US3231348A - Gasoline fuel containing substituted diethylenetriamines - Google Patents

Description

-rough idling, engine stalling, and loss of power.

United States Pate 3,231,348 GASOLINE FUEL CONTAINING SUBSTITUTED DIETHYLENETRIAMINES Eddie G. Lindstrom, Martinez, and Wallace L. Richardson, Lafayette, Calif., assignors to Chevron Research Company, a corporation of Delaware No Drawing. Filed Dec. 7, 1961, Ser. No. 157,834 '2 Ciaims. (CI. 44-72) This invention is concerned with motor fuels, and, in partlcular, with gasoline fuels used in spark-ignition in- .ternal combustion engines.

Formation of deposits by gasoline fuels in the induction system of an engine, particularly, in the throttle body section of the carburetor, in the intake manifold, in the ports and on the undersides of the valves, represents a well-known cause of interference \with the efficient operation of spark-ignition engines, and is responsible for The loss of power is due to throttling of the engine by the deposits in the intake manifold and ports, and on the valves.

Various additives to be incorporated in gasolines for the purpose of mitigating formation and build-up of these deposits in the induction system have been proposed in the past. Some of these additives have been reported to be successful for the purpose, others gave rise to new problems in engine operation, and a great number of additives proved to be completely impractical. Therefore, the search for new and effective additives to eliminate deposit formation is still continuing.

It has now been-found that the elimination or at least the reduction of these deposits in the induction system of spark-ignition internal combustion engines can be unexpectedly achieved by incorporating in the gasolines a minor amount, from about 10 to about 1000 parts per each million parts by weight of gasoline, of a certain acyclic amine material, apparently exercising a detergentlike action; namely, of a straightchain alkyl or alkenyl substituted diethylenetriamine.

The group of these efiective deposit-reducing organosubstituted diethylenetriamine derivatives consists of acyclic normal C -C monoalkyl-substituted and C C monoalkenyl-substituted diethylenetriamines. Among them, the C C substituted diethylenetriamines are particularly efiective. The n-octadecyl-substituted and noctadecenyl-substituted diethylenetriamines are found to be exceptionally satisfactory. These 'organo-substituted diethylenetriamines have the general formula:

wherein, in the two occurrences of R one R is hydrogen and the other R is a radical from the group consisting of normal C C alkyl and normal G -C alkenyl radicals.

Preferably the additive is incorporated into the gasoline in amounts which may range from about 10 to about 300 ppm. (parts per million), although amounts lower or higher but within the aforementioned 10 to 1000 ppm. range may be effectively employed whenever the particular engine conditions would so permit or require. The deposit reduction is obtained both when the additive is incorporated into a lead-free gasoline, i.e. one not compounded wi-th a lead alkyl anti-knock agent, such as tetraethyl lead, and when it is employed in leaded gasoline, for instance, in one which contains conventional amounts of tetraethyl lead, tetramethyl lead, or other similar lead alkyl agent added to increase the octane number of the gasoline fuel.

The method of preparation of the aforementioned diethylenetriamine derivatives is not critical. A represen- Patented Jan. 25, 1966 ice tative method, carried out in the laboratory to produce sufiicient quantity of the additive for eventual tests in gasoline, involved the following synthesis: 333 g. (1 mol) of octadecyl bromide, 500 ml. (5.1 mols) of diethylenetriamine and 500ml. of ethanol were placed in a .flask and heated to reflux temperature. Thereupon 45 g. of sodium hydroxide in 60 m1. of water was added to the contents of the flask over approximately 5 minutes. Refiuxing was continued for three hours, whereupon 400 ml. of n-butanol, 400 ml. of benzene and 2 liters of water were added, and the resulting mixture was allowed .to

stratify into two layers. The lower aqueous layer was withdrawn and discarded. The upper organic layer was washed twice with water, then dried, and the solvent evaporated on a steam plate. The remaining material was analyzed to be N-n-octadecyl diethylenetriamine in a 94% yield.

N-n-octadecenyl diethylenetriamine was prepared by a different method as follows:

180 g. of the mono-oleyl amide of diethylenetriamine (prepared from oleic acid and excess of diethylenetriamine) was charged into a pressure bomb of 0.5 liter capacity, into which there were also added approximately 30 g. of-Raney nickel and 200 ml. of absolute ethanol. The mixture was subjected to 280 atm. pressure of hydrogen and heated to C. for 6 hours. After cooling, the solution was filtered and the alcohol evaporated. The weight of the recovered N-oleyl diethylenetriamine product was 171 g. The equivalent combining weight, determined by titration, confirmed the nature of the product, which was, in addition, reconfirmed by infra red absorption analysis. The yield of N-n-octadecenyl diethylenetriamine was better than 99%.

The N-n-octadecyl diethylenetriamine material was subsequently compared with other similar polyamines in the glass throttle body engine test specially developed and designed to observe and to evaluate deposits in the carburetor. In the test, a glass throttle body is inserted between the venturi section and the cast iron throttle body of a conventional carburetor. This glass body represents a section of glass tubing A" thick, about 1 inside diameter and about 2" long. Holes are drilled diametrically about down from the upper edge of the glass to receive a conventional metal throttle shaft and plate. Both the carburetor and the engine in this test were those of a 6-cylinder Plymouth passenger automobile.

In each run, the engine was operated on different gasoline fuels at 500 rpm. idle, with 5 full throttle, noload accelerations, up to a speed of about 3,000 rpm. every 15 minutes during the whole test period. In each run, the blowby was piped to the engines induction system as, for instance, through a pipe connecting the crankcase to the air cleaner on top of the carburetor. When a run was terminated and the engine stopped, the glass throttle body was removed, and the extent of formation of deposits was rated on a scale rangingfrom 1 to 7. A rating of l referred to no deposits at all being formed. A rating of 7 designated substantially complete coating with black, heavy, opaque deposits. The intermediate ratings indicated various degrees of deposit formation between these two extremes. The test gives excellent correlation with the actual operation of an automobile engine in the field.

In this particular illustrative test, in addition to the N-n-octadecyl diethylenetriamine,other amine materials, i.e., N-dodecyl diethylenetriamine and N-n-dodecyl propylenediamine and were employed in the previously mentioned effective range of amounts as additives to the same base gasoline. This gasoline was a commercial regular gasoline, containing about 1.5 ml./gal. of tetraethyl lead, and was typical of nationally available automotive gasolines. The results of the tests are shown in the following table which indicates the composition of each fuel (giving the name of the additive), concentration of the additive in parts per million (p.p.m.), the number of runs on each fuel, and the average rating of the deposits observed after the test on each fuel.

Glass throttle body test for evalutation of carburetor Dodecyl chain is a propylene tetramer radical.

The data in the above table show the superiority with respect to the reduction of deposits in the carburetor of the acyclic straight-chain (normal) C C substituted diethylenetriamines as compared with like derivatives of acyclic normal substituted diamines and with derivatives of branched-chain substituted diethylenetriamines.

The same representative N-n-o-ctadecyl diethylenetriamine as in Test No. 2 in the table hereinabove was tested in a laboratory test in a 1956 V-8 Chevrolet automobile engine under conditions which closely simulated those of urban and suburban driving. This test lasted 150 hours. The displacement of the engine was 283 cubic inches, and the engine jacket temperature was maintained at 200 C. throughout the test. The gasoline used in this instance was a commercial, premium grade, leaded gasoline characterized by a Research octane number of 99.5. This test correlates well with the operations on the road under conditions apt to cause severe deposit formation in an engine. After each test, with and without the additive, the engine was dismantled, and the ports and undersides of the valves were examined and rated on an arbitrarily chosen scale from 0, indicating a perfect cleanliness, to 10, indicating very heavy deposit.

In the run employing the aforementioned leaded premium gasoline which contained 375 p.p.m. of the diethylenetriamine additive of the invention, deposits observed on the ports were given a rating of 3.3 and those observed on the valves were given a rating of 2.3. In the run without the additive being present in the gasoline, the ports were assigned a rating of 4.8 and the valves a rating of 7.8. This again confirmed the excellent effectiveness of the additive.

To obtain data on the performance of the diethylenetriamine additive of the invention in actual operation on the road under average normal driving conditions, two automobiles, a 6-cylinder Ford with an existing mileage of about 16,000 miles and an 8-cylinder Plymouth with an existing mileage of about 27,000 miles, were run on a regular leaded base gasoline compounded with the additive, which Was similar to the gasoline employed in the previously described glass throttle body test. The first automobile ran over 5,000 miles and the second over 2,000 miles, using the additive at 500 p.p.m. concentration. The reduction in deposite weight, as observed on dismantling the engines, was determined to be 50% and 33%, respectively.

In addition to the aforementioned normal long-chain C C monoalkyl and monoalkenyl derivatives of diethylenetriamine, the gasoline improved therewith may contain minor amounts of other conventional fuel additives, provided these amounts and these additives do not detract from the detergent and, consequently, deposit removing effect of diethylenetriamine derivatives of, the present invention.

Furthermore, to facilitate carrying off the deposits dispersed by the diethylenetriamine materials, in accordance with the invention, an oil solvent or carrier, such as a light mineral lubricating oil, may be advantageously employed in amounts from about 0.05 to about 0.5% by volume and thus will effectively contribute to the reduction of deposits in the area of the intake ports of the engine.

It is desirable to formulate and to dispense the diethylenetriamine additives of this invention to the trade in the form of concentrates easy to handle and to blend with the gasoline. Concentrates suitable for shipping and handling both inside and outside refinery premises can be prepared by dissolving the additive in suitable diluents or solvents boiling substantially in the gasoline boiling range. Such solvents are, for instance, hydrocarbon solvents, such as an aromatic hydrocarbon solvent boiling in the range from about 300 to about 400 F., and any one of compatible C -C saturated aliphatic alcohols, such as isopropanol, methyl isobutyl carbinol, n-butanol, and the like, as well as mixtures of mutally compatible hydrocarbon solvents and C -C saturated aliphatic alcohols in any desirable proportions to each other, as may be required under the circumstances in each particular case.

We claim:

1. A fuel composition consisting essentially of gasoline and from about 10 to about 1000 parts, based on one million parts by weight of said fuel composition, of an acyclic-substituted diethylenetriamine of the general formula:

wherein, in the two occurrences of R one R is hydrogen and the other R is a straight-chain hydrocarbon radical from the group consisting of Gig-C20 alkyl and C C alkenyl radicals.

2. An additive concentrate capable of incorporation into gasoline which is suitable for use in spark-ignition engines, said concentrate consisting essentially of a solution of an acyclic diethylenetriamine of the general for- References Cited by the Examiner UNITED STATES PATENTS 2,684,292 7/ 1954 Caron et al. 4474 X 3,011,879 12/1961 Buckmann et al 44-72 X 3,031,278 4/ 1962 Buckm-ann et al 4472 X 3,050,043 8/1962 Barusch 4472 FOREIGN PATENTS 793,448 4/ 1958 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

Claims (1)

1. A FUEL COMPOSITION CONSISTING ESSENTIALLY OF GASOLINE AND FROM ABOUT 10 TO ABOUT 1000 PARTS, BASED ON ONE MILLION PARTS BY WEIGHT OF SAID FUEL COMPOSITION, OF AN ACYCLIC-SUBSTITUTED DIETHYLENETRIAMINE OF THE GENERAL FORMULA: