Patent GB-679296-A (GB)
Title: Improvements in or relating to compounds for use as additives to lubricants and lubricants containing such additives
IPC: C07F9/04
Filed: 1950-06-19
Abstract: Compounds suitable for use as additives for lubricating oils are obtained by reacting a monocyclic terpene or substituted derivative thereof with elemental sulphur at an elevated temperature and then treating the resulting compound at an elevated temperature with a compound containing phosphorus and sulphur, preferably a phosphorus sulphide.  In a modification of the process the monocyclic terpene or substituted derivative thereof is reacted at elevated temperature simultaneously with sulphur and with the compound containing phosphorus and sulphur. The preferred phosphorus and sulphur containing compound is P4S3, but an organo-substituted thiophosphoric acid prepared by reacting a sulphide of phosphorus with an alcohol or phenol may also be employed, e.g. di - n - butyl - dithiophosphoric acid, di - (ethylhexyl) dithiophosphoric acid and di-(tert.-octylphenyl) dithiophosphoric acid.  Specified terpenic starting materials are: dipentene, terpinolene, limonene, terpineol and diterpenyl ethylene ether.  The alcohol and aldehyde derivatives of dipentene and terpinolene are also mentioned.  The reaction with sulphur may be effected at 120-200 DEG  C. and the subsequent treatment with the phosphorus and sulphur containing compound at 75 DEG  to 175 DEG  C. and the proportions of phosphorus sulphide used should be within the range of about 0.2 to about 10 per cent based on the weight of the sulphurized terpene.  Generally, about 1.5 atomic proportions of sulphur to one molecular proportion of terpene should be used.  In the modified form of the process the reaction is preferably conducted in the presence of a liquid medium especially a mineral lubricating oil and the temperature should be about 140 DEG to 200 DEG  C.  When large amounts of the phosphorus sulphide are used, it is desirable to employ a plasticizer for the reaction, e.g. an aliphatic alcohol containing at least eight carbon atoms.  In examples: (1) sulphurized dipentene prepared by reacting a commercial dipentene with elemental sulphur at elevated temperature is treated with P4S3 for 12 hours at 102 DEG  C.; (2) commercial dipentene is added to molten sulphur and the mixture heated under reflux for 3 hours at 165-175 DEG  C.  The product is then blended with mineral oil (naphthenic distillate) and heated with P4S3 at 125-150 DEG  C. for 2 1/2 hours.  Some C8 Oxo alcohol is then added and the heating continued.  The product is then blown with nitrogen at 125-150 DEG C.; (3) the sulphurized dipentene obtained in (2) and mineral oil (as in (2)) is added to P4S3 and the mixture heated under reflux at 125-150 DEG  C.  A C12 alcohol mixture is then added as plasticizer and the heating continued.  The product is then blown with nitrogen at 125 DEG  C.; (4) sulphurized dipentene obtained as in (2) is blended with an acid treated naphthenic petroleum distillate and added to P4S3.  The mixture is then heated under reflux and a C12 alcohol mixture added and the heating continued.  The product is then vacuum stripped; (5) part of a mixture of sulphur and P4S3 is heated and a mixture of a commercial dipentene and a refined coastal naphthenic lubricating oil added.  The mixture is then heated to 150 DEG  C. and the remainder of the dipentene lubricating oil mixture added followed by further heating.  A C8 Oxo alcohol is then added as plasticizer and the mixture heated for a further period. The product is finally blown with nitrogen at 155-175 DEG  C.; (6) a mixture of sulphur and P4S3 is heated and a mixture of commercial dipentene and the lubricating oil diluent of (5) is then added and the mixture heated, the product being then blown with nitrogen at room temperature.  The products may be used as additives for lubricating oils (see Group III).ALSO:A lubricating oil composition comprises a lubricating oil base and from 0.05 to 50 per cent by weight of an additive prepared by reacting a monocyclic terpene or substituted derivative thereof with elemental sulphur at an elevated temperature and then treating the resulting compound at an elevated temperature with a compound containing phosphorus and sulphur, preferably a phosphorus sulphide (see Group IV(b).  In a modification of the process the terpenic compound is reacted at elevated temperature simultaneously with sulphur and the compound containing phosphorus and sulphur.  The preferred phosphorus and sulphur compound is P4S3 although an organo-substituted thiophosphoric acid prepared by reacting a sulphide of phosphorus with an alcohol or phenol may be employed, e.g. di-n-butyl-, di-(ethylhexyl)-, and di-(tert-octylphenyl)-dithiophosphoric acids.  Specified terpenic materials are dipentene, terpinolene, limonene, terpineol and diterpenyl ethylene ether.  The alcohol and aldehyde derivatives of dipentene and terpinolene are also mentioned.  The products may be added to lubricating oil either alone or in combination with known extreme pressure additives, e.g. sulphurized and/or chlorinated long chain hydrocarbons, such as chlorinated wax, or sulphurized and phosphorus sulphide treated fatty materials or aliphatic esters such as fatty acids and fatty oils of 12 to 22 carbon atoms to the molecule, sulphurized and/or phosphorus sulphide treated abietic acid and its lower alkyl esters.  The lubricating oils may also be p compounded with detergent type additives such as metal soaps, metal petroleum sulphonates, metal phenates, metal alcoholates, metal alkyl phenol sulphides, metal organo phosphates, thiophosphates, phosphites and thiophosphites, metal salicylates, metal xanthates and thioxanthates, metal thiocarbamates, amines and amine derivatives, reaction products of metal phenates and sulphur or phosphorus sulphides, metal phenol sulphonates, phenols and phenol sulphides. Specified additives are barium tert-octyl phenol sulphide, calcium tert-amyl phenol sulphide, cadmium oleate, nickle oleate, barium octadecylate, calcium phenyl stearate, zinc di-isopropyl salicylate, aluminium naphthenate, calcium ceyl phosphate, barium di-tert-amyl phenol sulphide, calcium petroleum sulphonate, zinc methylcyclohexyl thiophosphate and calcium dichlorostearate.  The lubricating oil base stocks may be straight mineral oils or distillates derived from paraffinic, naphthenic, asphaltic, or mixed base crudes; or blended oils.  The oils may be refined by conventional methods or may be solvent extracted oils.  Hydrogenated or white oils may be employed as well as synthetic lubricants such as branched chain esters and synthetic oils prepared by the polymerization of olefines or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products.  Also cracking coil tar fractions, coal tar or shale oil distillates, and animal, vegetable or fish oils or their hydrogenated or voltolized products may be used in admixture with mineral oils.  Other agents which may also be used in addition to the additive are also specified, including colloidal solids such as graphite or zinc oxide, esters, ketones, alcohols, aldehydes, halogenated or nitrated compounds whilst higher alcohols such as octyl, lauryl, and stearyl alcohols may be added as plasticizers and defoamers. Several examples are given which show the effect of adding products, obtained by treating commercial dipentene with sulphur and P4S3, either consecutively or simultaneously, to mineral lubricating oils either alone or in combination with detergent and other additives.