Patent GB-735285-A (GB)
Title: Improvements in or relating to purification of oil-soluble mineral oil sulphonates
IPC: C07C309/62
Filed: 1951-06-05
Abstract: Purified oil-soluble mineral oil sulphonates are obtained from a crude mineral oil sulphonate comprising essentially a solution of oil-soluble alkali metal mineral oil sulphonates in major proportion of mineral oil comprising as impurities alkali metal green acid sulphonates and water-soluble inorganic sulphates and sulphites, by adding to the crude sulphonate water or an aqueous common salt solution and an emulsion-breaking oil-soluble at least partially water-soluble liquid having a boiling-point below the decomposition point of the sulphonates, the emulsion-breaking liquid consisting exclusively of carbon, hydrogen and oxygen and having 4 to 8 carbon atoms per molecule, there being present at least 5 parts by volume of the emulsion-breaking liquid and at least 10 parts by volume of water per 100 parts of mineral oil and mineral oil sulphonate, the amounts of emulsion-breaking liquid and water or aqueous salt solution added being sufficient to permit effective separation of an aqueous phase containing the green acid sulphonates and inorganic sulphates and sulphites in solution and a mineral oil phase containing mineral oil sulphonate, permitting the reaction mixture to settle and separating the aqueous phase.  By appropriate selection of proportions of water and emulsion-breaking liquid, the oil solution of sulphonates may be caused to split-out any desired amount of its oil content as a third layer.  Preferably, however, proportions used are such as produce only an aqueous phase and an oil phase, the latter being separately treated with additional water to split-out oil and provide a mineral oil sulphonate concentrate.  The purification is generally effected at about 140 DEG  to 200 DEG  F. batchwise or continuously. Preferred proportions of emulsion-breaking liquid and water are 5-25 vols. and 10-60 vols. respectively, per 100 vols. of mineral oil-mineral oil sulphonate mixture, the emulsion-breaking liquid used amounting to 10-50 per cent of the volume of water.  Specified emulsion-breaking liquids are various butyl and higher alcohols up to octanols, mesityl oxide, isopropyl acetate, isopropyl ether and methyl isobutyl ketone.  The oil concentrate of water-soluble oil-soluble sulphonate may be converted into a concentrate of water-insoluble polyvalent metal sulphonate by treatment with a polyvalent salt, e.g. a calcium, barium, strontium, aluminium, zinc, magnesium, lead, cobalt or nickel salt and then heating to remove water and emulsion-breaking liquid.  The preparation of an p  oil concentrate of calcium mineral oil sulphonate from a crude sodium mineral oil sulphonate containing 77 per cent oil is described in detail with reference to drawings utilizing batchwise and continuous parallel-flow or counter current procedures.  In general, the crude sodium sulphonate is mixed with water and, say, sec. butanol in appropriate amounts, the aqueous layer of impurities is removed; the purified sodium sulphonate-oil phase is mixed with water and the resulting oil concentrate of sodium sulphonate separated from the displaced oil. The sodium sulphonate-oil concentrate is reacted with aqueous calcium chloride forming a calcium sulphonate-oil concentrate which is separated from the aqueous phase and distilled, generally after further addition of calcium hydroxide or chloride, to remove water and the emulsion-breaking liquid.  Likewise, the displaced oil from the concentration step which contains some sodium sulphonate is reacted with aqueous calcium chloride to form an oil solution of the calcium soap.  The polyvalent metal soap-oil solutions may be used in lubricating oils and greases (see Group III).  U.S.A. Specifications 2,166,117, 2,168,315 and 2,453,690 are referred to.ALSO:Polyvalent metal mahogany soaps in concentrated mineral oil solution, free from green acid soaps and inorganic sulphates and sulphites and prepared in specified manner (see Group IV (b)), are used in lubricating oils imparting thereto rust-inhibiting, detergent and wear-reducing properties.  The calcium, barium, strontium, aluminium, zinc, magnesium, lead, cobalt and nickel soaps are mentioned.  The soap concentrates may be used with other additives such as sulphurized alcohols and hydrocarbons, thiophosphates, phenolic thioethers, phosphites, metal derivatives of these materials, oil-soluble detergent soaps, similar metal soaps of carboxylic acids obtained by oxidation of paraffins and organic solvents having anti-foaming properties.  A motor oil containing the calcium mahogany soap and calcium salts of tert.-amyl phenol sulphide and oxidized petroleum acids prevents rusting of engines by moisture; addition of octyl alcohol prevents corrosion by aqueous hydrobromic acid.  The soap concentrates may also be used with calcium, aluminium, barium, magnesium, zinc and lithium base greases.  U.S.A. Specifications 2,166,117, 2,168,315 and 2,453,690 are referred to.