Patent GB-759346-A (GB)
Title: A process for the preparation of basic products containing polyvalent metals
IPC: C07C51/41
Filed: 1954-10-28
Abstract: Basic polyvalent metal salts of aromatic hydroxycarboxylic acids or mixtures thereof with polyvalent metal phenolates are prepared by dissolving alkali-metal salts of aromatic hydroxycarboxylic acids, or mixtures thereof with alkali-metal phenolates, in an organic liquid which forms an azeotrope with water, adding an aqueous alkali-metal hydroxide solution containing at least 0.5 gm. mols. of hydroxide per gm. mol. of aromatic acid salt, heating to remove the water by azeotropic distillation, adding an aqueous inorganic polyvalent metal salt solution and removing the water by azeotropic distillation.  The aromatic hydroxycarboxylic acids may be mono- or poly-nuclear carboxylic acids containing a phenolic hydroxy group, such as hydroxycarboxylic acids of benzene, naphthalene or diphenyl, in which the carboxylic group may be in a sidechain or nucleus and wherein the acids may contain further substituents in the sidechain or nucleus such as carboxylic, hydroxyl, halogen, amino, nitro or hydrocarbon. Specified acids and phenols are alkyl salicylic acids and alkyl phenols containing one or more alkyl groups of from 8 to 20 carbon atoms.  Suitable mixtures of alkyl salicylic acids and alkyl phenols may be prepared by reacting alkyl phenols with carbon dioxide by the Kolke-Schmitt method using the modifications described in Specification 734,598. Organic azeotroping liquids specified are xylene, benzene, toluene and gasoline of b.p. 120-140 DEG  C. Alkalimetal hydroxides specified are sodium and potassium hydroxides. Specified polyvalent metal salts are chlorides and nitrates of calcium, magnesium, zinc and cobalt, used in aqueous concentrations of 10 per cent to 30 per cent by weight and in quantities at least equivalent to the alkali metal content of the reaction mixture. After the second azeotropic distillation, the inorganic salts formed such as sodium chloride are removed by filtration or by extraction with water, an aliphatic alcohol of 1 to 3 carbon atoms or with a mixture of both.  After replacing the xylene with lubricating oil, the products may be used as lubricating oil and anti-corrosion agent additives (see Group III).  In an example, sodium alkyl phenolates containing alkyl groups of from 14 to 18 carbon atoms are carboxylated with carbon dioxide, treated with sodium hydroxide solution, recarboxylated and xylene added when the solution is treated with aqueous sodium hydroxide and the water removed by azeotropic distillation, filtered and aqueous calcium chloride added, the water azeotroped off, the residue filtered and lubricating oil added followed by xylene removal by steam distillation to obtain the product.  Specification 729,376 also is referred to.ALSO:Lubricating oils and corrosion inhibitors are described containing additives which comprise polyvalent metal salts of aromatic hydroxycarboxylic acids or mixtures thereof with polyvalent metal phenolates prepared by dissolving alkalimetal salts of aromatic hydroxycarboxylic acids, or mixtures thereof with alkalimetal phenolates, in an organic liquid which forms an azeotrope with water, adding an aqueous alkali metal hydroxide solution containing at least 0.5 gm. moles of hydroxide per gm. mole of aromatic acid salt, removing the water by azeotropic distillation, adding an aqueous inorganic polyvalent metal salt solution and again removing the water by azeotropic distillation. The aromatic hydroxycarboxylic acid may be a mono- or polynuclear acid containing a phenolic hydroxy group; the carboxylic group may be in a side chain or nucleus and the acids may contain further substituents such as carboxylic, hydroxy, amino, nitro or hydrocarbon groups or halogen.  Specified acids and phenols are alkyl salicylic acids and alkyl phenols containing one or more alkyl groups of from 8 to 20 carbon atoms. The additives are used in the lubricating oils in amounts of from 0.1 per cent to 15 per cent by weight and may be used in mineral lubricating oils, synthetic lubricating oils, lubricating oils containing fatty oils, lubricating greases and in light hydrocarbon mixtures used as anti-corrosion agents.  The may be used in conjunction with detergents such as alkaline earth metal compounds of alkyl phenol-formaldehyde condensation products or alkaline earth metal salts of oil-soluble petroleum sulphonic acids, with antioxidants such as alkyl phenols and arylamines, and with other corrosion inhibitors and extreme pressure dopes.  An example describes the preparation of an additive using calcium as polyvalent metal and di- and mono-sodium alkyl salicylates and alkyl phenols comprising mono- and di-alkyl compounds with alkyl groups of 14-18 carbon atoms; the xylene solution of the product is blended with a mineral lubricating oil and the xylene removed by steam distillation. Specifications 729,376 and 734,598 [Group IV(b)] are referred to.