Patent GB-672875-A (GB)
Title: Improvements in lubricating compositions containing extreme pressure addition agents
IPC: C10M159/12
Filed: 1948-02-05
Abstract: An extreme pressure lubricating composition comprises a major proportion of a lubricating oil base, a minor proportion of an oil-soluble extreme pressure addition agent obtained by reacting a phosphorus-and sulphur-containing reagent with an organic material, and a minor proportion of an oil-soluble corrosion inhibitor chosen from a list given.  The load carrying ability of the lubricating oil base is substantially increased by the inclusion therein of the minor proportion of the extreme pressure addition agent, which is one whose effectiveness is dependent upon its ability to react chemically with the metallic surfaces to be lubricated, while the inclusion of the corrosion inhibitor does not substantially decrease the extreme pressure proportions imparted by the extreme pressure addition agent. The lubricating oil base may be of mineral, animal, vegetable or synthetic origin or may comprise a mixture of mineral and non-mineral oils.  Those fatty acids, such as oleic acid, which are oily liquids are included among the non-mineral oils.  Phosphorus- and sulphur-containing reagents which may be employed in preparing the extreme pressure addition agent are phosphorus sulphides, phosphorus sulphohalides, PS (MH2), P (CNS)3 and P4S4O6, while a list is given of suitable organic materials which may be reacted with the phosphorus- and sulphur-containing reagents in the preparation of the extreme pressure addition agent.  The organic materials in this list are arranged under the following headings: mineral oils and waxes, animal and vegetable oils, animal fats and waxes, vegetable waxes, carboxylic acids and their esters, alcohols and phenols, and unsaturated hydrocarbon materials.  If desired, the extreme pressure addition agents may be halogen-containing compounds.  The substances in the list of corrosion inhibitors are arranged under the following headings: organic nitrogen-containing corrosion inhibitors, organic nitrogen- and oxygen-containing corrosion inhibitors, organic nitrogen- and sulphur-containing corrosion inhibitors, heterocyclic organic nitrogen-containing corrosion inhibitors, organic oxygen-containing corrosion inhibitors, organic sulphur-containing corrosion inhibitors and organic phosphorus-containing corrosion inhibitors.  Particularly suitable corrosion inhibitors are amino compounds and organic phosphates and phosphites.  The lubricating composition may contain additional ingredients such as pour point depressors, antioxidants, oiliness improving agents, soaps and substances promoting the solubility of the corrosion inhibitor. Where the compound obtained by reacting a phosphorus- and sulphur-containing reagent with an organic material has no extreme pressure properties it may still be employed if used in the presence of a co-operative agent which will activate or combine with the compound so that as a result a reaction with the metal surface of the bearings takes place for the purpose of imparting extreme pressure characteristics to the oil.  A list is given of suitable radicles which may be introduced into the molecule of the extreme pressure addition agent or of the corrosion inhibitor for the purpose of imparting oil-solubility.  The lubricating compositions may be employed as lubricants in metal drawing and forming operations, as lubricants for gears and bearings under conditions of extreme pressure, as lubricants for internal combustion engines and as top cylinder lubricants.  In the examples, mineral lubricating oil compositions are described containing (1) 2 per cent of P2S5- treated 4-methyl cyclohexanol and 1 per cent o-amino phenol and (2) 5 per cent of P2S5- treated turpentine and 1 per cent catechol. Specification 581,243 is referred to The Specification as open to inspection under Sect. 91 refers to a lubricating composition comprising a major proportion of a lubricating oil base, a minor proportion of an oil-soluble extreme pressure addition agent and a minor proportion of an oil-soluble corrosion inhibitor. Additional examples of suitable sulphur-bearing extreme pressure addition agents are given.  This subject-matter does not appear in the Specification as accepted.