Patent ID: 8530396

Claim:
A grease composition for a constant velocity joint, said composition comprising a base oil, a thickening agent and additives, wherein: said thickening agent consists of (a) a diurea thickening agent which is a reaction product of diphenylmethane-4,4′-diisocyanate with octylamine and octadecylamine, said base oil consists of (b) a trimellitic acid-trialkyl ester oil and, (c) a mineral oil and/or a polyalphaolefin oil, and said additives comprise the following components (d) to (g): (d) a molybdenum dialkyldithiocarbamate of the following formula: (R 3 R 4 N—CS—S) 2 —Mo 2 O m S n wherein R 3 and R 4 represent C 1 -C 4 alkyl groups, m is 0-3, n is 1-4 and m+n=4, (e) molybdenum disulfide, (f) a polytetrafluoroethylene, and (g) a zinc dithiophosphate compound, wherein a flow point of the component (b) is not higher than −40° C., wherein a kinetic viscosity of the component (b) is not less than 40 mm 2 /S at 40° C., wherein the content of the component (a) is 2-20% by mass and is sufficient to make worked penetration of the grease composition within a range of 250-350, the content of the component (b) is 8.5-34% by mass, the content of the component (c) is 40-80% by mass, the content of component (d) is 0.5-5% by mass, the content of the component (e) is 0.5-5% by mass, the content of the component (f) is 0.5-5% by mass and the content of the component (g) is 0.5-5% by mass based on the total mass of the composition, wherein the base oil consists of 10 to 40% by mass of the component (b) and 90 to 60% by mass of the component (c) based on the total mass of the base oil.