OXIDATIVE STABILITY IMPROVER FOR LUBRICANT AND METHOD FOR IMPROVING OXIDATIVE STABILITY

摘要

PURPOSE:An oxidative stability improver containing a nonbasic nitrogen compound obtained from mineral oil by concentration and separation is added to a lubricant oil such as of mineral oil, alkylbenzenes, alkylnaphthalenes or mixtures thereof. CONSTITUTION:A nonbasic nitrogen compound obtained from mineral oil by concentration and separation such as carbazole or indole, their alkyl-substituted derivative is used as a major component to give an oxidative stability improver. The product is added to a lubricant, preferably by more than 16ppm based on the nonbasic nitrogen and less than 3ppm as the basic nitrogen. EFFECT:The improver shows high solubility in the lubricant oil.