Patent ID: 8664169

Claim:
A lubricating composition for gearboxes, with a kinematic viscosity at 100° C. measured according to the ASTM D445 standard of between 5.5 and 7 mm 2 /s, comprising: (a) one or more phosphorus-containing, sulfur-containing, or phosphorus-sulphur-containing antiwear and/or extreme pressure additives; (b) at least 30% by weight of at least one fatty acid methyl ester of formula RCOOCH 3 , wherein R is a paraffinic or olefinic group containing from 11 to 23 carbon atoms; and (c) at least one compound selected from the group of light polyalphaolefins with kinematic viscosity at 100° C., measured according to the ASTM D445 standard, comprised between 1.5 and 6 mm 2 /s, with a kinematic viscosity at 40° C., measured according to the ASTM D445 standard, comprised between 4 and 30 mm 2 /s and with a molecular mass by weight of less than 500 daltons in combination with one or more compounds of polymethacrylate type, with a molecular mass by weight of less than 30,000 daltons, and wherein the mass percentage of light polyalphaolefin(s) is at least 10%, and wherein the mass percentage of the polymethacrylate(s) and the fatty acid methyl ester(s) is collectively at least 60%.