Patent GB-804777-A (GB)
Title: Fluorinated organic dithiophosphates and their use as anti-wear agents in lubricating oil compositions
IPC: C10M137/10
Filed: 1957-05-17
Abstract: Fluorinated organic dithiophosphates containing from 0.01 to 1.0 per cent by weight of chemically combined fluorine, the dithiophosphate prior to fluorination being of formula <PICT:0804777/III/1> wherein R and R1 are radicals containing from 2 to 20 carbon atoms and may be aryl, alkyl, aralkyl, cycloalkyl, aryloxyalkyl, acylaryl or alkoxyaryl, M is hydrogen or a metal atom and n is the valency of M (see Group IV (b)) are used as anti-wear agents in lubricating oil compositions.  From 0.001 to 10 per cent by weight of the fluorinated dithiophosphate may be employed in synthetic lubricating oil, or, preferably, a mineral base lubricating oil.  Specified synthetic oils are ether alcohols of formula RO(CnH2nO)xH, wherein R is alkyl, n is 2-5 and x is 1-40 such as the monobutyl ether of tetradecapropylene glycol; monobasic caroxylic acid esters containing 20-80 carbon atoms; diesters of acids such as adipic or sebacic acids with hexyl, octyl or 2-ethylhexyl alcohols; esters of polyethylene glycols with C8-C18 branched-chain carboxylic acids; complex esters of polyhydric alcohols, polycarboxylic acids and monocarboxylic acids and/or monohydric alcohols; phosphoric acid esters and thioesters; halocarbon oils such as polychlorotrifluoroethylene; organo-siloxanes; sulhite esters; organic carbonates; mercaptals and formals.  In addition, viscosity index improvers such as polymethacrylate esters, fumarate- or maleate-vinyl acetate copolymers and polyalkyl styrenes; pour point depressants such as the condensation products of chlorinated wax with naptthalene or phenol and polymers and copolymers of unsaturated esters, e.g. a copolymer of fumaric acid esters of coconut oil and vinyl acetate; and various other additives such as phenothiazine, lauryl selenide, phenyl-alpha-naphthylamine, lecithin, metal sulphonates, sorbitan mono-oleate, lauryl mercaptoacetic acid, the barium salt of isononyl phenol sulphide and di-2-ethylhexylamine may be added to the compositions.  In examples, a composition of a fluorinated zinc di-(1 : 4-dimethyl-butyl dithiophosphate and a mineral diluent oil is blended with a mineral lubricating oil and the product compared in load-carrying, corrosion and oxidation tests with the corresponding lubricating composition containing the unfluorinated dithiophosphate.ALSO:The invention comprises fluorinated organic dithiophosphates containing from 0.01 to 1.0 weight per cent of chemically combined fluorine, the dithiophosphate prior to fluorination being of formula: <FORM:0804777/IV (b)/1> wherein R and R1 are radicals containing from 2 to 20 carbon atoms and may be aryl, alkyl, aralkyl, cycloalkyl, aryloxyalkyl, acylaryl or alkoxyaryl, M is hydrogen or a metal atom and n is the valency of M.  The compounds are used as anti-wear agents in lubricating oil compositions (see Group III).  The compounds are prepared by heating together an organic dithiophosphate of the formula given above and a mild fluorinating agent (as hereinafter defined) until the required amount of fluorine has been incorporated into the dithiophosphate.  The reaction may be carried out in a diluent oil and preferably under an inert atmosphere, such as nitrogen.  The mild fluorinating agents are defined as cobalt trifluoride, silver difluoride, manganic fluoride, lead tetrafluoride, cericfluoride, bismuth pentafluoride and thallic fluoride.  Specified dithiophosphates include dibutyl, dihexyl, dicapryl, dioctadecyl, diphenyl, di - (2 : 4 - diamyl - phenyl), di - (2 : 4-diamyl - phenoxyethyl), di - (lauroylphenyl) and di - (methoxyphenyl) dithiophosphate; the dithiophosphates prepared by reacting cyclopentanol, cyclohexanol or cycloheptanol, which may be alkyl-substituted, with phosphorus pentasulphide; and preferably the dialkyl dithiophosphates wherein each alkyl group has from 3 to 6 carbon atoms and the average of the carbon atoms in both groups is at least 5.  The dithiophosphates are preferably employed as the salts of metals such as iron, nickel, aluminium, cadmium, tin, zinc, magnesium, calcium, strontium and barium.  In examples, zinc di-(1 : 4-dimethyl-butyl) dithiophosphate, alone or diluted with a mineral oil, was heated with cobalt trifluoride in a nitrogen atmosphere.