Zinc Stearate Product Description (CAS# 557-05-1)

Zinc stearate (chemical name: zinc octadecanoate) has the molecular formula C₃₆H₇₀O₄Zn and a molecular weight of 632.33. At room temperature, it appears as a white solid powder with a slight fatty odor and a smooth, greasy feel. Its melting point ranges from 120°C to 130°C. Regarding solubility, zinc stearate is insoluble in water, ethanol, and diethyl ether, but soluble in organic solvents such as benzene, hot ethanol, and turpentine. It decomposes in the presence of dilute acids to yield stearic acid and the corresponding zinc salt. Industrially, zinc stearate is primarily produced through the reaction of stearic acid with zinc oxide under heating and in the presence of a catalyst. As an important metal soap compound, zinc stearate offers excellent lubricity, thermal stability, and non-toxicity; these unique properties make it highly valuable for applications across various sectors, including plastics, rubber, coatings, cosmetics, and pharmaceuticals.

Applications of Zinc Stearate (CAS# 557-05-1)

Zinc stearate is a vital, multifunctional additive widely used across various industries, including plastics, rubber, coatings, cosmetics, and pharmaceuticals.

In the plastics industry, zinc stearate serves as a non-toxic heat stabilizer for polyvinyl chloride (PVC); when used in combination with calcium stearate or barium stearate, it exhibits a synergistic effect that effectively enhances the light and heat stability of PVC products (typically at a dosage of less than one part per hundred resin). It also functions as an acid scavenger, lubricant, and mold release agent for polyolefin materials, offering good thermal stability, low odor, and resistance to plate-out. In the rubber industry, it acts as a softening lubricant and mold release agent for rubber products, as well as an activator for rubber vulcanization accelerators. In the coatings and paint industry, it is used as a flatting agent for paints and enamels. In the cosmetics industry, it serves as a lubricant and thickening agent, helping to improve product texture. In the pharmaceutical industry, it is used as a lubricant in the manufacture of tablets and capsules, at concentrations of up to 1.5% w/w. Additionally, zinc stearate is used as a polishing agent for textiles, a mold release agent in powder metallurgy, and a raw material for pencil lead production.