IMPROVED PROCESS FOR THE PREPARATION OF METALLIC DETERGENT-DISPERSANT ADDITIVES OF HIGH ALKALINITY ESPECIALLY FOR LUBRICATING OILS AND PRODUCT OBTAINED

A process of preparing metallic detergent-dispersant compositions is provided by: 1. Reacting sulfur with an alkylphenol, bearing one or more C6-C60 alkyl substituents, in the presence of a dilution oil, an alkaline-earth metal alkylbenzene sulfonate of a molecular weight of more than about 300 and a TBN of less than or equal to about 150, an alkaline-earth metal compound, optionally an alkaline-metal hydroxide, a base component of metallic detergent-dispersant of a TBN greater than or equal to 200 selected from among superalkalinized sulfurized alkaline-earth metal alkylphenates, alkaline-earth metal alkylbenzene sulfonates, and mixtures of superalkalinized sulfurized alkaline earth metal alkylphenates and alkaline-earth metal alkylbenzene sulfonates, and an alkylene glycol, at a temperature of between 100 DEG C. and 190 DEG C.; 2. Carbonating the resultant mixture with carbon dioxide at a temperature of between 100 DEG C. and 200 DEG C., the amount of CO2 being between that which can be completely absorbed and an excess of 30 percent of said amount; 3. Removing the alkylene glycol; and 4. Separating the metallic detergent-dispersant of high alkalinity thus obtained. The detergent-dispersants thus obtained are useful in improving the detergent-dispersant power of lubricating oils.