BACKGROUID 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 applacability 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
(1016 to 2032 kg) per thousand barrels (159 m³) of fuel.
[0005] To be useful commercially a gasoline additive for reducing and/or preventing 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 US-A-3,115,400 discloses the use of compounds of the structure

where R is a C₆-C₂₂ 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 US-A-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 8 to 30 carbon atoms, where R², R³,
R⁴ and R⁵ each may be hydrogen and where a and b may be integers from 1 to 75.
[0008] U.S. Patent US-A-4,231,883 discloses the use of a compound of the formula

where R₁ is a C₁₂-C₃₆ aliphatic hydrocarbon group, R₂ and R₃ 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-hydroxyethyll) hydrocarbylamines.
[0009] U.S. Patent US-A-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: R₁ is C₆-C₂₄ alkyl, aryl cycloaliphatic, heterocyclic, substituted alkyl or
substituted aryl; and R₂ and R₃ are the same or different and are C₁-C₂₄ alkyl, aryl,
substituted alkyl or aryl, cycloaliphatic or heterocyclic. R₂ and R₃ preferably comprise
hydroxy substituted alkyls. These compounds typically are added to gasoline in a concentration
within the range of 2.0 to 100 pounds (0,91 to 45.4 kg) of amine oxide per 1,000 barrels
(159 m³) of gasoline (ptb). Among the most preferred additives is bis(2-hydroxy ethyl)
cocoamine oxide.
[0010] U.S. Patent US-A-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.
[0018] The present invention provides 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,
cycloaliphatic or heterocyclic; and
(c) an amine oxide antifouling agent having the following structural formula:

where R₄ is selected from C₆₋₂₄ alkyl, aryl, cycloaliphatic, heterocyclic, substituted
alkyl, substituted aryl; R₅ and R₆ are independently selected from C₁₋₂₄ alkyl, aryl,
substituted alkyl, substituted aryl, cycloaliphatic, heterocyclic and mixtures thereof.
[0019] R₁ may be C₆ to C₂₀ alkyl (e.g., C₆₋₁₈ substituents derived from fatty acid), or
alkylated aryl; and, R₂ and R₃ independently may be hydroxy-substituted C₁ to C₁₂
alkyl.
[0020] The anti-fouling agent (b) may be 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.
[0021] The concentration of the anti-fouling agent (b) in the fuel may be in the range of
from 2 to 200 wppm (e.g. from 16 to 100 wppm).
[0022] The amine oxide (c) may be selected from bis(2-hydroxy ethyl) cocoamine oxide; bis(2-hydroxy
ethyl) stearylamine oxide; dimethylcocoamine oxide; dimethyl hydrogenated tallow amine
oxide; dimethylhexadecylamine oxide, and mixtures thereof.
[0023] The concentration of the amine oxide may be in the range of from 2 to 80 ppm (e.g.,
from 4 to 40 ppm).
[0024] The fuel composition may comprise a demulsifying agent (d) selected from the group
consisting of:
(i) acylated polyglycols;
(ii) alkylarylsulfonates, polyglycols, oxygenated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols;
(iv) alkylphenol-formaldehyde resins and polyglycols;
(v) oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0025] The concentration of the demulsifying agent (d) may be in the range of from 0.1 to
20 wppm (e.g. from 1.0 to 8.0 wppm).
[0026] The invention also provides a method of making a fuel composition as described, which
in one case, case (a), comprises adding to a fuel (e.g., gasoline) an additive concentrate
comprising :
(i) from 5 to 60 wt.% bis(2-hydroxy ethyl) cocoamine;
(ii) from 0.25 to 20 wt.% of a demulsifying agent selected from : acylated polyglycols,
or alkylarylsulfonates; polyglycols; oxyalkylated alkylphenol-formaldehyde resins;
or oxyalkalated alkylphenol-formaldehyde resins and polyglycols; or oxyalkylated alkylphenol-formaldehyde
resins; or mixtures thereof; and
(iii) from 40 to 95 wt.% solvent; and in another case, case (b), comprises adding
to the fuel an additive concentrate as for case (a) and, in addition, from 1 to 15
wt.% bis(2-hydroxy ethyl) cocoamine oxide.
[0027] The method may comprise adding to a fuel (e.g. gasoline) a concentrate comprising
:
. from 8 to 32 wt.% of an amine anti-fouling agent (b);
. from 2 to 8 wt.% of an amine oxide antifouling agent (c); and
. from 40 to 95 wt.% solvent.
[0028] The concentrate may comprise from 1 to 4 wt.% of a demulsifying agent as specified.
[0029] The invention further provides a method of minimizing and/or preventing fuel-injector
fouling in a multiport fuel-injected engine which comprises delivering to the fuel-injection
system of the engine either a fuel composition as described herein or a fuel composition
made by the method described herein.
[0030] The fuel-injection system may be electronically controlled.
[0031] The fuel-injection system may have sensor means disposed in the engine exhaust system
to regulate the air to fuel ratio of the fuel and air supplied to the engine.
[0032] A fuel composition according to the invention may comprise a fuel, such as gasoline,
and :
A. from 2 to 200 ppm bis(2-hydroxy ethyl) cocoamine; and
B. from 0.1 to 20 ppm of a demulsifying agent selected from the group consisting of
:
i. acylated polyglycols;
ii. alkyl aryl sulfonates, polygylcols, oxyalkylated alkylphenol-formaldehyde resins;
iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and,
iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
[0033] A fuel composition of the invention more preferably comprises :
A. from 20 to 120 ppm bis(2-hydroxy ethyl) cocoamine; and
B. from 1 to 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.
[0034] The preferred fuel composition also may comprise from 4 to 40 ppm of the bis(2-hydroxy
ethyl) cocoamine oxide.
[0035] A preferred fuel additive concentrate for internal combustion engines comprises :
A. from 5 to 60 wt.% bis(2-hydroxy ethyl) cocoamine;
B. from 0.25 to 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. from 40 to 95 wt.% solvent.
[0036] The fuel additive concentrate also may comprise from 1 to 15 wt.% of the bis(2-hydroxy
ethyl) cocoamine oxide.
[0037] The solvent preferably comprises an alkyl aromatic hydrocarbon solvent, such as xylene,
and a C₄+ alcohol, preferably a C₄-C₁₂ alcohol, more preferably a C₈ alcohol and most
preferably a C₈ 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.
DETAILED DESCRIPTION OF THE INVENTION
[0038] 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 injection fouling. The present invention is directed at a fuel 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, cycloaliphatic or heterocyclic; and
(c) an amine oxide antifouling agent having the following structural formula:

where R₄ is selected from C₆₋₂₄ alkyl, aryl, cycloaliphatic, heterocyclic, substituted
alkyl, substituted aryl; R₅ and R₆ are independently selected from C₁₋₂₄ alkyl, aryl,
substituted alkyl, substituted aryl, cycloaliphatic, heterocyclic and mixtures thereof.
[0039] The amine anti-fouling agent (b) preferably is selected from the group consisting
of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy
ethyl) oleyl amine and mixtures thereof. These additives are prepared in accordance
with known techniques, such as disclosed in US-A-2,541,678. A particularly preferred
anti-fouling agent is bis(2-hydroxy ethyl) cocoamine.
[0040] The amine oxide anti-fouling agents (c) 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.
[0041] The use of the amine oxide compounds (c) in combination with the previously described
amines (b) 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 US-A-3,387,953.
[0042] In fuel compositions containing the said amine and amine oxide components in combination
as the anti-fouling agent, the concentration of the amine typically will range between
2 and 200 ppm, preferably between 16 and 100 ppm, while the amine oxide concentration
will range between 2 and 80 ppm, preferably between 4 and 40 ppm.
[0043] 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, e.g. a ratio of 0.02 to 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.
[0044] 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 C₄-C₁₂ alcohol,
more preferably a C₈ 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 C₄-C₁₂
alcohol as described above to further decrease the possibility of two organic phase
formation.
[0045] A concentrate utilizing both the amine and amine oxide typically also comprises 40
to 95 wt.% solvent. A preferred composition range is as follows:

[0046] 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
[0047] 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 (5632.6 km) 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
mile (482.8 km) 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 V
clean and V
dirty are the measured volumes of mineral spirit passed through the clean and dirty fuel
injectors.

[0048] 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
[0049] A 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine having electronically
controlled fuel injection was driven for 2858 miles (4599.4 km) 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 (337.86 kPa) 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 (4599.4 km) on the detergent-free fuel are set forth in Table II as
the measurements at 0 miles (0 km) after HECA addition.
EXAMPLE I
[0050] 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 (495.7 km) 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.
[0051] 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 (or km) of driving.

COMPARATIVE EXAMPLE III
[0052] 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 (6462.9 km).
[0053] 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 (0 km) after HECA addition.
EXAMPLE II
[0054] 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 (574.5 km) 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.

[0055] 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.
[0056] 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.
[0057] 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.
[0058] The water, if any, typically has a pH ranging from 7 to 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
[0059] 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 (0.237 l) 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 (0.635 cm)
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
[0060] 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
[0061] A 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine was driven
on a mileage (i.e., distance) 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 (3701.4 km).
[0062] 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
(0 km) after additive addition.
EXAMPLE IV
[0063] 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
(484.4 km) of driving the driveability went from very poor to good.
[0064] 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.
[0065] 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.

[0066] 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.
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,
cycloaliphatic or heterocyclic; and
(c) an amine oxide antifouling agent having the following structural formula:

where R₄ is selected from C₆₋₂₄ alkyl, aryl, cycloaliphatic, heterocyclic, substituted
alkyl, substituted aryl; R₅ and R₆ are independently selected from C₁₋₂₄ alkyl, aryl,
substituted alkyl, substituted aryl, cycloaliphatic, heterocyclic and mixtures thereof.
2. The fuel composition of claim 1 wherein R₁ is C₆ to C₂₀ alkyl (e.g., C₆₋₁₈ substituents
derived from fatty acid), or alkylated aryl; and, R₂ and R₃ independently are hydroxy
substituted C₁ to C₁₂ alkyl.
3. The fuel composition of claim 1 or claim 2 wherein the anti-fouling agent (b) is
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.
4. The fuel composition of any one of claims 1 to 3 wherein the concentration of the
anti-fouling agent (b) in the fuel is in the range of from 2 to 200 wppm (e.g. from
16 to 100 wppm).
5. The composition of any one of claims 1 to 4 wherein the amine oxide (c) is selected
from bis(2-hydroxyethyl) cocoamine oxide; bis(2-hydroxyethyl) stearylamine oxide;
dimethylcocoamine oxide; dimethyl hydrogenated tallow amine oxide; dimethylhexadecylamine
oxide, and mixtures thereof.
6. The composition of any one of claims 1 to 5 wherein the concentration of the amine
oxide is in the range of from 2 to 80 ppm (e.g., from 4 to 40 ppm).
7. The composition of any one of claims 1 to 6 comprising a demulsifying agent (d)
selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkylarylsulfonates, polyglycols, oxygenated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols;
(iv) alkylphenol-formaldehyde resins and polyglycols;
(v) oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.
8. The fuel composition of claim 7 wherein the concentration of the demulsifying agent
(d) is in the range of from 0.1 to 20 wppm (e.g. from 1.0 to 8.0 wppm).
9. A method of making a fuel composition according to any one of claims 1 to 5 (case
(a)), or any one of claims 6 to 8 (case (b)), which in case (a), comprises adding
to a fuel (e.g., gasoline) an additive concentrate comprising :
(i) from 5 to 60 w% bis(2-hydroxyethyl) cocoamine;
(ii) from 0.25 to 10 w% of a demulsifying agent selected from : acylated polyglycols,
or alkylarylsulfonates; polyglycols; oxyalkylated alkylphenol-formaldehyde resins;
or oxyalkylated alkylphenol-formaldehyde resins and polyglycols; or oxyalkylated alkylphenolformaldehyde
resins; or mixtures thereof; and
(iii) from 40 to 95 w% solvent; and in case (b) comprises adding to the fuel an additive
concentrate as for case (a) and, in addition, from 1 to 15 w% bis(2-hydroxyethyl)
cocoamine oxide.
10. A method of making a fuel composition according to any one of claims 1 to 8 comprising
adding to a fuel (e.g., gasoline) a concentrate comprising :
. from 8 to 32 w% of an amine anti-fouling agent (b);
. from 2 to 8 w% of an amine oxide anti-fouling agent (c); and
. from 40 to 95 w% solvent.
11. A method as in claim 9 wherein the concentrate comprises from 1 to 4 w% of a demulsifying
agent as specified in claim 7.
12. A method of minimizing and/or preventing fuel-injector fouling in a multiport
fuel-injected engine which comprises delivering to the fuel-injection system of the
engine either a fuel composition in accordance with any one of claims 1 to 8 or a
fuel composition made by the method of claim 9 or claim 10.
13. A method as in claim 12 wherein the fuel-injection system is electronically controlled.
14. A method as in claim 12 or claim 13 wherein the fuel-injection system has sensor
means disposed in the engine exhaust system to regulate the air to fuel ratio of the
fuel and air supplied to the engine.
1. Treibstoffzusammensetzung für eine Verbrennungskraftmaschine, wobei diese Treibstoffzusammensetzung
umfaßt:
a) Treibstoff (z.B. Benzin);
b) ein Antifoulingmittel mit der Formel

worin R₁ ein C₆-C₂₄ Alkyl-, Aryl-, cycloaliphatischer, heterocyclischer, substituierter
Alkyl- oder substituierter Arylrest ist; R₂ und R₃ unabhängig C₁- C₂₄ substituierte
Alkyl-, Aryl-, cycloaliphatische oder heterocyclische Reste sind; und
c) ein Aminoxid-Antifoulingmittel mit der folgenden Strukturformel

worin R₄ ausgewählt wird aus C₆₋₂₄ Alkyl-, Aryl-, cycloaliphatischen, heterocyclischen,
substituierten Alkyl-, substituierten Arylresten; R₅ und R₆ unabhängig ausgewählt
werden aus C₁₋₂₄ Alkyl-, Aryl-substituierten Alkyl-, substituierten Aryl-, cycloaliphatischen,
heterocyclischen Resten und Mischungen davon.
2. Treibstoffzusammensetzung nach Anspruch 1, worin R₁ C₆-C₂₀ Alkyl (z.B. C₆₋₁₈ Substituenten,
abgeleitet von Fettsäure) oder alkyliertes Aryl ist und R₂ und R₃ unabhängig Hydroxy-substituiertes
C₁-C₁₂ Alkyl sind.
3. Treibstoffzusammensetzung nach Anspruch 1 oder 2, worin das Antifoulingmittel (b)
ausgewählt wird aus der Gruppe bestehend aus Bis (2-hydroxyethyl)cocosamin, Bis (2-hydroxyethyl)-Talg-amin,
Bis (2-hydroxyethyl)-stearylamin, Bis (2-hydroxyethyl)oleylamin und deren Mischungen.
4. Treibstoffzusammensetzung nach irgendeinem der Ansprüche 1 bis 3, worin die Konzentration
des Antifoulingmittels (b) in dem Treibstoff im Bereich von 2 bis 200 wppm (z.B. 16
bis 100 wppm) liegt.
5. Zusammensetzung nach irgendeinem der Ansprüche 1 bis 4, worin das Aminoxid (c)
ausgewählt wird aus Bis (2-hydroxyethyl) - stearylaminoxid; Dimethylcocosaminoxid;
Dimethyl-hydrierter Talg-aminoxid; Dimethylhexadecylaminoxid und deren Mischungen.
6. Zusammensetzung nach irgendeinem der Ansprüche 1 bis 5, worin die Konzentration
des Aminoxids im Bereich von 2 bis 80 ppm liegt (z.B. 4 bis 40 ppm).
7. Zusammensetzung nach irgendeinem der Ansprüche 1 bis 6, enthaltend einen Demulgator
(d), der ausgewählt wird aus der Gruppe bestehend aus:
(i) acylierten Polyglycolen;
(ii) Alkylarylsulfonaten, Polyglycolen, oxygenierten Alkylphenol-Formaldehyd-Harzen;
(iii) oxalkylierten Alkylphenol-Formaldehyd-Harzen und Polyglycolen;
(iv) Alkylphenol-Formaldehyd-Harzen und Polyglycolen;
(v) oxalkylierten Alkylphenol-Formaldehyd-Harzen; und Mischungen davon.
8. Treibstoffzusammensetzung nach Anspruch 7, worin die Konzentration des Demulgators
(d) im Bereich von 0,1 bis 20 wppm (z.B. 1,0 bis 8,0 wppm) liegt.
9. Verfahren zur Herstellung einer Treibstoffzusammensetzung nach irgendeinem der
Ansprüche 1 bis 5 (Fall (a)) oder irgendeinem der Ansprüche 6 bis 8 (Fall (b)), welches
Verfahren im Falle (a) das Zusetzen eines Additivkonzentrats enthaltend:
(i) 5 bis 60 Gew.-% Bis(2-hydroxyethyl)cocosamin;
(ii) 0,25 bis 10 Gew.-W% eines Demulgators, der ausgewählt wird aus: acylierten Polyglycolen
oder Alkylarylsulfonaten; Polyglycolen; oxalkylierten Alkylphenol-Formaldehyd Harzen;
oder oxalkylierten Alkylphenol-Formaldehyd-Harzen und Polyglycolen oder oxalkylierten
Alkylphenol-Formaldehyd-Harzen; oder Mischungen davon; und
(iii) 40 bis 95 Gew.-% Lösungsmittel; zu einem Treibstoff (z.B. Benzin) und im Falle
(b) das Zusetzen eines Additivkonzentrats wie im Fall (a) und zusätzlich 1 bis 15
Gew.-% Bis(2-hydroxyethyl)cocosaminoxid zu dem Treibstoff umfaßt.
10. Verfahren zur Herstellung einer Treibstoffzusammensetzung nach irgendeinem der
Ansprüche 1 bis 8, umfassend das Zusetzen eines Konzentrats enthaltend:
. 8 bis 32 Gew.-W% eines Amin-Antifoulingmittels (b);
. 2 bis 8 Gew.-% eines Aminoxid-Antifoulingmittels (c); und
. 40 bis 95 Gew.-Wo Lösungsmittel zu einem Treibstoff (z.B. Benzin).
11. Verfahren nach Anspruch 9, worin das Konzentrat 1 bis 4 Gew.-W% eines Demulgators
nach Anspruch 7 enthält.
12. Verfahren zum Minimieren und/oder Verhindern des Verschmutzens der Treibstoffeinspritzvorrichtung
in einem Motor mit Mehrlocheinspritzung, umfassend das Zuliefern einer Treibstoffzusammensetzung
nach einem der Ansprüche 1 bis 8 oder einer nach dem Verfahren von Anspruch 9 oder
10 hergestellten Treibstoffzusammensetzung an das Treibstoffeinspritzsystem des Motors.
13. Verfahren nach Anspruch 12, worin das Treibstoffeinspritzsystem elektronisch gesteuert
wird.
14. Verfahren nach Anspruch 12 oder 13, worin das Treibstoffeinspritzsystem Sensormittel
hat, die im Abgassystem des Motors angebracht sind, um das Luftzu-Treibstoff-Verhältnis
des Treibstoffes und der Luft, die dem Motor zugeführt werden, zu regeln.
1. Une composition de carburant pour moteur à combustion interne, ladite composition
de carburant comprenant :
a) un carburant (par ex. l'essence) ;
b) un agent de désencrassement répondant à la formule

dans laquelle R₁ est un alkyle en C₆ à C₂₄, un aryle, un reste cycloaliphatique,
hétérocyclique, un alkyle substitué ou un aryle substitué ; R₂ et R₃ sont, indépendamment,
un alkyle substitué en C₁ à C₂₄, un aryle, un reste cycloaliphatique ou hétérocyclique
et
c) un agent de désencrassement à base d'oxyde d'amine possédant la formule de constitution
suivante :

dans laquelle R₄ est choisi parmi un alkyle en C₆ à C₂₄, un aryle, un reste cycloaliphatique,
hétérocyclique, un alkyle substitué, un aryle substitué ; R₅ et R₆ sont choisis, indépendamment,
parmi un alkyle en C₁ à C₂₄, un aryle, un alkyle substitué, un aryle substitué, un
reste cycloaliphatique, hétérocyclique et leurs mélanges.
2. La composition de carburant selon la revendication 1, dans laquelle R₁ est un alkyle
en C₆ à C₂₀ (par ex. des substituants en C₆ à C₁₈ dérivés d'acides gras) ou un aryle
alkylé et R₂ et R₃ sont, indépendamment, un alkyle en C₁ à C₁₂ hydroxysubstitué.
3. La composition de carburant selon la revendication 1 ou la revendication 2, dans
laquelle l'agent de désencrassement b) est choisi dans le groupe consistant en bis(2-hvdroxyéthyl)
cocoamine, bis(2-hydroxyéthyl) suif amine, bis (2-hydroxyéthyl) stéarylamine, bis(2-hydroxyéthyl)
oléylamine et en leurs mélanges.
4. La composition de carburant selon l'une quelconque des revendications 1 à 3, dans
laquelle la concentration de l'agent de désencrassement b) dans le carburant se situe
dans la gamme de 2 à 200 ppm en poids (par ex. de 16 à 100 ppm en poids).
5. La composition selon l'une quelconque des revendications 1 à 4, dans laquelle l'oxyde
d'amine c) est choisi parmi l'oxyde de bis(2-hydroxyéthyl) cocoamine, l'oxyde de bis(2-hydroxyéthyl)
stéarylamine, l'oxyde de diméthylcocoamine, l'oxyde de diméthyl suif hydrogéné amine,
l'oxyde de diméthylhexadécylamine et leurs mélanges.
6. La composition selon l'une quelconque des revendications 1 à 5, dans laquelle la
concentration de l'oxyde d'amine de situe dans la gamme de 2 à 80 ppm (par ex. de
4 à 40 ppm).
7. La composition selon l'une quelconque des revendications 1 à 6 contenant un agent
désémulsifiant d) choisi dans le groupe consistant en
i) polyglycols acylés ;
ii) alkylarylsulfonates, polyglycols, résines d'alkylphénol-formaldéhyde oxygénées
;
iii) résines d'a!kylphénol-formaldéhyde oxyalkylées et polyglycols ;
iv) résines d'alkylphénol-formaldéhyde et polyglycols ;
v) résines d'alkylphénol-formaldéhyde oxyalkylées et en leurs mélanges.
8. La composition de carburant selon la revendication 7, dans laquelle la concentration
de l'agent désémulsifiant d) se situe dans la gamme de 0,1 à 20 ppm en poids (par
ex. 1,0 à 8,0 ppm en poids)
9. Un procédé de préparation d'une composition de carburant selon l'une quelconque
des revendications 1 à 5 (cas (a)) ou selon l'une quelconque des revendications 6
à 8 (cas (b)) qui, dans le cas a), consiste à ajouter à un carburant (par ex. l'essence)
un concentré d'additif contenant
i) 5 à 60% en poids de bis(2-hydroxyéthyl)cocoamine ;
ii) 0,25 à 10% en poids d'un agent désémulsifiant choisi parmi : des polyglycols acylés
ou des alkylarylsulfonates, des polyglycols, des résines d'alkylphénol-formaldéhyde
oxyalkylées ou des résines d'alkylphénol-formaldéhyde oxyalkylées et des polyglycols
ou des résines d'alkylphénol-formaldéhyde oxyalkylées ou leurs mélanges et
iii) 40 à 95% en poids de solvant et qui, dans le cas b), consiste à ajouter au carburant
un concentré d'additif comme pour le cas (a) et, en plus, 1 à 15% en poids d'oxyde
de bis (2-hydroxyéthyl)cocoamine.
10. Un procédé de préparation d'une composition de carburant selon l'une quelconque
des revendications 1 à 8 consistant à ajouter à un carburant (par ex. l'essence) un
concentré comprenant :
. 8 à 32% d'un agent de désencrassement à base d'amine (b) ;
. 2 à 8% en poids d'un agent de désencrassement à base d'oxyde d'amine (c) et
. 40 à 95% en poids de solvant.
11. Un procédé selon la revendication 9, dans lequel le concentré contient 1 à 4%
en poids d'un agent désémulsifiant tel que spécifié dans la revendication 7.
12. Un procédé pour minimiser et/ou empêcher l'encrassement de l'injecteur de carburant
dans un moteur à injection à orifices multiples qui consiste à fournir au système
d'injection de carburant du moteur soit une composition selon l'une quelconque des
revendications 1 à 8, soit une composition de carburant réalisée par le procédé de
la revendication 9 ou ou la revendication 10.
13. Un procédé selon la revendication 12, dans lequel le système d'injection de carburant
est à commande électronique.
14. Un procédé selon la revendication 12 ou la revendication 13, dans lequel le système
d'injection de carburant comporte des sondes disposées dans le système d'échappement
du moteur pour réguler le rapport air à carburant du carburant et de l'air alimentant
le moteur.