Zinc stearate is a white powder, insoluble in water, soluble in hot ethanol, benzene, toluene, turpentine and other organic solvents; it decomposes into stearin when exposed to acid. Acids and corresponding salts; fire hazard under dry conditions, autoignition point 900°C; hygroscopic. It is understood that zinc stearate is mainly used as a lubricant and release agent for styrene resin, phenolic resin, and amine resin. At the same time, it also has the functions of vulcanization activator and softener in rubber.
The synthesis methods of zinc stearate are as follows:
1. Preparation of sodium stearate solution. Dissolve stearic acid in 20 times (mass) hot water, then add caustic soda solution with a content of 1074kg/m3 (10°Bé), and proceed at about 75°C. Saponification reaction produces a dilute sodium stearate solution.
2. Add the zinc sulfate aqueous solution with a content of 1074kg/m3 (10°Bé) to the sodium stearate solution prepared above, at 60°C The metathesis reaction proceeds from left to right, and the product zinc stearate precipitates out. Then let it stand, filter, wash with water, and dry at about 90°C to get the finished product.
3. Dissolve 15g sodium stearate in 1L hot water, and add it to the excess zinc chloride solution with a concentration of 1% while it is hot. middle. Stir thoroughly to precipitate the zinc stearate soap solid, then wash with water by pouring method until no zinc salt is present. Dry in an air bath at 115-120°C for 10-12 hours to obtain a flaky zinc stearate product. After crushing, store it in a sealed glass bottle.
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