AU2012277805B2 - Quaternized nitrogen compounds and use thereof as additives in fuels and lubricants - Google Patents

Abstract

The invention relates to novel quaternized nitrogen compounds, to the production thereof, and to the use thereof as fuel additives and lubricant additives, such as in particular detergent additives, additive packages that contain said compounds, and fuels and lubricants to which said additive packages have been added. The invention further relates to the use of said quaternized nitrogen compounds as a fuel addition for reducing or preventing deposits in the 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 having common-rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common-rail injection systems.

Description

Guatemlzed nitrogen compounds and use thereof as additives In feats and lubricants

The present invention relates to novel quatemized nitrogen compounds, to the preparation thereof and to the use thereof as a fuel end lubricant additive, more particularly as a detergent additive, to additive packages which comprise these compounds; and to fuels and lubricants thus addltized. The present Invention further relates to the use of these qustemlzed nitrogen compounds 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 the fuel consumption of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, and for minimizing power loss In direct-injection diesel engines, especially in diesel engines with common-rail injection systems.

State of the art

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 of 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 tor diesel engines and 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-mil 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 in to toe 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 smaller variation in the 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 harsh combustion noises ("nailing") are reduced and the engine seems to run quietly; (2,) main Injection, which is responsible especially for a good torque profile; and ¢3,) post-injection, which especially ensures a low NQx value.

In this post-injection, the fuel is generally not combusted, but instead evaporated by residual heat in the cylinder. The exhaust gas/fue! 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 (NO*), carbon monoxide (CO) and ©specially 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 modem common-rail diesel engines, under particular conditions, for example when biodiesel-containing fuels or fuels with metal impurities such as zinc compounds, copper compounds, lead compounds and other metal compounds are used, deposits can form on the injector orifices, which adversely affect the injection 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 in 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, in the injection systems of modern diesel engines, deposits cause significant performance problems, it is common knowledge that such deposits in the spray channels can lead to a decrease in the fuel flow and hence to power &amp;s$< Deposits at the Injector tip, In contrast, impair the optimal formation of fuel spray mist and, as a result, cause worsened combustion and associated higher emissions and increased fuel consumption, in contrast to these conventional '‘external* deposition phenomena, Internal" deposits (referred to collectively as internal diesel injector deposits (IDID)} in particular parts of the injectors* such as at the nozzle needle,, at the control piston, at the valve piston, at the valve seat, In, the control unit and In the guides of these components,, also increasingly cause performance problems. Conventional additives exhibit inadequate action against these IDlDs, US 4,248,719 describes quatemlzed ammonium salts which are prepared by reacting an alkenylsucclnimide with a monocarboxylto ester and find use as dispersants m lubricant oils for prevention of sludge formation. More particularly, for example, the reaction of poiyieobutylsuccinic anhydride (PIBSA) with NsN*dimethylamlnopropyiamine (DMAPA) and quatemization with methyl salicylate is described. However, use in fuels, more particularly diesel fuels, Is not proposed therein. The use of PISSA with low bismaleatlon levels of < 2.0% Is not described therein, US 4,171,959 describes quatemized ammonium sails of hydrocartyl-eubetituted succinimides, which are suitable as detergent additives for gasoline fuel compositions. For quaternfzaiion, preference Is given to using alkyl halides. Also mentioned are organic CrCrhydrocarbyl carboxylates and sulfonates. Consequently, the quatemized ammonium salts provided according to the teaching therein have, as a counterion, either a halide or a Ca-Ca-hydrocarbyl carboxylate or a CrCrhydrocarbyl sulfonate group, The use of FIBSA with low bismaleatlon levels of < 20% Is likewise not described therein,

Ep-A-2 033 S45 discloses cold flow improvers which are prepared by qualernizing specific tertiary monoamines bearing at least one Ce^C^cralkyl radical with a CvC^-aikyl ester of specific carboxylic acids, Examples of such carboxylic esters are dimethyl oxalate, dimethyl maleate, dimethyl phfhsiste and dimethyl fumarate, Applications other than that of improving the CFFP value of middle distillates are not demonstrated in EP-A-2 033 945.. WO 2006/135881 describes quatemized ammonium salts prepared by condensation of a hydroearhyhsubstituted acylailng agent and of an oxygen or nitrogen atom-containing compound with a tertiary amino group, and subsequent customization by means of bydroearbyl epoxide In the presence of stoichiometric amounts of an acid, ©specially acetic acid. Further quaternizing agents claimed in WO 2006/135881 are dialkyl sulfates, benzyl halides and hydrocarbyl-substituted carbonates, and dimethyl sulfate, benzyl chloride and dimethyl carbonate have been studied experimentally.

The quaternizing agents used with preference in WO 2006/135881, however, have serious disadvantages such as: toxicity or carcinogenicity (for example in the case of dimethyl sulfate and alkylene oxides and benzyl halides), no residue-free combustion (for example in the case of dimethyl sulfate and alkyl halides), and inadequate reactivity which leads to incomplete quaternization or uneconomic reaction conditions (long reaction times, high reaction temperatures, excess of quaternizing agent; for example in the case of dimethyl carbonate).

Advantageously, the present invention may provide improved quaternized fuel additives, especially based on hydrocarbyl-substituted polycarboxylic acid compounds, which no longer have the disadvantages of the prior art mentioned.

Brief description of the invention:

The invention provides specific quaternized nitrogen compounds and fuel and lubricant compositions additized therewith.

Surprisingly, the inventive additives thus prepared are superior in several ways to the prior art additives prepared in a conventional manner: they have low toxicity (caused by the specific selection of the quaternizing agent, burn ashlessly, exhibit a high content of quaternized product, and allow an economic reaction regime in the preparation thereof, and surprisingly have improved handling properties, such as especially improved solubility, such as especially in diesel performance additive packages. At the same time, the inventive additives exhibit improved action with regard to prevention of deposits in diesel engines, as especially illustrated by the use examples appended.

Detailed description of the invention: A1) Specific embodiments

The present invention generally relates to the following embodiments: 1. A fuel or lubricant composition, especially fuel composition, comprising, in a majority of a customary fuel or lubricant, a proportion (especially an effective amount) of at least one reaction product comprising a quaternized nitrogen compound (or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification), said reaction product being obtainable by a. reacting a high molecular weight hydrocarbyl-substituted polycarboxylic acid compound with a compound comprising at least one oxygen or nitrogen group reactive (especially capable of addition or condensation) with the polycarboxylic acid, and comprising at least one quaternizable amino group, to obtain a quaternizable hydrocarbyl-substituted polycarboxylic acid compound (by addition or condensation), and b. subsequent reaction thereof with a quaternizing agent which converts the at least one hereafter quaternizable, for example tertiary, amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid (especially of a mono- or dicarboxylic acid) or of an aliphatic polycarboxylic acid (especially dicarboxylic acid). 2. A fuel or lubricant composition, especially fuel composition, comprising, in a majority of a customary fuel or lubricant, a proportion (especially an effective amount) of at least one reaction product comprising a quaternized nitrogen compound (or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification), said reaction product being obtainable by reacting a quaternizable high molecular weight hydrocarbyl-substituted polycarboxylic acid compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one hereafter quaternizable, for example tertiary, amino group to a quaternary ammonium group, said quatemizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic monger polycarboxylc acid (especially of a mono- or dlcarboxyllc acid) or of an aliphatic poly carboxylic acid (especially dlcarboxylic acid). 3. The fuel composition according to either of the preceding claims, wherein about 1.1 to about 2.0 or about 1.25 to about 2.0 equivalents, for example 1.3, 1.4, 1.5.1.6, 1,7, 1,6 or 1,9 equivalents, of quatemizing agent are used per equivalent of quatemlzable tertiary nitrogen atom. By Increasing the proportion of quatemizing agent within the rang© claimed, distinct improvements in product yields oars be achieved, 4. The fuel composition according to any of the preceding claims, wherein the bydrocarbyl-subsiltuted poiycarboxyfic add compound is a polyisobutenylsuccinfc acid or an anhydride thereof, said acid having a bismaieation level of equal to or less than about 20% or equal to or lass than about 16%, for example 16,14,13,12,11,10, 9, Ss 7, 6, 5, 4, 3, 2, 1 or 0.1%.

Lower levels of blsmaleation can contribute to a distinct improvement In the solubility of the additive and/or compatibility of the constituents in the formulation of additive 5. The fuel or lubricant composition, especially fuel composition, according to any of the preceding embodiments, wherein the quatemizing agent is a compound of the

In which R, is a low molecular weight hydrocarbyl radical, such as alkyl or alkenyl radical, especially a lower alkyl radical, such as especially methyl or ethyl, and Ra is an optionally substituted monocyclic hydrocarbyl radical, especially an aryl or cydoalkyl or cycloalkenyl radical, especially aryl such as phenyl, where the substituent Is selected from OH, NHj>, NO* 0(0)01¾ and Ri0C(0)-, In which Ri is as defined above and Rg is H or 1¾ where the substituent is especially OH, More particularly, the quatemizing agent is a phthslata or a salicylate, such as dimethyl phthalate or methyl salicylate. δ. The fuel or lubricant composition, especially fuel composition, according to any of the preceding embodiments, wherein the Cfuaternizing agent is a compound of the general formula 2

in which

Ri and Rta are each Independently a low molecular weight hytirocarbyi radical, such as an alkyl or alkenyl radical, especially a lower alkyl radical and A is hydrocarbylene (such as especially CrGrsIkylans or Cj-Graikenylene). 7, The fuel or lubricant composition, especially fuel composition, according to any of the preceding embodiments, wherein, the quaternized nitrogen compound has a number-average molecular weight in the range from 400 to 5000, especially 800 to 3000 or 900 to 1500, 8, The fuel or lubricant composition, especially fuel composition, according to any of the preceding embodiments, wherein the quaterriizing agent is selected from alkyl salicylates, dialkyt phthalates and dialkyl oxalates; particular mention should be made of alkyl salicylates, especially lower alkyi salicylates, such as methyl, ethyl and n* propyl salicylates* 9, The fuel or lubricant composition, especially fuel composition, according to embodiment 1f wherein the compound which is reactive (capable of addition or condensation) with the polycarboxylic acid and comprises an oxygen or nitrogen group and at least one customizable amino group is selected from a, hydroxyslkyfrsubslltuted mono- or poiysmmes having at least one quatemteable primary, secondary or tertiary amino group; b, straight-chain or branched, cyclic, heterocyclic, aromatic or nonaromatic polyamines having at least one primary or secondary amino group and having at least one quaternlzable primary, secondary or tertiary amino group; c, piperazines, and particular mention should be made of group a. 10, The fuel or lubricant composition according to embodiment S, wherein the compound which is reactive, especially capable of addition or condensation, with the polycarboxylie acid and comprises an oxygen or nitrogen group and at least one qysternizabfe amino group is selected from a, hydroxyalkyi-substityted primary, secondary or ternary monoamines and hydraxyalkyl-substltuted primary, secondary' or tertiary diamines, b. straight-chain or branched aliphatic diamines having two primary amino groups; di- or polyamines having at least one primary and at least one secondary amino group; dr- or polyamines having at least one primary and at least one tertiary amino group; aromatic carbocyclic diamines having two primary amino groups; aromatic heterocyclic poiyamines having two primary amino groups; aromatic or nonaromatic heterocyctes having one primary' and: one tertiary amino group; and particular mention should be made of group a, 11, The fuel composition according to any of the preceding embodiments, selected from diesel fuels, biodiesel fuels, gasoline fuels and aikanol-containing gasoline fuels, 12, The fuel or lubricant composition, especially fuel composition, according to any of die preceding embodiments, wherein the hydrocarbyl-substltuted polycarboxyilc acid compound Is a poiyisobutenylsuccinic acid or an anhydride (PtBSA) thereof, said acid having a low bismaleation level, especially 10% or less than 10%, for example 2 to 9 or 3 to 7%, More particularly, such PiBSAs are derived from HR-PI8 with an Mn in toe range from about 400 to 3000.

More particularly, the above compositions are fuel compositions, in particular diesel fuels. 13, The reaction product obtainable by a process as defined in any of the preceding embodiments, especially according to embodiment 3, 4, 5,. δ and in particular embodiment 8, 9 or 10, or quaternszed nitrogen compound obtained from the reaction product by partial or full purification. in a particular configuration (A) of the invention, quaternized reaction products which are prepared proceeding from potylsobytenyisuccinie add or an anhydride thereof are provided, this compound having a bismaleation level of equal to or less than about 20% or equal to or less than about 15%, for example 15, 14, 13,12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, I, or 0,1%, This poiyisobuienyisuccinlc add compound is reacted (especially by addition or condensation) with a compound comprising at least one oxygen or nitrogen group reactive {addabie or condensable) with the polyisohutenylsuocmic acid compound and containing at least one quaternfeable amino group, and then quaternized, in a particular configuration {B} of the invention, quaternized reaction products which are obtained by quaternizatlon using an excess of quatemlzing agent are provided, More particularly, about 1.1 to about 2,0 or about 1.25 to about 2.0 equivalents, for example 1.3, 1,4, 1,5,1.6,1,7,1.8 or 1.9, equivalents of quatemlzing agent are used per equivalent of guatemizable tertiary nitrogen atoms. Particularly useful quatemlzing agents are those of the formula (1), especially the lower alkyl esters of salicylic acid, such as methyl salicylate, ethyl salicylate, tv and i-propyl salicylate, and η-, i- or test-butyl salicylate.

In a further particular configuration (C)t configurations (A) and (B) are combined, i,e> the quatemizahla compounds prepared from the above polyisobutenyisuccinic acid compounds according to configuration (A) are quatamized according to configuration (B). 14, A process for preparing a quaternlzed nitrogen compound according to embodiment 13, comprising the reaction of a quatemizable hydrocarbyl-substituted poiycarboxyfic acid compound comprising at least one tertiary quatemizable amino group with a quatemlzing agent which converts the at feast one tertiary amino group to a quaternary ammonium group, said quatarnizing agent being the alkyl ester of a cydoaromatic or cycloaliphatic mono-or polyoarboxylic acid (especially of a mono- or dicarboxylic sold) or of an aliphatic polycarboxyiic add (especially dicarboxylic acid). 15. The use of a reaction product or of a quaternized nitrogen compound according to embodiment 13 or of a compound prepared according to embodiment 14 as a fuel additive or lubricant additive, especially fuel additive, especially diesel fuel additive. 16. The use according to embodiment 15 as an additive for reducing the fuel consumption of direct-injection diesel engines, especially of diesel engines with common-rail injection systems, as determined, for example, in an XUD9 test to CEC-F-23-01, and/or for minimizing power loss in direct-injection diesel engines, especially in diesel engines with common-rail injection systems, as determined, for example, in a DW10 test based on CEC-F-098-08. 17. The use according to embodiment 15 as a gasoline fuel additive for reducing the level of deposits in the intake system of a gasoline engine, such as especially DISI (direct injection spark ignition) and PFI (port fuel injector) engines. 18. The use according to embodiment 15 as a diesel fuel additive, especially as a cold flow improver, as a wax antisettling additive (WASA) or as an additive for reducing the level of and/or preventing deposits in the intake systems, such as especially the internal diesel injector deposits (IDIDs), and/or valve sticking in direct-injection diesel engines, especially in common-rail injection systems. 19. An additive concentrate comprising, in combination with further diesel fuel or gasoline fuel additives, especially diesel fuel additives, at least one quaternized nitrogen compound as defined in embodiment 13 or prepared according to embodiment 14.

In particular, in one embodiment, the invention provides a fuel composition comprising, in a majority of a customary fuel, a proportion of at least one reaction product comprising a quaternized nitrogen compound, or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification, said reaction product being obtainable by a1) reacting a hydrocarbyl-substituted polycarboxylic acid compound with a compound comprising at least one oxygen or nitrogen group reactive, with the polycarboxylic acid, and comprising at least one quaternizable amino group, to obtain a quaternizable hydrocarbyl-substituted polycarboxylic acid compound, and a2) subsequent reaction thereof with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, or of an aliphatic polycarboxylic acid; or b) reacting a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, or of an aliphatic polycarboxylic acid wherein about 1.1 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom; and/or the hydrocarbyl-substituted polycarboxylic acid compound is a polyisobutenylsuccinic acid or an anhydride thereof, said acid having a bismaleation level of 2 to 20% by weight, based in each case on the reaction product.

In another embodiment, the invention provides the use of a reaction product obtainable by a process of the invention or of a quaternized nitrogen compound obtained from the reaction product; or of a quaternized nitrogen compound prepared by a process comprising the reaction of a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one tertiary quaternizable amino group with a quaternizing agent which converts the at least one tertiary amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid or of an aliphatic polycarboxylic acid; as a fuel additive, and wherein about 1.1 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom. A2) General definitions A "condensation" or "condensation reaction" in the context of the present invention describes the reaction of two molecules with elimination of a relatively small molecule, especially of a water molecule. When such an elimination is not detectable analytically, more particularly not detectable in stoichiometric amounts, and the two molecules react nevertheless, for example with addition, the reaction In question of the two molecules is "without condensation".

In the absence of statements to the contrary, th© following general conditions apply: "Hydrocarbyl" can be interpreted widely and comprises both long-chain and short* chain, straight-chain and branched hydrocarbon radicals, which may optionally addition ally comprise heteroatoms, for example Ο, N, NH, S, In the chain thereof, "'Long-chain” or "high molecular weight” hydrocerbyl radicals have a number-average molecular weight (MB) of 85 to 20 000, few example 113 to 10 000, or 200 to 10 000 or 350 to 5000, for example 350 to· 3000, 500 to 2500, 700 to 2500, or 800 to 15D0. Mom particularly, they are formed essentially from Cs«, especially Csm, monomer units such as ethylene, propylene, n- or isobutylene or mixtures thereof,, where the different monomers may be copoly merited in random distribution or as blocks. Such long-chain hydrocarbyl radicals are also referred to as poiyalkylene radicals or poly-Ga·®- or poly-G^-alkyiene radicals. Suitable long-chain hydrocarbyl radicals and foe preparation thereof are also described, for example, in WO 2006/135881 and the literature cited therein.

Examples of particularly useful polyalkylene radicals are polyisohufenyl radicals derived from "high-readivity" polyisobutenes (HR-PIS) which are notable for a high content of terminal double bonds {of., for example, also Rath et a!., Lubrication Science ¢1999), 11-2, 175-185). Terminal double bonds are alpha-olefinlc double bonds of the type

which are also referred to collectively as vinyiidene double bonds. Suitable high-reactivity polyisobutenes are, for example, polyisobutenes which have a proportion of vinyiidene double bonds of greater than 70 mol%, especially greater than 80 mol% or greater than 85 rnol%. Preference is given especially to poiyisobutenes which have homogeneous polymer structures. Homogeneous polymer structures are possessed especially by those polylsobutenes formed from isobutene units to an extent of at feast 85% by weight, preferably to an extent of at least §0% by weight and more preferably to an extent of at least 95% by weight. Such high-reactivity polyisobutenes preferably have a number-average molecular weight within the abovementloned range, in addition, the high-reactivity polylsobutenes may have a polydlspersrty in the range from 1,05 to 7, especially of about 1,1 to 2.5, for example of less than 1.9 or lees than 1.5, Polydispersity is understood to mean the quotient of weight-average molecular weight Mw divided by the number-average molecular weight Mn.

Particularly suitable high-reactivity polyisobutenes are, for example, the Gilssopal brands from BASF SE, especially Gilssopal® 1000 (Mrs «1000), GiissopaP V 33 (Mn - 550), Gilssopal® 1300 (Mn ~ 1300) and Gilssopal® 2300 (Mn - 2300} f and mixtures thereof. Other number-average molecular weights can be established in a manner known in principle by mixing polyisobutenes of different number-average molecular weights or by extractive enrichment of poSyisobutenes of particular molecular weight ranges, PIBSA is prepared In a manner known in principle by reacting RIB with maleic anhydride (MAA), in principle forming a mixture of PIBSA and blsmaleated PIBSA (8M PIBSA, cf, scheme 1, below'), which Is generally not separated but used as such in further reactions,. The ratio of the two components to one another can be reported via the "bismalestion lever1 (BML). The BML is known per se (see also US 5,383,196). The BML can also be determined by the following formula: BML - 100% x |{wt-%(BM PiBSA))/(wl-%(6M PIBSA)+wi-%{RIBSA))| where wt-% (X) represents the proportion by weight of component X (X. “ PIBSA or BM PIBSA) In the reaction product of RIB with MSA,

Scheme 1

Hydrocarbyl-substituted polycarboxyiic acid compound with a low blsmaieatfen lover, especially corresponding polyisobutenyisuccinlc acids or anhydrides thereof (also referred to overall as PIBSA) are known from the prior art. Especially advantageous are bismaleatlon levels of 20% or lass, or 15% or less, for example 14, 13, 12 or 10%; or 10% or less, for example 2-S, 3-8, 4-7, 5 or 5%, The controlled preparation thereof is described, for example, In US 5,833,196. Suitable for preparation thereof are especially the above Ngh-reactMty polyisobutenes with an Μη in the range from about 500 to 2500,. for example 550 to 3000, 1000 to 2000 or 1000 to 1500, A nonlimiting example of a corresponding PIBSA is Gfissopal® SA, derived from RR-PI8 {Μη = 1000), with a bismaleatlon level of S%, "Short-chain hydrocarbyf or "low molecular weight hydnocarbyP is especially straight-chain or branched alkyl or alkenyl, optionally interrupted by one or more, for example 2, 3 or 4, heteroatom groups such as -O- or -NH-, or optionally mono- or poiysubslituted, for example di-, tri- or tetrasubstltuted. *A&amp;yf or "lower aikyf represents especially saturated, straight-chain or branched hydrocarbon radicals having 1 to 4,1 to 6, 1 to 5, or 1 to 10 or 1 to 20, carbon atoms, for example methyl, ethyl, n-propyl, 1-methylethyl, η-butyl, 1-methylpropyl, 2-methyl propyl, 1,1-dirnethyisthyl, n-pentyi, 1-methyl butyl, 2-methylbutyl, 3-methylbutyl, 2,2-di:methylpropylf 1-ethyfpropyi, n-hexyf, 1,1-dlmethylpropyl, 1,2-dimethylpropyl, 1-methyiperriyi, 2-methylpentyl, 3-methylpentyi, 4-methyipentyj, 1,1-dimethylbutyl, 1,2-dlmethylbuty], 1,3-dimethyibutyl, 2,2-dimsthylbufyl, 2,3-dimethyibutyl, 3,3-dlmethylbutyl, 1-eihylbuiyl, 2-ethyibutyl, 1,1,2-trimothyipropyl, 1,2,2-trlmethyipropyl, 1-eihyM-methylpropyl and 1-efhyi~2«methylpropyl:; and also n-heptyl, n-octyl, n-nonyi and n-decyl, and the singly or multiply branched analogs thereof.

“Hydroxyaikyr represent especially the mono* or polyhydroxylated, especially monohydroxylated, analogs of the above alkyl radicals, for example the monchydroxylated analogs of me above straight-chain or branched alkyl radicals, for example the linear hydroxyalkyj groups with a primary hydroxyl group, such as hydroxymethyl, 2-hydroxyethyi, 3-hydroxypropyt 4-hydroxybufyL

Alkeny* represents mono- or polyunsaturated, especially roonounsafurafed, straight-ctiain or branched hydrocarbon radicals having 2 to 4, 2 to 6, 2 to 8, 2 to 10 or 2 or to 20 carbon atoms and a double bond In any position, for example Ca-C«-aikenyj such as eibenyi, 1-pmpenyi, S-propenyl, 1-methylethenyl, 1-butenyi, 2-bufenyl, 3-butenyl, 1-methyl-1 -propenyl, 2-meihyM-propenyl, l-meihyi-2-propenyi, 2-meibyi-2-propenyl, 1-pentenyi, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-bufenyj, 2-methyl-l-buferty}, 3-methyl-l-butenyl, l-methyl-2-buienyl, 2-meiJiyf-2~butenyi( 3-m ethyl-2-butenyf 1-methyl-3-butenyi, 2-methyl-3-butenyis S-methyl-S-butenyl, 1(l-dlmefbyl“2- propen yf, 1,2-d Im ethyl-1 -propenyl, 1,2-d lmethyl-2-propenyl , 1 -ethyl -1 -progeny!, 1 -ethyl-2-propenyl, 1 -hexenyi, 2*hexenyl, 3-hexenyl, 4-hexenyl, S-bexenyls 1-methyM-pentenyl, 2-methyi-1-pentenyl, 3»m©thyM -pentenyl, 4~methyM-pentenyl, l-meihyi-2-pentenyl, 2-methyi-2-pentenyi, 3-methyJ-2-pentenyl, 4-nief:hyi-2'*pentei!iyi, l-metbyi-3-penteny!, 2-methyi~3-pentenyl, 3“methyl-3-pentenylf 4-methy!~3-pentenyl, l-methyi-4-pentenyJ, 2-methyl-4» pentenyl, 3-methyf-4-pentenyl, 4-meihyM-pentenyl, 1,1-bimeihy!»2-buienyi, 1 .l-dimethyl-S-buienyl, 1,2-dimethyM-butenyi, 1,2-dimethyJ-2-butenyl, 1,2-dlmethyJ-3~ butenyl 1 ,3-dimethyM-bulenyf, 1f3-dimethyl-2«buteny!r 1 ^S-dimethyl-S-butenyi, 2,2-dimethyl-3-butenyj, 2,3-dfmethyM-buteny], 2,3-dimethyl-2“butenyi, 2!3-dimefhyl-3-buteny I , 3,3-dimethyi-1 -bufenyi, 3,3-dlmeihyj-2“buteny I, 1 -ethy I-1«by teny I, 1 -ethy 1-2-butenyl, 1 -ethyl-3-butenyf 2-ethyM -butenyl, 2-ethyt-2-butenyi, 2-ethyl-3»butenyl, 1,1,2-tilmethyl-2-propenyl, l-efhyM-methyf-2-propenyi, 1-ethyl-2-methyl-1-propenyl and 1“ethyf-2-mefhyi-2-proper>yf.

"Aikyfene" represents straight-chain or mono- or polybranched hydrocarbon bridge groups having 1 to 10 carbon atoms, for example CrCralkyfene groups selected from -Cf-V, ~{CH2)rf -CHs-GHfCHs)-, -CH(CH*)-CHr, (CHS)^ -{CH^-CH{CH3K -CH3-CH(CH3)-CHr:, (CH3)<-, -(CHa)a-t .(CHa)«f «(CH3)r, ’CH{CH3}-CH8-€H2-CH(CH3}-or “CH(CH3}-GH2»CHs-t>i2-CH{CH3)- or Cs-Cx-alkylen© groups selected from -CH*-, - (CHi)a-, -(CHa)s-. -CH2-CH{CH3}-, -CH(GHs)-CHr, -(CH^CBiCHsh -CHr CH{CH3)-CHr. "Alkenyiene" represents the mono- or polyunsaturated, especially monounsaturated, analogs of the above sikylene groups having .2 to 10 carbon atoms, especially C2-C7-aikenylenes or CrCi-alkenylenes, such as -CH“CH~, -CH=CH~CH2~, *GHz*CH“CH“t -CM “CH-CHs-CHa“, -Ctfe-CH^CK-CHr, -GHa-CHKJH-CH-, -CH{CH3)-CH=CH-, -CHz“C(GHs)“CH-. "Cyclic hydrocarbyl radicals’* comprise especially: cycloaikyl: carbocyclfc radicals having 3 to 20 carbon atoms, for example CsrCti-cycloaikyl such as cyolcpropyl, cyciobufyt, cyciopentyl, cydohexyl, cycloheptyf, cyclooctyl, cyciononyl, cyclodecyi, cycioundecyl and eyclododecyl; preference is given to cyciopentyl, cyciohexyl, cycioheptyl, and also to cyclQpropyjmethyl, cyciopropylethyl, cydobutylmethyi, cyciobuiylethyi, cyclopentylmethyl, cyclopeniylethyl, cydohexySmethyt, or CrCi-cycloalkyl such as cyclopropyl, cydobutyt, cyclopentyl, cyclohexyl* cycioheptyl, cyciopropylmethyl, cyciopropylethyl, cyclobutyimethyi, cyclopentylefliyl, cyclohexylmethyl, where the bond to the rest of the molecule may be via any suitable carbon atom. cycloafkenyl: monocyclic, monounsaturated hydrocarbon groups having 5 to 8, preferably up to 6, carbon ring members, such as cyciopenten-1-yl, cyctopenten*3-yi, cyclohexen-1-yl, cycloliexen-3-yl and cydohexen-4-yi; aryl: mono- or polycyclic, preferably mono- or bicyclic, optionally substituted aromatic radicals having 6 to 20, for example 6 to 10, ring carbon atoms, for example phenyl, biphenyl, naphthyl such as 1- or 2*naphthyif tetrahydronaphthyl, fluorenyl, indenyi and phenanihrenyl. These aryl radicals may optionally bear 1, 2, 3, 4, 3 or δ Identical or different substituents. “Substituents" for radicals specified herein are especially, unless stated otherwise, selected from keto groups, -COGH, -COO-alkyl, -OH, -SH, -CN, amino, -NG2s alkyi, or alkenyl groups.

The term "about" In the context of a stated figure or of a value range denotes deviations from the specifically disclosed values. These are usually customary deviations. These may differ, for example, by ± 10% to ±0.1% from the specific values. Typically, such deviations are about ± 8% to± 1%or ± 5%, ± 4%, ± 3% or ± 2%, AS) Potycarboxyiic acid compounds and bydrocarbyl-substituted poiycarboxyifc acid compounds:

The polycarboxylic acid compounds used are aliphatic di- or polybaslc {for example trior tetrabasic), especially from di-, tri- or tetracarboxylic acids and analogs thereof, such as anhydrides or lower alkyl esters (partially or completely esfertfied), and is optionally substituted by one or more (for example 2 or 3), especially a long-chain alkyl radical and/or s high molecular weight hydrocarby! radical especially a polyalkylene radical, Example© are Cs~Ci» potycarboxyiic acids, such as the dlcarboxyllc acids maionie acid, succinic add, glutaric acid, adipic acid, pimellc add, suberic add, azelalc add and sebaoic acid, and the branched analogs thereof: and the tricarboxylic acid citric acid; and anhydrides or lower alkyl esters thereof of. The polycsrboxylic acid compounds can also be obtained from the corresponding monounsaturated acids and addition of at least one long-chain alkyl radical and/or high molecular weight hydrocarby! radical. Examples of suitable monounsaturated acids are fumade sold, maleic add, ifaconic acid.

The hydrophobic "long-chain" or "high molecular weight" hydrocarbyl radical which ensures sufficient solubility of the quaternlzed product in the fuel has a number-average molecular weight of 85 to 20 000, for example 113 to 10 000, or 200 to 10 000 or 350 to 5000, for example 350 to 3000, 500 to 2600, 700 to 2500, or 800 to 1500, Typical hydrophobic hydrocarby! radicals include polypropenyl, polybuienyl and polylsobutenyl radicals, for example with a number-average molecular weight of 3500 to 6000, 350 to 3000, 500 to 2500, 700 to 2500 and 800 to 1500.

Suitable hydrocarbyi-substifuted compounds are described, for example, in DE 43 19 872 and WO 2008/138838,

Suitable hydrocsrbyl-substituted potycarboxyiic acid compounds also comprise polymeric, especially dimeric, forms of such hydrocarbyl-substituted polycarboxylic add compounds. Dimeric forms comprise, for example, two acid anhydride groups which esn be reacted independently with the quatemlzabie nitrogen compound in the preparation process according to the invention. A4) Quaferoizing agents:

Useful quatemizing agents are in principle aff alkyl esters which are suitable as such and are those of a cycioaromaiic or cycioaiSphatic mono- or poiycarboxyiic add (especially of a mono- or dicarboxylte add) or of an aliphatic poiycarboxylic add (especially dicarfeoxyiic add), in a particular embodiment, however, the at least one quaternlzabSe tertiary nitrogen atom Is quaternlzed with at least one quatemfefng agent selected' from a) compounds of the general formula 1

in which

Rr is a lower alkyl radical and R* Ss m optionally substituted monocyclic aryl or cycloalkyl radical, where the substituent is selected from GH, m, NO* C(0)0Rs, and RtaoC(0)-t in which R,a Is as defined above for Ri and R3 is H or R-j; and b) compounds of the general formula 2

in which

Ri and Ria are each independently a Sower alkyl radical and A is hytfrocarbylene (such as afkylene or alkeoylene).

Partcusariy suitable compounds of the formula 1 are those In which

Ri is a Cr. Cr* or Crafky! radios f and

Rs is a substituted phenyl radical, where the substituent is HO- or an ester radical of the formula RiaOC(0)* which is in the para, meta or especially ortho position to the RiOC{0}~ radical on the aromatic ring.

Especially suitable quatemfzlng agents are the lower alkyl esters of salicylic add, such as methyl saflcyiate, ethyl salicylate, n- and i-propyl salicylate, and η-, I- or tart-butyl salicylate. AS) Quatemtzed or quatemlzabie nitrogen compounds:

The quatemizeble nitrogen compounds reactive with the poiycarboxyjfc acid compound are selected from 8' hydroxy alkyl-substituted mono- or polyamides having at least one quatemlzed (e.g. chciine) or qitaterntzabie primary, secondary or tertiary amino group; straight-chain or branched, cyclic, heterocyclic, aromatic or nonaromatic polyammes having at least one primary or secondary {anhydride-reactive) amino group and having at least one quatemteed or quafern liable primary', secondary or tertiary' amino group; c. piperazines, 1 he qua tern izable nitrogen compound is especially selected from d' hydroxyaHtyl-subsffluted primary, secondary, tertiary or quaternary monoamines and hydroxys!kyhsubstituted primary, secondary, tertiary or quaternary diamines; e' straight-chain or branched aliphatic diamines having two primary amino groups; Φ or pdyamfrses having at least one primary and at least one secondary amino group; di~ or pofyamines having at least one primary and at least one tertian amino group; dh or polyamides having at least one primary and at least one quaternary amino group; aromatic carbocycfte diamines having two primary amino groups; aromatic heterocyclic pofyamines having two primary amino groups, aromatic or nonaromatlc heterocydes having one primary and one tertiary amino group.

Examples of suitable "hydroxyaikyi-substituted mono- or polyamines" are those provided with at least one hydroxyaikyl substituted, for example 1, 2, 3, 4, 5 or 6 hydroxy alky I substituted.

Examples of "hy droxyal kyl-su bstltu ted monoamines" Include: N-hydroxyalkyl monoamines, N,N-dihydroxyaikyi monoamines and Ν,Ν,Ν-trihydroxyalkyl monoamines, where the hydroxy alky I groups are the same or different and are also as defined above. Hydroxy a Iky! Is especially 2-hydroxy ethyl, 3-hydroxy propyl or 4-hydroxy butyl.

For example, the following "hydroxyalkyPsubstifyted poSyamines" and especially "hydroxyalkyl-substituted diamines" may be mentioned: (N-hydroxyaikyi)aikylene-diamines, N,N-dlhydroxysikyialkytenediamines, where the hydroxyalkyl groups are the same or different and are also as defined above. Hydroxyalkyl is especially 2-hydroxyethyi, 3~bydroxypropyi or 4-hydroxybufyi; alkylene is especially ethylene, propylene or butylene.

Suitable "diamines* are alkylenedlamines, and the M-sIkyPsubsfituted analogs thereof, such as N-monoalkylated alkylenedlamines and the N,N- or N,N’‘dlalkylated alkylenedlamines. Alkylene is especially straight-chain or branched C?--r or C** alkylene as defined above,. Alky! is especially C-M-alkyl as defined above, Examples are especially ethylenediamine, 1,2-propyienediamine, 1,3-pf0pylenediamlne, 1,4-butyfenedlamlne and isomers thereof, pentanediamine and Isomers thereof, hexanediamfne and isomers thereof, heptanedismlne and isomers thereof, and singly or multiply, for example singly or doubly, Ci-C*-afkyfated, for example methylated, derivatives of the aforementioned' diamine compounds such as 3-dlmethylarmno-l-propylamine (DMAPA), Ν,Ν-dlethylaminopropylamine and Ν,Ν-di methyls mlno- athylamine.

Suitable straight-chain "polyamines" are, for example, dialkylenetriamlne, triafkylenetetrarnine, tetraalkyienepentamine, peniaalkylenehexamlne, and the N-alkyl-substituted analogs thereof, such as N-monoalkyiated and the N,N- or N,N’-diaSkylated alkylenepolyamlnes. Alkylene is especially straight-chain or branched Ci.r- or C-m. alkylene as defined above. Alkyl is especially C^-alkyl as defined above.

Examples are especially cflethyleneirtamine, Inethy lenetetra mine, teiraedtyienepentarn me, pentaethy tenehexaro In e, d Ipropylenetriarnine, tnpropyleneietra mine., tetraprapy Fenepenta mine, penta propylenehexam ine, dlbutyienetriarriine, tnbytyienetetrarmne, tetrabutylenepentamine, pentabutylenebexarnlne; and the Ν,Ν-dielkyl derivatives thereof, especially the N.M-di-C-M-aikyl derivatives thereof. Examples include; N^’dimethyldimethylenetriamine, Ν,Ν-diethyldgneihylanetifamine, N^N-dlpropyidimethyienetriamlne, N, N- di methy id j ethylene-1,2-triamfne, NfN-diethyldlethylane-1,2-triamine, n«N- dipropyidlethylerse-1,2-trlamine, N,N-dimeihyldipropyjene-1f3-trianiine (i,@s DMAPAPA), N.N-diethyldipropylene-1,3-trlamlne, N,N-dipropyldipropylene-1,3-trfamine, Μ,Ν- dimethysdibutyfene-1,44riam ine, bl.N-dietbyidlbufylena-l., 44r lamina, N, N- dipropy*dibuty!ene-1 thiamine, HN-dimetbyldlpentylene-1 ,5-triamlne. N(N- diethyldlpentylene-1 .S-friamine, N.N-dipropyidipentyiene-^S-trfamlne, N,M- d im ethyidihexy lene-1 ,6-triamine, NiN-dietiiyidlhexytene-l s6-triamlne and N(N- dlpropyldlhaxyiane-1 ,β-trlamine. "Aromatic carbocyclic diamines" having two primary amino groups are the diamino- substituted derivatives of benzene, biphenyl, naphthalene, tetrahydronaphthalene, fluorene, Indene and phenanthrene.

Aromatic or nonsromatic heterocyclic polyandries” having two primary amino groups are the derivatives, substituted by two amino groups, of the foliowing heterocycles: 5- or 6-membered, saturated or monounsaturated heterocydes comprising one to two nitrogen atoms and/or one oxygen or sulfur atom or one or two oxygen and/or sulfur atoms as ring members, for example tetrahydrofuran, pyrrolidine, isoxazolidine, ssoth i azolidS ne, pyrazosldlne, oxazolidine, thlazoildine, tmidazoiidine, pyrrollne, piperidine, pipendinyl, 1,3-dJoxarte, tetrahydropyran, hexahydropyrfdazine, hexahydropyrimId ine, piperazine; S-membered aromatic heterocycfes comprising, in addition to carbon atoms,, two or three nstrogen atoms or one or two nitrogen atoms and one sulfur or oxygen atom as ring members, for example furan, thiane, pyrrole, pyrazoie, oxszoie, thiazole, Imidazole and 1,3,4-triazoie; Isoxazole, isoihiazote, thisdlazoie, oxadrazoie; β-membered heterocydes comprising, in addition to carbon atoms, one or two, or one,, two or three, nitrogen atoms as ring members, for example pyridlnyi, pyridazine, pyrimidine, pyraztnyl, i ,2,4-triazine, 1,3,54riazlin-2-yi. BAromatic or nonaromatic heterccycies having one primary and one tertiary amino group” are, for example, the abovementioned N-heieracydes which are sminoalkylated on at least one ring nitrogen atom, and especially bear an amirio-C^-alkyl group, "Aromatic or nonaromatic heterocycles having a tertiary amino group and a hydroxyalkyl group” are, for example, the abovementloned N-heterocycies which are hydroxyalkylated on at least one ring nitrogen atom, and especially beer a hydraxy-C?. 4-eikyl group.

Mention should be made especially of the following groups of individual classes of quatemizable nitrogen compounds:

Group 1.:

A6) Preparation of inventive additives; a) Reaction with oxygen or nitrogen group

The hydrocarby [-substituted polycerboxyfic acid compound can be reacted with the quatemizabie nitrogen compound according to the present invention under thermally controlled conditions, such that there is essentially no condensation reaction. More particularly, no formation of water of reaction is observed in that case, More particularly, such a reaction is effected at a temperature in the range from 10 to 80*C, especially 20 to 60°C or 30 to 50*0, The reaction time may be in tile range from a few minutes or a few hours, for example about 1 minute up to about 10 hours. The reaction can be effected at a pressure of about 0.1 to 2 atm, but especially at approximately standard pressure. For example, an inert gas atmosphere, for example nitrogen, is appropriate,

More particularly, the reaction can also be effected at elevated temperatures which promote condensation, for exampie in the range from 90 to 1C0*C or 100 to 170*0.

The reaction «me may be In the region of a few minutes or a few hours, for example about 1 minute up to about 10 hours. The reaction can be effected at pressure at about 0>1 to 2 atm, but especially at about standard pressure.

The reactants are initially charged especially in about equimolar amounts; optionally, a small molar excess of the poiycarboxylic acid compound, for example a 0.05- to 0.5-fold, for example a 0.1- to 0.3-fbld, excess, is desirable. If required, the reactants can be imtiaisy charged in a suitable Inert organic aliphatic or aromatic solvent or a mixture thereof. Typical examples are, for example, solvents of the Solvesso series, toluene or xylene. Hie solvent can also serve, for example, to remove water of condensation azeotropicafty from the reaction mixture. More particularly, however, the reactions are performed without solvent,

The reaction product thus formed can theoretically be purified further, or the solvent can be removed. Usually, however, this is not absolutely necessary, such that the reaction step can be transferred without further purification Into the next synthesis step, the quaiemlzation, b) Customization i he quaternszalion in reaction step (b) is then carried out in a manner known per s@.

To perform the quaternlzahon, the reaction product or reaction mixture from stage a) is admixed with at least one compound of the above formula 1 or 2, especially in the stoichiometric amounts required to achieve the desired quaternlzation, it is possible to use, for example, 0,1 to 2.0, 0,2 to 1,5 or 0.5 to 1.25 equivalents, of quaternlzing agent per equ*v«tem of quaternizabfe tertiary nitrogen atom. More particularly, however, approximately equimolar proportions of the compound are used to quaternlze a tertiary amine group. Correspondingly higher use amounts are required to quatemize a secondary or primary amine group, in a further variant, the quatemlzlng agent is added in excess, for example 1,1 to 2.0,. 1,25 to 2 or 1,25 to 1.75 equivalents of quatemlzlng agent per equivalent of quaternizabfe tertiary nitrogen atom.

Typical working temperatures here are In the rang© from 50 to 180*0, for example from 90 to 160 C or 100 to 14Q“C, The reaction time may be in the range of a few minutes or a few hours, for example about 10 minutes up to about 24 hours, The reaction can be effected at a pressure of about 0.1 to 20 bar, for example 1 to 10 or 15 to 3 bar. but especially at about standard pressure.

If required, the reactants can be initially charged for the quatemization in a suitable inert organic aliphatic or aromatic solvent or a mixture thereof, or a sufficient proportion of solvent from reaction step a) is stilt present. Typical examples are, for example, solvents of the feoivesso series, toluene or xylene, The quatemization can, however,, also be performed in the absence of a solvent.

To perform the quatemteation, the addition of cataiyticaliy active amounts of an acid may be appropriate. Preference is given to aliphatic monocarbaxylic acids, for example ui“G«~manooarboxyHc acids such as especially laurio acid, Isononanoic acid or neodecanoic add,. The quaternl2atlon can aiso be performed in toe presence of a Lewis add. The quatemteation can, however, aiso be performed in the absence of any add, o) Workup of the reaction mixture

The reaction end product thus formed can theoreticaliy be purified further, or the solvent can be removed, in order to improve the further processability of the products, however, it is also possible to add solvent after the reaction, for example solvents from the Solvesso series, 2-efhyihexanol, or essentially aliphatic solvents. Usually, however, this Is not absolutely necessary, and so the reaction product is usable without further purification as an additive, optionally after blending with further additive components (see below}.,. B) Further additive components

The fuel addiiized with the inventive qualemized additive is a gasoline fuel or especially a middle distillate fuel, in particular a diesel fuel

The fue! may comprise further customary additives to improve efficacy and/or suppress wear. in the case of diesel fuels, these are primarily customary detergent additives, carrier o&amp;sf cold How improvers, lubricity improvers, corrosion inhibitors, demulsifiers, dehazers, antifoams, cetane number improvers, combustion: Improvers, antioxidants or stabilizers, antistats, metallocenes, metal deactivated, dyes and/or solvents.

In the case of gasoline fuels, these are in particular lubricity improvers (friction modifiers), corrosion inhibitors, demulsifiers, dehazers, antifbams, combustion improvers, antioxidants or stabilizers, antistats, metallocenes, metal deactivators, dyes and/or solvents.

Typical examples of suitable ccaddiflves are listed in tee following section.’ S1) Detergent additives

The customary detergent additives are preferably amphiphilic substances which possess at least one hydrophobic hydrocarbon radical with a number-average molecular weight (Mfl) of 85 to 20 000 and at least one polar moldy selected from: (Da) mono* or polyamino groups having up to 6 nitrogen atoms, at: least one nitrogen atom having basic properties; tDbj nitre 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) carboxyi groups or their alkali metal or alkaline earth metal salts; (De) sulfonic acid groups or their alkali mete! or alkaline earth metal salts; (Of) polyoxy-C2* to G^alkylerse moieties terminated by hydroxy! groups, mono* or poiysmino groups, at least one nitrogen atom having basic properties, or by carbamate groups; (Dg) carboxylic ester groups; (Dh) moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amldo and/or imldo groups; and/or (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 soiubfiiiy m the fuel, has a number-average molecular weight (M8) of 86 to 20 000s 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, polybutenyi and polyfeobutenyl radicals with a number-average molecular weight of preferably in each case 300 to 5000, more preferably 300 to 3000, even more preferably 500 to 2600, even more especially preferably 700 to 2500 and especially S00 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 polyalkenepolyamlnes based on polypropene or on hlgh-reactivty fi.e. having predominantly terminal double bonds) or conventional (i.e, having predominantly internal double bonds) polybutene or poiyisobuiene having M« “ 300 to 5000, more preferably 500 to 2500 and especially 700 to 2600, Such additives based on high-reactivity polyisobutene, which can be prepared from the poiyisobutene which may comprise up to 20% by weight of n-butene units by hydroformyiation and reductive amlnatton with ammonia, monoamines or polyamines such as dsmetbylammopropylamin e, ethySenedlam ine, d iethylenetrlaml ne, triethytenetetramine or fetraeihyfenepentamlne, are known especially from EP-A244 618, When polybutene or polyisobutene having predominantly internal double bonds (usually in the β and y positions) are used as starting materials In the preparation of the additives, a possible preparative route is by chlorination and subsequent amjnation or by oxidation of the double bond with air or ««one to give the carbonyl or carboxyl compound and subsequent aminatfon under reductive {hydrogenating) conditions. The amines used here for the aminatfon may be, for example, ammonia, monoamines or the abovementioned polyamines. Corresponding additives based on polypropene are described In particular in WG-A 94/24231,

Further particular 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 VVO-A 97/03948,

Further particular 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 20 282,

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 WQ-A 96/03367 and in WG-A. 96/03479, These reaction products are generally mixtures of pure nftropolyisobuienes (e,g, a,β-dinitropofyisobutene) and mixed hydroxynltropoiylsobytones (e,g, o-nitro-β-hydroxypolylsobutene).

Additives comprising hydroxyl groups in combination with mono- or polyamino groups (Do) are in particular reaction products of polyisobutene epoxides obtainable from poly Isobutene hsvirtg preferably predominantly terminal double bonds and Mn * 300 to 5000, with ammonia· or mono- or poiyamines, 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 (V to C^s-otefins with maleic anhydride which have a totas molar mass of 500 to 20 000 and some or sli 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 307 816. 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 pciyetberamines.

Additives comprising sulfonic acid groups or their alkali metal or alkaline earth metal salts (Da) are preferably alkali metal or alkaline earth metal salts of an alkyl suffosuccfnste, as described In particular in EP-A 630 632. Such additives serve mainly to prevent valve seat wear and can be used advantageously in combination with customary fuel detergents such as poly(lso}buteneamln@s or polyetheramlnes.

Additives comprising po!yoxy-Cs*G«*alkylene moieties <Df) are preferably polyethers or polyetheramines which are obtainable by reaction of Cr to Gee-alkanols, CV to C^-aikanediols, mono- or dl-Cr to Cas-alkylamines, C*- to Csj-alkyicyclohexanois or Gi~ to Gsralkyiphenois 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 toe polyetheramines, by subsequent reductive smlnation with ammonia, monoamines or polyamines. Such products are described In particular in ΕΡΆ 310 875, EP-A 356 725, EP-A 700 085 and US-A 4 877 416. In the case of polyeihers, such products also have ea rner oil properties. Typical examples of these are tridecanoi butoxylates, isotrtdecarsoi butoxytstes, isonony(phenol butoxylates and polyisobutenol butoxylaies 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 alkanois or polyols, in particular those having a minimum viscosity of 2 mm% at 10Q*C, as described In particular in DE-A 38 38 §18. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic adds, 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, phihaiates, Isophthalates, terephtbaiates and trimellltates of isooctanol, of Isonorsanol, of isodecanol and of IsotridecanoL Such products also have carrier oil properties.

Additives comprising moieties derived from succinic anhydride and having hydroxyl snd/or amino and/or amfdo and/or especially Imrdo groups (Dh) am preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and especially the corresponding derivatives of poiyisobutenyfsuccinlG anhydride which are obtainable fey reading conventional or high-readivlty polyisobutene having Mn -preferably 300 to 5000, more preferably 300 to 3000, even more preferably SCO 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 pofyisobufene. The moieties having hydroxyl and/or amino and/or amido and/or Imldo groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of dl- or polys mines which, in addition to the amide function, also have free amine groups, succinic acid derivatives having an acid and an amide function, carboxamides with monoamines, carboxlmides with dhor polyamines which, in addition to the amide function, also have free amine groups, or dlmides which are formed by the reaction of di- or pofyarolnes with two succinic add derivatives, In the presence of imido moieties 0(h), the 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 wife amines and more preferably the reaction products of polylsobutenyl-substMed succinic acids or derivatives thereof with amines. Of pedicular interest in this context are reaction products With aliphatic polyamines (polyaikylenelmines) such as especially ethylenediamine, diethyfenefrfemine, trtethyteneteiramine, ietraeihyienepeniamine, pentaethytenehexamlne and hexaethyfenehepfamine, which have an imide structure.

Additives comprising moieties (DO obtained by Mannlch reaction of substituted phenols with aldehydes and mono- or poiyamines are preferably reaction products of poiyisobutene-substituted phenois With formaldehyde and mono- or poiyamines such as ethyfenediamfne, diethyienairismine, triethyieneietramine, tetraethyfenepentemine or dimethylamlnopropyiamine. The polyisobirtenyi-substituted phenois may stem from conventional or high-reactivity pdyisobutene having JVfc> = 300 to 5000, Such ' polytsobulen© Mannich bases'·1 are described in particular in EP-A 831 141,

Om or mom 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 B2) Carrier oifs

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 brlghtstoch or base oifs having viscosities, tor example, from the SN 500 to 2000 class; but aiso aromauc hydrocarbons, paraffinic hydrocarbons and alkoxyalksnols, Likewise useful is a fraction which is obtained in the refining of mineral oil and is known as "hydrocracfc air (vacuum distillate cut having a boiling range from about 360 to SOOT, obtainable from natural mineral oil which has been catalyticaily 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 (polyalphaoieflns or polyinteroaioiefins}. (poiy}esterst (poly)atkoxytates, polyethers, aliphatic pofyefher-amines, aikylphenol-siartad poiyethers, alkylphenol-starfed polyetheramlnes and carboxylic esters of long-chain alkanols.

Examples of suitable polyolefins are olefin polymers having e 400 to 1800, in particular based on polybutene or polyisobutene (hydrogenated or unhydrogenaied).

Examples of suitable polyethers or poJyetheramlrves are preferably compounds comprising potyoxy-Ci* to Cvslkylene moieties which are obtainable by reacting c*- to Cw'aikanols, Or to Cao-atetediols, mono- or di-Cir to Cso-aikyiamines, Ci- to c«-aikyicycfohexanols or Cv to Cjraikyiphenols with 1 to 30 mol of ethylene oxide and/or propylene ox*^s and/or butylene oxide per hydroxyl group or amino group, and, in the case of the pdyetherammes, by subsequent reductive a ruination with ammonia, monoamines or polyamines, Such products are described in particular in EP-A 310 875, EP-A 356 725, EP-A 700 085 and US-A 4,877,416. For example, the polyetheramines used may be pofy-Cj- to CValkytene oxide amines or functional derivatives thereof. Typical examples thereof are trideeano! bufcxyiates or isotridecanoi butoxylates, isononyfphenol butoxylates and also polyisobufenol butoxylates and propoxylates, and also the corresponding reaction products with ammonia.

Examples of carboxylic esters of long-chain alfcanais are in particular esters of mono-dl- or tricarboxylic acids with long-chain alkanois or polyols, as described in particular In DE-A 38 38 918. The mono-, dh or tricarboxylic acids used may be ailphatic or aromat'C acsds; suitable ester alcohols or polyols are In particular long-chain representatives having, for example, 8 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthafates and trfmell states of IsooctanoJ, Isononanol, Isodecanol and isotridecanoi, for example d!{n- or Isotrldecyl) phthafefe.

Further suitable carrier oil systems are described, for example·, In DE-A 38 26 808, DE-A 41 42 241, DE-A 43 09 074, EP-A 452 328 and EP-A 548 617, fcxampses o? particularly suitable synthetic carrier oils are alcohol-started polyethers havmg about 5 to 35, preferably about 5 to 30,. more preferably 10 to 30 and especially 15 to 30 Ca- to (VaJkyien© oxide units, for example selected from propylene oxide, n-butylene oxide and isobutylene oxide units, or mixtures thereof, per alcohol molecule. Nonlimltihg 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 C$- to Cis-aikyl radical. Particular examples include trfdecano! and nonyiphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherjflcation products) of monohydric aliphatic Cr to Cir alcohols with Cr to C§~alkyfene oxides. Examples of monohydric aliphatic Cs-Cir alcohols are hexanol, heptanol, octanof, 2-ethylhexanoi, nanyl alcohol, decanoi, 3-propylhepfenol, undecartol, dodecsnol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol and the constitutional and positional isomers thereof. The alcohols can be used either In the form of the pore Isomers or in the form of technical grade mixtures. A particularly preferred alcohol is tddecanol. Examples of <V to Or alfcylen® oxides are propylene oxide, such as 1,2-propylene oxide, butylene oxide, such as 1,2~buty!ene oxide, 2,3-butylen® oxide, Isobutylene oxide or fetrahydrofuran, pentyiene oxide and hexylene oxide. Particular preference among these is given to Cs- to Crslkyfene oxides, La propylene oxide such as 1,2-propyl®ne oxide and butylene oxide such as 1,2-butytene oxide, 2,3»butyiene oxide and isobutylene oxide. Especially butylene oxide is used.

Further suitable synthetic carrier oils are aikoxyiafed aikyfphenols, as described in DE-A 10 102 913,

Particular carrier oils are synthetic carrier oils, particular preference being given ίο the above-described alcohol-started poiyeihers.

The carrier oil or the mixture of different carrier olis 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. B3) Cold flow improvers

Suitable cold flow improvers are in principle ail 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, ;n 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 fossli origin, Le, 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 anilsettllng additive (WASA) when used in customary diesel fuels. They can also act partly or predominantly as nucleate». It Is, though, also possible to use mixtures of organic compounds effective as MDFis and/or effective as WASAs and/or effective as nucleate».

The cold flow Improver is typically selected from {K1} ccposymers of a Cj- to C^oiefin with at feast one further eibyienicslfy unsaturated monomer; (K2) comb polymers; (K3) polyoxyalkylenes; (K4) polar nitrogen compounds; (K5) eulfbcarboxytic acids or sulfonic acids or derivatives thereof; and (K6) poiy{meth)acryiio asters,.

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 Cs- to G^-olefln 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 arra nged either tormina Ely {a-oleftns) or internally. However, preference Is given to α-olefins, more preferably oe olefins having 2: to 8 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 ethylenicaily unsaturated monomer Is preferably selected from aiksnyl carboxylsies, (meth)acrylic esters and further olefins, \Wten further olefins are also copolymenzed, they are preferably higher in molecular weight than the abovementioned Cs- to C^roiefin base monomer. When, for example, the oletln base monomer used Fa ethylene or propane, suitable further oleins are in particular Cia~ to Gw-a-olefins, Further olefins are in most cases only additionally copolymerized when monomers with carboxylic ester functions are also used.

Suitable (meth)acryisc esters are, for example, esters of {methjacrylic acid with Gv to Caralfcanols, especially €*- to C^-alkanofs, in particular with methanol, ethanol,, propanol, teopropanol, n-bufenoi, sec-butanol, isobutanol, tert-butano), penianol, hexanol, heptanoi, octanes, 2~ ethylhexanoi, nonanol and decanol, and structural isomers thereof.

Suitable alkenyl carboxytates are, for example, C3- to C«-alkeny! esters, for example the vinyl and progeny f 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 vinyl esters. Among the carboxylic adds with a branched hydrocarbon radical, preference Is given to those whose branch Is in the opposition to the carboxyl group, the owsarbon 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 carboxyiates are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethyihexanoate, vinyl neopentenoate, vinyl hexanoate, vinyl neon one noate, 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 ethyiene-vinyl acetate copolymers fEVAs"), 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 carboxyiates in copoiymerized form, which differ in the alkenyl function and/or In the carboxylic acid group. Likewise suitable are copolymers which, as well as the alkenyl carboxy!ate(s), comprise at least one olefin and/or at least one (meth}acryiic ester in copoiymerteed form,

Terpolymers of a Cj- to C^-a-otefin, a C?* to C^-alkyl ester of an efhylenlcatly unsaturated monocarboxyllc acid having 3 to 15 carbon atoms and a Cr to Cw-alkenyi 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 terpotymer of this kind is formed from ethylene, 2-ethylhexyi acrylate and vinyl acetate.

The at feast one or the further elhyienicaily unsaturated monomers} are copoiymerized in the copolymers of class (K1) in an amount of preferably 1 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 C* to C« base olefins.

The copolymers of class (K1) preferably have a number-average molecular weight IVk of 1000 to 20 G00t more preferably 1000 to 10 000 and in particular 1000 to 8000. * ypfcsl comb polymers of component {K2} are, for example, obtainable by the copofyrnerizatfon of maleic anhydride or fumaric acid with another ethyienlcaily unsaturated monomer, for example with an α-olefin or an unsaturated safer, such as vinyl acetate, and subsequent: esterification of the anhydride or add function with an alcohol having at least 10 carbon atoms. Further suitable comb polymers are copolymers of oi-olefins and estenfied comonomers, for example esterffied copolymers of styrene and maleic anhydride or esierified copolymers of styrene and fumaric add. Suitable comb polymers may also be polyfumamtes or polymaleaies. 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", H. A, Plate and V. P, Shibaev, J, Poly.. Sci, Macromotecular Revs. 8, pages 117 to 253 {1074)'*. Mixtures of comb polymers are also suitable,

Polyoxyalkyiene® suitable as components of class (K3) are, for example, polyoxyalkyiene esters,, polyoxyalkyiene ethers, mixed polyoxyalkyiene ester/ethers and mixtures thereof. These polyoxyalkyiene compounds preferably comprise at least one linear alkyl group, preferably at feast two linear alkyl groups, each having 10 to 30 carbon atoms and a polyoxyalkyiene group having a number-average molecular weight ο* up to 5000, Such polyoxyalkyiene compounds are described, for example, In EP-A u61 895 and also in US 4,491,455, Particular polyoxyalkyiene compounds are based on polyethylene glycols and polypropylene giycois having a number-average molecular weight of TDD to 5000. Additionally suitable are polyoxyalkyiene mono- and diesters of My acids having 10 to 30 carbon atoms, such as stearic add or behenio acid.

Polar nitrogen compounds suitable as components of class <K4) may be either ionic or nonsonsc 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 >NR? in wnieh R? tB B Ci?-to C^-hydrocarbon radical, The nitrogen substituents may also be quaterrazed, i,e. be in cationic form. An example of such nitrogen compounds is that of ammonium sails and/or amides which are obtainable by the reaction of at feast one amine substituted by at least one hydrocarbon radical with a carboxylic add having 1 to 4 carboxyl groups or with a suitable derivative thereof, The amines preferably comprise at least one linear Cr to C4o-alkyl radical Primary amines suitable for preparing the polar nitrogen compounds mentioned are, for example, octylamine, nonylamlne, decylamine, undecylamine, dodecylamine, tetradecyiamlne and the higher linear homologs. Secondary amines suitable for this purpose are, for example, dtoctadeeylamine 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 tallamlnes, as described, for example, in Ulimann'S Encyclopedia of industrial Chemistry, 6th Edition, "Aminas, aliphatic" chapter. Adds suitable for the reaction are, for example, cyclohexane*1 ,2-dlcarboxylic acid,. cyclohexane-1,2-dicarboxylio add, cyclopeotane-1,2-dfoarboxyilc add, napbihalenedicarboxyjic add, phthalic sold, 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 polyiCa-to Csa-carboxyiiD acids) having at least one tertiary amino group with primary or secondary amines. The polyfCr to Ca-cerboxyfic 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 add units. The carboxylic acid units are suitably bonded to the polycarboxylic adds, 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 poiy(Cr to C^-carboxylic adds) which have at least one tertiary amino group and are of the general formula Ha or lib

In which the vaffabk? Aisa slight-chain or branched Ca- to C*-8lf<ylene group or the moiety of the formula if I

and the variable 8 is a C<- to Ci»-afkylene group. The compounds of the general formulae I fa and Hb especially have the properties of a VVASA.

Moreover, the preferred oil-soluble reaction product of component (K4), especially that of the general formula !fa or IIP, 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.

Straight-chain or branched Cj- to (Vaikylene 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-roefhyM,3-propylene, 1,5-pentylene, 2-methyM,4-butylene, 2,2“dimeihyi-l,3-propylene, 1T6-hexyiene {hexamethytene) and In particular 1,2-ethylene. The variable A comprises preferably 2 to 4 and especially 2 or 3 carbon atoms,

Ci~ to Cis-a!ky!ene groups of the variable B are, for example, 1,2-ethylene, 1,3-propylene, 1,4-butytene, hexamethylene, ©ctaroethytene, decamethytene, dodecamethyiene, tefradecamethyfene, hexadecamethylene, octadecamethylene, nonadecamsthylene 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 pofycarboxylic 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 may optionally be bonded to one another.

These parent amines of the olf-soluble reaction products of component (K4) are usually secondary' amines and have the genera! formula HN{R8)3 in which the two variables R« are each Independently straight-chain or branched C«- to Chalky! radicals, especially C14- to Ca-afty! radicals. These relatively long-chain alkyl radicals are preferably strarght-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 R* radicals are preferably identical.

The secondary amines mentioned may be bonded to the poSycarboxySic 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 nitrilofrlacetlc acid, of ethylenediaminetetraacetic add or of propylene-1 s2-dlamlnetetraaoetic acid with In each case 0,5 to 1,5 mol per carboxyl group, especially 0.8 to 1.2 mo! per carboxyl group, of dioleylamln©, dipaint itinaroine, dicoconut fatty amine, distearyiamine, difcehenylamine or especially ditaiiow fatty amine. A particularly preferred component {K4} is the reaction product of 1 mo! of ethyienedlaminatetraacetic acid and 4 mol of hydrogenated ditaiiow fatty amine.

Further typical examples of component (K4) include the Ν,Ν-diaikylammoniym salts of 2-N’tN “diaikylamidoben^oates, tor example the reaction product of 1 mo! of phthaiic anhydride and 2 moi of ditaiiow fatty amine, the latter being hydrogenated or unhydrogenated, and the reaction product of 1 mol of an alkenylsplrobislactone with 2 mol of s dialkylsmine, for example ditaiiow 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 Song-chain primary or secondary amines with carboxylic add-containing polymers, as described in WO 93/181 IS.

Suifocarboxyiic acids, sulfonic adds or derivatives thereof which are suitable as cold' flow improvers of class (K5) are, for example, the oil-soluble carboxamides and: carboxylic esters of orthosuifobenzoic add, In which the sulfonic add function Is present as a sulfonate with alkyl-substituted ammonium cations, as described in EP-A 261 957..

Foly(metb)acryilc esters suitable as cold How 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 esterifiad alcohol, The copolymer optionally comprises another different olefinlcally unssturated monomer In copolymerized form. The· weight-average molecular weight of the polymer Is preferably 50 000 to 500 GOO. A particularly preferred polymer is a copolymer of methacrylic add and methaoryito esters of saturated Cm and C« alcohols, the acid groups having been neutralized with hydrogenated tallamine. Suitable poly{meth)acrylfc 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, B4} Lubricity improvers

Suitable lubricity Improvers or friction modifiers are based typically on fatty acids· or fatty add esters, Typical examples are tail oil fatty acid, as described, for example, In WO 98/004666, and glyceryl monoolaate. The reaction products, described In US 6 743 268 82, of natural or synthetic oils, for example triglycerides, and aikanolamlnes are also suitable as such lubricity improvers. BS) Corrosion Inhibitors

Suitable corrosion inhibitors are, for example, succinic esters, in particular with oolyols, fatty acid derivatives, for example oleic esters, oligomerized fatty acids, substituted ethanolamlnes, and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany) or HiTEC 536 (Ethyl Corporation). B8) Demulsifiers

Suitable demulsifiers are, for example, the alkali metal or alkaline earth metal salts of alkyl-substituted phenol- and naphthatenesultonates and the alkali metal or alkaline earth metal salts of fatty adds, and also neutral compounds such as alcohol alkoxyiates, e.g. aJcohoi athoxytates, phenol alkoxyiates, e.g. iert-buiylphenol ethoxyiate or terhpentylphenol ethoxylate, fatty acids, alkyiphenols, condensation products of ethylene oxide (EG) and propylene oxide (PO), for example including In the form of EO/PO block copolymers, polyethylene! mines or else polyslioxanes. 87} Debaters

Suitable dehazers are, for example, alkoxylated phenol-formaldehyde condensates, for example the products available under the trade names NALCO 7D07 (Naico) and TGLAD 2683 (Petrollte). 88) Antifoams

Suitabie antffoams are, for example, poiyether-modified poiyslfoxanes, for example the products available under the trade names TEGOPREN 5851 (Goldschmidt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc). 89) Cetane number Improvers

Suitable cetane number improvers are, for example, aliphatic nitrates such as Ξ-ethyl hexyl nitrate and cyclohexyj nitrate and peroxides such as dMert-butyi peroxide. BIO) Antioxidants

Suitable antioxidants are, for example substituted phenols, such as 2,6*df-tert” butyfphenoS and 6-dMert^uiyi-3^ethyiphenoi, end aiso phenytenediamihes such as N, N’-dkseobuty l-p-pheny ienediami no, B1 1} Metal deacllvators

Suitable metal deactivates are, for example, salicylic add derivatives such as N.N’-dssalicyildene-l, 2-'propanedlam i ne, 812} Solvents

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/Shetl Group) and EXXSOL (ExxonMobil), and also polar organic solvents, for example, alcohols such as 2-athyihexanoi, decanoi and isotndecanol. Such solvents are usually added to the diesel fuel together with the aforementioned additives and coadditives, which they are intended to dissolve or dilute for better handling, C) Fuels

The inventive additive is outstandingly suitable as a fuel additive and can be used In principle In any fuels. It brings about a whole series of advantageous effects in the operation of Internal combustion engines with fuels. Preference is given to uslnq the inventive quatemized additive in middle distillate fuels, especially diesel fuels.

The present Invention therefore also provides fuels, especially middle distillate fuels, with a content of the Inventive quatemized additive which Is 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 Wight, preferably 20 to 1500 ppm by weight, especially 25 ίο 1000 ppm by weight in particular 30 to 750 ppm by weight, based in each case on the total amount of fuel,

Middle distillate fuels such as diesel fuels or heating oils are preferably' miners] oil raffinates which typically have a boiling range from 100 to 400*C. These are usually distillates having a 95% point up to 3601¾ or even higher. These may also be so-called "ultra Sow sulfur diesel" or "city diesel", characterized by a 95% point of, for example, not more than 345eC and a sulfur content of not mom than 0,005% by weight or by a 95% point of, for example, 2B5flC and a sulfur content of not more than 0.001% by weight, In addition to the mineral middle distillate fuels or diasei fuels obtainable by refining, those obtainable by coal gasification or gas liquefaction ["gas to liquid" (GIL) 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 bloetoanof.

The qualities of the heating oils and diesel fuels are laid down In detail, for example, in D!N 51603 and EM 590 (cf, also Uiimann's Encyclopedia of Industrial Chemistry, 5fh 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 hydrocaiton mixtures, the inventive quaterrazed additive 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 add esters, preferably essentially on afkyi esters of fatty acids which derive horn vegetable and/or animal oils anchor fats. Alkyl esters are typically understood to mean lower alkyl esters, especially G?-C^-alkyl esters, which are obtainable by transesterifying the glycerides which occur in vegetable and/or ammaf oils and/or fats, especially triglycerides, by means of lower alcohols, for example etnanol 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 components thereof,, are, for example., sunflower methyl ester, palm oil methyl ester ("PME"), soya oil methyl ester CSME") and especially rapeseed oil methyl ester CRME").

The middle distillate fuels or diesel fuels are more preferably those having a. Sow sulfur content, U, 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 tee! 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 qu atomized additive is especially suitable as a fuel additive In fuel compositions, especially In diesel fuels, for overcoming tee problems outlined af the outset: in direct-injection diesel engines, In particular in those with common-rail injection systems.

The invention is now illustrated in detail by the working examples which follow. The test methods oescrfbed herein are not restricted to the specific working examples, but are part of the general disclosure of the description and can be employed generally In the context of the present invention.

Experimental section: A. General test methods

Engine fast b1) XUD9 test ~ determination of flow restriction

The procedure was according to the standard stipulations of CEO F-23-01, b2) DW10 ~ keep dean test

To examine the influence of the inventive compounds on the performance of direct-Nation diesel engines, the power loss was determined on the basis of the official test method CEC R3S8-08. The power loss is a direct measure of formation of deposits in the injectors.

The keep dean test is based on CEC test procedure F-088-0B issue 5, The same test setup and engine type (PEUGEOT DW10) as In the CEC procedure are used,

Special features of the test used: a) injectors so the tests, cleaned injectors were used. The cleaning time in an ultrasound bath in water at 60*C + 10% Supeideconfamine (intersciences, Brussels) was 4 b, b) Test run times the test penod was 12 h without shutdown phases, The one-hour test cycle (see table below) from CEO F-098*Q§ was run through 12 times,.

for range to be expected see CEC-G98-G8 ' ' ' ** target value c) Power determination the mitial power (Pa, KC [KWD is calculated from the measured torque at full load 4000/mtn directly after the test has started and the engine has warmed up. The procedure is described in Issue 5 of the test procedure CEC F-88-0S. The same test setup and the PEUGEOT DW10 engine type are used.

The final power (Pes£ir KC) is determined In the 12th cycle in stage 12, (see table above). Here too, tee operating point is full load 4000/min, P«*f KC (kWJ Is calculated from the measured torque. i he power loss In KC is calculated as follows?

The fuel used was a commercial diesel fuel from Haftermann {RF-C0-O3V To synthetically Induce the formation of deposits at tee injectors, 1 ppm of zinc was added thereto in the form of a zinc neodecanoaie solution. 8, Preparation examples:

Reactants used: RIBS A: Prepared from maleic anhydride and FIB 1000 in a known manner. For the Inventive preparation examples and comparative examples which follow, qualities with hydrolysis numbers In the region of 84-95 mg KOH/g were used. DMAPA was used with the particular PIBSA quality in a molar ratio of 1:1 according to the hydrolysis number. The PIBSA qualities used had bismaleation levels (BML) of less than 15%, DMAPA: Μ = 102.18 methyl salicylate: M ~ 152,14 dimethyl phthalale: M = 194,19 dimethyl oxalate: M - 118,09 dimethyl sulfate: Μ ~ 128,13 dimethyl carbonate M ” 90.08

Preparation example 1: Synthesis of an inventive quatemized succinimide fPIBSA*'DMAPA/dimettyi phitialate)

Folyisobuiylenesuccinle anhydride (1659 5} Is dissolved in Solvent Naphtha Heavy (SNH Bacon Mobil, GAS64742-95-5) (1220 q), and 3-d!rnethyiamlnQ-1~propyiamine (DMAPA, 1539} is added. The reaction solution Is stirred at 170*0 for 8 h, In the course of which water of condensation formed is distilled off continuously, This affords

the PIBSA-DMAPA succinimide as a solution in Solvent Naphtha Heavy (TBN 0.557 mrnoi/g). A portion of this solution of the PiSSA-DMAPA succinimide (181 g) is added to dimethyl pntheiaie (19,4 §)» and the resulting reaction solution is stirred at 12G*C for 11 h and then at 15GeC for 24 h, After cooling to room temperature, the product obtained is the ammonium carboxyfete as a solution in Solvent Naphtha Heavy. Ή NMR analysis confirms the quatemfzstron.

Preparation example 2: Synthesis of an inventive quatemfeed succinimide (Pi8SA/DMAPA/methyl salicylate)

PolyisobyfylanesuccNc anhydride (PlBSA; 2198 g) is heated to 11 OX. and 3-dlmethylamino-l-propylamine (OMAPA: 182 g) Is added within 40 min, in the course of which the reaction mixture heats up to 14QX. The reaction mixture is heated to 17ΌΧ and held at this temperature for 3h, in the course of which 28 g of distillate am coveted. This affords the PiBSA-DMAPA succinimide as a viscous oil (TBN 0,735 mmot's). A mature of this PIBSA-DMAPA succlnimide (284,5 g)t methyl salicylate (65,5 g) (i.e, about 2 equivalents of methyl salicylate per equivalent of tertiary amino group) and 3,3,5-trlmetnyiheptenosc add (from, BASF) (0,75 g) is heated to 140-1508 and the reaction mixture is stirred at this temperature for 6 h. After cooling to room temperature the product obtained is the ammonium salicylate as a viscous oil, Ή NMR analysis confirms the quatemfeatron. By adding Pilot 900 oil, Petrechem Carless Ltd,, the active ingredient content of the solution is adjusted to 50% by weight.

Preparation example 3: Synthesis of art inventive quatemteed succinimid© {PI SSA/DMAPA/dimethyi oxalate)

Polyisobutylenesucctnic anhydride (PIBSA; 2198 g) is heated to noeC, and 3-dlmethylamino-1 -propylamine (DMAPA; 182 g) is added within 40 min, in the course of which the reaction mixture heats up to 140*C. The reaction mixture is heated to 178°G and held at this temperature for 3 h, in the course of which 28 g of distillate are collected. This affords the PJBSA-DMAPA succinlrnide as a viscous oil (TBN 0.,735 mrnol/g). A mixture of this PSBSA-DMAPA sucoinimsde (211 g), dimethyl oxalate (34,5 g) and sauric acid t4.9 g) is heated to 120*0 and then stirred at this temperature for 4 h. Excess dimethyl oxalate is removed on a rotary evaporator under reduced pressure (p = 5 mbar) at 120*C. The product obtained is the ammonium methyl oxalate as a viscous oil Ή NMR analysis confirms the quatemization.

For comparison with the prior art, Examples 2 and 4 from WO 2006/135881 were worked up.

Preparation ©cample 4: Synthesis of a known quatemized succinimide (comparative exempts) (Example 2 from WG 2006/135881) A solution of PIBSA (420.2 g) In Pilot 900 oil, Petrochem Carless Ltd., (51,3 g) is initially charged and heated to 11Q*C. DMAPA (31.4 g) is metered in within 50 minutes, in the course of which a slightly exothermic reaction is observed. Within 80 minutes, the reaction mixture is heated to 150*0 and the mixture Is then kept at this temperature for 3 h, in the course of which the water of reaction which forms is distilled off. After cooling to room temperature, the PIBSA-DMAPA sucdnimide Is obtained as a solution in Pilot 9G0 oil (TBN 0.62 mmol/g), A. portion of foe PIBSA-DMAPA sucdnimide thus obtained as a solution in Pilot 9Q0 oil, Petrochem Carless ltd,, (354 g) Is initially charged and heated to 30° C. Dimethyl sUifete (25,3 g) is metered in, in the course of which the reaction temperature rises to 112*0, Subsequently, the reaction mixture is stirred at 1CKTC for 3 h. After cooling to mom temperature, the quaterniased PIBSA-DMAPA sucdnimide Is obtained as a solution in Plot 900 oil. NMR confirmed the quaternization. The output was adjusted to an active ingredient content of 50% by weight by adding Pilot SOO oil

Preparation example 5: Synthesis of a known quatembed sucdnimide (comparative example) (Example 4 from WO 2006/135881) A sosution of PIBSA (420.2 g) In Pilot 900 oil, Petrochem Carless Lid,, (51,3 g) is initially charged and heated to 110*C, DMAPA (31Λ g) is metered in within 50 minutes, m cowse of wh*'ch a slightly exothermic reaction is observed- Within 60 minutes, foe reaction mixture is heated to 1S0*C and foe mixture is then kept at this temperature for 3 hs in the course of which the water of reaction which forms is distil fed off. After cooling to room temperature, foe PIBSA-DMAPA sucdnimide is obtained as a solution in Pilot: 900 oil (TBN 0.82 mmol/g). A portion of the PIBSA-DMAPA sucdnimide thus obtained as a solution In Pilot 900 oil, Petrochem Cariess Ltd,, ¢130 g), dimethyl carbonate (20 g) and methanol (17.4) are charged into an autoclave and inerted with nitrogen, and a starting pressure of 1,3 bar is established. Subsequently, the reaction mixture is stared under autogenous pressure first at 9Q°C for 1 h, then at 140’C for 24 h. After cooling to room temperature, the autoclave is decompressed and the contents are rinsed out completely with a little toluene as a solvent. Ail iow-bolng constituents are subsequently removed on a rotary evaporator under reduced pressure to obtain the quaierrtecf PIBSA-DMAPA sucdnimide as a solution in Pilot 900 oil. 1H NMR analysis confirmed the partial quatemszation, The output is adjusted to an active ingredient content of 59% by weight by adding Pilot 900 oil. 0, Use examples: in the use examples which follow, the additives are used either as a pure substance {as synthesized In the above preparation examples) or in the form of an additive package, M u Additive according to preparation example 2 (lnventives quaternized with methyl salicylate) M2: Additive according to preparation example 4 (comparative, quatemized with di m ethyl sulfate) MS, Additive according to preparation example § (comparative, quatemized with dimethyl carbonate)

Use example 1: determination of foe additive action on foe formation of deposits in diesel engine injection nozzles a) XU09 Tests

Fuel used: RF-06-G3 (reference diesel, Haltermann Products, Hamburg)

The results are compiled in tabie 1:

Table 1: XUD9 tests

it was found that the inventive additive M1, with the same dosage, has an improved effect compared to the prior art (M2, M3). b) DWi 0 test

To study the influence of the inventive compound on the performance of direct-injection cfiesef engines, the power loss was determined based on the official test method CEC F-098-08 as described above, The power Joss is a direct measure of formation of deposits in the Injectors. A conventional direct-injection diesel engine with a common-rail system was used.

The fuel used was a commercial diesel fuel from Haltermann (RF-06-03). To synthetically induce the formation of deposits at the injectors, 1 ppm by weight of sane sn the form of a zinc didodecanoate solution was added thereto.

The table below shows the results of the determinations of the relative power loss at 4000 rpm after 12 hours of sustained operation without Interruption. The value Pe gives the power after 10 minutes and the value the power at the end of the measurement:

The test results are shown in table 2.

Table 2: Results of the DVV10 test

It was found that the Inventive additive Ml has an improved effect compared to the base value and has an improved effect at least compared to example M3.

Use example 2; Determination of the solubility properties

To determine the solubility properties, the following additive packages were produced and tested: M 4 {inventive}

M 5 (comparative, dimethyl sulfate)

M 6 (comparative, dimethyl carbonate}

The result of the solubility tests Is compiled In the table below. The minimum amount of solvent (Solvent Naphtha Heavy) needed to obtain a homogeneous, clear diesel performance package at room temperature with otherwise identical amounts of active substance, Pilot 900, antifoam and dehazer is reported.

Table 3: Determination of the solvent requirement

It was found that, surprisingly, the additive according to preparation example 2 has the best solubility properties, i.e. requires the least solvent.

Reference is made explicitly to the disclosure of the publications cited herein.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims (20)

1. Claims

   1. A fuel composition comprising, in a majority of a customary fuel, a proportion of at least one reaction product comprising a quaternized nitrogen compound, or a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification, said reaction product being obtainable by a1) reacting a hydrocarbyl-substituted polycarboxylic acid compound with a compound comprising at least one oxygen or nitrogen group reactive, with the polycarboxylic acid, and comprising at least one quaternizable amino group, to obtain a quaternizable hydrocarbyl-substituted polycarboxylic acid compound, and a2) subsequent reaction thereof with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, or of an aliphatic polycarboxylic acid; or b) reacting a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, or of an aliphatic polycarboxylic acid wherein about 1.1 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom; and/or the hydrocarbyl-substituted polycarboxylic acid compound is a polyisobutenylsuccinic acid or an anhydride thereof, said acid having a bismaleation level of 2 to 20% by weight, based in each case on the reaction product.
2. 2. The fuel composition according to claim 1, wherein the compound comprising at least one oxygen or nitrogen group is reactive with the polycarboxylic acid by addition or condensation.
3. 3. The fuel composition according to claim 1 or 2, wherein said quaternizing agent is an alkyl ester of a cycloaromatic or cycloaliphatic mono- or dicarboxylic acid, or of an aliphatic polycarboxylic acid.
4. 4. The fuel composition according to any one of claims 1 to 3, wherein about 1.25 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom.
5. 5. The fuel composition according to any one of claims 1 to 4, wherein the hydrocarbyl-substituted polycarboxylic acid compound is a polyisobutenylsuccinic acid or an anhydride thereof, said acid having a bismaleation level of 2 to 15% by weight, based in each case on the reaction product.
6. 6. The fuel composition according to any one of the preceding claims, wherein the quaternizing agent is a compound of the general formula 1

   in which Ri is a lower alkyl radical and R2 is an optionally substituted monocyclic aryl or cycloalkyl radical, where the substituent is selected from OH, NH2, NO2, C(0)0R3, and RiOC(O)-, in which R1 is as defined above and R3 is H or R1.
7. 7. The fuel composition according to any one of the preceding claims, wherein the quaternizing agent is a compound of the general formula 2

   in which Ri and Ria are each independently a lower alkyl radical and A is hydrocarbylene.
8. 8. The fuel composition according to any one of the preceding claims, wherein the quaternized nitrogen compound has a number-average molecular weight in the range from 500 to 5000.
9. 9. The fuel composition according to any one of the preceding claims, wherein the quaternized nitrogen compound has a number-average molecular weight in the range from 800 to 3000.
10. 10. The fuel composition according to any one of the preceding claims, wherein the quaternized nitrogen compound has a number-average molecular weight in the range from 900 to 1500.
11. 11. The fuel composition according to any one of the preceding claims, wherein the quaternizing agent is selected from alkyl salicylates, dialkyl phthalates and dialkyl oxalates.
12. 12. The fuel composition according to any one of claims 1 to 11, wherein the compound which is reactive with the polycarboxylic acid and comprises an oxygen or nitrogen group and at least one quaternizable amino group is selected from a. hydroxyalkyl-substituted mono- or polyamines having at least one quaternizable primary, secondary or tertiary amino group; b. straight-chain or branched, cyclic, heterocyclic, aromatic or nonaromatic polyamines having at least one primary or secondary amino group and having at least one quaternizable primary, secondary or tertiary amino group; c. piperazines.
13. 13. The fuel composition according to claim 12, wherein the compound which is reactive with the polycarboxylic acid and comprises an oxygen or nitrogen group and at least one quaternizable amino group is selected from a. hydroxyalkyl-substituted primary, secondary or tertiary monoamines and hydroxyalkyl-substituted primary, secondary or tertiary diamines, b. straight-chain or branched aliphatic diamines having two primary amino groups; di- or polyamines having at least one primary and at least one secondary amino group; di- or polyamines having at least one primary and at least one tertiary amino group; aromatic carbocyclic diamines having two primary amino groups; aromatic heterocyclic polyamines having two primary amino groups; aromatic or nonaromatic heterocycles having one primary and one tertiary amino group.
14. 14. The fuel composition according to any one of the preceding claims, selected from diesel fuels, biodiesel fuels, gasoline fuels and alkanol-containing gasoline fuels.
15. 15. The use of a reaction product obtainable by a process as defined in any one of the preceding claims or of quaternized nitrogen compound obtained from the reaction product; or of a quaternized nitrogen compound prepared by a process comprising the reaction of a quaternizable hydrocarbyl-substituted polycarboxylic acid compound comprising at least one tertiary quaternizable amino group with a quaternizing agent which converts the at least one tertiary amino group to a quaternary ammonium group, said quaternizing agent being the alkyl ester of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid or of an aliphatic polycarboxylic acid; as a fuel additive, and wherein about 1.1 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom.
16. 16. The use according to claim 15 as an additive for reducing the fuel consumption of direct-injection diesel engines, or diesel engines with common-rail injection systems, and/or for minimizing power loss in direct-injection diesel engines, or in diesel engines with common-rail injection systems.
17. 17. The use according to claim 15 as a gasoline fuel additive for reducing the level of deposits in the intake system of a gasoline engine, or DISI (direct injection spark ignition) and PFI (port fuel injector) engines.
18. 18. The use according to claim 15 as a diesel fuel additive, as a cold flow improver, as a wax antisettling additive (WASA) or as an additive for reducing the level of and/or preventing deposits in the intake systems, the internal diesel injector deposits (IDIDs), and/or valve sticking in direct-injection diesel engines, or in common-rail injection systems.
19. 19. The use according to any one of claims 15 to 18, wherein about 1.25 to about 2.0 equivalents of quaternizing agent are used per equivalent of quaternizable tertiary nitrogen atom.
20. 20. The use according to any one of claims 15 to 19, wherein said quaternizing agent is the alkyl ester of a cycloaromatic or cycloaliphatic mono- or dicarboxylic acid, or of an aliphatic polycarboxylic acid.