Metal Carboxylates



Soltex metal carboxylates are organometallic salts formed by the reaction of copper or zinc and naphthenic acid dissolved in a hydrocarbon solvent. Soltex offers 8% copper naphthenate and 8% zinc naphthenate.

Copper Naphthenate

Soltex 8% copper naphthenate is completely miscible (soluble) in all base oils in all proportions. Its color ranges from olive to dark green but is known to turn brown after several months of sunlight exposure.

Soltex copper naphthenate is light to medium viscosity, non-conductive, and has non-corrosive properties. It is not a significant threat to the environment and is not restricted when used as a pesticide.

Zinc Naphthenate

Soltex 8% zinc naphthenate is completely miscible (soluble) in all base oils in all proportions. It is a brown resinous liquid that may be used for transparent finishes. Soltex zinc naphthenate is light in viscosity and resists oxidation. It is anti-microbial and has preservative properties.


Application Benefits

Wood Products. Copper naphthenate is used as a wood preservative, including formulations for pressure treatments and maintenance/repair of utility poles and railroad ties. Utility poles treated with copper naphthenate are easier for utility workers to climb than poles treated with chromated copper arsenate (CCA). Copper naphthenate also reduces water absorption, cracking, splitting, and warping in all types of wood products. Copper naphthenate is a replacement for pentachlorophenol.

Resins. Copper naphthenate is used both in the synthesis of unsaturated polyester resins and to control the exotherm of their end formulation. It also has been observed to add shelf stability to promoted resins. Concentrations of 8% copper naphthenate as low as 0.01% can reduce or eliminate surface cracks and irregularities that can develop in large polyester castings, such as bathtubs and other products.

Veterinary Pharmaceuticals. Copper naphthenate is used as a formulant in veterinary pharmaceuticals, including Thrush Hoof treatments.

Paints and Inks. Zinc naphthenate are drying agents for coatings and printing inks. It acts as an auxiliary or co-dryer to improve hardness, maintain gloss, and stop wrinkling on the surface of the film body.

Lubricant Additives. Zinc naphthenate exhibits rust and corrosion inhibition, as well as anti-wear, acid neutralization, and dispersant properties when used as an additive in lubricating oils and greases. It is especially useful in boundary lubrication applications. It is also used as a rust preventive in metalworking fluids.

Fungicides. Zinc Naphthenate is effective against fungus, moss, and mildews.


Typical Properties

Metal Content 7.9-8.1 7.9-8.1
Density at 25C (kg/dm3) Max D 1298 0.975-1.015 0.930-0.970
% Non-Volatile Typical D-1644B 70 50
Appearance Visual Clear Clear
Water Content D95 <0.5 <0.5
Viscosity CPs/cSt D-2196/D445 <1000 <350
Color, Gardner Visual/D1544 Green <10

Registrations. When used as preservatives, copper and zinc require regulatory registrations with the EPA (USA) and PMRA (Canada). Soltex Canada has a Technical Grade Active Ingredient registration in Canada for 8% zinc/copper naphthenate.


Tolling Capabilities

Soltex Canada has a long tradition of providing toll manufacturing services to the oil and specialty additives industries, allowing customers to streamline their operations and free-up capacity at their facilities. With manufacturing in Canada and warehousing in multiple locations in the United States, Soltex tolling enables North American customers to have a domestic source of supply with shorter lead times on products.

Soltex has an in-house laboratory to streamline testing and quality assurance. Our facilities offer loading and offloading of railcars and road trucks, as well as steaming and transloading of railcars.

Soltex can handle water, oil, and solvent based products. The production facility produces volumes from 250 to 22,000 USG batches and packages products in pails, IBCs, road tankers and railcars.