METHOD OF PREPARING HIGH-ALKALINE ALKYLSALICYLATE ADDITION AGENT TO LUBRICANT OIL Russian patent published in 1996 - IPC

FIELD: petroleum chemistry, addition agents for lubricant oils. SUBSTANCE: method involves neutralization of alkylsalicylic acids containing 9-26 carbon atoms in alkyl radical of alkaline-earth metal in the presence of mineral oil and hydrocarbon solvent, neutralization product refining from mechanical impurities and its treatment with carbon dioxide and alkaline-earth metal hydroxide in the presence of hyrocarbon solvent and promoter at 65-80 C followed by water addition at amount 0.5-35 wt.-% (as measured for alkaline-earth metal alkylsalicylate). Then solvent and promoter were removed and obtained addition agent is refined from mechanical impurities. Before refining neutralization product is treated with alkylsalicylic acids at amount 5-30% per reaction mixture at 70-90 C. EFFECT: increased yield, enhanced quality, accelerated process. 2 cl, 2 tbl