[0001] This invention relates to fuel compositions and their use for internal combustion
engines which normally use low lead or unleaded gasoline. The fuels are further characterized
as containing an alcohol.
[0002] The removal of lead additives, such as tetraethyl lead, from gasoline in order to
reduce air pollution has led to several problems. It was found that the lead not only
acted as an anti-knock agent, but was also effective in the prevention of valve seat
recession. The exhaust valves in internal combustion engines generally seat against
the valve seat with a slight rotary motion. The rotary motion is imparted to the valve
stem during its operation to shift the relative position of the valve and to prevent
uneven wear on the valve tip. With the elimination of lead additives from gasoline,
it was found that a dramatic increase in the wear of the valve seats occurs. For example,
see Unleaded Versus Leaded Fuel Results in Laboratory Engine Tests, E. J. Fuchs, The
Lubrizol Corporation, presented at the Society of Automotive Engineers, National West
Coast Meeting, Vancouver, British Columbia, August 16-19, 1971 (32 pages).
[0003] Because valve seat wear is a function of engine design, load, speed conditions and
operating temperature it is highly desirable that a replacement for lead be employed.
The use of a lead replacement for minimizing valve seat recession is complicated by
the fact that a number of newer vehicles do not require lead additives. A number of
fuels on the market contain lower levels of lead and still other fuels are essentially
lead-free. It is further observed that alcohol-containing fuels such as gasohol or
fuels containing alcohols used to boost octane rating are also widely marketed. It,
therefore, becomes desirable to obtain a gasoline composition containing a lead replacement
which is capable of functioning in a multitude of gasoline based fuels.
[0004] Set out below are various references to fuels containing lead replacements and gasoline
additives. U.S. Patent No. 2,764,548 describes motor oils and motor fuels containing
various salts of dinonylnaphthalene sulfonic acid including the sodium, potassium,
calcium, barium, ammonium and amine salts. The salts are reported to be effective
rust inhibitors. U.S. Patent 3,506,416 describes leaded gasolines containing gasoline
soluble salts of a hydroxamic acid of the formula RC(O)NHOH where R is a hydrocarbon
group containing up to 30 carbon atoms. The metal may be selected from the Group Ia,
IIa, IIIa, Va, Ib, IIb, IIIb, IVb, Vb, VIb, VIIb, VIII and tin. U.S. Patent 3,182,019,
describes lubricating and fuel oils including complexes which contain an alkali or
alkaline earth metal carbonate in colloidal form.
[0005] The use of sodium in lead-free gasoline compositions for inhibiting valve seat recession
is suggested in U.S. Patent 3,955,938. The sodium may be incorporated into the fuel
in a number of different forms such as sodium derivatives of organic compounds which
are soluble, or dispersed in the gasoline. For example, simple sodium salts of an
organic acid such as sodium petroleum sulfonate can be utilized although the sodium
preferentially is added in the form of a sodium salt of an inorganic acid such as
sodium carbonate in a colloidal dispersion in oil. Other convenient forms for introducing
sodium into the fuel which are described in U.S. Patent 3,955,938 include various
sodium salts of sulfonic acids, sodium salts of saturated and unsaturated carboxylic
acids, sodium salts of phospho-sulfurized hydrocarbons such as may be prepared by
reacting P₂S₅ with petroleum fractions such as bright stock, and sodium salts of phenols
and alkylphenols. Various optional additives described include corrosion inhibitors,
rust inhibitors, anti-knock compounds, anti-oxidants, solvent oils, anti-static agents,
octane appreciators, e.g. t-butyl acetate, dyes, anti-icing agents, e.g. isopropanol,
hexyleneglycol, ashless dispersants, detergents, and the like. The amount of sodium
additive included in the fuel is an amount to provide from 1.43 to 57.2 preferably
1.43 to 28.6 g sodium per 1000 l (0.5 to 20, preferably 0.5 to 10 lbs. of sodium per
1000 barrels) of gasoline (2.86g/1000 liters is 1 lb/1000 bbl).
[0006] It also has been suggested that gasoline compositions can be improved by including
certain detergents and dispersants. U.S. Patent 3,443,918 describes the addition to
gasoline of mono-, bis-, or tris-alkenyl succinimides of a bis- or tris-polymethylene
polyamine. These additives are reported to minimize harmful deposit formation when
the fuels are used in internal combustion engines.
[0007] U.S. Patent Nos. 3,172,892; 3,219,666 3,272,746; 3,281,428 and 3,444,170 are directed
to polyalkenyl succinic type ashless additives, and the '170 patent teaches the use
of the additive disclosed therein as a fuel detergent. U.S. Patent No. 3,347,645 also
describes the use of alkenyl succinimides as dispersants in gasoline, but it is there
noted that the dispersants promote aqueous emulsion formation during storage and shipping.
U.S. Patent No. 3,649,229 teaches a fuel containing a detergent amount of a Mannich
base prepared using, among other reactants, an alkenyl succinic compound. U.S. Patent
4,240,803 also relates to hydrocarbon fuel compositions containing a detergent amount
of a specific alkenyl succinimide wherein the alkenyl group is derived from a mixture
of C16-28 olefins.
[0008] U.S. Patent 4,659,338 discloses compositions containing a hydrocarbon-soluble alkali
or alkaline earth metal-containing composition and a hydrocarbon-soluble ashless dispersant.
The Johnston compositions are useful for preventing valve seat recession.
[0009] British published patent application 2,177,418A discloses gasoline compositions containing
a succinic acid derivative containing from 20 to 200 carbon atoms.
[0010] U.S. Patent 4,708,809 discloses lubricants suitable for two-cycle engines. It is
further known from U.S. Patent 4,690,687 that deposit formation within the cylinders
may be avoided through a variety of means.
[0011] It has been observed that when hydrocarbon-soluble alkali metal or alkaline earth
metal-containing compositions in an oxygenated fuel (alcohol-containing) are contacted
with water that emulsions may form.
[0012] The present invention deals with compositions which are formulated to avoid emulsion/deemulsification
problems arising from the presence of water in a gasoline composition.
[0013] Throughout the specification and claims, percentages and ratios are by weight, temperatures
are in degrees Celsius and pressures are in KPascals unless otherwise indicated. Percentages
and ratios of components are considered exemplary and may be combined.
[0014] The present invention describes a fuel composition comprising:
(A) at least one hydrocarbon-soluble or dispersible neutral or basic alkali metal
or alkaline earth metal containing composition,
(B) at least one member selected from the group consisting of
(i) a hydrocarbyl substituted sulfonated phenol or salt thereof;
(ii) an ethylene oxide/propylene oxide copolymer, and
(iii) a hydrocarbyl substituted phenol, including hydrocarbyl substituted phenols
alkoxylated at the hydroxyl group, provided that the hydrocarbyl moiety comprises
10 to 30 carbon atoms when the hydroxyl group is substituted by an ethylene oxide
polymer, and
(iv) mixtures of any of (i), (ii) and (iii),
(C) gasoline, and
(D) at least one alcohol.
A further embodiment of the invention is a fuel composition as defined above comprising
additionally:
(E) at least one ashless dispersant selected from the group consisting of:
(i) at least one hydrocarbyl-substituted amine wherein the hydrocarbyl substituent
is substantially aliphatic and contains at least 8 carbon atoms;
(ii) at least one acylated, nitrogen-containing compound having a substituent of at
least 10 aliphatic carbon atoms producible by reacting a carboxylic acid acylating
agent with at least one amino compound containing at least one
-NH-
group, said acylating agent being linked to said amino compound through an imido,
amido, amidine, or acyloxy ammonium linkage;
(iii) at least one nitrogen-containing condensate of a phenol or aldehyde and an amino
compound having at least one
-NH-
group;
(iv) at least one ester of a substituted carboxylic acid;
(v) at least one polymeric dispersant;
(vi) at least one hydrocarbon substituted phenolic dispersant; and
(vii) at least one fuel soluble alkoxylated derivative of an alcohol, phenol, or amine.
[0015] A still further embodiment of the present invention is the use of said fuel composition
to minimize valve seat recession in internal combustion engines and to enhance water
tolerance to a vehicle fuel tank
[0016] The following describes the components, processing and use of the compositions of
the present invention.
THE ALKALI or ALKALINE EARTH METAL-CONTAINING COMPOSITION
[0017] The fuel compositions of the present invention will contain a minor amount of (A)
at least one hydrocarbon-soluble alkali or alkaline earth metal-containing composition.
The presence of such metal-containing compositions in the fuel compositions of the
present invention provides the fuel composition with a desirable ability to prevent
or minimize valve seat recession in internal combustion engines, particularly when
the fuel is an unleaded or low-lead fuel. The choice of the metal does not appear
to be particularly critical although alkali metals are preferred, with sodium or potassium
being the preferred alkali metals.
[0018] The metal-containing composition (A) may be alkali metal or alkaline earth metal
salts of sulfur acids, carboxylic acids, phenols and phosphorus acids. These salts
can be neutral or basic. The former contain an amount of metal cation just sufficient
to neutralize the acidic groups present in salt anion; the latter contain an excess
of metal cation and are often termed overbased. These basic and neutral salts can
be of oil-soluble organic sulfur acids such as sulfonic, sulfamic, thiosulfonic, sulfinic,
sulfenic, partial ester sulfuric, sulfurous and thiosulfuric acid. Generally they
are salts of aliphatic or aromatic sulfonic acids.
[0019] The sulfonic acids include the mono- or poly-nuclear aromatic or cycloaliphatic compounds.
The sulfonic acids can be represented for the most part by the following general formulae:
R¹(SO₃H)
r Formula I
(R²)
xT(SO₃H)
y Formula II
in which T is an aromatic or cyclic nucleus such as, for example, benzene, naphthalene,
anthracene, phenanthrene, diphenylene oxide, thianthrene, phenothioxine, diphenylene
sulfide, phenothiazine, diphenyl oxide, diphenyl sulfide, diphenylamine, cyclohexane,
petroleum naphthenes, decahydronaphthalene or cyclopentane; R¹ and R² are each independently
aliphatic groups, R¹ contains at least about 15 carbon atoms, the sum of the carbon
atoms in R² and T is at least about 15, and r, x and y are each independently 1 or
greater.
[0020] Specific examples of R¹ are groups derived from petrolatum, saturated and unsaturated
paraffin wax, and polyolefins, including polymerized C₂, C₃, C₄, C₅, C₆, etc., olefins
containing from about 15 to 7000 or more carbon atoms. The groups T, R¹ and R² in
the above formulae can also contain other inorganic or organic substituents in addition
to those enumerated above such as, for example, hydroxy, mercapto, halogen, nitro,
amino, nitroso, sulfide or disulfide. The subscript x is generally 1-3, and the subscripts
r + y generally have an average value of about 1-4 per molecule.
[0021] The following are specific examples of oil soluble sulfonic acids coming within the
scope of Formulae I and II above, and it is to be understood that such examples serve
also to illustrate the salts of such sulfonic acids useful in this invention. In other
words, for every sulfonic acid enumerated it is intended that the corresponding neutral
and basic metal salts thereof are also understood to be illustrated. Such sulfonic
acids are mahogany sulfonic acids; bright stock sulfonic acids; sulfonic acids derived
from lubricating oil fractions having a Saybolt viscosity from about 100 seconds at
100°F (37.7°C) to about 200 seconds at 210°F (99°C); petrolatum sulfonic acids; mono-
and poly-wax substituted sulfonic and polysulfonic acids of, e.g., benzene, diphenylamine,
thiophene or alpha-chloronaphthalene; other substituted sulfonic acids such as alkyl
benzene sulfonic acids (where the alkyl group has at least 8 carbons), cetylphenol
mono-sulfide sulfonic acids, dicetyl thianthrene disulfonic acids, dilauryl beta naphthyl
sulfonic acids, and alkaryl sulfonic acids such as dodecyl benzene "bottoms" sulfonic
acids.
[0022] The latter are acids derived from benzene which has been alkylated with propylene
tetramers or isobutene trimers to introduce 1, 2, 3 or more branched-chain C₁₂ substituents
on the benzene ring. Dodecyl benzene bottoms, principally mixtures of mono- and di-dodecyl
benzenes, are available as by-products from the manufacturer of household detergents.
Similar products obtained from alkylation bottoms formed during manufacture of linear
alkyl sulfonates (LAS) are also useful in making the sulfonates used in this invention.
[0023] The production of sulfonates from detergent manufacture by-products by reaction with,
e.g., SO₃, is well known to those skilled in the art. See, for example, the article
"Sulfonates" in Kirk-Othmer "Encyclopedia of Chemical Technology", Second Edition,
Vol. 19, pp. 291 et seq. published by John Wiley & Sons, N.Y. (1969).
[0024] Other descriptions of neutral and basic sulfonate salts and techniques for making
them can be found in the following U.S. Patents: 2,174,110; 2,174,506; 2,174,508;
2,193,824; 2,197,800; 2,202,781; 2,212,786; 2,213,360; 2,228,598; 2,223,676; 2,239,974;
2,263,312; 2,276,090; 2,276,097; 2,315,514; 2,319,121; 2,321,022; 2,333,568; 2,333,788;
2,335,259; 2,337,552; 2,347,568; 2,366,027; 2,374,193; 2,383,319; 3,312,618; 3,471,403;
3,488,284; 3,595,790 and 3,798,012.
[0025] With respect to the sulfonic acids or salts thereof described herein and in the appended
claims, it is intended herein to employ the term "petroleum sulfonic acids" or "petroleum
sulfonates" to cover all sulfonic acids or the salts thereof derived from petroleum
products. A particularly valuable group of petroleum sulfonic acids are the mahogany
sulfonic acids (so called because of their reddish-brown color) obtained as a by-product
from the manufacturer of petroleum white oils by a sulfuric acid process.
[0026] The carboxylic acids from which suitable neutral and basic alkali metal and alkaline
earth metal salts for use in this invention can be made include aliphatic, cycloaliphatic,
and aromatic mono and polybasic carboxylic acids such as the naphthenic acids, alkyl-
or alkenyl-substituted cyclopentanoic acids, the corresponding cyclohexanoic acids
and the corresponding aromatic acids. The aliphatic acids generally contain at least
eight carbon atoms and preferably at least twelve carbon atoms. Usually they have
no more than about 400 carbon atoms. Generally, if the aliphatic carbon chain is branched,
the acids are more oil soluble for any given carbon atom content. The cycloaliphatic
and aliphatic carboxylic acids can be saturated or unsaturated. Specific examples
include 2-ethylhexanoic acid, alpha-linolenic acid, behenic acid, isostearic acid,
pelargonic acid, capric acid, palmitoleic acid, linoleic acid, lauric acid, oleic
acid, ricinoleic acid, undecylic acid, dioctylcyclopentane carboxylic acid, myristic
acid, dilauryldecahydronaphthalene carboxylic acid, stearyl-octahydroindene carboxylic
acid, palmitic acid, commercially available mixtures of two or more carboxylic acids
such as tall oils acids or rosin acids. A group of oil-soluble carboxylic acids useful
in preparing the salts used in the present invention are the oil-soluble aromatic
carboxylic acids. These acids are represented by the general formula:
(R*)
aAr*(CXXH)
m Formula III
where R* is a hydrocarbyl (preferably aliphatic hydrocarbon-based) group of at least
four carbon atoms, and no more than about 400 aliphatic carbon atoms, a is an integer
of from one to four, Ar* is a polyvalent aromatic hydrocarbon nucleus of up to about
14 carbon atoms, each X is independently a sulfur or oxygen atom, and m is an integer
of from one to four with the proviso that R* and a are such that there is an average
of at least 8 aliphatic carbon atoms provided by the R* groups for each acid molecule
represented by Formula III. Examples of aromatic nuclei represented by the variable
Ar* are the polyvalent aromatic radicals derived from benzene, naphthalene, anthracene,
phenanthrene, indene, fluorene or biphenyl. Generally, the radical represented by
Ar* will be a polyvalent nucleus derived from benzene or naphthalene such as phenylenes
and naphthalene, e.g., methyl-phenylenes, ethoxyphenylenes, nitrophenylenes, isopropyl-phenylenes,
hydroxyphenylenes, mercaptophenylenes, N,N-diethylaminophenylenes, chlorophenylenes,
dipropoxynaphthylenes, triethylnaphthylenes, and similar tri-, tetra- or pentavalent
nuclei thereof.
[0027] The R* groups are usually purely hydrocarbon groups, preferably groups such as alkyl
or alkenyl radicals. However, the R* groups can contain a small number of substituents
such as phenyl, cycloalkyl (e.g., cyclohexyl, cyclopentyl, etc.) and nonhydrocarbon
groups such as nitro, amino, halo (e.g., chloro, bromo, etc.) lower alkoxy, lower
alkyl mercapto, oxo substituents (i.e.,=O), thio groups (i.e.,=S), interrupting groups
such as -NH-, -O- or -S- provided the essentially hydrocarbon character of the R*
group is retained. The hydrocarbon character is retained for purposes of this invention
so long as any non-carbon atoms present in the R* group do not account for more than
about 10% of the total weight of the R* groups.
[0028] Examples of R* groups include butyl, isobutyl, pentyl, octyl, nonyl, dodecyl, docosyl,
tetracontyl, 5-chlorohexyl, 4-ethoxypentyl, 2-hexenyl, cyclohexyloctyl, 4-(p-chlorophenyl)-octyl,
2,3,5-trimethylheptyl, 2-ethyl-5-methyloctyl, and substituents derived from polymerized
olefins such as polychloroprenes, polyethylenes, polypropylenes, polyisobutylenes,
ethylene-propylene copolymers, chlorinated olefin polymers or oxidized ethylene-propylene
copolymers. Likewise, the group Ar* may contain non-hydrocarbon substituents, for
example, such diverse substituents as lower alkoxy, lower alkyl mercapto, alkyl or
alkenyl groups of less than four carbon atoms, nitro, halo, hydroxy or mercapto.
[0029] A group of particularly useful carboxylic acids are those of the general formula:
R*
aAr* (CXXH)
m(XH)
p Formula IV
where R*, X, Ar*, m and a are as defined in Formula III and p is an integer of 1 to
4, usually 1 or 2. Within this group, an especially preferred class of oil-soluble
carboxylic acids are those of the general formula:
(R**)
aPh(COOH)
b(OH)
c Formula V
where R** in Formula V is an aliphatic hydrocarbon group containing at least 4 to
about 400 carbon atoms, Ph is a phenyl group, a is an integer of from 1 to 3, b is
1 or 2, c is zero, 1, or 2 and preferably 1 with the proviso that R** and a are such
that the acid molecules contain at least an average of about twelve aliphatic carbon
atoms in the aliphatic hydrocarbon substituents per acid molecule. And within this
latter group of oil-soluble carboxylic acids, the aliphatic-hydrocarbon substituted
salicylic acids wherein each aliphatic hydrocarbon substituent contains an average
of at least about sixteen carbon atoms per substituent and one to three substituents
per molecule are particularly useful. Salts prepared from such salicylic acids wherein
the aliphatic hydrocarbon substituents are derived from polymerized olefins, particularly
polymerized lower 1-mono-olefins such as polyethylene, polypropylene, polyisobutylene
or ethylene/propylene co-polymers and having average carbon contents of about 30 to
400 carbon atoms are also useful.
[0030] The carboxylic acids corresponding to Formulae III and IV above are well known or
can be prepared according to procedures known in the art. Carboxylic acids of the
type illustrated by the above formulae and processes for preparing their neutral and
basic metal salts are well known and disclosed, for example, in such U.S. Patents
as 2,197,832; 2,197,835; 2,252,662; 2,252,664; 2,714,092; 3,410,798 and 3,595,791.
[0031] Another type of neutral and basic carboxylate salt used in this invention are those
derived from alkenyl succinates of the general formula:
R*CH(COOH)CH₂COOH Formula VI
wherein R* is as defined above in Formula III. Such salts and means for making them
are set forth in U.S. Patents 3,271,130; 3,567,637 and 3,632,610. Generally, the molecular
weight of the polybasic carboxylates (polycarboxylates) will be about 400 to about
2000, preferably about 500 to about 1500. Such molecular weights will correspond to
about 28 to about 145, preferably about 35 to about 110 carbon atoms in the hydrocarbon
chain of the molecule. One such acid is propylene tetramer-substituted maleic acid.
Other patents specifically describing techniques for making basic salts of the hereinabove-described
sulfonic acids, carboxylic acids, and mixtures of any two or more of these include
U.S. Patent Nos. 2,501,731; 2,616,904; 2,616,905; 2,616,906; 2,616,911; 2,616,924;
2,616,925; 2,617,049; 2,777,874; 3,027,325; 3,256,186; 3,282,835; 3,384,585; 3,373,108;
3,368,396; 3,342,733; 3,320,162; 3,312,618; 3,318,809; 3,471,403; 3,488,284; 3,595,790
and 3,629,109.
[0032] Neutral and basic salts of phenols (generally known as phenates) are also useful
in the compositions of this invention and well known to those skilled in the art.
The phenols from which these phenates are formed are of the general formula:
(R*)
a-(Ar*)-(OH)
m Formula VII
wherein R*, a, Ar*, and m have the same meaning and preferences as described hereinabove
with reference to Formula III. The same examples described with respect to Formula
III also apply.
[0033] The commonly available class of phenates are those made from phenols of the general
formula:
(R')
a (R⁴)
z Ph(OH)
b Formula VIII
wherein a is an integer of 1-3, b is 1 or 2, z is 0 or 1, Ph is a phenyl group, R'
in Formula VIII is a substantially saturated hydrocarbon-based substituent having
an average of from about 30 to about 400 aliphatic carbon atoms and R⁴ is selected
from the group consisting of lower alkyl, lower alkoxyl, nitro, and halo groups.
[0034] One particular class of phenates for use in this invention are the basic (i.e., e.g.
overbased) alkali and alkaline earth metal sulfurized phenates made by sulfurizing
a phenol as described hereinabove with a sulfurizing agent such as sulfur, a sulfur
halide, or sulfide or hydrosulfide salt. Techniques for making these sulfurized phenates
are described in U.S. Patents 2,680,096; 3,036,971 and 3,775,321.
[0035] Other phenates that are useful are those that are made from phenols that have been
linked through alkylene (e.g., methylene) bridges. These are made by reacting single
or multi-ring phenols with aldehydes or ketones, typically, in the presence of an
acid or basic catalyst. Such linked phenates as well as sulfurized phenates are described
in detail in U.S. Patent 3,350,038; particularly columns 6-8 thereof.
[0036] Alkali and alkaline earth metal salts of phosphorus acids also are useful in the
fuel compositions of the invention. Examples, are the normal and basic salts of the
phosphonic and/or thiophosphonic acids prepared by reacting inorganic phosphorus reagents
such as P₂S₅ with petroleum fractions such as bright stock or polyolefins obtained
from olefins of 2 to 6 carbon atoms. Particular examples of the polyolefins are polybutenes
having a molecular weight of from 700 to 100,000. Other phosphorus-containing reagents
which have been reacted with olefins include phosphorus trichloride or phosphorus
trichloride-sulfur chloride mixture, (e.g., U.S. Patent Nos. 3,001,981 and 2,195,517),
phosphites and phosphite chlorides (e.g., U.S. Patent Nos. 3,033,890 and 2,863,834),
and air or oxygen with a phosphorus halide (e.g., U.S. Patent No. 2,939,841).
[0037] Mixtures of two or more neutral and basic salts of the hereinabove described organic
sulfur acids, carboxylic acids, phosphorus acids and phenols can be used in the compositions
of this invention. As mentioned above, the amount of alkali or alkaline earth metal
containing composition (A) included in the fuel composition will be an amount which
is sufficient to provide from about 1 to about 100 parts per million of the alkali
metal or alkaline earth metal in the fuel composition. When utilized in lead free
or low lead fuels, the amount of alkali metal or alkaline earth metal-containing composition
(A) included in the fuel is an amount which is sufficient to reduce valve seat recession
when the fuel is used in an internal combustion engine.
[0038] The following specific illustrative examples describe the preparation of exemplary
alkali and alkaline earth metal compositions (A) useful in the fuel compositions of
this invention.
Example A-1
[0039] A mixture of 1000 parts of a primary branched monoalkyl benzene sulfonic acid (M.W.,
approximately 522) in 637 parts of mineral oil is neutralized with 145.7 parts of
a 50% caustic soda solution and the excess water and caustic removed. The product
containing the sodium salt obtained in this manner contains 2.5% sodium and 3.7% sulfur.
Example A-2
[0040] The procedure of Example A-1 is repeated except that the caustic soda is replaced
by a chemically equivalent amount of Ca(OH)₂.
Example A-3
[0041] The procedure of Example A-1 is repeated except that the caustic soda is replaced
by a chemically equivalent amount of KOH.
Example A-4
[0042] A mixture of 906 parts of an alkyl phenyl sulfonic acid (having an average molecular
weight of 450, vapor phase osmometry), 564 parts mineral oil, 600 parts toluene, 98.7
parts magnesium oxide and 120 parts water is blown with carbon dioxide at a temperature
of 78-85°C for seven hours at a rate of about 3 cubic feet of carbon dioxide per hour
(85 l/hr). The reaction mixture is constantly agitated throughout the carbonation.
After carbonation, the reaction mixture is stripped to 165°C/20 torr (2.65 KPa) and
the residue filtered. The filtrate is an oil solution of the desired overbased magnesium
sulfonate having a metal ratio of about 3.
Example A-5
[0043] A mixture of 323 parts of mineral oil, 4.8 parts of water, 0.74 parts of calcium
chloride, 79 parts of lime, and 128 parts of methyl alcohol is prepared, and warmed
to a temperature of about 50°C. To this mixture there is added with mixing, 1000 parts
of an alkyl phenyl sulfonic acid having an average molecular weight (vapor phase osmometry)
of 500. The mixture then is blown with carbon dioxide at a temperature of about 50°C
at the rate of about 5.4 lbs. per hour (40.8g/minute) for about 2.5 hours. After carbonation,
102 additional parts of oil are added and the mixture is stripped of volatile materials
at a temperature of about 150-155°C at 55 mm (7.3 KPa) pressure. The residue is filtered
and the filtrate is the desired oil solution of the overbased calcium sulfonate having
calcium content of about 3.7% and a metal ratio of about 1.7.
THE WATER FIX
[0044] The second component of the composition of invention (B) is at least one member selected
from the group consisting of:
(i) a hydrocarbyl substituted sulfonated phenol or salt thereof;
(ii) an ethylene oxide/propylene oxide copolymer, and
(iii) a hydrocarbyl substituted phenol, or
(iv) mixtures of (i), (ii) and (iii).
[0045] Component (B)(i) may be obtained by preparing the sulfonic acid of (B)(iii) or the
salt of the sulfonic acid of B (iii). An ample disclosure of the sulfonic acids and
sulfonates is found in the description of component (A). The cationic portion of (B)(i)
is preferably ammonium. When a phenol is employed as the aromatic nucleus in (A),
the hydrocarbyl substituted phenol sulfonic acid or salt (B)(i) is obtained.
[0046] The second item (B)(ii) is an ethylene oxide/propylene oxide copolymer. Such materials
are well known in the art and are obtained by reacting ethylene oxide or a polymer
of ethylene oxide with propylene oxide or a polymer of propylene oxide. It is first
possible to obtain a random polymer of ethylene oxide and propylene oxide by simply
charging the desired quantities of each material and conducting the polymerization
as is known in the art. It is also possible to prepolymerize ethylene oxide to a desired
chain length and then to further react the ethylene oxide prepolymer by capping with
propylene oxide.
[0047] It is further possible to polymerize the propylene oxide to the desired molecular
weight and to then terminate the propylene oxide polymer with ethylene oxide. Of course,
the propylene oxide may be polymerized and then reacted with an ethylene oxide polymer.
The molecular weight of (B)(ii) is conveniently 400 to 10,000, preferably 600 to 5,000.
[0048] It is desirable that the amount of the ethylene oxide in the copolymer is from 10
to 90 weight percent, preferably 15 to 90 percent by weight of the copolymer. It is,
of course, recognized that as ethylene oxide has a lower molecular weight than propylene
oxide that a greater number of equivalents of ethylene oxide will be utilized on a
equivalent basis than of the propylene oxide.
[0049] Component (B)(iii) is a hydrocarbon substituted phenol. The hydrocarbon substituted
phenol generally corresponds to component (B)(i) the hydrocarbyl substituted sulfonated
phenol or salt thereof. Thus, component (B) (iii) is usually the raw material for
component (B) (i) and is commercially available. When mixtures of (B) (i) and (B)
(iii) are desired, it is possible to under-sulfonate the hydrocarbon substituted phenol.
Either of components (B)(i) or (iii) will typically contain about 10 to about 30 carbon
atoms on the hydrocarbyl chain on average, preferably about 14 to about 26 carbon
atoms.
[0050] The hydrocarbyl substituted phenol may also be crosslinked through the use of formaldehyde
to give a polymeric structure. That is, the hydrocarbyl substituted phenol is crosslinked
at the ortho (and often para position) to the hydroxyl groups. It is further possible
to alkoxylate the phenol. In this regard, the reader's attention is directed to the
discussion of ethylene oxide and propylene oxide given above. Each of the foregoing
materials may be condensed onto the hydroxyl group of the phenol whether polymeric
or monomeric.
[0051] It is further possible, as component (B)(iv), to utilize a mixture of any of the
foregoing components designated as component (B). A preferred species of component
(B) is, in fact, such a mixture.
[0052] When component (B) is (iv), it is desired that the weight ratio of component (B)(i)
to (B)(ii) is from about 10:1 to about 1:10, preferably about 5:1 to about 1:5. The
weight ratio of (B)(i) to (B)(iii) is typically from about 8:1 to about 1:8, preferably
about 5:1 to about 1:5. The desired ratio of component (B)(ii) to (iii) is typically
about 7:1 to about 1:7, preferably about 4:1 to about 1:4. When two of the three individual
components of (B) are employed, the ratios are also as described above.
THE GASOLINE COMPONENT
[0053] The gasoline component (C) useful in the present invention is obtained as a hydrocarbon
distillate. Gasolines are supplied in a number of different grades depending on the
type of service for which they are intended. The gasolines utilized in the present
invention include those designed as motor and aviation gasolines. Motor gasolines
include those defined by ASTM specification D-439-73 and are composed of a mixture
of various types of hydrocarbons including aromatics, olefins, paraffins, isoparaffins,
naphthenes and occasionally diolefins. Motor gasolines normally have a boiling range
within the limits of about 20°C to 230°C while aviation gasolines have narrower boiling
ranges, usually within the limits of about 37°C to 165°C.
[0054] The gasoline may have any of the typically added ingredients provided that there
are no adverse effects to obtaining performance for valve seat recession, obtaining
the desired water fix, and which do not cause a substantial reduction of the octane
value of the gasoline.
[0055] One such ingredient which is typically included in gasoline is lead in the form of
a compound such as tetraethyl lead or tetramethyl lead. It is first noted that lead
is being regulated out of gasoline in many countries. Those countries still allowing
some amounts of lead in the gasoline allow "low-lead" formulations. Typically, a low-lead
gasoline contains less than about 0.5 gram of lead per gallon of fuel (0,13 g/liter).
This invention is concerned in one aspect with low-lead fuels containing as little
as 0.1 gram of lead per gallon (0.026 g/liter) of gasoline.
[0056] It is further preferred in the present invention that the gasoline be lead-free.
By lead-free it is meant that small trace amounts of lead, significantly less than
the amounts in a low-lead fuel, are tolerated. That is, no-lead or lead-free gasoline
compositions occasionally contain trace amounts of lead due to contamination by leaded
fuels. Thus, the term no-lead or lead-free gasolines includes very small amounts of
lead; however, it is preferred that the end gasoline product be completely lead-free.
[0057] A further typical ingredient which is included with gasoline is a scavenger to remove
or reduce engine deposits. Typically, the scavenger will be ethylene dichloride or
ethylene dibromide or mixtures thereof. For a further discussion of scavengers useful
in the compositions of the present invention, the reader is directed to U.S. Patent
4,690,687
THE ALCOHOL
[0058] Alcohols (D) which are used in the present invention are typically those which are
normally added to gasoline. The use of alcohols in gasolines is primarily for three
purposes. The first purpose is as a partial fuel substitute for the hydrocarbons present
in the gasoline to extend the supply of the petroleum hydrocarbons. In this regard,
methanol and ethanol are typically utilized as partial replacements for the hydrocarbon
source in gasoline.
[0059] The second group of alcohols often used in fuels are those alcohols which have utility
as an octane enhancer. Typically, the octane enhancer alcohols will be materials such
as methanol, ethanol, isopropanol, t-amyl alcohol and t-butanol. Such alcohols aid
in the combustion of the hydrocarbon source and promote the clean burning of the fuel
in the internal combustion engine cylinders, thereby increasing power output.
[0060] The third use of alcohols in gasoline is to reduce levels of certain emissions. Such
emissions include evaporative or exhaust emissions which lead to photo-chemical smog.
The alcohols described inmediately above have such uses.
[0061] Overall, the alcohols which are typically employed in the present invention contain
up to about 8 carbon atoms, preferably from about 1 to about 6 carbon atoms. The preferred
alcohols for gasohol production are methanol and ethanol. The preferred alcohols for
octane enhancement are tertiary alcohols. Thus, t-butanol is a preferred octane enhancer.
An especially preferred combination of alcohols for use in octane enhancement is a
mixture of t-butanol and methanol, particularly in a weight ratio to one another of
10:1 to 1:10, preferably about 5:1 to about 1:5.
[0062] The level of usage of the alcohols in the present invention is typically from about
0.1 percent to about 45 percent by weight of the total gasoline composition. More
typically, the amount of alcohol present will be from about 0.5 percent to about 15
percent by weight of the total gasoline composition.
[0063] The preferred alcohols for use in gasoline compositions of the present invention
are monohydric alcohols.
THE DISPERSANT
[0064] The fuel compositions of the present invention desirably also contain a minor amount
of (E) at least one hydrocarbon soluble ashless dispersant. The compounds useful as
ashless dispersants generally are characterized by a "polar" group attached to a relatively
high molecular weight hydrocarbon chain. The "polar" group generally contains one
or more of the elements nitrogen, oxygen and phosphorus. The solubilizing hydrocarbon
chains are generally higher in molecular weight than those employed with the metallic
types, but in some instances they may be quite similar.
[0065] In general, any of the ashless dispersants which are known in the art for use in
lubricants and fuels can be utilized in the fuel compositions of the present invention.
[0066] In one embodiment of the present invention, the dispersant is selected from the group
consisting of
(i) at least one hydrocarbyl-substituted amine wherein the hydrocarbyl substituent
is substantially aliphatic and contains at least 8 carbon atoms;
(ii) at least one acylated, nitrogen-containing compound having a substituent of at
least 10 aliphatic carbon atoms producible by reacting a carboxylic acid acylating
agent with at least one amino compound containing at least one
-NH-
group, said acylating agent being linked to said amino compound through an imido,
amido, amidine, or acyloxy ammonium linkage;
(iii) at least one nitrogen-containing condensate of a phenol, aldehyde and amino
compound having at least one
-NH-
group;
(iv) at least one ester of a substituted carboxylic acid;
(v) at least one polymeric dispersant;
(vi) at least one hydrocarbon substituted phenolic dispersant; and
(vii) at least one fuel soluble alkoxylated derivative of an alcohol, phenol or amine.
[0067] The following specific examples illustrate the preparation of exemplary dispersants
useful in the fuel compositions of this invention.
Example E-1
[0068] A mixture of 1500 parts of chlorinated poly(isobutene) having a molecular weight
of about 950 and a chlorine content of 5.6%, 285 parts of an alkylene polyamine having
an average composition corresponding stoichiometrically to tetraethylene pentamine
and 1200 parts of benzene is heated to reflux. The temperature of the mixture is then
slowly increased over a 4-hour period to 170°C while benzene is removed. The cooled
mixture is diluted with an equal volume of mixed hexanes and absolute ethanol (1:1).
The mixture is heated to reflux and 1/3 volume of 10% aqueous sodium carbonate is
added to the mixture. After stirring, the mixture is allowed to cool and phase separate.
The organic phase is washed with water and stripped to provide the desired polyisobutenyl
poly-amine having a nitrogen content of 4.5% by weight.
Example E-2
[0069] A mixture of 140 parts of toluene and 400 parts of a polyisobutenyl succinic anhydride
(prepared from the poly(isobutene) having a molecular weight of about 850, vapor phase
osmometry) having a saponification number of 109, and 63.6 parts of an ethylene amine
mixture having an average composition corresponding in stoichiometry to tetraethylene
pentamine, is heated to 150°C while the water/toluene azeotrope is removed. The reaction
mixture is then heated to 150°C under reduced pressure until toluene ceases to distill.
The residual acylated polyamine has a nitrogen content of 4.7% by weight.
Example E-3
[0070] To 1,133 parts of commercial diethylene triamine heated at 110-150°C is slowly added
6820 parts of isostearic acid over a period of two hours. The mixture is held at 150°C
for one hour and then heated to 180°C over an additional hour. Finally, the mixture
is heated to 205°C over 0.5 hour; throughout this heating, the mixture is blown with
nitrogen to remove volatiles. The mixture is held at 205-230°C for a total of 11.5
hours and then stripped at 230°C/20 torr (2.65KPa) to provide the desired acylated
polyamine as residue containing 6.2% nitrogen by weight.
Example E-4
[0071] To a mixture of 50 parts of a polypropyl-substituted phenol (having a molecular weight
of about 900, vapor phase osmometry), 500 parts of mineral oil (a solvent refined
paraffinic oil having a viscosity of 100 SUS at 37,8°C (100°F)) and 130 parts of 9.5%
aqueous dimethylamine solution (equivalent to 12 parts amine) is added dropwise, over
an hour, 22 parts of a 37% aqueous solution of formaldehyde (corresponding to 8 parts
aldehyde). During the addition, the reaction temperature is slowly increased to 100°C
and held at that point for three hours while the mixture is blown with nitrogen. To
the cooled reaction mixture is added 100 parts of toluene and 50 parts of mixed butyl
alcohols. The organic phase is washed three times with water until neutral to litmus
paper and the organic phase filtered and stripped to 200°C/5-10 torr (0.66-1.33KPa).
The residue is an oil solution of the final product containing 0.45% nitrogen by weight.
Example E-5
[0072] A mixture of 140 parts of a mineral oil, 174 parts of a poly(isobutene)-substituted
succinic anhydride (molecular weight 1000) having a saponification number of 105 and
23 parts of isostearic acid is prepared at 90°C. To this mixture there is added 17.6
parts of a mixture of polyalkylene amines having an overall composition corresponding
to that of tetraethylene pentamine at 80°-100°C throughout a period of 1.3 hours.
The reaction is exothermic. The mixture is blown at 225°C with nitrogen at a rate
of 5 pounds (2.27 Kg) per hour for 3 hours whereupon 47 parts of an aqueous distillate
is obtained. The mixture is dried at 225°C for 1 hour, cooled to 100°C and filtered
to provide the desired final product in oil solution.
Example E-6
[0073] A substantially hydrocarbon-substituted succinic anhydride is prepared by chlorinating
a polyisobutene having a molecular weight of 1000 to a chlorine content of 4.5% and
then heating the chlorinated polyisobutene with 1.2 molar proportions of maleic anhydride
at a temperature of 150°-220°C. The succinic anhydride thus obtained has an acid number
of 130. A mixture of 874 grams (1 mole) of the succinic anhydride and 104 grams (1
mole) of neopentyl glycol is mixed at 240°-250°C/30 mm (4 KPa) for 12 hours. The residue
is a mixture of the esters resulting from the esterification of one and/or both hydroxy
radicals of the glycol. It has a saponification number of 101 and an alcoholic hydroxyl
content of 0.2% by weight.
Example E-7
[0074] The dimethyl ester of a substantially hydrocarbon-substituted succinic anhydride
is prepared by heating a mixture of 2185 grams of the anhydride, 480 grams of methanol,
and 1000 cc. of toluene at 50°-65°C while hydrogen chloride is bubbled through the
reaction mixture for 3 hours. The mixture is then heated at 60°-65°C for 2 hours,
dissolved in benzene, washed with water, dried and filtered. The filtrate is heated
at 150°C/60 mm (8 KPa) to rid it of volatile components. The residue is the defined
dimethyl ester.
Example E-8
[0075] A carboxylic acid ester is prepared by slowly adding 3240 parts of a high molecular
weight carboxylic acid (prepared by reacting chlorinated polyisobutylene and acrylic
acid in a 1:1 equivalent ratio and having an average molecular weight of 982) to a
mixture of 200 parts of sorbitol and 100 parts of diluent oil over a 1.5-hour period
while maintaining a temperature of 115°-125°C. Then 400 parts of additional diluent
oil are added and the mixture is maintained at about 195°-205°C for 16 hours while
blowing the mixture with nitrogen. An additional 755 parts of oil are then added,
the mixture cooled to 140°C, and filtered. The filtrate is an oil solution of the
desired ester.
Example E-9
[0076] An ester is prepared by heating 658 parts of a carboxylic acid having an average
molecular weight of 1018 (prepared by reacting chlorinated polyisobutene with acrylic
acid) with 22 parts of pentaerythritol while maintaining a temperature of about 180°-205°C
for about 18 hours during which time nitrogen is blown through the mixture. The mixture
is then filtered and the filtrate is the desired ester.
[0077] Further information on dispersants may be obtained from U.S. Patent 4,690,687.
AMOUNT OF THE COMPONENTS
[0078] The amount of the hydrocabon-soluble or dispersible alkali metal or alkaline earth
metal-containing composition (A) to the water fix (B) is typically about 1:2 to about
50:1, preferably 1:1 to about 40:1. The weight ratio of the water fix (B) to the ashless
dispersant (E) is typically from 2:1 to 1:50, preferably 1:1 to 1:40.
[0079] The amount of the ashless dispersant (E) to the gasoline is typically about 25 parts
to about 500 parts, more preferably about 35 parts to 400 parts by weight of the dispersant
per million parts of fuel. The weight ratio of the hydrocarbon-soluble or dispersible
alkali metal or alkaline earth metal-containing composition (A) to the ashless dispersant
(E) is typically from about 4:0.1 to about 1:4.
[0080] The amount of the hydrocarbon soluble alkali or alkaline earth metal-containing composition
(A) included in the fuel compositions of the present invention may vary over a wide
range although it is preferred not to include unnecessarily large excesses of the
metal composition. The amount included in the fuel should be an amount sufficient
to improve the desired properties such as the reduction of valve seat recession when
the fuel is burned in internal combustion engines which are not designed for use with
unleaded gas. For example, older engines which were designed for leaded fuels were
not constructed with specially hardened valve seats. Accordingly, the amount of metal
composition to be included in the fuel will depend in part on the amount of lead in
the fuel. For unleaded fuels, large amounts of the metal composition are required
to provide the desirable reduction in valve seat recession. When low-lead fuels are
treated in accordance with the present invention, lesser amounts of the metal-containing
composition generally are required.
[0081] In summary, the amount of component (A) included in the fuel compositions of the
present invention will be an amount which is sufficient to reduce valve seat recession
when such fuels are utilized in an internal combustion engine. Generally, the fuel
will contain less than about 2.0 gram, preferably less than 1.0 gram of the alkali
or alkaline earth metal compound per liter of fuel. In another embodiment, the fuel
composition of the present invention will contain from about 1 to about 100 parts
of the alkali metal or alkaline earth metal per million parts of fuel although amounts
of from 5 to about 60 parts per million appear to be adequate for most applications.
[0082] The amount of the hydrocarbon-soluble ashless dispersant optionally included in the
fuel compositions of this invention also can vary over a wide range. Typically, the
weight ratio of (B) the water fix to (E) the dispersant will be 2:1 to 1:50, preferably
1:1 to 1:40. The amount of (E) will depend in part on the amount of the metal-containing
composition (A). Typically the ashless dispersant (E) is used at about 4:0.1 to about
1:10 by weight to (A). The amount of the ashless dispersant to be included in the
particular fuel composition can be determined readily by one skilled in the art and,
obviously, the amount of dispersant contained in the fuel should not be so high as
to have deleterious effects such as forming deposits on engine parts when the engine
is cooled.
[0083] The following is an exemplification of the present invention.
Example 1
[0084] 48.8 parts of mineral oil are added to a mixing vat having stirring capacity. A mixture
of 0.6 parts of a C₂₄ alkylphenol sulfonate ammonium salt and 0.3 parts of a polyethylene
glycol/polypropylene glycol copolymer having a molecular weight of 600 is added to
the mixture. The copolymer is approximately 1:1 weight ratio of the monomers. A C₂₄
substituted phenol is added at 0.3 parts by weight.
[0085] To the foregoing mixture is added 8.4 parts of the ashless dispersant obtained from
Example E-2. A fluidizing oil (high viscosity mineral oil) is added at 8 parts by
weight. Lastly, 33.6 parts by weight of the active ingredient obtained from Example
A-1 are added to the mixture with stirring.
[0086] The foregoing mixture is added at 250 PTB (pounds per thousand barrels or 0.71 g/l)
to oxygenated gasoline as described below. The hydrocarbon content of the gasoline
is 93.8%, the methanol is 3.89% and the t-butanol is 2.4% by weight. The respective
volume ratio is 95:3:2.
[0087] The gasoline fuel is observed to have a high degree of water tolerance, i.e., any
emulsification is quickly broken with substantially complete separation into an organic
and a water phase. The product also functions to protect exhaust valve seats.
Example 2
[0088] This composition is formulated identically to Example 1, however, replacement of
the sodium alkylbenzene sulfonate salt with an equivalent amount (on a sodium basis)
of the neutral sodium salt of polyisobutylene succinic acid is employed. The molecular
weight of the anionic portion of the succinic acid salt is 950 and is obtained according
to U.S. Patent 3,271,370.
[0089] The product is otherwise obtained as previously described in Example 1 and blended
at the same level in gasoline. The product functions as an aid against valve seat
recession and is observed to break aqueous emulsions rapidly.