Improvements in or relating to a process for preparing oil-soluble basic calcium sulphonates

摘要

A basic calcium petroleum or alkyl aromatic sulphonate in hydrocarbon oil solution is prepared by mixing a solution of an alkali metal hydroxide with a wholly hydrocarbon oil solution containing a calcium petroleum or alkyl aromatic sulphonate and calcium chloride and removing the alkali metal chloride formed as a precipitate from the mixture, if necessary after removal of water, the amount of alkali metal hydroxide not exceeding the proportion of 2 mols. per mol. of the calcium chloride. Preferably, the alkali metal hydroxide solution is aqueous and the reaction mixture is dehydrated during the process. The calcium chloride in the oil solution employed may be added calcium chloride or that present as a contaminant in the calcium sulphonate as when for example a phenol raffinate of white oil or a C18+ alkyl aromatic hydrocarbon is sulphonated, the acid oil neutralized and the resulting sodium sulphonates in unchanged oil solution are converted into the calcium salts by reaction with excess of calcium chloride brine. Preferably about 0.5 mol. of calcium chloride is present initially per mol. of calcium sulphonate. The alkali reacts with the calcium chloride forming calcium hydroxide which is highly soluble in the hydrocarbon. Thereafter, the reaction mixture may be further diluted with oil, heated to remove water and then filtered hot with a filter aid to remove the alkali metal chloride. Experiments are described wherein hydrocarbon oil solutions containing calcium petroleum sulphonate and calcium chloride are treated with the stoichiometric amount of aqueous caustic soda or excess calcium hydroxide, dehydrated and filtered and it is shown that both products have similar high basicities.ALSO:A hydrocarbon oil solution of a basic calcium petroleum or alkyl-aryl sulphonate is prepared by mixing a solution, preferably an aqueous solution, of an alkali metal hydroxide with a wholly hydrocarbon oil solution containing a calcium petroleum or alkyl-aryl sulphonate and calcium chloride and removing the alkali metal chloride formed as a precipitate, if necessary after removal of water, the amount of alkali metal hydroxide not exceeding the proportion of 2 moles per mole of calcium chloride present (see Group IV(b)). The calcium chloride may be added calcium chloride or that present as a contaminant in the calcium sulphonate as results, for example, when a phenol raffinate of a white oil or a C18 + alkyl-aromatic hydrocarbon is sulphonated, the acid oil is neutralized and the resulting sodium sulphonates in unchanged oil solutions are converted into the calcium salts by means of excess of calcium chloride brine. Preferably, about 0.5 mole of calcium chloride is present per mole of calcium sulphonate. The calcium chloride is converted to the hydroxide which combines with the calcium sulphonate. The product is suitable as a motor oil detergent. Examples are given.