WO2013117616A1 - Imidazolium salts as additives for fuels and combustibles - Google Patents

Abstract

Use of imidazolium salts (I), wherein R1 and R3 stand independently of one another for an organic radical with 1 to 3000 carbon atoms, R2, R4 and R5 signify independently of one another hydrogen or an organic radical with 1 to 3000 carbon atoms, X designates an anion and n stands for the number 1, 2 or 3, as additives for fuels and combustibles, in particular as detergent additives for diesel fuels, as a wax anti-settling additive for middle distillate fuels and as lubricity improving agents, as well as for improving the usage properties of mineral and synthetic non-aqueous industrial fluids.

Description

 The present invention relates to the use of imidazolium salts as additives for fuels, in particular as detergent additives for diesel fuels, especially for diesel fuels used in direct-injection diesel engines, in particular in common-rail injection systems, to be burned. Furthermore, the present invention relates to an additive concentrate as well as a fuel or fuel composition containing such imidazolium salts. Furthermore, the present invention relates to novel imidazolium salts and their use in industrial fluids.

In direct-injection diesel engines, the fuel is injected through a multi-hole injection nozzle of the engine directly into the combustion chamber and finely distributed (nebulized) instead of being introduced into a pre- or swirl chamber as in the classic (chamber) diesel engine. The advantage of direct-injection diesel engines lies in their high performance for diesel engines and yet low consumption. In addition, these engines achieve a very high torque even at low speeds.

Essentially, three methods are currently used to inject the fuel directly into the combustion chamber of the diesel engine: the conventional distributor injection pump, the unit-injector system and the common-rail system. System.

In the common-rail system, the diesel fuel is pumped by a pump with pressures up to 2000 bar into a high-pressure line, the common rail. Starting from the common rail, spur lines run to the various injectors, which inject the fuel directly into the combustion chamber. In this case, the full pressure is always applied to the common rail, which allows a multiple injection or a special injection form. In the other injection systems, however, only a smaller variation of the injection is possible. Injection in the common rail is essentially subdivided into three groups: (1) pre-injection, which substantially achieves softer combustion, so that hard combustion noise ("nailing") is reduced and engine running appears quiet; (2.) main injection, which is responsible in particular for a good torque curve; and (3.) post-injection, which provides in particular for a low NCv value. In this post injection, the fuel is not burned in the rule, but evaporated by residual heat in the cylinder. The resulting exhaust gas / fuel mixture is transported to the exhaust system, where the fuel in the presence of suitable catalysts acts as a reducing agent for the nitrogen oxides NO _x . Due to the variable, cylinder-specific injection, the pollutant emissions of the engine, eg the emission of nitrogen oxides (NO _x ), carbon monoxide (CO) and particulate matter (soot), can be positively influenced in the common-rail injection system. This makes it possible, for example, that engines equipped with common-rail injection systems can theoretically meet the Euro 4 standard even without an additional particulate filter.

In modern common-rail diesel engines, under certain conditions, for example when using biodiesel-containing fuels or fuels with metal impurities such as zinc compounds, copper compounds,

Lead compounds and other metal compounds that form deposits on the injector orifices that adversely affect the fuel injection behavior and thereby adversely affect the performance of the engine, i. In particular, reduce the power, but in part also deteriorate the combustion. The formation of deposits is further enhanced by structural developments of the injectors, in particular by the change in the geometry of the nozzles (narrower, conical openings with rounded outlet). For a permanently optimal functioning of engine and injectors such deposits must be prevented or reduced in the nozzle openings by suitable fuel additives.

The international application WO 2012/004300 (1) describes acid-free quaternized nitrogen compounds as fuel additives which are obtained by addition of a compound containing at least one anhydride-reactive oxygen or nitrogen-containing group and additionally at least one quaternizable amino group to a polycarboxylic anhydride compound and subsequent quaternization with an epoxide in the absence of free acid. Polyamines having at least one primary or secondary amino group and at least one tertiary amino group are particularly suitable as compounds with an anhydride-reactive oxygen or nitrogen-containing group and additionally a quaternizable amino group. Particularly suitable polycarboxylic acid anhydrides are dicarboxylic acids such as succinic acid with a longer-chain hydrocarbyl substituent. Such a quaternized nitrogen compound is, for example, the reaction product of polyisobutenyl succinic anhydride obtained at 40 ° C with 3- (dimethylamino) propylamine, which is a polyisobutenylsuccinic acid hemiamide and which is then quaternized with styrene oxide in the absence of free acid at 70 ° C. Such acid-free quaternized nitrogen compounds are particularly suitable as fuel additive for reducing or preventing deposits in injection systems of direct-injection diesel engines, especially in common-rail injection systems, to reduce the fuel consumption of direct-injection diesel engines, especially diesel engines with common-rail injection systems, and / or to minimize the power loss in direct injection diesel engines, especially in diesel engines with common rail injection systems. The international application PCT / EP201 1/071683 (2) describes polytetrahydrobenzoxazines and bistetrahydrobenzoxazines as fuel additives which are obtainable by successively adding in a first reaction step a C 1 to C 20 -alkylenediamine having two primary amino functions, eg 1, 2 Ethylenediamine, with a Cr to Ci2-aldehyde, z. B. formaldehyde, and a Cr to Cs-alkanol at a temperature of 20 to 80 ° C with elimination and removal of water, wherein both the aldehyde and the alcohol are each used in more than twice the molar amount compared to the diamine, in a second reaction step, the resulting condensation product with a phenol which has at least one long-chain substituent, for. B. a tert-octyl, n-nonyl, n-dodecyl or polyisobutyl rest, in stoichiometric ratio to the originally used alkylenediamine of 1, 2: 1 to 3: 1 at a temperature of 30 to 120 ° C. and, if appropriate, in a third reaction step the bis-tetrahydrobenzoxazine thus obtained is heated to a temperature of from 125 to 280 ° C. for at least 10 minutes. Such polytetrahydrobenzoxazines and bisty-hexane-benzoxazines are particularly suitable as fuel additives for reducing or preventing deposits in injection systems of direct-injection diesel engines, in particular in common-rail injection systems, for reducing the fuel consumption of direct-injection diesel engines, in particular diesel engines with common rail engines.

Injection systems, and / or to minimize the power loss in direct injection diesel engines, especially in diesel engines with common rail injection systems. However, the above-mentioned acid-free quaternized nitrogen compounds and polytetrahydrobenzoxazines or bistetrahydrobenzoxazines are still in need of improvement in their properties as detergent additives for fuels and fuels. Furthermore, they should also have an improved corrosion protection effect, improved engine oil compatibility and improved low-temperature properties.

It was therefore an object to provide improved fuel and fuel additives, which no longer have the disadvantages of the prior art.

Accordingly, the use of imidazolium salts of the general formula (I)

in the the variables R 1 and R 3 independently of one another are an organic radical having 1 to 3000 carbon atoms, the variables R 2, R 4 and R 5, independently of one another, denote hydrogen or an organic radical having 1 to 3000 carbon atoms,

X denotes an anion and n represents the number 1, 2 or 3, found as additives for fuels.

Imidazolium salts of type (I) include - in addition to, for example, open-chain quaternary ammonium salts, pyridinium salts, pyridazinium salts, pyrimidinium salts, pyrazinium salts, pyrazolium salts, pyrazolinium salts, imidazolinium salts, thiazolium salts, Triazolium salts, pyrrolidinium salts and imidazolidinium salts - to the so-called ionic liquids, which are understood as meaning salts (ie compounds of cations and anions) which at normal pressure has a melting point of less than 200 ° C, usually even less than 80 ° C, Lonic liquids often contain an organic compound as a cation (organic cation). Depending on the valency of the anion, the ionic liquid may contain other cations, such as metal cations, in addition to the organic cation.

Imidazolium salts of type (I) are known in their use as detergents or dispersants in lubricant formulations. Thus, WO 2010/101801 A1 (3) describes oil-soluble ionic detergents as additive components in lubricating oils for internal combustion engines; Examples include, in addition to open-chain ionic systems and quaternized pyridinium detergents, quaternized imidazolium phenates, imidazolium chlorides, and imidazolium salicylates.

WO 2010/096168 A1 (4) describes ionic liquids such as pyridinium salts as additives for controlling the formation of deposits on the internal combustion engine internal surfaces. However, unlike the present invention, such additives are added to the lubricating oil rather than the fuel used to operate these engines. In addition, WO 2010/096168 A1 explicitly does not disclose imidazolium salts as such additives.

US Pat. No. 4,108,858 (5) discloses high molecular weight N-hydrocarbyl-substituted quaternized ammonium salts having a molecular weight of from 350 to 3,000 carbon atoms for the hydrocarbyl group as detergents and dispersants for fuels such as gasoline fuels and diesel fuels and for lubricating oils. As such high molecular weight N-hydrocarbyl-substituted quaternized ammonium salts, in addition to open-chain systems, salts of piperidines, piperazines, morpholines and pyridines are mentioned. When longer-chain hydrocarbyl radicals are, for example, polybutene or polypropylene radicals.

In a preferred embodiment of the present invention, the imidazolium salts (I) are used as detergent additives for diesel fuels. In this embodiment, the individual uses of the imidazolium salts (I) as an additive for reducing or avoiding deposits in injection systems of direct injection diesel engines, especially in common rail injection systems, to reduce the fuel consumption of direct injection diesel engines, in particular diesel engines with common rail Injection systems, and / or to minimize the power loss in direct injection diesel engines, especially in diesel engines with common rail injection systems, particularly preferred. In a further preferred embodiment, the imidazolium salts (I) are used as a wax anti-settling additive (WASA) for middle distillate fuels, in particular diesel fuels.

In a further preferred embodiment, the imidazolium salts (I) are used as lubricity improvers for fuels and fuels, in particular as friction modifiers for gasoline fuels and as lubricity additives for middle distillate fuels or diesel fuels.

The organic radicals for the variables R1 to R5 in the imidazolium salts of the general formula (I) preferably contain 1 to 1000, in particular 1 to 500, especially 1 to 250 carbon atoms. As a rule, these organic radicals are low molecular weight radicals, for example alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl or heteroaryl radicals, or polymeric radicals, for example polypropyl radicals or, in particular, polyisobutyl radicals. Low molecular weight radicals preferably contain 1 to 20 carbon atoms.

As organic radicals having 1 to 3000 carbon atoms for the variables R 1 to R 5 in the imidazolium salts of the general formula (I) are preferably C 1 to C 20 alkyl radicals, in particular C 1 to C 12 alkyl radicals, especially C 1 to C 7 alkyl radicals, and aryl thereof -, heteroaryl, cycloalkyl, halogeno, hydroxy, amino, carboxy, formyl, -O-, -CO-, -CO-O- or -CO-N <substituted components, for example methyl, Ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert-butyl), 1-pentyl, 2-pentyl , 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl , 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4 Methyl 2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1 butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, n-heptyl, n- Octyl, 2-ethylhexyl, n-nonyl, n-decyl, 2-propylheptyl, n- Undecyl, n-dodecyl, n-tridecyl, isotridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-lcosyl, phenylmethyl (benzyl), diphenylmethyl, triphenylmethyl , 2-phenylethyl, 3-phenylpropyl, cyclopentylmethyl, 2-cyclopentylethyl, 3-cyclopentylpropyl, cyclohexylmethyl, 2-cyclohexylethyl, 3-cyclohexylpropyl, methoxy, ethoxy, formyl, acetyl and also fluoroalkyl radicals such as monofluoromethyl, difluoromethyl, trifluoromethyl, pentafluoroethyl, 3,3,3-trifluoropropyl, perfluorohexyl, perfluorooctyl, perfluorodecyl or perfluorododecyl.

Suitable organic radicals having 1 to 20 carbon atoms for the variables R1 to R5 in the imidazolium salts of the general formula (I) are furthermore also C3 to C12 cycloalkyl radicals, in particular C5 to Cz cycloalkyl radicals, and their aryl, heteroaryl -, cycloalkyl, halogen, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O- substituted components, for example cyclopentyl, 2-methyl-1-cyclopentyl, 3-methyl 1 -cyclopentyl, cyclohexyl, 2-methyl-1-cyclohexyl, 3-methyl-1-cyclohexyl, 4-methyl-1-cyclohexyl and also fluorocyclohexyl radicals such as perfluorocyclohexyl.

Suitable organic radicals having 1 to 20 carbon atoms for the variables R1 to R5 in the imidazolium salts of the general formula (I) are also also C2 to C2o alkenyl radicals, in particular C3 to Cs alkenyl radicals, and their aryl, heteroaryl, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, -O-, -CO- or -CO-O- substituted components, for example vinyl, 2-propenyl (allyl), 3-butenyl, cis- 2-butenyl, trans-2-butenyl and also fluoroalkenyl radicals such as perfluoro-2-propenyl, perfluoro-3-butenyl or perfluoro-2-butenyls. Suitable organic radicals having 1 to 20 carbon atoms for the variables R 1 to R 5 in the imidazolium salts of the general formula (I) are furthermore also C 3 - to C 12 -cycloalkenyl radicals, in particular C 5 - to C 2 -cyclocoalkenyl radicals, and their aryl-, heteroaryl-, cycloalkyl, halo, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O-substituted components, for example 3-cyclopentenyl, 2-cyclohexenyl, 3-cyclohexenyl, 2.5 Cyclohexadienyl and also Fluorcycloalkenylreste such as fluorocyclohexenyl.

Suitable organic radicals having 1 to 20 carbon atoms for the variables R1 to R5 in the imidazolium salts of the general formula (I) are also also aryl or heteroaryl radicals having 3 to 20, in particular 5 to 10 carbon atoms and their alkyl, aryl, heteroaryl , cycloalkyl, halo, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O-substituted components, for example phenyl, 2-methyl-phenyl (2-tolyl), 3-methylphenyl (3-tolyl), 4-methylphenyl (4-tolyl), 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2,3-dimethylphenyl, 2, 4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 4-phenylphenyl, 1-naphthyl, 2- Naphthyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl and also fluoroaryl or fluoro heteroaryl radicals such as mono-, di-, tri-, tetra- or pentafluorophenyl. It is also possible for two adjacent radicals of the variables R 1 to R 5 to be an unsaturated, saturated or aromatic, optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles and optionally substituted by one or more oxygen and / or Form sulfur atoms and / or one or more substituted or unsubstituted imino groups interrupted ring.

The organic radicals having 1 to 3000 carbon atoms for the variables R 1 to R 5 may be synthetically produced radicals or-especially in the case of alkyl and alkenyl radicals-radicals based on naturally occurring compounds. The latter are derived, in particular, from naturally occurring glycerides or fatty acids, for example from stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid or tallow fatty acid. Such radicals based on naturally occurring compounds often represent mixtures of different, mostly homologous alkyl or alkenyl radicals.

As organic radicals having from 1 to 3000 carbon atoms for the variables R 1 to R 5 in the imidazolium salts of the general formula (I), preference is furthermore given to polyisobutyl radicals having from 16 to 3000, in particular from 20 to 1000, especially from 25 to 500, very particularly preferably from 30 up to 250 carbon atoms, into consideration. Such polyisobutyl radicals have a number-average molecular weight M _{n of} from 200 to 40,000, preferably from 500 to 15,000, in particular from 700 to 7000, especially from 900 to 3000, very particularly preferably from 900 to 110, by gel permeation chromatography. The polyisobutyl radicals may be attached directly or through a methylene group (-CH 2 -) to the imidazolium ring.

The organic radicals having 1 to 3000 carbon atoms for the variables R 1 to R 5, in particular the alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl and heteroaryl radicals mentioned, and also the polymeric radicals mentioned, may have one or more in their skeleton Heteroatoms such as oxygen atoms, sulfur atoms or optionally substituted by further usually low molecular weight organic radicals containing nitrogen atoms or one or more substituents or one or more functional groups, for example hydroxyl groups, halogen atoms such as fluorine, chlorine or bromine, pseudohalide groups such as thiocyanato or Dicyanamido, cyano groups, nitro groups , Sulfo groups, sulfonic acid groups, sulfonic acid ester groups, sulfonic acid amide groups, amino groups, carboxylic acid groups, carboxylic acid ester groups or carboxamide groups.

As a rule, imidazolium salts of the general formula (I) are used, in which the variables R 1 and R 3 have the abovementioned meanings of an organic radical having 1 to 3000 carbon atoms and the variables R 2, R 4 and R 5 are hydrogen. In a preferred embodiment of the present invention, imidazolium salts of the general formula (I) are used in which the variables R 1 and R 3 independently of one another are C 1 - to C 20 -alkyl groups, C 2 - to C 20 -alkenyl groups and / or polyisobutyl radicals having a number-average molecular weight ( M _n ) are from 200 to 40,000 and the variables R 2, R 4 and R 5 are each hydrogen. These C to C 20 -alkyl groups are preferably pure hydrocarbon radicals. Typical examples of such pure C to C 20 hydrocarbons are 2-ethylhexyl and tallow fatty alkyl. As anions X in the imidazolium salts of the general formula (I) come z. B. into consideration: chloride; Bromide, iodide; thiocyanate; hexafluorophosphate; Trifluoromethanesulfonate; methane; Carboxylates, in particular formate, acetate, propionate, butyrate or benzoate; mandelate; Nitrate; Nitrite; trifluoroacetate; Sulfate; Bisulfate; Methyl sulfate; ethyl sulfate; 1-propyl sulfate; 1-butyl sulfate; 1 -hexyl sulfate; 1-octyl sulfate; Phosphate; dihydrogen phosphate; Hydrogen phosphate; Ci-C4-dialkyl; propionate; Tetrachloroaluminate; AI2CI7 ^" ; chlorozincate; chloroferrate; bis (trifluoromethylsulfonyl) imide; bis (pentafluoroethylsulfonyl) imide; bis (methylsulfonyl) imide; bis (p-tolylsulfonyl) imide; tris (trifluoromethylsulfonyl) methide; bis (pentafluoroethylsulfonyl) methide p-tolylsulfonate; tetracarbonyl cobaltate; stearate; acrylate; methacrylate; maleate; hydrogen citrate; vinyl phosphonate; bis (pentafluoroethyl) phosphinate; borates such as bis [salicylato (2)] borate; bis [oxalato (2 -)] - borate, bis [1, 2-benzenediolato (2 -) - 0,0 '] - borate, tetracyano borate or tetrafluoroborate; dicyanamide; tris (pentafluoroethyl) trifluorophosphate; tris (heptafluoropropyl) trifluorophosphate, cyclic aryl phosphates such as catechol phosphate of the formula (C6H402) P (0) 0-; chlorocobaltate.

As a rule, the anions X are selected from the following group:

Alkyl sulfates of the formula R ^a OSO 3 ^" , where R ^{a is} a C 1 to C 12 alkyl group, preferably a C 1 to C 6 alkyl group;

The alkyl sulfonates of the formula R ^a SC "3 ^" ; wherein R ^{a is} a C 1 to C 12 alkyl group, preferably a C 1 to C 8 alkyl group;

Halgenides, especially chloride and bromide;

Pseudohalides, in particular thiocyanate and dicyanamide;

Carboxylates of the formula R ^a COO ^" , where R ^{a is} a C 1 to C 6 alkyl group, a C 2 to C 6 alkenyl group, a C 6 to C 6 o aryl group or a C 7 to C 6 alkyl-aryl or arylalkyl group, preferably a C 1 to C 20 alkyl group, a C 2 to C 20 alkenyl group, a C 6 to C 20 aryl group or a C 7 to C 20 alkylaryl or arylalkyl group, especially a C 2 to C 8 alkenyl group, a C 6 - to C12 aryl group or a C7 to C alkylaryl or -Arylalkylgruppe, in particular for Acetate, but also formate, propionate, butyrate, acrylate, methacrylate, benzoate, phenyl acetate or o-, m- or p-methylbenzoate;

Polycarboxylates of the formula R ^b (COO ^" ) _n , where n is the number 1, 2 or 3 and R ^{n is} an n-bonded hydrocarbon radical having 1 to 60, in particular 1 to 20, especially 1 to 14 carbon atoms; such radicals are malonate, succinate, glutarate, adipate, phthalate or terephthalate; further adapted as polycarboxylic boxylat anion also the oxalate anion OC-COO ^". · Phosphates, in particular dialkyl phosphates of the formula R ^a R ^b P0 ₄ -, wherein R ^a and R ^b independently of one another represent a C 1 to C ₆ alkyl group; in particular, R ^a and R ^{b are} the same alkyl group as in dimethyl phosphate and diethyl phosphate; Phosphonates, in particular monoalkylphosphonic acid esters of the formula R ^a R ^b P03 ^" , where R ^a and R ^b independently of one another represent a C 1 to C 6 alkyl group;

The TFSI anion of the formula N (S0 ₂ CF ₃ ) ₂ -; Tricyanomethamide of the formula (CN) 3 C ^" .

Frequently selected anions X are chloride, bromide, hydrogen sulfate, tetrachloroaluminate, thiocyanate, dicyanamide, methylsulfate, ethylsulfate, methanesulfonate, formate, acetate, dimethyl phosphate, diethyl phosphate, p-tolylsulfonate, tetrafluoroborate, hexafluorophosphate, methylmethylphosphonate, methylphosphonate, the TFSI- Anion, tricyanomethamide and trifluoromethanesulfonate.

In a preferred embodiment of the present invention imidazolium salts of the general formula (I) are used in which the anion X sulfate, an alkyl sulfate, an alkyl sulfonate, an alkyl carbonate, a halide, a pseudohalide, a carboxylate, a phosphate, a Phosphonate, nitrate, nitrite, the TFSI anion of formula N (SC "2CF3) 2 ^" or the tricyanomethamide anion. Anion X is very particularly preferably an alkyl carbonate, a pseudohalide, a carboxylate or the tricyanomethamide anion. It is also often advantageous if the anion X contains no phosphorus atom, no sulfur atom, no halogen atom and / or no boron atom.

The charge n of the anion X depends on its nature and may be 1, 2 or 3. Most often, n is 1 or 2, especially 1.

Typical examples of imidazolium salts (I) are 1, 3-dimethylimidazolium acetate, 1, 3-diethylimidazolium acetate, 1-ethyl-3-methylimidazolium acetate, 1-propyl-3-methylimidazolium acetate, 1-butyl-3-yl methylimidazolium acetate, 1-pentyl-3-yl methylimidazolium acetate, 1-hexyl-3-methylimidazolium acetate, 1-octyl-3-methylimidazolium acetate, 1- (2-ethylhexyl) -3-methylimidazolium acetate, 1,3-di (2-ethylhexyl) imidazolium acetate acetate, 1-decyl-3-methylimidazolium acetate, 1- (2-propylheptyl) -3-methylimidazolium acetate, 1, 3,4,5-tetramethylimidazolium acetate, 1,3-dimethyl-4,5-diphenylimidazolium acetate; acetate, 1, 4,5-trimethyl-3-ethylimidazolium acetate, 1-methyl-3-ethyl-4,5-diphenylimidazolium acetate, 1, 3-dimethylimidazolium methylcarbonate, 1, 3-diethylimidazolium methyl carbonate, 1 - Ethyl 3-methylimidazolium methylcarbonate, 1-propyl-3-methylimidazolium methylcarbonate, 1-butyl-3-methylimidazolium methylcarbonate, 1-pentyl-3-methylimidazolium methylcarbonate, 1 -hexyl-3-methylimidazolium methylcarbonate, 1 - Octyl-3-methylimidazolium methylcarbonate, 1- (2-ethylhexyl) -3-methylimidazolium methylcarbonate, 1, 3-di (2-ethylhexyl) imidazolium methylcarbonate, 1-decyl-3-methylimidazolium methylcarbonate, 1- (2 -Propylheptyl) -3-methylimidazo liummethyl carbonate, 1, 3,4,5-tetramethylimidazolium methylcarbonate, 1, 3-dimethyl-4,5-diphenylimidazolium methylcarbonate, 1, 4,5-trimethyl-3-ethylimidazolium methylcarbonate, 1-methyl-3-yl ethyl 4,5-diphenylimidazolium methyl carbonate, 1,3-dimethylimidazolium methylsulfate, 1,3-diethylimidazolium methylsulfate, 1-ethyl-3-methylimidazolium methylsulfate, 1-propyl-3-methylimidazolium methylsulfate, 1-butyl 3-methylimidazolium methylsulfate, 1-pentyl-3-methylimidazolium methylsulfate, 1-hexyl-3-methylimidazolium methylsulfate, 1-octyl-3-methylimidazolium methylsulfate, 1- (2-ethylhexyl) -3-methylimidazolium methylsulfate, 1, 3-di (2-ethylhexyl) imidazolium methylsulfate, 1-decyl-3-methylimidazolium methylsulfate, 1- (2-propylheptyl) -3-methylimidazolium methylsulfate, 1, 3,4,5-tetramethylimidazolium methylsulfate, 1, 3-dimethyl-4,5-diphenylimidazolium methylsulfate, 1, 4,5-trimethyl-3-ethylimidazolium methylsulfate, 1-methyl-3-ethyl-4,5-diphenylimidazolium methylsulfate, 1, 3-dimethylimidazo 1-Methyl-3-methylimidazolium methylsulfonate, 1-propyl-3-methylimidazolium methylsulfonate, 1-butyl-3-methylimidazolium methylsulfonate, 1-pentyl-3-methylimidazolium methylsulfonate, 1-hexyl-3-methylimidazolium methylsulfonate, 1-octyl-3-methylimidazolium methylsulfonate, 1- (2-ethylhexyl) -3-methylimidazolium methylsulfonate, 1,3-di (2-ethylhexyl) imidazolium methylsulfonate, 1-Decyl-3-methylimidazolium methylsulfonate, 1- (2-propylheptyl) -3-methylimidazolium methylsulfonate, 1, 3,4,5-tetramethylimidazolium methylsulfonate, 1,3-dimethyl-4,5-diphenylimidazolium methylsulfonate, 1, 4,5-trimethyl-3-ethylimidazolium methylsulfonate, 1-methyl-3-ethyl-4,5-diphenylimidazolium methylsulfonate, 1, 3-dimethylimidazolium diethyl phosphate, 1, 3-diethylimidazolium diethyl phosphate, 1-ethyl 3-methylimidazolium diethyl phosphate, 1-propyl-3-methylimidazolium diethyl phosphate, 1-butyl-3-methylimidazolium diethyl phosphate, 1-pentyl-3-methyl imidazolium diethyl phosphate, 1-hexyl-3-methylimidazolium diethyl phosphate, 1-octyl-3-methylimidazolium diethyl phosphate, 1- (2-ethylhexyl) -3-methylimidazolium diethyl phosphate, 1, 3-di (2-ethylhexyl) imidazolium diethyl phosphate, 1-decyl-3-methylimidazolium diethyl phosphate, 1- (2-propylheptyl) -3-methylimidazolium diethyl phosphate, 1, 3,4,5-tetramethylimidazolium diethyl phosphate, 1, 3-dimethyl-4,5- diphenylimidazolium diethyl phosphate, 1, 4,5-trimethyl-3-ethylimidazolium diethyl phosphate and 1-methyl-3-ethyl-4,5-diphenylimidazolium diethyl phosphate.

Typical individual examples of imidazolium salts (I) with polyisobutenyl radicals are 1-polyisobutyl-3-methylimidazolium acetate, 1-polyisobutyl-3-ethylimidazolium acetate, 1-polyisobutyl-3-propylimidazolium acetate, 1-polyisobutyl-3-butylimidazolium acetate, 1 - Polyisobutyl-3- (2-ethylhexyl) imidazolium acetate, 1,3-di (polyisobutyl) imidazolium acetate, 1-polyisobutyl-3-methylimidazolium methyl carbonate, 1-polyisobutyl-3-ethylimidazolium methyl carbonate, 1-polyisobutyl 3-propylimidazolium methyl carbonate, 1-polyisobutyl-3-butylimidazolium methyl carbonate, 1-polyisobutyl-3- (2-ethylhexyl) imidazolium methyl carbonate, 1, 3-di (polyisobutyl) imidazolium methyl carbonate, 1-polyisobutyl-3 methylimidazolium thiocyanate, 1-polyisobutyl-3-ethylimidazolium thiocyanate, 1-polyisobutyl-3-propylimidazolium thiocyanate, 1-polyisobutyl-3-butylimidazolium thiocyanate, 1-polyisobutyl-3- (2-ethylhexyl) imidazolium thiocyanate, 1 , 3-di (polyisobutyl) imidazolium thiocyanate, 1-polyisobutyl-3-methylimidazolium tricyanomethamide, 1 -

Polyisobutyl-3-ethylimidazolium tricyanomethamide, 1-polyisobutyl-3-propylimidazolium tricyanomethamide, 1-polyisobutyl-3-butylimidazolium tricyanomethamide, 1-polyisobutyl-3- (2-ethylhexyl) imidazolium tricyanomethamide and 1, 3-di (polyisobutyl ) imidazolium tricyanomethamide.

Imidazolium salts of type (I) with low molecular weight radicals are marketed commercially under the name Basionics ™ by BASF SE.

The preparation of the imidazolium salts of type (I) is familiar to the person skilled in the art. A typical synthetic route is based on imidazole formation from 1 mole of a 1,2-dicarbonyl compound, 1 mole of an appropriately substituted primary amine, 1 mole of ammonia and 1 mole of an aldehyde, affording N-alkylation with a suitable alkylie and thereafter, if desired, exchange the anion. For example, from glyoxal or benzil, a low molecular weight primary alkylamine or alkenylamine, e.g. B. a d- to Ci3-alkylamine, or a polyisobutylamine, ammonia and formaldehyde, an N-alkyl-4,5-diphenylimidazole or an N-alkylimidazole or an N-polyisobutyl-4,5-diphenylimidazole or an N- Polyisobutylimidazole forth and alkylates the unsubstituted second nitrogen atom with an epoxide such as ethylene oxide, propylene oxide, butylene oxide or styrene oxide in the presence of acetic acid or with a dialkylcarbonat, wherein the imidazolium salt then having an acetate anion or an alkyl carbonate anion. For introducing a polyisobutyl radical on the unsubstituted second nitrogen atom can use with a polyisobutene as alkylating agent.

In the preparation of imidazolium salts of type (I) having the same variables R1 and R3, advantageously 1 mole of a 1, 2-dicarbonyl compound is used together with 2 moles of an appropriately substituted primary amine and 1 mole of an aldehyde, optionally in the presence of a suitable solvent (e.g. It- acetic acid and water if an imidazolium acetate is to be obtained) in a one-step synthesis, usually at 20 to 120 ° C, in particular at 25 to 80 ° C to.

The fuel or fuel additized with one or more imidazolium salts (I) is a gasoline or, in particular, a middle distillate fuel, especially a diesel fuel. The fuel or fuel may contain other conventional additives ("co-additives") to improve the effectiveness and / or wear suppression.

In the case of diesel fuels, these are primarily conventional detergent additives, carrier oils, cold flow improvers, lubricity improvers,

Corrosion inhibitors, demulsifiers, dehazers, antifoam agents, cetane number improvers, combustion improvers, antioxidants or stabilizers, antistatic agents, metallocenes, metal deactivators, dyes and / or solvents. In the case of gasoline fuels, these are mainly friction modifiers, corrosion inhibitors, demulsifiers, dehazers, antifoams, combustion improvers, antioxidants or stabilizers, antistatic agents, metallocenes, metal deactivators, dyes and / or solvents. Typical examples of suitable co-additives are listed in the following sections.

The usual detergent additives are preferably amphiphilic substances which have at least one hydrophobic hydrocarbon radical with a number-average molecular weight (M _n ) of from 85 to 20 000 and at least one polar group selected from:

(Da) mono- or polyamino groups having up to 6 nitrogen atoms, wherein at least one nitrogen atom has basic properties;

(Db) nitro groups, optionally in combination with hydroxyl groups;

(De) hydroxyl groups in combination with mono- or polyamino groups, wherein at least one nitrogen atom has 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;

(Df) polyoxy-C 2 to C 4 -alkylene groups terminated by hydroxyl groups, mono- or polyamino groups, wherein at least one nitrogen atom has basic properties, or terminated by carbamate groups; (Dg) carboxylic acid ester groups;

(Ie) derived from succinic anhydride moieties having hydroxy and / or amino and / or amido and / or imido groups; and or

(Di) by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated groupings.

The hydrophobic hydrocarbon radical in the above detergent additives, which provides sufficient solubility in the fuel, has a number average molecular weight (M _n ) of from 85 to 20,000, preferably from 1 13 to 10,000, more preferably from 300 to 5,000 preferably from 300 to 3,000, even more preferably from 500 to 2,500 and in particular from 700 to 2,500, especially from 800 to 1500. As typical hydrophobic hydrocarbon radicals are in particular poly propenyl, polybutenyl and polyisobutenyl radicals having a number average molecular weight M _n of preferably in each case 300 to 5,000, particularly preferably 300 to 3,000, more preferably 500 to 2,500, even more preferably 700 to 2,500 and in particular 800 to 1,500 into consideration. As examples of the above groups of detergent additives, the following are mentioned:

Mono- or polyamino (Da) -containing additives are preferably polyalkylene mono- or polyalkene polyamines based on polypropene or of highly reactive (ie predominantly terminal double bonds) or conventional (ie predominantly intermediate double bonds) polybutene or polyisobutene having M _n = 300 to 5,000 , particularly preferably 500 to 2500 and in particular 700 to 2500. Such additives based on highly reactive polyisobutene, which from the polyisobutene, which may contain up to 20 wt .-% of n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine, are known in particular from EP-A 244 616. If one starts with the preparation of the additives of polybutene or polyisobutene with predominantly intermediate double bonds (usually in the β and γ position), the preparation route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. Amines such as ammonia, monoamines or the polyamines mentioned above can be used for the amination. Corresponding additives based on polypropene are described in particular in WO-A 94/24231.

Other special monoamine (Da) containing additives are the hydrogenation products of the reaction products of polyisobutenes with a middle poly 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 special monoamino (Da) -containing additives are the compounds obtained 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.

Nitro groups (Db), optionally in combination with hydroxyl groups, containing additives are preferably reaction products of polyisobutenes of 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-A96 / 03367 and in WO-A 96/03479 are described. As a rule, these reaction products are mixtures of pure nitropolyisobutenes (for example α, β-dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (for example α-nitro-β-hydroxy-polyisobutene).

Hydroxyl groups in combination with mono- or polyamino (De) containing additives are in particular reaction products of polyisobutene epoxides obtainable from preferably predominantly terminal double bonds having poly isobutene with M _n = 300 to 5000 with ammonia, mono- or polyamines, as described in particular in EP -A 476 485 are described.

Carboxyl groups or their alkali metal or alkaline earth metal salts (Dd) containing additives are preferably copolymers of C2 to C4o-olefins with maleic anhydride having a total molecular weight of 500 to 20,000, their carboxyl groups wholly or partly to the alkali metal or alkaline earth metal salts and a remaining Rest of the carboxyl groups are reacted with alcohols or amines. Such additives are known in particular from EP-A 307 815. Such additives are primarily used to prevent valve seat wear and, as described in WO-A 87/01 126, can be advantageously used in combination with conventional fuel detergents such as poly (iso) buteneamines or polyetheramines.

Sulfonic acid groups or their alkali metal or alkaline earth metal salts (De) containing additives are preferably alkali metal or alkaline earth metal salts of a Sulfobern- steinsäurealkylesters, as described in particular in EP-A 639 632. Such additives are mainly used to prevent valve seat wear and can be used to advantage in combination with conventional fuel detergents such as poly (iso) butenines or polyetheramines. Polyoxy-C2-C4-alkylene (Df) containing additives are preferably lyether or polyetheramines, which by reaction of C2 to C6o-alkanols, C6 to C3o-alkanediols, mono- or D1-C2 to C3o-alkylamines, C 1 -C 30 -alkylcyclohexanols or C 1 -C 30 -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene lenoxid and / or butylene oxide per hydroxyl group or amino group and, in the case of polyether amines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. 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 meet carrier oil properties. Typical examples of these are tridecanol or Isotridecanolbutoxylate, isononylphenol butoxylates and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia. Carboxylic ester groups (Dg) containing additives are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, especially those having a minimum viscosity of 2 mm ² / s at 100 ° C, as described in particular in DE-A 38 38 918 are described. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or polyols are long-chain representatives having, for example, 6 to 24 C atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of iso-octanol, iso-nonanol, iso-decanol and of isotridecanol. Such products also meet carrier oil properties. Succinic anhydride-derived groupings containing hydroxyl and / or amino and / or amido and / or imido groups (Dh) containing additives are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and in particular the corresponding derivatives of polyisobutenylsuccinic anhydride, which by reaction of conventional or highly reactive polyisobutene with M _n = preferably 300 to 5000, more preferably 300 to 3000, more preferably 500 to 2500, even more preferably 700 to 2500 and in particular 800 to 1500, with maleic anhydride by thermal means in an En Reaction or via the chlorinated polyisobutene are available. The groupings 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, still have free amine groups, succinic acid derivatives with an acid and an amide function, carboximides with monoamines, carboximides with di- or polyamines which, in addition to the imide function, still have free amine groups, or diimides which are formed by the reaction of di- or polyamines with two succinic acid derivatives. Such fuel additives are described in particular in US Pat. No. 4,849,572. Preference is given to the reaction products of alkyl- or alkenyl-substituted succinic acids or derivatives thereof with amines and particularly preferably to the reaction products of polyisobutenyl-substituted succinic acids or derivatives thereof with amines. Of particular interest here are reaction products with aliphatic polyamines (polyalkyleneimines), in particular ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, which have an imide structure. By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated moieties containing (di) additives 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 be derived from conventional or highly reactive polyisobutene having M _n = 300 to 5,000. Such "polyisobutene-Mannich bases" are described in particular in EP-A 831 141.

To the fuel, one or more of the above-mentioned detergent additives of the group (Da) to (Di) may be added in such an amount that the dosage rate of these detergent additives is preferably 25 to 2500 ppm by weight, especially 75 to 1500% by weight . ppm, especially 150 to 1000 ppm by weight.

Carrier oils used as co-additives may be mineral or synthetic. Suitable mineral carrier oils are fractions obtained in petroleum processing, such as bright stock or base oils having viscosities such as from class SN 500 to 2000, but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. It is also useful as a "hydrocrack oil" known and obtained in the refining of mineral oil fraction (Vakuumdestillatschnitt with a boiling range of about 360 to 500 ° C, available from high pressure catalytically hydrogenated and isomerized and dewaxed natural mineral oil). Also 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 polyetheramines, alkylphenol-initiated polyethers, alkylphenol-initiated polyetheramines and carboxylic acid esters of long-chain alkanols.

Examples of suitable polyolefins are olefin polymers having M _n = 400 to 1800, especially based on polybutene or polyisobutene (hydrogenated or non-hydrogenated). Examples of suitable polyethers or polyetheramines are preferably compounds containing polyoxy-C ₂ - to C ₄ -alkylene groups which are prepared by reacting C ₂ - to C ₆ -alkanols, C ₆ - to C ₃ -oxanediols, mono- or C 1 - to C 20 -alkylamines, C 1 -C 30 -alkylcyclohexanols or C 1 -C 30 -alkylphenols with 1 to 30 mol of ethylenoxide 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 are available. 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, as polyether amines P0IV-C2 to C6 Alkylenoxidamine or functional derivatives thereof may be used. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

Examples of carboxylic acid 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. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or 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, isononanol, isodecanol and of isotridecanol, eg. B. 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 from about 5 to 35, preferably about 5 to 30, particularly preferably 10 to 30 and in particular 15 to 30 C3 to C6 alkylene oxide units, for. 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 long-chain alkyl-substituted phenols, where the long-chain alkyl radical is, in particular, a straight-chain or branched C 6 - to C 18 -alkyl radical. Specific examples include tridecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherification products) of monohydric C6- to Cis-aliphatic alcohols with C3- to C6-alkylene oxides. Examples of monohydric C6-C18 aliphatic alcohols are hexanol, heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 2-propylheptanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol and their constitution and position isomers. The alcohols can be used both in the form of pure isomers and in the form of technical mixtures. A particularly preferred alcohol is tridecanol. Examples of C 3 - to C 6 -alkylene oxides are propylene oxide, such as 1, 2-propylene oxide, butylene oxide, such as 1, 2-butylene oxide, 2,3-butylene oxide, isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Among these, particularly preferred are C ₃ -C ₄ -alkylene oxides, ie, propylene oxide such as 1, 2-propylene oxide and butylene oxide such as 1, 2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Specifically, butylene oxide is used.

Further suitable synthetic carrier oils are alkoxylated alkylphenols, as described in DE-A 10 102 913.

Particular carrier oils are synthetic carrier oils, the alcohol-initiated polyethers described above being particularly preferred. The carrier oil or the mixture of different carrier oils is added to the fuel in an amount of preferably from 1 to 1000 ppm by weight, more preferably from 10 to 500 ppm by weight and in particular from 20 to 100 ppm by weight.

Suitable cold flow improvers as co-additives are in principle all organic compounds which are able to improve the flow behavior of middle distillate fuels or diesel fuels in the cold. Conveniently, they must have sufficient oil solubility. In particular, these are usually the middle distillates of fossil origin, so in conventional mineral diesel fuels used, cold flow improvers used ("middle distillate flow improvers", "MDFI") into consideration. However, it is also possible to use organic compounds which, when used in conventional diesel fuels, have in part or predominantly the properties of a wax anti-settling additive ("WASA"). The imidazolium salts (I) used according to the invention in the middle distillate fuels, in particular in diesel fuels, themselves have properties as WASA, which is also the subject matter of the present invention. Also, co-additives used as cold flow improvers can act partly or predominantly as nucleators. However, it is also possible to use mixtures of organic compounds which are active as MDFI and / or which act as WASA and / or as nucleators.

Typically, the cold flow improver is selected from:

(K1) copolymers of a C2- to C4o-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 their derivatives; and

(K6) poly (meth) acrylic acid esters.

Mixtures of different representatives from one of the respective classes (K1) to (K6) as well as mixtures of representatives from different classes (K1) to (K6) can be used.

Suitable C2 to C4o-olefin monomers for the copolymers of class (K1) are for example those having 2 to 20, in particular 2 to 10 carbon atoms and having 1 to 3, preferably 1 or 2, in particular having a carbon-carbon double bond. In the latter case, the carbon-carbon double bond can be arranged both terminally (α-olefins) and internally. However, preference is given to α-olefins, particularly preferably α-olefins having 2 to 6 carbon atoms, for example propene, 1-butene, 1-pentene, 1-hexene and, above all, ethylene. In the copolymers of class (K1), the at least one further ethylenically unsaturated monomer is preferably selected from carboxylic alkenyl esters, (meth) acrylic esters and further olefins. If further olefins are polymerized in, these are preferably higher molecular weight than the abovementioned C 2 - to C 4 -olefin base monomers. If, for example, ethylene or propene is used as the olefin base monomer, suitable further olefins are, in particular, C 10 - to C 40 -alpha-olefins. Other olefins are polymerized in most cases only when monomers with carboxylic acid ester functions are used.

Suitable (meth) acrylic esters are, for example, esters of (meth) acrylic acid with Cr to C 2 alkanols, in particular C 1 to C 1 alkanols, especially 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 carboxylic alkenyl esters are, for example, C2 to C-u-alkenyl esters, e.g. the vinyl and propenyl esters of carboxylic acids having from 2 to 21 carbon atoms, the hydrocarbon radical of which may be linear or branched. Preferred among these are the vinyl esters. Among the carboxylic acids having a branched hydrocarbon radical, preferred are those whose branch is in the α-position to the carboxyl group, the α-carbon atom being particularly preferably tertiary, ie. H. the carboxylic acid is a so-called neocarboxylic acid. Preferably, however, the hydrocarbon radical of the carboxylic acid is linear.

Examples of suitable carboxylic alkenyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, the vinyl esters being preferred. A particularly preferred carboxylic acid alkenyl ester is vinyl acetate; typical resulting copolymers of group (K1) are the most commonly used ethylene-vinyl acetate copolymers ("EVA"). Particularly advantageous ethylene-vinyl acetate copolymers and their preparation are described in WO 99/29748.

Also suitable as copolymers of class (K1) are those which contain two or more different carboxylic acid alkenyl esters in copolymerized form, these differing in the alkenyl function and / or in the carboxylic acid group. Also suitable are copolymers which, in addition to the carboxylic acid alkenyl ester (s), contain at least one olefin and / or at least one (meth) acrylic acid ester in copolymerized form. Terpolymers of a C2 to C4o-α-olefin, a C to C2o-alkyl ester of an ethylenically unsaturated monocarboxylic acid having 3 to 15 carbon atoms and a C2 to C4 alkenyl ester of a saturated monocarboxylic acid having 2 to 21 carbon atoms are also copolymers of the class ( K1) suitable. Such terpolymers are described in WO 2005/054314. A typical such terpolymer is composed of ethylene, 2-ethylhexyl acrylate and vinyl acetate.

The at least one or the other ethylenically unsaturated monomers are present in the copolymers of class (K1) in an amount of preferably from 1 to 50% by weight, in particular from 10 to 45% by weight and especially from 20 to 40% by weight. %, based on the total copolymer, copolymerized. The majority by weight of the monomer units in the copolymers of class (K1) thus usually comes from the C2 to C4o-based olefins. The copolymers of class (K1) preferably have a number average molecular weight M _{n of} from 1000 to 20,000, particularly preferably from 1000 to 10,000 and in particular from 1000 to 8000.

Typical comb polymers of component (K2) are, for example, by the copolymerization of maleic anhydride or fumaric acid with another ethylenically unsaturated monomer, for example with an α-olefin or an unsaturated ester, such as vinyl acetate, and subsequent esterification of the anhydride or acid function with an alcohol available with at least 10 carbon atoms. Further suitable comb polymers are copolymers of α-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 polymaleinates. In addition, homopolymers and copolymers of vinyl ethers are suitable comb polymers. Comb polymers suitable as component of class (K2) are also, for example, those described in WO 2004/035715 and in "Comb-Like Polymers, Structure and Properties", N.A. Plate and V.P. Shibaev, J.

Poly. Be. Macromolecular Revs. 8, pages 1 17 to 253 (1974). "Mixtures of comb polymers are also suitable.

Polyoxyalkylenes suitable as a component of class (K3) are, for example, polyalkylene esters, polyoxyalkylene ethers, mixed polyoxyalkylene ester ethers and mixtures thereof. These polyoxyalkylene compounds preferably comprise at least one, preferably at least two, linear alkyl groups each having from 10 to 30 carbon atoms and a polyoxyalkylene group having a number average molecular weight of up to 5,000. Such polyoxyalkylene compounds are described, for example, in EP-A 061 895 and in US Pat. No. 4,491,455. Particular polyoxyalkylene compounds are based on polyethylene glycols and polypropylene glycols having a number average molecular weight of 100 to 5000. Furthermore, polyoxyalkylene mono- and diesters of fatty acids having 10 to 30 carbon atoms such as stearic acid or behenic acid suitable.

Polar nitrogen compounds suitable as a component of the class (K4) may be of ionic or nonionic nature and preferably have at least one, in particular at least two, substituents in the form of a tertiary nitrogen atom of the general formula> NR ⁷ , where R ^{7 is} a to C4o hydrocarbon residue. The nitrogen substituents may also be quaternized, that is in cationic form. Examples of such nitrogen compounds are ammonium salts and / or amides obtainable by reacting at least one amine substituted with at least one hydrocarbon radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. Preferably, the amines contain at least one linear Cs to C4o-alkyl radical. Primary amines which are suitable for the preparation of said polar nitrogen compounds 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 industrially available amine mixtures such as fatty amines or hydrogenated tallamines, as described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, in the chapter "Amines, aliphatic". Suitable acids for the reaction are, for example, 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 at least one tertiary amino group-containing poly (C 2 - to C 20 -carboxylic acids) with primary or secondary amines. The poly (C 2 - to C 20 -carboxylic acids) which have at least one tertiary amino group and are based on this reaction product preferably contain at least 3 carboxyl groups, in particular 3 to 12, especially 3 to 5, carboxyl groups. The carboxylic acid units in the polycarboxylic acids preferably have 2 to 10 carbon atoms, in particular they are acetic acid units. The carboxylic acid units are suitably linked to the polycarboxylic acids, usually via one or more carbon and / or nitrogen atoms. Preferably, they are attached to tertiary nitrogen atoms, which are connected in the case of several nitrogen atoms via hydrocarbon chains.

The component of the class (K4) is preferably an oil-soluble reaction product based on poly (C 2 - to C 20 -carboxylic acids) having the general formula IIa or IIb and having at least one tertiary amino group

(Ib) in which the variable A is a straight-chain or branched C 2 - to C 6 -alkylene group or the grouping of the formula II I

_^ B _{^ ^} ΟΗ ₂ -ΟΗ ₂ -

HOOC

 i

 CH2-CH2

(I I I) and the variable B denotes a C to Cig alkylene group. The compounds of the general formula I Ia and Ib I have in particular the properties of a WASA.

Furthermore, the preferred oil-soluble reaction product of component (K4), in particular that of general formula I Ia or IIb, is an amide, an amide ammonium salt or an ammonium salt in which none, one or more carboxylic acid groups are converted into amide groups.

Straight-chain or branched C 2 - to C 6 -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 especially 1, 2-ethylene. Preferably, the variable A comprises 2 to 4, in particular 2 or 3 carbon atoms. Cr to Ci9-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, Nonadecamethylen and especially methylene. Preferably, the variable B comprises 1 to 10, in particular 1 to 4, carbon atoms.

The primary and secondary amines as reaction partners for the polycarboxylic acids to form the component (K4) are usually monoamines, in particular aliphatic monoamines. These primary and secondary amines may be selected from a variety of amines bearing hydrocarbon radicals, optionally linked together.

Most of these amines which are the oil-soluble reaction products of component (K4) are secondary amines and have the general formula HN (R ⁸ ) 2, in which the two variables R ⁸ are each independently straight-chain or branched C 10 to C 30 -alkyl radicals, in particular C 1 to C 24 -alkyl radicals. These longer-chain alkyl radicals are preferably straight-chain or only slightly branched. As a rule, the abovementioned secondary amines are derived with regard to their longer-chain alkyl radicals from naturally occurring fatty acid or from its derivatives. Preferably, the two radicals R ^{8 are the} same.

The abovementioned secondary amines can be bound to the polycarboxylic acids by means of amide structures or in the form of the ammonium salts, and only one part can be present as amide structures and another part as ammonium salts. Preferably, only a few or no free acid groups are present. Preferably, the oil-soluble reaction products of component (K4) are completely in the form of the amide structures. Typical examples of such components (K4) are reaction products of nitrilotriacetic acid, ethylenediaminetetraacetic acid or propylene-1,2-diaminetetraacetic acid with in each case 0.5 to 1.5 mol per carboxyl group, in particular 0.8 to 1.2 mol per carboxyl group, dioleylamine, dipalmitinamine, dicoco fatty amine, distearylamine, dibehenylamine or, in particular, Ditaigfettamin. A particularly preferred component (K4) is the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated dieth fatamine.

Other typical examples of the component (K4) include the N, N-dialkylammonium salts of 2-N ', N'-dialkylamidobenzoates, for example the reaction product of 1 mole of phthalic anhydride and 2 moles of Ditaigfettamin, the latter may be hydrogenated or unhydrogenated , and the reaction product of 1 mole of an alkenyl spiro-bis-lactone with 2 moles of a dialkylamine, for example, dinig fatty amine and / or tallow fatty amine, the latter two of which may be hydrogenated or unhydrogenated. Further typical structural types for the component of the class (K4) are cyclic compounds having tertiary amino groups or condensates of long-chain primary or secondary amines with carboxylic acid-containing polymers, as described in WO 93/181 15. Sulfocarboxylic acids, sulfonic acids or their derivatives which are suitable as cold flow improvers of the component of class (K5) are, for example, the oil-soluble carboxylic acid amides and carboxylic acid esters of ortho-sulfobenzoic acid in which the sulfonic acid function is present as sulfonate with alkyl-substituted ammonium cations, as described in EP -A 261 957.

As cold flow improvers of the component of the class (K6) suitable poly (meth) acrylic esters are both homo- and copolymers of acrylic and methacrylic esters. Preferred are copolymers of at least two different from each other (Meth) acrylic acid esters, which differ with respect to the condensed alcohol. Optionally, the copolymer contains a further, different of which olefinically unsaturated monomer copolymerized. 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 acid esters of saturated Cu and Cis alcohols wherein the acid groups are neutralized with hydrogenated tallamine. Suitable poly (meth) acrylic esters are described, for example, in WO 00/44857. The middle distillate fuel or diesel fuel is the cold flow improver or the mixture of various cold flow improvers in a total amount of preferably 10 to 5000 ppm by weight, more preferably from 20 to 2000 ppm by weight, more preferably from 50 to 1000 ppm by weight and in particular from 100 to 700 ppm by weight, for example from 200 to 500 ppm by weight.

Lubricity improvers or friction modifiers which are suitable as coadditives are usually based on fatty acids or fatty acid esters. Typical examples are tall oil fatty acid, as described for example in WO 98/004656, and glycerol monooleate. The reaction products of natural or synthetic oils, for example triglycerides, and alkanolamines described in US Pat. No. 6,743,266 B2 are also suitable as such lubricity improvers.

As co-additives suitable corrosion inhibitors are z. As succinic acid esters, especially with polyols, fatty acid derivatives, eg. For example, oleic acid esters, oligomerized fatty acids, substituted ethanolamines, N-acylated sarcosine, imidazoline derivatives, e.g. B. those which in the 2-position an alkyl group and the trivalent nitrogen atom, a functional organic radical (a typical imidazoline derivative is the reaction product of excess oleic acid with diethylenetriamine), and products sold under the trade name RC 4801 (Rhein Chemie Mannheim , Germany) or Hi-TEC 536 (Ethyl Corporation). The imidazoline derivatives mentioned are particularly effective as corrosion inhibitors when, in this application, they contain one or more carboxylic acid amides having one or more carboxylic acid amide functions in the molecule and longer-chain amide nitrogen radicals, for example the reaction product of maleic anhydride with a long-chain amine in an equimolar ratio, combined.

As co-additives suitable demulsifiers z. As the alkali or alkaline earth metal salts of alkyl-substituted phenol and naphthalenesulfonates and the alkali or alkaline earth metal salts of fatty acids, as well as neutral compounds such as alcohol alkoxylates, eg alcohol ethoxylates, phenol alkoxylates, eg tert-butylphenol ethoxylate or part. -Pentylphenol- ethoxylate, fatty acids, alkylphenols, condensation products of ethylene oxide (EO) and propylene oxide (PO), for example in the form of EO / PO block copolymers, polyethylene lenimine or polysiloxanes. Suitable co-additives Dehazer are z. Example, alkoxylated phenol-formaldehyde condensates, such as the available under the trade name NALCO 7D07 products (Nalco) and TOLAD 2683 (Petrolite).

As co-additives suitable antifoams are for. For example, polyether-modified polysiloxanes such as the TEGOPREN 5851 (Goldschmidt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc) products available under the trade name. Suitable co-additives Cetanzahlverbesserer z. As aliphatic nitrates such as 2-ethylhexyl nitrate and cyclohexyl nitrate and peroxides such as di-tert-butyl peroxide.

As co-additives suitable antioxidants are, for. Substituted, d. H. sterically hindered phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-3-methylphenol or products sold under the trade name IRGANOX® (BASF SE), e.g. B. 2,6-di-tert-butyl-4-alkoxycarbonylethyl-phenol (IRGANOX L135), and phenylenediamines such as N, N'-di-sec-butyl-p-phenylenediamine.

As co-additives suitable metal deactivators z. As salicylic acid derivatives such as Ν, Ν'-disalicylidene-1, 2-propanediamine or under the trade name IRGAMET® (BASF SE) marketed products based on N-substituted triazoles and tolutriazoles.

As concomitant solvents are z. For example, non-polar organic solvents such as aromatic and aliphatic hydrocarbons, for example toluene, xylenes, "white spirit" and products sold under the trade name SHELLSOL (Royal Dutch / Shell Group) and EXXSOL (ExxonMobil), as well as polar organic solvents, for example alcohols such as 2-ethylhexanol, decanol and isotridecanol and carboxylic acid esters with longer-chain alkyl groups such as C12 to C2o fatty acid methyl ester suitable. Such solvents usually get together with the imidazolium salts (I) and the abovementioned co-additives, which they are intended to dissolve or dilute for better handling, into the fuel or fuel, in particular the diesel fuel.

The imidazolium salts (I) to be used according to the invention are outstandingly suitable as a fuel or fuel additive and can, in principle, be used in all fuels and fuels. They bring about a whole series of advantageous effects in the operation of internal combustion engines with fuels. The imidazolium salts (I) to be used according to the invention are preferably used in middle distillate fuels, in particular diesel fuels.

The subject matter of the present invention is therefore also a fuel and fuel composition, in particular a middle distillate fuel composition, with an additive used to achieve advantageous effects in the operation of internal combustion engines, for example of diesel engines, in particular of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, effective content of the present invention to be used Imidazoli- umsalzen (I) in addition to the main amount of a conventional Grundkraft- or Grundbrennstof- fes. This effective content (metering rate) is generally from 10 to 5000 ppm by weight, preferably from 20 to 1500 ppm by weight, in particular from 25 to 1000 ppm by weight, especially from 30 to 750 ppm by weight, in each case based on the total amount of fuel or fuel. Middle distillate fuels, such as diesel fuels or fuel oils, are preferably petroleum raffinates, which usually have a boiling range of from 100 to 400.degree. These are mostly distillates with a 95% point up to 360 ° C or even beyond. However, these may also be so-called "Ultra Low Sulfur Diesel" or "City Diesel", characterized by a 95% point of, for example, a maximum of 345 ° C and a maximum sulfur content of 0.005 wt .-% or by a 95% point of for example, 285 ° C and a maximum sulfur content of 0.001% by weight. In addition to the mineral middle distillate mineral fuels or diesel fuels available through refining, those produced by coal gasification or gas liquefaction [GTL] or by biomass to liquid (BTL) fuels are also included. are available, suitable. Also suitable are mixtures of the abovementioned middle distillate fuels or diesel fuels with regenerative fuels, such as biodiesel or bioethanol.

The qualities of fuel oils and diesel fuels are specified in greater detail in, for example, DIN 51603 and EN 590 (cf., also, Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A12, page 617 et seq.).

The imidazolium salts (I) to be used according to the invention can be used not only for their use in the abovementioned middle distillate fuels of fossil, vegetable or animal origin, which are essentially hydrocarbon mixtures, but also in mixtures of such middle distillates with biofuel oils (biodiesel). For the purposes of the present invention, such mixtures are also encompassed by the term "middle distillate fuel". They are commercially available and usually contain the biofuel oils in minor amounts, typically in amounts of 1 to 30 wt .-%, in particular from 3 to 10 wt .-%, based on the total amount of middle distillate of fossil, vegetable or animal origin and biofuel.

Biofuel oils are generally based on fatty acid esters, usually substantially on alkyl esters of fatty acids derived from vegetable and / or animal oils and / or fats. Alkyl esters are usually lower alkyl esters, in particular C 1 to C 4 alkyl esters, understood by transesterification of occurring in vegetable and / or animal oils and / or fats glycerides, especially triglycerides, by means of lower alcohols, for example ethanol or especially methanol ("FAME"). Typical lower alkyl esters based on vegetable and / or animal oils and / or fats which are used as biofuel oil or components thereof include, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME") and in particular rapeseed oil methyl ester ("RME"). ,

The middle distillate fuels or diesel fuels are particularly preferably those with a low sulfur content, ie with a sulfur content of less than 0.05% by weight, preferably less than 0.02% by weight, in particular of less than 0.005% by weight and especially less than 0.001% by weight of sulfur.

As gasoline fuels are all commercially available gasoline fuel compositions into consideration. A typical representative here is the market-standard basic fuel of Eurosuper according to EN 228. Furthermore, gasoline compositions of the specification according to WO 00/47698 are also possible fields of use for the present invention.

The present invention also provides an additive concentrate which, in combination with at least one further fuel and fuel additive, in particular with at least one further diesel fuel additive, contains at least one imidazolium salt (I) to be used according to the invention. Usually, such an additive concentrate contains 10 to 60% by weight of at least one solvent or diluent, which may be an abovementioned solvent or the fuel or fuel itself. In addition to the at least one imidazolium salt (I) to be used according to the invention, the additive concentrate according to the invention preferably also comprises at least one detergent additive from the above-mentioned group (Da) to (Di), in particular at least one detergent additive of the type (Dh), and in US Pat In addition, in addition, at least one lubricity improver and / or a corrosion inhibitor and / or a demulsifier and / or a dehazer and / or an antifoam agent and / or a cetane number improver and / or an antioxidant and / or a metal deactivator in each case for this purpose contain usual quantity relations.

The imidazolium salts (I) to be used according to the invention are particularly suitable as an additive in fuel and fuel compositions, in particular in diesel fuels, to overcome the initially described problems in direct injection diesel engines, especially in those with common rail injection systems.

Since some of the described imidazolium salts are novel substances, the present invention likewise provides imidazolium salts of the general formula (Ia)

in which one of the variables R1 or R3 or both variables R1 and R3 independently of one another represent a linear alkyl or alkenyl radical having 14 to 3000 carbon atoms or a branched alkyl or alkenyl radical having 4 to 3000 carbon atoms, the variable R1 or R3 which is not a linear alkyl or alkenyl radical having 14 to 3000 carbon atoms or a branched alkyl or alkenyl radical having 4 to 3000 carbon atoms, an alkyl radical having 1 to 13 carbon atoms or an alkenyl radical having 2 to 13 carbon atoms, the variables R 2 R4 and R5 independently of one another denote hydrogen, an alkyl radical having 1 to 20 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms,

X denotes an anion and n represents the number 1, 2 or 3, wherein said variables R1 to R5, X and n have the abovementioned relevant individual meanings and preferred ranges.

Particularly preferred imidazolium salts of the general formula (Ia) are those in which one of the variables R 1 or R 3 or both variables R 1 and R 3 are independently of one another a linear alkyl or alkenyl radical having 14 to 20 carbon atoms or a branched alkyl or Alkenyl radical having 4 to 13 carbon atoms and the variables R2, R4 and R5 independently of one another are hydrogen, an alkyl radical having 1 to 20 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms.

Particularly preferred imidazolium salts of the general formula (Ia) are furthermore those in which the variables R 1 or R 3 or both variables R 1 and R 3 independently of one another are a polyisobutyl radical having a number average molecular weight of from 200 to 40 000 and the variables R 2, R 4 and R5 independently of one another are hydrogen, an alkyl radical having 1 to 20 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms. The new imidazolium salts of the general formula (Ia) are suitable not only for their use as additives for fuels and fuels, in particular as detergent additives for diesel fuels, but also for improving the service properties of mineral and synthetic non-aqueous industrial fluids. Among non-aqueous industrial fluids, which may contain water in individual cases, but whose essential effect is based on non-aqueous components, lubricants, lubricants and lubricating oils in the broadest sense, especially motor oils, gear oils, axle oils, hydraulic fluids, hydraulic oils, compressor fluids, compressor oils, Circulation oils, turbine oils, transformer oils, gas engine oils, wind turbine oils, runway oils, lubricating greases, coolants, wear protection oils for chains and conveyor systems, metalworking fluids, food grade lubricants for industrial processing of food, and cooker oils for cookers, sterilizers and steam peelers. Performance properties which are improved by the imidazolium salts (Ia) are, in particular, the lubricating effect, the frictional wear, the service life, the corrosion protection, the antimicrobial protection, the demulsibility for easier separation of water and impurities and the filterability. The invention will now be described in more detail with reference to the following exemplary embodiments:

Examples Preparation of 1,3-di (2-ethylhexyl) imidazolium acetate

300.3 g (3.0 mol) of a 30 wt.% Aqueous formaldehyde solution, 435.3 g (3.0 mol) of glyoxal and 180.2 g (3.0 mol) of anhydrous acetic acid were placed in the flask and slowly added with stirring at room temperature with 791, 3 g (6.0 mol) of 98 wt .-% 2-ethylhexylamine. The temperature of the reaction mixture rose rapidly to 38 ° C and was kept there by Eisbadkühlung until the end of the addition of the amine. The mixture was then stirred at 80 ° C for 5 hours. After separation of the upper aqueous phase 1038.4 g of 1, 3- (2-ethylhexyl) imidazolium acetate were obtained.

Preparation of 1, 3-di (polyisobutyl) imidazolium acetate

Analogously to the preparation of 1,3-di (2-ethylhexyl) imidazolium acetate described above, 3.0 mol of 30% strength by weight aqueous formaldehyde solution, 3.0 mol of glyoxal, 3.0 mol of anhydrous acetic acid and 6 , 0 mol of polyisobutylamine C4H9- (C4He) x-CH2NH2 with x = 17-18 (commercial product Kerocom® PIBA from BASF SE) 1, 3-di (polyisobutyl) imidazolium acetate. applications

To test the influence of the additives on the performance of direct injection diesel engines, the test method used was the DW10 engine test, in which power loss is determined by injector deposits in the common rail diesel engine based on the official test method CEC F-098-08 becomes. The power loss is a direct measure of the formation of deposits in the injectors. A direct injection diesel engine with common rail system was used according to test methods CEC F-098-08. The fuel used was a commercial diesel fuel from Haltermann (DF-79-07 / 5). To this was added 1 wt ppm zinc in the form of a zinc didodecanoate solution to artificially stimulate the formation of deposits on the injectors. The results illustrate the relative power loss measured at 4000 rpm during a 12-hour continuous operation. The value "to" indicates the power ("power") in kW at the start of the test and the value "t12" the power in kW at the end of the test.

As additives to be used according to the invention, the following imidazolium salts were used:

(1.1) 1-Ethyl-3-methylimidazolium acetate

 (1.2) 1-Butyl-3-methylimidazolium acetate

 (1.3) 1 -Octyl-3-methylimidazolium methyl carbonate

(I.4) 1, 3-di (2e ethylhexyl) imidazolium acetate

The compounds (1.1) and (I.2) are commercially available products; the compound (I.3) was prepared from N-octylimidazole by quaternization with dimethyl carbonate as a 30 wt% solution in methanol by a usual synthesis method; the compound (I.4) was prepared in accordance with the synthesis instructions given above.

In the test runs carried out, the additives (1.1) and (I.2) were used as pure substances and the additives (I.3) and (I.4) as solutions. The indicated dosage refers to the active ingredient.

The results of the power and powerloss determinations of the DW10 engine tests are summarized in the following table: Additive dosage [weight-tO [kW] t12 [kW] powerloss [%] ppm]

without 0 93.9 88.8 -5.4

 (1.1) 100 98.9 98.0 -0.9

 (I.2) 100 97.1 97.0 -0.1

 (I.2) 30 95.2 94.4 -0.8

 (I.3) ..33 96.9 97.2 +0.3

 (I.4) 50 95.8 95.1 -0.7

The additives (I.2) and (I.4) were additionally used to carry out a soiling and cleaning process in accordance with the DW10 test. For this purpose, the used common rail direct injection diesel engine used with the same commercial diesel fuel (containing 1 ppm by weight of zinc in the form of a zinc didodecanoate) was first operated for 12 hours without detergent additive, wherein the value t for the power in the experiment with (I.2) first fell successively from 96.2 kW to 89.8 kW. After adding 30 ppm by weight of the additive (I.2) and continuing to operate for 5 hours, the value t for the power returned to 95.7 kW, with the largest jump for t within the first two hours after the addition of (I.2) took place (after 1 hour t = 91, 4 kW, after 2 hours t = 94.5 kW). In the experiment with additives (I.4), the power dropped from 98.4 kW to 93.9 kW in the first 13 hours of operation without additives. After adding 50 ppm by weight of the additive (I.4) and continued operation for 12 hours, the value of t for the power returned to 96.3 kW, with the largest jump in power within the first two hours after the addition of (I.4) took place (after further lowering of the value after fuel change to 92.8 kW, power rose again after one hour to t = 94.5 kW, after 2 hours then to t = 95.5 kW).

With the additive (I.4) was also a "keep clean" motor test according to the test method CEC F-23-01 with the PSA engine XUD-9 A driven. The additive was used at a dosage of 50 ppm in a commercial diesel fuel from Haltermann (DF-79-07 / 5). For comparison, the engine was operated in a separate test run with the same diesel fuel without additive. The "flow restriction" at 0.1 mm "Needle elevation" in the fuel was 63% without additive and with 50 ppm by weight of additive (I.4) -32%.

Claims

 claims

1 . Use of imidazolium salts of the general formula (I)

 in which the variables R 1 and R 3 independently of one another represent an organic radical having 1 to 3000 carbon atoms, the variables R 2, R 4 and R 5, independently of one another, denote hydrogen or an organic radical having 1 to 3000 carbon atoms,

X denotes an anion and n represents the number 1, 2 or 3, as additives for fuels.

Use of imidazolium salts (I) according to claim 1 as detergent additives for diesel fuels.

Use of imidazolium salts (I) according to claim 2 as an additive for reducing or avoiding deposits in injection systems of direct injection diesel engines, in particular in common rail injection systems, for reducing the fuel consumption of direct injection diesel engines, especially of diesel engines with common rail injection systems, and / or to minimize the power loss in direct injection diesel engines, especially in diesel engines with common rail injection systems.

Use of imidazolium salts (I) according to claim 1 as a wax anti-settling additive (WASA) for middle distillate fuels, in particular diesel fuels.

Use of imidazolium salts (I) according to Claim 1 as lubricity improvers for fuels and fuels. Use of imidazolium salts (I) according to claims 1 to 5, in which the anion X sulphate, an alkyl sulphate, an alkyl sulphonate, an alkyl carbonate, a halide, a pseudohalide, a carboxylate, a phosphate, a phosphonate, nitrate, nitrite, the TFSI anion of the formula N (S02CFs) 2 ^" or the tricyanomethamide anion.

Use of imidazolium salts (I) according to claims 1 to 6, in which the variables R 1 and R 3 independently of one another are C 1 - to C 20 -alkyl groups, C 2 - to C 20 -alkenyl groups and / or polyisobutyl radicals having a number-average molecular weight of from 200 to 40 000 and the variables R2, R4 and R5 are each hydrogen.

8. An additive concentrate, comprising in combination with at least one further fuel and fuel additive, in particular with at least one further diesel fuel additive, at least one imidazolium salt (I) according to claim 1, 6 or 7.

9. A fuel or fuel composition comprising, in the majority of a conventional basic or base fuel, an effective amount of at least one imidazolium salt (I) according to claim 1, 6 or 7.

10. Imidazolium salts of the general formula (Ia)

 (La)

in which one of the variables R1 or R3 or both variables R1 and R3 are independently a linear alkyl or alkenyl radical having 14 to 3000 carbon atoms or a branched alkyl or alkenyl radical having 4 to 3000 carbon atoms, the variable R1 or R3, the is not a linear alkyl or alkenyl radical having 14 to 3000 carbon atoms or is a branched alkyl or alkenyl radical having 4 to 3000 carbon atoms, an alkyl radical having 1 to 13 carbon atoms or an alkenyl radical having 2 to 13 carbon atoms, the variables R 2, R 4 and R5 are independently hydrogen, an alkyl radical with 1 to 20 carbon atoms or an alkenyl radical with 2 to 20 carbon atoms,

X denotes an anion and n represents the number 1, 2 or 3.

1 1. Imidazolium salts of the general formula (Ia) according to claim 10, in which one of the variables R 1 or R 3 or both variables R 1 and R 3 is independently a linear alkyl or alkenyl radical having 14 to 20 carbon atoms or a branched alkyl or alkenyl radical having 4 to 13 carbon atoms and the variables R2, R4 and R5 independently of one another are hydrogen, an alkyl radical having 1 to 20 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms.

12. imidazolium salts of the general formula (Ia) according to claim 10, in which one of the variables R1 or R3 or both variables R1 and R3 independently of one another are a polyisobutyl radical having a number average molecular weight of 200 to 40,000 and the variables R2, R4 and R5 are independent each other hydrogen, an alkyl radical having 1 to 20 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms.

13. Use of imidazolium salts of the general formula (Ia) according to claims 10 to 12 for improving the performance of mineral see and synthetic non-aqueous industrial fluids.