| abstract |
A waterproof grease composition comprising a base oil of 10 to 400 mm2/s kinematic viscosity at 40°C composed of at least one of a mineral oil and a synthetic oil, a thickening agent, a surfactant, a metal soap, a fluorinated water repellent agent, a silicone water repellent agent, a pH adjusting agent and a water resistance imparting agent selected from among waxes, polymers and graphite. This waterproof grease composition even when water is mixed therein can avoid exfoliation, such as white tissue exfoliation. Further, there is provided a roller bearing for wheel support, comprising an inner member with a track surface on its outer circumferential surface; an outer member having on its inner circumferential surface a track surface opposed to the track surface of the inner member, the outer member disposed outside the inner member; and multiple rolling elements disposed rotatably between the two track surfaces, wherein the above waterproof grease composition is enclosed. This roller bearing excels in water resistance. |