Note: Descriptions are shown in the official language in which they were submitted.
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Quaternized copolymer
Description
The present invention relates to a quaternized copolymer which by the reaction
steps of
(A) copolymerization of one or more straight-chain, branched or cyclic,
ethylenically
unsaturated C2 to C1o0 hydrocarbons (monomer M1), which may bear one or more
oxygen- or nitrogen-functional substituents which cannot be reacted with
amines to
give amides or imides or with alcohols to give esters, with one or more
ethylenically
unsaturated C3- to C12-carboxylic acids or C3- to C12-carboxylic acid
derivatives
(monomer M2), which bear one or two carboxylic acid functions and can be
reacted
with amines to give amides or imides or with alcohols to give esters, to give
a
copolymer (CP) with a number-average molecular weight Mn of 500 to 20 000;
(B) partial or full amidation or imidation or esterification of the carboxylic
acid functions
of the (M2) units in the copolymer (CP) by reacting them with one or more
oligoamines (OA) having 2 to 6 nitrogen atoms or alcoholamines (AA), each of
which comprises at least one primary or secondary nitrogen atom or at least
one
hydroxyl group and at least one quaternizable tertiary nitrogen atom;
(C) partial or full quaternization of the at least one tertiary nitrogen atom
in the OA or
AA units with at least one quaternizing agent (QM);
where the sequence of steps (B) and (C) may also be reversed, such that the
partial or
full amidation or imidation of esterification of the carboxylic acid functions
of the (M2)
units in the copolymer (CP) can be effected by reacting with the oligoamines
(OA) or
alcoholamines (AA) already quaternized in reaction step (C).
The present invention further relates to a process for preparing such a
quaternized
copolymer.
The present invention also relates to fuels having a content of such a
quaternized
copolymer.
The present invention further relates to the use of this quaternized copolymer
as a fuel
additive for reducing or preventing deposits in the injection systems of
direct-injection
diesel engines, especially in common-rail injection systems, for reducing fuel
consumption in direct-injection diesel engines, especially in diesel engines
with common-
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rail injection systems, and for minimizing power loss in direct-injection
diesel engines,
especially in diesel engines with common-rail injection systems.
In direct-injection diesel engines, the fuel is injected and distributed
ultrafinely (nebulized)
by a multihole injection nozzle which reaches directly into the combustion
chamber in the
engine, instead of being introduced into a prechamber or swirl chamber as in
the case of
the conventional (chamber) diesel engine. The advantage of the direct-
injection diesel
engines lies in their high performance for diesel engines and a nevertheless
low fuel
consumption. Moreover, these engines achieve a very high torque even at low
speeds.
At present, essentially three methods are being used to inject the fuel
directly into the
combustion chamber of the diesel engine: the conventional distributor
injection pump, the
pump-nozzle system (unit-injector system or unit-pump system) and the common-
rail
system.
In the common-rail system, the diesel fuel is conveyed by a pump with
pressures up to
2000 bar into a high-pressure line, the common rail. Proceeding from the
common rail,
branch lines run to the different injectors which inject the fuel directly
into the combustion
chamber. The full pressure is always applied to the common rail, which enables
multiple
injection or a specific injection form. In the other injection systems, in
contrast, only one
injection is possible. The injection in the common rail is divided essentially
into three
groups: (1.) pre-injection, by which essentially softer combustion is
achieved, such that
hard combustion noises ("nailing") are reduced and the engine appears to run
quietly; (2.)
main injection, which is responsible especially for a good torque profile; and
(3.) post-
injection, which especially ensures a low NOx value. In this post-injection,
the fuel is
generally not combusted, but instead evaporated by residual heat in the
cylinder. The
exhaust gas/fuel mixture formed is transported to the exhaust gas system,
where the fuel,
in the presence of suitable catalysts, acts as a reducing agent for the
nitrogen oxides
NO.
The variable, cylinder-individual injection in the common-rail injection
system can
positively influence the pollutant emission of the engine, for example the
emission of
nitrogen oxides (NOx), carbon monoxide (CO) and especially of particulates
(soot). This
makes it possible, for example, that engines equipped with common-rail
injection systems
can meet the Euro 4 standard theoretically even without additional particulate
filters.
In modern common-rail diesel engines, under particular conditions, for example
when
biodiesel-containing fuels or fuels with metal impurities such as zinc
compounds are
used, deposits can form on the injector orifices, which adversely affect the
injection
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performance of the fuel and hence impair the performance of the engine, i.e.
especially
reduce the power, but in some cases also worsen the combustion. The formation
of
deposits is enhanced further by further developments of the injector
construction,
especially by the change in the geometry of the nozzles (narrower, conical
orifices with
rounded outlet). For lasting optimal functioning of engine and injectors, such
deposits in
the nozzle orifices must be prevented or reduced by suitable fuel additives.
It was therefore an object of the present invention to provide fuel additives
which remedy
the shortcomings outlined above, i.e. more particularly prevent or reduce
deposits in the
injection systems, in particular in the injectors, of direct-injection diesel
engines, reduce
fuel consumption in direct-injection diesel engines and minimize power losses
in such
engines.
The prior art discloses C8- to C200-alkyl- or -alkenylsuccinimides as
detergent additives for
fuels such as middle distillate fuels and gasoline fuels. For instance, WO
02/092645 (1)
describes polyalkenylsuccinimides such as polyisobutenylsuccinimides as
additives to
fuels such as diesel fuel, heating oil or gasoline fuel, or to lubricants,
which - obviously as
a result of the preparation - may comprise up to 30% by weight of the
corresponding
polyalkenylsuccinamides or -succinic monoamides. These polyalkenylsuccinimides
are
said to counteract engine deposits and deposits on the injection nozzles.
WO 2006/100083 (2) discloses that particular detergent additives reduce the
amount of
particulates in the exhaust gas emissions of direct-injection diesel engines
such as diesel
engines with common-rail injection systems. Detergent additives include
additives
comprising moieties which are derived from succinic anhydride and have
hydroxyl and/or
amino and/or amido and/or imido groups, such as the corresponding derivatives
of
polyisobutenylsuccinic anhydride, especially derivatives with aliphatic
polyamines. The
moieties with hydroxyl and/or amino and/or amido and/or imido groups are, for
example,
carboxylic acid groups, acid amides of monoamines, acid amides of di- or
polyamines,
which still have free amino groups as well as the amide function, succinic
acid derivatives
with one acid and one amide function, carboximides with monoamines,
carboximides with
di- or polyamines, which still have free amine groups as well as the imide
function, or
diimides which are formed by reaction of di- or polyamines with two succinic
acid
derivatives.
EP 1 887 074 Al (3) describes a process for removing or reducing injector
deposits in
diesel engines using reaction products between a hydrocarbyl-substituted
succinic acid or
anhydride thereof, for example polyisobutenylsuccinic anhydride, and
hydrazine. Among
these reaction products, monohydrazide structures are also mentioned.
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WO 2006/135881 (4) describes the condensation of hydrocarbyl-substituted
acylating
agents, which are obtainable by ene reaction of olefins with maleic anhydride,
with
amines having an additional tertiary amino group and subsequent quaternization
of the
tertiary amino group to give quaternary ammonium salts, which are suitable as
fuel
additives for cleaning and keeping clean intake systems of internal combustion
engines.
The above-described C8-C200-alkyl- or -alkenylsuccinimides which are known
from the
prior art and frequently used in practice, such as polyisobutenylsuccinimides
and related
systems, are capable of achieving the specific object outlined only to an
insufficient
degree; however, the additional use thereof in the present invention as
further fuel
additives in a minor amount is not harmful.
This object is achieved by the use of the quaternized copolymer cited at the
outset, which
is obtainably by reaction steps (A), (B) and (C).
The present application also provides a process for preparing a quaternized
copolymer,
which comprises performing the following reaction steps:
(A) copolymerization of one or more straight-chain, branched or cyclic,
ethylenically
unsaturated C2 to C1oo hydrocarbons (monomer M1), which may bear one or more
oxygen- or nitrogen-functional substituents which cannot be reacted with
amines to
give amides or imides or with alcohols to give esters, with one or more
ethylenically
unsaturated C3- to C12-carboxylic acids or C3- to C12-carboxylic acid
derivatives
(monomer M2), which bear one or two carboxylic acid functions and can be
reacted
with amines to give amides or imides or with alcohols to give esters, to give
a
copolymer (CP) with a number-average molecular weight M, of 500 to 20 000;
(B) partial or full amidation or imidation or esterification of the carboxylic
acid functions
of the (M2) units in the copolymer (CP) by reacting them with one or more
oligoamines (OA) having 2 to 6 nitrogen atoms or alcoholamines (AA), each of
which comprises at least one primary or secondary nitrogen atom or at least
one
hydroxyl group and at least one quaternizable tertiary nitrogen atom;
(C) partial or full quaternization of the at least one tertiary nitrogen atom
in the OA or
AA units with at least one quaternizing agent (QM);
where the sequence of steps (B) and (C) may also be reversed, such that the
partial or
full amidation or imidation of esterification of the carboxylic acid functions
of the (M2)
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units in the copolymer (CP) can be effected by reacting with the oligoamines
(OA) or
alcoholamines (AA) already quaternized in reaction step (C).
The copolymer (CP) obtained in reaction step (A) is known in principle from EP-
A 307
5 815 (6). The use of the copolymer (CP) in the form of the alkali metal or
alkaline earth
metal salts is recommended therein for prevention or reduction of wear
phenomena on
the valves of gasoline engines and for simultaneous reduction of corrosion in
gasoline
engines.
Examples of optional oxygen- or nitrogen-functional substitutes which may
occur in the
monomers (Ml) in reaction step (A) are ether oxygen atoms or carboxamide
moieties.
In a preferred embodiment, the monomers (Ml) in reaction step (A) are selected
from C2-
to Cao-alkenes, C3- to C,o-cycloolefins, alkyl vinyl ethers having 1 to 30
carbon atoms in
the alkyl group, cycloalkyl vinyl ethers having 3 to 10 carbon atoms in the
alkyl group and
oligo- or polyisobutenes having 8 to 96 carbon atoms.
Examples of very suitable straight-chain or branched C2- to Cao-alkenes are
ethylene,
propylene, butene-1, isobutene, pentene-1, 3-methylbutene-1, hexene-1, 4-
methyl-
pentene-1,3,3-dimethylbutene-1, heptene-1, 4-methylhexene-1, 5-methylhexene-1,
4,4-
dimethylpentene-1, octene-1, 2,4,4-trimethylpentene-1, 2,4,4-trimethylpentene-
2, isomer
mixture of 2,4,4-trimethylpentene-1 and 2,4,4-trimethylpentene-2
("diisobutene"), 4,4-
dimethylhexene-1, decene-1, dodecene-1, tetradecene-1, hexadecene-1,
octadecene-1,
C2o-olefin-1, C22-olefin-1, C2a-olefin-1, C26-olefin-1, C28-olefin-1, Cao-
olefin-1, C40-olefin-1,
C2o-24-olefin-1, C22/24-olefin-1, C2a-28-olefin-1, and mixtures of the alkenes
mentioned with
one another. Among these, preference is given to straight-chain or branched
C12- to C30-
alkenes, especially straight-chain or branched C16- to C26-alkenes, in
particular straight-
chain or branched C20- to C24-alkenes.
Examples of very suitable C3- to Cio-cycloolefins are cyclobutene,
cyclopentene,
cyclohexene, cycloheptene and cyclooctene, and mixtures of the cycloolefins
mentioned
with one another. Among these, cyclopentene and cyclohexene are preferred.
Examples of very suitable alkyl vinyl ethers having 1 to 30 carbon atoms in
the straight-
chain or branched alkyl group are methyl vinyl ether, ethyl vinyl ether, n-
propyl vinyl ether,
isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl
vinyl ether, n-pentyl
vinyl ether, n-hexyl vinyl ether, 2-methylpentyl vinyl ether, n-heptyl vinyl
ether, n-octyl
vinyl ether, 2-ethylhexyl vinyl ether, 2,2,4-trimethylpentyl vinyl ether, n-
decyl vinyl ether,
2-propylheptyl vinyl ether, n-dodecyl vinyl ether, isododecyl vinyl ether, n-
tridecyl vinyl
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ether, isotridecyl vinyl ether, n-tetradecyl vinyl ether, n-hexadecyl vinyl
ether, n-octadecyl
vinyl ether, n-eicosyl vinyl ether, n-docosyl vinyl ether, n-tetracosyl vinyl
ether, n-
hexacosyl vinyl ether, n-octacosyl vinyl ether, oleyl vinyl ether, and
mixtures of the alkyl
vinyl ethers mentioned with one another. Among these, preference is given to
alkyl vinyl
ethers with straight-chain or branched C8- to C26-alkyl groups, especially
straight-chain or
branched C12- to C24-alkyl groups, in particular straight-chain or branched
C16- to C22-alkyl
groups.
Examples of very suitable cycloalkyl vinyl ethers having 3 to 10 carbon atoms
in the
cycloalkyl group are cyclobutyl vinyl ether, cyclopentyl vinyl ether,
cyclohexyl vinyl ether,
cycloheptyl vinyl ether and cyclooctyl vinyl ether, and mixtures of the
cycloalkyl vinyl
ethers mentioned with one another. Among these, preference is give to
cyclopentyl vinyl
ether and cyclohexyl vinyl ether.
Useful oligo- or polyisobutenes having 8 to 96 carbon atoms, especially 44 to
92 carbon
atoms, are in particular polyisobutenes with a high content of terminal (a)
double bonds,
typically of at least 70 mol%, especially of at least 80 mol%, for example
those with a
number-average molecular weight Mn of 550, 700 or 1000.
In addition to the preferred monomers (Ml) mentioned, it is, for example, also
possible to
use acrylamides or methacrylamides such as N-(C,-C3o-alkyl)acrylamides, N,N-di-
(C,-C30-
alkyl)acrylam ides, N-(C,-C3o-alkyl)methacrylamides or N,N-di(C,-Cso-alkyl)-
methacrylamides as monomers (Ml).
The monomers (Ml) in reaction step (A) preferably bear the polymerizable
ethylenically
unsaturated double bond in the a position, i.e. the ethylenically unsaturated
double bond
is in the terminal position in the form of the structural element >C=H2 in the
monomer
(M1).
In a preferred embodiment, the monomers (M2) in reaction step (A) are selected
from
acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid,
and the
anhydrides thereof, halides thereof, i.e. the fluorides, chlorides, bromides
or iodides
thereof, and esters thereof, especially the Cl- to C30-alkyl esters thereof.
Particular
preference is given to maleic acid and maleic anhydride.
In addition to the preferred monomers (M2) mentioned, it is, for example, also
possible to
use crotonic acid, isocrotonic acid, but-1-enecarboxylic acid, pent-1-
enecarboxylic acid,
hex-1-enecarboxylic acid, hept-1-enecarboxylic acid, oct-1-enecarboxylic acid,
non-1-
enecarboxylic acid, dec-1-enecarboxylic acid, undec-1-enecarboxylic acid,
citraconic acid
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or mesaconic acid, and the anhydrides thereof, halides thereof, i.e. the
fluorides,
chlorides, bromides or iodides thereof, and esters thereof, especially the Cl-
to C3o-alkyl
esters thereof, as monomers (M2).
Typically, the monomer units (Ml) and (M2) are present in a weight ratio of
30:70 to
70:30, especially 40:60 to 60:40, in the copolymer (CP) of reaction step (A).
The copolymer (CP) has a number-average molecular weight Mn of 500 to 20 000,
especially of 1000 to 18 000, in particular of 4000 to 16 000 (determined in
each case by
gel permeation chromatography), and generally a polydispersity (quotient of
weight-
average molecular weight and number-average molecular weight: PDI = MW/Mn) of
1.3 to
10, especially of 1.6 to 5, in particular of 2.0 to 2.5.
The two monomer units (Ml) and (M2) are generally present in alternating or
random
distribution in the copolymer (CP). However, it is possible in principle by
particular
process regimes known to those skilled in the art also to obtain block
copolymers from
the monomers (Ml) and (M2).
The monomers (Ml) and (M2) are generally copolymerized by free-radical means.
The
copolymerization makes use of known customary polymerization techniques, such
as
bulk polymerization, suspension polymerization, precipitation polymerization
or solution
polymerization. It is generally initiated with the customary free-radical
initiators, for
example with acetylcyclohexanesulfonyl peroxide, diacetyl peroxydicarbonate,
dicyclohexyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, tert-butyl
perneodecanoate, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), tert-butyl
perpivalate,
tert-butyl per-2-ethylhexanoate, tert-butyl permaleate, 2,2'-azobis-
(isobutyronitrile),
bis(tert-butyl peroxide)cyclohexane, tert-butyl peroxyisopropylcarbonate, tert-
butyl
peracetate, dicumyl peroxide, di-tert-amyl peroxide, di-tert-butyl peroxide, p-
methane
hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide or mixtures of
the free-
radical initiators mentioned. Typically, these free-radical initiators are
used in amounts of
0.1 to 10% by weight, especially 0.2 to 5% by weight, calculated using the
total amount of
monomers used.
In general, the copolymerization is effected at temperatures of 40 to 250 C,
especially 80
to 220 C, appropriately working under pressure when using volatile monomers
(Ml) with
boiling points below the copolymerization temperature. The copolymerization is
typically
perfomed with exclusion of air or oxygen, i.e. if it is not possible to work
under boiling
conditions, inertizing agents such as nitrogen are used, since oxygen retards
the
copolymerization. The additional use of redox coinitiators, for example
benzoin,
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dimethylaniline, ascorbic acid, and organic-soluble complexes of heavy metals
such as
copper, cobalt, manganese, iron, nickel and chromium, can accelerate the
copolymerization.
To control the molecular weight, especially to obtain a copolymer with
relatively low
molecular weight, regulators can be used additionally. Suitable regulators
are, for
example, allyl alcohols and organic mercapto compounds, such as 2-
mercaptoethanol, 2-
mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid, tert-butyl
mercaptan, n-
octyl mercaptan, n-dodecyl mercaptan or tert-dodecyl mercaptan, which are
typically
used in amounts of 0.1 to 10% by weight, based on the total amount of the
monomers
used.
When the polymerization technique of suspension polymerization, precipitation
polymerization or solution polymerization is employed in the preparation of
(CP), the use
of a suitable inert solvent or solvent mixture is required. Suitable for this
purpose are
generally - of course always specifically for the particular polymerization
technique
employed - for example aliphatic and cycloaliphatic hydrocarbons such as
pentane,
hexane, heptane, octane, isooctane, cyclohexane, methylcyclohexane,
ethylcyclohexane,
dimethylcyclohexane or diethylcyclohexane, aromatic hydrocarbons such as
toluene,
xylenes, ethylbenzene or cumene, technical-grade mixtures of relatively high-
boiling
aromatic hydrocarbons, as commercially available under the "Solvesso" name in
particular, for example Solvesso 150 or Solvesso 200, aliphatic
halohydrocarbons such
as dichloromethane, chloroform, tetrachloromethane, 1,1- or 1,2-
dichloroethane, 1,1,1- or
1,1,2-tichloroethane, 1,1,2-trichloroethylene, tetrachloroethylene, 1,2-
dichloropropane,
butyl chloride, 1,1,2-trichloro-1,2,2-tifluoroethane, 1,1,1,2-tetrachloro-2,2-
difluoroethane
or 1,1,2,2-tetrachloro-1,2-difluoroethane, and ethers such as diethyl ether,
dipropyl ether,
dibutyl ether, methyl tert-butyl ether, dioxane, tetrahydrofuran, diethylene
glycol dimethyl
ether and mixtures of the solvents mentioned.
In precipitation polymerization and suspension polymerization, the additional
use of
protective colloids is, respectively, appropriate and necessary. Protective
colloids are
usually polymeric substances which have good solubility in the solvent used
and do not
enter into any reactions with the monomers. Suitable protective colloids which
can be
used in the preparation of (CP) are, for example, copolymers of maleic
anhydride with
vinyl alkyl ethers and/or olefins having 8 to 20 carbon atoms, and the
monoesters thereof
with C,o- to C2o-alcohols, or the mono- or diamides thereof with C,o- to C2o-
alkylamines,
and also polyalkyl vinyl ethers whose alkyl groups comprise 1 to 20 carbon
atoms, for
example polymethyl, polyethyl, polyisobutyl or polyoctadecyl vinyl ether. The
amounts of
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protective colloids added are typically 0.05 to 4% by weight, especially 0.1
to 2% by
weight, and it is often advantageous to combine a plurality of protective
colloids.
The reaction equation depicted below shows, in accordance with the present
invention,
by way of example, the structures of a copolymer CP formed from C22-olefin-1
and maleic
anhydride ("MA") (where "MW" is the number-average molecular weight Mn), the
corresponding amidation product with 3-(N,N-dimethylamino)propylamine
("DMPAP") and
the corresponding quaternization product with propylene oxide ("PO") / acetic
acid
("HOAc"):
nC H O DMAPA 0
22 45
O nCzzHas
n
n
C22-Olefin-MA Copolymer MW 4000-16000
*
HOAc, PO 0
nCz2Has N, OH
N
n O
The oligoamines (OA) used in reaction step (B) preferably have a total of 2 to
4 nitrogen
atoms, especially a total of 2 or 3 nitrogen atoms, in particular a total of 2
nitrogen atoms,
at least one of which in each case is a quaternizable tertiary nitrogen atom.
The alcoholamines (AA) used in reaction step (B) have preferably 1 to 3
nitrogen atoms,
at least one of which is a quaternizable tertiary nitrogen atom, and 1 to 3
hydroxyl groups,
especially one quaternizable nitrogen atom and 1 to 3 hydroxyl groups, in
particular one
quaternizable tertiary nitrogen atom and one hydroxyl group. The hydroxyl
groups are
generally alcoholic hydroxyl groups, i.e. they are borne by an spa-hybridized
carbon atom.
The oligoamines (OA) and alcoholamines (AA) used in reaction step (B)
typically have a
total carbon number of not more than 75, especially of not more than 50, in
particular of
not more than 30.
For the partial or full amidation or imidation of the carboxylic acid
functions of the units
(M2) in (CP) in reaction step (B), suitable oligoamines (OA) in a preferred
embodiment
CA 02803207 2012-12-19
are compounds of the general formula (la)
R1R2N-(CH2)n-NR3R4 (la)
5 in which
the variables R1 and R2 are each hydrogen or C,- to CM-alkyl groups, where at
least one
of the variables R1 and R2 is hydrogen,
10 the variables R3 and R4 each independently denote Cl- to C2o-alkyl groups
or, together
with the nitrogen atom to which they are bonded, form a saturated, partly
unsaturated or
unsaturated five-membered or six-membered heterocyclic ring, and
the variable n is from 1 to 12, especially from 2 to 6, in particular 2 or 3.
For the partial or full esterification of the carboxylic acid functions of the
units (M2) in (CP)
in reaction step (B), suitable alcoholamines (AA) in a preferred embodiment
are
compounds of the general formula (lb)
[HO-(CH2)m]XN(R5)y(R6)Z (lb)
in which
the variables R5 and R6 each independently denote Cl- to C2o-alkyl groups or,
in the case
that y = z = 1, together with the nitrogen atom to which they are bonded, form
a saturated,
partly unsaturated or unsaturated five-membered or six-membered heterocyclic
ring,
the variable m is from 1 to 12, especially from 2 to 6, in particular 2 or 3,
and
the variables x, y and z are each 0, 1, 2 or 3, where the sum of x + y + z
must give the
value of 3.
Examples of useful Cl- to C2o-alkyl groups which may occur as substituents in
the
compounds of the general formulae (la) and (lb) include methyl, ethyl, n-
propyl, iso-
propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, tert-
pentyl, n-hexyl, n-
heptyl, n-octyl, 2-ethylhexyl, n-nonyl, isononyl, 2-propylheptyl, n-decyl, n-
dodecyl, n-
tridecyl, isotridecyl, n-tetradecyl, n-hexydecyl, n-octadecyl and eicosyl.
Preferably C,- to
C8-alkyl groups occur here, especially Cr to C4-alkyl groups.
CA 02803207 2012-12-19
11
Examples of useful saturated, partly unsaturated or unsaturated five-membered
or six-
membered heterocyclic rings which may form the variables R3 and R4 or R5 and
R6
together with the nitrogen atom to which are they are bonded include
imidazoles,
benzimidazoles, pyrazoles, imidazolines, piperazines, piperidines or
pyridines.
Examples of compounds of the general formula (la) are 2-(N,N-dimethylamino)-
ethylamine, 2-(N,N-diethylamino)ethylamine, 2-(N,N-di-n-
propylamino)ethylamine, 2-
(N,N-diisopropylamino)ethylamine, 2-(N,N-di-n-butylamino)ethylamine, 3-(N,N-
dimethylamino)propylamine, 3-(N,N-diethylamino)propylamine, 3-(N,N-di-n-
propylamino)propylamine, 3-(N,N-diisopropylamino)propylamine, 3-(N,N-di-n-
butylamino)propylamine, N-(2-aminoethyl)imidazole, N-(2-
aminoethyl)benzimidazole, N-
(3-aminopropyl)imidazole, N-(3-aminopropyl)benzimidazole, N-methylpiperazine,
N-
ethylpiperazine, N-n-propylpiperazine, N-isopropylpiperazine and N-n-
butylpiperazine.
Examples of the compounds of the general formula (lb) are triethanolamine, tri-
n-
propanolamine, triisopropanolamine, N-methyldiethanolamine, N-methyl-di-n-
propanol-
amine, N-methyl-diisopropanolamine, N,N-dimethylethanolamine, N,N-
dimethylpropanolamine, N,N-dimethylisopropanolamine, N-(2-
hydroxyethyl)imidazole, N-
(2-hydroxyethyl)benzimidazole, N-(3-hydroxypropyl)imidazole, N-(3-
hydroxypropyl)-
benzimidazole, N-(2-hydroxyethyl)piperidine and N-(3-hydroxypropyl)piperidine.
The amidation, imidation or esterification in reaction step (B) is typically
performed in a
suitable solvent or solvent mixture, for example in aliphatic and
cycloaliphatic
hydrocarbons such as pentane, hexane, heptane, octane, isooctane, cyclohexane,
methylcyclohexane, ethylcyclohexane, dimethylcyclohexane or
diethylcyclohexane,
aromatic hydrocarbons such as toluene, xylenes, ethylbenzene or cumene,
technical-
grade mixtures of relatively high-boiling aromatic hydrocarbons, as
commercially
available under the "Solvesso" name in particular, for example Solvesso 150 or
Solvesso
200, aliphatic halohydrocarbons such as dichloromethane, chloroform,
tetrachloromethane, 1,1- or 1,2-dichloroethane, 1,1,1- or 1,1,2-
trichloroethane, 1,1,2-
trichloroethylene, tetrachloroethylene, 1,2-dichloropropane, butyl chloride,
1,1,2-trichloro-
1,2,2-trifluoroethane, 1, 1, 1,2-tetrachloro-2,2-difluoroethane or 1,1,2,2-
tetrachloro-1,2-
difluoroethane, and ethers such as diethyl ether, dipropyl ether, dibutyl
ether, methyl tert-
butyl ether, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether and
mixtures of the
solvents mentioned.
In the amidation and the esterification, the conditions are generally
temperatures of 20 to
150 C, especially of 25 to 120 C; the reaction is complete when all volatile
compounds
released in the reaction, such as water, hydrogen halide or alcohols, have
been removed.
CA 02803207 2012-12-19
12
In the case that an imide is obtained, the procedure in reaction step (B)
preferably has
two stages, by first performing an amidation - as described above - at
temperatures of 20
to 150 C, especially of 25 to 120 C, and then heating to higher temperatures,
appropriately to 120 to 250 C, especially to 150 to 200 C; it is advisable
here to use a
correspondingly higher-boiling solvent or solvent mixture, such as Solvesso
150 or
Solvesso 200, and/or to apply reduced pressure.
Useful quaternizing agents (QM) for reaction step (C) are in principle all
compounds
suitable as such. In a preferred embodiment, however, the quaternization in
reaction step
(C) of the at least one quaternizable tertiary nitrogen atom is effected with
at least one
quaternizing agent selected from epoxides, dialkyl sulfates, dialkyl sulfites,
alkyl halides,
arylalkyl halides; alkyl carboxylates and dialkyl carbonates.
Suitable epoxides are, for example, C2-C12-alkylene oxides such as ethylene
oxide,
propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 2-methyl-1,2-propene
oxide
(isobutene oxide), 1,2-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene
oxide, 3-
methyl- 1,2-butene oxide, 1,2-hexene oxide, 2,3-hexene oxide, 3,4-hexene
oxide, 2-
methyl-1,2-pentene oxide, 2-ethyl-1,2-butene oxide, 3-methyl-1,2-pentene
oxide, 1,2-
decene oxide, 1,2-dodecene oxide or 4-methyl-1,2-pentene oxide, and aromatic-
substituted ethylene oxides such as styrene oxide or 4-methylstyrene oxide.
In the case of use of epoxides as quaternizing agents, they are preferably
used in
combination with protic acids, especially with C,-C12-monocarboxylic acids
such as formic
acid, acetic acid or propionic acid, or C2-C12-dicarboxylic acids such as
oxalic acid or
adipic acid; also suitable, however, are sulfonic acids such as
benzenesulfonic acid or
toluenesulfonic acid, or aqueous mineral acids such as sulfuric acid or
hydrochloric acid.
Suitable dialkyl sulfates are preferably di(C,-C2o-alkyl) sulfates, especially
di(C,-C4-alkyl)
sulfates such as dimethyl sulfate or diethyl sulfate. On completion of
quaternization, the
monoalkyl sulfates and sulfates formed as counterions can be removed, i.e.
exchanged,
by treatment with anion exchangers.
Suitable dialkyl sulfites are preferably di(C,-C2o-alkyl) sulfites, especially
di(C,-C4-alkyl)
sulfites such as dimethyl sulfite or diethyl sulfite. On completion of
quaternization, the
monoalkyl sulfites and sulfites formed as counterions can be removed, i.e.
exchanged, by
treatment with anion exchangers.
Suitable alkyl halides are preferably C,-C20-alkyl fluorides, chlorides,
bromides or iodides,
especially C,-C4-alkyl fluorides, chlorides, bromides or iodides, such as
methyl chloride,
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methyl bromide, methyl iodide, ethyl chloride, ethyl bromide or ethyl iodide.
On
completion of quaternization, halide anions formed as counterions can be
removed, i.e.
exchanged, by treatment with anion exchangers.
Suitable benzyl halides are, for example, benzyl chloride, benzyl bromide or
benzyl
iodide; the benzene ring of the benzyl radical may in principle also bear one
or more
substituents such as C,-C4-alkyl groups. On completion of quaternization, the
halide
anions formed as counterions can be removed, i.e. exchanged, by treatment with
anion
exchangers.
Suitable alkyl carboxylates are preferably mono- or di(C,-C2o-alkyl) mono- or
dicarboxylates, especially mono- or di(C,-C4-alkyl) mono- or dicarboxylates,
where the
parent mono- or dicarboxylic acid has 1 to 12 or 2 to 12 carbon atoms
respectively, for
example methyl formate or dimethyl oxalate. Similarly to the case of the
epoxides, when
using alkyl carboxylates as quaternizing agents, it is often advisable to use
them
preferably in combination with protic acids, especially with C,-C,2-
monocarboxylic acids
such as formic acid, acetic acid or propionic acid, or C2-C,2-dicarboxylic
acids such as
oxalic acid or adipic acid, or else sulfonic acids such as benzenesulfonic
acid or
toluenesulfonic acid, or aqueous mineral acids such as sulfuric acid or
hydrochloric acid.
Suitable alkyl carbonates are preferably di(C,-C2o-alkyl) carbonates,
especially di(C,-C4-
alkyl) carbonates such as dimethyl carbonate or diethyl carbonate.
The quaternization of reaction step (C) - whether it be that of the isolated
oligoamines
(OA) or alcoholamines (AA) or that of the (OA) or (AA) units in the already
amidated,
imidated or esterified copolymer (CP) - is performed by known techniques
customary
therefor. The conditions here are typically temperatures in the range from 15
to 180 C,
especially from 20 to 150 C, and standard pressure or elevated pressure, at
elevated
pressure especially in the case of use of volatile quaternizing agents QM such
as short-
chain epoxides or alkyl halides, in which case it is appropriate to perform
the
quaternization reaction in a pressure vessel or autoclave. The quaternization
reaction can
be performed in an inert organic solvent such as toluene or xylene or in a
technical-grade
mixture of relatively high-boiling aromatic hydrocarbons, as commercially
available under
the "Solvesso" name in particular, for example in Solvesso 150 or Solvesso
200. In
general, 0.1 to 1.5 equivalents, especially 0.5 to 1.25 equivalents, of
quaternizing agent
are used per equivalent of quaternizable tertiary nitrogen atom, where the
quaternizing
agent may be a single chemical compound or a mixture of different chemical
compounds
suitable for quaternization. In the case of additional use of protic acids,
they are typically
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14
used in equimolar amounts or in an up to 2.5-fold excess to the quaternizing
agent; in this
case, it is possible to use a single protic acid or a mixture of different
protic acids.
The inventive quaternized copolymer is outstandingly suitable as a fuel
additive and can
in principle be used in any fuels. It brings about a whole series of
advantageous effects in
the operation of internal combustion engines with fuels. The inventive
quaternized
copolymer is preferably used in gasoline fuels, but especially in middle
distillate fuels.
The present invention therefore also provides fuels, especially middle
distillate fuels, with
a content of the inventive quaternized copolymer effective as an additive for
achieving
advantageous effects in the operation of internal combustion engines, for
example of
diesel engines, especially of direct-injection diesel engines, in particular
of diesel engines
with common-rail injection systems. This effective content (dosage) is
generally 10 to
5000 ppm by weight, preferably 20 to 1500 ppm by weight, especially 25 to 1000
ppm by
weight, in particular 30 to 750 ppm by weight, based in each case on the total
amount of
fuel.
The fuel additized with the inventive quaternized copolymer is usually a
gasoline fuel or
especially a middle distillate fuel, in particular a diesel fuel. The fuel may
comprise further
customary additives to improve efficacy and suppress wear. These include
primarily
customary detergent additives, carrier oils, lubricity additives, cetane
number improvers,
conductivity improvers, anticorrosion additives, antifoams and dehazers.
The customary detergent additives are preferably amphiphilic substances which
possess
at least one hydrophobic hydrocarbon radical with a number-average molecular
weight
(Mn) of 85 to 20 000 and at least one polar moiety selected from:
(Da) mono- or polyamino groups having up to 6 nitrogen atoms, at least one
nitrogen
atom having basic properties;
(Db) nitro groups, optionally in combination with hydroxyl groups;
(Dc) hydroxyl groups in combination with mono- or polyamino groups, at least
one
nitrogen atom having basic properties;
(Dd) carboxyl groups or their alkali metal or alkaline earth metal salts;
(De) sulfonic acid groups or their alkali metal or alkaline earth metal salts;
CA 02803207 2012-12-19
(Do polyoxy-C2- to C4-alkylene moieties terminated by hydroxyl groups, mono-
or
polyamino groups, at least one nitrogen atom having basic properties, or by
carbamate groups;
5 (Dg) carboxylic ester groups;
(Dh) moieties derived from succinic anhydride and having hydroxyl and/or amino
and/or
amido and/or imido groups; and/or
10 (Di) moieties obtained by Mannich reaction of substituted phenols with
aldehydes and
mono- or polyamines.
The hydrophobic hydrocarbon radical in the above detergent additives, which
ensures the
adequate solubility in the fuel, has a number-average molecular weight (Mn) of
85 to 20
15 000, preferably of 113 to 10 000, more preferably of 300 to 5000, even more
preferably of
300 to 3000, even more especially preferably of 500 to 2500 and especially of
700 to
2500, in particular of 800 to 1500. As typical hydrophobic hydrocarbon
radicals, especially
in conjunction with the polar especially polypropenyl, polybutenyl and
polyisobutenyl
radicals with a number-average molecular weight Mn of preferably in each case
300 to
5000, more preferably 300 to 3000, even more preferably 500 to 2500, even more
especially preferably 700 to 2500 and especially 800 to 1500 into
consideration.
Examples of the above groups of detergent additives include the following:
Additives comprising mono- or polyamino groups (Da) are preferably
polyalkenemono- or
polyalkenepolyamines based on polypropene or on high-reactivity (i.e. having
predominantly terminal double bonds) or conventional (i.e. having
predominantly internal
double bonds) polybutene or polyisobutene having Mn = 300 to 5000, more
preferably
500 to 2500 and especially 700 to 2500. Such additives based on high-
reactivity
polyisobutene, which can be prepared from the polyisobutene which may comprise
up to
20% by weight of n-butene units by hydroformylation and reductive amination
with
ammonia, monoamines or polyamines such as dimethylaminopropylamine,
ethylenediamine, diethylenetriamine, triethylenetetramine or
tetraethylenepentamine, are
known especially from EP-A 244 616. When polybutene or polyisobutene having
predominantly internal double bonds (usually in the 3 and y positions) are
used as starting
materials in the preparation of the additives, a possible preparative route is
by
chlorination and subsequent amination or by oxidation of the double bond with
air or
ozone to give the carbonyl or carboxyl compound and subsequent amination under
reductive (hydrogenating) conditions. The amines used here for the amination
may be, for
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example, ammonia, monoamines or the abovementioned polyamines. Corresponding
additives based on polypropene are described in particular in WO-A 94/24231.
Further preferred additives comprising monoamino groups (Da) are the
hydrogenation
products of the reaction products of polyisobutenes having an average degree
of
polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen
oxides and
oxygen, as described in particular in WO-A 97/03946.
Further preferred additives comprising monoamino groups (Da) are the compounds
obtainable from polyisobutene epoxides by reaction with amines and subsequent
dehydration and reduction of the amino alcohols, as described in particular in
DE-A
196 20 262.
Additives comprising nitro groups (Db), optionally in combination with
hydroxyl groups,
are preferably reaction products of polyisobutenes having an average degree of
polymerization P = 5 to 100 or 10 to 100 with nitrogen oxides or mixtures of
nitrogen
oxides and oxygen, as described in particular in WO-A 96/03367 and in WO-A
96/03479.
These reaction products are generally mixtures of pure nitropolyisobutenes
(e.g. a,(3-
dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (e.g. a-nitro-(3-
hydroxypolyisobutene).
Additives comprising hydroxyl groups in combination with mono- or polyamino
groups
(Dc) are in particular reaction products of polyisobutene epoxides obtainable
from
polyisobutene having preferably predominantly terminal double bonds and Mn =
300 to
5000, with ammonia or mono- or polyamines, as described in particular in EP-A
476 485.
Additives comprising carboxyl groups or their alkali metal or alkaline earth
metal salts
(Dd) are preferably copolymers of C2- to C40-olefins with maleic anhydride
which have a
total molar mass of 500 to 20 000 and some or all of whose carboxyl groups
have been
converted to the alkali metal or alkaline earth metal salts and any remainder
of the
carboxyl groups has been reacted with alcohols or amines. Such additives are
disclosed
in particular by EP-A 307 815. Such additives serve mainly to prevent valve
seat wear
and can, as described in WO-A 87/01126, advantageously be used in combination
with
customary fuel detergents such as poly(iso)buteneamines or polyetheramines.
Additives comprising sulfonic acid groups or their alkali metal or alkaline
earth metal salts
(De) are preferably alkali metal or alkaline earth metal salts of an alkyl
sulfosuccinate, as
described in particular in EP-A 639 632. Such additives serve mainly to
prevent valve
CA 02803207 2012-12-19
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seat wear and can be used advantageously in combination with customary fuel
detergents such as poly(iso)buteneamines or polyetheramines.
Additives comprising polyoxy-C2- to C4-alkylene moieties (DO are preferably
polyethers or
polyetheramines which are obtainable by reaction of C2- to Cso-alkanols, C6-
to C30-
alkanediols, mono- or di-C2- to C3o-alkylamines, Cl- to C3o-alkylcyclohexanols
or C,- to
C3o-alkylphenols with 1 to 30 mol of ethylene oxide and/or propylene oxide
and/or
butylene oxide per hydroxyl group or amino group and, in the case of the
polyetheramines, by subsequent reductive amination with ammonia, monoamines or
polyamines. Such products are described in particular in EP-A 310 875, EP-A
356 725,
EP-A 700 985 and US-A 4 877 416. In the case of polyethers, such products also
have
carrier oil properties. Typical examples of these are tridecanol butoxylates,
isotridecanol
butoxylates, isononylphenol butoxylates and polyisobutenol butoxylates and
propoxylates
and also the corresponding reaction products with ammonia.
Additives comprising carboxylic ester groups (Dg) are preferably esters of
mono-, di- or
tricarboxylic acids with long-chain alkanols or polyols, in particular those
having a
minimum viscosity of 2 mm2/s at 100 C, as described in particular in DE-A 38
38 918. The
mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids, and
particularly
suitable ester alcohols or ester polyols are long-chain representatives
having, for
example, 6 to 24 carbon atoms. Typical representatives of the esters are
adipates,
phthalates, isophthalates, terephthalates and trimellitates of isooctanol, of
isononanol, of
isodecanol and of isotridecanol. Such products also have carrier oil
properties.
Additives comprising moieties derived from succinic anhydride and having
hydroxyl
and/or amino and/or amido and/or especially imido groups (Dh) are preferably
corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride
and
especially the corresponding derivatives of polyisobutenylsuccinic anhydride
which are
obtainable by reacting conventional or high-reactivity polyisobutene having Mn
=
preferably 300 to 5000, more preferably 300 to 3000, even more preferably 500
to 2500,
even more especially preferably 700 to 2500 and especially 800 to 1500, with
maleic
anhydride by a thermal route in an ene reaction or via the chlorinated
polyisobutene. The
moieties having hydroxyl and/or amino and/or amido and/or imido groups are,
for
example, carboxylic acid groups, acid amides of monoamines, acid amides of di-
or
polyamines which, in addition to the amide function, also have free amine
groups,
succinic acid derivatives having an acid and an amide function, carboximides
with
monoamines, carboximides with di- or polyamines which, in addition to the
imide function,
also have free amine groups, or diimides which are formed by the reaction of
di- or
polyamines with two succinic acid derivatives. In the presence of imido
moieties D(h), the
CA 02803207 2012-12-19
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further detergent additive in the context of the present invention is,
however, used only up
to a maximum of 100% of the weight of compounds with betaine structure. Such
fuel
additives are common knowledge and are described, for example, in documents
(1) and
(2). They are preferably the reaction products of alkyl- or alkenyl-
substituted succinic
acids or derivatives thereof with amines and more preferably the reaction
products of
polyisobutenyl-substituted succinic acids or derivatives thereof with amines.
Of particular
interest in this context are reaction products with aliphatic polyamines
(polyalkyleneimines) such as especially ethylenediamine, diethylenetriamine,
triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and
hexaethyleneheptamine, which have an imide structure.
Additives comprising moieties (Di) obtained by Mannich reaction of substituted
phenols
with aldehydes and mono- or polyamines are preferably reaction products of
polyisobutene-substituted phenols with formaldehyde and mono- or polyamines
such as
ethylenediamine, diethylenetriamine, triethylenetetramine,
tetraethylenepentamine or
dimethylaminopropylamine. The polyisobutenyl-substituted phenols may stem from
conventional or high-reactivity polyisobutene having Mn = 300 to 5000. Such
"polyisobutene Mannich bases" are described in particular in EP-A 831 141.
One or more of the detergent additives mentioned can be added to the fuel in
such an
amount that the dosage of these detergent additives is preferably 25 to 2500
ppm by
weight, especially 75 to 1500 ppm by weight, in particular 150 to 1000 ppm by
weight.
Carrier oils additionally used may be of mineral or synthetic nature. Suitable
mineral
carrier oils are the fractions obtained in crude oil processing, such as
brightstock or base
oils having viscosities, for example, from the SN 500 to 2000 class; but also
aromatic
hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. Likewise useful is a
fraction
which is obtained in the refining of mineral oil and is known as "hydrocrack
oil" (vacuum
distillate cut having a boiling range from about 360 to 500 C, obtainable from
natural
mineral oil which has been catalytically hydrogenated and isomerized under
high
pressure and also deparaffinized). Likewise suitable are mixtures of the
abovementioned
mineral carrier oils.
Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins
or
polyinternalolefins), (poly)esters, (poly)alkoxylates, polyethers, aliphatic
polyether-
amines, alkylphenol-started polyethers, alkylphenol-started polyetheramines
and
carboxylic esters of long-chain alkanols.
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Examples of suitable polyolefins are olefin polymers having Mn = 400 to 1800,
in
particular based on polybutene or polyisobutene (hydrogenated or
unhydrogenated).
Examples of suitable polyethers or polyetheramines are preferably compounds
comprising polyoxy-C2- to C4-alkylene moieties which are obtainable by
reacting C2- to
Cho-alkanols, C6- to C3o-alkanediols, mono- or di-C2- to C3o-alkylamines, Cl-
to C30-
alkylcyclohexanols or Cr to C3o-alkylphenols with 1 to 30 mol of ethylene
oxide and/or
propylene oxide and/or butylene oxide per hydroxyl group or amino group, and,
in the
case of the polyetheramines, by subsequent reductive amination with ammonia,
monoamines or polyamines. Such products are described in particular in
EP-A 310 875, EP-A 356 725, EP-A 700 985 and US-A 4,877,416. For example, the
polyetheramines used may be poly-C2- to C6-alkylene oxide amines or functional
derivatives thereof. Typical examples thereof are tridecanol butoxylates or
isotridecanol
butoxylates, isononyiphenol butoxylates and also polyisobutenol butoxylates
and
propoxylates, and also the corresponding reaction products with ammonia.
Examples of carboxylic esters of long-chain alkanols are in particular esters
of mono-, di-
or tricarboxylic acids with long-chain alkanols or polyols, as described in
particular in DE-
A 38 38 918. The mono-, di- or tricarboxylic acids used may be aliphatic or
aromatic
acids; suitable ester alcohols or polyols are in particular long-chain
representatives
having, for example, 6 to 24 carbon atoms. Typical representatives of the
esters are
adipates, phthalates, isophthalates, terephthalates and trimellitates of
isooctanol,
isononanol, isodecanol and isotridecanol, for example di(n- or isotridecyl)
phthalate.
Further suitable carrier oil systems are described, for example, in DE-A 38 26
608, DE-A
41 42 241, DE-A 43 09 074, EP-A 452 328 and EP-A 548 617.
Examples of particularly suitable synthetic carrier oils are alcohol-started
polyethers
having about 5 to 35, preferably about 5 to 30, more preferably 10 to 30 and
especially 15
to 30 C3- to C6-alkylene oxide units, for example selected from propylene
oxide, n-
butylene oxide and isobutylene oxide units, or mixtures thereof, per alcohol
molecule.
Nonlimiting examples of suitable starter alcohols are long-chain alkanols or
phenols
substituted by long-chain alkyl in which the long-chain alkyl radical is in
particular a
straight-chain or branched C6- to C18-alkyl radical. Preferred examples
include tridecanol
and nonylphenol. Particularly preferred alcohol-started polyethers are the
reaction
products (polyetherification products) of monohydric aliphatic C6- to C18-
alcohols with Ca-
to C6-alkylene oxides. Examples of monohydric aliphatic C6-C,$-alcohols are
hexanol,
heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 3-propylheptanol,
undecanol,
dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol
and the
CA 02803207 2012-12-19
constitutional and positional isomers thereof. The alcohols can be used either
in the form
of the pure isomers or in the form of technical grade mixtures. A particularly
preferred
alcohol is tridecanol. Examples of C3- to C6-alkylene oxides are propylene
oxide, such as
1,2-propylene oxide, butylene oxide, such as 1,2-butylene oxide, 2,3-butylene
oxide,
5 isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide.
Particular
preference among these is given to C3- to C4-alkylene oxides, i.e. propylene
oxide such
as 1,2-propylene oxide and butylene oxide such as 1,2-butylene oxide, 2,3-
butylene oxide
and isobutylene oxide. Especially butylene oxide is used.
10 Further suitable synthetic carrier oils are alkoxylated alkylphenols, as
described in DE-A
10 102 913.
Preferred carrier oils are synthetic carrier oils, particular preference being
given to the
above-described alcohol-started polyethers.
The carrier oil or the mixture of different carrier oils is added to the fuel
in an amount of
preferably 1 to 1000 ppm by weight, more preferably of 10 to 500 ppm by weight
and
especially of 20 to 100 ppm by weight.
It is also possible for the fuel to comprise further customary additives and
coadditives in
the amounts customary therefor. In the case of middle distillate fuels,
especially diesel
fuels, these are in particular cold flow improvers, lubricity improvers,
corrosion inhibitors,
demulsifiers, dehazers, antifoams, cetane number improvers, combustion
improvers,
antioxidants or stabilizers, antistats, metallocenes, metal deactivators, dyes
and/or
solvents. In the case of gasoline fuels, these are in particular friction
modifiers, corrosion
inhibitors, demulsifiers, dehazers, antifoams, combustion improvers,
antioxidants or
stabilizers, antistats, metallocenes, metal deactivators, dyes and/or
solvents.
Suitable cold flow improvers are in principle all organic compounds which are
capable of
improving the flow performance of middle distillate fuels or diesel fuels
under cold
conditions. For the intended purpose, they must have sufficient oil
solubility. In particular,
useful cold flow improvers for this purpose are the cold flow improvers
(middle distillate
flow improvers, MDFIs) typically used in the case of middle distillates of
fossil origin, i.e.
in the case of customary mineral diesel fuels. However, it is also possible to
use organic
compounds which partly or predominantly have the properties of a wax
antisettling
additive (WASA) when used in customary diesel fuels. They can also act partly
or
predominantly as nucleators. It is, though, also possible to use mixtures of
organic
compounds effective as MDFIs and/or effective as WASAs and/or effective as
nucleators.
CA 02803207 2012-12-19
21
The cold flow improver is typically selected from
(K1) copolymers of a C2- to Cao-olefin with at least one further ethylenically
unsaturated
monomer;
(K2) comb polymers;
(K3) polyoxyalkylenes;
(K4) polar nitrogen compounds;
(K5) sulfocarboxylic acids or sulfonic acids or derivatives thereof; and
(K6) poly(meth)acrylic esters.
It is possible to use either mixtures of different representatives from one of
the particular
classes (K1) to (K6) or mixtures of representatives from different classes
(K1) to (K6).
Suitable C2- to Coo-olefin monomers for the copolymers of class (K1) are, for
example,
those having 2 to 20 and especially 2 to 10 carbon atoms, and 1 to 3 and
preferably 1 or
2 carbon-carbon double bonds, especially having one carbon-carbon double bond.
In the
latter case, the carbon-carbon double bond may be arranged either terminally
(a-olefins)
or internally. However, preference is given to a-olefins, more preferably a-
olefins having 2
to 6 carbon atoms, for example propene, 1-butene, 1-pentene, 1-hexene and in
particular
ethylene.
In the copolymers of class (K1), the at least one further ethylenically
unsaturated
monomer is preferably selected from alkenyl carboxylates, (meth)acrylic esters
and
further olefins.
When further olefins are also copolymerized, they are preferably higher in
molecular
weight than the abovementioned C2- to Cao-olefin base monomer. When, for
example, the
olefin base monomer used is ethylene or propene, suitable further olefins are
in particular
C10- to Cao-a-olefins. Further olefins are in most cases only additionally
copolymerized
when monomers with carboxylic ester functions are also used.
Suitable (meth)acrylic esters are, for example, esters of (meth)acrylic acid
with C,- to C20-
alkanols, especially Cr to C,o-alkanols, in particular with methanol, ethanol,
propanol,
isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, pentanol,
hexanol, heptanol,
octanol, 2-ethylhexanol, nonanol and decanol, and structural isomers thereof.
Suitable alkenyl carboxylates are, for example, C2- to C14-alkenyl esters, for
example the
vinyl and propenyl esters, of carboxylic acids having 2 to 21 carbon atoms,
whose
hydrocarbon radical may be linear or branched. Among these, preference is
given to the
CA 02803207 2012-12-19
22
vinyl esters. Among the carboxylic acids with a branched hydrocarbon radical,
preference
is given to those whose branch is in the a-position to the carboxyl group, the
a-carbon
atom more preferably being tertiary, i.e. the carboxylic acid being a so-
called
neocarboxylic acid. However, the hydrocarbon radical of the carboxylic acid is
preferably
linear.
Examples of suitable alkenyl carboxylates are vinyl acetate, vinyl propionate,
vinyl
butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl
neononanoate, vinyl neodecanoate and the corresponding propenyl esters,
preference
being given to the vinyl esters. A particularly preferred alkenyl carboxylate
is vinyl
acetate; typical copolymers of group (K1) resulting therefrom are ethylene-
vinyl acetate
copolymers ("EVAs"), which are some of the most frequently used. Ethylene-
vinyl acetate
copolymers usable particularly advantageously and their preparation are
described in WO
99/29748.
Suitable copolymers of class (K1) are also those which comprise two or more
different
alkenyl carboxylates in copolymerized form, which differ in the alkenyl
function and/or in
the carboxylic acid group. Likewise suitable are copolymers which, as well as
the alkenyl
carboxylate(s), comprise at least one olefin and/or at least one (meth)acrylic
ester in
copolymerized form.
Terpolymers of a C2- to Coo-a-olefin, a Cl- to C2o-alkyl ester of an
ethylenically
unsaturated monocarboxylic acid having 3 to 15 carbon atoms and a C2- to C14-
alkenyl
ester of a saturated monocarboxylic acid having 2 to 21 carbon atoms are also
suitable
as copolymers of class (K1). Terpolymers of this kind are described in WO
2005/054314.
A typical terpolymer of this kind is formed from ethylene, 2-ethylhexyl
acrylate and vinyl
acetate.
The at least one or the further ethylenically unsaturated monomer(s) are
copolymerized
into the copolymers of class (K1) in an amount of preferably I to 50% by
weight,
especially 10 to 45% by weight and in particular 20 to 40% by weight, based on
the
overall copolymer. The main proportion in terms of weight of the monomer units
in the
copolymers of class (K1) therefore originates generally from the C2 to Coo
base olefins.
The copolymers of class (K1) preferably have a number-average molecular weight
M, of
1000 to 20 000, more preferably 1000 to 10 000 and in particular 1000 to 8000.
Typical comb polymers of component (K2) are, for example, obtainable by the
copolymerization of maleic anhydride or fumaric acid with another
ethylenically
CA 02803207 2012-12-19
23
unsaturated monomer, for example with an cc-olefin or an unsaturated ester,
such as vinyl
acetate, and subsequent esterification of the anhydride or acid function with
an alcohol
having at least 10 carbon atoms. Further suitable comb polymers are copolymers
of a-
olefins and esterified comonomers, for example esterified copolymers of
styrene and
maleic anhydride or esterified copolymers of styrene and fumaric acid.
Suitable comb
polymers may also be polyfumarates or polymaleates. Homo- and copolymers of
vinyl
ethers are also suitable comb polymers. Comb polymers suitable as components
of class
(K2) are, for example, also those described in WO 2004/035715 and in "Comb-
Like
Polymers. Structure and Properties", N. A. Plate and V. P. Shibaev, J. Poly.
Sci.
Macromolecular Revs. 8, pages 117 to 253 (1974)". Mixtures of comb polymers
are also
suitable.
Polyoxyalkylenes suitable as components of class (K3) are, for example,
polyoxyalkylene
esters, polyoxyalkylene ethers, mixed polyoxyalkylene ester/ethers and
mixtures thereof.
These polyoxyalkylene compounds preferably comprise at least one linear alkyl
group,
preferably at least two linear alkyl groups, each having 10 to 30 carbon atoms
and a
polyoxyalkylene group having a number-average molecular weight of up to 5000.
Such
polyoxyalkylene compounds are described, for example, in EP-A 061 895 and also
in
US 4,491,455. Preferred polyoxyalkylene compounds are based on polyethylene
glycols
and polypropylene glycols having a number-average molecular weight of 100 to
5000.
Additionally suitable are polyoxyalkylene mono- and diesters of fatty acids
having 10 to
carbon atoms, such as stearic acid or behenic acid.
Polar nitrogen compounds suitable as components of class (K4) may be either
ionic or
25 nonionic and preferably have at least one substituent, in particular at
least two
substituents, in the form of a tertiary nitrogen atom of the general formula
>NR7 in which
R7 is a C8- to C40-hydrocarbon radical. The nitrogen substituents may also be
quaternized, i.e. be in cationic form. An example of such nitrogen compounds
is that of
ammonium salts and/or amides which are obtainable by the reaction of at least
one
30 amine substituted by at least one hydrocarbon radical with a carboxylic
acid having 1 to 4
carboxyl groups or with a suitable derivative thereof. The amines preferably
comprise at
least one linear C8- to C40-alkyl radical. Primary amines suitable for
preparing the polar
nitrogen compounds mentioned are, for example, octylamine, nonylamine,
decylamine,
undecylamine, dodecylamine, tetradecylamine and the higher linear homologs.
Secondary amines suitable for this purpose are, for example, dioctadecylamine
and
methylbehenylamine. Also suitable for this purpose are amine mixtures, in
particular
amine mixtures obtainable on the industrial scale, such as fatty amines or
hydrogenated
tallamines, as described, for example, in Ullmann's Encyclopedia of Industrial
Chemistry,
6th Edition, "Amines, aliphatic" chapter. Acids suitable for the reaction are,
for example,
CA 02803207 2012-12-19
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cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid,
cyclopentane-1,2-
dicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic
acid,
terephthalic acid, and succinic acids substituted by long-chain hydrocarbon
radicals.
In particular, the component of class (K4) is an oil-soluble reaction product
of poly(C2- to
C20-carboxylic acids) having at least one tertiary amino group with primary or
secondary
amines. The poly(C2- to C2o-carboxylic acids) which have at least one tertiary
amino
group and form the basis of this reaction product comprise preferably at least
3 carboxyl
groups, especially 3 to 12 and in particular 3 to 5 carboxyl groups. The
carboxylic acid
units in the polycarboxylic acids have preferably 2 to 10 carbon atoms, and
are especially
acetic acid units. The carboxylic acid units are suitably bonded to the
polycarboxylic
acids, usually via one or more carbon and/or nitrogen atoms. They are
preferably
attached to tertiary nitrogen atoms which, in the case of a plurality of
nitrogen atoms, are
bonded via hydrocarbon chains.
The component of class (K4) is preferably an oil-soluble reaction product
based on
poly(C2- to C20-carboxylic acids) which have at least one tertiary amino group
and are of
the general formula Ila or Ilb
HOOC,B B, 000H
HOOC, ,N, N, COON
B A B (Ila)
HOOC'B,NB,COOH
B, 000H (Ilb)
in which the variable A is a straight-chain or branched C2- to C6-alkylene
group or the
moiety of the formula III
HOOC"B,N'CH2 CH2
i
CH2-CH 2 (III)
and the variable B is a Cr to C19-alkylene group. The compounds of the general
formulae
Ila and Ilb especially have the properties of a WASA.
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Moreover, the preferred oil-soluble reaction product of component (K4),
especially that of
the general formula Ila or IIb, is an amide, an amide-ammonium salt or an
ammonium salt
in which no, one or more carboxylic acid groups have been converted to amide
groups.
5 Straight-chain or branched C2- to C6-alkylene groups of the variable A are,
for example,
1,1-ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1, 3-butylene, 1,4-
butylene,
2-methyl-1,3-propylene, 1,5-pentylene, 2-methyl-1,4-butylene, 2,2-dimethyl-1,3-
propylene, 1,6-hexylene (hexamethylene) and in particular 1,2-ethylene. The
variable A
comprises preferably 2 to 4 and especially 2 or 3 carbon atoms.
Cr to C19-alkylene groups of the variable B are, for example, 1,2-ethylene,
1,3-propylene,
1,4-butylene, hexamethylene, octamethylene, decamethylene, dodecamethylene,
tetradecamethylene, hexadecamethylene, octadecamethylene, nonadecamethylene
and
especially methylene. The variable B comprises preferably 1 to 10 and
especially 1 to 4
carbon atoms.
The primary and secondary amines as a reaction partner for the polycarboxylic
acids to
form component (K4) are typically monoamines, especially aliphatic monoamines.
These
primary and secondary amines may be selected from a multitude of amines which
bear
hydrocarbon radicals which are optionally bonded to one another if
appropriate.
These parent amines of the oil-soluble reaction products of component (K4) are
usually
secondary amines and have the general formula HN(R8)2 in which the two
variables R8
are each independently straight-chain or branched C10- to C3o-alkyl radicals,
especially
C14- to C24-alkyl radicals. These relatively long-chain alkyl radicals are
preferably straight-
chain or only slightly branched. In general, the secondary amines mentioned,
with regard
to their relatively long-chain alkyl radicals, derive from naturally occurring
fatty acid and
from derivatives thereof. The two R8 radicals are preferably identical.
The secondary amines mentioned may be bonded to the polycarboxylic acids by
means
of amide structures or in the form of the ammonium salts; it is also possible
for only a
portion to be present as amide structures and another portion as ammonium
salts.
Preferably only few, if any, free acid groups are present. The oil-soluble
reaction products
of component (K4) are preferably present completely in the form of the amide
structures.
Typical examples of such components (K4) are reaction products of
nitrilotriacetic acid, of
ethylenediaminetetraacetic acid or of propylene-1,2-diaminetetraacetic acid
with in each
case 0.5 to 1.5 mol per carboxyl group, especially 0.8 to 1.2 mol per carboxyl
group, of
dioleylamine, dipalmitinamine, dicoconut fatty amine, distearylamine,
dibehenylamine or
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especially ditallow fatty amine. A particularly preferred component (K4) is
the reaction
product of 1 mol of ethylenediaminetetraacetic acid and 4 mol of hydrogenated
ditallow
fatty amine.
Further typical examples of component (K4) include the N,N-dialkylammonium
salts of 2-
N',N'-dialkylamidobenzoates, for example the reaction product of 1 mol of
phthalic
anhydride and 2 mol of ditallow fatty amine, the latter being hydrogenated or
unhydrogenated, and the reaction product of 1 mol of an alkenylspirobislactone
with
2 mol of a dialkylamine, for example ditallow fatty amine and/or tallow fatty
amine, the last
two being hydrogenated or unhydrogenated.
Further typical structure types for the component of class (K4) are cyclic
compounds with
tertiary amino groups or condensates of long-chain primary or secondary amines
with
carboxylic acid-containing polymers, as described in WO 93/18115.
Sulfocarboxylic acids, sulfonic acids or derivatives thereof which are
suitable as cold flow
improvers of class (K5) are, for example, the oil-soluble carboxamides and
carboxylic
esters of ortho-sulfobenzoic acid, in which the sulfonic acid function is
present as a
sulfonate with alkyl-substituted ammonium cations, as described in EP-A 261
957.
Poly(meth)acrylic esters suitable as cold flow improvers of class (K6) are
either homo- or
copolymers of acrylic and methacrylic esters. Preference is given to
copolymers of at
least two different (meth)acrylic esters which differ with regard to the
esterified alcohol.
Optionally, the copolymer comprises another different olefinically unsaturated
monomer in
copolymerized form. The weight-average molecular weight of the polymer is
preferably
50 000 to 500 000. A particularly preferred polymer is a copolymer of
methacrylic acid
and methacrylic esters of saturated C14 and C15 alcohols, the acid groups
having been
neutralized with hydrogenated tallamine. Suitable poly(meth)acrylic esters are
described,
for example, in WO 00/44857.
The cold flow improver or the mixture of different cold flow improvers is
added to the
middle distillate fuel or diesel fuel in a total amount of preferably 10 to
5000 ppm by
weight, more preferably of 20 to 2000 ppm by weight, even more preferably of
50 to 1000
ppm by weight and especially of 100 to 700 ppm by weight, for example of 200
to 500
ppm by weight.
Suitable lubricity improvers or friction modifiers are based typically on
fatty acids or fatty
acid esters. Typical examples are tall oil fatty acid, as described, for
example, in WO
98/004656, and glyceryl monooleate. The reaction products, described in US 6
743 266
CA 02803207 2012-12-19
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B2, of natural or synthetic oils, for example triglycerides, and alkanolamines
are also
suitable as such lubricity improvers.
Suitable corrosion inhibitors are, for example, succinic esters, in particular
with polyols,
fatty acid derivatives, for example oleic esters, oligomerized fatty acids,
substituted
ethanolamines, and products sold under the trade name RC 4801 (Rhein Chemie
Mannheim, Germany) or HiTEC 536 (Ethyl Corporation).
Suitable demulsifiers are, for example, the alkali metal or alkaline earth
metal salts of
alkyl-substituted phenol- and naphthalenesulfonates and the alkali metal or
alkaline earth
metal salts of fatty acids, and also neutral compounds such as alcohol
alkoxylates, e.g.
alcohol ethoxylates, phenol alkoxylates, e.g. tert-butylphenol ethoxylate or
tert-
pentylphenol ethoxylate, fatty acids, alkylphenols, condensation products of
ethylene
oxide (EO) and propylene oxide (PO), for example including in the form of
EO/PO block
copolymers, polyethyleneimines or else polysiloxanes.
Suitable dehazers are, for example, alkoxylated phenol-formaldehyde
condensates, for
example the products available under the trade names NALCO 7D07 (Nalco) and
TOLAD
2683 (Petrolite).
Suitable antifoams are, for example, polyether-modified polysiloxanes, for
example the
products available under the trade names TEGOPREN 5851 (Goldschmidt), Q 25907
(Dow Corning) and RHODOSIL (Rhone Poulenc).
Suitable cetane number improvers are, for example, aliphatic nitrates such as
2-ethylhexyl nitrate and cyclohexyl nitrate and peroxides such as di-tert-
butyl peroxide.
Suitable antioxidants are, for example substituted phenols, such as 2,6-di-
tert-butylphenol
and 6-di-tert-butyl-3-methylphenol, and also phenylenediamines such as N,N'-di-
sec-
butyl-p-phenylenediamine.
Suitable metal deactivators are, for example, salicylic acid derivatives such
as
N,N'-disalicylidene-l,2-propanediamine.
Suitable solvents are, for example, nonpolar organic solvents such as aromatic
and
aliphatic hydrocarbons, for example toluene, xylenes, white spirit and
products sold under
the trade names SHELLSOL (Royal Dutch/Shell Group) and EXXSOL (ExxonMobil),
and
also polar organic solvents, for example, alcohols such as 2-ethylhexanol,
decanol and
isotridecanol. Such solvents are usually added to the diesel fuel together
with the
CA 02803207 2012-12-19
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aforementioned additives and coadditives, which they are intended to dissolve
or dilute
for better handling.
Middle distillate fuels such as diesel fuels or heating oils are preferably
mineral oil
raffinates which typically have a boiling range from 100 to 400 C. These are
usually
distillates having a 95% point up to 360 C or even higher. These may also be
so-called
"ultra low sulfur diesel" or "city diesel", characterized by a 95% point of,
for example, not
more than 345 C and a sulfur content of not more than 0.005% by weight or by a
95%
point of, for example, 285 C and a sulfur content of not more than 0.001 % by
weight. In
addition to the mineral middle distillate fuels or diesel fuels obtainable by
refining, those
obtainable by coal gasification or gas liquefaction ["gas to liquid" (GTL)
fuels] or by
biomass liquefaction ["biomass to liquid" (BTL) fuels] are also suitable. Also
suitable are
mixtures of the aforementioned middle distillate fuels or diesel fuels with
renewable fuels,
such as biodiesel or bioethanol.
The qualities of the heating oils and diesel fuels are laid down in detail,
for example, in
DIN 51603 and EN 590 (cf. also Ullmann's Encyclopedia of Industrial Chemistry,
5th
edition, Volume A12, p. 617 ff.).
In addition to the use thereof in the abovementioned middle distillate fuels
of fossil,
vegetable or animal origin, which are essentially hydrocarbon mixtures, the
inventive
quaternized copolymer can also be used in mixtures of such middle distillates
with biofuel
oils (biodiesel). Such mixtures are also encompassed by the term "middle
distillate fuel" in
the context of the present invention. They are commercially available and
usually
comprise the biofuel oils in minor amounts, typically in amounts of 1 to 30%
by weight,
especially of 3 to 10% by weight, based on the total amount of middle
distillate of fossil,
vegetable or animal origin and biofuel oil.
Biofuel oils are generally based on fatty acid esters, preferably essentially
on alkyl esters
of fatty acids which derive from vegetable and/or animal oils and/or fats.
Alkyl esters are
typically understood to mean lower alkyl esters, especially C,-C4-alkyl
esters, which are
obtainable by transesterifying the glycerides which occur in vegetable and/or
animal oils
and/or fats, especially triglycerides, by means of lower alcohols, for example
ethanol or in
particular methanol ("FAME"). Typical lower alkyl esters based on vegetable
and/or
animal oils and/or fats, which find use as a biofuel oil or component thereof,
are, for
example, sunflower methyl ester, palm oil methyl ester ("PME"), soya oil
methyl ester
("SME") and especially rapeseed oil methyl ester ("RME").
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The middle distillate fuels or diesel fuels are more preferably those having a
low sulfur
content, i.e. having a sulfur content of less than 0.05% by weight, preferably
of less than
0.02% by weight, more particularly of less than 0.005% by weight and
especially of less
than 0.001 % by weight of sulfur.
Useful gasoline fuels include all commercial gasoline fuel compositions. One
typical
representative which shall be mentioned here is the Eurosuper base fuel to EN
228,
which is customary on the market. In addition, gasoline fuel compositions of
the
specification according to WO 00/47698 are also possible fields of use for the
present
invention.
The inventive quaternized copolymer is especially suitable as a fuel additive
in fuel
compositions, especially in diesel fuels, for overcoming the problems outlined
at the
outset in direct-injection diesel engines, in particular in those with common-
rail injection
systems.
The present invention thus also provides for the use of the inventive
quaternized
copolymer as a fuel additive for reducing or preventing deposits in the
injection systems,
especially in the injectors, or direct-injection diesel engines, especially in
common-rail
injection systems.
In addition, the present invention therefore also provides for the use of the
inventive
quaternized copolymer as a fuel additive for reducing the fuel consumption of
direct-
injection diesel engines, especially of diesel engines with common-rail
injection systems.
In addition, the present invention therefore also provides for the use of the
inventive
quaternized copolymer as a fuel additive for minimizing power loss in direct-
injection
diesel engines, especially in diesel engines with common-rail injection
systems.
The examples which follow are intended to illustrate the invention without
restricting it.
Preparation example
Example 1a: Preparation of a C20-24-olefin-1-maleic anhydride copolymer
The copolymer was prepared by free-radical solution polymerization according
to the
teaching of EP-A 307 815. To this end, the C20-24-olefin-1 (400 g,
corresponding to
1.35 mol) was melted at 80 C and dissolved in Solvesso 150 (400 g) at 150 C.
Subsequently, di-tert-butyl peroxide (5.4 g, 0.037 mol), dissolved in Solvesso
150 (30 g),
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and the liquid maleic anhydride (132 g, 1.35 mol) heated in a dropping funnel
heated to
70 C, were simultaneously added dropwise to the olefin solution in Solvesso
150 heated
to 150 C over the course of 5 hours. The copolymer obtained possessed a
hydrolysis
number (HN) of 107.4 mg KOH/g, a number-average molecular weight (Mn) of 1470
5 g/mol, a weight-average molecular weight (Mw) of 3290 g/mol and a
polydispersity (PDI)
of 2.2.
Example 1b: Imidation of the C20-24-olefin-1-maleic anhydride copolymer
10 The copolymer prepared in example 1a was reacted with 3-(N,N-dimethylamino)-
propylamine in a molar ratio of the carboxylic anhydride functions in the
copolymer to the
amine of 1:1 to give the corresponding imidated copolymer with repeat N-(3-
dimethylaminopropyl)succinamide units. For this purpose, the C20-24-olefin-1-
maleic
anhydride copolymer dissolved in Solvesso 150 was reacted with the
abovementioned
15 amine at 25 C in an addition reaction. The resulting amide precipitated out
of the reaction
mixture after a short time. The imidation was effected at 170 C and a pressure
of 1 mbar
within 2 hours.
Example 1 c: Quaternization of the imidated copolymer with propylene oxide
The imidated copolymer from example 1 b was reacted with propylene oxide in an
equimolar ratio to the tertiary nitrogen atom in the oligoamine radical, in
the presence of
an equimolar amount of acetic acid. This was done by dissolving the imidated
copolymer
in Solvesso 150 in an autoclave, admixing with the acetic acid and heating to
130 C.
Nitrogen was used to set an initial pressure of 5 bar, then the propylene
oxide was
metered in over the course of 20 minutes, and the mixture was stirred at 130 C
for a
further 6 hours. The quaternized copolymer was obtained in quantitative yield
in the form
of a dark-colored solution.
Use example
Example 2: Measurement of power losses in a direct-injection diesel engine
To study the influence of the inventive quaternized terpolymer on the
performance of
direct-injection diesel engines, the power loss was determined on the basis of
the official
test method CEC F-98-08. The power loss (or the power increase in the case of
negative
values) is a direct measure of formation or elimination of deposits in the
injectors. A
standard direct-injection diesel engine with a common-rail system was used.
CA 02803207 2012-12-19
31
The fuel used was a commercial diesel fuel from Haltermann (RF-06-03). To
artificially
induce the formation of deposits at the injectors, 1 ppm by weight of zinc
didodecanoate
was added thereto.
The table which follows shows the results of the power loss determinations at
4000 rpm
after 10 minutes and 1 hour, and the quaternized copolymer was used in the
form of the
solution obtained in example 1c:
Test run No. Fuel additive Dosage Power loss Power loss
[ppm by weight 10 minutes 1 hour
of active
substance]
Blank none - 3.59% 1.83%
with quaternized CP from ex. 1c 100 0.59 % -1.50 %
with quaternized CP from ex. 1c 200 -1.76 % -1.13 %
