PROCESS FOR THE AFTER-TREATMENT OF PASTE-FORMING POLYVINYL CHLORIDE POWDERS

摘要

A process is disclosed for the after-treatment of a paste-forming plastics powder of a vinyl chloride polymer obtained by the polymerisation of vinyl chloride with or without other copolymerisable monomers in aqueous solution in the presence of a water-soluble catalyst and an alkali metal salt of a fatty acid as emulsifier, followed by spray-drying. In the process, the plastics powder is treated with water in a weight ratio of powder : water of from 1 : 2 to 1 : 15, and is then separated from the water and dried. The eventual pastes exhibit a viscosity one or more orders of magnitude lower than pastes formed from untreated plastics powder.