LATENT MERCAPTAN STABILIZERS FOR IMPROVED WEATHERABILITY OF CLEAR HALOGEN-CONTAINING POLYMER COMPOSITIONS.

摘要

PURPOSE: A latent mercaptan stabilizers is provided to exhibit improved ultra violet light stability and weatherability without detracting from their thermal performance. CONSTITUTION: Stabilizer compositions useful for protecting clear polyvinyl chloride and other clear halogen-containing polymer compositions used in the manufacture of exterior weatherable products against discoloration and degradation caused by exposure to ultra violet light and weathering in addition to heat comprising a latent mercaptan which degrades during processing of the composition at an elevated temperature to liberate a free mercaptan in combination with a synergistic amount of a free phenyl salicylate compound. The latent mercaptan may be the sole heat stabilizer additive in the stabilizer composition, but the free mercaptan released during processing may also synergize the activity of organic-based or metal-based heat stabilizers such as organotin carboxylates and organotin mercantile in the polymer composition.