Calcium stearate is also called calcium octadecanoate. White light crystalline powder. Chemical formula (C17H35COO) 2CA.

Molecular weight 607.00. Melting point 179 ~ 180℃, by high thermal decomposition. Insoluble in water, cold ethanol and ether, soluble in hot benzene, toluene and turpentine, slightly soluble in hot ethanol and ether.

Decomposed with strong acids into stearic acid and corresponding calcium salts. Water is absorbed in air. Intolerant to lipopolytic microorganisms. It decomposes at high temperature to form stearic ketones and hydrocarbons. Non-toxic.

The corresponding oleate is often mixed in industrial products. Used as a stabilizer and lubricant of PVC;

In polyethylene, polypropylene as halogen absorbent; Lubricants for polyolefin fibers and molded products;

Phenolic, amino and other thermosetting plastics lubricant and release agent; Thickening agent of grease; Waterproofing agent for waterproof fabrics; Paint leveling agent and pencil lead lubricants.

Food-grade calcium stearate is used as an anticaking agent. It is prepared by the reaction of baked stearic acid with sodium hydroxide to make dilute soap solution and then react with calcium chloride.

This product can be used as heat stabilizer of PVC and has excellent lubricity.

The thermal stability is general, inferior to barium stearate, lead stearate, tin stearate and cadmium stearate. However, it is cheap, easy to obtain, less toxic and good in processing. It has synergistic effect with zinc soap and epoxy compound, can improve thermal stability, is often used in food packaging film, medical equipment and other non-toxic soft products.

It can be used in hard products with lead salt and lead soap to improve the gelation speed. Calcium stearate is used in polyethylene and polypropylene to eliminate the adverse effects of residual catalysts on the color and stability of resins.

The product is also widely used as lubricant and release agent for thermosetting plastics such as polyolefin, polyester reinforced plastics, phenolic resins and amino resins.

The disadvantage of calcium stearate is that there is initial coloring. When heating above 100℃ for a long time, it will make the white PVC plastic become reddish, especially when there is titanium dioxide in the formula, coloring is particularly serious. At this time, if 0.06-0.12% Na2CO3 or 0.09-0.19 NaHCO3 are added, this shortcoming can be overcome, but these substances are too alkaline, so they are not used in practice.

In addition, when the dosage of this product is large, there is the phenomenon of segregation and scaling.