Metal soaps are the salts of fatty acids with magnesium, calcium or aluminium. This term does not include sodium and potassium salts. The water-soluble fatty acid salts of sodium and potassium salts are called "soaps".
Frequently used metal soaps are mostly based on long-chain fatty acids such as stearic, palmitic and lauric acid. Furthermore on the unsaturated fatty acids linoleic and oleic acid. In addition, hydroxycarboxylic acids such as ricinoleic acid are also used. Metal soaps can also be based on naphthenic acids and resin acids.
Metallic soaps are used in cosmetic formulations and act as thickening and matting agents, emulsion stabilizers, lubricants and adhesives.