Patent ID: 7709427

Claim:
A lubricant composition, comprising: a grease; and buffer particles comprised of a polyurethane resin, wherein the polyurethane resin is obtained by a production method comprising the step of synthesizing the polyurethane resin to form the buffer particles by reacting: (1) a long-chain polyol having a number-average molecular weight, Mn, of not less than 500 obtained by mixing (A) aliphatic polyester polyol A, obtained by reacting and synthesizing an aliphatic carboxylic acid and low-molecular-weight polyol, and (B) aromatic polyester polyol B, obtained by reacting and synthesizing an aromatic carboxylic acid and low-molecular-weight polyol, at a weight ratio of A/B ranging from 5/95 to 95/5; (2) a cross-linking agent having three or more active hydrogen groups in one molecule and present in an amount ranging from 0.1 to 5 moles per mole of the long-chain polyol; and (3) a polyisocyanate; wherein the grease has a consistency, in a state where the buffer particles are added thereto, reported as an NLGI number which ranges from No. 2 to No. 000.