EP1098953B1 - Fuel compositions containing propoxilate - Google Patents

Description

The present invention relates to new propoxylate-containing Fuel compositions and new additive concentrates.

Carburetors and intake systems of gasoline engines, but also injection systems for fuel metering in petrol and diesel engines are increasingly contaminated. The Impurities are caused by dust particles from the Air sucked in by the engine, unburned hydrocarbon residues from the combustion chamber and the ventilation gases led into the carburetor from the crankcase.

These residues shift the air-fuel ratio in the Idling and in the lower part load range, so that the mixture fatter and the combustion becomes incomplete. As a consequence of this the proportion of unburned or partially burned hydrocarbons increases in exhaust gas and gasoline consumption increases.

It is known that to avoid these disadvantages, fuel additives for keeping valves and carburetor or injection systems clean can be used (see e.g. M. Rossenbeck in catalysts, Surfactants, mineral oil additives, ed. J. Falbe, U. Hasserodt, P. 223, G. Thieme Verlag, Stuttgart 1978). Depending on the mode of action and preferred place of action of such detergent additives you two generations today. The first generation of additives could only prevent the formation of deposits in the intake system, but do not remove any existing deposits. The Second generation additives, on the other hand, can prevent deposits and eliminate (keep-clean and clean-up effect). This is particularly due to their excellent thermal stability Zones of higher temperature, such as particularly at the inlet valves, allows.

The molecular construction principle of these additives, which act as detergents the second generation is based on the combination of polar Structures with mostly higher molecular weight, non-polar or oleophilic Residues.

Products are typical representatives of the second generation of additives based on polyisobutene in the non-polar part of the molecule, such as in particular Polyisobutylamine type additives. Such detergents are based on polyisobutenes, according to two different Multi-stage synthesis process can be produced: The first process proceeds via chlorination of the polymeric base body, followed from a nucleophilic substitution of the polymeric base by amines or preferably ammonia. A disadvantage of this Process is the use of chlorine, which has the consequence that Products containing chlorine or chloride occur, which is not the case today is more desirable. In the second process, the polyisobutylamines starting from polyisobutene via hydroformylation and then reductive amination according to EP-A-0 244 616.

Detergent additives from a variety of chemical substance classes can generally come in combination with a Carrier oil for use. The carrier oils practice an additional one "Washing function", often support and promote the detergents in their effect and can reduce the needed Amount of detergent. Unfold certain detergents their effect only in combination with a carrier liquid. Viscous, high-boiling oils are usually used as carrier oils and in particular thermostable liquids are used. You overdraw the hot metal surface (e.g. the inlet valves) a thin film of liquid and thereby prevent or delay to a certain extent the formation or deposition of Decomposition products on the metal surfaces, but without the To be able to replace detergent additive component.

Suitable carrier oils for fuels for internal combustion engines are z. B. high-boiling, refined mineral oil fractions, but also synthetic liquids. Suitable mineral carrier oils are z. B. in the oil processing fractions.

Examples of suitable synthetic carrier oils are polyolefins, (Poly) esters, (poly) alkoxylates, and in particular aliphatic polyethers, aliphatic polyetheramines, alkylphenol-started polyethers and alkylphenol started polyetheramines.

Adducts of butylene oxide with alcohols are excellent Solubility in fuels, however, are comparatively expensive Products and butylene oxide must be proportionate are manufactured in a complex manner.

Inexpensive carrier oils can be in the form of adducts of propylene oxide of alcohols.

EP-A-0 704 519 describes propoxylates as a carrier oil component in combination with a high molecular amine and a hydrocarbon polymer.

EP-A-0 374 461 describes such propoxylates for use as a carrier oil in combination with esters from mono- or polycarboxylic acids and alcohols or polyols and amino or amido groups containing detergents. EP-A-0 374 461 expressly teaches (see p. 4, lines 29ff.) that the sole use of the therein described propoxylates only an insufficient reduction in Inlet valve deposits, namely from 80 to 220 mg leads per valve.

The known additive systems of the prior art, the carrier oils contain on propylene oxide, but still show not the optimal cleaning effect in the engine. Continue to prepare such adducts of propylene oxide with alcohols often cause problems their limited solubility in and due to fuels their lack of compatibility with other additives, so that segregation can occur. This effect occurs particularly come to light dramatically when additive concentrates - as such additive systems are usually marketed - formulated should.

The invention was therefore based on the object of novel fuel compositions for internal combustion engines with improved Provide properties. In particular, the new Fuel compositions at significantly reduced intake valve deposits to lead.

worin

n

für einen ganzzahligen Wert von 14 bis 18 steht und

R¹

für einen geradkettigen oder verzweigten C₈-C₁₈-Alkyl- oder C₈-C₁₈-Alkenylrest, vorzugsweise C₈-C₁₈-Alkyl steht.

Surprisingly, the object according to the invention was achieved by providing a fuel composition for fuel engines, comprising a main amount of a liquid hydrocarbon fuel and a cleaning component, in particular reducing intake valve deposits, of at least one propoxylate additive of the formula I.

wherein

n

stands for an integer value from 14 to 18 and

R ¹

represents a straight-chain or branched C ₈ -C ₁₈ alkyl or C ₈ -C ₁₈ alkenyl radical, preferably C ₈ -C ₁₈ alkyl.

The fuel compositions according to the invention have the surprising advantage that they have deposits in the area of Reduce intake valves significantly better than the corresponding ones shorter-chain or longer-chain propoxylates. This is particularly so surprising because so far assumed was that compounds of the type used only as carrier oils are useful for fuel compositions, carrier oils however, not a satisfactory intake system-cleaning per se Have an effect.

In order to bring about the effect shown according to the invention, the Propoxylates of formula I above in a proportion of about 50 to 5000 mg / kg fuel, preferably about 100 to 2500 mg / kg Fuel, especially about 300 to 1000 mg / kg of fuel used become.

i) wenigstens ein Propoxilat-Additiv, vorzugsweise Alkanolpropoxilat, obiger Formel I sowie

ii) wenigstens ein Detergensadditiv.

The above object according to the invention is also achieved by providing fuel compositions for internal combustion engines which contain a major amount of a liquid hydrocarbon fuel and a cleaning component of an additive combination which significantly reduces contaminants in the intake system, the additive combination comprising:

i) at least one propoxylate additive, preferably alkanol propoxylate, formula I above and

ii) at least one detergent additive.

The fuel compositions of the invention, which the have above-mentioned additive combination, also effect Surprisingly, significantly reduced intake valve deposits.

(a) Mono- oder Polyaminogruppen mit bis zu 6 Stickstoffatomen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat,

(b) Nitrogruppen, ggf. in Kombination mit Hydroxylgruppen,

(c) Hydroxylgruppen in Kombination mit Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat,

(d) Carboxylgruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen,

(e) Sulfonsäuregruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen,

(f) Polyoxy-C₂-C₄-alkylengruppierungen, die durch Hydroxylgruppen, Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat, oder durch Carbamatgruppen terminiert sind,

(g) Carbonsäureestergruppen,

(h) aus Bernsteinsäureanhydrid abgeleitete Gruppierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen und

(i) durch Mannich-Umsetzung von substituierten Phenolen mit Aldehyden und Mono- oder Polyaminen erzeugte Gruppierungen.

Examples of suitable detergent additives ii) are those which show detergent action or valve seat wear-inhibiting action and in particular those with at least one hydrophobic hydrocarbon radical with a number average molecular weight (M _N ) of 85 to 20,000 and at least one polar, preferably terminal grouping selected from

(a) mono- or polyamino groups with up to 6 nitrogen atoms, at least one nitrogen atom having basic properties,

(b) nitro groups, optionally in combination with hydroxyl groups,

(c) hydroxyl groups in combination with mono- or polyamino groups, where at least one nitrogen atom has basic properties,

(d) carboxyl groups or their alkali metal or alkaline earth metal salts,

(e) sulfonic acid groups or their alkali metal or alkaline earth metal salts,

(f) polyoxy-C ₂ -C ₄ -alkylene groupings which are terminated by hydroxyl groups, mono- or polyamino groups, where at least one nitrogen atom has basic properties, or are terminated by carbamate groups,

(g) carboxylic ester groups,

(h) Groups derived from succinic anhydride with hydroxyl and / or amino and / or amido and / or imido groups and

(i) Groups generated by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines.

The hydrophobic hydrocarbon radical preferably has a number average molecular weight (M _N ) of 113 to 10,000, in particular 300 to 5000. The typical hydrophobic hydrocarbon radical, in particular in connection with the polar groups (a), (c), (h) and (i), are the polypropenyl, polybutenyl and polyisobutenyl radicals, each with M _N = 300 to 5000, in particular 500 to 2500 everything from 750 to 2250.

Examples of additives containing mono- or polyamino groups (a) are preferably polyalkene mono- or polyalkene-polyamines based on polypropene or highly reactive (ie with predominantly terminal double bonds - mostly in the α- and β-position) or conventional (ie with predominantly central double bonds) Polybutene or polyisobutene with M _N = 300 to 5000. Such additives based on highly reactive polyisobutene, which from the polyisobutene, which can contain up to 20 wt .-% n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or Polyamines such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylene tetramine or tetraethylene pentamine can be produced, are known in particular from EP-A 244 616. If one starts from the production of the additives of polybutene or polyisobutene with predominantly central double bonds (mostly in the β and γ position), the production route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to form carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. The same amines as above for the reductive amination of the hydroformylated, highly reactive polyisobutene can be used here for the amination. Corresponding additives based on polypropene are described in particular in WO-A 94/24231.

R²

für einen geradkettigen oder verzweigten Polyalkylrest mit einem zahlenmittleren Molekulargewicht von etwa 500 bis 5000 steht.

Preferred examples of amine additives of this type are polyalkylamines of the formula II R ² -NH ₂ wherein

R ²

represents a straight-chain or branched polyalkyl radical with a number average molecular weight of about 500 to 5000.

Further preferred additives containing monoamino groups (a) are the hydrogenation products of the reaction products from polyisobutenes with an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen as they are are described in particular in WO-A 97/03946.

Further preferred additives containing monoamino groups (a) are that of polyisobutene epoxides by reaction with amines and subsequent ones Dehydration and reduction of the amino alcohols available Compounds as described in particular in DE-A 196 20 262 are.

Nitro groups, optionally in combination with hydroxyl groups, containing (b) Additives are preferably reaction products made from polyisobutenes the average degree of polymerization P = 5 to 100 or 10 to 100 with nitrogen oxides or mixtures of nitrogen oxides and Oxygen, as described in particular in WO-A 96/03367 and WO-A 96/03479 are described. These implementation products provide usually mixtures of pure nitropolyisobutanes (e.g. α, β-dinitropolyisobutane) and mixed hydroxynitropolyisobutanes (e.g. α-nitro-β-hydroxypolyisobutane).

Additives containing hydroxyl groups in combination with mono- or polyamino groups (c) are, in particular, reaction products of polyisobutene epoxides, obtainable from polyisobutene preferably having predominantly double bonds with M _N = 300 to 5000, with ammonia, mono- or polyamines, as described in particular in EP-A -0 476 485 are described.

Additives containing carboxyl groups or their alkali metal or alkaline earth metal salts (d) are preferably copolymers of C ₂ -C ₄₀ olefins with maleic anhydride with a total molar mass of 500 to 20,000, the carboxyl groups of which are wholly or partly to the alkali metal or alkaline earth metal salts and a remaining one The rest of the carboxyl groups are reacted with alcohols or amines. Such additives are known in particular from EP-A-0 307 815. Such additives mainly serve to prevent valve seat wear and, as described in WO-A 87/01126, can advantageously be used in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Sulphonic acid groups or their alkali metal or alkaline earth metal salts Additives containing (e) are preferably alkali metal or Alkaline earth metal salts of an alkyl sulfosuccinate, as described in particular in EP-A-0 639 632. such Additives are mainly used to prevent valve seat wear and can be advantageous in combination with usual Fuel detergents such as poly (iso) butenamines or polyether amines be used.

Polyoxy-C ₂ -C ₄ -alkylene (f) additives are preferably polyethers or polyetheramines which are obtainable by reaction of C ₂ - to C ₆₀ alkanols, C ₆ - to C ₃₀ alkanediols, mono- or di-C ₂ - C ₃₀ alkyl amines, C ₁ -C ₃₀ alkylcyclohexanols or C ₁ -C ₃₀ alkyl phenols with 1 to 30 mol ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of the polyether amines, by subsequent reductive amination with Ammonia, monoamines or polyamines are available. Such products are described in particular in EP-A-0 310 875, EP-A-0 356 725, EP-A-0 700 985 and US-A-4,877,416. In the case of polyethers, such products also have carrier oil properties. Typical examples of this are tridecanol or isotridecanol butoxylates, isononylphenol butoxylates and polyisobutenol butoxylates and propoxylates as well as the corresponding reaction products with ammonia.

Additives containing carboxylic acid ester groups (g) are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, in particular those with a minimum viscosity of 2 mm ² / s at 100 ° C., as described in particular in DE-A-38 38 918 are described. Aliphatic or aromatic acids can be used as mono-, di- or tricarboxylic acids, and long-chain representatives with, for example, 6 to 24 carbon atoms are particularly suitable as ester alcohols or polyols. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of iso-octanol, iso-nonanol, iso-decanol and iso-tridecanol. Such products also have carrier oil properties.

Groups derived from succinic anhydride and containing hydroxyl and / or amino and / or amido and / or imido groups (h) are preferably corresponding derivatives of polyisobutenylsuccinic anhydride, which are obtained by reacting conventional or highly reactive polyisobutene with M _N = 300 to 5000 with maleic anhydride on thermal Ways or through which chlorinated polyisobutene are available. Derivatives with aliphatic polyamines such as ethylene diamine, diethylene triamine, triethylene tetramine or tetraethylene pentamine are of particular interest. Such gasoline fuel additives are described in particular in US-A-4,849,572.

Additives containing groups (i) produced by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols can be derived from conventional or highly reactive polyisobutene with M _N = 300 to 5000. Such "polyisobutene Mannich bases" are described in particular in EP-A-0 831 141.

For a more precise definition of the individual additives listed here on the revelations of the above-mentioned documents of the state expressly referred to the technology.

In the fuel compositions described above, the second embodiment is the additives i) and the additives ii) such as B. of formula II, in a total proportion of together about 100 to 10,000 mg / kg, preferably about 300 to 5000 mg / kg, especially about 500 to 3000 mg / kg, contain fuel. there are the additives i) and ii), in particular of the formula I and of formula II in a molar ratio in the range of about 1:10 to 10: 1, such as B. approximately in the range from 1: 5 to approximately 5: 1, in particular in the range from about 1: 2 to 2: 1.

C ₈ -C ₁₈ alkyl radicals suitable according to the invention in additives of the formula I are straight-chain or branched, saturated carbon chains with 8 to 18 carbon atoms. For example, the following radicals can be mentioned: n-hexyl, 1-, 2- or 3-methylpentyl, unbranched heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl and the one - or multiply branched analogues thereof. Preferred long-chain radicals are branched or unbranched C ₁₀ -C ₁₆ -, in particular C ₁₂ -C ₁₄ alkyl. Tridecyl residues are particularly preferred.

C ₈ -C ₁₈ alkenyl residues suitable according to the invention in additives of the formula I are straight-chain or branched carbon chains with at least one carbon-carbon double bond and with 8 to 18 carbon atoms. Examples of monounsaturated C ₈ -C ₁₈ alkenyl radicals which can be mentioned are radicals such as unbranched octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, pentadecenyl, hexadecenyl, heptadecenyl and octadecenyl, and the branched analogues thereof, the double bond in any one Position can occur. According to the invention, both the cis and the trans isomers of the above C ₈ -C ₁₈ alkenyl radicals are included. Preferred monounsaturated long-chain radicals are the C ₁₀ -C ₁₆ alkenyl radicals.

Polyalkyl radicals suitable according to the invention in additives of the formula II are preferably obtainable by homo- or copolymerization of straight-chain or branched C ₂ -C ₃₀ -alkenes, C ₂ -C ₆ -alkenes and in particular C ₂ -C ₄ -alkenes being preferred. Particularly preferred C ₂ -C ₄ alkenes are 1-alkenes, such as propylene, 1-butene and isobutene. The number average molecular weight of such polyalkyl radicals is approximately in the range from 500 to 5000, preferably approximately 800 to 1500, in particular approximately 1000. For example, the polyalkyl radical can be derived from a copolymer of 1-butene and isobutene and z. B. have a number average molecular weight of about 800 to about 1500.

Propoxylates of the formula I which are particularly preferred according to the invention are compounds in which R ^{1 represents} straight-chain or branched alkyl radicals having 10 to 16 carbon atoms, or mixtures thereof. Propoxylates of the formula I in which the radical R ^{1 is} an alkyl radical having 12 to 14 carbon atoms or a mixture of such alkyl radicals are particularly preferred. A propoxylate of the formula I in which the radical R ^{1 has} 13 carbon atoms is particularly preferred.

aufgebaut. Die am meisten bevorzugte Klasse von Propoxilaten umfasst 15 wiederkehrende Propoxilateinheiten. Dabei ist zu berücksichtigen, dass obige Zahlenangaben für n auch Mittelwerte darstellen können, da viele der bekannten Herstellungsmethoden für derartige Addukte von Alkylenoxiden an Alkohole üblicherweise zu einem Produktgemisch mit unterschiedlicher Molekulargewichtsverteilung führen.Another group of propoxylates preferred according to the invention consists of 14 to 18 repeating units of the formula, in particular 14 to 17 and especially 14 to 16 repeating units

built up. The most preferred class of propoxylates includes 15 repeating propoxylate units. It should be taken into account that the above numerical values for n can also represent mean values, since many of the known production methods for such adducts of alkylene oxides with alcohols usually lead to a product mixture with a different molecular weight distribution.

Most preferred alkoxylates of the formula I according to the invention are adducts of 14 to 16, in particular 15 propylene oxide units of the above formula, with a branched C ₁₃ alcohol, in particular C ₁₃ monoalcohol. Branched C ₁₃ alcohols which can be used according to the invention are, for. B. also obtainable by oligomerization of C ₂ -C ₆ olefins, in particular C ₃ - or C ₄ -olefins, and subsequent hydroformylation. An optionally occurring reaction mixture, the z. B. could include various alcohol isomers, can be used directly for the preparation of the additive components used according to the invention. A previous separation of the reaction mixture can, however, also be carried out if necessary.

The alkanol propoxylates preferably used according to the invention are made in a conventional manner by using an alcohol as a starter molecule with propylene oxide in the presence of alkali, such as B. sodium hydroxide solution, potassium hydroxide solution, sodium methylate, potassium methylate or other alkali alkoxides, at temperatures in the range of about 120 to 160 ° C, preferably about 130 to 160 ° C, to the desired ones Adducts implemented. After the alkoxylation has ended Propoxylate, for example by treatment with magnesium silicate, freed from the catalyst. The production takes place in analogy to the phenol started described in DE-A-41 42 241 Alkoxylates.

The polyalkylamines of the general formula II are compounds known per se and can be prepared by hydroformylation of reactive polyalkenes and subsequent reductive amination of the oxo product. The reactive polyalkenes with an average molecular weight of about 500 to 5000 are homo- or copolymers of straight-chain or branched C ₂ -C ₃₀ -alkenes, preferably C ₂ -C ₆ -alkenes, in particular C ₂ -C ₄ -alkenes. Reactive polyalkenes comprise unsaturated polymers of high chemical homogeneity, with more than 10% of the double bonds being alpha-permanent. One way of producing reactive polyalkenes is disclosed in DE-A-27 02 604. Those reactive polyalkenes which are produced from 1-alkenes, such as in particular propylene, 1-butene, isobutene or mixtures thereof, are particularly preferred.

Also suitable as polyalkylamines of the general formula II are amines according to EP-A-0 244 616 and EP-A-0 695 338, the content of which is hereby incorporated by reference. EP-A-0 244 616 describes in particular those polyalklamines in which the radical R ^{2 is} derived from isobutene and up to 20% by weight of n-butene. EP-A-0 695 338 describes in particular those polyalkylamines in which the radical R ^{2 is} derived from one or more 1-n-alkenes having 3 to 6 carbon atoms and up to 50% by weight of ethene.

Fuel compositions according to the invention include both diesel fuels as well as fuels for gasoline engines. As fuels leaded and especially unleaded come for gasoline engines Regular and super gasoline into consideration. The gasoline can components other than hydrocarbons, e.g. B. alcohols, such as methanol, ethanol, tert-butanol, and ether, e.g. B. methyl tertiary butyl ether, contain. In addition to the additives above Formula I and optionally II can the invention Fuel compositions contain other additive components.

Further additives which can be used according to the invention are, for example described in European patent applications EP-A-0 277 345, 0 356 725, 0 476 485, 0 484 736, 0 539 821, 0 543 225, 0 548 617, 0 561 214, 0 567 810 and 0 568 873; in the German patent applications DE-A-39 42 860, 43 09 074, 43 09 271, 43 13 088, 44 12 489, 44 25 834, 195 25 938, 196 06 845, 196 06 846, 196 15 404, 196 06 844, 196 16 569, 196 18 270 and 196 14 349; as well as in the WO-A-96 / 03,479th

Particularly useful liquid detergent additives are sold by BASF AG, Ludwigshafen, under the trade name Kerocom®PIBA. These contain polyisobutenamines dissolved in aliphatic C _10-14 hydrocarbons.

In addition to the above additives, there may be other common fuel additives included, such as Corrosion inhibitors, demulsifiers, Stabilizers, antioxidants, antistatic agents, metallocenes, such as ferrocene or methylcyclopentadiene-manganese tricarbonyl, Lubricity improvers and dyes (markers).

Corrosion inhibitors are mostly ammonium salts of organic carboxylic acids, by the corresponding structure of the starting compounds tend to form films. Also amines for lowering the pH are often found in corrosion inhibitors or can be added to the fuel as such. As non-ferrous metal corrosion protection heterocyclic aromatics are mostly used.

Amines in particular are antioxidants or stabilizers such as para-phenylenediamine, dicyclohexylamine, morpholine or derivatives to call these amines. Phenolic antioxidants such as 2,4-di-tert-butylphenol or 3,5-di-tert-butyl-4-hydroxiphenylpropionic acid and their derivatives are added to fuels.

Salts of fatty and sulfonic acids are usually found as demulsifiers Use.

Examples of lubricity improvers are certain carboxylic acids or fatty acids, alkenyl succinic acid esters, Bis (hydroxyalkyl) fatty amines; Hydroxyacetamide or castor oil. Suitable lubricity additives are e.g. B. described in EP-A-0 780 460, 0 829 527, 0 869 163, 0 605 857, WO 97/45507, 98/30658 and in US-A-5,756,435 and 5,505,867, which hereafter each explicit reference is made. The carboxylic acids mentioned or fatty acids can be used as monomers and / or dimeric species available.

Carrier oils may also be added, where appropriate the carrier oils differ from the compounds of the formula I.

As examples of usable carrier oils or carrier liquids mineral carrier oils, synthetic carrier oils and Mixtures thereof with the above additive (s) and Are fuel compatible. Suitable mineral carrier oils are fractions, such as kerosene, that occur during oil processing or naphtha, brightstock or mineral oils with viscosity in the range SN 500 - 900; but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols.

Examples of suitable synthetic carrier oils are polyolefins, (poly) esters, (poly) alkoxylates, and in particular aliphatic polyethers, aliphatic polyetheramines, alkylphenol-started polyethers and alkylphenol-started polyetheramines. Suitable carrier oil systems are described, for example, in DE-A-38 38 918, DE-A-38 26 608, DE-A-41 42 241, DE-A-43 09 074, US-A-4,877,416 and EP-A-0 452 328. Examples of particularly suitable synthetic carrier oils are alcohol-initiated polyethers having about 20 to 25 C ₃ -C ₆ alkylene oxide units, such as, for example, selected from propylene oxide, n-butylene oxide and i-butylene oxide units or mixtures thereof.

As examples of suitable additive combinations for fuels Combinations of at least one propoxylate are to be mentioned Formula I above, at least one detergent additive, such as. B. according to formula II above, according to at least one lubricity additive The above definition and / or at least one corrosion inhibitor if necessary as defined above.

Another object of the present invention relates Fuel additive mixtures, which are preferably in the form of additive concentrates and as an inlet valve cleaner component at least one propoxylate additive of the formula I as defined above, in particular an alkanol propoxylate of the formula I above, if appropriate in combination with at least one polyalkylamine of formula II as defined above and optionally at least contain another remaining fuel additive. According to one preferred embodiment contain the invention Fuel additive mixtures propoxylate and polyalkylamine in one indicated above for the fuel compositions according to the invention molar ratio.

Another object of the present invention relates to Use of at least one propoxylate of the above general Formula I optionally in combination with at least one detergent additive as defined above, in particular a polyalkylamine General Formula II above, as an intake valve cleaner additive for fuel compositions for internal combustion engines.

The present invention will now be illustrated by the following examples explained in more detail.

Examples Example 1: Engine test to test the effect as an intake system cleaner

The engine tests were carried out in an Opel Kadett 1.2 l engine according to CEC F / 04 / A / 87 performed. Fuel used: Euro-Super unleaded.

The additives used were according to the following general rule manufactured.

A dewatered mixture of the alcohol and KOH used as starter is placed in a pressure vessel, the amount of KOH used being about 0.01 to 1% by weight, preferably 0.05 to 0.5% by weight, of expected total weight of the reaction product is. The apparatus is then flushed several times with nitrogen, heated to approximately 135 ° C. and the propylene oxide is then metered in with stirring at a constant temperature and a pressure between 3 and 30 bar via an immersion tube or onto the surface. After the metering has ended, the reaction mixture is stirred until the pressure is constant. After the reactor contents have cooled to about 50 ° C., the reaction vessel is let down and flushed with nitrogen. The product is freed from volatile constituents, advantageously in vacuo, and possibly clarified by filtration. Before the filtration, removal of the catalyst by means of methods known to the person skilled in the art, such as, for B. treatment with ion exchanger, precipitation or adsorption, etc. carried out. additive Dosage [mg / kg] Intake valve deposits [mg] valves 1 2 3 4 Tridecanol x 10 propylene oxide 400 13
(277) 2
(175) 11
(183) 58
(337) Tridecanol x 15 propylene oxide 400 4
(277) 0
(175) 1
(183) 0
(337) Tridecanol x 20 propylene oxide 400 17
(277) 0
(175) 0
(183) 22
(337) Tridecanol x 25 propylene oxide 400 144
(514) 34
(303) 305
(300) 41
(519) Tridecanol x 30 propylene oxide 400 160
(514) 2
(303) 28
(300) 86
(519)

Example 2: Interaction of tridecanol propoxylate and polyisobutenamine

The following test results (engine: Mercedes Benz M 102 E) show that a maximum effect is also achieved with a tridecanol propoxylate with 15 moles of propylene oxide. In a fuel additive package containing polyisobutenamine (PIBA content 25% by weight), the carrier oil component was varied in the manner indicated. additive dosage [Mg / kg] Intake valve deposits [mg] valves 1 2 3 4 basic value - 283 132 232 290 Tridecanol x 15 propylene oxide 500 7 10 89 19 Tridecanol x 25 propylene oxide 500 59 97 39 40

Example 3: Compatibility study

The following test results show that a tridecanol propoxylate with 15 moles of propylene oxide optimal compatibility with the Components of an additive package (concentrate).

In a fuel additive package containing polyisobutenamine the carrier oil component by the tridecanol propoxylate according to the invention with 15 moles of propylene oxide or a corresponding one propoxilate not according to the invention replaced with 25 moles of propylene oxide. The formulation with the component according to the invention was homogeneous, while in the comparison formulation when left standing phase separation occurred at 20 ° C.

Claims (14)

1. A fuel composition for internal combustion engines, containing a principal amount of a liquid hydrocarbon fuel, comprising an amount, which has an intake system cleaning effect, of at least one propoxylate additive of the formula I

   

   where

   n

   is an integer from 14 to 18 and

   R¹

   is straight-chain or branched C₈-C₁₈-alkyl or C₈-C₁₈-alkenyl.

2. A fuel composition as claimed in claim 1, which contains the propoxylate of the formula I in an amount of from 50 to 5000 mg/kg of fuel.
3. A fuel composition for internal combustion engines, containing a principal amount of a liquid hydrocarbon fuel, comprising an amount, which has an intake system cleaning effect, of an additive combination comprising

   i) at least one propoxylate additive of the formula I as claimed in claim 1; and

   ii) at least one detergent additive which is selected from polyalkylamine additives of the formula II; R²-NH₂

   where
   R² is a straight-chain or branched polyalkyl radical having a number average molecular weight of from about 500 to about 5000
   if required, in combination with at least one lubricity additive.
4. A fuel composition as claimed in claim 3, which contains the additives i) and ii) in a total amount of from 100 to 10,000 mg/kg of fuel.
5. A fuel composition as claimed in either of claims 3 and 4, which contains the additives i) and ii) in a molar ratio of from 1:10 to 10:1.
6. A fuel composition as claimed in either of claims 4 and 5, comprising at least one polyalkylamine additive of the formula II, where R² is a radical derived from identical or different C₂-C₃₀-alkenes.
7. A fuel composition as claimed in any of claims 4 to 6, which contains, as an additive of the formula II, at least one polyisobutenamine having a number average molecular weight of from 800 to 1500.
8. A fuel composition as claimed in any of the preceding claims, which comprises at least one additive of the formula I, where n is the integer of 15 and R¹ is straight-chain or branched C₁₃-alkyl.
9. A fuel additive mixture which contains, as intake system cleaner component, at least one propoxylate according to the definition in claim 1, if required in combination with at least one detergent additive and, if required, together with further conventional fuel additives.
10. A fuel additive mixture as claimed in claim 9, which contains propoxylate and polyalkylamine in a molar ratio of from about 1:10 to 10:1.
11. A fuel additive mixture as claimed in claim 9 or 10, which contains as a further additive component at least one lubricity additive.
12. A fuel additive mixture as claimed in any of claims 9 to 11 formulated as an additive concentrate.
13. The use of at least one propoxylate according to the formula I

    

    where

    n

    is an integer from 14 to 18 and

    R¹

    is straight-chain or branched C₈-C₁₈-alkyl or c₈-C₁₈-alkenyl;

    as an intake system cleaner additive for fuel compositions for internal combustion engines.
14. The use as claimed in claim 13, in combination with at least one detergent additive.