LUBRICATING OIL COMPOSITIONS

摘要

Disclosed herein is a neutral or overbased salt of a sulfurized alkylhydroxyaromatic compound obtained by the process comprising the steps of (a) sulfurizing an alkylhydroxyaromatic compound derived from alkylation of a hydroxyaromatic compound with one or more olefins comprising C9 to C18 oligomers of monomers selected from propylene, butylene or mixtures thereof to provide a sulfurized alkylhydroxyaromatic reaction product; (b) removing any unsulfurized alkylhydroxyaromatic compound from the sulfurized alkylhydroxyaromatic reaction product of step (a) to obtain a sulfurized alkylhydroxyaromatic compound substantially free of the unsulfurized alkylhydroxyaromatic compound; and (c) neutralizing the sulfurized alkylhydroxyaromatic compound of step (b) to provide a salt of the sulfurized alkylhydroxyaromatic compound, wherein the overbased salt of the sulfurized alkylhydroxyaromatic compound contains less than about 2% by combined mass of the unsulfurized alkylhydroxyaromatic compound and its unsulfurized metal salt.