PVC heat stabilizer is widely used in the PVC industry. Its role is to prevent the molecular chain of PVC resin from causing damage and degradation under the action of heat and shear, and also prevent the degradation under the action of photooxygen and thermal oxygen in the process of storage and use. At present, PVC heat stabilizers mainly include composite stabilizers, organotin stabilizers and environmental protection stabilizers (calcium and zinc stabilizers).
1, compound stabilizer Compound stabilizer has good thermal stability, but in the process of processing will remain free S042-, Cl- ions, if the content of these ions is too high, under the direct action of visible light, and Pb2+, resulting in gray spots on the surface, sometimes gray mixed with yellow, At the same time, Pb2+ remaining in the product is easy to react with S2- in the air to generate black PbS, which is easy to turn black on the surface of the product.
2, organotin heat stabilizer organotin heat stabilizer has good thermal stability and transparency, but the light transmittance of organotin is close to PVC, can not effectively protect the damage of UV on PVC molecules, so the weather resistance is worse than lead salt and all kinds of environmental protection (calcium and zinc) heat stabilizer, only a large number of shielding titanium dioxide can meet the weather resistance requirements.
3, environmental protection stabilizer All kinds of environmental protection stabilizer (calcium and zinc stabilizer) the main components of calcium and zinc soap salt, auxiliary heat stabilizer, antioxidant, lubricant; It plays a stabilizing role at the same time, can absorb ultraviolet light, all kinds of environmental protection (calcium and zinc) heat stabilizer to add a large number of different kinds of antioxidants, such as 1010,1076 can alleviate the degradation of PVC under the action of photooxygen and thermal oxygen, especially on the PVC profile weather resistance has a greater role.