GB759344A - Improvements in or relating to the preparation of basic metallic compounds of alkyl phenols and alkyl salicylic acids - Google Patents

Abstract

A mixture of polyvalent metal alkyl phenolates and polyvalent metal alkyl salicylates having a basicity of at least 100 per cent is prepared by carboxylating an alkali-metal alkyl phenolate with carbon dioxide under anhydrous conditions, reacting the product with an alkali-metal, alkali-metal hydroxide or alkali-metal alcoholate, and treating the mixture so formed with an inorganic polyvalent metal salt in an amount at least equivalent to the alkali-metal content of the mixture and with an oxide or hydroxide of the polyvalent metal in an amount at least equal to the theoretical quantity required for the formation of a product having a basicity of 100 per cent; basicity being defined as in the parent Specification. After the carboxylation and alkali treatment described above, water or alcohol formed may be removed and a second or third carboxylation may be performed which may or may not be followed by the alkali treatment prior to reaction with the polyvalent metal salt and oxide. The polyvalent metal salt and oxide specified are calcium chloride and calcium oxide. Alkali metals specified are sodium and potassium and the phenolates may contain one or more alkyl groups of 8 to 20 carbon atoms. The carboxylation is effected by heating the solid alkali-metal phenolate to 140 DEG C. under 5-6 atmospheres of carbon dioxide or by heating a solution or suspension of the phenolate in an organic liquid such as toluene, xylene, tetrahydronaphthalene, liquid paraffin, dioxan, pyridine, quinoline or a lower dialkyl ketone with carbon dioxide at atmospheric pressure on to 100-300 DEG C. at up to 140 atmospheres pressure. The product is reacted with 0.9 to 2.0 gm/equivalents of the alkali-metal or alkali-metal base per gm/equivalent of salicylate present, and is dried by heating under reduced pressure or by azeotropic distillation. It may then be subjected to the subsequent optional carboxylations. The treatment with inorganic polyvalent metal salt and oxide or hydroxide is effected as described in the parent Specification. In examples (1) phenol is reacted with mixed alkenes-1 of chain length 14-18 carbon atoms, the product treated with sodium hydroxide and reacted with carbon dioxide under pressure and the resulting mixed sodium alkyl phenolates and alkyl salicylates treated, portion (a), by the process of parent Specification and, portion (b), by addition of sodium hydroxide, drying and recarboxylation as above, dilution with xylene and reaction with calcium chloride in ethanol and calcium oxide, the alcohol and excess solids being removed to give a calcium containing product of basicity 202 per cent; (2) describes experiments showing differences between products from Examples 1 (a) and 1 (b) above when used as lubricating oil additives (see Group III); (3) mixed sodium alkyl salicylates and sodium alkyl phenates were reacted with sodium hydroxide, dried and reacted with calcium chloride in methanol, calcium oxide was added and the alcohol distilled off, benzene was added and excess solids removed and the benzene stripped to give a calcium-containing product of basicity 196 per cent. Specification 734,598 is referred to.ALSO:A lubricating oil additive consists of a mixture of polyvalent metal alkyl phenolates and polyvalent metal alkyl salicylates having a basicity of at least 100 per cent and prepared by carboxylating an alkali-metal alkyl phenolate with carbon dioxide under anhydrous conditions, reacting the product with an alkali-metal, alkali-metal hydroxide or alkali-metal alcoholate and treating the mixture so formed with an inorganic polyvalent metal salt in an amount at least equivalent to the alkali-metal content of the mixture and with an oxide or hydroxide of the polyvalent metal in an amount at least equal to the theoretical quantity required for the formation of a product having a basicity of 100 per cent, basicity being defined as in the parent Specification. The carboxylation may be repeated once or twice after the alkali treatment stage described above. The polyvalent metal specified is calcium and alkalimetals are sodium and potassium. The phenolates may contain one or more alkyl groups of 8 to 20 carbon atoms. In an example (II), the product of the invention, dissolved in sufficient mineral lubricating oil to give a composition of calcium content 0.135 per cent by weight, is compared with a similar composition containing a product prepared by the process of the parent Specification. Specification 734,598 [Group IV(b)] is referred to.