CN112789346A

CN112789346A - Negative hydrogen ion donors as additives to reduce low speed pre-ignition events

Info

Publication number: CN112789346A
Application number: CN201980065359.8A
Authority: CN
Inventors: R·E·切派克; I·G·埃利奥特; T·L·古纳万; A·G·玛丽亚
Original assignee: Chevron USA Inc; Chevron Oronite Co LLC
Current assignee: Chevron USA Inc; Chevron Oronite Co LLC
Priority date: 2018-10-04
Filing date: 2019-10-02
Publication date: 2021-05-11
Anticipated expiration: 2039-10-02
Also published as: US20200109343A1; JP2022512603A; WO2020070672A1; AU2019353900A1; CN112789346B; CA3115036A1; KR20210069064A; EP3861089A1; MX2021003690A; SG11202103198WA; ZA202102156B; CO2021005685A2

Abstract

Fuel and lubricant compositions are provided that include an organic negative hydrogen ion-based reducing agent. Methods of using these compositions to prevent or reduce low speed pre-ignition events in internal combustion engines are also provided.

Description

Negative hydrogen ion donors as additives to reduce low speed pre-ignition events

Technical Field

The present disclosure relates to fuel and lubricant compositions and methods of using the same to reduce low speed pre-ignition activity in internal combustion engines. The composition includes an organic negative hydrogen ion donor as a fuel or lubricant additive.

Background

Pre-ignition in an internal combustion engine is an undesirable event in which undesired ignition of the air-fuel mixture occurs prior to desired ignition of the air-fuel mixture (e.g., by a spark plug). During high load engine operation, pre-ignition may be a problem because heat from engine operation may heat a portion of the combustion chamber to a temperature sufficient to ignite the air-fuel mixture at the time of contact.

In recent years, engine manufacturers have developed smaller engines that can provide higher power densities and excellent performance while reducing friction and pumping losses. This improvement in performance is accomplished by increasing boost pressure using a turbocharger or supercharger, and by decelerating the engine using a higher transmission gear ratio allowed by the higher torque produced at lower engine speeds. Disadvantageously, these engines are typically operated under low speed and high load driving conditions, making the engines more susceptible to a pre-ignition phenomenon known as random pre-ignition or low speed pre-ignition (LSPI). In the worst case, extremely high peak cylinder pressures can build up and cause catastrophic engine failure. This sensitivity prevents engine manufacturers from adequately optimizing engine torque at lower engine speeds in such smaller, high output engines.

Summary of the invention

In one aspect, a fuel composition is provided that includes (1) greater than 50 wt.% of a hydrocarbon fuel boiling in the gasoline or diesel range and (2) a minor amount of one or more organic negative hydrogen ion-based reducing agents.

In another aspect, a method for preventing or reducing low speed pre-ignition events in an internal combustion engine is provided, the method comprising supplying to the engine a fuel composition comprising (1) greater than 50 wt.% of a hydrocarbon fuel boiling in the gasoline or diesel range and (2) a minor amount of one or more organic negative hydrogen ion-based reductants.

In another aspect, a lubricating oil composition is provided that includes (1) greater than 50 wt.% base oil and (2) a minor amount of one or more organic negative hydrogen ion-based reducing agents.

In yet another aspect, a method for preventing or reducing low speed pre-ignition events in a spark-ignited internal combustion engine is provided, the method comprising supplying to the engine a lubricating oil composition comprising (1) greater than 50 wt.% base oil and (2) a minor amount of one or more organic negative hydrogen ion-based reducing agents.

Detailed Description

Definition of

In the present specification, if the following words and expressions are used, they have the following meanings.

The term "supercharging" refers to operating an engine at a higher suction pressure than a naturally aspirated engine. The boost condition can be achieved by using a turbocharger (driven by exhaust) or supercharger (driven by the engine). "supercharging" allows engine manufacturers to use smaller engines that can provide higher power densities to provide superior performance while reducing friction and pumping losses.

The term "oil-soluble" refers to an amount that can be incorporated by dissolving, dispersing or suspending in an oil of lubricating viscosity to provide a desired level of activity or performance for a given additive. Typically, this means that at least 0.001 wt.% of the additive can be incorporated into the lubricating oil composition. The term "fuel-soluble" is a similar expression that the additive is dissolved, dispersed or suspended in the fuel.

"gasoline" or "gasoline boiling range component" means a gasoline containing at least predominantly C₄-C₁₂A composition of hydrocarbons. In one embodiment, a gasoline or gasoline boiling range component is further defined as comprising at least predominantly C₄-C₁₂A hydrocarbon and further a composition having a boiling range of from about 37.8 ℃ (100 ° F) to about 204 ℃ (400 ° F). In an alternative embodiment, a gasoline or gasoline boiling range component is defined as comprising at least predominantly C₄-C₁₂A hydrocarbon having a boiling range from 37.8 ℃ (100 ° F) to about 204 ℃ (400 ° F) and further defined as a composition conforming to ASTM D4814.

The term "diesel fuel" is a fuel containing at least predominantly C₁₀-C₂₅A hydrocarbon middle distillate fuel. In one embodiment, diesel is further defined to mean comprising at least primarily C₁₀-C₂₅A hydrocarbon and further boiling range from about 165.6 ℃ (330 ° F) to about 371.1 ℃ (700 ° F). In an alternative embodiment, diesel fuel is as defined above and means comprising at least predominantly C₁₀-C₂₅A hydrocarbon having a boiling range from about 165.6 ℃ (330 ° F) to about 371.1 ℃ (700 ° F) and further defined as a composition conforming to ASTM D975.

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

By "minor amount" is meant less than 50% by weight of the composition, expressed relative to the additive and relative to the total weight of the composition, of active ingredient considered to be an additive.

A "reducing agent" is a reducing agent that donates an electron to another chemical species in a redox reaction, and a "hydrogen anion-based reducing agent" donates a hydrogen anion (the anion of hydrogen) to another chemical species in a redox reaction.

In the context of hydrocarbon-based formulations (particularly lubricants), the term "ash" refers to metal compounds that remain after the hydrocarbons have been calcined. This ash originates mainly from the chemicals used in certain additives as well as solids. The term "ashless" refers to a formulation or additive that does not produce ash or limit ash production. Ashless additives are generally free of metals (including boron), silicon, halogens, or contain these elements at concentrations below the detection limit of typical instruments.

"halogen" is a generic term for each substituent, including, for example, fluorine, chlorine, bromine, iodine, and the like.

An "analog" is a compound that has a structure similar to another compound but differs in some portion, e.g., one or more atoms, functional groups, substructures, which are substituted with other atoms, groups, or substructures.

"homologue" refers to a compound consisting of a series of compounds whose repeating units differ from one another. Alkanes are examples of homologs. For example, ethane and propane are homologs in that they are only in the repeat unit (-CH)₂-) differ in length. Homologs may be considered as a particular type of analog.

A "derivative" is a compound that is derived from a similar compound by a chemical reaction (e.g., an acid-base reaction, hydrogenation, etc.), and in the case of a substituent, a derivative may be a combination of one or more moieties. For example, the phenolic moiety can be considered to be a derivative of the aryl moiety and the hydroxyl moiety, and one of ordinary skill in the relevant art will know what is considered to be the boundary and boundary of the derivative.

An "engine" or "combustion engine" is a heat engine in which combustion of a fuel occurs within a combustion chamber. An "internal combustion engine" is a heat engine in which combustion of fuel occurs in a confined space ("combustion chamber"). A "spark ignition engine" is a thermal engine in which combustion is usually ignited by a spark (usually a spark plug), in contrast to a "compression ignition engine" (usually a diesel engine) in which the heat generated by compression and fuel injection are sufficient to initiate combustion in the absence of an external spark.

Introduction to

One possible cause of low speed pre-ignition (LSPI) is auto-ignition of engine oil droplets entering the engine combustion chamber from piston crevices at high pressures during periods when the engine is operating at low speeds and the compression stroke time is longest. Factors such as turbocharger usage, engine design, engine coatings, piston shape, fuel selection, or engine oil additives may lead to an increase in LSPI events. While some engine knock and pre-ignition problems may be addressed by using new engine technologies or optimizing engine operating conditions, reduction of LSPI by new fuel and/or lubricating oil compositions may be the most economical approach.

The present disclosure describes hydrocarbon-based compositions (e.g., fuels, lubricating oils) and methods of use thereof, wherein the hydrocarbon-based compositions prevent LSPI events or reduce LSPI activity during engine operation. Suitable hydrocarbon-based compositions will have an organo-hydride based reductant additive according to the present disclosure.

Organic negative hydrogen ion base reducing agent

Provided herein are organic negative hydrogen ion-based reductants that prevent LSPI events or reduce LSPI activity in combustion engines. These organic negative hydrogen ion-based reducing agents are organic molecules that readily provide negative hydrogen ions in the negative hydrogen ion transfer step. These reducing agents are ashless additives, typically containing carbon, hydrogen, nitrogen and/or oxygen atoms. Depending on the application, the organic hydride-based reducing agent is oil-soluble or fuel-soluble.

Negative hydrogen ion transfer is a key step in many well-known organic reactions, including important biochemical reactions and industrial redox reactions. In these types of reactions, the reducing agent will provide a negative hydrogen ion (H)^-) Transfer to a substrate, for example, carbonyl compounds, carbon dioxide, imines, compounds containing a reactive C ═ C bond, and the like. The precise mechanism of negative hydrogen ion transfer is often complex and may vary with temperature,Substrate, negative hydrogen ion donor, availability of protons, presence of lewis acid, etc. In some cases, negative hydrogen ion transfer can occur by direct transfer of the negative hydrogen ion from the negative hydrogen ion donor to the substrate, or can occur in a continuous step (e.g., electron transfer to the substrate followed by a hydrogen atom or proton and a second electron).

Without being limited by theory, it is believed that a suitable negative hydrogen ion donor according to the present invention may reduce LSPI activity in an internal combustion engine by acting against oxidative labile chemicals that may initiate LSPI events. This may involve reducing an oxidatively unstable chemical species to a more stable, less reactive reducing species, thereby inhibiting the LSPI event.

According to one or more embodiments of the present invention, the organic negative hydrogen ion-based reducing agent includes at least one of the following organic negative hydrogen ion donors: dihydropyridine (DHPD), reduced Nicotinamide Adenine Dinucleotide (NADH), methylenetetrahydrobiopterin, acridine, triarylmethane, triamine, arylbenzimidazoline, dioxolane, diether cyclohexadiene, cycloheptatriene, Flavin Adenine Dinucleotide (FADH)₂) Hexahydrotriazaphthalenes, their analogs, their homologs and their derivatives.

The following chemical structures of the organohydridion-based reducing agents are provided for illustration. Each reducing agent or type of reducing agent is represented by a generic structure that includes an upper R group (e.g., R) at each substitution position₁,R₂,R₃Etc.). Each R group may be a member selected from a group of suitable substituents. Varying the combination of R group substituents can produce a set of related structures, where each resulting structure is an analog of the other structures within the set. The desirability of a substituent group may depend on a number of factors including, but not limited to, the target ability of the organic negative hydrogen ion-based donor to provide a negative hydrogen ion, stability, solubility in oil or fuel, and the like.

Dihydropyridines (DHPD)

The DHPD or DHPD-type reducing agent is illustrated by the general structure (formula 1). Reference formula 1, R₁And R₂Are each independently(ii) a member selected from the group consisting of: H. ester moieties, amide moieties, cyanide moieties, any derivative thereof, and the like. R₃And R₄Are members each independently selected from the group consisting of: H. alkyl moieties, any derivatives thereof, and the like. R₅Is a member selected from the group consisting of: H. alkyl moieties, allyl moieties, aryl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like.

Suitable analogs of DHPD include

Reduced form of Nicotinamide Adenine Dinucleotide (NADH)

The NADH or NADH type reducing agent is illustrated by the general structure (formula 2). Reference formula 2, R₁And R₂Are members each independently selected from the group consisting of: H. ester moieties, amide moieties, cyanide moieties, any derivative thereof, and the like. R₃And R₄Are members each independently selected from the group consisting of: H. alkyl moieties, any derivatives thereof, and the like. R₅Is a member selected from the group consisting of: H. alkyl moieties, allyl moieties, aryl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like. R₆A member selected from the group consisting of: H. alkyl moieties, any derivatives thereof, and the like. In some embodiments, R₁And R₃Or R₁And R₄A cyclic structure (e.g., formula 2C and 2E) may be formed.

Suitable analogs of NADH include

Methylene tetrahydrobiopterin

The methylene tetrahydromethylpterin or methylene tetrahydromethylpterin-type reducing agent is represented by the general structure (formula 3). Reference formula 3, R₁、R₂、R₃And R₄Are members each independently selected from the group consisting of: H. alkyl moieties, allyl moieties, alkanol moieties, any derivatives thereof, and the like. R₅Selected from the group consisting of: H. alkyl moieties, any derivatives thereof, and the like.

Suitable analogues of methylenetetrahydromethotrexate include

Acridine

Acridine or acridine-type reducing agents are illustrated by the general structure (formula 4). Referring to formula 4, X is N or O (formula 4H). When X is N, R₁Selected from the group consisting of: H. alkyl moieties, allyl moieties, aryl moieties, benzyl moieties, any derivative thereof, and the like. R₂Selected from the group consisting of: H. alkyl moieties, allyl moieties, aryl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like. R₃And R₄Are members each independently selected from the group consisting of: H. alkyl moieties, aryl moieties, benzyl moieties, amine moieties, alkoxy moieties, heteroatoms, any derivatives thereof, and the like. And, R₃And R₄May independently occupy more than one substitution position within their respective rings. In some embodiments, R₁And R₃Or R₁And R₄Can form a ring structure(e.g., formulas 4E and 4F).

Suitable analogues of acridine include

Triarylmethanes

Triarylmethane or triarylmethane-type reducing agents are illustrated by the general structure (formula 5). Reference formula 5, R₁、R₂And R₃Are each independently selected from the group: h, an alkyl moiety, an aryl moiety, a benzyl moiety, an allyl moiety, an amide moiety, an ester moiety, an ether moiety, a hydroxyl moiety, an amine moiety, any derivative thereof, and the like. In some embodiments, R₁、R₂And R₃May independently occupy more than one substitution position within their respective rings (e.g., formulas 5A and 5B).

Suitable analogues of triarylmethane include

Triamines (meth) acrylic acid esters)

The triamine or triamine-based reducing agent is illustrated by the general structure (formula 6), wherein R₁、R₂、R₃、R₄、R₅And R₆Three rings (e.g., formulas 6A-6C) are connected.

Suitable analogs of triamines include

Arylbenzimidazolines

Aryl benzimidazolines or aryl benzimidazoline type reducing agents are illustrated by the general structure (formula 7). Referring to formula 7, X is N, O or S. If X is N, R₁And R₂Are members each independently selected from the group consisting of: H. alkyl moieties, any derivatives thereof, and the like. R₃Selected from the group consisting of: H. alkyl moieties, alkene moieties, alkyne moieties, aryl moieties, benzyl moieties, any derivative thereof, and the like. R₄Selected from the group consisting of: H. alkyl moieties, aryl moieties, benzyl moieties, allyl moieties, any derivative thereof, and the like. In some embodiments, R₄May independently occupy more than one substitution position.

Suitable analogues of arylbenzimidazolines include

Dioxolanes

Dioxolane or dioxolane type reducing agents are illustrated by the general structure (formula 8). Referring to formula 8, R is a member selected from the group consisting of: H. alkyl moieties, allyl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like.

Suitable analogues of dioxolane include

Diether cyclohexadienes

Diether cyclohexadienes or diether cyclohexadienes-type reductants are illustrated by the general structure (formula 9). Referring to formula 9, R is a member selected from the group consisting of: H. alkyl moieties, allyl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like.

Suitable analogues of diether cyclohexadienes include

Cycloheptatriene

The cycloheptatriene or cycloheptatriene-type reducing agents are illustrated by the general structure (formula 10). Referring to formula 10, R is a member selected from the group consisting of: H. alkyl moieties, allyl moieties, benzyl moieties, alkanol moieties, any derivative thereof, and the like. In some embodiments, R may independently occupy more than one substitution position (e.g., formula 10B).

Suitable analogues of cycloheptatrienes include

The negative hydrogen ion donors described herein may be synthetic or purchased from chemical suppliers. The following examples are provided for illustrative purposes only and are not intended to limit the present invention. DHPD and DHPD-type reducing agents can be synthesized by using switchable convertible acyl donor protocols with different 1,4 dihydropyridine amide forms (org. biomol. chem.2015,13, 185-198). Dimethyl 3, 5-dicarboxylate pyridine may be purchased from Sigma-Aldrich (st. louis, MO), or prepared by known methods (j.am. chem. soc.2000,122, 9014-9018). Formula 6A can be synthesized by a known protocol (Syn. Comm.1994,24, 3109-. P-methoxybenzo-benzimidazoline or p-tert-butylbenzoimidazoline can be obtained by known synthetic methods (syn. Comm.1983,13, 1033-. Formula 2F (org. Lett.2013,15,180-183) can be obtained by employing known synthetic methods.

Fuel composition

The organic negative hydrogen ion-based donors of the present disclosure can be used as additives in hydrocarbon fuels to prevent or reduce undesirable ignition events in internal combustion engines. When used in fuels, the appropriate concentration of additive necessary to achieve the desired LSPI reduction or efficacy depends on a variety of factors, including the type of fuel used, the presence of other detergents or dispersants or other additives, and the like. The concentration of the additive of the present invention in the hydrocarbon fuel may range from 25 to 5000 parts per million by weight (ppmw) (including, but not limited to, 50 to 4000ppm, 100 to 3500, 150 to 3000, 200 to 2500, 250 to 2000, 300 to 1500, 350 to 1000, etc.). If other negative hydrogen ion donors are present in the fuel composition, then minor amounts of additives may be used.

In some embodiments, the compounds of the present disclosure may be formulated into concentrates using inert stable lipophilic (i.e., soluble in hydrocarbon fuels) organic solvents that boil in the range of 65 ℃ to 205 ℃. Aliphatic or aromatic hydrocarbon solvents such as benzene, toluene, xylene or higher boiling aromatics or aromatic diluents may be used. Aliphatic alcohols having 2 to 8 carbon atoms, such as ethanol, isopropanol, methyl isobutyl carbinol, n-butanol, and the like, in combination with hydrocarbon solvents are also suitable for use with the additives of the present invention. The amount of additive in the concentrate may be in the range of 10 to 70 wt% (e.g., 20 to 40 wt%).

In gasoline or gasoline fuels, other well known additives may be used, including oxygenates (e.g., ethanol, methyl tertiary 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 may be used, such as pour point depressants, flow improvers, cetane number improvers, lubricity additives, and the like.

Fuel-soluble, non-volatile carrier fluids or oils may also be used with the compounds of the present disclosure. The carrier fluid is a chemically inert hydrocarbon-soluble liquid vehicle that significantly increases the non-volatile residue (NVR) or solvent-free liquid fraction of the fuel additive composition without causing an increase in octane requirement. The carrier fluid may be a natural or synthetic oil, such as mineral oil, refined petroleum, synthetic polyalkanes and alkenes, including hydrogenated and unhydrogenated polyalphaolefins, synthetic polyoxyalkylene derived oils, such as those described in U.S. patent nos.3,756,793; 4,191,537; and 5,004,478; and those described in european patent application publication nos.356,726 and 382,159.

The carrier fluid may be used in an amount of 35 to 5000ppm by weight of the hydrocarbon fuel (e.g., 50 to 3000ppm of the fuel). When used in a fuel concentrate, the carrier fluid may be present in an amount of 20 to 60 wt.% (e.g., 30 to 50 wt.%).

Lubricating oil composition

The organic negative hydrogen ion donors of the present disclosure can be used as additives in lubricating oils to prevent or reduce undesirable ignition events in internal combustion engines. When used in this manner, the concentration of the additive in the lubricating oil composition is typically from 0.001 to 10 wt.%, based on the total weight of the lubricating oil composition (including, but not limited to, 0.01 to 5 wt.%, 0.2 to 4 wt.%, 0.5 to 3 wt.%, 1 to 2 wt.%, etc.). If other negative hydrogen ion donors are present in the lubricating oil composition, then minor amounts of additives may be used.

The oils used as the base oils are selected or blended according to the desired end use and additives in the finished oil to provide the desired grade of engine oil, for example, a lubricating oil composition having an Society of Automotive Engineers (SAE) viscosity grade of 0W,0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W-20, 10W-30, 10W-40, 10W-50, 15W-20, 15W-30, or 15W-40.

Oils of lubricating viscosity (sometimes referred to as "base stocks" or "base oils") are the major liquid component of a lubricant, into which additives and possibly other oils are mixed, such as may be made into a finished lubricant (or lubricant composition). The base oils which may be used to prepare the concentrates and lubricating oil compositions therefrom may be selected from natural (vegetable, animal or mineral) and synthetic lubricating oils and mixtures thereof.

The definition of Base Oils and Base Oils in this disclosure is the same as that in American Petroleum Institute (API) publication 1509 annex E ("API Base Oil interchange Guidelines for Passenger Car Motor Oils and Diesel Engine Oils", 2016, 12 months). Using the test methods specified in table E-1, group I base stocks have a saturates content of less than 90% and/or a sulfur content of greater than 0.03% and a viscosity index of greater than or equal to 80 and less than 120. Using the test methods specified in Table E-1, the saturates in the group II base stocks were equal to or greater than 90% and the sulfur content was less than or equal to 0.03% and the viscosity index was greater than or equal to 80 and less than 120. Using the test methods specified in Table E-1, group III basestocks have greater than or equal to 90% saturates and less than or equal to 0.03% sulfur and a viscosity index greater than or equal to 120. Group IV basestocks are Polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in group I, II, III or IV.

Natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils. Animal and vegetable oils having good thermo-oxidative stability can be used. Among natural oils, mineral oils are preferred. The crude oil sources of mineral oils vary widely, for example, whether they are paraffinic, naphthenic or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful. Natural oils are also produced and purified by different methods, such as distillation range and whether straight run or cracked, hydrofinished or solvent extracted.

Synthetic oils include hydrocarbon oils. Hydrocarbon oils include oils such as polymerized and copolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alpha-olefin copolymers). Polyalphaolefin (PAO) oil basestocks are commonly used synthetic hydrocarbon oils. For example, derived from C₈To C₁₄Olefin PAOs, for example, may be C₈、C₁₀、C₁₂、C₁₄Olefins or mixtures thereof.

Other useful fluids for use as base oils include unconventional base stocks, which have been processed, preferably catalyzed or synthesized, to provide high performance characteristics.

Unconventional base oils/base stocks include one or more base oil blends derived from one or more gas-to-liquids (GTL) materials, as well as isomerate/isoparaffinic dewaxed base oils derived from natural waxes or waxy feeds, mineral waxes or non-mineral oil waxy feeds such as slack waxes, natural waxes, and waxy feeds such as gas oils, waxy fuel hydrocracked bottoms, waxy raffinate, hydrocracked oils, thermally cracked oils or other mineral, mineral oils, even non-petroleum derived waxy materials such as waxy materials obtained from coal liquefaction or shale oils, and mixtures of such base oils.

The base oils used in the lubricating oil compositions of the present disclosure are any of the various oils corresponding to API group I, group II, group III, group IV, and group V oils, and mixtures thereof, preferably API group II, group III, group IV, and group V oils, and mixtures thereof, and more preferably group III to group V base oils because of their excellent volatility, stability, viscosity, and cleanliness characteristics.

Typically, the base oil has a kinematic viscosity (ASTM D445) at 100 ℃ of from 2.5 to 20mm²S (e.g. 3 to 12 mm)²S, 4 to 10mm²S, or 4.5 to 8mm²/s)。

The lubricating oil compositions of the present invention may also contain conventional lubricant additives to impart ancillary functions to the finished lubricating oil composition in which these additives are dispersed or dissolved. For example, the lubricating oil composition may 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 compatibilisers, corrosion-inhibitors, dyes, extreme pressure agents and the like and mixtures thereof. Various additives are known and commercially available. These additives or their analogous compounds can be used in the preparation of the lubricating oil compositions of the present invention by conventional mixing methods.

When used, each of the foregoing additives is used in a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if the additive is an ashless dispersant, a functionally effective amount of such ashless dispersant will be an amount sufficient to impart the desired dispersancy properties to the lubricant. Generally, unless otherwise specified, the concentration of each of these additives may range from about 0.001 to about 20 weight percent, for example from about 0.01 to about 10 weight percent.

Examples

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

While LSPI can affect many types of internal combustion engines, it produces brake mean effective pressure levels greater than 1000kPa (10bar) at engine speeds of 1500 to 2500 revolutions per minute (rpm), such as at engine speeds of 1500 to 2000rpm, when operated in direct injection, supercharged (turbo-or turbo-charged), spark ignition (gasoline) internal combustion engines. Brake Mean Effective Pressure (BMEP) is defined as the work done during an engine cycle divided by the engine displacement, engine torque normalized by the engine displacement. The term "braking" refers to the actual torque or power on the engine flywheel measured on the dynamometer, and thus BMEP is a measure of the useful energy output of the engine.

It has now been found that the fuel composition or lubricating oil composition of the present disclosure can prevent or minimize the problem of pre-ignition in an internal combustion engine.

Examples 1 to 8

Test compounds were incorporated into gasoline or lubricating oil and their ability to reduce LSPI events was determined using the test method described below.

A general purpose automobile (GM)2.0L LHU 4-cylinder gasoline turbocharged direct injection engine was used for the LSPI test. Each cylinder is equipped with a combustion pressure sensor.

A six-stage test procedure was used to determine the number of LSPI events that occurred at engine speed of 2000rpm and load conditions of 275 Nm. The LSPI test conditions were run for 28 minutes and each segment was separated by an idle period. Each segment is slightly truncated (truncated) to eliminate transient portions. Each truncated segment typically has approximately 110000 combustion cycles (27500 combustion cycles/cylinder). In summary, the six truncated segments have approximately 660000 combustion cycles (165000 combustion cycles per cylinder).

The LSPI-affected combustion cycle is determined by monitoring the crank angle and peak cylinder pressure (PP) at 5% total heat release (AI 5). The combustion cycle affected by LSPI is defined as having (1) PP five standard deviations greater than the average PP for a given cylinder and cutoff, and (2) AI5 five standard deviations greater than the average for a given cylinder and cutoff.

The LSPI frequency is reported as the number of LSPI affected combustion cycles per million combustion cycles, and is calculated as follows:

LSPI frequency ═ [ (total number of LSPI-affected combustion cycles in six truncated segments)/(total number of combustion cycles in six truncated segments) ] × 1000000

Additives associated with test fuels and/or test lubricants having reduced LSPI frequencies are considered LSPI frequency mitigating additives when compared to corresponding reference fuels and/or reference lubricants. For the purposes of the tests herein, the reference fuel was a conventional 49 national premium unleaded gasoline fuel without any deposit control additives, and the reference lubricant represented a conventional engine oil meeting the ILSAC GF-5 and API SN specifications. The test results are shown in Table 1.

The examples summarize the results of testing various fuel or lubricating oil additives. For example, example 1 shows the results of DHPD as a fuel additive in the test fuel fluid at 1000 ppmw. The number of LSPI events observed when testing additive-containing fuels or lubricants is listed in the column entitled "LSPI activity", while the number of LSPI events observed when testing non-additive-containing fuels or lubricants is listed in the column entitled "reference". For the given example, the inclusion or omission of additives is the only difference between LSPI activity and the fuel or lubricant components tested in the reference column.

Claims

1. A fuel composition comprising (1) greater than 50 wt.% of a hydrocarbon fuel boiling in the gasoline or diesel range and (2) a minor amount of one or more organic negative hydrogen ion-based reducing agents.

2. The fuel composition of claim 1, wherein the organo-hydride based reductant is substantially free of halogen, boron or silicon.

3. The fuel composition of claim 1, wherein the organic negative hydrogen ion-based reducing agent is dihydropyridine, nicotinamide adenine dinucleotide, methylenetetrahydrobiopterin, acridine, triarylmethane, hexahydrotriazophorbine, triamine, arylbenzimidazoline, dioxolane, diether cyclohexadiene, cycloheptatriene, flavin adenine dinucleotide, or the like.

4. The fuel composition of claim 1, wherein the organic negative hydrogen ion-based reducing agent is present in an amount of 25 to 5000ppm by weight.

5. The fuel composition of claim 1, wherein the organic negative hydrogen ion-based reducing agent is present in an amount of 250 to 2000ppm by weight.

6. The fuel composition of claim 1, further comprising:

an oxygenate, an antiknock agent, a detergent, a dispersant, a friction modifier, an antioxidant, a metal deactivator, a demulsifier, a pour point depressant, a flow improver, a cetane number improver, or a lubricity additive.

7. A method of preventing or reducing undesired ignition events in an internal combustion engine, the method comprising:

supplying to the engine a fuel composition comprising (1) greater than 50 wt% of a hydrocarbon fuel boiling in the gasoline or diesel range and (2) a minor amount of one or more organic negative hydrogen ion based reducing agents.

8. The method of claim 7, wherein the internal combustion engine is spark ignited.

9. The method of claim 7, wherein the internal combustion engine operates at less than 3000 rpm.

10. The method according to claim 7, wherein the spark ignition type internal combustion engine is operated under a load at which a brake mean effective pressure is at least 1MPa (10 bar).

11. A lubricating oil composition comprising (1) greater than 50 wt.% base oil and (2) a minor amount of one or more organo-hydride based reducing agents.

12. The lubricating oil composition of claim 11, wherein the organo-hydride based reducing agent is substantially free of halogen, boron, or silicon.

13. The lubricating oil composition of claim 11, wherein the organic negative hydrogen ion-based reducing agent is dihydropyridine, nicotinamide adenine dinucleotide, methylenetetrahydrobiopterin, acridine, triarylmethane, hexahydrotriazophorphine, triamine, arylbenzimidazoline, dioxolane, diether cyclohexadiene, cycloheptatriene, flavin adenine dinucleotide, or an analog thereof.

14. The lubricating oil composition of claim 11, wherein the organo-hydride based reducing agent is present in an amount of 0.001 to 10 wt.%.

15. The lubricating oil composition of claim 11, wherein the organo-hydride based reducing agent is present in an amount of 0.5 to 5 wt.%.

16. The lubricating oil composition of claim 11, further comprising:

antioxidants, ashless dispersants, anti-wear agents, detergents, rust inhibitors, dehazing agents, demulsifying agents, friction modifiers, metal deactivators, pour point depressants, viscosity modifiers, antifoaming agents, co-solvents, package compatibilisers, corrosion-inhibitors, dyes or extreme pressure agents.

17. A method of preventing or reducing undesired ignition events in an internal combustion engine, the method comprising:

supplying to the engine a lubricating oil composition comprising (1) greater than 50 wt.% base oil and (2) a minor amount of one or more organic negative hydrogen ion-based reducing agents.

18. The method of claim 17, wherein the internal combustion engine is spark ignited.

19. The method of claim 17, wherein the internal combustion engine operates at less than 3000 rpm.

20. The method of claim 17, wherein the internal combustion engine is operated at a load with a brake mean effective pressure of at least 1MPa (10 bar).