Patent GB-588090-A (GB)
Title: Improvements in or relating to the production of lubricating oil compositions and ofadditives therefor
IPC: C07F9/165
Filed: 1943-09-01
Abstract: Hydrocarbon lubricating oils are stabilised against oxidation and sludge-deposition by dispersing therein a dithiophosphoric acid ester complex obtained by heating together phosphorus pentasulphide, a monohydric alcohol or phenol, and a saturated monocarboxylic acid, and continuing the heating till the evolution of hydrogen sulphide is substantially complete.  Alternatively, instead of the ester, a polyvalent metal salt of the ester may be dispersed in the oil.  Such esters may be of the general formula: <FORM:0588090/III/1> where R is the residue of a monocarboxylic acid RCOOH and R1 is the residue of an alcohol or phenol R1OH.  Suitable metal salts are the calcium, barium, strontium, magnesium, aluminium, chromium, nickel, zinc, or tin salts and they may be derived from mixtures of alcohols or phenols R1OH or mixtures of acids RCOOH.  Numerous alcohols or phenols and monocarboxylic acids from which the esters may be derived are specified.  If desired, the metal salt may be dispersed in the lubricating oil to give a solution of 25-50 per cent. strength which can be diluted when required to give the 0.1-5 per cent. solution suitable for use in the crankcases of internal combustion engines. Other additional substances such as the mono- and -dialkyl phenol mono- and poly-sulphides and their metal salts may be dispersed in the lubricating oil.  In examples, the barium salts of dithiophosphoric esters derived from the following alcohols or phenols and acids are dispersed in mineral lubricating oil:-(a) n-amyl alcohol, B24 alcohol (a synthetic product containing methyl hexanols together with other alcohols, ketones and esters and obtained by the hydrogenation of oxides of carbon), lauryl alcohol and lauric acid; (b) fusel oil, lauryl alcohol and palmitic acid; (c) n-amyl alcohol, B24 alcohol and myristic acid; (d) n-amyl alcohol, B24 alcohol and lauric acid; (e) n-amyl alcohol, B24 alcohol, lauryl alcohol and hydrogenated rosin; (f) lauryl alcohol and 9.10-dichlorostearic acid; (g) n-amyl alcohol, lauryl alcohol and palmitic acid; (h) lauryl alcohol and naphthenic acid; (i) p-tertiary amyl phenol and myristic acid; (j) lauryl alcohol, p-tertiary amyl phenol and myristic acid; (k) fusel oil, B24 alcohol, lauryl alcohol and palmitic acid; (1) p-tertiary amyl phenol and palmitic acid; (m) 2.4-di-n-amyl phenol and palmitic acid; (n) n-amyl alcohol, B24 alcohol, lauryl alcohol and myristic acid; (o) n-amyl alcohol, B24 alcohol, lauryl alcohol and palmitic acid.  The preparation of dispersions in mineral lubricating oil of the zinc salt of ester (e) and of the calcium, strontium and zinc salts of esters (f)-(o) is also described.  Details are given of the results of tests applied to lubricating compositions comprising the barium salts of esters (e), (f), (g), (j), or (m) in mineral lubricating oil with added iron naphthenate.  The Specification as open to inspection under Sect. 91 contains additional examples in which the barium, calcium, strontium and zinc salts of a dithiophosphoric ester derived from lauryl alcohol and p-hydroxy phenylstearic acid are dispersed in mineral lubricating oil.  Details are also given of the results of tests applied to a lubricating composition comprising the barium salt of this ester in mineral lubricating oil with added iron naphthenate. This subject-matter does not appear in the Specification as accepted.ALSO:Dithiophosphoric acid ester complexes, which are useful as such or in the form of their polyvalent metal salts as additives for hydrocarbon lubricating oils, are prepared by heating together phosphorus pentasulphide, a monohydric alcohol or phenol, and a saturated monocarboxylic acid, and continuing the heating till the evolution of hydrogen sulphide is substantially complete. Such esters may be of the general formula <FORM:0588090/IV/1> where R is the residue of a monocarboxylic acid RCOOH and R1 is the residue of an alcohol or phenol R1OH.  Among the salts mentioned are the calcium, barium, strontium and magnesium salts and they may be derived from mixtures of alcohols or phenols R1OH or mixtures of acids RCOOH. Numerous alcohols or phenols and monocarboxylic acids from which the esters may be derived are specified.  In examples, the preparation of the barium salts of dithiophosphoric esters derived from the following alcohols or phenols and acids is described: (a) n-amyl alcohol, B24 alcohol (a synthetic product containing methyl hexanols together with other alcohols, ketones and esters and obtained by the hydrogenation of oxides of carbon), lauryl alcohol and lauric acid; (b) fusel oil, lauryl alcohol and palmitic acid; (c) n-amyl alcohol, B24 alcohol and myristic acid; (d) n-amyl alcohol, B24 alcohol and lauric acid; (e) n-amyl alcohol, B24 alcohol, lauryl alcohol and hydrogenated rosin; (f) lauryl alcohol and 9.10-dichlorostearic acid; (g) n-amyl alcohol, lauryl alcohol and palmitic acid; (h) lauryl alcohol and naphthenic acid; (i) p-tertiary amyl phenol and myristic acid; (j) lauryl alcohol, p-tertiary amyl phenol and myristic acid; (k) fusel oil, B24 alcohol, lauryl alcohol and palmitic acid; (l) p-tertiary amyl phenol and palmitic acid; (m) 2.4-di-n-amyl phenol and palmitic acid; (n) n-amyl alcohol, B24 alcohol, lauryl alcohol and myristic acid; and (o) n-amyl alcohol, B24 alcohol, lauryl alcohol and palmitic acid.  The preparation of the calcium and strontium salts of esters (f)-(o) is also described.  The Specification as open to inspection under Sect. 91 contains additional examples in which the calcium, barium and strontium salts of a dithiophosphoric ester derived from lauryl alcohol and p-hydroxy phenylstearic acid are prepared.  This subject-matter does not appear in the Specification as accepted.