Calcium Stearate

About This Product

Calcium stearate is produced by reacting stearic acid with a calcium source, giving a water-insoluble white solid. It is supplied at 6.5-7.1% calcium, free fatty acid 0.5% maximum, melting point 149-155C and heating loss 3.0% maximum, as 125, 200 or 325 mesh powder and as beads and granules, the latter melting at 140-160C and chosen for low-dust handling. Vegetable-based, from palm-derived fatty acids.

Metallic soaps are among the oldest oleochemical derivatives still in large-scale industrial use, and calcium stearate does three quite different jobs depending on where it is put. As a lubricant it migrates to the interface between a melt and the metal confining it, the polar carboxylate end anchoring to the surface while the C18 chains present a low-friction layer; as a release agent that same hydrophobic layer stops the article wetting the tool. As an acid acceptor it does something chemically distinct: the stearate takes up acidic species, the calcium binding the acid and liberating stearic acid in its place, which is why it is chosen where residual catalyst or evolved acid would otherwise attack the polymer. For buyers working down the palm value chain it is a step beyond splitting and fractionation: the fatty acid has been converted into a functional derivative with a defined metal content, rather than sold as a commodity chain-length cut.

It is used in metallic soap manufacture, as a lubricant and release agent, in fatty acid derivatives and in industrial compounding.

Bio Green Oleo supplies calcium stearate to specification on calcium content, free fatty acid, melting point, heating loss, mesh or granular form and packaging.