05/419973

03/25/1975

11/29/1973

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E. I. du Pont de Nemours and Company (Wilmington, DE)

44/408

252/392

C10L1/222; C10L1/10; C10L1/22

44/DIG.1,66 252/392

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Gantz, Delbert E.

Vaughn I.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows

1. Composition exhibitng good anti-stalling, anti-icing, anti-rust, detergent and water interaction properties and comprising a hydrocarbon mixture boiling in the gasoline range and 0.004-0.02% by weight, based on the weight of the hydrocarbon mixture, of an amine carboxylate salt of the formula ##SPC4##

2. Additive for imparting good anti-stalling, anti-icing, anti-rust, detergent and water interaction properties to a hydrocarbon mixture boiling in the gasoline range, said additive comprising a 40-80% by weight solution of an amine carboxylate salt of the formula ##SPC5##

3. Additive of claim 2 wherein the solution is a xylene solution.

4. Additive of claim 2 wherein R is alkyl or alkenyl, each of R² and R³ is H and the number of (CH₂ CH₂ O) groups is ≥ 0.7 per carbon atom of R¹.

5. Additive of claim 4 wherein ##SPC6##

6. Additive of claim 4 wherein R¹ is C₁₈ n-alkyl or n-alkenyl and the sum of a and b is 4-6.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to improved gasolines having good anti-icing, anti-rust, anti-stalling, detergent and water interaction properties.

2. Description of the Prior Art

In the operation of spark ignition internal combustion engines, as in motor vehicle uses, numerous operational difficulties may preclude trouble-free operation. One difficulty is encountered when an internal combustion engine is operated under cool, humid atmospheric conditions, especially when the fuel is a winter grade gasoline having a 50 percent ASTM distillation point of 220°F. or below. Under such conditions engine stalling may occur at idling speeds during the warm-up period, particularly when such idling follows a period of light load. Generally, too, the above type of stalling occurs when the atmospheric relative humidity is greater than about 65% and the ambient temperature is in the range 30-60°F. Such conditions are conducive to the deposition of ice on the throttle plate and on the adjacent carburetor walls so that, when idling with the throttle plate substantially closed, the ice deposits restrict air intake and cause stalling.

Engine stalling may also be encountered by the accumulation of deposits other than ice in the carburetor, for example, on the throttle plate and on the surrounding walls. These deposits are believed to be derived from contaminants in the fuel and in the air, including the fumes vented from the engine crankcase. The accumulation of deposits around the throttle plate results in rough idling and frequent stalling. In contrast to stalling caused by icing, which difficulty is usually eliminated when the engine warms up sufficiently to melt the ice, the difficulty caused by the non-ice deposits is more permanent. Corrective measures include costly carburetor cleaning or increasing the idling speed; the latter results in greater difficulty in handling the vehicle and loss of fuel.

The engines in the automotive vehicles presently being produced may provide additional problems, particularly during the engine warm-up periods, which problems may be manifested as frequent engine stalling, rough idling and hesitation. Such problems are generally recognized as consequences of the various engine modifications and the added devices designed to control exhaust emissions of hydrocarbons, carbon monoxide and oxides of nitrogen. These difficulties may be compounded by the aforesaid operational difficulties brought about by the accumulation of ice and other deposits in the carburetor.

Since motor fuels are unavoidably contacted with water and ferrous metal surfaces during processing, transportation, storage and use, the inclusion of an effective corrosion inhibitor in the fuel is considered essential. Another essential requirement of a commercially acceptable motor fuel additive is that it not interfere with the separation of the fuel from any aqueous phase with which it may come in contact. Moreover, such contacts with water should not lead to extraction of any additive from the fuel or emulsification of water into the motor fuel phase. The presence of appreciable amounts of internal water in the fuel is undesirable because of its corrosive effect on metal engine parts and because of the possibility of its forming ice crystals in cold weather.

For simplified handling and economy the desired properties in gasoline should be provided with a minimum number of additives which are effective in small amounts; most desirable in a single multifunctional additive, that is, one which provides a number of properties. Although many multifunctional additives for gasoline are known in the art, they may not be commercially acceptable either because they introduce some undesirable side effects or because they must be used in excessive amounts to provide all the desired properties. Thus, for example, if an additive provides exceptional anti-icing protection at a relatively low concentration but must be used at a considerably greater concentration to provide anti-corrosion protection as well, much of the multifunctional benifit may be lost if it is more economical to add an independent, more effective corrosion inhibitor.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a motor fuel or gasoline composition having good anti-icing, anti-stalling, anti-corrosion, detergent and water interaction properties. It is a further object to provide such a composition wherein these properties are provided by a multi-functional additive which is effective at low concentrations.

In summary, this invention resides in a composition exhibiting good anti-stalling, anti-icing, anti-rust, detergent and water interaction properties and comprising a hydrocarbon mixture boiling in the gasoline range and an effective amount, usually 0.004-0.02% by weight, based on the weight of the hydrocarbon mixture, of an amine carboxylate salt of the formula ##SPC2##

wherein R is C ₁₁ -21 saturated or unsaturated aliphatic hydrocarbyl, R ¹ is C ₈ -24 saturated or unsaturated aliphatic hydrocarbyl, each of R ² an R ³ is selected from H and CH ₃ , each of a and b is 1-14 and the sum of a and b is 2-15, said salt having at least two (CH ₂ CH ₂ O) groups, said composition having a Federal water rating of 1.

DETAILED DISCUSSION OF THE INVENTION

As used in the context of the following description the minimum amount of amine carboxylate salt required for imparting an anti-corrosion property to the gasoline refers to the least amount of the salt which will provide satisfactory inhibition of rusting in ASTM D-665 (Procedure A) test method of the American Society of Testing Materials. By the minimum amount required to impart anti-icing protection is meant the least amount of the salt required in gasoline to provide at least 25 cycles without stalling in an anti-icing test hereinafter described. Water interaction properties described herein are measured according to Federal Test Method Standard No. 791B Method 3251.7, with a rating of 1 considered satisfactory in the context of this invention.

The amine salt, as defined above, is multifunctional in that it provides desirable anti-stalling, anti-icing, anti-corrosion and detergent properties in gasolines at low concentrations without adversely affecting the desirable water interaction properties of the gasoline, that is, good separation of the hydrocarbon phase from water is maintained. The preferred amine carboxylate salt is derived from tall oil fatty acid and a C ₁₂ -18 alkyl or alkenyl amine containing about 3-7 oxyethylene groups. Most preferred is a reaction product of tall oil fatty acid and a C ₁₈ alkyl or alkenyl amine containing about 4-6 oxyethylene groups.

The amine component of the amine carboxylate salt is a tertiary monoamine of the formula ##SPC3##

wherein R ¹ , R ² , R ³ , a and b are as previously defined. Examples of the above-defined R ¹ groups include alkyl, alkenyl, alkadienyl and alkatrienyl groups, such as octyl, nonyl, decyl, decenyl, undecyl, dodecyl, tridecyl, tetradecyl, tetradecenyl, pentadecyl, hexadecyl, hexadecenyl, heptadecyl, octadecyl, octadecenyl, octadecatrienyl, nonadecyl, eicosyl, heneicosyl, docosyl, 9-phenyloctadecyl and 10-phenylocatodecyl. straight chain groups are preferred. Mixtures of R ¹ groups may be present; such mixtures may be derived from mixed amines. Useful mixed amines include those derived from certain naturally occurring fats and oils, such as coconut oil, corn oil, cottonseed oil, tallow and soybean oil. The amines prepared from tallow are ordinarily mixtures wherein the aliphatic hydrocarbyl groups are tetradecyl, tetradecenyl, hexadecyl, hexadecenyl, octadecyl, octadecenyl, octadecadienyl and eicosyl; those prepared from soybean oil are mixtures containing hexadecyl, octadecyl, octadecenyl, octadecadienyl and eicosyl groups; those prepared from cottonseed oil are mixtures ordinarily containing tetradecyl, hexadecyl, octadecyl, octadecadienyl and eicosyl groups; and those prepared from coconut oil are mixtures containing octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, octadecenyl and octadecadienyl groups. The amines derived from naturally occurring fats and oils are commercially available and for reason of economy are preferred for the preparation of the amine carboxylate salts employed herein. Preferred R ¹ groups include alkyl and alkenyl groups of 12-18 carbon atoms.

The oxyalkylene portions of the aforesaid tertiary monoamine are produced by reacting an appropriate primary amine with an alkylene oxide under either acidic or alkaline conditions, alkaline conditons being preferred. The reaction of a primary amine and an alkylene oxide is well known in the art. In such a process a single product generally is not obtained; the product is usually characterized as having an average number of oxyalkylene groups, the average number depending upon the molar ratio of the alkylene oxide to the amine. Thus, in the context of the present invention the values of a and b in the aforesaid formula represent average values. An amine containing oxyethylene groups can be readily prepared by reacting the appropriate primary amine with the requisite amount of ethylene oxide. Amines containing both oxyethylene groups and oxypropylene groups can be readily prepared by reacting the primary amine with ethylene oxide and 1,2-propylene oxide, such reaction being carried out by condensing the primary amine initially with ethylene oxide and then further condensing the reaction product with 1,2-propylene oxide; by initially condensing the primary amine with 1,2-propylene oxide and then further condensing the reaction product with ethylene oxide; by condensing the primary amine with a mixture of ethylene oxide and propylene oxide; or by combinations of any two or more of the above sequences.

In order for a salt, as described above, to have maximum utility as a practical multifunctional additive for gasoline, that is, providing the properties of anti-stalling, anti-icing, anti-corrosion, detergency and good water interaction, the total number of oxyalkylene groups present should be 2-15; at least two oxyethylene groups must be present. The oxyethylene groups in the amine confer anti-corrosion and anti-icing properties on the amine carboxylates prepared therefrom; the oxopropylene groups, when present, contribute to anti-icing but have little anti-corrosion effect. When only oxyethylene groups are present and when the number of oxyethylene groups is greater than about 0.7 per carbon atom of the amine R ¹ group, unfavorable water interaction properties may be obtained and the minimum amount of the amine carboxylate salt required for satisfactory anti-icing and anti-corrosion properties may exceed the maximum amount of the salt at which satisfactory water interaction is obtained. Oxypropylene groups are not deleterious to water interaction and, therefore, can be incorporated into the molecule to mitigate the tendency of the oxyethylene groups to adversely affect the water interaction rating. Thus, it is possible to have more oxyethylene groups than the above indicated 0.7 oxyethylene group per carbon atom of the R ¹ aliphatic hydrocarbyl group provided one or more oxypropylene groups are also present. The maximum allowable number of oxyethylene groups in combination with oxypropylene groups can be determined readily by those skilled in the art by following the teachings given herein. Preferably, the amine carboxylate salt contains 3-7 oxyethylene groups, more preferably, 4-6 oxyethylene groups.

The carboxylic acid component of the amine carboxylate salt employed in this invention is an aliphatic hydrocarbon monocarboxylic acid of 12-22 carbon atoms; the acid may be saturated or unsaturated. Included are dodecanoic, tridecanoic, tetradecanoic, tetradecenoic, hexadecanoic, hexadecenoic, octadecnoic, octadecenoic, octadecadienoic, eicosanoic, uneicosanoic and doeicosanoic acids. Mixed acids can be employed. Acid mixtures, such as those obtained by hydrolysis of natural fats and oils, containing alkyl, alkenyl and alkadienyl groups, such as those enumerated above for the amine mixtures from these same sources, are useful. A particularly useful and preferred acid mixture is tall oil fatty stearic, acid obtained from tall oil. Tall oil is a mixture of rosin and fatty acids released by acidulation of the black liquor soap skimmed off the black liquor from the sulfate process in the manufacture of Kraft paper. Crude tall oil is commonly fractionally distilled to provide cuts wherein the ratio of fatty acids to rosin acids varies from 1:99 to 99:1. In the context of this description tall oil fatty acid is intended to include tall oil compositions having a fatty acid content of at least about 50% by weight, the balance being mainly rosin acids in admixture with minor amounts of unsaponifiable materials of unknown chemical composition. The fatty acids in tall oil fatty acids consist mainly of oleic, linoleic, conjugated linoleic, palmitic, steric, palmitoleic, arachidic and behenic stearic, Tall oil fatty acids which are commercially available include those with the following compositions: palmitic (0.1-5.3%); palmitoleic (0.1-2.1%); stearic (2.1-2.6%); oleic (39.3-49.5%); linoleic (38.1-41.4%); eicosanoic (1.2-1.9%); eicosadienoic (0.5-3.2%); eicosatrienoic (0.4-2.9%); and behenic (0.4-0.9%) acids, with the balance being rosin acids, unidentified acids and unsaponifiable materials.

The amine carboxylate salts employed in this invention are produced by reacting the above-described tertiary monoamine and the carboxylic acid. Generally, one mole of the acid is used with one mole of the amine but up to a molar excess of either the acid or the amine can be present. The reaction of the amine and the acid is that of neutralizaton, with the formation of the amine salt of the acid, and can be carried out in known manner. If desired, the reaction can be accelerated by employing slightly elevated temperatures of 100°-200°F. Solvents, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone chloroform, carbon tetrachloride, benzene, toluene and xylene, as well as mixtures of solvents, can be used. For ease of handling and subsequent incorporation into gasoline, the amine carboxylate salt is dissolved in a suitable solvent, such as one of those recited above. Such solutions or concentrates generally contain 10-90% by weight of salt, preferably 40-80%. The preferred solvent is xylene.

The amine carboxylate salt is added to gasoline, that is, a mixture of hydrocarbons boiling in the gasoline boiling range. The base fuel can consist of straight chain or branched chain paraffins, cycloparaffins, olefins and aromatic compounds or any mixture of such hydrocarbons obtainable from straight run naphtha, polymer gasoline, natural gasoline, thermally or catalytically cracked hydrocarbon stocks and catalytically reformed stocks. The gasoline can also contain varying amounts of conventional fuel additives, such as antiknock compounds, including tetramethyllead, tetraethyllead and mixed alkyllead, scavenging agents, dyes, antioxidants, anti-icing agents, rust inhibitors, detergents and anti-preignition agents. Generally, the concentration of amine carboxylate salt in the gasoline is about 0.004-0.02% by weight (10 to 50 pounds per thousand barrels of gasoline), preferably 0.006-0.008% by weight (15 to 20 pounds per thousand barrels of gasoline).

The anti-rust properties of the salts employed in this invention are determined according to the method of ASTM D-665 (Procedure A). In this test 300 ml. of the gasoline containing the additive under test is stirred with 30 ml. of distilled water at a temperature of 32°C. (90°F.) with a cylindrical steel specimen completely immersed therein. The test is carried out for 20 hours. With the base fuel alone the steel specimen usually has about 80% of the surface covered with rust spots after 20 hours. For the purpose of this invention and for the comparison of anti-corrosion efficiency, the minimum amount of the amine carboxylate salt required to afford substantially complete rust protection was determined. Representative results are tabulated in the examples which follow.

The anti-icing properties of the salts employed in this invention are determined by using a gasoline containing the additive and measuring the number of cycles before stalling. The test is carried out with a Chevrolet, 230 cubic inch, 6 cylinder engine. The environment of the carburetor is maintained at 40°F. (4°C.) and 95% relative humidity. At these conditions essentially water saturated cool air is drawn through the carburetor. The test consists of running the engine on a two part cycle, namely, 20 seconds with open throttle at an engine speed to 1,600 r.p.m. and 10 seconds with the throttle almost closed at 400 r.p.m. (idling speed). During the test ice forms on the throttle plate and on the surrounding carburetor walls and causes the engine to stall by blocking the flow of air when the throttle plate is almost closed during the idling portion of the cycle. The base gasoline is chosen so that, normally, in the absence of an effective anti-icing additive, engine stalling occurs in about 3-5 cycles. Generally, an additive is considered effective if it prevents stalling to about 10 cycles; an excellent anti-icing agent prevents stalling to at least about 25 cycles. The base gasoline used has a 50% distillation point of 197°F. (92°C.) according to ASTM Method D-86. To illustrate the anti-icing efficiency of the amine carboxylate salts employed in this invention, minimum concentrations of the salts to prevent stalling to at least 25 cycles were determined. REpresentative results are tabulated in the examples which follow.

The water interaction properties (United States Federal Water Rating) of gasoline containing the amine carboxylate salts employed in this invention were determined according to Federal Test Method Standard No. 791B Method 3251,7 wherein the gasoline containing the additive is vigorously shaken with an aqueous phosphate buffer solution (pH 7) and after standing for 5 minutes the change in volume of the aqueous phase and the condition of the interface is observed. The condition of the interface is reported in terms of the following ratings:

Rating Appearance ______________________________________ 1 clear and clean 1b a few small clear bubbles covering not more than an estimated 50% of the interface and - no shreds, lace and/or film at the interface 2 shred of lace and/or film at interface 3 loose lace and/or slight scum 4 tight lace and/or heavy scum. ______________________________________

The Federal Water Rating provides a measure of the ease of separation of the gasoline from water after vigorous mixing. It is generally considered that a rating of 1b is required for a satisfactory separation involving commercial fuels. For the purpose of the present invention a rating of 1 was chosen as representing satisfactory water interaction properties. The maximum concentration of the amine carboxylate salt in gasoline which still provides a water rating of 1 was determined. If this maximum concentration is exceeded, water interaction is excessive in the context of this invention. The maximum concentration which provides a rating of 1 is important for commercially practical multifunctional gasoline additives since an additive which imparts, for example, outstanding anti-corrosion and anti-icing properties, would be of little value if the maximum concentration of the additive at which a water rating of 1 is obtained is considerably lower than the minimum concentration required to provide effective anti-corrosion and anti-icing protection. Results obtained with amine carboxylate salts employed in this invention are tabulated in the examples which follow.

EXAMPLES 1-9

These examples illustrate the multifunctional activities of the amine carboxylate salts employed in this invention. The salts were prepared by mixing a molar equivalent amount of the amine with a molar equivalent amount of tall oil fatty acid. The amines are designated in Table I in terms of the initial amine followed by the number of oxyalkylene groups incorporated, ether ethylene oxide (EO) or propylene oxide (PO). Thus, in Example 1, the initial amine is cocoamine, a mixture of amines derived from coconut oil, into which an average of 2 units of ethylene oxide have been incorporated. The tall oil fatty acid is a commercially available composition containing 44% oleic acid, 32% non-conjugated linoleic acid, 8% conjugated linoleic acid, 5% saturated acid (palmitic and stearic) and 11% unidentified acids and unsaponifiable material. Additive concentrations are given in the table in terms of % by weight and pounds per thousand barrels (PTB).

TABLE I ____________________________________________________________ ______________ Anti-rust Anti-icing Tall Oil Fatty Conc'n. for (ASTM D-665) Conc'n. Ex. Acid Carboxylate Federal Water Conc'n. to Provide No. of Rating of 1 for 0% Rust 25 + Cycles ____________________________________________________________ ______________ Wt. % PTB Wt. % PTB Wt. % PTB ____________________________________________________________ ______________ 1 Cocoamine ^. 2EO 0.02 50 0.008 20 0.006 15 2 Tallowamine ^. 2EO 0.02 50 0.006 15 0.009 22.5 3 Oleylamine ^. 5EO 0.008 20 0.006 15 0.006 15 4 Tallowamine ^. 5EO 0.012 30 0.006 15 0.008 20 5 Stearylamine ^. 5EO 0.008 20 0.006 15 0.008 20 6 Phenylstearyl- 0.02 50 0.006 15 0.012 30 amine ^. 5EO A Tallowamine ^. 15EO <0.006 <15 0.006 15 0.006 15 7 2-Ethylhexylamine ^. 2EO 0.02 ≥50 0.012 30 0.02 ≤30 8 Cocoamine ^. (2PO ^. 2EO) 0.02 ≥50 0.012 ≤30 0.02 ≤30 9 Cocoamine ^. (10PO ^. 5EO) 0.02 ≥50 0.012 30 0.02 ≤30 ____________________________________________________________ ______________ < = less than ≥ = equal to or greater than ≤ = equal to or less than

The above results show that the amine carboxylate salts provide outstanding corrosion and icing protection at very low concentrations. The results also show that water interaction (Federal Water Rating of 1) is good at the minimum concentrations to provide anti-rust and anti-icing protection. Comparative Example A shows that when the number of ethylene oxide groups is greater than about 0.7 per carbon atom of the amine R ¹ group, poor Federal Water Rating is obtained even though anti-rust and anti-icing properties are satisfactory.

EXAMPLE 10

The usefulness of the amine carboxylate salts employed in this invention as carburetor detergents is demonstrated by two series of tests. The first test measures the effectiveness of the salts in removing deposits already present in the carburetor. The second test measures the effectiveness of the salts in keeping the carburetor clean. In the first test deposits are initially accumulated in the carburetor under specified conditions. The effectiveness of an additive as a carburetor detergent is then determined by operating the engine with fuel containing the additive and measuring the amount of accumulated deposit removed.

Chevrolet, 6 cylinder, 230 cubic inch engines having Carter No. 3511-S carburetors and ice towers with heaters were used. One engine was used to produce, in the shortest time, sufficient throttle body deposit for the clean-up phase of the test. Since the deposit accumulation phase of the test is carried out over a period of about 10 hours and the clean-up phase of the test requires about 50 hours, by utilizing one engine for deposit accumulation and several engines for the clean-up portion of the test, the testing may be accomplished in a relatively short time. In the deposit accumulation engine the ring gap of the top piston ring was increased by 0.125 inch (0.32 cm.) to 0.138 inch (0.35 cm.) and the ring was installed in place of the second compression ring, leaving the top ring groove empty and thus increasing the blowby. The total blowby was directed to the carburetor air cleaner from the dome cover. The air cleaner element was eliminated. The exhaust line was modified to supply engine exhaust to the carburetor air cleaner. The engine was operated under the following conditions: the distributor vacuum advance was eliminated to maintain spark advance of 4° before top center; engine speed at 700 ± 10 r.p.m.; water outlet temperature 175° ± 2.5°F. (79° ± 1.5°C.); air/fuel mixture at maximum vacuum; carburetor air cooled by passage through an ice tower and then reheated to 90°-95°F. (32°-35°C.); and engine exhaust supplied to carburetor air inlet as described below. The fuel used was MS-08, an industry standard fuel used for Sequence MS oil testing.

The engine was started with the exhaust feed valve to engine inlet air closed. The speed was adjusted to 700 r.p.m. at maximum vacuum. The exhaust feed valve was opened and the engine speed was maintained at 700 r.p.m. (the exhaust feed valve setting is critical). The setting was such as to feed the maximum amount of exhaust that the engine would accept and still operate smoothly without stalling. The engine was operated for about 10 hours or until it could no longer be kept running under these conditions. The carburetor was removed and rated using a visual rating chart. A rating of 100 is considered as clean. If a rating cleaner than 30 is obtained, additional deposit accumulation is required.

For the clean-up phase of the test, the dirty carburetor was installed in another engine and the operating conditions described above were used except that normal piston rings were used and the blowby and exhuast were not fed into the air inlet. Before the test new spark plugs were installed, SAE 30 low detergent oil was placed in the crankcase and the air cleaner housing and exhaust system were cleaned. The clean-up procedure was carried out for 50 hours in five 10-hr. segments, the ratings beng made at appropriate intervals to determine the amount and speed of clean-up. The percent clean-up was determined according to the following formula

% Clean-up = R ₀ - R _D /100 - R _D × 100

wherein R _D is the carburetor rating after deposit accumulation and R _O is the carburetor rating after clean-up.

The second test, the carburetor keep-clean test (Onan), is carried out in a single cylinder engine to which a controlled amount of exhaust gas from another engine is mixed with air supplied to the test carburetor. THe test carburetor throat consists of a two piece stainless steel liner fitted around the throttle plate shaft. The liner is easily removed for inspection and rating. The engine is operated under cycling conditions of one minute idling and three minutes of part throttle until an overall test period of two hours is achieved. A visual rating scale of 10 for a clean carburetor and 0 for a very dirty carburetor is used. Generally, a rating of about 7 or greater is considered satisfactory carburetor keep-clean. The results of the carburetor detergency tests are summarized in Table II. In the table are also given the results of Onan keep-clean tests with the amine and the tall oil fatty acid used individually.

TABLE II ____________________________________________________________ ______________ Run Conc'n. Onan Keep-Clean No. Additive Wt. % Rating Δ Rating Clean-up ____________________________________________________________ ______________ 1 None -- 4.5 -- 18 2 Oleylamine ^. 5EO 0.003 6.1 1.6 -- 3 Tall oil fatty acid 0.0018 5.9 1.4 -- 4 Example 3 0.0048 8.7 4.2 -- 5 Example 3 0.006 8.3 3.8 25 ____________________________________________________________ ______________

The above results show that the amine carboxylate salts employed in this invention are also effective as a carburetor detergent, not only inhibiting deposit formation but removing deposits already present. The carburetor detergency activity is demonstrated at the concentration level found to be effective for anti-corrosion and anti-icing protection as shown in Table I. Table II also shows that neither the amine nor the carboxylic acid component of the amine carboxylate salt is as effective as the salt as a carburetor detergent at the same molar concentraton. Thus, oleylamine . 5EO increases the Onan rating 1.6 over the control fuel (Run 2) and tall oil fatty acid increases the Onan rating 1.4 (Run 3) over the control fuel whereas the amine salt produced from the amine and the carboxylic acid increases the rating by 4.2 (Run 4) which is 1.2 units greater than the expected rating increase of 3.0.