WO2022263244A1

WO2022263244A1 - Quaternized betaines as additives in fuels

Info

Publication number: WO2022263244A1
Application number: PCT/EP2022/065477
Authority: WO
Inventors: Markus Hansch; Harald Boehnke; Matthias ZORN; Maxim Peretolchin; Jochen Mezger
Original assignee: Basf Se
Priority date: 2021-06-16
Filing date: 2022-06-08
Publication date: 2022-12-22

Abstract

The present invention relates to the use of quaternized betaines in a specific manner as a fuel additive, such as, more particularly, as a deposit control additive; for reducing the level of 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; and as an additive for gasoline fuels, especially for operation of DISI engines.

Description

Quaternized betaines as additives in fuels Description

The present invention relates to the use of quaternized betaines in a specific manner as a fuel additive, such as, more particularly, as a deposit control additive; for reducing the level of 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; and as an additive for gasoline fuels, especially for operation of direct injection spark ignition (DISI) engines, and against deposits in the fuel system that is used to operate the engine, including fuel filters.

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 direct injection diesel engines lies in their high performance for 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 for injection of the fuel directly into the combustion chamber of the diesel engine: the conventional distributor injection pump, the pump-nozzle system (unit-injector system or unit-pump system), and the common rail system.

In the common rail system, the diesel fuel is conveyed by a pump with pressures up to and even over 2000 bar into a high-pressure line, the common rail. Proceeding from the common rail, branch lines run to the different injectors which inject the fuel directly into the combustion chamber. The full pressure is always applied to the common rail, which enables multiple injection or a specific injection form. In the other injection systems, in contrast, only a smaller variation in the injection is possible. Injection in the common rail is divided essentially into three groups: (1.) pre-/pilot-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 NO_x value. In this post-injection, the fuel is generally not combusted, but instead vaporized by residual heat in the cylinder. The exhaust gas/fuel mixture formed is transported to the exhaust gas system, where the fuel, in the presence of suitable catalysts, acts as a reducing agent for the nitrogen oxides NO_x.

In modern types, the common rail system is capable of multiple injections to optimize combustion profile and emissions. 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_x), carbon monoxide (CO) and especially of particulates (soot). This makes it possible, for example, for engines equipped with common rail injection systems to meet the Euro 4 standard theoretically even without additional particulate filters.

In modern common rail diesel engines, under particular conditions, for example when biodiesel- containing fuels or fuels with metal impurities such as zinc compounds, 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 loss. 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 IDIDs.

The "injection system" is understood to mean the part of the fuel system in motor vehicles from the fuel pump up to and including the injector outlet. "Fuel system" is understood to mean the components of motor vehicles that are in contact with the particular fuel, preferably the region from the tank up to and including the injector outlet.

WO 2006/135881 describes quaternized ammonium salts prepared by condensation of a hydrocarbyl-substituted acylating agent and of an oxygen or nitrogen atom-containing compound with a tertiary amino group, and subsequent quaternization by means of hydrocarbyl epoxide in combination with stoichiometric amounts of an acid such as, more particularly, 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.

WO 2010/132259 and WO 12/004300 both describe similar amide-group-containing quaternized ammonium salts prepared by reaction of a hydrocarbyl-substituted acylating agent and of an oxygen or nitrogen atom-containing compound with a tertiary amino group, in which in the subsequent quaternization by means of hydrocarbyl epoxide the addition of acid can be omitted.

WO 2014/202425 preparation and use of betaine-compounds as fuel additives is described, inter alia for diesel fuels. Quaternization takes place using a halocarboxylic acid such as chloroacetic acid. As a by-product metal chloride is formed and has to be removed from the reaction mixture costly since it causes corrosion.

It was therefore an object of the present invention to provide further fuel additives which prevent deposits in the injector tip and internal injector deposits in the course of operation of common rail diesel engines.

Brief description of the invention:

It has now been found that, surprisingly, the above object is achieved by providing certain quaternized betaine compounds and fuel compositions additized therewith.

Surprisingly, the inventive additives, as illustrated more particularly by the appended use examples, are surprisingly effective in common rail diesel engines and are notable for their particular suitability as an additive for reducing power loss resulting from external deposits and cold start problems resulting from internal deposits. These additives furthermore improve the injector cleanliness of gasoline direct injection engines.

Furthermore, these betaines easily form formulations in additive packages or fuels.

Detailed description of the invention:

Subject matter of the present invention are betaine compounds of formula (I)

wherein

R¹ is an organic substituent with 10 to 200 carbon atoms,

R² is a divalent organic group with 2 to 6 carbon atoms, preferably an alkylene group, optionally bearing one or more hydroxy groups,

R³ and R⁴ independently of another are Ci- to C4-alkyl- or hydroxy-Ci- to C4-alkyl groups,

R⁵ is a divalent alkylene group with 1 to 12 carbon atoms or alkenylene group with 2 to 12 carbon atoms,

R⁶ is a Ci- to C4-alkyl-, hydroxy-Ci- to C4-alkyl or C7- to Ci2-aralkyl group.

Another object of the present invention are fuel additive packages and fuels comprising such betaine compounds, a process for preparation of such betaines, and the use of such betaine compounds in as additive in fuels.

In the betaine compounds of formula (I) the substituents R¹ to R⁶ are defined as follows:

R¹ is an organic substituent with 10 to 200 carbon atoms and may optionally contain one or more heteroatoms, i.e. other than carbon or hydrogen, preferably oxygen or nitrogen, more preferably oxygen. The number of heteroatoms is preferably one to five, more preferably one to three. Heteroatoms are preferably present in the form of ether or carboxylic acid ester groups.

In a preferred embodiment R¹ is a hydrocarbon.

R¹ may be linear or branched and may be aliphatic, aromatic, araliphatic, cycloaliphatic, preferably aliphatic or araliphatic, more preferably aliphatic.

An aliphatic residue R¹ may be saturated or unsaturated, and in the latter may contain one or more, preferably one to three, more preferably one or two, and especially exactly one double bond.

Preferably R¹ comprises 11 to 150 carbon atoms, more preferably 12 to 100 carbon atoms.

In one embodiment substituent R¹ is of the formula R11R12CH- wherein

R¹¹ and R¹² independently of another are Cg- to Cioo-alkyl, -alkenyl or -aralkyl, or an organic Cg- to Cioo-residue comprising one or more oxygen and/or nitrogen atoms, and

R¹² additionally may be hydrogen or R¹¹ and R¹² together with the carbon atom of the methin group form a five- to twelve- membered ring.

In another embodiment substituent R¹ is a linear or branched C10- to Cioo-alkyl, -alkenyl or -aralkyl, preferably linear or branched C12- to Cgo-alkyl or -alkenyl, and more preferably linear or branched C13- to Cso-alkyl or -alkenyl. In another embodiment R¹ is an aliphatic hydrocarbon residue with 10 to 30, more preferably 11 to 25, and especially 12 to 20 carbon atoms, which may be saturated or unsaturated.

In another embodiment R¹ is an aliphatic hydrocarbon residue with 35 to 150, more preferably 50 to 100 carbon atoms, which may be saturated or unsaturated, preferably saturated.

In this embodiment R¹ preferably is a polyolefin-homo- or copolymer, preferably a polypropylene, polybutene or polyisobutene residue, with a number-average molecular weight (M_n) of 500 to 2500, 700 to 2300, 800 to 1500 or 900 to 1300. Preferred are polypropenyl, polybutenyl and polyisobutenyl radicals, for example with a number-average molecular weight M_n of 500 to 2500, 700 to 2300, 800 to 1500, 900 to 1300 or 950 to 1050 g/mol.

In another embodiment R¹ is an alkoxylate of formula

R¹³-[-X-]_n-H wherein

R¹³ is a linear or branched Cm- to C2o-alkyl, n is a positive integer from 1 to 25, preferably from 1 to 20, more preferably from 1 to 15, and most preferably from 1 to 10, and

Xi is for every i from 1 to n selected from the group consisting of -O-CH2-CH2-, -0-CH₂-CH(CH₃)-, -0-CH(CH₃)-CH₂-, -0-CH₂-C(CH₃)₂-, -0-C(CH₃)₂-CH₂-, -0-CH₂-CH(C₂H₅)-, -0-CH(C₂H₅)-CH₂- und -0-CH(CH₃)-CH(CH₃)-, preferably selected from the group consisting of -0-CH₂-CH(CH₃)-, -0-CH(CH₃)-CH₂-, -0-CH₂-C(CH₃)₂-, -0-C(CH₃)₂-CH₂-, -0-CH₂-CH(C₂H₅)-, -0-CH(C₂H₅)-CH₂- und -0-CH(CH₃)-CH(CH₃)-, more preferably selected from the group consisting of -0-CH₂-CH(CH₃)-, -0-CH(CH₃)-CH₂-, -0-CH₂-C(CH₃)₂-, -0-C(CH₃)₂-CH₂-, -0-CH2-CH(C2H5)- und -0-CH(C2H5)-CH2-, most preferably selected from the group consisting of -0-CH₂-CH(C₂H₅)-, -0-CH(C₂H₅)-CH₂-, -0-CH₂-CH(CH₃)- und -0-CH(CH₃)-CH₂-, and especially -0-CH₂-CH(CH₃)- or -0-CH(CH₃)-CH₂-.

R² is a divalent organic group with 2 to 6 carbon atoms, preferably an alkylene group, optionally bearing one or more hydroxy groups.

In one embodiment R² may contain one or more heteroatoms, i.e. other than carbon or hydrogen, preferably oxygen or nitrogen, more preferably oxygen. The number of heteroatoms is preferably one or two, more preferably one. Heteroatoms within R² are preferably present in the form of ether groups.

In a preferred embodiment R² is an alkylene group, optionally bearing one or more hydroxy groups. More preferably R² is selected from the group consisting of 1,2-ethylene, 1,2-propylene, 1,3- propylene and 2-hydroxy-1,3-propylene, and most preferably 1,3-propylene. R³ and R⁴ independently of another are C1- to C4-alkyl- or hydroxy-C1- to C4-alkyl groups or together with the nitrogen atom form a five- to seven-membered ring. C1 to C4-alkyl is in the context of the present document, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl or tert butyl, preferably methyl, ethyl or n-butyl, more preferably methyl or ethyl, and even more preferably methyl. Hydroxy-C1 to C4-alkyl is in the context of the present document, hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl or 2-hydroxybutyl, preferably 2-hydroxyethyl or 2- hydroxypropyl.2-hydroxypropyl comprises both isomers 2-hydroxyprop-1-yl as well as 2- hydroxy-1-methyleth-1-yl, preferably 2-hydroxyprop-1-yl. In case R³ and R⁴ together with the nitrogen atom form a five- to seven-membered ring R³ and R⁴ together form a 1,5-pentylene-, 1,5-3-oxa-pentylene-, 1,5-3-aza-pentylene-, or 1,4-butylene- chain. In a preferred embodiment both residues R³ and R⁴ are C₁- to C₄-alkyl-, preferably both are methyl. In another preferred embodiment both residues R³ and R⁴ are hydroxy-C₁- to C₄-alkyl-, preferably both are 2-hydroxyethyl. In another preferred embodiment R³ is C1- to C4-alkyl- and R⁴ is hydroxy-C1- to C4-alkyl-, preferably R³ is methyl and R⁴ is 2-hydroxyethyl. R⁵ is a divalent alkylene group with 1 to 12 carbon atoms or alkenylene group with 2 to 12 carbon atoms or arylene group with 6 to 10 carbon atoms. Examples for alkylene groups are methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,6- hexylene, and 1,8-octylene. Examples for alkenylene groups are 1,2-vinylidene, 1,3-propenyle, or 1,4-butenylene. Examples for arylene groups are 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, and 1,2- naphthylene. In a preferred embodiment R⁵ is 1,2-ethylene, 1,3-propylene, 1,2-vinylidene or 1,2-phenylene, more preferably 1,2-ethylene. R⁶ is a C1- to C4-alkyl-, hydroxy-C1- to C4-alkyl or C7- to C12-aralkyl group. In a preferred embodiment R⁶ is selected from the group consisting of methyl, ethyl, n-butyl, 2- hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl, and benzyl, more preferably selected from the group consisting of methyl and 2-hydroxypropyl, especially 2-hydroxypropyl.

Preparation

Another aspect of the present invention is a process for preparing betaine compounds (I) according to the present invention by in a first step reacting and amine of formula (II)

with an anhydride of formula (III)

and subsequently reacting the reaction product with a quaternising agent, preferably selected from the group consisting of alkylene oxides, alkyl halides, benzyl halides, dialkyl carbonates, dialkyl sulfates, and alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid.

The amines according to formula (II) are preferably obtainable by reaction of an amine (IV)

H₂N-R²-NR³R⁴ with an alcohol (V)

R¹-OH or the corresponding aldehyde, ketone or carboxylic acid by amination respectively reductive amination.

In these formulae the residues R¹ to R⁵ are defined as above, the same preferences apply. Examples for amines of formula (IV) are those comprising one primary amino group and one tertiary amino group. It is also possible, however, less preferred that the amine possesses a secondary amino group with a bulky substituent instead of a tertiary amino group.

Preferred amines of formula (V) are 1-aminopiperidine, 1-(2-aminoethyl)piperidine, 1-(3- aminopropyl)-2-pipecoline, 1-methyl-( 4-methylamino)piperidine, 4-(1-pyrrolidinyl)piperidine, 1- (2-aminoethyl)pyrrolidine, 2-(2-aminoethyl)-1-methylpyrrolidine, N-(3-Aminopropyl)imidazole, N,N-diethylethylenediamine (H₂NCH2CH2N(C₂H5)2), CAS-No. 100-36-7), N ,N- dimethylethylenediamine, N ,N-di-n-butylethylenediamine, N,N-dimethyl-1,3-diaminopropane (3- dimethylaminopropylamine, H₂NCH2CH₂CH2N(CH3)2, DMAPA, CAS-No. 109-55-7), N,N-diethyl- 1,3-diaminopropane (3-diethylaminopropylamine, H₂NCH2CH2CH2N(C₂H5)2, CAS-No. 104-78-9), 3-di-n-butylaminopropylamine, N,N,2,2-tetramethyl-1 ,3-propanediamine, N,N-dimethyl-3-oxa- 1 ,5-diaminopentane, N,N-dimethyl-1 ,2-diaminopropane, 2-amino-5-diethylaminopentane, N,N,N',N'-tetraethyldiethylenetriamine, 3,3'-diamino-N-methyldipropylamine, 3,3'-iminobis(N,N- dimethylpropylamine), or combinations thereof.

Very preferred amines of formula (V) are N-(3-aminopropyl)imidazole, N,N- diethylethylenediamine, N,N-dimethylethylenediamine, N ,N-di-n-butylethylenediamine, N,N- dimethyl-1 ,3-diaminopropane, N,N-diethyl-1 ,3-diaminopropane, 3-di-n-butylaminopropylamine, N,N-dimethyl-1 ,2-diaminopropane, and 3,3'-iminobis(N,N-dimethylpropylamine), especially N-(3- aminopropyl)imidazole, N,N-dimethylethylenediamine, N,N-dimethyl-1,3-diaminopropane, and N,N-diethyl-1 ,3-diaminopropane with N,N-dimethyl-1,3-diaminopropane being particularly pre ferred.

Examples for alcohols of formula (V) R¹-OH are fatty alcohols, preferably decyl alcohol (capric alcohol), undecyl alcohol, dodecyl alcohol (lauryl alcohol), tridecyl alcohol, tetradecyl alcohol (myristyl alcohol), pentadecyl alcohol, hexadecyl alcohol (cetyl alcohol, palmityl alcohol), hepta- decyl alcohol, octadecyl alcohol (stearyl alcohol), oleyl alcohol, elaidyl alcohol, linoleyl alcohol, linolenyl alcohol, nonadecyl alcohol, eicosyl alcohol (arachyl alcohol) or mixtures thereof or the corresponding aldehydes.

Further examples are branched synthetic alcohols, such as 2-propylheptanol and mixtures of isomers of C13 or C17 alkanols:

Mixtures of alcohols having 13 carbon atoms are preferably obtainable by hydroformylation from a C12 olefin mixture which is in turn obtainable by oligomerization of an olefin mixture comprising predominantly hydrocarbons having four carbon atoms.

On statistical average, this olefin mixture has 11 to 13 carbon atoms, preferably 11.1 to 12.9, more preferably 11.2 to 12.8, even more preferably 11.5 to 12.5 and especially 11.8 to 12.2.

In one embodiment, such an alcohol R¹-OH has an average degree of branching, measured as the ISO index, of 2.8 to 3.7. More particularly, such an alcohol R¹-OH is obtained by a process as described in WO 00/02978 or WO 00/50543.

In a further embodiment, the R¹-OH is a mixture of alcohols having 17 carbon atoms, obtainable by hydroformylation from a Ci₆ olefin mixture which is in turn obtainable by oligomerization of an olefin mixture comprising predominantly hydrocarbons having four carbon atoms.

On statistical average, this olefin mixture has 15 to 17 carbon atoms, preferably 15.1 to 16.9, more preferably 15.2 to 16.8, even more preferably 15.5 to 16.5 and especially 15.8 to 16.2.

In one embodiment, such an alcohol R¹-OH has an average degree of branching, measured as the ISO index, of 2.8 to 3.7.

More particularly, such an alcohol R¹-OH is obtained by a process as described in WO 2009/124979 A1 , particularly page 5 line 4 to page 16 line 29 therein, and the examples at page 19 line 19 to page 21 line 25, which is hereby incorporated into the present disclosure by refer ence.

Further examples are Guerbet alcohols with C8 to C36 aliphatic groups, for example Guerbet alcohols with C12, C14, C16 (CAS-No. 2425-77-6, Eutanol G 16, BASF), C18, C20 (CAS-No. 5333-42-6, Eutanol G, BASF), C22, C24, C26, C28, C30 or C32 or mixtures thereof.

In a further embodiment the alcohol R¹-OFI is if the formula R¹¹R¹²CFI-OFI, respectively the cor responding aldehyde or ketone is of formula R¹¹-(C=0)-R¹², wherein the residues R¹¹ and R¹² are defined as above, the same preferences apply.

Examples of such compounds are derivatives of aliphatic, aromatic or araliphatic aldehydes, preferably aromatic or araliphatic aldehydes. Preferred examples are derivatives of benzalde- hyde bearing one or more, preferably one or two, more preferably one substituent, such as Ci- to C2o-alkyl groups or Ci- to C2o-alkyloxy groups, at the aromatic ring or derivatives of cinnamic aldehyde bearing one or more, preferably one or two, more preferably one substituent, such as Ci- to C2o-alkyl groups or Ci- to C2o-alkyloxy groups, at the aromatic ring or at the double bond. Preferred is a - Ci- to C2o-alkyl cinnamic aldehyde, more preferably a- Ci- to Cio-alkyl cinnamic aldehyde, even more preferably a- Ci- to C₆-alkyl cinnamic aldehyde, especially a-methyl cin namic aldehyde, a-amyl cinnamic aldehyde, or a-hexyl cinnamic aldehyde.

In another embodiment in which R¹ is an aliphatic hydrocarbon residue with 35 to 150, more preferably 50 to 100 carbon atoms, which may be saturated or unsaturated, preferably saturat ed the alcohol R¹-OFI or the corresponding aldehyde is obtainable by homo- or copolymerisation of olefins, preferably propene, 1 -butene, and/or isobutene to the corresponding polyolefins, preferably with a number-average molecular weight (M_n) of 500 to 2500, 700 to 2300, 800 to 1500 or 900 to 1300, followed by hydroformylation as described. The reaction mixture usually is a mixture of alcohols and aldehydes and can be used for the following reaction with the amine of formula (IV).

Reaction conditions for the amination respectively reductive amination of alcohols of formula (V) or the corresponding aldehydes or ketones with amines of formula (IV) to obtain amines of for mula (II) are known per se, for example described in EP-A 244616.

It is also possible to obtain amines according to formula (II) from the corresponding carboxylic acids of alcohol (V): First the corresponding amides with the amines (IV) are obtained and such amines afterwards reduced, preferably by using metal hydrides, such as lithium hydride, lithium aluminium hydride, or di isobutyl aluminium hydride.

The amines of formula (II) are further reacted with anhydrides of formula (III)

with R⁵ defined as above.

Preferred examples for anhydrides of formula (III) are maleic acid anhydride, succinic acid an hydride, and glutaric acid anhydride, preferably maleic acid anhydride and succinic acid anhy dride, more preferably succinic acid anhydride.

The anhydride compound of formula (III) is reacted with the amines of formula (II) preferably under thermally controlled conditions, such that there is essentially no condensation reaction. More particularly no formation of water of reaction is observed. More particularly, the reaction is effected at a temperature in the range from 10 to 80°C, especially 20 to 60°C or 30 to 50°C. The reaction time may be in the range from a few minutes or a few hours, for example about 1 mi nute 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. In particular, an inert gas atmosphere, for exam ple nitrogen, is appropriate.

The reactants are initially charged especially in about equimolar amounts; optionally, a small molar excess of the anhydride, for example a 0.05- to 0.5-fold, for example a 0.1- to 0.3-fold, excess, is desirable. If required, the reactants can be initially 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. However, in another particular embodiment, the reaction is effected in the absence of organic solvents, especially protic solvents. In the case of performance of the reaction, the anhydride ring is opened with addition of the amine of formula (II) via the secondary amino group thereof, and without the elimination of wa ter of condensation. The reaction product obtained comprises a polycarboxylic intermediate with at least one newly formed acid amide group and at least one intramolecular, bound, newly formed carboxylic acid or carboxylate group, in a stoichiometric proportion relative to the sec ondary amino group bound intramolecularly by the addition reaction.

The reaction product thus formed can theoretically be purified further, or the solvent can be re moved. Usually, however, this is not absolutely necessary, such that the reaction step can be transferred without further purification into the next synthesis step, the quaternization.

The quaternizing agent is preferably selected from the group consisting of alkylene oxides, alkyl halides, benzyl halides, dialkyl carbonates, dialkyl sulfates, and alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, more preferably alkylene oxides, dialkyl car bonates, and alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, even more preferably alkylene oxides and alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, and especially alkylene oxides.

Alkylene oxides

Suitable alkylene oxides are, for example, aliphatic and aromatic substituted alkylene oxides, such as especially C2-i2-alkylene oxides, such as ethylene oxide, propylene oxide, 1 ,2-butylene oxide, 2,3-butylene oxide, 2-methyl-1,2-propene oxide (isobutene oxide), 1 ,2-pentene oxide,

2.3-pentene oxide, 2-methyl-1 ,2-butene oxide, 3-methyl-1 ,2-butene oxide, 1,2-hexene oxide,

2.3-hexene oxide, 3,4-hexene oxide, 2-methyl-1 ,2-pentene oxide, 2-ethyl- 1,2-butene oxide, 3- methyl-1,2-pentene oxide, 1,2-decene oxide, 1 ,2-dodecene oxide or 4-methyl-1 ,2-pentene ox ide; and also aromatic-substituted ethylene oxides, such as optionally substituted styrene oxide, especially styrene oxide or 4-methylstyrene oxide.

Preferred alkylene oxides are propylene oxide, 1,2-butylene oxide, and styrene oxide, more preferred are propylene oxide and styrene oxide, with propylene oxide being especially pre ferred.,

Epoxides as quaternizing agents are used especially in the absence of free acids, especially in the absence of free protic acids, such as in particular with Ci-12-monocarboxylic acids such as formic acid, acetic acid or propionic acid, or C2-i2-dicarboxylic acids such as oxalic acid or adipic acid; or else in the absence of sulfonic acids such as benzenesulfonic acid or toluenesulfonic acid, or aqueous mineral acids such as sulfuric acid or hydrochloric acid. The quaternization product thus prepared is thus "acid-free" in the context of the present invention.

It is an advantage of the present invention that the free carboxylic acid group formed in the re action of the acid anhydride of formula (III) with the amine of formula (II) is usually sufficient acidic to enable the reaction of the epoxide with the tertiary amine group. It is possible, however, less preferred to add further protic acid during the quaternization reac tion of the epoxide.

Alkyl halides

Alkyl halides are preferably Ci- to C4-alkyl halides, such as fluorides, chlorides, bromides or iodides, preferably chlorides or bromides, more preferably chlorides.

Preferred examples are methyl chloride, methyl chloride, methyl iodide, and ethyl chloride.

Benzyl halides

Examples of benzyl halides are benzyl chloride and benzyl bromide.

Dialkyl carbonates

Dialkyl carbonates are preferably di Ci- to C4-alkyl carbonates, more preferably dimethyl car bonate or diethyl carbonate, even more preferably dimethyl carbonate.

Also possible, however, less preferred, are ethylene carbonate, 1 ,2-propylene carbonate or 1 ,3- propylene carbonate.

Dialkyl sulfates

Dialkyl sulfates are preferably di Ci- to C4-alkyl sulfates, more preferably dimethyl sulfates or diethyl sulfates, even more preferably dimethyl sulfates.

Alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid

In one embodiment the at least one quaternizing agent is selected from a) compounds of the general formula 1

R⁶0C(0)R⁶¹ (1) in which

R⁶ is a Ci- to C4-alkyl radical, preferably methyl or ethyl, and more preferably methyl, and R⁶¹ is an optionally substituted monocyclic aryl or cycloalkyl radical, where the substituent is selected from OH, NH2, NO2, C(0)OR^6a, wherein R^6a is as defined for R⁶ and may be identical or different from R⁶, and b) compounds of the general formula 2

R⁶0C(0)-R⁶²-C(0)0R^6a (2) in which

R⁶and R^6a are each independently a Ci- to C4-alkyl radical, preferably methyl or ethyl, and more preferably methyl, and

R⁶² is a single bond or Ci- to C₆-hydrocarbylene (such as alkylene or alkenylene, phenylene).

Particularly suitable compounds of the formula 1 are those in which R⁶ is a Ci-, C2- or C3-alkyl radical and

R⁶¹ is a substituted phenyl radical, where the substituent is HO- or an ester radical of the for mula R^6a0C(0)- which is in the para, meta or especially ortho position to the R⁶0C(0)- radical on the aromatic ring.

Especially suitable quaternizing agents are the lower alkyl esters of salicylic acid, such as me thyl salicylate, ethyl salicylate, n- and i-propyl salicylate, and n-, i- or tert-butyl salicylate. Very preferred are methyl salicylate and methyl 2-nitrobenzoate and methyl aminobenzoate.

Furthermore, phthalic acid dimethyl ester, maleic acid dimethyl ester, malonic acid dimethyl es ter, oxalic acid dimethyl ester, and oxalic acid diethyl ester are preferred, with oxalic acid dime thyl ester being especially preferred.

The quaternization is performed in a manner known per se.

To perform the quaternization with alkyl halides, benzyl halides, dialkyl carbonates, dialkyl sul fates or alkyl esters of a cycloaromatic or cycloaliphatic mono- or polycarboxylic acid, the ter tiary amine is admixed with at least one these compounds, especially in the stoichiometric amounts required to achieve the desired quaternization. It is possible to use, for example, 0.1 to 5.0, 0.2 to 3.0 or 0.5 to 2.5 equivalents of quaternizing agent per equivalent of quaternizable tertiary nitrogen atom. More particularly, however, about 1 to 2 equivalents of quaternizing agent are used in relation to the tertiary amine, in order to fully quaternize the tertiary amine group.

Typical working temperatures here are in the range from 50 to 180 °C, for example 90 to 160 °C or 100 to 140 °C. The reaction time may be in the region 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 1 ,5 to 3 bar, but especially at about standard pres sure.

If required, the reactants can be initially charged for the quaternization 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, or ethylhexanol. The quaternization can, however, also be performed in the absence of a solvent.

To perform the quaternization, the addition of catalytically active amounts of an acid may be appropriate, however is less preferred. Preference is given to aliphatic monocarboxylic acids, for example Ci-Ci₈-monocarboxylic acids such as, more particularly, lauric acid, isononanoic acid or 3,3,5-trimethylhexanoic acid or neodecanoic acid, but also aliphatic dicarboxylic acids or polybasic aliphatic carboxylic acids with a carbon atom number in the range specified above.

The quaternization can also be performed in the presence of a Lewis acid. The quaternization can, preferably, also be performed in the absence of any acid.

In case of epoxides as quaternizing agent the quaternization is carried out without addition of acid. The carboxyl radical formed by amine addition promotes the epoxide ring opening and hence the quaternization of the amino group. The reaction product obtained therefore does not have a free acid anion. Nevertheless, the product is uncharged owing to its betaine structure.

To perform the quaternization, the reaction product or reaction mixture from from the reaction with the anhydride is admixed with at least one epoxide compound mentioned above, especially in the stoichiometric amounts required to achieve the desired quaternization. It is possible to use, for example, 0.1 to 1.5 equivalents, or 0.5 to 1.25 equivalents, of quaternizing agent per equivalent of quaternizable tertiary nitrogen atom. More particularly, however, approximately equimolar proportions of the epoxide are used to quaternize a tertiary amine group. Corre spondingly higher use amounts are required to quaternize a secondary or primary amine group.

Typical working temperatures here are in the range from 15 to 90°C, especially from 20 to 80°C or 30 to 70°C. The reaction time may be in the range of a few minutes or a few hours, for exam ple 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 1.5 to 3 bar, but especially at about standard pressure. More particularly, an inert gas atmosphere, for example nitrogen, is appropriate.

If required, the reactants can be initially charged for the epoxidation in a suitable inert organic aliphatic or aromatic solvent or a mixture thereof, or a sufficient proportion of solvent from previ ous reaction step is still present. Typical examples are, for example, solvents of the Solvesso series, toluene or xylene. In a further particular embodiment, the reaction, however, is per formed in the absence of organic solvents, especially protic (organic) solvents.

"Protic solvents", which are especially not used in accordance with the invention, are especially those with a dielectric constant of greater than 9. Such protic solvents usually comprise at least one HO group and may additionally contain water. Typical examples are, for example, glycols and glycol ethers, and alcohols such as aliphatic, cyclic-aliphatic, aromatic or heterocyclic alco hols. c) Workup of the reaction mixture The reaction end product thus formed can theoretically be purified further, or the solvent can be removed. Usually, however, this is not absolutely necessary, and so the reaction product is us able without further purification as an additive, optionally after blending with further additive components (see below), especially since there are of course also no corrosive free protic acids present in the reaction product.

Another object of the present invention is the use of the betaines according to formula (I) in ad ditive packages for fuels.

In one embodiment the betaines according to formula (I) can be used as constituents in additive packages for Diesel fuels.

Accordingly, subject matter of the present invention are additive packages for Diesel fuels, comprising at least one betaine according to formula (I) and further comprising at least one Die sel additive.

In another embodiment the betaines according to formula (I) can be used as constituents in ad ditive packages for gasoline fuels.

Accordingly, subject matter of the present invention are additive packages for gasoline fuels, comprising at least one betaine according to formula (I) and further comprising at least one gasoline additive.

Typical additives are described in the following:

Diesel additives

Another aspect of the present invention are additive packages for Diesel fuels, comprising at least one betaine according to formula (I) and further comprising at least one Diesel additive, selected from the group consisting of

- deposit control additives, selected from the group consisting of -- quaternary nitrogen compounds and

-- polyisobutenylsuccinimides,

- dehazers, and

- cetane number improvers.

Other additives, such as solvents, defoamers, colorants, and fuel markers, may be present. The above-mentioned additives are described in more detail as follows:

Quaternary nitrogen compounds The at least one quaternary nitrogen component refer, in the context of the present invention, to nitrogen compounds quaternized in the presence of an acid or in an acid-free manner, prefera bly obtainable by addition of a compound comprising at least one oxygen- or nitrogen- containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization.

For the sake of clarity such quaternary nitrogen components are others than the betaines ac cording to formula (I).

In most cases the quaternary nitrogen component is an ammonium compound, however in the context of the present document morpholinium, piperidinium, piperazinium, pyrrolidinium, imid- azolinium or pyridinium cations are also encompassed by the phrase "quaternary nitrogen com ponent".

The quaternary ammonium compounds are preferably of the formula ⁺NR¹⁴R¹⁵R¹⁶R¹⁷ A- in which

A stands for an anion, preferably a carboxylate R¹⁸COO or a carbonate R¹⁸0-COO , and

R¹⁴, R¹⁵, R¹⁶, R¹⁷, and R¹⁸ independently of another are an organic residue with from 1 to 100 carbon atoms, substituted or unsubstituted, preferably unsubstituted, linear or branched alkyl, alkenyl or hydroxyalkyl residue with 1 to 100, more preferably 1 to 75, even more preferably 1 to 30, most preferably 1 to 25 and especially 1 to 20 carbon atoms,

R¹⁸ additionally may be substituted or unsubstituted cycloalkyl or aryl residues bearing 5 to 20, preferably 5 to 12 carbon atoms.

It is also possible that the anion may be multiply charged negatively, e.g. if anions of dibasic acids are used, in this case the stoichiometric ratio of the ammonium ions to the anions corre sponds to the ratio of positive and negative charges.

The same is true for salts in which the cation bears more than one ammonium ion, e.g. of the substituents connect two or more ammonium ions.

In the organic residues the carbon atoms may be interrupted by one or more oxygen and/or sulphur atoms and/or one or more substituted or unsubstituted imino groups, and may be sub stituted by C6-Ci2-aryl, C5-Ci2-cycloalkyl or a five- or six-membered, oxygen-, nitrogen- and/or sulphur-containing heterocycle or two of them together form an unsaturated, saturated or aro- matic ring which may be interrupted by one or more oxygen and/or sulphur atoms and/or one or more substituted or unsubstituted imino groups, where the radicals mentioned may each be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or het erocycles.

Two of the residues R¹⁴ to R¹⁷ may together form an unsaturated, saturated or aromatic ring, preferably a five-, six- or seven-membered ring (including the nitrogen atom of the ammonium ion).

In this case the ammonium cation may be a morpholinium, piperidinium, piperazinium, pyrroli- dinium, imidazolinium or pyridinium cation.

In these definitions

Ci-C2o-alkyl which may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halo gen, heteroatoms and/or heterocycles is, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, decyl, do- decyl, tetradecyl, heptadecyl, octadecyl, eicosyl, 1,1-dimethylpropyl, 1 , 1 -dimethylbutyl, 1, 1,3,3- tetramethylbutyl, benzyl, 1-phenylethyl, 2-phenylethyl, a,a-dimethylbenzyl, benzhydryl, p- tolylmethyl,1-(p-butylphenyl)ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p-methoxybenzyl, m- ethoxybenzyl, 2-cyanoethyl, 2-cyanopropyl, 2-methoxycarbonylethyl, 2-ethoxycarbonylethyl, 2- butoxycarbonylpropyl, 1 ,2-di-(methoxycarbonyl)ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2- butoxyethyl, diethoxymethyl, diethoxyethyl, 1,3-dioxolan-2-yl, 1,3-dioxan-2-yl, 2-methyl-1,3- dioxolan-2-yl, 4-methyl-1,3-dioxolan-2-yl, 2-isopropoxyethyl, 2-butoxypropyl, 2-octyloxyethyl, chloromethyl, 2-chloroethyl, trichloromethyl, trifluoromethyl, 1 ,1-dimethyl-2-chloroethyl, 2- methoxyisopropyl, 2-ethoxyethyl, butylthiomethyl, 2-dodecylthioethyl, 2-phenylthioethyl, 2,2,2-trifluoroethyl, 2-hydroxyethyl, 2- hydroxy propyl, 3-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl, 2-aminoethyl, 2-aminopropyl, 3-aminopropyl, 4-aminobutyl, 6-aminohexyl, 2- methylaminoethyl, 2-methylaminopropyl, 3-methylaminopropyl, 4-methylaminobutyl, 6- methylaminohexyl, 2-dimethylaminoethyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 4- dimethylaminobutyl, 6-dimethylaminohexyl, 2-hydroxy-2,2-dimethylethyl, 2-phenoxyethyl, 2- phenoxypropyl, 3-phenoxypropyl, 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2- methoxypropyl, 3-methoxypropyl, 4-methoxybutyl, 6- m ethoxy hexyl, 2-ethoxyethyl, 2- ethoxypropyl, 3-ethoxypropyl, 4-ethoxybutyl or 6-ethoxy hexyl, and

C2-C2o-alkyl interrupted by one or more oxygen and/or sulphur atoms and/or one or more sub stituted or unsubstituted imino groups is, for example, 5-hydroxy- 3-oxa-pentyl, 8-hydroxy-3,6- dioxaoctyl, 11 -hydroxy-3, 6, 9-trioxaundecyl, 7-hydroxy-4-oxaheptyl, 11 -hydroxy-4, 8- dioxaundecyl, 15-hydroxy-4,8,12-trioxapentadecyl, 9-hydroxy- 5-oxanonyl, 14-hydroxy-5,10- oxatetradecyl, 5-methoxy-3-oxapentyl, 8-methoxy-3,6-dioxaoctyl, 11-methoxy-3,6,9- trioxaundecyl, 7-methoxy-4-oxaheptyl, 11-methoxy-4,8-dioxa-undecyl, 15-methoxy-4,8,12- trioxapentadecyl, 9-methoxy- 5-oxanonyl, 14-methoxy-5,10-oxatetradecyl, 5-ethoxy- 3-oxapentyl, 8-ethoxy-3,6-dioxaoctyl, 11 -ethoxy-3, 6, 9-trioxaundecyl, 7-ethoxy-4-oxaheptyl, 11 -ethoxy-4,8- dioxaundecyl, 15-ethoxy-4,8,12-trioxapentadecyl, 9-ethoxy- 5-oxanonyl or 14-ethoxy-5,10- oxatetradecyl.

If two radicals form a ring, they can together be 1,3-propylene, 1,4-butylene, 1 ,5-pentylene, 2- oxa-1 ,3-propylene, 1-oxa-1, 3-propylene, 2-oxa-1, 3-propylene, 1-oxa-1,3-propenylene, 1-aza-

1.3-propenylene, 1-Ci-C₄-alkyl-1-aza-1,3-propenylene, 1,4-buta-1,3-dienylene, 1-aza-1,4-buta-

1.3-dienylene or 2-aza-1 ,4-buta-1 ,3-dienylene.

The number of oxygen and/or sulphur atoms and/or imino groups is not subject to any re strictions. In general, there will be no more than 5 in the radical, preferably no more than 4 and very particularly preferably no more than 3.

Furthermore, there is generally at least one carbon atom, preferably at least two carbon atoms, between any two heteroatoms.

Substituted and unsubstituted imino groups can be, for example, imino, methylimino, isopropy- limino, n-butylimino ortert-butylimino.

Furthermore, functional groups can be carboxy, carboxamide, hydroxy, di(Ci-C4-alkyl)amino, C1-C4- alkyloxycarbonyl, cyano or Ci-C4-alkyloxy,

C6-Ci2-aryl which may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halo gen, heteroatoms and/or heterocycles is, for example, phenyl, tolyl, xylyl, a-naphthyl, b- naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, diethylphenyl, isopropylphenyl, tert- butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, hexyloxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl, ethoxynaphthyl, 2,6-dimethylphenyl, 2,4,6- trimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, 4-bromophenyl, 2- or 4-nitrophenyl,

2.4- or 2,6-dinitrophenyl, 4-dimethylaminophenyl, 4-acetylphenyl, methoxyethylphenyl or ethox- ymethylphenyl,

C5-Ci2-cycloalkyl which may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or heterocycles is, for example, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, diethylcyclohexyl, butylcyclohexyl, methoxycyclohexyl, dimethoxycyclohexyl, diethoxycyclohex- yl, butylthiocyclohexyl, chlorocyclohexyl, dichlorocyclohexyl, dichlorocyclopentyl or a saturated or unsaturated bicyclic system such as norbornyl or norbornenyl, a five- or six-membered, oxygen-, nitrogen- and/or sulphur-containing heterocycle is, for exam ple, furyl, thienyl, pyrryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxyl, benzimidazolyl, benzothi- azolyl, dimethylpyridyl, methylquinolyl, dim ethyl pyrryl, methoxyfuryl, dimethoxypyridyl, difluoro- pyridyl, methylthienyl, isopropylthienyl or tert-butylthienyl and

Ci to C4-alkyl is, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl or tert-butyl.

The residues R¹⁴ to R¹⁸ are preferably C2-Cis-alkyl or C6-Ci2-aryl, more preferably C4-Ci6-alkyl or C6-Ci2-aryl, and even more preferably C4-Ci6-alkyl or C₆-aryl.

The residues R¹⁴ to R¹⁸ may be saturated or unsaturated, preferably saturated.

Preferred residues R¹⁴ to R¹⁸ do not bear any heteroatoms other than carbon of hydrogen.

Preferred examples of R¹⁴ to R¹⁷ are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert- butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, 2-propylheptyl, decyl, do- decyl, tetradecyl, heptadecyl, octadecyl, eicosyl, 1 ,1-dimethylpropyl, 1 , 1 -dimethylbutyl, 1 , 1 ,3,3- tetramethylbutyl, benzyl, 1-phenylethyl, 2-phenylethyl, a,a-dimethylbenzyl, benzhydryl, p- tolylmethyl or 1-(p-butylphenyl)ethyl.

In a preferred embodiment at least one of the residues R¹⁴ to R¹⁷ is selected from the group consisting of 2-hydroxyethyl, hydroxyprop-1-yl, hydroxyprop-2-yl, 2- hydroxy butyl or 2-hydroxy-2- phenylethyl.

In one embodiment R¹⁸ is a polyolefin-homo- or copolymer, preferably a polypropylene, poly butene or polyisobutene residue, with a number-average molecular weight (M_n) of 85 to 20000, for example 113 to 10 000, or 200 to 10000 or 350 to 5000, for example 350 to 3000, 500 to 2500, 700 to 2500, or 800 to 1500. Preferred are polypropenyl, polybutenyl and polyisobutenyl radicals, for example with a number-average molecular weight M_n of 3500 to 5000, 350 to 3000, 500 to 2500, 700 to 2500 and 800 to 1500 g/mol.

Preferred examples of anions A are the anions of acetic acid, propionic acid, butyric acid, 2- ethylhexanoic acid, trimethylhexanoic acid, 2-propylheptanoic acid, isononanoic acid, versatic acids, decanoic acid, undecanoic acid, dodecanoic acid, saturated or unsaturated fatty acids with 12 to 24 carbon atoms, or mixtures thereof, salicylic acid, oxalic acid mono-Ci-C4-alkyl es ter, phthalic acid mono-Ci-C4-alkyl ester, Ci2-Cioo-alkyl- and -alkenyl succinic acid, especially dodecenyl succinic acid, hexadecenyl succinic acid, eicosenyl succinic acid, and polyisobutenyl succinic acid. Further examples are methyl carbonate, ethyl carbonate, n-butyl carbonate, 2- hydroxyethyl carbonate, and 2-hydroxypropyl carbonate.

In one preferred embodiment the nitrogen compounds quaternized in the presence of an acid or in an acid-free manner are obtainable by addition of a compound which comprises at least one oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quater- nization, especially with an epoxide, e.g. styrene or propylene oxide, in the absence of free acid, as described in WO 2012/004300, or with a carboxylic ester, e.g. dimethyl oxalate or methyl salicylate. Suitable compounds having at least one oxygen- or nitrogen-containing group reac tive with anhydride and additionally at least one quaternizable amino group are especially poly amines having at least one primary or secondary amino group and at least one tertiary amino group, especially N,N-dimethyl-1 ,3-propane diamine, N,N-dimethyl-1 ,2-ethane diamine or N,N,

N '-tri m ethyl- 1 , 2-ethane diamine. Useful polycarboxylic anhydrides are especially dicarboxylic acids such as succinic acid, having a relatively long-chain hydrocarbyl substituent, preferably having a number-average molecular weight M_n for the hydrocarbyl substituent of 200 to 10.000, in particular of 350 to 5000. Such a quaternized nitrogen compound is, for example, the reaction product, obtained at 40°C, of polyisobutenylsuccinic anhydride, in which the polyisobutenyl radi cal typically has an M_n of 1000, with 3-(dimethylamino)propylamine, which constitutes a polyiso butenylsuccinic monoamide and which is subsequently quaternized with dimethyl oxalate or methyl salicylate or with styrene oxide or propylene oxide in the absence of free acid.

Further quaternized nitrogen compounds suitable as compounds are described in WO 2006/135881 A1 , page 5, line 13 to page 12, line 14;

WO 10/132259 A1 , page 3, line 28 to page 10, line 25;

WO 2008/060888 A2, page 6, line 15 to page 14, line 29;

WO 2011/095819 A1 , page 4, line 5 to page 9, line 29;

GB 2496514 A, paragraph [00012] to paragraph [00041];

WO 2013/117616 A1 , page 3, line 34 to page 11 , line 2;

WO 14/202425 A2, page 3, line 14 to page 5, line 9;

WO 14/195464 A1 , page 15, line 31 to page 45, line 26 and page 75, lines 1 to 4;

WO 15/040147 A1 , page 4, line 34 to page 5, line 18 and page 19, line 11 to page 50, line 10;

WO 14/064151 A1 , page 5, line 14 to page 6, line 17 and page 16, line 10 to page 18, line 12;

WO 2013/064689 A1 , page 18, line 16 to page 29, line 8; and WO 2013/087701 A1 , page 13, line 25 to page 19, line 30,

WO 13/000997 A1 , page 17, line 4 to page 25, line 3,

WO 12/004300, page 5, lines 20 to 30, page 8, line 1 to page 10, line 10, and page 19, line 29 to page 28, line 3, each of which is incorporated herein by reference.

In one embodiment the quaternized ammonium compound is of formula

wherein in this formula PIB stands for a polyisobutenyl residue having a number average molecular weight M_n of from 550 to 2300, preferably from 650 to 1500 and more preferably from 750 to 1300 g/mol,

R stands for an Ci- to C4-alkyl or hydroxy-Ci- to C4-alkyl, preferably methyl or 2-hydroxypropyl, and

A stands for an anion, preferably carboxylate R¹⁸COO or a carbonate R¹⁸0-COO as defined above, more preferably acetate, salicylate or methyl oxalate.

In another preferred embodiment the quaternized ammonium compound is of formula

wherein in this formula

PIB stands for a polyisobutenyl residue having a number average molecular weight M_n of from 550 to 2300, preferably from 650 to 1500 and more preferably from 750 to 1300 g/mol,

R stands for a hydroxy-Ci- to C4-alkyl, preferably 2-hydroxypropyl.

In another embodiment the quaternized compound is of formula

wherein in this formula

R stands for an Ci- to C4-alkyl or hydroxy-Ci- to C4-alkyl, preferably methyl, and

A stands for an anion, preferably carboxylate R¹⁸COO or a carbonate R¹⁸0-COO as defined above, more preferably salicylate or methyloxalate.

In another embodiment the quaternized ammonium compound is of formula

wherein in this formula R^a stands for C₁–C₂₀-alkyl, preferably C₉- to C₁₇-alkyl, more preferably for undecyl, tridecyl, pen- tadecyl or heptadecyl, R^b stands for a hydroxy-C1- to C4-alkyl, preferably 2-hydroxypropyl or 2-hydroxybutyl, and A- stands for an anion, preferably carboxylate R¹⁸COO-, as defined above, more preferably R¹⁸COO- being a carboxylate of a fatty acid, especially A- being acetate, 2-ethylhexanoate, ole- ate or polyisobutenyl succinate. In one embodiment the quaternized ammonium compound is of formula

wherein in this formula X_i for i = 1 to n and 1 to m are independently of another selected from the group consisting of - CH2-CH2-O-, -CH2-CH(CH3)-O-, -CH(CH3)-CH2-O-, -CH2-C(CH3)2-O-, -C(CH3)2-CH2-O-, -CH2- CH(C2H5)-O-, -CH(C2H5)-CH2-O- and -CH(CH3)-CH(CH3)-O-, preferably selected from the group consisting of -CH₂-CH(CH₃)-O-, -CH(CH₃)-CH₂-O-, -CH₂-C(CH₃)₂-O-, -C(CH₃)₂-CH₂-O-, -CH₂- CH(C₂H₅)-O-, -CH(C₂H₅)-CH₂-O- and -CH(CH₃)-CH(CH₃)-O-, more preferably selected from the group consisting of -CH2-CH(CH3)-O-, -CH(CH3)-CH2-O-, -CH2-C(CH3)2-O-, -C(CH3)2-CH2-O-, - CH2-CH(C2H5)-O- and -CH(C2H5)-CH2-O-, most preferably selected from the group consisting of -CH₂-CH(C₂H₅)-O-, -CH(C₂H₅)-CH₂-O-, -CH₂-CH(CH₃)-O- and -CH(CH₃)-CH₂-O-, and especially selected from the group consisting of -CH2-CH(CH3)-O- and -CH(CH3)-CH2-O-, m and n independently of another are positive integers, with the proviso that the sum (m + n) is from 2 to 50, preferably from 5 to 40, more preferably from 10 to 30, and especially from 15 to 25, R stands for an C₁- to C₄-alkyl, preferably methyl, and A- stands for an anion, preferably carboxylate R¹⁸COO- or a carbonate R¹⁸O-COO- as defined above, more preferably salicylate or methyloxalate. In another preferred embodiment the quaternized ammonium compound is of formula

wherein in this formula R^a and R^b independently of another stand for C1–C20-alkyl or hydroxy-C1- to C4-alkyl, preferably R^a stands for C1–C20-alkyl, preferably ethyl, n-butyl, n-octyl, n-dodecyl, tetradecyl or hexadecyl, and R^b stands for hydroxy-C1- to C4-alkyl, preferably 2-hydroxypropyl, A- stands for an anion, preferably carboxylate R¹⁸COO- or a carbonate R¹⁸O-COO- as defined above, more preferably C12-C100-alkyl- and -alkenyl succinic acid, especially dodecenyl succinic acid, hexadecenyl succinic acid, eicosenyl succinic acid, and polyisobutenyl succinic acid. Polyisobutenylsuccinimides Polyisobutenylsuccinimides are of formula

wherein in this formula PIB stands for a polyisobutenyl residue having a number average molecular weight M_n of from 550 to 2300, preferably from 650 to 1500 and more preferably from 750 to 1300 g/mol, and n stands for a positive integer of from 2 to 6, preferably 2 to 5, and more preferably 3 or 4. Among the deposit control agents quaternary nitrogen compounds are preferred over the poly- isobutenylsuccinimides. Dehazers Dehazers as additive components are preferably selected from - alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and/or other oxides, e.g. epoxy based resins; and - alkoxylated phenol formaldehyde resins. Such dehazer components are normally commercially available products, e.g. the dehazer products available from Baker Petrolite under the brand name of Tolad® such as Tolad® 2898, 9360K, 9348, 9352K, 9327 or 286K. Cetane number improvers Cetane number improvers used are typically organic nitrates. Such organic nitrates are espe- cially nitrate esters of unsubstituted or substituted aliphatic or cycloaliphatic alcohols, usually having up to about 10, in particular having 2 to 10 carbon atoms. The alkyl group in these nitrate esters may be linear or branched, and saturated or unsaturated. Typical examples of such ni- trate esters are methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate, allyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, isoamyl nitrate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate, n-hexyl nitrate, n-heptyl nitrate, sec-heptyl nitrate, n- octyl nitrate, 2-ethylhexyl nitrate, sec-octyl nitrate, n-nonyl nitrate, n-decyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate and isopropylcyclohexyl nitrate and also branched decyl nitrates of the formula R^aR^bCH-CH2-O-NO2 in which R^a is an n-propyl or isopro- pyl radical and R^b is a linear or branched alkyl radical having 5 carbon atoms, as described in WO 2008/092809. Additionally suitable are, for example, nitrate esters of alkoxy-substituted aliphatic alcohols such as 2-ethoxyethyl nitrate, 2-(2-ethoxy-ethoxy)ethyl nitrate, 1- methoxypropyl nitrate or 4-ethoxybutyl nitrate. Additionally, suitable are also diol nitrates such as 1,6-hexamethylene dinitrate. Among the cetane number improver classes mentioned, prefer- ence is given to primary amyl nitrates, primary hexyl nitrates, octyl nitrates and mixtures thereof. Most preferably, 2-ethylhexyl nitrate is present in the fuel oils as the sole cetane number im- prover or in a mixture with other cetane number improvers. Such fuel additive concentrates suitable for use in Diesel fuel, usually comprise 0.01 to 40% by weight, preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight, of betaines according to formula (I); 0 to 40% by weight, preferably 5 to 35% by weight, more preferably 10 to 30% by weight, of at least one compound selected from the group consisting of -- quaternary nitrogen compounds and -- polyisobutenylsuccinimides; 0 to 5% by weight, preferably 0.01 to 5 by weight, more preferably 0.02 to 3.5% by weight, most preferably 0.05 to 2% by weight, of at least one dehazer selected from - alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and/or other oxides, e.g. epoxy based resins, and

- alkoxylated phenol formaldehyde resins;

0 to 75% by weight, preferably 5 to 75% by weight, more preferably 10 to 70% by weight, of at least one cetane number improver;

0 to 50% by weight, preferably 5 to 50% by weight, more preferably 10 to 40% by weight, of at least one solvent or diluent.

In each case, the sum of all components results in 100%.

Gasoline additives

Another aspect of the present invention are additive packages for gasoline fuels, comprising at least one betaine according to formula (I) and further comprising at least one gasoline additive, selected from the group consisting of

- deposit control additives, selected from the group consisting of -- quaternary nitrogen compounds,

-- Mannich adducts, and

-- polyalkenemono- or polyalkenepolyamines having a number average molecular weight in the range 300 to 5000,

- corrosion inhibitors, and

- carrier oils.

The deposit control additives are preferably selected from the group consisting of

- quaternary nitrogen compounds, and

- polyalkenemono- or polyalkenepolyamines having a number average molecular weight in the range 300 to 5000

Other additives, such as friction modifier, dehazers, antioxidants, metal deactivators, and sol vents may be present.

The above-mentioned additives are described in more detail as follows:

Quaternary nitrogen compounds

As quaternary nitrogen compounds the same compounds as described for the Diesel additive packages may be used also in gasoline additive packages, the same preferences apply.

Mannich adducts Typical Mannich adducts are described in US 8449630 B2, preferred are Mannich adducts ac cording to formula I of US 8449630 B2, which are incorporated by reference to the present doc ument.

In a preferred embodiment the Mannich adducts are obtainable as described in US 8449630 B2, column 7, line 35 to column 9, line 52.

Preferably the Mannich adducts are obtainable by reaction of

- at least one hydrocarbyl-substituted phenol, preferably a phenol of formula V of US 8449630 B2, more preferably para hydrocarbyl-substituted phenol or para hydrocarbyl-substituted ortho- cresol, with

- at least one aldehyde, preferably acetaldehyde or formaldehyde, more preferably formalde hyde, and

- at least one amine according to variant 2 of US 8449630 B2, preferably selected from the group consisting of octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecyl- amine, octadecylamine, nonadecylamine, eicosylamine, cyclooctylamine, cyclodecylamine di-n-butylamine, diisobutylamine, di-tert-butylamine, dipentylamine, dihexylamine, diheptyla- mine, dioctylamine, di(2-ethylhexylamine), dinonylamine, didecylamine, N- methylcyclohexylamine, N-ethylcyclohexylamine, dicyclohexylamine, triethylenetetramine, tetra- ethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, dibutylenetriamine, tributylenetetramine, tetrabutylenepentamine, N, N-dipropylmethylenediamine, N, N-dipropylethylene-1 , 2-diamine, N, N-dimethylpropylene- 1, 3- diamine, N, N-diethylpropylene- 1, 3-diamine, N, N-dipropylpropylene-1, 3-diamine, N, N- diethylbutylene-1 , 4-diamine, N, N-dipropylbutylene-1, 4-diamine, N, N-dimethylpentylene-1, 3- diamine, N, N-diethylpentylene- 1, 5-diamine, N, N-dipropylpentylene-1, 5-diamine, N, N- dimethylhexylene-1, 6-diamine, N, N-diethylhexylene- 1, 6-diamine, N, N-dipropylhexylene-1, 6- diamine, bis [2-(N,N-dimethylamino)ethyl] amine, bis [2-(N,N-dipropylamino)ethyl]amine, bis[3- (N, N-dimethylamino)propyl]amine, bis[3-(N, N-diethylamino)-propyl]amine, bis [3-(N,N- dipropylamino)propyl] amine, bis[4-(N, Ndimethylamino) butyl]amine, bis[4-(N, N-diethylamino) butyl]amine, bis[4-(N, N-dipropylamino)butyl]amine, bis[5-(N, N-dimethylamino)-pentyl] amine, bis[5-(N, N-diethylamino)pentyl]amine, bis[5-(N, N-dipropylamino)pentyl]amine, bis[6-(N, N- dimethylamino)-hexyl]amine, bis [6-(N,N-diethylamino)hexyl] amine, bis[6-(N, N-dipropylamino) hexyl]amine, tris[2-(N, N-dimethylamino) ethyl]amine, tris[2-(N, N-dipropylamino)ethyl]amine, tris[3-(N, N-dimethylamino)propyl] amine, tri s [3-(N,Ndiethylamino)propyl]amine, tris[3-(N, N- dipropylamino)propyl]amine, tris[4-(N, N-dimethylamino)butyl]amine, tris[4-(N,N-diethylamino)- butyl] amine, tris[4-(N, Ndipropylamino)butyl]amine, tris[5-(N, N-dimethylamino)pentyl]amine, tris[5-(N, N-diethylamino)pentyl]amine, tris[5-(N,N-dipropylamino)pentyl]amine, tris[6-(N, N- dimethylamino)hexyl]amine, tris[6-(N, N-diethylamino)-hexyl]amine, and tris[6-(N, N- dipropylamino)hexyl]amine, more preferably selected from the group consisting of dimethylamine, diethylamine, di-n- butylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylene hexamine, N, N-dimethylpropylene- 1, 3-diamine, and N, N-diethylpropylene- 1, 3-diamine. The hydrocarbyl residue of the at least one hydrocarbyl-substituted phenol preferably has a number average molecular weight Mn of from 85 to 5000, preferably of from 113 to 2500, more preferably of from 550 to 1500, and especially from 750 to 1100.

In a preferred embodiment the hydrocarbyl residue is a polyisobutene radical of the before- mentioned molecular weight, more preferably derived from a "reactive" polyisobutene radical as defined in US 8449630 B2. In a preferred embodiment the Mannich adduct is of formula

wherein

R³⁰ is a hydrocarbyl residue with a number average molecular weight Mn of from 85 to 5000, preferably of from 113 to 2500, more preferably of from 550 to 1500, and most preferably of from 750 to 1100, and especially is a polyisobutene radical of the before-mentioned molecular weight, more preferably derived from a "reactive" polyisobutene radical,

R³¹ is hydrogen, methyl, ethyl, iso-propyl, n-butyl, tert-butyl, but-2-yl, or amyl, preferably hydro gen or methyl, and more preferably methyl, R³² and R³³ independently of another are Ci- to C₆-alkyl, preferably Ci- to C4-alkyl, more prefer ably are methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, even more preferably are methyl, ethyl or n-butyl, or R³² and R³³ together the nitrogen atom form a five- or six-membered ring, preferably a pyrrolidine, piperidine or morpholine ring, and

R³⁴ is bivalent alkylene residue having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, more preferably 2 or 3 carbon atoms, most preferably selected from the group consisting of methylene, 1 ,2-ethylene, 1 ,2-propylene, 1 ,3-propylene, 1 ,4-butylene, and 1 ,6-hexylene, and especially being 1,2-ethylene or 1,3-propylene.

Polyalkenemono- or polyalkenepolyamines

Polyalkenemono- or polyalkenepolyamines are preferably based on polypropene or on high- reactivity (i.e. having predominantly terminal double bonds) or conventional (i.e. having predom inantly internal double bonds) polybutene or especially polyisobutene with M_n = 300 to 5000, more preferably 500 to 2500 and especially 700 to 2500. Such additives based on high- reactivity polyisobutene, which can be prepared from the polyisobutene which may comprise up to 20% by weight of n-butene units by hydroformylation and reductive amination with ammonia, monoamines or polyamines such as dimethylaminopropylamine, ethylenediamine, diethylenetri- amine, triethylenetetramine or tetraethylenepentamine, are known especially from EP-A 244 616. When polybutene or polyisobutene having predominantly internal double bonds (usually in the b and g positions) are used as starting materials in the preparation of the additives, a possi ble preparative route is by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to give the carbonyl or carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. The amines used here for the amination may be, for example, ammonia, monoamines or the abovementioned polyamines. Corresponding additives based on polypropene are described more particularly in WO-A 94/24231.

Further particular additives comprising monoamino groups 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 more particu larly in WO-A 97/03946.

Further particular additives comprising monoamino groups are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described more particularly in DE-A 19620262.

Examples of particularly useful polyalkylene radicals are polyisobutenyl radicals derived from what are called "high-reactivity" polyisobutenes which feature a high content of terminal double bonds. Terminal double bonds are alpha-olefinic double bonds of the type

Polymer

which are also referred to collectively as vinylidene double bonds. Suitable high-reactivity polyisobutenes are, for example, polyisobutenes which have a proportion of vinylidene double bonds of greater than 70 mol%, especially greater than 80 mol% or greater than 85 mol%. Preference is given especially to polyisobutenes which have homogeneous polymer skeletons. Flomogeneous polymer skeletons are possessed especially by those polyisobutenes formed from isobutene units to an extent of at least 85% by weight, preferably to an extent of at least 90% 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 abovementioned range. In addition, the high-reactivity polyisobutenes may have a polydispersity in the range from 1.05 to 7, especially of about 1.1 to 2.5, for example of less than 1.9 or less 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 Glissopal brands from BASF SE, especially Glissopal® 1000 (Mn = 1000), Glissopal® V 33 (Mn = 550) and Glissopal® 2300 (Mn = 2300), 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 polyisobutenes of particular molecular weight ranges.

Due to their high proportion of vinylidene double bonds these polyisobutenes are especially reactive to undergo hydroformylation and subsequent amination, preferably with ammonia, to yield the corresponding polyisobutene amines, which represent a preferred embodiment of the present invention.

Corrosion inhibitors

As corrosion inhibitors in principle all compounds known in the art for application in fuels may be used.

Suitable corrosion inhibitors are, for example, succinic esters or hemiesters, in particular with polyols, fatty acid derivatives, for example oleic esters, oligomerized fatty acids, such as dimeric fatty acid, substituted ethanolamines, and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany) or HiTEC 536 (Afton Corporation).

According to US 6043199 the latter is believed to be a reaction product of linear or branched alkyl or alkenyl substituted succinic anhydride with substituted amino-imidazolines resulting in what are believed to be linear or branched alkyl or alkenyl substituted succinimide or amine substituted succinimides.

In a preferred embodiment the corrosion inhibitor is selected from the group consisting of

- fatty acids or fatty acid derivatives, preferably oleic acid or its esters,

- oligomerized fatty acids, preferably dimeric fatty acid, more preferably dimeric oleic acid (CAS: 61788-89-4),

- alkyl or alkenyl substituted succinic acids, esters or hemiesters, and

- olefin-carboxylic acid copolymers (see below).

In a more preferred embodiment the corrosion inhibitor is selected from the group consisting of - oligomerized fatty acids, preferably dimeric fatty acid, more preferably dimeric oleic acid (CAS: 61788-89-4), - alkyl or alkenyl substituted succinic acids, esters or hemiesters, and

- olefin-carboxylic acid copolymers (see below).

Alkyl or alkenyl substituted succinic acids, esters or hemiesters

The succinic acids, esters or hemiesters are preferably substituted with Cs- to Cioo-alkyl or -alkenyl radicals.

In a preferred embodiment the succinic acids or hemiesters follow formula

wherein

R²⁰ is a Cs- to Cioo-alkyl or Cs- to Cioo-alkenyl group, preferably Cs- to Cioo-alkenyl, more prefer ably Ci2- to Cgo-alkenyl, and even more preferably Ci₆- to Cso-alkenyl group, and R²¹ is hydrogen or Ci- to C2o-alkyl or C2- to C4-hydroxyalkyl, preferably hydrogen.

The underlying succinic acid anhydrides are obtainable by thermal ene reaction of Cs- to Cioo-alkenes, preferably oligomers or polymers of propene, 1 -butene or isobutene, with maleic anhydride. The above-mentioned corrosion inhibitors are obtainable from such anhydrides by hydrolysis or reaction with the appropriate alcohol.

Olefin-carboxylic acid copolymers

The olefin-carboxylic acid copolymer (A) is a copolymer obtainable by - in a first reaction step (I) copolymerizing

(Aa) at least one ethylenically unsaturated mono- or dicarboxylic acid or derivatives thereof, preferably a dicarboxylic acid,

(Ab) at least one a-olefin having from at least 12 up to and including 30 carbon atoms,

(Ac) optionally at least one further aliphatic or cycloaliphatic olefin which has at least 4 carbon atoms and is different than (Ab) and (Ad) optionally one or more further copolymerizable monomers other than monomers (Aa), (Ab) and (Ac), selected from the group consisting of (Ada) vinyl esters,

(Adb) vinyl ethers,

(Adc) (meth)acrylic esters of alcohols having at least 5 carbon atoms,

(Add) allyl alcohols or ethers thereof,

(Ade) N-vinyl compounds selected from the group consisting of vinyl compounds of heterocy cles containing at least one nitrogen atom, N-vinylamides or N-vinyllactams,

(Adf) ethylenically unsaturated aromatics,

(Adg) a,b-ethylenically unsaturated nitriles,

(Adh) (meth)acrylamides and (Adi) allylamines, followed by

- in a second optional reaction step (II) partly or fully hydrolyzing and/or saponifying anhydride or carboxylic ester functionalities present in the copolymer obtained from (I), the second reac tion step being run at least when the copolymer obtained from reaction step (I) does not com prise any free carboxylic functionalities.

Description of the copolymer (A)

The monomer (Aa) is at least one, preferably one to three, more preferably one or two and most preferably exactly one ethylenically unsaturated, preferably a,b-ethylenically unsaturated, mono- or dicarboxylic acid(s) or derivatives thereof, preferably a dicarboxylic acid or derivatives there of.

Derivatives are understood to mean

- the corresponding anhydrides in monomeric or else polymeric form,

- mono- or dialkyl esters, preferably mono- or di-Ci-C4-alkyl esters, more preferably mono- or dimethyl esters or the corresponding mono- or diethyl esters, and

- mixed esters, preferably mixed esters having different C1-C4 alkyl components, more prefera bly mixed methyl ethyl esters.

Preferably, the derivatives are anhydrides in monomeric form or di-Ci-C4-alkyl esters, more preferably anhydrides in monomeric form.

In the context of this document, Ci-C4-alkyl is understood to mean methyl, ethyl, /isopropyl, n- propyl, n-butyl, /sobutyl, sec-butyl and tert- butyl, preferably methyl and ethyl, more preferably methyl.

Examples of a,b-ethylenically unsaturated mono- or dicarboxylic acids are those mono- or di carboxylic acids or derivatives thereof in which the carboxyl group or, in the case of dicarboxylic acids, at least one carboxyl group, preferably both carboxyl groups, is/are conjugated to the ethylenically unsaturated double bond.

Examples of ethylenically unsaturated mono- or dicarboxylic acids that are not a,b-ethylenically unsaturated are cis-5-norbornene-endo-2,3-dicarboxylic anhydride, exo-3,6-epoxy-1 ,2,3,6- tetrahydrophthalic anhydride and cis-4-cyclohexene-1 ,2-dicarboxylic anhydride.

Examples of a,b-ethylenically unsaturated monocarboxylic acids are acrylic acid, methacrylic acid, crotonic acid and ethylacrylic acid, preferably acrylic acid and methacrylic acid, referred to in this document as (meth)acrylic acid for short, and more preferably acrylic acid.

Particularly preferred derivatives of a,b-ethylenically unsaturated monocarboxylic acids are me thyl acrylate, ethyl acrylate, n-butyl acrylate and methyl methacrylate.

Examples of dicarboxylic acids are maleic acid, fumaric acid, itaconic acid (2- methylenebutanedioic acid), citraconic acid (2-methylmaleic acid), glutaconic acid (pent-2-ene- 1 ,5-dicarboxylic acid), 2,3-dimethylmaleic acid, 2-methylfumaric acid, 2,3-dimethylfumaric acid, methylenemalonic acid and tetrahydrophthalic acid, preferably maleic acid and fumaric acid and more preferably maleic acid and derivatives thereof.

More particularly, monomer (Aa) is maleic anhydride.

Monomer (Ab) is at least one, preferably one to four, more preferably one to three, even more preferably one or two and most preferably exactly one a-olefin(s) having from at least 12 up to and including 30 carbon atoms. The a-olefins (Ab) preferably have at least 14, more preferably at least 16 and most preferably at least 18 carbon atoms. Preferably, the a-olefins (Ab) have up to and including 28, more preferably up to and including 26 and most preferably up to and in cluding 24 carbon atoms.

Preferably, the a-olefins may be one or more linear or branched, preferably linear, 1-alkene.

Examples of these are 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1- octadecene, 1-nonodecene, 1-eicosene, 1-docosene, 1-tetracosene, 1- hexacosene, preference being given to 1 -octadecene, 1-eicosene, 1-docosene and 1- tetracosene, and mixtures thereof.

Further examples of a-olefin (Ab) are those olefins which are oligomers or polymers of C2 to C12 olefins, preferably of C3 to C10 olefins, more preferably of C4 to C₆ olefins. Examples thereof are ethene, propene, 1 -butene, 2-butene, isobutene, pentene isomers and hexene isomers, prefer ence being given to ethene, propene, 1 -butene, 2-butene and isobutene.

Named examples of a-olefins (Ab) include oligomers and polymers of propene, 1 -butene, 2- butene, isobutene, and mixtures thereof, particularly oligomers and polymers of propene or iso- butene or of mixtures of 1 -butene and 2-butene. Among the oligomers, preference is given to the trimers, tetramers, pentamers and hexamers, and mixtures thereof.

In addition to the olefin (Ab), it is optionally possible to incorporate at least one, preferably one to four, more preferably one to three, even more preferably one or two and especially exactly one further aliphatic or cycloaliphatic olefin(s) (Ac) which has/have at least 4 carbon atoms and is/are different than (Ab) by polymerization into the inventive copolymer.

The olefins (Ac) may be olefins having a terminal (a-)double bond or those having a non terminal double bond, preferably having an a-double bond. The olefin (Ac) preferably comprises olefins having 4 to fewer than 12 or more than 30 carbon atoms. If the olefin (Ac) is an olefin having 12 to 30 carbon atoms, this olefin (Ac) does not have an a-double bond.

Examples of aliphatic olefins (Ac) are 1 -butene, 2-butene, isobutene, pentene isomers, hexene isomers, heptene isomers, octene isomers, nonene isomers, decene isomers, undecene iso mers and mixtures thereof.

Examples of cycloaliphatic olefins (Ac) are cyclopentene, cyclohexene, cyclooctene, cyclode- cene, cyclododecene, a- or b-pinene and mixtures thereof, limonene and norbornene.

Further examples of olefins (Ac) are polymers having more than 30 carbon atoms of propene, 1 - butene, 2-butene or isobutene or of olefin mixtures comprising the latter, preferably of isobutene or of olefin mixtures comprising the latter, more preferably having a mean molecular weight M_w in the range from 500 to 5000 g/mol, preferably 650 to 3000 and more preferably 800 to 1500 g/mol.

Preferably, the oligomers or polymers comprising isobutene in copolymerized form have a high content of terminal ethylenic double bonds (a-double bonds), for example at least 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol% and most preferably at least 80 mol%.

For the preparation of such oligomers or polymers comprising isobutene in copolymerized form, suitable isobutene sources are either pure isobutene or isobutene-containing C4 hydrocarbon streams, for example C4 raffinates, especially "raffinate 1", C4 cuts from isobutane dehydro genation, C4 cuts from steamcrackers and from FCC crackers (fluid catalyzed cracking), pro vided that they have substantially been freed of 1 ,3-butadiene present therein. A C4 hydrocar bon stream from an FCC refinery unit is also known as a "b/b" stream. Further suitable isobu tene-containing C4 hydrocarbon streams are, for example, the product stream of a propylene- isobutane cooxidation or the product stream from a metathesis unit, which are generally used after customary purification and/or concentration. Suitable C4 hydrocarbon streams comprise generally less than 500 ppm, preferably less than 200 ppm, of butadiene. The presence of 1- butene and of cis- and trans-2-butene is substantially uncritical. Typically, the isobutene con centration in said C4 hydrocarbon streams is in the range from 40% to 60% by weight. For in stance, raffinate 1 generally consists essentially of 30% to 50% by weight of isobutene, 10% to 50% by weight of 1 -butene, 10% to 40% by weight of cis- and trans-2-butene and 2% to 35% by weight of butanes; in the polymerization process the unbranched butenes in the raffinate 1 are generally virtually inert, and only the isobutene is polymerized.

In a preferred embodiment, the monomer source used for polymerization is a technical C4 hy drocarbon stream having an isobutene content of 1% to 100% by weight, especially of 1% to 99% by weight, in particular of 1% to 90% by weight, more preferably of 30% to 60% by weight, especially a raffinate 1 stream, a b/b stream from an FCC refinery unit, a product stream from a propylene-isobutane cooxidation or a product stream from a metathesis unit.

Especially when a raffinate 1 stream is used as isobutene source, the use of water as the sole initiator or as further initiator has been found to be useful, particularly when polymerization is effected at temperatures of -20°C to +30°C, especially of 0°C to +20°C. At temperatures of - 20°C to +30°C, especially of 0°C to +20°C, however, it is possible to dispense with the use of an initiator when using a raffinate 1 stream as isobutene source.

Said isobutene-containing monomer mixture may comprise small amounts of contaminants such as water, carboxylic acids or mineral acids without causing any critical yield or selectivity losses. It is appropriate to the purpose to avoid accumulation of these impurities by removing such harmful substances from the isobutene-containing monomer mixture, for example, by ad sorption on solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

It is also possible, albeit less preferable, to convert monomer mixtures of isobutene or of the isobutene-containing hydrocarbon mixture with olefinically unsaturated monomers copolymeriz- able with isobutene. If monomer mixtures of isobutene with suitable comonomers are to be co polymerized, the monomer mixture comprises preferably at least 5% by weight, more preferably at least 10% by weight and especially at least 20% by weight of isobutene, and preferably at most 95% by weight, more preferably at most 90% by weight and especially at most 80% by weight of comonomers.

In a preferred embodiment, the mixture of the olefins (Ab) and optionally (Ac), averaged to their molar amounts, have at least 12 carbon atoms, preferably at least 14, more preferably at least 16 and most preferably at least 17 carbon atoms.

For example, a 2:3 mixture of docosene and tetradecene has an averaged value for the carbon atoms of 0.4 x 22 + 0.6 x 14 = 17.2.

The upper limit is less relevant and is generally not more than 60 carbon atoms, preferably not more than 55, more preferably not more than 50, even more preferably not more than 45 and especially not more than 40 carbon atoms.

The optional monomer (Ad) is at least one monomer, preferably one to three, more preferably one or two and most preferably exactly one monomer(s) selected from the group consisting of (Ada) vinyl esters, (Adb) vinyl ethers, (Adc) (meth)acrylic esters of alcohols having at least 5 carbon atoms, (Add) allyl alcohols or ethers thereof, (Ade) N-vinyl compounds selected from the group consisting of vinyl compounds of heterocy- cles containing at least one nitrogen atom, N-vinylamides or N-vinyllactams, (Adf) ethylenically unsaturated aromatics and (Adg) α,β-ethylenically unsaturated nitriles, (Adh) (meth)acrylamides and (Adi) allylamines. Examples of vinyl esters (Ada) are vinyl esters of C2- to C12-carboxylic acids, preferably vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pentanoate, vinyl hexanoate, vinyl octanoate, vinyl 2-ethylhexanoate, vinyl decanoate, and vinyl esters of Versatic Acids 5 to 10, preferably vinyl esters of 2,2-dimethylpropionic acid (pivalic acid, Versatic Acid 5), 2,2-dimethylbutyric acid (neohexanoic acid, Versatic Acid 6), 2,2-dimethylpentanoic acid (neoheptanoic acid, Versatic Acid 7), 2,2-dimethylhexanoic acid (neooctanoic acid, Versatic Acid 8), 2,2-dimethylheptanoic acid (neononanoic acid, Versatic Acid 9) or 2,2-dimethyloctanoic acid (neodecanoic acid, Ver- satic Acid 10). Examples of vinyl ethers (Adb) are vinyl ethers of C1- to C12-alkanols, preferably vinyl ethers of methanol, ethanol, iso-propanol, n-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n- hexanol, n-heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol) or 2-ethylhexanol. Preferred (meth)acrylic esters (Adc) are (meth)acrylic esters of C5- to C12-alkanols, preferably of n-pentanol, n-hexanol, n-heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol), 2- ethylhexanol or 2-propylheptanol. Particular preference is given to pentyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate. Examples of monomers (Add) are allyl alcohols and allyl ethers of C₂- to C₁₂-alkanols, prefera- bly allyl ethers of methanol, ethanol, iso-propanol, n-propanol, n-butanol, iso-butanol, sec- butanol, tert-butanol, n-hexanol, n-heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol) or 2-ethylhexanol. Examples of vinyl compounds (Ade) of heterocycles comprising at least one nitrogen atom are N-vinylpyridine, N-vinylimidazole and N-vinylmorpholine. Preferred compounds (Ade) are N-vinylamides or N-vinyllactams. Examples of N-vinylamides or N-vinyllactams (Ade) are N-vinylformamide, N-vinylacetamide, N- vinylpyrrolidone and N-vinylcaprolactam. Examples of ethylenically unsaturated aromatics (Adf) are styrene and α-methylstyrene. Examples of a,b-ethylenically unsaturated nitriles (Adg) are acrylonitrile and methacrylonitrile.

Examples of (meth)acrylamides (Adh) are acrylamide and methacrylamide.

Examples of allylamines (Adi) are allylamine, dialkylallylamine and trialkylallylammonium hal ides.

Preferred monomers (Ad) are (Ada), (Adb), (Adc), (Ade) and/or (Adf), more preferably (Ada), (Adb) and/or (Adc), even more preferably (Ada) and/or (Adc) and especially (Adc).

The incorporation ratio of the monomers (Aa) and (Ab) and optionally (Ac) and optionally (Ad) in the polymer obtained from reaction step (I) is generally as follows:

The molar ratio of (Aa)/((Ab) and (Ac)) (in total) is generally from 10:1 to 1 :10, preferably 8:1 to 1 :8, more preferably 5:1 to 1 :5, even more preferably 3:1 to 1 :3, particularly 2:1 to 1 :2 and es pecially 1 .5:1 to 1 :1.5. In the preferred particular case of maleic anhydride as monomer (Aa), the molar incorporation ratio of maleic anhydride to monomers ((Ab) and (Ac)) (in total) is about 1 :1.

The molar ratio of obligatory monomer (Ab) to monomer (Ac), if present, is generally of 1 :0.05 to 10, preferably of 1 :0.1 to 6, more preferably of 1 :0.2 to 4, even more preferably of 1 :0.3 to 2.5 and especially 1 :0.5 to 1.5.

In a preferred embodiment, no optional monomer (Ac) is present in addition to monomer (Ab).

The proportion of one or more of the monomers (Ad), if present, based on the amount of the monomers (Aa), (Ab) and optionally (Ac) (in total) is generally 5 to 200 mol%, preferably 10 to 150 mol%, more preferably 15 to 100 mol%, even more preferably 20 to 50 mol% and especial ly 0 to 25 mol%.

In a preferred embodiment, no optional monomer (Ad) is present.

In a second reaction step (II), the anhydride or carboxylic ester functionalities present in the copolymer obtained from (I) are partly or fully hydrolyzed and/or saponified.

Reaction step (II) is obligatory in case the copolymer obtained from reaction step (I) does not comprise free carboxylic acid groups.

Hydrolization of anhydride groups is preferred over saponification of ester groups. Preferably, 10% to 100% of the anhydride or carboxylic ester functionalities present are hydro lyzed and/or saponified, preferably at least 20%, more preferably at least 30%, even more pref erably at least 50% and particularly at least 75% and especially at least 85%.

For a hydrolysis, based on the anhydride functionalities present, the amount of water that corre sponds to the desired hydrolysis level is added and the copolymer obtained from (I) is heated in the presence of the added water. In general, a temperature of preferably 20 to 150°C is suffi cient for the purpose, preferably 60 to 100°C. If required, the reaction can be conducted under pressure in order to prevent the escape of water. Under these reaction conditions, in general, the anhydride functionalities in the copolymer are converted selectively, whereas any carboxylic ester functionalities present in the copolymer react at least only to a minor degree, if at all.

For a saponification, the copolymer is reacted with an amount of a strong base corresponding to the desired saponification level in the presence of water.

Strong bases used may preferably be hydroxides, oxides, carbonates or hydrogencarbonates of alkali metals or alkaline earth metals.

The copolymer obtained from (I) is then heated in the presence of the added water and the strong base. In general, a temperature of preferably 20 to 130°C is sufficient for the purpose, preferably 50 to 110°C. If required, the reaction can be conducted under pressure.

It is also possible to hydrolyze the carboxylic ester functionalities with water in the presence of an acid. Acids used are preferably mineral acids, carboxylic acids, sulfonic acids or phosphorus acids having a pKa of not more than 5, more preferably not more than 4.

Examples are acetic acid, formic acid, oxalic acid, salicylic acid, substituted succinic acids, aro matically substituted or unsubstituted benzenesulfonic acids, sulfuric acid, nitric acid, hydrochlo ric acid or phosphoric acid; the use of acidic ion exchange resins is also conceivable.

In a preferred embodiment for anhydrides, especially maleic anhydride being monomers (Aa), such anhydride moieties are partly or fully, especially fully hydrolysed while potentially existing ester groups in the copolymer remain intact. In this case no saponification in step (II) takes place.

The copolymer obtained from (I) is then heated in the presence of the added water and the acid. In general, a temperature of preferably 40 to 200°C is sufficient for the purpose, preferably 80 to 150°C. If required, the reaction can be conducted under pressure.

Should the copolymers obtained from step (II) still comprise residues of acid anions, it may be preferable to remove these acid anions from the copolymer with the aid of an ion exchanger and preferably exchange them for hydroxide ions or carboxylate ions, more preferably hydroxide ions. This is the case especially when the acid anions present in the copolymer are halides or contain sulfur or nitrogen.

The copolymer obtained from reaction step (II) generally has a weight-average molecular weight Mw of 0.5 to 20 kDa, preferably 0.6 to 15, more preferably 0.7 to 7, even more preferably 1 to 7 and especially 1.5 to 4 kDa (determined by gel permeation chromatography with tetrahydrofuran and polystyrene as standard).

The number-average molecular weight Mn is usually from 0.5 to 10 kDa, preferably 0.6 to 5, more preferably 0.7 to 4, even more preferably 0.8 to 3 and especially 1 to 2 kDa (determined by gel permeation chromatography with tetrahydrofuran and polystyrene as standard).

The polydispersity is generally from 1 to 10, preferably from 1.1 to 8, more preferably from 1.2 to 7, even more preferably from 1.3 to 5 and especially from 1.5 to 3.

The content of acid groups in the copolymer is preferably from 1 to 8 mmol/g of copolymer, more preferably from 2 to 7.5, even more preferably from 3 to 7 mmol/g of copolymer.

In a preferred embodiment, the copolymers comprise a high proportion of adjacent carboxylic acid groups, which is determined by a measurement of adjacency. For this purpose, a sample of the copolymer is heat-treated between two Teflon films at a temperature of 290°C for a period of 30 minutes and an FTIR spectrum is recorded at a bubble-free site. The IR spectrum of Tef lon is subtracted from the spectra obtained, the layer thickness is determined and the content of cyclic anhydride is determined.

In a preferred embodiment, the adjacency is at least 10%, preferably at least 15%, more prefer ably at least 20%, even more preferably at least 25% and especially at least 30%.

The olefin-carboxylic acid copolymer (A) is applied in the form of the free acid, i.e. COOFI groups are present, or in the form of the anhydride which may be an intramolecular anhydride or an intermolecular anhydride linking two dicarboxylic acid molecules together, preferably in the form of a free acid. To a minor extent, some of the carboxylic functions may be present in salt form, e.g. as alkali or alkaline metal salts salts or as ammonium or substituted ammonium salts, depending on the pH value of the liquid phase. Preferably at least 50 % of all carboxylic acid groups are available in the form of the free acid as COOH-groups, more preferably at least 66 %, very preferably at least 75 %, even more preferably at least 85 %, and especially at least 95%. A single olefin-carboxylic acid copolymer (A) or a mixture of different olefin-carboxylic acid copolymers (A) may be used.

Carrier oils

Carrier oils additionally used may be of mineral or synthetic nature. Suitable mineral carrier oils are fractions obtained in crude oil processing, such as brightstock or base oils having viscosi- ties, for example, from the SN 500 - 2000 class; but also aromatic hydrocarbons, paraffinic hy drocarbons and alkoxyalkanols. Likewise useful is a fraction which is obtained in the refining of mineral oil and is known as "hydrocrack oil" (vacuum distillate cut having a boiling range of from about 360 to 500°C, obtainable from natural mineral oil which has been catalytically hydrogen ated under high pressure and isomerized and also deparaffinized). Likewise suitable are mix tures of the abovementioned mineral carrier oils.

Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins or polyinternalole- fins), (poly)esters, (poly)alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-started polyethers, alkylphenol-started polyetheramines and carboxylic esters of long-chain alkanols.

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

Examples of suitable polyethers or polyetheramines are preferably compounds comprising pol- yoxy-C2- to C4-alkylene moieties obtainable by reacting C2- to C₆o-alkanols, C₆- to C30- alkanediols, mono- or di-C2- to C3o-alkylamines, Ci- to C30-alkylcyclohexanols or Ci- to C30- alkylphenols with 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl group or amino group, and, in the case of the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines. Such products are described more particularly in EP-A 310875, EP-A 356725, EP-A 700985 and US-A 4,877,416. For ex ample, the polyetheramines used may be poly-C2- to C₆-alkylene oxide amines or functional derivatives thereof. Typical examples thereof are tridecanol butoxylates or isotridecanol butox- ylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates, and also the corresponding reaction products with ammonia.

Examples of carboxylic esters of long-chain alkanols are more particularly esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, as described more particularly in DE-A 38 38 918. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids; par ticularly suitable ester alcohols or ester polyols are long-chain representatives having, for ex ample, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, for example di(n- or isotridecyl) phthalate.

Further suitable carrier oil systems are described, for example, in DE-A 3826 608, DE-A 41 42 241 , DE-A 4309074, EP-A 452 328 and EP-A 548 617.

Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers having about 5 to 35, preferably about 5 to 30, more preferably 10 to 30 and especially 15 to 30 C3- to C₆-alkylene oxide units, for example propylene oxide, n-butylene oxide and isobutylene oxide units, or mixtures thereof, per alcohol molecule. Nonlimiting examples of suitable starter alco hols are long-chain alkanols or phenols substituted by long-chain alkyl in which the long-chain alkyl radical is especially a straight-chain or branched C_&- to Cis-alkyl radical. Particular exam- pies include tridecanol, heptadecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherification products) of monohydric aliphatic C_&- to Ci₈-alcohols with C3- to C₆-alkylene oxides. Examples of monohydric aliphatic C₆-Ci₈-alcohols are hexanol, heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 3-propylheptanol, un- decanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octa- decanol and the constitutional and positional isomers thereof. The alcohols can be used either in the form of the pure isomers or in the form of technical grade mixtures. A particularly pre ferred alcohol is tridecanol. Examples of C3- to C₆-alkylene oxides are propylene oxide, such as 1 ,2-propylene oxide, butylene oxide, such as 1 ,2-butylene oxide, 2,3-butylene oxide, isobutyl ene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Particular preference among these is given to C3- to C4-alkylene oxides, i.e. propylene oxide such as 1,2-propylene oxide and butylene oxide such as 1 ,2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Especially butylene oxide is used.

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

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

Other additives

Typical other additives in the additive packages or fuels according to the invention may be fric tion modifier, dehazers, antioxidants, metal deactivators, and solvents for the packages.

Friction modifier

Suitable friction modifiers are based typically on fatty acids or fatty acid esters. Typical exam ples are tall oil fatty acid, as described, for example, in WO 98/004656, and glyceryl monoole- ate. The reaction products, described in US 6743266 B2, of natural or synthetic oils, for exam ple triglycerides, and alkanolamines are also suitable as such friction modifier.

Preferred lubricity improvers are described in WO 15/059063 and WO 10/005720. Furthermore, hydroxyl group-substituted tertiary amines as disclosed in WO 2014/23853 are preferred as friction modifiers.

Dehazer

Suitable dehazer are, for example, the alkali metal or alkaline earth metal salts of alkyl- substituted phenol- and naphthalenesulfonates and the alkali metal or alkaline earth metal salts of fatty acids, and also neutral compounds such as alcohol alkoxylates, e.g. alcohol ethoxylates, phenol alkoxylates, e.g. tert-butylphenol ethoxylate or tert-pentylphenol ethoxylate, fatty acids, alkylphenols, condensation products of ethylene oxide (EO) and propylene oxide (PO), for ex- ample including in the form of EO/PO block copolymers, polyethyleneimines or else polysilox- anes.

Further suitable dehazers are EO/PO-based alkoxylates of alkylphenol-formaldehyde conden sates (Novolac, resol or calixarene type), EO/PO-based alkoxylates of diols (e.g. propandiol, ethylene glycole), triols (e.g. glycerol or trimethylolpropane), ethylene diamine, or polyethylene- imine. Further suitable dehazers are alkybenzene sulfonic acids, dialkylsulfosuccinates or alkali metal or ammonium salts thereof. Suitable dehazers are described in WO 96/22343. Further suitable dehazers based on diglycidyl ethers are described in US 3383326 and US 3511882.

Other suitable dehazers are, for example, alkoxylated phenol-formaldehyde condensates, for example the products available under the trade names NALCO 7D07 (Nalco) and TOLAD 2683 (Petrolite).

Antioxidants

Suitable antioxidants are, for example, substituted phenols, such as 2,6-di-tert-butylphenol, 2,6- di-tert-butyl-4-methyl phenol, 2,4-di-tert-butyl-6-methylphenol, preferably hindered phenols with an ester group bearing radical in paraposition, such as 3-[3,5-bis-(dimethylethyl)-4-hydroxy- phenyl] propanoic acid C_&- to C2o-alkyl esters, e.g. 2-ethylhexyl- or stearylester, and also phe- nylenediamines such as N,N'-di-sec-butyl-p-phenylenediamine.

Metal deactivators

Suitable metal deactivators are, for example, salicylic acid derivatives such as N,N'- disalicylidene-1 ,2-propanediamine.

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 SFIELLSOL (Royal Dutch/Shell Group) and EXXSOL (ExxonMobil), and also polar or ganic solvents, for example, alcohols such as 2-ethylhexanol, 2-propylheptanol, decanol, isotridecanol and isoheptadecanol. Such solvents are usually added to the fuel together with the aforementioned additives and coadditives, which they are intended to dissolve or dilute for bet ter handling.

Subject matter of the present invention is also a fuel additive concentrate suitable for use in gasoline fuels comprising

0.01 to 40% by weight, preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight, of the betaine according to formula (I); 10 to 70% by weight, preferably 15 to 60% by weight, more preferably 20 to 50% by weight, of the at least one deposit control agent;

0.25 to 5% by weight, preferably 0.5 to 5 by weight, more preferably 0.75 to 3.5% by weight, most preferably 1.0 to 2% by weight, of at least one corrosion inhibitor;

0 to 80% by weight, preferably 5 to 60% by weight, more preferably 10 to 40% by weight, of at least one carrier oil;

0 to 80% by weight, preferably 5 to 50% by weight, more preferably 10 to 40% by weight, of at least one solvent or diluent; and

0 to 15% by weight, preferably 0.5 to 10 by weight, more preferably 1 to 8% by weight, most preferably 3 to 7% by weight, of each of the other additive components described above, if any; with the proviso that the sum of components always results in 100%.

Diesel Fuels

Diesel fuels or middle distillate fuels are typically mineral oil raffinates which generally have a boiling range from 100 to 400°C. These are usually distillates having a 95% point up to 360°C or even higher. However, these may also be what is called "ultra low sulfur diesel" or "city diesel", characterized by a 95% point of, for example, not more than 345°C and a sulfur content of not more than 0.005% by weight, or by a 95% point of, for example, 285°C and a sulfur content of not more than 0.001% by weight. In addition to the diesel fuels obtainable by refining, the main constituents of which are relatively long-chain paraffins, those obtainable in a synthetic way by coal gasification or gas liquefaction ["gas to liquid" (GTL) fuels] are suitable, too. Also suitable are mixtures of the aforementioned diesel fuels with renewable fuels (biofuel oils) such as bio diesel or bioethanol. Of particular interest at present are diesel fuels with low sulfur content, i.e. with a sulfur content of less than 0.05% by weight, preferably of less than 0.02% by weight, par ticularly of less than 0.005% by weight and especially of less than 0.001 % by weight of sulfur.

In a preferred embodiment, the betaine compounds according to formula (I) are used together with at least one Diesel additive as described in Diesel fuels which comprise

(a) to an extent of 0.1 to 100% by weight, preferably to an extent of 0.1 to less than 100% by weight, especially to an extent of 10 to 95% by weight and in particular to an extent of 30 to 90% by weight at least one biofuel oil based on fatty acid esters, and

(b) to an extent of 0 to 99.9% by weight, preferably to an extent of more than 0 to 99.9% by weight, especially to an extent of 5 to 90% by weight, and in particular to an extent of 10 to 70% by weight, of middle distillates of fossil origin and/or of synthetic origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid es ters.

The betaine compounds according to formula (I) may in another preferred embodiment also be used together with at least one Diesel additive as described in Diesel fuels which consist exclu sively of middle distillates of fossil origin and/or of synthetic origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters.

Diesel fuel component (a) is usually also referred to as "biodiesel". This preferably comprises essentially alkyl esters of fatty acids which derive from vegetable and/or animal oils and/or fats. Alkyl esters typically refer to lower alkyl esters, especially Ci- to C4-alkyl esters, which are ob tainable by transesterifying the glycerides which occur in vegetable and/or animal oils and/or fats, especially triglycerides, by means of lower alcohols, for example, ethanol, n-propanol, iso propanol, n-butanol, isobutanol, sec-butanol, tert-butanol or especially methanol ("FAME").

Examples of vegetable oils which can be converted to corresponding alkyl esters and can thus serve as the basis of biodiesel are castor oil, olive oil, peanut oil, palm kernel oil, coconut oil, mustard oil, cottonseed oil, and especially sunflower oil, palm oil, soybean oil and rapeseed oil. Further examples include oils which can be obtained from wheat, jute, sesame and shea tree nut; it is additionally also possible to use arachis oil, jatropha oil and linseed oil. The extraction of these oils and the conversion thereof to the alkyl esters are known from the prior art or can be inferred therefrom.

It is also possible to convert already used vegetable oils, for example used deep fat fryer oil, optionally after appropriate cleaning, to alkyl esters, and thus for them to serve as the basis of biodiesel.

Vegetable fats can in principle likewise be used as a source for biodiesel, but play a minor role.

Examples of animal oils and fats which can be converted to corresponding alkyl esters and can thus serve as the basis of biodiesel are fish oil, bovine tallow, porcine tallow and similar fats and oils obtained as wastes in the slaughter or utilization of farm animals or wild animals.

The parent saturated or unsaturated fatty acids of said vegetable and/or animal oils and/or fats, which usually have 12 to 22 carbon atoms and may bear an additional functional group such as hydroxyl groups, and which occur in the alkyl esters, are especially lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, erucic acid and/or ricinoleic acid.

Typical lower alkyl esters based on vegetable and/or animal oils and/or fats, which find use as biodiesel or biodiesel components, are, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME"), tallow methyl ester ("TME"), and especially rapeseed oil methyl ester ("RME"). However, it is also possible to use the monoglycerides, diglycerides and especially triglycerides themselves, for example castor oil, or mixtures of such glycerides, as biodiesel or components for biodiesel.

In the context of the present invention, the Diesel fuel component (b) shall be understood to mean the abovementioned middle distillate fuels, especially diesel fuels, especially those which boil in the range from 120 to 450°C.

The Diesel fuels according to the present invention comprise said at least one betaine com pound according to formula (I) in an amount of from 10 to 1000 ppm, preferably from 15 to 500 ppm, more preferably from 20 to 300 ppm, most preferably from 25 to 150 ppm.

The deposit control agent or mixture of a plurality of such additives is present in the Diesel fuels in the case of polyisobutenylsuccinimides typically in an amount of from 10 to 1000 ppm by weight, preferably of from 25 to 500 ppm by weight, more preferably of from 50 to 250 ppm by weight.

In the case of quaternary ammonium compounds as deposit control agents they are typically present in the Diesel fuels in an amount of from 10 to 100 ppm by weight, preferably of from 20 to 50 ppm by weight,

One or more dehazers as additive component, if any, are present in the Diesel fuels generally in an amount of from 0.5 to 100 ppm by weight, preferably of from 1 to 50 ppm by weight, more preferably of from 1.5 to 40 ppm by weight, most preferably of from 2 to 30 ppm by weight, for example of from 3 to 20 ppm by weight.

The other additive components described above each, if any, are present in the Diesel fuels generally in an amount of from 0.5 to 200 ppm by weight, preferably of from 1 to 100 ppm by weight, more preferably of from 1.5 to 40 ppm by weight, most preferably of from 2 to 30 ppm by weight.

Gasoline Fuels

In the context of the present invention, gasoline fuels mean liquid hydrocarbon distillate fuels boiling in the gasoline range. It is in principle suitable for use in all types of gasoline, including "light" and "severe" gasoline species. The gasoline fuels may also contain amounts of other fuels such as, for example, ethanol.

Typically, gasoline fuels, which may be used according to the present invention exhibit, in addi tion, one or more of the following features: The aromatics content of the gasoline fuel is preferably not more than 50 volume % and more preferably not more than 35 volume %. Preferred ranges for the aromatics content are from 1 to 45 volume % and particularly from 5 to 35 volume %.

The sulfur content of the gasoline fuel is preferably not more than 100 ppm by weight and more preferably not more than 10 ppm by weight. Preferred ranges for the sulfur content are from 0.5 to 150 ppm by weight and particularly from 1 to 10 ppm by weight.

The gasoline fuel has an olefin content of not more than 21 volume %, preferably not more than 18 volume %, and more preferably not more than 10 volume %. Preferred ranges for the olefin content are from 0.1 to 21 volume % and particularly from 2 to 18 volume %.

The gasoline fuel has a benzene content of not more than 1.0 volume % and preferably not more than 0.9 volume %. Preferred ranges for the benzene content are from 0 to 1.0 volume % and preferably from 0.05 to 0.9 volume %.

The gasoline fuel has an oxygen content of not more than 45 weight %, preferably from 0 to 45 weight %, and most preferably from 0.1 to 3.7 weight % (first type) or most preferably from 3.7 to 45 weight % (second type). The gasoline fuel of the second type mentioned above is a mixture of lower alcohols such as methanol or especially ethanol, which derive preferably from natural source like plants, with mineral oil based gasoline, i.e. usual gasoline produced from crude oil. An example for such gasoline is "E 85", a mixture of 85 volume % of ethanol with 15 volume % of mineral oil based gasoline. Also a fuel containing 100 % of a lower alcohol, espe cially ethanol, is suitable.

The amount of alcohols and ethers contained in the gasoline may vary over wide ranges. Typi cal maximum contents are e.g. methanol 15% by volume, ethanol 85% by volume, isopropanol 20% by volume, tert-butanol 15% by volume, isobutanol 20% by volume and ethers containing 5 or more carbon atoms in the molecule 30% by volume.

The summer vapor pressure of the gasoline fuel is usually not more than 70 kPa and preferably not more than 60 kPa (at 37°C).

The research octane number ("RON") of the gasoline fuel is usually from 90 to 100. A usual range for the corresponding motor octane number ("MON") is from 80 to 90.

The above characteristics are determined by conventional methods (DIN EN 228).

The gasoline fuels according to the present invention comprise said at least one betaine com pound according to formula (I) in an amount of from 5 to 3000 ppm, preferably from 10 to 500 ppm, more preferably from 10 to 250 ppm, most preferably from 15 to 100 ppm. The deposit control agent or mixture of a plurality of such additives is present in the gasoline fuels in the case of polyalkenemono- or polyalkenepolyamines or Mannich adducts typically in an amount of from 10 to 1000 ppm by weight, preferably of from 25 to 500 ppm by weight, more preferably of from 50 to 250 ppm by weight.

In the case of quaternary ammonium compounds as deposit control agents they are typically present in the gasoline fuels in an amount of from 10 to 100 ppm by weight, preferably of from 20 to 50 ppm by weight,

The one or more corrosion inhibitors, if any, are present in the gasoline fuels normally in an amount of from 0.1 to 10 ppm by weight, preferably of from 0.2 to 8 ppm by weight, more pref erably of from 0.3 to 7 ppm by weight, most preferably of from 0.5 to 5 ppm by weight, for ex ample of from 1 to 3 ppm by weight.

The one or more carrier oils, if any, are present in the gasoline fuels normally in an amount of form 10 to 3.000 ppm by weight, preferably of from 20 to 1000 ppm by weight, more preferably of from 50 to 700 ppm by weight, most preferably of from 70 to 500 ppm by weight.

One or more dehazers as additive component, if any, are present in the gasoline fuels generally in an amount of from 0.5 to 100 ppm by weight, preferably of from 1 to 50 ppm by weight, more preferably of from 1.5 to 40 ppm by weight, most preferably of from 2 to 30 ppm by weight, for example of from 3 to 20 ppm by weight.

The other additive components described above each, if any, are present in the gasoline fuels generally in an amount of from 0.5 to 200 ppm by weight, preferably of from 1 to 100 ppm by weight, more preferably of from 1.5 to 40 ppm by weight, most preferably of from 2 to 30 ppm by weight.

Uses

Surprisingly, the inventive additives are surprisingly effective in common rail diesel engines and are notable for their particular suitability as an additive for reducing power loss resulting from external deposits and cold start problems resulting from internal deposits.

For preferred betaines even a power gain is observed. This resulting power gain is generally relative to the engine operating under similar if not identical conditions and being supplied an identical fuel composition except that the betaine is not present in the fuel. The power output of the engine (measured in kW) is measured after each completed test cycle in an engine test run in a clean-up mode and compared to show the power gain the example gives over the baseline (non-additized) fuel as described in SAE Technical Paper 2014-01-2721 or WO 2011/149799. The power gain is different from a power loss which usually relates to the power that is lost due to the formation of injector deposits which form over time as a result of fuel degradation / oxida tion products and fuel contaminants. While a power loss is a certain percentage of power output below 100% of baseline power output a power gain is greater than 100% of baseline power out put. Preferred inventive betaines show a power gain at a level of 1.0-1.7% comparable to qua ternary ammonium salts described in WO 2011/149799, however at a much lower dosage of 60 ppm compared to 500 ppm.

Furthermore, they are effective against internal deposits (referred to collectively as internal die sel injector deposits (I DID)) 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. Such deposits may be especially wax or soap-like deposits and/or carbon like polymeric deposits. The IDIDs occur either in the form of wax- or soap-like deposits (fatty acid residues and/or C12- or Ci₆-alkyl succinic acid residues detectable analytically) or in the form of polymeric carbon deposits. The soap-like deposits may often be sodium-, potassium-, calcium- and/or zinc-based deposits.

These additives furthermore improve the injector cleanliness of gasoline direct injection en gines.

Furthermore, these betaines easily form formulations in additive packages or fuels and have a reduced tendency to demix so that the storage stability of the additive packages is improved and/or the amount of solvents for the preparation of formulations may be reduced.

Especially in gasoline the betaines furthermore exhibit an anti-corrosion activity, especially against corrosion of steel, cast iron, and iron-containing alloys.

The amounts given throughout the text refer to the pure components excluding e.g. solvent, unless stated otherwise.

Examples

Reagents:

Propylene oxide (PO), 2-Ethylhexanol, 3-(Dimethylamino)propylamine (DMAPA, CAS-No. 109- 55-7), Lauryl/Myristyl alcohol (C12/C140FI) Lorol® C12-C14 S, maleic anhydride, Bis-(2- ethylhexyl)maleate from BASF; Alpha-Flexylcinnamaldehyde (CAS-No. 101-86-0), Isostearic acid CAS-No. 54680-48-7, Flexadecenylsuccinic anhydride (FIDSA, CAS-No. 32072-96-1, 94%) from TCI; Solvent Naphtha 150 ND (naphthalene depleted): Shellsol A150 ND; C13-C15- Aldehyde (CAS-No. 93821-14-8) was obtained by Rhodium-catalyzed hydroformylation of C12- C14-a-olefine as described in Example 1 of WO 2002/000580; Oleic acid (technical grade, 90%), succinic anhydride (>99%) from Aldrich, Tallow fatty acid Emery 536 from Emery. The Mannich product from Polyisobutylene (PIB) 1000 cresol, DMAPA and formaldehyde was pre pared according to Darby Kozak, Mark Davies, David Moreton & Brian Vincent (2009) The Ad sorption of Nonionic Surfactants onto Stainless Steel Surfaces from Iso-Octane, Journal of Dis persion Science and Technology, 30:6, 782-788. The purity of the Mannich product was deter mined by ¹FI-NMR to be 90%. PIB1000DMAPA was obtained by hydroformylation of high reac- tive PIB with M_n = 1000 g/mol (Glissopal 1000, Fa. BASF) followed by amination with DMAPA in analogy to WO2015/140023. C12/C140FI^*4P0^*DMAPA was obtained by base catalyzed propoxylation of C12/C140FI followed by amination with DMAPA in analogy to WO2015/140023. iC13^*15PO^*DMAPA was obtained by propoxylation of iC130H (Tridecanol N from BASF) followed by amination with DMAPA in analogy to WO2015/140023.

Methods:

Total amine number (Total N) was determined in mg KOFI/g according to DIN 13716. Tertiary amine number (Tert. N) was determined in mg KOFI/g according to DIN 13713. Primary amine number (Prim. N) was determined in mg KOFI/g after derivatization with acetyl acetone and subsequent titration with NaOMe. Secondary amine number (in mg KOFI/g) was then calculat ed: Secondary amine number = Total amine number - tertiary amine number - primary amine number. Secondary amine number is abbreviated as Sec. N.

General synthetic procedures:

1. Reductive amination of aldehydes with DMAPA was done according to A. F. Abdel- Magid et al., J. Org. Chem. 1996, 61, 3849-3862 (method II).

2. Carboxylic acid chlorides were obtained by reaction of carboxylic acids with SOCI2 as described in: Organikum, Organisch-chemisches Grundpraktikum, 24. Auflage, Wiley- VCH, 2015, page 510 f.

3. Amidation of carboxylic acid chlorides with DMAPA: To a solution of DMAPA (1.0 eq.) and NEt3 (1.2 eq.) in dichloromethane (1 L/mol DMAPA) the carboxylic acid chloride (1.0 eq.) was added at ambient temperature under cooling with an ice-bath. The reaction mixture was stirred at room temperature overnight. The solvent was removed, ethyl ace tate (1 L/mol DMAPA) was added. The organic phase was washed with water (3x450 ml/mol DMAPA) and dried over magnesium sulfate. Removal of the solvent yielded the desired carboxylic acid amide.

4. Reduction of carboxylic acid amides to diamines: This was done by reduction with lithium aluminium hydride as described in L. J. Powers, E. O. Dillingham, G. E. Bass, Journal of Pharmaceutical Sciences 1975, Vol. 64, No. 5, page 883-885.

5. Amidation of diamines to amic acid amines and quaternization with propylene oxide: The diamine (1.0 eq. according to secondary amine number) and succinic anhydride (1.0 eq.) were reacted for 4-6 h at 80°C. Completion of the reaction was checked by IR. An auto clave was filled with a solution of the amic acid amine thus obtained in 2-ethylhexanol. The amount of 2-ethylhexanol was calculated to obtain the final product solution as 50 wt% active. The autoclave was flushed with nitrogen, the solution was heated to 50°C and a pressure of 2 bar was adjusted with nitrogen. Propylene oxide (2.0 eq.) was add ed within 30 minutes. The reaction mixture was stirred at 50°C for 20 h. The reaction mixture was cooled to 25°C and the autoclave was flushed with nitrogen to obtain the product solution. The solution was transferred to a double-walled reactor. Unreacted propylene oxide was removed by nitrogen purging (10 l/h) at 50°C under vacuum (70 mbar) for 6 h. The betaine product was obtained as 50 wt% solution in 2-ethylhexanol. 1FI-NMR (CDCI3) confirmed the quaternization. The following table summarizes the synthetic inventive examples:

Inventive Example 8

The Mannich product from o-cresol substituted with a polyisobutene residue of the number av erage molecular weight Mn of 1000, DMAPA and formaldehyde (315 g, 90%, 0,232 mol) and succinic anhydride (23,1 g, 0,231 mol) were reacted for 6 h at 80°C in Solvent Naphtha 150 ND (135 g) as solvent. Completion of the reaction was checked by IR. An autoclave was filled with the amic acid amine solution thus obtained. The autoclave was flushed with nitrogen, the solu tion was heated to 50°C and a pressure of 5 bar was adjusted with nitrogen. Propylene oxide (28,1 g, 0,484 mol) was added within 30 minutes. The reaction mixture was stirred at 50°C for 15 h. The reaction mixture was cooled to 25°C and the autoclave was flushed with nitrogen to obtain the product solution. The solution was diluted with 2-ethylhexanol (216,5 g) and trans ferred to a double-walled reactor. Unreacted propylene oxide was removed by nitrogen purging (10 l/h) at 50°C under vacuum (70 mbar) for 6 h. The betaine product was obtained as 50 wt% solution. ¹H-NMR (CDCI3) confirmed the quaternization.I Inventive Example 9.

PIB1000DMAPA (253 g, total amine number 95,1 mg KOH/g, 0,214 mol) was dissolved in tolu ene (120 g) and succinic anhydride (21,4 g, 0,214 mol) was added in 3 portions over 2 h at 80°C. The reaction mixture was heated to reflux for 3 h. Completion of the reaction was checked by IR. The solvent was removed using a rotary evaporator yielding the intermediate amic acid amine. A portion of the intermediate (233 g) was dissolved in 2-ethylhexanol (244 g). An autoclave was filled with this solution. The autoclave was flushed with nitrogen, the solution was heated to 50°C and a pressure of 5 bar was adjusted with nitrogen. Propylene oxide (21,3 g, 0,367 mol) was added within 30 minutes. The reaction mixture was stirred at 50°C for 15 h. The reaction mixture was cooled to 25°C and the autoclave was flushed with nitrogen to obtain the product solution. The solution was transferred to a double-walled reactor. Unreacted propyl ene oxide was removed by nitrogen purging (10 l/h) at 50°C under vacuum (70 mbar) for 6 h. The betaine product was obtained as 50 wt% solution. ¹H-NMR (CDCI3) confirmed the quaterni- zation.

Inventive Example 10.

3. PO

In analogy to G. Bosica, A. J. Debono, Tetrahedron 2014, 70, 6607-6612 Bis-(2- ethylhexyl)maleate (170 g, 0,50 mol) and DMAPA (61 ,7 g, 0,60 mol) were reacted at 50°C for 24 h. Excess DMAPA was removed at 100°C/2 mbar using a rotary evaporator yielding the pure aza-Michael intermediate, which was further reacted with succinic anhydride and PO to the cor responding betaine according to general procedure 5.

Inventive Example 11.

The product was prepared as described in example 3 using maleic anhydride instead of succin ic anhydride.

Comparative Examples:

Comparative Example 1 : Inventive Examples 6 and 7 from WO2017/096159: Amidation of HDSA with DMAPA followed by quaternization with PO.

Comparative Example 2: Analogous to Comparative Example 1 using dodecenylsuccinic acid anhydride isomeric mixture (CAS 26544-38-7) from Aldrich instead of HDSA.

Comparative Example 3: Analogous to Comparative Example 1 using a C16+-alkenylated suc cinic acid anhydride (C16+-ASA) instead of HDSA. The C16+-ASA was derived from thermal ene reaction of C16+ olefin mixture from BASF SE (butene homopolymer, CAS 9003-29-6, max. 3 wt% C12 olefine, min. 65 wt% C16 olefine, max. 35 wt% C20+ olefin) and maleic anhydride.

Comparative Example 4: Example 3 from WO2010/132259 (succinic acid anhydride alkenylated with polyisobutene of the number average molecular weight Mn of 1000 and amidated with DMAPA, quaternized with PO).

Application Examples

Formulation for Diesel Performance Packages:

For storage stability testing, water separation tests the comparative and inventive examples were formulated in the following formulation

• 120 mg/kg solution with 50 wt% active content of the examples 1-10

• 3 mg/kg Si-containing antifoam (Fa. Momentive)

• 3 mg/kg demulsifier (Fa. Baker Hughes)

• 120 mg/kg solvent (Solvent Naphtha Heavy)

•

Test Fuels

For the application tests the packages were dosed at a treat rate of 246 mg/kg to · EN590 BO fuel from Haltermann Carless reference fuel RF 79-07/RF 06-03

• EN590 B7 fuel - from Aral refinery in Gelsenkirchen

• EN 228 compliant E0 gasoline from Haltermann (based on RF 83)

Injector nozzle coking test according to CEC F 23-01 (Peugeot XU D9) The nozzle coking performance of the comparative and inventive examples was determined in a Peugeot XUD9 engine according to CEC F 23-01. The reported flow restriction was measured at different treat rates at 0,1 mm nozzle lift (as described in the standard test method). The low er the numbers the lower is the coking.

The data show that the inventive examples show a of better performance in the nozzle coking test.

Power loss recovery / power gain based on a Peugeot DW10B clean up performance Injector nozzle fouling is investigated according to a test based on the CEC F 98-08 test set up in a Peugeot DW10B engine. For the shown clean up results the procedure CEC F-98-08 was shortened and modified. The test was accelerated by using higher Zn concentration as contam inants during the dirty up to create more severe conditions

The procedure allows to obtain injector deposits and hence power loss quicker than in standard CEC F-98-08 procedure: for the dirty up the engine was run for 4.28 hours at full load (4000 rpm) with RF 79-07 containing 3 mg/kg Zn.

The clean up/power recovery was performed within 8 hours without stops according to the CEC F-98-08 profile in RF 79-07. The fuel for clean up was contaminated with 1 mg/kg Zn and addi- tized at the treat rates stated in the table.

The clean up was calculated according to the following formula:

% clean up: (power EOT CU-power EOT DU)/(power SOT DU-power EOT DU)^*100

The power gain was calculated according to the following formula:

% power gain = ((power EOTCU/power SOT)-1)^*100. A negative value indicates a power loss compared to start of test.

SOT : Start of test EOT : End of test DU: Dirty Up CU: Clean Up

The results show clearly the significantly higher power after clean up with the inventive candi dates compared to the state of the art comparative examples.

Compared to the comparative examples the inventive components showed even a power gain at a comparable level as reported in US 9239000, however, at a much lower treat rate of 60 mg/kg compared to 500 mg/kg. The performance of the inventive betaines is much stronger than market known components as Comparative Example 4. IDID Test-Determination of Additive Effect on Internal Injector Deposits and sodium-based spray hole deposits The formation of deposits within the injector was characterized by the deviations in the exhaust gas temperatures of the cylinders at the cylinder outlet on cold starting of the DW10 engine (5 min idle mode). The formation of deposits in the injector spray holes is characterized by examin- ing maximum engine power at 4000 rpm, as described in CEC F-98-08 version 5, during the test run. To promote the formation of deposits, 1 mg/kg of Na in the form of a salt of an organic acid (so- dium naphthenate) and 20 mg/kg of dodecenylsuccinic acid were added to the fuel. I. Dirty-Up: (du) The test was conducted without addition of additive compounds according to this invention. The test run time was shortened to 6 hours; the CEC F-98-08 method was conducted without addi- tion of Zn, but with addition of 1 mg/kg sodium as sodium naphthenate and 20 mg/kg dodecen- ylsuccinic acid (DDSA), see above. In the event of deviations of the individual cylinder tempera- tures of greater than 45° C during the run from the mean for all 4 cylinders, the test run is stopped earlier and immediately, in order to avoid engine damage. After the dirty-up run, the engine was left to cool and then restarted and operated in idling mode for 5 minutes. During these 5 minutes, the engine was warmed up. The exhaust gas temperature of each cylinder was recorded. The smaller the differences between the exhaust: gas temperatures found, the smaller the amount of IDIDs formed. The exhaust gas temperatures of the 4 cylinders ("C1" to "C4") were measured at each of the cylinder outlets after 0 minutes ("ϑ0") and after 5 minutes ("ϑ5"). The results of the exhaust gas temperature measurements with average values ("A") and the greatest differences from A in the downward and upward ("+") directions for the two test runs are summarized in the over- view which follows. II. Clean-Up (cu) The test was shortened to 6 hours; the CEC F-98-08 method was conducted without addition of Zn. However, as in the dirty-up run, 1 mg/kg of Na in the form of sodium naphthenate and 20 mg/kg of dodecenylsuccinic acid were added in each case, and the engine power was deter- mined. This test was conducted by addition of additive compounds according to this invention. In the event of deviations of the individual cylinder temperatures of greater than 45 °C during the run from the mean for all 4 cylinders, the test run is stopped earlier and immediately. After the clean-up, the engine was cooled down over at least 8h and restarted. The exhaust gas temperature of each cylinder was recorded. The smaller the differences between the exhaust gas temperatures found, the smaller the amount of IDIDs formed. The exhaust gas temperatures of the 4 cylinders ("C1" to "C4") were measured at each of the cylinder outlets after 0 minutes ("ϑ0") and after 5 minutes ("ϑ5"). The results of the exhaust gas temperature measurements with average values ("A") and the greatest differences from A in the downward ("−") and upward ("+") directions are summarized in the overview which follows. Test fuel: RF 06-03

The deviation from the mean temperature of the exhaust gases is low, which suggests the re- moval of IDIDs. The compounds described by the invention are very effective against the formation of IDIDs in direct injection engines, as can be seen by the example of the Peugeot DW10, which is used in the test in a similar manner to the CEC F-98-08 procedure, but in the presence of 1 mg/kg of Na in the form of sodium naphthenate and 20 mg/kg of dodecenylsuccinic acid. DW10 Na Power Loss Test (Clean Up) To study the efficacy of the compounds of the invention against power loss, caused by metals such as Na, K, Ca and others (and not by Zn as described above) and deposits formed in the injection spray holes through the presence of those compounds, an IDID engine test as de- scribed above was used. During the dirty-up and clean-up run, the performance is measured according to CEC F-098-08, with a shortened clean-up period as described above. Power loss in the DU is calculated as follows: Powerloss,du[%]=(1−Pend,du/P0,du)*100 Power loss in the CU test is calculated as follows (negative number for power loss in the CU test means performance increase): Powerloss(DU,CU)[%]=((Pend,du−Pend,cu)/P0,du)*100 Power regain = (P after cu – P after du)/(P before du - P after du)*100% Test fuel: RF 06-03

The compounds described in this invention are effective against the formation of deposits which are caused by metals other than Zn, such as Na, K, Ca, as shown by the above Na power loss test.

Diesel Deposit Formation Test (DDFT): Prevention of Soap Like Deposits 600 mL Haltermann RF 79 07 is contaminated with a Sodium Naphthenate and dodecenylsuc- cinic acid (DDSA) solution to react 1 mg/kg Na contamination and 20 g/kg DDSA contamination in the fuel. The solution is degassed with dried air for 6 min. Afterwards the solution is pumped within 150 min through an apparatus optimized for Diesel testing (provided by PAC based on jet fuel thermal oxidation test according to ASTM D 324). Within the apparatus the fuel is flowing through a heated slit mimicking the interior of a Diesel injector. Sodium soap deposits (compa rable to internal injector deposits observed in the CEC F 110-16) are formed in specific temper ature regimes on the incorporated heater tube. After the test is finished and tube is cooled down to room temperature the tube is rinsed with pentane to remove soluble deposits.

After drying the deposit on the heater tube are investigated in maximum height and deposit vol- ume via ellipsometry (OptiReader by PAC).

The results show a significantly reduced formation of deposits formation in the test with the in ventive examples

Examples for package formulations and stability evaluation. The comparative and inventive components were formulated into a Diesel performance pack age formulation of the following composition:

• 120 mg/kg solution with 50 wt% active content of the inventive and comparative examples

• 3 mg/kg Si-containing antifoam

• 3 mg/kg demulsifier · 120 mg/kg solvent (Solvent Naphtha Heavy)

The formulations were stored at -15°C and 20°C in a conical centrifuge vial. The vials were ob served for turbidity or phase separation phenomena for 28 days. If the sample showed turbidity or phase separation the formulation failed the stability test.

Lubricant compatibility according to DGMK 531-1

Lubricant compatibility of the new detergent molecules was evaluated according to DGMK 531- 1. According to methods the lubricant and the additive are mixed and stored at 90°C for 3 days. Afterwards the mixture is diluted with diesel fuel and filtered via an 0,8 pm filter. The results show the filtration time of a mixture of an engine lubricant

Foaming performance according to BNPe NF M 07-075

Diesel fuel foaming tendency was evaluated according to BNPe NF M 07-075. The table state the foam volume and collapse time

The results show that the inventive components show slightly less foaming than the compara tive examples.

Water separation speed based on ASTM D 1094 test procedure

B7 diesel fuel was additized with 246 mg/kg of the diesel performance package formulations. Based on the ASTM D 1094 80 ml B7 diesel fuel and 20 ml. of a pH 7 buffer solution was shak en for 2 min. Afterwards the time was recorded until 15 ml and the full 20 ml. of the buffer solu tion separated

The results show that the inventive detergent molecules separate faster than or comparable to the fuel additized with the comparative formulations Injector Cleanliness in Gasoline Direct Injection Engines: The effect injector nozzle coking was measured in a Volkswagen EA 111 gasoline direct injec- tion engine The test method is a preliminary version of the upcoming CEC test for injector foul- ing in DISI engines (TDG-F-113) and was published by D. Weissenberger, J. Pilbeam, "Charac- terisation of Gasoline Fuels in a DISI Engine", lecture held at Technische Akademie Esslingen, June, 2017. The test engine is a VW EA1111.4L TSI engine with 125 kW. The test procedure is a steady state test at an engine speed of 2000 rpm and a constant torque of 56 Nm. The test procedure is performed with the following injectors: Magneti Marelli 03C 906036 E. Reference oil RL-271 from Haltermann Carless was used as engine oil. As base fuel a E0 gaso- line according to DIN EN 228 from Haltermann Carless (DISI TF Low Sulphur, Batch GJ0203T456, Orig. Batch 4) with the following properties was used: The injector fouling is observed via the Δ ti (change in injection time) compared to start of test within 20 h. The Δ ti is calculated according to the following formula: The following results were obtained:

The results show that the inventive components are also highly active against deposits in gaso line direct injection (GDI/DISI) engines Steel Corrosion Protection behavior in Gasoline Fuel acc. to ASTM D 665 A

The effect of the inventive components was tested according to ASTM D 665 A in EN 228 com pliant E0 gasoline (Haltermann CEC-RF 12-09).

Rating:

A 100% rust free

B++ 0.1 % or less of the surface covered with rust B+ 0.1 % to 5% of the surface covered with rust B 5 % to 25% of the surface covered with rust C 25 % to 50% of the surface covered with rust D 50 % to 75% of the surface covered with rust E 75 % to 100% of the surface covered with rust

Fuel without additive: Rating E

Fuel with 50 mg/kg additive of Inventive Example 2: Rating A

Fuel with 50 mg/kg additive of Inventive Example 3: Rating A

Claims

Claims 1. Betaine compounds of formula (I) _

wherein R¹ is an organic substituent with 10 to 200 carbon atoms, R² is a divalent organic group with 2 to 6 carbon atoms, preferably an alkylene group, op- tionally bearing one or more hydroxy groups, R³ and R⁴ independently of another are C1- to C4-alkyl- or hydroxy-C1- to C4-alkyl groups, R⁵ is a divalent alkylene group with 1 to 12 carbon atoms or alkenylene group with 2 to 12 carbon atoms, R⁶ is a C1- to C4-alkyl-, hydroxy-C1- to C4-alkyl or C7- to C12-aralkyl group. 2. Betaine compounds according to Claim 1, wherein substituent R¹ is of the formula R¹¹R¹²CH- wherein R¹¹ and R¹² independently of another are C9- to C100-alkyl, -alkenyl or -aralkyl, or an organic C₉- to C₁₀₀-residue comprising one or more oxygen and/or nitrogen atoms, and R¹² additionally may be hydrogen or R¹¹ and R¹² together with the carbon atom of the methin group form a five- to twelve- membered ring. 3. Betaine compounds according to Claim 1, wherein substituent R¹ is a linear or branched C₁₀- to C₁₀₀-alkyl, -alkenyl or -aralkyl, preferably linear or branched C₁₂- to C₉₀-alkyl or -alkenyl, and more preferably linear or branched C13- to C80-alkyl or -alkenyl. 4. Betaine compounds according to Claim 1, wherein substituent R¹ is of formula R¹³O-[-Xi-]n-H wherein R¹³ is a linear or branched C10- to C20-alkyl, n is a positive integer from 1 to 25, preferably from 1 to 20, more preferably from 1 to 15, and most preferably from 1 to 10, and Xi is for every i from 1 to n selected from the group consisting of -O-CH2-CH2-, -O-CH2-CH(CH3)-, -O-CH(CH3)-CH2-, -O-CH2-C(CH3)2-, -O-C(CH3)2-CH2-, -O-CH2-CH(C2H5)-, -O-CH(C2H5)-CH2- und -O-CH(CH3)-CH(CH3)-, preferably selected from the group consisting of -O-CH₂-CH(CH₃)-, -O-CH(CH₃)-CH₂-, -O-CH₂-C(CH₃)₂-, -O-C(CH3)2-CH2-, -O-CH2-CH(C2H5)-, -O-CH(C2H5)-CH2- und -O-CH(CH3)-CH(CH3)-, more preferably selected from the group consisting of -O-CH2-CH(CH3)-, -O-CH(CH3)-CH2-, -O-CH₂-C(CH₃)₂-, -O-C(CH₃)₂-CH₂-, -O-CH₂-CH(C₂H₅)- und -O-CH(C₂H₅)-CH₂-, most prefer- ably selected from the group consisting of -O-CH2-CH(C2H5)-, -O-CH(C2H5)-CH2-, -O-CH2-CH(CH3)- und -O-CH(CH3)-CH2-, and especially -O-CH2-CH(CH3)- or -O-CH(CH₃)-CH₂-. 5. Betaine compounds according to any of the preceding claims, wherein substituent R² is C2- to C6-alkylene, preferably C2- to C4-alkylene, more preferably 1,2-ethylene, 1,2-propylene or 1,3-propylene, and most preferably 1,3-propylene. 6. Betaine compounds according to any of the preceding claims, wherein substituents R³ and R⁴ independently of another are selected from the group consisting of methyl, ethyl, 2- hydroxyethyl, 2-hydroxypropyl or together may form together with the nitrogen atom form a five- to seven-membered ring, preferably are selected from the group consisting of methyl and ethyl, or together may form a 1,5-pentylene-, 1,5-3-oxa-pentylene-, 1,5-3-aza- pentylene-, or 1,4-butylene-chain, more preferably are methyl or ethyl, and most preferably are both methyl. 7. Betaine compounds according to any of the preceding claims, wherein substituent R⁵ is C₁- to C12-alkylene or C2- to C6-alkenylene, preferably C2- to C4-alkylene or C2- to C3-alkenylene, more preferably 1,2-ethylene, 1,3-propylene, 1,4-butylene or 1,2-ethenlene, and most pref- erably 1,2-ethylene. 8. Betaine compounds according to any of the preceding claims, wherein substituent R⁶ is se- lected from the group consisting of 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl, methyl, ethyl, and benzyl. 9. The use of betaine compounds of the general formula (I) according to any of the preceding claims as additives for fuels, preferably Diesel fuels or gasoline. 10. The use of betaine compounds (I) according to any of the claims 1 to 8 as deposit control additives for Diesel fuels as an additive for reducing or avoiding deposits in injection sys- tems of direct injection diesel engines, preferably in common rail injection systems, especial- ly against internal diesel injector deposits (IDIDs), and/or valve sticking in direct injection diesel engines, especially against for reducing fuel consumption of direct injection diesel en- gines, especially of diesel engines with common rail injection systems, and/or for minimiza- tion of power loss in direct injection diesel engines, preferably in diesel engines with com- mon rail injection systems, especially against power loss because of zinc and/or sodium containing deposits, and/or for increasing the power during the operation of an internal com- bustion engine. 11. The use of betaine compounds (I) according to any of the claims 1 to 8 as deposit control additives for Diesel fuels as an additive for reducing or avoiding deposits in indirect injection diesel engines. 12. The use of betaine compounds (I) according to any of the claims 1 to 8 as additives for gas- oline fuels as an additive for reducing or avoiding deposits in indirect or preferably direct in- jection gasoline engines, preferably for reducing or avoiding deposits in injectors, valves and/or combustion space, more preferably for reducing or avoiding deposits in injectors. 13. An additive concentrate comprising, in combination with at least one further fuel additive, especially with at least one further diesel fuel additive, at least one betaine compound (I) ac- cording to claim 1 to 8. 14. A fuel composition comprising, in a majority of a customary base fuel, an effective amount of at least one betaine compound (I) according to claim 1 to 8. 15. A process for preparing betaine compounds (I) according to claim 1 to 8 suitable for use in fuels by in a first step reacting and amine of formula (II)

with an anhydride of formula (III)

and subsequently reacting the reaction product with a quaternising agent, preferably select- ed from the group consisting of alkylene oxides, alkyl halides, benzyl halides, dialkyl car- bonates, dialkyl sulfates, and alkyl esters of a cycloaromatic or cycloaliphatic mono- or poly- carboxylic acid. 16. The process according to claim 15, wherein the amine of formula (II) is obtained by reaction of an amine of formula (IIa) H2N-R²-NR³R⁴ with and aldehyde or ketone of formula (IIb) R¹¹R¹²C=O and subsequent hydrogenation. 17. A process for providing a gain in power during the operation of an internal combustion en- gine comprising - supplying to said engine a fuel comprising -- a fuel which is liquid at room temperature, and -- a betaine according to any of Claims 1 to 8.