| abstract |
There are disclosed antioxidant additives for lubricating oils which exhibit reduced phosphorus volatility, the additives being sodium, potassium, lithiu m or oil soluble amine salts of a dialkyldithiophosphoric acid prepared by reacting P2S5 with a mixture of alcohols consisting of (a) a polyol of the formula R(OH)n where R is a C2-C20 hydrocarbyl group and n is 2-10 and (b) a n aliphatic monohydric alcohol having 3-18 carbon atoms, the mixture containin g relative amounts of polyol and monohydric alcohol such that 50 mole % of the total OH groups are OH groups of the polyol. |