METHOD OF PREPARING HIGH-ALKALINITY MODIFIED SULFONATE ADDITIVE FOR LUBRICATING OILS Russian patent published in 2005 - IPC

FIELD: lubricants.

SUBSTANCE: invention concerns additives for carburetor and diesel engines and provides an additive preparation method wherein alkali-earth metal sulfonate, prior to be carbonized, is treated with modifier including sulfidized C₉-C₁₈-alkylphenol alkali-earth metal salt and/or C₁₄-C₂₂-alkylsalicylic acid alkali-earth metal salt, and/or succinimide-type ashless dispersant, or Mannich base in the form of 30-65% solution in mineral oil at 20 to 65^оС in hydrocarbon solvent in presence of promoter. Carbonized product is supplemented by stabilizer including neutral sulfonates and/or alkali-earth metal C₁₄-C₂₂-alkylsalicylates, and/or succinimide-type ashless dispersants. Promoter can represent 85-95% aqueous solutions of primary or secondary aliphatic С₁-С₅-alcohols or their mixtures with aromatic С₆-С₁₂-alcohols and/or with С₁-С₄-carboxylic acids, and/or with alkylbenzenesulfonic acids with molecular weight 400-550. Preferred modifier/promoter/alkali-earth metal sulfonate weight ratio is (0.3-1.25):(0.5-1.25):1.0. Preferred amount of added stabilizer corresponds to 1-35% of the carbonized product.

EFFECT: increased hydrolytic stability and resistance to exhaustion of high-alkalinity sulfonate additives.

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