The Type of Lead Salt Stabilizer
Three basic lead sulfate, the formula is: 3PbO · PbSO4 · H2O, code TLS, white powder, density 6.4g / cm3. Three basic lead sulfate is a commonly used stabilizer varieties, generally with the two basic lead phosphite and use, due to non-lubricity and need to be equipped with lubricant. Mainly used for PVC rigid opaque products, the amount is generally 2 to 7 copies.
Two basic lead phosphite, the formula: 2PbO · PbHPO3 · 1 / 2H2O, code DL, white powder, density 6.1g / cm3. The thermal stability of the two basic lead phosphite is slightly lower than that of the three basic lead sulphates, but the weatherability is better than that of the three basic lead sulphates. Dibasic lead phosphite often used with three basic lead sulfate, the amount is generally about three basic lead sulfate lead.
Dibasic lead stearate, code-named DLS, not as three basic lead sulfate, two basic lead phosphite commonly used, with lubrication. Often with three basic lead sulfate, dibasic lead phosphite and the amount of 0.5 to 1.5 copies.
In order to prevent the toxic powder lead salt stabilizer scattering, serious pollution of the production environment, improve the dispersion effect of stabilizers, domestic and foreign has developed a dust-free composite lead salt heat stabilizer. The manufacturing process is:
Under the conditions of heating and mixing will have a synergistic effect of various lead salt stabilizer, auxiliary heat stabilizer and internal and external lubricants and other fully dispersed mixed into granular or flaky lead salt compound stabilizer. It will be added in a certain number of copies of PVC resin (no longer add other stabilizers and lubricants) that can achieve thermal stability and internal and external lubrication of the technical requirements.
There are information on the manufacture of clean lead salt composite stabilizer, the use of lead salt stabilizer particles fine, and thus the surface area with hydrogen chloride increased. And with the internal and external lubricant compound, so that the dispersion of good, heat stability efficiency is significantly improved, the amount can be reduced.
