Polyamide Fuel Additive

Abstract

A method for preventing or reducing corrosion or wear in a gasoline engine is provided, the method comprising the step of providing a fuel composition comprising the reaction product of a fatty acid and a polyamine.

Description

[Technical field]

[0001] The present disclosure relates to fuel additive compositions and fuel compositions. More specifically, the present disclosure relates to long chain aliphatic polyamide compounds that can inhibit corrosion and rust while providing antiwear and friction protection. [Background technology]

[0002] In recent years, great efforts have been made to improve the fuel economy of vehicles. In general, the presence of an effective lubricant, especially at the interface of moving parts that are subject to high friction and excessive wear, greatly improves the efficiency of automobile engines. Therefore, as one approach to improve fuel economy, lubricants and lubricant additives have been developed that reduce engine friction and thus reduce the energy required.

[0003] Some of these efforts have focused on friction modifiers, known as lubricant additives that can adsorb to or react with metal surfaces and form thin, low-shear strength films to reduce boundary friction.

[0004] Friction modifiers have been used in limited slip gear oils, automatic transmission fluids, slideway lubricants, and multi-purpose tractor fluids. In particular, friction modifiers have been added to automotive crankcase lubricants due to the desire for improved fuel economy. These friction modifiers generally work by forming a monolayer or reaction layer of physisorbed polar oil-soluble products that exhibit significantly lower friction than conventional antiwear or extreme pressure agents at temperatures where antiwear and extreme pressure agents do not yet react under boundary layer conditions. However, under more severe conditions or in mixed lubrication environments, these friction modifiers are added together with antiwear or extreme pressure agents.

[0005] The most common type of antiwear or extreme pressure agent is zinc dialkyldithiophosphate (ZnDTP or ZDDP). ZDDPs limit wear by forming a thick, protective tribofilm on the rubbing surfaces. ZDDPs have been widely used in automobiles for decades, but several recent studies have shown that phosphorus-based antiwear films can significantly increase thin-film friction in high-pressure lubricated contacts. This, in turn, can have a negative impact on fuel economy.

[0006] While reducing friction with lubricant additives is important, fuel additives can be used to further improve fuel economy. Because conditions in the internal combustion chamber are significantly different from those in the crankcase, a particular additive or type of additive that provides a performance benefit in a lubricant may not provide the same benefit in a fuel. Thus, there is a need to develop fuel additives that can reduce friction and / or improve fuel economy. [Brief description of the drawings]

[0007] [Figure 1] This will be explained in the Examples section. Summary of the Invention

[0008] In one embodiment, a method is provided for preventing or reducing corrosion or wear in a gasoline engine by providing a fuel composition comprising the reaction product of a fatty acid and a polyamine.

[0009] In another aspect, there is provided a method for preventing or reducing corrosion or wear in a gasoline engine while providing anti-wear or friction protection by providing a fuel composition comprising a fuel additive comprising the reaction product of a fatty acid and a polyamine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] overview In this specification, the following words and expressions, if used, have the meanings given below.

[0011] "Gasoline" or "gasoline boiling range components" means gasoline or gasoline-based fuels consisting of at least primarily C4-C 12 It refers to a composition that contains hydrocarbons. In one embodiment, the gasoline or gasoline boiling range components are at least primarily C4-C 12 It is further defined to mean a composition containing hydrocarbons and having a boiling range of about 37.8° C. (100° F.) to about 204° C. (400° F.). In another embodiment, the gasoline or gasoline boiling range components are at least primarily C4-C 12 It is defined to refer to a composition that contains hydrocarbons and has a boiling point range of about 37.8° C. (100° F.) to about 204° C. (400° F.), and is further defined as meeting ASTM D4814.

[0012] The term "diesel" refers at least primarily to 10 -C 25 In one embodiment, diesel refers to a middle distillate fuel containing at least primarily C 10 -C 25 Diesel is further defined as a composition that contains hydrocarbons and has a boiling point range of about 165.6° C. (330° F.) to about 371.1° C. (700° F.). In an alternative embodiment, diesel is a composition that is at least primarily composed of C 10 -C 25 It is defined above as referring to a composition that contains a hydrocarbon and has a boiling point range of about 165.6° C. (330° F.) to about 371.1° C. (700° F.), and is further defined as meeting ASTM D975.

[0013] The term "oil-soluble" means that the amount of a given additive required to impart a desired level of activity or performance can be incorporated by dissolving, dispersing, or suspending in an oil having lubricating viscosity. Typically, "oil-soluble" means that at least 0.001 wt. % of the additive can be incorporated into a lubricating oil composition. The term "fuel-soluble" is an analogy to an additive that is dissolved, dispersed, or suspended in a fuel.

[0014] "Minor amount" is a term expressed in relation to the total weight of the described additive and composition, and means less than 50% by weight of the composition considered as the active ingredient of the additive.

[0015] An "engine" or "combustion engine" is a heat engine in which the combustion of fuel takes place in a combustion chamber. An "internal combustion engine" is a heat engine in which the combustion of fuel takes place in a restricted space (the "combustion chamber"). A "spark ignition engine" is a heat engine in which the combustion is ignited by a spark, usually from a spark plug. This contrasts with a "compression ignition engine", typically a "diesel engine", in which the heat generated by compression together with the injection of the fuel is sufficient to initiate combustion without an external spark.

[0016] The present invention provides fuel additive compositions and fuel compositions having one or more performance benefits. In some embodiments, the compositions are effective in preventing or reducing corrosion or rust. In some embodiments, the compositions are effective in preventing or reducing wear or friction. In particular, friction may be reduced to improve fuel economy. In some embodiments, the compositions are multifunctional in that two or more benefits (e.g., reduced corrosion / rust and reduced wear / friction) are provided.

[0017] Generally, the fuel additive composition is the reaction product of a fatty acid and a polyamine to produce a long chain polyamide. Whereas conventional rust and / or wear inhibitors rely on organic acid based compositions, the polyamides of the present invention are non-acidic, minimizing interaction with potential contaminants in the refinery process that may cause deposit formation and increased filter plugging. Other advantages will become apparent from the disclosure herein.

[0018] fatty acid According to the present invention, the fuel additive is the product of an amidation reaction between a fatty acid and a polyamine. Any fatty acid compatible with the present invention may be used. Exemplary fatty acids have the following structure: [ka] wherein R is an organic moiety having about 5-40 carbon atoms, e.g., 8-35 carbon atoms, 10-30 carbon atoms, or 15-25 carbon atoms. In some embodiments, R includes one or more heteroatoms. Suitable fatty acids include saturated and unsaturated fatty acids. The fatty acid may also be a monocarboxylic acid or may have one or more acid moieties (e.g., a dicarboxylic acid).

[0019] In some embodiments, the fatty acid is an aliphatic fatty acid. Examples of saturated fatty acids include aliphatic fatty acids. The aliphatic group may be straight or branched.

[0020] Suitable fatty acids include, but are not limited to, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, 2-ethylbutyric acid, 3,3-dimethylbutyric acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylpentanoic acid, 2-propylpentanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid, 4-methyloctanoic acid, 4-methylnonanoic acid, isodecanoic acid, 2-butyloctanoic acid, isotridecanoic acid, 2-hexyldecanoic acid, isopalmitic acid, isostearic acid, 3-cyclohexylpropionic acid, 4-cyclohexylbutyric acid, and cyclohexanepentanoic acid.

[0021] Suitable unsaturated fatty acids include fatty acids containing double or triple carbon-carbon bonds. Representative unsaturated fatty acids include palmitoleic acid, myristoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, linoleic acid, linoelaidic acid, α-linoelaidic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, and docasahexaenoic acid.

[0022] Polyamines The polyamine preferably has at least 3 amine nitrogen atoms per molecule, more preferably 4 to 12 amine nitrogen atoms per molecule, and most preferably, the polyamine has about 6 to 10 nitrogen atoms per molecule.

[0023] Preferred polyalkene polyamines also contain from about 4 to 20 carbon atoms, preferably from 2 to 3 carbon atoms, per alkylene unit. The polyamines preferably have a carbon to nitrogen ratio of from 1:1 to 10:1.

[0024] Suitable polyamines include polyalkylenepolyamines. Such polyamines will typically contain from about 2 to about 12 nitrogen atoms and from about 2 to about 24 carbon atoms. Specific examples include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and heavy poly-alkylene-amines (HPA).

[0025] Other specific examples of polyamines include N,N'-bis-(2-aminoethyl)piperazine) (bisAEP), N-[(2-aminoethyl)2-aminoethyl]piperazine) (PEEDA), 1-(2-aminoethyl)-4-[(2-aminoethyl)amino]ethyl]-piperazine) (AEPEEDA), and 1-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine) (PEDETA).

[0026] Many of the polyamines suitable for use in the present invention are commercially available, and others can be prepared by methods well known in the art. For example, methods for preparing amines and their reactions are detailed in Sidgewick's "The Organic Chemistry of Nitrogen", Clarendon Press, Oxford, 1966; Noller's "Chemistry of Organic Compounds", Saunders, Philadelphia, 2nd Ed., 1957; and Kirk-Othmer's "Encyclopedia of Chemical Technology", 2nd Ed., especially Volume 2, pp. 99 116.

[0027] The polyamine reactant may be a single compound, but will typically be a mixture of compounds that reflects commercially available polyamines. Usually, commercially available polyamines will be a mixture of one or more compounds with predominantly the average composition shown. For example, tetraethylenepentamine prepared by polymerization of aziridine or reaction of dichloroethylene with ammonia will contain both lower and higher amine components, such as triethylenetetramine, substituted piperazines, and pentaethylenehexamine, but the composition will be predominantly tetraethylenepentamine, and the empirical formula of the overall amine composition will be very close to that of tetraethylenepentamine.

[0028] Other examples of suitable polyamines include mixtures of amines with various molecular weights, such as mixtures of diethylenetriamine and heavy polyamines. A preferred polyamine mixture is one that contains 20% by weight of diethylenetriamine and 80% by weight of heavy polyamine.

[0029] reaction The fuel additive of the present invention is a reaction product of a fatty acid and a polyamine. The reaction product is a polyamide or a fatty acid polyamide. The polyamide of the present invention is commercially available or may be synthesized by any known method.

[0030] As an illustrative example, the reaction of fatty acids with polyamines is described in U.S. Pat. No. 3,169,980, which is incorporated herein by reference. Here, polyamides are prepared by reacting fatty acids with polyamines at temperatures ranging from about 120° C. (248° F.) to about 260° C. (500° F.). The amidation reaction takes about 2 to 10 hours. The condensed water is then removed. To achieve amidation at lower reaction temperatures, reduced pressure may be required. The ratio of fatty acids to polyamines may be such that the moles of fatty acid are equal to the molar equivalents of amine groups in the polyamine.

[0031] A polyamide obtained from tetraethylenepentamine and a mixture of linear and branched fatty acids is described below. A reaction vessel is charged with a mixture of tetraethylenepentamine and silicone antifoaming agent. The mixture is blanketed with nitrogen gas and heated to about 120°C. A mixture of fatty acids is then introduced and the reaction temperature is increased to remove water. The temperature is increased again at atmospheric pressure for about 1 hour and then maintained under vacuum for about 7 hours.

[0032] fuel composition The compounds of the present disclosure may be useful as additives for hydrocarbon fuels in the boiling range of gasoline or diesel.

[0033] The concentration of the polyamide compounds of the present disclosure in the hydrocarbon fuel may range from 25 to 5000 parts per million (ppm) (eg, 50 to 1000 ppm) on a weight basis.

[0034] The compounds of the present disclosure may be formulated as concentrates using inert, stable, lipophilic (i.e., soluble in hydrocarbon fuels) organic solvents with boiling points ranging from 65°C to 205°C. Aliphatic or aromatic hydrocarbon solvents such as benzene, toluene, xylene, or higher boiling aromatic compounds or aromatic diluents may be used. Aliphatic alcohols containing 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 additive. The amount of additive in the concentrate may range from 10 to 70% by weight (e.g., 20 to 40% by weight).

[0035] In gasoline fuels, other well-known additives may be used, including oxygenates (e.g., ethanol, methyl tert-butyl ether), other anti-knock agents, and detergents and 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.

[0036] Other well-known additives may be used in diesel fuels, such as pour point depressants, flow improvers, cetane improvers, and the like.

[0037] Fuel-soluble non-volatile carrier fluids or oils may also be used with the compounds of the present disclosure. Carrier fluids are chemically inert, hydrocarbon-soluble liquid vehicles that somewhat aid in increasing octane requirements, but substantially increase the non-volatile residue (NVR) or solvent-free fluid fraction of the fuel additive composition. Carrier fluids may be natural or synthetic oils, such as mineral oils, refined petroleum oils, synthetic polyalkanes and alkenes, including hydrogenated and non-hydrogenated polyalphaolefins, synthetic polyoxyalkylene-derived oils, such as those described in U.S. Pat. Nos. 3,756,793; 4,191,537; and 5,004,478; and European Patent Publications Nos. 356,726 and 382,159.

[0038] Carrier fluids may be used in amounts ranging from 35 to 5000 ppm by weight of the hydrocarbon fuel (e.g., 50 to 3000 ppm of the fuel). When used in a fuel concentrate, the carrier fluid may be present in an amount ranging from 20 to 60% by weight (e.g., 30 to 50% by weight).

[0039] The following illustrative examples are intended to be non-limiting. EXAMPLES

[0040] The polyamide tested is the reaction product of isostearic acid and tetraethylenepentamine (TEPA). Initially, six samples were prepared and subjected to corrosion testing according to ASTM D665B. The samples contained various amounts of base fuel only (samples 1 and 2) or base fuel and polyamide (samples 3, 4, 5, and 6).

[0041] A summary of the samples tested and the corrosion results (ASTM D665B) are shown below in Table 1. A visual confirmation of the corrosion test is clearly shown in Figure 1. [Table 1]

[0042] Additional tests were performed to measure the frictional performance of the polyamides according to ASTM 6079. Sample 7 contains only base fuel. Samples 8, 9, 10, and 11 contain either Reference Formulation 1 or Reference Formulation 2 with various amounts of polyamide.

[0043] Table 2 summarizes the samples tested and the results (ASTM 6079). [Table 2] Reference Formulation 1 (BL1): Base fuel + fuel detergent mixture + 5% by volume of methyl tert-butyl ether Reference formulation 2 (BL2): Base fuel + fuel detergent mixture + E10

Claims

1. 1. Use of a fuel composition to prevent or reduce corrosion and wear in a gasoline engine while providing anti-wear or friction protection by supplying to the engine a fuel composition containing a fuel additive comprising a reaction product of a fatty acid and a polyamine.

2. 10. The use of the fuel composition of claim 1, wherein the fuel composition comprises a hydrocarbon fuel within the boiling range of gasoline or diesel.

3. The fatty acid is an aliphatic fatty acid having 2 to 30 carbon atoms, and optionally 2. The use of a fuel composition according to claim 1, wherein the aliphatic fatty acid is hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, 2-ethylbutyric acid, 3,3-dimethylbutyric acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylpentanoic acid, 2-propylpentanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid, 4-methyloctanoic acid, 4-methylnonanoic acid, isodecanoic acid, 2-butyloctanoic acid, isotridecanoic acid, 2-hexyldecanoic acid, isopalmitic acid, isostearic acid, 3-cyclohexylpropionic acid, 4-cyclohexylbutyric acid, or cyclohexanepentanoic acid.

4. 10. The use of the fuel composition of claim 1, wherein the polyamine has from about 2 to about 12 nitrogen atoms and from about 2 to about 24 carbon atoms.

5. 2. Use of the fuel composition of claim 1, wherein the polyamine is diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, a poly-alkylene-amine, N,N'-bis-(2-aminoethyl)piperazine), N-[(2-aminoethyl)2-aminoethyl]piperazine), 1-(2-aminoethyl)-4-[(2-aminoethyl)amino]ethyl]-piperazine), or 1-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine).

6. 1. Use of a fuel additive comprising a reaction product of a fatty acid and a polyamine in a fuel composition to prevent or reduce corrosion and wear while providing antiwear or friction protection in a gasoline engine provided by the fuel composition.

7. 7. The use of the fuel additive of claim 6, wherein the fuel composition comprises a hydrocarbon fuel within the boiling range of gasoline or diesel.

8. The fatty acid is an aliphatic fatty acid having 2 to 30 carbon atoms, and optionally 7. The use of a fuel additive according to claim 6, wherein the aliphatic fatty acid is hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, 2-ethylbutyric acid, 3,3-dimethylbutyric acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylpentanoic acid, 2-propylpentanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid, 4-methyloctanoic acid, 4-methylnonanoic acid, isodecanoic acid, 2-butyloctanoic acid, isotridecanoic acid, 2-hexyldecanoic acid, isopalmitic acid, isostearic acid, 3-cyclohexylpropionic acid, 4-cyclohexylbutyric acid, or cyclohexanepentanoic acid.

9. 7. The use of a fuel additive according to claim 6, wherein the polyamine has from about 2 to about 12 nitrogen atoms and from about 2 to about 24 carbon atoms.

10. 7. The use of a fuel additive according to claim 6, wherein the polyamine is diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, a poly-alkylene-amine, N,N'-bis-(2-aminoethyl)piperazine), N-[(2-aminoethyl)2-aminoethyl]piperazine), 1-(2-aminoethyl)-4-[(2-aminoethyl)amino]ethyl]-piperazine), or 1-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine).

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