Patent GB-616881-A (GB)
Title: Improvements in or relating to lubricating compositions
IPC: C10M135/00
Filed: 1946-05-27
Abstract: A mineral lubricating oil composition contains the following ingredients which render it substantially non-corrosive, especially to composite metal bearings, inhibit the formation or deposition of sludge and increase the film rupture strength of the composition: (a) a petroleum sulphonate of an alkaline earth metal, and (b) a hydroxy-substituted aromatic thio-ether or di- or poly-sulphide, or (c) a phosphite or thiophosphite ester of such thioether or di- or poly-sulphide.  The composition may contain ingredients (a), (b) and (c), or, in addition to ingredients (a) and (b), it may contain (d) a tri-aryl phosphite, or (e) a mercapto arylene thiazole or an arylene thiazyl disulphide or a derivative thereof such as an ether, hydroxy ether or ester of a mercapto arylene thiazole.  Ingredient (a) is a mahogany soap, particularly calcium mahogany soap, while ingredient (b) may be di-(3-carbomethoxy-4 - hydroxyphenyl) disulphide, di - (3 - carbo - methoxy-4-hydroxyphenyl) tri- and tetra-sulphide, p-tertiary amyl phenol thioether, p-tertiary amyl phenol disulphide, di-(3-carbobutoxy-4-hydroxyphenyl) thioether, and any of the complex mixtures of sulphides derived from methyl salicylate described in Specification 561,898.  Ingredient (b) preferably has an ester substituent and may be a compound of this type mentioned in Specifications 455,236, [Group V], or 561,898.  Examples of phosphite or thiophosphite esters which may be employed as ingredient (c) are given in Specification 574,445, while tri-aryl phosphites which may be employed as ingredient (d) are triphenyl phosphite, tricresyl phosphite or tri-tertiary amyl phenyl phosphite.  Ingredient (e) may be mercaptobenzothiazole, benzothiazole disulphide or benzothiazole hydroxymethyl sulphide. In the examples, mineral lubricating oil compositions are described which contain (1 calcium petroleum sulphonate, di-(3-carbomethoxy-4-hydroxyphenyl) thio ether and, if desired, one of di-(3-carbomethoxy-4-hydroxyphenyl) thioether cresyl phosphite, tri-(p-tertiary amyl phenyl phosphite, mercaptobenzothiazole, benzothiazole disulphide and tricresyl phosphite; (2) calcium petroleum sulphonate and one of p,p1-dihydroxy diphenyl thioether, di - (3 - pentadecyl - 4 - hydroxyphenyl) thioether, di-(2-t-amyl-5-hydroxyphenyl) disulphide and p,p1-dihydroxy diphenyl thioether phenyl phosphite; (3) barium petroleum sulphonate and one of di-(3-carbomethoxy-4-hydroxyphenyl) polysulphide, di-(2-hydroxynaphthyl) thioether, di - (3 - carbomethoxy - 4 - hydroxyphenyl) thioether cresyl phosphite and tertiary butyl cresol thioether phosphite; (4) strontium petroleum sulphonate and tertiary butyl cresol thioether; (5) basic calcium petroleum sulphonate and tertiary butyl cresol thioether phosphite; (6) strontium petroleum sulphonate and di-(3-carbomethoxy - 4 - hydroxyphenyl) disulphide; (7) strontium petroleum sulphonate, di-(3-carbomethoxy-4-hydroxyphenyl) disulphide and tricresyl phosphite; and (8) calcium petroleum sulphonate, di - (3 - carbomethoxy - 4 - hydroxyphenyl) thioether and di-(3-carbomethoxy-4-hydroxyphenyl) thioether phosphite.  Tests are described in which the mineral lubricating oil compositions of the examples are compared with mineral lubricating oil compositions containing: (i) calcium petroleum sulphonate; (ii) tricresyl phosphite; (iii) strontium petroleum sulphonate and tricresyl phosphate; and (iv) calcium petroleum sulphonate, di-(3-carbomethoxy-4-hydroxyphenyl) thioether and tributyl phosphite.ALSO:The following phenolic thio-compounds are employed as lubricating oil additives: di-(3-pentadecyl - 4 - hydroxyphenyl) thio-ether, prepared by reacting together 3-pentadecyl phenol and sulphur dichloride in benzene; di-(2-tertiary amyl - 5 - hydroxyphenyl) disulphide, similarly prepared from p-tertiary amyl phenol and sulphur monochloride; tertiary butyl cresol thioether, similarly prepared from tertiary butyl cresol and sulphur dichloride. The tertiary butyl cresol thioether is converted to its phosphite ester by refluxing it with phosphorus trichloride until evolution of hydrogen chloride ceases.