Note: Descriptions are shown in the official language in which they were submitted.
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GASOLINE CONTAINING POLYALPHAOLEFIN AND POLYOXYALKYLENE
A T1T1 T'T' T VR R
This,invention relates to gasoline compositions comprising a
major amount of a gasoline suitable for use in spark-ignition
engines and a minor amount of at least one additive, and to
additive concentrates suitable for addition to gasoline to prepare
such gasoline compositions.
EP-A-290 088 discloses gasoline compositions comprising a
major amount of a gasoline suitable for use in spark-ignition
engines, and a minor amount of a polyalphaolefin having a viscosity
at 100°C from 2 x 10 6 to 2 x 10 5 m2/s (2 to 20 centistokes),
preferably a hydrogenated oligomer containing 18 to 80 carbon atoms
derived from an alphaolefinic monomer containing from 8 to 12
carbon atoms, and optionally minor amounts of an oil-soluble
aliphatic polyamine and/or an alkali metal or alkaline-earth metal
salt of a succinic acid derivative having a polyolefin substituent
on at least one of its carbon atoms and/or a polyolefin derived
from a C2 to C6 monomer having a number average molecular weight
(Mn) between 500 and 1500.
US Patent No. 3,901,665 discloses liquid hydrocarbon fuel
compositions characterised by improved anti-icing and carburetor
detergency comprising
A. a major amount of_a liquid hydrocarbon fuel comprising
hydrocarbons boiling in the gasoline range, and based on the weight
of said fuel
B. about from 0.01 to about 0.06 percent by weight of a 3- or 4-
carbon olefin, preferably polyisobutylene, having a molecular
weight of from about 400 to about 1400, preferably about 400 to
about 900, and
C. from about 0.008 to about 4.016 percent by weight of a
polyoxyalkylene compound of the formula
2 ~1Q~825~
CH3fr
1
R(OCH2CH)xOH
wherein R is alkyl of 1 to 20 carbon atoms, preferably 10 to 18
carbon atoms, and x has an average value of 4 to 20; and
additive compositions consisting essentially of B and C.
US Patent No. 3,658,494 discloses fuel compositions comprising
a major amount of at least one normally liquid fuel and a minor
amount of an additive combination soluble in said fuel, the
additive combination comprising (a) at least one oxy compound which
is a monoether of a glycol or polyglycol and (b) at least one
fuel-soluble dispersant selected from the class consisting of
esters, amides, imides, amidines, and amine salts of at least one
substantially saturated carboxylic acid characterised by the
presence within the acyl radical thereof of at least 30 aliphatic
carbon atoms, the weight ratio of oxy compound to dispersant being
about 0.1:1 to about 1:0.1, but preferably 0.1:1 to about 2.5:1.
In the examples the oxy compounds used are ethylene glycol
mono-n-butyl ether, dipropylene glycol monomethyl ether,
triethylene glycol monoethyl ether, and ethylene glycol monophenyl
ether.
EP-A-384 605 discloses a motor fuel composition which
comprises a mixture of hydrocarbons boiling in the gasoline boiling
range and additionally (1) the reaction product of a defined
hydrocarbyl-substituted dibasic acid and a defined polyoxyalkylene
diamine, (ii) a polymeric component which is a polyolefin polymer,
copolymer, or the corresponding aminated or hydrogenated polymer or
copolymer, or mixtures thereof, of a C2-10 hydrocarbon, said
polyolefin polymer or copolymer having a molecular weight in the
range of 500 to 10,000; (iii) a polyalkylene glycol having a
molecular weight in the range of 500-2000; and (iv) a lubricating
oil. In relation to (ii) it is stated (Page 9 lines 39, 40) in
general the olefin monomers from which the polyolefin polymer
component is prepared are preferably unsaturated C2-6 hydrocarbons.
The polyalkylene glycol (iii) is said (Page 10 lines 39, 40)
_ 3 _ X904825
preferably to be selected from the group consisting of polyethylene
glycol, polypropylene glycol and polybutylene glycol.
EP-A-526129 (published on 3 February 1993) discloses a fuel
additive concentrate for controlling octane requirement increase in
S
internal combustion engines comprising the reaction product of (i)
polyamine and (ii) at least one acyclic hydrocarbyl substituted
succinic acylating agent, and an un~ydrotreated poly-alpha-olefin.
Whilt EP-A-526 129 further and more specifically provides a fuel
composition comprising a major amount of hydrocarbons in the
gasoline boiling range, or hydrocarbon/oxygenate mixtures, or
oxygenates containing a minor, but effective amount, of (a) a fuel
additive comprising the reaction product of (i) polyamine and (ii)
at least one acyclic hydrocarbyl substituted succinic acylating
agent; (b) an unhydrotreated poly-alpha-olefin having a volatility
of about 50$ or less as determined by a test method described
therein; (c) and optionally (A) a mineral oil having a viscosity
index of less than about 90 and a volatility of 50$ or less as
determined by a test method described therein; (B) an antioxidant,
or (C) a demulsifier, or (D) an aromatic hydrocarbon solvent, or
(E) a corrosion inhibitor, or any combination of any two, three,
four, or all five of components (A), (B), (C), (D) and (E), it is
clearly an essential feature that the poly-alpha-olefin present is
an unhydrotreated poly-alpha-olefin. The demulsifier (c) includes
polyoxyalkylene glycols and oxyalkylated phenolic resins, and in
particular mixtures of these.
It has now surprisingly been found that gasolines
incorporating combinations of particular polyalphaolefins and
particular polyoxyalkylene glycol derivatives can give surprisingly
enhanced engine performance in terms of an advantageous combination
of minimised engine inlet system deposits and minimised valve
sticking.
According to the present invention there is provided a
gasoline composition comprising a major amount of a gasoline
suitable for use in spark-ignition engines, a minor amount of a
polyalphaolefin having a viscosity at 100°C in the range 2 x 10 6
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to 2 x 10-5 m2/s (2 to 20 centistokes) , being a hydrogenated
oligomer containing 18 to 80 carbon atoms derived from at
least one alphaolefinic monomer containing from 8 to 16
carbon atoms, and a minor amount of a polyoxyalkylene
compound selected from glycols, mono- and diethers thereof,
having number average molecular weight (Mn) in the range 400
to 3000, the weight. ratio polyalphaolefin:polyoxyalkylene
compound being in the range 1:10 to 10:1.
According to another aspect of the present
invention there is provided gasoline composition comprising
a major amount of a gasoline suitable for use in spark-
ignition engines, an amount of a polyalphaolefin having a
viscosity at 100°C in the range 2 x 10-6 to 2 x 10-5 m2/s (2
to 20 centistokes), being a hydrogenated oligomer containing
18 to 80 carbon atoms derived from at least one
alphaolefinic monomer containing from 8 to 16 carbon atoms,
and an amount of a polyoxyalkylene compound selected from
glycols, mono- and diethers thereof, having number average
molecular weight (Mn) in the range 400 to 3000, the weight
ratio polyalphaolefin:polyoxyalkylene compound being in the
range 1:10 to 10:1, and the amount of the polyalphaolefin
and the polyoxyalkylene compound together being in the range
of 100 to 1500 ppmw based on total composition.
The polyalphaolefins used in the gasoline
compositions of the invention are primarily trimers,
tetramers and pentamers, and synthesis of such materials is
outlined in Campen et al., "Growing use of synlubes",
Hydrocarbon Processing February 1982, Pages 75 to 82. The
polyalphaolefin is preferably derived from an alphaolefinic
monomer containing from 8 to 12 carbon atoms.
Polyalphaolefins derived from decene-1 have been found to be
very effective. The polyalphaolefin preferably has viscosity
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at 100°C in the range 6 x 10-6 to 1 x 10-s mz/s (6 to 10
centistokes). Polyalphaolefin having a viscosity at 100°C of
8 x 10-6 mz/s (8 centistokes) has been found to be very
effective.
The polyoxyalkylene compound may be represented by
the formula
Ri-~R-~R2 ( I )
wherein R1 and Rz independently represent hydrogen atoms or
hydrocarbyl, preferably, C1_4p hydrocarbyl, e.g. alkyl,
cycloalkyl, phenyl or alkyl phenyl groups, each R
independently represents an alkylene, preferably a Cz_8
alkylene, group, and n is such that M~, of the polyoxyalkylene
compound is in the range 400 to 3000, preferably 700 to 2000,
more preferably 1000 to 1500.
Preferably R1 represents a C$-z0 alkyl group and Rz
represents a hydrogen atom. R1 preferably represents a Clo-la
alkyl group, more preferably a Clz-is alkyl group . R1 may
conveniently be a mixture of Clz-is alkyl groups .
In formula I the groups R are preferably 1,2-
alkylene groups. ,
Preferably each group R independently represents a
Cz_4 alkylene group, e.g. an ethylene or 1,2-propylene group.
Very
X104825
effective results have been obtained using polyalkylene compounds
wherein each group R represents a 1,2-propylene group.
The polyalphaolefin and the polyoxyalkylene compound together
may advantageously be present in the gasoline composition in an
amount in the range 100 to 1200 ppmw, preferably 100 to 600 ppmw,
more preferably 150 to 500 ppmw, based on total composition.
The weight ratio polyalphaolef~n:polyoxyalkylene compound in
the gasoline composition is preferably in the range 1:8 to 8:1,
more preferably 1:5 to 5:1. Weight ratios in the range 1:4 to 4:1
hare been found to be very effective.
The gasoline compositions of the present invention desirably
also contain a minor amount of at least one hydrocarbon-soluble
ashless dispersant. The compounds useful as ashless dispersants
generally are characterised 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 solubilising chains are generally
higher in molecular weight than those employed with the metallic
types, but in some instances they may be quite similar.
In general, any of the ashless dispersants which are known in
the art for use in lubricants and fuels can be utilised in the
gasoline compositions of the present invention.
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 hydrocarbon-based substituent of at least 10 aliphatic
carbon atoms made by reacting a carboxylic acid acylating agent
with at least one amino compound containing at least one
group, said acylating agent being linked to said amino compound
X104825 -s:
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
S -
group;
x
(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.
The hydrocarbyl-substituted amines used in the gasoline
compositions of this invention are well known to those skilled in
the art and they are described in a number of patents. Among these
are U.S. Patents Nos. 3,275,554, 3,438,757, 3,454,555, 3,565,804,
3,755,433 and 3,822,209. These patents disclose suitable
hydrocarbyl-substituted amines for use in the present invention
including their method of preparation.
A typical hydrocarbyl-substituted amine has the general
formula:
f~lxf-N(f-~-lat-UQIb)lyR3~H1+2y+ay-c (1I)
wherein A is hydrogen, a hydrocarbyl group of from 1 to 10 carbon
atoms, or hydroxyhydrocarbyl group of from 1 to 10 carbon atoms; X
is hydrogen, a hydrocarbyl group of from 1 to 10 carbon atoms, or
hydroxyhydrocarbyl group of from 1 to 10 carbon atoms, and may be
taken together with A and N to form a ring of from 5 to 6 annular
members and up to 12 carbon atoms; U is an alkylene group of from 2
to 10 carbon atoms, any necessary hydrocarbons to accommodate the
trivalent nitrogens are implied herein, R3 is an aliphatic
hydrocarbon of from 30 to 400 carbon atoms; Q is a piperazine
structure; a is an integer of from 0 to 10; b is an integer of from
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_,_
0 to 1; a+2b is an integer of from 1 to 10; c is an integer of from
1 to 5 and is an average in the range of 1 to 4, and equal to or
less than the number of nitrogen atoms in the molecule; x is an
integer of from 0 to 1; y is an integer of from 0 to 1; and x+y is
S equal to 1.
In interpreting this formula, it is to be understood that the
R3 and H atoms are attached to the unsatisfied nitrogen valences
within the brackets of the formula.. Thus, for example, the formula
includes sub-generic formulae wherein the R3 is attached to
terminal nitrogens and isomeric subgeneric formulae wherein it is
attached to non-terminal nitrogen atoms. Nitrogen atoms not
attached to an R3 may bear a hydrogen or an AXN substituent.
The hydrocarbyl-substituted amines useful in this invention
and embraced by formula II above include monoamines such as
poly(propylene)amine, N,N-dimethyl-n-poly(ethylene/propylene)amine
(50:50 mole ratio of monomers), poly(isobutene)amine,
N,N-di(hydroxyethyl)-N-poly(isobutene)amine, poly(isobutene/1-
butene/2-butene)amine (50:25:25 mole ratio of monomers),
N-(2-hydroxyethyl)-N-poly(isobutene)amine, N-(2-hydroxypropyl)-
N-poly(isobutene)amine, N-poly(1-butene)-aniline, and N-poly-
(isobutene)-morpholine; and polyamines such as N-poly(isobutene)
ethylene diamine, N-polypropylene) trimethylene diamine,
N-poly(1-butene) diethylene triamine, N',N'-poly(isobutene)
tetraethylene pentamine, N,N-dimethyl-N'-poly(propylene), and
1,3-propylene diamine.
The hydrocarbyl-subsituted amines useful in the gasoline
compositions of the invention also include certain
N-amino-hydrocarbyl morpholines of the general formula:
R3N(A)UM (III)
wherein R3 is an aliphatic hydrocarbon group of from 30 to 400
carbons, A is hydrogen, a hydrocarbyl group of from 1 to 10 carbon
atoms or hydroxyhydrocarbyl group of from 1 to 10 carbon atoms, U
is an alkylene group of from 2 to 10 carbon atoms, and M is a
X904825
morpholine structure. These hydrocarbyl-substituted
aminohydrocarbyl morpholines as well as the polyamines described by
formula II are among the typical hydrocarbyl-substituted amines
used in preparing compositions of this invention.
A number of acylated, nitrogen-containing compounds having a
hydrocarbon-based substituent of at least 10 aliphatic carbon atoms
and made by reacting a carboxylic arid acylating agent with an
amino compound are known to those skilled in the art. The
acylating agent is linked to the amino compound through an imido,
~ido, amidine or acyloxy. ammonium linkage. The hydrocarbon-based
substituent of at least 10 aliphatic carbon atoms may be in either
the carboxylic acid acylating agent derived portion of the molecule
or in the amino compound derived portion of the molecule.
Preferably, however, it is in the acylating agent portion. The
acylating agent can vary from formic acid and it acylating
derivatives to acylating agents having high molecular weight
aliphatic substituents of up to 5,000, 10,000 or 20,000 carbon
atoms. The amino compounds can vary from ammonia itself to amines
having aliphatic substituents of up to 30 carbon atoms.
A typical class of acylated, nitrogen-containing compounds
useful in the compositions of this invention are those made by
reacting an acylating agent having an aliphatic substituent of at
least 10 carbon atoms and a nitrogen compound characterised by the
presence of at least one -NH- group. Typically, the acylating
agent will be a mono- or polycarboxylic acid (or reactive
equivalent thereof) such as a substituted succinic or propionic
acid and the amino compound will be a polyamine or mixture of
polyamines, most typically, a mixture of ethylene polyamines. The
amine may also be a hydroxyalkyl-substituted polyamine. The
aliphatic substituent in such acylating agents preferably averages
at least 30 or 50 and up to 400 carbon atoms.
Illustrative hydrocarbon-based substituent groups containing
at least ten aliphatic carbon atoms are n-decyl, n-dodecyl,
tetrapropenyl, n-octadecyl, oleyl, chlorooctadecyl and
triicontanyl. Generally, the hydrocarbon-based substituerits are
~104a25
made from homo- or interpolymers (e.g., copolymers, terpolymers) of
mono- and diolefins having 2 to 10 carbon atoms, such as ethylene,
propylene, butene-1, isobutene, butadiene, isoprene, 1-hexene and,
1-octene. Typically, these olefins are 1-monoolefins. The
S substituent can also be derived from the halogenated (e. g.,
chlorinated or brominated) analogues of such homo- or
interpolymers. The substituent cane however, be made from other
sources, such as monomeric high molecular weight alkenes (e. g.,
1-tetracontene) and chlorinated analogues and hydrochlorinated
analogues thereof, aliphatic petroleum fractions, particularly
paraffin waxes and cracked and chlorinated analogues and
hydrochlorinated analogues thereof, white oils, synthetic alkenes
such as those produced by the Ziegler-Natta process (e. g.,
polyethylene) greases) and other sources known to those skilled in
the art. Any unsaturation in the substituent may be reduced or
eliminated by hydrogenation according to procedures known in the
art.
As used in this specification, the term "hydrocarbon-based"
denotes a group having a carbon atom directly attached to the
remainder of the molecule and having a predominantly hydrocarbon
character within the context of this invention. Therefore,
hydrocarbon-based groups can contain up to one non-hydrocarbon
group for every ten carbon atoms provided this non-hydrocarbon
group does not significantly alter the predominantly hydrocarbon
character of the group. Those skilled in the art will be aware of
such groups, which include, for example, hydroxyl, halo (especially
chloro and fluoro), alkoxyl, alkyl mercapto and alkyl sulphoxy
groups. Usually, however, the hydrocarbon-based substituents are
purely hydrocarbyl and contain no such non-hydrocarbyl groups.
The hydrocarbon-based substituents are substantially
saturated, that is, they contain no more than one carbon-to-carbon
unsaturated bond for every ten carbon-to-carbon single bonds
present. Usually, they contain no more than one carbon-to-carbon
non-aromatic unsaturated bond for every 50 carbon-to-carbon bonds
present.
- 10 -
The hydrocarbon-based substituents are also substantially
aliphatic in nature, that is, they contain no more than one non-
aliphatic moiety (cycloalkyl, cycloalkenyl or aromatic) group of
six or less carbon atoms for every ten carbon atoms in the
S substituent. Usually, however, the substituents contain no more
than one such non-aliphatic group for every fifty carbon atoms, and
in many cases, they contain no such non-aliphatic groups at all;
that is, the typical substituents are purely aliphatic. Typically,
these purely aliphatic substituents are alkyl or alkenyl groups.
Specific examples of the substantially saturated hydrocarbon-
based substituents containing an average of more than 30 carbon
atoms are the following: a mixture of poly(ethylene/propylene)
groups of 35 to 70 carbon atoms, a mixture of oxidatively or
mechanically degraded poly(ethylene/propylene) groups of 35 to 70
carbon atoms, a mixture of of ro lene 1-hexene
p y(p p / ) groups of 80 to
150 carbon atoms, and a mixture of polyisobutene groups having an
average of 50 to 75 carbon atoms.
A preferred source of the substituents are polyisobutenes
obtained by polymerisation of a C4 refinery stream having a butene
content of 35 to 75 weight per cent and isobutene content of 30 to
60 weight per cent in the presence of a Lewis acid catalyst such as
aluminium trichloride or boron trifluoride. These polyisobutenes
contain predominantly (greater than 80~ of total repeating units)
isobutene repeating units of the configuration:
-C(CH3)2CH2-
Exemplary of amino compounds useful in making these acylated
compounds are the following:
(1) polyalkylene polyamines of the general formula:
(R4)2N~P_NCR4)~mR4 (IV)
wherein each R4 is independently a hydrogen atom, a hydrocarbyl
group or a hydroxy-substituted hydrocarbyl group containing up to
21~~~'~~
11 -
30 carbon atoms, with the proviso that at least one R4 is a
hydrogen atom, m is a whole number of 1 to 10 and P is a X1_18
alkylene group;
(2) hydroxyalkyl-substituted polyamines wherein the polyamines are
as described above;
(3) heterocyclic-substituted polyamines wherein the polyamines are
as described above and the heterocyclic substituent is derived
from, for example, piperazine, imidazoline, pyrimidine or
morpholine; and
(4) aromatic polyamines of the general formula:
Ar(NR42)z (V)
wherein Ar is an aromatic nucleus of 6 to 20 carbon atoms, each R4
is as defined above and z is 2 to 8.
Specific examples of polyalkylene polyamines of formula IV are
ethylene diamine, tetra(ethylene)pentamine, tri-(trimethylene)-
tetramine and 1,2-propylene diamine.
Specific examples of hydroxyalkyl-substituted polyamines
include N-(2-hydroxyethyl) ethylene diamine, N,N'-bis-(2-hydroxy
ethyl) ethylene diamine and N-(3-hydroxybutyl) tetramethylene
diamine.
Specific examples of heterocyclic-substituted polyamines are
N-2-aminoethyl piperazine, N-2- and N-3-amino propyl morpholine,
N-3-(dimethyl amino) propyl piperazine, 2-heptyl-3-(2-aminopropyl)
imidazoline, 1,4-bis (2-aminoethyl) piperazine, 1-(2-hydroxy ethyl)
piperazine, and 2-heptadecyl-1-(2-hydroxyethyl)-imidazoline.
Specific examples of aromatic polyamines are the various
isomeric phenylene diamines and the various isomeric naphthalene
diamines.
Many patents have described useful acylated nitrogen compounds
including U.S. Patents Nos. 3,172,892, 3,219,666, 3,272,746,
3,310,492, 3,341,542, 3,444,170, 3,455,831, 3,455,832, 3,576,743,
3,630,904, 3,632,511, 3,804,763 and 4,234,435. A typical acylated
nitrogen-containing compound of this class is that made by reacting
21a~8~
- 12 -
a polyisobutene-substituted succinic anhydride acylating agent
wherein the polyisobutene substituent has from 50 to 400 carbon
atoms with a mixture of ethylene polyamines having 3 to 7 amino
nitrogen atoms per ethylene polyamine.
Another type of acylated nitrogen compound belonging to this
class is that made by reacting the aforementioned alkylene amines
with the aforementioned substituted succinic acids or anhydrides
and aliphatic monocarboxylic acids having from 2 to 22 carbon
atoms. In these types of acylated nitrogen compounds, the mole
ratio of succinic acid to monocarboxylic acid is in the range from
1:0.1 to 1:1. Typical of the monocarboxylic acid are formic acid,
acetic acid, dodecanoic acid, butanoic acid, oleic acid, stearic
acid, the commercial mixture of stearic acid isomers known as
isostearic acid and tolyl acid. Such materials are more fully
described in U.S. Patents Nos. 3,216,936 and 3,250,715.
Still another type of acylated nitrogen compound useful in the
gasoline compositions of the invention is the product of the
reaction of a fatty monocarboxylic acid of 12 to 30 carbon atoms
and the aforementioned alkylene amines, typically, ethylene,
propylene or trimethylene polyamines containing 2 to 8 amino groups
and mixtures thereof. The fatty monocarboxylic acids are generally
mixtures of straight and branched chain fatty carboxylic acids
containing 12 to 30 carbon atoms. A widely used type of acylated
nitrogen compound is made by reacting the aforementioned alkylene
polyamines with a mixture of fatty acids having from 5 to 30 mole
per cent straight chain acid and 70 to 95 mole per cent branched
chain fatty acids. Among the commercially available mixtures are
those known widely in the trade as isostearic acid. These mixtures
are produced as a by-product from the dimerisation of unsaturated
fatty acids as described in U.S. Patents Nos. 2,812,342 and
3,260,671.
The branched chain fatty acids can also include those in which
the branch is not alkyl in nature, such as found in phenyl and
cyclohexyl stearic acid and the chloro-stearic acids. Branched
chain fatty carboxylic acid/alkylene polyamine products have been
214~:82~
- 13 -
described, for example in U.S. Patents Nos. 3,110,673, 3,251,853,
3,326,801, 3,337,459, 3,405,064, 3,429,674, 3,468,639 and
3,857,791.
The phenol/aldehyde/amino compound condensates useful as
S
dispersants in the gasoline compositions of the invention include
those generically referred to as Mannich condensates. Generally,
they are made by reacting simultaneously or sequentially at least
one active hydrogen compound such as a hydrocarbon-substituted
phenol (e. g., an alkyl phenol wherein the alkyl group has at least
an average of 12 to 400, preferably 30 to 400, carbon atoms),
having at least one hydrogen atom bonded to an aromatic carbon,
with at least one aldehyde or aldehyde-producing material
(typically formaldehyde precursor) and at least one amino or
polyamino compound having at least one NH group. The amino
compounds include primary or secondary monoamines having
hydrocarbon substituents of 1 to 30 carbon atoms or
hydroxyl-substituted hydrocarbon substituents of 1 to 30 carbon
atoms. Another type of typical amino compound are the polyamines
described during the discussion of the acylated nitrogen-containing
compounds.
Exemplary monoamines include methyl etheyl amine, methyl
octadecyl amines, aniline, diethyl amine, diethanol amine and
dipropyl amine. The following patents contain extensive
descriptions of Mannich condensates: U.S. Patents Nos. 2,459,112,
3 413,347, 3,558,743, 2,962,442, 3,442,808, 3,586,629, 2,984,550,
3,448,047, 3,591,598, 3,036,003, 3,454,497, 3,600,372, 3,166,516,
3,459,661, 3,634,515, 3,236,770, 3,461,172, 3,649,229, 3,355,270,
3,493,520, 3,697,574, 3,368,972 and 3,539,633.
Condensates made from sulphur-containing reactants can also be
used in the gasoline compositions of the present invention. Such
sulphur-containing condensates are described in U.S. Patents Nos.
3,368,972 , 3,649,229, 3,600,372, 3,649,659 and 3,741,896. These
patents also disclose sulphur-containing Mannich condensates.
Generally the condensates used in making compositions of this
invention are made from a phenol bearing an alkyl substituent of 6
,,-.
~I~48~
- 14 -
to 400 carbon atoms, more typically, 30 to 250 carbon atoms. These
typical condensates are made from formaldehyde or C2-~ aliphatic
aldehyde and an amino compound such as those used in making the
acylated nitrogen-containing compounds described above.
These preferred condensates are prepared by reacting one molar
portion of phenolic compound with 1 to 2 molar portions of aldehyde
and 1 to 5 equivalent portions of amino compound (an equivalent of
amino compound is its molecular weight divided by the number of -NH
groups present). The conditions under which such condensation
reactions are carried out are well known to those skilled in the
art.
A particularly preferred class of nitrogen-containing
condensation products for use in the gasoline compositions of the
present invention are those made by (1) reacting at least one
hydroxy aromatic compound containing an aliphatic-based or
cycloaliphatic-based substituent which has at least 30 carbon atoms
and up to 400 carbon atoms with a lower aliphatic C1-~ aldehyde or
reversible polymer thereof in the presence of an alkaline reagent,
such as an alkali metal hydroxide, at a temperature up to 150°C;
(2) substantially neutralising the intermediate reaction mixture
thus formed; and (3) reacting the neutralised intermediate with at
least one compound which contains an amino group having at least
one -NH- group.
More preferably, these condensates are made from (a) phenols
bearing a hydrocarbon-based substituent having 30 to 250 carbon
atoms, said substituent being derived from a polymer of propylene,
1-butene, 2-butene, or isobutene and (b) formaldehyde, or
reversible polymer thereof, (e.g., trioxane, paraformaldehyde) or
functional equivalent thereof, (e. g., methylol) and (c) an alkylene
polyamine such as ethylene polyamines having from 2 to 10 nitrogen
atoms.
The esters useful as dispersants in the gasoline compositions
of the invention are derivatives of substituted carboxylic acids in
which the substituent is a substantially aliphatic, substantially
saturated hydrocarbon-based group containing at least 30,'
21~~-825
- 15
preferably at least 50, up to 750 aliphatic carbon atoms. As used
herein, the term "hydrocarbon-based group" denotes a group having a
carbon atom directly attached to the remainder of the molecule and
having predominantly hydrocarbon character within the context of
S this invention. Such groups include the following:
(1) Hydrocarbon groups; that is, aliphatic groups, aromatic-
andalicyclic-substituted aliphatic groups, and the like, of the
type known to those skilled in the art.
(2) Substituted hydrocarbon groups; that is, groups containing
non-hydrocarbon substituents which, in the context of this
invention, do not alter the predominantly hydrocarbon character of
the group. Those skilled in the art will be aware of suitable
substituents; examples are halo, nitro, hydroxy, alkoxy, carbalkoxy
and alkylthio.
(3) Hetero groups; that is, groups which, while predominantly
hydrocarbon in character within the context of this invention,
contain atoms other than carbon present in a chain or ring
otherwise composed of carbon atoms. Suitable hetero atoms will be
apparent to those skilled in the art and include, for example,
nitrogen, oxygen and sulphur.
In general, no more than about three substituents or hetero
atoms, and preferably no more than one, will be present for each 10
carbon atoms in the hydrocarbon-based group.
The substituted carboxylic acids are normally prepared by the
alkylation of an unsaturated acid, or a derivative thereof such as
an anhydride, with a source of the desired hydrocarbon-based group.
Suitable unsaturated acids and derivatives thereof include acrylic
acid, methacrylic acid, maleic acid, malefic anhydride, fumaric
acid, itaconic acid, itaconic anhydride, citraconic acid,
citraconic anhydride, mesaconic acid, glutaconic acid, chloromaleic
acid, aconitic acid, crotonic acid, methylcrotonic acid, sorbic
acid, 3-hexenoic acid, 10-decenoic acid and 2-pentene-1,3,5-tri-
carboxylic acid. Particularly preferred are the unsaturated
dicarboxylic acids and their derivatives, especially malefic acid,
f~aric acid and malefic anhydride.
21~48~~
- 16 -
Suitable alkylating agents include homopolymers and inter-
polymers of polymerisable olefin monomers containing from 2 to 10
and usually from 2 to 6 carbon atoms, and polar substituent-
containing derivatives thereof. Such polymers are substantially
saturated (i.e., they contain no more than about 5% olefinic
linkages) and substantially aliphatic (i.e., they contain at least
80% and preferably at least 95% by weight of units derived from
aliphatic monoolefins). Illustrative monomers which may be used to
produce such polymers are ethylene, propylene, 1-butene, 2-butene,
isobutene, 1-octene and 1-decene. Any unsaturated units may be
derived from conjugated dienes such as 1,3-butadiene and isoprene;
non-conjugated dienes such as 1,4-hexadiene, 1,4-cyclohexadiene,
5-ethylidene-2-norbornene and 1,6-octadiene; and trienes such as
1-isopropylidene-3a,4,7,7a-tetrahydroindene, 1-isopropylidene-
dicyclopentadiene and 2-(2-methylene-4-methyl-3-pentenyl)[2.2.1]-
bicyclo-5-heptene.
A first preferred class of polymers comprises those of
terminal olefins such as propylene, 1-butene, isobutene and
1-hexene. Especially preferred within this class are polybutenes
comprising predominantly isobutene units. A second preferred class
comprises terpolymers of ethylene, a C3-8 alpha-monoolefin and a
polyene selected from the group consisting of non-conjugated dienes
(which are especially preferred) and trienes. Illustrative of
these terpolymers is "Ortholeum 2052" manufactured by E.I. duPont
de Nemours & Company, which is a terpolymer containing about 48
mole per cent ethylene groups, 48 mole per cent propylene groups
and 4 mole per cent 1,4-hexadiene groups and having an inherent
viscosity of 1.35 (8.2 grams of polymer in 10 ml of carbon
tetrachloride at 30°C).
Methods for the preparation of the substituted carboxylic
acids and derivatives thereof are well known in the art and need
not be described in detail. Reference is made, for example, to
U.S. Patents Nos. 3,272,746, 3,522,179 and 4,234,435. The mole
ratio of the polymer to the unsaturated acid or derivative thereof
may be equal to, greater than or less than 1, depending on the type
_ - 17 -
of product desired.
The esters are those of the above-described substituted
carboxylic acids with hydroxy compounds which may be aliphatic
compounds such as monohydric and polyhydric alcohols or aromatic
compounds such as phenols and naphthols. Examples of aromatic
hydroxy compounds include phenol, beta-naphthol, alpha-naphthol,
cresol, resorcinol, catechol, p,p'-dihydroxybiphenyl,
2-chlorophenol, 2,4-dibutylphenol, propene tetramer-substituted
phenol, didodecylphenol, 4,4'-methylene-bis-phenol,
alpha-decyl-beta-naphthol, polyisobutene (molecular weight of
1000)-substituted phenol, the condensation product of heptylphenol
with formaldehyde, the condensation product of octyl-phenol with
acetone, di(hydroxyphenyl)-oxide, di(hydroxyphenyl)sulphide,
di(hydroxyphenyl)disulphide, and 4-cyclo-hexylphenol. Phenol and
alkylated phenols having up to three alkyl substituents are
preferred. Each of the alkyl substituents may contain 100 or more
carbon atoms.
The aliphatic alcohols from which the esters may be derived
preferably contain up to 40 aliphatic carbon atoms. They may be
monohydric alcohols such as methanol, ethanol, isooctanol,
dodecanol, cyclohexanol, cyclopentanol, behenyl alcohol,
hexatriacontanol, neopentyl alcohol, isobutyl alcohol, benzyl
alcohol, beta-phenylethyl alcohol, 2-methylcyclohexanol,
beta-chloroethanol, monomethyl ether of ethylene glycol, monobutyl
ether of ethylene glycol, monopropyl ether of diethylene glycol,
monododecyl ether of triethylene glycol, monooleate of ethylene
glycol, monostearate of diethylene glycol, secpentyl alcohol,
tertbutyl alcohol, 5-bromo-dodecanol, nitro-octadecanol and
dioleate of glycerol. The polyhydric alcohols preferably contain
from 2 to 10 hydroxy radicals. They are illustrated by, for
example, ethylene glycol, diethylene glycol, triethylene glycol,
tetraethylene glycol, dipropylene glycol, tripropylene glycol,
dibutylene glycol, tri-butylene glycol, and other alkylene glycols
in which the alkylene radical contains from 2 to 8 carbon atoms.
Other useful polyhydric alcohols include glycerol, monool~ate of
r-,
- 18 -
glycerol, monostearate of glycerol, monomethyl ether of glycerol,
pentaerythritol, 9,10-dihydroxy stearic acid, methyl ester of
9,10-dihydroxy stearic acid, 1,2-butanediol, 2,3-hexanediol,
2,4-hexanediol, penacol, erythritol, arabitol, sorbitol, mannitol,
S 1,2-cyclohexanediol, and xylene glycol. Carbohydrates such as
sugars, starches and cellulose may also yield esters useful in this
invention. The carbohydrates may be exemplified by glucose,
fructose, sucrose, rhamnose, mannose, glyceraldehyde and galactose.
An especially preferred class of polyhydric alcohols are those
having at least three hydroxy radicals, some of which have been
esterified with a monocarboxylic acid having from 8 to 30 carbon
atoms, such as octanoic acid, oleic acid, stearic acid, linoleic
acid, dodecanoic acid, or tall oil acid. Examples of such
partially esterified polyhydric alcohols are the monooleate of
sorbitol, distearate of sorbitol, monooleate of glycerol,
monostearate of glycerol, di-dodecanoate of erythritol.
The esters may also be derived from unsaturated alcohols such
as allyl alcohol, cinnamyl alcohol, propargyl alcohol,
1-cyclohexene-3-of and oleyl alcohol. Still another class of the
alcohols capable of yielding the esters useful in this invention
comprise the ether-alcohols and amino-alcohols including, for
example, the oxyalkylene-, oxyarylene-, amino-alkylene- and
amino-arylene-substituted alcohols having one or more oxyalkylene,
oxyarylene, amino-alkylene or amino-arylene radicals. They are
exemplified by Cellosolve, carbitol, phenoxyethanol,
heptylphenyl-(oxypropylene)6-H, octyl-(oxyethylene)30-H,
phenyl-(oxyoctylene)2-H, mono(heptylphenyl-oxypropylene)-
substituted glycerol, polystyrene oxide), amino-ethanol, 3-amino
ethyl-pentanol, di(hydroxyethyl) amine, p-amino-phenol,
tri(hydroxypropyl)amine, N-hydroxyethyl ethylene diamine and
N,N,N',N'-tetrahydroxy-trimethylene diarnine. For the most part,
the ether-alcohols having up to about 150 oxyalkylene radicals in
which the alkylene radical contains from 1 to 8 carbon atoms are
preferred.
-- 21Q~.8~~
19 -
The esters may be diesters of succinic acids or acidic esters,
i.e., partially esterified polyhydric alcohols or phenols, i.e.,
esters having free alcoholic or phenolic hydroxyl radicals.
Mixtures of the above-illustrated esters likewise are contemplated
within the scope of the invention.
The succinic acid esters may be prepared by one of several
methods. The method which is preferred because of convenience and
superior properties of the esters it produces, involves the
reaction of a suitable alcohol or phenol with a substantially
hydrocarbon-substituted succinic anhydride. The esterification is
usually carried out at a temperature above about 100°C, preferably
between 150°C and 300°C.
The water formed as a by-product is removed by distillation as
the esterification proceeds. A solvent may be used in the
esterification to facilitate mixing and temperature control. It
also facilitates the removal of water from the reaction mixture.
The useful solvents include xylene, toluene, diphenyl ether,
chlorobenzene and mineral oil.
A modification of the above process involves the replacement
of the substituted succinic anhydride with the corresponding
succinic acid. However, succinic acids readily undergo dehydration
at temperatures above about 100°C and are thus converted to their
anhydrides which are then esterified by the reaction with the
alcohol reactant. In this regard, succinic acids appear to be the
substantial equivalent of their anhydrides in the process.
The relative proportions of the succinic reactant and the
hydroxy reactant which are to be used depend to a large measure
upon the type of the product desired and the number of hydroxyl
groups present in the molecule of the hydroxy reactant. For
instance, the formation of a half ester of a succinic acid, i.e.,
one in which only one of the two acid radicals is esterified,
involves the use of one mole of a monohydric alcohol for each mole
of the substituted succinic acid reactant, whereas the formation of
a diester of a succinic acid involves the use of two moles of the
alcohol for each mole of the acid. On the other hand, one mole of
2~0~-8°2~
~,.....
- 20 -
a hexahydric alcohol may combine with as many as six moles of a
succinic acid to form an ester in which each of the six hydroxyl
radicals of the alcohol is esterified with one of the two acid
radicals of the succinic acid. Thus, the maximum proportion of the
S succinic acid to be used with a polyhydric alcohol is determined by
the number of hydroxyl groups present in the molecule of the
hydroxy reactant. For the purposes of this invention, it has been
found that esters obtained by the reaction of equimolar amounts of
the succinic acid reactant and hydroxy reactant have superior
properties and are therefore preferred.
In some instances, it is advantageous to carry out the
esterification in the presence of a catalyst such as sulphuric
acid, pyridine hydrochloride, hydrochloric acid, benzenesulphonic
acid, p-toluenesulphonic acid, phosphoric acid, or any other known
esterification catalyst. The amount of the catalyst in the
reaction may be as little as 0.01 (by weight of the reaction
mixture), more often from 0.1$ to 5$.
The succinic acid esters may alternatively be obtained by the
reaction of a substituted succinic acid or anhydride with an
epoxide or a mixture of an epoxide and water. Such reaction is
similar to one involving the acid or anhydride with a glycol. For
instance, the product may be prepared by the reaction of a
substituted succinic acid with one mole of ethylene oxide.
Similarly, the product may be obtained by the reaction of a
substituted succinic acid with two moles of ethylene oxide. Other
epoxides which are commonly available for use in such reaction
include, for example, propylene oxide, styrene oxide, 1,2-butylene
oxide, 2,3-butylene oxide, epichlorohydrin, cyclohexene oxide,
1,2-octylene oxide, epoxidised soya bean oil, methyl ester of
9,10-epoxy-stearic acid and butadiene mono-epoxide. For the most
part, the epoxides are the alkylene oxides in which the alkylene
radical has from 2 to 8 carbon atoms; or the epoxidised fatty acid
esters in which the fatty acid radical has up to 30 carbon atoms
and the ester radical is derived from a lower alcohol having up to
g carbon atoms. '
21~~g'2~
,...
- 21 -
In lieu of the succinic acid or anhydride, a lactone acid or a
substituted succinic acid halide may be used in the processes
illustrated above. Such acid halides may be acid dibromides, acid
dichlorides, acid monochlorides, and acid monobrornides. The
S substituted succinic anhydrides and acids can be prepared by, for
example, the reaction of malefic anhydride with a high molecular
weight olefin or a halogenated hydrocarbon such as is obtained by
the chlorination of an olefin polymer described previously. The
reaction involves merely heating the reactants at a temperature
preferably from 100°C to 250°C. The product from such a reaction
is an alkenyl succinic anhydride. The alkenyl group may be
hydrogenated to an alkyl group. The anhydride may be hydrolysed by
treatment with water or steam to the corresponding acid. Another
method useful for preparing the succinic acids or anhydrides
involves the reaction of itaconic acid or anhydride with an olefin
or a chlorinated hydrocarbon at a temperature usually within the
range from 100°C to 250°C. The succinic acid halides can be
prepared by the reaction of the acids or their anhydrides with a
halogenation agent such as phosphorous tribromide, phosphorus
pentachloride, or thionyl chloride. These and other methods of
preparing the succinic compounds are well known in the art and need
not be illustrated in further detail here.
Still further methods of preparing esters useful in the
gasoline compositions of the present invention are available. For
instance, the esters may be obtained by the reaction of malefic acid
or anhydride with an alcohol such as is illustrated above to form a
mono- or di-ester of malefic acid and then the reaction of this
ester with an olefin or a chlorinated hydrocarbon such as is
illustrated above. They may also be obtained by first esterifying
itaconic anhydride or acid and subsequently reacting the ester
intermediate with an olefin or a chlorinated hydrocarbon under
conditions similar to those described hereinabove.
A large number of different types of polymeric dispersants
have been suggested as useful in lubricating oil formulations, and
such polymeric dispersants are useful in the gasoline compositions
210-~2~
_ 22 _
of the present invention. Often, such additives have been
described as being useful in lubricating formulations as viscosity
index improvers with dispersing characteristics. The polymeric
dispersants generally are polymers or copolymers having a long
S carbon chain and containing "polar" groups to impart the
dispersancy characteristics. Examples of polar groups include
amino, amido, imino, imido, hydroxyl and ether groups. For
example, the polymeric dispersants may be copolymers of
methacrylates or acrylates containing additional polar groups,
ethylene/propylene copolymers containing polar groups or vinyl
acetate/fumaric acid ester copolymers.
Many such polymeric dispersants have been described in the
prior art, for example in U.S. Patents Nos. 4,402,844, 3,356,763
and 3,891,721.
A number of the polymeric dispersants may be prepared by
grafting polar monomers on to polyolefinic backbones. For example,
U.S. Patent Nos. 3,687,849 and 3,687,905 describe the use of malefic
anhydride as a graft monomer to a polyolefinic backbone. Malefic
acid or anhydride is particularly desirable as a graft monomer
because this monomer is relatively inexpensive, provides an
economical route to the incorporation of dispersant nitrogen
compounds into polymers by further reaction of the carboxyl groups
of the malefic acid or anhydride with, for example, nitrogen
compounds or hydroxy compounds. U.S. Patent No. 4,160,739
describes graft copolymers obtained by the grafting of a monomer
system comprising malefic acid or anhydride and at least one other
different monomer which is addition copolymerisable therewith, the
grafted monomer system then being post-reacted with a polyamine.
The monomers which are copolymerisable with malefic acid or
a~ydride are any alpha, beta-monoethylenically unsaturated
monomers which are sufficiently soluble in the reaction medium and
reactive towards malefic acid or anhydride so that substantially
larger amounts of malefic acid or anhydride can be incorporated into
the grafted polymeric product. Accordingly, suitable monomers
include the esters, amides and nitriles of acrylic and methacrylic
21~~.82~
' - 23 -
acid, and monomers containing no free acid groups. The
incorporation of heterocyclic monomers into graft polymers is
described by a process which comprises a first step of graft
polymerising an alkyl ester of acrylic acid or methacrylic acid,
S alone or in combination with styrene, onto a backbone copolymer
which is a hydrogenated block copolymer of styrene and a conjugated
diene having 4 to 6 carbon atoms to form a first graft polymer. In
the second step, a polymerisable heterocyclic monomer, alone or in
combination with a hydrophobising vinyl ester is co-polymerised
onto the first graft copolymer to form a second graft copolymer.
Other patents describing graft polymers useful as dispersants
in the gasoline compositions of this invention include U.S. Patents
Nos. 3,243,481, 3,475,514, 3,723,575, 4,026,167, 4,085,055,
4,181,618 and 4,476,283.
Another class of polymeric dispersant useful in the gasoline
compositions of the invention are the so-called "star" polymers and
copolymers. Such polymers are described in, for example U.S.
Patents Nos. 4,346,193, 4,141,847, 4,358,565, 4,409,120 and
4,077,893.
The hydrocarbon-substituted phenolic dispersants useful in the
gasoline compositions of the present invention include the
hydrocarbon-substituted phenolic compounds wherein the hydrocarbon
substituents have a molecular weight which is sufficient to render
the phenolic compound fuel soluble. Generally, the hydrocarbon
substituent will be a substantially saturated, hydrocarbon-based
group of at least 30 carbon atoms. The phenolic compounds may be
represented generally by the following formula:
(R5)e-Arl-(OH)f (VI)
wherein R5 is a substantially saturated hydrocarbon-based
substituent having an average of from 30 to 400 aliphatic carbon
atoms, and a and f are each 1, 2 or 3. Arl is an aromatic moiety
such as a benzene nucleus, naphthalene nucleus or linked benzene
nuclei. Optionally, the above phenates as represented by'formula
2~0~~~
- 24 -
VI may contain other substituents such as lower alkyl, lower
alkoxy, nitro, amino and halo groups. Preferred examples of
optional substituents are the nitro and amino groups.
The substantially saturated hydrocarbon-based group R5 in
formula VI may contain up to 750 aliphatic carbon atoms although it
usually has a maximum of an average of 400 carbon atoms. In some
instances R5 has a minimum of 50 carbon atoms. As noted, the
phenolic compounds may contain more than one R5 group for each
aromatic nucleus in the aromatic moiety Arl.
Generally, the hydrocarbon-based groups RS are derived from
homo- or interpolymers (e.g., copolymers, terpolymers) of mono- and
diolefins having 2 to 10 carbon atoms, such as ethylene, propylene,
butene-1, isobutene, butadiene, isoprene, 1-hexene and 1-octene.
Typically, these olefins are 1-monoolefins. The R5 groups can also
be derived from the halogenated (e. g., chlorinated or brominated)
analogues of such homo- or interpolymers. The R5 groups can,
however, be made from other sources, such as monomeric high
molecular weight alkenes (e. g. 1-tetracontene) and chlorinated
analogues and hydrochlorinated analogues thereof, aliphatic
petroleum fractions, particularly paraffin waxes and cracked and
chlorinated analogues and hydrochlorinated analogues thereof, white
oils, synthetic alkenes such as those produced by the Ziegler-Natta
process (e.g., poly(ethylene) greases) and other sources known to
those skilled in the art. Any unsaturation in the R5 groups may be
reduced or eliminated by hydrogenation according to procedures
known in the art before the nitration step described hereafter.
Specific examples of the substantially saturated hydrocarbon-
based RS groups are the following: a tetracontanyl group, a
henpentacontanyl group, a mixture of poly(ethylene/propylene)
groups of 35 to 70 carbon atoms, a mixture of oxidatively or
mechanically degraded poly(ethylene/propylene) groups of 35 to 70
carbon atoms, a mixture of poly(propylene/1-hexene) groups of 80 to
150 carbon atoms, a mixture of polyisobutene groups having 20 to 32
carbon atoms, and a mixture of polyisobutene groups having an
average of 50 to 75 carbon atoms.
2104-8~~
- 25 -
A preferred source of the group R5 are polyisobutenes obtained
by polymerisation of a C4 refinery stream having a butene content
of 35 to 75 weight per cent and isobutene content of 30 to 60
weight per cent in the presence of a Lewis acid catalyst such as
aluminium trichloride or boron trifluoride. These polyisobutenes
contain predominatly (greater than 80$ of total repeat units)
isobutene repeating units of the configuration.
-C(CH3)2CH2_
The attachment of the hydrocarbon-based group R5 to the
aromatic moiety Arl can be accomplished by a number of techniques
well known to those skilled in the art.
In one preferred embodiment, the phenolic dispersants useful
in the gasoline compositions of the present invention are
hydrocarbon-substituted vitro phenols as represented by formula VI
wherein the optional substituent is one or more vitro groups. The
vitro phenols can be conveniently prepared by nitrating appropriate
phenols, and typically, the vitro phenols are formed by nitration
of alkyl phenols having an alkyl group of at least 30 and
preferably at least 50 carbon atoms. The preparation of a number
of hydrocarbon-substituted vitro phenols useful in the gasoline
compositions of the present invention is described in U.S. Patent
No. 4,347,148.
In another preferred embodiment, the hydrocarbon-substituted
phenol dispersants useful in the present invention are hydrocarbon-
substituted amino phenols such as represented by formula VI wherein
the optional substituent is one or more amino groups. These amino
phenols can conveniently be prepared by nitrating an appropriate
hydroxy aromatic compound as described above and thereafter
reducing the vitro groups to amino groups. Typically, the useful
amino phenols are formed by nitration and reduction of alkyl
phenols having an alkyl or alkenyl group of at least 30 and
preferably at least 50 carbon atoms. The preparation of a large
number of hydrocarbon-substituted amino phenols useful as'
21~~2~
- 26 -
dispersants in the present invention is described in U.S. Patent
No. 4,320,021.
Also useful as dispersants in the gasoline compositions of the
present invention are fuel-soluble alkoxylated derivatives of
alcohols, phenols and amines. A wide variety of such derivatives
can be utilised as long as the derivatives are fuel-soluble. More
preferably, the derivatives in addition to being fuel-soluble
should be water-insoluble. Accordingly, in a preferred embodiment,
the fuel-soluble alkoxylated derivatives useful as the dispersants
are characterised as having an HLB of from 1 to 13.
As is well known to those skilled in the art, the
fuel-solubility and water-insolubility characteristics of the
alkoxylated derivatives can be controlled by selection of the
alcohol, phenol or amine, selection of the particular alkoxy
reactant, and by selection of the amount of alkoxy reactant which
is reacted with the alcohol, phenol or amine. Accordingly, the
alcohols which are utilised to prepare the alkoxylated derivatives
are hydrocarbon- based alcohols while the amines are
hydrocarbyl-substituted amines as described above. The phenols may
be phenols or hydrocarbon-substituted phenols and the hydrocarbon
substituent may contain as few as 1 carbon atom.
The alkoxylated derivatives are obtained by reacting the
alcohol, phenol or amine with an epoxide or a mixture of an epoxide
and water. For example, the derivative may be prepared by the
reaction of the alcohol, phenol or amine with an equal molar amount
or an excess of ethylene oxide. Other epoxides which can be
reacted with the alcohol, phenol or amine include, for example,
propylene oxide, styrene oxide, 1,2-butylene oxide, 2,3-butylene
oxide, epichlorohydrin, cyclohexene oxide and 1,2-octylene oxide.
Preferably, the epoxides are the alkylene oxides in which the
alkylene group has from 2 to 8 carbon atoms. As mentioned above,
it is desirable and preferred that the amount of alkylene oxide
reacted with the alcohol, phenol or amine be insufficient to render
the derivative water-soluble.
2104.82
,.,.
- 27 -
The following are examples of commercially available alkylene
oxide derivatives which may be utilised as dispersants in the
gasoline compositions of the present invention: Ethomeen S/12,
tertiary amines ethylene oxide condensation products of the primary
fatty amines (HLB, 4.15; Armak Industries); and Plurafac A-24, an
oxyethylated straight-chain alcohol available from BASF Wyandotte
Industries (HLB 5.0). Other suitable fuel-soluble alkoxylated
derivatives of alcohols, phenols and amines will be readily
apparent to those skilled in the art.
In a particularly preferred embodiment, further to the
polyalphaolefin and the polyoxyalkylene compound, the gasoline
composition of the invention may additionally contain, as ashless
dispersant, a minor amount of a polyolefin-substituted succinimide
derivative wherein the polyolefin has Mn in the range 800 to 5000,
preferably 1000 to 5000, more preferably at least 1750, 1800 or
1850 and at most 4000, 3500, 3000 or 2500. The amine from which
the succinimide is formed is preferably a Cl-30 amine, especially a
C4-12 amine containing 3 to 7 nitrogen atoms, e.g. diethylene
triamine, triethylene tetramine, tetramethylene pentamine,
pentaethylene hexamine, hexaethylene heptamine, tripropylene
tetramine and mixtures of any 2 or more thereof.
Preferably the hydrocarbon-soluble ashless dispersant is
present in an amount in the range 30 to 500 ppmw, more preferably
100 to 300 ppmw, based on total composition.
The gasoline composition may additionally include (e.g. as an
alternative to inclusion of succinimide derivative) an oil soluble
polyamine as described in EP-A-290 088 or an N-substituted
carbamate as described in EP-A-414 963, in each case in similar
quantities to those described therein.
The gasoline composition may further include, as flame-speed
improver, an alkali metal or alkaline earth metal salt of a
succinic acid derivative as described in EP-A-290 088, in similar
quantities to those described therein.
Apart from components already described above, the gasoline
composition may also contain other additives. Thus, it can contain
2~~~8~5
_ 2g _
a lead compound as anti-knock additive, and accordingly the
gasoline composition according to the invention includes both
leaded and unleaded gasoline. The gasoline composition can also
contain antioxidants such as phenolics, e.g. 2,6-di-tert-butyl-
S phenol, or phenylenediamines, e.g. N,NI-di-sec-butyl-p-phenylene-
diamine, or antiknock additives other than lead compounds, or
polyether amino additives, e.g. as described in US Patent No.
4,477,261 and EP-A-151 621.
The gasoline composition according to the invention comprises
a major amount of a gasoline (base fuel) suitable for use in
spark-ignition engines. This includes hydrocarbon base fuels
boiling essentially in the gasoline boiling range from 30 to 230°C.
These base fuels may comprise mixtures of saturated, olefinic and
aromatic hydrocarbons. They can be derived from straight-run
gasoline, synthetically produced aromatic hydrocarbon mixtures,
thermally or catalytically cracked hydrocarbon feedstocks,
hydrocracked petroleum fractions or catalytically reformed
hydrocarbons. The octane number of the base fuel is not critical
and will generally be above 65. In the gasoline, hydrocarbons can
be replaced up to substantial amounts by alcohols, ethers, ketones,
or esters. Naturally, the base fuels are desirably substantially
free of water, since water may impede a smooth combustion.
The polyalphaolefin and polyoxyalkylene compound may
conveniently be added as a blend with other chosen additives. A
convenient method for preparing the gasoline composition is
therefore to prepare a concentrate of the polyalphaolefin and
polyoxyalkylene compound together with the other additives, and
then to add this concentrate to the gasoline in the amount required
to produce the required final concentrations of additives.
The invention accordingly further provides a concentrate
suitable for addition to gasoline which comprises a gasoline-
compatible diluent, a polyalphaolefin as defined above, a
polyoxyalkylene compound as defined above, the weight ratio
polyalphaolefin:polyoxyalkylene compound being in the range 1:10 to
,~ z ~ a ~. $ z .~
- 29 -
10:1, and optionally also at least one hydrocarbon-soluble ashless
dispersant.
Advantageously, the polyalphaolefin and the polyoxyalkylene
compound together are present in an amount in the range 20~ to
80$ w and the ashless dispersant, if present, is present in an
amount in the range 5~ to 30$ w, all percentages being calculated
on the diluent.
Suitable gasoline-compatible diluents include hydrocarbons,
e.g. heptane, alcohols or ethers, such as methanol, ethanol,
propanol, 2-butoxyethanol or methyl tert-butyl ether. Preferably
the diluent is an aromatic hydrocarbon solvent such as toluene,
xylene, mixtures thereof or mixtures of toluene or xylene with an
alcohol. The solvent is preferably toluene. Optionally, the
concentrate may contain a dehazer, particularly a polyether-type
ethoxylated alkylphenol-formaldehyde resin. The dehazer, if
employed, can suitably be present in the concentrate in an amount
of from 0.01 to 2~w, calculated on the diluent.
In a further aspect, the invention provides a method for
operating a spark-ignition internal combustion engine which
comprises introducing into the combustion chambers of said engine a
gasoline composition as defined above in accordance with the
invention.
The invention will be further understood from the following
illustrative examples. In the examples, various additives are
designated as follows:-
(a) "PGHE" is a polyoxypropylene glycol hemiether (monoether)
prepared using a mixture of C12-15 alcohols as initiator, and
having Mn in the range 1200 to 1500 and a kinematic viscosity in
the range 72 to 82 mm2/s at 40°C according to ASTM D 445, available
under the trade designation "SAP 949" from member companies of the
Royal Dutch/Shell group;
(b) "PAO" is a polyalphaolefin, being a hydrogenated oligomer of
decease-1 having a viscosity at 100°C of 8 x 10 6 m2/s (8
centistokes).
- 30 -
(c) "PMP" is a 40~ w/w solution in xylene of polyisobutylene
succinimide prepared by reaction of a polyisobutylene of number
average molecular weight (Mn) 2470 (determined by quantitative
reaction With ozone) with maleic anhydride, followed by reaction of
the resulting polyisobutylene succinic anhydride product with a
mixture of tetraethylene pentamine, pentaethylene hexarnine and
hexamethylene heptamine (molar ratio 1:2:1) in molar ratio
anhydride: amine of 2:1.
In the examples which follow, amounts of PMP are quoted as
mounts of solution, and where amounts of xylene are quoted, these
do not include the xylene associated in the 40$ w/w solutions of
PMP.
In the examples, additive concentrates were prepared by taking
samples of PMP and adding, with stirring at 20°C, amounts of PAO
(and additional xylene), followed by addition of amounts of PGHE.
Samples of these additive concentrates were then incorporated into
gasoline compositions, with stirring, in amounts to give desired
concentrations of components. This mirrors actual industry
practice, and it is important both for the additive concentrates to
be fully stable, and for gasolines containing the additives to give
good performance in terms of engine cleanliness and avoidance of
valve sticking.
EXAMPLES 1 to 8
Additive concentrates in accordance with the invention and
comparative examples were prepared as described above and stored
for 6 weeks at 20°C and -20°C, after which stability was
assessed
visually. Results are given in Table I.
TABLE I
uantities
Addi- Ratio
Additive tional PHGE: Storage (6 weeks)
Oil
Example PMP PHGE PAO Xylene PAO at 20C and -20C
Comp. 20 25 105 1:0 deposits
A
1 20 12.5 12.5 40 1:1 clear '
21~482~
- 31
TABLE I (continued)
Quantities
(
)
Addi- Ratio
Additive tional PHGE: Storage (6 weeks)
Oil
Example PMP PHGE PAO Xylene PAO at 20C and -20C
Comp. 30 30 - 100 1:0 slightly hazy
B +
2 30 15 15 40 1:1 clear
Comp. 30 40 - 90 1:0 phase separation
C +
3 30 20 20 60 1:1 clear
4 30 25 15 80 1.67:1 clear
Comp. 40 40 - 100 phase separation
D +
5 40 20 20 70 1:1 clear
6 40 10 30 40 1:3 clear
7 20 17.5 17.5 50 1:1 clear
8 25 20 20 60 1:1 clear
+ = 20°C storage only
As can readily be observed, the additive concentrates of the
invention, containing both PHGE and PAO, had good storage
stability, whilst the comparative examples, containing PHGE alone
were insufficiently stable.
EXAMPLES 9 and 10
A standard VW Polo motor car, equipped with a single
carburettor, 4 cylinder, 1.043 litre capacity engine, was used for
evaluation of inlet valve cleanliness in a standard road test
sequence (Volkswagen Polo Road Test).
Before test inlet parts and combustion chambers were cleaned
and new, pre-weighed inlet valves and new spark plugs were fitted
to the engine, a new oil filter was fitted and the engine filled
with new engine oil. A small wind board was fixed to the roof of
the test vehicle to increase wind resistance, and hence engine
load. The fuel tank was drained and filled with test gasoline
composition prior to operation over a 5000 krn test distance. 37
minute test cycles were employed, wherein the vehicle was driven
for 30 minutes at 4500 r.p.m, in 4th gear (105 kph) and then
"... 21 ~ ~-~2~
- 32 -
allowed to idle for 7 minutes. 12 cycles were covered each day for
8 consecutive days to cover the test distance of 5000 km. At the
end of the test, the inlet valves were removed and weighed in order
to assess average weight of inlet valve deposits.
Gasoline compositions in accordance with the invention were
subject to comparative testing in tests carried out using unleaded
gasoline (95 ULG) containing no additives (base gasoline) or
containing PMP and either or both of PHGE and PAO. Results are
given in Table II following.
TABLE II
Concentrations
(ppmw)
Additive Average inlet valve
Oil
Test No. PMP PHGE PAO deposit weight (mg)
Comp. E - - - 387
Example 250 250 250 31
9
Comp. F 250 500 - 54
Comp. G 250 - 500 82
Example 300 200 200 20
10
Comp. H 300 300 - 44
The data in Table II show that in the instances (Examples 9
and 10) where additive oil comprises a combination of PHGE and PAO,
weights of deposit on the inlet valves are significantly and
surprisingly lower compared with the case where the corresponding
amount of additive oil consists solely of one or other PHGE and
3 0 p~,0 .
EXAMPLES 11 to 23
A standard Opel Ascona 1.6 motor car, equipped with a standard
4-cylinder 1.6 litre Type 16SH engine, was used for evaluation of
valve sticking by a standard test method.
' - 33
The test method involved driving the vehicle using a test
gasoline composition on normal city roads over a total distance of
130 km over a low-duty cycle (maximum speed 50 kph). The vehicle
was then stored overnight at -20°C, and the maximum compression
S pressure in each cylinder was measured and the average of the four
values was calculated. The higher the pressure value, the better
the result.
In similar manner to Table II, the compositions of the test
gasoline compositions, and the results obtained, are given in Table
III following, wherein "additive oil" consisted of PHGE and/or PAO:
TABLE III
Concentrations Ratio
mw PHGE:PAO Compression
Additive (w/w) in pressure
Test No. PMP Oil Additive Oil (bar)(x10 Pa)
Example 11 600 1050 1:1 13.1
Comp. I 600 1500 1:0 3:3
Example 12 600 1500 4:1 13.3
Example 13 600 1500 1.5:1 13.5
Example 14 600 1500 1:1.5 12.1
Example 15 600 1500 1:4 13.8
Comp. J 600 1500 0:1 10.3
Example 16 750 1200 1:1 11.1
Comp. K 750 1500 1:0 3.8
Example 17 750 1500 4:1 7.4
Example 18 750 1500 1.5:1 12.9
Example 19 750 1500 1:1.5 10.4
Example 20 750 1500 1:4 13.3
Comp. L 750 1500 0:1 13.5
Comp. M 900 900 1:0 0.5
Example 21 900 900 1.5:1 13.3
Example 22 900 900 1:1 13.8
Comp. N 900 900 0:1 13.4
Comp. 0 900 1200 1:0 3.5
Example 23 900 1200 1:1 13.0
Comp. P 900 1200 0:1 11.8
'
21~~-8~5
- 34 -
Those skilled in the art will appreciate that the above
concentrations represent three times normal commercial
concentrations in order to increase test severity.
The above results show that when the additive oil is a
combination of PHGE and PAO, the compression pressure result is
very good, always significantly superior to PHGE alone,
significantly better than would be predicted for intermediate
values between those for PHGE alone and PAO alone, and generally
comparable with, and sometimes even superior to those for PAO
alone.
EXAMPLES 24 to 47
The effect of gasoline composition on engine inlet system
deposits was assessed by induction system deposit simulator (ISD)
testing. In this test method, a gasoline composition was metered
to a spray nozzle from which it was expelled in a flat spray
pattern onto the surface of an aluminium tube heated to 250°C. The
base gasoline used incorporated aged thermally cracked gasoline, in
order to encourage formation of deposits. Under the test
conditions, such base gasolines alone form a central carbonaceous
deposit on.the tube surface. Cleanliness-promoting agents prevent
deposition in the central area and result in a ring-like deposit on
the tube. Residue formation is assessed visually according to the
following scale:
0 - clean
1-2 - nearly clean
3-4 - slightly coked
5-6 - medium coked
7-8 - medium to heavily
coked
9-10 - heavily coked
over 10 - very heavily coked
In similar manner to Table III, results of the ISD testing are
given in Table IV following:
- 35 -
TABLE IV
Concentrations Ratio
(p mw)
Additive PHGE:PAO in
Test No. PMP Oil Additive Oil ISD Rating
Example 24 100 175 1:1 6
Example 25 100 200 1:1 4
Comp. Q 100 250 1:0 5
Example 26 100 250 4:1 6
Example 27 100 250 1.5:1 7
Example 28 100 250 1:1.5 6
Example 29 100 250 1:4 6
Comp. R 100 250 0:1 14
Comp. S 125 250 1:0 3
Example 30 125 250 4:1 3
Example 31 125 250 1.5:1 4
Example 32 125 250 1:1.5 7
Example 33 125 250 1:4 6
Comp. T 125 250 0:1 14
Comp. U 150 150 1:0 2
Example 34 150 150 1:1 3
Comp. V 150 150 0:1 12
Comp. W 150 200 1:0 4
Example 35 150 200 1:1 3
Comp. X 150 200 0:1 12
Example 36 200 350 1:1 3
Comp. Y 200 500 1:0 2
Example 37 200 500 4:1 1
Example 38 200 500 1.5:1 2
Example 39 200 500 1:1.5 3
Example 40 200 500 1:4 4
Comp. Z 200 500 0:1 9
Example 41 250 400 1:1 3
Comp. AA 250 500 1:0 1
Example 42 250 500 4:1 1
Example 43 250 500 1.5:1 2
Example 44 250 500 1:1.5 3
Example 45 250 500 1:4 3
Comp. BB 250 500 0:1 6
r..
s
- 36 -
TABLE IV (continued)
Concentrations Ratio
( mw)
Additive PHGE:PAO in
Test No. PMP Oil Additive Oil ISD Rating
Comp. CC 300 300 1:0 1
Example 46 300 300 1:1 2
Comp. DD 300 300 0:1 7
Comp. EE 300 400 1:0 1
Example 47 300 400 1:1 3
Comp. FF 300 400 0:1 7
The results in Table IV show that when the additive oil is a
combination of PHGE and PAO, the ISD rating is generally good,
always superior to PAO alone, significantly better than would be
predicted for intermediate values between those for PHGE alone and
PAO alone, and generally comparable with those for PHGE alone.
In conclusion, it can be noted that additive concentrates
containing both PHGE and PAO had good storage stability, by
comparision with similar concentrates containing PHGE but not PAO;
inlet valve deposits were found to be lower in gasolines containing
additive oil in the form of a combination of PHGE and PAO compared
with those in which the additive oil was solely PHGE or PAO;
avoidance of valve sticking, as evidenced by compression pressure
assessment, was significantly superior for combinations of PHGE and
PAO than for PHGE alone, and generally comparable to PAO alone; and
avoidance of deposit formation, as evidenced by ISD testing, was
significantly superior for combinations of PHGE and PAO than for
PAO alone, and generally comparable to PHGE alone.
