GB715505A - Improvements in or relating to improved additives for hydrocarbon oils and particularly for lubricating oils and production thereof - Google Patents

Abstract

A process for the purification of alkylphenol sulphides, whereby they are adapted for use as improved additives for hydrocarbon oils and particularly lubricating oils, either as such or as the corresponding metal salt derivatives, comprises treating a crude alkylphenol sulphide with a basic reacting barium compound and subsequently hydrolysing the product to form an alkyl phenol sulphide substantially free of barium. The crude alkyl phenol sulphide may be prepared, usually in a solvent, by treating an alkyl phenol preferably at above 70 DEG F., e.g. 80 DEG to 95 DEG F., with a sulphur chloride to form a product having 1 to 4 sulphur atoms interconnecting benzene nuclei. Preferably about 2 mols. of the phenol to about 1.5 to 2.0 mols. of sulphur chloride are used. Preferred phenols are those having 4 to 20 carbon atoms in at least one alkyl group. Such alkyl groups are n-butyl, tert.-butyl, tert.-amyl, n-hexyl, tert.-octyl, n-decyl, cetyl, stearyl and wax-alkyl groups. Cycloaliphatic groups may also be present. Generally at least an equivalent of 0.1 mol. and preferably 0.2 to 0.6 mol. of barium for each mol. of -OH radical in the alkyl phenol sulphide is employed, although the alkyl phenol sulphide may be completely neutralized. Treatment with the p barium compound may be effected at about 175 DEG to 300 DEG F. or higher. Specified barium compounds are barium hydroxide penta- and octahydrates, barium oxide and barium carbonate. The partial barium salt may be hydrolysed with excess concentrated mineral acid at ordinary temperatures, inorganic barium salts and excess acid being removed by waterwashing. The treating and hydrolysis steps are preferably effected with an oil solution of the phenol sulphide. The treated and hydrolysed sulphide may be converted to salts, e.g. by reaction in oil at about 175 DEG to 300 DEG F. (with removal of water) with the oxide, hydroxide, hydride, alkoxide of e.g. calcium, barium, magnesium, sodium, potassium, lithium, nickel, cobalt, tin, lead, zinc, copper, cadmium, manganese, chromium, or a mixture of such compounds (e.g. of calcium and barium). In an example: (1) p-tert.-octyl phenol (2 mols.) and sulphur dichloride (1.6 mols.) are reacted in ethylene dichloride. After removal of solvent and HCl vapour, the product, dissolved in oil, is reacted at 250 DEG F. with barium hydroxide octahydrate (0.22 mols. per mol. of -OH in the sulphide), while blowing with nitrogen to remove water. The product is treated with hydrochloric acid and washed, to remove barium. The treated phenol sulphide is converted to its calcium salt by reaction with hydrated lime in the presence of isopropyl alcohol. For comparison there are prepared other products by (D) neutralizing with lime a tert.-octyl phenol/sulphur dichloride reaction product prepared as above; (E) treatment of a tert.-octyl-phenol/sulphur monochloride reaction product prepared as above with lime (0.18 mols. per mol. of -OH radical in the sulphide) followed by removal of the calcium by hydrolysis with water. A table gives results of corrosion tests on the crude and treated p-tert.-octyl phenol sulphide in hydrocarbon oils. The products may be used in lubricating or heating oils and in diesel fuels, with or without other additives.ALSO:A process for the purification of alkylphenol sulphides whereby they are adapted for use as improved additives for hydrocarbon oils and particularly lubricating oils, either as such or as the corresponding metal salt derivatives, comprises treating a crude alkyl phenol sulphide with a basic reacting barium compound and subsequently hydrolysing the product to form an alykyl phenol sulphide substantially free of barium. The crude alkyphenol sulphide may be a product having 1 to 4 sulphur atoms connecting benzene nuclei. Preferred phenols are those having 4 to 20 carbon atoms in at least one alkyl group. Such groups mentioned are n-butyl, tert.-butyl, tert.-amyl, n-hexyl, tert.-octyl, n-decyl, cetyl, stearyl, and wax-alkyl groups. Cycloaliphatic groups may also be present. The treated sulphide may be used as its salts with, e.g. calcium, barium, magnesium, sodium, potassium, lithium, nickel, cobalt, tin, lead, zinc, copper, cadmium, manganese, or chromium, or a mixture of such salts may be used. The products may be added to lubricating oils in amount 0.01 to 10 per cent. or to heating oils in amount 0.002 to 0.1 per cent. by weight based on the total composition and also to automotive and diesel fuels. Other additives such as antioxidants, metal deactivators or oil soluble petroleum sulphonates may also be present. A table gives results of corrosion tests in the p-tert.-octyl-phenol sulphide which has been barium-treated as described above, and its calcium salts, and also, for comparison, on the crude tert.-octyl-phenol sulphide, its calcium salt, and the corresponding calcium-treated compound, the sulphide being dissolved in diesel-type lubricant and in a solvent-extracted Mid-Continent base oil. The preparation and treatment of such sulphides is described (see Group IV (b)).