Prepn. of overbased magnesium sulphonate(s) - by contacting a magnesium sulphonate, magnesium oxide, a carboxylic acid deriv. an alkanol deriv. and water with carbon di:oxide

摘要

Overbased oil-soluble Mg sulphonates are prepd. by first forming a reaction mixt. comprising (a) an oil-soluble Mg sulphonate, (b) 1 to 4 (pref. 10-40) equivs. of a light MgO, (c) 0.5-5 (pref. 0.7-1.3) equivs. of an oil-insoluble 1-5C carboxylic acid, anhydride, metal salt or ester, (d) =30 (pref. 2-30) equivs. of H2O, (e) 0-35 (pref. 4-20) equivs. of a 1-5C alkanol or alkoxyalkanol, and (f) an invert solvent. The reaction mixt. is contacted with an acidic gas (esp. CO2) at a temp. between 50 degrees F and reflux temp. (pref. 50-200 degrees F) until the desired degree of absorption is reached, and then stripped to remove volatiles. The products are useful as detergent and acid-neutralising additives for lubricants, greases and fuels. Products with a high metal ratio (Mg/sulphonate equiv. ratio), esp. 20-40, can be obtd. in a one-step operation.