Calcium stearate

Calcium stearate is a carboxylate of calcium, classified as a calcium soap. It is a component of some lubricants, surfactants, as well as many foodstuffs. It is a white waxy powder.[1]

Calcium stearate
Names
IUPAC name
Calcium octadecanoate
Other names
E470
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.014.976
UNII
Properties
C36H70CaO4
Molar mass 607.030 g·mol−1
Appearance white to yellowish-white powder
Density 1.08 g/cm3
Melting point 155 °C (311 °F; 428 K)
0.004 g/100 mL (15 °C)
Solubility soluble in hot pyridine
slightly soluble in oil
insoluble in alcohol, ether
Hazards
NFPA 704 (fire diamond)
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
2
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Production and occurrence

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.[2] 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 E470.

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.[1]

  • Calcium stearate is used as a flow agent and surface conditioner in some candies such as Smarties, jawbreakers and Sprees.
  • It is a waterproofing agent for fabrics.
  • A lubricant in pencils and crayons.
  • The concrete industry uses calcium stearate for efflorescence control of cementitious products used in the production of concrete masonry units i.e. paver and block, as well as waterproofing.[3]
  • In paper production, calcium stearate is used as a lubricant to provide good gloss, preventing dusting and fold cracking in paper and paperboard making.[4]
  • 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.[5]

References
  1. Nora A, Szczepanek A, Koenen G (2001). "Metallic Soaps". doi:10.1002/14356007.a16_361. Cite journal requires |journal= (help)
  2. Weingärtner H, Franck EU, Wiegand G, Dahmen N, Schwedt G, Frimmel FH, Gordalla BC, Johannsen K, Summers RS, Höll W, Jekel M, Gimbel R, Rautenbach R, Glaze WH (2000). "Water". doi:10.1002/14356007.a28_001. Cite journal requires |journal= (help)
  3. Preventing Efflorescence, Portland Cement Association
  4. US 5527383
  5. Lück E, von Rymon Lipinski GW (2000). "Foods, 3. Food Additives". doi:10.1002/14356007.a11_561. Cite journal requires |journal= (help)
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