US 3615294 A
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III I e Inventor Ronald W. Von AlImen Hopewell Junction, NIT. Appl. No. 23,027 Filed Mar. 26, 1970 Patented Oct. 26, 1971 Assignee Texaco Inc.
New York, NY.
DETERGENT MOTOR FUEL CONTAINING  References Cited UNITED STATES PATENTS 2,839,372 6/1958 Lindstrom et a] 44/66 3,468,639 9/1969 Lindstrom et al 44/66 Primary Examiner-Daniel E. Wyman Assistant Examiner-W. J. Shine Attorneys-Thomas H. Whaley and Carl G. Ries ABSTRACT: A class of substituted ureas represented by the formula:
I I I I R--N(CHz)x-NCNICHDr-NR in which x has a value from two to four, R is hydrogen or a hydrocarbyl radical and R and R" are hydrocarbyl radicals having from eight to 20 carbon atoms have been found to be useful as carburetor detergents in a motor fuel composition.
DETERGENT MOTOR FIUEIL CONTAINING SUESTITUTHED UREAS BACKGROUND OF THE INVENTION Field of the Invention deposits in and around the throttle plate area of the carburetor. These deposits restrict the flow of air through the carburetor at idle and at low speeds so that an overrich fuelmixture results. This condition produces rough engine idling, stalling and also results in excessive hydrocarbon exhaust emissions to the atmosphere.
DESCRIPTION OF THE PRIOR ART Numerous patents have issued disclosing the use of urea derivatives to effect improvements in gasoline compositions.
US. Pat. No. 2,373,372 discloses alkylated and arylated ureas for improving the antiknock value of gasoline. U.S. Pat. No. 2,683,08l discloses N-hydrocarbyLN'-hydroxyphenyl ureas as anti-oxidants for gasoline. U.S. Pat. No. 2,772,148 discloses N-alkyl-N',N-di(carboxymethyl) urea as a rust inhibitor for hydrocarbon fuels.
SUMMARY OF THE INVENTION A class of relatively high molecular weight substituted ureas are provided as carburetor detergents when employed in a liquid hydrocarbonaceous fuel for an internal combustion engine. These ureas are characterized by having a pair of long chain alkylamino alkyl radicals substituted on the basic urea structure and appear to be unique in their detergency properties.
The fuel composition of the invention mitigates or overcomes the problem of deposits laydown in the carburetor of an internal combustion engine. When a gasoline of the invention is employed in a carburetor which has a substantial buildup of deposits from prior operations, a severe test of the detergency property of the fuel, this gasoline is very effective for removing substantial amounts of these preformed deposits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The substituted urea additive employed in this invention has the formula:
H O H in which x has the value of from two to four, R is hydrogen or a hydrocarbyl radical having from one to four carbon atoms, and R and R" respectively are hydrocarbyl radicals having from eight to 20 carbon atoms each.
In a preferred embodiment R is hydrogen .1: has a value of 3,
and R and R" each represent a saturated secondary aliphatic radical having from [0 to 15 carbon atoms.
The additive of the invention can be prepared by reacting urea with a suitable dihydrocarbon-substituted amine or diamine to produce the noted compound. A preferred reaction is to react urea with an Nalkyl-substituted trimethylenediamine. In this procedure, two moles of the diamine are reacted with a mole of urea at an elevated temperature to produce the desired product. The molar proportion of the reaction, the reaction product can be dissolved in a suitable solvent, such as ether-benzene, washed with dilute acidic and basic solutions until the product is slightly basic, dried, and recovered from the solvent by vacuum distillation. This reaction is described in Synthesis of Symmetrical Ureas by Heating Urea With a Primary Amine" by J. G. Erickson, .I. Am. Chem. 500., 76, 3977 I954).
Examples of compounds that are effective carburetor detergents in gasoline include 3,3-di(dodecylamino) di-n-propylurea, 3,3'-di(tetradecylamino) di-n-propylurea, 3,3'-di(octadecylamino) di-n-propylurea, 3-dodecylamino-3'-octadecylamino di-n-propylurea, 2,2'-di(dodecylamino) di-nethylurea, 4,4'-di(hexadecylamino) di-n-butylurea, 3,3- di(sec. C ,H alkylamine) di-n-propylurea and 3,3- di(octadecenylamine) di-n-propylurea.
Any gasoline suitable for a spark-ignited, internal combustion engine can be used in the practice of this invention. In general, the base fuel will consist of a mixture of hydrocarbons in the gasoline boiling range, i.e. from about 75 to 450 F.
The hydrocarbon components can consist of paraffinic,
naphthenic, aromatic and olefinic hydrocarbons obtained by thermal or catalytic cracking or reforming of petroleum hydrocarbons. This base fuel will generally have a Research Octane Number above and preferably above 90.
The substituted urea of the invention can be advantageously employed in the motor fuel at a concentration ranging from about 0.0005 to 0.05 weight percent. The preferred concentration ofthe additive is from about 0.001 to 0.0l weight percent.
The following examples illustrate the preparation of the substituted ureas of the invention.
EXAMPLEI 180 g. (0.60 mole) of N-cocoprop ylenediamine (commercial Duomeen C) was placed in a 500 ml. flask equipped with a thermometer, condenser, magnetic stirrer and a sintered glass tube. 18 g. (0.30 mole) of urea was added and themixture heated for 3 hours at I60" C. A slow steady nitrogen flow was maintained to sweep out ammonia being evolved. The nitrogen flow was continued until the reaction product returned to room temperatures. The reaction product was diluted with approximately 600 ml. of ether-benzene and washed alternately with 6Xl00 ml. of 1.5 N hydrochloric acid. After washing with 6Xl00 ml. of 10 percent sodium carbonate, the product was washed with water until the wash was slightly basic, i.e. less than pH 8. The product was dried over CaSO, and Na sO filtered and the solvent removed by vacuum distillation at 0.5 mm. Hg. ove-ra steam bath.
The N-cocopropylenediamine-urea derivative, also known as 3,3'di(cocoamino) di-n-propylurea, had a total Base Number (ASTM D-664) of 167 (Theory 178) and a nitrogen content of 9.3 percent (Theory 8.9). Duomeen C is an Armour Company product having the formula R-NH-(Cll h- NH, where R is an alkyl radical derived from coconut fatty acids.
EXAMPLE II 0.60 moles of N-oleyl propylenediamine (commercial Duomeen 0) and 0.30 moles of urea were reacted as in example I. The substituted urea derivative, 3l,3'di(oleylamino) di-npropylurea, had a total base number of (Theory and a nitrogen content of 7.04 percent (Theory 7.02). Duomeen 0 is similar in structure to Duomeen C except that the alkyl radical represented by R in the formula above is octadecenyl.
EXAMPLE II] 0.60 moles of N-(B-undecyU-l,3-propanediamine (commercial Duomeen L-l 1) and 0.30 moles of urea were reacted as in example I above. The substituted urea derivative had a total base number of I78 (Theory 194) and a nitrogen content of9.9 percent (Theory 9.7
EXAMPLE IV 0.60 moles of N-(B-pentadecyD-l,3-propanediamine (commercial Duomeen L-l) and 0.30 moles of urea were reacted as in example I. The substituted urea derivative had a total base number of 140 (Theory 162) and a nitrogen content of 8.3 percent (Theory 8.1).
EXAMPLE V 0.60 moles of N-sec.(C -C alkyl-1,3-propanediamine and 0.30 moles of urea were reacted as in example I. The substituted urea had a total base number of 205 (Theory 204) and a nitrogen content of 10.7 (Theory 10.2).
EXAMPLE VI hydrocarbons, 20 percent olefinic hydrocarbons and 55 percent paraffmic hydrocarbons and boiled in the range from about 90 F. to 360 F.
The carburetor detergency test results obtained from the base fuel containing the substituted ureas described above are set forth in the following table. The additive-containing fuels contained the active detergent additive at a concentration of 5 ptb (pounds per thousand barrels of fuel), a concentration equal to about 0.002 weight percent. A minor amount of a light distillate mineral oil carrier introduced in the fuel with the additive has no significant effect on the test results.
The foregoing tests, Runs 2, 4, 6, 8 and 10, show that the substituted urea additive of the invention provides a very substantial improvement in the detergent properties of gasoline as compared to the base fuel. These improvements are also in marked contrast to the results obtained with a gasoline containing di-N-sec. (C alkylurea and the ineffectiveness of Run 12 shows that there is criticality in the structure of the substituted urea in order to obtain effective carburetor detergency.
The motor fuel composition of the invention can contain any of the additives normally used in gasoline including corrosion inhibitors, antioxidants, anti-icing TABLE I.- ClIEVROLET (/ARBUREIOR DETERGENCY TEST DEPUSIT REMOVAL Deposit Deposit Percent huildremoved, A Fuel up, mg. 1 mg. tive percent BasofueL. 16.7 6.3 38 Base plus 51TB Example 1 22.5 18.1 80 42 Basefuel.......... 22.2 4.5 20 Base plus 5 PTB Example 11.... 23.6 15.3 65 .Basefuel 21.6 4.!) 23 Base plus 5 PTB Example 111 1 24. 4 20. 7 85 62 Base fuel 18. 5 3. 9 21 Base plus 5 P'IB Example IV, 23.3 14.2 61 40 Base fuel 1 27.1 2 +2.8 -10 Base plus 5 PTB Example V 24. 1 12.6 52 62 Base fuel 17.4 +2.5 14.4 Base plus 5 PTB Example Vl.. 15.5 +2.3 l3.2 1.2
1 Built up with base fuel. 1 Additional deposits formed.
a Chevrolet V-8 engine mounted on a test stand using amodified four barrel carburetor. The two secondary barrels of the carburetor are sealed and the feed to each of the primary barrels arranged so that an additive fuel can be run in one barrel and a base fuel run in the other. The primary carburetor barrels were also modified so that they had removable aluminum inserts in the throttle plate area in order that deposits formed on the inserts in this area could be conveniently weighed.
In the procedure designed to determine the effectiveness of an additive fuel to remove preformed deposits in the carburetor, the engine is run for a period of time usually 24 or 48 hours using the base fuel as the feed to both barrels with engine blow-by circulated to the air inlet of the carburetor. The weight of the deposits on both sleeves is determined and recorded. The engine is then cycled for 24 additional hours with base fuel being fed to one barrel, additive fuel to the other and no blow-by to the carburetor air inlet. The inserts are then removed from the carburetor and weighed to determine the difference between the performance of the additive and nonadditive fuels in removing the preformed deposits. After the aluminum inserts are cleaned, they are replaced in the carburetor and the process repeated with the fuels reversed in the carburetor barrels to minimize differences in fuel distribution and barrel construction. The deposit weights in the two runs are averaged and the effectiveness of the base fuel and of the additive fuel for removing deposits expressed in percent.
The base fuel employed in the following examples was a premium grade gasoline having a Research Octane Number of about 101 and containing 3 cc. of tetraethyl lead per gallon. This gasoline consisted of about 25 percent aromatic compounds and antiknock agents, such as tetraethyl lead, tetramethyl lead and mixtures thereof.
l. A motor fuel composition comprising a mixture of hydrocarbon in the gasoline boiling range and a minor detergent amount of a substituted urea represented by the formula:
in which x has a value from 2 to 4 R is hydrogen or a hydrocarbyl radical having from one to four carbon atoms and R and R respectively are hydrocarbyl radicals having from eight to 20 carbon atoms. g "I w 2. A motor fuel composition according to claim 1 in which x has a value of 3 and R and R are aliphatic hydrocarbon radicals.
3. A motor fuel composition according to claim 1 containing from about 0.0005 to 0.05 weight percent of said substituted urea.
4. A motor fuel composition according to claim 1 m which 1: has a value of 3 and R and R are aliphatic hydrocarbon radicals having from 10-15 carbon atoms.
5. A motor fuel composition according to claim 1 in which said substituted urea is 3.3 '-di(cocoamino) di-n-propylurea.
6. A motor fuel composition according to claim 1 in which said substituted urea is 3,3'-di[sec.(C C, )alkylamino]-din-propylurea.
7. A motor fuel according to claim 1 in which said substituted urea is 3,3-di(oleylamino)-di-n-propylurea.