Nafettsyrasalter

Nafettsyrasalter, or naphthenate salts, are salts formed from naphthenic acids and bases such as sodium, potassium, calcium, or ammonium. Naphthenic acids are a broad, complex mixture of cycloaliphatic carboxylic acids that occur in crude oil and refined petroleum products. When these acids react with metal hydroxides, carbonates, or other cations, metal naphthenates or ammonium naphthenates are produced.

Occurrence and properties are tied to their origin in petroleum and industrial processes. In crude oil and some refined streams, naphthenic acids can contribute to corrosion and material degradation, especially at elevated temperatures. The resulting salts are often soluble in organic solvents and vary in solubility and stability depending on the metal ion involved. This makes naphthenate salts useful as functional additives in various formulations.

Applications are diverse. Calcium and zinc naphthenates are well known as drying agents (bituminous and alkyd coatings), accelerating the oxidative drying of oils in paints and varnishes. As lubricants additives, certain naphthenate salts serve as detergents, dispersants, or rust inhibitors, helping to keep metal surfaces cleaner and better protected in engine oils and industrial lubricants. They can also act as stabilizers or processing aids in some polymer and coating formulations.

Preparation methods typically involve neutralizing naphthenic acids with metal hydroxides or carbonates to form the corresponding metal salts, or performing metathesis with appropriate metal salts to yield a desired cation.

Safety and environmental considerations depend on the specific salt and formulation. Handling requires standard chemical safety practices; some components may irritate skin or eyes, and environmental persistence varies with metal and formulation. See also naphthenic acids and metal soaps for related context.