US2935390A - Fuel additives - Google Patents

Description

United States Patent cc FUEL ADDITIVES John D. Bartleson, Franklin, Mich.,.assignor to Ethyl Corporation, New York, N.Y., a corporation of Delaware No Drawing. Application January 29, 1954 Serial N0. 407,165

8 Claims. (Cl. 44-69) This invention relates to novel compositions comprising organophosphorus materials and minor proportions of an amine and to uses thereof. This application is a continuation-in-part of my prior applications, Serial Nos. 374,151 and 374,156, both filed August 13, 1953, now Patent Nos. 2,794,718 and 2,794,713 respectively, both granted June 4, 1957.

2,935,390 Patented May 3, 1960 taining fuels, especially those used in spark ignition type internal combustion engines, having improved solubility characteristics and stability against the adverse affects of deteriorative environments during compounding, blending and storage. It is also an object of this invention to provide improved compositions comprising a hydro- When leaded fuels are utilized in internal combustion,

engines, there is an accumulation of deposits in the combustion chambers which results in a number of serious problems including deposit-induced autoignition or wild ping, spark plug fouling, reduction in exhaust valve life and the like. The magnitude of these problems is intensified each time the lead concentration in the fuel is raised to coincide with increase in compression ratio of internal combustion engines in passenger cars and trucks. v

A method for modifying engine deposits and decreasing their ill effects by utilizing phosphorus-containing materials has been proposed in the prior art. For example, it has been shown that certain organophosphorus-containing materials such as those obtained by the reaction of a phosphorus sulfide with an olefinic hydrocarbon (Serial No. 374,151 noted above), and'the product obtained by reaction between a phosphorus sulfide and an active hydrogen-containing aromatic compound (Serial No. 374,156 noted above), when used as fuel additives, resulted in the diminution of deposit-induced engine problems. However, it was found that such phosphoruscontaining materials, while not in the strict sense of the word insoluble in gasoline, do, upon addition to gasolines, form incomplete solutions typified by the creation of a haze or other indications of a colloidal dispersion. Furthermore, it was also found that the phosphorus-containing materials discussed above were not completely soluble in tetraethyllead-containing fluids and on standing resulted in the deposition of a heavy white sludge. It is seen, therefore, that aneed exists for a composition of matter comprising phosphorus-containing materials possessing increased solubility and stability in order that they may be added to fuels and to fluids containing organolead compounds, scavengers and other components, without any harmful effects.

It is, therefore, an object of this invention to provide novel organophosphorus-containing materials possessing enhanced stability. and solubility characteristics. It is likewise, an object of the present invention to provide novel compositions of matter comprising the product obtained by the reaction between a phosphorus sulfide and a hydrocarbon, and a minor portion of a basic amine. Another object of this invention is to provide means of improving compositions such as antiknock fluids and fuels which contain organolead antiknock agents and organophosphorus compounds by incorporating a small amount of a basic amine therein. Another object of this invention is to provide improved organolead compositions such as anti-knock fluidsand organolead-com carbon fuel, an organophosphorus compound and a minor proportion of a basic amine. Another object is to provide improved fuel composition which, when used in spark-fired internal combustion engines, simultaneously alleviate spark plug fouling and increase exhaust valve life. Other important objects of this invention will be apparent from the discussion which follows. I

It hasbeen found that the above and other objects of this invention are obtained by providing compositions of matter comprising the product obtained by reaction between a phosphorus sulfide and a hydrocarbon selected from the group consisting of an active hydrogen-containing aromatic compound and an olefinic hydrocarbon, and a minor amount of a basic amine having a dissociation constant characteristic of a base of not less than about 1 10 I have also found that when organophosphorus compounds which are not completely soluble in fuels, are added to such fuels in the form of the novel compositions of matter of this invention, they are completely soluble therein and no haze or precipitate forms even after prolonged storage.

I have also discovered that the compositions of matter of my invention can be readily blended with organolead antiknock fluids. Such organolead fluids containing organophosphorus and amine components show no signs of decomposition of the organolead compound. This is in contrast to the case where organophosphorus compounds are added without any amine, whereupon a heavy white precipitate slowly settles out indicating that the phosphorus compound causes the organolead compound to slowly decompose.

In like manner, the composition of this invention comprising an organophosphorus compound and abasic amine having a dissociation constant characteristic of a base of not less than about 1X10 can be blended with fuels containing organo antiknock fluids. The presence of the amine in this composition prevents the destruction of the organolead compound by the phosphorus compound.

. The resulting fuel is thus endowed with the beneficial base of not less than about 1 10- and the product obtained by the reaction between such compounds as phosphorus pentasulfide (P 8 (P 8 phosphorus heptasulfide (P 8 and the like, and an olefinic hydro carbon or an active hydrogen-containing aromatic compound, that is, a compound which contains at least one aryl radical and a hydrogen atom activated thereby.

An embodiment of this invention is the product obtained by the reaction of a basic amine of the type described previously with the reaction product of a phosphorus sulfide andan olefinic polymer having a molecular weight in the range of from about 100 to about 500. One example of an olefinic material that can be used is the hydrocarbon fraction of an olefinic gasoline made by the polymerization of propylenes and butylenes by known methods from which have been removed all components enes.by.known methodsv This polymer hasan. ayeragei;

boiling below 250 F. The average molecular weight of such an olefin is about 140. Another olefinic polymer employed is. one obtained by polymerizing mixed butylmolecular weight of about 420. An illustrative example of the trihydrocarbon substituted methanes used in the preparation of the organophosphorus compounds employed in this invention is isopropylbenzene.

The organophosphorus compounds discussed above are formed by using from about 0.2 to about 2.0 moles of phosphorus sulfide per mole of an olefinic hydrocarbon or an active hydrogen-containing aromatic compound in the reaction.

Although, as will be shown later, the effect obtained is not due to the mere addition of a base, it has nevertheless been found that the maximum beneficial results are obtained when the dissociation constant, characteristic of a base, of the amine used is not less than about l The amine or amines can be aliphatic, alicyclic or heterocyclic, primary or secondary, containing about 5 to about 36 carbon atoms. The aliphatic amines can be straight or branched chain as for example, amylamine, octylamine, dibutylamine, the diamylamines both straight and branched chain, diisopropylamine, ethylpropylamine, isopropylbutylamine, dodecylamine, dioctadecylamine, and the like. Examples of alicyclic amines are piperidine and the like. The aromatic amines can be illustrated by such examples as pyridine, quinoline and the like. Any one of the above types of amines or a mixture of two or more of such amines can be used in my invention in cornbination with an organophosphorus sulfide reaction prodnet or of mixtures of various such organophosphorus products to make my novel compositions of matter.

I have also found that only a small proportion of amine need be present in my new composition of matter to obtain the beneficial effects desired. For example, very good results are obtained when the amine is present in the weight ratio of from about 0.0129 to about 0.065 nitrogen-to-phosphorus on the basis of the phosphorus in the phosphorus-containing reaction product. While the above is a preferred embodiment I can, in fact, use greater amounts of the amine or amines. However, the beneficial effect observed relative to the proportion of amine added over and above the ratio of 0.065 nitrogen-to-phosphorus, rapidly diminishes so that the practical upper limit on the amount used is such that the nitrogen-to-phosphorus ratio is 0.129.

That the beneficial effects observed on employing the compositions of the invention are not merely the result of a neutralization of acidic groups in the organophosphorus compounds is evidenced by the fact that neutralization of said organo-phosphorus compounds with an alkali bicarbonate and removal of the water soluble salts does not improve the resulting product with respect to stability and solubility as will be shown hereinbelow. On the other hand, the mere addition of approximately 2 percent of an amine, of the kind described above, to a reaction product of a phosphorus sulfide and an olefin or an active hydrogen-containing aromatic compound, renders the resulting material soluble in fluids and fuels which can contain organolead compounds, and in which there can also be present other components such as scavengers, dyes and solvents such as kerosene and the like which are of the nature of those employed in antiknock fluids. To illustrate, it has been found that when a phosphorus sulfide-olefin reaction product, which has been treated with a bicarbonate wash, is dissolved in a fluid or fuel containing an organolead compound and allowed to stand for a short period of time, there settles out a heavy white sludge, which is probably due to some reaction between the phosphorus sulfur-containing compound and the organolead compound, resulting in a decomposition of the latter. On the other hand, when a small amount of an amine is added to the phosphorus sulfur-containing compound either before or shortly after adding the latter to the organolead composition, it is noticed that no sludge settles out even after standing a considerable length of time. This is true of the amine addition regardless of whether the phosphorus sulfur-contain-v ing compound has or has not been treated with a bicarbonate wash. These observations appear to indicate that the added amine reacts with certain functional groups in the phosphorus and sulfur-containing organic product to form a type of chemical bond or electron configuration different from that in other superficially related base neutralized products. That the phenomena observed, namely, the solubilization of the'phosphorus sulfur-containing product and the prevention of sludge formation, is not due to the solvent action of the amine per se, was evidenced by the fact that the addition of the amine after the sludge had formed did not result in the re-dissolving of said sludge.

In order to demonstrate the beneficial effect of employing a small amount of an amine in conjunction with the phosphorus sulfur-containing organic compound in solutions containing organolead compounds together with scavengers, dyes and the like, such as organolead antiknock fluids and fuels, a number of tests were conducted both with and without the amine being present. The results of these tests are contained in the examples given below.

The term theory is used in the examples in denoting the amount of halogen and of phosphorus present. A theory of a halogen is defined as the theoretical amount of halogen required to react with the lead present to form lead dihalide. One theory of phosphorus is defined as that amount of phosphorus required to combine with a given amount of lead to form Pb (PO Alternatively, a theory of a halogen is defined as that amount of halogen being present which corresponds to an atom ratio of 2:1 halogen-to-lead. Similarly, a theory of phosphorus is that amount of phosphorus which corresponds to an atom ratio of 2:3 phosphorusto-lead.

The following examples more specifically illustrate the methods of blending and the beneficial effects obtained by my new compositions of matter.

Example I To 49 parts by weight of the product obtained by the reaction of P S with a hydrocarbon fraction of an olefinic gasoline made by the polymerization of propylenes and butylenes by known methods and from which the components boiling below 250 F. have been removed, is added one part of dodecylamine. The two components are then subjected to agitation by means of stirring until a homogeneous mixture is obtained. This constitutes one method of making the new compositions of matter of my invention.

While in the above example no heat is required for the reaction of the amine with the organophosphorus compound, it may sometime be found advantageous to apply heat while agitating the mixture in order to hasten or aid the reaction. This will, of course, depend on the particular amine and the organophosphorus compound employed.

Example II To 40 parts by weight of a petroleum hydrocarbon fuel available as an article of commerce is added one part of the composition of Example I. The mixture is agitated by means of stirring until a homogeneous solution results. No haziness is observed in the fuel blended in this manner and standing for a period of thirty days does not result in the formation of any precipitate, thus illustrating the beneficial effect of the compositions of matter of this invention.

Example III To 32 parts by weight of conventional antiknock fluid containing 19.7 parts of tetraethyllead, 0.5 theory of bromine as ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride, together with kerosene and a dye, is added 0.2 theory of phosphorus in the form of the composition of Example I. The mixture is thor- To 300 parts by weight of a petroleum hydrocarbon fuel available as an article of' commerce is added 1 part of the composition of Example III. On stirring until a homogeneous mixture results, it is found that no cloudiness appears and allowing the solution to stand for more than thirty days does not result in the formation of any precipitate.

Example V One part of P S -olefin reaction product was added to 2700 parts by weight of a petroleum hydrocarbon fuel of the gasoline boiling range which contained 8 parts of conventional antiknock fluid. The mixture was thoroughly stirred but the 'organophosphorus compound would not go into solution, remaining in the form of a cloudy dispersion which slowly settled out. To this mixture was next added 2% by weight of dodecyl amine, based on the amount of the organophosphorus substances present. The mixture was again thoroughly agitated and it was found that a clear solution resulted with no sediment formation even after standing for 10 days.

Example VI To 40 parts by weight of a petroleum hydrocarbon fuel available as an article of commerce was added one part of the product obtained by the reaction of P 8 with a hydrocarbon fraction of an olefinlc gasoline made by the polymerization of propylenes and butylenes from which the components boiling below 250" F. had been removed. Immediately upon addition a haze formed. and a precipitate separated slowly. To this solutionwas then added 2% of dodecylamine based upon the weight of the phosphorus sulfide-olefin reaction prod-, uct. The addition of the amine dissipated the haze or precipitate from the solution and it did not reappear even after standing for a period of over 20 days. Thisillustrates the remarkable. effectiveness of a very small amount of an amine on the solubility of the phosphoruscontaining compound.

Example VII To 32 parts of conventional antiknock fluid containing 19.7 parts of tetraethyllead, 0.5 theory of bromine as ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride, together with kerosene and a dye, was added 0.1 theory of phosphorus as the P S -olefin reaction product which had been treated with a potassium bicarbonate wash. On first addition the solution was clear but on standing, a heavy'white precipitate settled out. After allowing this solution to stand for three days, 2% of dodecylamine, based upon the weight of the organophosphorus compound present, was added. The resulting solution was subjected to agitation but the white precipitate would not go into solution.

. ExampleV III To 32 parts of conventional tetraethyllead antiknock fluid described in Example VII was added 0.2 theory of phosphorus as the P S -olefin reaction product. -On first 6 6 Example IX To 32 parts of tetraethyllead fluid described in Example VII was added 0.2 theory of phosphorus as the olefin reaction product which had been treated with a potassium bicarbonate wash. The solution was clear on first addition but upon standing for 30 minutes it became cloudy. Two percent of dodecylamine based upon the weight organophosphorus compound was then added. The cloudiness disappeared and on standing for five days there was no evidence of any white precipitate or sludge being formed.

Example X To 32 parts of conventional antiknock fluid containing 19.7 parts of tetraethyllead, 0.5 theory of bromine as ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride, the theories of halogen being based upon the amount of lead present in the form of tetraethyllead, and kerosene together with a dye, was added 0.1 theory of phosphorus as the P S -olefin reaction product. The solution became turbid immediately upon the addition of the organophosphorus compound. -To this solution was then added 2% dodecylamine based upon the weightof the organophosphorus compound present. The turbidity disappeared from the solution. The mixture was allowed to stand for 10 days during which time no change was noted in its appearance. No white precipitate was formed.

The foregoing examples illustrate the fact that a small amount of the amine is essential to render the organophosphorus compounds of the type discussed previously in this application, soluble and stable in fuels and in conventional organolead antiknock fluids. Example VII, given above, illustrates that treating a P S -olefin reaction product with a bicarbonate wash does not, on addition of the product to the antiknock fluid, render the solution stable. However, Examples II, III, IV, V, VI, VIII, IX and X illustrate the fact that regardless of whether or not the organophosphorus compound was treated with a bicarbonate solution, the addition of a small amount of a basic amine not only makes the organophosphorus compound soluble in fuel and in conventional organolead antiknock fluid but the amine imparts a stabilizing influence which inhibits reaction with, and decomposition of the organolead compound and thus prevents the formation of the white precipitate.

,It is also seen from the examples given above that there are several ways in which the new compositions of my invention can be utilized. For instance, the amine can be added to the organophosphorus compound before the. addition to the fuel or fluid as in Examples II and III, or'first one component can be added and then the other as in Examples V, VI, VIII, IX and X. Another alternative is to add the two components simultaneously.

Fuel compositions described in Examples IV and V were each used as a fuel in a standard six-cylinder automotive engine. It was found that a great reduction in spark plug fouling as well as a substantial increase in exhaust valve life was achieved, as compared to eflects observed when the improved organophosphorus-amine compositions of this invention were not included in the fuel.

Although the antiknock fluid used in the examples with the fuels will depend on the use for which it is required. For instance, it will vary from about 1.58 to about 3.17 grams of lead per gallon in the form of tetraethyllead when used in automobile engines, and up to as high as about 6.4 grams of lead per gallon when used in fuels for aviation engines. However, concentrations slightly above and below those recited can be used if conditions so require.

In all the compositions wherein the organophosphorus and amine compositions of the present invention are utilized, the amount of phosphorus present is from about 0.1 to about 0.35 theory, based on the amount of lead present, which is equivalent to an atom ratio of from about 0.2:3 to about 0.7 :3 phosphorus-to-l'ead. When no lead is present the organophosphorus compound can be employed in the fuel in amounts equivalent to from about 0.016 to about 0.23 gram of phosphorus per gal on of fuel. The amine as stated previously is employed in the weight ratio of from about 0.0129 to about 0.129 nitrogen-to-phosphorus on the basis of the phosphorus present as the organophosphorus compound.

The improved combined organophosphorus and amine product of this invention can be effectively utilized by supplemental injection in the-internal combustion engines and in dual fuel systems for the effectiveness desired from such use, as described in my co-pending applications mentioned hereinbefore. Likewise, concentrated fuels containing varying amounts of organolead antiknock compounds and combined organophosphorus and amine products of my invention for internal combustion engines can be utilzed in this manner.

The organophosphorus-amine of this invention can be used in antiknock fluids and fuels containing various halide scavengers such as ethylenedibromide, ethylenedichloride, mixed dibromotoluenes, trichlorobenzenes, and in general such organic halide scavengers as those disclosed in US. 1,592,954; 1,668,022; 2,364,921; 2,398,281; 2,479,900; 2,479,901; 2,479,902; 2,479,903; and 2,496,983. Likewise, the adjuvants of this invention can be used in conjunction with other motor fuel additives such as antioxidants, organolead stabilizers, organic dyes, solubilizers, and indeed with other catalytically active materials frequently employed in fuel.

Having fully described the nature of the present invention, the need therefor, and the best mode devised for carrying it out, it is not intended that this invention be limited except within the spirit and scope of the appended claims.

I claim:

1. An antiknock fluid composition for use as an adjuvant for hydrocarbons of the gasoline boiling range and which consists essentially of an organolead antiknock agent, a halohydrocarbon scavenger for said agent and a product obtained by reaction between (a) a phosphorus sulfide selected from the group consaid product being in said composition in amount such that the phosphoruszlead atom ratio is from about 0.2:3 to about 07:3.

2. An antiknock fluid consisting essentially of tetraethyllead, a scavenging agent for said tetraethyllead, said scavenging agent being selected from the group consisting of ethylene dichloride, ethylene dibromide and mixtures thereof, and a reaction product of (a) a phosphorus sulfide selected from the group consisting of P S and P487,

(b) an olefinic hydrocarbon polymer having a molecular weight in the range of from about to about 500,

(c) an amine containing about 5 to about 36 carbon atoms and having a dissociation constant characteristic of a base of not less than about 1 10' said product being in said composition in amount such that the phosphoruszlead atom ratio is from about 0.2:3 to about 0.713; and said amine being present in said reaction product in amount such that the weight ratio of nitrogen to phosphorus is from about 0.0129 to about 0.129 based on the phosphorus contained in said product.

3. The composition of claim 1 wherein said amine is dodecyl amine.

4. Hydrocarbon fuel of the gasoline boiling range adapted for use in spark ignition internal combustion engines, said fuel containing the composition of claim 1 in an amount such that the composition provides from about 1.58 to about 6.4 grams of lead per gallon of the fuel.

5. The composition of claim 2 further characterized in that said polymer used to form said product is ob tained by the polymerization of propylenes and butylenes and has an average molecular weight of about 140.

6. Hydrocarbon fuel of the gasoline boiling range adapted for use in spark ignition internal combustion engines, said fuel containing the composition of claim 2 in an amount such that the composition provides from about 1.58 to about 6.4 grams of lead per gallon of the fuel.

7. Hydrocarbon fuel of the gasoline boiling range adapted for use in spark ignition internal combustion engines, said fuel containing the composition of claim 3 in an amount such that the composition'provides from about 1.58 to about 6.4 grams of lead per gallon of the fuel.

8. Hydrocarbon fuel of the gasoline boiling range adapted for use in spark ignition internal combustion engines, said fuel containing the composition of claim 5 in an amount such that the composition provides from about 1.58 to about 6.4 grams of lead per gallon of the fuel.

References Cited in the file of this patent UNITED STATES PATENTS 2,137,584 Ott Nov. 22, 1938 2,316,082 Loane et al. Apr. 6, 1943 2,398,281 Bartholomew Apr. 9, 1946 2,405,560 Campbell Aug. 13, 1946 2,507,731 Mixon et al May 16, 1950 2,534,217 Bartleson Dec. 19, 1950 2,636,858 Jones et al. Apr. 28, 1953 2,712,528 Hill et a1. July 5, 1955 2,734,863 Jones et a1. Feb. 14, 1956 FOREIGN PATENTS 683,405 Great Britain Nov. 26, 1952

Claims (2)

1. 2. AN ANTIKNOCK FLUID CONSISTING ESSENTIALLY OF TETRAETHYLLEAD, A SCAVENGING AGENT FOR TETRAETHYLLEAD, SAID SCAVENGING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF ETHYLENE DICHLORIDE, ETHYLENE DIBROMIDE AND MIXTURES THEREOF, AND A REACTION PRODUCT OF (A) A PHOSPHROUS SULFIDE SELECTED FROM THE GROUP CONSISTING OF P2S5 AND P4S7, (B) AN OLEFINIC HYDROCARBON POLYMER HAVING A MOLECULAR WEIGHT IN THE RANGE OF FROM ABOUT 100 TO ABOUT 500, (C) AN AMINE CONTAINING ABOUT 5 TO ABOUT 36 CARBON ATOMS AND HAVING A DISSOCIATION CONSTANT CHARACTERISTIC OF A BASE OF NOT LESS THAN ABOUT 1X10**-9, SAID PRODUCT BEING IN SAID COMPOSITION IN AMOUNT SUCH THAT THE PHOSPHORUS: LEAD ATOM RATIO IS FROM ABOUT 0.2:3 TO ABOUT 0.7:3, AND SAID AMINE BEING PRESENT IN SAID REACTION PRODUCT IN AMOUNT SUCH THAT THE WEIGHT RATIO OF NITROGEN TO PHOSPHORUS IS FROM ABOUT 0.0129 TO ABOUT 0.129 BASED ON THE PHOSPHORUS CONTAINED IN SAID PRODUCT.
2. 5. THE COMPOSITION OF CLAIM 2 FURTHER CHARACTERIZED IN THAT SAID POLYMER USED TO FORM SAID PRODUCT IS OBTAINED BY THE POLYMERIZATION OF PROPYLENES AND BUTYLENES AND HAS AN AVERAGE MOLECULAR WEIGHT OF ABOUT 140.