BACKGROUND OF THE INVENTION
[0001] This invention is directed to an anti- fouling fuel composition and to a method for
using same. More specifically, the present invention is directed at a fuel composition
having particular applicability in minimizing and/or preventing injector fouling in
gasoline engines equipped with electronically controlled multiport fuel injectors.
[0002] Over the past several years, improvements have been made in the performance of internal
combustion engines. One of the most significant improvements which has been made has
been the widespread use of fuel injection to improve the performance and fuel economy
of internal combustion engines. While carburetor- equipped internal combustion engines
admix the air and fuel for distribution through a manifold to all of the cylinders,
in a fuel injected engine the fuel is injected into the manifold close to the intake
valve of each cylinder for combustion. Fuel injection systems are of two basic types,
mechanically controlled and electronically controlled. The early fuel injected engines
were controlled mechanically, i.e., the operation of each injector was controlled
by pressure. Recently, however, the use of electronically controlled fuel injection
engines has become increasingly widespread. In an electronically controlled fuel injection
system sensors disposed in the exhaust are employed to maintain the air to fuel ratio
within narrow limits. Electronically controlled fuel injection systems offer the same
performance and fuel economy benefits that would be achieved with mechanically controlled
fuel injection systems and also serve. to more closely regulate fuel-air mixtures
to thereby enable the catalytic converter to oxidize carbon monoxide and hydrocarbons
to
' carbon dioxide and simultaneously to reduce nitrogen oxides and thus meet emissions
control legislation. Such legislation imposing as it did strict control of exhaust
pollutants utimately led to the development and widespread application of new technologies
such as electronic fuel injection.
[0003] It has been found that the electronically controlled fuel injector systems have small
port openings which are prone to fouling by deposits. These deposits are believed
to occur, at least in part, by gasoline and oil vapor, which is present in close proximity
to the injector tip, becoming baked onto the hot surfaces of the injector pintle and
on the surfaces of the annulus surrounding the pintle when the engine is shut off.
These deposits restrict the fuel flow to that particular cylinder. This, in turn,
causes a sensor disposed in the exhaust to detect a higher than desired oxygen to
fuel ratio. The sensor will attempt to correct this condition by increasing the amount
of fuel injected into all of the cylinders. This, in turn, will result in a richer
than desired fuel to air ratio in the exhaust. The sensor then will attempt to correct
this by decreasing the amount of fuel injected into each cylinder. This cyclical adjustment
of the fuel to air ratio ranging between too lean a mixture and too rich a mixture
can at times result in poor operating performance of the vehicle. In addition; close
tolerances in this new type of injector and concurrently higher underhood temperature
also tend to enhance deposit formation resulting in poor vehicle driveability and
exceeding exhaust pollutant levels set by emissions control legislation..
[0004] It has been found that conventional gasoline detergents, which have proven effective
in preventing and/or eliminating carburetor deposits are not particularly effective
in removing and/or preventing deposit build-up that may occur in electronically controlled
fuel injection systems. Presently available methods for removing deposits from fuel
injector orifices typically comprise either mechanically cleaning the injectors or
the addition to the fuel of relatively large quantities of particular additives. Mechanical
cleaning, which may involve either the complete removal of the injector for manual
deposit removal or the use of polar solvents for flushing the deposits free, is not
desired because of the relatively high cost and inconvenience. Currently available
additives are not particularly -desirable because product recommendations indicate
they-must be used at relatively high concentrations, i.e. about one to about two tons
per thousand barrels of fuel.
[0005] To be useful -commercially a gasoline additive for reducing and/or prevent injector
port fouling must be effective at low concentration, must not significantly affect
the combustion characteristics of the fuel and must not foul the catalytic converter
catalyst.
[0006] Additives have been added to gasoline to improve certain properties of the fuel.
U.S. Patent No. 3,115,400 discloses the use of compounds of the structure

where R is a C
6-C
22 aliphatic hydrocarbon radical, X is an integer from 2 to 4, Y is an integer of at
least 1, and Z is an integer of at least 1, for use in motor fuel to prevent or reduce
carburetor icing.
[0007] U.S. Patent No. 4,409,000 discloses combination of hydroxy amines and hydrocarbon-soluble
carboxylic dispersants as engine and carburetor detergents for normally liquid fuels.
Among the hydroxy amines disclosed are compounds of the formula

where R' may be an alkyl radical containing from about 8 to about 30 carbon atoms,
where R
2, R
3, R
4 and
R5 each may be hydrogen and where a and b may be integers from 1 to 75.
[0008] U.S. Patent No. 4,231,883 discloses the use of a compound of the formula

where R
1 is a
C12-C
36 aliphatic hydrocarbon group, R
2 and R
3 are divalent hydrocarbon radicals containing 2-4 carbon atoms and X and Y are integers
from 1-4, for friction reduction in lube oils. Preferred compounds comprise N,N-bis
(2-hydroxyethyl) hydrocarbylamines.
[0009] U.S. Patent No. 3,387;953 is directed at the use of organo-substituted nitrogen oxides,
particularly amine oxides for rust.inhibition and as anti-icing agents in gasoline.
Several representative formulas for amine oxides are given including the following:

where: R
1 is C
6-C
24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
and R
2 and R
3 are the same or different and are C
l-C
24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic or heterocylic. R
2 and R
3 preferably comprise hydroxy substituted alkyls. These compounds typically are added
to gasoline in a concentration within the range . of about 2.0 to about 100 pounds
of amine oxide per 1,000 barrels of gasoline (ptb). Among the most preferred additives
is bis(2-hydroxy ethyl) cocoamine oxide.
[0010] U.S. Patent No. 3,594,139 is directed at a rust-inhibitor concentrate that can be
blended with gasoline year-round. This patent also discloses the use of amine oxides
having the aforementioned formula for use as gasoline additives for rust prevention.
This patent also discloses a particularly preferred concentrate comprising bis(2-hydroxy
ethyl) cocoamine oxide.
[0011] The amine oxides described above have been typically used to inhibit rust and carburetor
icing, although these amines also were known as carburetor detergents.
[0012] It has been discovered that use of hydroxy substituted amine oxides can result in
additive losses because of high water solubility and adsorption on polar surfaces.
[0013] Accordingly, it would be desirable to provide an additive package for gasoline which
will be effective in reducing and/or eliminating fouling without appreciable additive
losses.
[0014] It also would be desirable to provide an additive package having a demulsifying agent
which is effective in the presence of both neutral and basic waters.
[0015] Accordingly, it would be desirable to provide a gasoline additive package which is
relatively inexpensive and effective at low concentrations to reduce and/or eliminate
injector fouling.
[0016] It also would be desirable to provide a gasoline additive package which is non-corrosive,
non- deleterious to the catalyst, and does not affect the combustion characteristics
of the fuel.
[0017] It also-would be desirable to provide a gasoline additive package which could be
easily added to the finished gasoline at any point during the storage and/or distribution
system.
SUMMARY OF THE INVENTION
[0018] The present invention is directed at a fuel composition for minimizing and/or preventing
injector fouling in a multiport electronically controlled fuel injected engine. The
composition comprises:
A. fuel (e.g., gasoline)
B. an anti-fouling agent having the formula:

where: R1 is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
and R2 and R3 independently are C1-C24 substituted alkyl, aryl, cycloaliphatic or heterocylic; and,
C. a demulsifying agent selected from the group consisting of :
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0019] In this composition R
1 preferably is C
6-C
20 alkyl, or alkylated aryl, and R
2 and R
3 independently are C
l-C
l2 hydroxy substituted alkyl. In a more preferred composition R
1, comprises C
8-C
18 substituents derived from fatty acid. The additive preferably is selected from the
group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine,
. bis(2-hydroxy ethyl) stearyl-amine, bis(2-hydroxy ethyl) oleyl amine and mixtures
thereof. A particularly preferred additive is bis(2-hydroxy ethyl) cocoamine. The
anti-fouling agent concentration in the fuel typically may range between about 2 to
about 200 ppm, (parts per million by weight based on the total weight of the fuel
composition) preferably between about 20 to about 80 ppm. The active concentration
of the demulsifying agent may range between about 0.1 and about 20 ppm, preferably
between about 1.0 and about 8 ppm. A preferred demulsifier is selected from the group
consisting of:
i. acylated polyglycols;
ii. alkyl phenol-formaldehyde resins and polyglycols; and,
iii. oxyalkylated alkylphenol-formaldehyde resin; and mixtures thereof.
[0020] The fuel additive also may include a second, amine oxide anti-fouling agent having
the following structural formula:

where R
4 is C
6-C
24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R
5 and R
6 independently are C
1-C
24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic, and mixtures
thereof; and,
[0021] Preferred amine oxide anti-fouling agents include compounds wherein: R
4 is C
6-C
20 alkyl, or alkylated aryl; and R
5 and R
6 independently are hydroxy substituted C
1-C
12 alkyl. Particularly preferred compounds are compounds wherein R
1 comprises a C
8-C
18 substituent. The amine oxide additive preferably is selected from the group consisting
of bis (2-hydroxy ethyl) cocoamine oxide, bis(2-hydroxy ethyl) stearylamine oxide,
dimethylcocoamine oxide dimethyl hydrogenated tallow amine oxide, dimethylhexadecylamine
oxide , and mixtures thereof. A particularly preferred amine oxide anti-fouling agent
is bis(2-hydroxy ethyl) cocoamine oxide.
[0022] A fuel composition such as gasoline, typically may further comprise:
A. about 2 to about 200 ppm bis(2-hydroxy ethyl) cocoamine; and,
B. about 0.1 to about 20 ppm of a demulsifying agent selected from the group consisting
of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0023] The fuel composition more preferably comprises:
A. about 20 to about 120 ppm bis(2-hydroxy ethyl) cocoamine; and,
B. about 1 to about 12 ppm of a demulsifying agent selected from the group consisting
of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0024] The preferred fuel composition also may comprise about 4 to about 40 ppm bis(2-hydroxy
ethyl) cocoamine oxide.
[0025] A preferred fuel additive concentrate for internal combustion engines comprises:
A. about 5 to about 60 wt.% bis(2-hydroxy ethyl) cocoamine;
B. about 0.25 to about 10 wt.% of a demulsifying agent selected from the group consisting
of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
C. about 40 to about 95 wt.% solvent.
[0026] The fuel additive concentrate also may comprise about 1 to about 15 wt.% bis(2-hydroxy
ethyl) cocoamine oxide.
[0027] The solvent preferably comprises an alkyl aromatic hydrocarbon solvent, such as xylene,
and a C
4+ alcohol, preferably a C
4-C
12 alcohol, more preferably a C
8 alcohol and most preferably a C
8 oxo alcohol. Where the ratio of the concentration of water relative to amine oxide
exceeds about 0.05, a highly water and hydrocarbon soluble alcohol, preferably isopropanol,
also should be added.
[0028] The present invention also is directed at a method for reducing and/or preventing
fouling in a multi-port electronically controlled fuel injection system for an internal
combustion engine, said method comprising delivering to said fuel injection system
a fuel comprised of an effective amount of an additive comprising

where: R
1 is C
6-C
24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
R
2 and
R3 independently C
1 to C
24 substituted alkyl, aryl, cycloaliphatic or heterocyclic. The_R
2 and R
3 preferably are hydroxyl substituted.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The present invention is directed at-a fuel composition, a fuel (e.g. gasoline) additive
package, and a method for delivering the fuel composition to a fuel injection system
in which the composition has been found to be particularly effective in reducing and/or
eliminating injector fouling. The present invention is directed at a fuel comprising:
A. fuel (e.g., gasoline);
B. an anti-fouling agent having the, following structural formula:

where R1 is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R2
and R3 independently are Cl-C24 substituted alkyl or aryl, cycloaliphatic, heterocyclic, and mixtures thereof; and,
C. a demulsifying agent selected from the group consisting of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and-polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0030] Preferred anti-fouling agents include compounds wherein: R
1 is C
6-C
20 alkyl, or alkylated aryl; and R
2 and R
3 independently are hydroxy substituted C
1-C
12 alkyl. Particularly preferred compounds are compounds wherein R
1 comprises a C
8-C
18 substituent. The additive preferably is selected from the group consisting of bis
(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxyethyl)
oleyl amine and mixtures thereof. These additives are prepared in accordance with
known techniques, such as disclosed in U.S. Patent 2,541,678 the disclosure of which
is incorporated herein by reference. A particularly preferred anti-fouling agent is
bis(2-hydroxy ethyl) cocoamine.
[0031] Amine oxides also have been found to be effective as anti-fouling agents. While these
compounds may be extracted to varying degrees into any water present, these compounds
also provide anti-rust properties to the fuels. These compounds have the following
structural formula:

where
R4 is C
6-C
24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R
5 and
R6 independently are C
l-C
24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures
thereof.
[0032] Therefore, the use of these amine oxides compounds in combination with the previously
described amines may provide an effective anti-fouling composition also providing
anti-rust properties. These amine oxides may be prepared by well-known techniques,
such as disclosed in U.S. Patent No. 3,387,953.
[0033] Where amine and amine oxides are used in combination as the anti-fouling agent, the
concentration of the amine typically will range between about 2 and about 200 ppm,
preferably between about 16 and about 100 ppm, while the amine oxide concentration
will range between about 2 and about 80 ppm, preferably between about 4 and about
40 ppm.
[0034] The amine oxide typically has water present from the manufacturing process. While
it is possible to remove most of the water, removal of the water to relatively low
levels, i.e. a ratio of about 0.02 to about 0.04 of water to amine oxide, adds complexity
to the manufacturing process. Therefore, the amine oxide is commercially available
as a solution comprising water and a solvent, which typically is isopropyl alcohol.
It has been found that when a concentrate comprising the above amine oxide solution
and a solvent containing demulsifiers was admixed with gasoline and terminal tank
water bottoms a three phase system resulted, two organic phases and a water phase.
[0035] Formation of two organic layers is not desirable, since this was found -to result-in
uneven distribution-of the amine oxide between layers. In addition, the second organic
layer, which has a much higher amine-oxide concentration, tends to adhere to surfaces,
resulting in additive loss and potential contamination of subsequent hydrocarbon products
that might contact these surfaces. It has-been found that replacement of a portion
of the isopropanol by a higher alcohol, preferably a C
4-C
l2 alcohol, more preferably a C
8 oxo alcohol, decreases the likelihood of-forming a two organic layer system. While
the admixture of the amine with the amine oxide may also decrease the formation of
two organic phases, it is preferred that the solvent comprise a C
4-C
l2 alcohol as described above to further decrease the possibility of two organic phase
formation.
[0036] A concentrate utilizing both the amine and amine oxide typically also comprises about
40 to about 95 wt.% solvent. A preferred composition range is as follows:

[0037] The following Comparative Examples and Examples demonstrate the-utility of the anti-fouling
agent in reducing and/or eliminating fuel injector fouling. In the following Comparative
Examples and Examples, the octane rating of the fuel utilized is the posted octane
rating which is defined as:

COMPARATIVE EXAMPLE I
[0038] In this test three 1985 Oldsmobile 98's having electronically controlled,, fuel injected,
3.8 liter, six cylinder engines were driven on a commercial, unleaded, 87 octane reference
fuel having a detergent concentration of about 32 ppm by weight of the fuel for approximately
3500 miles under the following driving cycle: 0.5 hours city-type driving, 0.5 hour
engine off, 0.5 hour highway driving, 0.5 hour engine off. Driveability on all four
vehicles became poor to very poor. The vehicles then were driven for 300 miles with
a commercial premium grade 92 octane unleaded fuel containing 2.5 times the detergent
used in the above reference fuel. Driveability remained unchanged. The data in Table
I below show that there was still a marked reduction in fuel flow indicating that
a high level of deposit was unaffected by the detergent even at the high treat rate.
The percent fuel flow reduction was determined by measuring the volume of a mineral
spirit that flowed through the injector under predetermined standardized conditions,
including fuel pressure, pulse width and duty-cycle. The percent reduction is calculated
using the formula:

where Vclean and Vdirty are the measured volumes of mineral spirit passed through
the clean and dirty fuel injectors.

[0039] From Table I it can be seen that this conventional, known carburetor detergent was
ineffective in removing deposits from injector ports and in fact permitted deposits
to form.
COMPARATIVE EXAMPLE II
[0040] A 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine having electronically
controlled fuel injection was driven for 2858 miles on a mileage accumulation dynamometer
using a typical regular grade, 87 octane, unleaded, detergent-free gasoline. The driving
was based on repetition of the following cycle: 30 minutes city driving, 30 minutes
engine off, 30 minutes highway driving, 30 minutes engine off. The driveability became
very poor as typified by rough idle, severe hesitation, backfire and roughness during
acceleration. The hydrocarbon emissions measured before the catalytic converter were
804 ppm at engine idle and 725 ppm at 2500 rpm. The injector fouling also was measured
using a pressure differential test. In this test the fuel rail is pressurized to 49
psig and an injector is pulsed for 0.5 seconds. The difference in the pressure drop
between the injectors is a rough measure of the degree to which the injectors are
obstructed, i.e. the greater the numerical difference between the highest and lowest
values, the greater the injector fouling. A summary of the results at 2585 miles on
the detergent-free fuel are set forth in Table II as the measurements at 0 miles after
HECA addition.
EXAMPLE I
[0041] Following the test set forth in Comparative Example II, the vehicle was refueled
with the same fuel except that the fuel also contained 80 ppm of bis(2-hydroxy ethyl)
cocoamine (HECA). The vehicle then was driven on the following cycle: 15 minutes city
driving, 30 minutes highway driving, 15 minutes city driving, 2 hours engine off.
This test continued until 308 miles were accumulated on the vehicle. At the end of
this test period the driveability was very good. The hydrocarbon emissions at idle
before the catalytic converter were reduced to 65 ppm and to 16 ppm at 2500 rpm. The
emissions before the catalytic converter at idle and at 2500, rpm and the pressure
differentials measured at various intervals during the clean-up driving are summarized
in Table II. The injector flow reduction measurements are summarized in Table III.
[0042] From the data of Example I and Tables II and III, it can be seen that the use of
a relatively low concentration of HECA was able to produce a significant improvement
in driveability. The idle emissions were significantly reduced and the pressure differential
and percent flow reduction of the flow injectors were returned to "as new" conditions
after a relatively few miles of driving.

COMPARATIVE EXAMPLE III
[0043] A second 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine was
driven on a mileage accumulation dynamometer using a regular grade 87 octane unleaded,
detergent-free gasoline from a different batch from that of Comparative Example II
and Example I. The same driving cycle was used in this Comparative Example as was
used in Comparative Example I. The engine was judged to be fouled and the driveability
poor after 4016 miles.
[0044] The emissions before the catalytic converter and the pressure differential across
each injector were measured and are presented in Table IV as the measurements-at 0
miles after HECAaddition.
EXAMPLE II
[0045] Approximately 60 ppm of bis(2-hydroxyethyl) cocoamine was added to the fuel of Comparative
Example III and the vehicle of Comparative Example III was driven on the same driving
cycle described in Example I. Measurements of the emissions before the catalytic converter
and the pressure differential across each injector were measured as previously described.
These results are presented in Table IV. Driveability was judged to be good after
only 357 miles of driving. At the termination of the test the injectors were removed
and flow tested as previously described. These results are presented in Table V.

[0046] From a review of Tables II-V it can be seen that the use of relatively low concentrations
of HECA was able to reduce the injector tip deposits in a relatively short period
of time. By comparison, the use of a conventional carburetor detergent was unable
to prevent a relatively rapid deposit buildup of injector tip deposits.
[0047] While the data presented above has demonstrated the utility of the anti-fouling agent
in gasoline, the anti-fouling agent also may be of utility in other fuels, such as
diesel fuel.
[0048] While the presently described anti-fouling agent may be used alone, it also may be
desirable to utilize the present invention in combination with a demulsifying agent
to facilitate the separation of the gasoline from any foreign substances which may
be present in the distribution system, such as water and sediment.
[0049] The water, if any, typically has a pH ranging from about 7 to about 13. Thus, a demulsifying
agent for use with the anti-fouling agent preferably should be effective over this
pH range. The following Comparative Examples and Examples demonstrate the utility
of various demulsifying agents.
COMPARATIVE EXAMPLE IV
[0050] In this Comparative Example the effectiveness of various commercially available demulsifying
agents were tested in a 90 wt.% fuel - 10 wt.% water system. The fuel contained an
additive package comprising approximately 60 ppm HECA and 2 ppm of the various additives
noted below. The effectiveness of the various demulsifying agents was determined using
a modified Multiple Contact Emulsion Test. In this test 10 ml of terminal water bottoms
having a pH of approximately 10 was added to separate half-pint bottles. To each bottle
was added 100 ml of gasoline. The bottles were capped, placed on their sides in a
mechanical shaker and agitated at approximately 180 cycles per minute for ten minutes.
The bottles then were placed upright and allowed to stand for 1 hour. The mixture
then was rated considering the gasoline layer, the water layer and the interface using
the rating scale set forth in Table VI below. After the ratings were completed, the
gasoline level was sucked down to a level about 1/4 inch above the interface or emulsion
layer without disturbing the interface or water layer. The withdrawn fuel was discarded
and 100 ml -of fresh gasoline was added to each bottle. The mixture was then shaken
and the test repeated for the indicated number of times with the worst rating noted.
The trade names of the commercially available additives utilized, the worst ratings
of each mixture and the number of times the test was run are set forth in Table VII
below.

EXAMPLE III
[0051] A 100 ml gasoline sample containing 60 ppm of HECA was admixed with 10 ml of the
terminal water bottoms of Comparative Example IV: However, in place of the demulsifiers
listed in Table
VII the following demulsifiers were utilized individually: Tolad T-500; Tolad T-284;
Tolad T-286; Tolad T-326; and Nalco 5455. The modified Multiple Contact Emulsion Test
previously described was utilized to determine the effectiveness of each demulsifier.
These test results are summarized in Table VIII below. A description of each additive
is presented in Table IX below.

COMPARATIVE EXAMPLE V
[0052] .A 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine was driven
on a mileage accumulation dynamometer using. a regular grade 87 octane unleaded detergent-free
fuel. The driving cycle to foul the injectors was 30 minutes city-type driving, 30
minutes soak, 30 minutes highway driving, 30 minutes soak. The engine was judged to
be fouled after 2,300 miles.
[0053] The emissions before the catalytic converter and the pressure differential across
each injector were measured and are presented in Table X as the measurement at 0 miles
after additive addition.
EXAMPLE IV
[0054] This Example demonstrates the utility of using an additive comprising the combination
of an amine and an amine oxide in cleaning up fouled injectors in the vehicle of Comparative
Example V. The fuel utilized was similar to that of Comparative Example V, but further
comprised 80 ppm of bis(2-hydroxy ethyl) cocoamine and 10 ppm of bis(2-hydroxy ethyl)
cocoamine oxide. The driving cycle was the same as that of Example I. After 301 miles
of driving the driveability went from very poor to good.
[0055] The measurements of the emissions before the catalytic converter and the pressure
differential across each injector also were measured as previously described. These
results also are presented in Table
X. At the termination of the test the injectors were removed and flow tested as previously
described. These results are presented in Table XI.
[0056] Based on these results, it can be seen that the use of an additive comprising the
amine and amine oxide in combination cleaned fouled injectors. Additional tests were
run on other test vehicles. In almost all cases it has been found that this combination
of amine and amine oxide cleaned fouled injectors in a relatively short period.

[0057] Where the presently described invention is used as a gasoline additive, the additive
package may be added to the gasoline at any point after the gasoline has been refined,
i.e., the additive package can be added at the refinery or in the distribution system.
[0058] In this patent specification, the following conversions of units are employed:

[0059] "Oldsmobile", "Chrysler" and "Le Baron" are trade marks.
1. A fuel composition for an internal combustion engine said fuel composition comprising:
A. fuel (e.g., gasoline);
B. an antifouling agent having the formula

wherein: R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatid or heterocyclic; and
C. a demulsifying agent selected from the group consisting of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,-
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
2. The fuel composition of claim 1 wherein R1 is C6 to C20 alkyl, or alkylated aryl; and, R2 and R3 independently are hydroxy substituted C1 to C12 alkyl.
3. A fuel additive concentrate for internal combustion engines, said additive concentrate
comprising:
A. about 5 to about 60 wt.,% bis(2-hydroxy ethyl) cocoamine;
B. about 0.25 to about 10 wt. % of a demulsifying agent selected from the group consisting
of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof; and,
C. about 40 to about 95 wt.% solvent.
4. The fuel additive concentrate of claim 3 further comprising about 1 to about 15
wt.% bis(2-hydroxy ethyl) cocoamine oxide.
5. A fuel additive concentrate for internal combustion engines, said additive concentrate
comprising:
A. about 8 to about 32 wt.% amine;
B. about 2 to about 8 wt.% amine oxide;
C. about 40 to about 95 wt.% solvent; and,
D. about 1 to about 4 wt.% demulsifier.
6. A method for reducing and/or preventing fouling in a multi-port, electronically
controlled fuel injection system for an internal combustion engine, said method comprising
delivering to said fuel injection system a fuel comprised of an effective amount of
an anti-fouling agent comprising

wherein: R
1 is C
6 to C
24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
R
2 and R
3 independently are C
1 to C
24 substituted alkyl, aryl, cycloaliphatic or heterocyclic.
7. The method of claim 6 wherein R1 is C6 to C24 alkyl, or alkylated aryl; and, R2 and R3 independently are hydroxy substituted C1 to C12 alkyl. or alkylated aryl; and, R2 and R3 independently are hydroxy substituted C1 to C12 alkyl.
8. A method for reducing and/or preventing fouling in a multi-port fuel injection
system having a sensor means disposed in the exhaust adapted to regulate the air to
fuel ratio, said method comprising delivering to the fuel injection system a fuel
comprising:
A. fuel (e.g., unleaded gasoline);
B. an anti-fouling agent selected from the group consisting of bis(2-hydroxy ethyl)
cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy
ethyl) oleyl amine and mixtures thereof; and
C. a demulsifying agent selected from the group consisting of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkyiphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
9. A method for combusting a fuel (e.g. gasoline) in an internal combustion engine
wherein fuel is delivered to the combustion zone of the engine by means of a multi-port,
electronically controlled fuel injection system, the method comprising combusting
fuel (e.g.. a gasoline) including:
A. an effective amount of an anti-fouling agent selected from the group consisting
of bis(2-hydroxy ethyl) cocoamine, bis (2-hydroxy ethyl) tallow amine, bis(2-hydroxy
ethyl) stearylamine, bis (2-hydroxy ethyl) oleyl amine and mixtures thereof; and,
B. a demulsifying agent selected from the group consisting of:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polyglycols,. oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
10. A fuel composition for an internal combustion engine said engine composition comprising:
A. fuel (e.g., gasoline);
B. an amine anti-fouling agent having the formula:

wherein: R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic; and,
C. an amine oxide anti-fouling-agent having the following structural formula:

where R4 is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R5 and R6 independently are Cl-C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures
thereof.