GB739434A - Process for preparing highly basic polyvalent metal salts of organic sulphonic acids - Google Patents

Abstract

A process for preparing highly basic polyvalent metal salts of organic sulphonic acids comprises gradually adding an alkali metal hydroxide dissolved in water or in an aliphatic alcohol having 1 to 3 carbon atoms or in a mixture of such an alcohol with water, to a solution of a polyvalent metal salt of an organic sulphonic acid and an inorganic salt of the polyvalent metal in a solvent which consists, to the extent of at least 25 per cent by weight, of an aliphatic alcohol having 1 to 3 carbon atoms. The process can be effected by treating the free organic sulphonic acid or an alkali metal, ammonium or organic base salt thereof, dissolved in the said solvent, with an excess of the inorganic salt of the polyvalent metal, after which the alkali metal hydroxide solution is gradually added. The product may be separated from the components which precipitate during the reaction by extraction with a light hydrocarbon oil. Neutral polyvalent metal sulphonates are preferred starting materials, but sulphonates which already have a certain basicity can be used. The invention is applicable to the production of salts of such metals as the alkaline earth metals, magnesium and zinc, and also of metals of higher valency, e.g. iron or chromium. Chlorides, bromides and nitrates are suitable salts. The sulphonates may be derived from aliphatic, cycloaliphatic, hydraromatic, aromatic, heterocyclic or mixed type sulphonic acids. Examples of suitable sulphonic acids are alkyl sulphonic acids such as amyl, octyl, lauryl and dodecyl sulphonic acids, sulphonic acids of alkylated or non-alkylated aromatic hydrocarbons such as benzene, toluene, naphthalene, diphenyl, triisopropylnaphthalene and polyamylnaphthalene sulphonic acids, sulphonic acids of phenols which may be mono- or polycyclic and mono- or polyhydric and may contain alkyl and/or aryl groups, sulphonic acids of completely or partly hydrogenated aromatic compounds, petroleum sulphonic acids, and the sulphonation products of extracts rich in aromatics obtained by extracting a hydrocarbon oil with a selective solvent, which extracts may have been alkylated before sulphonation. Disulphonic acids are also suitable. The process may be carried out batchwise or continuously and in the latter case part of the solution run off at the end of the reaction space may be recycled. Suitable solutions contain the sulphonate in concentration 1 to 10 per cent by weight and the inorganic salt in excess with respect to sulphonate. Isopropanol is the preferred alcohol. It may be mixed with hydrocarbons, e.g. those containing up to 10 carbon atoms in the molecule or with water, in forming the starting solution. In extracting the product from the precipitate formed in the reaction hydrocarbons with a final boiling point not higher than 300 DEG C., e.g. benzene, heptane or gasoline, may be used. The solution from the reaction product may be further treated to produce additional amounts of the basic sulphonate. If desired a mixture of the products with unconverted sulphonates may be prepared by evaporating the liquids from the reaction mixture and extracting the highly basic and the unreacted sulphonate together from the solid residue, with a hydrocarbon as used in extracting the basic sulphonate alone. If the products are intended as lubricating oil additives their solvent solution may be added to the lubricating oil and the solvent evaporated. In examples (1) an ethanolic solution of sodium hydroxide is added to a solution prepared by adding excess calcium chloride to an isopropanol solution of the sodium salt of the monosulphonic acid of a mixture of monoalkylnaphthalenes in which the alkyl groups have a straight chain of 14 to 18 carbon atoms. From the separated solids the basic calcium sulphonate is extracted with gasoline; (2) a similar process is applied to the product obtained by sulphonating with oleum an aromatic extract (B.Pt. 180 DEG to 275 DEG C.), obtained by extracting kerosine with SO2) which has been alkylated with a mixture of olefins having 9 to 15 carbon atoms (obtained by cracking paraffin wax in the vapour phase). Specification 687,490 is referred to.ALSO:Highly basic polyvalent metal sulphonates for use as additives to lubricating oils (to which antioxidants and extreme pressure dopes may also be added), fuel oils and lubricating greases are prepared by a process which comprises gradually adding an alkali metal hydroxide dissolved in water or an aliphatic alcohol having 1 to 3 carbon atoms or in a mixture of such an alcohol with water, to a solution of a polyvalent metal salt of an organic sulphonic acid and an inorganic salt of the polyvalent metal in a solvent which consists, to the extent of at least 25 per cent by weight, of an alcohol having 1 to 3 carbon atoms. The process can be effected by treating the free organic sulphonic acid or an alkali metal, ammonium or organic base salt thereof with an excess of the inorganic salt of the polyvalent metal, after which the alkali metal hydroxide solution is gradually added. The project can be separated from the components which precipitate during the reaction by extraction with a light hydrocarbon oil. Neutral polyvalent metal sulphonates are preferred starting materials but sulphonates which already have a certain degree of basicity can also be used. The invention is applicable to the production of salts of such metals as the alkaline earth metals, magnesium and zinc and also of metals of higher valency, e.g. iron and chromium. Chlorides, bromides and nitrates are suitable salts. The sulphonates may be derived from aliphatic, cycloaliphatic, hydroaromatic, aromatic, heterocyclic or mixed type sulphonic acids. Examples of suitable sulphonic acids are alkyl sulphonic acids such as amyl, octyl, lauryl and dodecyl sulphonic acids, sulphonic acids of alkylated or non-alkylated aromatic hydrocarbons such as benzene, toluene, naphthalene, diphenyl, tri-isopropylnaphthalene, and polyamylnaphthalene sulphonic acids, sulphonic acids of phenols which may be mono- or polycyclic and mono- or polyhydric, and may contain alkyl and/or aryl substituents, sulphonic acids of completely or partly hydrogenated aromatic compounds, petroleum sulphonic acids, and the sulphonation products of extracts rich in aromatics obtained by extracting a hydrocarbon oil with a selective solvent, which extracts may have been alkylated before the sulphonation. Disulphonic acids are also suitable. The process may be effected batchwise or continuously and in the latter case part of the solution run off at the end of the reaction space may be recycled. Suitable solutions contain the sulphonate in concentration 1 to 10 per cent by weight and the inorganic salt in excess with respect to sulphonate. Isopropanol is the preferred solvent. It may bemixed with hydrocarbons, e.g. those containing up to 10 carbon atoms in the molecule, or with water, in forming the starting solution. In extracting the product from the precipitate formed in the reaction hydrocarbons with a final boiling point not higher than 300 DEG C., e.g. benzene heptane or gasoline, may be used. The solution from the reaction product may be further treated to produce additional amounts of the basic sulphonate. If desired a mixture of the products with unconverted sulphonates may be prepared by evaporating the liquids from the reaction mixture and extracting the highly basic and the unreacted sulphonate together from the solid residue, with a hydrocarbon as used in extracting the basic sulphonate alone. If the products are intended as lubricating oil additives their solvent solution may be added to the lubricating oil, and the solvent be evaporated. In examples (1) an ethanolic solution of sodium hydroxide is added to a solution prepared by adding excess calcium chloride to an isopropanol solution of the sodium salt of the monosulphonic acid of a mixture of monoalkylnaphthalenes in which the alkyl groups have a straight chain of 14 to 18 carbon atoms. From the separated solids the basic calcium sulphonate is extracted with gasoline; (2) a similar process is applied to the product obtained by sulphonating with oleum an aromatic extract (B. Pt. 180 DEG to 275 DEG C., obtained by extracting kerosine with SO2) which has been alkylated with a mixture of olefins having 9 to 15 carbon atoms obtained by cracking paraffin wax in the vapour phase. The products are of use as additives to lubricating oils, e.g. in concentrations 0.1 to 15 per cent by weight, fuel oils, light hydrocarbon mixtures used as anti-corrosives, and lubricating greases. Specification 687,490 is referred to.