摘要 |
PURPOSE:To obtain a novel oil-soluble additive which gives high friction coefficient and has an action to make a surface smooth by using a colloidal silica which has a specific particle size of reduced secondary agglomeration and an oil-soluble surfactant at a specific ratio as essential components. CONSTITUTION:The subject additive is composed of, as essential components, (A) 1 pt.wt. of a colloidal silica of primary particle size of less than 400mmu, preferably less than 100mmu, with reduced secondary agglomeration, and (B) more than 0.5 pts.wt. of an oil-soluble surfactant such as diethylene-triamine polybutenyl succinate. The base oil to which the additive can be added is, for example, mineral oil, ester synthetic oil, poly-alpha-olefin, polyoxyalkylene glycol synthetic oil. |