US2999739A - Antiknock fluids - Google Patents

Description

tedf tates The instant invention relates to "improved antiknock fluids which, when blended in fuels for internal combustion engines, provide products of superior performance qualities. This application is a continuation-in-part of my co-pending application, Serial No. 313,615, filed October 7, 1952, and now abandoned.

Shortly after the pioneering discovery of the antiknock efiectiveness of organolead compounds, particularly tetraethyllead, it became apparent that commercial utilization of such antiknock agents depended upon providing a method for reducing the amount of lead salts which accumulated on engine parts. Accordingly, this reduction in the deposition of lead saltshas been accomplished by providing corrective agents or scavengers for use with organolead antiknock agents. Such mixtures of organolead antiknock agents and scavengers are known in the art as antiknock fluids. The use of fuels containing these antiknock fluids causes the lead to be converted to fairly volatile lead salts which are discharged from the engine in the exhaust gas stream. Many corrective agents or scavengers have been proposed of which the most successful have been organic bromine and chlorine compounds, notably ethylene dibromide and ethylene dichloride. Thus, for commercial purposes, the most suc cessful antiknock composition for use in aviation fuels has been a mixture of tetraethyllead and ethylene dibromide, the dibromide being present in an amount of one theory, which is the quantity theoretically required to stoichiometrically react with all the tetraethyllead to form lead dibromide. Such a composition has two bromine atoms for each atom of lead. In the case of automotive fluids, the most efficacious composition comprises tetraethyllead in admixtures with one-half theory of bromine as ethylene dibromide and one theory of chlorine as ethylene dichloride. However, in spite of the high efiiciency of scavenging produced by such compositions,

the deposition of a certain amount of lead salts on engine parts is not entirely prevented.

One of the more serious problems directly attributed to such deposits is spark plug failure, commonly termed spark plug fouling. This results from the formation on the spark plug insulators of deposits that are somewhat electrically conductive, thereby unduly lowering the electrical resistance between the spark plug electrodes. When this resistance becomes too low, the production of a spark at the spark gap is prevented. To inhibit such spark plug failures, it has been proposed in the prior art to utilize phosphorous-containing materials as additives to leaded fuels. In this manner the lead deposits become converted to lead phosphates, which have higher electrical resistivities and are less prone to cause spark plug fouling.

The phosphorus-containing materials have been proposed as additives to supplement or to partially or totally replace halide scavengers. Although satisfactory engine operation can be obtained with such compositions, it has been found that the alleviation of spark plug fouling is attained at the expense of exhaust valve life. As will be more apparent from the discussion hereinafter, this serious reduction in exhaust valve life is ultimately the result of exhaust valve burning and corrosion which are promoted by such phosphorus-containing materials when Patented Sept. 12, 11961 employed in accordance with the teachings of the prior art. More particularly this reduction in exhaust valve life is a reduction in the length of time during which the valve operates withouteither excessive leakage or in extreme cases by mechanical failure because of the separation of the valve head from its stem. Such eflects in turn result from corrosion and/or burning away of the valve, particularly at its head and throat area. The local removal of metal from the valve face causes valve leakage, and the removalof metal from the throat area can so Weaken the resistance of the valve to tensile stresses that the valve stretches in length and may even break apart. Corrosion and burning is most readily measured by the weight loss of the valve.

Among the objects of the present invention is the provision of improved antiknock fluids and fuels which obviate spark plug fouling and also improve exhaust valve life. Other important objects of the present invention will become apparent from the following description of some of its exemplifications.

It has-been discoveredthat excessive corrosion and burning of exhaust valves caused by the addition of the phosphorous-containing spark plug anti-fouling compound to the above composition is strikingly decreased by a critical increase in the organic bromine content of the scavenger. At the same time, this increase does not significantly impair any of the other operating or storage characteristics of the fuels or fluids.

This eflect is quite unexpected since in the absence of the phosphorus-containing material, an increase in halogen content, and particularly bromine, was known to cause excessive exhaust valve corrosion and burning. For some unexplained reason, however, when the added bromine content is-present along with the phosphorus compounds, neither is eifective to produce the expected corrosion and burning. On the other hand, the phosphorus compounds in such a composition still produce their antifouling results.

The critical increase in the organic bromine content of the scavenger used in combination with the phosphorus-containing, organolead compositions according to this invention is a 15 to 20 percent increase above the bromine scavenger content used in standard commercial practice. in aviation applications, this practice has been the provision of one theory of bromine as a bromine scavenger, the brominezlead atom ratio therefore being 2:1. In automotive applications, this practice has been the provision of 0.5 theory of bromine as a bromine scavenger and 1.0 theory of chlorine as a chlorine scavenger, in which case the bromineglead atom ratio was 1:1.

According to this invention greatly enhanced engine performance is achieved by improving an antiknock composition consisting essentially of organolead material as the principal antiknock ingredient, organic halogen scavenger material of the class of that providing two atoms of chlorine plus one atom of bromine per atom of lead, and that providing two atoms of bromine per atom of lead, and a phosphorus-containing spark plug antifouling compound, the phosphorus-to-lead atom ratio of said composition being from about 0.02:3 to about 0.7 :3 by increasing the bromine content of the organic halogen scavenger material by about '15 to 20 percent.

One embodiment of this invention is an antiknock composition consisting essentially of an organolead antiknock compound-preferably a lead alkyl antiknock compounda phosphorus-containing spark plug anti-fouling a) compound present in amount such that the phosphorusto-lead atom ratio of said composition is from about 0.02:3 to about 0.7:3, andan organic halogen scavenger complement selected from the group consisting of (1) an organic bromine scavenger capable of reacting with the lead during engine combustion to form volatile lead salts containing bromine and present in amount such that the bromine-to-lead atom ratio is from about 2.3:1 to about 2.4:1; and (2-) a mixture of an organic chlorine'scavenger and an organic bromine scavenger. capable of reacting with the lead during engine combustion to form volatile lead salts containing chlorine and bromine, .said organic chlorine scavenger being present inamount'such that the chlorine-to-lead atom ratio is about-2:1 andasaid organic bromine scavenger being present in amount such that the brornine-to-lead atom ratio is from about 1.15:1 to about 1.2:1. Another embodiment of this invention is hydrocarbons of the gasoline boiling range containing an antiknock quantity of the above antiknock compositions. Such antiknock quantity ranges from about 0.5 to about 6.3 grams of lead per gallon of gasoline.

The amount of'phosphorus-containing. material used is generally between the limits of 0.01 to 0.35 theory of phosphorus, one theory ofphosphorus being defined in the amount of phosphorus theoretically required to react with the lead to form lead orthophosphate, which quantity is two atoms of phosphorus per three atoms of lead. On a pho'sphorus-to-lead atom ratio basis, the above amounts to from 0.02:3 to 07:3. Particularly favorable results can be obtained with amounts of phosphoruscontaining materials contributing at'least 0.05 theory of phosphorus. More than 0.2 theory of phosphorus is not as desirable as the lower concentration. On a phosphorusto-lead atom ratio basis, this particularly favorable range is from 0.1:3 to 0.4:3.

The above improvements are obtained without exception from all types of phosphorus compounds that are soluble in the fuel in the above proportions. It is preferable to use organo-phosphorus materials, that is, materials in which phosphorus is linked either directly to a carbon atom in an organic radical, or is linked to an organic radical through oxygen, nitrogen or sulfur. However, inorganic compounds, such as triphosphonitrilic chloride ({PNCl l and tetraphosphorus trisulfide (1 ,8 are also eiiective. The organic phosphorus-containing materials include phosphines and related compounds; halophosphines; halophosphine halides and phosphonyl halides; quaternary phosphonium compounds; tertiary phosphine oxides and sulfides; phosphinou-s, phosphonous and phosphonic acids, the sulfur analogs and esters of the aforesaid acids, phosphites and thiophosphites; phosphates; halophosphates and thio analogs; compounds with phosphorus-to-nitrogen bonds; and derivatives of anhydro phosphorus acids.

As used in the discussion hereinafter, the term organic radicals denotes a univalent aliphatic, alicyclic or aromatic radical which can be further substituted with negative radicals, such as hydroxy, halide and the like. By the term univalent aliphatic radical is intended a univalent radical derived from an open chain saturated or unsaturated carbon compound, that is, an acyclic radical. The term univalent alicyclic radical denotes a monovalent radical derived from the corresponding aliphatic compounds by ring formation. The term univalent aromatic radical denotes a monovalent radical derived from a compound of the benzene series containing a ring with the peculiar type of unsaturation inherent in such aromatic compounds.

Thus, when the organic radical or radicals of the organo-phosphorus materials of the improved antiknock fluids of the present invention is a univalent aliphatic radical or radicals, such can be a radical or radicals selected from the group consisting of alkyl, alkenyl, aralkyl, and aralkenyl. Consequently, when the organic radical or radicals of the organophosphorus materials described hereinafter is a univalent aliphatic radical, it can be an alkyl radical, such as for example, methyl, ethyl n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-amyl, and the various positional isomers thereof as, for example, l-methylbutyl; 2-methylbutyl; 3-methylbuty1; 1, l-dimethylpropyl; 1,2-dimethylpropyl; 2,2-dimethylpropyl and l-ethylpropyl, and likewise the corresponding straight and branched chain isomers of hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octodecyl, nondecyl, eicosyl and thc'like. In addition, the univalent aliphatic radical or radicals of the organophosphorus materials of the improved antiknock fluids of this invention can be an alkenyl radical, such as for example, ethenyl; n -propenyl; A prop'enyl; isopropenyl; A -buteny1; LW-butenyl; A -butenyl, and the corresponding branched chainv isomers thereof as, for example, A -isobutenyl; M-isobutenyl; A -secbutenyl; o -sec-butenyl; Al-pentenyl; A -pentenyl; A pentenyl; M-pentenyl, and the corresponding branched chain isomers thereof; Abhexenyl; A -hexenyl; A -hexenyl; n -hexenyl; A -hexenyl; and the corresponding branched chain isomers thereof, including 3,3-dimethyl-A -butenyl; 2.,3-dimethylA -butenyl; 2,3-dimethyl-.A -butenyl; 2,3-dimCithYlPA -bUtEHYI; and 1-methyl-l-ethyl-A -propenyl; and similarly, the various isomers of heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadeoenyl, octodecenyhnondecenyl, eicosenyl, andv the like. Moreover, when the organic radical or radicals of the organophosphorus materials described hereinafter is a univalent aliphatic radical, it canbe an :aralkyl radical, such as for example, benzyl; u-phenyl-ethyl', B-phenyl-ethyl; a-phenylpropyl; B-phenyl-propyl; 'y-phenyl-propyl; a-pheny-l-isopropyl; fi-phenyl-isopropyl; a-phenyl-butyl; fi-phenyh butyl; -phenyl-butyl; 6-phenyl-butyl; u-phenyldsobutyl; fl-phenyl-isobutyl; -phenylsisobutyl; a-phenyl-sec-butyl; B-phenyl-sec-butyl; 'y-phenyl-sec-butyl; fl-phenyl-t-butyl; a-naphthyl-methyl', 5'-naphthyl-methyl; u-(a'-naphthyl)- ethyl; a-(5-naphthyl)-ethyl; fi-(d-naphthyD-ethyl; fi-(finaphthyl) -ethyl; ozoU-naphthyl -propyl; a-( fl-naphthyl) p p B-( P y )-p py fi-(fi'-n p y )p py 'v- (a'-naphthyl)-propyl; 7 (fi-naphthyl)-propyl; a (en'- naphtl1yl)-isopropyl;' rx-(ff-naphthyl)-isopropyl; a-(cdnaphthyl)-butyl; a-(fi'-naphthyl)-butyl; B-(M-naphthyD- butyl; B-(d-naphthybbutyl; 'y-(a'-naphthyl)-butyl; 'y-(B' naphthyl)-butyl; 6-(ix-naphthyl)-butyl; 6-(B'-naphthyl)- butyl; oc-( a'-naphthy1)-isobutyl; a-(fl'-naphthyl)-isobutyl; fi-(oU-naphthyl)-isobutyl; fl-(H-naphthyl)-isobutyl; 'y-(oc'- naphthyl)-isobutyl; 'y-(H-naphthyD-isobutyl; m-(d-naphthyl)-sec-butyl; a (,8-naphthyl) -sec-butyl; B (a'-naphthyl)-sec-butyl; 5-(B'-naphthyl)-sec-butyl; 'y- (of-naphthyl)-sec-butyl; '7-(B'd'laPhlZhYD-SGC-blllYl; ,8- (ad-naphthyl)-t-butyl; B-(,8'-naphthyl)-t-butyl; the corresponding a' and ,8'-naphthyl derivatives of n-amyland the various positional isomers thereof such as, for example, said derivatives of l-rnethyl-butyl; 2-methyl-butyl; 3-methylbutyl; 1,1-dimethyl-propyl; 1,2-dimethyl-propyl; 2,2-dimethyl-propyl; l-ethyl-propyl, and likewise said derivatives of the corresponding isomers of hexyl, heptyl, octyl, and the like including eicosyl Other such aralkyl radicals of the organophosphorus compounds of the improved antiknock fluids of this invention include the a-, fi-, and 'y-anthryl derivatives of alkyl radicals, such as for example, u'-anthryl-methyl; a-(;8'-anthryl)-ethyl; B-(vanthryl)-ethyl; a (a-anthryl)-butyl; B (B-anthryl)-2- methyl-amyl, and the like, and the corresponding alkyl derivatives of phenanthrene, fluorene, acenaphthene, chrysene, pyrene, triphenylene, naphthacene, and the like. Moreover, the univalent aliphatic radical or radicals of the organophosphorus materials of the improved antiknock fluids of the instant invention can be an aralkenyl radical such as for example a-phenyl-ethenyl; fl-phenylethenyl; a-phenyl-n -propenyl; ,3-phenyl-A -propenyl; 'yphenyl-N-propenyl; a-phenyl-A propenyh fi-phenyl-d aeeavse propenyl; 'y-phenyl-A -propenyl; a-phenyl-isopropenyl; 8- phenyl-isopropenyl; -y-phenyl-isopropenyl; and similarly the phenyl derivatives of the isomers of butenyl, pentenyl, hexenyl, heptenyl, and the like, up to and including about eicosenyl. Other such arylalkenyls include a-(oU-naphthyl) -ethenyl; a-(B-naphthyl)-ethenyl; fi-(oJ-naphthyD- ethenyl; ,8 (B'-naphthyl)-ethenyl; a (a'-naphthy1) -A propenyl; a-( 3'-naphthyl) -A -propenyl; B-(oU-naphthyD- a -propenyl; fi-(fi'-naphthyl)-A -propenyl; -a- (a'-naphthyl)-A -propenyl; a-(fl'-naphthyl)-A -propenyl; (a'- naphthyD-M-propenyl; ;8-(fi-naphthyl)-A -propenyl; a- (a'-naphthyl)-isopropenyl; u (,B'-naphthyl) -isopropenyl; fi-(cU-naphthyl)-isopropenyl; B-(fl'-naphthyl)-isopropenyl, and the like. In addition, such aromatic derivatives of alkenyls, that is, aralkenyl radicals include derivatives of phenanthrene, fluorene, acenaphthene, chrysene, pyrene, triphenylene, naphthacene, and the like.

When the organic radical or radicals of the organophosphorus materials utilized in the improved antiknock compositions of the present invention is a univalent alicyclic radical or radicals, these can be selected from the group consisting of cycloalkyl and cycloalkenyl radicals. Thus, the univalent alicyclic radicals can be cycloalkyl radicals, such as rfor example, cyclopropyl, cyclobutyl, cycloamyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, cyclotridecyl, cyclotetradecyl, cyclopentadecyl, cyclohexadecyl, cycloheptadecyl, cyclooctadecyl, cyclononadecyl, cycloeicosyl, and such cycloaliphatic radicals as a-cyclopropylethyl, B-cyclopropylethyl, a-cyclobutylpropyl, fi-cyclobutylpropyl, 'y-cyclobutylpropyl, a-cycloamylisopropyl, flcycloamylisopropyl, and the like. Similarly, the alicyclic radicals of the organophosphorus materials of the im-.

proved antiknock fluids of the present invention can be cycloalkenyl radicals, such as for example, m-cyclohexylethenyl; B-cyclohexylethenyl; a-cycloheptyl-A propenyl; 'y cycloheptyl-N-propenyl; oz cyclooetyl-a -propenyl; ficyclooctyl-A -propenyl; 'y-cyclooctyl-A -propenyl; B-cyclononylisopropyl; a-methylene-fl-cyclododecylethyl, and the like.

When the organic radical or radicals of the organophosphorus materials of the improved antiknock fluids of the present invention is a univalent aromatic radical or radicals, these can be selected from the group consisting of aryl and alkaryl radicals. Thus, the univalent aromatic radical or radicals can be aryl radicals, such as for example, ocnaphthyl, fl-naphthyl, a-anthryl, B-anthryl, y-anthryl, and the like, including the various monovalent radicals of such aromatic as indene, isoindene, acenaphthene, fluorene, phenanthrene, naphthacene, chrysene, pyrene, triphenylene, and the like. Moreover, the univalent aromatic radical or radicals can be alkaryl radicals, such as for example, o-tolyl, m-tolyl, p-tolyl, 2,3- xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xy1yl, 3,5-xylyl, o-cumenyl, m-cumenyl, p-cumenyl, mesityl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2-methyl-u-naphthyl, 3- methyl-u-naphthyl, 4-methyl-a-naphthyl, S-methyl-a-naphthyl, 6-methyl-a-naphthyl, 7-methyl-u-naphthyl, 8-methy1- anaphthyl, l-ethyl-B-naphthyl, 3-ethyl-fi-naphthyl, 4- ethyl-fi-naphthyl, S-ethyl-fi-naphthyl, 6-ethyl-fi-naphthyl, 7-ethyl-fl-naphthyl, 8-ethyl-fi-naphthyl, 2,3-dipr0pyl, otnaphthyl, 5,S-diisopropyl-B-naphthyl, and the like.

The term phosphines and related compounds is considered herein as being generic to such compounds as phosphines, biphosphines and phosphine methylenes.

Phosphines are derivatives of trivalent phosphorus in which one or more phosphorus-to-carbon bond exists, with the remaining phosphorus valences, if any, being bound by hydrogen. Therefore, phosphines can be represented by the general formula can be the same or different and is selected from the group consisting DEE hydrogen and organic radicals. Illustrative examples of phosphine include ethylphosphine,

propylphosphine, isopropylphosphine, isobutylphosphine, isoamylphosphine, phenylphosphine, isopropenylphosphine, A -pentenylphosphine, a-phenylethylphosphine, 'y-phenylbutylphosphine, fi-phenylethenylphosphine, cyclohexylphosphine, o-tolylphosphine, 3-methyl-a-naphthylphosphine, dimethylphosphine, methylethylphosphine,

diethylpho sphine, methylisopropylphosphine, ethylbutylphosphine, isopropylisobutylphosphine, diisoamylphosphine, methylphenylphosphine, diphenylphosphine, phenyl-m-tolylphosphine, sec-butylethenylphosphine, di-A -butenylphosphine,

dia-phenylpropyl) -phosphine, methyla-phenylethenyl) -phosphine, butylcycloamylphosphine, dicyclohexylphosphine, di-(2,3-xylyl) -phosphine, trimethylphosphine, tni-(chloromethyU-phosphine, triethylphosphine, triisopropylphosphine, tributylphosphine, triphenylphosphine,

tri( 2-chlorophenyl) -phosphine, tri- (Z-methylphenyl) -phosphine, dimethyl- (ethylphenyl) -phosphine, dimethylphenylphosphine, diethylpropylphosphine, diethylphenylphosphine, dipropylphenylphosphine, diallylphenylphosphine, diisobutylphenylphosphine, diphenylmethylphosphine, diphenyl-p-tolylphosphine, dicyclobutylphenylphosphine, ethylisopropylis obutylphosphine,

and the like.

Biphosphines are derivatives of phosphines containing a phosphorus-to-phosphorus bond which can be represented by the general formulae wherein R is an organic radical and each of R R and R; can be the same or difierent and is selected from the group consisting of hydrogen and organic radicals. Illustrative examples of biphosphines include tetraphenyl biphosphine, diphenyl biphosphine, tetramethyl biphosphine, and the like.

Phosphinemethylenes are derivatives of phosphines wherein the three organic radicals on the phosphorus atom are supplemented by a fourth group attached to the phosphorus by a semipolar bond. Illustrative examples of phosphinernethylenes include (C H P=C(C H (C H P=C(C H -o) and the like.

Halophosphines can be dihalophosphines or monohalophosphines represented by the general formulae wherein R is an organic radical and R is hydrogen: or

an organic radical; wherein each of X X and X can be the same or different, and is selected from thegroup consisting of bromide, chloride, and iodide radicals. Thus, halophosphines include such compounds as, for example,

ethyldichlorophosphine, propyldichlorophosphine, isopropyldichlorophosphine, butyldichlorophosphjne, butyldibromophosphine, isobutyldichlorophosphine, isoamyldichlorophosphine, phenyldichlorophosphine, phenyldibromophosphine, phenyldiiodophosphine, 4-chlorophenyldichlorophosphine, 4-brornophenyldichlorophosphine, 4-methylphenyldichlorophosphine, 4-methylphenyldibromophosphine, 4-111ethylphenyldiiodophosphine, 1 4-methylphenyldibromophosphine, 2,4-dimethylphenyldichlorophosphine, a-naphthyldichlorophosphine, methylethylchlorophosphine, methylethylbromophosphine, methylethyliodophosphine, diethylchlorophosphine, diethylbromophosphine, diethyliodophosphine, dipropylchlorophosphine, dipropylbromophosphine, propyliodophosphine, methylphenylchlorophosphine, methylphenylbromophosphine, ethylphenylchlorophosphine, diphenylchlorophosphine, diphenylbromophosphine,

diphenyl -phosphine,

and the like.

Halophosphine halides and phosphenyl halides are halogen derivatives of phosphorus in its higher oxidation wherein R is an organic radical and each of R and R can be the same or different and is selected from the group consisting of hydrogen and organic radicals; each of X X and X can be the sameior different: and is selected from the group consisting of bromide, chloride and iodide radicals and Ch is a divalent radical selected from the group consisting of oxygen, sulfur and selenium, that is, a chalkogen. Illustrative examples of halophosphine halides include such compounds as ethyl phosphorus tetrachloride, propyl phosphorus tetrachloride, isopropyl phosphorus tetrachloride, isobutyl phosphorus tetrachloride, phenyl phosphorus tetrachloride, phenyl phosphorus dibrornidedichloride, 'phenyl phosphorus tetrabromide, 4- chlorophenyl phosphorus tetrachloride, 4-chlorophenyl phosphorus dichloiidedibromide, 4-bromophenyl phosphorus tetrachloride, 4-methylphenyl'phosphorus tetrabrornide, Z-indenyl phosphorus tetrachloride, a-naphthyl phosphorus tetrachloride, diphenyl phosphorus trichloride, (4-=bromophenyl)-phenyl phosphorus trichloride, m-

tolyl phenyl phosphorus trichloride, {2,4,5-trimethylphenyl)-pheny1 phosphorus trichloride, triethyl phosphorus dichloride, diethyl phenyl phosphorus. dichloride, triphenyl phosphorus dichloride, triphenyl phosphorus dibromide, tri-,(2,4,5-trimethylphenyl)-phosphorus dichloride, and the like. 1

Illustrative examples of phosphenyl halides include such compounds asamethanmphosphonyl dichloride, ,8-

chloroethane phosphonyl dichloride, 3-hromoethane phosphonyl dichloride, propane phosphonyl dichloride, isobutane phosphonyl' dichloride, cyclohexane phosphonyl dichloride, dimethyl phosphonyl chloride, methylethyl phosphonyl chloride, diethyl phosphonyl chloride, benzene phosphonyl dichloride, 4-chhorobenzene phosphonyl dichloride, 2-chloro-4-methylbenzene phosphonyl dichloride; 4-methylbenzene phosphonyl bromochloride, 2,4,5- trimethylbenzene phosphonyl dichloride, methylphenyl phosphonyl chloride, di-(phenyl)-phosphonyl chloride, hexanethiono phosphonyl dibromide, isobutane thiono phosphonyl dichloride, methylcyclohexyl phosphonyl chloride, ethanethiono -phosphonyl dichloride, benzene phosphonyl dibromide, and the like.

Quaternary phosphonium compounds can he represented by the general formula wherein R is an organic radical and each of R R and R., can be the same or different and is selected from the group consisting of hydrogen and organic radicals and X is selected from the group consisting of chloride, bromide, iodide and hydroxyl radicals. Illustrative examples of quaternary'phosphonium compounds include tetrarnethyl phosphoniumhydroxide, tetraethyl phosphonium chloride, tetrapropyl phosphonium iodide, tetraisopropyl phosphonium bromide, tetrabutyl phosphonium iodide tetraphenyl phosphoniurn iodide, tetraphenyl phosphonium bromide, tetraphenyl phosphonium hydroxide, tetra-ptolyl' phosphonium chloride, trimethylethyl phosphonium chloride, trimethyl-(B-bromoethyl)-phosphonium bromide, trirnethyl-(isoarnyl)-phosphoniurn iodide, trimethyl-(iodomethylene)-phosphonium chloride, triethylpropyl phosphonium chloride, triethylphenyl phosphonium bromide, tripropylethyl phosphonium, iodide, dimethylethylphenyl phosphonium. iodide, diethylmethylphenyl phosphonium iodide, diethylmethyl-rn-tolyl phosphoniurn iodide, diisobutylethylphenyl phosphonium iodide, dimethyldiethyl phosphonium chloride, phenylethyltetramethylene phosphonium iodide, phenylethylpentamethylene phosphonium iodide, and the like.

Tertiary phosphine oxides and sulfides are compounds consisting of three radicals bound by phosphorus-carbon bonds to the phosphoryl and thiophosphoryl groups respectively. Thus, the compounds can be represented by the general formula wherein R is an organic radical and each of R and R .can be the same'or dhferentand is selected from the group consisting of oxygen and sulfur, that is,- a chalkegen. Illustrative examples of tertiary phosphoneoxides include such compounds as trimethyl phosphine oxide, trichloromethyl phosphine oxide, triethyl phosphine oxide, tripropyl phosphine oxide, triphenylphosphine oxide, tri- 2,3,-xylyl phosphine oxide, tri-3-indelyl phosphine oxide, dimethylethyl phosphine oxide, dimethylphenyl phosphine voxide, diphenylmethyl phosphine oxide, diphenylethyl phosphine oxide, methylethylphenyl phosphine oxide, methylpropylphenyl phosphine oxide, and the like. Illustrative examples of tertiary phosphine sulfides include such compounds as trimethyl phosphine sulfide, triethyl phosphine sulfide, triisohutyl phosphine sulfide, triphenyl phosphine sulfied, -tri-(4-methylphenyl)-phosphine sulfide, tri-( 8-naphthyl)-phosphine sulfide, diethyl phosphine sulfide, ,diphenylethyl phosphine sulfide, diphenyl-(isoamyl)-phospl1ine sulfide, and the like.-

Cornpounds of the generic term phosphinous, phosphonous and phosphenic acids, their sulfur analogs and esters of the aforesaid acids are compounds possessing one or two organic radicals bound directly to the central phosphorus atom, the residual valences of which constitute an acid function or ester based on such acid function. Thus, in |general,--such substances can be primary or .secondaryphosphonic acids,-phosphonous acids, phosphiuous acids, the thio analogs of the aforesaid substances in which one or more oxygen atoms are replaced with sulfur including primary and secondary thiophosphionous acids, and the esters of all of the aforesaid acids invwhich one or more acidic hydrogen atoms are replaced by organic radicals.

Phosphinous and thiophosphionous acids and esters thereof can be represented by the general formula wherein each of R R and R, can be the same or dif ferent and is selected from the group consisting of hydrogen and organic radicals but wherein not all of R R and R are hydrogen, and Ch is a divalent radical selected from the group consisting of oxygen and sulfur, that is, a chalkogen. Illustrative examples of such compounds in clude diethyl phosphinous acid, diphenylbutyl phosphinite, dipropyl thiophosphinous acid, phenylpropylmethyl thiophosphinite, dicresylphenyl phos'phiuite and the like. Phosphonous and thiophosphonous acids and esters thereof can be represented by the general formula R P( 1 2) z s) wherein each of R R and R can be the same or different and is selected fromthe group consisting of hydrogen and organic radicals but are not all hydrogen,

and each of Ch and Ch can be the same or different, and is selected from the group consisting of divalent 1 1) 2 2) s s); 4 5 4) -M 6) wherein R is hydrogen or an organic radical and each of R R R R and R can be the same ortdiiferent and is selected from the group consisting of hydrogen and organic radicals and each of Ch Ch Chg, Ch and Ch can be the same or different and is selected from the group consisting of divalent oxygen and sulfur radicals, that is, chalkogens. Illustrative examples of phosphonic and thiophosphonic acids and esters thereof include such compounds as diethylmethane phosphonate, dibutylbenzene phosphonate, diisopropylbutane phosphonate, diethylbenzene phosphonate, di (2 ethylhexyl) benzene phosphonate, diphenylpropane phosphonate, dicresylbenzene phosphonate, benzene phosphonic acid, ethylphenyl phosphonic acid, dimethylbutane thiophosphonate, methylethylbenzene thiophosphonate, diamylbenzene thiophosphonate, diphenylbenzene thiophosphonate, dicresylbenzene thiophosphonate, benzene thiophosphonic acid, ethylphenyl thiophosphonic acid, and the like.

Phosphites and thiophosphites are the esters of phosphorus acid and thiophosphorus acid. Thus, phosphites and thiophosphites can be represented by the general formulae 1 2) 2 2) s s);

wherein R R and R are organic radicals and each of R R R R R and R can be the same or difierent and is selected from the group consisting of hydrogen and organic radicals, and each of Ch Ch Ch Chi Ch Ch Chq, Chg and Chg can be the same or different and is selected from the groupconsisting of divalent oxygen and sulfur radicals, that is, chal-kogens. 'Illustrative examples of phosphites and thiophosphites ire elude such substances as monomethyl phosphite, monoethyl phosphite, monoisopropyl phosphite, dimethyl phosphite, diethyl phosphite, dipropyl phosphite, diisopropyl phosphite, diisobutyl phosphite, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, triisopropyl phos phite, tributyl phosphite, tri-o-cresyl phosphite, triisoamyl phosphite, tri-o-cyclohexyl phosphite, triethyl thiophosphite, tripropyl thiophosphite, tributyl thiophosphite, triphenyl thiophosphite, monoethoxydiethyl thiophosphite, diethoxymono thiophosphite, and the like.

Phosphates, halophosphates and thio analogs are the esters of phosphoric acid and the esters of halides of phosphoric acid, including analogs of such substances wherein either part or all of the oxygen atoms are replaced by sulfur. =Thus, phosphates can be represented by the general formulae wherein R R and R are organic radicals and each of R R R R R and R can be the same or different and is selected from the group consisting of hydrogen and organic radicals and each of Ch Ch Chg, and Ch; can be the same or different and is selected from the group consisting of oxygen and sulfur, that is, chalkogens. Illustrative examples of phosphates and thiophosphates include such compounds as dimethyl phosphate, tn'butyl phosphate, tri-o-cresyl phosphate, tri-m-cresyl phosphate,

tri-p-cresyl phosphate, phenyldicresyl phosphate, methyl- 1 1) X1 2; a z) a a a wherein each of R and R are organic radicals and R hydrogen or an organic radical; each of Ch Ch and Ch can be the same or different and is selected from the group consisting of divalent oxygen and sulfur radicals, that is, chalkogens, and each of X X2 and X can be the same or different and is selected from the group consisting of fluoride, bromide, chloride and iodide radicals. Illustrative examples of halophosphates and halothiophosphates include such compounds as ethyldifluorophosphate, methyldichlorophosphate, ethyldichlorophosphate, butyldichlorophosphate, isopropyldibromophos phate, ethyldifluorothionophosphate, ethylfluorochlorothionophosphate, methyldichlorothionophosphate, ethyldichlorothionophosphate, propyldichlorthionophosphate, butyldichlorothionophosphate, isobutyldichlorothionophosphate, ethyldibromothionophosphate, (S)-ethyldichlorothiothionophosphate, dimethylfluorothiophosphate, diethylfluorophosphate, dipropylfiuorophosphate, dimethylchlorothionophosphate, diethylchlorothionophosphate, dibutylchlorothionophosphate, di-(SS)-ethylfiuorodithiophosphate, di-(SS)-ethylchlorodithiophosphate, di-(SS)- ethylchlorodithiothionophosphate, phenyldichlorophosphate, 2-1nethylphenyldichlorophosphate, Z-isopropyl-S- methylp-henyldichlorophosphate, 4-butyl-2-methylphenyldichlorophosphate, (4 tert-butylphenyl) dichlorophosphate, phenyldichlorothionophosphate, phenyldibromothionophosphate, (S)-phenyldichlorothiothionophosphate, diphenylfiuorophosphate, diphenylchlorophosphate, ethylphenylchlorophosphate, diphenylchlorothionophosphate, diphenylbromothionophosphate, diphenylchlorothiophosphate, and the like.

Compounds with phosphorus-to-nitrogen bonds are compounds containing single, double or semi-polar bonds, and are represented by amides of phosphorus acid, phosphoric acid, the halides and esters thereof, phosphonic acids, and the thio analogs of each of the aforesaid classes of compounds. Furthermore, compounds with phosphorus-to-nitrogen bonds include a class of imido derivatives of the aforesaid classes of compounds as well as compounds known as phosphinimines which are essentially semi-polarly linked substances. Illustrative .eX- amples of compounds containing phosphorus-to-nitrogen bonds include such substances as ethyl-N,N-dimethyldiamidophosphate; N,N'-diphenyldiamidophosphate; dichloro N,N di-ethylamidophosphate; N,N',N" triethylphosphoric triamide; N,N',N"-triethylphosphorus tri-- examples of derivatives of anhydrophosphorus acids inelude such substances as tetraethylpyrophosphite, tetrapropylpyrophosphite, tetrabutylpyrophosphite, tetrarnethylpyrophosphate, tetraethylpyrophosp'hate, tetraisopropylpyrophosphate, tetrabutylpyrophosphate, tetraethylpyrophosphonate, methyl-m-phosphate, ethyl-m-phosphate, phenyl-rn-phosp-honite and the like.

The general methods for the preparation of the organophosphorus compounds fully enumerated hereinbefore, are known to those skilled in the art. methods are fully described in kosolapoff, Organo Phosphorus Compounds." Although the preceding discussion with regard to organophosphorus compounds has been concerned with pure phosphorus compounds, there are available as articles of commerce, mixtures of the various positional isomers of given phosphorus compounds. Such mixtures are also within the spirit and scope of the present invention, for I have found that I can successfully employ in my improved antiknock fluids such mixtures as the various positional isomers of tributyl phosphates, triamyl phosphates, tributyl thiophosphates, triamyl thiophos phates, tricresyl phosphates, tritolyl phosphates, tripropyl phosphites, tributyl phosphites, triamyl phosphites and the like.

The scavengers of the improved antiknock fluids of my invention can, in addition to ethylene dibromide and ethylene dichloride, be those disclosed in. U.S. 1,592,954; 1,668,022; 2,364,921; 2,389,281; 2,479,900; 2,479,901; 2,479,902; 2,479,903; 2,496,983. Illustrative examples of such additional scavengers include such substances as carbon tetrachloride; hexylchloride; ethyl chloride; carbon tetraibromide; hexyl bromide; ethyl bromide; carbon tetraiodide; hexyl iodide; ethyl iodide; propylene dibromide; butylene dichloride; trichloroanil ine; 1,3,4-tribromopen tane; 4,5-dibromo-1,2-dirnethylbenzene; 1,6-dibromohexane; 1,2,5 tribromopentene 1; 1,2,3-tribromopentane; 1,2,3-tribromobutane; 3,4-dibron1omethylcyclohexane; 6- bromo-4- bromomethyl) heptenel; 1,2-dibromocyclohexane; 1,2,3-tri bromo-2-methylpropane; (5-chloroamyl) benzene; 1,8-dichloroctane; 1,2,4-triclllordbenzene; 2,4- dichloro-toluene; l-chlorooctane; 4-bromo-i',2-dimethyl' benzene; 3-bromo-1,2-dimethylbenzene; l-bromo-4-ethyl benzene; 1,1-dichlorobutane; 1,4-dichlorobutane; 2,3- diohlorobutane; l,3-dichloropentane; 2,3-dichloropentane; 3,3 dichloropentane; 1,3-dibromo-Z,Z-dimethylpropane;

Most of these general 12 3,4-dichloroc-umene; 2,4-clichlorotoluene; B,fl'-dibromodiethyl ether; a-bromobutyl-B-bromoethyl ether; B-chloroethyl-B-chloroisopropyl ether; and the like.

Any organic halides can the used as scavengers in accordance with the present invention so long as they do not resist decomposition by the combustion in the cylinders. Some aryl chlorides, such as monochlornaphthalene, are not good scavengers. 'For example, alkyl halides, aryl bromides and chlorobenzenes are very efiective. However, to obtain the improved exhaust valve life described above, the bromine content of the fluid or fuel should be increased 15 to 20 percent above those of the standard prior art compositions. An increase in chlorine content without an accompanying increase in bromine does not appear to give any improvement. On the otherhand, a

gdecrease in chlorine content Without compensating increases in bromine significantly reduces the scavenging.

The minor proportions of the improved antiknock fluids of the present invention which are employed in fuels for internal combustion engines are the same as with conventional antiknock fluids. Thus, in providing improved fuels for automotive engines and the like, amounts of the improved antiknock fluids of the present invention equivalent to up to 2.5 or 3 .milliliters of tetraethyllead per gallon are used. In providing improved fiuels for use in aviation engines, amounts of the improvedantiknoolt fluids of the invention equivalent to up to 6 milliliters of tetraethyllead per gallon can be used.

Although the antiknock agent utilized in the improved antiknock fluids of the present invention can be any of the diverse organolead compounds possessing antilcnock activity, a preferred embodiment of the present invention consists of improved antiknock fluids comprising the phosphorus-containing materials and the halide corrective agents or scavengers in combination with tetraalkyllead' compounds, particularly tetraethyllead. Likewise, the socalled mixed alkyllead antiknocks which havefrorn time to time been proposed can be so employed, such as, for example, mixtures of the various methylethyllead antiknocks, such as methyltriethyh, dimethyldiethylandtrirnethylethyllead as well as tetramethyllead itself.

In compounding the improved antiknock fluids of the instant invention, phosphorus compounds that are mutually soluble organolead compounds and/or in organic halides are the simplest to use. Those phosphorus compounds which do no't possess the requisite solubility in the aforesaid organic materials can be incorporated with the help of a common solubilizing agent, such as acetone or alcohol. In some cases, the maximum solubility of the phosphorus compound is adequate but the solution rateis low, so that it is advantageous to warm and/ or agitate a mixture of the components'of the improved antiknock fluids of the present invention in compounding operations.

In order to demonstrate the beneficial eifects of the invention, the following specific examples are given:

EXAMPLE I To 1000 gallons of a commercial blend of straight-run and catalytically and thermally cracked stocks was added three liters of tetraethyllead in a fluid containing 1.0 theory of chlorine as ethylene dichloride, and 0.5 theory of bromine as ethylene dibromide. The resulting blend was intimately mixed producing a homogeneous fuel composition containing 3.0 milliliters of tetraethyllead per gallon. A truck containing a standard six-cylinder I-head engine having a displacement of 235 cubic inches and a 6.7 to 1 compression ratio was operated with this fuel under heavy duty road operating conditions until two exhaust valve failures were detected. It was found that under such heavy duty road operating conditions the truck ran an average of 17,040 miles before two valve failures.

13 EXAMPLE H To 1000 gallons of the commercially availablefuel described in the preceding example was added 3 liters of tetraethyllead in a fluid comprising 1.0 theory of chlorine as ethylene dichloride, 0.5 theory of bromine as ethylene dibromide and 0.2 theory of phosphorus as tricresyl phosphate. A homogeneous fuel composition was producedv by intimately mixing the aforementioned components which thus contained 3.0 milliliters of tetraethyllead EXAMPLE HI To 100 gallons of the commercial base stock described in Example I was added 300 milliliters of tetraethyllead in a fluid containing 1.0 theory of chlorine as ethylene dichloride and 0.5 theory of bromine as ethylene dibromide. The resulting blend was intimately mixed producing a homogeneous fuel composition containing 3.0 milliliters of tetraethyllead per gallon. A modern sixcylinder truck engine was operated on the aforementioned fuel composition for a period of 387 hours under light duty cycling service operating conditions. It was found that during this period of operation, no exhaust valve failures occurred.

EXAMPLE IV To 100 gallons of the commercial base stock described in Example I was added 300 milliliters of tetraethyllead as a fluid comprising 1.0 theory of chlorine as ethylene dichloride, 0.5 theory of bromine as ethylene dibromide and 0.2 theory of phosphorus as tricresyl phosphate. The resulting blend was intimately mixed producing a homogeneous fuel composition containing 3.0 milliliters of tetraethyllead per gallon. The same truck engine as described in the preceding example was operated under the same light duty cycling service operating conditions until two exhaust valve failures were detected. It was found that the average time required for such failures was 140 hours. Therefore, the incorporation of phosphorus-com taining materials in an anti-knock fluid in accordance with the teachings of the prior art produced a reduction in exhaust valve life amounting to 63.8 percent.

EXAMPLE V To 100 gallons of a standard paraftinic fuel containing 0.003 percent of sulfur was added 400 milliliters of tetra- V ethyllead as a fluid comprising 1.2 theories of bromine as ethylene dibromide (EtBr and 0.1 theory of phosphorus as tricresyl phosphate (TCP). The resulting blend was intimately mixed producing a homogeneous fuel composition containing 4.0 milliliters of tetrethyllead per gallon, that is, one of the improved antiknock fuels of the present invention was provided. A single-cylinder laboratory test engine having a 17.6 cubic inch displacement and equipped with a hemispherical combustion chamber was operated on the aforementioned improved fuel containing one of the improved antiknock fluids of the present invention for a period of 100 hours under conditions such that the exhaust valve throat temperature was 1450 F. The same engine was then operated on three other phosphorus-containing fuels produced by adding to the 14 standard paraflinic' fuel antiknock fluids containing phos'-- phorus materials in accordance with the teachings of the prior art. The criteria for exhaust valve performance were the weight loss of the exhaust valve which occurred during hours of engine operation and the reduction in exhaust valve throat area during the same period of time. The data are presented in Table I.

Table I Exhaust Reduction in valve weight exhaust valve Fluid Mix loss per 100 throat area hours, grams per 100 hours,

percent 1.2 '1 EtBm+0.1 T TOP 0. 41 3. 6 1.0 T EtBn+0.2 '1 TOP 1. 77 14. 9 1.0 T EtBrg+0.l '1 'IGP-... 1. 74 14. 4 1.0 I EtBlz+0.05 T TOP 0.60 5.6

EXAMPLE VI on the improved antiknock fuel containing one. of the' improved antiknock fluids of the present invention for a period of 100 hours under conditions such that the exhaust valve throat temperature was 1385" F. The same engine was then operated on two other phosphoruscontaining fuels produced by adding to the standard paraffinic fuel antiknock fluids containing phosphorus materials in accordance with the teachings of the prior art. As in the preceding example, the criteria for exhaust valve performance were the weight loss of the exhaust valve which occurred during 100 hours of engine operation, and the reduction in exhaust valve throat area during the same period of time. The data are shown in Table II. 7

Table II (DON EXAMPLE VII Road tests-multi-cylinder engines.A fleet of standard 1953 automobiles was operated on the road under controlled driving conditions. These fleet tests were designed to study the effect of various fuel additive com binations on the engine durability of the test cars. One criterion in this series of tests was the effect of these fuel additive combinations on exhaust valve life.

The vehicles were operated on a closely controlled 60 miles per hour top-speed schedule and accumulated approximately 5000 miles per week at an average speed of 54 miles per hour. The cars were equipped with new cylinder heads and standard exhaust valves at the beginning of the test. These cars were then operated. on the road under the above conditions until an exhaust valve failure was detected. The defective valve was then re- 7 moved and replaced with a new valve and the test oontinned until a second valve failure occurred. Thus, in each test the exhaust valve life was expressed as the average of the number of miles to the first failure and the number of miles to the second failure.

The cars were operated on the same test gasoline and crankcase lubricating oil. The inspection data of the fuel and lubricating oil used are as follows:

FUEL

Process composition, percent vol.: 7

Straight run 100- TEL content, ml./ gal 3.00 Dissolved gum, mg./ 100 m1 0.4 Oxidation stability, min 1440 Total sulfur, percent weight 0.006 Gravity, API 66.7 Vapor pressure, p.s.i 6.6 Distillation, F.: 1

Initial evaporation 10% evaporated 50% evaporated 184 90% evaporated 239 Final evaporation"; 300

Octane number: F-l (research)-.. 91.8 F-Z (motor) 88.4 Hydrocarbon type, percent vol.: e I

Parafiins Olefins I Aromatics 8 Naphthenes 34 OIL In all of the tests the above test gasoline contained 3 milliliters of tetraethyllead per gallon. In one series of tests this leaded fuel contained 0.5 theory of bromine as ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride. In another series of tests this leaded fuel contained 0.5 theory of bromine as ethylene dibromide, 1.0 theory of chlorine as ethylene dichloride and 0.2 theory of phosphorus as tri-(fi-chloropropyl)-thionophosphate, which is herein designated as phosphorus additive A. 'In a third series oftests the leaded fuel contained 0.6 theory of bromine as ethylene dibromide, 1.0 theory of chlorine as ethylene dichloride and 0.2 theory of phosphorus as phosphorus additive A. As used herein, the term ftheory is used in .its established sense in the-art.-

16 One theory of bromine or chlorine is defined as the amount thereof theoretically required to react with the lead to form lead bromide or lead chloride, respectively. Thus, one theory of these halogens is two atoms of halogen per atom of lead. The term theory as applied to the phosphorus fuel additive is defined as the amount of phosphorus theoretically required to react with the lead to form lead orthophosphate, that is, two atoms of phosphorus per each three atoms of lead. For example, a phosphorus concentration of 0.2 theory (T) is equivalent to a phosphorus-to-lead atom ratio of 0.413.

The results of these road tests are shown in Table Ill.

Dynamometer tests-multi-cylinder engines-Another series of durabilityengine tests. designed to demonstrate the. effect of.various fuel additive combinations on exhaust valve life wasconducted. In these tests a standard 1953 automobile engine attached to an engine dynamorneter was operated at 2500 r.p.m. constant speed with alternate three-minute periods at half throttle and at full throttle. This engine was operated under these conditions until an exhaust valve failure was encountered. The defective valve was removed and replaced with a new valve and the test Iecontinued until a second valve failure occurred. In thisinstance, the criterion of exhaust valve life in any one test was the average of hours to the first failure and hours to the second failure.

The engine was operated on a commercial gasoline containing 3.0 milliliters of tetraethyllead per gallon. The inspection data of the test gasoline are as follows FUEL Process composition, percent vol.:

Catalytically. cracked 92 Thermally cracked 6 Reformed 2 TEL content, mL/gal 3.00 Dissolved gum, mg./ ml 0.7 Oxidation stability, min 790 Total sulfur,--percent weight 0.043

1 Includes naphthenes.

v nude.

17 The crankcase lubricating oil was the same as that used in the multi-cylinder engine road tests described hereinabove.

Tests were made to show the effect of three different fuel additive combinations on exhaust valve life. One

such combination was 0.5 theory of bromine and 1.0;"

theory of chlorine as ethylene dibromide and ethylene dichloride, respectively. Another fuel additive combina-' tion tested was 0.5 theory of bromine as ethylene dibromide, 1.0 theory of chlorine asethylene dichloride and 0.2 theory of phosphorus as phosphorus additive -A.

The other combination tested was 0.6 theroy of bromine as ethylene dibrcmide, 1.0 theory of chlorine asethylene dichloride and 0.2 theory of phosphorus as phosphorus additive A.

The data obtained from these tests are shown in Table IV.

Dynamoineter tsts-single-cylinder engines.-Another series of engine tests was conducted to determine the effect of various fuel additive combinations on exhaust valve life. In these tests the test equipment comprised 17.6 single-cylinder engines attached to engine dynamometers. These engines were equipped with XOR exhaust valves and Stellite No. 3 exhaust valveseat inserts. These engines were operated at 2700 r.p.m., 100 F. intake air, 212 F. jacket temperature and a fuel-air ratio of 0.07. These conditions resulted in a valve throat operating temperature of l540 F.:30 F.

The gasoline used was a standard reference fuel, technical isooctane, containing 3.0 milliliters of tetraethyllead per gallon. The sulfur content of gasoline was adjusted to 0.05 percent by weight of sulfur by the addition of disulfide oil. A conventional Grade 1120 avia- Total sulfur, percent wt 0.-17

In series of tests the criterion of exhaust valve life was the average hours required to produce an exhaust valve failure. A

The fuel additive combinations studied in series 1 phosphorus as phosphorus additive A. The phosphorus content of fuel additive combinations designated above as (2) and (3) was such that the phosphorus-to-lead atom ratio was 02:3 in each instance. 1

The results of these engine tests are shownin Table Vt Table V Phds- Relaphorus Num- Hours tlve Halohydrocarbon scavenger addiber of to tailhours tive tests ure to iailcone. I we 0.5 T of'bromine (ethylene "dibromide), 1.0 T of chlorine (ethylene dichloride) None 3 120 100 Do 0.11 3 108 90 0.6 'I of bromine (ethylene dlbromide), 1.0 T of chlorine (ethylene dichloride) 0.1'1 3 205 171 l P:Pb=0.2:3.

EXAMPLE X Recognizing the fact that exhaust valve throat corrosion was a problem in some aircraft engines with some valve materials, a series of tests was initiated to determine the extent by which this objectionable corrosion was increased by the use of phosphorus additives and means'by which it might be reduced. In series of tests, 17.6 engines coupled to engines were equipped with either of two types of exhaust valves fabricated by an exhaust valve manufacturer of materials currently in use for large aircraft engine valves.

The engines were operated at 2700 r.p.m., 0.07 fuelair ratio, 20 spark advance, F. intake air temperature, 212 F. jacket temperature and at an indicated mean efiective pressure (I'M-EP) of 114' (a nieasure of power output). V

The gasoline used in these tests .was technical isooctane and contained 4.0 milliliters of tetraethyllead per gallon and had a sulfur content of 0.003 percent by weight. A commercially available crankcase lubricating oil, Aviation Grade 1120, was used in the engines. This inspection data for this oil are set forth in the description concerning the next preceding series of tests.

In all, six engine tests were conducteithree tests using exhaust valves fabricated of one type of materials of construction and the remaining three tests using exhaust valves fabricated from other materials of construction. Each of these two types of valves was representative of exhaust valves used in aircraft engines.

Three different fuel additive combinations were tested. One such combination involved use of the above leaded fuel containing 1.0 theory of bromine as ethylene dibromide. Another combination was that the above leaded gasoline contained 1.0 theory of bromine as ethylene dibromide and 0.1 theory of phosphorus as tricresyl phosphate. The third fuel additive combination used was 1.2 theory of bromine as ethylene dibromide and 0.1 theory of phosphorus as tricresyl phosphate.

In these tests the measures of exhaust valve performance were the corrosion of the exhaust valves measured by weight loss of the valves incurred per 100 hours of engine operation and the'reduction in the throat area of the exhaust valves incurred per 100 hours of engine operation. v

The results of these engine tests are shown in Table Table VI axnaus r-vs-Lvn MATERIAL 1'.

p Phos- Valve-weight "Reduction in r phorus loss, gin/100 thrust ares Test Halohydrocarbon addi- Hours scavenger tive cone. Gr. Hrs. .Per- Percent 7 cent 100 hrs.

1 1.0 'r of bromine (ethylms V 240 0.659 0.274 o a ene dlbromlde). 2;--. do- 0.1 '1'. g 150 2.613 1.74 23.8 15.9 a 1.2 T of bromine (ethyl- 1 o. 1 T 240 0. 975 u; 405 8.7 3.03

sue dibromide) nxnansr VALVE m'rnnmn 2..

4 1.0 'r of bromlnetethyl None 240 a. 060 1. 214 s; 1 an:

em dibromlde): a; d 0.1 T 150 a. 904 2. so 24. 0 16. 0 o. 1.21 or bromine (ethyl- 1 0.1 T 240 a. 273 1. as 22. 0 9.17 ens dthromide).

I P:Pb=0.2:3.

The same degrees of improvement are obtained by emamount of metallic lead present insuch solids. These reploy flg .infuels, for internal combustion engines minor proportions of such fluids as, for example, tetraethyllead in combination with 1.2 theories of bromine as the various isomers of dibromotoluene, and 0.1 theory of phosphorus as triphenylthiophosphite; tetraethylleadin combination with 1.0 theory of chlorineas ethylene dichloride, 0.6 theory of bromine as ethylene dibromide, ,andftll theory .of phosphorus, as triphenylphosphite; tetraethyllead in combination with 1.1 theories ofehlorine as ethylene dichloride, 0.6' theory of bromine as ethylenedibromide, and 0.15 theory of phosphorus as dibutylbenzenephosphonate; tetraethyllead in combination with 1.4 theories of chlorine as ethylene dichloride, 0.6 theory of bromine a's ethylene dibromide, and 0.2 theory ofphosphorus as tricresylthiophosphate; tetraethyllead in combination with 1.0 theory of chlorine-as 1,2,4-trichlorobenzene, 061th cry of bromine as dibromotoluene,and 0.1 theory of phosphorus as diphenylbenzenethionophosphonate; tetraethyllead in combination with 1.0 theory of'chlorine as 1,2-dichloroethane, 0.6 theory of bromine as 1,2-dibromoethane and 0.1 theory of phosphorus as diphenylnrono- 'cresylphosphate; tetraethylleadin combination-"with- 1.2

theory-of chlorine as hexachlorocyclohexane, 0.6- theory ofbromine as hexabromocyclohexane, and 0.15 theory of phosphorus as diphenylpliosphine; tetramethyllead in combination with 1.4 theories of chlorineas-'-1,2,4-trichlorobenzene, 0.6 theory of bromine as dibromotoluenes, 0.05 theory of phosphorus as diphenylbutylphos- -phinite;. tetrabutyllead in combination with: 1.1 theories of chlorine as 1,2-dichloroethane, 0.6 theory of bromine as 2-bromo-2-methylpropane, 0.1.theory of phosphorus as dicresylbenzenethiophosphonate, and the like. 7

An additional advantage produced by the improved antiknock fluids of the instant invention is the fact that some of the phosphoruscontaining materials described 'hereinbefore, such as tricresylphosphate, triphenylphosphate, and pyrocatecholphosphite, impart to such fluids -the stabilizing or antioxidant eflectiveness' of such materials. Furthermore, some of the phosphorus-containing materials, such astriphenylphosphite, tricresylphosphitc, tricresylphosphate, trilaurylphosphite, and tri-(p-tertbutylphenyD-phosphate, are known to alleviate corrosion problems particularly in fuel storage tanks madeof aluminum, magnesium, and diversealloys thereof. Moreover,

some of the phosphorus-containingmaterials, such as tri- (3 chloropropyl)thionophosphate, dimethyltolylphosphate, and dimethylxylylphosphate, are particularly good preignition suppressants- Additional advantages of the improved antiknock [fluids and fuels of the present invention are the reduction of the total amount of solids normally found in the crankcase'and a reduction in the total ductions lessen the likelihood of interferences with normal oil flow and lubrication of critical engine parts. e

In compounding some of the improved antiknock fluids of the present inventioml can also employ other antioxidants and other stabilizing compositions including ortho dialkylated phenols and N,N'-di-sec-butyl-p-phenylene. diamine. .PFnrthermore, I can also employ diverse or: ganic dyes and the like which have long been recognized in the prior art, in such improved antiknock fluids of the present invention. 7 I

The improved antiknock fluids of this invention can be effectively utilized by supplemental injection into internal combustion engines and in dual fuel systems. Likewise, concentrated fuels containing substantially greater amounts of my antiknock fluids'than ordinary treated fuels for internalcombustion engines can be utilized. in this manner.

Having fully described myinvention, the need therefor, and the best method devised for carrying it out, it is not intended thatit be limited except within the spirit and scope of the appended claims.

I claim:

1. In an antiknock composition consisting essentiallyof organolead material as theprincipal antiknock ingredient, organic halogen scavenger material selected from the class consistingof that having two atoms of chlorine plus one atom of bromine per atom of said anti-knock lead, and that having. two atoms of bromine per atom of said antilcno'ck lead, and 'a gasoline soluble phosphorus-containing, spark plug anti-fouling'compound, the phosphorus-to-lead atom ratio of said composition being from about 0.02:3 to about 0.7:3; the improvement in which the bromine contentotf the organic halogen scavenger material is increased by..about 15 to. 20 percent. r Y

2. In an antiknock composition consisting essentially of tetraethyllead, ethylene dichloride, ethylene dibromide, and a gasoline soluble phosphorus-containing, spark plug anti-fouling compound, the phosphorus-to-lead atom ratio of said composition being from about 0.153 to about 0.423, and the ethylene dichloride content being that which furnishes about'tw'o atoms of chlorine for every atom of lead, the improvement in which .the ethylene dibromide content is such that for every atom of lead therearelz atoms ofbromine. f

3. The "antiknock oompositionof claim 2 wherein the phosphorus-containing compound is tricresylphosphate.

4. The antiknock composition of claim 2 wherein the phosphorus-containing compound is tri-B-(chloropropyl) thionophosphate. I

5. In anantiknock composition consisting essentially of tetraethyllad, ethylene dibromide and a gasoline sol- References Cited in the file of this patent UNITED STATES PATENTS Bartholomew Apr. 9, 1946 Yust et a1. Oct. 2, 1956 FOREIGN PATENTS Great Britain Apr. 2, 1948 Belgium Jan. 31, 1951

Claims (2)

1. IN AN ANTIKNOCK COMPOSITION CONSISTING ESSENTIALLY OF ORGANOLEAD MATERIAL AS THE PRINCIPAL ANTIKNOCK INGREDIENT, ORGANIC HALOGEN SCAVENGER MATERIAL SELECTED FROM THE CLASS CONSISTING OF THAT HAVING TWO ATOMS OF CHLORINE PLUS ONE ATOM OF BROMINE PER ATOM OF SAID ANTI-KNOCK LEAD, AND THAT HAVING TWO ATOMS OF BROMINE PER ATOM OF SAID ANTIKNOCK LEAD, AND A GASOLINE SOLUBLE PHOSPHORUS-CONTAINING, SPARK PLUG ANTI-FOULING COMPOUND, THE PHOSPHORUS-TO-LEAD ATOM RATIO OF SAID COMPOSITION BEING FROM ABOUT 0.02:3 TO ABOUT 0.7:3, THE IMPROVEMENT IN WHICH THE BROMINE CONTENT OF THE ORGANIC HALOGEN SCAVENGER MATERIAL IS INCREASED BY ABOUT 15 TO 20 PERCENT.

6. A GASOLINE CONTAINING THE COMPOSITION OF CLAIM 1 IN AMOUNT SUFFICIENT TO PROVIDE EFFECTIVELY IMPROVED ANTIKNOCK, BUT NOT MORE THAN EQUIVALENT TO SIX MILLILITERS OF TETRAETHYLLEAD PER GALLON.