High temperature anti-friction bearing grease

A grease composition having a worked penetration below 260 mn/10/77 DEG F. and a running-in temperature below 30 DEG F. (in a bearing test described in the Specification) comprises a lubricating oil containing 15-40 wt. % of a mixture of sodium crotonate and the sodium soap of a C14-22 unsaturated monocarboxylic acid, the molar ratio of crotonate : soap being between 0.1 : 1 and 10 : 1, plus 0.1-15 wt. % of di- or tri-sodium phosphate, the three sodium salts being heated to 300-425 DEG F. for 1/3 -4 hours in admixture with at least a dispersing portion of the lubricating oil. The lubricating oil may have a viscosity of 40-140 SUS/210 DEG F. and a V.I. of 40-120. Mineral oils are preferred but animal, vegetable and synthetic oils may also be used, e.g. silicone fluids, diesters such as di-l-ethyl-hexyl sebacate, complex esters such as di-l-ethyl hexanol/polyethylene glycol/adipic acid, and phosphonates. The crotonate may be derived from a commercial mixture containing at least 80% crotonic acid and the unsaturated C14-22 acid may be lauroleic, myristoleic, palmitoleic, gadoleic or erucic acid or a commerical mixture thereof, preferably having an iodine number of 80-100. Optional ingredients specified are up to 10% of additional thickeners, e.g. lithium or calcium soaps and calcium acetate/calcium soap complexes; tackiness agents, e.g. polyisobutylene; E.P. agents, e.g. calcium acetate; and oxidation inhibitors, e.g. phenyl alpha naphthylamine. In examples, greases are prepared from mineral oil, oleic acid, crotonic acid, sodium hydroxide, trisodium phosphate, phenyl alpha naphthylamine and (in one example) sodium petroleum sulphonate.