| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject composition hardly reducing friction-decreasing properties in a long term use by blending a specific zinc dithiophosphate and a sulfur compound with a molydbenum-nitrogen compound. SOLUTION: This composition comprises (A) a molybdenum-nitrogen compound obtained by reacting a pentavalent or hexavalent molybdenum compound (preferably, the hexavalent molybdenum compound, e.g. molybdenum trioxide and molybdic acid) with a basic nitrogen-containing compound (e.g. a succinimide and a carboxylic acid amid'), (B) zinc thiophosphate of the formula [R<1> and R<2> are each a primary alkyl; (a) is 0-1/3], and (C) a compound containing sulfur atom and not containing metal atom (e. g. elemental sulfur and a sulfurated olefin), in a lubricant base oil. A preferable blending amount of each component is 1-10,000 ppm component A expressed in terms of the amount of the molybdenum, 1-10,000 ppm component B expressed in terms of the amount of phosphorus, and 1-20 wt.% component C, based on the amount of the lubricant base oil. |
