conditions so as to prevent thiourea from remaining within products. In particular, the equivalent weight of thiourea to be used in a reaction may be adjusted to a predetermined range, thereby reducing the amount of unreacted thiourea, and thiourea may be removed once more in a sub sequent process, thereby effectively removing remaining thiourea while achieving a high yield. The polythiol thus produced does not contain residual thiourea, and thus does not show discoloration or cloudiness caused by precipitates even under prolonged storage or high-temperature conditions.

Dependencies are inferred from the claim text.