U.S. patent application number 11/477876 was filed with the patent office on 2006-11-02 for fuels compositions for direct injection gasoline engines.
Invention is credited to Timothy J. Henly, Dennis J. Malfer, Scott D. Schwab.
Application Number | 20060242893 11/477876 |
Document ID | / |
Family ID | 25492715 |
Filed Date | 2006-11-02 |
United States Patent
Application |
20060242893 |
Kind Code |
A1 |
Malfer; Dennis J. ; et
al. |
November 2, 2006 |
Fuels compositions for direct injection gasoline engines
Abstract
Injector deposits in a direct injection gasoline engine are
reduced by providing as fuel for the operation of said direct
injection engine a fuel composition comprising a fuel-soluble
compound having the formula (I): ##STR1## wherein R.sub.1 and
R.sub.2 are independently C.sub.1-4 alkyl, R.sub.3 is a radical of
the formula C.sub.mH.sub.2m wherein m is an integer of 2 to 6,
R.sub.4 and R.sub.5 are each independently (i) hydrogen (ii)
C.sub.1-4alkyl, ##STR2## wherein R.sub.6 is selected from the group
consisting of hydrogen and C.sub.1-4 alkyls and R.sub.7 is selected
from the group consisting of hydrogen and C.sub.1-30 alkyl, (iv)
##STR3## wherein R.sub.8 is a saturated or unsaturated, linear,
branched or cyclic, C.sub.7-23 hydrocarbyl group or (v) wherein
R.sub.4 and R.sub.5 together with the nitrogen atom to which they
are bonded, form a cyclic ring in which further hetero atoms.
Inventors: |
Malfer; Dennis J.; (Glen
Allen, VA) ; Schwab; Scott D.; (Richmond, VA)
; Henly; Timothy J.; (Maidens, VA) |
Correspondence
Address: |
NEW MARKET SERVICES CORPORATION;(FORMERLY ETHYL CORPORATION)
330 SOUTH 4TH STREET
RICHMOND
VA
23219
US
|
Family ID: |
25492715 |
Appl. No.: |
11/477876 |
Filed: |
June 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09952260 |
Sep 14, 2001 |
|
|
|
11477876 |
Jun 29, 2006 |
|
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Current U.S.
Class: |
44/412 |
Current CPC
Class: |
C10L 1/22 20130101; Y02T
10/123 20130101; C10L 1/1641 20130101; C10L 10/04 20130101; C10L
1/198 20130101; C10L 1/2222 20130101; F02B 2075/125 20130101; C10L
1/1616 20130101; C10L 1/2383 20130101; Y02T 10/12 20130101; C10L
1/2225 20130101; C10L 1/238 20130101; C10L 1/1985 20130101; C10L
1/143 20130101; C10L 1/2387 20130101; C10L 1/232 20130101; C10L
1/224 20130101 |
Class at
Publication: |
044/412 |
International
Class: |
C10L 1/22 20060101
C10L001/22 |
Claims
1. A method for controlling injector deposits in a direct injection
gasoline engine which comprises introducing into a direct injection
gasoline engine with the combustion intake charge a spark-ignition
fuel composition comprising a) a spark-ignition fuel and b) a
fuel-soluble compound having the formula (I): ##STR17## wherein
R.sub.1 and R.sub.2 are independently C.sub.1-4 alkyl, R.sub.3 is a
radical of the formula C.sub.mH.sub.2m wherein m is an integer of 2
to 6, R.sub.4 and R.sub.5 are each independently (i) ##STR18##
wherein R.sub.6 is selected from the group consisting of hydrogen
and C.sub.1-4 alkyls and R.sub.7 is selected from the group
consisting of hydrogen and C.sub.1-30 alkyl, (ii) ##STR19## wherein
R.sub.8 is a saturated or unsaturated, linear, branched or cyclic,
C.sub.7-23 hydrocarbyl group or (iii) wherein R.sub.4 and R.sub.5
together with the nitrogen atom to which they are bonded, form a
cyclic ring in which further hetero atoms may be incorporated.
2. The method of claim 1 wherein the spark-ignition fuel
composition comprises the fuel-soluble compound (b) in proportions
effective to reduce the volume of injector deposits in a direct
injection gasoline engine operated on a spark-ignition fuel
containing an injector deposit-controlling amount of said
fuel-soluble compound (b) to below the volume of injector deposits
in said direct injection gasoline engine operated in the same
manner on the same spark-ignition fuel except that it is devoid of
a fuel-soluble compound (b).
3. The method of claim 1 wherein the spark-ignition fuel comprises
gasoline.
4. The method of claim 1 wherein the spark-ignition fuel comprises
a blend of hydrocarbons of the gasoline boiling range and a
fuel-soluble oxygenated compound.
5-8. (canceled)
9. The method of claim 1 wherein said fuel-soluble compound (b)
comprises a compound of the formula: ##STR20##
10. The method of claim 1 wherein the fuel-soluble compound (b) is
present in an amount sufficient to provide 0.1-15 pounds by weight
of compound (b) per thousand barrels by volume of fuel.
11. The method of claim 10 wherein the fuel-soluble compound (b) is
present in an amount sufficient to provide 0.3-10 pounds by weight
of compound (b) per thousand barrels by volume of fuel.
12. The method of claim 1 wherein the fuel composition further
comprises at least one amine detergent.
13. The method of claim 12 wherein said amine detergent comprises
at least one member selected from the group consisting of
nitrogen-containing derivatives of hydrocarbyl succinic acylating
agents, high molecular weight Mannich condensation products,
hydrocarbyl amines and polyetheramines.
14. The method of claim 1 wherein the fuel composition further
comprises a carrier fluid selected from the group consisting of 1)
a mineral oil or a blend of mineral oils that have a viscosity
index of less than about 120, 2) one or more poly-.alpha.-olefin
oligomers, 3) one or more poly (oxyalkylene) compounds having an
average molecular weight in the range of about 500 to about 3000,
4) one or more polyalkenes, 5) one or more polyalkyl-substituted
hydroxyaromatic compounds and 6) mixtures thereof.
15. The method of claim 14 wherein the carrier fluid comprises at
least one poly (oxyalkylene) compound.
16. The method of claim 1 wherein the fuel composition further
comprises at least one additive selected from the group consisting
of antioxidants, carrier fluids, metal deactivators, dyes, markers,
corrosion inhibitors, biocides, antistatic additives, drag reducing
agents, demulsifiers, emulsifiers, dehazers, anti-icing additives,
antiknock additives, anti-valve-seat recession additives,
surfactants, lubricity additives and combustion improvers.
17-23. (canceled)
24. A method of controlling deposits in a direct injection gasoline
engine comprising adding to a spark-ignition fuel a fuel-soluble
compound comprising b) a fuel-soluble compound having the formula
(I): ##STR21## wherein R.sub.1 and R.sub.2 are independently
C.sub.1-4 alkyl, R.sub.3 is a radical of the formula
C.sub.mH.sub.2m wherein m is an integer of 2 to 6, R.sub.4 and
R.sub.5 are each independently (i) ##STR22## wherein R.sub.6 is
selected from the group consisting of hydrogen and C.sub.1-4 alkyls
and R.sub.7 is selected from the group consisting of hydrogen and
C.sub.1-30 alkyl, (ii) ##STR23## wherein R.sub.8 is a saturated or
unsaturated, linear, branched or cyclic, C.sub.7-23 hydrocarbyl
group or (iii) wherein R.sub.4 and R.sub.5 together with the
nitrogen atom to which they are bonded, form a cyclic ring in which
further hetero atoms may be incorporated and operating a direct
injection gasoline engine using said fuel containing b).
Description
FIELD OF THE INVENTION
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/952,260, filed on Sep. 14, 2001. That
application is incorporated by reference herein in its
entirety.
[0002] The present invention relates to new spark-ignition fuel
compositions and methods for controlling, i.e. reducing or
eliminating, deposits and reducing soot formation in direct
injection gasoline (DIG) engines. More particularly, the invention
relates to fuel compositions comprising a spark-ignition fuel and a
fuel-soluble deposit control additive comprising a specific amine
compound or derivative thereof and the use of said fuel
compositions in DIG engines to reduce injector plugging.
BACKGROUND OF THE INVENTION
[0003] Over the years considerable work has been devoted to
additives for controlling (preventing or reducing) deposit
formation in the fuel induction systems of spark-ignition internal
combustion engines. In particular, additives that can effectively
control fuel injector deposits, intake valve deposits and
combustion chamber deposits represent the focal point of
considerable research activities in the field and despite these
efforts, further improvements are desired.
[0004] Direct injection gasoline (DIG) technology is currently on a
steep developmental curve because of its high potential for
improved fuel economy and power. Environmentally, the fuel economy
benefits translate directly into lower carbon dioxide emissions, a
greenhouse gas that could contribute to possible global
warming.
[0005] Conventional multi-port injection (MPI) engines form a
homogeneous pre-mixture of gasoline and air by injecting gasoline
into the intake port, while a direct injection gasoline engine
injects gasoline directly into the combustion chamber like a diesel
engine so that it becomes possible to form a stratified fuel
mixture which contains greater than the stoichiometric amount of
fuel in the neighborhood of the spark plug but highly lean in the
entire combustion chamber. Due to the formation of such a
stratified fuel mixture, combustion with the overall highly lean
mixture can be achieved, leading to an improvement in fuel
consumption approaching that of a diesel engine.
[0006] Injection timing is controlled to match load conditions. The
fuel control provides combustion of an ultra lean mixture of
gasoline and air for higher fuel efficiency than diesel engines.
Also, a compression ratio of about 12.0 compared to that of about
10.5 for multi port injection engines delivers higher volumetric
efficiency and response, surpassing conventional MPI engine
performance.
[0007] There are a number of technical issues to be resolved with
DIG technology, and one of them is injector performance with
different gasoline fuels on the world market. Being located in the
combustion chamber, DIG injectors are exposed to a much harsher
environment than conventional spark-ignition engines with port fuel
injectors (PFI). This more severe environment can accelerate fuel
degradation and oxidation resulting in increased deposits.
[0008] DIG technology promises about a third less carbon dioxide
emissions than comparable conventional multi-port injection. This
is achieved with a 10-15% improvement in fuel consumption when
operating in the homogeneous mode, and up to 35% when operating in
the lean stratified mode. Fuel economy benefits also translate into
fossil energy conservation and savings for the consumer. In
addition, the DIG operation platform facilitates up to a 10% power
increase for the same fuel burned in the equivalent MPI
configuration.
[0009] Current generation DIG technologies have experienced deposit
problems. Areas of concern include fuel rails, injectors,
combustion chamber (CCD), crankcase soot loadings, and intake
valves (IVD).
[0010] Fuel related deposits in DIG engines are an issue of current
interest since this technology is now commercial in Japan and
Europe. Fuel injector performance is at the forefront of this issue
because the DIG combustion system relies heavily on fuel spray
consistency to realize its advantages in fuel economy and power,
and to minimize exhaust emissions. A consistent spray pattern
enables more precise electronic control of the combustion event and
the exhaust after-treatment system.
[0011] There is a desire in the petroleum industry to produce a
fuel suitable for use in both MPI and DIG engines, that is a fuel
having effective IVD control for a MPI engine as well as a fuel
having effective injector deposit control suitable for a DIG
engine. Additives useful in reducing or controlling intake valve
deposits in a MPI engine may have little or no effect or even an
adverse effect in controlling or reducing injector deposits in a
DIG engine. Likewise, additives useful in controlling or reducing
injector deposits in a DIG engine may have little or no effect or
even an adverse effect in controlling or reducing intake valve
deposits in a MPI engine. An object of the present invention is to
provide fuel compositions that provide effective injector deposit
control in DIG engines as well as providing fuel compositions which
provide effective deposit control in both MPI and DIG engines.
[0012] There are references teaching fuel compositions containing
amines and amine derivatives compounds, for example, U.S. Pat. Nos.
5,643,951; 5,725,612 and 6,176,886. However, none of these
references teach the use of fuel compositions containing the amine
compounds and derivatives of the present invention in direct
injection gasoline engines or the impact such compounds have on
deposits in these engines.
SUMMARY OF THE INVENTION
[0013] The present invention is directed to a fuel composition
comprising (a) a spark-ignition internal combustion fuel; and (b)
an fuel-soluble deposit control additive. Further, this invention
is directed to methods of controlling deposits in direct injection
gasoline engines. In another embodiment, the inventive composition
is provided as an aftermarket or "top treat" composition.
DETAILED DESCRIPTION OF THE INVENTION
Deposit Control Additives
[0014] The deposit control additives of the present invention can
be represented by the formula (I): ##STR4## wherein R.sub.1 and
R.sub.2 are independently C.sub.1-4 alkyl, R.sub.3 is a radical of
the formula C.sub.mH.sub.2m wherein m is an integer of 2 to 6,
R.sub.4 and R.sub.5 are each independently (i) hydrogen (ii)
C.sub.1-4 alkyl, ##STR5## wherein R.sub.6 is selected from the
group consisting of hydrogen and C.sub.1-4 alkyls and R.sub.7 is
selected from the group consisting of hydrogen and C.sub.1-30
alkyl, (iv) ##STR6## wherein R.sub.8 is a saturated or unsaturated,
linear, branched or cyclic, C.sub.7-23 hydrocarbyl group or (v)
wherein R.sub.4 and R.sub.5 together with the nitrogen atom to
which they are bonded, form a cyclic ring in which further hetero
atoms may be incorporated.
[0015] Preferred injector deposit control additives b) include 1)
aliphatic diamines having one and only one primary or secondary
amino group and one tertiary amino group wherein R.sub.4 and
R.sub.5 are each independently selected from hydrogen and C.sub.1-4
alkyls, 2) substituted triazines wherein R.sub.4 and R.sub.5
together with the nitrogen atom to which they are bonded form a
cyclic ring, 3) low molecular weight Mannich condensation products
wherein at least one of R.sub.4 or R.sub.5 is of the formula:
##STR7## and 4) amides wherein at least one of R.sub.4 or R.sub.5
is of the formula: ##STR8##
[0016] Representative aliphatic diamines include N,N-dihydrocarbyl
alkylene diamines such as N,N-dimethyl-1,3-propanediamine (also
referred to as N,N-dimethylaminopropylamine (DMAPA)), wherein
R.sub.1.dbd.R.sub.2.dbd.--CH.sub.3, R.sub.3.dbd.--C.sub.3H.sub.6--
and R.sub.4.dbd.R.sub.5.dbd.H; and
N,N,N'-trimethyl-1,3-propanediamine, wherein
R.sub.1.dbd.R.sub.2.dbd.--CH.sub.3,
R.sub.3.dbd.--C.sub.3H.sub.6--R.sub.4.dbd.H and
R.sub.5.dbd.--CH.sub.3.
[0017] Hetero-ring materials, preferably substituted triazines, can
be prepared by reacting in appropriate proportions the primary
diamines described above, i.e., R.sub.4 and R.sub.5 are each
hydrogen, with formaldehyde or a formaldehyde source (such as
paraformaldehyde) under conditions known in the art to form a
triazine ring. When forming the hetero-ring deposit control
additives of the present invention, mixtures of the above-described
aliphatic primary diamines and other primary amines may be used,
however, it is preferred that the substituted triazines are
prepared from aliphatic diamines, as described above, as the only
amine. Suitable substituted triazines of the present invention may
be represented by the formula: ##STR9## wherein R.sub.1, R.sub.2
and R.sub.3 are as defined above. A particularly preferred
substituted triazine is one prepared from
3-dimethylaminopropylamine as the sole amine, the product so formed
principally comprises
1,3,5-tris[3-(dimethylamino)propyl]hexahydro-1,3,5-triazine.
Preparation of such compounds is described in the literature, for
example, U.S. Pat. Nos. 2,675,382; 5,162,049; 5,215,547; 5,746,783;
and 5,830,243, the disclosures of which are incorporated herein in
their entirety.
[0018] Representative low molecular weight Mannich condensation
products suitable for use as the deposit control additives of the
present invention may be prepared by the reaction of a low
molecular weight alkyl-substituted hydroxyaromatic compound, an
aldehyde and an aliphatic diamine having one and only one primary
or secondary amino group and one tertiary amino group under
suitable Mannich reaction conditions.
[0019] The low molecular weight alkyl-substituted hydroxyaromatic
compounds and aldehydes used in the preparation of the Mannich
reaction products of the present invention may be any such
compounds known and applied in the art, in accordance with the
foregoing limitations.
[0020] The alkyl-substituted hydroxyaromatic compounds that may be
used in forming the present low molecular weight Mannich
condensation products may be prepared by alkylating a
hydroxyaromatic compound, such as phenol or cresol. The
hydroxyaromatic compound may be mono-alkylated or di-alkylated. The
alkylation of the hydroxyaromatic compound is typically performed
in the presence of an alkylating catalyst at a temperature in the
range of about 50 to about 200.degree. C. Acidic catalysts are
generally used to promote Friedel-Crafts alkylation. Typical
catalysts used in commercial production include sulphuric acid,
BF.sub.3, aluminum phenoxide, methanesulphonic acid, cationic
exchange resin, acidic clays and modified zeolites.
[0021] The low molecular weight alkyl-substituents on the
hydroxyaromatic compound contain from 9 to 30 carbon atoms,
preferably 12 to 18 carbon atoms. The low molecular weight alkyl
substituents include alpha-olefins having single carbon number
fraction between C.sub.9 and C.sub.30 or a mixture of carbon number
fractions between C.sub.9 and C.sub.30. The alpha-olefins may be
isomerized to produce an olefin containing an internal double bond,
which may be used for alkylation of the hydroxyaromatic compound.
Also useful as the low molecular weight alkyl substituent are
oligomers of 1-olefins. Preferred olefin oligomers include
propylene trimers (C.sub.9) and propylene tetramers (C.sub.12). The
low molecular weight Mannich condensation products may be, and
preferably are, made from a low molecular weight alkyl-substituted
phenol or cresol.
[0022] The preferred configuration of the alkyl-substituted
hydroxyaromatic compound is that of a para-substituted
mono-alkylphenol or para-substituted mono-alkylcresol. However, any
alkylphenol or alkylcresol readily reactive in the Mannich
condensation reaction may be employed.
[0023] Representative aldehydes for use in the preparation of the
low molecular weight Mannich condensation products include the
aliphatic aldehydes such as formaldehyde, acetaldehyde,
propionaldehyde, butyraldehyde, valeraldehyde, caproaldehyde,
heptaldehyde, stearaldehyde. Aromatic aldehydes that may be used
include benzaldehyde and salicylaldehyde. Illustrative heterocyclic
aldehydes for use herein are furfural and thiophene aldehyde, etc.
Also useful as aldehydes in the present invention are
formaldehyde-producing reagents such as paraformaldehyde, or
aqueous formaldehyde solutions such as formalin. Most preferred is
formaldehyde or formalin.
[0024] The condensation reaction among the low molecular weight
alkyl-substituted hydroxyaromatic compound, the amine and the
aldehyde may be conducted at a temperature in the range of about 40
to about 200.degree. C. The reaction can be conducted in bulk (no
diluent or solvent) or in a solvent or diluent. Water is evolved
and can be removed by azeotropic distillation during the course of
the reaction. Typically, the Mannich additives are formed by
reacting the alkyl-substituted hydroxyaromatic compound, amine and
aldehyde in the molar ratio of 1.0:0.5-2.0:0.5-3.0,
respectively.
[0025] The deposit control additives of the present invention also
include amides obtained by reacting the aliphatic diamines
described above with a monocarboxylic acid wherein at least one of
R.sub.4 or R.sub.5 is of the formula: ##STR10## and R.sub.8 is a
saturated or unsaturated, linear, branched or cyclic, C.sub.7-23
hydrocarbyl group. Suitable acids include 2-ethylhexanoic acid,
capric acid, myristic acid, palmitic acid, stearic acid, tall oil
acids, linoleic acid, oleic acid, naphthenic acids, as well as
isomers and mixtures thereof. In a preferred embodiment, the acids
used to form the reaction products will contain low amounts of
unsaturation, preferably no unsaturation, such that the reaction
products of the present invention have Iodine Values of 150 or
less. As those skilled in the art will appreciate, Iodine Value is
a measure of unsaturation. Preferably the reaction products will
have an Iodine Value of 125 or less, more preferably 75 or less,
even more preferably 25 or less and most preferably 5 or less.
While the reaction products of the present invention effectively
control injector deposits in DIG engines, it is preferred to use
reaction products having low Iodine Values in fuels that may or
will be used in MPI engines.
[0026] The amide deposit control additives of the present invention
are prepared by reacting a monocarboxylic acid and the diamine
under conditions suitable to form amides. The condensation reaction
among the monocarboxylic acid and the diamine may be conducted at a
temperature typically in the range of from 40 to 250.degree. C. The
reaction can be conducted in bulk (no diluent or solvent) or in a
solvent or diluent, for example, a hydrocarbon solvent. Water is
evolved and can be removed by azeotropic distillation during the
course of the reaction. In a preferred embodiment, the mole ratio
of monocarboxylic acid to diamine will be in the range of 0.8 to
1.2, preferably 1, mole of monocarboxylic acid to 1 mole of
diamine.
[0027] The above-described reaction products are preferably added
to the fuel composition in an amount sufficient to provide control,
including reduction or elimination of, deposits. For example, the
reaction products are preferably added to the fuel in proportions
effective to reduce the volume of injector deposits in a direct
injection gasoline engine operated on said fuel containing said
reaction products to below the volume of injector deposits in said
engine operated in the same manner on the same fuel except that it
is devoid of said reaction products. Economically, it is desirable
to use the least amount of additive effective for the desired
purpose. Typically, the reaction products of the present invention
are present in an amount sufficient to provide 0.1 to 15,
preferably 0.3 to 10, more preferably 0.5 to 7, and most preferably
0.5 to 5, pounds of additive per 1000 barrels of fuel.
[0028] The fuel compositions of the present invention may contain
supplemental additives in addition to the injector deposit control
additives described above. Said supplemental additives include
dispersants/detergents, antioxidants, carrier fluids, metal
deactivators, dyes, markers, corrosion inhibitors, biocides,
antistatic additives, drag reducing agents, demulsifiers,
emulsifiers, dehazers, anti-icing additives, antiknock additives,
anti-valve-seat recession additives, surfactants, lubricity
additives and combustion improvers.
[0029] The fuel compositions of the present invention may, and
typically do, contain high molecular weight amine detergents. The
amine detergents include those well known in the art for use in
fuels for MPI engines to control intake valve deposits. Suitable
amine detergents for use in the present invention include
nitrogen-containing derivatives of hydrocarbyl succinic acylating
agents, Mannich condensation products, hydrocarbyl amines and
polyetheramines. When used, the amine detergents are typically
present in an amount sufficient to control intake valve deposits
and are typically present in an amount of from 5 to 100 pounds by
weight of additive per thousand barrels by volume of fuel.
[0030] The nitrogen-containing derivatives of hydrocarbyl succinic
acylating agents suitable for use in the present invention include
hydrocarbyl succinimides, succinamides, succinimide-amides and
succinimide-esters. The nitrogen-containing derivatives of
hydrocarbyl succinic acylating agents are typically prepared by
reacting a hydrocarbyl-substituted succinic acylating agent with a
polyamine.
[0031] The hydrocarbyl-substituted succinic acylating agents
include the hydrocarbyl-substituted succinic acids, the
hydrocarbyl-substituted succinic anhydrides, the
hydrocarbyl-substituted succinic acid halides (especially the acid
fluorides and acid chlorides), and the esters of the
hydrocarbyl-substituted succinic acids and lower alcohols (e.g.,
those containing up to 7 carbon atoms), that is,
hydrocarbyl-substituted compounds which can function as carboxylic
acylating agents. Of these compounds, the hydrocarbyl-substituted
succinic acids and the hydrocarbyl-substituted succinic anhydrides
and mixtures of such acids and anhydrides are generally preferred,
the hydrocarbyl-substituted succinic anhydrides being particularly
preferred.
[0032] The acylating agent for producing the detergent is
preferably made by reacting a polyolefin of appropriate molecular
weight (with or without chlorine) with maleic anhydride. However,
similar carboxylic reactants can be employed such as maleic acid,
fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic
anhydride, citraconic acid, citraconic anhydride, mesaconic acid,
ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid,
dimethylmaleic acid, hexylmaleic acid, and the like, including the
corresponding acid halides and lower aliphatic esters.
[0033] For example, hydrocarbyl-substituted succinic anhydrides may
be prepared by the thermal reaction of a polyolefin and maleic
anhydride, as described, for example in U.S. Pat. Nos. 3,361,673
and 3,676,089. Alternatively, the substituted succinic anhydrides
can be prepared by the reaction of chlorinated polyolefins with
maleic anhydride, as described, for example, in U.S. Pat. No.
3,172,892. A further discussion of hydrocarbyl-substituted succinic
anhydrides can be found, for example, in U.S. Pat. Nos. 4,234,435;
5,620,486 and 5,393,309.
[0034] The mole ratio of maleic anhydride to olefin can vary
widely. It may vary, for example, from 5:1 to 1:5, a more preferred
range is 3:1 to 1:3, preferably the maleic anhydride is used in
stoichiometric excess, e.g. 1.1-5 moles maleic anhydride per mole
of olefin. The unreacted maleic anhydride can be vaporized from the
resultant reaction mixture.
[0035] Polyalkenyl succinic anhydrides may be converted to
polyalkyl succinic anhydrides by using conventional reducing
conditions such as catalytic hydrogenation. For catalytic
hydrogenation, a preferred catalyst is palladium on carbon.
Likewise, polyalkenyl succinimides may be converted to polyalkyl
succinimides using similar reducing conditions.
[0036] The hydrocarbyl substituent on the succinic anhydrides
employed in the invention is generally derived from polyolefins
that are polymers or copolymers of mono-olefins, particularly
1-mono-olefins, such as ethylene, propylene, butylene, and the
like. Preferably, the mono-olefin employed will have 2 to about 24
carbon atoms, and more preferably, about 3 to 12 carbon atoms. More
preferred mono-olefins include propylene, butylene, particularly
isobutylene, 1-octene and 1-decene. Polyolefins prepared from such
mono-olefins include polypropylene, polybutene, polyisobutene, and
the polyalphaolefins produced from 1-octene and 1-decene.
[0037] A particularly preferred polyalkyl or polyalkenyl
substituent is one derived from polyisobutene. Suitable
polyisobutenes for use in preparing the succinimide-acids of the
present invention include those polyisobutenes that comprise at
least about 20% of the more reactive methylvinylidene isomer,
preferably at least 50% and more preferably at least 70%. Suitable
polyisobutenes include those prepared using BF.sub.3 catalysts. The
preparation of such polyisobutenes in which the methylvinylidene
isomer comprises a high percentage of the total composition is
described in U.S. Pat. Nos. 4,152,499 and 4,605,808.
[0038] Hydrocarbyl succinimides are obtained by reacting a
hydrocarbyl-substitued succinic anhydride, acid, acid-ester or
lower alkyl ester with an amine containing at least one primary
amine group. Representative examples are given in U.S. Pat. Nos.
3,172,892; 3,202,678; 3,219,666; 3,272,746; 3,254,025, 3,216,936,
4,234,435; and 5,575,823. The alkenyl succinic anhydride may be
prepared readily by heating a mixture of olefin and maleic
anhydride to about 180-220.degree. C. The olefin is preferably a
polymer or copolymer of a lower monoolefin such as ethylene,
propylene, isobutene and the like. The more preferred source of
alkenyl group is from polyisobutene having a molecular weight up to
5000 or higher. In a still more, preferred embodiment the alkenyl
is a polyisobutene group having a molecular weight of about
500-2000 and most preferably about 700-1500.
[0039] Amines which may be reacted with the alkenyl succinic
anhydride to form the hydrocarbyl-succinimide include any that have
at least one primary amine group that can react to form an imide
group. A few representative examples are: methylamine,
2-ethylhexylamine, n-dodecylamine, stearylamine,
N,N-dimethyl-propanediamine, N-(3-aminopropyl)morpholine, N-dodecyl
propanediamine, N-aminopropyl piperazine ethanolamine, N-ethanol
ethylene diamine and the like. Preferred amines include the
alkylene polyamines such as propylene diamine, dipropylene
triamine, di-(1,2-butylene)-triamine,
tetra-(1,2-propylene)pentaamine.
[0040] The most preferred amines are the ethylene polyamines which
have the formula H.sub.2N(CH.sub.2CH.sub.2NH).sub.nH wherein n is
an integer from one to ten. These ethylene polyamines include
ethylene diamine, diethylene triamine, triethylene tetraamine,
tetraethylene pentaamine, pentaethylene hexaamine, and the like,
including mixtures thereof in which case n is the average value of
the mixture. These ethylene polyamines have a primary amine group
at each end so can form mono-alkenylsuccinimides and
bis-alkenylsuccinimides. Thus especially preferred hydrocarbyl
succinimides for use in the present invention are the products of
reaction of a polyethylenepolyamine, e.g. triethylene tetramine or
tetraethylene pentamine, with a hydrocarbon substituted carboxylic
acid or anhydride made by reaction of a polyolefin, preferably
polyisobutene, having a molecular weight of 500 to 2,000,
especially 700 to 1500, with an unsaturated polycarboxylic acid or
anhydride, e.g. maleic anhydride.
[0041] The Mannich base detergents suitable for use in the present
invention include the reaction products of a high molecular weight
alkyl-substituted hydroxyaromatic compound, aldehydes and amines.
The alkyl-substituted hydroxyaromatic compound, aldehydes and
amines used in making the Mannich reaction products of the present
invention may be any such compounds known and applied in the art,
in accordance with the foregoing limitations.
[0042] The high molecular weight alkyl substituents on the benzene
ring of the hydroxyaromatic compound are derived from polyolefin
having a number average molecular weight (M.sub.n) of from about
500 to about 3000, preferably from about 700 to about 2100, as
determined by gel permeation chromatography (GPC). It is also
preferred that the polyolefin used have a polydispersity (weight
average molecular weight/number average molecular weight) in the
range of about 1 to about 4 (preferably from about 1 to about 2) as
determined by GPC.
[0043] The alkylation of the hydroxyaromatic compound is typically
performed in the presence of an alkylating catalyst at a
temperature in the range of about 0 to about 200 .degree. C.,
preferably 0 to 100.degree. C. Acidic catalysts are generally used
to promote Friedel-Crafts alkylation. Typical catalysts used in
commercial production include sulphuric acid, BF.sub.3, aluminum
phenoxide, methanesulphonic acid, cationic exchange resin, acidic
clays and modified zeolites.
[0044] Polyolefins suitable for forming the high molecular weight
alkyl-substituted hydroxyaromatic compounds include polypropylene,
polybutenes, polyisobutylene, copolymers of butylene and/or
butylene and propylene, copolymers of butylene and/or isobutylene
and/or propylene, and one or more mono-olefinic comonomers
copolymerizable therewith (e.g., ethylene, 1-pentene, 1-hexene,
1-octene, 1-decene, etc.) where the copolymer molecule contains at
least 50% by weight, of butylene and/or isobutylene and/or
propylene units. The comonomers polymerized with propylene or such
butenes may be aliphatic and can also contain non-aliphatic groups,
e.g., styrene, o-methylstyrene, p-methylstyrene, divinyl benzene
and the like. Thus in any case the resulting polymers and
copolymers used in forming the high molecular weight
alkyl-substituted hydroxyaromatic compounds are substantially
aliphatic hydrocarbon polymers.
[0045] Polybutylene is preferred. Unless otherwise specified
herein, the term "polybutylene" is used in a generic sense to
include polymers made from "pure" or "substantially pure" 1-butene
or isobutene, and polymers made from mixtures of two or all three
of 1-butene, 2-butene and isobutene. Commercial grades of such
polymers may also contain insignificant amounts of other olefins.
So-called high reactivity polyisobutenes having relatively high
proportions of polymer molecules having a terminal vinylidene group
are also suitable for use in forming the long chain alkylated
phenol reactant. Suitable high-reactivity polyisobutenes include
those polyisobutenes that comprise at least about 20% of the more
reactive methylvinylidene isomer, preferably at least 50% and more
preferably at least 70%. Suitable polyisobutenes include those
prepared using BF.sub.3 catalysts. The preparation of such
polyisobutenes in which the methylvinylidene isomer comprises a
high percentage of the total composition is described in U.S. Pat.
Nos. 4,152,499 and 4,605,808.
[0046] The Mannich detergent may be made from a high molecular
weight alkylphenol or alkylcresol. However, other phenolic
compounds may be used including high molecular weight
alkyl-substituted derivatives of resorcinol, hydroquinone,
catechol, hydroxydiphenyl, benzylphenol, phenethylphenol, naphthol,
tolylnaphthol, among others. Preferred for the preparation of the
Mannich detergents are the polyalkylphenol and polyalkylcresol
reactants, e.g., polypropylphenol, polybutylphenol,
polypropylcresol and polybutylcresol, wherein the alkyl group has a
number average molecular weight of about 500 to about 2100, while
the most preferred alkyl group is a polybutyl group derived from
polyisobutylene having a number average molecular weight in the
range of about 700 to about 1300.
[0047] The preferred configuration of the high molecular weight
alkyl-substituted hydroxyaromatic compound is that of a
para-substituted mono-alkylphenol or a para-substituted mono-alkyl
ortho-cresol. However, any hydroxyaromatic compound readily
reactive in the Mannich condensation reaction may be employed.
Thus, Mannich products made from hydroxyaromatic compounds having
only one ring alkyl substituent, or two or more ring alkyl
substituents are suitable for use in this invention. The long chain
alkyl substituents may contain some residual unsaturation, but in
general, are substantially saturated alkyl groups.
[0048] Representative amine reactants include, but are not limited
to, alkylene polyamines having at least one suitably reactive
primary or secondary amino group in the molecule. Other
substituents such as hydroxyl, cyano, amido, etc., can be present
in the polyamine. In a preferred embodiment, the alkylene polyamine
is a polyethylene polyamine. Suitable alkylene polyamine reactants
include ethylenediamine, diethylenetriamine, triethylenetetramine,
tetraethylenepentamine and mixtures of such amines having nitrogen
contents corresponding to alkylene polyamines of the formula
H.sub.2N-(A-NH--).sub.nH, where A is divalent ethylene or propylene
and n is an integer of from 1 to 10, preferably 1 to 4. The
alkylene polyamines may be obtained by the reaction of ammonia and
dihalo alkanes, such as dichloro alkanes.
[0049] The amine may also be an aliphatic diamine having one
primary or secondary amino group and at least one tertiary amino
group in the molecule. Examples of suitable polyamines include
N,N,N'',N''-tetraalkyldialkylenetriamines (two terminal tertiary
amino groups and one central secondary amino group),
N,N,N',N''-tetraalkyltrialkylenetetramines (one terminal tertiary
amino group, two internal tertiary amino groups and one terminal
primary amino group),
N,N,N',N'',N'''-pentaalkyltrialkylenetetramines (one terminal
tertiary amino group, two internal tertiary amino groups and one
terminal secondary amino group), N,N-dihydroxyalkyl-alpha,
omega-alkylenediamines (one terminal tertiary amino group and one
terminal primary amino group), N,N,N'-trihydroxyalkyl-alpha,
omega-alkylenediamines (one terminal tertiary amino group and one
terminal secondary amino group),
tris(dialkylaminoalkyl)aminoalkylmethanes (three terminal tertiary
amino groups and one terminal primary amino group), and similar
compounds, wherein the alkyl groups are the same or different and
typically contain no more than about 12 carbon atoms each, and
which preferably contain from 1 to 4 carbon atoms each. Most
preferably these alkyl groups are methyl and/or ethyl groups.
Preferred polyamine reactants are N,N-dialkyl-alpha,
omega-alkylenediamine, such as those having from 3 to about 6
carbon atoms in the alkylene group and from 1 to about 12 carbon
atoms in each of the alkyl groups, which most preferably are the
same but which can be different. Most preferred is
N,N-dimethyl-1,3-propanediamine and N-methyl piperazine.
[0050] Examples of polyamines having one reactive primary or
secondary amino group that can participate in the Mannich
condensation reaction, and at least one sterically hindered amino
group that cannot participate directly in the Mannich condensation
reaction to any appreciable extent include
N-(tert-butyl)-1,3-propanediamine, N-neopentyl-1,3-propanediamine,
N-(tert-butyl)-1-methyl-1,2-ethanediamine,
N-(tert-butyl)-1-methyl-1,3-propanediamine, and
3,5-di(tert-butyl)aminoethylpiperazine.
[0051] Representative aldehydes for use in the preparation of the
Mannich base products include the aliphatic aldehydes such as
formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde,
valeraldehyde, caproaldehyde, heptaldehyde, stearaldehyde. Aromatic
aldehydes which may be used include benzaldehyde and
salicylaldehyde. Illustrative heterocyclic aldehydes for use herein
are furfural and thiophene aldehyde, etc. Also useful are
formaldehyde-producing reagents such as paraformaldehyde, or
aqueous formaldehyde solutions such as formalin. Most preferred is
formaldehyde or formalin.
[0052] The condensation reaction among the alkylphenol, the
specified amine(s) and the aldehyde may be conducted at a
temperature typically in the range of about 40.degree. to about
200.degree. C. The reaction can be conducted in bulk (no diluent or
solvent) or in a solvent or diluent. Water is evolved and can be
removed by azeotropic distillation during the course of the
reaction. Typically, the Mannich reaction products are formed by
reacting the alkyl-substituted hydroxyaromatic compound, the amine
and aldehyde in the molar ratio of 1.0:0.5-2.0:1.0-3.0,
respectively.
[0053] Suitable Mannich base detergents for use in the present
invention include those detergents taught in U.S. Pat. Nos.
4,231,759; 5,514,190; 5,634,951; 5,697,988; 5,725,612; and
5,876,468, the disclosures of which are incorporated herein by
reference.
[0054] Hydrocarbyl amine detergents are known materials prepared by
known process technology. One common process involves halogenation
of a long chain aliphatic hydrocarbon such as a polymer of
ethylene, propylene, butylene, isobutene, or copolymers such as
ethylene and propylene, butylene and isobutylene, and the like,
followed by reaction of the resultant halogenated hydrocarbon with
a polyamine. If desired, at least some of the product can be
converted into an amine salt by treatment with an appropriate
quantity of an acid. The products formed by the halogenation route
often contain a small amount of residual halogen such as chlorine.
Another way of producing suitable aliphatic polyamines involves
controlled oxidation (e.g., with air or a peroxide) of a polyolefin
such as polyisobutene followed by reaction of the oxidized
polyolefin with a polyamine. For synthesis details for preparing
such aliphatic polyamine detergent/dispersants, see for example
U.S. Pat. Nos. 3,438,757; 3,454,555; 3,485,601; 3,565,804;
3,573,010; 3,574,576; 3,671,511; 3,746,520; 3,756,793; 3,844,958;
3,852,258; 3,864,098; 3,876,704; 3,884,647; 3,898,056; 3,950,426;
3,960,515; 4,022,589; 4,039,300; 4,128,403; 4,166,726; 4,168,242;
5,034,471; 5,086,115; 5,112,364; and 5,124,484; and published
European Patent Application 384,086. The disclosures of each of the
foregoing documents are incorporated herein by reference. The long
chain substituent(s) of the hydrocarbyl amine detergent most
preferably contain(s) an average of 50 to 350 carbon atoms in the
form of alkyl or alkenyl groups (with or without a small residual
amount of halogen substitution). Alkenyl substituents derived from
poly-alpha-olefin homopolymers or copolymers of appropriate
molecular weight (e.g., propene homopolymers, butene homopolymers,
C.sub.3 and C.sub.4 alpha-olefin copolymers, and the like) are
suitable. Most preferably, the substituent is a polyisobutenyl
group formed from polyisobutene having a number average molecular
weight (as determined by gel permeation chromatography) in the
range of 500 to 2000, preferably 600 to 1800, most preferably 700
to 1600.
[0055] Polyetheramines suitable for use as the detergents of the
present invention are "single molecule" additives, incorporating
both amine and polyether functionalities within the same molecule.
The polyether backbone can be based on propylene oxide, ethylene
oxide, butylene oxide, or mixtures of these. The most preferred are
propylene oxide or butylene oxide or mixture thereof to impart good
fuel solubility. The polyetheramines can be monoamines, diamines or
triamines. Examples of commercially available polyetheramines are
those under the tradename Jeffamines.TM. available from Huntsman
Chemical company and the poly(oxyalkylene)carbamates available from
Chevron Chemical Company. The molecular weight of the
polyetheramines will typically range from 500 to 3000. Other
suitable polyetheramines are those compounds taught in U.S. Pat.
Nos. 4,191,537; 4,236,020; 4,288,612; 5,089,029; 5,112,364;
5,322,529; 5,514,190 and 5,522,906.
[0056] When formulating the fuel compositions of this invention,
the injector deposit control additive (with our without other
additives) is employed in amounts sufficient to reduce or eliminate
deposits including injector deposits and/or control soot formation.
Thus the fuels will contain minor amounts of the injector deposit
control additive proportioned so as to prevent or reduce formation
of engine deposits, especially fuel injector deposits. Generally
speaking the fuel compositions of this invention will contain an
amount of injector deposit control additive sufficient to provide
from about 0.1-100, preferably 0.3-10, more preferably 0.5-5,
pounds by weight of additive per thousand barrels by volume of
fuel.
[0057] The base fuels used in formulating the fuel compositions of
the present invention include any base fuels suitable for use in
the operation of direct injection gasoline engines such as leaded
or unleaded motor gasolines, and so-called reformulated gasolines
which typically contain both hydrocarbons of the gasoline boiling
range and fuel-soluble oxygenated blending agents ("oxygenates"),
such as alcohols, ethers and other suitable oxygen-containing
organic compounds. Preferably, the fuel is a mixture of
hydrocarbons boiling in the gasoline boiling range. This fuel may
consist of straight chain or branch chain paraffins,
cycloparaffins, olefins, aromatic hydrocarbons or any mixture of
these. The gasoline can be derived from straight run naptha,
polymer gasoline, natural gasoline or from catalytically reformed
stocks boiling in the range from about 80.degree. to about
450.degree. F. The octane level of the gasoline is not critical and
any conventional gasoline may be employed in the practice of this
invention.
[0058] Oxygenates suitable for use in the present invention include
methanol, ethanol, isopropanol, t-butanol, mixed C1 to C5 alcohols,
methyl tertiary butyl ether, tertiary amyl methyl ether, ethyl
tertiary butyl ether and mixed ethers. Oxygenates, when used, will
normally be present in the base fuel in an amount below about 30%
by volume, and preferably in an amount that provides an oxygen
content in the overall fuel in the range of about 0.5 to about 5
percent by volume.
[0059] In a preferred embodiment, the detergents are preferably
used with a liquid carrier or induction aid. Such carriers can be
of various types, such as for example liquid poly-.alpha.-olefin
oligomers, mineral oils, liquid poly(oxyalkylene) compounds, liquid
alcohols or polyols, polyalkenes, liquid esters, and similar liquid
carriers. Mixtures of two or more such carriers can be
employed.
[0060] Preferred liquid carriers include 1) a mineral oil or a
blend of mineral oils that have a viscosity index of less than
about 120, 2) one or more poly-.alpha.-olefin oligomers, 3) one or
more poly(oxyalkylene) compounds having an average molecular weight
in the range of about 500 to about 3000, 4) polyalkenes, 5)
polyalkyl-substituted hydroxyaromatic compounds or 6) mixtures
thereof. The mineral oil carrier fluids that can be used include
paraffinic, naphthenic and asphaltic oils, and can be derived from
various petroleum crude oils and processed in any suitable manner.
For example, the mineral oils may be solvent extracted or
hydrotreated oils. Reclaimed mineral oils can also be used.
Hydrotreated oils are the most preferred. Preferably the mineral
oil used has a viscosity at 40.degree. C. of less than about 1600
SUS, and more preferably between about 300 and 1500 SUS at
40.degree. C. Paraffinic mineral oils most preferably have
viscosities at 40.degree. C. in the range of about 475 SUS to about
700 SUS. For best results, it is highly desirable that the mineral
oil have a viscosity index of less than about 100, more preferably,
less than about 70 and most preferably in the range of from about
30 to about 60.
[0061] The poly-.alpha.-olefins (PAO) suitable for use as carrier
fluids are the hydrotreated and unhydrotreated poly-.alpha.-olefin
oligomers, i.e., hydrogenated or unhydrogenated products, primarily
trimers, tetramers and pentamers of .alpha.-olefin monomers, which
monomers contain from 6 to 12, generally 8 to 12 and most
preferably about 10 carbon atoms. Their synthesis is outlined in
Hydrocarbon Processing, February 1982, page 75 et seq., and in U.S.
Pat. Nos. 3,763,244; 3,780,128; 4,172,855; 4,218,330; and
4,950,822. The usual process essentially comprises catalytic
oligomerization of short chain linear alpha olefins (suitably
obtained by catalytic treatment of ethylene). The
poly-.alpha.-olefins used as carriers will usually have a viscosity
(measured at 100.degree. C.) in the range of 2 to 20 centistokes
(cSt). Preferably, the poly-.alpha.-olefin has a viscosity of at
least 8 cSt, and most preferably about 10 cSt at 100.degree. C.
[0062] The poly (oxyalkylene) compounds which are among the
preferred carrier fluids for use in this invention are fuel-soluble
compounds which can be represented by the following formula
R.sub.A--(R.sub.B-0).sub.n-R.sub.C wherein R.sub.A is typically a
hydrogen, alkoxy, cycloalkoxy, hydroxy, amino, hydrocarbyl (e.g.,
alkyl, cycloalkyl, aryl, alkylaryl, aralkyl, etc.),
amino-substituted hydrocarbyl, or hydroxy-substituted hydrocarbyl
group, R.sub.B is an alkylene group having 2-10 carbon atoms
(preferably 2-4 carbon atoms), R.sub.C is typically a hydrogen,
alkoxy, cycloalkoxy, hydroxy, amino, hydrocarbyl (e.g., alkyl,
cycloalkyl, aryl, alkylaryl, aralkyl, etc.), amino-substituted
hydrocarbyl, or hydroxy-substituted hydrocarbyl group, and n is an
integer from 1 to 500 and preferably in the range of from 3 to 120
representing the number (usually an average number) of repeating
alkyleneoxy groups. In compounds having multiple --R.sub.B--O--
groups, R.sub.B can be the same or different alkylene group and
where different, can be arranged randomly or in blocks. Preferred
poly (oxyalkylene) compounds are monools comprised of repeating
units formed by reacting an alcohol with one or more alkylene
oxides, preferably one alkylene oxide, more preferably propylene
oxide or butylene oxide.
[0063] The average molecular weight of the poly (oxyalkylene)
compounds used as carrier fluids is preferably in the range of from
about 500 to about 3000, more preferably from about 750 to about
2500, and most preferably from above about 1000 to about 2000.
[0064] One useful sub-group of poly (oxyalkylene) compounds is
comprised of the hydrocarbyl-terminated poly(oxyalkylene) monools
such as are referred to in the passage at column 6, line 20 to
column 7 line 14 of U.S. Pat. No. 4,877,416 and references cited in
that passage, said passage and said references being fully
incorporated herein by reference.
[0065] A preferred sub-group of poly (oxyalkylene) compounds is
comprised of one or a mixture of alkylpoly (oxyalkylene)monools
which in its undiluted state is a gasoline-soluble liquid having a
viscosity of at least about 70 centistokes (cSt) at 40.degree. C.
and at least about 13 cSt at 100.degree. C. Of these compounds,
monools formed by propoxylation of one or a mixture of alkanols
having at least about 8 carbon atoms, and more preferably in the
range of about 10 to about 18 carbon atoms, are particularly
preferred.
[0066] The poly (oxyalkylene) carriers used in the practice of this
invention preferably have viscosities in their undiluted state of
at least about 60 cSt at 40.degree. C. (more preferably at least
about 70 cSt at 40.degree. C.) and at least about 11 cSt at
100.degree. C. (more preferably at least about 13 cSt at
100.degree. C.). In addition, the poly (oxyalkylene) compounds used
in the practice of this invention preferably have viscosities in
their undiluted state of no more than about 400 cSt at 40.degree.
C. and no more than about 50 cSt at 100.degree. C. More preferably,
their viscosities will not exceed about 300 cSt at 40.degree. C.
and will not exceed about 40 cSt at 100.degree. C.
[0067] Preferred poly (oxyalkylene) compounds also include poly
(oxyalkylene) glycol compounds and monoether derivatives thereof
that satisfy the above viscosity requirements and that are
comprised of repeating units formed by reacting an alcohol or
polyalcohol with an alkylene oxide, such as propylene oxide and/or
butylene oxide with or without use of ethylene oxide, and
especially products in which at least 80 mole % of the oxyalkylene
groups in the molecule are derived from 1,2-propylene oxide.
Details concerning preparation of such poly(oxyalkylene) compounds
are referred to, for example, in Kirk-Othmer, Encyclopedia of
Chemical Technology, Third Edition, Volume 18, pages 633-645
(Copyright 1982 by John Wiley & Sons), and in references cited
therein, the foregoing excerpt of the Kirk-Othmer encyclopedia and
the references cited therein being incorporated herein in toto by
reference. U.S. Pat. Nos. 2,425,755; 2,425,845; 2,448,664; and
2,457,139 also describe such procedures, and are fully incorporated
herein by reference.
[0068] The poly (oxyalkylene) compounds, when used, pursuant to
this invention will contain a sufficient number of branched
oxyalkylene units (e.g., methyldimethyleneoxy units and/or
ethyldimethyleneoxy units) to render the poly (oxyalkylene)
compound gasoline soluble.
[0069] Suitable poly (oxyalkylene) compounds for use in the present
invention include those taught in U.S. Pat. Nos. 5,514,190;
5,634,951; 5,697,988; 5,725,612; 5,814,111 and 5,873,917, the
disclosures of which are incorporated herein by reference.
[0070] The polyalkenes suitable for use as carrier fluids in the
present invention include polypropene and polybutene. The
polyalkenes of the present invention preferably have a molecular
weight distribution (Mw/Mn) of less than 4. In a preferred
embodiment, the polyalkenes have a MWD of 1.4 or below. Preferred
polybutenes have a number average molecular weight (Mn) of from
about 500 to about 2000, preferably 600 to about 1000, as
determined by gel permeation chromatography (GPC). Suitable
polyalkenes for use in the present invention are taught in U.S.
Pat. No. 6,048,373.
[0071] The polyalkyl-substituted hydroxyaromatic compounds suitable
for use as carrier fluid in the present invention include those
compounds known in the art as taught in U.S. Pat. Nos. 3,849,085;
4,231,759; 4,238,628; 5,300,701; 5,755,835 and 5,873,917, the
disclosures of which are incorporated herein by reference.
[0072] When the carrier fluids are used in combination with the
amine detergents, the ratio (wt/wt) of detergent to carrier
fluid(s) is typically in the range of from 1:0.1 to 1:3.
[0073] The additives used in formulating the preferred fuels of the
present invention can be blended into the base fuel individually or
in various sub-combinations. However, it is preferable to blend all
of the components concurrently using an additive concentrate as
this takes advantage of the mutual compatibility afforded by the
combination of ingredients when in the form of an additive
concentrate. Also use of a concentrate reduces blending time and
lessens the possibility of blending errors.
[0074] A preferred embodiment of the present invention comprises a
method for controlling injector deposits in a direct injection
gasoline engine which comprises introducing into a direct injection
gasoline engine with the combustion intake charge a spark-ignition
fuel composition comprising a) a spark-ignition fuel and b) a
fuel-soluble injector deposit control additive as described
herein.
[0075] Further, the fuel-soluble additives (b) may be supplied in
the form of a concentrate for use as an after-market additive or
top treat for addition to the fuel in the vehicle or fuel storage
facility.
[0076] Another preferred embodiment of the present invention
comprises fuel compositions containing the fuel-soluble additives
(b) described herein.
EXAMPLES
[0077] The practice and advantages of this invention are
demonstrated by the following examples which are presented for
purposes of illustration and not limitation.
[0078] To demonstrate the effectiveness of the additive systems of
the present invention in reducing deposits in direct injection
gasoline engines, tests were conducted in a 1982 Nissan Z22e (2.2
liter) dual-sparkplug, four-cylinder engine modified to run in a
homogeneous direct injection mode, at a fuel rich lambda of 0.8 to
accelerate injector deposit formation. Details of this test are set
forth in Aradi, A. A., Imoehl, B., Avery, N. L., Wells, P. P., and
Grosser, R. W.: "The Effect of Fuel Composition and Engine
Operating Parameters on Injector Deposits in a High-Pressure Direct
Injection Gasoline (DIG) Research Engine", SAE Technical Paper
1999-01-3690 (1999).
[0079] Modifications to the engine included replacing the
exhaust-side spark plugs with pre-production high-pressure common
rail direct injectors, removing the OEM spark and fuel system, and
installing a high-pressure fuel system and universal engine
controller. Table 1 summarizes the specifications of the modified
test engine. For homogeneous combustion, flat-top pistons and the
conventional gasoline spark ignition combustion chamber design were
found to be sufficient for this type of research work. The
injectors were located on the hot (i.e. exhaust) side of the engine
to favor high tip temperatures to promote injector deposit.
[0080] The rate of injector deposit formation was evaluated through
the use of this specially developed steady-state engine test.
Engine operating conditions for each test point were determined by
mapping injector tip temperatures throughout the engine operating
map range. The injectors were modified with thermocouples at the
tip. Key parameters were inlet air and fuel temperatures, engine
speed, and engine load. The inlet air and fuel temperatures were
subsequently controlled at 35.degree. C. and 32.degree. C.,
respectively. TABLE-US-00001 TABLE 1 Test Engine Specifications
Four Cylinder In-Line 2.2 L Nissan Type Engine Converted for DI
Operation Displacement 2187 cubic centimeters Plugs/cylinder 1
(stock configuration: 2) Valves/cylinder 2 Bore 87 millimeters
Stroke 92 millimeters Fuel System Common Rail High Pressure Direct
Injection Fuel Pressure 6900 kPa (closed loop) Engine Controller
Universal Laboratory System Injection Timing 300 degrees BTDC
Coolant Temperature (.degree. C.) 85 Oil Temperature (.degree. C.)
95
[0081] At constant inlet air/fuel temperature and engine load, tip
temperature remained constant at engine speeds of 1500, 2000, 2500,
and 3000 rpm. However, at constant engine speed, tip temperatures
increase with load. For five load points, 200, 300, 400, 500, and
600 mg/stroke air charge, increasing tip temperatures of 120, 140,
157, 173, and 184.degree. C., respectively, were observed for each
load.
[0082] Through previous research, it was determined that a tip
temperature of 173.degree. C. provided optimum conditions for
injector deposit formation in this engine. Table 2 sets forth the
key test conditions used in performing the evaluation of the
additives of the present invention. TABLE-US-00002 TABLE 2 Key Test
Conditions Engine Speed (rpm) 2500 Inlet Air Temp. (.degree. C.) 35
Inlet Fuel Temp. (.degree. C.) 32 Exit Coolant Temp. (.degree. C.)
85 Exit Oil Temp. (.degree. C.) 95 Load (mg air/stroke) 500
Injector Tip Temp. (.degree. C.) 173
[0083] The test was divided into three periods: engine warm-up, an
operator-assisted period, and test period. Engine speed was
controlled using the engine dynamometer controller, and the engine
throttle was manipulated to control air charge using a standard
automotive airflow meter as feedback in a closed-loop control
system. Engine fueling was controlled in two ways. During warm-up,
injector pulse width was controlled using a standard mass airflow
strategy and exhaust gas sensor controlling the air/fuel mixture to
stoichiometric. During the operator interaction period, the pulse
width was manually set for each injector using wide-range lambda
sensors in the exhaust port of each cylinder. Fuel flow was
measured using a volumetric flow meter and a temperature-corrected
density value was used to calculate mass flow.
[0084] Each fuel was run at a load condition of 500 mg/stroke.
Injector deposit formation was followed by measuring total engine
fuel flow at fixed speed, air charge (mass of air per intake
stroke), and the lambda signal from each cylinder over a test
period of six hours.
[0085] To help minimize injector-to-injector variability the same
set of injectors was used for all tests at a particular engine
load, with each injector always in the same cylinder.
[0086] The additives of the invention and the comparative additives
tested were prepared as follows:
Deposit Control Additive 1
[0087] 16.2 grams of 3-dimethylaminopropylamine and 60 grams of
heptane were added to a flask equipped for distillation. While
stirring, 12.8 grams of a 37% aqueous formaldehyde solution was
slowly added to the flask. Heptane and water were removed by
heating the mixture to 80.degree. C. under vacuum. The resulting
product was clear and colorless. The product was identified as
principally
1,3,5-tris[3-(dimethylamino)propyl]hexahydro-1,3,5-triazine by IR
and NMR spectroscopies, having the structure: ##STR11## Deposit
Control Additive 2 62.64 grams of linoleyl amine, 49.03 grams of
3-dimethylaminopropylamine and 48 grams of heptane were added to a
flask equipped for distillation. While stirring, 65.60 grams of a
37% aqueous formaldehyde solution was slowly added to the flask.
Heptane and water were removed by heating the mixture to 90.degree.
C. under vacuum. The resulting product was clear and light yellow.
The product is believed to principally contain a substituted
triazine of the formula: ##STR12## Deposit Control Additive 3
p-Cresol (50.3 g, 0.465 mol) and 37.7 g of 37% aqueous formaldehyde
(0.465 mol) were dissolved in 50 ml of isopropanol in a 500-ml
round bottom flask. To this solution was added 47.5 g (0.465 mol)
of N,N-dimethylaminopropyl amine (DMAPA) in 50 ml of isopropanol.
The resulting solution was then refluxed for 2 hours. After
cooling, the resulting solution was evaporated under reduced
pressure to afford 98.7 g of product. The product formed is
believed to principally be a p-cresol/DMAPA Mannich having the
following formula: ##STR13## Deposit Control Additive 4
N,N-dimethylaminopropyl amine (DMAPA) having the formula: ##STR14##
Deposit Control Additive 5 288.12 grams (1.006 moles) of tall oil
fatty acid, 103.52 grams (1.012 moles) were added to a reaction
flask containing xylenes. The flask was equipped with a Dean-Stark
trap. The mixture was heated to reflux (about 150.degree. C.) and
water produced in the reaction was collected in the trap. After
about 1.0 moles of water had been produced by the reaction, the
xylenes solvent was removed by vacuum distillation. The resulting
product was a dark brown viscous liquid. The product formed is
believed to principally be an amide having the following formula:
##STR15## wherein R is the residue of the tall oil fatty acid.
Comparative Deposit Control Additive 1 (C.1) 21.05 grams of
Armeen.RTM. CD (cocoalkyl (predominantly C.sub.14) amine obtained
from Akzo Nobel) and 60 grams of heptane were added to a flask
equipped for distillation. While stirring, 8.36 grams of a 37%
aqueous formaldehyde solution was slowly added to the flask.
Heptane and water were removed by heating the mixture to 90.degree.
C. under vacuum. The resulting product was clear and colorless. The
product formed is believed to principally be a cocoalkylamine
triazine having the following formula: ##STR16##
[0088] Gasoline fuel compositions were subjected to the
above-described engine tests whereby the substantial effectiveness
of these compositions in minimizing injector deposit formation was
conclusively demonstrated. The fuel used for these tests was a
Howell EEE fuel having a T.sub.90 (.degree. C.) of 160, an olefin
content of 1.2% and a sulfur content of 20 ppm. The injector
deposit control additives used, the percent flow loss and the
improvement in flow loss compared to base fuel are set forth in
Table 3. TABLE-US-00003 TABLE 3 Keep Clean Performance. Deposit
Average Flow Loss Reduction Control Additive Treat (avg. of 4
injectors in Flow Run Additive Rate (PTB) after 12 hours, %) Loss
(%).sup.A 1* None -- 14.6 -- 2 1 3.0 2.2 85 3* None -- 16.0 -- 4 1
2.0 5.4 66 5* None -- 24.2 -- 6 2 3.0 5.8 76 7* None -- 16.0 -- 8 3
3.0 2.6 84 9* None -- 14.9 -- 10 4 3.0 5.6 62 11* None -- 28.05 --
12 5 3.0 6.1 78.3 13* None -- 25.2 -- 14* C.1 3.0 23.5 7
*Comparative examples .sup.AAverage of base fuel runs run closest
in time before and after the additive run.
[0089] It is clear that the fuel compositions of the present
invention (Runs 2, 4, 6, 8 and 10) exhibit significantly reduced
volume of injector deposits, compared to the base fuel or base fuel
plus derivatives not of the invention (Run 14)) as evidenced by the
reduced amount of flow loss exhibited in injectors operated on
fuels containing the additives of the present invention.
[0090] The ability of the additives of the present invention to
clean up dirty injectors is demonstrated in the following examples.
The Nissan DIG engine was run for 12 hours on unadditized fuel as
described above. Next, with the dirty injectors undisturbed, the
engine was run for 12 hours on base fuel plus additive. Conditions
were the same for both the dirty-up and clean-up phases of the
test. The results of the Clean Up are shown in Table 4 in terms of
percent flow restored to the injectors. TABLE-US-00004 TABLE 4
Injector Clean Up Deposit Control Additive Flow Restored Additive
Treat Rate (PTB) (%) 1 1 79 1 5 94
[0091] It is clear from the above Table 4, that even very low doses
of the additives of the present invention significantly reduce the
injector deposits and restore flow to the injectors.
[0092] It is to be understood that the reactants and components
referred to by chemical name anywhere in the specification or
claims hereof, whether referred to in the singular or plural, are
identified as they exist prior to coming into contact with another
substance referred to by chemical name or chemical type (e.g., base
fuel, solvent, etc.). It matters not what chemical changes,
transformations and/or reactions, if any, take place in the
resulting mixture or solution or reaction medium as such changes,
transformations and/or reactions are the natural result of bringing
the specified reactants and/or components together under the
conditions called for pursuant to this disclosure. Thus the
reactants and components are identified as ingredients to be
brought together either in performing a desired chemical reaction
(such as a Mannich condensation reaction) or in forming a desired
composition (such as an additive concentrate or additized fuel
blend). It will also be recognized that the additive components can
be added or blended into or with the base fuels individually per se
and/or as components used in forming preformed additive
combinations and/or sub-combinations. Accordingly, even though the
claims hereinafter may refer to substances, components and/or
ingredients in the present tense ("comprises", "is", etc.), the
reference is to the substance, components or ingredient as it
existed at the time just before it was first blended or mixed with
one or more other substances, components and/or ingredients in
accordance with the present disclosure. The fact that the
substance, components or ingredient may have lost its original
identity through a chemical reaction or transformation during the
course of such blending or mixing operations is thus wholly
immaterial for an accurate understanding and appreciation of this
disclosure and the claims thereof.
[0093] As used herein the term "fuel-soluble" or "gasoline-soluble"
means that the substance under discussion should be sufficiently
soluble at 20.degree. C. in the base fuel selected for use to reach
at least the minimum concentration required to enable the substance
to serve its intended function. Preferably, the substance will have
a substantially greater solubility in the base fuel than this.
However, the substance need not dissolve in the base fuel in all
proportions.
[0094] At numerous places throughout this specification, reference
has been made to a number of U.S. Patents. All such cited documents
are expressly incorporated in full into this disclosure as if fully
set forth herein.
[0095] This invention is susceptible to considerable variation in
its practice. Therefore the foregoing description is not intended
to limit, and should not be construed as limiting, the invention to
the particular exemplifications presented hereinabove. Rather, what
is intended to be covered is as set forth in the ensuing claims and
the equivalents thereof permitted as a matter of law.
* * * * *