BACKGROUND OF THE INVENTION
Field of the Invention
[0001] This invention relates to fuel additive compositions containing Mannich condensation
products and hydrocarbyl-substituted polyoxyalkylene amines. In a further aspect this
invention relates to the use of these additive compositions in fuel compositions to
prevent and control engine oil screen plugging.
Description of the Related Art
[0002] It is well known that automobile engines end to form deposits on the surface of engine
components, such as carburetor ports, throttle bodies, fuel injectors, intake ports,
intake valves, and combustion chambers, due to the oxidation and polymerization of
hydrocarbon fuel. Thes deposits, even when present in relatively minor amounts, often
cause noticeable driveability problems, such as stalling and poor acceleration. Moreover,
engine deposits can significantly increase an automobile's fuel consumption and production
of exhaust pollutants. Therefore, the development of effective fuel detergents or
"deposit control" additives to prevent or control such deposits is of considerable
importance and numerous such materials are known in the art.
[0003] For example, polyoxyalkylene amines, or polyether amines, are known to reduce engine
deposits when used in fuel compositions. Thus, U.S. Patent No. 5,112,364, issued May
12, 1992 to Rath et al., discloses gasoline-engine fuels which contain from 10 to
2,000 parts per million by weight of a polyetheramine and/or a polyetheramine derivative,
wherein the polyetheramine is prepared by reductive amination of a phenol-initiated
or alkylphenol-initiated polyether alcohol with ammonia or a primary amine.
[0004] U.S. Patent No. 5,660,601, issued August 26, 1997 to Oppenlander et al., discloses
fuels for gasoline engines containing from 10 to 2,000 mg per kg of fuel (i.e., 10
to 2,000 parts per million) of an alkyl-terminated polyetheramine, wherein the alkyl
group contains from 2 to 30 carbon atoms and the polyether moiety contains from 12
to 28 butylene oxide units. This patent further teaches that the polyetheramines are
prepared by the reaction of an alcohol with butylene oxide, and subsequent amination
with ammonia or an amine.
[0005] U.S. Patent No. 4,332,595, issued June 1, 1982 to Herbstman et al., discloses a gasoline
detergent additive which is a hydrocarbyl-substituted polyoxypropylene diamine, wherein
the hydrocarbyl substituent contains 8 to 18 carbon atoms. This patent further teaches
that the additive is prepared by reductive amination of a hydrocarbyl-substituted
polyoxypropylene alcohol with ammonia to give a polyoxypropylene amine, which is subsequently
reacted with acrylonitrile to give the corresponding
N-2-cyanoethyl derivative. Hydrogenation in the presence of ammonia then provides the
desired hydrocarbyl-substituted polyoxypropylene
N-3-aminopropyl amine.
[0006] U.S. Patent No. 3,440,029, issued April 22, 1969 to Little et al., discloses a gasoline
anti-icing additive which is a hydrocarbyl-substituted polyoxyalkylene amine, wherein
the hydrocarbyl substituent contains 8 to 24 carbon atoms. This patent teaches that
the additive may be prepared by known processes wherein a hydroxy compound is condensed
with an alkylene oxide or mixture of alkylene oxides and then the terminal amino group
is attached by either reductive amination or by cyanoethylation followed by hydrogenation.
Alternatively, the hydroxy compound or oxyalkylated derivative thereof may be reacted
with bis(2-chloroethyl)ether and alkali to make a chlorine-terminated compound, which
is then reacted with ammonia to produce the amine-terminated final product.
[0007] U.S. Patent No. 4,247,301, issued January 27, 1981 to Honnen, discloses hydrocarbyl-substituted
poly(oxyalkylene) polyamines, wherein the hydrocarbyl group contains from 1 to 30
carbon atoms and the polyamine moiety contains from 2 to. 12 amine nitrogen atoms
and from 2 to 40 carbon atoms. This patent teaches that the additives may be prepared
by the reaction of a suitable hydrocarbyl-terminated polyether alcohol with a halogenating
agent such as HC1, thionyl chloride, or epichlorohydrin to form a polyether chloride,
followed by reaction of the polyether chloride with a polyamine to form the desired
poly(oxyalkylene) polyamine. This patent also teaches at Example 6 that the polyether
chloride may be reacted with ammonia or dimethylamine to form the corresponding polyether
amine or polyether dimethylamine.
[0008] U.S. Patent No. 5,752,991 issued May 19, 1998 to Plavac, discloses fuel compositions
containing from about 50 to about 2,500 parts per million by weight of a long chain
alkylphenyl polyoxyalkylene amine, wherein the alkyl substituent on the phenyl ring
has at least 40 carbon atoms.
[0009] Mannich condensation products are also known in the art as fuel additives for the
prevention and control of engine deposits. For example, U.S. Patent No. 4, 231,759,
issued November 4, 1980 to Udelhofen et al., discloses reaction products obtained
by the Mannich condensation of a high molecular weight alkyl-substituted hydroxyaromatic
compound, an amine containing an amino group having at least one active hydrogen atom,
and an aldehyde, such as formaldehyde. This patent further teaches that such Mannich
condensation products are useful detergent additives in fuels for the control of deposits
on carburetor surfaces and intake valves.
[0010] U.S. Patent No. 5,514, 190, issued May 7, 1996 to Cunningham et al., discloses a
fuel additive composition for the control of intake valve deposits which comprises
(a) the Mannich reaction product of a high molecular weight alkyl-substituted phenol,
an amine, and an aldehyde, (b) a poly(oxyalkylene) carbamate, and (c) a poly(oxyalkylene)
alcohol, glycol or polyol, or a mono or diether thereof.
[0011] U.S. Parent No. 5,697,988, issued December 16, 1997 to Malfer et al., discloses a
fuel additive composition which provides reduced fuel injector, intake valve and combustion
chamber deposits which comprises (a) the Mannich reaction product of a high molecular
weight alkyl-substituted phenol, an amine, and an aldehyde, (b) a polyoxyalkylene
compound, preferably a polyoxyalkylene glycol or monoether derivative thereof, and
(c) optionally a poly-alpha-olefin.
[0012] Although hydrocarbyl-substituted polyoxyalkylene amines are generally known to be
effective deposit control fuel additives, particularly on engine intake systems and
combustion chambers, it has now been found that certain polyoxyalkylene amines may
contribute to crankcase sludge and varnish build-up which can ultimately result in
engine oil screen plugging and catastrophic engine failure. Accordingly, there exists
a need in the art for polyoxyalkylene amine-containing fuel additive compositions
which effectively control intake system and combustion chambers deposits, without
contributing to the problem of engine oil screen plugging.
SUMMARY OF THE INVENTION
[0013] It has now been discovered that the combination of certain Mannich condensation products
with certain hydrocarbyl-substituted polyoxyalkylene amines affords a unique fuel
additive composition which provides excellent control of engine oil screen plugging.
[0014] Accordingly, the present invention provides a novel fuel additive composition comprising:
(a) a Mannich condensation product of (1) a high molecular weight alkyl-substituted
hydroxyaromatic compound wherein the alkyl group has a number average molecular weight
of from about 300 to about 5,000 (2) an amine which contains an amino group having
at least one active hydrogen atom, and (3) an aldehyde, wherein the respective molar
ratio of reactants (1), (2) and (3) is 1:0.1-10:0.1-10; and
(b) a hydrocarbyl-substituted polyoxyalkylene amine having the formula:

or a fuel-soluble salt thereof;
wherein R is a hydrocarbyl group having from about 1 to about 30 carbon atoms;
one of R1 and R2 is methyl or ethyl and the other is hydrogen, and each R1 and R2 is independently selected in each -O-CHR1-CHR2- unit;
A is amino, N-alkyl amino having about 1 to about 20 carbon atoms in the alkyl group,
N,N-dialkyl amino having about 1 to about 20 carbon atoms in each alkyl group, or
a polyamine moiety having about 2 to about 12 amine nitrogen atoms and about 2 to
about 40 carbon atoms; and
x is an integer from about 5 to about 100;
and wherein the weight ratio of polyoxyalkylene amine to Mannich condensation product
is from about 0.5:1 to about 12:1.
[0015] The present invention further provides a fuel composition comprising a major amount
of hydrocarbons boiling in the gasoline or diesel range and an amount effective to
control engine oil screen plugging of a fuel additive composition of the present invention.
[0016] The present invention additionally provides a fuel concentrate comprising an inert
stable oleophilic organic solvent boiling in the range of from about 150°F to 400°F
and from about 10 to about 70 weight percent of a fuel additive composition of the
present invention.
[0017] Among other factors, the present invention is based on the surprising discovery that
the unique combination of certain Mannich condensation products with certain hydrocarbyl-substituted
polyoxyalkylene amines provides excellent control of engine oil screen plugging when
employed as additives in fuel compositions.
DETAILED DESCRIPTION OF THE INVENTION
I. The Mannich Condensation Product
[0018] The Mannich reaction products employed in this invention are obtained by condensing
an alkyl-substituted hydroxyaromatic compound whose alkyl-substituent has a number
average molecular weight of from about 300 to about 5,000 (Mn), preferably polyalkylphenol
whose polyalkyl substituent is derived from 1-mono-olefin polymers having a number
average molecular weight of from about 300 to about 5,000, more preferably from about
400 to about 3,000; an amine containing at least one >NH group, preferably an alkylene
polyamine of the formula
H
2N-(B-NH-)
mH
wherein B is a divalent alkylene radical having 1 to about 10 carbon atoms and m is
an integer from 1 to about 10; and an aldehyde, preferably formaldehyde, in the presence
of a solvent.
[0019] High molecular weight Mannich reaction products useful as additives in the fuel additive
compositions of this invention are preferably prepared according to conventional methods
employed for the preparation of Mannich condensation products, using the above-named
reactants in the respective molar ratios of high molecular weight alkyl-substituted
hydroxyaromatic compound, amine, and aldehyde of approximately 1.0:0.1-10:1-10. A
suitable condensation procedure involves adding at a temperature of from room temperature
to about 95°C., the formaldehyde reagent (e.g., formalin) to a mixture of amine and
alkyl-substituted hydroxyaromatic compounds alone or in an easily removed organic
solvent, such as benzene, xylene, or toluene or in solvent-refined neutral oil, and
then heating the reaction mixture at an elevated temperature (120°-175°C) while the
water of reaction is distilled overhead and separated. The reaction product so obtained
is finished by filtration and dilution with solvent as desired.
[0020] Preferred Mannich reaction product additives employed in this invention are derived
from high molecular weight Mannich condensation products, formed by reacting an alkylphenol,
an ethylene polyamine, and a formaldehyde affording reactants in the respective molar
ratio of 1.0:0.5-2.0:1.0-3.0, wherein the alkyl group of the alkylphenol has a number
average weight (Mn) of from about 300 to about 5,000. Representative of the high molecular
weight alkyl-substituted hydroxyaromatic compounds are polypropylphenol, polybutylphenol
and other polyalkylphenols, with polyisobutylphenol being the most preferred. Polyalkylphenols
may be obtained by the alkylation, in the presence of an alkylating catalyst such
as BF
3, of phenol with high molecular weight polypropylene, polybutylene and other polyalkylene
compounds to give alkyl substiltuents on the benzene ring of phenol having a number
average molecular weight (Mn) of from about 300 to about 5,000.
[0021] The alkyl substituents on the hydroxyaromatic compounds may be derived from high
molecular weight polypropylenes, polybutenes, and other polymers of mono-olefins,
principally 1-mono-olefins. Also useful are copolymers of mono-olefins with monomers
copolymerizable therewith, wherein the copolymer molecule contains at least 90% by
weight of mono-olefin units. Specific examples are copolymers of butenes (butene-1,
butene-2, and isobutylene) with monomers copolymerizable therewith wherein the copolymer
molecule contains at least 90% by weight of propylene and butene units, respectively.
Said monomers copolymerizable with propylene or said butenes include monomers containing
a small proportion of unreactive polar groups, such as chloro, bromo, keto, ether,
or aldehyde, which do not appreciably lower the oil-solubility of the polymer. The
comonomers polymerized with propylene or said butenes may be aliphatic and can also
contain non-aliphatic groups, e.g., styrene, methylstyrene, p-dimethylstyrene, divinyl
benzene and the like. From the foregoing limitation placed on the monomer copolymerized
with propylene or said butenes, it is clear that said polymers and copolymers of propylene
and said butenes are substantially aliphatic hydrocarbon polymers. Thus, the resulting
alkylated phenols contain substantially alkyl hydrocarbon substitutents having a number
average molecular weight (Mn) of from about 300 to about 5,000.
[0022] In addition to the foregoing high molecular weight hydroxyaromatic compounds, other
phenolic compounds which may be used include, high molecular weight alkyl-substituted
derivatives of resorcinol, hydroquinone, cresol, cathechol, xylenol, hydroxy-di-phenyl,
benzylphenol, phenethylphenol, naphthol, tolylnaphthol, among others. Preferred for
the preparation of such preferred Mannich condensation products are the polyalkylphenol
reactants, e.g., polypropylphenol and polybutylphenol, particularly polyisobutylphenol,
whose alkyl gmup has a number average molecular weight of about 300 to about 5,000,
preferably about 400 to about 3,000, more preferably about 500 to about 2,000, and
most preferably about 700 to about 1,500.
[0023] As noted above, the polyalkyl substituent on the polyalkyl hydroxyaromatic compounds
employed in the invention may be generally derived from polyolefins which 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, especially polyisobutene,
and the polyalphaolefins produced from 1-octene and 1-decene.
[0024] The preferred polyisobutenes used to prepare the presently employed polyalkyl hydroxyaromatic
compounds are polyisobutenes which comprise at least about 20% of the more reactive
methylvinylidene isomer, preferably at least about 50% and more preferably at least
about 70% methylvinylidene isomer. Suitable polyisobutenes include those prepared
using BF
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. Patent Nos.
4,12,499 and 4,605,808.
[0025] Examples of suitable polyisobutenes having a high alkylvinylidene content include
Ultravis 10, a polyisobutene having a molecular weight of about 950 and a methylvinylidine
content of about 76%, and Ultravis 30, a polyisobutene having a molecular weight of
about 1300 and a methylvinylidene content of about 74%, both available from British
Petroleum, and Glissopal 1000, 1300 and 2200, available from BASF.
[0026] The preferred configuration of the alkyl-substituted hydroxyaromatic compound is
that of a para-substituted mono-alkylphenol. However, any alkylphenol readily reactive
in the Mannich condensation reaction may be employed. Accordingly, ortho mono-alkylphenols
and dialkylphenols are suitable for use in this invention.
[0027] Representative amine reactants are alkylene polyamines, principally polyethylene
polyamines. Other representative organic compounds containing at least one HN< group
suitable for use in the preparation of the Mannich reaction products are well known
and include the mono and di-amino alkanes and their substituted analogs, e.g., ethylamine,
dimethylamine, dimethylaminopropyl amine, and diethanol amine; aromatic diamines,
e.g., phenylene diamine, diamino naphthalenes; heterocyclic amines, e.g., morpholine,
pyrrole, pyrrolidine, imidazole, imidazolinidine, and piperidine; melamine and their
substituted analogs.
[0028] The alkylene polyamine reactants which are useful with this invention include polyamines
which are linear, branched, or cyclic; or a mixture of linear, branched and/or cyclic
polyamines wherein each alkylene group contains from about 1 to about 10 carbon atoms.
A preferred polyamine is a polyamine containing from 2 to 10 nitrogen atoms per molecule
or a mixture of polyamines containing an average of from about 2 to about 10 nitrogen
atoms per molecule such as ethylenediamine, diethylene triamine, triethylene tetramine,
tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, heptaethylene
octamine, octaethylene nonamine, monaethylene decamine, and mixtures of such amines.
Corresponding propylene polyamines such as propylene diamine, dipropylene triamine,
tripropylene'tetramine, tetrapropylene pentamine, and pentapropylene hexamine are
also suitable reactants. A particularly preferred polyamine is a polyamine or mixture
of polyamines having from about 3 to 7 nitrogen atoms, with diethylene triamine or
a combination or mixture of ethylene polyamines whose physical and chemical properties
approximate that of diethylene triamine being the most preferred. In selecting an
appropriate polyamine, consideration should be given to the compatibility of the resulting
detergent/dispersant with the gasoline fuel mixture with which it is mixed.
[0029] Ordinarily the most highly preferred polyamine, diethylene triamine, will comprise
a commercially available mixture having the general overall physical and/or chemical
composition approximating that of diethylene triamine but which can contain minor
amounts of branched-chain and cyclic species as well as some linear polyethylene polyamines
such as triethylene tetramine and tetraethylene pentamine. For best results, such
mixtures should contain at least 50% and preferably at least 70% by weight of the
linear polyethylene polyamines enriched in diethylene triamine.
[0030] The alkylene polyamines are usually obtained by the reaction of ammonia and dihalo
alkanes, such as dichloro alkanes. Thus, the alkylene polyamines are obtained from
the reaction of 2 to 11 moles of ammonia with 1 to 10 moles of dichloro alkanes having
2 to 6 carbon atoms and the chlorines on different carbons.
[0031] Representative aldehydes for use in the preparation of the high molecular weight
Mannich reaction products employed in this invention include the aliphatic aldehydes
such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde,
caproaldehyde, heptaldehyde, and 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.
II. The Hydrocarbyl-Susbstituted Polyoxyalkylene Amine
[0032] The hydrocarbyl-substituted polyoxyalkylene amines employed in the present invention
have the general formula:

wherein R, R
1, R
2, A, and x are as defined above.
[0033] In Formula I, above, R is a hydrocarbyl group having from about 1 to about 30 carbon
atoms. Preferably, R is an alkyl or alkylphenyl group. More preferably, R is an alkylphenyl
group, wherein the alkyl moiety is a straight or branched chain alkyl of from about
1 to about 24 carbon atoms.
[0034] Also in Formula I above, one of R
1 and R
2 is methyl or ethyl, and the other is hydrogen. In other words, the oxyalkylene units
may be oxypropylene or oxybutylene. Mixtures of oxypropylene and oxybutylene units
are also contemplated for use in this invention. Preferably one of R
1 and R
2 is methyl, and the other is hydrogen. That is, the preferred oxyalkylene unit is
oxypropylene.
[0035] In general, A is amino, N-alkyl amino having from about 1 to about 20 carbon atoms
in the alkyl group, preferably about 1 to about 6 carbon atoms, more preferably about
1 to about 4 carbon atoms; N,N-dialkyl amino having from about 1 to about 20 carbon
atoms in each alkyl group, preferably about 1 to about 6 carbon atoms, more preferably
about 1 to about 4 carbon atoms; or a polyamine moiety having from about 2 to about
12 amine nitrogen atoms and from about 2 to about 40 carbon atoms, preferably about
2 to 12 amine nitrogen atoms and about 2 to 24 carbon atoms. More preferably, A is
amino or a polyamine moiety derived from a polyalkylene polyamine, including alkylene
diamine. Most preferably, A is amino or a polyamine moiety derived from ethylene diamine
or diethylene triamine.
[0036] Preferably, x is an integer from about 5 to about 50, more preferably from about
8 to about 30, and most preferably from about 10 to about 25.
[0037] The compounds employed in the present invention will generally have a sufficient
molecular weight so as to be non-volatile at normal engine intake valve operating
temperatures (about 200°-250°C.). Typically, the molecular weight of the polyoxyalkylene
amine compounds employed in this invention will range from about 600 to about 10,000.
[0038] Fuel-soluble salts of the compounds of formula I can be readily prepared for those
compounds containing an amino or substituted amino group and such salts are contemplated
to be useful for preventing or controlling engine deposits. Suitable salts include,
for example, those obtained by protonating the amino moiety with a strong organic
acid, such as an alkyl- or arylsulfonic acid. Preferred salts are derived from toluenesulfonic
acid and methanesulfonic acid.
Definitions
[0039] As used herein, the following terms have the following meanings unless expressly
stated to the contrary.
[0040] The term "amino" refers to the group: -NH
2.
[0041] The term "
N-alkylamino" refers to the group: -NHR
a wherein R
a is an alkyl group. The term "
N,N-dialkylamino" refers to the group: ―NR
bR
c, wherein R
b and R
c are alkyl groups.
[0042] The term "hydrocarbyl" refers to an organic radical primarily composed of carbon
and hydrogen which may be aliphatic, alicyclic, aromatic or combinations thereof,
e.g., aralkyl or alkaryl. Such hydrocarbyl groups are generally free of aliphatic
unsaturation, i.e., olefinic or acetylenic unsaturation, but may contain minor amounts
of heteroatoms, such as oxygen or nitrogen, or halogens, such as chlorine. The term
"alkyl" refers to both straight- and branched-chain alkyl groups.
[0043] The term "lower alkyl" refers to alkyl groups having 1 to about 6 carbon atoms and
includes primary, secondary, and tertiary alkyl groups. Typical lower alkyl groups
include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl,
n-pentyl, n-hexyl, and the like.
[0044] The term "alkylene" refers to straight- and branched-chain alkylene groups having
at least 2 carbon atoms. Typical alkylene groups include, for example, ethylene (-CH
2CH
2-), propylene (-CH
2CH
2CH
2-), isopropylene (-CH(CH
3)CH
2-), n-butylene (-CH
2CH
2CH
2CH
2-), sec-butylene (-CH(CH
2CH
3)CH
2-), n-pentylene (-CH
2CH
2CH
2CH
2CH
2-), and the like.
[0045] The term "polyoxyalkylene" refers to a polymer or oligomer having the general formula:

wherein R
i and Rj are each independently hydrogen or lower alkyl groups, and y is an integer
from about 5 to about 100. When referring herein to the number of oxyalkylene units
in a particular polyoxyalkylene compound, it is to be understood that this number
refers to the average number of oxyalkylene units in such compounds unless expressly
stated to the contrary.
General Synthetic Procedures
[0046] The hydrocarbyl-substituted polyoxyalkylene amines employed in this invention may
be prepared by the following general methods and procedures. It should be appreciated
that where typical or preferred process conditions (e.g., reaction temperatures, times,
mole ratios of reactants, solvents, pressures, etc.) are given, other process conditions
may also be used unless otherwise stated. Optimum reaction conditions may vary with
the particular reactants or solvents used, but such conditions can be determined by
one skilled in the art by routine optimization procedures.
[0047] The hydrocarbyl-substituted polyoxyalkylene amines employed in the present invention
contain (a) a hydrocarbyl-substituted polyoxyalkylene component, and (b) an amine
component.
A. The Hydrocarbyl-Substituted Polyoxyalkylene Component
[0048] The hydrocarbyl-substituted polyoxyalkylene polymers which are utilized in preparing
the hydrocarbyl-substituted polyoxyalkylene amines employed in the present invention
are monohydroxy compounds, i.e., alcohols, often termed hydrocarbyl "capped" polyoxyalkylene
glycols and are to be distinguished from the polyoxyalkylene glycols (diols), which
are not hydrocarbyl terminated, i.e., not capped. The hydrocarbyl-substituted polyoxyalkylene
alcohols are produced by the addition of lower alkylene oxides, such as propylene
oxide, or the butylene oxides, to the hydroxy compound, ROH, under polymerization
conditions, wherein R is the hydrocarbyl group, as defined above, which caps the polyoxyalkylene
chain. Preferred polyoxyalkylene polymers are those derived from C
3 to C
4 oxyalkylene units. Methods of production and properties of these polymers are disclosed
in U.S. Patent Nos. 2,841,479 and 2,782,240 and Kirk-Othmer's
"Encyclopedia of Chemical Technology ", Volume 19, page 507. In the polymerization reaction, a single type of alkylene oxide
may be employed, e.g., propylene oxide, in which case the product is a homopolymer,
e.g., a polyoxypropylene alcohol. However, copolymers are equally satisfactory and
random copolymers are readily prepared by contacting the hydroxy-containing compound
with a mixture of alkylene oxides, such as a mixture of propylene and butylene oxides.
Block copolymers of oxyalkylene units also provide satisfactory polyoxyalkylene units
for the practice of the present invention.
[0049] The amount of alkylene oxide employed in this reaction will generally depend on the
number of oxyalkylene units desired in the product. Typically, the molar ratio of
alkylene oxide to hydroxy-containing compound will range from about 5:1 to about 100:1;
preferably, from about 5:1 to about 50:1, more preferably from about 8:1 to about
30:1.
[0050] Alkylene oxides suitable for use in this polymerization reaction include propylene
oxide and butylene oxides, such as 1,2-butylene oxide (1,2-epoxybutane) and 2,3-butylene
oxide (2,3-epoxybutane). Preferred alkylene oxides are propylene oxide and 1,2-butylene
oxide, both individually and in mixtures thereof.
[0051] The hydrocarbyl moiety, R, which terminates the polyoxyalkylene chain will generally
contain from about 1 to about 30 carbon atoms, preferably from about 2 to about 20
carbon atoms, and more preferably from about 4 to about 18 carbon atoms, and is generally
derived from the monohydroxy compound, ROH, which is the initial site of the alkylene
oxide addition in the polymerization reaction. Such monohydroxy compounds are preferably
aliphatic or aromatic alcohols having from about 1 to about 30 carbon atoms, more
preferably and alkanol or an alkylphenol, and most preferably an alkyphenol wherein
the alkyl substituent is a straight or branched chain alkyl of from about 1 to about
24 carbon atoms. Preferred alkylphenols include those wherein the alkyl substituent
contains from about 4 to about 16 carbon atoms. An especially preferred alkylphenol
is one wherein the alkyl group is obtained by polymerizing propylene to an average
of 4 propylene units, that is, about 12 carbon atoms, having the common name of propylene
tetramer. The resulting alkylphenol is commonly called tetrapropenylphenol or, more
generically, dodecylphenol. Preferred alkylphenol-initiated polyoxyalkylene compounds
may be termed either alkylphenylpolyoxyalkylene alcohols or polyalkoxylated alkylphenols.
B. The Amine Component
[0052] As indicated above, the hydrocarbyl-substituted polyoxyalkylene amines employed in
the present invention contain an amine component.
[0053] In general, the amine component will contain an average of at least about one basic
nitrogen atom per molecule. A "basic nitrogen atom" is one that is titratable by a
strong acid, for example, a primary, secondary, or tertiary amine nitrogen; as distinguished
from, for example, an carbamyl nitrogen, e.g., -OC(O)NH-, which is not titratable
with a strong acid. Preferably, at least one of the basic nitrogen atoms of the amine
component will be primary or secondary amine nitrogen, more preferably at least one
will be a primary amine nitrogen.
[0054] The amine component of the hydrocarbyl-substituted polyoxyalkylene amines employed
in this invention is preferably derived from ammonia, a primary alkyl or secondary
dialkyl monoamine, or a polyamine having a terminal amino nitrogen atom.
[0055] Primary alkyl monoamines useful in preparing compounds of the present invention contain
1 nitrogen atom and from about 1 to about 20 carbon atoms, more preferably about 1
to 6 carbon atoms, most preferably 1 to 4 carbon atoms. Examples of suitable monoamines
include
N-methylamine,
N-ethylamine,
N-n-propylamine,
N-isopropylamine,
N-n-butylamine,
N-isobutylamine,
N-sec-butylamine,
N-tert-butylamine,
N-n-pentylamine, N-cyclopentylamine, N-n-hexylamine, N-cyclohexylamine, N-octylamine,
N-decylamine, N-dodecylamine, N-octadecylamine, N-benzylamine, N-(2-phenylethyl)amine,
2-aminoethanol, 3-amino-1-propanol, 2-(2-aminoethoxy)ethanol, N-(2-methoxyethyl)amine,
N-(2-ethoxyethyl)amine and the like. Preferred primary amines are N-methylamine, N-ethylamine
and N-n-propylamine.
[0056] The amine component of the presently employed fuel additive may also be derived from
a secondary dialkyl monoamine. The alkyl groups of the secondary amine may be the
same or different and will generally each contain about 1 to about 20 carbon atoms,
more preferably about 1 to about 6 carbon atoms, most preferably about 1 to about
4 carbon atoms. One or both of the alkyl groups may also contain one or more oxygen
atoms.
[0057] Preferably, the alkyl groups of the secondary amine are independently selected from
the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-hydroxyethyl
and 2-methoxyethyl. More preferably, the alkyl groups are methyl, ethyl or propyl.
[0058] Typical secondary amines which may be used in this invention include N,N-dimethylamine,
N,N-diethylamine, N,N-di-n-propylamine, N,N-diisopropylamine, N,N-di-n-butylamine,
N,N-di-sec-butylamine, N,N-di-n-pentylamine, N,N-di-n-hexylamine, N,N-dicyclohexylamine,
N,N-dioctylamine, N-cthyl-N-methylamine, N-methyl-N-n-propylamine, N-n-butyl-N-methylamine,
N-methyl-N-octylamine, N-ethyl-N-isopropylamine, N-ethyl-N-octylamine, N,N-di(2-hydroxyethyl)amine,
N,N-di(3-hydroxypropyl)amine, N,N-di(ethoxyethyl)amine, N,N-di(propoxyethyl)amine
and the like. Preferred secondary amines are N,N-dimethylamine, N,N-diethylamine and
N,N-di-n-propylamine.
[0059] Cyclic secondary amines may also be used to form the additives employed in this invention.
In such cyclic compounds, the alkyl groups, when taken together, form one or more
5- or 6-membered rings containing up to about 20 carbon atoms. The ring containing
the amine nitrogen atom is generally saturated, but may be fused to one or more saturated
or unsaturated rings. The rings may be substituted with hydrocarbyl groups of from
1 to about 10 carbon atoms and may contain one or more oxygen atoms.
[0060] Suitable cyclic secondary amines include piperidine, 4-methylpiperidine, pyrrolidine,
morpholine, 2,6-dimethylmorpholine and the like.
[0061] Suitable polyamines can have a straight- or branched-chain structure and maybe cyclic
or acyclic or combinations thereof. Generally, the amine nitrogen atoms of such polyamines
will be separated from one another by at least two carbon atoms, i.e., polyamines
having an aminal structure are not suitable. The polyamine may also contain one or
more oxygen atoms, typically present as an ether or a hydroxyl group. Polyamines having
a carbon-to-nitrogen ratio of from about 1:1 to about 10:1 are particularly preferred.
[0062] In preparing the polyoxyalkylene amine compounds employed in this invention using
a polyamine where the various nitrogen atoms of the polyamine are not geometrically
equivalent, several substitutional isomers are possible and each of these possible
isomers is encompassed within this invention.
[0063] A particularly preferred group of polyamines for use in the present invention are
polyalkylene polyamines, including alkylene diamines. Such polyalkylene polyamines
will typically contain from about 2 to about 12 nitrogen atoms and from about 2 to
about 40 carbon atoms, preferably about 2 to 24 carbon atoms. Preferably, the alkylene
groups of such polyalkylene polyamines will contain from about 2 to about 6 carbon
atoms, more preferably from about 2 to about 4 carbon atoms.
[0064] Examples of suitable polyalkylene polyamines include ethylenediamine, propylenediamine,
isopropylenediamine, butylenediamine, pentylenediamine, hexylenediamine, diethylenetriamine,
dipropylenetriamine, dimethylaminopropylamine, diisopropylenetriamine, dibutylenetriamine,
di-sec-butylenetriamine, triethylenetetraamine, tripropylenetetraamine, triisobutylenetetraamine,
tetraethylenepentamine, pentaethylenehexamine, dimethylaminopropylamine, and mixtures
thereof.
[0065] Particularly suitable polyalkylene polyamines are those having the formula:
H
2N-(R
3-NH)
z-H
wherein R
3 is a straight- or branched-chain alkylene group having from about 2 to about 6 carbon
atoms, preferably from about 2 to about 4 carbon atoms, most preferably about 2 carbon
atoms, i.e., ethylene (-CH
2CH
2-); and z is an integer from about 1 to about 4, preferably about 1 or about 2.
[0066] Particularly preferred polyalkylene polyamines are ethylenediamine, diethylenetriamine,
triethylenetetraamine, and tetraethylenepentamine. Most preferred are ethylenediamine
and diethylenetriamine, especially ethylenediamine.
[0067] Also contemplated for use in the present invention are cyclic polyamines having one
or more 5- to 6-membered rings. Such cyclic polyamines compounds include piperazine,
2-methylpiperazine, N-(2-aminoethyl)piperazine, N-(2-hydroxyethyl)piperazine, 1,2-bis-(N-piperazinyl)ethane,
3-aminopyrrolidine, N-(2-aminoethyl)pyrrolidine, and the like. Among the cyclic polyamines,
the piperazines are preferred.
[0068] Many of the polyamines suitable for use in the present invention are commercially
available and others may be prepared by methods which are well known in the art. For
example, methods for preparing amines and their reactions are detailed in Sidgewick's
"The Organic Chemistry of Nitrogen", Clarendon Press, Oxford, 1966; Noller's "
Chemistry of Organic Compounds", Saunders, Philadelphia, 2nd Ed., 1957; and Kirk-Othmer's
"Encyclopedia of Chemical Technology", 2nd Ed., especially Volume 2, pp. 99-116.
C. Preparation of the Hydrocarbyl-Substituted Polyoxyalkylene Amine
[0069] The polyoxyalkylene amine additives employed in this invention may be conveniently
prepared by reacting a hydrocarbyl-substituted polyoxyalkylene alcohol, either directly
or through an intermediate, with a nitrogen-containing compound, such as ammonia,
a primary or secondary alkyl monoamine or a polyamine, as described herein.
[0070] The hydrocarbyl-substituted polyoxyalkylene alcohols used to form the polyoxyalkylene
amines employed in the present invention are typically known compounds that can be
prepared using conventional procedures. Suitable procedures for preparing such compounds
are taught, for example, in U.S. Patent Nos. 2,782,240 and 2,841,479, as well as U.S.
Patent No. 4,881,945, the disclosures of which are incorporated herein by reference.
[0071] Preferably, the polyoxyalkylene alcohols are prepared by contacting an alkoxide or
phenoxide metal salt with from about 5 to about 100 molar equivalents of an alkylene
oxide, such as propylene oxide or butylene oxide, or mixtures of alkylene oxides.
[0072] Typically, the alkoxide or phenoxide metal salt is prepared by contacting the corresponding
hydroxy compound with a strong base, such as sodium hydride, potassium hydride, sodium
amide, and the like, in an inert solvent, such as toluene, xylene, and the like, under
substantially anhydrous conditions at a temperature in the range from about -10°C
to about 120°C for from about 0.25 to about 3 hours.
[0073] The alkoxide or phenoxide metal salt is generally not isolated, but is reacted
in situ with the alkylene oxide or mixture of alkylene oxides to provide, after neutralization,
the polyoxyalkylene alcohol. This polymerization reaction is typically conducted in
a substantially anhydrous inert solvent at a temperature of from about 30°C to about
150°C for from about 2 to about 120 hours. Suitable solvents for this reaction, include
toluene, xylene, and the like. Typically, the reaction is conducted at a pressure
sufficient to contain the reactants and the solvent, preferably at atmospheric or
ambient pressure.
[0074] The hydrocarbyl-substituted polyoxyalkylene alcohol may then be converted to the
desired polyoxyalkylene amine by a variety of procedures known in the art.
[0075] For example, the terminal hydroxy group on the hydrocarbyl-substituted polyoxyalkylene
alcohol may first be converted to a suitable leaving group, such as a mesylate, chloride
or bromide, and the like, by reaction with a suitable reagent, such as methanesulfonyl
chloride. The resulting polyoxyalkylene mesylate or equivalent intermediate may then
be converted to a phthalimide derivative by reaction with potassium phthalimide in
the presence of a suitable solvent, such as
N,N-dimethylformamide. The polyoxyalkylene phthalimide derivative is subsequently converted
to the desired hydrocarbyl-substituted polyoxyalkylene amine by reaction with a suitable
amine, such as hydrazine.
[0076] The polyoxyalkylene alcohol may also be converted to the corresponding polyoxyalkylene
chloride by reaction with a suitable halogenating agent, such as HC1, thionyl chloride,
or epichlorohydrin, followed by displacement of the chloride with a suitable amine,
such as ammonia, a primary or secondary alkyl monoamine, or a polyamine, as described,
for example, in U.S. Patent No. 4,247,301 to Honnen, the disclosure of which is incorporated
herein by reference.
[0077] Alternatively, the hydrocarbyl-substituted polyoxyalkylene amines employed in the
present invention may be prepared from the corresponding polyoxyalkylene alcohol by
a process commonly referred to as reductive amination, such as described in U.S. Patent
No. 5,112,364 to Rath et al. and U.S. Patent No. 4,332,595 to Herbstman et al., the
disclosures of which are incorporated herein by reference.
[0078] In the reductive amination procedure, the hydrocarbyl-substituted polyoxyalkylene
alcohol is aminated with an appropriate amine, such as ammonia or a primary alkyl
monoamine, in the presence of hydrogen and a hydrogenation-dehydrogenation catalyst.
The amination reaction is typically carried out at temperatures in the range of about
160°C to about 250°C and pressures of about 1,000 to about 5.000 psig, preferably
about 1,500 to about 3,000 psig. Suitable hydrogenatiion-dehydrogenation catalysts
include those containing platinum, palladium, cobalt, nickel, copper, or chromium,
or mixtures thereof. Generally, an excess of the ammonia or amine reactant is used,
such as about a 5-fold to about 60-fold molar excess, and preferably about a 10-fold
to about 40-fold molar excess, of ammonia or amine.
[0079] When the reductive amination is carried out with a polyamine reactant, tine amination
is preferably conducted using a two-step procedure as described in European Patent
Application Publication No. EP 0,781,793, published July 2. 1997, the disclosure of
which is incorporated herein by reference in its entirety. According to this procedure,
a polyoxyalkylene alcohol is first contacted with a hydrogenation-dehydrogenation
catalyst at a temperature of at least 230°C to provide a polymeric carbonyl intermediate,
which is subsequently reacted with a polyamine at a temperature below about 190°C
in the presence of hydrogen and a hydrogenation catalyst to produce the polyoxyalkylene
polyamine adduct.
[0080] The hydrocarbyl-substituted polyoxyalkylene amines obtained by amination can be added
as such to hydrocarbon fuels.
Fuel Compositions
[0081] The fuel additive composition of the present invention will generally be employed
in hydrocarbon fuels to prevent and control engine oil screen plugging. Typically,
the desired control of oil screen plugging will be achieved by operating an internal
combustion engine with a fuel composition containing the additive composition of the
present invention. The proper concentration of additive necessary to achieve the desired
control of oil screen plugging varies depending upon the type of fuel employed, the
type of engine, engine oil, operating conditions and the presence of other fuel additives.
[0082] Generally, the present fuel additive composition will be employed in a hydrocarbon
fuel in a concentration ranging from about 20 to about 4,000 parts per million (ppm)
by weight, preferably from about 20 to about 2,500 ppm.
[0083] In terms of individual components, hydrocarbon fuel containing the fuel additive
composition of this invention will generally contain about 10 to about 2,000 ppm,
preferably about 10 to about 500 ppm, of the Mannich condensation product component
and about 10 to about 2,000 ppm, preferably about 10 to about 1,000 ppm, of the polyoxyalkylene
amine component. The weight ratio of the polyoxyalkylene amine to Mannich condensation
product will generally range from about 0.5:1 to about 12:1, and will preferably be
about 0.5:1 to about 5:1.
[0084] The fuel additive composition of the present invention may be formulated as a concentrate
using an inert stable oleophilic (i.e., dissolves in gasoline) organic solvent boiling
in the range of about 150°F. to 400°F. (about 65°C. to 205°C.). Preferably, an aliphatic
or an aromatic hydrocarbon solvent is used, such as benzene, toluene, xylene or higher-boiling
aromatics or aromatic thinners. Aliphatic alcohols containing about 3 to 8 carbon
atoms, such as isopropanol, isobutylcarbinol, n-butanol and the like, in combination
with hydrocarbon solvents are also suitable for use with the present additives. In
the concentrate, the amount of the additive will generally range from about 10 to
about 70 weight percent, preferably 10 to 50 weight percent, more preferably from
20 to 40 weight percent.
[0085] In gasoline fuels, other fuel additives may be employed with the additive composition
of the present invention, including, for example, oxygenates, such as t-butyl methyl
ether, antiknock agents, such as methylcyclopentadienyl manganese tricarbonyl, and
other dispersants/detergents, such as hydrocarbyl amines, or succinimides. Additionally,
antioxidants, metal deactivators, demulsifiers and carburetor or fuel injector detergents
may be present.
[0086] In diesel fuels, other well-known additives can be employed, such as pour point depressants,
flow improvers, cetane improvers, and the like.
[0087] A fuel-soluble, nonvolatile carrier fluid or oil may also be used with the fuel additive
composition of this invention. The carrier fluid is a chemically inert hydrocarbon-soluble
liquid vehicle which substantially increases the nonvolatile residue (NVR), or solvent-free
liquid fraction of the fuel additive composition while not overwhelmingly contributing
to octane requirement increase. The carrier fluid may be a natural or synthetic fluid,
such as mineral oil, refined petroleum oils, synthetic polyalkanes and alkenes, including
hydrogenated and unhydrogenated polyalphaolefins, and synthetic polyoxyalkylene-derived
fluids, such as those described, for example, in U.S. Patent No. 4,191,537 to Lewis,
and polyesters, such as those described, for example, in U.S. Patent Nos. 3,756,793
to Robinson and 5,004,478 to Vogel et al., and in European Patent Application Nos.
356,726, published March 7, 1990, and 382,159, published August 16, 1990.
[0088] These carrier fluids are believed to act as a carrier for the fuel additive composition
of the present invention and to assist in the control of oil screen plugging, as well
as engine intake system deposits. The carrier fluid may also exhibit synergistic oil
screen plugging control properties when used in combination with the fuel additive
composition of this invention.
[0089] The carrier fluids are typically employed in amounts ranging from about 25 to about
5000 ppm by weight of the hydrocarbon fuel, preferably from 100 to 3000 ppm of the
fuel. Preferably, the ratio of carrier fluid to fuel additive will range from about
0.2:1 to about 10:1, more preferably from 0.5:1 to 3:1.
[0090] When employed in a fuel concentrate, carrier fluids will generally be present in
amounts ranging from about 20 to about 60 weight percent, preferably from 30 to 50
weight percent.
EXAMPLES
[0091] The following examples are presented to illustrate specific embodiments of the present
invention and synthetic preparations thereof and should not be interpreted as limitations
upon the scope of the invention.
Example 1
Preparation of Dodecylphenoxy Poly(oxypropylene) Amine
[0092] A dodecylphenoxypoly(oxypropylene) amine was prepared by the reductive amination
with ammonia a dodecylphenoxy poly(oxypropylene) alcohol having an average molecular
weight of about 1000. The dodecylphenoxypoly(oxypropylene) alcohol was prepared from
dodecylphenol and propylene oxide, in accordance with the procedures described in
U.S. Patent Nos. 4,191,537; 2,782,240 and 2,841,479, as well as in Kirk-Othmer, "Encyclopedia
of Chemical Technology", 4th edition, Volume 19, 1996, page 722. The reductive amination
of the dodecylphenoxypoly(oxypropylene) alcohol was carried out using conventional
techniques as described in U.S. Patent Nos. 5,112,364; 4,609,377 and 3,440,029.
Example 2
Preparation of Dodecylphenoxy Poly(oxypropylene) Amine
[0093] A dodecylphenoxypoly(oxypropylene) amine was prepared by the reductive animation
with ammonia a dodecylphenoxy poly(oxypropylene) alcohol having an average molecular
weight of about 1400. The dodecylphenoxypoly(oxypropylene) alcohol was prepared from
dodecylphenol and propylene oxide, in accordance with the procedures described in
U.S. Patent Nos. 4,191,537; 2,782,240 and 2,841,479, as well as in Kirk-Othmer, "Encyclopedia
of Chemical Technology", 4th edition, Volume 19, 1996, page 722. The reductive amination
of the dodecylphenoxypoly(oxypropylene) alcohol was carried out using conventional
techniques as described in U.S. Patent Nos. 5,112,364; 4,609,377 and 3,440,029.
Example 3
Preparation of Dodecylphenoxy Poly(oxybutylene) Amine
[0094] A dodecylphenoxypoly(oxybutylene) amine was prepared by the reductive amination with
ammonia of a dodecylphenoxy poly(oxybutylene) alcohol having an average molecular
weight of about 1600. The dodecylphenoxy poly(oxybutylene) alcohol was prepared from
dodecylphenol and butylene oxide, in accordance with the procedures described in U.S.
Patent Nos. 4,191,537; 2,782,240 and 2,841,479, as well as in Kirk-Othmer, "Encyclopedia
of Chemical Technology", 4th edition, Volume 19, 1996, page 722. The reductive amination
of the dodecylphenoxy poly(oxybutylene) alcohol was carried out using conventional
techniques as described in U.S. Patent Nos. 5,112,364; 4,609,377 and 3,440,029.
Example 4
Preparation of Dodecylphenoxy Poly(oxybutylene)poly(oxypropylene) Amine
[0095] A dodecylphenoxypoly(oxybutylene)poly(oxypropylene) amine was prepared by the reductive
amination with ammonia of the random copolymer poly(oxyalkylene) alcohol, dodecylphenoxy
poly(oxybutylene)poly(oxypropylene) alcohol, wherein the alcohol has an average molecular
weight of about 1598. The poly(oxyalkylene) alcohol was prepared from dodecylphenol
using a 75/25 weight/weight ratio of butylene oxide and propylene oxide, in accordance
with the procedures described in U.S. Patent Nos. 4,191,537; 2,782,240 and 2,841,479,
as well as in Kirk-Othmer, "Encyclopedia of Chemical Technology", 4th edition, Volume
19, 1996, page 722. The reductive amination of the poly(oxyalkylene) alcohol was carried
out using conventional techniques as described in U.S. Patent Nos. 5,112,364; 4,609,377
and 3,440,029.
Example 5
Preparation of Mannich Condensation Product
[0096] Phenol was combined with Glissopal 1000 polyisobutylene (about 950 molecular weight,
available from BASF) containing at least 70% material with methylvinylidene end groups,
in the presence of a BF
3-phenol catalyst, to produce a polyisobutylphenol that was essentially all mono-substituted
in the para-position. After BF
3 neutralization and removal and dilution with Exxon Aromatic 100 solvent, the diluted
polyisobutylphenol had a hydroxyl number of 40.3 mg KOH/g and a nonvolatile residue
content of 76.4%. The alkylation process, while the nonvolatile residue contained
7% unconverted polyisobutylene. 3232 g of the aforementioned diluted polyisobutylphenol
were charged to a 5-L glass reaction vessel equipped with an agitator, heating mantle,
overhead condenser, and Dean-Stark trap. With the reactor temperature at ambient (23°C),
240.6 g of diethylenetriamine (Baker Chemical Company, 99.38% assay) was charged to
the reactor and mixed to uniformity with the diluted polyisobutylphenol. The reactor
was then heated to 80°C over 30 minutes in preparation for formalin charging.
[0097] The formalin was from Baker Chemical Company and contained 37.3% formaldehyde, 12%
methanol, and 50.7% water. The formalin was charged over 150 minutes while continuing
to heat to 91-93°C. The temperature reached a maximum of 99°C during this heating
period due to the exothermic reaction with the formaldehyde. A temperature of 91-92°C
was held for 60 minutes to complete the initial reaction.
[0098] The reaction mixture was then heated to 150°C over 81 minutes and at the same time
the pressure was reduced to 240 mm Hg. Much of the water of reaction and some solvent
were distilled overhead and separated during the heating. Except for the solvent hold-up
in the Dean-Stark trap, the rest of the distilled solvent was continuously returned
to the reactor. The final conditions of 144-151°C and 233-243 mm Hg were held for
136 minutes to complete the reaction and removal of water.
[0099] The reaction yield was 3508 g of crude Mannich. After cooling the reactor contents
to 85°C, a sample of the crude Mannich gave a nonvolatile residue analysis of 82.0%.
The crude Mannich was then diluted with 1940 g of Exxon Aromatic 100 solvent. It was
then filtered using 36 g of Celite HyFlo Super Cel diatomaceous earth as body feed
and 16 g as a filter precoat. The yield of bright and clear filtrate was 5265 g.
The nonvolatile residue content of the filtered product was 51.9% and the nitrogen
content was 1.74%. The actives content was 50% based on the assumption that the unconverted
polyisobutylene in the nonvolatile residue is not an active dispersant.
Example 6
Multi-Cylinder Crankcase Harm Screening Test
[0100] The fuel additive composition of the present invention was tested in a laboratory
multi-cylinder engine to evaluate its performance in controlling oil screen plugging.
[0101] A 1994 Ford 2.3 liter single overhead cam, in-line four cylinder engine was used.
The major engine dimensions set forth in Table I. Each test was carried out for 80
hours (24 hours per day) on a prescribed test cycle, at the end of which the engine
was disassembled and the crankcase oil pick-up tube and screen assembly was removed.
The cycle for engine operation during the test is set forth in Table II. The oil pick-up
tube inlet screen was then evaluated using methodology described in Coordinating Research
Council Manual 12 (Sludge Rating Manual, CRC manual 12) to determine the percentage
of area clogged. A clean oil screen (free of sludge or debris) indicates favorable
crankcase performance. An oil screen with significant clogging indicates poor crankcase
performance.
[0103] The test compounds were admixed with the base fuel to give the concentrations indicated
in Table V. The percentage of oil screen plugging is also reported in Table V for
each of the test samples.

[0104] The data in Table V demonstrates that the combination of a polyoxyalkylene amine
and a Mannich condensation product has a beneficial effect and gives significantly
better control of oil screen plugging than the polyoxyalkylene amine component alone.
1. A fuel additive composition comprising:
(a) a Mannich condensation product of (1) a high molecular weight alkyl-substituted
hydroxyaromatic compound wherein the alkyl group has a number average molecular weight
of from about 300 to about 5,000 (2) an amine which contains an amino group having
at least one active hydrogen atom, and (3) an aldehyde, wherein the respective molar
ratio of reactants (1), (2) and (3) is 1:0.1-10:0.1-10; and
(b) a hydrocarbyl-substituted polyoxyalkylene amine having the formula:

or a fuel-soluble salt thereof;
wherein R is a hydrocarbyl group having from about 1 to about 30 carbon atoms;
one of R1 and R2 is methyl or ethyl and the other is hydrogen, and each R1 and R2 is independently selected in each -O-CHR1-CHR2- unit;
A is amino, N-alkyl amino having about 1 to about 20 carbon atoms in the alkyl group,
N,N-dialkyl amino having about 1 to about 20 carbon atoms in each alkyl group, or
a polyamine moiety having about 2 to about 12 amine nitrogen atoms and about 2 to
about 40 carbon atoms; and
x is an integer from about 5 to about 100;
and wherein the weight ratio of polyoxyalkylene amine to Mannich condensation product
is from about 0.5:1 to about 12:1.
2. The fuel additive composition according to Claim 1, wherein the alkyl group on the
alkyl-substituted hydroxyaromatic compound has a number average molecular weight of
about 400 to about 3,000.
3. The fuel additive composition according to Claim 2, wherein the alkyl group has a
number average molecular weight of about 500 to about 2,000.
4. The fuel additive composition according to Claim 3, wherein the alkyl group has a
number average molecular weight of about 700 to about 1,500.
5. The fuel additive composition according to Claim 1, wherein the alkyl-substituted
hydroxyaromatic compound is a polyalkylphenol.
6. The fuel additive composition according to Claim 6, wherein the polyalkylphenol is
polypropylphenol or polyisobutylphenol.
7. The fuel additive composition according to Claim 6, wherein the polyalkylphenol is
polyisobutylphenol.
8. The fuel additive composition according to Claim 7, wherein the polyisobutylphenol
is derived from polyisobutene containing at least about 70% methylvinylidine isomer.
9. The fuel additive composition according to Claim 1, wherein the amine component of
the Mannich condensation product is an alkylene polyamine having the formula:
H2N-(B-NH)m-H
wherein B is a divalent alkylene radical having 1 to about 10 carbon atoms and m is
an integer from 1 to about 10.
10. The fuel additive composition according to Claim 9, wherein the alkylene polyamine
is polyethylene polyamine.
11. The fuel additive composition according to Claim 10, wherein the polyethylene polyamine
is diethylene triamine.
12. The fuel additive composition according to Claim 1, wherein the aldehyde component
of the Mannich condensation product is formaldehyde, paraformaldehyde or formalin.
13. The fuel additive composition according to Claim 1, wherein R is an alkyl or alkylphenyl
group.
14. The fuel additive composition according to Claim 13, wherein R is an alkylphenyl group.
15. The fuel additive composition according to Claim 1, wherein one of R1 and R2 is methyl, and the other is hydrogen.
16. The fuel additive composition according to Claim 1, wherein x is an integer of from
about 5 to about 50.
17. The fuel additive composition according to Claim 16, wherein x is an integer of from
about 8 to about 30.
18. The fuel additive composition according to Claim 17, wherein x is an integer of from
about 10 to about 25.
19. The fuel additive composition according to Claim 1, wherein A is amino, N-alkylamino
or a polyamine moiety.
20. The fuel additive composition according to Claim 19, wherein A is amino or N-alkyl
amino having from about 1 to about 4 carbon atoms.
21. The fuel additive composition according to Claim 20, wherein A is amino.
22. The fuel additive composition according to Claim 19, wherein A is a polyamine moiety
having from about 2 to about 12 amine nitrogen atoms and from about 2 to about 40
carbon atoms.
23. The fuel additive composition according to Claim 22, wherein A is a polyamine moiety
derived from a polyalkylene polyamine containing from about 2 to about 12 amine nitrogen
atoms and from about 2 to about 24 carbon atoms.
24. The fuel additive composition according to Claim 23, wherein the polyalkylene polyamine
has the formula:
H2N-(R3-NH)z-H
wherein R3 is an alkylene group having from about 2 to about 6 carbon atoms and z is an integer
from about 1 to about 4.
25. The fuel additive composition according to Claim 24, wherein R3 is an alkylene group having from about 2 to about 4 carbon atoms.
26. The fuel additive composition according to Claim 24, wherein the polyalkylene polyamine
is ethylene diamine or diethylene triamine.
27. The fuel additive composition according to Claim 26, wherein the polyalkylene polyamine
is ethylene diamine.
28. The fuel additive composition according to Claim 1, wherein the weight ratio of polyoxyalkylene
amine to Mannich condensation product is from about 0.5:1 to about 3:1.
29. A fuel composition comprising a major amount of hydrocarbons boiling in the gasoline
or diesel range and an amount effective to control engine oil screen plugging of a
fuel additive composition as claimed in any preceding claim.
30. The fuel composition according to Claim 29, wherein the composition contains from
about 10 to about 2,000 ppm of the Mannich condensation product and from about 10
to about 2,000 ppm of the polyoxyalkylene amine.
31. The fuel composition according to Claim 29, wherein the composition further contains
from about 25 to 5,000 ppm by weight of a fuel-soluble, nonvolatile carrier fluid.
32. The fuel composition according to Claim 29, wherein the weight ratio of polyoxyalkylene
amine to Mannich condensation product is from about 0.5:1 to about 3:1.
33. A fuel concentrate comprising an inert stable oleophilic organic solvent boiling in
the range of from about 150°F to 400°F and from about 10 to about 70 weight percent
of a fuel additive composition as claimed in any one of claims 1 to 28.
34. The fuel concentrate according to Claim 33, wherein the concentrate further contains
from about 20 to about 60 weight percent of a fuel-soluble, nonvolatile carrier fluid.