Preparation of alkyl mercaptocarboxylate/dialkyl thiodicarboxylate mixture using sulfur and/or water cocatalyst

摘要

An olefinically unsaturated alkyl carboxylate is reacted with hydrogen sulfide in the presence of a lower alkanol using an addition catalyst with water and/or sulfur cocatalyst to give an alkyl mercaptocarboxylate/dialkyl thiodicarboxylate mixture having a high proportion of the mercaptocarboxylate. If sulfur is contained in the cocatalyst, dialkyl dithiodicarboxylates are also formed. The resulting mixture on transesterification with a poly(oxyalkylene)-polyol gives a poly(oxyalkylene)-polyester-poly(monosulfide)-polythiol or a poly(oxyalkylene)-polyester-poly(monosulfide)-poly(disulfide)-polythiol having a good balance of properties.