EP1278814B1 - Fuel additive compositions for fuels for internal combustion engines with improved viscosity properties and good ivd performance - Google Patents

Description

The invention relates to gasoline fuel additive compositions and additives for these fuels for gasoline engines, wherein the gasoline additive packages according to the invention in addition to a very good performance in the intake system purity improved viscosity properties, especially at low temperatures have.

Carburettors and intake systems of gasoline engines, but also injection systems for fuel metering are increasingly burdened by impurities caused by dust particles from the air, unburned hydrocarbon residues from the combustion chamber and the guided into the carburetor crankcase vent gases.

These residues shift the air-fuel ratio at idle and in the lower part-load range, so that the mixture leaner, the incomplete combustion and turn the proportions of unburned or partially combusted hydrocarbons in the exhaust gas and gasoline consumption increases.

It is known that in order to avoid these disadvantages, fuel additives are used for keeping valves and carburetors or injection systems of gasoline engines clean (cf., for example: M. Rossenbeck in Catalysts, Surfactants, Mineral Oil Additives, eds. J. Falbe, U. Hasserodt, S. 223, G. Thieme Verlag, Stuttgart 1978).

Depending on the mode of action, but also the preferred site of action of such detergent additives today distinguishes two generations.

The first additive generation could only prevent the formation of deposits in the intake system, but not remove already existing deposits, whereas the modern additives of the second generation can cause both (keep-clean and clean-up effect) and especially because of their excellent thermal stability at higher temperature zones, namely at the inlet valves. Such detergents which can come from a variety of chemical classes of substances, such as polyalkeneamines, polyetheramines, polybutene Mannich bases or Polybutensuccinimide, are generally used in combination with carrier oils and sometimes other additive components, such as corrosion inhibitors and demulsifiers, for use. The carrier oils perform a solvent or wash function in combination with the detergents. Carrier oils are typically high boiling, viscous, thermostable liquids which coat the hot metal surface thereby preventing the build-up of impurities on the metal surface.

• a) mineralölbasierend (d.h. es werden nur mineralölbasierende (mineralische) Trägeröle verwendet),
• b) vollsynthetisch (d.h. es werden nur synthetische Trägeröle verwendet) oder in untergeordnetem eingesetzten Maße
• c) semisynthetisch (d.h. es werden Mischungen aus mineralölbasierenden und synthetischen Trägerölen verwendet).

Such formulations of detergents with carrier oils can in principle be classified as follows (depending on the nature of the carrier oil (carrier oil):

• a) Mineral oil-based (ie only mineral oil-based (mineral) carrier oils are used),
• b) fully synthetic (ie only synthetic carrier oils are used) or in subordinate dimensions
• c) semi-synthetic (ie mixtures of mineral oil-based and synthetic carrier oils are used).

It is known from the prior art that such described additive formulations are used in gasoline fuels. It is generally true that fully synthetic additive packages have better retention properties than mineral oil-based. Furthermore, it is generally the case that such fully synthetic additive packages have lower viscosities, especially at lower temperatures, than mineral oil-based formulations. Thus, fully synthetic detergent additive packages so far have significant advantages, since they can be better handled and processed in addition to good einlaßsystemreinhaltenden properties, especially at lower temperatures.

In the classes of purely mineral oil-based and semisynthetic formulations there is a need for optimization compared to the above-mentioned fully synthetic additive packages.

It was therefore an object to provide semisynthetic fuel additive packages for gasoline fuels, which are characterized both by improved viscosity properties and by very good clean-up effects in the intake system.

It has now been found according to the invention that can be provided by the production of defined mixtures of mineral oil-based and synthetic carrier oils in combination with detergent additives formulations for gasoline fuels, both very good properties with respect to the intake system as well as with respect to their low-temperature viscosity.

Surprisingly, such semisynthetic additive formulations according to the invention showed that on the one hand they ensure very good performance with regard to their purity-retaining properties and, moreover, they are distinguished by surprisingly significantly lower viscosities at lower temperatures. Lower viscosities of additive formulations, in turn, provide advantages in processing since less solvent must be used to set the desired viscosity.

A first aspect of the invention therefore relates to fuel additive compositions according to claim 1.

Preferred fuel additive compositions are those whose mineral carrier oil component has a viscosity of 350 to a maximum of 410 mm ² / s, determined at + 20 ° C. according to DIN 51562, part 1.

Further preferred fuel additive compositions according to the invention are those whose synthetic carrier oil component (polyether) has a viscosity of 140 to 240 mm ² / s, determined at + 20 ° C. according to DIN 51562, part 1.

Particularly preferred fuel additive compositions contain mineral carrier oil component and synthetic carrier oil component in a weight ratio of 10: 1 to 1:10, especially 5: 1 to 1: 5, preferably 4: 1 to 1: 4.

The weight ratio of detergent additive component to carrier oil component (sum of mineral and synthetic carrier oil) is in the range from 1:20 to 20: 1, in particular 1:10 to 10: 1, preferably 1: 5 to 5: 1 or 2: 3 to 4: 1.

• a) 10 bis 80 Gew.-%, beispielsweise 40 bis 80 Gew.-%, Detergensadditiv(e);
• b) 20 bis 90 Gew.-%, beispielsweise 20 bis 60 Gew.-% Trägerölgemisch; und
• c) gegebenenfalls 0 bis 30 Gew.-%, beispielsweise 1 bis 20 Gew.-%, weiterer üblicher Kraftstoffadditivkomponenten

enthält.For example, useful fuel additive compositions are included

• a) 10 to 80 wt .-%, for example 40 to 80 wt .-%, detergent additive (s);
• b) from 20 to 90% by weight, for example from 20 to 60% by weight of carrier oil mixture; and
• c) optionally 0 to 30 wt .-%, for example 1 to 20 wt .-%, of other conventional fuel additive components

contains.

Fuel additive compositions preferred according to the invention comprise as detergent additive component (component a) a detergent additive selected from polyalkene mono- and polyamines, polyetheramines and mixtures thereof. Examples of useful polyetheramines are poly-C ₂ -C ₆ -alkylenoxideamines, and examples of polyalkeneamines are poly-C ₂ -C ₆ -alkeneamines, and functional derivatives thereof, each having a preferred Mn of 150 to 5000, preferably 500 to 2000, in particular 700 to 1500 g. "Amines" in this context include both mono- and polyamines, preferably having up to 6 nitrogen atoms.

Useful polyalkene mono- or polyalkene polyamines or functional derivatives thereof according to the invention are in particular poly-C ₂ -C ₆ -alkeneamines or functional derivatives thereof, for example based on polypropene, polybutene or polyisobutene.

Examples of functional derivatives of the above additives are compounds which, for example in the amine part, carry one or more polar substituents, in particular hydroxyl groups.

Preferred additives which can be used according to the invention are polyalkene mono- or polyalkene polyamines based on polypropene or of highly reactive (ie predominantly terminal double bonds - usually in the alpha and beta positions) or conventional (ie predominantly intermediate double bonds) polybutene or polyisobutene having Mn = 150 to 5000, preferably 500 to 2000, in particular 800 to 1500 g.

Such additives based on highly reactive polyisobutene, which of polyisobutene, which may contain up to 20 wt .-% of n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or Tetraethylenepentamine, are particularly known from EP-A-244 616 or EP-A-0 578 323.

If one starts with the preparation of the additives of polybutene or polyisobutene with predominantly central double bonds (usually in the beta and gamma position), the preparation route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. For amination, the same amines as described above can be used for the reductive amination of the hydroformylated highly reactive polyisobutene. Corresponding additives based on polypropene are described in particular in WO-A-94/24231.

Further preferred monoamine-containing polyalkene amine additives are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular in WO-A-97/03946.

Further preferred monoamino-containing additives are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described in particular in DE-A 196 20 262.

Particularly useful polyalkenamine-type detergent additives are sold by BASF AG, Ludwigshafen under the tradename Kerocom PIBA. These contain polyisobuteneamines dissolved in aliphatic C ₁₀ -C ₁₄ hydrocarbons and can be used as such in the additive packages according to the invention.

Examples of useful carrier oils or carrier oil liquids (component b) include combinations of mineral carrier oil (s) and synthetic carrier oil (s) which are compatible with the additive (s) used and the fuel.

Suitable mineral carrier oils, which fulfill the above viscosity criterion according to the invention, are fractions obtained in petroleum processing, such as bright stock or base oils with viscosities such as, for example, from the class SN 500-2000; but also aromatic hydrocarbons and paraffinic hydrocarbons Also useful is one known as "hydrocrack oil" and in refining mineral oil fraction (vacuum distillate section having a boiling range of 360 to 500 ° C, available from high pressure catalytically hydrogenated and isomerized and deparaffinized natural mineral oil). Also suitable are mixtures of the abovementioned mineral carrier oils.

Synthetic carrier oils which can be used according to the invention and which meet the above viscosity criterion according to the invention are selected from polyethers.

Examples of suitable polyethers are preferably compounds containing polyoxy-C ₂ -C ₄ -alkylene groups which are prepared by reacting C ₂ -C ₆₀ -alkanols, C ₆ -C ₃₀ -alkanediols, mono- or di-C ₂ -C ₃₀ -alkylamines , C ₁ -C ₃₀ -alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group are obtainable. Such products are described in particular in EP-A-310 875 EP-A-356 725, EP-A-700 985 and US-A-4,877,416. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates.

Further suitable carrier oil systems are described, for example, in DE-A-38 26 608, DE-A-41 42 241, EP-A-0 452 328 and EP-A-0 548 617, to which reference is expressly made.

Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers having 5 to 35, such as 5 to 30, C ₃ -C ₆ alkylene oxide units, for example selected from propylene oxide, n-butylene oxide and i-butylene oxide units, or mixtures thereof. Nonlimiting examples of suitable starter alcohols are long-chain alkanols or long-chain alkyl-substituted phenols, where the long-chain alkyl radical is in particular a straight-chain or branched C ₆ -C ₁₈ -alkyl radical, especially C ₈ -C ₁₅ -alkyl radical. Preferred examples are tridecanol and nonylphenol.

• a) 20 bis 80 Gew.-%, vorzugsweise 40 bis 80 Gew.-%, wenigstens eines Polyisobutenamins oder eines funktionellen Derivates davon,
• b) 20 bis 80 Gew.-%, vorzugsweise 20 bis 60 Gew.-%, einer Mischung aus wenigstens eines Polyethers beispielsweise aufgebaut aus etwa 10 bis 35, wie z.B. 15 bis 30, C₃-C₆-Alkylenoxideinheiten, wie z.B. Propylenoxid-, n- und i-Butylenoxideinheiten oder Gemische davon, und wenigstens eines mineralölbasierenden Trägeröls; wobei das Mischungsverhältnis im Bereich von 10:1 bis 1:10 liegt.

An example of a composition preferred according to the invention, typical of a semisynthetic gasoline fuel additive package, comprises:

• a) from 20 to 80% by weight, preferably from 40 to 80% by weight, of at least one polyisobutene amine or of a functional derivative thereof,
• b) 20 to 80 wt .-%, preferably 20 to 60 wt .-%, of a mixture of at least one polyether, for example, composed of about 10 to 35, such as 15 to 30, C ₃ -C ₆ alkylene oxide, such as propylene oxide -, n- and i-butylene oxide units or mixtures thereof, and at least one mineral oil-based carrier oil; wherein the mixing ratio is in the range of 10: 1 to 1:10.

• (ab) Nitrogruppen, ggf. in Kombination mit Hydroxylgruppen, enthaltende Additive;
• (ac) Hydroxylgruppen in Kombination mit Mono- oder Polyaminogruppen enthaltende Additive, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
• (ad) Carboxylgruppen oder deren Alkalimetall- oder Erdalkalimetallsalze enthaltende Additive;
• (ae) Sulfonsäuregruppen oder deren Alkalimetall- oder Erdalkalimetallsalze enthaltende Additive;
• (af) Additive, die von Bernsteinsäureanhydrid abgeleitete Grup-pierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen enthalten; und
• (ag) durch Mannich-Umsetzung von Alkylphenolen mit Aldehyden und Mono- oder Polyaminen erzeugte Gruppierungen enthaltende Additive.

In addition to the main detergent additive component (a) (polyetheramine and / or polyalkenamine), one or more other detergent additives may be included, provided that the beneficial effects observed in accordance with the invention are not adversely affected thereby. Examples of other useful detergent additives are those having at least one hydrophobic hydrocarbon radical having a number average molecular weight (Mn) of 85 to 20,000 and at least one polar grouping selected from additive groups (ab) to (ag):

• (ab) nitro groups, optionally in combination with hydroxyl groups, containing additives;
• (ac) hydroxyl groups in combination with mono or polyamino group-containing additives, wherein at least one nitrogen atom has basic properties;
• (ad) additives containing carboxyl groups or their alkali metal or alkaline earth metal salts;
• (ae) sulfonic acid groups or their alkali metal or alkaline earth metal containing additives;
• (af) additives containing succinic anhydride-derived groups having hydroxy and / or amino and / or amido and / or imido groups; and
• (ag) by Mannich reaction of alkylphenols with aldehydes and mono- or polyamines generated groupings containing additives.

The hydrophobic hydrocarbon radical in these detergent additives, which provides sufficient solubility in the fuel, has a number average molecular weight (Mn) of 85 to 20,000, in particular from 113 to 10,000, especially from 300 to 5000. As a typical hydrophobic hydrocarbon radical, especially in conjunction with the polar groups (ac), (af) and (ag), the polypropenyl, polybutenyl and polyisobutenyl with each Mn = 150 to 5000, in particular 500 to 2500, especially 700 to 2250, come into consideration.

Nitro groups, optionally in combination with hydroxyl groups, containing additives (ab) are preferably reaction products of polyisobutenes of 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 in WO-A 96/03479 are described. These reaction products typically are mixtures of pure nitropolyisobutanes (e.g., α, β-dinitropolyisobutane) and mixed hydroxynitropolyisobutanes (e.g., α-nitro-β-hydroxypolyisobutane).

Hydroxyl groups in combination with mono- or polyamino-containing additives (ac) are, in particular, reaction products of polyisobutene epoxides obtainable from polyisobutene preferably having predominantly terminal double bonds with Mn = 150 to 5000, with ammonia, mono- or polyamines, as described in particular in EP-A 476 485 are described.

Carboxyl groups or their alkali metal or alkaline earth metal salts containing additives (ad) are preferably copolymers of C ₂ -C ₄₀ olefins with maleic anhydride having a total molecular weight of 500 to 20,000, their carboxyl groups wholly or partially to the alkali metal or alkaline earth metal salts and a remainder the carboxyl groups reacted with alcohols or amines are. Such additives are known in particular from EP-A 307 815. Such additives are mainly used to prevent valve seat wear and, as described in WO-A 87/01126, can be advantageously used in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Sulfonic acid groups or their alkali metal or alkaline earth metal salts containing additives (ae) are preferably alkali metal or alkaline earth metal salts of a Sulfobernsteinsäurealkylesters, as described in particular in EP-A-639 632. Such additives are primarily used to prevent valve seat wear and can be used to advantage in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Succinic anhydride derived groupings containing hydroxyl and / or amino and / or amido and / or imido groups are preferably corresponding derivatives of polyisobutenyl succinic anhydride obtained by reacting conventional or highly reactive polyisobutene having Mn = 150 to 5000 with maleic anhydride thermal or via the chlorinated polyisobutene are available. Of particular interest here are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine. Such gasoline additives are described in particular in US-A-4,849,572. By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated moieties containing additives (ag) are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or di-methylamino-propylamine , The polyisobutene-substituted phenols may be derived from conventional or highly reactive polyisobutene having Mn = 150 to 5,000. Such "polyisobutene-Mannich bases" are described in particular in EP-A 831 141.

Further detergent additives suitable according to the invention are described, for example, in European patent applications EP-A-0 277 345, EP-A-0 356 725, EP-A-0 484 736, EP-A-0 539 821, EP-A-0 543 225 EP-A-0 548 617, EP-A-0 561 214, EP-A-0 567 810 and EP-A-0 568 873; in the German patent applications DE-A-39 42 860, DE-A-43 09 074, DE-A-43 09 271, DE-A-43 13 088, DE-A-44 12 489, DE-A-044 25 834, DE-A-195 25 938, DE-A-196 06 845, DE-A-196 06 846, DE-A-196 15 404, DE-A-196 06 844, DE-A-196 16 569, DE-A-196 18 270 and DE-A-196 14 349.

For a more detailed definition of the individual petrol additives listed above, reference is expressly made to the disclosures of the abovementioned publications of the prior art.

Further customary additives (component (c)) are corrosion inhibitors, for example based on film-forming ammonium salts of organic carboxylic acids or heterocyclic aromatics in non-ferrous metal corrosion protection, dyes, antioxidants or stabilizers, for example based on amines such as p-phenylenediamine, dicyclohexylamine or derivatives thereof or phenols such as 2,4-di-tert-butylphenol or 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid, demulsifiers, antistatic agents, metallocenes such as ferrocene or methylcyclopentadienyl manganese tricarbonyl, other lubricity improvers (lubricity additives) such as certain fatty acids , Alkenylbernsteinsäureester, bis (hydroxyalkyl) fatty amines or hydroxyacetamides and dyes (markers). Optionally, amines are added to lower the pH of the fuel.

The novel fuel additive combinations, optionally in combination with one or more of the above-mentioned further fuel additives with the polar groups, as well as the other components mentioned, are added to the fuel and unfold their effect there. The components or additives can be added to the fuel individually or as a previously prepared concentrate ("additive package").

As a solvent or diluent (when providing additive packages) are aliphatic and aromatic hydrocarbons, e.g. Solvent naphtha or kerosene, into consideration.

The fuel additive mixtures according to the invention are added to the fuel, for example, in an amount in the range of 10 to 5000 ppm (mg / kg fuel), preferably 20 to 1500 ppm (mg / kg fuel).

The optionally used further fuel additives with the polar groups are added to the fuel usually in an amount of 10 to 5000 ppm, in particular 50 to 1000 ppm, and the other components and additives mentioned, if desired, in customary amounts.

The fuel to which the fuel additive mixtures of the present invention are added is not particularly limited in itself. It can be e.g. to trade a petrol according to DIN EN 228. The fuel may be, for example, a gasoline having an aromatics content of at most 42% by volume, e.g. 20 to 42% by volume and a maximum sulfur content of 150 ppm, e.g. 0.5 to 150 ppm.

The gasoline may also have an olefin content of not more than 21% by volume, e.g. from 6 to 21 vol.%.

The benzene content may be a maximum of 1.0% by volume, e.g. 0.5 to 1.0 vol .-%, amount; the oxygen content may e.g. in the range of 0.1 to 2.7 wt .-% are.

The content of alcohols and ethers in gasoline is usually relatively low. Typical maximum contents for methanol are 3% by volume, for ethanol 5% by volume, for isopropanol 10% by volume, for tert-butanol 7% by volume, for isobutanol 10% by volume and for ethers 5 or more C atoms in the molecule 15 vol .-%.

The summer vapor pressure of the gasoline is usually not more than 70 kPa, in particular 60 kPa (each at 37 ° C).

The research octane number ("RON") of the gasoline is typically 90 to 100. A common range for the corresponding engine octane number ("MOZ") is 80 to 90.

The specified specifications are determined by conventional methods (DIN EN 228).

The following non-limiting examples serve to illustrate the invention.

Production Example A (Inventive):

A mixture of 50% by weight of a conventional detergent additive (about 50% by weight of polyisobuteneamine with Mn = 1000, dissolved in n-paraffin mixture having a viscosity of <20 mm ² / s at 20 ° C., tradename Kerocom PIBA from BASF ), 38% of a mineral base oil (viscosity at + 20 ° C: 407 mm ² / s) and 10% of a synthetic butylene oxide carrier (tridecanol etherified with butylene oxide units) (viscosity at + 20 ° C: 157 mm ² / s ) ago.

Production Example B (Comparison):

A mixture is prepared analogously to Example A, wherein only the mineral carrier oil is replaced by a non-inventive base oil having a viscosity at + 20 ° C of 432 mm ² / s.

Test Example 1: Comparison of Cryogenic Viscosities

For Examples A (according to the invention) and B (not according to the invention), low-temperature viscosities in mm ² / s (DIN 51562 part 1) are determined at different temperatures. The results are summarized in Table 1 below. Table 1 Viscosity at the specified temperature mixture + 20 ° C - 10 ° C - 15 ° C - 20 ° C A 114 853 1401 3016 B 114 916 1568 3462

Surprisingly, a significantly lower viscosity increase with decreasing temperature is observed for the additive composition according to the invention.

Test Example 2: Comparison of IVD performance

The IVD performance test of the compositions of Examples A and B was tested in bench tests with a Mercedes Benz M102E engine in accordance with CEC F-05-A-93. The dosing rate of mixtures A and B was 700 mg / kg each. Commercially available petrol according to EN 228 was used. The results are summarized in the following Table 2. Table 2 additive Average inlet valve deposits [mg] Without (basic value) 455 Additive from Example A (according to the invention) 4 Additive from example B (comparison) 28

The composition according to the invention surprisingly shows a clearly advantageous IVD performance.

Preparation Example C (according to the invention):

A mixture of 60% by weight of a conventional detergent additive (about 50% by weight of polyisobuteneamine with Mn = 1000, dissolved in n-paraffin mixture having a viscosity of <20 MM ² / s at 20 ° C., tradename Kerocom PIBA from BASF ), 20 wt .-% of a base oil (viscosity at + 20 ° C: 407 mm ² / s) and 20 wt .-% of a propylene oxide carrier (tridecanol etherified with propylene oxide units) (viscosity at + 20 ° C: 166 mm ² / s).

Production Example D (Comparison):

Production Example C is repeated, the mineral carrier oil being replaced by a non-inventive base oil having viscosity at +20 ° C. of 432 mm ² / s.

Production Example E (Inventive):

A mixture of 60% by weight of a conventional detergent additive (about 50% by weight of polyisobuteneamine with Mn = 1000, dissolved in n-paraffin mixture having a viscosity of <20 mm ² / s at 20 ° C., trade name Kerocom PIBA from BASF ), 20 wt .-% of a base oil (viscosity at + 20 ° C: 407 mm ² / s) and 20 wt .-% of a butylene oxide carrier (tridecanol etherified with butylene oxide units) (viscosity at + 20 ° C: 157 mm ² / s).

Production Example F (Comparison):

Production Example E is repeated, the mineral carrier oil being replaced by a non-inventive base oil with viscosity at + 20 ° C. of 432 mm ² / s.

Test Example 3:

For examples C, D, E and F, low-temperature viscosities in mm ² / s (DIN 51562 part 1) are determined at -20 ° C. The results are summarized in the following Table 3: Table 3 Viscosity at the specified temperature mixture + 20 ° C - 20 ° C C 74.4 1237 D (comparison) 74.7 1353 e 89.7 1496 F (comparison) 90.8 1655

Considerably higher viscosities at -20 ° C. are observed for the mixtures not according to the invention.

Claims (11)

1. A fuel additive composition, which comprises

   a) at least one detergent additive,

   b) a carrier oil mixture comprising

   i) at least one synthetic carrier oil selected from polyethers having a viscosity of from 120 to 270 mm²/s, determined at +20°C according to DIN 51562, part 1; and

   ii) at least one mineral carrier oil having a viscosity of from 250 to 410 mm²/s, determined at +20°C according to DIN 51562, part 1; and

   c) if appropriate, further conventional fuel additive components.
2. The fuel additive composition according to claim 1, wherein the mineral carrier oil component is a carrier oil selected from brightstock, base oils having viscosities from class SN 500 - 2000; aromatic hydrocarbons, paraffinic hydrocarbons and hydrocrack oil; or mixtures thereof.
3. The fuel additive composition according to any of the preceding claims, wherein mineral carrier oil components and synthetic carrier oil components are present in a weight ratio of from 10:1 to 1:10.
4. The fuel additive composition according to any of the preceding claims, wherein the detergent additive component comprises a detergent additive selected from polyalkenemonoamines, polyalkenepolyamines, polyetheramines and mixtures thereof.
5. The fuel additive composition according to claim 4, wherein the detergent additive comprises a poly-C₂-C₆-alkeneamine or poly-C₂-C₆-alkylene oxide amine.
6. The fuel additive composition according to claim 5, wherein the detergent additive comprises a poly-C₂-C₆-alkeneamine or poly-C₂-C₆-alkylene oxide amine having an Mn of from 150 to 5000.
7. The fuel additive composition according to any of the preceding claims, which comprises

   a) from 10 to 80% by weight of detergent additive(s),

   b) from 20 to 90% by weight of a carrier oil mixture, and

   c) if appropriate, from 0 to 30% by weight of further conventional fuel additive components.
8. A fuel composition, which comprises, in addition to a main amount of a hydrocarbon fuel, an amount, which has detergent activity and reduces intake valve deposits, of an additive composition according to any of the preceding claims.
9. The fuel composition according to claim 8, wherein the additive composition is present in an amount of from 10 to 5000 mg/kg of fuel.
10. The use of a fuel additive composition according to any of claims 1 to 7 for reducing the intake valve deposits in internal combustion engines.
11. A fuel additive concentrate comprising a fuel additive composition according to any of claims 1 to 7.