The effect of organotin on PVC


Organotin is one of the main heat stabilizers in PVC pr […]

Organotin is one of the main heat stabilizers in PVC processing and the best performance. It has been applied for 60 years in the world and has developed rapidly in foreign countries, especially in North America. It is mainly made of organotin as a lead stabilizer. Alternative products, their domestic production and application are also increasing year by year.
However, in terms of replacing the lead salt system, the use in China is not strong, due to various aspects:
(1) The organotin has high corrosion resistance and coating requirements on the surface of the screw, barrel and crusher. Most of the existing processing equipment is only suitable for the traditional lead salt formula system;
(2) Most PVC-U profiles produced by plastic products enterprises are white. If they are directly converted into a mercaptan organotin formulation system, sometimes the mercaptan organotin and lead may be caused by a slight carelessness in a certain part of the processing. Sulfurized pollution causes a gray pattern on the surface of the pipe, and the contaminated product will cause secondary pollution when it is broken.
(3) The formula design and process control of the organotin system are quite different from those of the lead system, and the decomposition speed is faster. PVC products with organotin stabilizer systems are FDA-approved and can be used in food contact applications. However, some of the organotin stabilizers for methyl mercaptan tin are currently high in trimethyltin (trimethyl). There are also some activities such as ventilation and other protection at the operation site, resulting in organotin poisoning.