Patent GB-682441-A (GB)
Title: Improvements in liquid hydrocarbon compositions stabilised against oxidation and polymerisation
IPC: C10L1/26
Filed: 1948-02-05
Abstract: Oil-soluble phosphorus-containing products resulting from the reaction of PCl3 with lactic acid, or with an ester or salt of lactic acid, are employed as ingredients in liquid hydrocarbon compositions (see Group III).  Instead of the oil - soluble phosphorus - containing products themselves, oil-soluble salts or ester-salts of the oil-soluble phosphorus-containing products may be so employed. Alcohols which may be esterified with lactic acid in order to provide suitable esters for reacting with PCl3 include methyl, ethyl, propyl, butyl, benzyl and furfuryl alcohols, ethylene glycol, propylene glycol, trimethylene glycol and cyclohexanol.  Instead of reacting PCl3 solely with lactic acid or with a single lactic acid ester, PCl3 may be reacted (a) with a mixture of different esters of lactic acid or a mixture of lactic acid with one or more esters of lactic acid, or (b) with 1 or 2 molecules of lactic acid or lactic acid ester per molecule of PCl3 and the reaction completed with another reactant of the class consisting of lactic acid and its esters, different from that which was initially employed.  Oil-soluble salts may be prepared from the oil-soluble phosphorus-containing reaction products by saponifying one or more carboxyl or esterified carboxyl radicles therein, for example, with sodium potassium ammonium or substituted ammonium hydroxides.  Salts and ester-salts of metals other than the alkali metals may be prepared from the salts and ester-salts of alkali metals by double decomposition.  The oil-soluble phosphorus-containing reaction products are believed to contain compounds of the formul  <FORM:0682441/IV (b)/1> and <FORM:0682441/IV (b)/2> where R, R1 and R11 are selected from the class consisting of an organic radicle, a metal, a metallic radicle and hydrogen.  Thus the reaction product of methyl lactate with PCl3 is believed to consist principally of the phosphite esters P(OC2H4COOCH3)3 and POH(OC2H4 COOCH3)2, although the methyl ester of chlorpropionic acid is also believed to be present. Details are given of the preparation of the reaction product of methyl lactate with PCl3.ALSO:Liquid hydrocarbons are stabilized against oxidation and/or polymerization by the inclusion therein of a minor proportion of an oil-soluble phosphorus-containing product resulting from the reaction of PCl3 with lactic acid or with an ester or salt of lactic acid.  Instead of a minor proportion of the oil-soluble phosphorus-containing product itself, a minor proportion of an oil-soluble salt or estersalt of the oil - soluble phosphorus-containing product may be employed.  Liquid hydrocarbons which may be stabilized in this way include mineral lubricating oils and lighter petroleum fractions such as are used as fuels.  Alcohols which may be esterified with lactic acid in order to provide suitable esters for reacting with PCl3 include methyl, ethyl, propyl, butyl, benzyl and furfuryl alcohols, ethylene glycol, propylene glycol, trimethylene glycol and cyclohexanol.  Instead of reacting PCl3 solely with lactic acid or with a single lactic acid ester, PCl3 may be reacted (a) with a mixture of different esters of lactic acid or a mixture of lactic acid with one or more esters of lactic acid, or (b) with 1 or 2 molecules of lactic acid or lactic acid ester per molecule of PCl3 and the reaction completed with another reactant of the class consistinpg of lactic acid and its esters, different from that which was initially employed. Oil-soluble salts or ester-salts may be prepared from the oil-soluble phosphorus-containing reaction products by saponifying one or more carboxyl or esterified carboxyl radicles therein, for example with sodium, potassium, ammonium or substituted ammonium hydroxides. Salts and ester-salts of metals other than the alkali metals may be prepared from the salts and ester-salts of alkali metals by double decomposition.  The oil-soluble phosphorus-containing reaction products are believed to contain compounds of the formulae <FORM:0682441/III/1> , <FORM:0682441/III/2> and <FORM:0682441/III/3> , where R, R1 and R11 are selected from the class consisting of an organic radicle, a metal, a metallic radicle and hydrogen.  Thus the reaction product of methyl lactate with PCl3 is believed to consist principally of the phosphite esters P(OC2H4COOCH3)3 and POH(OC2H4COOCH3)2, although the methyl ester of chlorpropionic acid is also believed to be present.  The liquid hydrocarbon composition may also contain other additives. Thus in the case of mineral lubricating oils, extreme pressure addition agents such as halogen, phosphorus and/or sulphur compounds, corrosion inhibitors such as phosphorus compounds, and pour-point depressors, may be added.  In the case of fuels, diesel fuel dopes, antioxidants, or anti-knock compounds such as tetraethyl lead or iron carbonyl may be added. Furthermore the oil-soluble phosphorus containing reaction products or their salts or their ester-salts may be added to a heavy liquid hydrocarbon such as mineral lubricating oil and this mixture then added to a light liquid hydrocarbon such as diesel fuel or gasoline. In examples, the reaction product of methyl lactate with PCl3 is added, as such or after distillation to remove the more volatile constituents, to mineral lubricating oil.  Tests are described in which such a mineral lubricating oil composition, which may optionally contain (a) methyl dichlorstearate, (b) hexachlor diphenyl oxide and o-dichlorbenzene, (c) hexachlordiphenyloxide, o-dichlorbenzene, methyl stearate and butyl stearate, is compared with similar compositions which do not contain the methyl lactate-PCl3 reaction product.