GB791212A - Improvements in or relating to the preparation of oil solutions of oil-soluble polyvalent metal petroleum sulphonates - Google Patents

Abstract

Oil solutions of polyvalent metal petroleum sulphonates are prepared by sulphonating at above about 15 DEG C. a petroleum fraction having a viscosity of between 50 and 120 secs. Redwood I at 140 DEG F. and a viscosity index greater than 70, diluting the product with up to 25 per cent of water based on the weight of sulphonating agent used, separating an acid oil containing sulphonates, neutralizing the acid oil with an aqueous alkali metal or ammonium base and simultaneously or subsequently adding sufficient of a lower aliphatic alcohol, with or without water and if necessary, a soluble inorganic salt, to cause the resulting mixture to separate into an oil phase, an alcoholic phase containing oil and alkali metal or ammonium petroleum sulphonates, and an aqueous inorganic salt phase, separating the alcoholic phase, stripping the alcohol therefrom, treating the resulting oil solution of petroleum sulphonates in the presence of water with a water-soluble polyvalent metal salt and a polyvalent metal base, removing substantially all the water from the reacted mixture and then removing any suspended solid material by a mechanical treatment. In one modification, the separated acid oil is neutralized with aqueous alkali metal or ammonium base and simultaneously or subsequently there is added sufficient of a lower aliphatic alcohol with or without water to cause the mixture to separate into an oil-phase and an aqueous alcoholic phase containing oil and neutralized sulphonic acids, the latter phase is removed and treated with more of the alcohol with or without water to form an alcoholic phase containing oil and the sulphonates and an aqueous phase and this alcoholic phase is treated as above to obtain the desired oil solution of polyvalent metal sulphonates. In a further modification, the wet oil solution of polyvalent metal sulphonates obtained by either of the above methods is treated with a further quantity of polyvalent metal base and then with carbon dioxide as described in Specification 790,471 to give a wet oil-solution of more highly basic polyvalent metal sulphonates which is worked up as above. The alcohols used in the phase separation contain up to 4 carbon atoms and may be mono- or poly-hydric. In the formation of the polyvalent metal salts, it is preferred to form alkaline earth metal sulphonates using 1.5 to 3 equivalents of an alkaline earth metal chloride and 1 equivalent of an alkaline earth metal base. The formation of zinc sulphonates is also mentioned. The oil-solutions of polyvalent metal sulphonates may be used as lubricant additives. According to Examples (1)-(4), using illustrated apparatus, a lubricating oil, viscosity 65 secs. and V.I. about 95, is pretreated with sulphuric acid, acid sludge is removed and the purified oil is sulphonated with oleum, while air-blowing; the sulphonated oil is diluted with 10-20 per cent of water based on the oleum and settled; the resulting acid oil phase is removed, neutralized with aqueous NaOH and then is mixed with aqueous isopropyl alcohol to give an oil phase and an aqueous alcoholic phase containing the sulphonates and some oil, and the aqueous alcoholic phase is separated and mixed with more aqueous isopropyl alcohol to give an alcoholic phase still containing oil and the sulphonates and an aqueous layer, or the neutralized acid oil phase is mixed with aqueous isopropyl alcohol and sodium chloride (sodium carbonate is also specified) to provide an oil phase, an aqueous phase and an alcoholic phase directly; the alcoholic phase is removed, stripped of its alcohol and the remaining oil solution of sodium sulphonates is reacted first with aqueous calcium chloride and then with aqueous calcium hydroxide solution, dried and filtered to give an oil solution of basic calcium sulphonates. In Example (5), a wet oil solution of calcium petroleum sulphonates obtained in the method of (1) is slurried with calcium hydroxide, carbonated with CO2 at 85 DEG C., dried and filtered. Specifications 603,238 and 629,525 also are referred to.ALSO:Lubricating oils contain, as an additive, an oil solution of polyvalent metal petroleum sulphonates, the solution being obtained by sulphonating a petroleum fraction having a viscosity of between 50 and 120 secs. Redwood I at 140 DEG F. and a V.I. greater than 70, at a temperature above about 15 DEG C., diluting the product with up to 25 per cent of water based on the weight of sulphonating agent, separating the resulting oil layer containing sulphonic acids and neutralizing it with aqueous alkali metal or ammonium base, simultaneously or subsequently adding a lower aliphatic alcohol, separating the mixture in a specified manner (see Group IV (b)) into an oil layer, an aqueous inorganic salt layer and an alcoholic layer containing the sulphonates and oil, stripping alcohol from the alcoholic layer so yielding an oil solution of the sulphonates, treating the oil solution in the presence of water with a watersoluble polyvalent metal salt and a polyvalent metal base and then either drying the resulting wet oil solution of polyvalent metal sulphonates and removing suspended solids therefrom by a mechanical treatment, or treating the wet oil solution with a further quantity of polyvalent metal base and carbonating the mixture with carbon dioxide, followed by drying and removal of solid suspended material. Examples describe the preparation of oil-solution of basic calcium sulphonates; other alkaline earth metal sulphonates and zinc sulphonates may be prepared similarly. The oil layer obtained in the phase-separation step has a higher V.I. than the feed-stock and, suitably after treatment with an active earth and lime, may be used as a lubricant. Specifications 603,238, 629,525 and 790,471 are referred to.