RU2810335C2 - Quaternary ammonium compound and fuel composition - Google Patents

Abstract

FIELD: diesel fuel.

SUBSTANCE: present invention is related to a method for the preparation, composition and use of quaternary ammonium compounds as additives for diesel fuel compositions that are used to operate diesel engines with high pressure fuel systems. A method for producing a quaternary ammonium compound having formula (I) involves reacting a tertiary amine having formula R¹R²R³N with an epoxide in the presence of a compound having formula (IIB)

where X represents CH₂CHR or CRHCH₂, R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; R⁴ represents an unsubstituted alkylene group having from 1 to 12 carbon atoms; n is from 1 to 20; c is at least 1; W represents O^- or OH; b is equal to 1 if W is OH and b is equal to 2 if W is O^-; and wherein each of R¹ and R² independently represents an alkyl group containing from 1 to 12 carbon atoms; and R³ is selected from an alkyl group containing from 1 to 24 carbon atoms, or benzyl, or a hydroxyalkyl or hydroxyalkoxyalkyl group containing from 2 to 20 carbon atoms; and R⁰ represents a group having the formula

where each of R⁹, R¹⁰, R¹¹ represent hydrogen and R¹² represents hydrogen, phenyl, an alkyl group containing from 1 to 50 carbon atoms, CH₂OR¹³ or CH₂OCOR¹⁴, R¹³ represents an alkyl or aryl group containing from 1 to 30 carbon atoms, and R¹⁴ represents an alkyl or aryl group containing from 1 to 30 carbon atoms.

EFFECT: provision of a method, a composition and their application that make it possible to improve the performance characteristics of a diesel engine, in particular, including a high-pressure fuel system, to prevent or reduce the intensity of the formation of internal deposits in diesel engine injectors (IDDI), to reduce or remove existing IDDI, to provide control of external deposits on the injector and/or deposits on the fuel filter.

17 cl, 3 dwg, 10 tbl, 6 ex

Description

The present invention relates to new quaternary ammonium compounds, to compositions comprising these compounds, and to methods and uses related thereto. In particular, the invention relates to compositions, methods and uses aimed at improving the performance of engines, in particular diesel engines, using fuel additives. In addition, the invention relates to additives for diesel fuel compositions that are used to operate diesel engines with high pressure fuel systems.

Due to both consumer and legal requirements, diesel engines have become much more energy efficient and have improved performance over time, resulting in lower emissions.

Improved performance and reduced emissions are made possible by improved combustion processes. To achieve sufficient fuel atomization to improve combustion, fuel injection equipment has been developed that uses higher injection pressures and reduced fuel injector nozzle orifices. Currently, the fuel pressure in the injection nozzle exceeds 1500 bar (1.5×10 ⁸ Pa). To achieve such pressures, work must be done on the fuel, which also increases the temperature of the fuel. High pressures and temperatures can cause fuel decomposition. In addition, increasingly high precision is required to control injection timing, injection quantity, and control fuel injection. Maintaining accurate fuel metering is essential to achieving optimal performance.

Diesel engines with high pressure fuel systems may include, but are not limited to, heavy duty diesel engines and smaller passenger vehicle diesel engines. Heavy duty diesel engines can include very powerful engines such as the MTU 4000 series diesel engine, which includes 20 cylinder models designed primarily for ships and has power outputs of up to 4300 kW, or engines such as the Renault dXi 7, which includes 6 cylinders and having a power of approximately 240 kW. A typical diesel passenger car engine is the Peugeot DW10, which has 4 cylinders and has an output of 100 kW or less depending on the model.

A common problem with diesel engines is clogged injectors, particularly the injector body and injector nozzle. In addition, the fuel filter may become clogged. A clogged injector nozzle occurs when the nozzle becomes clogged with diesel deposits. Clogged fuel filters can be caused by fuel being recirculated back into the fuel tank. The formation of deposits intensifies as the fuel decomposes. Deposits may form as carbon-containing coke-like residues, varnish deposits, or sticky or tar-like residues. Diesel fuels become more and more unstable as they are heated, particularly when heated under pressure. Therefore, increased fuel degradation may occur in diesel engines with high pressure fuel systems. In recent years, the design of injection systems has been constantly updated to meet the requirements for reducing emissions into the atmosphere. This leads to more complex injector designs and their low resistance to deposit formation.

Injector clogging can occur when using any type of diesel fuel. However, some fuels may be particularly prone to clogging, or clogging may occur more quickly with these fuels. For example, increased deposit formation may occur with the use of fuels containing biodiesel and fuels containing metal compounds.

If the injectors are completely or partially clogged, the fuel supply is reduced and the mixing of fuel with air deteriorates. Over time, this leads to reduced engine power, increased exhaust emissions and reduced fuel economy.

Deposits are known to form in the injector spray channels, resulting in reduced flow and reduced power. The smaller the injector nozzle opening size, the greater the relative impact of deposit build-up. Deposits are also known to form at the tip of the injector. Such deposits negatively affect the fuel atomization pattern, resulting in reduced combustion efficiency and increased air emissions, as well as increased fuel consumption.

In addition to these "external" deposits in the injector nozzle bore and at the injector tip, which impede fuel flow and cause loss of power, deposits can form inside the injector body, causing additional problems. These deposits can be called internal diesel injector deposits (abbreviated as internal diesel injector deposits, abbreviated as IDID). VOFDs are additionally formed inside the injector on important moving parts. They can impede the movement of such parts, negatively affecting the timing of injection and the amount of fuel injected. Because modern diesel engines must operate with very high precision, these deposits can seriously impair performance.

The formation of VOFD causes a number of problems, including reduced power and reduced fuel economy due to less than optimal fuel metering and combustion. Initially, the engine may experience problems during cold starts and/or the engine may start to run rough. The formation of such deposits can lead to more serious clogging of the injectors. This occurs when deposits obstruct the movement of injector parts, causing the injector to stop working. Clogging of some or all of the injectors can cause the engine to stop completely.

Experts in this field of technology recognize that the formation of VOFD is a serious problem, and the organization that oversees this branch of technology, i.e. The Coordinating European Council (abbreviated CEC) has developed a new engine test. A definition of the DW10C engine's VOC has been developed that distinguishes fuels that do not produce detectable deposits from fuels that produce deposits that will unacceptably reduce the engine's ability to start easily. The objective of the test is to be able to classify fuels according to their ability to form VOPD in diesel engines with a common rail (pressure pipeline) direct injection.

The inventors of the present invention conducted a study of internal deposits on diesel engine injectors and found that these deposits contain a number of components. Along with carbonaceous deposits, varnish deposits and/or carboxylate residues present can cause the injector to seize (stick due to clogging).

Varnish deposits are deposits similar to varnish coatings that are insoluble in fuel and common organic solvents. When analyzing some varnish deposits, they were found to contain amide functional groups, which suggested that they were formed due to the presence of substances containing low molecular weight amides in the fuel.

Carboxylate residues can enter fuel from various sources. According to the invention, carboxylate residues are understood to mean salts of carboxylic acids. They may be short-chain carboxylic acid residues, but more often they are long-chain fatty acid residues. Carboxylic acid residues may be present as ammonium and/or metal salts. Both carboxylic acids and metals can enter diesel fuel from a variety of sources. Carboxylic acids can result from fuel oxidation, can be formed during combustion, and are commonly added to fuels as lubricity additives and/or corrosion inhibitors. Residual fatty acids may be present in the fatty acid methyl esters contained in biodiesel, and they may also be present as by-products in other additives. Fuel may also contain fatty acid derivatives that can react or decompose to form carboxylic acids.

Various metal compounds may be present in fuel compositions. They may result from contamination of the fuel during its production, storage, transportation or use, or as a result of contamination of fuel additives. Metal compounds can also be added to fuel intentionally. For example, transition metals are sometimes added to fuels as catalysts carried with the fuel (fuel catalysts), for example to improve the performance of diesel particulate filters (particulate filters).

The present inventors believe that one of the many causes of injector jamming is the reaction products of metal or ammonium compounds with carboxylic acid derivatives found in the fuel. For example, injector jamming occurs when the fuel is contaminated with sodium compounds. Sodium contaminants can occur for a number of different reasons. For example, the washing step used in the hydrodesulfurization process may involve the use of sodium hydroxide, the presence of which can lead to the formation of contaminants. Sodium can also be introduced into fuel through the use of pipeline corrosion inhibitors containing sodium. Alternatively, contamination may be due to the presence of calcium, such as from interaction with a lubricant or from contamination by a lubricant, or from calcium chloride found in refinery processing salts. Other contaminant metals may be present, such as those released during transport from water cushions at the bottom of oil tanks.

It is believed that one of the reasons for injector jamming is contamination of diesel fuel with salts of carboxylic acids, which are formed as a result of the action of metal compounds. Another important reason for a stuck injector is the formation of varnish deposits.

One option for combating VOPF and injector sticking due to the presence of carboxylate salts is to eliminate the source of the contaminating metal and/or carboxylic acids or attempt to eliminate the carboxylic acids causing the most acute problems. Such attempts have not been completely successful, that is, there is still a need to create additives that provide the ability to regulate the formation of VOPD.

Deposit control additives are often included in fuel to control deposits in the injector nozzle or injector tip. In the context of the present invention, these deposits may be referred to as "external nozzle deposits". Additives are also used to control the formation and condition of deposits on vehicle fuel filters. However, it has been found that additives suitable for controlling "external deposits" and deposits on fuel filters do not always control the formation of VOPF. Thus, the challenge for additive manufacturers is to provide more effective detergents.

An object of the present invention is to provide methods and applications for improving the performance of a diesel engine, in particular a diesel engine including a high pressure fuel system. This can be achieved, for example, by preventing or reducing the formation of VOPD and/or reducing or removing existing VOPD. It is also another object of the invention to provide methods and applications for controlling "external injector deposits" and/or fuel filter deposits.

Reducing or preventing the formation of deposits can be considered to provide a "keep clean" characteristic. Reducing or removing existing deposits may be considered to provide a "cleaning" characteristic. It is an object of the present invention to provide "keeping clean" and/or "cleaning" characteristics. Another object of the present invention is to provide "keeping clean" and/or "cleaning" characteristics.

There are many different compounds known in the art that are added to fuel oil compositions as detergent additives to control deposit formation in engines.

The present invention relates to novel quaternary ammonium compounds containing a polycarboxylic acid partial ester counterion, which are used as detergent additives.

The first aspect of the present invention relates to a quaternary ammonium compound having formula (I):

where each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group, X represents a connecting group; R ⁴ represents an optionally substituted alkylene group; n is a positive integer; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

In some embodiments, b is 2 and W is O ^- .

In some preferred embodiments, b is 1 and W is OH.

The present invention relates to quaternary ammonium compounds containing the following anion (IIA):

where c is at least 1. In some embodiments, c may be greater than 1.

The anion is suitably prepared from an anion precursor which is a dicarboxylic acid having formula (IIB):

The anion precursor (IIB) is suitably prepared by the reaction of a diol having the formula HO(R ⁴ O) _nH and a dicarboxylic acid having the formula HOOCXCOOH or an anhydride thereof. In preferred embodiments, the anion precursor (IIB) is formed by the reaction of a diol having the formula HO(R ⁴ O) _n H and an anhydride.

The value of c depends on the diacid/anhydride:diol ratio used to synthesize the precursor (IIB) anion.

In some embodiments, c may be greater than 1.

In preferred embodiments, c is 1. In such embodiments, the diacid/anhydride:diol ratio used in the synthesis of the anion precursor (IIB) is preferably at least 1.5:1, more preferably at least 1.8:1, preferably at least 2:1.

The quaternary ammonium compound having formula (I) includes at least one quaternary ammonium cationic species having formula (III):

In some embodiments, W is OH, b is 1, and the compound having formula (I) has formula (IA):

In some embodiments, W is O ^- , b is 2, and the compound having formula (I) has structure (IB):

In those embodiments in which the quaternary ammonium compound is a compound having formula (IB), all cationic species having formula (III) may be the same or different.

In some preferred embodiments, all quaternary ammonium species (III) are the same.

Each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group.

As used herein, the term “hydrocarbyl” substituent or group has its usual meaning, which is well known to those skilled in the art. In particular, the term means a group containing a carbon atom directly attached to the rest of the molecule and having a substantially hydrocarbon character. Examples of hydrocarbyl groups include:

(i) hydrocarbon groups, i.e. aliphatic (which may be saturated or unsaturated, straight or branched, e.g. alkyl or alkenyl), epicyclic (e.g. cycloalkyl, cycloalkenyl) substituents and aromatic (including aromatic groups substituted by aliphatic and epicyclic groups) substituents, as well as cyclic substituents in which the ring is completed by another part of the molecule (for example, two substituents together form a ring);

(ii) substituted hydrocarbon groups, that is, substituents containing non-hydrocarbon groups (for example, halogen (in particular chlorine and fluorine), hydroxy, alkoxy, keto, acyl, cyano, mercapto, alkylmercapto, amino, alkylamino, nitro, nitroso and sulfoxy );

(iii) heterosubstituents, that is, substituents which, despite their predominantly hydrocarbon character in the context of the present invention, contain atoms other than carbon in a ring or chain otherwise consisting of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and are included with substituents such as pyridyl, furyl, thienyl, and imidazolyl. In general, for every ten carbon atoms of the hydrocarbyl group there are no more than two, preferably no more than one, non-hydrocarbon substituent; usually the hydrocarbyl group does not contain non-hydrocarbon substituents.

Preferably, R ⁰ , R ¹ , R ² and R ³ are each an optionally substituted alkyl, alkenyl or aryl group.

Unless otherwise indicated, references herein to optionally substituted alkyl groups may include aryl-substituted alkyl groups, and references to optionally substituted aryl groups may include alkyl-substituted or alkenyl-substituted aryl groups.

The quaternary ammonium compound of the present invention can be produced by any suitable method. Suitable methods are known to those skilled in the art.

In some embodiments, R ⁰ may be a lower alkyl group and the quaternary ammonium compound is prepared from an ester having the formula R ⁰ OOCXCO[O(R ⁴ O) _n COXCO] _c OR ⁰ . In such embodiments, R ⁰ is preferably methyl.

In some embodiments, R ⁰ may be a lower alkyl group and the quaternary ammonium compound may be prepared using an ester quaternizing agent having the formula RCOOR ⁰ followed by an ion exchange reaction with an acid having the formula HOOCXCO[O(R ⁴ O) _n COXCO ] _cOH . In such embodiments, R may be an optionally substituted aryl or alkyl group or an ester. For example, ^R0 may be methyl, and ^RCOOR0 may be methyl salicylate or dimethyl oxalate.

In some embodiments ^{, R0} is preferably a C1-C5 alkyl group, preferably methyl.

In preferred embodiments, the quaternary ammonium compound is derived from a tertiary amine, an acid-activated alkylating agent and an acid. Thus, R ⁰ is preferably an alkylating agent residue.

Preferably the alkylating agent is an epoxide.

In preferred embodiments, the first aspect of the present invention relates to a quaternary ammonium compound, which is the reaction product of the following compounds:

(a) a tertiary amine having the formula R ¹ R ² R ³ N;

(b) epoxide; And

(c) a compound having formula (IIB):

where R ⁴ represents an optionally substituted alkylene group, X represents a connecting group, n is a positive integer, and c is at least 1.

A second aspect of the present invention relates to a process for preparing a quaternary ammonium compound, wherein the process comprises reacting (a) a tertiary amine having the formula R ¹ R ² R ³ N with (b) an epoxide in the presence of (c) a compound having the formula (IIB):

where R ⁴ represents an optionally substituted alkylene group, X represents a connecting group, n is a positive integer, and c is at least 1.

Discussed below are preferred features of the first and second aspects of the invention.

According to the invention, any feature of any aspect of the invention may be suitably combined with any feature of any other aspect.

X represents a connecting group. Preferably X represents an optionally substituted alkylene or arylene group. X is discussed further below.

The present invention relates to a composition, method and use that relate to a quaternary ammonium salt. In this work, this compound may be called "quaternary ammonium salt" or "quaternary ammonium compound".

The quaternary ammonium salt may comprise one compound. In some embodiments, mixtures containing more than one quaternary ammonium salt additive may be used. References herein to a "quaternary ammonium salt", a "quaternary ammonium compound" according to the invention, or "quaternary ammonium salts" or "quaternary ammonium compounds" include mixtures comprising two or more such compounds.

Component (a) used to prepare the quaternary ammonium salts/compounds of the present invention is a tertiary amine. Any suitable tertiary amine may be used.

In some embodiments of the present invention, the tertiary amine may be a small compound having low complexity and low molecular weight. In some embodiments, the tertiary amine may be a complex molecule and/or a high molecular weight molecule that includes a tertiary amine moiety.

The tertiary amines of the present invention preferably do not include primary or secondary amine groups. In some embodiments, they can be prepared from compounds containing such groups, but preferably these groups are then reacted to form additional tertiary amine compounds. The tertiary amine used as component (a) may contain more than one tertiary amine group. However, tertiary amines containing primary or secondary amine groups are included within the scope of the invention, provided that these groups do not prevent the quaternization of the tertiary amine compounds.

Tertiary amines suitable for use according to the invention are preferably compounds having the formula R ¹ R ² R ³ N, wherein R ¹ , R ² and R ³ each independently represent an optionally substituted alkyl, alkenyl or aryl group.

The groups R ¹ , R ² and R ³ may be the same or different. In some preferred embodiments, R ¹ and R ² are the same and R ³ is different.

Preferably, R ¹ and R ² are each independently an optionally substituted alkyl, alkenyl or aryl group containing from 1 to 50 carbon atoms, preferably from 1 to 40 carbon atoms, more preferably from 1 to 30 carbon atoms.

Each of R ¹ and R ² may be optionally substituted with one or more groups selected from halogen (particularly chlorine and fluorine), hydroxy, alkoxy, keto, acyl, cyano, mercapto, alkyl mercapto, dialkylamino, nitro, nitroso and sulfoxy. The alkyl groups of the listed substituents may be further substituted.

Preferably, R ¹ and R ² are each independently an optionally substituted alkyl or alkenyl group. Preferably, R ¹ and R ² are each independently an optionally substituted alkyl group. Preferably, R ¹ and R ² are each independently an optionally substituted alkyl or alkenyl group containing 1 to 50 carbon atoms, preferably 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms , preferably 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, for example 1 to 6 carbon atoms.

In some embodiments, R ¹ and R ² are each methyl, and R ³ is a C ₆ -C ₃₆ , preferably a C ₁₀ -C ₃₀ alkyl or alkenyl group.

In some embodiments, R ¹ is methyl, and R ² and R ³ are each a C ₆ -C ₃₆ , preferably a C ₁₀ -C ₃₀ alkyl or alkenyl group.

Preferably R ¹ represents an optionally substituted alkyl or alkenyl group, preferably containing from 1 to 10, preferably from 1 to 4 carbon atoms. Preferably R ¹ represents an alkyl group. It may be a substituted alkyl group, for example a hydroxyl substituted alkyl group. Preferably R ¹ represents an unsubstituted alkyl group. The alkyl chain can be straight or branched. In some preferred embodiments, R ¹ is selected from methyl, ethyl, propyl and butyl, including isomers thereof. In some particularly preferred embodiments, R ¹ is methyl or ethyl.

Preferably R ² represents an optionally substituted alkyl or alkenyl group, preferably containing from 1 to 10, preferably from 1 to 4 carbon atoms. Preferably R ² represents an alkyl group. It may be a substituted alkyl group, for example a hydroxyl substituted alkyl group. Preferably R ² represents an unsubstituted alkyl group. The alkyl chain can be straight or branched. In some preferred embodiments, R ² is selected from methyl, ethyl, propyl and butyl, including isomers thereof. In some particularly preferred embodiments, R ² is methyl or ethyl.

In some embodiments, R ³ is an optionally substituted alkyl or alkenyl group containing from 1 to 50 carbon atoms, preferably from 1 to 40 carbon atoms, more preferably from 1 to 30 carbon atoms, more preferably from 1 to 20 carbon atoms, more preferably from 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, for example 1 to 6 carbon atoms. Suitable substituents include halogen (especially chlorine and fluorine), hydroxy, alkoxy, keto, acyl, cyano, mercapto, alkylmercapto, amino, alkylamino, nitro, nitroso, sulfoxy, amido, alkylamido, imido and alkylimido. The alkyl groups of the listed substituents may be further substituted.

In some embodiments, R ³ is an optionally substituted alkyl or alkenyl group, preferably containing from 1 to 10, preferably from 1 to 4 carbon atoms. Preferably R ³ represents an optionally substituted alkyl group. In some embodiments, R ³ is an unsubstituted alkyl group, for example, a C ₁ -C ₁₀ , preferably a C ₁ -C ₆ or C ₁ -C ₄ alkyl group. The alkyl group may be straight or branched.

In some preferred embodiments, R ³ is a substituted alkyl group. Preferred substituents include alkoxy and hydroxyl groups.

In some embodiments, one or more heteroatoms, such as one or more oxygen atoms, may be included in the alkyl chain.

In some preferred embodiments, R ³ is a hydroxy-substituted alkyl group. The alkyl chain may be straight or branched. In some particularly preferred embodiments, R ³ is a hydroxyethyl group.

In one embodiment, R ³ represents a hydroxyethyloxyethyl group.

In some embodiments, R ¹ , R ² and R ³ are each independently selected from an alkyl or hydroxyalkyl group containing 1 to 12, preferably 1 to 6, more preferably 1 to 4 carbon atoms.

In some embodiments, trialkylamines and hydroxyalkyl dialkylamines are particularly preferred.

In some embodiments, R ³ is an optionally substituted hydrocarbyl group, such as an optionally substituted hydrocarbyl group containing from 1 to 300 carbon atoms, such as from 1 to 200 carbon atoms. R ³ may be an optionally substituted hydrocarbyl group having a number average molecular weight of from 100 to 5000, preferably from 500 to 2500.

In some embodiments, R ¹ and R ² are each methyl, and R ³ is an optionally substituted alkaryl group, preferably a benzyl group.

In some embodiments, R ³ is an optionally substituted alkyl or alkenyl group. R ³ may represent an unsubstituted alkyl or alkenyl group. Preferably R ³ represents an alkyl or alkenyl group containing from 1 to 200 carbon atoms.

In some embodiments, R ³ is an alkyl group or an alkenyl group containing from 10 to 36 carbon atoms.

In some embodiments, R ³ is a polyisobutenyl group, preferably a polyisobutenyl group, having a number average molecular weight of 100 to 5000, preferably 300 to 4000, preferably 450 to 2500, for example 500 to 2000 or 600 to 1500.

In some embodiments, R ³ is an optionally substituted alkylene phenol moiety, and the tertiary amine R ¹ R ² R ³ N is the product of a Mannich reaction between an aldehyde, an optionally substituted phenol, and an amine. Preferably the aldehyde is formaldehyde. The amine used to prepare the Mannich reaction product compound may be a monoamine, and R ³ has the structure (X):

The amine used to prepare the Mannich reaction product compound may be a polyamine containing at least one tertiary amino group, and R ³ may have the structure (Y):

In structures (X) and (Y), n is from 0 to 4, preferably 1, each of R ^x represents an optionally substituted hydrocarbyl group, R ^y represents an optionally substituted alkyl, alkenyl or aryl group; and L represents a connecting group.

R ^y and L may together form a heterocyclic group.

R ^y is preferably an alkyl group, preferably an unsubstituted alkyl group. R ^y preferably represents a C ₁ -C ₄ alkyl group.

Preferably L represents an optionally substituted alkylene group, preferably an alkylene group containing from 1 to 10, preferably from 1 to 6 carbon atoms. More preferably, L is an unsubstituted alkylene group, for example ethylene, propylene or butylene. Most preferably, L is a propylene group.

In some preferred embodiments, the phenol includes a methyl substituent at the ortho position and an additional R ^x substituent at the para position.

In one preferred embodiment, n is 1 and the optionally substituted hydrocarbyl substituent R is preferably para to the hydroxyl group.

The optionally substituted hydrocarbyl substituent R ^x of phenol may contain from 6 to 400 carbon atoms, preferably from 30 to 180 carbon atoms, for example from 10 or 40 to 110 carbon atoms. Such a hydrocarbyl substituent may be derived from an olefin or a polyolefin.

Polyolefins that can form hydrocarbyl substituents can be prepared by polymerizing olefin monomers by well known polymerization methods and are also commercially available.

Some preferred polyolefins include polyisobutylenes having a number average molecular weight of from 200 to 3000, in another example from 400 to 2500, and in a further example from 400 or 500 to 1500.

In some embodiments, the phenol may include a low molecular weight alkyl substituent, for example, a phenol comprising one or more alkyl chains having a total of less than 28 carbon atoms, preferably less than 20 carbon atoms, more preferably less than 14 carbon atoms.

Preferred may be a monoalkylphenol, preferably containing from 4 to 20 carbon atoms, preferably from 8 to 16 carbon atoms, for example a phenol containing a C ₁₂ alkyl substituent.

In some embodiments, R ³ may include an ether, amide, or ester group.

In some embodiments, R ³ includes a succinimide moiety. ^R3 may have the following formula:

where R ^z represents an optionally substituted hydrocarbyl group, and L represents a connecting group.

In some embodiments, the optionally substituted hydrocarbyl substituent R ^z may contain from 6 to 36 carbon atoms, preferably from 8 to 22, for example from 10 to 18 or from 16 to 18 carbon atoms.

In some embodiments, the optionally substituted hydrocarbyl substituent R ^z may contain from 6 to 400 carbon atoms, preferably from 30 to 180 carbon atoms, for example from 10 or 40 to 110 carbon atoms. Such a hydrocarbyl substituent may be derived from an olefin or a polyolefin.

Some preferred polyolefins include polyisobutylenes having a number average molecular weight of from 200 to 3000, in another example from 400 to 2500, and in a further example from 400 or 500 to 1500.

Preferably L represents an optionally substituted alkylene group, preferably an alkylene group containing from 1 to 10, preferably from 1 to 6 carbon atoms. More preferably, L is an unsubstituted alkylene group, for example ethylene, propylene or butylene. Most preferably, L is a propylene group.

R ³ may preferably be selected from an optionally substituted alkyl or alkenyl group containing from 1 to 10 carbon atoms; an optionally substituted hydrocarbyl group whose number average molecular weight is from 100 to 5000; an optionally substituted alkylene phenol moiety and an optionally substituted alkylene succinimide group.

Tertiary amines suitable for use as component (a) include simple alkylamines and hydroxyalkylamines; trialkylamines having a high molecular weight substituent; Mannich reaction products including a tertiary amine and substituted acylated amines or alcohols including a tertiary amine.

The simple alkylamino and hydroxyalkylamine derivatives are preferably compounds having the formula R ¹ R ² R ³ N, wherein R ¹ , R ² and R ³ each represent an alkyl group or a hydroxyalkyl group. All R ¹ , R ² and R ³ may be the same or different. Preferably, R ¹ , R ² and R ³ are each independently selected from an alkyl or hydroxyalkyl group containing 1 to 10, preferably 1 to 6 carbon atoms, for example 1 to 4 carbon atoms. Each of R ¹ , R ² and R ³ may be independently selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl and hydroxyhexyl. Component (a) may be a trialkylamine, dialkylhydroxyalkylamine, dihydroxyalkylalkylamine or trihydroxyalkylamine. There are many different compounds of this type, and they are known to one skilled in the art.

In some embodiments, the amine may include alkyl or hydroxyalkyl groups that have reacted with an epoxide (eg, ethylene oxide or propylene oxide) to form an ether.

Trialkylamines having a high molecular weight substituent suitable for use according to the invention are typically polyalkene-substituted amines containing at least one tertiary amino group.

The polyalkene-substituted amines of the present invention containing at least one tertiary amine group can be prepared from an olefin polymer and an amine, for example, ammonia, monoamines, polyamines or mixtures thereof. They can be obtained by various methods, such as those discussed and cited in US 2008/0113890.

Preferably, the polyalkene substituent of the polyalkene-substituted amine is derived from polyisobutylene.

Amines that can be used to prepare a polyalkene-substituted amine include ammonia, monoamines, polyamines, or mixtures thereof, including mixtures of various monoamines, mixtures of various polyamines, and mixtures of monoamines and polyamines (which include diamines). Amines include aliphatic, aromatic, heterocyclic and carbocyclic amines. Preferred amines are typically substituted with at least one hydrocarbyl group containing from 1 to about 50 carbon atoms, preferably from 1 to 30 carbon atoms. Particularly preferred are saturated aliphatic hydrocarbon radicals.

Monoamines and polyamines preferably include at least one primary or secondary amino group.

The number average molecular weight of the polyalkene-substituted amines may be from 500 to 5000 or from 500 to 3000, for example from 1000 to 1500.

Any of the polyalkene-substituted amines disclosed above, which are secondary or primary amines, can be alkylated with alkylating agents to form tertiary amines. Suitable alkylating agents and methods for their use are known to those skilled in the art.

Mannich reaction products containing a tertiary amine suitable for use as component (a) are discussed in US 2008/0052985.

The Mannich reaction product containing a tertiary amino group is obtained by the reaction of a phenol having an optionally substituted hydrocarbyl substituent, an aldehyde and an amine. The phenol having an optionally substituted hydrocarbyl substituent is preferably the compound discussed above.

Preferably, the phenol having an optionally substituted hydrocarbyl substituent is a polyisobutenyl-substituted phenol or a polyisobutenyl-substituted cresol.

The aldehyde used to produce the Mannich reaction detergent additive may contain from 1 to 10 carbon atoms and is typically formaldehyde or a reactive equivalent such as formaldehyde or paraformaldehyde.

The aldehyde used to obtain the Mannich reaction product detergent additive may be a monoamine or a polyamine.

Examples of monoamines and polyamines are known to one skilled in the art.

Preferred polyamines are polyethylene polyamines.

In particularly preferred embodiments, the amine used to produce the Mannich reaction product detergent additive includes a diamine. Preferably it comprises a primary or secondary amine which undergoes a Mannich reaction and, in addition, a tertiary amine.

One preferred amine is dimethylaminopropylamine.

In preferred embodiments, the Mannich reaction product detergent additive is a product directly obtained from the Mannich reaction, which includes a tertiary amine. For example, the amine may comprise one primary or secondary amine which, upon completion of the Mannich reaction, forms a tertiary amine suitable for quaternization. Alternatively, the amine may include a primary or secondary amine that can undergo a Mannich reaction, as well as a tertiary amine suitable for quaternization. However, the Mannich reaction detergent additive may include a compound that has been produced by the Mannich reaction and then reacted to form a tertiary amine; for example, the Mannich reaction can produce a secondary amine, which is then alkylated to produce a tertiary amine.

Suitable preferred amines include dimethylamine and dibutylamine.

Substituted acylated amines or alcohols including a tertiary amine and suitable for use as component (a) comprise the reaction product of an acylating agent having an optionally substituted hydrocarbyl substituent and a compound containing an oxygen or nitrogen atom which is capable of condensing with such an acylating agent and further has a tertiary amino group.

The acylating agent having an optionally substituted hydrocarbyl substituent is preferably a mono- or polycarboxylic acid (or reactive equivalent thereof), for example a substituted succinic, phthalic or propionic acid.

Preferred hydrocarbyl-substituted acylating agents for the preparation of component (i) are polyisobutenyl-substituted succinic acid derivatives. Preferred are compounds in which the number average molecular weight of the polyisobutenyl group is from 100 to 5000, preferably from 300 to 4000, preferably from 450 to 2500, for example from 500 to 2000 or from 600 to 1500.

In some preferred embodiments, the tertiary amine includes a compound prepared by the reaction of an acylating agent having an optionally substituted hydrocarbyl substituent and an amine having formula (Y) or (Z):

where R ⁶ and R ⁷ represent the same or different alkyl, alkenyl or aryl groups containing from 1 to 22 carbon atoms; A represents a bond or alkylene group containing from 1 to 20 carbon atoms; n ranges from 0 to 20; m ranges from 1 to 5; and R ⁴ represents hydrogen or a C ₁ -C ₂₂ alkyl group.

The above reaction conditions may be selected such that the resulting tertiary amine component(s) does not contain acidic groups. For example, if a compound having formula (Y) is reacted with an acylating agent derived from succinic acid, the reaction conditions or reactant ratio are selected so as to form an imide or diamide. No monoamide is formed. When a compound having formula (Z) is reacted with an acylating agent derived from succinic acid, the reaction conditions or reactant ratio are selected so as to form a diester. No monoester is formed.

If a compound having formula (Y) is used, R ⁸ is preferably hydrogen or a C ₁ -C ₁₈ , preferably a C ₁ -C ₁₆ alkyl group. More preferably, R ⁸ is selected from hydrogen, methyl, ethyl, propyl, butyl and isomers thereof. Most preferably, R ⁸ is hydrogen.

If a compound having formula (Z) is used, m is preferably 2 or 3, most preferably 2; n is preferably 0 to 15, preferably 0 to 10, more preferably 0 to 5. Most preferably, n is 0, and the compound having formula (Z) is an alcohol.

In some preferred embodiments, an acylating agent having an optionally substituted hydrocarbyl substituent is reacted with a diamine having formula (Y).

R ⁶ and R ⁷ represent the same or different alkyl, alkenyl or aryl groups containing from 1 to 22 carbon atoms. In some embodiments, R ⁶ and R ⁷ may be linked to each other to form a cyclic structure, such as a piperidine, imidazole, or morpholine moiety. Thus, R ⁶ and R ⁷ may together form an aromatic and/or heterocyclic moiety. R ⁶ and R ⁷ may be branched alkyl or alkenyl groups. Each group may be substituted, for example, with a hydroxyl or alkoxy substituent.

Preferably, R ⁶ and R ⁷ are each independently a C ₁ -C ₁₆ alkyl group, preferably a C ₁ -C ₁₀ alkyl group. R ⁶ and R ⁷ independently may be methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, or an isomer of any of these groups. Preferably, R ⁶ and R ⁷ are each independently C ₁ -C ₄ alkyl. Preferably R ⁶ is methyl. Preferably R ⁷ is methyl.

A represents a bond or alkylene group containing from 1 to 20 carbon atoms. A is preferably an alkylene group containing 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, for example 2 to 6 carbon atoms or 2 to 5 carbon atoms. Most preferably, A is an ethylene, propylene or butylene group, in particular a propylene group.

Examples of compounds having formula (Y) suitable for use according to the invention are known to one skilled in the art.

In some preferred embodiments, the compound having formula (Y) is selected from dimethylaminopropylamine, N,N-diethyl-1,3-diaminopropane, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N-dibutylethylenediamine, or combinations thereof.

Examples of compounds having formula (Z) suitable for use according to the invention are known to one skilled in the art.

In some preferred embodiments, the compound having formula (Z) is selected from triisopropanolamine, 1-[2-hydroxyethyl]piperidine, 2-[2-(dimethylamine)ethoxy]ethanol, N-ethyldiethanolamine, N-methyldiethanolamine, N-butyldiethanolamine , N,N-diethylaminoethanol, N,N-dimethylaminoethanol, 2-dimethylamino-2-methyl-1-propanol, dimethylaminopropanol or combinations thereof.

A particularly preferred compound having formula (Y) is dimethylaminopropylamine.

A particularly preferred compound having formula (Z) is dimethylaminopropanol.

In some preferred embodiments, the tertiary amine (a) is the reaction product of an acylating agent derived from polyisobutenyl-substituted succinic acid and a compound having formula (Y) or (Z).

Preferably, the acylating agent derived from polyisobutenyl-substituted succinic acid is polyisobutenyl-substituted succinic acid or polyisobutenyl-substituted succinic anhydride, the number average molecular weight of which is from 200 to 3000, preferably from 400 to 2000, preferably from 500 to 1500 , for example, from 700 to 1300.

The compound having formula (Y) or (Z) may preferably be selected from dimethylaminopropylamine, N,N-diethyl-1,3-diaminopropane, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N-dibutylethylenediamine, triisopropanolamine , 1-[2-hydroxyethyl]piperidine, 2-[2-(dimethylamine)ethoxy]-ethanol, N-ethyldiethanolamine, N-methyldiethanolamine, N-butyldiethanolamine, N,N-diethylaminoethanol, N,N-dimethylaminoethanol, 2-dimethylamino -2-methyl-1-propanol, dimethylaminopropanol or combinations thereof.

Preferred compounds having formula (Y) or (Z) are dimethylaminopropylamine and dimethylaminopropanol.

In one embodiment, the tertiary amine component (a) is the reaction product of a succinic anhydride substituted with a polyisobutenyl group having a number average molecular weight of 700 to 1300 and an amine selected from dimethylaminopropylamine and dimethylaminopropanol.

Other particularly preferred tertiary amines (a) are formed by the reaction of a compound comprising a primary amino group and a tertiary amino group with polyisobutenyl-substituted succinic acid. One particularly preferred amine having primary and tertiary amino groups is dimethylaminopropylamine. The number average molecular weight of the polyisobutenyl substituent is preferably 300 to 2500, preferably 500 to 1500. Thus, one particularly preferred compound for use as component (a) is polyisobutenyl-substituted succinimide derived from dimethylaminopropylamine.

In some preferred embodiments, R ¹ is a C ₁ -C ₄ alkyl group, R ² is a C ₁ -C ₄ alkyl group, and R ³ is an alkyl or aryl group containing from 1 to 30 carbon atoms.

In some preferred embodiments, R ¹ is methyl or ethyl, R ² is ethyl or methyl, and R ³ is selected from hydroxyalkyl, hydroxyalkoxyalkyl, benzyl and a C ₁₂ -C ₂₄ alkyl group.

In some preferred embodiments, R ¹ is methyl or ethyl, R ² is methyl or ethyl, and R ³ is selected from hydroxyethyl, hydroxyethoxyethyl, benzyl and octadecyl.

Some tertiary amines preferred for use as component (a) include N,N-dimethylethanolamine, dimethyloctadecylamine, tall oil N-methyl N,N-diamine, N,N-diethylethanolamine, triethylamine, tripropylamine and tributylamine.

Tertiary amines preferred for use as component (a) include N,N-dimethylethanolamine, dimethyloctadecylamine, N-methyl-N,N-tall oil diamine, N,N-diethylethanolamine, triethylamine, tripropylamine, tributylamine, dimethylbenzylamine and dimethylaminoethoxyethanol.

Some particularly preferred tertiary amines for use as component (a) include N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylamine and tributylamine.

Particularly preferred tertiary amines for use as component (a) include N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylamine, tributylamine, dimethylbenzylamine and dimethylaminoethoxyethanol.

Other suitable amines that can be used as component (a) include small cyclic amines. These include, for example, N-alkylheterocyclic compounds, preferably selected from pyrrolidine, piperidine, morpholine, piperazine, pyrrole, imidazole and dihydropyrrole, pyridine, pyrimidine, isoxazole and oxazole. Suitable amines of this type as starting materials are discussed, for example, in patent application WO 2017/017454 filed by the applicants of the present invention.

Component (b) used to prepare the quaternary ammonium compound according to the present invention is an epoxide.

Any suitable epoxy compound can be used. Suitable epoxides are compounds having the following formula:

wherein each of R ⁹ , R ¹⁰ , R ¹¹ , R ¹² is independently selected from hydrogen or an optionally substituted alkyl, alkenyl or aryl group.

In such embodiments, the group R ⁰ represented by formula (I) is therefore preferably a group having the formula:

or

Preferably at least one of the groups ^R9 , ^R10 , ^R11 and ^R12 is hydrogen. Preferably, at least two of R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are hydrogen atoms. Most preferably, three of the groups R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are hydrogen atoms. The groups R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may all represent hydrogen atoms.

In the above structure and subsequent definitions, R ⁹ and R ¹⁰ are used interchangeably, and thus, if these groups are different, then either an enantiomer or a diastereomer can be used as component (b).

In the above structure and subsequent definitions, R ¹¹ and R ¹² are used interchangeably, and thus, if these groups are different, then either an enantiomer or a diastereomer can be used as component (b).

Preferably R ⁹ represents hydrogen or an optionally substituted alkyl, alkenyl or aryl group, preferably containing from 1 to 10, preferably from 1 to 4 carbon atoms. Preferably R ⁹ represents hydrogen or an alkyl group. Most preferably, R ⁹ is hydrogen.

Preferably R ¹⁰ represents hydrogen or an optionally substituted alkyl, alkenyl or aryl group, preferably containing from 1 to 10 carbon atoms. For example, R ¹⁰ may be benzyl.

In some preferred embodiments, R ¹⁰ is an optionally substituted aryl group. For example, R ¹⁰ may be phenyl.

In some preferred embodiments, R ¹⁰ is an optionally substituted alkyl or alkenyl group. Preferably R ¹⁰ represents an alkyl group, for example an unsubstituted alkyl group. R ¹⁰ may represent an alkyl group containing from 1 to 12, for example from 1 to 8 or from 1 to 4 carbon atoms.

Preferably R ¹⁰ represents hydrogen or an alkyl group. Most preferably, R ¹⁰ is hydrogen.

Preferably R ¹¹ represents hydrogen or an optionally substituted alkyl, alkenyl or aryl group, preferably containing from 1 to 10, preferably from 1 to 4 carbon atoms. Preferably R ¹¹ represents hydrogen or an alkyl group. Most preferably, R ¹¹ is hydrogen.

Preferably R ¹² represents hydrogen or an optionally substituted alkyl, alkenyl or aryl group.

In some preferred embodiments, R ¹² is an optionally substituted aryl group. For example, R ¹² may be phenyl.

In some preferred embodiments, R ¹² is an optionally substituted alkyl or alkenyl group. R ¹² may represent an alkyl group, for example an unsubstituted alkyl group. R ¹² may represent an alkyl group containing from 1 to 50 carbon atoms, preferably from 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

In some embodiments, R ¹² is an alkyl group containing 1 to 12 carbon atoms, preferably 1 to 8, preferably 1 to 4 carbon atoms.

In one embodiment, R ¹² is butyl.

In some embodiments, R ¹² is an alkyl group containing from 6 to 20 carbon atoms, preferably from 8 to 16 carbon atoms, for example, 12 carbon atoms.

In some embodiments, R ¹² is hydrogen.

In some preferred embodiments, R ¹² is a CH ₂ OR ¹³ or CH ₂ OCOR ¹⁴ moiety, wherein each of R ¹³ and R ¹⁴ may be optionally substituted with an alkyl, alkenyl or aryl group.

R ¹³ preferably represents an optionally substituted alkyl or aryl group, preferably containing from 1 to 30 carbon atoms, preferably from 1 to 20 carbon atoms, more preferably from 1 to 12 carbon atoms. If R ¹³ represents an alkyl group, it may be straight or branched. In some embodiments, it is a branched group. R ¹³ may be an optionally substituted phenyl group.

In one embodiment, R ¹³ represents a 2-methylphenyl group. In another embodiment, R ¹³ is CH ₂ C(CH ₂ CH ₃ )CH ₂ CH ₂ CH ₂ CH ₃ .

R ¹⁴ may be optionally substituted with an alkyl, alkenyl or aryl group.

R ¹⁴ preferably represents an optionally substituted alkyl or aryl group, preferably containing from 1 to 30 carbon atoms, preferably from 1 to 20 carbon atoms, more preferably from 1 to 12 carbon atoms. If R ¹⁴ represents an alkyl group, it may be straight or branched. In some preferred embodiments, it is a branched group. R ¹⁴ may be an optionally substituted phenyl group.

In one embodiment, R ¹⁴ is C(CH ₃ )R ₂ , where each R represents an alkyl group. The R groups may be the same or different.

Component (b) is an epoxy.

Some preferred epoxy compounds for use as component (b) include 2-ethylhexylglycidyl ether, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, dodecyl epoxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides containing from 2 to 50 carbon atoms, including other glycidyl ethers.

Preferred epoxy compounds for use as component (b) include styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides containing from 2 to 50 carbon atoms.

Other suitable epoxy compounds include glycidyl ethers and glycidyl esters, for example, glycidyl-2-methylphenyl ether and Versatic acid glycidyl ester.

Some preferred epoxy compounds for use as component (b) include 2-ethylhexylglycidyl ether, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, dodecyl epoxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides or glycidyl ethers containing from 2 to 50 carbon atoms.

In some preferred embodiments, component (b) is selected from 2-ethylhexylglycidyl ether, butylene oxide, styrene oxide and dodecyl epoxide.

Preferably, the quaternary ammonium compound is prepared by the reaction of (a) a quaternary amine; (b) epoxide; and (c) an acid having formula (IIB):

The compound having formula (IIB) is preferably an ester which is the reaction product of an optionally substituted dicarboxylic acid or an anhydride thereof and an alcohol having the formula HO(R ⁴ O) _n H.

Preferably, the molar ratio of acid/anhydride to polyhydric alcohol used in the preparation of the ester having formula (IIB) is at least 1.5:1, preferably at least 1.7:1, for example at least 1.9 :1.

The molar ratio of acid/anhydride to polyhydric alcohol used in preparing the ester having formula (IIB) can be up to 10:1, for example up to 5:1.

Preferably, the molar ratio of acid/anhydride to polyhydric alcohol used in preparing the ester having formula (IIB) is 2.5:1 to 1.8:1, for example 2.2:1 to 1.9:1 .

Preferably, the compound having formula (IIB) is a bis-ester.

In some embodiments, the dicarboxylic acid or corresponding anhydride is unsubstituted. In preferred embodiments, the additive is derived from a hydrocarbyl-substituted dicarboxylic acid or its anhydride.

Suitable dicarboxylic acids include maleic acid, glutaric acid, fumaric acid, oxalic acid, malonic acid, pimelic acid, suberic acid, adipic acid, phthalic acid, succinic acid, azelaic acid, sebacic acid and dimerized fatty acids. Anhydrides of the listed acids can also be used.

In some embodiments, the ester may be derived from a dicarboxylic acid having the formula HOOC(CH ₂ ) _n COOH, where n is from 1 to 20, preferably from 2 to 16, more preferably from 4 to 12, for example from 6 to 10 In one embodiment, the dicarboxylic acid is sebacic acid.

In some embodiments, the compound having formula (IIB) (component (c)) is prepared from a dimerized fatty acid. Such compounds are formed by the dimerization of unsaturated fatty acids, for example unsaturated fatty acids containing from 6 to 50, preferably from 8 to 40, preferably from 10 to 36, for example from 10 to 20 carbon atoms or from 16 to 20 carbon atoms.

Such dimerized fatty acids may contain from 12 to 100 carbon atoms, preferably from 16 to 72 carbon atoms, suitably from 20 to 40 carbon atoms, for example from 32 to 40 carbon atoms.

These compounds are well known in the art and are particularly used as corrosion inhibitors. Particularly preferred dimerized fatty acids are mixtures of C36 dimer acids, such as those obtained by dimerization of oleic acid, linoleic acid and mixtures including oleic and linoleic acids, for example, tall oil fatty acids.

The quaternary ammonium compound having formula (I) includes at least two X connecting groups. All X groups may be the same or different. Preferably all X groups are the same. To avoid any confusion, it should be stated that references to X in this work refer to each X group present in the compound.

Preferably X includes a hydrocarbyl substituent. Preferably X represents an optionally substituted arylene or alkylene group.

In some embodiments, component (c) is derived from phthalic acid or its anhydride, which have formula (A1) or (A2):

wherein each of R ^p , R ^q , R ^r and R ^s independently represents hydrogen or an optionally substituted hydrocarbyl group.

Preferably, R ^p , R ^q , R ^r and R ^s are each hydrogen or an optionally substituted alkyl or alkenyl group. Preferably, three radicals of R ^p , R ^q , R ^r and R ^s are hydrogen atoms, and the remaining radical is an optionally substituted C ₁ -C ₅₀₀ alkyl or alkenyl group, preferably a C ₂ -C ₁₀₀ alkyl or alkenyl group, more preferably C _{a 6} -C ₅₀ alkyl or alkenyl group, more preferably a C ₈ -C ₄₀ alkyl or alkenyl group, more preferably a C ₁₀ -C ₃₆ alkyl or alkenyl group, more preferably a C ₁₂ -C ₂₂ alkyl or alkenyl group, more preferably a C ₁₆ -C ₂₈ alkyl or alkenyl group, for example, a C ₂₀ -C ₂₄ alkyl or alkenyl group. The alkyl or alkenyl group may be straight or branched. Preferably, R ^p , R ^q and R ^s represent hydrogen atoms, and R ^r represents an optionally substituted alkyl or alkenyl group.

In formula (I), X preferably represents an optionally substituted hydrocarbylene group. Preferably X represents an optionally substituted alkylene group. Preferably X represents a substituted alkylene group.

Preferably X represents an alkylene group substituted with alkyl or alkenyl.

Preferably X represents an alkylene group substituted with alkyl.

Preferably X is an alkylene group substituted with alkyl, wherein the alkylene group contains 1 to 10, preferably 1 to 6, more preferably 1 to 4, more preferably 2 or 3, and most preferably 2 carbon atoms in the alkylene chain.

In some preferred embodiments, X is CH ₂ CHR or CHRCH ₂ wherein R is an optionally substituted hydrocarbyl group.

Preferably, component (c) used to prepare the quaternary ammonium compound of the present invention is the reaction product of an alcohol having the formula HO(R ⁴ O)H and an optionally substituted succinic acid or an anhydride thereof having the formula (A3) or (A4) :

where R represents hydrogen or an optionally substituted hydrocarbyl group. Preferably R represents an optionally substituted alkyl or alkenyl group.

In some embodiments, R is an optionally substituted C ₁ -C ₅₀₀ alkyl or alkenyl group, preferably a C ₂ -C ₁₀₀ alkyl or alkenyl group, preferably a C ₆ -C ₅₀ alkyl or alkenyl group, preferably a C ₈ -C ₄₀ alkyl or alkenyl group group, more preferably a C ₁₀ -C ₃₈ alkyl or alkenyl group, preferably a C ₁₆ -C ₃₆ alkyl or alkenyl group, preferably a C ₁₈ -C ₃₂ alkyl or alkenyl group.

R may be substituted with one or more groups selected from halogen (eg chlorine, fluorine or bromine), nitro, hydroxy, mercapto, sulfoxy, amino, nitrile, acyl, carboxy, alkyl (eg C ₁ -C ₄ alkyl), alkoxy group (for example, C ₁ -C ₄ alkoxy group), amido, keto, sulfoxy and cyano groups.

Preferably R represents an unsubstituted alkyl or alkenyl group. Substituted succinic acid or its anhydrides can be suitably prepared by reacting maleic anhydride with an alkene.

In some embodiments, the molecular weight of R is from 100 to 5000, preferably from 300 to 4000, preferably from 450 to 2500, for example from 500 to 2000 or from 600 to 1500.

In some embodiments, the substituted succinic acid or anhydride thereof may comprise a mixture of compounds comprising R groups of varying lengths. In such embodiments, any reference to the molecular weight of the R group refers to the number average molecular weight of the mixture.

In some embodiments, R is a polyisobutenyl group whose number average molecular weight is preferably from 100 to 5000, preferably from 200 to 2000, preferably from 220 to 1300, for example from 240 to 900, preferably from 400 to 700.

In some embodiments, R is a polyisobutenyl group having a number average molecular weight of 180 to 400.

In some embodiments, R is a polyisobutenyl group having a number average molecular weight of 800 to 1200.

In some embodiments, R is an alkyl or alkenyl group containing from 6 to 40 carbon atoms, preferably from 10 to 38 carbon atoms.

In some preferred embodiments, R is an alkyl or alkenyl group containing from 16 to 36 carbon atoms, preferably from 18 to 26 carbon atoms, for example from 20 to 24 carbon atoms.

In some embodiments, R is an alkyl or alkenyl group containing from 8 to 16 carbon atoms, such as 12 carbon atoms.

In some embodiments, R is an alkyl or alkenyl group containing from 26 to 28 carbon atoms.

In some embodiments, R may be an olefin moiety with an internal double bond. In such embodiments, the compound having formula (A3) or (A4) is preferably prepared by reacting maleic acid with an olefin having an internal double bond.

In the context of the present invention, an internal olefin means any olefin substantially containing a non-alpha double bond, that is, a beta or higher order olefin. Preferably, such materials are substantially all beta-olefins or higher order olefins, for example, contain less than 10% by weight. alpha olefin, more preferably less than 5% by weight. or less than 2% wt. Typical internal olefins include Neodene 1518IO, available from Shell.

Sometimes olefins with an internal double bond are called isomerized olefins; they can be obtained from alpha-olefins by isomerization known in the art, or can be obtained from other sources. The fact that they are also called internal olefins reflects that they do not necessarily need to be produced by isomerization.

In some particularly preferred embodiments, component (c) is derived from succinic acid or succinic anhydride containing a C ₁₀ -C ₃₀ , preferably a C ₂₀ -C ₂₄ alkyl or alkenyl group.

In some preferred embodiments, the acid used to prepare the compound of formula (IIB) contains less than 32 carbon atoms, preferably less than 30 carbon atoms.

In some embodiments, a compound having formula (IIB) is the reaction product of succinic acid or succinic anhydride having formula (A3) or (A4) and an alcohol having formula H-(OR ⁴ ) _n -OH, where R ¹ is is an alkyl or alkenyl group containing from 6 to 36 carbon atoms, or a polyisobutenyl group, the number average molecular weight of which is from 200 to 1300.

Preferably, the compound having formula (IIB) is the reaction product of a polyhydric alcohol and at least 1.5 equivalents of optionally substituted succinic acid or its anhydride.

Thus, component (c) may include compounds having formula (B1) or (B2):

where one group of X and Y represents hydrogen and the other group represents R ¹ , the definition of which was given above when considering structures (A3) or (A4).

Preferably, the acid/anhydride and alcohol are reacted in a molar ratio of 10:1 to 1:1, preferably 5:1 to 1.5:1, more preferably 3:1 to 1.8:1, e.g. from 2.5:1 to 2:1.

Most preferably, the acid/anhydride and alcohol are reacted in a molar ratio of approximately 2:1, for example 2.2:1 to 1.8:1.

Preferably, the compound having formula (IIB) is the reaction product of a hydrocarbyl-substituted polycarboxylic acid or anhydride thereof and an alcohol having the formula H-(OR ⁴ ) _n -OH, wherein R is an optionally substituted alkylene group and n is at least 1 wherein the acid/anhydride and alcohol are preferably reacted in a molar ratio of approximately 2:1, for example 2.2:1 to 1.8:1 or 2.1:1 to 1.9:1.

In some embodiments, the compound having formula (IIB) is the reaction product of an acid having the formula HOOC(CHR ^x ) _n COOH, wherein each R ^x group independently represents hydrogen or an optionally substituted hydrocarbyl group.

n may be from 1 to 50, preferably from 1 to 30, more preferably from 1 to 20, more preferably from 2 to 16, more preferably from 4 to 12, more preferably from 6 to 10. Preferably 0 or 1 R ^x group is optionally a substituted hydrocarbyl group, and all other groups are hydrogen atoms. If R ^x represents an optionally substituted hydrocarbyl, it preferably represents the group R ¹ as defined above in connection with compounds (A3) and (A4).

Most preferably, each R ^x group is hydrogen, and the compound having formula (IIB) has a structure corresponding to formula (D):

In one particularly preferred embodiment, n is 8 and the ester additive is the reaction product of sebacic acid and an alcohol having the formula H-(OR ⁴ ) _n -OH.

In preferred embodiments, an alcohol having the formula H-(OR ⁴ ) _n -OH is reacted with approximately 2 molar equivalents of a polycarboxylic acid. The additives obtained in this case contain the remains of two acidic fragments in one molecule. The two acid moieties may be the same or different. In some embodiments, both acid moieties are the same. In some embodiments, the two acid moieties are different.

In some embodiments, a compound having formula (IIB) can be prepared by reacting a polyhydric alcohol having the formula H-(OR ⁴ ) _n -OH with approximately one equivalent of a first polycarboxylic acid or anhydride thereof and one equivalent of a second polycarboxylic acid or its anhydride.

For example, a compound having formula (IIB) can be prepared by reacting a polyhydric alcohol having the formula H-(OR ⁴ ) _n -OH with about one equivalent of succinic acid or succinic anhydride substituted with an alkyl or alkenyl group containing from 6 to 36 carbon atoms, and one equivalent of succinic acid or succinic anhydride, substituted by a polyisobutenyl group, the number average molecular weight of which is from 200 to 1300.

In another example, a compound having formula (IIB) can be prepared by reacting a polyhydric alcohol having the formula H-(OR ⁴ ) _n -OH with about one equivalent of succinic acid or succinic anhydride substituted with an alkyl or alkenyl group containing from 6 up to 36 carbon atoms, and one equivalent of unsubstituted succinic acid.

In preferred embodiments, the compound having formula (IIB) is the reaction product of a substituted succinic acid or a substituted succinic anhydride. In such embodiments, the additive preferably includes compounds having formulas (C1), (C2) or (C3), as well as mixtures thereof and isomers thereof:

In structures (B1), (B2), (D), (C1), (C2) and (C3), all acid residues present may be the same or different.

In some embodiments, all acid residues are the same. In some embodiments, the acid moieties are different.

Preferably n is from 1 to 30, preferably from 1 to 20, preferably from 1 to 16.

Preferably R ⁴ represents an alkylene group containing from 1 to 12, preferably from 1 to 6, more preferably 2 or 3 carbon atoms.

R ⁴ represents an optionally substituted alkylene group.

In some embodiments, the alcohol having the formula H-(OR ⁴ ) _n -OH contains more than 2 hydroxy groups, and the R ⁴ group is a hydroxyl-substituted alkylene group. Such a group may contain 1, 2 or more hydroxyl groups.

In some embodiments, the alcohol H-(OR ⁴ ) _n -OH may be a sugar-derived molecule in which R includes one or more hydroxyl residues.

The R group may be substituted such that it forms a cyclic alkylene moiety. The cyclic alkylene moiety may contain one or more heteroatoms. For example, the moiety may contain an ether linking structure.

In some embodiments, R may represent one or more saccharide moieties or may be substituted by one or more saccharide moieties.

For example, in some embodiments, the alcohol H-(OR ⁴ ) _n -OH may be glycerol, pentaerythritol, or trimethylolpropane.

In some embodiments, H-(OR ⁴ ) _n -OH may be a sugar, such as trehalose or sorbitol.

Preferably R ⁴ represents an unsubstituted alkylene group.

Preferably R ⁴ is an optionally substituted alkylene group containing from 1 to 50 carbon atoms, preferably from 1 to 40 carbon atoms, more preferably from 1 to 30 carbon atoms, more preferably from 1 to 20 carbon atoms, more preferably from 1 to 10 carbon atoms , for example, from 2 to 6 or from 2 to 4 carbon atoms.

Preferably R ⁴ represents an unsubstituted alkylene group containing from 1 to 50 carbon atoms, preferably from 1 to 20, more preferably from 1 to 10, preferably from 2 to 6, for example from 2 to 4 carbon atoms. R ⁴ may be a straight or branched group.

Preferably, R ⁴ may be an ethylene, propylene, butylene, pentylene or hexylene group. If R ⁴ contains more than 2 carbon atoms, then any isomer may be present. Preferably R ⁴ represents an ethylene or propylene group, most preferably a propylene group.

In those embodiments in which n is 1, R ⁴ may be a group having the formula (CH ₂ ) _x where x is from 2 to 12, preferably from 2 to 6.

In some preferred embodiments in which n is 1, R ⁴ represents a straight or branched alkylene group containing from 2 to 8, preferably from 3 to 6 carbon atoms.

Suitable compounds of this type include propylene glycol, 1,3-propanediol, 1,6-hexanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol and neopentyl glycol.

In some preferred embodiments, R ⁴ is preferably CR ^a R ^b CR ^c R ^d , and the polyhydric alcohol has the formula H-(OCR ^a R ^b CR ^c R ^d ) _n OH, wherein each of R ^a , R ^b , R ^c and R ^d independently represents hydrogen or an optionally substituted alkyl group. Preferably, R ^a , R ^b , R ^c and R ^d are each independently selected from hydrogen or an optionally substituted alkyl group containing from 1 to 20, preferably from 1 to 12, more preferably from 1 to 4, for example from 1 to 2 atoms carbon.

Preferably, R ^a , R ^b , R ^c and R ^d are each independently selected from hydrogen and an unsubstituted alkyl group, preferably containing from 1 to 20 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 4 atoms, e.g. or 2 carbon atoms. Preferably at least two of R ^a , R ^b , R ^c and R ^d are hydrogen atoms, more preferably at least three of R ^a , R ^b , R ^c and R ^d are hydrogen atoms.

In some embodiments, R ^a , R ^b , R ^c and R ^d are all hydrogen atoms and R is ethylene, CH ₂ CH ₂ .

In some embodiments, three radicals of R ^a , R ^b , R ^c , and R ^d are hydrogen atoms and the remaining radical is an unsubstituted alkyl group containing 1 to 12, preferably 1 to 4, preferably 1 to 2 carbon atoms, and most preferably 1 carbon atom.

In some embodiments, the polyols used to prepare component (c) are derived from epoxides, preferably epoxide-terminated epoxides.

R ⁴ may include a mixture of isomers. For example, if R ⁴ is propylene, then the polyhydric alcohol may include -CH ₂ CH(CH ₃ )- and -CH(CH ₃ )CH ₂ - moieties distributed in any order along the chain.

R ⁴ may include a mixture of different groups, for example, ethylene, propylene or butylene units. In such embodiments, block copolymer units are preferred.

R ⁴ preferably represents an ethylene, propylene or butylene group. R ⁴ may be an n-propylene or n-butylene group, or an isopropylene or isobutylene group. For example, R ⁴ may be -CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )-, -CH ₂ C(CH ₃ ) ₂ , -CH(CH ₃ )CH(CH ₃ )- or -CH ₂ CH (CH ₂ CH ₃ ) -.

Preferably R ⁴ is ethylene or propylene. More preferably, R ⁴ is -CH ₂ CH ₂ - or -CH(CH ₃ )CH ₂ -. Most preferably, R ⁴ is -CH(CH ₃ )CH ₂ -.

n is at least 1. Preferably n is from 1 to 100, preferably from 1 to 50, more preferably from 1 to 30, more preferably from 1 to 24, preferably from 1 to 20, preferably from 1 to 16, preferably from 1 to 14.

In some embodiments, n is from 4 to 10, such as from 6 to 8.

In some embodiments, n is from 1 to 6, preferably from 2 to 5, such as 3 or 4.

In some embodiments, n is from 8 to 16, such as from 11 to 14.

Preferably, the number average molecular weight of the polybasic alcohol is 60 to 6000, preferably 60 to 3000, more preferably 60 to 2000, more preferably 60 to 1500, preferably 60 to 1200, preferably 60 to 1000, preferably 60 to 850.

In some embodiments, the number average molecular weight of the alcohol is from 190 to 600, such as from 280 to 490.

In some embodiments, the number average molecular weight of the alcohol is from 60 to 370, preferably from 110 to 320, such as from 190 to 260 or from 140 to 200.

In some embodiments, the number average molecular weight of the alcohol is from 360 to 950, such as from 500 to 840.

In some embodiments, the polyhydric alcohol may be polypropylene glycol having a number average molecular weight of 425.

In some embodiments, the polyhydric alcohol may be selected from triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol.

In some embodiments, the polyhydric alcohol may be polypropylene glycol having a number average molecular weight of 725.

In some embodiments, the polyhydric alcohol may be polyethylene glycol having a number average molecular weight of 400.

In some embodiments, the polyol may be selected from triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol.

In some embodiments, the polyol is selected from ethylene glycol, propylene glycol, and oligomers or polymers thereof.

One skilled in the art will appreciate that commercial sources of alcohols having the formula H-(OR ⁴ ) _n -OH often contain mixtures of compounds in which, for example, n can range from 6 to 10.

Commercial sources of substituted succinic acids and anhydrides may also contain mixtures of compounds, for example, including various compounds with substituents containing from 20 to 24 carbon atoms.

In some embodiments, n is from 10 to 40, preferably from 15 to 30, more preferably from 20 to 25, and R ⁴ is ethylene or propylene, most preferably propylene.

In some embodiments, the compound having formula (IIB) is the reaction product of a polyhydric alcohol having the formula H-(OR ⁴ ) _n -OH selected from ethylene glycol, propylene glycol and oligomers or polymers thereof; alkanediols containing from 1 to 12, preferably from 3 to 6 carbon atoms, and sugar alcohols and at least 1.5 molar equivalents of one or more optionally substituted polycarboxylic acids or their anhydrides selected from pyromellitic acid, malonic acid, sebacic acid and succinic acid.

In some embodiments, the compound having formula (IIB) is the reaction product of a polyhydric alcohol having the formula H-(OR ⁴ ) _n -OH selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, trehalose, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and polyethylene glycol or polypropylene glycol, the number average molecular weight of which is from 300 to 1200; and at least 1.5 molar equivalents of one or more optionally substituted polycarboxylic acids or their anhydrides selected from pyromellitic acid and succinic acid.

In some embodiments, the compound having formula (IIB) is the reaction product of an alcohol having the formula H-(OR ⁴ ) _n -OH selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, trehalose, sorbitol, glycerol, pentaerythritol, trimethylolpropane, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and polyethylene glycol or polypropylene glycol, the number average molecular weight of which is between 300 to 1200; and at least 1.5 molar equivalents of one or more optionally substituted succinic acids or their anhydrides having formula (A3) or (A4), where each R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms, or polyisobutenyl a group whose number-average molecular weight ranges from 200 to 1300.

In some embodiments, the compound having formula (IIB) is the reaction product of an alcohol having the formula H-(OR ⁴ ) _n -OH selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, trehalose, sorbitol, glycerol, pentaerythritol, trimethylolpropane, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and polyethylene glycol or polypropylene glycol, the number average molecular weight of which is between 300 to 1200; about one molar equivalent of an optionally substituted succinic acid or succinic anhydride having formula (A3) or (A4), wherein R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; and about one molar equivalent of an optionally substituted succinic acid or succinic anhydride having formula (A3) or (A4), wherein R is a polyisobutenyl group having a number average molecular weight of from 200 to 1300.

In some embodiments, the compound having formula (IIB) is the reaction product of polypropylene glycol having a number average molecular weight of from 300 to 800, and at least 1.5 molar equivalents of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 6 to 36 carbon atoms.

In some embodiments, the compound having formula (IIB) is the reaction product of a polyhydric alcohol selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and tetrapropylene glycol and at least 1.5 molar equivalents of succinic acid or its anhydride, having an alkyl or alkenyl substituent containing from 6 to 36 carbon atoms.

In some embodiments, the compound having formula (IIB) is the reaction product of a polyhydric alcohol selected from glycerol, pentaerythritol and trimethylolpropane, and at least 1.5 molar equivalents of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 6 up to 36 carbon atoms.

In some particularly preferred embodiments, the compound having formula (IIB) is the reaction product of polyethylene glycol or polypropylene glycol containing from 4 to 16, preferably from 6 to 8 alkoxy groups, and at least 1.5 molar equivalents of succinic acid or succinic anhydride having C ₁₀ -C ₃₀ , preferably C ₂₀ -C ₂₄ alkyl or alkenyl substituent.

In some embodiments, the compound having formula (IIB) is the reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 6 to 36 carbon atoms and an alcohol selected from propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1-4-butanediol, 1,6-hexanediol and neopentyl glycol.

In some embodiments, the compound having formula (IIB) is the reaction product of succinic acid or succinic anhydride containing a C ₁₀ -C3 ₀ , preferably a C ₂₀ -C ₂₄ alkyl or alkenyl substituent, and an alcohol selected from propylene glycol, dipropylene glycol, 1, 3-propanediol, 1,2-butanediol, 1,3-butanediol, 1-4-butanediol, 1,6-hexanediol and neopentyl glycol.

In some preferred embodiments, the compound having formula (IIB) is the reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing less than 30 carbon atoms, preferably less than 26 carbon atoms, and an alcohol selected from ethylene glycol, diethylene glycol, triethylene glycol , tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, polyethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1-4-butanediol, 1,6-hexanediol and neopentyl glycol.

In some embodiments, the compound having formula (IIB) is the reaction product of succinic acid or succinic anhydride having formula (A3) or (A4) and an alcohol having formula H-(OR ⁴ ) _n -OH; where R ¹ represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms, or a polyisobutenyl group whose number average molecular weight is from 200 to 1300; and an alcohol selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, polyethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol ola, trehalose , 1,6-hexanediol and neopentyl glycol.

In some embodiments, component (c) used to prepare the quaternary ammonium compound of the present invention is the reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 6 to 36 carbon atoms and polypropylene glycol having a number average molecular weight of from 300 to 800.

In some particularly preferred embodiments, the compound having formula (IIB) is the reaction product of succinic acid or succinic anhydride having a C ₂₀ -C ₂₄ alkyl or alkenyl substituent and an alcohol selected from 1,2-butanediol, 1,3-butanediol , 1,4-butanediol, tripropylene glycol and polypropylene glycols, the number average molecular weight of which is from 300 to 600.

For the avoidance of doubt, it should be noted that component (c) may include a mixture of compounds. Compounds that may be present include mixtures formed by a reaction mixture comprising various polyols and a polycarboxylic acid, and/or mixtures formed by the reaction of a polyol and a mixture of polycarboxylic acids, and/or compounds formed by a reaction mixture comprising polyols and a mixture carboxylic acids. Such mixtures may also include mixtures of initially pure complete esters and water.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine having the formula R ¹ R ² R ³ N, in which R ¹ and R ² are each an optionally substituted alkyl or alkenyl group, and R ³ is selected from:

- an alkyl, hydroxyalkyl or hydroxyalkoxyalkyl group containing from 1 to 20 carbon atoms;

- an optionally substituted alkaryl group, for example benzyl;

- a polyisobutyl group, the number average molecular weight of which is from 100 to 5000;

- an optionally substituted alkylene phenol moiety having formula (X) or (Y):

where n is from 0 to 4, preferably 1, each R ^x represents an optionally substituted hydrocarbyl group, R ^y represents an optionally substituted alkyl, alkenyl or aryl group; and L represents a connecting group; And

- a succinimide fragment having the formula (Z):

where R ^z represents an optionally substituted hydrocarbyl group, and L represents a connecting group;

(b) epoxide; And

(c) the reaction product of an alcohol having the formula H-(OR ⁴ )-OH and an optionally substituted succinic acid or an anhydride thereof, wherein R ⁴ represents an optionally substituted alkylene group.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine having the formula R ¹ R ² R ³ N, in which R ¹ and R ² are each a C ₁ -C ₄ alkyl group, and R ³ is selected from a C ₁ -C ₂₄ alkyl group; benzyl; and hydroxyalkyl or hydroxyalkoxyalkyl groups containing from 2 to 20 carbon atoms;

(b) an epoxide having the formula:

where R ⁹ is hydrogen, R ¹⁰ is hydrogen, phenyl or C ₁ -C ₄ alkyl, R ¹¹ is hydrogen, and R ¹² is hydrogen, C ₁ -C ₃₀ alkyl, phenyl or CH ₂ OR ¹³ where R ¹³ represents C ₁ -C ₁₂ alkyl; And

(c) a reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 1 to 200 carbon atoms, and an alcohol selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, polyethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, trehalose, 1,6-hexanediol and neopentyl glycol.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine having the formula R ¹ R ² R ³ N, in which R ¹ and R ² are each a C _{1 -C 4} alkyl group, and R ³ is selected from a C ₁ -C ₂₄ alkyl group; benzyl; and hydroxyalkyl or hydroxyalkoxyalkyl groups containing from 2 to 20 carbon atoms;

(b) an epoxide having the formula:

where R ⁹ represents hydrogen, R ¹⁰ represents hydrogen, phenyl or C ₁ -C ₄ alkyl, R ¹¹ represents hydrogen, and R ¹² represents C ₁ -C ₃₀ alkyl, phenyl or CH ₂ OR ¹³ where R ¹³ represents C ₁ -C ₁₂ alkyl; And

(c) the reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing from 6 to 36 carbon atoms, and polyethylene glycol or polypropylene glycol, the number average molecular weight of which is from 200 to 1000.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine selected from N,N-dimethylethanolamine, dimethyloctadecylamine, N-methyl-N,N-diamine tall oil, N,N-diethylethanolamine, triethylamine, tripropylamine and tributylamine, dimethylbenzylamine and dimethylaminoethoxyethanol;

(b) an epoxide selected from 2-ethylhexylglycidyl ether, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, dodecyl epoxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides or glycidyl ethers containing from 2 to 50 carbon atoms, in particular , from 2-ethylhexylglycidyl ether, butylene oxide, styrene oxide and dodecyl epoxide; And

(c) a reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing less than 30, for example from 20 to 24 carbon atoms, and polyethylene glycol or polypropylene glycol, the number average molecular weight of which is 200 to 1000.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine selected from N,N-dimethylethanolamine, dimethyloctadecylamine, N-methyl-N,N-diamine tall oil, N,N-diethylethanolamine, triethylamine, tripropylamine and tributylamine, dimethylbenzylamine and dimethylaminoethoxyethanol;

(b) an epoxide selected from 2-ethylhexylglycidyl ether, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, dodecyl epoxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides or glycidyl ethers containing from 2 to 50 carbon atoms, in particular , from 2-ethylhexylglycidyl ether, butylene oxide, styrene oxide and dodecyl epoxide; And

(c) a reaction product of succinic acid or its anhydride having an alkyl or alkenyl substituent containing less than 30, for example from 20 to 24 carbon atoms, and an alcohol selected from ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1 ,3-butanediol, 1,4-butanediol, trehalose, 1,6-hexanediol and neopentyl glycol.

In some preferred embodiments, the quaternary ammonium compound (I) of the present invention is a reaction product:

(a) a tertiary amine selected from N,N-dimethylethanolamine, dimethyloctadecylamine, N-methyl-N,N-diamine tall oil, N,N-diethylethanolamine, triethylamine, tripropylamine and tributylamine, dimethylbenzylamine and dimethylaminoethoxyethanol;

(b) an epoxide selected from 2-ethylhexylglycidyl ether, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, epoxyhexane, octene oxide, dodecyl epoxide, stilbene oxide and other alkyl epoxides and alkenyl epoxides or glycidyl ethers containing from 2 to 50 carbon atoms, in particular , from 2-ethylhexylglycidyl ether, butylene oxide, styrene oxide and dodecyl epoxide; And

(c) a reaction product of succinic acid or its anhydride containing a polyisobutenyl substituent whose number average molecular weight is from 500 to 2500, for example, whose number average molecular weight is from 500 to 1500, and an alcohol selected from ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, trehalose, 1,6-hexanediol and neopentyl glycol.

The third aspect of the present invention relates to a composition comprising a quaternary ammonium compound having formula (I):

where each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group, X represents a connecting group; R ⁴ represents an optionally substituted alkylene group; n is equal to a positive integer; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

Preferred features of the third aspect are disclosed in consideration of the first and second aspects.

In some embodiments, the composition of the third aspect is an additive composition comprising a quaternary ammonium compound of the first aspect, and a diluent or carrier.

The additive composition may be a lubricating oil additive composition.

Preferably, the additive composition is an additive composition for a fuel composition, preferably a diesel fuel composition.

The quaternary ammonium compound is preferably present in the additive composition in an amount ranging from 1 to 99% by weight, for example, from 1 to 75% by weight.

The additive composition may include a mixture of two or more quaternary ammonium compounds according to the present invention. In such embodiments, the above amounts preferably refer to the total amount of all such compounds present in the composition.

The additive composition may include one or more additional additives. They may be selected from antioxidants, dispersants, detergents, metal deactivating compounds, anti-wax deposition additives, cold flow improvers, cetane number improvers, haze reducing agents, stabilizers, demulsifiers, antifoam agents, corrosion inhibitors , lubricity additives, dyes, markers, combustion additives, metal deactivators, odor masking agents, friction modifiers and conductivity enhancing agents.

In some preferred embodiments, the additive composition includes one or more additional nitrogen-containing detergent additives.

A third aspect of the present invention may relate to a fuel composition or a lubricating oil composition comprising a quaternary ammonium salt/compound according to the first aspect.

In some embodiments, the present invention provides a lubricant composition comprising an oil having a viscosity suitable for lubricants and, as an additive, a quaternary ammonium compound having formula (I):

where each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group, X represents a connecting group; R ⁴ represents an optionally substituted alkylene group; n is equal to a positive integer; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

In some preferred embodiments, a third aspect of the present invention relates to a fuel composition comprising as an additive a quaternary ammonium compound having formula (I):

where each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group, X represents a connecting group; R ⁴ represents an optionally substituted alkylene group; n is equal to a positive integer; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

The present invention may further relate to a method for producing a fuel composition, which includes producing a quaternary ammonium compound according to the first aspect and mixing the quaternary ammonium compound with a fuel.

The fuel composition according to the present invention is preferably a diesel fuel composition.

Preferably, the quaternary ammonium compound additive is contained in the diesel fuel composition in an amount of at least 0.1 ppm, preferably at least 1 ppm, more preferably at least 5 ppm, more preferably at least 10 ppm, preferably at least 20 ppm, for example at least 30 ppm or at least 50 ppm.

Preferably, the quaternary ammonium additive is contained in the diesel fuel composition in an amount of less than 10,000 ppm, preferably less than 1,000 ppm, preferably less than 500 ppm, preferably less than 300 ppm, for example less than 250 ppm .

In some embodiments, the quaternary ammonium additive is contained in the diesel fuel composition in an amount preferably less than 200 ppm, such as less than 150 ppm.

Preferably, the quaternary ammonium additive is present in the diesel fuel in an amount ranging from 80 to 130 ppm.

Any reference to parts per million in this work refers to parts per million by mass.

The diesel fuel compositions of the present invention may include a mixture of two or more quaternary ammonium compounds. In such embodiments, the above amounts refer to the total amount of all such additives present in the composition.

The use of mixtures may be advantageous due to the availability of starting materials, or the use of a particular mixture may be deliberately chosen to achieve a particular beneficial effect. For example, the use of a particular mixture may facilitate processing operations, improve overall performance, or have a synergistic effect on performance.

Any reference herein to “additives” or “additives of the invention” includes embodiments in which one additive compound is present and embodiments in which two or more additive compounds are present. Those embodiments in which two or more compounds are present may include mixtures prepared from the mixture of starting materials used to prepare the additive compounds (for example, mixtures of polyols and/or mixtures of polycarboxylic acids and/or mixtures of tertiary amines and/or or mixtures of quaternizing agents). Alternatively and/or additionally, two or more preformed compounds having formula (I) may be added to the composition, for example a fuel or lubricant composition.

Quaternary ammonium salt additives can be added to diesel fuel at any suitable stage in the value chain. For example, additives may be added to the fuel at the refinery, at the distribution terminal site, or after the fuel has been transported from the distribution terminal. If an additive is added to fuel after it has been transported from a distribution terminal, this is referred to as aftermarket application of the additive. After-market applications include such circumstances as adding the additive to fuel in a delivery tanker, directly into a customer-owned bulk tank, or directly into an end-user-owned tanker truck. Aftermarket applications may include the supply of the fuel additive in small bottles suitable for direct addition to fuel storage tanks or tanker trucks.

By the term diesel fuel, the inventors include any fuel suitable for driving both diesel engines of road vehicles and other types of diesel engines. This fuel includes, but is not limited to, fuels referred to as diesel fuel, marine diesel fuel, heavy fuel oil, industrial fuel oil, etc.

The diesel fuel composition of the present invention may include a petroleum-based fuel oil, in particular a middle distillate fuel oil. The boiling points of distillate fuel oils typically range from 110°C to 500°C, for example from 150°C to 400°C. Diesel fuel may include atmospheric distillate or vacuum distillate, cracked gas oil, or a mixture of any proportions of straight distillates and refinery streams such as thermal and/or catalytic cracking and hydrocracking distillates.

The diesel fuel composition may include non-renewable Fischer-Tropsch fuels such as fuels referred to as GTL fuels, gas-to-liquid fuels, CTL fuels. i.e. obtained using the “coal-to-liquid” processing technology, English coal-to-liquid) and OTL fuel (i.e. obtained using the “oil sands-to-liquid” processing technology, English oil sands-to-liquid).

The diesel fuel composition may include a renewable fuel such as a biofuel composition or a biodiesel composition.

The diesel fuel composition may include first generation biodiesel. First generation biodiesel contains esters of, for example, vegetable oils, animal fats and used cooking oils. This form of biodiesel can be produced by trans-esterifying oils such as canola oil, soybean oil, canola oil, safflower oil, palm oil, corn oil, peanut oil, cottonseed oil, tallow, coconut oil, butter laxative nut (jatropha oil), sunflower oil, waste cooking oils, hydrogenated vegetable oils or any mixtures of these oils, under the influence of an alcohol, usually a monoalcohol, usually in the presence of a catalyst.

The diesel fuel composition may include second generation biodiesel. Second-generation biodiesel is produced from renewable sources such as vegetable oils and animal fats and processed, often in a refinery and often using hydroprocessing such as the H-Bio process developed by Petrobras. Second-generation biodiesel can be similar in properties and quality to petroleum-based fuel oil streams, and an example is the renewable diesel fuel produced from vegetable oils, animal fats, etc., which ConocoPhillips markets under the name Renewable Diesel , and Neste - under the name NExBTL.

The diesel fuel composition may include third generation biodiesel. To obtain third-generation biodiesel fuel, including fuel called BTL fuel (i.e., obtained using biomass-to-liquid technology), gasification and the Fischer-Tropsch method are used. Third-generation biodiesel is not very different from some types of second-generation biodiesel, but to obtain it, the entire plant (biomass) is processed, which significantly expands the raw material base.

The diesel fuel composition may contain mixtures of any or all of the above diesel fuel compositions.

In some embodiments, the diesel fuel composition may be a diesel fuel blend including biodiesel. In such mixtures, the amount of biodiesel fuel can be, for example, up to 0.5%, up to 1%, up to 2%, up to 3%, up to 4%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95% or up to 99%.

In some embodiments, the fuel composition may include pure biodiesel.

In some preferred embodiments, the fuel composition includes at least 5% of the mass. biodiesel fuel.

In some embodiments, the fuel composition may include pure GTL fuel.

In some embodiments, the diesel fuel composition may include a secondary fuel, such as ethanol. However, the diesel fuel composition preferably does not contain ethanol.

The diesel fuel composition used in accordance with the present invention may include a relatively high sulfur content, for example, more than 0.05% by weight, such as 0.1% or 0.2%.

However, in preferred embodiments, the maximum sulfur content of diesel fuel is 0.05% by weight, more preferably 0.035% by weight, in particular not more than 0.015%. Fuels with even lower sulfur content are also suitable, such as fuels containing less than 50 ppm by weight of sulfur, preferably less than 20 ppm, such as 10 ppm or less.

The diesel fuel composition of the present invention preferably includes at least 5 wt% biodiesel and less than 50 ppm sulfur.

The quaternary ammonium compound additives of the present invention have been found to effectively control deposit formation in fuel and lubricant compositions.

The present invention may relate to the use of a quaternary ammonium compound according to the first aspect as an additive in fuel compositions and lubricating oil compositions.

The present invention may relate to the use of a quaternary ammonium compound according to the first aspect as an additive in fuel compositions and lubricating oil compositions that control deposit formation.

The present invention may relate to the use of a quaternary ammonium compound according to the first aspect as a deposit control additive in a lubricating oil composition.

The present invention may relate to the use of a quaternary ammonium compound according to the first aspect as a deposit control additive in fuel compositions.

The present invention may relate to the use of a quaternary ammonium compound according to the first aspect as a deposit control additive in a diesel fuel composition.

The fourth aspect of the present invention relates to the use of a quaternary ammonium compound having formula (I):

as an additive, wherein each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted alkyl, alkenyl or aryl group; X represents a connecting group; R ⁴ represents an optionally substituted alkylene group; n is a positive integer; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

Preferred features of the fourth aspect are disclosed in consideration of the first, second and third aspects.

The use according to the fourth aspect preferably relates to the use of a quaternary ammonium compound as a fuel additive, preferably a diesel fuel additive.

Preferably, the use according to the fourth aspect relates to the use of the quaternary ammonium compound according to the first aspect as a detergent additive.

A fourth aspect of the present invention may relate to the use of a quaternary ammonium compound having formula (I) to improve engine performance. Application preferably involves combustion of a composition comprising a quaternary ammonium compound in an engine.

Preferably the engine is a diesel engine.

A fifth aspect of the present invention relates to a method for improving engine performance, the method comprising burning in an engine a fuel composition comprising as an additive a quaternary ammonium compound having formula (I):

wherein each of R ⁰ , R ¹ , R ² and R ³ independently represents an optionally substituted hydrocarbyl group, X represents a connecting group, R ⁴ represents an optionally substituted alkylene group; n is a positive integer, c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH, and b is equal to 2 if W is O ^- .

Preferred features of the fifth aspect of the invention are disclosed in connection with the first, second, third and fourth aspects.

The method according to the fifth aspect preferably includes burning the composition according to the third aspect in an engine.

A fifth aspect of the invention relates to a method for improving engine performance.

Preferably the engine is a diesel engine.

Most preferably, the engine is a direct injection diesel engine.

The present invention relates to improving the performance of diesel engines by burning diesel fuel compositions including a quaternary ammonium compound.

Preferably, improved engine performance is achieved by controlling engine deposits.

In preferred embodiments, a fifth aspect of the present invention relates to a method for controlling deposits in an engine, preferably a diesel engine.

The method can be implemented by burning in the engine a composition comprising a quaternary ammonium compound, which acts as a detergent additive.

Thus, the present invention can provide a method for controlling deposits in a diesel engine, where the method includes burning in the engine a fuel composition including a quaternary ammonium compound as an additive according to the first aspect.

Preferably, the use of the additive disclosed in the fourth aspect improves the performance of an engine, preferably a diesel engine. This improvement in performance can be achieved, for example, by counteracting the formation of deposits in the engine.

A fourth aspect of the present invention relates to the use of a quaternary ammonium compound additive as a detergent additive.

Reference herein to performance improvement and/or deposit control may refer to the fourth and/or fifth aspects of the invention.

The quaternary ammonium additives used in accordance with the present invention have been found to be particularly beneficial in modern diesel engines incorporating a high pressure fuel system. Some features of engines of this type were discussed above.

Preferably, the present invention provides deposit control and/or performance improvement for a diesel engine including a high pressure fuel system. Preferably, the pressure in the diesel engine is greater than 1350 bar (1.35×10 ⁸ Pa). The pressure in a diesel engine can be up to 2000 bar (2×10 ⁸ Pa) or more.

Two non-limiting examples of such high pressure fuel systems are: a common rail injection system, in which the fuel is compressed by a high pressure pump that supplies fuel to the injection valves through a common rail, and a unit injector system, in which the high pressure pump pressure and fuel injection valve are integrated in one unit, which makes it possible to achieve the highest possible injection pressures exceeding 2000 bar (2 × 10 ⁸ Pa). In both systems, when the fuel is compressed, it is heated, often to temperatures of approximately 100°C or higher.

In systems with a common discharge line, fuel is stored at high pressure in a central storage line or separate storage tanks before being supplied to the injectors. Often some of the heated fuel is returned to the low pressure section of the fuel system or returned to the fuel tank. To achieve high injection pressures in a pump injector system, the fuel is compressed inside the injector. This, in turn, increases the temperature of the fuel.

In both systems, before injection, the fuel is located in the injector body, where it is additionally heated by the combustion chamber. The fuel temperature at the nozzle tip can reach 250-350°C.

Thus, before injection, the fuel is compressed to pressures ranging from 1350 bar (1.35×10 ⁸ Pa) to more than 2000 bar (2×10 ⁸ Pa), and fuel temperatures reaching from about 100° C. to 350 °C, and sometimes the fuel is recycled back into the fuel system, thus increasing the period of time the fuel remains under the described conditions.

A common problem with diesel engines is clogged injectors, particularly the injector body and injector nozzle. The fuel filter may also become clogged. A clogged injector nozzle occurs when the nozzle becomes clogged with diesel deposits. Clogged fuel filters can be caused by fuel being recirculated back into the fuel tank. The formation of deposits intensifies as the fuel decomposes. Deposits may form as carbon-containing coke-like residues, varnish deposits, or sticky or tar-like residues. Diesel fuels become more and more unstable as they are heated, particularly when heated under pressure. Therefore, increased fuel degradation may occur in diesel engines with high pressure fuel systems. In recent years, the design of injection systems has been constantly updated to meet the requirements for reducing emissions into the atmosphere. This leads to more complex injector designs and low resistance to deposit formation.

Injector clogging can occur when using any type of diesel fuel. However, some fuels may be particularly prone to clogging, or clogging may occur more quickly with these fuels. For example, increased deposit formation may occur with the use of fuels containing biodiesel and fuels containing metal compounds.

If the injectors are completely or partially clogged, the fuel supply is reduced and the mixing of fuel with air deteriorates. Over time, this leads to reduced engine power, increased exhaust emissions and reduced fuel economy.

Deposits are known to form in the injector spray channels, resulting in reduced flow and reduced power. The smaller the injector nozzle opening size, the greater the relative impact of deposit build-up. Deposits are also known to form at the tip of the injector. Such deposits negatively affect the fuel atomization pattern, resulting in reduced combustion efficiency and increased air emissions, as well as increased fuel consumption.

In addition to these "external" deposits in the injector nozzle bore and injector tip, which impede fuel flow and cause loss of power, deposits can form inside the injector body, causing additional problems. These deposits can be called internal diesel injector deposits (abbreviated as internal diesel injector deposits, abbreviated as IDID). VOFDs are additionally formed inside the injector on important moving parts. They can impede the movement of such parts, negatively affecting the timing of injection and the amount of fuel injected. Because modern diesel engines must operate with very high precision, these deposits can seriously impair performance.

The formation of VOFD causes a number of problems, including reduced power and reduced fuel economy due to less than optimal fuel metering and combustion. Initially, the engine may experience problems during cold starts and/or the engine may start to run rough. The formation of such deposits can lead to more serious clogging of the injectors. This occurs when deposits obstruct the movement of injector parts, causing the injector to stop working. Clogging of some or all of the injectors can cause the engine to stop completely.

CEC recently introduced the Diesel Engine Injector Injector Deposit Assessment test, CEC F-110-16, which distinguishes between fuels that have different potential for forming HIPS in common rail direct injection diesel engines.

As noted above, the problem of injector clogging is more likely to occur when using fuel compositions that include metal compounds. Various metal compounds may be present in fuel compositions. They may appear as a result of fuel contamination during its production, storage, transportation or use, or as a result of contamination of fuel additives. Metal compounds can also be added to fuel intentionally. For example, transition metals are sometimes added to fuels as catalysts carried with the fuel (fuel catalysts), for example to improve the performance of diesel particulate filters (particulate filters).

Injector jamming can occur as a result of the reaction of metal or ammonium compounds, in particular sodium compounds, with compounds containing carboxyl groups in the fuel.

It is believed that the main cause of stuck injectors is sodium-containing contaminants contained in diesel fuel and the carboxylate salts formed from them.

In some embodiments, the diesel fuel compositions used in accordance with the present invention include sodium and/or calcium. Preferably the compositions include sodium. The total amount of sodium and/or calcium in the composition is typically 0.01 to 50 ppm, preferably 0.05 to 5 ppm, more preferably 0.1 to 2 ppm, e.g. 1 ppm.

Contaminants may also be other metal-containing compounds, such as compounds introduced into fuels as a result of the corrosive action of acidic compounds in fuels or lubricants on metal surfaces and surfaces containing metal oxides. The use of fuels such as diesel fuel involves constant contact of the fuel with metal surfaces, such as in vehicle fuel delivery systems, fuel tanks, fuel transport means, etc. Typically, metal-containing contaminants may include transition metals such as zinc, iron and copper, Group I or Group II metals, and other metals such as lead.

The presence of metallic compounds can cause deposits to form on fuel filters and/or external parts of injectors, including injector tip deposits and/or nozzle deposits.

In addition to the introduction of metal-containing particles into diesel fuel as a result of its contamination, in some cases metal-containing compounds may be added to the fuel intentionally. For example, as is known in the art, metal-containing fuel catalysts can be added to the fuel to promote regeneration of soot eliminators. The presence of such catalysts can also cause injector clogging when the corresponding fuel is supplied to a diesel engine incorporating a high pressure fuel system.

Depending on the source, metal-containing contamination may be in the form of an insoluble powdery substance or soluble compounds or complexes. Metal-containing fuel catalysts are often soluble compounds or complexes or colloidal particles.

In some embodiments, the diesel fuel may contain metal-containing compounds including a fuel catalyst. Preferably, the fuel catalyst includes one or more metals selected from iron, cerium, platinum, manganese, Group I and Group II metals, for example calcium and strontium. Most preferably, the fuel catalyst includes a metal selected from iron and cerium.

In some embodiments, the diesel fuel may include a metal-containing compound including zinc. Zinc may be present in an amount ranging from 0.01 to 50 ppm, preferably from 0.05 to 5 ppm, more preferably 0.1 to 1.5 ppm.

Typically, the total amount of all metal-containing compounds in diesel fuel, expressed as the total mass of metal contained in the compounds, ranges from 0.1 to 50 mass. parts per million, for example from 0.1 to 20 parts per million, preferably from 0.1 to 10 mass. parts per million by weight of diesel fuel.

It would be useful to provide a diesel fuel composition that prevents or reduces the formation of deposits in a diesel engine. In some embodiments, such deposits may include "external" nozzle deposits, such as deposits in and around the nozzle opening and at the nozzle tip. In some preferred embodiments, the deposits include "internal" deposits on the injector or FOAP. We can say that the created fuel compositions provide the function of “maintaining cleanliness”, i.e. they prevent or slow down the formation of clogs. It is also desirable to provide a diesel fuel composition that promotes the removal of these types of deposits. When such a fuel composition is burned in a diesel engine, deposits are removed from engine parts, which thus leads to the “cleaning” of an already dirty engine.

As with the "keep clean" property, "cleaning" a dirty engine can provide significant benefits. For example, improved cleaning may result in increased power and/or improved fuel economy. In addition, removing deposits from the engine, particularly from the injectors, can increase the time interval between routine repairs or injector replacements, thereby reducing maintenance costs.

Although, for the reasons stated above, injector deposits are a serious problem in modern diesel engines equipped with high pressure fuel systems, it is desirable to provide a diesel fuel composition that also provides effective cleaning action in older generation conventional diesel engines. so that the same fuel supplied to the pumps can be used to operate all types of engines.

It is also desirable for fuel compositions to reduce clogging of vehicle fuel filters. It would be useful to provide compositions that prevent or retard the formation of deposits on fuel filters, i.e. providing the function of “maintaining cleanliness”. It would be useful to create compositions that help remove existing deposits from fuel filters, i.e. providing a "cleaning" function. Compositions that combine these two functions would be especially useful.

The method of the present invention is particularly effective for controlling deposits in a modern diesel engine equipped with a high pressure fuel system.

Such diesel engines may have a number of characteristics.

These engines are typically equipped with fuel injection equipment that meets or exceeds "Euro 5" emissions requirements or equivalent US or foreign regulations.

Such engines are typically equipped with fuel injectors having a plurality of through passages, each passage having an inlet and an outlet portion.

These engines may feature through-channels that taper so that the diameter of the spray inlet is larger than the diameter of the channel outlet.

Such modern engines may feature through passages in which the outlet diameter is less than 500 microns, preferably less than 200 microns, more preferably less than 150 microns, more preferably less than 100 microns, most preferably less than 80 microns or less.

Characteristic of such modern engines may be through channels in which the edge of the inlet port is rounded.

Characteristic of such modern engines may be injectors having more than one through-channel, preferably more than 2 through-channels, preferably more than 4 through-channels, for example 6 or more through-channels.

Operating temperatures at the injector tip boundary exceeding 250°C can be typical for such modern engines.

Such modern engines may be characterized by having a fuel injection system capable of generating a fuel pressure greater than 1350 bar (1.35⋅10 ⁸ Pa), preferably greater than 1500 bar (1.5⋅10 ⁸ Pa), more preferably greater than 2000 bar (2⋅ 10 ⁸ Pa). Preferably, the diesel engine has a fuel injection system that includes a common rail injection system.

The use of the method of the present invention preferably combats deposits in an engine having one or more of the characteristics discussed above.

The use of the present invention preferably improves engine performance. Improved engine performance is preferably achieved by reducing engine deposits.

A first aspect of the present invention relates to a method for controlling deposits in a diesel engine. Deposit control may involve reducing or preventing the formation of deposits in the engine compared to an engine running on fuel without appropriate additives. This method can be considered to provide a "keep clean" characteristic.

Deposit control may involve removing existing engine deposits. This can be seen as a "cleaning" characteristic.

In particularly preferred embodiments, the method according to the fifth aspect and the use according to the fourth aspect of the present invention can be implemented to provide "keeping clean" and "cleaning" characteristics.

As stated above, deposits can form in various areas of a diesel engine, such as a modern diesel engine.

The present invention is particularly suitable for preventing or reducing or removing internal deposits in the injectors of engines operating at high pressures and temperatures with possible fuel recirculation, where the injectors have many small channels (orifices) through which fuel is directed into the engine. The present invention can be applied to engines of high-power vehicles and passenger vehicles. The application of the present invention may be useful, for example, for passenger vehicles incorporating high speed direct injection (HSDI) engines.

The present invention can also provide improved performance to modern diesel engines having high pressure fuel systems by controlling the amount of external injector deposits, such as deposits formed in the injector nozzle and/or at the injector tip. The ability to control the formation of internal nozzle deposits and external nozzle deposits is a major advantage of the present invention.

Preferably, the present invention can reduce or prevent the formation of external deposits on the nozzle. Thus, the present invention can provide a "keep clean" performance against external deposits on the nozzle.

Preferably, the present invention may reduce or remove existing external deposits on the nozzle. Thus, the invention can provide "cleaning" of external deposits on the nozzle.

Preferably, the present invention can reduce or prevent the formation of internal deposits in diesel engine injectors. Thus, the invention can provide a "keep clean" performance against internal deposits on diesel engine injectors.

Preferably, the present invention can reduce or remove existing internal deposits in diesel engine injectors. Thus, the invention can provide "cleaning" of internal deposits from a diesel engine injector.

The present invention may also relate to the control of deposits on vehicle fuel filters. This may include reducing or preventing the formation of deposits (the "keep clean" characteristic) or reducing or removing existing deposits (the "cleaning" characteristic).

Removing or reducing the VOPD according to the present invention may result in improved engine performance.

Improvement in the performance of a diesel engine system can be determined using a number of methods. The choice of appropriate methods depends on the type of engine and whether the characteristic is being defined as “maintaining cleanliness” and/or “cleaning”.

Improvement in the "keep clean" performance can be determined by comparison with the base fuel. The "clean" characteristic can be defined by improving the performance of an already dirty engine.

The effectiveness of fuel additives is often assessed by testing the engine under controlled conditions.

In Europe, the Coordinating European Council for the development of performance tests for transportation fuels, lubricants and other fluids (an industry organization abbreviated as CEC) developed a test to test the properties of additives for modern diesel engines such as HSDI engines. The CEC F-98-08 test is used to assess whether diesel fuel for engine operation complies with the new European Union air emissions regulations, called Euro 5 regulations. The test uses a Peugeot DW10 engine incorporating Euro 5 injectors and is commonly referred to as the DW10B test. This test measures the reduction in engine power caused by injector deposits and is further discussed below in Example 4.

Preferably, use of the fuel composition of the present invention results in a reduction in deposit formation detected in the DW10B test. When determining the "keep clean" characteristic, a reduction in the occurrence of deposits is preferably observed.

When determining the "cleaning" performance, it is preferable to evaluate the removal of deposits. The DW10B test is used to determine power loss in modern diesel engines incorporating high pressure fuel systems.

Advantageously, the use of the fuel composition of the present invention can provide a "keep clean" characteristic in modern diesel engines, that is, slow down or prevent the formation of deposits on the injectors of these engines. Preferably, this characteristic, as determined in the DW10B test, is such that the power loss is less than 5%, preferably less than 2%, after 32 hours of engine operation.

Advantageously, the use of the fuel composition according to the present invention can provide a "cleaning" characteristic in modern diesel engines, that is, deposits already present on the injectors of a dirty engine can be removed. Preferably, this characteristic, as determined in the DW10B test, is such that the power of the dirty engine can be, within 16 hours, preferably 12 hours, more preferably 8 hours, reduced to a level within 1% of the level achieved with clean injectors.

In some preferred embodiments, cleaning may also result in increased power. In this way, a dirty engine can be treated to remove existing deposits and provide additional power gains.

Clean injectors may include new injectors or injectors that have been removed from the engine and cleaned by physical means, such as in an ultrasonic bath.

The CJEU has also developed a new test, commonly referred to as DW10C, which assesses the ability of a fuel composition to prevent the formation of HFPD, which leads to injector seizure. This test is discussed in Example 5. A modified version of this test, adapted to determine the degree of purification, is discussed in Example 6.

The DW10C test can be used to determine the "keep clean" or "clean" performance of an engine.

In some embodiments, the present invention provides a "keep clean" characteristic with respect to the formation of VOPD. On the DW10C test rating scale, this characteristic may be at least 7, preferably at least 8, more preferably at least 9.

In some embodiments, a score of at least 9.3, such as at least 9.4, at least 9.5, at least 9.6, or at least 9.7, can be achieved.

In some embodiments, the present invention provides a "cleanup" characteristic with respect to the VOPD, which allows existing VOPD to be removed. This characteristic is discussed in the Examples.

The diesel fuel compositions of the present invention may also provide improved performance in conventional diesel engines. Preferably, improved performance is experienced when the diesel fuel compositions are burned in modern diesel engines incorporating high pressure fuel systems and when the compositions are burned in conventional diesel engines. This is important to note because it allows the same fuel to be used in both new engines and older vehicles.

Improvement in performance of older engines can be determined in the XUD9 test. This test is discussed in Example 5.

Advantageously, the use of the fuel composition of the present invention can provide "cleanliness" in conventional diesel engines, that is, it can slow down or prevent the formation of deposits on the injectors of these engines. Preferably, due to the "keep clean" characteristic, after 10 hours of engine operation in the XUD-9 test, a flow reduction of less than 50%, preferably less than 30%, is observed.

Advantageously, the use of the fuel composition of the present invention can provide a "cleaning" characteristic in conventional diesel engines that allows the removal of deposits from the injectors of an already clogged engine. Advantageously, due to this characteristic, the flow attenuation in a clogged engine can be reduced by 10% or more during 10 hours of engine operation in the XUD-9 test.

The beneficial effects provided by the present invention make it possible to perform engine maintenance much less frequently, which increases savings and increases the duration of maintenance-free maintenance.

Preferably, the method and application according to the present invention improves the performance of a diesel engine. The performance improvement is preferably selected from one or more of the following beneficial effects:

- reducing engine power loss;

- reduction of external deposits on diesel engine injectors;

- reducing internal deposits on diesel engine injectors;

- increasing fuel economy;

- reducing deposits on the fuel filter;

- reducing emissions into the atmosphere; And

- increasing the duration of maintenance-free maintenance.

In addition to the beneficial effects listed above, supplements according to

the present invention may have additional beneficial effects.

For example, the additive may provide lubricity and/or corrosion inhibition and/or improve cold flow.

The diesel fuel compositions of the present invention may include one or more additional additives, such as additives typically added to diesel fuels. These include, for example, antioxidants, dispersants, detergents, metal deactivating compounds, anti-wax additives, cold flow improvers, cetane number improvers, haze reducers, stabilizers, demulsifiers, antifoam agents, corrosion inhibitors , lubricity additives, dyes, markers, combustion additives, metal deactivators, odor masking agents, friction modifiers and conductivity enhancing agents. Examples of suitable amounts of each of these types of additives are known to those skilled in the art.

In some embodiments, the combination of an additive according to the invention and an additional additive can lead to a synergistic effect in improving performance.

For example, use of the quaternary ammonium compound additive of the invention in combination with a cold flow improver may result in unexpected improvements in detergency and/or cold flow compared to the use of either additive alone.

In some embodiments, the use of the quaternary ammonium compound additive of the present invention allows the cold flow additive content to be reduced.

For example, using the quaternary ammonium compound additive of the invention in combination with a corrosion inhibitor may result in unexpected improvements in detergency and/or corrosion inhibition compared to using either additive alone.

In some embodiments, the use of a quaternary ammonium compound additive according to the present invention can reduce the amount of corrosion inhibitor added.

For example, using the quaternary ammonium compound additive of the invention in combination with a lubricity additive can result in unexpected improvements in detergency and/or lubricity compared to using either additive alone.

In some embodiments, the use of a quaternary ammonium compound additive according to the present invention allows the content of the lubricity additive to be reduced.

In some preferred embodiments, the diesel fuel composition of the present invention includes one or more additional detergent additives. Nitrogen-containing detergent additives are preferred.

One or more additional detergent additives may provide a synergistic effect such that the performance of the combination of the quaternary ammonium compound additive of the invention and the nitrogen-containing detergent additive is superior to that achieved by adding an equivalent amount of each additive separately.

The use of a combination of a quaternary ammonium compound additive and a nitrogen-containing detergent additive can also combat deposits and improve the performance of a conventional diesel engine.

One or more additional detergent additives may be selected from:

(i) additives based on a quaternary ammonium salt, which is not a compound having formula (I);

(ii) a Mannich reaction product between an aldehyde, an amine and an optionally substituted phenol;

(iii) a reaction product of a carboxylic acid-derived acylating agent and an amine;

(iv) a reaction product of a carboxylic acid-derived acylating agent and hydrazine;

(v) a salt formed by reacting a carboxylic acid with di-n-butylamine or tri-n-butylamine;

(vi) a reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride with an amino-containing compound or salt, wherein the product includes at least one aminotriazole group; And

(vii) a substituted polyaromatic detergent additive.

Preferably, the one or more additional detergent additives are selected from one or more of the following:

(i) additives based on a quaternary ammonium salt, which is not a compound having formula (I);

(ii) a Mannich reaction product between an aldehyde, an amine and an optionally substituted phenol; And

(iii) the reaction product of a carboxylic acid-derived acylating agent and an amine.

The ratio of the amount of quaternary ammonium compound additive to the amount of nitrogen-containing detergent additive is preferably 5:1 to 1:5, more preferably 2:1 to 1:2.

In some embodiments, the diesel fuel composition further includes (i) a quaternary ammonium salt additive that is not a compound of formula (I).

The quaternary ammonium salt additive is preferably the reaction product of a nitrogen-containing compound having at least one tertiary amino group and a quaternizing agent.

The nitrogen-containing compound may be selected from:

(x) a reaction product of a hydrocarbyl-substituted acylating agent and a compound containing at least one tertiary amino group and a primary amino group, a secondary amino group or an alcohol group;

(y) a Mannich reaction product containing a tertiary amino group; And

(z) an amine substituted with a polyalkylene containing at least one tertiary amino group.

Examples of quaternary ammonium salts and methods for their preparation are discussed in the following patents, which are incorporated herein by reference: US 2008/0307698, US 2008/0052985, US 2008/0113890 and US 2013/031827.

The preparation of some suitable additives based on quaternary ammonium salts in which the nitrogen-containing compound includes component (x) is discussed in WO 2006/135881 and WO 2011/095819.

Component (y) is a Mannich reaction product containing a tertiary amino group. The preparation of quaternary ammonium salts formed by a nitrogen-containing compound including component (y) is discussed in document US 2008/0052985.

The preparation of additives based on quaternary ammonium salts, including the use of a nitrogen-containing compound including component (z), is discussed, for example, in document US 2008/0113890.

To obtain an additive based on a quaternary ammonium salt (i), a nitrogen-containing compound having a tertiary amino group is reacted with a quaternizing agent.

The quaternizing agent may preferably be selected from esters and non-esters.

Quaternizing agents preferred for use in the present invention include dimethyl oxalate, methyl 2-nitrobenzoate, methyl salicylate, and styrene oxide or propylene oxide, optionally in combination with an additional acid.

A particularly preferred additional quaternary ammonium salt suitable for use in the present invention is formed by the reaction of methyl salicylate or dimethyl oxalate with the reaction product of polyisobutylene-substituted succinic anhydride, in which PIB has a number average molecular weight of 700 up to 1300, and dimethylaminopropylamine.

Other suitable quaternary ammonium salts include quaternized terpolymers, such as those discussed in US 2011/0258917, quaternized copolymers, such as those discussed in US 2011/0315107, and acid-free quaternized nitrogen compounds discussed in US 2012/0010112.

Additional quaternary ammonium compounds suitable for practice of the present invention include the quaternary ammonium compounds discussed in the applications of the present inventors co-pending with this work, i.e. in WO 2011095819, WO 2013/017889, WO 2015/011506, WO 2015/011507, WO 2016/016641 and PCT/GB 2016/052312.

In some embodiments, the diesel fuel composition used in accordance with the present invention includes from 1 to 500 ppm, preferably from 50 to 250 ppm of the quaternary ammonium compound additive according to the present invention and from 1 to 500 ppm, preferably from 50 to 250 ppm of another additive (i) based on a quaternary ammonium compound.

In some embodiments, the diesel fuel composition further includes (ii) a Mannich reaction product between an aldehyde, an amine and an optionally substituted phenol. Such a Mannich reaction product is preferably not a quaternary ammonium salt.

Preferably, an aliphatic aldehyde is used as the aldehyde component used to prepare the Mannich reaction product additive. Preferably the aldehyde contains from 1 to 10 carbon atoms. Most preferably, the aldehyde is formaldehyde.

Amines suitable for the preparation of Mannich reaction product additives include monoamines and polyamines. One suitable monoamine is butylamine.

The amine used to prepare the Mannich reaction product additive is preferably a polyamine. It may be selected from any compound containing two or more amino groups. Preferably the polyamine is a polyalkylene polyamine, preferably a polyethylene polyamine. Most preferably, the polyamine includes tetraethylenepentamine or ethylenediamine.

Optionally, the substituted phenol component used to prepare the Mannich reaction product additive may have from 0 to 4 substituents on the aromatic ring (other than the phenolic OH group). For example, it may be a hydrocarbyl-substituted cresol. Most preferably, the phenolic component is a monophenol. Preferably it is a phenol substituted with hydrocarbyl. Preferred hydrocarbyl substituents are alkyl substituents containing from 4 to 28 carbon atoms, in particular from 10 to 14 carbon atoms. Other preferred hydrocarbyl substituents are polyalkenyl substituents. The number average molecular weight of the polyisobutenyl substituents is from 400 to 2500, for example from 500 to 1500.

In some embodiments, the diesel fuel composition of the present invention includes from 1 to 500 ppm, preferably from 50 to 250 ppm, of a quaternary ammonium compound according to the first aspect and from 1 to 500 ppm, preferably from 50 to 250 ppm additives (ii) based on the Mannich reaction product.

In some embodiments, the diesel fuel composition further includes (iii) the reaction product of an acylating agent derived from a carboxylic acid and an amine.

In this work, such products can also be generally referred to as acylated nitrogen-containing compounds.

Suitable acylated nitrogen-containing compounds can be prepared by reacting a carboxylic acid acylating agent with an amine and are known to those skilled in the art.

Preferred hydrocarbyl substituted acylating agents are polyisobutenyl succinic anhydrides. These compounds are commonly referred to as "PIBSA" (from polyisobutenyl succinic anhydride) and are known to those skilled in the art.

Both traditional polyisobutenes and so-called “highly reactive” polyisobutenes are suitable for the implementation of the invention.

Particularly preferred PIBSAs are compounds in which the molecular weight (Mn) of the PIB is from 300 to 2800, preferably from 450 to 2300, more preferably from 500 to 1300.

In preferred embodiments, the reaction product of a carboxylic acid-derived acylating agent and an amine includes at least one primary or secondary amine group.

Preferred acylated nitrogen-containing compounds used in the present invention are prepared by the reaction of an acylating agent derived from a polyisobutene-substituted succinic acid (e.g., anhydride, acid, ester, etc.), wherein the number average molecular weight (Mn) of the polyisobutene substituent is between 170 to 2800, with a mixture of ethylene polyamines containing from 2 to about 9 amino nitrogen atoms, preferably from about 2 to about 8 nitrogen atoms per ethylene polyamine, and from about 1 to about 8 ethylene groups. Such acylated nitrogen-containing compounds are preferably prepared in the reaction, in wherein the molar ratio of acylating agent:amino compound is from 10:1 to 1:10, preferably from 5:1 to 1:5, more preferably from 2:1 to 1:2 and most preferably from 2:1 to 1:1. In particularly preferred embodiments, the acylated nitrogen-containing compounds are prepared by reacting an acylating agent with an amino compound at a molar ratio of 1.8:1 to 1:1.2, preferably 1.6:1 to 1:1.2, more preferably from 1.4:1 to 1:1.1 and most preferably from 1.2:1 to 1:1. Acylated amino compounds of this type and their preparation are well known to those skilled in the art and are discussed, for example, in EP 0565285 and US 5925151.

In some preferred embodiments, the composition includes a detergent additive that is formed by the reaction of an acylating agent derived from polyisobutene-substituted succinic acid and a polyethylene polyamine. Suitable connections are discussed, for example, in the document WO 2009/040583.

In some embodiments, the diesel fuel composition of the present invention includes from 1 to 500 ppm, preferably from 50 to 250 ppm, of a quaternary ammonium compound according to the first aspect and from 1 to 500 ppm, preferably from 50 to 250 ppm additive, which is a reaction product of acylating agents and amine (iii).

In some embodiments, the diesel fuel composition includes (iv) a reaction product of an acylating agent derived from a carboxylic acid and hydrazine.

Preferably, the additive comprises the reaction product of hydrocarbyl-substituted succinic acid or anhydride with hydrazine.

Preferably, the hydrocarbyl group of the hydrocarbyl-substituted succinic acid or anhydride includes a C ₈ -C ₃₆ group, preferably a C ₈ -C ₁₈ group. Alternatively, the hydrocarbyl group may be a polyisobutylene group having a number average molecular weight of 200 to 2500, preferably 800 to 1200.

Hydrazine has the formula NH ₂ -NH ₂ . Hydrazine can be hydrated or non-hydrated. Preferred is the use of hydrazine monohydrate.

The reaction between hydrocarbyl-substituted succinic acid or anhydride and hydrazine produces various products, as discussed in US 2008/0060259.

In some embodiments, the diesel fuel composition further includes (v) a salt obtained by reacting a carboxylic acid with di-n-butylamine or tri-n-butylamine. Examples of connections of this type are discussed in document US 2008/0060608.

Such additives may preferably be salts of di-n-butylamine or tri-n-butylamine and a fatty acid having the formula [R'(COOH)x] _y' , in which each of R' independently represents a hydrocarbon group containing from 2 up to 45 carbon atoms, and x is an integer ranging from 1 to 4.

In a preferred embodiment, the carboxylic acid includes tall oil fatty acid (abbreviated as TOA).

Additional advantageous features of additives of this type are discussed in EP 1900795.

In some embodiments, the diesel fuel composition further includes (vi) a reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride with an amine-containing compound or salt, wherein the product includes at least one aminotriazole group.

Additional preferred features of additive compounds of this type are discussed in US 2009/0282731.

In some embodiments, the diesel fuel composition further includes (vii) a substituted polyaromatic detergent additive.

One preferred compound of this type is the reaction product of xyl and other naphthol and paraformaldehyde, which is then reacted with a hydrocarbyl-substituted acylating agent.

Additional advantageous features of such detergent additives are discussed in EP 1884556.

Any feature of the invention may be combined with any other suitable feature of the invention.

The invention is discussed in more detail below with the help of the following non-limiting examples. In the examples given, amounts added expressed in parts per million indicate amounts of the active ingredient and not amounts of the composition containing the active ingredient added. All parts per million are parts by weight.

DESCRIPTION OF EXAMPLES OF IMPLEMENTATION OF THE INVENTION

Example 1

Additive A1, which is a quaternary ammonium salt additive compound according to the invention, was prepared as follows:

(a) A mixture of alkenes containing 20 to 24 carbon atoms was heated with 1.2 molar equivalents of maleic anhydride. Upon completion of the reaction, excess maleic anhydride was removed by distillation. The anhydride number of the resulting substituted succinic anhydride was determined, which was 2.591 mmol⋅g ^-1 .

This product was then heated with 0.5 molar equivalent of polypropylene glycol, which has a number average molecular weight of 425, and the reaction progress was monitored using Fourier transform infrared spectroscopy (abbreviated FTIR), resulting in the bis ester .

(b) The reaction of 1 molar equivalent of diethylethanolamine with 1.5 molar equivalents of butylene oxide and 6 molar equivalents of water was carried out at 60° C. in toluene for 10 hours in the presence of the bis-ester obtained in step (a), obtaining a quaternary ammonium compound. Volatile substances were distilled off in vacuum.

In some embodiments, one molar equivalent of amine per one molar equivalent of bis-ester is used. In some embodiments, two moles of amine are used per molar equivalent of bis-ester.

Compounds A2-A28, A30 and A31 listed in Table 1 were prepared in a similar manner.

Compounds A1-A15 and A21-A31 were prepared using one molar equivalent of amine per molar equivalent of bis-ester. In this case, quaternary ammonium salts were obtained, including one ammonium cation and one proton per bis-ester anion.

Compounds A16-A20 were prepared using two molar equivalents of amine per molar equivalent of bis-ester. In this case, quaternary ammonium salts were obtained, including two ammonium cations per one bis-ester anion.

(a) A mixture of alkenes containing 20 to 24 carbon atoms was heated with 1.2 molar equivalents of maleic anhydride. Upon completion of the reaction, excess maleic anhydride was removed by distillation.

This product was then heated with 1 molar equivalent of tripropylene glycol, which was calculated based on the loading masses and the average molecular weight of the alkenyl succinic anhydride prepared as described above. The reaction progress was monitored by FTIR to give the half-ester. The resulting half-ester was then heated with one equivalent of succinic anhydride to give the desired bis-ester.

(b) The reaction of 1 molar equivalent of dimethylethanolamine with 1 molar equivalent of 2-ethylhexylglycidyl ether and 6 molar equivalents of water was carried out at 95°C in toluene for 10 hours in the presence of the bis-ester obtained in step (a), obtaining a quaternary ammonium compound. Volatile substances were distilled off in vacuum.

Example 2

Diesel fuel compositions were prepared by dosing additives into aliquots taken from one batch of RF06 base fuel.

The compositions were tested using a screening test, the results of which correlated with the ability to combat VOFD, determined in the DW10C test.

In this test, fuel compositions were tested in a jet fuel thermal oxidation tester. In this modified test, 800 ml of fuel was passed over a heated tube at a pressure of approximately 540 psi (approximately 3.7 x 10 ⁶ Pa). The duration of the test was 2.5 hours. At the end of the test, the amount of deposits on the tube was compared with the reference value.

The values given in Table 2 represent the percentage reduction in deposit thickness compared to deposits obtained by passing the base fuel.

Comparative additive C1 is succinic acid substituted with dodecenyl.

Comparative additive C2 is succinic acid substituted with polyisobutenyl (PIB), where the number average molecular weight of PIB is 1000.

Table 3 below shows the characteristics of the main fuel RF06.

Example 3

The performance characteristics of fuel compositions according to Example 2 when burned in modern diesel engines with a high-pressure fuel system can be determined by the CECF-98-08 DW10 method. In this work, this method is called the DW10B test.

To determine injector clogging, a PSA DW10BTED4 engine was used. In general, the engine had the following characteristics:

This engine was selected as representative of the design of European high-speed modern direct injection diesel engines that can meet current and future European emissions requirements. The common rail injection system features a highly efficient nozzle design with a rounded inlet edge and conical spray channels for optimal hydraulic flow characteristics. By operating this type of nozzle with high-pressure fuel, increased combustion efficiency, reduced noise, and reduced fuel consumption can be achieved, but such nozzles are sensitive to influences that may disrupt fuel flow, such as deposits in the spray ports. The presence of such deposits causes a significant reduction in engine power and increased emissions of untreated gases into the atmosphere.

The test was carried out on advanced injector designs, which are an example of Euro V injector designs that may be used in the future.

It is believed that before commencing clogging testing it would be prudent to reliably establish a reference point for the initial condition of the injectors, and thus a sixteen hour preparation program for injector testing using a non-clogging reference fuel was proposed.

A detailed description of the CEC F-98-08 test method can be provided to the CEC. The coking cycle is briefly described below.

1. Warm-up cycle (12 minutes) in the following mode:

2. 8 hours of engine operation consisted of 8 repetitions of the following cycle:

3. Cool down to idle for 60 seconds and idle for 10 seconds

4. 4 hour soaking period

The standard test method CEC F-98-08 consists of 32 hours of engine operation, including 4 repetitions of stages 1-3 above and 3 repetitions of stage 4, i.e. The total test duration is 56 hours, excluding warm-up and cool-down periods.

Example 4

A diesel fuel composition including additive A26 (100 ppm active) was tested by the CECF-98-08 DW10B test method discussed in Example 3, modified to determine the "cleaning" characteristic as described below.

The first 32 hour cycle was run using new injectors and RF-06 base fuel to which 1 ppm Zn (as neodecanoate) had been added. This resulted in a corresponding level of power loss as a result of clogged injectors.

A second 32-hour cycle was then carried out as a “cleaning” phase. The injectors contaminated in the first phase were left in the engine, replacing the fuel with base fuel RF-06, to which 1 ppm Zn (as neodecanoate) and the test additive were added.

In FIG. Figure 1 shows the power removed from the engine when using a fuel composition including the A26 additive during the test period.

Example 5

The ability of the additives according to the invention to remove "internal deposits on diesel injectors" (IDF) can be determined by the test method CEC F-110-16 developed by the European Coordination Council. The PSA DW10C engine used in this test is used.

The engine has the following characteristics:

The test fuel (RF06) was supplemented with 0.5 mg/kg Na in the form of sodium naphthenate + 10 mg/kg dodecyl succinic acid (denoted DDSA).

The test procedure consists of main stroke cycles, followed by dwell periods, followed by a cold start (cold start).

The main stroke cycle consists of two stages of operation at a certain speed and load, which are repeated for 6 hours as indicated below.

Acceleration periods of 30 seconds were included in the duration of each stage (see Figure 2).

Each cycle was repeated 6 times, that is, the full phase of the main stroke was 6 hours.

During the main stroke, parameters including gas pedal position, ECU (engine control unit) error codes, injector balance coefficient and spontaneous engine shutdowns were observed and recorded.

The engine is then kept at normal temperature for 8 hours.

After a holding period, the engine is restarted. The starting device (starter) operates for 5 seconds; If the engine does not start, then leave the engine for another 60 seconds and then make another attempt. No more than 5 attempts are allowed.

If the engine starts, leave the engine idling for 5 minutes. Determine individual exhaust gas temperatures and record the maximum temperature difference. Increased variation in exhaust gas temperatures between cylinders is a clear indication that HFDFs are being deposited on the injectors, causing either a slowdown in injector opening or an unnecessary increase in open time.

Below is an example showing all exhaust gas temperatures with a deviation of <30°C, indicating that there is no sticking caused by the VOFD (see Fig. 3).

The full test includes 6 cold starts, but does not include the Zero hour cold start, and five 6-hour main stroke cycles, for a total engine run time of 30 hours.

The obtained data was entered into the Merit Rating Chart. This allows an assessment to be made based on the test results. The maximum rating indicates that there were no problems with the running or roadworthiness of the engine during the entire test.

One example is given below:

Example 6

The effectiveness of the additives according to the invention on conventional older generation diesel engines was assessed using a standard industry test - test method CEC No. CEC F-23-A-01.

This test determines the coking of the injector nozzle on a Peugeot XUD9 A/L engine and allows fuels to be differentiated by their tendency to form coke-like deposits on the injector nozzle. The formation of coke on the nozzle is the result of carbon deposition between the nozzle needle and the needle seat. Carbon deposits are caused by exposure of the injector needle and seat to combustion gases and can cause undesirable variations in engine performance.

The Peugeot XUD9 A/L engine is a 1.9 liter 4 cylinder indirect injection diesel engine provided by Peugeot Citroen Motors specifically for the CEC PF023 study.

Clean injectors with blunt injector needles were installed in the test engine. Before testing, the air flow was determined at various needle raised positions using a flow meter. The engine was operated for 10 hours in cyclic mode.

The ability of a fuel to increase fuel injector deposit formation was determined by re-measuring the air flow through the injector nozzle at the end of the test and comparing the results with the values obtained before the test. The results are expressed as the percentage reduction in air flow at various needle-up positions in all nozzles. The level of nozzle coking when burning a certain fuel was taken to be the average reduction in air flow when the needle was raised by 0.1 mm in all four nozzles.

Claims (54)

1. Method for producing a quaternary ammonium compound having formula (I) wherein the method comprises reacting (a) a tertiary amine having the formula R ¹ R ² R ³ N with (b) an epoxide in the presence of (c) a compound having the formula (IIB) where X represents CH ₂ CHR or CRHCH ₂ where R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; R ⁴ represents an unsubstituted alkylene group having from 1 to 12 carbon atoms; n is from 1 to 20; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH and b is equal to 2 if W is O ^- ; and wherein each of R ¹ and R ² independently represents an alkyl group containing from 1 to 12 carbon atoms; and R ³ selected from: (1) an alkyl group containing from 1 to 24 carbon atoms; (2) benzyl or hydroxyalkyl or hydroxyalkoxyalkyl group containing from 2 to 20 carbon atoms; And where R ⁰ represents a group having the formula where each of R ⁹ , R ¹⁰ , R ¹¹ represents hydrogen and R ¹² represents hydrogen, phenyl, an alkyl group containing from 1 to 50 carbon atoms, CH ₂ OR ¹³ or CH ₂ OCOR ¹⁴ where R ¹³ represents an alkyl or aryl group containing from 1 to 30 carbon atoms, and R ¹⁴ represents an alkyl or aryl group containing from 1 to 30 carbon atoms. 2. A fuel or lubricant composition comprising a quaternary ammonium compound having formula (I) where X represents CH ₂ CHR or CRHCH ₂ where R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; R ⁴ represents an unsubstituted alkylene group containing from 1 to 12 carbon atoms; n is from 1 to 20; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH and b is equal to 2 if W is O ^- ; and wherein each of R ¹ and R ² independently represents an alkyl group containing from 1 to 12 carbon atoms; and R ³ selected from: (1) an alkyl group containing from 1 to 24 carbon atoms; (2) benzyl or hydroxyalkyl or hydroxyalkoxyalkyl group containing from 2 to 20 carbon atoms; And where R ⁰ represents a group having the formula where each of R ⁹ , R ¹⁰ , R ¹¹ represents hydrogen and R ¹² represents hydrogen, phenyl, an alkyl group containing from 1 to 50 carbon atoms, CH ₂ OR ¹³ or CH ₂ OCOR ¹⁴ where R ¹³ represents an alkyl or aryl group containing from 1 to 30 carbon atoms, and R ¹⁴ represents an alkyl or aryl group containing from 1 to 30 carbon atoms. 3. The composition according to claim 2, characterized in that the composition is a fuel composition, preferably a diesel fuel composition. 4. Use of a quaternary ammonium compound having formula (I) as an additive to fuel or lubricating oil, where X represents CH ₂ CHR or CRHCH ₂ where R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; R ⁴ represents an unsubstituted alkylene group containing from 1 to 12 carbon atoms; n is from 1 to 20; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH and b is equal to 2 if W is O ^- ; and wherein each of R ¹ and R ² independently represents an alkyl group containing from 1 to 12 carbon atoms; and R ³ selected from: (1) an alkyl group containing from 1 to 24 carbon atoms; (2) benzyl or hydroxyalkyl or hydroxyalkoxyalkyl group containing from 2 to 20 carbon atoms; And where R ⁰ represents a group having the formula where each of R ⁹ , R ¹⁰ , R ¹¹ represents hydrogen and R ¹² represents hydrogen, phenyl, an alkyl group containing from 1 to 50 carbon atoms, CH ₂ OR ¹³ or CH ₂ OCOR ¹⁴ where R ¹³ represents an alkyl or aryl group containing from 1 to 30 carbon atoms, and R ¹⁴ represents an alkyl or aryl group containing from 1 to 30 carbon atoms. 5. A method for improving the performance characteristics of an engine, where the method includes burning in the engine a fuel composition containing as an additive a quaternary ammonium compound having formula (I) where X represents CH ₂ CHR or CRHCH ₂ where R represents an alkyl or alkenyl group containing from 6 to 36 carbon atoms; R ⁴ represents an unsubstituted alkylene group containing from 1 to 12 carbon atoms; n is from 1 to 20; c is at least 1; W represents O ^- or OH; b is equal to 1 if W is OH and b is equal to 2 if W is O ^- ; and wherein each of R ¹ and R ² independently represents an alkyl group containing from 1 to 12 carbon atoms; and R ³ selected from: (1) an alkyl group containing from 1 to 24 carbon atoms; (2) benzyl or hydroxyalkyl or hydroxyalkoxyalkyl group containing from 2 to 20 carbon atoms; And where R ⁰ represents a group having the formula where each of R ⁹ , R ¹⁰ , R ¹¹ represents hydrogen and R ¹² represents hydrogen, phenyl, an alkyl group containing from 1 to 50 carbon atoms, CH ₂ OR ¹³ or CH ₂ OCOR ¹⁴ where R ¹³ represents an alkyl or aryl group containing from 1 to 30 carbon atoms, and R ¹⁴ represents an alkyl or aryl group containing from 1 to 30 carbon atoms. 6. The composition, method or use according to any of the preceding claims, wherein the anion precursor having formula (IIB) is derived from hydrocarbyl-substituted succinic acid or hydrocarbyl-substituted succinic anhydride. 7. The composition, method or use of any of the preceding claims, wherein each R ⁴ is ethylene or propylene, preferably -CH ₂ CH ₂ - or -CH(CH ₃ )CH ₂ -, more preferably -CH(CH ₃ )CH ₂ -. 8. Composition, method or use according to any one of paragraphs. 2-7, where the composition is a diesel fuel composition. 9. The composition, method or use of claim 8, wherein the diesel fuel composition includes one or more additional detergent additives selected from: (i) quaternary ammonium salt additives; (ii) a Mannich reaction product between an aldehyde, an amine and an optionally substituted phenol; (iii) the reaction product of an acylating agent derived from a carboxylic acid and an amine; (iv) the reaction product of an acylating agent derived from a carboxylic acid and hydrazine; (v) a salt obtained by reacting a carboxylic acid with di-n-butylamine or tri-n-butylamine; (vi) a reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride and an amine or salt, wherein the resulting product includes at least one aminotriazole group; And (vii) a substituted polyaromatic detergent additive. 10. Composition, method or use according to any one of paragraphs. 2-9, where the diesel fuel composition includes a mixture of two or more quaternary ammonium compounds. 11. Method or use according to any one of paragraphs. 4-10, wherein the additive is used as a detergent additive to control deposits in a diesel fuel composition in a diesel engine. 12. Method or use according to any one of paragraphs. 4-11, carried out in a modern diesel engine equipped with a high pressure fuel system. 13. Method or use according to any one of paragraphs. 4-12, which provide a "keep clean" feature by reducing or preventing the formation of deposits in the engine compared to an engine running on pure fuel. 14. Method or use according to any one of paragraphs. 4-13, which provide a "cleaning" characteristic by removing existing engine deposits. 15. Method or use according to any one of paragraphs. 4-14, where the deposits are deposits on the injectors. 16. The method or use of claim 15, wherein the deposits are internal deposits on diesel engine injectors. 17. Composition according to any one of paragraphs. 2, 3 or 6-10, which further includes one or more additional additives selected from lubricity additives, corrosion inhibitors and cold flow additives.