Calcium stearate

Calcium stearate is produced by heating stearic acid and calcium oxide: : 2 C17H35COOH + CaO → (C17H35COO)2Ca + H2O It is also the main component of soap scum, a white solid that forms when soap is mixed with hard water. Unlike soaps containing sodium and potassium, calcium stearate is insoluble in water and does not lather well. Commercially it is sold as a 50% dispersion in water or as a spray-dried powder. As a food additive, it is known by the generic E number E470a (sodium, potassium and calcium salts of fatty acids). ==Applications==

Calcium stearate is a waxy material with low solubility in water, unlike traditional sodium and potassium soaps. It is also easy and cheap to produce, and exhibits low toxicity. These attributes are the basis of many of its applications. Related applications exist for the magnesium stearate. • In paper production, calcium stearate is used as a lubricant to provide good gloss, preventing dusting and fold cracking in paper and paperboard making. • In plastics, it can act as an acid scavenger or neutralizer at concentrations up to 1000ppm, a lubricant and a release agent. It may be used in plastic colorant concentrates to improve pigment wetting. In rigid PVC, it can accelerate fusion, improve flow, and reduce die swell. • Applications in the personal care and pharmaceutical industry include tablet mold release, anti-tack agent, and gelling agent. • Calcium stearate is a component in some types of defoamers. • Anticaking agent for drugs etc. == References ==