The appearance of liquid calcium zinc stabilizer is mainly light yellow oily liquid. There is not much difference in the stability between powder and liquid. Liquid calcium zinc stabilizers usually have greater solubility and good dispersion in PVC resin powder, and their impact on transparency is much smaller than that of powder stabilizers. However, liquid stabilizers have a greater risk of precipitation. A suitable solvent needs to be selected.
Liquid stabilizers are usually used in PVC products with a total plasticizer content greater than 10 to 20 phr.
Metallic soaps and additives have large solubility in solvents; low volatility, high flash point, low viscosity, colorless or light color, no odor, non-toxic or low toxicity. For example, liquid paraffin, white oil, diesel oil, spindle oil and other mineral oils can be used as solvents. It is worth noting that some solvents contain polycyclic aromatic hydrocarbons. According to the relevant provisions of Section 30 of the German Food and Commodity Law (LMBG), the maximum allowable limit of total PAH is 10mg/kg (10PPM), BaP benzo (a ) The maximum allowable limit of pyrene is 1mg/kg (1PPM), and some EU countries are also preparing to adopt this standard. The auxiliary stabilizer itself does not have a thermal stabilization function, but it can improve the stabilization efficiency. Because there is no cadmium single-component assistance, the main auxiliary substances such as phosphites, epoxy compounds, phenolic antioxidants, β-diketones, etc. appears to be particularly important.