Superbasic calcium sulphonate, for addn. to lubricants - by reacting alkylbenzene sulphonic acid with moderately active calcium oxide and passage of carbon dioxide

摘要

Superbasic Ca sulphonates (I) are prepd. by reacting an alkylbenzene sulphonic acid, in which the alkyl gp. has mol. wt. 250-2000, with CaO which had a moderate reactivity with water, according to AST M C 110, and bubbling CO2 into the reaction mixt. (I) is recovered by filtration or centrifuging. (I) are used in engine lubricants. (I) have high reserve alkalinity, e.g. >300 mg KOH/g, are clear, and are easily filtered. The CaO has reaction time with H2O of 8-25 mins. In the sulphonic acid the alkyl gp. is pref. polypropylene or poly-n-butene; the acid is pref. free of H2SO4. The reaction mixt. is pref. alkaline.