The same dose of calcium zinc stabilizer and lead salt stabilizer through the production of the product comparison found that lead salt stabilizer produced PVC product appearance color is lighter. In the process of production, the thermal stability of PVC produced by calcium zinc stabilizer is slightly higher than that produced by calcium zinc stabilizer. Because the unstable chlorine atoms (such as allyl chloride) on the macromolecular chain of PVC are easily removed from HCL when heated, forming polyene structures with conjugated double bonds, resulting in the following changes in THE color of PVC: Colorless (or white) light yellow yellow orange red orange red brown brown, therefore, from the depth of color can judge the advantages and disadvantages of heat stabilizer in PVC processing effect.
In addition, combined with the situation of smell generation in the production site, the smell of calcium and zinc stabilizer is slightly stronger than that of lead salt heat stabilizer. Therefore, it can be judged that the heat stability effect of lead salt stabilizer with the same dose is slightly better than that of calcium and zinc stabilizer in the hot processing process. Through the tension test from the product performance results, the lead salt stabilizer products are slightly better than the calcium zinc composite heat stabilizer products, elongation at break and trapezoidal tearing strength, but they meet the requirements of GB12952-2011 (PVC waterproof coil specification) tension.
The appearance comparison of class L PVC products produced by lead salt stabilizer and calcium zinc stabilizer through anti-aging test after 720h heat treatment at 80℃. After 720h heat treatment at 80℃, the yellowing of products containing lead salt stabilizer is more obvious, while the yellowing of products containing calcium zinc stabilizer is much less. It shows that the products containing calcium and zinc stabilizer have much better thermal aging resistance than the products containing lead salt stabilizer in the later period. This is because the calcium and zinc stabilizer contains antioxidant 1010 and other antioxidant components. Although the stability of the calcium and zinc stabilizer is slightly worse in the short time of high temperature processing, the long-term thermal stability effect is better. This is where calcium and zinc stabilizers come in handy.