AU3422000A

AU3422000A - Fuel composition

Info

Publication number: AU3422000A
Application number: AU34220/00A
Authority: AU
Inventors: Dietmar Posselt; Harald Schwahn
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1999-02-09
Filing date: 2000-02-05
Publication date: 2000-08-29
Anticipated expiration: 2020-02-05
Also published as: WO2000047698A1; DE19905211A1; AR022534A1; NZ513306A; KR20010111491A; HUP0200270A3; ZA200107409B; EP1155102A1; CZ20012854A3; MY121511A; PL349860A1; JP2002536531A; AU766424B2; HUP0200270A2; IL144375A; RU2238300C2; SK10852001A3; EP1277828A3; PL191309B1; EE200100420A

Description

Fuel Composition Description 5 The present invention relates to a fuel composition containing, as major component, a specific gasoline and, as minor component, selected gasoline additives. Carburettors and inlet systems of Otto engines, and also injec 10 tion systems for fuel proportioning, are subjected to increasing load due to contamination caused by dust particles from the air, unburned hydrocarbon residues from the combustion chamber and crankcase breather gases passed to the carburettor. 15 These residues shift the air-to-fuel ratio during idling and in the lower partial load region, so that the mixture becomes leaner and combustion less complete and consequently the content of un burned or partly burned hydrocarbons in the exhaust gas increases and the gasoline comsumption rises. 20 It is known to avoid these drawbacks by using fuel additives for cleaning the valves and carburettors or injection systems of Otto engines (cf eg: M. Rossenbeck in "Katalysatoren, Tenside, Miner albladditive", edited by J. Falbe, U. Hasserodt, page 223, G. 25 Thieme Verlag, Stuttgart 1978). Furthermore, the problem of valve seat wear occurs in the case of Otto engines of less recent design when fuelled with unleaded gasolines. To counteract this, anti-valve-seat-wear additives 30 based on alkali metal or alkaline earth metal compounds have been developed. For trouble-free running, modern Otto engines require automotive fuels having a complex set of properties which can only be guar 35 anteed when use is made of appropriate gasoline additives. Such gasolines usually consist of a complex mixture of chemical com pounds and are characterized by physical parameters. The inter relationship between gasolines and appropriate additives in known fuel compositions is still unsatisfactory as regards their deter 40 gent action or their pollution-abating properties and their anti valve-seat-wear action. It is thus an object of the present invention to provide a more effective gasoline/additive formulation for Otto engine fuels. 45 2 Accordingly, we have found a fuel composition which contains, as major component, a gasoline having an aromatics content of not more than 42 vol% and a sulfur content of not more than 150 ppm by weight, and, as minor component, at least one gasoline addi 5 tive having a detergent action or an anti-valve-seat-wear action, which gasoline additive contains at least one hydrophobic hydro carbon group having a number-average molecular weight (Mn) of from 85 to 20,000 and at contain least one polar grouping selected from 10 (a) monoamino or polyamino groups containing up to 6 nitrogen atoms, of which at least one has alkaline properties, (b) nitro groups, optionally combined with hydroxyl groups, 15 (c) hydroxyl groups combined with monoamino or polyamino groups, where at least one nitrogen atom has alkaline properties, 20 (d) carboxlylic groups or the alkali metal or alkaline earth metal salts thereof, (e) sulfo groups or the alkali metal or alkaline earth metal salts thereof, 25 (f) polyoxy-(C 2 -C4 alkylene) groupings which are terminated by hydroxyl groups, by monoamino or polyamino groups, in which at least one nitrogen atom has alkaline properties, or by carbamate groups, 30 (g) carboxylate groups, (h) groupings derived from succinic anhydride and containing hydroxyl and/or amino and/or amido and/or imido groups 35 and (i) groupings produced by Mannich reaction of phenolic hy droxyl groups with aldehydes and mono- or poly-amines. 40 The aromatics content of the gasoline is preferably not more than 40 vol% and more preferably not more than 38 vol%. Preferred ranges for the aromatics content are from 20 to 42 vol% and par ticularly from 25 to 40 vol%. 45 3 The sulfur content of the gasoline is preferably not more than 100 ppm by weight and more preferably not more than 50 ppm by weight. Preferred ranges for the sulfur content are from 0.5 to 150 ppm by weight and particularly from 1 to 100 ppm by weight. 5 In a preferred embodiment, the gasoline has an olefin content of not more than 21 vol%, preferably not more than 18 vol% and more preferably not more than 10 vol%. Preferred ranges for the olefin content are from 6 to 21 vol% and particularly from 7 to 18 vol%. 10 In another preferred embodiment, the gasoline has a benzene con tent of not more than 1.0 vol% and preferably not more than 0.9 vol%. Preferred ranges for the benzene content are from 0.5 to 1.0 vol% and preferably from 0.6 to 0.9 vol%. 15 In another preferred embodiment, the gasoline has an oxygen con tent of not more than 2.7 wt%, preferably from 0.1 to 2.7 wt%, more preferably from 1.0 to 2.7 wt%, and most preferably from 1.2 to 2.0 wt%. 20 Particular preference is given to a gasoline which has an aromat ics content of not more than 38 vol% and at the same time an ole fin content of not more than 21 vol%, a sulfur content of not more than 50 ppm by weight, a benzene content of not more than 25 1.0 vol% and an oxygen content of from 1.0 to 2.7 wt%. The content of alcohols and ethers in the gasoline is normally relatively low. Typical maximum contents are methanol 3 vol%, ethanol 5 vol%, isopropanol 10 vol%, tert-butanol 7 vol%, isobu 30 tanol 10 vol% and ethers containing 5 or more carbon atoms in the molecule 15 vol%. The summer vapor pressure of the gasoline is usually not more than 70 kPa and preferably not more than 60 kPa (at 37 0 C). 35 The research octane number ("RON") of the gasoline is usually from 90 to 100. A usual range for the corresponding motor octane number ("MON") is from 80 to 90. 40 The above characteristics are determined by conventional methods (DIN EN 228). The hydrophobic hydrocarbon group in the gasoline additives, which provides sufficient solubility in the fuel, has a number 45 average molecular weight (Ma) of from 85 to 20,000, preferably from 113 to 10,000 and more preferably from 300 to 5000. Typical hydrophobic hydrocarbon groups, particularly in conjunction with 4 the polar groupings (a), (c), (h) and (i), are polypropenyl, polybutenyl and polyisobutenyl groups having molecular weights Mn of from 300 to 5000, preferably from 500 to 2500 and more prefer ably from 750 to 2250. 5 The following examples of individual gasoline additives having a detergent action or an anti-valve-seat-wear effect are mentioned by way of example. 10 Additives containing monoamino or polyamino groups (a) are pre ferably polyalkene monoamines or polyalkene polyamines based on polypropylene or highly reactive (ie containing predominantly terminal double bonds - mostly in the P and ypositions) or conven tional (ie containing predominantly centered double bonds) poly 15 butylene or polyisobutylene having a molecular weight Mn of from 300 to 5000. Such additives based on highly reactive polyisobuty lene which can be prepared from the polyisobutylene containing up to 20 wt% of n-butylene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines such as dimethy 20 laminopropylamine, ethylenediamine, diethylenetriamine, triethy lenetetramine or tetrethylenepentamine, are disclosed, in partic ular, in EP-A 244,616. If the synthesis of the additives is based on polybutylene or polyisobutylene having predominantly centered double bonds (mostly in the fand ypositions) as starting materi 25 als, an obvious choice is the synthesis method involving chlo rination and subsequent amination, or oxidation of the double bond with air or ozone to form the carbonyl or carboxyl compound, with subsequent amination under reductive (hydrogenating) condi tions. This amination may be carried out using the same amines as 30 mentioned above for the reductive amination of hydroformylated, highly reactive polyisobutylene. Corresponding additives based on polypropylene are described, in particular, in WO-A 94/24231. Further preferred additives containing monoamino groups (a) are 35 the hydrogenation products of the reaction products of polyisobu tylenes having an average degree of polymerization P of from 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxy gen, as described, in particular, in WO-A 97/03946. 40 Further preferred additives containing monoamino groups (a) are the compounds produced from polyisobutylene epoxides by reaction with amines followed by dehydration and reduction of the amino alcohols, as described, in particular, in DE-A 196 20 262. 45 Additives containing nitro groups, optionally combined with hy droxyl groups (b), are preferably reaction products of polyisobu tylenes having an average degree of polymerization P of from 5 to 5 100 or from 10 to 100 with nitrogen oxides or mixtures of nitro gen oxides and oxygen, as described, in particular, in WO-A 96/03367 and WO-A 96/03479. These reaction products are usually mixtures of pure nitropolyisobutanes (eg a,p-dinitropolyisobu 5 tane) and mixed hydroxynitropolyisobutanes (eg a-nitro-P-hydroxy polyisobutane). Additives containing hydroxyl groups combined with monoamino or polyamino groups (c) are in particular reaction products of poly 10 isobutylene epoxides, obtainable from polyisobutylene preferably containing predominantly terminal double bonds and having a mo lecular weight Mn of from 300 to 5000, with ammonia or mono- or poly-amines, as described, in particular, in EP-A 476,485. 15 Additives containing carboxlylic groups or the alkali metal or alkaline earth metal salts thereof (d) are preferably copolymers of C 2

-C

4 0 olefins with maleic anhydride having a total molecular weight of from 500 to 20,000 whose carboxlylic groups have been converted entirely or partially to the alkali metal or alkaline 20 earth metal salts and the remainder of the carboxlylic groups has been caused to react with alcohols or amines. Such additives are disclosed, in particular, in EP-A 307,815. Said additives mainly serve to prevent valve seat wear and can be used, as described in WO-A 87/01126, with advantage combined with conventional fuel de 25 tergents such as poly(iso)butylene amines or polyether amines. Additives containing sulfo groups or the alkali metal or alkaline earth metal salts thereof (e) are preferably alkali metal or al kaline earth metal salts of an alkyl sulfosuccinate, as de 30 scribed, in particular, in EP-A 639,632. Such additives mainly serve to prevent valve seat wear and can be used with advantage combined with conventional fuel detergents such as poly(iso)buty lene amines or polyether amines. 35 Additives containing polyoxy-(C2-C4 alkylene) groupings (f) are preferably polyethers or polyether amines, which are obtained by reaction of C 2

-C

60 alkanols, C6-C30 alkanediols, mono- or di-(C 2

-C

3 0 alkyl)amines, (Ci-C 30 alkyl)cyclohexanols or (C 1

-C

30 alkyl)phenols with from 1 to 30 mol of ethylene oxide and/or propylene oxide 40 and/or butylene oxide per hydroxyl group or amino group and, in the case of polyether amines, by subsequent reductive amination with ammonia, monoamines or polyamines. Such products are de scribed, in particular, in EP-A 310,875, EP-A 356,725, EP-A 700,985 and US-A 4,877,416. In the case of polyethers such prod 45 ucts also have flotation oil characteristics. Typical examples thereof are tridecanol butoxylates or isotridecanol butoxylates, isononylphenol butoxylates, polyisobutenol butoxylates and poly- 6 isobutenol propoxylates and the corresponding reaction products with ammonia. Additives containing carboxylate groups (g) are preferably esters 5 of mono-, di- or tri-carboxylic acids with long-chain alkanols or polyols, in particular those having a minimum viscosity of 2 nmM 2 /s at 100 0 C, as described, in particular, in DE-A 3,838,918. The mono-, di- or tri-carboxylic acids used can be aliphatic or aro matic acids, and suitable ester alcohols or ester polyols are 10 primarily long-chain representatives containing, for example, from 6 to 24 carbon atoms. Typical representatives of these es ters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotride canol. Such products also have flotation oil characteristics. 15 Additives containing groupings derived from succinic anhydride and containing hydroxyl and/or amino and/or amido and/or imido groups (h) are preferably corresponding derivatives of polyisobu tenyl succinic anhydride, which are obtained by reaction of con 20 ventional or highly reactive polyisobutylene having a molecular weight M, of from 300 to 5000 with maleic anhydride by thermal treatment or via chlorinated polyisobutylene. Of special interest in this respect are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or te 25 trethylenepentamine. Such gasoline additives are described, in particular, in US-A 4,849,572. Additives containing groupings produced by Mannich reaction of phenolic hydroxyl groups with aldehydes and mono- or poly-amines 30 (i) are preferably reaction products of polyisobutylene-substi tuted phenols with formaldehyde and mono- or poly-amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetre thylenepentamine or dimethylaminopropylamine. The polyisobutenyl substituted phenols can be derived from conventional or highly 35 reactive polyisobutylene having a molecular weight Mn of from 300 to 5000. Such "polyisobutylene Mannich bases" are described, in particular, in EP-A 831,141. To provide a more precise definition of the individual gasoline 40 additives mentioned above, the disclosures of the aforementioned specifications of the prior art are included herein by reference. The fuel composition of the invention can contain yet other con ventional components and additives. Foremost examples thereof are 45 flotation oils not having any marked detergent action, for exam ple mineral flotation oils (base oils), in particular those of the viscosity class "Solvent Neutral (SN) 500 to 2000", and syn- 7 thetic flotation oils based on olefin polymers having a molecular weight Mn of from 400 to 1800, mainly based on polybutylene or polyisobutylene (hydrogenated or non- hydrogenated), on poly(a-olefin)s or poly(internal olefin)s. 5 Suitable solvents or diluents (for use in additive packs) are al iphatic and aromatic hydrocarbons, eg solvent naphtha. Further conventional additives are corrosion inhibitors based, 10 for example, on film-forming ammonium salts of organic carboxylic acids or heterocyclic aromatics for nonferrous metal corrosion protection, antioxidants or stabilizing agents based, for exam ple, on amines such as p-phenylenediamine, dicyclohexylamine or derivatives thereof or phenols such as 2,4-di-tert-butylphenol or 15 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid, demulsifiers, antistatic agents, metallocenes such as ferrocene or methylcyclo pentadienyl manganese tricarbonyl, lubricity additives such as specific fatty acids, alkenyl succinates, bis(hydroxyalkyl)fatty amines, hydroxyacetamide or castor oil and also colorants (la 20 bels). Sometimes amines are also added to lower the pH of the au tomotive fuel. Other suitable fuel compositions of the invention comprise, in particular, blends of the gasoline described above with a mixture 25 of gasoline additives containing the polar grouping (f) and cor rosion inhibitors and/or lubricity improvers based on carboxylic acids or fatty acids, which can be present as monomeric and/or dimeric species. Typical mixtures of this type contain polyisobu tylene amines combined with alkanol-initiated polyethers such as 30 tridecanol or isotridecanol butoxylates or propoxylates, polyiso butylene amines combined with alkanol-initiated polyether amines such as reaction products of tridecanol or isotridecanol butoxy late with ammonia and alkanol-initiated polyether amines such as reaction products of tridecanol or isotridecanol butoxylate with 35 ammonia combined with alkanol-initiated polyethers such as tride canol or isotridecanol butoxylates or propoxylates, in each case combined with said corrosion inhibitors or lubricity improvers. Said gasoline additives containing the polar groupings (a) to (i) 40 and said other components are metered to the gasoline, where they become effective. The components or additives can be added to the gasoline individually or as a previously prepared concentrate (additive pack). 45 Said gasoline additives containing the polar groupings (a) to (i) are added to the gasoline usually in an amount of from 1 to 5000 ppm by weight, preferably from 5 to 3000 ppm by weight and 8 more preferebly from 10 to 1000 ppm by weight. The other compo nents and additives mentioned,if desired, are added in conven tional amounts. 5 The fuel composition of the invention surprisingly allows for the use of distinctly less detergent or anti-valve-seat-wear agent to achieve the same detergent or pullution-abating action or anti valve-seat-wear action as in the case of conventional fuel com positions of the prior art. Furthermore when the same amounts of 10 detergent or anti-valve-seat-wear agent are used in the fuel com position of the invention as in conventional fuel compositions there is achieved, surprisingly, a distinctly better detergent or pollution-abating or anti-valve-seat-wear action. 15 Furthermore, the fuel composition of the invention has additional advantages in that less sedimentation occurs in the combustion chamber of the Otto engine and less additive migrates to the mo tor oil due to fuel dilution. 20 The invention is illustrated by, but not restricted to, the fol lowing examples. Examples: 25 The gasolines used were those listed in Table 1 complying to the specifications stated, where OF 1 stands for a typical commercial Otto fuel. Table 1 30 Grading OF1 (for comparison) OF2 (invention) aromatics content [vol%) 48.4 41.8 benzene content [vol%] 2.0 1.0 35 olefin content [vol%] 22.6 7.8 oxygen content [wt%] 0.5 1.7 sulfur content [ppm by 245 90 weight] summer vapor pressure 78.4 69.3 40 (at 37 0 c) [kPa] 45 9 Preparation of the fuel compositions Example 1 (comparative example) 5 700 mg of a polyisobutylene amine, prepared from highly reactive polyisobutylene having a molecular weight Mn of 1000 by hydrofor mylation and subsequent reductive amination with ammonia and dilution to equal parts by weight with C 10

-C

14 paraffin (Kerocom® PIBA sold by BASF Aktiengesellschaft), were dissolved in 1 kg of 10 OFi as indicated in Table 1. Example 2 (invention) 700 mg of the same polyisobutylene amine as used in Example 1 15 were dissolved in 1 kg of OF2 as indicated in Table 1. Example 3 (comparative example) 600 mg of a commercial additive formulation for gasolines, con 20 taining a conventional amount of a detergent containing carbamate groups as in grouping (f), were dissolved in 1 kg of OFI as indi cated in Table 1. Example 4 (invention) 25 600 mg of the same commercial additive formulation for gasolines as used in Example 3 were dissolved in 1 kg of OF2 as indicated in Table 1. 30 Example 5 (comparative example) 400 mg of a commercial additive formulation for gasolines, con taining a detergent, prepared by chlorination and subsequent amination of polyisobutylene having a molecular weight Ma of 950 35 and having predominantly centered double bonds, were dissolved in 1 kg of OFi as indicated in Table 1. Example 6 (invention) 40 400 mg of the same commercial additive formulation for gasolines as used in Example 5 were dissolved in 1 kg of OF2 as indicated in Table 1. 45 10 Example 7 (comparative example) 750 mg of a commercial additive formulation for gasolines, con taining 50 wt% of the same polyisobutylene amine as used in Exam 5 ple 1 and also mineral and synthetic flotation oils and corrosion control agents (Keropur®3222 sold by BASF Aktiengesellschaft) in conventional amounts, were dissolved in 1 kg of OF1 as indicated in Table 1. 10 Example 8 (invention) 350 mg of the same commercial additive formulation for gasolines as used in Example 7 were dissolved in 1 kg of OF2 as indicated in Table 1. 15 Example 9 (comparative example) 500 mg of a commercial additive formulation for gasolines, con taining 60 wt% of the same polyisobutylene amine as used in Exam 20 ple 1 and also mineral flotation oil and corrosion control means (Keropur83233 sold by BASF Aktiengesellschaft) in conventional amounts, were dissolved in 1 kg of OF1 as indicated in Table 1. Example 10 (invention) 25 500 mg of the same commercial additive formulation for gasolines as used in Example 9 were dissolved in 1 kg of OF2 as indicated in Table 1. 30 Example 11 (comparative example) 700 mg of a mixture of 50 wt% of the same polyisobutylene amine as used in Example 1 and 50 wt% of a commercial antiwear additive (Kerocom03280 sold by BASF Aktiengesellschaft) were dissolved in 35 1 kg of OF1 as indicated in Table 1. Example 12 (invention) 700 mg of the same additive formulation for gasolines as used in 40 Example 11 were dissolved in 1 kg of OF2 as indicated in Table 1. 45 11 Working tests Example 13 (comparative example) 5 Gasoline of Example 1 was examined as regards its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests employing a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no 10 additive is used, as shown in Table 2 below. Example 14 (invention) Gasoline of Example 2 was examined as regards its suitability for 15 maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. It was surprising to find that 20 compared with Example 13 perfect cleaning of the inlet valves is achieved using the same amount of fuel additive. Example 15 (comparative example) 25 Gasoline of Example 3 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no 30 additive is used, as shown in Table 2 below. Example 16 (invention) Gasoline of Example 4 was examined to determine its suitability 35 for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. It was surprising to 40 find that compared with Example 15 virtually perfect cleaning of the inlet valves is achieved using the same amount of fuel addi tive. Example 17 (comparative example) 45 12 Gasoline of Example 5 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet 5 valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. Example 18 (invention) 10 Gasoline of Example 6 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no 15 additive is used, as shown in Table 2 below. It was surprising to find that compared with Example 17 virtually perfect cleaning of the inlet valves is achieved using the same amount of fuel addi tive. 20 Example 19 (comparative example) Gasoline of Example 7 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz 25 engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. Example 20 (invention) 30 Gasoline of Example 8 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet 35 valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. It was surprising to find that distinctly less fuel additive is required than in Exam ple 19 to achieve a similar degree of inlet valve cleanliness. 40 Example 21 (comparative example) Gasoline of Example 9 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz 45 engine CEC F-05-A-93. As expected, the deposits on the inlet 13 valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. Example 22 (invention) 5 Gasoline of Example 10 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet 10 valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. It was surprising to find that compared with Example 21 distinctly better cleaning of the inlet valves is achieved using the same amount of fuel addi tive. 15 Example 23 (comparative example) Gasoline of Example 11 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying 20 out engine tests in the form of bench tests on a Mercedes-Benz engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. 25 Example 24 (invention) Gasoline of Example 12 was examined to determine its suitability for maintaining a clean inlet system. This was done by carrying out engine tests in the form of bench tests on a Mercedes-Benz 30 engine CEC F-05-A-93. As expected, the deposits on the inlet valves were distinctly less than the basic value obtained when no additive is used, as shown in Table 2 below. It was surprising to find that compared with Example 23 distinctly better cleaning of the inlet valves was achieved using the same amount of fuel addi 35 tive. 40 45 14 Table 2 Additive Dosage [mg/ Deposits on the inlet valves 5 kg] [mg/valve] valve 1 valve 2 valve 3 valve 4 average Ex. 13 700 40 157 7 87 73 (547) Ex. 14 700 0 0 0 0 0 (239) Ex. 15 600 19 60 86 34 50 (274) 10 Ex. 16 600 0 1 0 2 1 (239) Ex. 17 400 0 75 17 182 69 (402) Ex. 18 400 0 2 2 0 1 (239) Ex. 19 750 31 120 111 30 73 (592) Ex. 20 350 46 68 38 67 55 (239) 15 Ex. 21 500 181 95 26 68 93 (475) Ex. 22 500 27 33 14 77 38 (239) Ex. 23 700 123 12 98 55 72 (558) Ex. 24 700 82 12 23 22 35 (239) 20 (the values in brackets refer to the basic value of the automo tive fuel not containing any additive) 25 30 35 40 45

Claims

1. A fuel composition containing, as major component, a gasoline having an aromatics content of not more than 42 vol% and a 5 sulfur content of not more than 150 ppm by weight, and, as minor component, at least one gasoline additive having a de tergent action or an anti-valve-seat-wear action, wherein this gasoline additive contains at least one hydrophobic hy drocarbon group having a number-average molecular weight (Mn) of from 85 to 20,000 and at least one polar group selected 10 from (a) monoamino or polyamino groups containing up to 6 nitrogen atoms, of which at least one has alkaline properties, is (b) nitro groups, optionally combined with hydroxyl groups, (c) hydroxyl groups combined with monoamino or polyamino groups, in which at least one nitrogen atom has alkaline properties, 20 (d) carboxylic groups or the alkali metal or alkaline earth metal salts thereof, (e) sulfo groups or the alkali metal or alkaline earth metal salts thereof, 25 (f) polyoxy-(C 2 -C 4 alkylene) groups which are terminated by hydroxyl groups, monoamino or polyamino groups, in which at least one nitrogen atom has alkaline properties, or by carbamate groups, 30 (g) carboxylate groups, (h) groups derived from succinic anhydride and containing hy droxyl and/or amino and/or amido and/or imido groups and 35 (i) groups produced by Mannich reaction of substituted phe nols with aldehydes and mono- or poly-amines.

2. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (a), polyalkene mono 40 amine or polyalkene polyamines based on polypropylene, poly butylene or polyisobutylene having a molecular weight Ma of from 300 to 5000. 45 16

3. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (b), reaction products of polyisobutenes having an average degree of polymerization P of from 5 to 100 with nitrogen oxides or mixtures of nitro 5 gen oxides and oxygen.

4. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (c), reaction products of polyisobutene epoxides, obtained from polyisobutylene con taining predominantly terminal double bonds and having a mo 10 lecular weight Mn of from 300 to 5000, with ammonia, mono- or poly-amines.

5. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (d), copolymers of 15 C 2 -C 4 0 olefins with maleic anhydride having a total molecular weight of from 500 to 20,000 whose carboxylic groups are com pletely or partially converted to the alkali metal or alka line earth metal salts and the remainder of the carboxylic groups has been caused to react with an alcohol or amine. 20

6. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (e), an alkali metal or alkaline earth metal salt of an alkyl sulfosuccinate.

7. A fuel composition as defined in claim 1, containing, as gas 25 oline additive containing polar groups (f), a polyether or polyether amine, obtainable by reaction of a C 2 -C 3 0 alkanol, C 6 -C 6 0 alkanediol, mono- or di-(C 2 -C 3 0 alkyl)amine, C 1 -C 3 0 al kylcyclohexanol or C 1 -C 3 0 alkylphenol with from 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl group or amino group and, in the case of poly 30 ether amines, by subsequent reductive amination with ammonia, a monoamine or a polyamine.

8. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (g), an ester of a 35 mono-, di- or tri-carboxylic acid with a long-chain alkanol or polyol.

9. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (h), a derivative of polyisobutenylsuccinic anhydride, obtained by reaction of conventional or highly reactive polyisobutylene having a mo lecular weight Ma of from 300 to 5000 with maleic anhydride by thermal treatment or via the chlorinated polyisobutylene. 45 17

10. A fuel composition as defined in claim 1, containing, as gas oline additive containing polar groups (i), a reaction prod uct of a polyisobutene-substituted phenol with formaldehyde and a mono- or poly-amine. 5

11. A fuel composition as defined in any of claims 1 to 10, con taining a gasoline having an olefin content of not more than 21 vol%.

12. A fuel composition as defined in any of claims 1 to 11, con 10 taining a gasoline having a benzene content of not more than 1.0 vol%.

13. A fuel composition as defined in any of claims 1 to 12, con taining a gasoline having an oxygen content of not more than 15 2.7 wt%.

14. A fuel composition as defined in any of claims 1 to 13, con taining the gasoline additives containing the polar groups (a) to (i) in a concentration of from 1 to 5000 ppm by weight. 20 25 30 35 40 45