| 摘要 |
PROBLEM TO BE SOLVED: To obtain an extreme-pressure additive not using a surfactant, completely water-soluble, having a good smelling and hue, excellent in anti-foaming property and rust proof property and also having a high load-resisting performance and lubricating performance equivalent to those of the oily lubricant. SOLUTION: This extreme-pressure additive consists of a sulfidized hydroxy unsaturated fatty acid condensed material salt, which is characterized by containing 8-15 wt.(mass)% sulfur content, and having <=6 hue and 80-200 acid value, and the cutting liquid or grinding liquid contains the above additive and water. The extreme-pressure additive is obtained by reacting a hydroxy unsaturated fatty acid with sulfur and hydrogen sulfide under heating and a high pressure to sulfurize the hydroxy unsaturated fatty acid and also condense it, and then neutralizing the obtained reaction product with a base. |
