Grease composition for rolling bearing

[0047]78 g of 12-hydroxystearic acid and 6.2 g of lithium hydroxide were reacted in 552 g of a poly-α-olefin to produce 80 g of a lithium soap. The lithium soap thus produced was then allowed to cool to room temperature to prepare a gel. The gel thus prepared and 368 g of a polyol ester were then kneaded to prepare a grease composition. The grease composition thus prepared was diluted with hexane, and then attached to a copper mesh having a collodion film applied thereto. The specimen was then observed under transmission electron microscope. As shown in FIG. 1A, a long fiber-like material having a major axis length of not smaller than 3 μm was observed.

[0048]168 g of stearic acid and 14.2 g of lithium hydroxide were reacted in 705 g of a poly-α-olefin to produce 170 g of a lithium soap. The lithium soap thus produced was then allowed to cool to room temperature to prepare a gel. The gel thus prepared and 125 g of a polyol ester were then kneaded to prepare a grease composition. The grease composition thus prepared was then observed under transmission electron microscope in the same manner as in Example 1. As a result, a long fiber-like material having a major axis length of not smaller than 3 μm was observed.

[0049]116 g of stearic acid and 9.8 g of lithium hydroxide were reacted in 528 g of a poly-α-olefin to produce 120 g of a lithium soap. The lithium soap thus produced was then allowed to cool to room temperature to prepare a gel. The gel thus prepared and a mixture of 26 g of a polyol ester and 106 g of diphenyl ether were then kneaded to prepare a grease composition. The grease composition thus prepared was then observed under transmission electron microscope in the same manner as in Example 1. As a result, a long fiber-like material having a major axis length of not smaller than 3 μm was observed.