摘要 |
A process for the preparation of overbased oil soluble magnesium sulfonates comprises contacting an acidic gas at a temperature between about 50 DEG F. up to the reflux temperature of the mixture, with a mixture consisting essentially of a sulfonic acid or salt thereof, a volatile aliphatic or aromatic or chlorinated hydrocarbon solvent, a non-volatile diluent oil, a light magnesium oxide, water, methanol and combination of promoters, wherein the first promoter is one selected from an oil soluble naphthenic acid and an oil soluble carboxylic acid or salt thereof; and a second promoter being one selected from: <IMAGE> (a) wherein X is one of H, OH, NH2, CO2H, OCOCH3 and SH, and Y is one of H, CH3 and CH2CH3, wherein the second promoter is less oil soluble than the first promoter; and (b) a water soluble C1-C6 carboxylic acid. The volatile components are stripped from the reaction mixture after absorption of the acidic gas is completed, to give a highly commercially desirable overbased magnesium sulfonate. Relatively small amounts of about 1.0 to 1.5% of the combined promoters produce overbased magnesium sulfonates of exceptionally high alkalinity value up to 500 or more, with minimum sediment.
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