Кальций стеарат

Химические свойства

Calcium stearate occurs as a fine, white to yellowish-white, bulky powder having a slight, characteristic odor. It is unctuous and free from grittiness. It is found in some lubricants and surfactants.

Подготовка

Calcium stearate is produced by heating stearic acid, a fatty acid, and calcium oxide:
2C₁₇H₃₅COOH + 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 E470. .

Методы производства

Calcium stearate is prepared by the reaction of calcium chloride with a mixture of the sodium salts of stearic and palmitic acids. The calcium stearate formed is collected and washed with water to remove any sodium chloride.

прикладной

Calcium stearate is used as a flow agent in powders including some foods (such as Smarties), a surface conditioner in hard candies such as Sprees, 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.
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.

Опасность

A nuisance dust.

Фармацевтические приложения

Calcium stearate is primarily used in pharmaceutical formulations as a lubricant in tablet and capsule manufacture at concentrations up to 1.0% w/w. Although it has good antiadherent and lubricant properties, calcium stearate has poor glidant properties.
Calcium stearate is also employed as an emulsifier, stabilizing agent, and suspending agent, and is also used in cosmetics and food products.

Профиль безопасности

A nuisance dust. When heated to decomposition it emits acrid smoke and irritating fumes.

Безопасность

Calcium stearate is used in oral pharmaceutical formulations and is generally regarded as a relatively nontoxic and nonirritant material.

хранилище

Calcium stearate is stable and should be stored in a well-closed container in a cool, dry place.

Регуляторный статус

GRAS listed. Included in the FDA Inactive Ingredients Database (oral capsules and tablets). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.