Patent GB-610056-A (GB)
Title: Method of making dithiophosphoric acid esters of an alkyl-substituted phenol and mineral oils containing these compounds
IPC: C07F9/18
Filed: 1945-10-24
Abstract: A mineral oil composition is obtained by the addition of a dithiophosphoric acid ester of an alkyl-substituted phenol, or a metal salt thereof, to a mineral oil.  The composition may be prepared by reacting an alkyl halide with a phenol in the presence of a Friedel-Craft catalyst, and reacting in a mineral oil medium the resulting alkyl-substituted phenol with phosphorus pentusulphide to yield the required ester.  Suitable metals for salt formation are alkali and alkaline earth metals, aluminium, tin and lead.  Suitable phenols are phenol, resorcinol, hydroquinone, catechol, cresol, xylenol, the oxydiphenyls, the hydroxydiphenyl-methanes, phenethylphenol (C6H5CH2CH2C6H4 OH), phenol resins, methyl-hydroxy-diphenyls, guiacol, alpha and beta naphthol, alkyl, aryl and aralkyl substituted naphthols, anthranol, the phenanthrols, monomethyl ether of catechol, and chlorophenols.  Any alkyl halide may be used, preferably those of high molecular weight, e.g. those obtained by chlorinating wax such as petroleum wax.  The samples furnished under Sect. 2 (5) comprise the barium salts of the dithiophosphoric acid esters derived from wax-naphthol, wax-hydroquinone, wax-catechol and wax-resorcinol and phosphorus pentasulphide dissolved in mineral oil.ALSO:A dithiophosphoric acid ester of an alkyl substituted phenol is prepared by reacting an alkyl halide with a phenol in the presence of a Friedel-Craft catalyst and then reacting the reaction mixture with phosphorus pentasulphide, e.g., a chlorinated paraffin wax may be reacted with a phenol in the presence of aluminium chloride at a temperature not greater than 175 DEG  C. and the reaction mixture is then reacted with phosphorus pentasulphide.  The proportion of the alkyl-substituted phenol to the phosphorus pentasulphide may be in the molecular ratio of 4 : 1, and the reaction may be effected in a substantially inert hydrocarbon diluent, e.g. a mineral lubricating oil fraction.  The Friedel-Craft complex may be destroyed with water before isolating the required esters, or the reaction mixture may be treated with a small amount of zinc dust before adding water to destroy the Friedel-Craft complex. The dithiophosphoric acid ester may be converted to a metal salt by treatment with a metal compound, e.g. as described in U.S.A. Specification 2,410,650.  Suitable metals for the formation of salts are the alkali and alkaline earth metals and also aluminium, tin and lead.  Suitable phenols are phenol, resorcinol, hydroquinone, catechol, cresol, xylenol, the oxidiphenyls, the hydroxydiphenyl methanes, phenethylphenol (C6H5CH2CH2C4 H DEG OH), phenol resins, p methyl-hydroxy-diphenyls, quiacol, alpha and beta naphthol, alkyl, aryl and aralkyl substituted naphthols, anthranol, the phenanthrols, monomethyl ether of catechol. and chlorophenols. Any alkyl halide may be used for the process of the invention but preferably those of high-molecular weight, e.g. those obtained by chlorinating wax such as petroleum wax.  In an example, petroleum wax is chlorinated and the chlorowax reacted with phenol in the presence of aluminium chloride and mineral oil, and then phosphorus pentasulphide is added to the reaction mixture to yield the dithiophosphoric acid ester of a wax phenol.  The samples furnished under Sect. 2 (5) comprise the barium salts of the dithiophosphoric acid esters derived from wax-naphthol, wax-hydroquinone, wax-catechol and wax-resorcinol and phosphorus pentasulphide.