2024 年 69 巻 5 号 p. 358-363
ZnDTP is used in lubricating oils as an antioxidant to inhibit oxidation. However, the use of ZnDTP has been discouraged because it contains phosphorus, which has a high environmental burden, and a new multifunctional additive is required. Thus, fullerenes are attracting attention as a new multifunctional additive to replace ZnDTP. In this paper, we describe the radical scavenging effect of fullerenes and the structural changes of fullerenes associated with it. Also, we introduce a new degradation diagnostic method for fullerene-added oils. From our study, it was found that the lubricating oils with fullerenes exhibit a radical scavenging effect depending on the amounts of fullerenes. And the UV absorption spectrum decreased, and the color of the membrane patch changed by scavenging radicals. These consequences indicate that the double bond of the fullerenes is cleaved during the radical scavenging and the resulting fullerene reactants are trapped in the membrane filter. Thus, it is suggested the consumption of fullerenes can be easily detected by observing the change in hue.
