| 摘要 |
PROBLEM TO BE SOLVED: To obtain a long-life lubricant, not only excellent in abrasion resistance but also low in friction coefficient and usable in various machines and apparatuses by using an oil or a grease containing boron nitride. SOLUTION: This lubricant comprises a base oil and boron nitride and is used for a sliding member in which at least one surface of opposite sliding surfaces is composed of cast iron (preferably spherical graphite cast iron). Hexagonal boron nitride is preferably used as the boron nitride and the grain diameter size thereof is >=1 and <=30μm expressed in terms of average grain diameter. The grain diameter of secondary grains is <=30μm at the maximum and preferably <=20μm. A boron nitride having <=4 graphitization index for the hexagonal boron nitride is preferably selected for use. The content of the boron nitride is preferably 0.5-20wt.% in the total amount of the composition. Thereby, the resultant lubricant is effectively used for automobiles, ships, iron-manufacturing equipment and construction machines, high-temperature and high-speed bearings, etc. |
