| 摘要 |
A lubricating oil composition is described which comprises a major amount of an oil of lubricating viscosity and (A) at least about 1 % by weight of at least one carboxylic derivative composition produced by reacting (A-1) at least one substituted succinic acylating agent containing at least about 50 carbon atoms in the substituent with (A-2) from about 0.5 equivalent up to about 2 moles, per equivalent of acylating agent (A-1), of at least one amine compound characterized by the presence within its structure of at least one HN< group; and (B) at least one alkali metal overbased salt of a hydrocarbyl-substituted carboxylic acid or a mixture of a hydrocarbyl carboxylic acid and a hydrocarbyl-substituted sulfonic acid having a metal ratio of greater than 2 in an amount sufficient to provide at least about 0.002 equivalent of alkali metal per 100 grams of the lubricating oil composition wherein the hydrocarbyl substituent of the carboxylic acid contains at least about 50 carbon atoms, provided that when the alkali metal salt comprises a mixture of overbased alkali metal salts of a hydrocarbyl-substituted carboxylic acid and a hydrocarbyl-substituted sulfonic acid, then the carboxylic acid comprises more than 50 % of the acid equivalents of the mixture, and provided further that when the substituted succinic acylating agent (A-1) consists of substituent groups and succinic groups and said acylating agent is characterized by the presence within its structure of an average of at least 1.3 succinic groups for each equivalent weight of substituent groups the metal ratio of the alkali metal overbased salt (B) is greater than 1. |
