主权项 |
1. A grease composition containing base oil, a thickener, and an additive, wherein said additive contains at least one kind selected from among a phosphite ester shown by a chemical formula (1) or a phosphite ester shown by a chemical formula (2); a content of said phosphite ester is 0.5 to 4 parts by weight for 100 parts by weight which is a total of an amount of said base oil and that of said thickener: in chemical formulas (1) and (2), R1, R2, R3, R4, and R5 denote a methyl group or an ethyl group; R1 and R2 are the same group or different groups; R3, R4, and R5 are the same group or different groups. |