Calcium stearate

Calcium stearate

Names
Preferred IUPAC name Calcium di(octadecanoate)
Other names E470
Identifiers
CAS Number	1592-23-0  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:190296
ChEMBL	ChEMBL2106092  N
ChemSpider	14587  Y
ECHA InfoCard	100.014.976
PubChem CID	15324
UNII	776XM7047L  Y
CompTox Dashboard (EPA)	DTXSID7027419
InChI InChI=1S/2C18H36O2.Ca/c2*1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20;/h2*2-17H2,1H3,(H,19,20);/q;;+2/p-2 Y Key: CJZGTCYPCWQAJB-UHFFFAOYSA-L Y InChI=1/2C18H36O2.Ca/c2*1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20;/h2*2-17H2,1H3,(H,19,20);/q;;+2/p-2 Key: CJZGTCYPCWQAJB-NUQVWONBAL
SMILES [Ca+2].[O-]C(=O)CCCCCCCCCCCCCCCCC.[O-]C(=O)CCCCCCCCCCCCCCCCC
Properties
Chemical formula	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)
Solubility in water	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)	2 1 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

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

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 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. ^[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.
• A lubricant in the dry drawing method of wire production.
• 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 for drugs etc. ^[5]

References

1. Nora A, Szczepanek A, Koenen G (2001). "Metallic Soaps". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_361. ISBN   3527306730.
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". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a28_001. ISBN   3527306730.
3. Preventing Efflorescence, Portland Cement Association
4. US 5527383,Flynn, Gregory J.; Krasniewski, John M.& Wilson Jr., Joseph,"Lubricant additives for paper coating compositions",published 1996-06-18, assigned to Henkel Corp.  
5. Lück E, von Rymon Lipinski GW (2000). "Foods, 3. Food Additives". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a11_561. ISBN   3527306730.