Zinc stearate

Last updated
Zinc stearate
Zn4(Stearate)6O.png
Names
IUPAC name
zinc octadecanoate
Other names
zinc distearate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.321 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 209-151-9
PubChem CID
RTECS number
  • ZH5200000
UNII
UN number 3077
  • InChI=1S/2C18H36O2.Zn/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 Yes check.svgY
    Key: XOOUIPVCVHRTMJ-UHFFFAOYSA-L Yes check.svgY
  • InChI=1/2C18H36O2.Zn/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: XOOUIPVCVHRTMJ-NUQVWONBAX
  • [Zn+2].[O-]C(=O)CCCCCCCCCCCCCCCCC.[O-]C(=O)CCCCCCCCCCCCCCCCC
Properties
C36H70O4Zn
Molar mass 632.33 g·mol−1
Appearancesoft, white powder
Odor slight, characteristic [1]
Density 1.095 g/cm3, solid
Melting point 120 to 130 °C (248 to 266 °F; 393 to 403 K)
Boiling point decomposes
insoluble
Solubility in Ethanol insoluble
Solubility in ether insoluble
Solubility in benzene slightly soluble
Hazards
GHS labelling: [2]
GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
Warning
H335, H400, H413
P261, P271, P273, P304+P340, P312, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
1
2
0
Flash point 277 °C (531 °F; 550 K)
420 °C (788 °F; 693 K)
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) [1]
REL (Recommended)
TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp) [1]
IDLH (Immediate danger)
N.D. [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Zinc stearate is a "zinc soap" that is widely used industrially. In this context, soap is used in its formal sense, a metal salt of a fatty acid: in this case stearic acid. It is a white solid that repels water. It is insoluble in polar solvents such as alcohol and ether but soluble in aromatic hydrocarbons (e.g., benzene) and chlorinated hydrocarbons when heated. It is the most powerful mold release agent among all metal soaps. It contains no electrolyte and has a hydrophobic effect. Its main application areas are the plastics and rubber industry, where it is used as a releasing agent and lubricant which can be easily incorporated. [3]

Contents

Zinc carboxylates, e.g. basic zinc acetate, adopt complex formulas, and are not simply dicarboxylates of zinc. Instead the formula for most zinc carboxylates is Zn4O(O2CR)6, consisting of a Zn4O6+ core with carboxylate ligands spanning the edges.

Applications

It is widely used as a release agent for the production of many kinds of objects: rubber, polyurethane, polyester processing system, powder metallurgy. These applications exploit its "non-stick" properties. [3] In cosmetics, zinc stearate is a lubricant and thickening agent used to improve texture. [4]

It is an "activator" for accelerated rubber sulfur vulcanization. As discovered in the early days of vulcanization, zinc has a beneficial effect on the reaction of the sulfur with the polyolefin. The stearate is a form of zinc that is highly soluble in the nonpolar medium of the polyolefins.

Being lipophilic, it functions as a phase transfer catalyst for the saponification of fats. [3]

Niche uses

It is a component of some paints, imparting gloss. As a chief ingredient in "fanning powder", it is used by magicians performing card manipulation to decrease the friction between playing cards.

Related Research Articles

<span class="mw-page-title-main">Vulcanization</span> Process of hardening rubber

Vulcanization is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides.

Saponification is a process of converting esters into soaps and alcohols by the action of aqueous alkali. Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. Sodium stearate is a typical soap.

<span class="mw-page-title-main">Stearic acid</span> Eighteen-carbon straight-chain fatty acid

Stearic acid is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a soft waxy solid with the formula CH3(CH2)16CO2H. The triglyceride derived from three molecules of stearic acid is called stearin.

<span class="mw-page-title-main">Zinc oxide</span> White powder insoluble in water

Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.

<span class="mw-page-title-main">Zinc chloride</span> Chemical compound

Zinc chloride is the name of inorganic chemical compounds with the formula ZnCl2. It forms hydrates. Zinc chloride, anhydrous and its hydrates are colorless or white crystalline solids, and are highly soluble in water. Five hydrates of zinc chloride are known, as well as four forms of anhydrous zinc chloride. This salt is hygroscopic and even deliquescent. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

<span class="mw-page-title-main">Magnesium stearate</span> Chemical compound

Magnesium stearate is the chemical compound with the formula Mg(C
18
H
35
O
2
)
2
. It is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate is a white, water-insoluble powder. Its applications exploit its softness, insolubility in many solvents, and low toxicity. It is used as a release agent and as a component or lubricant in the production of pharmaceuticals and cosmetics.

<span class="mw-page-title-main">Extreme pressure additive</span>

Extreme pressure additives, or EP additives, are additives for lubricants with a role to decrease wear of the parts of the gears exposed to very high pressures. They are also added to cutting fluids for machining of metals.

<span class="mw-page-title-main">Sodium stearate</span> Chemical compound

Sodium stearate is the sodium salt of stearic acid. This white solid is the most common soap. It is found in many types of solid deodorants, rubbers, latex paints, and inks. It is also a component of some food additives and food flavorings.

<span class="mw-page-title-main">Beryllium hydroxide</span> Chemical compound

Beryllium hydroxide, Be(OH)2, is an amphoteric hydroxide, dissolving in both acids and alkalis. Industrially, it is produced as a by-product in the extraction of beryllium metal from the ores beryl and bertrandite. The natural pure beryllium hydroxide is rare (in form of the mineral behoite, orthorhombic) or very rare (clinobehoite, monoclinic). When alkali is added to beryllium salt solutions the α-form (a gel) is formed. If this left to stand or boiled, the rhombic β-form precipitates. This has the same structure as zinc hydroxide, Zn(OH)2, with tetrahedral beryllium centers.

<span class="mw-page-title-main">Dithiocarbamate</span> Chemical group (>N–C(=S)–S–)

In organic chemistry, a dithiocarbamate is a functional group with the general formula R2NC(S)SR and structure >N−C(=S)−S−. It is the analog of a carbamate in which both oxygen atoms are replaced by sulfur atoms.

<span class="mw-page-title-main">Calcium stearate</span> Chemical compound

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.

A metallic soap is a metallic salt of a fatty acid. Theoretically, soaps can be made of any metal, although not all enjoy practical uses. Varying the metal can strongly affect the properties of the compound, particularly its solubility.

Copper naphthenate is the copper salt of naphthenic acid. Naphthenic acid is a term commonly used in the petroleum industry to collectively refer to all of the carboxylic acids naturally occurring in crude oil. Naphthenic acids are primarily cycloaliphatic carboxylic acids with 10 to 24 or more carbons, although substantial quantities of non-cyclic, aromatic and heteroatom- containing carboxylic acids are also present. Copper naphthenate is most widely used in wood preservation and for protecting other cellulosic materials such as textiles and cordage from damage by decay fungi and insects. Other metal naphthenates are used as paint driers, rubber adhesion promoters, lubricant additives, and catalysts where oil solubility is required.

<span class="mw-page-title-main">2-Octanol</span> Chemical compound

2-Octanol is an organic compound with the chemical formula CH3CH(OH)(CH2)5CH3. It is a colorless oily liquid that is poorly soluble in water but soluble in most organic solvents. 2-Octanol is classified fatty alcohol. A secondary alcohol, it is chiral.

<span class="mw-page-title-main">Sulfur vulcanization</span> Process to transform the material properties of natural rubber

Sulfur vulcanization is a chemical process for converting natural rubber or related polymers into materials of varying hardness, elasticity, and mechanical durability by heating them with sulfur or sulfur-containing compounds. Sulfur forms cross-linking bridges between sections of polymer chains which affects the mechanical and electronic properties. Many products are made with vulcanized rubber, including tires, shoe soles, hoses, and conveyor belts. The term vulcanization is derived from Vulcan, the Roman god of fire.

Zinc laurate is an metal-organic compound with the chemical formula C
24
H
46
ZnO
4
. It is classified as a metallic soap, i.e. a metal derivative of a fatty acid.

Nickel(II) stearate is a metal-organic compound, a salt of nickel and stearic acid with the chemical formula C
36
H
70
NiO
4
. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid. The compound is harmful if swallowed and may cause skin sensitization.

Strontium stearate is a metal-organic compound, a salt of strontium and stearic acid with the chemical formula C
36
H
70
SrO
4
. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.

Cerium stearate is a metal-organic compound, a salt of cerium and stearic acid with the chemical formula C
54
H
105
CeO
6
. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.

Potassium stearate is a metal-organic compound, a salt of potassium and stearic acid with the chemical formula C
18
H
35
KO
2
. The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid.

References

  1. 1 2 3 4 NIOSH Pocket Guide to Chemical Hazards. "#0676". National Institute for Occupational Safety and Health (NIOSH).
  2. "ZINC stearate". pubchem.ncbi.nlm.nih.gov.
  3. 1 2 3 David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a10_245.pub2
  4. "Zinc Stearate | Cosmetics Info". cosmeticsinfo.org. Archived from the original on 2013-09-06.