| abstract |
(57) [Problem] To provide a method for producing an unsulfurized alkali metal-free additive for lubricating oil. SOLUTION: At least one containing 1 to 4 carbon atoms Neutralization of an alkylphenol with an alkaline earth base, in the presence of various carboxylic acids, in the absence of an alkali base, in the absence of a dialcohol, and in the absence of a monoalcohol, after neutralization A process comprising carboxylation of the alkyl phenate produced in the stage and filtration of the product of the carboxylation stage. |