Patent GB-596150-A (GB)
Title: Mineral lubricating oil compositions and manufacture of aryl sulphide additives therefor
Filed: 1945-07-23
Abstract: Mineral lubricating oil compositions contain a small proportion of a mixed o-hydroxy-aryl alkyl ketone thioether or disulphide of the general formula <FORM:0596150/III/1> wherein "M" is a metal other than an alkali metal, "x" is the valency of "M," "R" is an alkyl radical of at least 10 carbon atoms, and "n" is 1 or 2, the benzene rings containing no other substituents.  "R" is preferably saturated and a straight or branched aliphatic chain, "M" is preferably Ca, Ba, Al, Cr, Zn, Sn, Ni, Co, or Mn.  The compounds specified comprise the metallic derivatives of the thioethers and disulphides derived from o-hydroxy-stearophenone, o-hydroxylaurophenone, o-hydroxypalmitophenone, and o-hydroxyphenyl ketones of mixed acids, e.g., from naturally-occurring mixed acids obtainable by the saponification of fatty oils such as coconut oil.  The compounds emphasized comprise the Ba, Sn and Cr salts of o-hydroxy-stearophenone thioether.  The compositions may also contain a small proportion of the metal soap of the free fatty acid corresponding to "R" in the general formula besides other possible by-products formed during the preparation of the additives.  The compositions may further contain a small proportion of an organic phosphite ester such as trialkyl phosphite, triaryl phosphite, or a phosphite derived from an aromatic hydroxy-substituted thioether, or polysulphide, e.g., as described in Specification 574,445.  Compounds emphasized comprise di (3-carbomethoxy-4-hydroxyphenyl) thioether cresyl phosphite; tributyl phosphite; and 3-pentadecyl phenol thioether phosphite.  The ketone additives may be prepared by first synthesising the ketones, then converting them into corresponding thioethers or disulphides, and finally preparing the metallic derivatives thereof.  The ketones may be prepared by heating a phenol, with at least one o-position unsubstituted, with a higher fatty acid in the presence of anhydrous zinc chloride with continuous distillation of water from the reaction mixture followed by boiling with water to remove zinc chloride and then dissolving the separated product in benzene filtering and distilling off the solvent. Alternatively, phenol, anhydrous AlCl3 and the fatty acid chloride are reacted together and further heated for 2 hours at 170 DEG -180 DEG C.  The preparation of o-hydroxystearophenone by the first method is described in detail.  The thioethers or disulphides are then prepared by refluxing the ketones in an anhydrous solvent such as benzene with sulphur dichloride or monochloride respectively.  The preparation of the thioether of the above ketone is further described in detail.  The metallic derivatives are finally prepared such as by double decomposition in aqueous solution, or by reacting an oil concentrate of the ketone thioether with the desired metal hydroxide. The preparation of the Ba, Sn, and Cr salts of the above thioether is also described in detail.ALSO:o-Hydroxy-aryl alkyl ketones wherein the alkyl radical is of at least 10 carbon atoms such as o-hydroxystearophenone, o-hydroxylaurophenone, o - hydroxypalmitophenone, and o-hydroxyphenyl ketones of mixed acids, e.g. from naturally-occurring mixed acids obtainable by the saponification of fatty oils such as coconut oil, are prepared by heating a phenol, with at least one o-position unsubstituted, with the higher fatty acid in the presence of anhydrous zinc chloride with continuous distillation operated from the reaction mixture, followed by boiling with water to remove zinc chloride and then dissolving the separated product in benzene, filtering and distilling off the solvent.  Alternatively, phenol, anhydrous AlCl3 and the fatty acid chloride are reacted together and further heated for 2 hours at 170-180 DEG  C.  The preparation of o-hydroxystearophenone by the first method is described in detail. Thioethers or disulphides of such ketones are prepared by refluxing the ketones in ananhydrous solvent such as benzene with sulphur dichloride or monochloride respectively.  The preparation of the thioether of the above ketone is further described in detail.  The metal salts of these thioether or disulphide derivatives are prepared by double decomposition in aqueous solution or by reacting an oil concentrate of the ketone thioether with the desired metal hydroxide.  The preparation of the Ba, Sn and Cr salts of the above thioether is also described in detail. Specification 574,445 is referred to.