PVC heat stabilizers are mainly used for PVC and other chlorine-containing polymers. It has been found that PVC plastics can only be shaped at temperatures above 160°C, but they begin to decompose at 120°C to 130°C, releasing HCl gas. If the production of HCl is not inhibited, the decomposition will be further exacerbated. This problem has been a problem. The main problems in the development and application of PVC plastics.
The study found that if the PVC plastic contains a small amount of impurities such as lead salts, metal soaps, phenols, aromatic amines, it will not affect its processing and application, but also to a certain extent, play a role in delaying its thermal decomposition. The above problems have been solved, which has led to the establishment and continuous development of the field of thermal stabilizer research.
Generally classified according to the chemical components of thermal stabilizers, it can be basic lead salts, metal soaps, organic tin, epoxy compounds, phosphites, polyols, etc. According to the size of the action, the PVC stabilizer can be divided into a main stabilizer and an auxiliary stabilizer. The auxiliary stabilizer itself has little or no thermal stabilization effect, but it has a synergistic effect with the main stabilizer. The main stabilizer is generally a metal-containing thermal stabilizer. Pure organic compounds such as epoxy compounds, phosphites, and polyols are generally used as auxiliary stabilizers.
Because it is often necessary to use a variety of PVC heat stabilizers to achieve good PVC stability, some commercial PVC stabilizers are compounded with a variety of ingredients to become composite stabilizers, such as cadmium telluride stabilizers, yttrium and zinc stabilizing agents. Agents, etc. These compound stabilizers have usually been added with additives such as lubricants required for the processing of polyvinyl chloride to facilitate user use. There are many types of composite stabilizers, including powder, paste, and liquid.
Therefore, there are several categories of thermal stabilizers:
1, lead salt composite stabilizer
2. OBS organic stabilizer
3, organic tin stabilizer
4, liquid compound stabilizer
5, calcium and zinc composite stabilizer
6, yttrium-zinc composite stabilizer
7, potassium and zinc composite stabilizer