Patent Description:
Turbocharged or supercharged engines (i.e., boosted internal combustion engines) may exhibit an abnormal combustion phenomenon known as stochastic pre-ignition or low-speed pre-ignition (or "LSPI"). LSPI is an event that may include very high pressure spikes, early combustion during an inappropriate crank angle, and knock. All of these, individually and in combination, have the potential to cause degradation and/or severe damage to the engine. However, because LSPI events occur only sporadically and in an uncontrolled fashion, it is difficult to identify the causes for this phenomenon and to develop solutions to suppress it.

Pre-ignition is a form of combustion that results in ignition of the air-fuel mixture in the combustion chamber prior to the desired ignition of the air-fuel mixture by the igniter. Pre-ignition has typically been a problem during high load engine operation since heat from operation of the engine may heat a part of the combustion chamber to a sufficient temperature to ignite the air-fuel mixture upon contact. This type of pre-ignition is sometimes referred to as hot-spot pre-ignition.

More recently, intermittent abnormal combustion has been observed in boosted internal combustion engines at low speeds and medium-to-high loads. For example, during operation of the engine at <NUM> rpm or less, under load, with a brake mean effective pressure (BMEP) of at least <NUM> bar, low-speed pre-ignition (LSPI) may occur in a random and stochastic fashion. During low speed engine operation, the compression stroke time is longest.

Previous studies have demonstrated that turbocharger use, engine design, engine coatings, piston shape, fuel choice, and/or engine oil additives may contribute to an increase in LSPI events. Accordingly, there is a need for fuel and engine oil additive components and/or combinations that are effective to reduce or eliminate LSPI. <CIT> describes the use of at least one, optionally alkylated diarylamine in a fuel or a fuel additive for cleaning the combustion chamber of an internal combustion engine, in particular of a motor vehicle engine.

In one aspect, there is provided a method of reducing low-speed pre-ignition events in an engine comprising providing a fuel composition to the engine, wherein the fuel composition comprises (<NUM>) greater than <NUM> wt % of a hydrocarbon fuel boiling in the gasoline or diesel range and (<NUM>) a minor amount of a low-speed pre-ignition (LSPI)-reducing additive comprising one or more of a triazole, an amidine, a beta-amino alkanol having the structure
<CHM>
, wherein R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently selected from hydrogen, aromatic ring and a C<NUM>-C<NUM> alkyl group and R<NUM> is hydrogen or an alcohol having the structure -(CH)R<NUM>-OH wherein R<NUM> is hydrogen, a C<NUM>-C<NUM> alkyl group, or a C<NUM>-C<NUM> alkenyl group, or a salt thereof, and wherein the engine is a direct-injected, spark-ignited, internal combustion engine, that, in operation, generates a break mean effect pressure level of greater than <NUM> kPa at an engine speed of from <NUM> to <NUM> rotations per minute.

In another aspect, there is provided a use of a fuel composition comprising (<NUM>) greater than <NUM> wt % of a hydrocarbon fuel boiling in the gasoline or diesel range and (<NUM>) a minor amount of:.

In a further aspect, there is provided a use of a low-speed pre-ignition (LSPI)-reducing additive comprising one or more of an amidine, or a beta-amino alkanol having the structure
<CHM>
wherein R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently selected from hydrogen, aromatic ring, and a C<NUM>-C<NUM> alkyl group and R<NUM> is hydrogen or an alcohol having the structure -(CH)R<NUM>-OH wherein R<NUM> is hydrogen, a C<NUM>-C<NUM> alkyl group, or a C<NUM>-C<NUM> alkenyl group, or a salt thereof, in a fuel composition, to reduce LSPI events, as determined by the method described herein, in a direct-injected, boosted, spark-ignited, internal combustion engine, that, in operation, generates a brake mean effect pressure level of greater than <NUM> kPa at an engine speed of from <NUM> to <NUM> rotations per minute, wherein the direct-injected, boosted, spark-ignited, internal combustion engine is fueled with the fuel composition, and wherein the fuel composition comprises (<NUM>) greater than <NUM> wt % of a hydrocarbon fuel boiling in the gasoline range and (<NUM>) a minor amount of said low-speed pre-ignition (LSPI)-reducing additive.

In this specification, the following words and expressions, if and when used, have the meanings ascribed below.

"Gasoline" or "gasoline boiling range components" refers to a composition containing at least predominantly C<NUM>-C<NUM> hydrocarbons. In one embodiment, gasoline or gasoline boiling range components is further defined to refer to a composition containing at least predominantly C<NUM>-C<NUM> hydrocarbons and further having a boiling range of from about <NUM>°F (<NUM>) to about <NUM>°F (<NUM>). In an alternative embodiment, gasoline or gasoline boiling range components is defined to refer to a composition containing at least predominantly C<NUM>-C<NUM> hydrocarbons, having a boiling range of from about <NUM>°F (<NUM>) to about <NUM>°F (<NUM>), and further defined to meet ASTM D4814.

The term "diesel" refers to middle distillate fuels containing at least predominantly C<NUM>-C<NUM> hydrocarbons. In one embodiment, diesel is further defined to refer to a composition containing at least predominantly C<NUM>-C<NUM> hydrocarbons, and further having a boiling range of from about <NUM> (<NUM>°F) to about <NUM> (<NUM>°F). In an alternative embodiment, diesel is as defined above to refer to a composition containing at least predominantly C<NUM>-C<NUM> hydrocarbons, having a boiling range of from about <NUM> (<NUM>°F) to about <NUM> (<NUM>°F), and further defined to meet ASTM D975.

The term "oil soluble" means that for a given additive, the amount needed to provide the desired level of activity or performance can be incorporated by being dissolved, dispersed or suspended in an oil of lubricating viscosity. Usually, this means that at least <NUM>% by weight of the additive can be incorporated in a lubricating oil composition. The term "fuel soluble" is an analogous expression for additives dissolved, dispersed or suspended in fuel.

The term "alkyl" refers to saturated hydrocarbon groups, which can be linear, branched, cyclic, or a combination of cyclic, linear and/or branched.

An "alkanol" is an alkyl group, as described herein, having a hydroxy substituent (i.e., an -OH group).

A "minor amount" means less than <NUM> wt % of a composition, expressed in respect of the stated additive and in respect of the total weight of the composition, reckoned as active ingredient of the additive.

An "analog" is a compound having a structure similar to another compound but differing from it in respect to a certain component such as one or more atoms, functional groups, substructures, which are replaced with other atoms, groups, or substructures.

A "homolog" is a compound belonging to a series of compounds that differ from each other by a repeating unit. Alkanes are examples of homologs. For example, ethane and propane are homologs because they differ only in the length of a repeating unit (-CH<NUM>-). A homolog may be considered a specific type of analog.

A "derivative" is a compound that is derived from a similar compound via a chemical reaction (e.g., acid-base reaction, hydrogenation, etc.). In the context of substituent groups, a derivative may be a combination of one or more moiety. For example, a phenol moiety may be considered a derivative of aryl moiety and hydroxyl moiety. A person of ordinary skill in the related art would know the metes and bounds of what is considered a derivative. The term "substituted" refers to a substitution or replacement of an atom or atoms of a compound. As an illustrative example, a "substituted alkyl group" may refer to, among other things, an ethanol.

An "engine" or a "combustion engine" is a heat engine where the combustion of fuel occurs in a combustion chamber. An "internal combustion engine" is a heat engine where the combustion of fuel occurs in a confined space ("combustion chamber"). A "spark ignition engine" is a heat engine where the combustion is ignited by a spark, usually from a spark plug. This is contrast to a "compression-ignition engine," typically a diesel engine, where the heat generated from compression together with injection of fuel is sufficient to initiate combustion without an external spark.

Low Speed Pre-Ignition (LSPI) is most or more likely to occur in direct-injected, boosted (turbocharged or supercharged), spark-ignited (gasoline) internal combustion engines that, in operation, generate a brake mean effective pressure level of greater than <NUM> kPa (<NUM> bar) at engine speeds of from <NUM> to <NUM> rotations per minute (rpm), such as at engine speeds of from <NUM> to <NUM> rpm. "Brake mean effective pressure" (BMEP) is defined as the work accomplished during on engine cycle, divided by the engine swept volume, the engine torque normalized by engine displacement. The word "brake" denotes the actual torque or power available at the engine flywheel, as measured on a dynamometer. Thus, BMEP is a measure of the useful energy output of the engine.

It has now been found that the fuel compositions or lubricating oil compositions of this disclosure which are particularly useful in high pressure spark-ignited internal combustion engines and, when used in the high pressure spark-ignited internal combustion engines, will prevent or minimize engine knocking and pre-ignition problems.

The following are descriptions of primary additives that can be utilized as a fuel or lubricant additive to reduce LSPI activity. Primary LSPI-reducing additives can be used as standalone additives and/or with other primary additive(s) and/or with of one or more secondary LSPI-reducing additive (described later). When more than one additive is used, the additives may be in salt form. Moreover, when two or more additives are used, there may be synergy between the two or more additives. In general, these additives are fuel or oil soluble at concentrations needed to achieved a desired LSPI reduction level. Table <NUM> summarizes the primary additive types.

The fuel additive or lubricating oil additive of this disclosure may be a β-amino alkanol, a substituted β-amino alkanol, a derivative thereof or an acceptable salt thereof. Useful β-amino alkanols include those that can be represented by the following general formula:
<CHM>
wherein R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently selected from hydrogen and a C<NUM>-C<NUM> alkyl (e.g., C<NUM>-C<NUM> alkyl) group; and two or more of R<NUM>, R<NUM>, R<NUM>, and R<NUM> optionally can be bonded together to form a ring structure (e.g., a five-, six-, or seven-membered ring). In some embodiments, R<NUM>, R<NUM>, R<NUM>, and R<NUM> may independently include one or more aromatic rings. R<NUM> is hydrogen or an alcohol having the structure -(CH)R<NUM>-OH wherein R<NUM> is hydrogen, a C<NUM>-C<NUM> alkyl group, or a C<NUM>-C<NUM> alkenyl group. In some embodiments, R<NUM> is hydrogen. In some embodiments, R<NUM> is an alcohol having the structure -(CH)R<NUM>-OH wherein R<NUM> is hydrogen, a C<NUM>-C<NUM> alkyl group, or a C<NUM>-C<NUM> alkenyl group.

In embodiments, the β-amino alkanol is not the following:
<CHM>.

In certain embodiments, the fuel composition does not comprise the following:
<CHM>.

In certain embodiments, the fuel concentrate does not comprise the following:
<CHM>.

In certain embodiments, the beta-amino alkanol used in the method of reducing low-speed-pre-ignition events in an engine is not the following:
<CHM>.

In certain embodiments, the low-speed pre-ignition (LSPI)-reducing additive does not comprise the following:
<CHM>.

In certain embodiments, the amino alcohol is not the following:
<CHM>.

The β-amino alkanol has at least <NUM> carbon atoms (e.g., from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, from <NUM> to <NUM> carbon atoms, or from <NUM> to <NUM> carbon atoms).

Representative examples of suitable β-amino alkanols include ethanolamine (Formula 1A), <NUM>-amino-<NUM>-propanol (Formula 1B), alaninol (Formula 1C), <NUM>-(methylamino)ethanol (Formula 1D), <NUM>-(ethylamino)ethanol (Formula 1E), <NUM>-amino-<NUM>-methyl-<NUM>-propanol (Formula 1F), <NUM>-amino-<NUM>-butanol (Formula <NUM>), <NUM>-amino-<NUM>-pentanol (Formula <NUM>), valinol (Formula <NUM>), <NUM>-amino-<NUM>-hexanol (Formula 1J), leucinol (Formula <NUM>), isoleucinol (Formula <NUM>), cycloleucinol (Formula <NUM>), cyclohexylglycinol (Formula 1N), prolinol (Formula 1O), <NUM>-(hydroxymethyl)piperidine (Formula 1P), <NUM>-aminocyclopentanol (Formula 1Q), <NUM>-aminocyclohexanol (Formula 1R), aminoheptyl propanediol (<NUM>-(heptan-<NUM>-ylamino)propane-<NUM>,<NUM>-diol) (Formula 1T), aminooctyl propanediol (<NUM>-(methyl(octyl)amino)propane-<NUM>,<NUM>-diol) (Formula 1U), and aminododecyl ethanol (<NUM>-(dodecyl(methyl)amino)ethan-<NUM>-ol) (Formula 1V). In certain embodiments, the β-amino alkanol is aminoheptyl propanediol (<NUM>-(heptan-<NUM>-ylamino)propane-<NUM>,<NUM>-diol) (Formula 1T). In certain embodiments, the β-amino alkanol is aminooctyl propanediol (<NUM>-(methyl(octyl)amino)propane-<NUM>,<NUM>-diol) (Formula 1U). In certain embodiments, the β-amino alkanol is aminododecyl ethanol (<NUM>-(dodecyl(methyl)amino)ethan-<NUM>-ol) (Formula 1V). Representative structures are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

In certain embodiments, the β-amino alkanol is not the following:
<CHM>.

In certain embodiments, the β-amino alkanol is or comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

In certain embodiments, the fuel composition comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

In certain embodiments, the fuel concentrate comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

In certain embodiments, the beta-amimo alkanol used in the method of reducing low-speed-pre-ignition events in an engine is or comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

In certain embodiments, the low-speed pre-ignition (LSPI)-reducing additive is or comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

In certain embodiments, the amino alcohol is or comprises aminoheptyl propanediol, with the proviso that it is not the following:
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be an aliphatic amino acid, a substituted aliphatic amino acid, or a derivative thereof, or an acceptable salt thereof. Useful amino acids include those that can be represented by the following general formula:
<CHM>
wherein R is an "aliphatic" or "aromatic" side chain. Amino acid side chains can be broadly classified as aromatic or aliphatic. An aromatic side chain includes an aromatic ring. Examples of amino acids with aromatic side chains include for example, histidine (Formula 2A), phenylalanine (Formula 2B), tyrosine (Formula 2C), tryptophan (Formula 2D) and the like. Non-aromatic side chains are broadly grouped as "aliphatic" and include, for example, alanine (Formula 2E), glycine (Formula 2F), cysteine (Formula <NUM>), and the like.

The amino acid(s) can be natural and/or non-natural α-amino acids. Natural amino acids are those encoded by the genetic code, as well as amino acids derived therefrom. These include, for example, hydroxyproline (Formula <NUM>), γ-carboxyglutamate (Formula <NUM>), and citrulline (Formula 2J). In this specification, the term "amino acid" also includes amino acid analogs and mimetics. Analogs are compounds having the same general structure of a natural amino acid, except that the R group is not one found among the natural amino acids.

Representative examples of analogs of naturally occurring amino acids include homoserine (Formula <NUM>), norleucine (Formula <NUM>), homoproline (Formula <NUM>) and proline (Formula 2N). An amino acid mimetic is a compound that has a structure different from the general chemical structure of an α-amino acid but functions in a manner similar to one. The amino acid may be an L- or D-amino acid. Representative structures are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be an amino ester, a substituted amino ester, or a derivative thereof, or an acceptable salt thereof. Amino esters can be derived from amino acids (as described above) and alcohols. Amino esters and amino acids may be considered derivatives of each other. Useful amino esters include those that can be represented by the following general formula:
<CHM>
wherein R is an aliphatic side chain and R<NUM> is a carbon chain <NUM> to <NUM> carbon atoms in length, preferably <NUM> to <NUM> carbon atoms, in particular, methanol or ethanol, preferably methanol.

The amino esters may include aromatic or aliphatic side chains. Representative examples of amino esters include methyl alaninate (Formula 3A), ethyl alaninate (Formula 3B), methyl glycinate (Formula 3C), and ethyl glycinate (Formula 3D). Representative structures are shown below. <CHM>
<CHM>.

A fuel additive or lubricating oil additive of this disclosure may have a N=C-X motif as shown in the generalized structure below
<CHM>
wherein R is H, monovalent organic group, or monovalent heterorganic group (described in greater detail below), X<NUM> and X<NUM> are independently H, C, N, O, or S and wherein X<NUM> or X<NUM> independently includes one or more C<NUM>-C<NUM> alkyl group (e.g., C<NUM>-C<NUM> alkyl) or one or more aromatic ring. In some embodiments, X<NUM> and X<NUM> may include a cyclic structure (e.g., a five-, six-, or seven-membered ring). Cyclic structures may be aromatic or non-aromatic, as well as vary from being fully saturated to fully unsaturated. Suitable examples of additives compatible with Formula <NUM> include amidines, guanidines, imidazoles, benzamidines, benzimidazoles, and aminobenzimidazoles.

The fuel additive or lubricating oil additive of this disclosure may be an amidine, a substituted amidine, or a derivative thereof or an acceptable salt thereof. Useful amidines include those that can be represented by the following general formula:
<CHM>
wherein R<NUM>, R<NUM>, R<NUM> and R<NUM> are each independently selected from hydrogen, monovalent organic groups, monovalent heterorganic groups (e.g., comprising nitrogen, oxygen, sulfur or phosphorus, in the form of groups or moieties that are bonded through a carbon atom and that do not contain acid functionality such as carboxylic or sulfonic), and combinations thereof; and wherein any two or more of R<NUM>, R<NUM>, R<NUM> and R<NUM> optionally can be bonded together to form a cyclic structure (e.g., a five-, six, or seven-membered ring). The cyclic structures may be aromatic or non-aromatic, as well as vary from being fully saturated to fully unsaturated. The organic and heterorganic groups may have from <NUM> to <NUM> carbon atoms (e.g., <NUM> to <NUM> carbon atoms).

Representative examples of suitable amidines include <NUM>,<NUM>,<NUM>,<NUM>-tetrahydropyrimidine (Formula 5A), <NUM>,<NUM>-dimethyl-<NUM>,<NUM>,<NUM>,<NUM>-tetrahydropyrimidine (Formula 5B), <NUM>,<NUM>-diethyl-<NUM>,<NUM>,<NUM>,<NUM>-tetrahydropyrimidine (Formula 5C), <NUM>,<NUM>-diazabicyclo[<NUM>. <NUM>]non-<NUM>-ene (DBN; Formula 5D), <NUM>,<NUM>-diazabicyclo[<NUM>. <NUM>]-undeca-<NUM>-ene (DBU; Formula 5E), benzamidine (Formula 5F), benzimidazole (Formula <NUM>) and <NUM>-phenyl-<NUM>-benzo[d]imidazole (Formula <NUM>). Representative structures are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be a guanidine, a substituted guanidine, or a derivative thereof, or an acceptable salt thereof. Useful guanidines include those that can be represented by the following general formula,
<CHM>
wherein R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are each independently selected from hydrogen, monovalent organic groups, monovalent heterorganic groups (e.g., comprising nitrogen, oxygen, sulfur or phosphorus, in the form of groups or moieties that are bonded through a carbon atom and that do not contain acid functionality such as carboxylic or sulfonic), and combinations thereof; and wherein any two or more of R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> optionally can be bonded together to form a cyclic structure (e.g., a five-, six, or seven-membered ring). The cyclic structures may be aromatic or non-aromatic, as well as vary from being fully saturated to fully unsaturated. The organic and heterorganic groups may have from <NUM> to <NUM> carbon atoms (e.g., <NUM> to <NUM> carbon atoms).

Representative examples of suitable guanidines include <NUM>,<NUM>,<NUM>,<NUM>-tetramethylguanidine (TMG; Formula 6A), <NUM>-tert-butyl-<NUM>,<NUM>,<NUM>,<NUM>-tetramethylguanidine (BTMG; Formula 6B), <NUM>,<NUM>,<NUM>-triazabicyclo[<NUM>. <NUM>]dec-<NUM>-ene (TBD; Formula 6C), <NUM>-methyl-<NUM>,<NUM>,<NUM>-triazabicyclo[<NUM>. <NUM>]dec-<NUM>-ene (MTBD; Formula 6D) and <NUM>,<NUM>-diphenylguanidine (Formula <NUM>). Representative structures shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be an imidazole, a substituted imidazole, or a derivative thereof, or an acceptable salt thereof. Suitable imidazoles include imidazole (Formula 7A), <NUM>-methylimidazole (Formula 7B), <NUM>-ethylimidazole (Formula 7D), <NUM>-propylimidazole (Formula 7E), <NUM>-n-butylimidazole (Formula 7F), <NUM>-decylimidazole, <NUM>-dodecylimidazole, <NUM>-methylimidazole (Formula <NUM>), <NUM>-ethylimidazole, <NUM>-isopropylimidazole (Formula <NUM>), <NUM>-methylimidazole (Formula <NUM>), <NUM>,<NUM>-dimethylimidazole (Formula 7J), <NUM>-ethyl-<NUM>(<NUM>)-methylimidazole (Formula <NUM>), and <NUM>-vinylimidazole (Formula <NUM>). Representative structures are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be a triazole, a substituted triazole, or a derivative thereof, or an acceptable salt thereof. Suitable triazoles include <NUM>, <NUM>, <NUM>-triazole (Formula 8A), <NUM>,<NUM>-dimethylbenzotriazole (Formula 8B), <NUM>, <NUM>, <NUM>-triazole (Formula 8C), piperidine-substituted triazole (Formula 8D) and benzotriazole analog, for example, an alkyl-substituted benzotriazole, such as a methyl substituted benzotriazole (Formula 8E). Representative structures are shown below. <CHM>
<CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be a benzamidinium, a substituted benzamidinium, or a derivative thereof, or an acceptable salt thereof. Useful benzamidinium additives include those that can be represented by the following general formula <NUM>, wherein R<NUM>, R<NUM>, and R<NUM> are independently C<NUM>-C<NUM> alkyl groups.

Suitable benzamidiniums include N,N-dimethyl-N-octylbenzamidium-<NUM>-oxide (Formula 9A). Representative structures are shown below. <CHM>
<CHM>.

The fuel additive or lubricating oil additive of this disclosure may be a benzoxazole, a substituted benzoxazole, or a derivative thereof, or an acceptable salt thereof. Suitable benzoxazoles include benzoxazole (Formula 10A) and <NUM>-aminobenzoxazole (Formula 10B). Representative structures are shown below.

The fuel additive or lubricating oil additive of this disclosure may be an aromatic amine, a substituted aromatic amine, or a derivative thereof, or an acceptable salt thereof. Aromatic amine additives can have the generalized structure shown in Formula <NUM>-<NUM> or <NUM>-<NUM>,
<CHM>
wherein R is independently one or more H or C<NUM>-C<NUM> alkyl group and X is N (e.g., R-N-R) or O-.

Suitable aromatic amines include <NUM>-methylquinolin-<NUM>-amine (Formula 11A). Representative structures are shown below. <CHM>
<CHM>.

Suitable aliphatic amines are shown below. <CHM>
<CHM>.

The following are descriptions of secondary LSPI-reducing additives that can be utilized as fuel or lubricating additives to reduce LSPI activity. In general, a secondary LSPI-reducing additive, a substituted secondary LSPI-reducing additive, or a derivative thereof will be used in their salt form and in combination with a primary additive to reduce LSPI activity. For example, β-amino alkanol (primary additive) and aliphatic acid (secondary additive) can be combined and utilized as an LSPI additive. Table <NUM> lists the secondary additive types. Some additives can act as a primary additive and/or secondary additive.

Aliphatic acids are non-aromatic carboxylic acids. Suitable aliphatic acids include mono-carboxylic acids having the following structure
<CHM>
wherein R is an aliphatic group having between <NUM> to <NUM> carbon atoms. The aliphatic group may be linear or branched and may contain heteroatoms.

Suitable aliphatic acids include hexanoic acid (Formula 13A), heptanoic acid (Formula 13B), octanoic acid (Formula 13C), nonanoic acid (Formula 13D), decanoic acid (Formula 13E), undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid (C<NUM>), behenic acid (C<NUM>), <NUM>-ethylbutyric acid (Formula 13F), <NUM>,<NUM>-dimethylbutyric acid, <NUM>-methylpentanoic acid (C<NUM>), <NUM>-methylhexanoic acid (C<NUM>), <NUM>-methylhexanoic acid (C<NUM>), <NUM>-methylhexanoic acid (C<NUM>), <NUM>,<NUM>-dimethylpentanoic acid (C<NUM>), <NUM>-propylpentanoic acid (C<NUM>), <NUM>-ethylhexanoic acid (Formula <NUM>), <NUM>-methylheptanoic acid (C<NUM>), isooctanoic acid (C<NUM>), <NUM>,<NUM>,<NUM>-trimethylhexanoic acid (C<NUM>), <NUM>-methyloctanoic acid (C<NUM>), <NUM>-methylnonanoic acid, (C<NUM>), isodecanoic acid ((<NUM>), <NUM>-butyloctanoic acid (C<NUM>), isotridecanoic acid (C<NUM>), <NUM>-hexyldecanoic acid (C<NUM>), isopalmitic acid (C<NUM>), isostearic acid (Formula <NUM>), <NUM>-cyclohexylpropionic acid, <NUM>-cyclohexylbutyric acid (Formula <NUM>), and cyclohexanepentanoic acid. Representative structures are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

Suitable unsaturated acids include any organic acids that contain double or triple carbon-carbon bond. Representative unsaturated acids include maleic acid (Formula 14A), fumaric acid (Formula 14B), as well as unsaturated fatty acids such as palmitoleic acid (Formula 14C) and oleic acid (Formula 14D). Representative structures are shown below. <CHM>
<CHM>
<CHM>.

Suitable alkylaromatic acids include both mono-carboxylic acids and dicarboxylic acids. The alkyl carboxylic acid may have <NUM> or more carbon atoms (e.g., <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, or even <NUM> to <NUM> carbon atoms). The alkyl moiety may be optionally substituted with one or more substituents such as hydroxy, alkoxy and carbonyl (e.g., aldehydic or ketonic) groups. Suitable examples of alkylaromatic acid include methylbenzoic acid (Formula 15A) and ethylbenzoic acid (Formula 15B). Representative structures are shown below.

Suitable aromatic acids include both mono-carboxylic acids and dicarboxylic acids. The alkyl carboxylic acid may have <NUM> or more carbon atoms (e.g., <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, or even <NUM> to <NUM> carbon atoms). The alkyl moiety may be optionally substituted with one or more substituents such as hydroxy, alkoxy and carbonyl (e.g., aldehydic or ketonic) groups. Suitable aromatic acids include benzoic acid (Formula 16A), hydroxybenzoic acid (Formula 16B), and tetralin carboxylic acid (Formula 16C). Representative structures are shown below.

Suitable hydroxy acids include those that can be represented by the following general formula:
<CHM>
wherein n = <NUM> to <NUM>. Suitable examples of hydroxy acid include glycolic acid (Formula 17A), lactic acid (Formula 17B), malic acid (Formula 17C), tartaric acid (Formula 17D), and citric acid (Formula 17E). Representative structures are shown below. <CHM>
<CHM>.

Amino acids can be utilized as primary and/or secondary additives. Suitable amino acids were previously described above.

Suitable phenols include, thymol (Formula 18A), eugenol (Formula 18B), hydroquinone (Formula 18C), resorcinol (Formula 18D), cresol (Formula 18E) and <NUM>-methylquinolin-<NUM>-ol (Formula <NUM>). Representative structures are shown below. <CHM>
<CHM>
<CHM>.

Suitable examples of <NUM>,<NUM> diketone compounds include acetylacetone (Formula 19A), , and curcumin (Formula 19B). Representative structures are shown below. <CHM>
<CHM>.

Suitable <NUM>,<NUM> ketoesters are shown below.

A hydroxamide is a hydroxy derivative of an amide. Useful hydroxamides include those that can be represented by the following general formula:
<CHM>
wherein R<NUM> and R<NUM> are each independently selected from hydrogen or C<NUM>-C<NUM> (e.g., C<NUM>-C<NUM>) alkyl group. Suitable hydroxamide includes hydroxy methylacetamide (Formula 21A). Representative structures are shown below.

Suitable antioxidants include both mono-carboxylic acids and dicarboxylic acids. The alkyl carboxylic acid may have <NUM> or more carbon atoms (e.g., <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, <NUM> to <NUM> carbon atoms, or even <NUM> to <NUM> carbon atoms). The alkyl moiety may be optionally substituted with one or more substituents such as hydroxy, alkoxy and carbonyl (e.g., aldehydic or ketonic) groups. Suitable antioxidants include the following.

Suitable salicylates include <NUM>-hydroxy-<NUM>-(tetracosa-<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-dodecayn-<NUM>-yl)benzoic acid--dihydrogen (Formula 23E). Suitable salicylates are shown below. <CHM>
<CHM>.

The salts of this disclosure may be prepared by conventional means, for example, by mixing the primary additive with a suitable secondary additive in an aprotic solvent. The order in which one additive is added to the other is not important. The primary additive and secondary additive are usually mixed together in an approximately equimolar ratio. An excess of the primary or secondary additive component may be used. For example, the molar ratio of base relative to the alkyl carboxylic acid may be about <NUM>:<NUM> to <NUM>:<NUM> (e.g., <NUM>:<NUM> to <NUM>:<NUM>). Representative salts are shown below. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The compounds of the present disclosure may be useful as additives in hydrocarbon fuels to prevent or reduce engine knock or pre-ignition events in spark-ignited internal combustion engines.

The concentration of the compounds of the present disclosure in hydrocarbon fuel may range from <NUM> to <NUM> parts per million (ppm) by weight (e.g., <NUM> to <NUM> ppm).

The compounds of the present disclosure may be formulated as a concentrate using an inert stable oleophilic (i.e., soluble in hydrocarbon fuel) organic solvent boiling in a range of <NUM> to <NUM>. An aliphatic or an aromatic hydrocarbon solvent may be used, such as benzene, toluene, xylene, or higher-boiling aromatics or aromatic thinners. Aliphatic alcohols containing <NUM> to <NUM> carbon atoms, such as ethanol, isopropanol, methyl isobutyl carbinol, n-butanol and the like, in combination with the hydrocarbon solvents are also suitable for use with the present additives. In the concentrate, the amount of the additive may range from <NUM> to <NUM> wt % (e.g., <NUM> to <NUM> wt %).

In gasoline fuels, other well-known additives can be employed including oxygenates (e.g., ethanol, methyl tert-butyl ether), other anti-knock agents, and detergents/dispersants (e.g., hydrocarbyl amines, hydrocarbyl poly(oxyalkylene) amines, succinimides, Mannich reaction products, aromatic esters of polyalkylphenoxyalkanols, or polyalkylphenoxyaminoalkanes). Additionally, friction modifiers, antioxidants, metal deactivators and demulsifiers may be present.

In diesel fuels, other well-known additives can be employed, such as pour point depressants, flow improvers, cetane improvers, and the like.

A fuel-soluble, non-volatile carrier fluid or oil may also be used with compounds of this disclosure. The carrier fluid is a chemically inert hydrocarbon-soluble liquid vehicle which substantially increases the non-volatile residue (NVR), or solvent-free liquid fraction of the fuel additive composition while not overwhelmingly contributing to octane requirement increase. The carrier fluid may be a natural or synthetic oil, such as mineral oil, refined petroleum oils, synthetic polyalkanes and alkenes, including hydrogenated and unhydrogenated polyalphaolefins, synthetic polyoxyalkylene-derived oils, such as those described in <CIT>; <CIT>; and <CIT>; and in <CIT>and <CIT>.

The carrier fluids may be employed in amounts ranging from <NUM> to <NUM> ppm by weight of the hydrocarbon fuel (e.g., <NUM> to <NUM> ppm of the fuel). When employed in a fuel concentrate, carrier fluids may be present in amounts ranging from <NUM> to <NUM> wt % (e.g., <NUM> to <NUM> wt %).

The compounds of the present disclosure may be useful as additives in lubricating oils to prevent or reduce engine knock or pre-ignition events in spark-ignited internal combustion engines.

The concentration of the compounds of the present disclosure in the lubricating oil composition may range from <NUM> to <NUM> wt % (e.g., <NUM> to <NUM> wt %), based on the total weight of the lubricating oil composition.

Definitions for the base stocks and base oils in this disclosure are the same as those found in American Petroleum Institute (API) Publication <NUM> Annex E ("API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils," December <NUM>). Group I base stocks contain less than <NUM>% saturates and/or greater than <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> and less than <NUM> using the test methods specified in Table E-<NUM>. Group II base stocks contain greater than or equal to <NUM>% saturates and less than or equal to <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> and less than <NUM> using the test methods specified in Table E-<NUM>. Group III base stocks contain greater than or equal to <NUM>% saturates and less than or equal to <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> using the test methods specified in Table E-<NUM>. Group IV base stocks are polyalphaolefins (PAO). Group V base stocks include all other base stocks not included in Group I, II, III, or IV.

Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alphaolefin copolymers). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oil. By way of example, PAOs derived from C<NUM> to C<NUM> olefins, e.g., C<NUM>, C<NUM>, C<NUM>, C<NUM> olefins or mixtures thereof, may be utilized.

Typically, the base oil will have a kinematic viscosity at <NUM> (ASTM D445) in a range of <NUM> to <NUM><NUM>/s (e.g., <NUM> to <NUM><NUM>/s, <NUM> to <NUM><NUM>/s, or <NUM> to <NUM><NUM>/s).

The present lubricating oil compositions may also contain conventional lubricant additives for imparting auxiliary functions to give a finished lubricating oil composition in which these additives are dispersed or dissolved. For example, the lubricating oil compositions can be blended with antioxidants, ashless dispersants, anti-wear agents, detergents such as metal detergents, rust inhibitors, dehazing agents, demulsifying agents, friction modifiers, metal deactivating agents, pour point depressants, viscosity modifiers, antifoaming agents, co-solvents, package compatibilizers, corrosion-inhibitors, dyes, extreme pressure agents and the like and mixtures thereof. A variety of the additives are known and commercially available. These additives, or their analogous compounds, can be employed for the preparation of the lubricating oil compositions of the invention by the usual blending procedures.

Each of the foregoing additives, when used, is used at a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if an additive is an ashless dispersant, a functionally effective amount of this ashless dispersant would be an amount sufficient to impart the desired dispersancy characteristics to the lubricant. Generally, the concentration of each of these additives, when used, may range, unless otherwise specified, from about <NUM> to about <NUM> wt %, such as about <NUM> to about <NUM> wt %.

The following illustrative examples are intended to be non-limiting.

The test compounds were blended in gasoline or lube oil and their capacity for reducing LSPI events were determined using the test method described below.

A GM <NUM> LHU <NUM>-cylinder gasoline turbocharged direct-injected engine was used for LSPI testing. Each cylinder was equipped with a combustion pressure sensor.

A six-segment test procedure was used to determine the number of LSPI events that occurred under conditions of an engine speed of <NUM> rpm and a load of <NUM>. The LSPI test condition is run for <NUM> minutes with each segment separated by an idle period. The first segment is used to condition the oil and the number of LSPI events are not counted. Each segment is slightly truncated to eliminate the transient portion. Each truncated segment typically has approximately <NUM>,<NUM> combustion cycles (<NUM>,<NUM> combustion cycles per cylinder). In total, the five truncated segments where LSPI events are counted have approximately <NUM>,<NUM> combustion cycles (<NUM>,<NUM> combustion cycles per cylinder). There may be instances of shortened tests in the event the engine cannot complete all six segments.

LSPI-impacted combustion cycles were determined by monitoring peak cylinder pressure (PP) and crank angle at <NUM>% total heat release (Al5). LSPI-impacted combustion cycles are defined as having both (<NUM>) a PP greater than five standard deviations than the average PP for a given cylinder and truncated segment and (<NUM>) an Al5 greater than five standard deviations less than the average for a given cylinder and truncated segment.

The LSPI frequency is reported as the number of LSPI-impacted combustion cycles per million combustion cycles and is calculated as follows: <MAT>.

An additive associated with a test fuel and/or test lubricant that reduces the LSPI frequency, when compared to the corresponding baseline fuel and/or baseline lubricant, is considered an additive that mitigates LSPI frequency. The test results are set forth in Table <NUM>.

Claim 1:
A method of reducing low-speed pre-ignition events in an engine comprising:
providing a fuel composition to the engine, wherein the fuel composition comprises
(<NUM>) greater than <NUM> wt % of a hydrocarbon fuel boiling in the gasoline range and
(<NUM>) a minor amount of a low-speed pre-ignition (LSPI)-reducing additive comprising one or more of:
a triazole, an amidine, or a beta-amino alkanol having the structure
<CHM>
wherein R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently selected from hydrogen, aromatic ring and a C<NUM>-C<NUM> alkyl group and R<NUM> is hydrogen or an alcohol having the structure -(CH)R<NUM>-OH wherein R<NUM> is hydrogen, a C<NUM>-C<NUM> alkyl group, or a C<NUM>-C<NUM> alkenyl group, or a salt thereof, and
wherein the engine is a direct-injected, boosted spark-ignited, internal combustion engine, that, in operation, generates a brake mean effect pressure level of greater than <NUM> kPa at an engine speed of from <NUM> to <NUM> rotations per minute.