Patent GB-670620-A (GB)
Title: Process for the production of mineral oil solutions of alkaline earth metal sulfonates
IPC: C07C309/62
Filed: 1948-08-13
Abstract: A mineral oil concentrate of oil-soluble alkaline earth metal sulphonates is prepared by a process which comprises the steps of contacting a sludge-free sulphuric-acid treated mineral oil, containing oil-soluble sulphonic acids of at least 400 combining weight, with an aqueous solution of an aliphatic alcohol to extract said acids, separating and adding mineral oil to the alcohol extract thus formed, neutralizing the sulphonic acids therein with a basic alkaline earth (including magnesium) compound, adding water in such amount that, on layer separation of an oil layer and an aqueous alcohol layer, a solution of alkaline earth metal sulphonates in the oil layer is produced, and adjusting the amount of the added mineral oil so as to yield a final mineral oil concentrate containing at least 20 per cent, preferably 30-70 per cent, by weight of sulphonates based on the total weight of the concentrate.  In one modification, the neutralizing agent used is a calcium compound and the neutralization of the sulphonic acids in the extract is effected prior to the addition of mineral oil to the extract whereby a solution of calcium sulphonates in aqueous alcohol is produced, to which mineral oil and water are added as above.  In a further modification, the neutralizing agent is a barium compound and the concentration of water in the aqueous alcohol employed to extract the acids is such that a solution of barium sulphonates in the oil layer is produced by neutralization of the acids without the addition of water.  The sulphonates are preferably prepared by treating a mineral oil to obtain a maximum of the higher oil-soluble sulphonic acids followed by treatment with finely divided filter aid and filtration to remove impurities and then air-blowing to remove SO2.  The extraction of the sulphonic acids is preferably effected with an aqueous solution containing 40-60 per cent of an aliphatic alcohol, the amount of solution being such that the alcohol extract contains about 10 per cent of sulphonic acids.  The neutralizing agents may be added in solid form or saturated solution, or used dissolved in sufficient water that the steps of neutralization and addition of water are combined in the single operation.  The water addition to effect transfer of the sulphonates from the aqueous alcohol to the added mineral oil is generally such as to reduce the alcohol concentration of the alcoholic solution to 25-35 per cent, though the barium sulphonates are readily precipitated from 50 per cent aqueous alcohol solution.  Formation of an oil layer containing the sulphonates is facilitated by heating to about 70-80 DEG  C.  The oil layer is then removed, additional alkaline earth metal hydroxide or carbonate added, if desired, to provide excess alkalinity and the product heated to remove residual alcohol and water and finally blown with an inert gas.  The oil concentrate is diluted with an inert gas. The oil concentrate is diluted with lubricating oil or other oleaginous liquid for use. In examples: (1) extracted pale coastal oil is treated with oleum at 70 DEG  C., acid-sludge removed and the acid-oil diluted with a neutral oil, treated with a filter-aid to remove pepper sludge and air-blown, after which oil-soluble sulphonic acids (combining weight above 400) are extracted with 50 per cent aqueous isopropanol, the extract is mixed with pale coastal oil and Ba(OH)2.8H2O added with stirring, giving a mineral oil layer on settling containing 30 per cent barium sulphonates to which additional barium hydroxide is added and the concentrate is finally dried; (2) the alcohol extract of (1) is mixed with pale oil, Sr(OH)2.8H2O is added with stirring and then the temperature is raised and hot water added; on settling, the oil layer is removed, additional strontium hydroxide added and the resulting 30 per cent concentrate dried; (3) a similar isopropanol extract of a sulphonic acid (combining weight 524) is treated with Ba(OH)2.SH2O by the method of (2), a silicone fluid being added during the final drying to prevent foaming; (4) an isopropanol extract of a sulphonic acid (combining weight 420) obtained from a pale oil in a manner similar to that of (1) is also treated with Ba(OH)2.SH2O by the method of (2); (5) the alcohol extract of (4) is heated under reflux with calcium carbonate, filtered, the resulting solution of calcium sulphonates in 50 per cent alcohol mixed with pale coastal oil, heated and hot water added whereupon an oil layer of sulphonate is formed; some calcium hydrate is added to the oil concentrate to provide excess alkalinity.  In place of isopropanol, there may be used n-propyl, n-butyl and isobutyl alcohols.  Specifications 587,624, [Group III], and 613,424 are referred to.  The Specification as open to inspection under Sect. 91 is not limited to the use of those sulphonic acids having a combining weight of at least 400. This subject-matter does not appear in the Specification as accepted.ALSO:A mineral oil concentrate of oil-soluble alkaline earth metal sulphonates is prepared by a process which comprises the steps of contacting a sludge-free sulphuricacid treated mineral oil, containing oil-soluble sulphonic acids of at least 400 combining weight, with an aqueous solution of an aliphatic alcohol to extract said acids, separating and adding mineral oil to the alcohol extract thus formed, neutralizing the sulphonic acids therein with a basic alkaline earth (including magnesium) compound, adding water in such amount that, on layer separation of an oil layer and an aqueous alcohol layer, a solution of alkaline earth metal sulphonates in the oil layer is produced, and adjusting the amount of the added mineral oil so as to yield a final mineral oil concentrate containing at least 20 per cent, preferably 30-70 per cent, by weight of sulphonates based on the total weight of the concentrate.  In one modification the neutralizing agent used is a calcium compound and the neutralization of the sulphonic acids in the extract is effected prior to the addition of mineral oil to the extract whereby a solution of calcium sulphonates in aqueous alcohol is produced, to which mineral oil and water are added as above.  In a further modification, the neutralizing agent is a barium compound and the concentration of water in the aqueous alcohol employed to extract the acids is such that a solution of barium sulphonates in the oil layer is produced by neutralization of the acids without the addition of water.  The sulphonates are preferably prepared by treating a mineral oil to obtain a maximum of the higher oil-soluble sulphonic acids followed by treatment with finely divided filter-aid and filtration to remove impurities and then air-blowing to remove SO2.  The extraction of the sulphonic acids is preferably effected with an aqueous solution containing 40-60 per cent of an aliphatic alcohol, the amount of solution being such that the alcohol extract contains about 10 per cent of sulphonic acids.  The neutralizing agents may be added in solid form or saturated solution, or used dissolved in sufficient water that the steps of neutralization and addition of water are combined in the single operation.  The water addition to effect transfer of the sulphonates from the aqueous alcohol to the added mineral oil is generally such as to reduce the alcohol concentration of the alcoholic solution to 25-35 per cent, though the barium sulphonates are readily precipitated from 50 per cent aqueous alcohol solution.  Formation of an oil layer containing the sulphonates is facilitated by heating to about 70-80 DEG C.  The oil layer is then removed, additional alkaline earth metal hydroxide or carbonate added, if desired, to provide excess alkalinity and the product heated to remove residual alcohol and water and finally blown with an inert gas.  The oil concentrate is diluted with lubricating oil or other oleaginous liquid for use. In examples: (1) extracted pale coastal oil is treated with oleum at 70 DEG C, acid-sludge removed and the acid-oil diluted with a neutral oil, treated with a filter-aid to remove pepper sludge and air-blown, after which oil-soluble sulphonic acids (combining weight above 400) are extracted with 50 per cent aqueous isopropanol, the extract is mixed with pale coastal oil and Ba(OH)2.8H2O added with stirring, giving a mineral oil layer on settling containing 30 per cent barium sulphonates to which additional barium hydroxide is added and the concentrate is finally dried; (2) the alcohol extract of (1) is mixed with pale oil, Sr(OH)2.8H2O is added with stirring, and then the temperature is raised and hot water added; on settling, the oil layer is removed, additional strontium hydroxide added and the resulting 30 per cent concentrate dried; (3) a similar isopropanol extract of a sulphonic acid (combining weight 524) is treated with Ba(OH)2.8H2O by the method of (2) a silicone fluid being added during the final drying to prevent foaming; (4) an isopropanol extract of a sulphonic acid (combining weight 420) obtained from a pale oil in a manner similar to that of (1) is also treated with Ba(OH)2.8H2O by the method of (2); (5) the alcohol extract of (4) is heated under reflux with calcium carbonate, filtered, the resulting solution of calcium sulphonates in 50 per cent alcohol mixed with pale coastal oil, heated, and hot water added, whereupon an oil layer of sulphonate is formed; some calcium hydrate is added to the oil concentrate to provide excess alkalinity.  In place of isopropanol there may be used n-propyl, n-butyl and isobutyl alcohols.  Specifications 587,624 and 613,424 are referred to.  The Specification as open to inspection under Sect. 91 is not limited to the use of those sulphonic acids having a combining weight of at least 400.  This subject-matter does not appear in the Specification as accepted.