低迁移量环保食品罐密封圈的制备及其性能研究

以聚氯乙烯（PVC）糊树脂、Dinch增塑剂、聚酯增塑剂等其他助剂制备低迁移量环保密封圈。研究了PVC糊树脂的聚合度、发泡剂含量、加工温度和胶料存放时间对密封圈耐迁移性能的影响。结果表明，在聚合方法相同、颗粒形态相近的条件下，随着PVC糊树脂聚合度的提高，树脂吸收增塑剂的能力变强，密封圈的耐迁移性能随之提高；随着添加的发泡剂含量的增加，密封圈的泡孔变大且数量增加，与模拟液的接触面积变大而导致增塑剂迁移量变多；加工温度为195 ℃时制备得到的密封圈的增塑剂迁移量较少，加工温度过高或者过低会使密封圈部分结构受到破坏或者塑化程度过低，体系内游离的增塑剂含量较多；随着胶料存放时间的延长，密封胶的稳定性降低，密封圈的耐迁移性能随之降低。

Preparation and Properties of Environmentally-friendly Food Cans Sealing Rings with Low Migration

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.