Description

Bismuth carboxylates are readily soluble in hydrocarbon solvents, including many lubricant base oils (e.g. Group II/III, PAO). Bismuth carboxylates are also effective extreme-pressure (EP) lubricant additives in greases and oils, providing improved lubricity and anti-wear benefits in moving metal parts (e.g. pistons, gears). It has been shown that bismuth carboxylates, especially bismuth neodecanoate (Bi NDA) and bismuth 2-ethylhexanoate (Bi Oct) have excellent synergistic EP properties when combined with a variety of sulfur-based additives. For example, Bi NDA (5 wt%) and polysulfide-based active sulfur (1 wt%) give excellent 4-Ball Weld Load results while also providing modest anti-wear activity when used in a Group II base oil system. Please see our peer-reviewed article for more details: Bismuth Sulfide (Bi2S3) as the Active Species in Extreme Pressure Lubricants Containing Bismuth Carboxylates and Sulfur Compounds. R. T. Hart, A. A. Kerr, N. A. Eckert. Trib. Trans. 2010, 53 (1), 22 – 28.