Treating polyvinyl chloride resins

摘要

A method for reducing the vinyl chloride monomer content of polyvinyl chloride resins. The polyvinyl chloride-water slurry is placed in a vessel, and heat is applied to the vessel for a sufficient time to raise it to a suitable temperature for removal of vinyl chloride monomer from the resin. The resin slurry is agitated and also subjected to a vacuum to reduce the temperature during the heat stripping step. In a preferred method, the polvinyl chloride-water slurry is agitated in a closed vessel, heat is applied to rapidly heat the slurry to a temperature of at least about 50 DEG C, and vacuum is applied to the vessel. The slurry is then rapidly cooled by suitable means. The slurry is then dewatered and dried. Dried polyvinyl chloride resins produced by this process have been found to have a vinyl chloride monomer content below a detectable limit of about 2.0 ppm.