Flexible and semi-rigid vinyl chloride resin compositions comprising a combination of a latent mercaptan and a zinc salt of oxidized polyethylene (a zinc ionomer) as a heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent mercaptan and the zinc ionomer. The oxidized polyethylene is split out from the ionomer to act as an adhesion promoter for aqueous inks and paints, and the residual zinc carboxylate functions as a co-stabilizer with the latent mercaptan in the composition. The latent mercaptan is exemplified by a 2-S-(tetrahydropyranyl)thioalkanol, a carboxylic acid ester thereof, a 2-S-(tetrahydropyranyl)-thiocarboxylic acid, an ester thereof, and the furanyl homologs of each.