Patent GB-786167-A (GB)
Title: Improvements in or relating to the preparation of basic oil-soluble polyvalent metalsalts of organic acids and solutions of said basic salts in oils, and the resultingsalts
Inventor: ELLIS GLYN
IPC: C10M159/20
Filed: 1954-09-27
Abstract: A solution of a basic oil-soluble polyvalent metal salt of an organic acid in an oil (i.e. a liquid which is not miscible with water) is prepared by reacting, at a temperature between 20 DEG  and 70 DEG C., an oil-soluble polyvalent metal salt of the organic acid, in the presence of the oil and a water-miscible oxygen-containing organic solvent, with a polyvalent metal carbonate which is formed in situ in the reaction mixture.  The in situ formation of the polyvalent metal carbonate is defined as either the reaction of a polyvalent metal base such as the oxide or hydroxide or an alkoxide with carbon dioxide or carbonic acid or the interaction of polyvalent metal ions and carbonate ions.  The reaction mixture obtained by the process is worked up to remove the oxygen-containing solvent and water. Preferably the reaction mixture contains a small amount not exceeding 10 per cent by volume of water, other than the water formed during the reaction, and is stirred or agitated.  The oil-soluble polyvalent metal salt used as starting material is usually formed as a first step in the process by the reaction of the organic acid (or a salt thereof other than a polyvalent metal salt) with a compound of the polyvalent metal, preferably the hydroxide, and this salt may itself be a basic salt.  Mixtures of acids may be used as starting materials.  Specified polyvalent metals, the salts of which may be prepared by the process, are calcium, barium, strontium, magnesium, copper, zinc, manganese, cobalt and lead.  The organic acids which may be used are aliphatic, cycloaliphatic and aromatic acids comprising carboxylic acids, sulphur containing acids such as sulphonic acids and phosphoric acids and the corresponding thio-acids.  Phenols and partial esters of sulphur- and phosphorus-containing acids can also be used.  Specified acids are alkyl-substituted aromatic, cycloaliphatic and heterocyclic sulphonic acids having at least 12 carbon atoms in the alkyl substituent or substituents such as petroleum sulphonic acids; petroleum naphthene sulphonic acids; aromatic carboxylic acids with an oil-solubilizing radical or radicals having at least about 12 carbon atoms such as mono- or poly-wax substituted benzoic or naphthoic acids or alkyl salicylic acids; naphthenic acids; aliphatic, cycloaliphatic and aromatic phosphoric and thiophosphoric acids having at least 12 carbon atoms per molecule; octyl-, dodecyl-, octadecyl-, diisopropyl- and dihexyl-phenols and the condensation products of phenols with aldehydes or ketones such as the reaction products of octyl phenol and formaldehyde. Specified oils are mineral oils, gasoline, carbon tetrachloride, xylenes, benzene, toluene, cyclohexane, iso-octane and decane. Specified water-miscible oxygen-containing organic solvents are aliphatic alcohols containing not more than 5 carbon atoms such as methanol and ethanol, polyhydric alcohols such as ethylene glycol, ketones containing less than 6 carbon atoms such as acetone, ethers such as diisopropyl ether, methyl and ethyl ethers of ethylene glycol and 1 : 3- and 1 : 4-dioxane and esters such as ethyl lactate.  In a preferred procedure, a solution of the organic acid in a hydrocarbon solvent is contacted with the solid material obtained during the working up of the reaction product, and then an excess of polyvalent metal hydroxide over that required to form the salt is added.  The oxygen-containing solvent may be present during this first stage or may be added after it. Carbon dioxide is then passed into the reaction mixture and forms the polyvalent metal carbonate in situ. The product of the carbonation stage comprises the basic polyvalent metal salt of the organic acid, the basicity of which depends inter alia on the amount of polyvalent metal hydroxide and the duration of the carbon dioxide treatment, unused polyvalent metal hydroxide and byproduct carbonate both in the solid state and the liquids comprising the hydrocarbon solvent, the oxygen-containing solvent and water.  The mixture is clarified, e.g. by centrifuging and the solid material recycled.  The clarified material is subjected to phase separation to yield an oxygen-containing solvent phase containing water and a hydrocarbon solvent phase containing the desired basic salt.  The hydrocarbon solvent phase may be further worked up by the addition of a light mineral oil followed by steam distillation to remove the hydrocarbon solvent.  The resultant mineral oil concentrate of the basic salt, and the basic salts generally, are used as additives for lubricating and fuel oils (see Group III).  The process may be carried out batchwise or continuously.  In examples: (1) a solution of alkyl salicylic acids in xylene, methanol and an excess of calcium hydroxide were mixed together and carbon dioxide passed in, the product being worked up as described above to give an oil solution of basic calcium alkyl salicylates; (2) as in (1) but using carbon dioxide diluted with air and working up the reaction product by centrifuging to remove the solids and distilling off the methanol, water and xylene to give the basic salt; (3) as in (1) but water added and a carbon dioxide/air mixture used; (4) as in (2) but using acetone instead of methanol and working up the basic salt as an oil solution; (5) as in 1 but using a solution of naphthenic acids in xylene; (6) as in (5) but using barium oxide, the product being a solution of the basic barium naphthenate in xylene; (7) an acid oil obtained by the sulphonation of a lubricating oil was mixed with an excess of a slurry of calcium hydroxide in methanol, carbon dioxide was passed through and the mixture filtered to give a mineral oil solution of basic calcium petroleum sulphonates; (8) a mixture of basic calcium petroleum sulphonates and alkyl salicylates was dissolved in xylene, a slurry of calcium hydroxide in methanol added, carbon dioxide passed in and the product worked up as a mineral oil solution of the mixed basic salts. Specifications 734,598, 734,622 and 738,359 are referred to.ALSO:Basic oil-soluble polyvalent metal salts of organic acids, which are used as additives for lubricating oils, are prepared in solution in an oil (i.e. a liquid which is not miscible with water) by reacting at a temperature between 20 DEG  and 70 DEG  C., an oil-soluble polyvalent metal salt of the organic acid, in the presence of the oil and a water-miscible oxygen-containing organic solvent, with a polyvalent metal carbonate which is formed in situ in the reaction mixture (see Group IV (b)).  The basic salts are preferably further worked up as solutions in oils of relatively high viscosity such as mineral lubricating oils or synthetic lubricants for use as additives.  Specified oils of relatively high viscosity are polymerized olefins, alkylated aromatic hydrocarbons, liquid polysiloxanes or fluorocarbons, ester lubricants, such as di(2-ethylhexyl) sebacate or adipate and trioctyl phosphate or a fatty oil such as castor oil.  Specified polyvalent metals the salts of which may be prepared by the process are calcium, barium, strontium, magnesium, copper, zinc, manganese, cobalt and lead.  The organic acids which may be used are aliphatic, cycloaliphatic and aromatic acids comprising carboxylic acids, sulphur-containing acids such as sulphonic acids, and phosphoric acids and the corresponding thio-acids. Phenols and partial esters of sulphur- and phosphorus-containing acids can also be used.  Specified acids are alkyl-substituted aromatic, cycloaliphatic, and heterocyclic sulphonic acids having at least 12 carbon atoms in the alkyl substituent or substituents, such as petroleum sulphonic acids; petroleum naphthene sulphonic acids; aromatic carboxylic acids with an oil-solubilizing radical or radicals having at least about 12 carbon atoms such as mono- or poly-wax substituted benzoic or naphthoic acids or alkyl salicylic acids; naphthenic acids; aliphatic, cycloaliphatic and aromatic phosphoric and thiophosphoric acids having at least 12 carbon atoms per molecule; octyl-, dodecyl-, octadecyl-, diisopropyl- and dihexyl-phenols and the condensation products of phenols with aldehydes or ketones such as the reaction products of octyl phenol and formaldehyde.  Specified additional ingredients in the lubricating oil compositions are octyl formol and Anglamol 304 (the word "Anglamol" is a Registered Trade Mark).  In examples, spindle oil solutions of basic calcium alkyl salicylates and mineral oil solutions of a basic calcium naphthenate and of a mixture of basic calcium alkyl salicyates and petroleum sulphonates are prepared.