Abstract: A lubricative composition which can retain lubricating oil or grease without degrading it, which is heat-resistant and mechanically strong, and can be used continuously for a much longer time than conventional ones without the possibility of shortage of lubricant supply. It includes a first component, which is a modified silicone oil having reactive organic groups, a second component, which is a curing agent having organic groups that react with the reactive organic groups, and a third component, which is a lubricating oil or grease. The third component is retained in a three-dimensionally reticulated structure of silicone formed by polymerizing the first and second components in the third component. The third component has no compatibility with either the first or second components.

Abstract: A grease composition sealed in a rolling contact bearing contains a base oil in the form of a mixture of an alkyldiphenylether oil and a poly-.alpha.-olefin oil. The weight ratio of the former to the latter is between 20:80 and 80:20. 5-40% by weight of thickening agent which is at least one of an aromatic diurea compound and an aromatic urea-urethane compound is added to the base oil. Further, a passivation oxidizing agent and an organic sulfonate are added.