Patent GB-686074-A (GB)
Title: Extreme pressure additives for lubricating compositions
IPC: C07F9/02
Filed: 1950-05-31
Abstract: Extreme pressure additives for lubricants are obtained by reacting at an elevated temperature a non-aromatic cyclic hydrocarbon or oxygenated hydrocarbon having a six-membered unsaturated ring and two unsaturated bonds in the molecule with a sulphur chloride in an amount of approximately 1 to 2 molecular proportions per molecular proportion of the cyclic hydrocarbon or oxygenated hydrocarbon and further reacting the product with a phosphorus sulphide at an elevated temperature in an amount of less than 1 molecular proportion per molecular proportion of the cyclic hydrocarbon or oxygenated hydrocarbon.  The preferred cyclic hydrocarbons are the monocyclic terpenes such as limonene, dipentene, terpinolene and alpha terpinene.  Oxygenated derivatives of monocyclic terpenes, e.g. esters, acids, alcohol and ketonic derivatives of monocyclic terpenes may also be employed and abietic acid and its C1 to C4 alkyl esters are other starting materials specified.  The preferred sulphur chloride is the monochloride (S2Cl2) whilst the preferred phosphorus sulphide is the sesquisulphide (P4S3), although the other phosphorus sulphides, e.g. the pentasulphide (P2S5) may be used.  The phosphorus sulphide treatment may be effected in the presence of a primary alcohol having between 10 and 20 carbon atoms per molecule or a mixture of such alcohols to increase the plasticity of the resulting additive.  When sulphur monochloride is employed the reaction temperature may be between 60 DEG  and 125 DEG  C., but if the dichloride (SCl2) is used it should be added at a lower temperature, e.g. 30 DEG  to 60 DEG  C., and the reaction then completed at a higher temperature such as 75 DEG  to 125 DEG  C.  The phosphorus sulphide reaction may be conducted at 100 DEG  to 175 DEG  C.  In examples: (1) sulphur monochloride is added to a "special dipentene" (a mixture of dipentene and terpinolene containing a small amount of a -pinene, a -terpineol, para-cymene and para-menthadiene) at 75-100 DEG  C., and the product then heated at 75-100 DEG  C.  The product is then diluted with a naphthenic lubricating oil distillate and P4S3 added and the mixture heated at 125-150 DEG  C.  A mixture of high aliphatic alcohols, mainly C12, is then added and heating continued. The product is then blown with nitrogen and filtered to give the final product containing chlorine, sulphur and phosphorus; (2) SCl2 is added to the "special dipentene" as used in (1) and the temperature maintained at 40 DEG  to 60 DEG , then at 20 DEG  C., and finally at 75 DEG  to 100 DEG  C.  A mineral base oil and P4S3 are then added and the mixture heated at 125-150 DEG  C. and a high aliphatic alcohol mixture added as in (1).  After further heating the final product is obtained as in (1).  Examples of the use of the products as extreme pressure additives for lubricating oils are given (see Group III).ALSO:A lubricating composition comprises a lubricating oil, preferably a mineral lubricating oil, and an extreme pressure additive obtained by reacting at elevated temperature a non-aromatic cyclic hydrocarbon or oxygenated hydrocarbon having a six-membered unsaturated ring and two unsaturated bonds in the molecule with a sulphur chloride in an amount of approximately 1 to 2 molecular proportions per molecular proportion of the cyclic hydrocarbon or oxygenated hydrocarbon and then reacting the processes at elevated temperature with a phosphorus sulphide in an amount of less than one molecular proportion per molecular proportion of the cyclic hydrocarbon or oxygenated hydrocarbon (see Group IV (b)).  The specified starting materials are the monocyclic terpenes such as limonene, dipentene, terpinolene and alpha terpinene and oxygenated derivatives, e.g. esters, acids, alcohol and ketonic derivatives of monocyclic terpenes, abietic acid and its C1 to C4 alkyl esters being also specified.  Specified sulphur chlorides are the mono- and dichloride.  The phosphorus sulphide treatment may be carried out in the presence of a primary aliphatic alcohol having between 10 and 20 carbon atoms per molecule to increase the plasticity of the additive. The finished lubricant preferably contains a conventional chlorinated long chain aliphatic hydrocarbon such as chlorinated wax or chlorinated kerosene and the additives may be used in mineral oils, synthetic oils, or both or in lubricating greases.  Other conventional additives such as antioxidants, viscosity index improvers, thickeners, tackiness agents and pour point depressors may also be present.  In examples: (1) an additive obtained by reacting "special dipentene" (a mixture of dipentene and terpinolene containing a small amount of a-pinene, a-terpineol, paracymene and para menthadiene) with sulphur monochloride and then with P4S3 in the presence of a mixture of high aliphatic primary alcohols (mainly C12) as plasticizer is made into a blend containing 90 per cent of a mixture of about equal parts of a steam refined Pennsylvania cylinder oil and a Mid-Continent acid refined oil, 7.5 per cent chlorinated wax, and 2.5 per cent of the additive product and its performance tested; (2) the product obtained by reacting "special dipentene" as used in (1) with SCl2 and then with P4S3 as in (1) is made into a blend containing 2.5 per cent of the additive in a mixed lubricating oil containing chlorinated wax as in (1) and its performance tested for extreme pressure properties.