PROCESS FOR PREPARING OVERBASED OIL SOLUBLE MAGNESIUM SALTS

Abstract: A process for preparing an over-based, oil-soluble mag­ nesium salt of a sulphonic acid comprises contacting an acidic gas in the presence of a promoter system with a mixture of an oil-soluble magnesium salt of a sulphonic acid, a light mag­ nesium oxide and an inert diluent. The promoter system comprises (1) a carboxylic compound selected from the group of compounds consisting of lower carboxylic acids, lower carboxylic anhydrides, substituted lower carboxylic acids, and metal salts and esters of lower carboxylic acids, (2) water, and optionally (3) a lower alkanol or lower alkoxy alkanol. The reaction is carried out at a temperature ranging from approx­ imately 10°C (50°F) up to reflux temperature of the mixture. The volatile components are stripped from the reaction mix­ ture after absorption of the acidic gas is at a desired level to give an over-based, oil-soluble magnewium salt of the sul­ phonic acid.

Description: h process for preparing over-based, oil-soluble magnesium salts. This invention relates to over-based, oil-soluble magnesium salts of sulphonic acids having metal ratios ranging from approximately 10 up to approximately 40 and processes for preparing such over-based magnesium salts of sulphonic acids. Over-based, oil-soluble magnesium salts of sulphonic acids are used as additives in oil-based compositions, such as lubricants, greases, fuels, and the like. ¯ They function as detergents and acid neutralizers, thereby reducing wear and corrosion and extending the engine life. Highly basic magnesium salts of a sulphonic acid having a metal ratio of equivalents of magnesium to equivalents of sulphonic acid ranging from 10 up to 40 or more, particularly the higher metal ratios of 20 to 40 have been difficult to prepare in a one-step operation using #gO as a Mg source. In systems previously described, either insufficient magnesium was dispersed or an unfiltered product resulted. It has been discovered that over-based magnesium sulphonates may be prepared in a one-step operation by using a reaction promoter system comprising (1) a carboxylic compound selected from the group of compounds consisting of lower carboxylic acids, lower carboxylic anhydriaes, substi tuted lower carboxylic acids, metal salts and esters of lower carboxylic acids and mixtures thereof, all having from 1 to 5 carbon atoms; (2) water and optionally (3) an alcohol selected from the group of compounds consisting of lower alkanols, lower alkoxy alkanols and mixtures thereof, all having from 1 to 5 carbon atoms. Such a promoter system gives a high quality over-based magnesium sulphonate having very high metal ratios which is suitable for use in various types of oil-based compositions. It is therefore an object of the invention to provide a process for manufacturing oil-soluble, over-based magnesium salts of sulphonic acids having metal ratios ranging from approximately 10 and upwards to approximately 40 or more where the product is prepared in a one-step operation of contacting the reaction mixture with an acidic gas. It is a further object of the invention to provide a reaction promoter system for use in processes for manufacturing oil-soluble, over-based magnesium salts of sulphonic acids having metal ratios of 10 up to 40 or more. It is another object of the invention to provide a process for preparing a magnesium salt of a sulphonic acid having very high metal ratios wherein over-basing of the sulphonic acid is accomplished by using a promoter system in combination with a light form of magnesium oxide. This invention provides a reaction promoter system for use in the manufacture of an over-based, oil-soluble magnesium salt of a sulphonic acid having metal ratios of from approximately 10 up to approximately 40 or more, in a one-step operation of contacting an acidic gas with a mixture containing the sulphonic acid to be over-based. According to the present invention there is provided a process for preparing an over-based oil soluble magnesium salt of a sulphonic acit having a metal ratio of equivalents of magnesium to equivalents of sulphonic acid of from approx - mately 10 to approximately 40; comprising contacting an acidic gas with a mixture comprising: (a) an oil-soluble magnesium salt of a sulphonic acid1 (b) from approximately 10 equivalents up to approximately 40 equivalertm of a light magnesium oxide per equivalent of sulphonic acid, (c) a promoter system comprising: : (1) from approximately 0.5 to approximately 5 eouinalents of an essentially oil-insoluble carboxylic compounc per equivalent of Eulphonic acid, said compound being selected from the group of compounds consisting of lower carboxylic acids, lower carboxylic anhydrides, substituted lower carboxylic acids, and mixtures thereof, all having from 1 to 5 carbon atoms, -(2) from approximately 2 to approximately 30 equivalents of water per equivalent of sulphonic acid, and (3) from 0 to approximately 35 equivalents of an alcohol per equivalent of sulphonic acid, said alcohol being selected from the group of components consisting of lower alkanols, lower alkoxy alkanols and mixtures thereof, all having from 1 to 5 carbon atoms, and ( ) an inert solvent for lowering the viscosity of said mixture to facilitate mixing; said contacting being conducted at a temperature ranging from approximately 1000 (500F) up to reflux temperature of said mixture and the volatile components being stripped from the reaction mixture after absorption of the acidic gas by the reaction mixture is at a desired level to give an over-based, oil-soluble magnesium salt of a sulphonic acid. The reaction mixture may be filtered either before or after the stripping of the volatile components to give the product in solution or in concentrated form. Additional water and/or alcohol may be added continuously or portion-wise to the reaction mixture during the time that the acidic gas is contacted with the mixture. The amount of water used in total should not exceed 30 equ{va- lents per equivalent of sulphonic acid and the total amount of alcohol used should not exceed 35 equivalents per ¯rliva- lent of sulphonic acid. The aforementioned, and other objects, advantages a@ features of the invention will become apparent in the following detailed discussion of preferred embouiments accor#.\±# to this invention. It is understood that the followin, preferred embodiments are not to be interpreted as li#¯ing the scope of the invention. Promoter System The essentially oil-insoluble carboxylic compound i represeated by the formula: XCOOY wherein x is H, -CH2OF, -CH2Cl, -OE2#r, -OH2C0CR3, i or RNH2 and Y is E, R, or E where R is an alkyl radial of from n to 4 carbon atoms, the sum of all the carbo atoms in the R radicals not exceeding 5, and Mn is an a@ali or alkaline earth metal atom wherein n is an intege# .Jf 1 or 2. Preferred oil-insoluble carboxylic compounds of his inven- tion are acetic acid, propionic acid, butanoi@@@id, glycine, chloroacetic acid, bromoacetic acid, glyolic acid, ethyl ac#toacetate, sodium acetate, calcium Fetate, and magnesium acetate. These compounds may be ued individually or in combination with one another where tn amount of this promoter ranges from .5 up to 5 equivalent per equivalent of oil-soluble sulphonic acid. Preferab#' the amount ranges from 0.7 to 1.3 equivalents. It *8 been found in most instances that if over 5 equivalen@ of the promoter are used, the reaction mixture becomes@ery viscous and although a product is obtained, the vJcosity of the mixture makes the isolation of the product @@ the introduction of acidic gas into the mixture during @e latter part of the process difficult. The initial reaction mixture should have at least 2 equiva- lents of water per equivalent of sulphonic acid. The mix- ture may have up to 15 equivalents of water where the preferred range in the initial mixture is from 2 to 8 equivalents of water per equivalent of sulphonic acid. Although the mechanism of the reaction is not fully understood1 it is theorised that the presence of water in the reaction mixture initiates absorption of the acidic gas by the reaction mixture. There is, however, a competing reaction for the water in the formation of hydroxides of the magnesium oxide. It is therefore preferred to minimise the reaction of water with the magnesium oxide by carryice out additions of small amounts of water to the reaction mixture during the time that the acidic gas is contacted with the reaction mixture so as to ensure that water is available in the system to promote the absorption of the acidic gas. The amount of water used determines to a certain extent the value of the metal ratio in that higher amounts of water used gives a higher metal ratio; however, with higher amounts of water, there is usually a resultant haziness in the product. On the other hand, a deficiency of water causes higher viscosity in the reaction mixture and a lower metal ratio. The total amount of water added to the mixture over the entire reaction time should not exceed 30 equivalents per equivalent of oil-soluble sulphonic acid used. The optimum amount of water to be used is determined by the amount of magnesium oxide used and the metal ratio desired because a larger amount of water results in a product having a higher metal ratio. Depending upon the end use of the product, it may be acceptable for the product to be hazy if used, for example, in bunker fuel oils and the like; however, higher clarity products are required in lubricating oils. The alcohols used in this process include lower aliphatic alkanols, alkoxy alkanols, and mixtures thereof, where the number of carbon atoms does not exceed 5. Examples of the alcohols include methanol, ethanol, isopropanol, n-propÅanol, butanol, and pentanolt The preferred alcohol is methanol because of the low cost and ease of removal from the reaction mixture. Examples of the alkoxy alkanols include methoxy ethanol and ethoxy ethanol. In order to initiate absorption of the acidic gas in the reaction mixture, it is not necessary to have an alcohol present in the initial mixture. It is believed, however, that the primary function of the alcohol is to promote the stability of the colloidal dispersion of magnesium salts in the oil. To this end there may be none or a small amount of alcohol in the initial reaction mixture and during the contacting with the acidic gas further amounts of alcohol are added either separately or in combination with the addition of water. It nas been found that lower metal ratios result if the total amount of alcohol to be added exceeds 35 equivalents per equivalent of sulphonic acid. The preferred amount tr be used ranges from 4 to 20 equivalents per equiv- alent of sulphonic acid. SulDhonic Acids The suiphonic acids to be used in this process are those which are widely known by thole skilled in the art as oilsoluble sulphonic acids. Such compounds may be derived from natural petroleum fractions or various synthetically prepared sulphonated compounds. Typical oil-soluble sulphonic acids which may be used include: alkane sulphonic acids, aromatic sulphonic acids, alkaryl sulphonic acids, aralkyl sulphonic acids, petroleum sulphonic acids such as mahogany sulphonic acid, petroleum sulphonic acid, paraffin wax sulphonic acid, petroleum naphthene sulphonic acid, polyalkylated sulphonic acid, and other types of sulphonic acids whiCh may be obtained by fuming sulphuric acid treatment of petroleum fractions. It is understood, of course, that mlxtllres of the sulphonic acids may be used in preparing an over-based magnesium Maphonate. The process according to this invention is operative with low sulphonate concentrations which thereby allows the use of oil-based feed stock compositions containing as little as 10% by weight of magnesium sulphonate without further concentration of the oil-based stock. Acidic Gas As is appreciated by those skilled in the art, various types of acidic gases may be used in over-basing magnesium sulphonates. The preferred acidic gases are carbon dioxide, sulphur dioxide, nitrogen dioxide, and hydrogen sulphide. These gases are bubbled through the reaction mixture as it is being mixed so that the selected gas or gases become intimately mixed and in contact with the components of the reaction mixture. The temperatures at which the contacting of the gas with the reaction mixture according to a preferred embodiment may vary from 10 to 93.3 C (50 to 200 F), although preferably within the 48.9 to ?6.?oC (120 to 1700F) range. Magnesium Oxide The type of magnesium oxide used in a preferred embodiment of the process is the light or active form. Such magnesium oxides are sold under the Trade Marks: MAGNESITE, available from Martin Marietta Chemicals, Hunt Valley, maryland; MICHIGAN No. 3, MICHIGAN No. 15, MICHIGAN No. 340, available from OSchigan Chemical Corporation, Chicago, Illinois; DOW I-2, DOW C-1, available from Dow Chemical Co., Midland, Li chigan; ELASTOMAG 170, and ELASTOItiAG 20, available from M rton Chemical Co., Chicago, Illinois; MAGLITE Y, available from Whittacker, Clark and Daniels, South Plainfield, New York; LYCAL 93/?11, and LYCAL 9O/575 available from Pigment and Chemicals, Toronto, Canada; and MAGOX PREI#IU?:1 available from Basic Chemical, Cleveland, Ohio. The amount of magnesium oxide used is dependent upon the metal ratio desired in the final product. The metal ratio is the ratio of the number of equivalents of magnesium in the over-based compound to the equivalents of sulphonic acid in the over-based compound. Therefore, to obtain a metal ratio of, for example, 30, there must be at least thirty equivalents of magnesium oxide per equivalent of sulphonic acid in the initial reaction mixture. It is apparent that when the reaction is carried out under less favourable conditions at lower efficiencies, an excess of magnesium oxide beyond that determined by the metal ratio should be used to ensure sufficient incorporation of magnesium with the structure of the over-based magnesium salt of the sulphonic acid. Inert Diluents Several different types of volatile and non-volatile diluents may be used in this process. The non-volatile diluents are generally mineral or synthetic lubricating oils, such as lubricating oils having a viscosity around 100 SUS at 37.800 (100 F) or higher. The volatile diluents which are inert to the reaction are preferably hydrocarbons with boiling points ranging from 65.6 to 148.900 (150 to 3000F). These can be aliphatic, aromatic, or a mixture of both types-of solvents. Por example, naptha is a particularly useful diluent. Other types of suitable diluents include Stoddard solvent, cycloaliphatic and aromatic hydrocarbons, and corresponding halogenated hydrocarbons, such as chlorobenzene, and other conventional organic diluents generally employed in the over-basing procedures in this particular art of manufacture The amount of diluents used is sufficient to lower the visl cosity of the reaction mixture to facilitate mixing thereof during the introduction and contacting of the acidic gases with the mixture. The length of time that the acidic gas is contacted with the reaction mixture depends upon the desired level of magnesium in the over-based magnesium sulphonate. The contacting of the gas with the mixture may be continued until no further gas is absorbed to indicate that substantially all of the magnesium oxide originally introduced into the system has been reacted to form an over-based magnesium sulphonate. To determine wben the absorption of the gas is complete, the flow rate of the acidic gas being introouced is compared to the flow rate of the gas leaving the system. When the flow rate of leaving gas almost equals the flow rate of the in trounce gas, then the absorbtion is substantially complete. As can be appreciated by those skilled in the art, impurities and other variations in the selected petroleum feed stocks and magnesium oxides, according to this inventions can cause the resultant product to have slightly different metal ratios than that achieved in the following examples. These examples are intended to illustrate various aspects of the invention and are notintended to limit the scope of the invention in any way. Preparation 1 An oil-soluble magnesium sulphonate was prepared by charging into a I litre reactor, equipped with stirrer, dropping funnel, thermometer, cooling and vent, 310 gm. of a solvent refined lubricating oil having a viscosity of 330 SUS at 37¯8 C (100 F) and while stirring vigorously, 103 gm. of 25 percent by weight oleum was added dropwise over a half hour period. The temperature was maintained at 32.2 to 43.30C (90 to 110 F). The mixture was stirred for an additional 10 minutes and then quenched with 25 gm. water, 310 gm. WM#P naphtha was added and the mixture allowed to settle in a separatory funnel for 3 hours; 80 gm. spent acid wss separated and removed. The organic naphtha layer was washed with 120 gm. pater and the aqueous lower yellowish layer was separated and discarded. To the upper sulphonic acid/naphtha layer was added 100 gin. water, 10 gm. methanol and 8 Em- magnesium-oxide. The mixture was stirred at 600C (140 F) effecting neutralisation of the sulphonic acid and allowed to stand. The bottom aqueous layer wnich separated was discarded and the naphtha layer was stripped of solvent and water to give a 30 wt.% solution of magnesium sulphonate in oil. Example 1 Into a 1000 ml. flask fitted with mechanical stirrer, thermometer, condenser, dropping funnel and a course cylindrical dispersion tube were charged 85 gm. of the magnesium sulphonate of Preparation 1, 25 gm. lubricating oil of 100 SUS viscosity at 37.8 C (1000F), 140 gm. naphtha and 30 gm. magnesium oxide (MAGNESITE No. 569). The mixture was heated to 54.40C (1300F) and 6 gm. magnesium acetate was added. Heating was continued, and at 600C (140 Z) a mixture of water/methanol of 20 gm/16 gm. respectively '.#s added dropwise through the dropping funnel over a period of 66 minutes. At the same time carbonation was initiated at 75 ml/ min. and continued for 3 hours The product of carbonation was then filtered with the aid of diatomaceous filter aid. Water, methanol and naptha were then stripped off by heating to 204.4 C (4000P) leaving a product which was clear and bright with a magnesium content of 9.2% which is equivalent to a metal ratio of 27.0. Example 2 The following reagents were mixed together in a 1000 ml blask fitted with mechanical stirrer, thermometer, condenser and a course cylindrical dispersion tube: 137g naphtha (3.P. 115.6#143.30O (240-290 Z)) 8g methanol. 4g water 32g lubricating oil 100 gm magnesium sulphonate solution made up of 455 magnesium sulphonate, 42% lubricating oil, and 139 naphtha. The sulphonic acid used to make the magnesium sulphonate is a straight chain alkyl benzene sulphonic acid of molecular weight about 500 which may be obtained from Continental Oil 30g magnesium oxide sold under the Trade Yiark MAGNESIA1 No. 569 available from Martin Marietta Co. (USA) and 5.25g glacial acetic acid. The mixture was heated near its reflux temperature 65.6 C (150 F) and carbon dioxide was introduced while mixing via the dispersion tube into the mixture at a flow rate of 100 Crbonation was continued for 2-1/2 hours, during which 8 gm. water and 8 gm. methanol were added after 40 minutes of carbonation and further 4 gm. of water and 8 gm. methanol were added after 80 minutes of carbonation. The product of the carbonation was filtered with the aid of diatomaceous filter aid. The volatile components of solvent water, methanol and naphtha were stripped off by beating to 204.4 C (400 F). h stream of C02 was introduced to the heated mixture to remove the last traces of solvents. The final product thus obtained was aclear and bright oil soluble solution which contained 9.4% by weight magnesium, 26.5% by weight magnesium sulphonate and had a viscosity of 525 SUS at 96.9 C (2I00F). he metal ratio of the product was 14.8. Exaintle 3 This example illustrates the effect of temperature during carbonation. The exact procedure of Example 2 was followed except that the mixture was maintained at 32.2 to 43.300 (90 to 1100F) during carbonation. The final product was a clear and bright oil soluble solution which contained 6.9N by weight magnesium, 26.9% by weight magnesium sulphonate. The metal ratio of the product was 10.7. Examples 4 to 7 The results of a series of experiments are listed in T#ble 1 which illustrates the effect on the metal ratio in varying the amounts of methanol and water used during the carbonation step. The procedure is as for Example 2 with water/ methanol additions made at 0, 40 and 80 minutes during the carbonation step. TABIE 1 Example Time of Water Methanol Metal % Mg.by Appearance Water/ gin. gin. Ratio Wt. of ethanol Product Addition During Carbonation Minutes 4 0 8 16 16.3 9.8 Hazy 40 8 8 80 8 8 5 0 4 16 15.7 9.4 Hazy 40 8 8 80 8 8 6 0 4 8 16.3 9.8 Hazy 40 8 8 80 & 8 8 7 0 4 8 16.0 9.7 Bright and Fluid 40 8 8 80 4 6 Examples 8 to 11 Table 2 summarizes results of a series of experiments which illustrate the effect of adding the water/methanol at dif ferent time intervals. The procedure used in each experi ment is similar to that used in Example 2. TABLE 2 Example Time of Water Methanol Metal % Ug.by Appearance Water/ gm. gm. Ratio Wt. of Methanol Product Addition During Carbonation Minutes 8 0 4 8 15.5 9.3 Slight Haze 30 8 8 60 4 8 9 0 4 8 155 9.3 Bright and fluid 40 8 8 80 4 8 10 0 4 8 14.7 8.8 Bright and fluid 50 8 8 100 4 8 11 0 4 8 14.2 8.5 Bright and Fluid 60 8 8 120 4 8 EXamples 12 to 23 This series of experiments illustrate the effect of the amount of promoter used in terms of product quality. The results of these experiments are summarised in Table 3. The procedure for each experiment is similar to that used in Example 2. TABLE 3 Example Promoter: No. of Metal high by Appearance #Viscosity Equivalents of Ratio Wt. of SUS (AcOH) per Product 98.9 C Equivalent of (210 F) Sulphonic Acid ¯¯¯¯¯ ¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯ 12 0 .5 -- Bright 13 .51 13.6 -- Bright - 14 .68 15.5 9.3 Bright 750 15 .68 15.5 9.3 Bright 1200 16 .68 15.5 9.3 Bright 1700 17 1.02 15.7 9.4 Bright 525 18 1.02 15.8 9.5 Bright 560 19 1.02 15.7 9.4 Bright 525 20 1.56 16.0 9.7 Bright 630 21 1.56 16.3 9.8 Bright 660 22 1.56 15.7 9.4 Bright 500 23 1.87 15.7 9.4 Hazy Viscous gel Examples 24 to 29 Table 4 summarises the results of a series of experiments which illustrate the use of different promoters. All conditions of the procedure in each experiment are similar to that used in Example 2 except for using an equivalent molar amount of the different promoters as listed. TABlE 4 Example Promoter Netal Appearance Ratio 24 Acetic Acid 16.3 Bright,clear;fluid product 25 Glycine 14.7 Bright,clear;fluid product 26 Formic Acid .7 Hazy; fluid 27 Ammonium Acetate -- Did not absorb CO2 28 Benzoic Acid 10.9 Viscous to solid 29 Ethylene Diamine 11.2 Bright, clear; fluid Diformate Examples 30 to 33 These examples illustrate how the sulphonic acids affect the product quality when using this process for production of magnesium containing lubricating oils. The results of the experiments are summarised in Table 5. The procedure of each experiment is similar to that used in Example 2. TABIS 5 Example Source of Basic Structure Netal Appearance magnesium & Approximate Ratio Sulphonate Molecular Weight Used 30 prepared from Straight Chain 16.0 Clear1 bright; Union Carbide Alkyl Benzene fluid "Ucane H.A." M.W. 410 31 prepared from Straight Chain 16.5 Clear1bright; ; Continental Alkyl Benzene fluid Oil D 26 #.W. 400 Alkylate 32 Esso France Branched Chain 15.8 Very viscous, SA 119 Alkyl Benzene heat promotes approx.M.W.430 viscosity in crease until product became solid 33 Edwin Cooper Straight Chain 15.7 low viscosity Sulphonic Alkyl Benzene product,slight acid l '. 380 haze in hexane solution Examples 34 to 46 The results of these experiments are summarised in Table 6 to illustrate the effect on the product obtained by using different commercially available magnesium oxides. The procedure in each experiment is similar to that of Example 2. TABLE 6 Example Source of Metal Magnesium Oxide Ratio Appearance 34 Magnesite 369 17.4 Viscosity increase during reaction;product very hazy 35 Maagnesite 569 17.1 Bright and fluid 36 Michigan No.3 17.3 Viscous during reaction 37 michigan No. 15 Solidifies during reaction 38 Dow 1-2 18.6 Increase in viscosity during reaction; product hazy 39 Dow C-1 14.5 Viscosity increase during initial stage or reaction; product excellent 40 Elastomag 170 16.7 Viscosity increase during initial stages of reaction; product hazy 41 X,agox Premium Solidifies during reaction 42 Licothion Tab Viscosity increase during (China) reaction; solidifies on stripping 43 Elastomag 20 17.8 Viscosity increase during initial stage of reaction; product hazy 44 X,aglite Y 16.9 Hazy product 45 Lycal 93/711 12.2 Product hazy 46 Local 96/575 Solidifies during reaction Examples 47 to 49 These experiments illustrate the use of different lower alcohols in the procedure of Example 2. The results of the experiments are summarised in Table 7. TABLE 7 Example Alcohol Netal Appearance Ratio 47 Isoproponal 12 Slight haze,and fluid product N-pentanol 8 Slight haze,and fluid product 49 Methoxy ethanol 12 Hazy and fluid product It can be appreciated from the results of these experiments that high quality, over-based magnesium salts of sulphonic acids may be manufactured and used as additives in lubricating oils, greases and other types of oil-based products, such as fuel oils, bunker oils, etc., where the metal ratio of the additives are in the range of 5 to 40. The products are permanently soluble in many organic environments and therefore find application as additives in the field of lubricants and fuels. Although various preferred embodiments of the invention have been described herein in detail, it will be appreciated by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims: C#A1I#iS': 1. A process for preparing an over-based oil-soluble magnesium salt of a siipionic acid having a metal ratio of equivalents of magnesium to equivalents of sulphonic acid of from approximately 10 to approximately 40; comprising contacting an acidic gas with a mixture comprising: (a) an oil-soluble magnesium salt of a sulphonic acid, (b) from approximately ten equivalents up to approximately 40 equivalents of a light magnesium oxide per equivalent of sulphonic acid, (c) a promoter system comprising: : (1) from approximately 0.5 to approximately 5 equivalents of an essentially oil-insoluble carboxylic compound per equivalent of sulphonic acid, said compound being selected from the group of compounds consisting of lower carbox ylic acids1 lower carboxylic anhydrides, substituted lower carboxylic acids, and mix tures thereof, all having from 1 to 5 carbon atoms, (2) from approximately 2 to approximately 30 equiv alents of water per equivalent of sulphonic acid, and (3) from 0 to approximately 35 equivalents of an alcohol per equivalent of sulphonic acid, said alcohol being selected from the group of compon ents consisting of lower alkanols, lower alkoxy alkanols and mixtures thereof, all having from n to 5 carbon atoms, and (d) an inert solvent for lowering the viscosity of said mixture to facilitate mixing; ; said contacting being conducted at 2 temperature ranging from approximately d0 C (50 B) up to reflux temperature of said mixture and the volatile components being stripped from the reaction mixture after absorption of the acidic gas by the reaction mixture is at a desired level to give an over-based, oil-soluble magnesium salt of a sulphonic acid. 2. A process according to Claim 1 wherein said contacting is carried out at a temperature of from 100C to 93.30C (500F to 2000F). 3. h process according to Claim 2 in which said contacting is carried out at a temperature of from 48.90C to 76.70C (1200F to 1700F). 4. 4# A process according to Claim 1, 2 or 3 in which the acidic gas is contacted with the mixture until absorption of the gas by the mixture is esseotielly complete. 5. A process according to any one of the preceding claims in which the promoter system includes from approximately 0.5 to approximately 3 equivalents of the essentially oil-insoluble carboxylic compound per equivalent of sulphonic acid. 6. A process according to any one of the preceding claims wherein approximately 0.7 to 1.3 equivalents of the carboxylic compound are used. A A process according to any one of the preceding claims wherein the initial amount of water is less than 30 equivalents and additional water is added to the mixture during the time that acidic gas is contacted with the mixture to bring the total amount of water used to not more than 30 equivalents per equivalent of sulphonic acid. 8. A process according to any one of the preceding claims wherein an initial amount of selected alcohol is present in said mixture sufficient to initiate absorption of the acidic gas and an additional amount of alcohol is added to said mixture during the time that the acidic gas is contacted with the mixture to bring the total amount of alcohol used to not more than 35 equivalents per equivalent of sulphonic acid. 9. A process according to any one of the preceding claims wherein said acidic gas is selected from the group consisting of carbon dioxide, sulfur dioxide hydrogen sulfide and nitrogen dioxide. 10. h process according to any one of the preceding claims wherein said acidic gas is carbon dioxide. 11. A process according to any one of the preceding claims wherein the amount of water present in the mixture prior to contacting the mixture with acidic gas ranges from approximately 2 to approximately 15 equivalents. 12. h process according to any one of the preceding claims wherein the amount of water present in the mixture prior to contacting the mixture with carbon dioxide gas ranges from approximately 2 to approximately 8 equivalents. 13. X process according to any one of the preceding claims wherein the total amount of alcohol used ranges from approximately 4 to approximately 20 equivalents. 14. h process according to any one of the preceding claims wherein said alcohol is selected from the group consisting of methanol, ethanol, isopropanol, n propanol, butanol, pentanol, methoxy ethanol, and thoxy ethanol. 15. A process according to any one of the preceding claims wherein said carboxylic compound is represented by the formula: XCOOY wherein X is H, -Ch20#, -CX2Cl, -CX2Br, -CH2COCH31 R, or and andY is H, R, or Iln where R is an alkyl radical of from 1 to 4 carbon atoms, the sum of all the carbon atoms in the R radicals not exceeding 5 and Nn is an alkali or alkaline earth metal atoms wherein n is an integer of from 1 to 2. 16. A process according to Claim 15 wherein said carboxylic compound is selected from the group consisting of acetic acid, propionic acid, butanoic acid, glycine, chloroacetic acid, bromoacetic acid, glycolic acid, ethyl acetoacetate, sodium acetate, calcium acetate, magnesium acetate and mixtures thereof. 17. An overbased, oil-soluble magnesium salt of sulphonic acid having a metal ratio of from approximately 10 up to approximately 40 prepared by the process according to any one of the preceding claims.

Inventors: ELIADES, THEO IOANNOU, HORNER, JAMES DONALD, MUIR, RONALD JOHNSTON
Applicants: SURPASS CHEMICALS LIMITED
Application year: 1978
Main classification: C07C143
IPC codes: C10M159