EP4038166A1 - Use of nitrogen compounds quaternised with alkylene oxide and hydrocarbyl-substituted polycarboxylic acid as additives in fuels and lubricants - Google Patents

Abstract

The present invention relates to the use of nitrogen compounds quaternized in a specific manner as an additive for gasoline fuels, especially for operation of direct injection spark ignition (DISI) engines.

Description

Use of nitrogen compounds quaternised with alkylene oxide and hydrocarbyl-substituted polycarboxylic acid as additives in fuels and lubricants

The present invention relates to the use of nitrogen compounds quaternized in a specific manner as an additive for gasoline fuels, especially for operation of direct injection spark ignition (DISI) engines.

State of the art:

Technical Background

Modern gasolines are unleaded in order to be compatible with catalytic convertors, and fuel in- jection has to be used in modern spark ignition engines, in order to achieve the required stoichi- ometric fuel/air mixtures. A typical fuel-injected spark ignition engine has multipoint fuel injec- tion, in which fuel from the injectors impinges directly onto inlet valves. An unleaded base gaso- line in such an engine tends to give rise to inlet valve deposits. A relatively new class of spark ignition engines is the class described as direct injection spark ignition engines, also known as gasoline direct injection engines; problems in such direct injection engines can arise with un- leaded gasoline by fouling of injector nozzles.

For trouble-free running, modern direct injection spark ignition engines require automotive fuels having a complex set of properties which can only be guaranteed when use is made of appro- priate gasoline additives. Such fuels usually consist of a complex mixture of chemical com- pounds and are characterized by physical parameters. Fuel additives are used among other things in order to avoid formation of deposits in the intake system and the intake valves of en- gines (keep-clean effect); on the other hand, fuel additives may be used in order to remove de- posits already formed at the valves and in the intake system (clean-up effect). Special additives have been developed to reduce or minimise inlet valve deposits and also injector nozzle fouling.

WO 2013/070503 discloses the use of quaternary ammonium salts with a certain weight loss in thermogravimetric analysis (TGA) in fuels for direct injected gasoline engines.

WO 2014/195464 discloses quaternized reaction products of tertiary alkyl amines bearing Cs- to C₄o-hydrocarbyl radicals, especially branched hydrocarbyl, with hydrocarbyl epoxides in combination with a free hydrocarbyl-substituted polycarboxylic acid as fuel additives in diesel or gasoline fuels for reducing deposits. WO 2017/9208 discloses quaternized reaction products of tertiary alkyl amines bearing Cs- to C₄o-hydrocarbyl radicals, especially branched hydrocarbyl, with hydrocarbyl epoxides in combination with a free hydrocarbyl-substituted polycarboxylic acid as corrosion inhibitors in fuels.

WO 2016/16641 discloses quaternary ammonium salts of ammonium salts substituted with optionally substituted alkyl, alkenyl or aryl groups having less than 8 carbon atoms with a carboxylic acid anion as counterion. Therefore, the substituents may contain up to 28 carbon atoms and are comparably hydrophobic as the ammonium ions disclosed in WO 2014/195464 or WO 2017/9208.

Furthermore, no anticorrosive action of such quaternary ammonium salts is disclosed, in contrast, additive or fuel compositions require addition of further corrosion inhibitors so that a potential anticorrosive action of such quaternary ammonium salts was obviously not observed.

It is a disadvantage of the compounds according to WO 2014/195464, WO 2016/16641, and WO 2017/9208 that they act as emulsifiers and tend to delay water separation of water/fuel- mixtures. Furthermore, an improved corrosion resistance is required.

The performance of the additives of the art to reduce or minimise inlet valve deposits and/or injector nozzle fouling in direct injection spark ignition engines and their interrelationship with gasoline fuels and further fuel additives in fuel compositions may still be unsatisfactory. It is, therefore, an object of the present invention to provide an improved additive for reducing inlet valve deposits and/or injector nozzle fouling and to provide an improved fuel additive formula- tion which allow an efficient control of deposits formed in the engine, especially an improved injector nozzle fouling clean-up and keep-clean performance.

It was therefore an object of the present invention to provide further fuel additives which prevent injector deposits in the operation of direct injection spark ignition (DISI) engines. Another object of the invention was to provide fuel additives which exhibit a higher electric conductivity in order to prevent electrostatic charging of fuels which may lead to ignition of fuel/oxygen-mixtures.

Brief description of the invention:

It has now been found that, surprisingly, the above object is achieved by providing quaternized nitrogen compounds of certain hydrocarbylamine compounds, and gasoline fuel compositions additized therewith. Surprisingly, the inventive additives, as illustrated more particularly by the appended use examples, are surprisingly effective in their suitability as an additive for reducing or preventing injector fouling of direct injection gasoline engines without the effect of emulsifying water/fuel- mixtures. It has furthermore been found that the compounds according to the present invention are effective in reducing and/or preventing internal valve deposits (IVD) in direct injection gasoline engines, especially Port Fuel Injection (PFI) engines.

Detailed description of the invention:

A1) Specific embodiments

The present invention relates especially to the following specific embodiments:

1. A gasoline fuel composition comprising, in a majority of a customary gasoline fuel, a proportion, especially an effective amount, of at least one reaction product comprising a quaternized nitrogen compound said reaction product being obtainable by reacting at least one compound of the following general formula 3

R_aR_bR_cN (3) in which at least one of the R_a, R_b and R_c radicals, preferably one or two, more preferably one, is a cyclic or straight-chain C₂-C₈-hydrocarbyl radical, especially straight-chain C₂-C₈-alkyl or C₅- to C₆-cycloalkyl, and the other radicals are identical or different, straight-chain or branched, saturated or unsaturated C₁-C₆-hydrocarbyl radicals, especially C₁-C₆-alkyl with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid as quaternizing agent;

2. The gasoline fuel composition according to embodiments 1 , wherein the quaternizing agent comprises an epoxide of the general formula 4 where the R_d radicals present therein are the same or different and are each H or a hydrocarbyl radical, the hydrocarbyl radical being an aliphatic or aromatic radical having at least 1 to 10 carbon atoms.

3. The gasoline fuel composition according to any of embodiments 1 to 2, wherein the free hydrocarbyl-substituted polycarboxylic acid of the quaternizing agent is a hydrocarbyl- substituted C₃-C₂₈-dicarboxylic acid. . The gasoline fuel composition according to any of embodiments 1 to 3, wherein the hydrocarbyl substituent of the hydrocarbyl-substituted polycarboxylic acid is a polyalkylene radical having a degree of polymerization of 2 to 100, or 3 to 50 or 4 to 25.

5. The gasoline fuel composition according to any of the preceding embodiments, wherein in formula 3 one of the R_a, R_b and R_c radicals is a straight-chain C₄-C₈-alkyl radical and the other radicals are C₁-C₄-alkyl.

6. The gasoline fuel composition according to any of the preceding embodiments, wherein the quaternizing agent is selected from the group consisting of ethylene oxide, propylene oxide, 1 -butene oxide, 2-butene oxide, isobutene oxide, and styrene oxide in combination with a hydrocarbyl-substituted polycarboxylic acid.

7. The gasoline fuel composition according to any of the preceding embodiments, selected from gasoline fuels, and alkanol-containing, preferably methanol, ethanol, propanol, or butanol-containing gasoline fuels, preferably bioethanol-containing fuels.

8. A quaternized nitrogen compound as defined in any of embodiments 1 to 7.

9. A process for preparing a quaternized nitrogen compound according to embodiment 8, comprising the reaction of a compound of formula (3) with a hydrocarbyl epoxide in combination with a hydrocarbyl-substituted polycarboxylic acid.

10. The use of a quaternized nitrogen compound according to embodiment 8 or prepared according to embodiment 9 as a gasoline fuel additive. 11. The use according to embodiment 10 as a gasoline fuel additive for reducing the level of deposits in the intake system of a gasoline engine, such as, more particularly, DISI and PFI (port fuel injector) engines.

12. The use according to embodiment 10 as a gasoline fuel additive for reducing the corrosion of a gasoline engine, preferably in the intake system.

13. The use according to embodiment 10 as a gasoline fuel additive for improving the level of dehazing of gasoline-water-mixtures.

14. An additive concentrate comprising, in combination with further gasoline fuel additives, at least one quaternized nitrogen compound as defined in embodiment 8 or prepared according to embodiment 9.

Test methods suitable in each case for testing the above-designated applications are known to those skilled in the art, or are described in the experimental section which follows, to which general reference is hereby explicitly made.

A2) General definitions

In the absence of statements to the contrary, the following general conditions apply:

"Quaternizable" nitrogen groups or amino groups comprise especially primary, secondary and, in particular, tertiary amino groups.

"Hydrocarbyl" should be interpreted broadly and comprises both long-chain and short-chain, straight-chain and branched hydrocarbyl radicals having 1 to 50 carbon atoms, which may optionally additionally comprise heteroatoms, for example O, N, NH, S, in the chain thereof. A specific group of hydrocarbyl radicals comprises both long-chain and short-chain, straight-chain or branched alkyl radicals having 1 to 1000, 3 to 500 or 4 to 400 carbon atoms.

"Long-chain" or "high molecular weight" hydrocarbyl radicals are straight-chain or branched hydrocarbyl radicals and have 7 to 50 or 8 to 50 or 8 to 40 or 10 to 20 carbon atoms, which may optionally additionally comprise heteroatoms, for example O, N, NH, S, in the chain thereof. In addition, the radicals may be mono- or polyunsaturated and have one or more noncumulated, for example 1 to 5, such as 1 , 2 or 3, C-C double bonds or C-C triple bonds, especially 1 , 2 or 3 double bonds. They may be of natural or synthetic origin.

They may also have a number-average molecular weight (M_n) of 85 to 20000, for example 113 to 10000, or 200 to 10 000 or 350 to 5000, for example 350 to 3000, 500 to 2500, 700 to 2500, or 800 to 1500. In that case, they are more particularly formed essentially from C_2-6, especially C_2-4, monomer units such as ethylene, propylene, n- or isobutylene or mixtures thereof, where the different monomers may be copolymerized in random distribution or as blocks. Such long- chain hydrocarbyl radicals are also referred to as polyalkylene radicals or poly-C_2-6- or poly-C₂-4- alkylene radicals. Suitable long-chain hydrocarbyl radicals and the preparation thereof are also described, for example, in WO 2006/135881 and the literature cited therein.

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. Homogeneous 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.

A specific group of long-chain hydrocarbyl radicals comprises straight-chain or branched alkyl radicals ("long-chain alkyl radicals") having 8 to 50, for example 8 to 40 or 8 to 30 or 10 to 20, carbon atoms.

A further group of specific long-chain hydrocarbyl radicals comprises polyalkylene radicals which are formed essentially from C₂-6, especially C_2-4, monomer units, such as ethylene, propylene, n- or isobutylene or mixtures thereof and have a degree of polymerization of 2 to 100, or 3 to 50 or 4 to 25.

"Short-chain hydrocarbyl" or "low molecular weight hydrocarbyl" is especially straight-chain or branched alkyl or alkenyl, optionally interrupted by one or more, for example 2, 3 or 4, heteroatom groups such as -O- or-NH-, or optionally mono- or polysubstituted, for example di-, tri- or tetrasubstituted.

"Hydrocarbylene" represents straight-chain or singly or multiply branched bridge groups having 1 to 10 carbon atoms, optionally interrupted by one or more, for example 2, 3 or 4, heteroatom groups such as -O- or -NH-, or optionally mono- or polysubstituted, for example di-, tri- or tetrasubstituted.

"Hydroxyalkyl" represents, in particular, the mono- or polyhydroxylated, for example the monohydroxylated, analogs of the above alkyl radicals, for example the linear hydroxyalkyl groups, for example those having a primary (terminal) hydroxyl group, such as hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, or those having nonterminal hydroxyl groups, such as 1-hydroxyethyl, 1- or 2-hydroxypropyl, 1- or 2-hydroxybutyl or 1-, 2- or 3-hydroxybutyl.

"Alkyl" or "lower alkyl" represents especially saturated, straight-chain or branched hydrocarbon radicals having 1 to 4, preferably 1 to 3, more preferably 1 to 2, very preferably 1 carbon atoms, for example methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1- dimethylethyl, and the singly or multiply branched analogs thereof, preferably methyl, ethyl, n- propyl, and n-butyl, more preferably methyl or ethyl, and very preferably methyl.

"Long-chain alkyl" represents, for example, saturated straight-chain or branched hydrocarbyl radicals having 8 to 50, for example 8 to 40 or 8 to 30 or 10 to 20, carbon atoms, such as octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, hencosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, squalyl, constitutional isomers, especially singly or multiply branched isomers and higher homologs thereof.

"Hydroxyalkyl" represents, in particular, the mono- or polyhydroxylated, for example the monohydroxylated, analogs of the above alkyl radicals, for example the linear hydroxyalkyl groups, for example those having a primary (terminal) hydroxyl group, such as hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, or those having nonterminal hydroxyl groups, such as 1-hydroxyethyl, 1- or 2-hydroxypropyl, 1- or 2-hydroxybutyl or 1-, 2- or 3-hydroxybutyl.

"Alkenyl" represents mono- or polyunsaturated, especially monounsaturated, straight-chain or branched hydrocarbyl radicals having 2 to 4, 2 to 6, or 2 to 7 carbon atoms and one double bond in any position, e.g. C₂-C6-alkenyl such as ethenyl, 1-propenyl, 2-propenyl, 1- methylethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1 -methyl-1 -propenyl, 2-methyl-1-propenyl, 1- methyl-2-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1- methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2- butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1 ,1- dimethyl-2-propenyl, 1 ,2-dimethyl-1 -propenyl, 1 ,2-dimethyl-2-propenyl, 1 -ethyl-1 -propenyl, 1- ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl,

1 -methyl-1 -pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1 ,1- dimethyl-2-butenyl, 1 , 1 -dimethyl-3-butenyl, 1 ,2-dimethyl-1 -butenyl,

1 .2-dimethyl-2-butenyl, 1 ,2-dimethyl-3-butenyl, 1 ,3-dimethyl-1 -butenyl,

1 .3-dimethyl-2-butenyl, 1 ,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl,

2.3-dimethyl-1 -butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl,

3.3-dimethyl-1 -butenyl, 3,3-dimethyl-2-butenyl, 1 -ethyl-1 -butenyl, 1-ethyl-2-butenyl,

1-ethyl-3-butenyl, 2-ethyl-1 -butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl,

1 ,1 ,2-trimethyl-2-propenyl, 1 -ethyl-1 -methyl-2-propenyl, 1-ethyl-2-methyl-1 -propenyl and 1-ethyl-

2-methyl-2-propenyl.

"Hydroxyalkenyl" represents, in particular, the mono- or polyhydroxylated, especially monohydroxylated, analogs of the above alkenyl radicals. "Aminoalkyl" and "aminoalkenyl" represent, in particular, the mono- or polyaminated, especially monoaminated, analogs of the above alkyl and alkenyl radicals respectively, or analogs of the above hydroxyalkyl where the OH group has been replaced by an amino group.

"Alkylene" represents straight-chain or singly or multiply branched hydrocarbyl bridging groups having 1 to 10 carbon atoms, for example C₁-C₇-alkylene groups selected from -CH₂-, -(CH₂)₂-, - (CH₂)₃-,-(CH₂)₄-, -(CH₂)₂-CH(CH₃)-, -CH₂-CH(CH₃)-CH₂-, (CH₂)₄-, -(CH₂)₅-, -(CH₂)₆, -(CH₂)₇-, - CH(CH₃)-CH₂-CH₂-CH(CH₃)- or -CH(CH₃)-CH₂-CH₂-CH₂-CH(CH₃)-, or Ci-C₄-alkylene groups selected from -CH₂-, -(CH₂)₂-, -(CH₂)₃-, -(CH₂)₄-, -(CH₂)₂-CH(CH₃)-, -CH₂-CH(CH₃)-CH₂- or C₂-C₆-alkylene groups, for example

-CH₂-CH(CH₃)-, -CH(CH₃)-CH₂-, -CH(CH₃)-CH(CH₃)-, -C(CH₃)₂-CH₂-, -CH₂-C(CH₃)₂-, -C(CH₃)₂-CH(CH₃)-, -CH(CH₃)-C(CH₃)₂-, -CH₂-CH(Et)-, -CH(CH₂CH₃)-CH₂-, -CH(CH₂CH₃)-CH(CH₂CH₃)-, -C(CH₂CH₃)₂-CH₂-, -CH₂-C(CH₂CH₃)₂-,

-CH₂-CH(n-propyl)-, -CH(n-propyl)-CH₂-, -CH(n-propyl)-CH(CH₃)-, -CH₂-CH(n-butyl)-, -CH(n-butyl)-CH₂-, -CH(CH₃)-CH(CH₂CH₃)-, -CH(CH₃)-CH(n-propyl)-, -CH(CH₂CH₃)-CH(CH₃)-, - CH(CH₃)-CH(CH₂CH₃)-, or C₂-C₄-alkylene groups, for example selected from -(CH₂)₂-, -CH₂- CH(CH₃)-, -CH(CH₃)-CH₂-, -CH(CH₃)-CH(CH₃)-, -C(CH₃)₂-CH₂-, -CH₂-C(CH₃)₂-, -CH₂- CH(CH₂CH₃)-, -CH(CH₂CH₃)-CH₂-.

"Oxyalkylene radicals" correspond to the definition of the above straight-chain or singly or multiply branched alkylene radicals having 2 to 10 carbon atoms, where the carbon chain is interrupted once or more than once, especially once, by an oxygen heteroatom. Nonlimiting examples include: -CH₂-0-CH₂-, -(CH₂)₂-0-(CH₂)₂-, -(CH₂)₃-0-(CH₂)₃-, or -CH₂-0-(CH₂)₂-, -(CH₂)₂-0-(CH₂)₃-, -CH₂-0-(CH₂)₃

"Aminoalkylene" corresponds to the definition of the above straight-chain or singly or multiply branched alkylene radicals having 2 to 10 carbon atoms, where the carbon chain is interrupted once or more than once, especially once, by a nitrogen group (especially -NH group). Nonlimiting examples include: -CH₂-NH-CH₂-, -(CH₂)₂-NH-(CH₂)₂-, -(CH₂)₃-NH-(CH₂)₃-, or -CH₂- NH-(CH₂)₂-, -(CH₂)₂-NH-(CH₂)₃-, -CH₂-NH-(CH₂)₃.

"Alkenylene" represents the mono- or polyunsaturated, especially monounsaturated, analogs of the above alkylene groups having 2 to 10 carbon atoms, especially C₂-C7-alkenylenes or C₂-C₄- alkenylene, such as -CH=CH-, -CH=CH-CH₂-, -CH₂-CH=CH-, -CH=CH-CH₂-CH₂-, -CH₂- CH=CH-CH₂-, -CH₂-CH₂-CH=CH-, -CH(CH₃)-CH=CH-, -CH₂-C(CH₃)=CH-. "Cycloalkyl" represents carbocyclic radicals having 3 to 20 carbon atoms, for example C₃-C₁₂- cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and cyclododecyl; preference is given to cyclopentyl, cyclohexyl, cycloheptyl, and also cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, or C₃-C7-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclopentylethyl, cyclohexylmethyl, where the bond to the rest of the molecule may be via any suitable carbon atom.

"Cycloalkenyl" or "mono- or polyunsaturated cycloalkyl" represents, in particular, monocyclic, mono- or polyunsaturated hydrocarbyl groups having 5 to 8, preferably up to 6, carbon ring members, for example monounsaturated cyclopenten-1-yl, cyclopenten-3-yl, cyclohexen-1-yl, cyclohexen-3-yl and cyclohexen-4-yl radicals.

"Aryl" represents mono- or polycyclic, preferably mono- or bicyclic, optionally substituted aromatic radicals having 6 to 20, for example 6 to 10, ring carbon atoms, for example phenyl, biphenyl, naphthyl such as 1- or 2-naphthyl, tetrahydronaphthyl, fluorenyl, indenyl and phenanthrenyl. These aryl radicals may optionally bear 1 , 2, 3, 4, 5 or 6 identical or different substituents.

"Alkylaryl" represents the alkyl-substituted analogs of the above aryl radicals with mono- or polysubstitution, especially mono- or disubstitution, in any ring position, where aryl likewise has the definitions given above, for example C₁-C₄-alkylphenyl, where the C₁-C₄-alkyl radicals may be in any ring position.

"Substituents" for radicals specified herein are especially, unless stated otherwise, selected from keto groups, -COOH, -COO-alkyl, -OH, -SH, -CN, amino, -NO₂, alkyl, or alkenyl groups.

"Mn" represents the number-average molecular weight and is determined in a conventional manner; more particularly, such figures relate to Mn values determined by relative methods, such as gel permeation chromatography with THF as the eluent and polystyrene standards, or absolute methods, such as vapor phase osmometry using toluene as the solvent.

"Mw" represents the weight-average molecular weight and is determined in a conventional manner; more particularly, such figures relate to Mw values determined by relative methods, such as gel permeation chromatography with THF as the eluent and polystyrene standards, or absolute methods, such as light scattering.

The "degree of polymerization" usually refers to the numerical mean degree of polymerization (determination method: gel permeation chromatography with THF as the eluent and polystyrene standards; or GC-MS coupling).

A3) Quaternizable nitrogen compounds

Quaternizable nitrogen compounds are especially:

A3.1) Tertiary amines

The tertiary amine reactant is of formula (3) in which at least one of the R_a, R_b and R_c radicals, preferably one or two, more preferably one, is a cyclic or straight-chain C₂-C₈- hydrocarbyl radical, especially straight-chain C₂-C₈-alkyl or C₅- to C₆-cycloalkyl, and the other radicals are identical or different, straight-chain or branched, saturated or unsaturated C₁-C₆-hydrocarbyl radicals, especially C₁-C₆-alkyl. In a preferred embodiment the tertiary amine bears a segment of the formula NR_aR_b where one or both, more preferably one of the radicals are a straight chain alkyl group having 2 to 8 carbon atoms. The R_c radical is a short-chain C₁-C₄-alkyl radical, such as a methyl, ethyl or propyl group. R_a and R_b are straight-chain, and may be the same or different. For example, R_a and R_b may be a straight-chain C₂-C₈-alkyl group. Alternatively, only one of the two radicals may be a C₂- to Cs-alkyl group and the other may be a methyl, ethyl or n-propyl group.

Preferred amines are those of formula

R¹⁰ _xNR¹¹ _(3-x) wherein

R¹⁰ is C₂- to C₈-alkyl or C_5- to C₆-cycloalkyl radical,

R¹¹ is C1- to C₄-alkyl, preferably C₁- to C₂-alkyl, and x is 1 or 2, preferably 1.

In a preferred embodiment one of the R_a, R_b and R_c radicals is a straight-chain C₄-C₈-alkyl radical and the other radicals are C₁-C₄-alkyl, preferably methyl. In another preferred embodiment radical R_a is cyclopentyl or cyclohexyl and the other radicals are C₁-C₄-alkyl, preferably methyl.

Further nonlimiting examples of suitable amines are:

N,N-dimethyl-N-n-octyl amine,

N,N-diethyl-N-n-octyl amine,

N,N-dimethyl-N-n-heptyl amine,

N,N-diethyl-N-n-heptyl amine,

N,N-dimethyl-N-n-hexyl amine,

N,N-diethyl-N-n-hexyl amine,

N,N-dimethyl-N-n-pentyl amine,

N,N-diethyl-N-n-pentyl amine,

N,N-dimethyl-N-n-butyl amine,

N,N-diethyl-N-n-butyl amine,

N,N-dimethyl-N-n-propyl amine,

N,N-diethyl-N-n-propyl amine,

N,N-dimethyl-N-ethyl amine, triethyl amine,

N,N-dimethyl-N-cyclopentyl amine,

N,N-diethyl-N- cyclopentyl amine,

N,N-dimethyl-N-cyclohexyl amine, and N,N-diethyl-N- cyclohexyl amine.

Preferred suitable amines are N,N-dimethyl-N-n-octyl amine,

N,N-dimethyl-N-n-heptyl amine,

N,N-dimethyl-N-n-hexyl amine,

N,N-dimethyl-N-n-pentyl amine,

N,N-dimethyl-N-n-butyl amine,

N,N-dimethyl-N-n-propyl amine,

N,N-dimethyl-N-ethyl amine,

N,N-dimethyl-N-cyclopentyl amine, and N,N-dimethyl-N-cyclohexyl amine.

More preferred suitable amines are N,N-dimethyl-N-n-octyl amine,

N,N-dimethyl-N-n-hexyl amine, N,N-dimethyl-N-n-pentyl amine,

N,N-dimethyl-N-n-butyl amine,

N,N-dimethyl-N-n-propyl amine,

N,N-dimethyl-N-ethyl amine,

N,N-dimethyl-N-cyclopentyl amine, and N,N-dimethyl-N-cyclohexyl amine.

Very preferred suitable amines are N,N-dimethyl-N-n-octyl amine,

N,N-dimethyl-N-n-hexyl amine,

N,N-dimethyl-N-n-butyl amine,

N,N-dimethyl-N-cyclopentyl amine, and N,N-dimethyl-N-cyclohexyl amine.

A4) Quaternizing agents:

In a further particular embodiment, the compound of formula (3) is quaternized with at least one quaternizing agent selected from epoxides, especially hydrocarbyl epoxides. where the R_d radicals present therein are the same or different and are each H or a hydrocarbyl radical, where the hydrocarbyl radical has at least 1 to 10 carbon atoms. More particularly, these are aliphatic or aromatic radicals, for example linear or branched Ci_io-alkyl radicals, or aromatic radicals, such as phenyl or C_1-4-alkylphenyl.

Examples of suitable hydrocarbyl epoxides include aliphatic and aromatic alkylene oxides such as, more particularly, C_2-12-alkylene oxides such as ethylene oxide, propylene oxide, 1 ,2- butylene oxide, 2,3-butylene oxide, 2-methyl-1 ,2-propene oxide (isobutene oxide), 1 ,2-pentene oxide, 2,3-pentene oxide, 2-methyl-1 ,2-butene oxide, 3-methyl-1 ,2-butene oxide, 1 ,2-hexene oxide, 2,3-hexene oxide, 3,4-hexene oxide, 2-methyl-1 ,2-pentene oxide, 2-ethyl-1 ,2-butene oxide, 3-methyl-1 ,2-pentene oxide, 1 ,2-decene oxide, 1 ,2-dodecene oxide or 4-methyl-1 ,2- pentene oxide; and aromatic-substituted ethylene oxides such as optionally substituted styrene oxide, especially styrene oxide or 4-methylstyrene oxide. Preferred hydrocarbyl epoxides are propylene oxide, 1 ,2-butylene oxide, 2,3-butylene oxide, isobutene oxide and styrene oxide.

More preferred hydrocarbyl epoxides are propylene oxide and 1 ,2-butylene oxide.

The most preferred hydrocarbyl epoxides is propylene oxide.

A5) Hydrocarbyl-substituted dicarboxylic acids:

The epoxides as quaternizing agents are used in the presence of free hydrocarbyl-substituted unsaturated, especially saturated, optionally substituted, especially unsubstituted, protic acids, such as particularly with hydrocarbyl-substituted dicarboxylic acids, especially hydrocarbyl- substituted C₃-C₂₈or C₃-C₁₂-dicarboxylic acids, especially unsubstituted saturated C₃-C₆- dicarboxylic acid, very preferably C₄-dicarboxylic acids.

Suitable dicarboxylic acids here are saturated acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid, or higher molecular weight acids, such as tetra-, hexa- or octadecanedioic acid; substituted acids, such as malic acid, a-ketoglutaric acid, oxaloacetic acid; glutamic acid; aspartic acid; and unsaturated acids, such as maleic acid and fumaric acid; such as, more particularly, malonic acid, succinic acid, glutaric acid, adipic acid and pimelic acid.

Additionally suitable are aromatic dicarboxylic acids, for example phthalic acid, terephthalic acid, and iso phthalic acid.

If required or desired, it is also possible to use hydrocarbyl-substituted dicarboxylic acids in their anhydride form. For the quaternization, the ring opening of the anhydride is then brought about by addition of water.

Further configurations relating to hydrocarbyl-substituted dicarboxylic acids:

The hydrocarbyl-substituted dicarboxylic acids can be prepared by hydrolysis of the correspond- ing hydrocarbyl-substituted dicarboxylic anhydrides in a manner known in principle, as de- scribed, for example, in DE 2443537. The hydrolysis is preferably conducted with stoichiometric amounts of water at temperatures of 50 to 150°C, but it is also possible to use an excess of water. The hydrolysis can be conducted without solvent or in the presence of an inert solvent. Typical examples are, for example, solvents from the Solvesso series, toluene, xylene or straight-chain and branched saturated hydrocarbons such as paraffins or naphthenes. The sol- vent can be removed after the hydrolysis, but preferably remains, and is used as solvent or cosolvent for the subsequent quaternization.

In a preferred embodiment in the hydrocarbyl-substituted dicarboxylic acid the hydrocarbyl sub- stituent is derived from oligomerisation or polymerisation of propene and/or isobutene with a degree of polymerisation of from 3 to 50, preferably from 4 to 40. Preferred are polypropylene- or polyisobutylene-substituted succinic acids.

Preferred hydrocarbyl-substituted dicarboxylic anhydrides are hydrocarbyl-substituted succinic anhydrides, as sold, for example, by Pentagon: n-dodecenylsuccinic anhydride CAS 19780-11 - 1 , n-octadecenylsuccinic anhydride CAS 28777-98-2, i-octadecenylsuccinic anhydride CAS 28777-98-2, i-hexadecenylsuccinic anhydride/i-octadecenylsuccinic anhydride CAS 32072-96-1 & 28777-98-2, n-octenylsuccinic anhydride CAS 26680-54-6, tetrapropenylsuccinic anhydride CAS 26544-38-7.

Additionally preferred is polyisobutenesuccinic anhydride (PIBSA). The preparation of PIBSA from polyisobutene (PIB) and maleic anhydride (MA) is known in principle and leads to a mix- ture of PIBSA and bismaleated PIBSA (BM PIBSA, please see scheme 1 below), which is gen- erally not purified but processed further as it is. The ratio of the two components to one another can be reported as the bismaleation level (BML). The BML is known in principle (see US 5,883,196) and is determined as described in US 5,883,196.

Scheme 1

Especially preferred is PIBSA having a bismaleation level of up to 30%, preferably up to 25% and more preferably up to 20%. In general, the bismaleation level is at least 2%, preferably at least 5% and more preferably at least 10%. Controlled preparation is described, for example, in US 5,883,196. For the preparation, high-reactivity PIB (HR-PIB) having Mn in the range from 500 to 3000, for example 550 to 2500, 800 to 1200 or 900 to 1100 is particularly suitable. Mn is determined by means of GPC as described in US 5,883,196. Particularly preferred PIBSA pre- pared from HR-PIB (Mn = 1000) has hydrolysis numbers of 85-95 mg KOH/g.

A nonlimiting example of a particularly suitable PIBSA is Glissopal^® SA F from BASF, prepared from H R-PIB (Mn = 1000) having a bismaleation level of 15% and a hydrolysis number of 90 mg KOH/g.

It is also conceivable, albeit less preferable, to react the abovementioned hydrocarbyl- substituted dicarboxylic anhydrides not with water but with an alcohol, preferably a monoalco- hol, more preferably an alkanol, or an amine to give the corresponding monoester or monoam- ide of the hydrocarbyl-substituted dicarboxylic acids. What is important is that one acid function remains in the molecule in the case of such a reaction.

We the quaternization is conducted in the presence of an alcohol, preference is given to using the same alcohol for such a reaction of the hydrocarbyl-substituted dicarboxylic anhydrides as that used as solvent in the quaternization, i.e. preferably 2-ethylhexanol or 2-propylheptanol, or else butyldiglycol, butylglycol, methoxypropoxypropanol or butoxydipropanol.

Such an alcoholysis is preferably conducted with stoichiometric amounts of alcohol or amine at temperatures of 50 to 150°C, but it is also possible to use an excess of alcohol or amine, pref- erably alcohol. In that case, the latter appropriately remains in the reaction mixture and serves as solvent in the subsequent quaternization.

A5) Preparation of inventive additives: a) Quaternization

The quaternization of amine (3) with an epoxide of the formula (4) is likewise based on known processes. When the boiling temperature of one component of the reaction mixture, especially of the epoxide, at standard pressure is above the reaction temperature, the reaction is appropriately performed in an autoclave.

For example, in an autoclave, a solution of the tertiary amine is admixed with the organic hydrocarbyl-substituted dicarboxylic acid (for example polyisobutenesuccinic acid) in the required, approximately stoichiometric amounts. It is possible to use, for example, 0.1 to 2.0, 0.2 to 1.5 or 0.5 to 1.25 equivalents of dicarboxylic acid per equivalent of quaternizable tertiary nitrogen atom. More particularly, however, approximately molar proportions of the dicarboxylic acid are used. This is followed by sufficient purging with N2, and establishment of a suitable supply pressure, and metered addition of the epoxide (e.g. propylene oxide) in the stoichiometric amounts required at a temperature between 20°C and 180°C. It is possible to use, for example, 0.1 to 4.0, 0.2 to 3 or 0.5 to 2 equivalents of epoxide per equivalent of quaternizable tertiary nitrogen atom. More particularly, however, about 1 to 2 equivalents of epoxide are used in relation to the tertiary amine, in order to fully quaternize the tertiary amine group. More particularly, it is also possible to use a molar excess of alkylene oxide, as a result of which the free carboxyl group of the dicarboxylic acid is partly or fully esterified. This is followed by stirring over a suitably long period of a few minutes to about 24 hours, for example about 10 h, at a temperature between 20°C and 180°C (e.g. 50°C), cooling, for example to about 20 to 50°C, purging with N2 and emptying of the reactor.

The reaction can be effected at a pressure of about 0.1 to 20 bar, for example 1 to 10 or 1.5 to 5 bar. However, the reaction can also be effected at standard pressure. An inert gas atmosphere is particularly appropriate, for example nitrogen.

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 from the Solvesso series, toluene or xylene or 2-ethylhexanol, or 2-propylheptanol, and also butyldiglycol, butylglycol, methoxypropoxypropanol, butoxydipropanol or straight-chain or branched saturated hydrocarbons such as paraffins or naphthenes. However, the quaternization can also be performed in the absence of a solvent.

The quaternization can preferably be performed in the presence of a protic solvent, optionally also in combination with an aliphatic or aromatic solvent. Suitable protic solvents especially have a dielectric constant (at 20°C) of greater than 7. The protic solvent may comprise one or more OH groups and may also be water. Suitable solvents may also be alcohols, glycols and glycol ethers. More particularly, suitable protic solvents may be those specified in WO 2010132259. Especially suitable solvents are methanol, ethanol, n-propanol, isopropanol, all isomers of butanol, all isomers of pentanol, all isomers of hexanol, 2-ethylhexanol, 2- propylheptanol, and also mixtures of various alcohols. The presence of a protic solvent can have a positive effect on the conversion and the reaction rate of the quaternization. b) Workup of the reaction mixture The reaction end product thus formed can theoretically be purified further, or the solvent can be removed. Optionally, excess reagent, for example excess epoxide, can be removed. This can be accomplished, for example, by introducing nitrogen at standard pressure or under reduced pressure. In order to improve the further processability of the products, however, it is also possible to add solvents after the reaction, for example solvents of the Solvesso series, 2- ethylhexanol, or essentially aliphatic solvents. Usually, however, this is not absolutely necessary, and so the reaction product is usable without further purification as an additive, optionally after blending with further additive components (see below).

In a preferred embodiment of the present invention, the quaternized ammonium compounds have a weight loss in a thermogravimetric analysis (TGA) at 350°C of less than 50% by weight, for example not more than than 45%, not more than than 40%, not more than than 35%, not more than than 30% weight loss.

For this purpose, a thermogravimetric analysis (TGA) is conducted in accordance with standard ISO-4154. Specifically, in the test, a run from 50° to 900°C is conducted at a rate of temperature rise of 20°C per minute under a nitrogen atmosphere at a flow rate of 60 ml. per minute.

B) Further additive components

The fuel additized with the inventive quaternized additive is a gasoline fuel.

The fuel may comprise further customary additives to improve efficacy and/or suppress wear.

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

Typical examples of suitable coadditives are listed in the following section:

B1) Deposit control additives

The customary deposit control additives are preferably amphiphilic substances which possess at least one hydrophobic hydrocarbon radical with a number-average molecular weight (M_n) of 85 to 20000 and at least one polar moiety selected from: (Da) mono- or polyamino groups having up to 6 nitrogen atoms, at least one nitrogen atom having basic properties;

(Df) polyoxy-C₂- to C₄-alkylene moieties terminated by hydroxyl groups, mono- or polyamino groups, at least one nitrogen atom having basic properties, or by carbamate groups;

(Dg) carboxylic ester groups;

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

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

The hydrophobic hydrocarbon radical in the above deposit control additives, which ensures adequate solubility in the fuel, has a number-average molecular weight (M_n) of 85 to 20000, preferably of 113 to 10000, more preferably of 300 to 5000, even more preferably of 300 to 3000, even more especially preferably of 500 to 2500 and especially of 700 to 2500, in particular of 800 to 1500. As typical hydrophobic hydrocarbon radicals, especially in conjunction with the polar, especially polypropenyl, polybutenyl and polyisobutenyl radicals with a number- average molecular weight M_n of preferably in each case 300 to 5000, more preferably 300 to 3000, even more preferably 500 to 2500, even more especially preferably 700 to 2500 and especially 800 to 1500 into consideration.

Examples of the above groups of deposit control additives include the following:

Additives comprising mono- or polyamino groups (Da) are preferably polyalkenemono- or polyalkenepolyamines based on polypropene or on high-reactivity (i.e. having predominantly terminal double bonds) or conventional (i.e. having predominantly internal double bonds) polybutene or polyisobutene 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, diethylenetriamine, 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 possible preparative route is by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to give the carbonyl or carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. The amines used here for the amination may be, for 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 (Da) are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described more particularly in WO-A 97/03946.

Further particular additives comprising monoamino groups (Da) are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described more particularly in DE-A 196 20262.

Additives comprising polyoxy-C₂-C₄-alkylene moieties (Df) are preferably polyethers or polyetheramines which are obtainable by reaction of C₂- to C₆₀-alkanols, C₆- to C₃₀-alkanediols, mono- or di-C₂- to C₃₀-alkylamines, C₁- to C₃₀-alkylcyclohexanols or C₁- 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 310 875, EP-A 356 725, EP-A 700 985 and US-A 4 877416. In the case of polyethers, such products also have carrier oil properties. Typical examples thereof are tridecanol butoxylates or isotridecanol butoxylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates, and also the corresponding reaction products with ammonia.

Additives comprising carboxylic ester groups (Dg) are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, especially those having a minimum viscosity of 2 mm²/s at 100°C, as described more particularly in DE-A 38 38 918. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids, and particularly suitable ester alcohols or ester polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, of isononanol, of isodecanol and of isotridecanol. Such products also satisfy carrier oil properties. Additives comprising moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or especially imido groups (Dh) are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and especially the corresponding derivatives of polyisobutenylsuccinic anhydride which are obtainable by reacting conventional or high-reactivity polyisobutene having M_n = preferably 300 to 5000, more preferably 300 to 3000, even more preferably 500 to 2500, even more especially preferably 700 to 2500 and especially 800 to 1500, with maleic anhydride by a thermal route in an ene reaction or via the chlorinated polyisobutene. The moieties having hydroxyl and/or amino and/or amido and/or imido groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of di- or polyamines which, in addition to the amide function, also have free amine groups, succinic acid derivatives having an acid and an amide function, carboximides with monoamines, carboximides with di- or polyamines which, in addition to the imide function, also have free amine groups, or diimides which are formed by the reaction of di- or polyamines with two succinic acid derivatives. In the presence of imido moieties D(h), the further deposit control additive in the context of the present invention is, however, used only up to a maximum of 100% of the weight of compounds with betaine structure. Such fuel additives are common knowledge and are described, for example, in documents (1) and (2). They are preferably the reaction products of alkyl- or alkenyl-substituted succinic acids or derivatives thereof with amines and more preferably the reaction products of polyisobutenyl-substituted succinic acids or derivatives thereof with amines. Of particular interest in this context are reaction products with aliphatic polyamines (polyalkyleneimines) such as especially ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, which have an imide structure.

Additives comprising moieties (Di) obtained by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines are preferably reaction products of polyisobutene- substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols may originate from conventional or high-reactivity polyisobutene having M_n = 300 to 5000. Such "polyisobutene Mannich bases" are described more particularly in EP-A 831 141.

One or more of the deposit control additives mentioned can be added to the fuel in such an amount that the dosage of these deposit control additives is preferably 25 to 2500 ppm by weight, especially 75 to 1500 ppm by weight, in particular 150 to 1000 ppm by weight. B2) Carrier 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 viscosities, for example, from the SN 500 - 2000 class; but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. Likewise useful is a fraction which is obtained in the refining of mineral oil and is known as “hydrocrack oil” (vacuum distillate cut having a boiling range of from about 360 to 500°C, obtainable from natural mineral oil which has been catalytically hydrogenated under high pressure and isomerized and also deparaffinized). Likewise suitable are mixtures of the abovementioned mineral carrier oils.

Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins or polyinternalolefins), (poly)esters, (poly)alkoxylates, polyethers, aliphatic 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 polyoxy-C₂- to C₄-alkylene moieties obtainable by reacting C₂- to C₆₀-alkanols, C₆- to C₃₀- alkanediols, mono- or di-C₂- to C₃₀-alkylamines, C₁- to C₃₀-alkylcyclohexanols or C₁- 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 310 875, EP-A 356725, EP-A 700 985 and US-A 4,877,416. For example, the polyetheramines used may be poly-C₂- to C₆-alkylene oxide amines or functional derivatives thereof. Typical examples thereof are tridecanol butoxylates or isotridecanol butoxylates, 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 3838 918. The mono-, di- or tricarboxylic acids used may be aliphatic or aromatic acids; particularly suitable ester alcohols or ester polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, for example di(n- or isotridecyl) phthalate.

Further suitable carrier oil systems are described, for example, in DE-A 3826608, DE-A 41 42 241 , DE-A 4309074, EP-A 452 328 and EP-A 548617.

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 alcohols 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 C₆- to Cis-alkyl radical. Particular examples include tridecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherification products) of monohydric aliphatic C₆- to Cis- alcohols with C₃- to C₆-alkylene oxides. Examples of monohydric aliphatic C₆-C₁₈-alcohols are hexanol, heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 3-propylheptanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol 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 preferred alcohol is tridecanol. Examples of C₃- to C₆-alkylene oxides are propylene oxide, such as 1,2-propylene oxide, butylene oxide, such as 1 ,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Particular preference among these is given to C₃- to C₄-alkylene oxides, i.e. propylene oxide such as 1,2-propylene oxide and butylene oxide such as 1 ,2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Especially butylene oxide is used.

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.

The carrier oil or the mixture of different carrier oils is added to the fuel in an amount of preferably 1 to 1000 ppm by weight, more preferably of 10 to 500 ppm by weight and especially of 20 to 100 ppm by weight.

B4) Lubricity improvers Suitable lubricity improvers or friction modifiers are based typically on fatty acids or fatty acid esters. Typical examples are tall oil fatty acid, as described, for example, in WO 98/004656, and glyceryl monooleate. The reaction products, described in US 6743266 B2, of natural or synthetic oils, for example triglycerides, and alkanolamines are also suitable as such lubricity improvers.

B5) Corrosion inhibitors

Suitable corrosion inhibitors are, for example, succinic esters, 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).

B6) Demulsifiers

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

B7) Dehazers

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).

B10) Antioxidants

Suitable antioxidants are, for example, substituted phenols, such as 2,6-di-tert-butylphenol and 6-di-tert-butyl-3-methylphenol, and also phenylenediamines such as N,N'-di-sec-butyl-p- phenylenediamine.

B11) Metal deactivators Suitable metal deactivators are, for example, salicylic acid derivatives such as N,N'- disalicylidene-1 ,2-propanediamine.

B12) Solvents

Suitable solvents are, for example, nonpolar organic solvents such as aromatic and aliphatic hydrocarbons, for example toluene, xylenes, white spirit and products sold under the trade names SHELLSOL (Royal Dutch/Shell Group) and EXXSOL (ExxonMobil), and also polar organic solvents, for example, alcohols such as 2-ethylhexanol, decanol and isotridecanol. Such solvents are usually added to the fuel together with the aforementioned additives and coadditives, which they are intended to dissolve or dilute for better handling.

C) Fuels

Useful gasoline fuels include all commercial gasoline fuel compositions. One typical representative which shall be mentioned here is the Eurosuper base fuel to EN 228, which is customary on the market. In addition, gasoline fuel compositions of the specification according to WO 00/47698 are also possible fields of use for the present invention.

The term "gasoline" includes blends of distillate hydrocarbon fuels with oxygenated compounds such as ethanol, as well as the distillate fuels themselves.

Suitable gasolines are e.g. those described in Ullmann’s Encyclopedia of Industrial Chemistry, 5th edition, 1990, volume A16, page 719 ff.

Suitable gasolines are e.g. those having an aromatics content of not more than 60% by volume, e.g. not more than 42% by volume or not more than 35% by volume and/or a sulfur content of not more than 2000 ppm by weight, e.g. not more than 150 ppm by weight or not more than 10 ppm by weight.

In a preferred embodiment, the aromatics content of the gasoline is e.g. from 10 to 50% by volume, e.g. from 30 to 42% by volume, in particular from 32 to 40% by volume or not more than 35% by volume.

In another preferred embodiment, the sulfur content is e.g. of from 2 to 500 ppm by weight, e.g. of from 5 to 100 or not more than 10 ppm by weight. In another preferred embodiment, the olefin content of the gasoline can be up to 50% by volume, e.g. from 6 to 21% by volume, in particular from 7 to 18% by volume.

In another preferred embodiment, the gasoline has a benzene content of not more than 5% by volume, e.g. from 0.5 to 1.0% by volume, in particular from 0.6 to 0.9% by volume.

In another preferred embodiment, the gasoline has an oxygen content of not more than 30% by weight, e.g. up to 10% by weight or from 1.0 to 3.7% by weight, and in particular from 1.2 to 2.7% by weight.

Particular preference is given to a gasoline which has an aromatics content of not more than 38% by volume or preferably not more than 35% by volume, and at the same time an olefin content of not more than 21 % by volume, a sulfur content of not more than 50 or 10 ppm by weight, a benzene content of not more than 1.0% by volume and an oxy-gen content of from 1.0 to 2.7% by weight.

The amount of alcohols and ethers contained in the gasoline may vary over wide ranges.

Typical 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.

It is also possible to use pure alcohols as fuels, especially pure ethanol (E100 fuel) or pre methanol.

The summer vapor pressure of the gasoline (at 37°C) is usually not more than 70kPa, in particular not more than 60kPa.

The research octane number (RON) of the gasoline is usually from 75 to 105. A usual range for the corresponding motor octane number (MON) is from 65 to 95.

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

Experimental:

B. Preparation examples: Preparation examples 1 to 4: Quaternization of tertiary amines with propylene oxide in the presence of hydrocarbyl-substituted succinic acids R₁ here represents long-chain hydrocarbyl; R₂, R₃ and R₄ correspond to R_a, R_b and R_c as defined above; R₅ corresponds to R_d as defined above; and R is H or a radical obtained by esterification with the epoxide, for example -CH CH(R )OH a) Reagents used: Polyisobutylene succinic anhydride (PIBSA, Glissopal® SA (BASF)):

Prepared from maleic anhydride and high-reactive polyisobutylene Mn = 1000 g/mol via thermal ene reaction, saponification number 89,7 mg KOH/g (M = 1251 g/mol). Polyisobutylene succinic acid (M = 1269 g/mol) was prepared from PIBSA by hydrolysis with the equimolar amount of water at 80 °C.

N,N-Dimethylethylamine (CAS 926-63-6, 99%), N,N-Dimethyl-n-octylamine (CAS 7378-99-6, 95%) from Aldrich; N,N-Dimethyl-n-butylamine (CAS 927-62-8, 99%) from TCI; N,N- Dimethylcyclohexylamine (CAS 98-94-2, 99%), propylene oxide (PO), 2-Ethylhexanol from BASF; Demulsifier: Tolad 9360K® from Baker Flughes; Carrier oil: Tridecanol propoxylated with 15 mol propylene oxide from BASF; Kerocom PIBA: Polyisobutylene 1000 primary amine derived from hydroformylation of highly reactive polyisobutylene (Mn = 1000 g/mol, Glissopal® 1000, BASF) followed by amination with ammonia according to DE10314809A1, 65 wt% solution in aliphatic solvent, from BASF. b) General synthesis method

A 2 I autoclave was filled with a solution of the respective amine and polyisobutylene succinic acid in 2-ethylhexanol. 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 was added 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 2 I double-walled reactor. Unreacted propylene oxide was removed by ni- trogen purging (10 l/h) at 50°C under vacuum (70 mbar) for 6 h. The product was obtained as 50 wt% solution in 2-ethylhexanol. 1 H-NMR (CDCl₃) confirmed the quaternization. The degree of quaternization was determined by 1 H-NMR (CDCb) as described in WO 2014/195464. For thermogravimetric analysis (TGA) the solvent was removed using a Kugelrohr distillation appa- ratus (T = 70°C, 3 h, p = 10^-3 mbar). Subsequently TGA was measured from 30°C to 350°C with a temperature increase of 20°C/min under a nitrogen atmosphere at a flow rate of 60 mL/min. c) Experiments conducted

Table 1 summarizes the reagents and masses employed in the inventive examples. In addition, Table 1 summarizes characteristic ¹H-NMR shifts of the products, the degrees of quaternization, and the mass changes at T = 350 °C according to TGA

Table 1. d [ppm]: ¹H-NMR shift for RN(CH₃)₂CH₂CH(OH)Me. (¹ H-NMR, CDCI₃)

Comparative Example 1 : Inventive example 6 from WO 2014/195464. The degree of quaternization was determined to be 96%. C. Use examples:

In the use examples which follow, the additives are used either as a pure substance (as synthesized in the above preparation examples) or in the form of an additive package. Application Examples

1. Injector cleanliness in direct injecting gasoline engines (Direct Injection Spark Ignition (DISI) or Gasoline Direct Injection (GDI)): Keep-clean performance The test method is a preliminary version of the upcoming CEC test for injector fouling in DISI engines (TDG-F-113) and was published by D. Weissenberger, J. Pilbeam, "Characterisation of Gasoline Fuels in a DISI Engine", lecture held at Technische Akademie Esslingen, June, 2017. The test engine is a VW EA111 1 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:

Nozzle coking is measured as change of activation time of the injector (tij), which is measured periodically within the test procedure. Due to nozzle coking, the hole diameters of the injector holes are reduced, and the activation time adjusted by the Engine Control Unit (ECU) accord- ingly. The activation time in milliseconds is a direct readout from the ECU via ECU control soft- ware. A prolongation of activation time is an indicator for nozzle coking. The test duration was 48 h.

After a run-in period of 30 minutes 3 data points for ti J were determined within 15 minutes, which mean value gives the activation time at start of test. At the end of the test 3 data points were determined within 15 minutes, which mean value gives the activation time at end of test. The test result is the relative change of activation time of the injectors.

Table 1. DISI keep-clean results. The test results demonstrate excellent keep-clean results against DISI injector fouling within the accuracy of measurement for both inventive example 4 and comparative example 1 at the same dosage of 81.5 mg/kg active substance. 2. Injector cleanliness in direct injecting gasoline engines (Direct Injection Spark Ignition (DISI) or Gasoline Direct Injection (GDI)): Clean-up performance

In the dirty-up-clean-up sequence dirty-up is achieved by running the engine over 48 hours as described for the keep-clean procedure (see above) with base fuel. The relative change of acti- vation time is determined as described above for the keep-clean test. The subsequent clean-up run is done with additized base fuel over 10 h. At the end of the test 3 data points are deter- mined within 15 minutes, which mean value gives the activation time at end of clean-up test.

The test result for the clean-up is the relative change of activation time of the injectors relative to the average activation time determined at the end of the dirty-up phase. The results are summa- rized in table 2.

Table 2. DISI clean-up results. The test results show that PI BA alone is not capable of completely removing the deposits formed during the dirty-up at a dosage of 300 mg/kg (tests No. 1 and 2). The results further show that both comparative example 1 and inventive example 4 at dosages of 30 mg/kg (15 mg/kg active) as top-up to 300 mg/kg Kerocom PIBA are capable of completely removing the deposits formed during the dirty-up (tests No. 3-6). 3. Demulsification behavior according to ASTM D 1094-07.

The following fuel additive packages were tested for their demulsification behavior according to ASTM D 1094-07 (standard test method for water reaction). As base fuel a E0 gasoline CEC RF-12-09 Batch 9 from Haltermann Carless was used.

The rating according to ASTM D 1094-07 is as follows: Separation

Interface Table 3a. Demulsification behavior according to ASTM D1094-07.

Table 3b. Demulsification behavior according to ASTM D1094-07 (continued).

The test results show that surprisingly fuel additive package 2 containing inventive example 4 has a more favorable demulsification behavior compared to fuel additive package 1 containing comparative example 1 (compare entry 1 with 5, 2 with 6, and 3 with 7, respectively). In addi- tion, the fuel additive package 2 containing inventive example 4 surprisingly responds more fa- vorable to the addition of a small dosage of demulsifier Tolad 9360K compared to the fuel addi- tive package 1 containing comparative example 1 (compare entry 4 with 8). 4. Corrosion test according to ASTM D665-14 (Standard Test Method for Rust-Preventing

Characteristics of Inhibited Mineral Oil in the Presence of Water) Corrosion tests according to ASTM D665-14 were performed with fuel additive packages 1 and 2, respectively. As base fuel a E0 gasoline CEC RF-12-09 Batch 9 from Haltermann Carless was used. The tests were performed at room temperature instead of 60°C. The test results are summarized in table 4.

Table 4. Corrosion test results according to ASTM D665-14.

The test results show that fuel additive package 2 containing inventive example 4 shows a slightly improvedlevel of corrosion protection performance in water, respectively a comparable corrosion protection performance in synthetic sea water compared to fuel additive package 1 containing comparable example 1 at the same dosage.

The test was evaluated by the NACE assessment as listed in the table below:

5. Electric Conductivity Test

The electric conductivity of isoparaffinic solvent Isopar M™ (Exxon Mobil) as a model for fuels and lubricant basestocks containing 400 mg /kg (200 mg/kg active compound) of the quaternary ammonium compounds were determined. The results are summarized in Table 5.

Table 5. Electric conductivity

The tests show that Inventive Examples 1 and 4 are capable of inducing much higher electric conductivities compared to Comparative Example 1.

Claims

Claims

1. A gasoline fuel composition comprising, in a majority of a customary gasoline fuel, a proportion, especially an effective amount, of at least one reaction product comprising a quaternized nitrogen compound said reaction product being obtainable by reacting at least one compound of the following general formula 3

R_aR_bR_cN (3) in which at least one of the R_a, R_b and R_c radicals, preferably one or two, more preferably one, is a cyclic or straight-chain C₂-C₈-hydrocarbyl radical, especially straight-chain C₂-C₈-alkyl or C₅- to C₆-cycloalkyl, and the other radicals are identical or different, straight-chain or branched, saturated or unsaturated C₁-C₆-hydrocarbyl radicals, especially C₁-C₆-alkyl with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid as quaternizing agent.

2. The gasoline fuel composition according to claim 1 , wherein the quaternizing agent comprises an epoxide of the general formula 4 where the R_d radicals present therein are the same or different and are each H or a hydrocarbyl radical, the hydrocarbyl radical being an aliphatic or aromatic radical having at least 1 to 10 carbon atoms.

3. The gasoline fuel composition according to any of claims 1 to 2, wherein the free hydrocarbyl-substituted polycarboxylic acid of the quaternizing agent is a hydrocarbyl- substituted C₃-C₂₈-dicarboxylic acid.

4. The gasoline fuel composition according to any of claims 1 to 3, wherein the hydrocarbyl substituent of the hydrocarbyl-substituted polycarboxylic acid is a polyalkylene radical having a degree of polymerization of 2 to 100, or 3 to 50 or 4 to 25.

5. The gasoline fuel composition according to any of the preceding claims, wherein in formula 3 one of the R_a, R_b and R_c radicals is a straight-chain C₄-C₈-alkyl radical and the other radicals are C₁-C₄-alkyl.

6. The gasoline fuel composition according to any of the preceding claims, wherein in formula (3) R_a is selected from the group consisting of ethyl, n-butyl, n-pentyl, n-hexyl, and n-octyl and R_b and R_c are methyl.

7. The gasoline fuel composition according to any of the claims 1 to 5, wherein in formula (3) R_a is selected from the group consisting of cyclopentyl and cyclohexyl and R_b and R_c are methyl.

8. The gasoline fuel composition according to any of the preceding claims, wherein the quaternizing agent is selected from the group consisting of ethylene oxide, propylene oxide, 1 -butene oxide, 2-butene oxide, isobutene oxide, and styrene oxide in combination with a hydrocarbyl-substituted polycarboxylic acid.

9. The gasoline fuel composition according to any of the preceding claims, wherein the quaternized ammonium compounds have a weight loss in a thermogravimetric analysis (TGA, conducted in accordance with standard ISO-4154 from 50° to 900°C at a rate of temperature rise of 20°C per minute under a nitrogen atmosphere at a flow rate of 60 mL per minute) at 350°C of less than 50% by weight.

10. The gasoline fuel composition according to any of the preceding claims, selected from gasoline fuels and alkanol-containing, preferably methanol, ethanol, propanol, or butanol- containing gasoline fuels, more preferably bioethanol-containing fuels.

11. A quaternized nitrogen compound as defined in any of claims 1 to 9.

12. A process for preparing a quaternized nitrogen compound according to claim 11 , comprising the reaction of a compound of formula (3) with a hydrocarbyl epoxide in combination with a hydrocarbyl-substituted polycarboxylic acid.

13. The use of a quaternized nitrogen compound according to claim 11 or prepared according to claim 12 as a gasoline fuel additive.

14. The use according to claim 13 as a gasoline fuel additive for reducing the level of deposits in the intake system of a gasoline engine, such as, more particularly, DISI and PFI (port fuel injector) engines.

15. The use according to claim 13 as a gasoline fuel additive for reducing the corrosion of a gasoline engine, preferably in the intake system.

16. The use according to claim 13 as a gasoline fuel additive for improving the level of dehazing of gasoline-water-mixtures.

17. An additive concentrate comprising, in combination with further gasoline fuel additives, at least one quaternized nitrogen compound as defined in claim 11 or prepared according to claim 12.