MXPA98003036A - Super base magnesium sulphonates - Google Patents

Abstract

A process for the production of over-based magnesium sulfonates, which makes it possible to prepare products with high base numbers, which have very low post-carbonation sediments, and which can be purified by rapid filtration.

Description

BASE-BASED MAGNESIUM SULPHONATES FIELD OF THE INVENTION The present invention relates to a process for the production of over-based magnesium sulfonates, and to over-based magnesium sulfonates prepared by the process. In particular, the present invention relates to over-based magnesium sulfonates prepared from high molecular weight sulfonic acids. The over-based magnesium sulfonates prepared by the process are particularly useful as additives for oil-based compositions, especially lubricating oils, and the invention also relates to oil-based compositions containing these super-based metal sulfonates. BACKGROUND OF THE INVENTION [0002] The super-based magnesium sulfonates are well known, as well as their use as additives in oil-based compositions, for example, lubricants, fats, and fuels. They work as detergents and acid neutralizers, thus reducing wear, and corrosion, and when used in engines, extend engine life. Many processes have been proposed for the production of overbased sulphonates, generally involving the preferred processes carbonation, in the presence of an organic solvent or diluent, of a mixture of an oil-soluble sulfonate and / or a sulfonic acid soluble in water. oil, and an excess of a previous desired metal compound that is required to react with any acid present. It is known that over-based magnesium sulphonates are generally more difficult to prepare than the corresponding calcium compounds, and the processes proposed for the preparation of the over-based magnesium sulfonates have involved different special measures, for example, the use of particular reaction conditions, and / or the incorporation of one or more additional substances in the mixture to be carbonated, including these additional substances, for example, water, alcohols and promoters of different types. It has proven to be particularly difficult to prepare super-based magnesium sulfonates from high molecular weight sulfonic acids. It is important that the over-based materials to be used as additives in oil-based compositions, such as lubricating oils and fuels, are clear liquids and are free of sediments. The product obtained at the end of the carbonation in the processes for the preparation of over-based magnesium sulphonates, will contain some undesired material (usually hard sediment and / or gelatinous material formed during the over-based process referred to as sediment after the carbonation (SPC) From an economic point of view, it is desirable to be able to remove in a fast and simple way, preferably by filtration, and it is also desirable that the amount of sediment that is to be removed is as low as possible. Gelatinous material, if present, will tend to inhibit or impede filtration by blocking the filter.Wherever purification by filtration is possible, it is desirably carried out as quickly as possible.If there are large amounts of sediment present, the sediment should normally be remove by centrifugation instead of filtration, and even small amounts of sediment may have a tendency to block the filters if the process is carried out on a large scale, this tendency being particularly noticeable if the system contains gelatinous material formed during the over-based process. It is desirable that the over-based materials to be used as additives, for oil-based compositions have a relatively high basicity. These are high base number additives. The terms "low base number" and "high base number", used to define sulfonates, should be understood in relation to ASTM D2896-88"Standard Test Method for Base Number of Petroleum Products by Potentiometric Acid Titration Perchloric. " This test method is related to the determination of the basic constituents in petroleum products, by potentiometric titration with perchloric acid in glacial acetic acid. The result of this test method is cited as a base number which is the base equivalence in milligrams of KOH g "1. Therefore the term" low base number "refers to the numerical values of the base number that are less than 50 milligrams of KOH g "1 and the term" high base number "refers to the numerical values of the base number that are greater than 50 milligrams of KOH g" 1, and may be as high as 400 milligrams of KOH g'1, or even higher than, for example, 600 milligrams of KOH g "1. For some applications, it is preferred that the base number be at least 350, preferably at least 380, and more preferably at least 400 milligrams of KOH g "1, as measured by ASTM D2896-88. High base number overbased materials, however, often result in significantly higher sediment levels at the end of the carbonation step, than the processes to produce low base number overbased materials. produce high base number sulfonates from synthetic high molecular weight sulfonic acids, ie, synthetic acids of average molecular weights of 500 or greater, which also have a low viscosity and low sediment levels (SPC). try with conventional processes, you get high viscosity products that have a base number lower than expected, and that may have unacceptable levels Highly sediment after carbonation, high viscosity, low filtration rate, or a combination of these deficiencies. The proportion of sediments in the reaction mixture immediately after carbonation (ie, before centrifugation or filtration to remove sediment) is usually referred to as the "post-carbonation sediment," or "SPC," and it is usually expressed as the volume percentage of sediments subsequent to carbonation based on the volume of the reaction mixture. When comparing the proportions of sediment in the different systems, it is important that the percentage of sediment after carbonation is calculated in comparable systems, preferably "purified" systems free of any volatile materials, for example, water, methanol, and solvents. , which are included in the reaction mixture for the purposes of the reaction, but which are not required in the final over-based product. In some processes, these volatile materials are not removed until after sediment removal, and therefore, the percentage of sediments after carbonation reported is based on the volume of a reaction system that still contains the volatile materials, but by an appropriate calculation, it is possible to arrive, for comparison purposes, at a value for the percentage of sediments after carbonation in a notional system free of volatile materials. When the above-based magnesium sulfonates are carbonated, the magnesium oxide and / or the magnesium hydroxide present are converted to carbonate. There are different carbonates that can be produced alone or mixed with one or more of others. These carbonates are natural artinite (MgC03 Mg (OH) 23H20), hydromagnesite (3MgC03Mg (OH) 2 3H20) and nesquehonite (MgC03 3H20). It is preferred for colloidal stability and low sedimentation that the carbonate present is predominantly hydromagnesite. When over-based magnesium sulphonates are prepared from low molecular weight sulfonic acids (from 400 to 500), the carbonation reaction appears to be self-limiting, such that most of the desirable carbonate, hydromagnesite, is preferred. It is formed at the end of carbonation. With very low molecular weight sulfonic acids (less than 300), which has high levels of solubility in water, the product is over-carbonated, and the undesirable form of nesquehonite predominates. When high molecular weight sulfonic acids are used in these conventional processes, artinite is produced during carbonation, which is undesirable. Up to now, it has not been possible to provide super-based magnesium sulfonates from high molecular weight sulfonic acids which at the end of carbonation predominantly contain the hydromagnesite form of magnesium carbonate. By removing the volatile solvents, a basic magnesium carbonate is formed, which is sterically stabilized in suspension by the magnesium sulphonate soap. Accordingly, there remains a need for a suitable process for the preparation of over-based magnesium sulphonates from high molecular weight sulfonic acids, and having a high base number, low levels of sediments subsequent to carbonation, and in where a relatively rapid filtration of the reaction product containing the sediment is possible. SUMMARY OF THE INVENTION Applicants have discovered, in a surprising manner, that, by using a partially or fully water soluble sulfonic acid, or a magnesium salt thereof, in the preparation of magnesium sulphonates based on From high molecular weight sulphonic acids, it is possible to ensure that, at the end of carbonation, practically all the magnesium oxide used in the process is converted to the desired hydromagnesite (3 MgC03Mg (OH) 2 3H20), and consequently, it is possible to prepare over-based magnesium sulphonates from high molecular weight sulfonic acids having a high base number, and low levels of post-carbonation sediments and acceptable filtration viscosities and rates. The amount of hydromagnesite or artinite produced can be determined by conducting a mass balance on the amount of CO 2 absorbed during carbonation, after allowing the amount of MgO consumed to react with the sulphonic acid load. For the hydromagnesite to be formed, each over-based magnesium molecule will react with 0.75 molecules of C02; for artinite to be formed each over-based magnesium molecule will only react with 0.5 molecules of C02. The amount of each can be easily determined by solving simultaneous equations, and then, after determining the amount of C02 absorbed, the amount of hydromagnesite and artinite can easily be determined by simple arithmetic. The use of a low molecular weight sulfonic acid which is partially or completely soluble in water, or a magnesium salt thereof, in the process of its manufacture, makes it possible to obtain magnesium sulphonates based on a high number of base, which have low values of percentages of sediments after carbonation, from sulfonic acids of high molecular weight. DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, there is provided a process for the production of an over-based magnesium sulfonate, which comprises the steps of: (i) carbonating a mixture comprising a mixture of at least the components (a) to (g), wherein: (a) is at least one high molecular weight sulfonic acid soluble in oil; (b) is at least a low molecular weight sulfonic acid that is totally or partially soluble in water, or a magnesium salt thereof; (c) it is magnesium oxide in excess of that required to react completely with component (a) and component (b); (d) is a hydrocarbon solvent. (e) it is water; (f) is a water soluble alcohol; and (g) is a promoter, and (ii) removing the volatile solvent from the mixture of step (i).

In the process of the present invention, the magnesium oxide can be reacted with the component (b) before the addition of the component (g), or the magnesium oxide can be mixed with the component (g) before the addition of the component (b) or component (a). Also, component (g) can be mixed with component (b) before the addition of component (a) and component (c). The present invention further provides an over-based magnesium sulfonate composition, from which no volatile solvents have been removed (eg, have not been purified), which comprises at least one magnesium sulphonate derived from an acid sulphonic high molecular weight oil soluble, and at least one magnesium sulphonate derived from a low molecular weight sulfonic acid which is totally or partially soluble in water, wherein at least 50 weight percent of the total sulfonate in the composition it is derived from the acid or high molecular weight sulfonic acids, and the magnesium carbonate in the composition is in its hydromagnesite form. This composition is the product produced at the end of the carbonation (step (i)), and before removing the volatile solvents (step (ii)). When the volatile solvents are removed, both C02 and H20 of the hydromagnesite are lost, and a sterically stabilized colloidal suspension of basic magnesium carbonate is formed. Accordingly, the present invention further provides an over-based magnesium sulfonate composition which comprises at least one magnesium sulphonate derived from a high molecular weight sulfonic acid soluble in oil, and at least one magnesium sulphonate derived from a low molecular weight sulfonic acid which is totally or partially soluble in water, and a stabilized colloidal suspension of basic magnesium carbonate, wherein at least 50 weight percent of the total sulfonate in the composition is derived from of high molecular weight sulfonic acid (s). The base number of the composition, for example, may be at least 400 milligrams of KOH g "1. It is preferred that the composition comprises at least 60 weight percent, based on sulfonate sulfonate derived from the acid high molecular weight sulfonic acid, and more preferably at least 75 weight percent of the metal sulfonate, preferably in the range of 50 to 92 weight percent, and more preferably 75 to 94 weight percent. it is preferred that the kinematic viscosity of the over-based magnesium sulfonate composition at 100 ° C be 700 centistokes (cS) or less, for example 300 cS or less, and more preferably 150 cS or less, and very preferably on the scale of 30 to 150 cS (1 cS = I0"6m2s" 1) The post-carbonation sediment of the resulting over-based magnesium sulfonate may be 2 percent or less, preferably 1.8 percent or less, more preferably 1 .6 percent, or less, and in some cases it can be 1 percent or less, based on a reaction system free of volatile materials. The fact that very low amounts of sediment can be obtained according to the invention is convenient from an ecological point of view when working on a large scale, since there is less wasted material to be discarded. The resulting over-based magnesium sulfonates are also rapidly filtered after removal of the solvent, typically at a rate of at least 150, preferably at least at a rate of 200 and especially at least 250 kg / m2 / hour. The products also have relatively low viscosities. The over-based magnesium sulfonate composition of the present invention, from which the volatile solvents have not been removed, can comprise at least 16 percent by weight, based on the total weight of the sulfonate composition. Even higher sulfonate compositions are possible in the composition. In accordance with the above, it is preferred that the composition comprises at least 20 weight percent sulfonate, more preferably at least 25 weight percent sulfonate. It is preferred that the sulfonate be present in the range of 16 to 30 weight percent, and more preferably in the range of 20 to 30 weight percent, based on the total weight of the composition. The term "high molecular weight oil soluble sulfonic acid" means an alkylsulfonic acid soluble in synthetic oil, or an alkarylsulfonic acid, the acid having a number average molecular weight greater than 500, preferably 600 or greater, such as 700. The high molecular weight sulfonic acid may be a single high molecular weight sulfonic acid, or may be a mixture of high molecular weight sulfonic acids, ie, a mixed sulphonic acid. The mixed sulphonic acid can be a mixture of different high molecular weight sulfonic acids. The number average molecular weight can be determined by available techniques, such as that described in ASTM D-3712. It is preferred that the high molecular weight sulfonic acid is an alkarylsulfonic acid, such as, for example, an alkylbenzenesulfonic acid, alkyl toluene sulfonic acid, or alkyl xylene sulfonic acid. It is also preferred that it be a mixed sulphonic acid of sulfonic acids of 15 to 60 carbon atoms + alkylbenzene, or 15 to 60 carbon atoms + alkylxylene, or 15 to 60 carbon atoms + alkyltoluene, or mixtures of two or more of these acids. Preferred high molecular weight sulfonic acids are those which are derived from aromatic alkylates prepared from polyolefins of 2, 3, or 4 carbon atoms, such as polyethylene, polypropylene, or normal polybutene. It is preferred that these be prepared from normal polybutene. When the sulphonic acid is a mixed sulphonic acid, and is derived from normal polybutene, it is preferred that it has a number average molecular weight of at least 600, and preferably from 600 to 700. It is also possible to replace something or all the high molecular weight acid with the acid-neutral magnesium sulfonate in the process of the present invention. However, it is preferred to use the acid in place of the neutral sulfonate in the process of the present invention. The total or partially water soluble sulfonic acid is preferably a low molecular weight alkaryl sulfonic acid, and more preferably is a mixture of sulfonic acids of 9 to 36 carbon atoms + alkylbenzene or alkyl toluene or alkylxylene substituted by alkyl. The alkyl group can be a branched or straight chain hydrocarbyl group that is free of heteroatoms such as oxygen and nitrogen. It is preferred that the total or partially water soluble sulfonic acid have a number average molecular weight of less than 500, preferably less than 490, and more preferably less than 450. It is preferred that the molecular weight be in the range of 300 to 490 , and preferably from 310 to 450, and more preferably from 320 to 400. The total or partially water soluble sulfonic acid may be a mixture of sulfonic acids wholly or partially soluble in water, for example, a mixture of chain alkylarylsulfonic acid Straight of 18 carbon atoms and 15 to 36 carbon atoms + branched chain alkylarylsulfonic acid. A particularly preferred water soluble sulfonic acid is a dodecylbenzenesulfonic acid of 10 to 14 carbon atoms, for example the commercially available sulfonic acids known as Sinnozon DBS, LAS-sirene 113, and branched Sinnozon TBP. "Totally or partially soluble sulfonic acid in water" means a sulphonic acid which, when stirred on contact with water, is completely miscible with water, forming a solution, or shows a significant degree of miscibility with water, so that some of the acid is transferred to the aqueous phase. In this context, a sulfonic acid partially soluble in water is preferably an acid having at least 5 weight percent transferred to the water phase when 100 grams of acid is stirred with 100 grams of water under ambient conditions. More preferably, at least 10 percent by weight is transferred, and more preferably at least 20 percent by weight is transferred. It is preferred that this sulfonic acid be fully soluble in water, and that it has an average molecular weight of less than 380, and more preferably in the range of 320 to 380. It is also possible to replace some or all of the total or partially soluble acid in water with the neutral magnesium sulfonate of the acid in the process of the present invention. However, it is preferred to use the acid totally or partially soluble in water instead of the neutral sulfonate in the process. The amount of total or partially soluble sulfonic acid in water used in the process of the present invention, depends in part on the solubility of the sulfonic acid. As the solubility decreases, greater amounts of total or partially soluble sulfonic acid in water are required. If too much sulfonic acid is used wholly or partially soluble in water, the neschegonite of the undesirable magnesium carbonate is formed. In the process of the present invention, at least 2 weight percent of the total or partially water soluble sulfonic acid must be used, based on the total weight of the sulfonic acid used, preferably at least 6 percent by weight is used. weight, and most preferably 6 to 25 weight percent is used. The above-based magnesium sulphonates to which the present invention relates, comprise a water solution of magnesium sulfonate, which acts as a surfactant to disperse the colloidal magnesium derivatives, for example carbonate, oxide, and / or the magnesium hydroxide. Therefore, it is important that the high molecular weight sulfonic acid be soluble in oil. The proportion of dispersed colloidal magnesium derivatives, such as carbonate, oxide, and / or magnesium hydroxide, in the above-based magnesium sulphonates, determines the basicity of the products. The magnesium oxide used as starting material is used in an amount sufficient to give the desired base number in the product. Conveniently, the magnesium oxide is used in a corresponding total amount of 1 to 45, preferably 1 to 25 equivalents of magnesium for each equivalent of sulphonic acid used, including both sulfonic acids used. The magnesium oxide can be any magnesium oxide. The relatively reactive forms of magnesium oxide are commonly known as "light", "active" or "burned caustic" magnesium oxides. These forms of magnesium oxide have a relatively low density, and a relatively high surface area, in contrast to the "heavy" or "dead burned" forms of magnesium oxide, which are relatively dense, and of a relatively low surface area, and they tend to be relatively chemically inert. The preferred magnesium oxides used in accordance with the invention are "heavy", or a mixture of "light" and "heavy". Preferably, the "heavy" magnesium oxide has a citric acid number (as hereinafter defined herein) greater than 200 seconds, and a surface area measured by the single-point BET method of less than 12 square meters / gram , the particle size being at least 92 percent by volume of the magnesium oxide greater than 2 microns. Preferably, the "light" magnesium oxide may be a portion of the mixture having a citric acid number less than 200 seconds, and a surface area greater than 12 square meters / gram. As defined herein, the citric acid number is the time in seconds required to neutralize, at 22 ° C, a stirred mixture of 1.7 grams of magnesium oxide, 100 milliliters of water, and 100 milliliters of a citric acid solution having 26 grams of citric acid monohydrate and 0.1 grams of phenolphthalein in 1 liter of solution watery Neutralization is indicated when the mixture turns pink. The citric acid number of the "heavy" magnesium oxide used according to the invention, conveniently is at most 700 seconds, and more conveniently is in the range of 200 to 600 seconds, preferably 400 to 500 seconds. The citric acid number of the "light" magnesium oxide is at most 200 seconds, and preferably it is in the range of 20 to 140 seconds. The single-point BET method for measuring the surface areas of particulate solids is described in Journal of Analytical Chemistry, Volume 26, Number 4, pages 734-735 (1954) - M. J. Katz, An Explicit Function for Specific Surface Area. The surface area, measured by this method, of the "heavy" forms of the magnesium oxide to be used according to the invention, is conveniently less than 10 square meters / gram, and preferably is in the range of 2 to 10 square meters /gram. The surface area of the "light" magnesium oxide is greater than 12 square meters / gram, and preferably is on the scale of 20 to 70 square meters / gram. The particle size of at least 92 percent by volume of the "heavy" magnesium oxide used according to the invention is greater than 2 microns. Conveniently, at least 94 percent by volume of the magnesium oxide has a particle size greater than 2 microns. Preferred magnesium oxides according to the invention preferably have a purity, measured by titration of ethylenediaminetetraacetic acid, of at least 95 percent. In the titration method of ethylenediaminetetraacetic acid, a sample of magnesium oxide is dissolved in dilute hydrochloric acid, and the solution is adjusted to a pH of about 10, and then titrated with a solution of the disodium salt of ethylenediaminetetraacetic acid. The disodium salt forms a complex with the magnesium ions in the solution, so that the concentration of magnesium ions can be calculated from the amount of the disodium salt used. The mass of magnesium, expressed as magnesium oxide, is compared to the mass of the original sample to give the percentage of purity. When a mixture of "heavy" and "light" magnesium oxides is used, it is preferred that the "light" magnesium oxide be present at 50 weight percent or less, more preferably at 40 weight percent or less , and preferably is in the range of 25 to 45 weight percent, and most preferably in the range of 30 to 40 weight percent of the total weight of magnesium oxide. The hydrocarbon solvent used in the carbonation mixture is a solvent wherein the high molecular weight sulfonic acid and the sulfonate overbased are at least partially soluble, and are used in an amount sufficient to maintain the fluid mixture during carbonation. The solvent is suitably volatile, preferably with a boiling point at atmospheric pressure of less than 150 ° C, so that it can be removed after the carbonation is finished. Examples of suitable hydrocarbon solvents are aliic hydrocarbons, for example hexane or heptane, and aromatic hydrocarbons, for example benzene, toluene or xylene, with the preferred solvent being toluene. Typically, the solvent is used in an amount of about 3 to 4 parts by mass per part by mass of the magnesium oxide. As well as the hydrocarbon solvent, the carbonation mixture may comprise a non-volatile diluting oil, for example, a mineral oil, although the use of this oil during carbonation is not essential. In the process of the invention, preferably a non-volatile diluting oil is used only if this oil is present in the high molecular weight sulfonic acid starting material. However, diluent oil can be added to the magnesium sulphonate after the carbonation is finished, which in some cases may be convenient to facilitate the handling of the product. The total amount of water introduced into the mixture is at least 0.5 moles, conveniently at least 1 mole, per mole of the excess magnesium oxide (ie, the available magnesium oxide to form basically reactive, colloidally dispersed products) . Conveniently, the amount of water introduced does not exceed 5 moles, and preferably does not exceed 2.5 moles, per mole of over-based magnesium oxide. As examples of water-soluble alcohols suitable for use in accordance with the invention, there may be mentioned the lower aliphatic alkanols, the alkoxyalkanols, and mixtures of two or more of these compounds, wherein the maximum number of carbon atoms is usually from when 5. Examples of suitable alkanols are methanol, ethanol, isopropanol, n-propanol, butanol, and pentanoi.

Methanol is preferred. An example of a suitable alkoxyalkanol is methoxyethanol. For a guide, the mass ratio of water to alcohol will typically be in the range of 10 to 0.1: 1, especially 7 to 1.0: 1, more preferably 5 to 1.5 to 1, and most preferably 5 to 1.6: 1 . Examples of suitable promoters for use in the process of the present invention are ammonia, ammonium compounds, monoamines and polyamines (eg, ethylene diamine), and carbamates of these amines. Preferred promoters are carbamates, and in particular carbamates prepared from polyamines. The most preferred carbamates are those prepared from ethylene polyamines, and in particular ethylenediamine. This carbamate can be prepared by the reaction of ethylenediamine in a methanol / water solvent with carbon dioxide. The reaction is exothermic, and produces a solution of the carbamate. The promoter can be pre-reacted in a convenient manner with the sulfonic acid totally or partially soluble in water, before or after the addition of the magnesium oxide. Preferably, the molar ratio of the promoter to the total or partially soluble sulfonic acid in water is 0.1: 5, preferably 0.1 to 1: 2.5, more preferably 0.1 to 1: 1, whether it is previously reacted or not . Preferably, the promoter, when in the form of a carbamate, is always added to a basic reaction mixture, ie, after the addition of the magnesium oxide. If it is added before the addition of the magnesium oxide, it is preferred that the sulfonic acids are added after the addition of the magnesium oxide. Accordingly, it is more preferred that the magnesium oxide and the sulfonic acid, wholly or partially soluble in water, be reacted initially, followed by the addition of the carbamate promoter to a reaction mixture which is basic due to the presence of an excess of magnesium oxide, on that required to neutralize the sulfonic acid totally or partially soluble in water. To ensure maximum conversion of magnesium oxide to colloidal products, carbonation is normally continued until there is no further significant recovery of carbon dioxide. The minimum temperature that can be used is the one at which the carbonation mixture remains fluid, and the maximum is the decomposition temperature of the component with the lowest decomposition temperature, or the lowest temperature at which an unacceptable amount is lost of one or more volatile components of the mixture. The carbonation is preferably carried out with the apparatus set for total reflux. The temperature of the reagents is usually adjusted to a chosen value before carbonation begins, and then allowed to vary during carbonation as the reaction proceeds. In general, carbonation is carried out at a temperature in the range of 20 ° C to 200 ° C, preferably 40 ° C to 80 ° C, more preferably 40 ° C to 70 ° C, and most preferably 40 ° C. C at 66 ° C. It is preferred that the carbonation starts at least at 35 ° C, preferably at 40 ° C or slightly less. When there is no significant further recovery of carbon dioxide, the carbonation mixture is separated to remove volatile materials such as water, alcohol, and volatile solvents, and any solids left in the mixture are removed, preferably by filtration. . The mixture can be separated before or after the solids are removed. If desired, more carbon dioxide can be passed through the reaction mixture during separation, carbon dioxide acting primarily to remove volatile materials. As indicated above, in a surprising manner, the invention makes it possible to obtain over-based magnesium sulphonates having high base numbers, which have an extremely low proportion of sediments subsequent to carbonation, and which are capable of being purified by filtration. It is preferred that the separation begin within the first hour of carbonation.

Conveniently, the magnesium sulfonate can be further treated with an anhydride or carboxylic acid material. It has been found that this is particularly convenient when sulfonate is to be used in formulated oils that come into contact with fluoroelastomer seals. It has also been found that this improves compatibility with water and sulfonate tolerance. Preferred anhydride or carboxylic acid materials are dicarboxylic acids and their anhydrides, in particular aliphatic hydrocarbyl dicarboxylic acids and anhydrides. The most preferred dicarboxylic acids with the vicinyl dicarboxylic acids, examples of which include maleic and fumaric acids, with fumaric acid being particularly preferred. It is preferred that the post-treatment be undertaken after carbonation, and that the carboxylic acid or anhydride be used in an amount sufficient to react with any active hydrogen-nitrogen groups that are present in the carbonated product. These groups are present in the product due to the residual promoter that has not been removed after the reaction. Conveniently, the acid or anhydride is used in excess, and in doing so, imparts a better water tolerance to the sulfonate. Typically, the acid is used from 1.0 to 5 percent by weight, preferably from 1 to 2.5 percent by weight, and more preferably from 1 to 2.0 percent by weight, based on the weight of the over-based magnesium sulfonate. The exact amounts used depend on the amount of promoter used, and the residual amount of promoter after carbonation and product separation. The over-based magnesium sulfonates obtained by the process of the invention are useful as additives for oil-based compositions, for example lubricants, fats and fuels, and therefore, the invention also provides compositions containing magnesium sulfonates over-based. When used in motor lubricants, over-based magnesium sulfonates neutralize the acids formed by motor operation, and help disperse the solids in the oil to reduce the formation of harmful deposits. They also improve the anticorrosive properties of lubricants. The amount of over-based magnesium sulfonate to be included in the oil-based composition depends on the type of composition and its proposed application. Lubricating oils of automotive crankshafts preferably contain 0.01 percent to 6 percent by mass, preferably 0.2 to 4 percent by mass of the magnesium sulphonate over-based, on an active ingredient basis, based on the mass of the oil. The over-based magnesium sulfonates prepared according to the invention are soluble in oil, or (in common with other additives referred to below) can be dissolved in oil with the aid of a suitable solvent, or are stably dispersible materials. Soluble in oil, which can be dissolved, or stably dispersible, as that terminology is used herein, does not necessarily indicate that the materials are soluble, dissolvable, miscible, or capable of being suspended in oil in all proportions. However, it does mean that the materials are, for example, soluble or stably dispersible in oil to a sufficient degree to exert their intended effect in the environment in which the oil is used. Moreover, the further incorporation of other additives may also allow the incorporation of higher levels of a particular additive, if desired. The lubricating oil can be selected from any of the synthetic or natural oils used as crankshaft lubricating oils for spark ignited and compression ignited engines. The lubricant oil base supply conveniently has a viscosity of about 2.5 to about 12 cSt or mm2 / second, and preferably from about 2.5 to about 9 cSt or mm2 / second to 100"C. If desired, mixtures of synthetic and natural base oils can be used Examples of the additives that can be included in the lubricating oil compositions They are viscosity index improvers, corrosion inhibitors, oxidation inhibitors, friction modifiers, dispersants, detergents, metal oxide inhibitors, antiwear agents, melting point depressants, and antifoaming agents. water-soluble polymeric hydrocarbon base structure having functional groups that are capable of associating with the particles to be dispersed Typically, the dispersants comprise amine, alcohol, amide, or polar ester moieties attached to the base structure of the polymer, often by means of a bridge group, the ashless dispersant can be selected, for example, from and oil-soluble salts, esters, amino esters, amides, imides, and oxazolines of mono- and di-carboxylic acids substituted by long-chain hydrocarbons or their anhydrides; long chain hydrocarbon thiocarboxylate derivatives; long chain aliphatic hydrocarbons having a polyamine attached directly thereto, and Mannich condensation products formed by the condensation of a long chain substituted phenol with formaldehyde and polyalkylene polyamine. The base structure of the oil-soluble polymeric hydrocarbon is typically an olefin polymer or a polyene, especially polymers comprising a higher molar amount (ie, greater than 50 mole percent) of an olefin of 2 to 18 carbon atoms (per example, ethylene, propylene, butylene, isobutylene, pentene, octene-1, styrene), and typically an olefin of 2 to 5 carbon atoms. The base structure of oil-soluble polymeric hydrocarbon may be a homopolymer (e.g., polypropylene or polyisobutylene), or a copolymer of two or more of these olefins (e.g., copolymers of ethylene and an alpha-olefin, such as propylene or butylene) , or copolymers of two different alpha-olefins). Other copolymers include those in which a lower molar amount of the copolymer monomers, for example 1 to 10 mole percent, is an α-diene, such as an unconjugated diolefin of 3 to 22 carbon atoms (e.g. a copolymer of isobutylene and butadiene, or a copolymer of ethylene, propylene, and 1,4-hexadiene or 5-ethylidene-2-norbornene). An atactic propylene oligomer typically having an Mn of 700 to 5,000 may also be used, as described in European Patent Number EP-A-490454, as well as heteropolymers such as polyepoxides. A preferred class of polyolefin polymers is polybutenes, and specifically polyisobutenes (PIB) or normal n-polybutenes, such as can be prepared by the polymerization of a refinery stream of 4 carbon atoms. Other preferred classes of olefin polymers are ethylene-alpha-olefin copolymers (EAO) and alpha-olefin homopolymers and co-polymers having in each case a high degree (eg,> 30 percent) of unsaturation of vinylidene terminal. That is, the polymer has the following structure: R P - C === CH, wherein P is the polymer chain, and R is an alkyl group of 1 to 18 carbon atoms, typically methyl or ethyl. Preferably, the polymers will have at least 50 percent of the polymer chains with terminal vinylidene unsaturation. The ethylene-alpha-olefin copolymers of this type preferably contain from 1 to 50 weight percent ethylene, and more preferably from 5 to 48 weight percent ethylene. These polymers may contain more than one alpha-olefin, and may contain one or more diolefins of 3 to 22 carbon atoms. Also useful are mixtures of ethylene-alpha-olefin copolymers of a variable ethylene content. It is also possible to mix different types of polymers, for example, EAO and PIB, as well as polymers with different Mn; it is also possible to mix components derived therefrom. Suitable olefin polymers and copolymers can be prepared by different catalytic polymerization processes. In one method, the hydrocarbon feed streams, typically monomers of 3 to 5 carbon atoms, are cationically polymerized in the presence of a Lewis acid catalyst, and optionally a catalytic promoter, for example an organoaluminum catalyst, such as ethylaluminum dichloride, and an optional promoter such as HCl. Most commonly, the polyisobutylene polymers are derived from the Rafinate I refinery feed streams. Different reactor configurations can be used, for example tubular or stirred tank reactors, as well as fixed bed catalyst systems in addition to the homogeneous catalysts. These polymerization processes and catalysts are described, for example, in U.S. Patent Nos. 4,935,576; 4,952,739; and 4,982,045, and in the UK Patent Number UK-A 2,001662. Also conventional Ziegler-Natta polymerization processes can be employed to provide olefin polymers suitable for use in the preparation of dispersants and other additives. However, preferred polymers can be prepared by polymerizing the appropriate monomers in the presence of a particular type of Ziegler-Natta catalyst system comprising at least one metallocene (eg, a cyclopentadienyl transition metal compound), and preferably a cocatalyst or an activator, for example an alumoxane compound or an ionizing ionic activator such as tri (n-butyl) ammonium-tetra (pentafluorophenyl) boron. Metallocene catalysts are, for example, bulky ligand transition metal compounds of the formula: wherein L is a bulky ligand; A is an exit group, M is a transition metal, and m and n are such that the valence of total ligand corresponds to the valence of the transition metal. Preferably, the catalyst is tetra coordinate, such that the compound is ionizable to a valence state of 1+. The ligands L and A can be bridged with one another, and if there are two ligands A and / or L present, they can be bridged. The metallocene compound may be a complete sandwich compound having two or more ligands, L, which may be cyclopentadienyl ligands, or cyclopentadienyl-derived ligands, or may be half-sandwich compounds having a ligand L. The ligand it can be mono- or poly-nuclear, or any other ligand capable of being linked by? -5 to the transition metal. One or more of the ligands may be linked by p to the transition metal atom, which may be a transition metal of Group 4, 5, or 6, and / or a lanthanide or actinide transition metal, with zirconium, titanium being particularly preferred. , and hafnium. The ligands may be substituted or unsubstituted, and a mono-, di-, tri-, tetra-, and penta-substitution of the cyclopentadienyl ring is possible. Optionally, the substituents can act as one or more bridges between the ligands and / or exit groups and / or transition metal. These bridges typically comprise one or more of a radical containing carbon atoms, germanium, silicon, phosphorus, or nitrogen, and preferably the bridge puts an atomic bond between the entities that are bridging, although that atom can, and often carries other substituents. The metallocene may also contain an additional displaceable ligand, preferably displaced by a cocatalyst - an leaving group - which is normally selected from a wide variety of hydrocarbyl and halogen groups. These polymerizations, catalysts, and cocatalysts or activators are described, for example, in U.S. Patents Nos. 4,530,914.; 4,665,208; 4,808,561; 4,871,705; 4,897,455; 4,937,299; 4,952,716; 5,017,714; 5,055,438; 5,057,475; 5,064,8021; 5,096,867; 5,120,867; 5,124,418; 5,153,157; ,198,401; 5,227,440; and 5,241,025; in U.S. Patent Application Serial Number 992,690 (filed December 17, 1992), in European Patent Numbers EP-A-129,368; 277,003; 277.004; 420.436; and 520,732; and in the International Publications Numbers WO 91/04257; 92 / 00333.1; 93/08199; 93 / 08221.1; and 94/07928. The base structure of oil-soluble polymeric hydrocarbon will normally have a number-average molecular weight (Mn) within the range of 300 to 20,000. The Mn of the polymer base structure is preferably within the range of 500 to 10,000, more preferably 700 to 5,000, where its use is to prepare a component that has the primary dispersant function. Polymers of both a relatively low molecular weight (for example, Mn = from 500 to 1,500), and a relatively high molecular weight (for example, Mn = from 1,500 to 5,000 or more) are useful for making dispersants. Particularly useful olefin polymers for use in dispersants have an Mn within the range of 1,500 to 3,000. Where it is intended that the oil additive component also have a viscosity modifying effect, it is desirable to use a higher molecular weight polymer, typically with an Mn of 2,000 to 20,000; and if the component is intended to function primarily as a viscosity modifier, then the molecular weight may be still higher, for example, Mn of 20,000 to 500,000 or more. In addition, the olefin polymers used to prepare dispersants, preferably have approximately one double bond per polymer chain, preferably as a terminal double bond. The molecular weight of the polymer, specifically Mn, can be determined by different known techniques. A convenient method is gel permeation chromatography (CPG), which additionally provides information on molecular weight distribution (see WW Yau, JJ Kirkland and DD Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979). Another useful method, particularly for the lower molecular weight polymers, is vapor pressure osmometry (see, for example, ASTM D3592). The base structure of oil soluble polymeric hydrocarbon may be operable to incorporate a functional group in the base structure of the polymer, or as one or more pendant groups of the polymer base structure. The functional group will typically be polar, and will contain one or more heteroatoms, such as P, 0, S, N, halogen, or boron. It can be attached to a saturated portion of the hydrocarbon of the base structure of the oil-soluble polymeric hydrocarbon by substitution reactions, or to an olefinic portion by means of addition or cycloaddition reactions. Alternatively, the functional group can be incorporated into the polymer in conjunction with the oxidation or dissociation of the end of the polymer chain (eg, as in ozonolysis). Useful and functional reactions include: halogenation of the polymer in an olefinic bond, and the subsequent reaction of the halogenated polymer with an ethylenically unsaturated functional compound (eg, maleation, wherein the polymer is reacted with maleic acid or anhydride); reaction of the polymer with an unsaturated functional compound by the "ene" reaction without halogenation; reaction of the polymer with at least one phenol group (this allows derivatization in a Mannich base-type condensation); reaction of the polymer at a point of unsaturation with carbon monoxide, using a Koch reaction to introduce a carbonyl group in an iso or neo position; reaction of the polymer with the functionalizing compound by addition of free radicals, using a free radical catalyst; reaction with a thiocarboxylic acid derivative; and reaction of the polymer by oxidation methods in air, epoxidation, chlorination, or ozonolysis. The base structure of polymeric hydrocarbon soluble in operable oil is then further derived with a nucleophilic reagent, such as an amine compound, aminoalcohol, alcohol, metal, or a mixture thereof, to form a corresponding derivative. Amine compounds useful for deriving operable polymers comprise at least one amine, and may comprise one or more additional amines or other reactive or polar groups. These amines may be hydrocarbylamines, or they may be predominantly hydrocarbylamines wherein the hydrocarbyl group includes other groups, for example hydroxy groups, alkoxy groups, amide groups, nitriles, imidazoline groups, and the like. Particularly useful amine compounds include mono- and poly-amines, for example polyalkylene and polyoxyalkylene polyamines of from about 2 to 60, conveniently from 2 to 40 (e.g., from 3 to 20) total carbon atoms, and from about 1 to 12, conveniently from 3 to 12, and preferably from 3 to 9 nitrogen atoms in the molecule. Conveniently mixtures of amine compounds, such as those prepared by the reaction of alkylene dihalide with ammonia, can be used. Preferred amines are saturated aliphatic amines, including, for example, 1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane, 1,1,6-diaminohexane; polyethyleneamines such as diethylenetriamine; triethylenetetramine; tetraethylenepentamine; and polypropylene-namines, such as 1,2-propylene diamine; and di- (1,2-propylene) triamine.

Other useful amine compounds include: alicyclic diamines such as 1,4-di (aminomethyl) cyclohexane, and heterocyclic nitrogen compounds such as imidazolines. A particularly useful class of amines is that of the related polyamido- and amido-amines, as disclosed in U.S. Patent Nos. 4,857,217; 4,956,107; 4,963,275; and 5,229,022. Tris (hydroxymethyl) aminomethane (THAM) can also be used, as described in U.S. Patent Nos. 4,102,798; 4,113,639, and 4,116,876; and in the United Kingdom Patent Number UK 989,409. Dendrimers, amines of star type, and amines of comb structure can also be used. In a similar manner, the condensed amines disclosed in U.S. Patent No. 5,053,152 can be used. The functional polymer is reacted with the amine compound according to conventional techniques, as described in Patent Numbers EP-A-208,560; US 4,234,435 and US 5,229,022. The soluble oil-soluble polymeric hydrocarbon base structures can also be derivatized with hydroxy compounds, such as monohydric and polyhydric alcohols, or with aromatic compounds such as phenols and naphthols. Preferred are polyhydric alcohols, for example alkylene glycols, wherein the alkylene radical contains from 2 to 8 carbon atoms. Other useful polyhydric alcohols include glycerol, glycerol monooleate, glycerol monostearate, glycerol monomethyl ether, pentaerythritol, dipentaerythritol, and mixtures thereof. An ester dispersant can also be derived from unsaturated alcohols, such as allyl alcohol, cinnamyl alcohol, propargyl alcohol, l-cyclohexan-3-ol, and oleyl alcohol. Still other classes of the alcohols capable of producing ashless dispersants comprise the ether alcohols, which include, for example, oxyalkylene and oxyarylene. These are exemplified by the ether alcohols having up to 150 oxyalkylene radicals, wherein the alkylene radical contains from 1 to 8 carbon atoms. The ester dispersants can be diesters of succinic acids, or acid esters, that is to say, partially esterified succinic acids, as well as partially esterified polyhydric alcohols or phenols, that is, esters having hydroxyl radicals free of alcohols or phenols. An ester dispersant can be prepared by one of several known methods, as illustrated, for example, in U.S. Patent No. 3,381,022. A preferred group of ashless dispersants includes those derived from polyisobutylene substituted with succinic anhydride groups, and reacted with polyethylene amines (e.g., tetraethylenepentamine, pentaethylene (di) (penty) amine, polyoxypropylene diamine), amino alcohols, such as trimethylolaminomethane, and optionally additional reagents such as alcohols and reactive metals, for example pentaerythritol, and combinations thereof. Dispersants are also useful where a polyamine is directly attached to the long-chain aliphatic hydrocarbon, as shown in U.S. Patent Nos. 3,275,554 and 3,565,804, wherein a halogen group on a halogenated hydrocarbon is displaced by different alkylene polyamines. Another class of ashless dispersants comprises Mannich base condensation products. In general, these are prepared by the condensation of about 1 mole of a mono- or poly-hydroxybenzene substituted by alkyl, with from about 1 to 2.5 moles of carbonyl compounds (eg, formaldehyde and paraformaldehyde), and from about 0.5 to 2 moles of polyalkylene polyamine, as disclosed, for example, in U.S. Patent Number US 3442,808. These Mannich condensation products may include a long chain, high molecular weight hydrocarbon (for example, Mn of 1,500 or more) on the benzene group, or they may be reacted with a compound containing this hydrocarbon, for example polyalkenylsuccinic anhydride , as shown in United States Patent Number 3,442,808. Examples of the operable olefin polymers and / or derivatives based on polymers synthesized using metallocene catalyst systems are described in U.S. Patents Numbers US 5,128,056; 5,151,204; 5,200,103; 5,225,092; and 5,266,223; in the United States of America Patent Applications with Series Numbers US $ 992,192 (filed December 17, 1992); 992,403 (filed December 17, 1992); 070,752 (filed on June 2, 1993); and in European Patents Nos. EP-A-440, 506; 513,157 and 513,211. The functionality and / or derivations and / or subsequent treatments described in the following patents may also be adapted for the operation and / or derivative of the preferred polymers described above: US Pat. Nos. 3,087,936; 3,254,025; 3,275,554; 3,442,808, and 3,565,804. The dispersant can be further treated further by a variety of conventional after-treatments, such as borax, as taught in general in U.S. Patent Nos. 3,087,936, and 3,254,025. This is easily accomplished by the treatment of a dispersant containing acyl nitrogen, with a boron compound selected from the group consisting of boron oxide, boron halides, boron acids, and boron acid esters, in a amount to provide from about 0.1 atomic ratio of boron per each mole of the acylated nitrogen composition, to about 20 atomic proportions of boron per each atomic nitrogen ratio of the acylated nitrogen composition. Utilitatively, the dispersants contain from about 0.05 to 2.0 weight percent, for example from 0.05 to 0.7 weight percent of boron, based on the total weight of the borated acyl nitrogen compound. Boron, which appears to be in the product as dehydrated boric acid polymers (primarily (HB02) 3), is believed to bind to the imides and diimides of the dispersant as amine salts, for example, the diimide metaborate salt . Boration is easily accomplished by the addition of about 0.05 to 4, for example 1 to 3 weight percent (based on the weight of the acyl nitrogen compound) of a boron compound, preferably boric acid, usually as a paste, to the acyl nitrogen compound, and heated with stirring from 130 ° C to 190 ° C, for example from 140 ° C to 170 ° C, for 1 to 5 hours, followed by nitrogen removal. Alternatively, the boron treatment can be carried out by the addition of boric acid to a hot reaction mixture of the dicarboxylic acid and amine material, while stirring the water.

Viscosity modifiers (or viscosity index improvers) impart high and low temperature operability to a lubricating oil. Viscosity modifiers that also function as dispersants are also known, and can be prepared as described above for the ashless dispersants. In general, these viscosity modifiers of the dispersant are functional polymers (for example, ethylene-propylene interpolymers subsequently grafted with an active monomer, such as maleic anhydride), which are then derived, for example, with an alcohol or an amine. The lubricant can be formulated with or without a conventional viscosity modifier, and with or without a viscosity modifier of the dispersant. Suitable compounds to be used as viscosity modifiers are generally high molecular weight hydrocarbon polymers, including polyesters. The oil-soluble viscosity modifying polymers generally have weight average molecular weights of from about 10,000 to 1,000,000, preferably from 20,000 to 500,000, which can be determined by gel permeation chromatography (as described above), or by dispersion of light. Representative examples of suitable viscosity modifiers are polyisobutylene, copolymers of ethylene and propylene and higher alpha-olefins, polymethacrylates, polyalkylmethacrylates, methacrylate copolymers, copolymers of an unsaturated dicarboxylic acid and a vinyl compound, styrene interpolymers and acrylic esters, and partially hydrogenated copolymers of styrene-isoprene, styrene / butadiene, and isoprene / butadiene, as well as the partially hydrogenated homopolymers of butadiene and isoprene, and isoprene / divinylbenzene. Metal-containing or ash-forming detergents work both as detergents to reduce or remove deposits, as acid neutralizers or corrosion inhibitors, thereby reducing wear and corrosion, and extending engine life. Detergents generally comprise a polar head with a long hydrophobic glue, the polar head comprising a metal salt of an acidic organic compound. The salts may contain a substantially stoichiometric amount of the metal, in which case, they are normally described as normal or neutral salts, and would typically have a total base number or TBN (as can be measured by ASTM D2896) from 0 to 80. It is possible to include large amounts of a metal base by reacting an excess of a metal compound, such as an oxide or hydroxide, with an acid gas such as carbon dioxide. The resulting over-based detergent comprises the neutralized detergent as the outer layer of a metal base mycelium (eg, carbonate). These over-based detergents can have a total base number of 150 or greater, and typically 250 to 450 or more. Detergents that can be used include sulphonates, phenates, sulfurized phenates, thiophosphonates, salicylates, and neutral, oil-soluble over-based naphthenates, and other oil-soluble metal carboxylates, particularly alkaline earth metals, for example sodium, potassium, lithium, calcium, and magnesium. The most commonly used metals are calcium and magnesium, which can both be present in the detergents used in a lubricant, and mixtures of calcium and / or magnesium with sodium. Particularly convenient metal detergents are neutral and over-based calcium sulfonates having a total base number of from 20 to 450, and neutral and over-based calcium phenates and sulfur phenates having a total base number of 50 to 450. Sulfonates can be prepared from sulphonic acids, which are typically obtained by the sulfonation of alkyl-substituted aromatic hydrocarbons, such as those obtained from the fractionation of petroleum., or by the alkylation of aromatic hydrocarbons. Examples include those obtained by the alkylation of benzene, toluene, xylene, naphthalene, diphenyl, or their halogen derivatives, such as chlorobenzene, chlorotoluene, and chloronaphthalene. The alkylation can be carried out in the presence of a catalyst with alkylating agents having from about 3 to more than 70 carbon atoms. The alkaryl sulfonates typically contain from about 9 to about 80 or more carbon atoms, preferably from about 16 to about 60 carbon atoms per alkyl-substituted aromatic moiety. The sulfonates or the oil-soluble alcarylsulfonic acids can be neutralized with oxides, hydroxides, alkoxides, carbonates, carboxylates, sulphides, hydrosulfides, nitrates, borates, and ethers of the metal. The amount of the metal compound is selected by considering the desired total base number of the final product, but is typically from about 100 to 220 weight percent (preferably at least 125 weight percent). The metal salts of phenols and sulfur phenols are prepared by reaction with an appropriate metal compound, such as an oxide or hydroxide, and the neutral or overbased products can be obtained by methods well known in the art. The sulfurized phenols can be prepared by the reaction of a phenol with sulfur or with a sulfur-containing compound such as hydrogen sulfide, sulfur monohalide, or sulfur dihalide, to form products which are generally mixtures of the compounds wherein two or more phenols are bridged by bridges that contain sulfur. The metal salts of dihydrocarbyl dithiophosphate are frequently used as anti-wear agents and antioxidants. The metal can be an alkaline or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel, or copper. Zinc salts are most commonly used in lubricating oil in amounts of 0.1 to 10, preferably 0.2 to 2 percent by weight, based on the total weight of the lubricating oil composition. They can be prepared according to known techniques, by first forming a dihydrocarbyldithiophosphoric acid (DDPA), usually by reacting one or more alcohols or a phenol with P2S5-- AND then neutralizing the dihydrocarbyldithiophosphoric acid formed with a zinc compound. The dihydrocarbyl zinc dithiophosphates can be made from mixed dihydrocarbyldithiophosphoric acid, which in turn can be made from mixed alcohols. Alternatively, multiple dihydrocarbyl zinc dithiophosphates can be made, and subsequently they can be mixed. Accordingly, the dithiophosphoric acid containing secondary hydrocarbyl groups used in this invention can be made by the reaction of mixtures of primary and secondary alcohols. Alternatively, multiple dithiophosphoric acids may be prepared, wherein the hydrocarbyl groups of one are of an entirely secondary character, and the hydrocarbyl groups of the others are of an entirely primary character. To make the zinc salt, any basic or neutral zinc compound could be used, but in general oxides, hydroxides, and carbonates are more commonly used. Commercial additives often contain an excess of zinc, due to the use of an excess of the basic zinc compound in the neutralization reaction. The preferred zinc dihydrocarbyl dithiophosphates useful in the present invention are oil soluble salts of dihydrocarbyldithiophosphoric acids, and may be represented by the following formula: wherein R and R 'can be the same or different hydrocarbyl radicals containing from 1 to 18, preferably from 2 to 12 carbon atoms, and including radicals such as alkyl, alkenyl, aryl, arylalkyl, alkaryl, and cycloaliphatic radicals. Particularly preferred groups R and R1 are alkyl groups of 2 to 8 carbon atoms. Accordingly, the radicals may be, for example, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, amyl, n-hexyl, isohexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl. , phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. In order to obtain the solubility in oil, the total number of carbon atoms (ie, R and R ') in the dithiophosphoric acid will generally be about 5 or greater. Accordingly, zinc dihydrocarbyl dithiophosphate can comprise zinc dialkyl dithiophosphates. At least 50 percent (molar) of the alcohols used to introduce the hydrocarbyl groups into the dithiophosphoric acids are secondary alcohols. Typically, additional additives are incorporated in the compositions of the present invention. Examples of these additives are antioxidants, anti-wear agents, friction modifiers, corrosion inhibitors, antifoaming agents, demulsifiers, and melting point depressants. Oxidation inhibitors or antioxidants reduce the tendency of mineral oils to deteriorate in service, whose deterioration can be evidenced by oxidation products, such as sludge and varnish type deposits on metal surfaces, and by the growth of the viscosity. These oxidation inhibitors include hindered phenols, alkaline earth metal salts of alkylphenol thioesters preferably having alkyl side chains of 5 to 12 carbon atoms, calcium nonylphenol sulfide, ash-soluble oil-soluble phenates and sulfurized phenates, phosphosulfurized hydrocarbons. or sulfur, phosphorus esters, metal thiocarbamates, oil-soluble copper compounds as described in U.S. Patent Number US 4,867,890, and compounds containing molybdenum. Examples of the molybdenum compounds include molybdenum salts of the inorganic and organic acids (see, for example, U.S. Patent Number US 4,705,641), particularly molybdenum salts of the monocarboxylic acids having from 1 to 50 , preferably from 8 to 18 carbon atoms, for example, octoate (2-ethyl hexanoate), naphthenate, or molybdenum stearate; complexes containing overbased molybdenum, as disclosed in European Patent Number EP 404 650A, molybdenum dithiocarbamates and molybdenum dithiophosphates; oil soluble molybdenum xanthates and thioxantates, as disclosed in U.S. Patent Nos. 4,995,996 and 4,966,719; complexes containing molybdenum and sulfur soluble in oil; and aromatic amines, preferably having at least two aromatic groups directly attached to the nitrogen.

Typical oil-soluble aromatic amines, which have at least two aromatic groups directly attached to a nitrogen of the amine, contain from 6 to 16 carbon atoms. The amines can contain more than two aromatic groups. Compounds having a total of at least three aromatic groups, wherein two aromatic groups are linked by a covalent bond or by an atom or group (for example, an oxygen or sulfur atom, or a group -CO-, - S02-, or alkylene), and two are directly attached to a nitrogen of the amine, also considered aromatic amines having at least two aromatic groups directly attached to the nitrogen. The aromatic rings are typically substituted by one or more substituents selected from alkyl, cycloalkyl, alkoxy groups, aryloxy, acyl, acylamino, hydroxy, and nitro. Friction modifiers may be included to improve fuel economy. In addition to the aliphatic, oxyalkylene, or oil soluble arylalkyl amines described above for adding the total nitrogen base number, other friction modifiers are known. Among these are the esters formed by the reaction of carboxylic acids and anhydrides with alkanols. Other conventional friction modifiers generally consist of a terminal polar group (eg, carboxyl or hydroxyl) covalently bonded to an oleophilic hydrocarbon chain. The esters of carboxylic acids and anhydrides with alcohols are described in U.S. Patent No. US 4,702,850. Examples of other conventional friction modifiers are described by M. Beizer in "Journal of Tribology" (1992), Volume 114, pages 675-682, and M. Belzer and S. Jahanmir in "Lubrication Science" (1988), Volume 1, pages 3-26. Oxidation inhibitors selected from the group consisting of nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and anionic alkylsulfonic acids can be used.

When the formulation of the present invention is used, these inhibitors against oxidation are generally not required. Corrosion inhibitors carrying copper and lead can be used, but are typically not required with the formulation of the present invention. Typically, these compounds are the thiadiazole polysulfides containing from 5 to 50 carbon atoms, their derivatives, and polymers thereof. Typical are 1, 3, 4-thiadiazole derivatives, such as those described in U.S. Patent Nos. 2,719,125; 2,719,126, and 3,087,932. Other similar materials are described in the Patents of the United States of North America Nos. 3,821,236; 3,904,537; 4,097,387; 4,107,059; 4,136,043; 4,188,299, and 4,193,882. Other additives are the thio- and polythio-sulfenamides of thiadiazoles, such as are described in UK Patent Specification Number 1,560,830. The benzotriazole derivatives also fall into this class of additives. When these compounds are included in the lubricant composition, they are preferably present in an amount not exceeding 0.2 weight percent active ingredient. A small amount of a demulsifying component can be used. A preferred demulsifier component is described in European Patent Number EP 330,522. It is obtained by the reaction of an alkylene oxide with an adduct obtained by the reaction of a bis-epoxide with a polyhydric alcohol. The hardener should be used at a level that does not exceed 0.1 percent by mass of active ingredient. A treatment concentration of 0.001 to 0.05 percent by mass of active ingredient is desirable. Melting point depressants, otherwise known as lubricant oil flow improvers, lower the minimum temperature at which it will flow or may be poured out of the fluid. These additives are well known. Typical additives that improve fluidity at low fluid temperature are copolymers of dialkyl fumarate of 8 to 18 carbon atoms / vinyl acetate, and polyalkyl methacrylates. The control of the foam can be provided by many compounds, including a defoamer of the polysiloxane type, for example silicone oil or polydimethylsiloxane. Some of the aforementioned additives can provide a multiplicity of effects; consequently, for example, a single additive can act as an oxidant-dispersant-inhibitor. This approach is well known, and does not require further elaboration. When the lubricant compositions contain one or more of the aforementioned additives, each additive is typically mixed in the base oil in an amount that makes it possible for the additive to provide its desired function. The representative effective amounts of these additives, when used in crankshaft lubricants, are mentioned below. All listed values are listed as a percentage by mass of active ingredient. ADDITIVE% IN MASS% IN MASS (Broad) (Preferred) Dispersant without ashes 0.1-20 1-8 Metal detergents 0.1-6 0.2-4 Corrosion inhibitor 0-5 0-1.5 Dihydro0.1-6 0.1 Di6thiophosphate 0.1-4 metal carbide. Complementary Antioxidant 0-5 0.01-1.5 Depressor of the 0.01-5 0.01-1.5 point fusion.

Antifoaming agent 0-5 0.001-0.15 Anti-wear agents 0-0.5 0-0.2 complementary. Friction modifier 0-5 0-1.5 Viscosity modifier 1 0.01-6 0-4 Mineral base oil or the rest the synthetic rest. 1. Viscosity modifiers are only used in multi-grade oils.

For applications other than the crankshaft, the amounts and / or proportions of the above additives may be varied; for example, marine diesel cylinder lubricants use relatively higher amounts of metal detergents, which can form 10 to 50 weight percent of the lubricant. The components can be incorporated into a base oil in any convenient manner. Thus, each of the components can be added directly to the oil by dispersing or dissolving it in the oil at the desired concentration level. This mixture can be presented at room temperature or at an elevated temperature. Preferably, all additives, with the exception of the viscosity modifier and the melting point depressant, are mixed in a concentrate or additive package, which is subsequently mixed in the base supply to make the finished lubricant. The use of these concentrates is conventional. The concentrate will typically be formulated to contain the additives in the appropriate amounts in order to provide the desired concentration in the final formulation when the concentrate is combined with a predetermined amount of base lubricant. Preferably, the concentrate is made in accordance with the method described in U.S. Patent No. US 4,938,880. That patent describes the manufacture of a premix of ashless dispersant and metal detergents, which is premixed at a temperature of at least about 100 ° C. Subsequently, the premix is cooled to at least 85 ° C, and additional components are added. The final formulations can employ from 2 to 15 percent by mass, and preferably from 5 to 10 percent by mass, typically from about 7 to 8 percent by mass of the concentrate or additive package, the remainder being the base oil . The invention will now be described by an illustration only with reference to the following examples. EXAMPLES OF THE INVENTION EXAMPLE 1 476 grams of toluene, 15.4 grams of methanol, and 44 grams of a straight-chain sulfonic acid cut from dodecylbenzene (Sinnozon DBS, 96.5 percent active ingredient) were mixed and heated to a high degree of agitation. 30 ° C-35 ° C in a reactor adapted with a reflux condenser, a gas distribution tube, and a temperature controller. Then 152 grams of magnesium oxide were added, and a rapid exotherm occurred as the low molecular weight sulfonic acid was neutralized, and the temperature rose to 40 ° C. To this mixture was added 56.5 grams of a solution of ethylenediamine carbamate (18.9 weight percent in methanol / water). The mixture was kept at 40 ° C for a period of 20 minutes, then 247 grams of a 83 percent by mass solution of a high molecular weight alkylbenzenesulfonic acid (molecular weight 670) in diluent oil were added, along with a addition of more than 49 grams of methanol and 108 grams of water.An immediate exotherm occurred, and the temperature reached 66 ° C maximum, while simultaneously starting the injection of carbon dioxide into the mixture, at a speed of 45 grams / hour During carbonation, the temperature of the carbonation mixture was allowed to continue its natural course, and slowly increased to about 72 ° C, and then fell again when the reaction ceased, and the oxide was consumed When the temperature had dropped to approximately 60 ° C, heat was applied, and the temperature was maintained at 60 ° C until the carbonation was finished After 3 hours with 30 minutes of carbon At the same time, the apparatus was changed from a reflux to a distillation configuration, while maintaining the temperature of the mixture at 60 ° C, 370 grams of diluent oil were added, also at 60 ° C, and the mixture thus obtained was distilled at atmospheric pressure while introducing a stream of nitrogen. When the temperature of the distillation reached 165 ° C, a vacuum was applied, and it was maintained for a period of 2 hours, to remove the last traces of water, methanol, and toluene. After releasing the vacuum, a 50 milliliter sample of the purified mixture was removed and diluted with 50 milliliters of toluene. This diluted sample was then centrifuged to demonstrate that 1.0 percent by volume of sediment (SPC) remained in the purified mixture. The product was filtered with the use of a filter help, and the filtered product was bright and transparent, and had a total base number of 417 milligrams of KOH / gram. Example 2 Example 1 was repeated, with the exception that 73 grams of an aromatic alkylsulfonic acid of 18 linear carbon atoms of a molecular weight of 408, and with 83.4 mass percent of active ingredient (MX1245), were used, instead of dodecylbenzenesulfonic acid. Also 309 grams of high molecular weight sulfonic acid with 60.6 mass percent active ingredient, and a molecular weight of 670 were used. The results are given in Table 1. Example 3 Example 1 was repeated, with the exception of that 46 grams of a branched dodecylbenzenesulfonic acid was used instead of dodecylbenzenesulfonic acid. The results are given in Table 1. Example 4 Example 1 was repeated, with the exception that ethylenediamine was not reacted with carbon dioxide, but was previously reacted in situ with the straight chain dodecylbenzenesulfonic acid. The results are given in Table 1. Example 5 Example 1 was repeated, with the exception that both sulphonic acids that were used were added simultaneously at the point where the addition of the dodecylbenzenesulfonic acid was made in Example 1. The The results are given in Table 1. EXAMPLE 6 Example 1 was repeated, with the exception that the charge of ethylenediamine (9.7 grams) in water, was previously reacted with the dodecylbenzenesulfonic acid, and this was used in place of the promoter. ethylenediamine carbamate. The results are given in Table 1. Example 7 Example 1 was repeated, with the exception that the magnesium oxide used was a mixture of 70 mass percent of a "heavy" magnesium oxide with a citric acid number of 391 seconds, and a BET surface area of 9 square meters / gram, and 30 mass percent of a "light" magnesium oxide with a citric acid number of 80 seconds, and a BET surface area of 25 square meters /gram. The results are given in Table 1. EXAMPLE 8 Example 1 was repeated, with the exception that 54.5 grams of a straight chain aromatic alkylsulfonic acid of 18 carbon atoms, with a molecular weight of 427, was used instead of dodecylbenzenesulfonic acid. The results are given in Table 1. Example 9 Example 1 was repeated, with the exception that 92 grams of a mixture of straight chain sulfonic acids of 18 carbon atoms and branched chain of 15 to 36 or more were used. carbon atoms (molecular weight of 490, and 69 percent by mass of active ingredient), instead of dodecylbenzenesulfonic acid. Also 314 grams of a 60 percent by mass solution of active ingredient, of a high molecular weight alkylbenzenesulfonic acid (molecular weight of 670) were used. The loading of diluting oil was 260 grams. The low molecular weight sulfonic acid was also neutralized separately before the addition of the high molecular weight sulfonic acid. The results are given in Table 1. EXAMPLE 10 Example 9 was repeated, with the exception that 63 grams of a branched-chain alkyl xylenesulfonic acid of 12 carbon atoms, with a number average molecular weight of 370, were used, and 82 percent by mass of active ingredient, instead of the mixture of straight chain sulfonic acids of 18 carbon atoms and branched chain of 15 to 36 or more carbon atoms. The results are given in Table 1. Example 11 Example 9 was repeated, with the exception that 38 grams of a Polymer of PIB, acid (polyisobutylene) sulfonic acid, of a number average molecular weight of 397 was used, and the 87 percent by mass of active ingredient, instead of the mixture of straight chain sulfonic acids of 18 carbon atoms and branched chain of 15 to 36 carbon atoms. The results are given in Table 1.

EXAMPLE 12 In a first vessel, the magnesium sulphonate of a straight chain-cut dodecylbenzenesulfonic acid (Sinnozon DBS) was made, charging 148 grams of toluene, 2.2 grams of methanol, and 44 grams of a straight chain-cut dodecylbenzenesulfonic acid (Sinnozon). DBS, 96.5 percent active ingredient), starting with mixing and heating the contents of the container from 30 ° C to 35 ° C Then 5.9 grams of magnesium oxide were added, and a rapid exotherm occurred as it was neutralized the low molecular weight sulfonic acid, and the temperature was raised to 40 ° C. In a second vessel, the magnesium sulphonate of high molecular weight sulfonic acid was prepared by charging 328 grams of toluene, 13.2 grams of methanol, 7.4 grams of water, and 247 grams of an 83 percent by mass solution of a high molecular weight alkylbenzene sulfonic acid (molecular weight of 670) in diluent oil, beginning with the mixing and heating the contents of the container at 40 ° C Then 9.6 grams of magnesium oxide were added, and a rapid exotherm was presented at 66 ° C maximum, as the high molecular weight sulfonic acid was neutralized. The contents of the first vessel were transferred to a stirred reactor adapted with a reflux condenser, a gas distribution pipe, and a temperature controller. To the mixture was added 56.5 grams of a solution of ethylenediamine carbamate (18.9 weight percent in methanol / water). The mixture was maintained at 40 ° C for 15 to 20 minutes. Then 136.5 grams of magnesium oxide were added. Then the content of the second vessel was transferred to the reactor, together with a larger addition of methanol (49 grams) and water (100.6 grams). Carbon dioxide was injected into the mixture at a rate of 45 grams / hour, as described in Example 1. This diluted sample was then centrifuged to demonstrate that 1.2 percent by volume of sediment (SPC) remained in the purified mixture. . The product was filtered with the use of a filter aid; the filtered product was bright and transparent, and had a total base number of 408 milligrams of KOH / gram. The result is given in Table 1. Comparative Example 1 The process of Example 1 was repeated, with the exception that no water-soluble sulfonic acid was used. The resulting product had unacceptably high levels of sediment, and gelled during the removal of the solvent. The data presented in Table 1 illustrate that the process of the present invention produces over-based magnesium sulphonates, primarily from high molecular weight sulfonic acids, which have high total base numbers, high filtration rates, low viscosities, and low sediment levels.

TABLE I

Claims (19)

1. NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty, and therefore, property is claimed as contained in the following: CLAIMS 1. A process for the production of an over-based magnesium sulphonate, the which comprises: (i) the steps of carbonating a mixture comprising a mixture of at least the following components (a) to (g), inclusive, wherein: (a) is at least one sulfonic acid of high molecular weight soluble in oil, having a number average molecular weight greater than 500, and from which at least 50 weight percent of the total sulfonate is derived; (b) is at least a low molecular weight sulfonic acid, having a number average molecular weight of 450 or less, which is totally or partially soluble in water, or a magnesium salt thereof; (c) is magnesium oxide in excess of that required to react completely with component (a) and with component (b); (d) is a hydrocarbon solvent; (e) it is water; (f) is a water soluble alcohol; (g) is a promoter, and (ii) remove the volatile solvent from the mixture of step (i).
2. 2. A process according to claim 1, characterized in that the promoter comprises at least one substance selected from ammonia, ammonium compounds, monoamines, polyamines, and carbamates of these amines.
3. 3. The process according to claim 1 in any of the preceding claims, characterized in that the high molecular weight sulfonic acid has a number average molecular weight of 600 or greater.
4. 4. A process according to claim as claimed in any of the preceding claims, characterized in that the carbonation takes place at a temperature within the range of 40 ° C to 80 ° C.
5. 5. A process according to claim 1 in any of the preceding claims, characterized in that the magnesium oxide is reacted with the component (b) before the addition of the component (g).
6. 6. A process according to claim 1 in any of claims 1 to 4, characterized in that the magnesium oxide is mixed with the component (g) before the addition of component (b) or component (a).
7. 7. A process according to claim 1 in any of claims 1 to 4, characterized in that the component (g) is mixed with the component (b) before the addition of the component (a) and the component (c).
8. 8. A process according to claim as claimed in any of the preceding claims, characterized in that the magnesium oxide has a citric acid number in the range of 200 to 600 seconds.
9. 9. A process according to claim 1 in any of claims 1 to 7, characterized in that the magnesium oxide is a mixture of at least one magnesium oxide having a citric acid number on the scale of 200 to 600 seconds, and when minus a magnesium oxide having a citric acid number in the range of 20 to 140 seconds.
10. 10. An over-based magnesium sulfonate composition, comprising at least one magnesium sulfonate derived from an oil-soluble high molecular weight sulfonic acid, having a number average molecular weight greater than 500, and at least a magnesium sulphonate derived from a low molecular weight sulfonic acid having a number average molecular weight of 450 or less, which is totally or partially soluble in water, and magnesium carbonate in its hydromagnesite form, wherein when less than 50 weight percent of the total sulfonate in the composition is derived from the high molecular weight sulfonic acid or acids, and at least 2 weight percent of the total sulfonate in the composition is derived from the acid or sulfonic acids of low molecular weight.
11. 11. An over-based magnesium sulfonate composition, comprising at least one magnesium sulfonate derived from a high molecular weight sulfonic acid oil soluble, having a number average molecular weight greater than 500, and at least one magnesium sulfonate derived from a low molecular weight sulfonic acid having a number average molecular weight of 450 or less, which is totally or partially soluble in water, and a stabilized colloidal suspension of basic magnesium carbonate, wherein at least 50 percent by weight of the total sulfonate in the composition is derived from the high molecular weight sulfonic acid (s), and at least 2% by weight. percent by weight of the total sulfonate in the composition is derived from the low molecular weight acid or sulfonic acid.
12. 12. An over-based magnesium sulfonate composition according to claim 11, characterized in that it has the total base number of at least 400 milligrams of KOH g "1.
13. 13. A composition of magnesium sulphonate over- based on the claim of any of claims 10 to 12, characterized in that at least 60 percent by weight of the total sulfonate is derived from the high molecular weight sulphonic acid
14. 14. A magnesium sulphonate composition over- based on the claim of any of claims 11 to 13, characterized in that the post-carbonation sediments of the over-based magnesium sulfonate are 2 percent or less.
15. 15. An over-based magnesium sulfonate composition according to claim 10, characterized in that it has a filtration rate of at least 150 kilograms / square meter / hour.
16. 16. An overbased magnesium sulfonate composition according to claim 10, characterized in that the low molecular weight sulfonic acid is a mixture of alkylsulfonic acids of 9 to 36 or more substituted carbon atoms. by benzene, toluene, or xylene.
17. 17. An over-based magnesium sulfonate composition according to claim 11, characterized in that it comprises at least 16 percent by weight of sulfonate, preferably at least 20 percent by weight, and more preferably at least 25 weight percent.
18. 18. A lubricating oil composition, which comprises lubricating oil as a major component, and an over-based magnesium sulfonate composition as claimed in any of claims 10 to 17, or made by the process of either claims 1 to 9. A lubricating oil concentrate, which comprises one or more lubricating additives, and an over-based magnesium sulfonate composition in accordance with claim 10, or made by the process of any of claims 1 to 9.