Patent GB-687490-A (GB)
Title: Improvements in and relating to basic metal sulphonates and compositions containing them
IPC: C10L1/24
Filed: 1949-12-02
Abstract: A process for the preparation of an oil-soluble polyvalent metal hydrocarbon sulphonate having a greater free basicity than the corresponding simple basic sulphonate of the general formula (RSO3)aM(OH)b, wherein R is a hydrocarbon radical, M is a polyvalent metal and a and b are integers the sum of which equals the valency of the metal M, comprises intimately contacting an oil soluble polyvalent metal hydrocarbon sulphonate with an alcoholate of the same polyvalent metal under substantially anhydrous conditions to produce a complex of the sulphonate and alcoholate, subsequently hydrolysing the alcoholate portion of this complex by treating it with water and removing unreacted water from the product.  The products may be employed in oleaginous compositions (see Group III). The starting material sulphonates may be prepared from mahogany acids produced by the sulphonation of petroleum lubricating oil distillates which may be represented by the formula R.SO3H, wherein R is a naphthenyl, alkyl naphthenyl, alkaryl or naphthenaryl radical such that the molecular weight of the acids is from 350 to 500 and synthetic oil soluble alkylated aromatic sulphonic acids.  The polyvalent metal salts may be prepared by neutralizing the sulphonic acids directly with the oxide or hydroxide of the desired metal or by double decomposition between an alkali metal sulphonate and a salt of the desired metal, e.g. an alcoholic solution of the sodium mahogany sulphonates may be treated with an alkaline earth metal salt or an oil solution of sodium mahogany sulphonates may be treated with an alkaline earth metal salt or an oil solution of sodium mahogany sulphonates may be emulsified with an aqueous solution of an alkaline earth metal salt.  Polyvalent metals mentioned from which the sulphonates may be derived include alkaline earth metals, magnesium, zinc aluminium, cobalt and tin. The alcoholates of the alkaline earth metals and those of magnesium, zinc and aluminium may be prepared by interaction between a suitable alcohol, preferably an aliphatic monohydric alcohol of from one to four carbon atoms and which gives a water hydrolysable alcoholate such as methanol, ethanol, the propanols and butanols.  Alcoholates of the higher alicyclic and acyclic alcohols may be used but more vigorous conditions for hydrolysis of the resulting sulphonate-alcoholate complex may be required. Suitable water-immiscible solvents include mineral oils of lubricating viscosity, mixtures of petroleum hydrocarbons, aromatic and non-aromatic hydrocarbons and mixtures thereof and halogenated hydrocarbons.  Solvents unsuitable as lubricants should preferably be removed by distillation where the product is intended for use in a lubricating oil.  The alcoholate may be added to the sulphonate solution in a further portion of the alcohol from which the alcoholates is made and the reaction mixture may be warmed if necessary.  When reaction is complete any water soluble solvent and undissolved material is removed and the addition product, dissolved in the original water-immiscible solvent or in any other such medium if the original solvent is removed along with the water-soluble solvent, is intimately contacted with water or an aqueous solution of a water soluble salt of the polyvalent metal to hydrolyse the alcoholate portion of the addition product.  The hydrolysis may be carried out at a temperature near the boiling point of the solvent or with steam which may be superheated.  In examples: (I) magnesium methylate is warmed with magnesium petroleum sulphonate in benzene solution and the complex formed is hydrolysed with aqueous magnesium chloride; (II) a similar process is carried out employing water for hydrolysis, antifoaming agents such as alkyl silicones and silicates being employed if desired when boiling off excess water; (III) and (IV) basic oil-soluble calcium petroleum sulphonates are prepared by treating a calcium petroleum sulphonate and a commercial calcium basic petroleum sulphonate respectively with calcium ethylate.  In preparing the sulphonate starting materials in examples (I) an oil-soluble sodium petroleum sulphate in benzene is heated with aqueous magnesium chloride and the aqueous layer is separated and heated to remove benzene and water (II) an oil soluble petroleum sulphonate dissolved in a refined mineral lubricating oil is warmed with aqueous magnesium chloride, the aqueous layer is removed and the oil layer heated to drive off water (III) calcium chloride is treated similarly to the magnesium chloride in (I).  Alcoholate starting materials are prepared by reacting in examples (I) and (II) magnesium and methanol (III) calcium and ethyl alcohol.  The Specification as open to inspection under Sect. 91, comprises also the use of water-soluble petroleum sulphonates and lower alkane sulphonates such as calcium methane sulphonate as starting materials and the production of water-soluble highly basic sulphonates which are stated to be useful in the preparation of oil and water emulsions.  This subject-matter does not appear in the Specification as accepted.ALSO:An oleaginous composition comprises a major proportion of an oleaginous substance and a minor proportion of an oil soluble basic polyvalent metal hydrocarbon sulphonate which has a greater free basicity than the corresponding simple basic sulphonate of the general formula (RSO3)a M(OH)b, wherein R is a hydrocarbon radical, M is a polyvalent metal atom and a and b are integers the sum of which equals the valency of the polyvalent metal M.  Such an oil-soluble sulphonate is produced by a process which comprises intimately contacting an oil-soluble polyvalent metal hydrocarbon sulphonate with an alcoholate of the same polyvalent metal under substantially anhydrous conditions to produce a complex of the sulphonate and alcoholate, subsequently hydrolyzing the alcoholate portion of this complex by treating it with water and removing unreacted water from the product.  The highly basic sulphonates may be used in lubricating and other oil compositions together with any of the well known additives used to impart oxidation stability or extreme pressure properties, in fuel compositions and other light hydrocarbon compositions such as rust preventive compositions, oil and water emulsions and spray oils.  In examples (I) and (II) highly basic magnesium petroleum sulphonates are added to a refined mineral oil and the compositions obtained are compared with similar compositions obtained using simple basic and neutral petroleum sulphonates, while in examples (III) and (IV) oil solutions and lubricating oil compositions comprising highly basic calcium petroleum sulphonates are referred to.  The highly basic polyvalent metal petroleum sulphonates are produced, (see Group IV(b) in examples (I) and (II) by reacting magnesium methylate and normal magnesium petroleum sulphonate, while in examples (III) and (IV) they are prepared by reacting calcium petroleum sulphonate and a commercial basic petroleum sulphonate respectively with calcium ethylate and hydrolyzing the products.  The Specification as open to inspection under Sect. 91, comprises also the use of water-soluble highly basic sulphonates in the preparation of oil and water emulsions.  This subject-matter does not appear in the Specification as accepted.