GB633188A - Improvements in and relating to lubricating oil compositions - Google Patents

Abstract

A mineral lubricating oil composition, especially suitable as a crank-case lubricant in engines operating at high speeds and high temperatures, contains minor proportions of a sulphurization product of one or more unsaturated hydrocarbons containing at least 10 carbon atoms in the molecule and of a mineral-oil-soluble phenol free from water-solubilizing groups and containing at least one nuclear alkyl or alkenyl substituent of at least 8 carbon atoms. Unsaturated hydrocarbons suitable for sulphurization are one or more of the mono-alkenes such as decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, cetene, cerotene and melene. Mixtures of mono-alkenes boiling above about 300 DEG C., such as may be obtained by the cracking or chlorination and dehydrochlorination of paraffin wax or by the dehydration of long chain fatty alcohols, may also be employed. Unsaturated hydrocarbons containing more than one double bond such as di-isoprene or containing an acetylenic linkage, such as the higher alkynes, may also be used. Sulphurization may be effected (i) by heating with sulphur; (ii) by treating with hydrogen sulphide at elevated temperature and pressure or under the influence of ultra-violet light, or (iii) by treating with inorganic sulphides or polysulphides such as ammonium polysulphide or phosphorus pentasulphide. Suitable phenols are octyl phenols, octenyl phenols, nonyl phenols, decyl phenols, undecyl phenols, dodecyl phenols, tetradecyl phenols, pentadecenyl phenols, hexadecyl phenols and octadecyl phenols, particularly those with branched chain alkyl or alkenyl groups. Mixtures of phenols made by the alkylation of phenols, such as phenol, cresol, a - or b -naphthol, with mixtures of alkenes such as those derived from paraffin wax by cracking or by chlorination and dehydrochlorination or from higher fatty alcohols by dehydration may be used. More than one alkyl or alkenyl group may be present in the phenol as in the case of compounds made by the di- or trialkylation of phenols with alkenes, alkyl halides, alcohols or ethers or of compounds made by the mono-alkylation of cresol, xylenol, carvacrol or cardanol. Other nuclear substituents such as halogen, alkoxy, alkyl mercapto and alkyl amino groups may be present in the phenol. Moreover di- or poly-hydric phenols such as catechol, resorcinol, pyrogallol and the di-hydroxy naphthalenes may be alkylated to give suitable phenols. Alkenyl phenols which may be used are cardanol, anacardol and urushiol, and these may be used in the purified state or as the mixtures present in the distillate and distillate residues of oils extracted from the Anacardium genus, for example cashew nut oil. The lubricating oil compositions may contain additional ingredients such as pour point depressors, thickeners, oxidation inhibitors, sludge dispersers, oiliness agents, anti-foaming agents, viscosity index improvers, anti-corrosion agents and extreme pressure additives. Specific additional ingredients mentioned are olefine polymers, amine soaps of fatty acids, amine soaps of naphthenic acids, amine soaps of naphthasulphonic acids, organic phosphates, organic phosphites, organic thiophosphates, organic thiophosphites, sulphurized mineral or fatty oils, sulphurized unsaturated fatty acids, high molecular weight carboxylic acids such as are obtained by the condensation of long chain alkenes with maleic anhydride, reaction products of fatty acids with phosphorus pentasulphide, alicyclic alcohols, alicyclic esters. Metal-containing additives which may also be present are metal soaps of fatty acids, metal soaps of naphthenic acids, metal soaps of naphtha-sulphonic acids, metal phenates, metal salicylates, metal alcoholates, metal salts of alkyl phenol sulphides, metal salts of the condensation products of alkyl phenols and formaldehyde, metal organophosphates and thiophosphates. In the examples, mineral lubricating oil compositions containing a sulphurized mixture of alkenes and either (a) a mixture of alkyl phenols made by alkylating phenol with a mixture of alkenes, or (b) distilled cardanol are described. The mixture of alkenes which is sulphurized and the mixture of alkenes which is used as an alkylating agent are both obtained by cracking paraffin wax. Sulphurization of the mixture of alkenes is effected by heating with sulphur. For comparison purposes, mineral lubricating oil compositions are described containing only the sulphurized mixture of alkenes just described or the ingredient (a).ALSO:Sulphurization products of unsaturated hydrocarbons.-Sulphurization products of one or more unsaturated hydrocarbons containing at least 10 carbon atoms in the molecule are employed as lubricating oil additions. Unsaturated hydrocarbons suitable for sulphurization are one or more of the mono-alkenes, such as decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, cetene, cerotene and melene. Mixtures of monoalkenes boiling above about 300 DEG C., such as may be obtained by the cracking or chlorination and dehydrochlorination of paraffin wax or by the dehydration of long-chain fatty alcohols, may be employed. Unsaturated hydrocarbons containing more than one double bond such as di-isoprene or containing an acetylenic linkage, such as the higher alkynes, may also be used. Sulphurization may be effected (i) by heating with sulphur; (ii) by treating with hydrogen sulphide at elevated temperature and pressure or under the influence of ultra-violet light; or (iii) by treating with inorganic sulphides or polysulphides such as ammonium polysulphide or phosphorus pentasulphide. In an example, a mixture of alkenes, obtained by cracking paraffin wax, is sulphurized by heating with sulphur. Phenols with alkyl or alkenyl substituents.-Mineral-oil-soluble phenols free from water-solubilizing groups and containing at least one nuclear alkyl or alkenyl substituent of at least 8 carbon atoms are employed as lubricating oil additives. Mixtures of phenols made by the alkylation of phenols, such as phenol, cresol, a - or b -naphthol, with mixtures of alkenes such as those derived from paraffin wax by cracking or by chlorination and dehydrochlorination or from higher fatty alcohols by dehydration may be used. More than one alkyl or alkenyl group may be present in the phenol as in the case of compounds made by the di- or tri-alkylation of phenols with alkenes, alkyl halides, alcohols or ethers or of compounds made by the monoalkylation of cresol, xylenol, carvacrol or cardanol. Other nuclear substituents such as halogen, alkoxy, alkyl mercapto and alkyl amino groups may be present in the phenol. Moreover, di- or poly-hydric phenols such as catechol, resorcinol, pyrogallol and the dihydroxy naphthalenes may be alkylated to give suitable phenols. In an example, a mixture of alkyl phenols is made by alkylating phenol with a mixture of alkenes obtained by cracking paraffin wax.