Abstract: Sealing rings with low migration were prepared from PVC paste resin, Dinch and polyester plasticizers and other additives. Effect of the degree of polymerization of PVC, the content of foaming agent, processing temperature, and storage time on migration resistance of the sealing rings was studied. It showed that with increasing degree of polymerization of PVC, the capacity of plasticizer absorption became stronger, and the migration resistance of the sealing rings was improved. With increasing amount of blowing agent, foam cells of the sealing ring became larger and more popular and the plasticizer migration was increased. When the processing temperature was 195 ℃, the plasticizer migration was the minimum, higher or lower processing temperature would damage the degree of plasticizing. With increasing storage time, the resistance to migration was reduced.

Key words: poly(vinyl chloride) paste resin, migration rule, plasticizer, saling ring