Patent GB-720372-A (GB)
Title: Lubricating oil additive
Inventor: JONES GWYNETH EUGENIE MARY
IPC: C10M169/00
Filed: 1951-07-23
Abstract: A lubricating oil additive is prepared by reacting at an elevated temperature one or more alkaline earth metal oxides, hydrated oxides, hydroxides and alcoholates with one or more nuclear alkylated phenols, heating the reaction product with sulphur and then further reacting the sulphurized product with one or more of the above alkaline earth metal compounds at an elevated temperature, the total amount of the said alkaline earth metal compounds added is such that the molar ratio of alkaline earth metal to the phenol is between 0.55 : 1 and 1.1 to 1, preferably 0.76 : 1 and 0.85 : 1.  The reactions with the alkaline earth metal compounds may be carried out at between 90 DEG  and 270 DEG  C. and preferably between 170 DEG  and 190 DEG C., the preferred temperature for the sulphurization reaction being between 90 DEG  and 210 DEG  C. and preferably between 160 DEG  and 190 DEG  C.  The molar ratio of alkaline earth compound to the phenol in the first stage may be between 0.5 : 1 and 0.8 : 1 and preferably between 0.6 : 1 and 0.75 : 1, and in the final stage the ratio may be between 0.05 : 1 and 0.03 : 1 and preferably between 0.07 : 1 and 0.23 : 1.  The sulphur to phenol molar ratio is preferably between 1 : 1 and 2 : 1, e.g. 1.2 : 1 to 1.5 : 1.  The reaction can be carried out in an inert solvent, preferably a mineral oil distillate such as a mineral lubricating oil.  A minor proportion (preferably between 3 and 15 per cent by weight of the reaction mixture) of a higher aliphatic alcohol having from 8 to 20 carbon atoms used with the mineral oil solvent prevents foaming and acts as an auxiliary solvent.  The preferred nuclear alkylated phenols are the p-tert-alkylphenols, e.g. p-tert.-octylphenol.  The alkaline earth metal compounds may be calcium or barium compounds or mixtures thereof.  The final reaction product may be blown with carbon dioxide and/or volatile materials removed by steam stripping.  In the example, an additive is prepared by heating in a mineral oil p-isoctylphenol and barium oxide, the reaction product is then heated with sulphur and the sulphurized product is heated with a further quantity of barium oxide.  Specification 586,841 is referred to.  The Provisional Specification further discloses the use of thiophenols in place of the alkylated phenols in the above process.ALSO:A lubricating composition comprising a mineral lubricating oil and a minor proportion, preferably between 0.5 and 20 per cent. by weight, of an oil additive obtained by reacting at an elevated temperature one or more alkaline earth metal oxides, hydrated oxides, hydroxides and alcoholates with one or more nuclear alkylated phenols, heating the reaction product with sulphur and then further reacting the sulphurized product at an elevated temperature with one or more of the above alkaline earth metal compounds.  The total amount of the said alkaline earth metal compounds added is such that the molar ratio of alkaline earth metal to phenol is between 0.55:1 and 1.1:1 [see Group IV (b)]. The preferred quantity of oil additive is between 1 and 10 per cent. by weight.  The composition may contain also a minor proportion of alkaline earth metal mahogany sulphonate-preferably between 0.5 and 20 per cent. by weight, e.g. between 1 and 10 per cent. by weight.  A minor proportion, e.g. between 3 and 15 per cent. by weight of the composition, of a higher aliphatic alcohol having from 8 to 20 carbon atoms may be added to the composition, e.g. lauryl, cetyl, stearyl or wool fat alcohol may be present.  Antioxidants which are normally used in motor oils may be added to the composition.  Specification 586,841 is referred to. The Provisional Specification further discloses the use of an oil additive obtained by using a thiophenol in place of the alkylated phenols referred to above.