Due to the strong hydrophobicity of zinc stearate powder, the direct preparation of aqueous dispersions from it often results in instability such as water partitioning, pasting and delamination; while the preparation of dispersions by high temperature emulsification of zinc stearate is a complicated and costly process.
As a lubricant, zinc stearate is widely used in rubber, paper, coating and cosmetic industries.
Zinc stearate is water-insoluble and generally appears as a white, soft, fine powder, but also as granules and flakes, and can be classified as a special metal soap among chemicals, so it can be suspended in water with the help of dispersants and other additives.
Stearic acid and sodium hydroxide solution for saponification reaction to obtain the intermediate product sodium stearate, sodium stearate and zinc sulfate solution for complex decomposition reaction to obtain the product zinc stearate, followed by 60 ℃ water washing, pressure filter dehydration, drying, crushing, packaging and other production processes, the method requires the treatment of sodium hydroxide and zinc sulfate aqueous solution, sodium sulfate recovery costs are high and the amount of wastewater discharge is large.
Stearic acid reacts directly with zinc oxide at high temperature to produce zinc stearate. The degree of reaction is based on the free acid content after the reaction, and the reaction is finished by cooling, pressing, crushing, packaging and other post-processing.