EXTREME-PRESSURE ADDITIVE AND INDUSTRIAL LUBRICATING OIL

摘要

PROBLEM TO BE SOLVED: To obtain an extreme-pressure additive capable of improving the lubricity of various industrial lubricating oils without using organic chlorine compound or phosphorus compound to ensure the safety to human body and the conservation of environment by using a specific perbasic zinc sulfonate composition. SOLUTION: The perbasic zinc sulfonate composition to be used in the present additive is composed of fine particles of calcium carbonate (D) and fine particles of calcium hydroxide (B) dispersed in an oil-soluble aromatic hydrocarbon sulfonic acid zinc salt (A) and is produced by carbonating the component B in a solvent containing the components A and B using calcium chloride (C) in an amount of 1-5wt.% based on the component B. Preferably, the particle diameters of the component D and the component B are 0.005-0.1μm each and the contents of the components A, B and D in the extreme-pressure additive are 20-50wt.%, 2-10wt.% and 1.5-40wt.%, respectively.