DE102010039039A1 - Use of an organic compound as a fuel additive to reduce the fuel consumption of diesel engines, preferably direct-injection diesel engines, with common rail injection systems - Google Patents

Abstract

Use of at least one organic compound (I) as a fuel additive to reduce the fuel consumption of diesel engines, is claimed, where (I) has a molecular weight of 59-1500, and at least one structural element nitrogen-oxygen-carbon (N-O-C), in which the two free valences on the nitrogen atom and the three free valences on the carbon atom are saturated by carbon atoms and/or hydrogen atoms, and the structural element N-O-C is not a part of a ring system. Use of at least one organic compound (I) as a fuel additive to reduce the fuel consumption of diesel engines, is claimed, where (I) has a molecular weight of 59-1500, and at least one structural element N-O-C (nitrogen-oxygen-carbon), in which the two free valences on the nitrogen atom and the three free valences on the carbon atom are saturated by carbon atoms and/or hydrogen atoms, and the structural element N-O-C is not a part of a ring system.

Description

The present invention relates to the use of special low molecular weight organic compounds having at least one structural element N-O-C, in particular hydroxylamines and oxime ethers substituted on the oxygen atom, as a fuel additive for reducing the fuel consumption of diesel engines.

The depletion of fossil fuel deposits will occur in the foreseeable future, and regenerative fuels will not be available to any extent. Therefore, there are ongoing efforts to reduce the fuel and fuel consumption of combustion devices such as engines operated therewith. One approach is the addition of certain additives to fuels that reduce fuel consumption.

In the FR-A 2 305 491 (1) Additive mixtures which, in addition to halogenated aromatics, aromatic amines, organic phosphorus compounds and aromatic alcohols, aliphatic ketones, for example, 2,6-dialkylheptan-4-ones, described for fuels such as diesel fuel, which cause a reduction in fuel consumption.

From the US 5,433,756 (2) Combustion improver formulations are known which are added to gasoline or diesel fuels and contain as solvents the ketones 2-heptanone, 5-methyl-3-heptanone or 4-methyl-3-penten-2-one. These formulations also continue to reduce emissions in the exhaust gases and reduce fuel consumption.

In the EP-A 630 958 (3) describes an additive mixture for diesel fuel, which may contain in addition to aliphatic amines, aliphatic amines and paraffins aliphatic ketones such as ethylamyl ketone or methyl isobutyl ketone. The additive mixture reduces emissions in the exhaust gases and reduces fuel consumption.

Fuel additives from the compound classes of the hydroxylamines and the oximes and their derivatives are known from the documents mentioned below; however, nothing is disclosed herein about a possible effect of such additives to reduce fuel and fuel consumption.

At the oxygen atom unsubstituted hydroxylamines are in the WO 2002/068334 (4), the WO 2002/068570 (5) and the WO 2003/020852 (6) for use as combustion improvers in fuels.

In the US 4,233,035 (7) discloses specific oxime ethers as metal deactivators for fuels, particularly for aircraft propellants. All of these oxime ethers contain either an aromatic substituent having a hydroxyl group or an arylhydroxymethyl substituent.

In the US 4,069,226 (8) acylisoxazolines are described as corrosion and oxidation inhibitors in fuels and lubricants.

From the US 3,799,984 (9) and the US Pat. No. 3,965,177 (10) alkoxylated oximes are known as corrosion inhibitors and anti-icing agents for fuels.

In the JP 2006-104301 A1 (11) Among other classes of compounds, oximes and oxime ethers are also disclosed as additives for stabilizing the running behavior of internal combustion engines. The oxime ethers mentioned there carry on the oxygen atom a C ₁ - to C ₂₀ -hydrocarbyl group, which may be linear or branched and may contain oxygen and nitrogen atoms. However, this general statement about the possible structure of the oxime ethers is not specified further by structural examples in the description or in the experimental part of the specification.

However, the fuel economy achieved by means of the additives of the prior art, in particular according to documents (1) to (3), is still unsatisfactory.

Another approach is to increase the efficiency of the engine, which is achieved in particular by optimizing the combustion processes in the combustion chamber by direct injection.

In direct-injection diesel engines, the fuel is injected through a directly into the combustion chamber-reaching multi-hole injection nozzle of the engine and finely distributed (nebulized), instead of being introduced as in the classic (chamber) diesel engine in a vortex or vortex chamber. The advantage of direct-injection diesel engines lies in their high performance for diesel engines and nevertheless comparatively low consumption. In addition, these engines achieve a very high torque even at low speeds.

Currently, diesel engines use essentially three methods to inject the fuel directly into the combustion chamber: the conventional distributor injection pump, the unit-injector system and the common-rail system. System.

In the common-rail system, the diesel fuel is pumped by a pump with pressures up to 2000 bar into a high-pressure line, the common rail (literally "common line"). Starting from the common rail, spur lines run to the various injectors, which inject the fuel directly into the combustion chamber. In this case, the full pressure is always applied to the common rail, which allows a multiple injection or a special injection form. For the other injection systems, however, only one injection is possible.

Even though fuel consumption has already been reduced by the optimized injection geometry in direct-injection diesel engines, there is still a need for an even greater reduction in consumption.

It was an object of the present invention to provide additives which reduce the fuel consumption of diesel engines, in particular direct-injection diesel engines and, above all, of diesel engines with a common-rail injection system even more effectively.

The object is achieved by the use of at least one organic compound (I) having a molecular weight of 59 to 1500 and at least one structural element NOC, in which the two free valencies on the N atom and the three free valencies on the carbon atom in each case by carbon atoms and and / or hydrogen atoms are saturated and wherein the structural element NOC is not a constituent of a ring system, as a fuel additive for reducing the fuel consumption of diesel engines.

in denen die Variablen R¹ und R⁴ jeweils für C₁- bis C₂₀-Alkyl-, C₅- bis C₈-Cycloalkyl-, C₂- bis C₂₀-Alkenyl-, C₁- bis C₂₀-Alkylcarbonyl-, C₂- bis C₂₀-Alkenylcarbonyl-, C₆- bis C₂₀-Aryl-, C₆- bis C₂₀-Arylcarbonyl-, C₇- bis C₂₆-Arylalkyl- oder C₇- bis C₂₆-Arylalkylcarbonylreste stehen, wobei die Variablen R¹ und R⁴ jeweils noch zusätzlich Carbonsäureester- und/oder Carbonsäureamidgruppen tragen können und/oder vorliegende Alkyl- und Alkenylketten in diesen Variablen durch ein oder mehrere Sauerstoff- und/oder Stickstoffatome unterbrochen sein können, und
in denen die Variablen R² und R³ unabhängig voneinander C₁- bis C₂₀-Alkyl-, C₅- bis C₈-Cycloalkyl-, C₂- bis C₂₀-Alkenyl-, C₁- bis C₂₀-Alkylcarbonyl-, C₂- bis C₂₀-Alkenylcarbonyl-, C₆- bis C₂₀-Aryl-, C₆- bis C₂₀-Arylcarbonyl-, C₇- bis C₂₆-Arylalkyl- oder C₇- bis C₂₆-Arylalkylcarbonylreste bezeichnen, wobei die Variablen R² und R³ jeweils noch zusätzlich Carbonsäureester- und/oder Carbonsäureamidgruppen tragen können, vorliegende Alkyl- und Alkenylketten in diesen Variablen durch ein oder mehrere Sauerstoff- und/oder Stickstoffatome unterbrochen sein können und/oder die Variablen R² und R³ zusammen mit dem sie verbindenden N-Atom einen fünf- oder sechsgliedrigen Ring ausbilden können, und
in denen die Variablen R⁵ und R⁶ unabhängig voneinander Wasserstoff, C₁- bis C₂₀-Alkyl-, C₅- bis C₈-Cycloalkyl-, C₂- bis C₂₀-Alkenyl-, C₁- bis C₂₀-Alkylcarbonyl-, C₂- bis C₂₀-Alkenylcarbonyl-, C₆- bis C₂₀-Aryl-, C₆- bis C₂₀-Arylcarbonyl-, C₇- bis C₂₆-Arylalkyl- oder C₇- bis C₂₆-Arylalkylcarbonylreste bezeichnen, wobei die Variablen R⁵ und R⁶ jeweils noch zusätzlich Carbonsäureester- und/oder Carbonsäureamidgruppen tragen können, vorliegende Alkyl- und Alkenylketten in diesen Variablen durch ein oder mehrere Sauerstoff- und/oder Stickstoffatome unterbrochen sein können und/oder die Variablen R⁵ und R⁶ zusammen mit dem sie verbindenden C-Atom einen fünf- oder sechsgliedrigen Ring ausbilden können.Preferably, for the present invention, at least one organic compound (I) represented by the general formula (Ia) or (Ib) is used

in which the variables R ¹ and R ^{4 are} each C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl, C ₁ - to C ₂₀ -alkylcarbonyl , C ₂ to C ₂₀ alkenylcarbonyl, C ₆ to C ₂₀ aryl, C ₆ to C ₂₀ arylcarbonyl, C ₇ to C ₂₆ arylalkyl or C ₇ to C ₂₆ arylalkylcarbonyl radicals in which the variables R ¹ and R ^{4 may} each additionally carry carboxylic acid ester and / or carboxamide groups and / or present alkyl and alkenyl chains in these variables may be interrupted by one or more oxygen and / or nitrogen atoms, and
in which the variables R ² and R ³ independently of one another are C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl, C ₁ - to C ₂₀ -alkylcarbonyl , C ₂ to C ₂₀ alkenylcarbonyl, C ₆ to C ₂₀ aryl, C ₆ to C ₂₀ arylcarbonyl, C ₇ to C ₂₆ arylalkyl or C ₇ to C ₂₆ arylalkylcarbonyl radicals in which the variables R ² and R ^{3 may} each additionally carry carboxylic acid ester and / or carboxamide groups, present alkyl and alkenyl chains in these variables may be interrupted by one or more oxygen and / or nitrogen atoms and / or the variables R ² and R ³ together with the connecting N-atom can form a five- or six-membered ring, and
in which the variables R ⁵ and R ⁶ independently of one another are hydrogen, C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl, C ₁ - to C ₂₀ - Alkylcarbonyl, C ₂ - to C ₂₀ -alkenylcarbonyl, C ₆ - to C ₂₀ -aryl, C ₆ - to C ₂₀ -arylcarbonyl, C ₇ - to C ₂₆ -arylalkyl or C ₇ - to C ₂₆ - Arylalkylcarbonylreste denote, where the variables R ⁵ and R ⁶ each additionally can carry carboxylic acid ester and / or carboxamide, present alkyl and alkenyl chains may be interrupted in these variables by one or more oxygen and / or nitrogen atoms and / or the variables R ⁵ and R ⁶ together with the C-atom connecting them can form a five- or six-membered ring.

The molecular weight of the low molecular weight organic compound (I) or (Ia) or (Ib) is preferably 75 to 1200, in particular 103 to 900, especially 117 to 750, particularly preferably 131 to 650.

In a preferred embodiment, at least one organic compound (Ia) or (Ib) is used for the present invention, in which at least one of the variables R ¹ to R ³ or R ⁴ to R ^{6 is} a radical having at least 4 carbon atoms, in particular at least 8 Carbon atoms, especially at least 10 carbon atoms, represents. The organic compounds (Ia) or (Ib) preferably each contain one or two such longer-chain radicals.

In a further preferred embodiment, at least one organic compound (Ia) or (Ib) in which the two variables R ² and R ³ or R ⁵ and R ^{6 are} identical is used for the present invention.

The present invention is preferably useful for reducing fuel consumption of direct injection diesel engines.

In particular, direct-injection diesel engines are those with common-rail injection systems.

Suitable C ₁ - to C ₂₀ -alkyl radicals are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl , tert-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, iso-nonyl, 2-propylheptyl, n-decyl, n-dodecyl, n-tridecyl, iso-tridecyl, n-tetradecyl, n-hexydecyl, n-octadecyl and eicosyl. Preference is given to C ₁ - to C ₁₀ -alkyl radicals, in particular C ₁ - to C ₆ -alkyl radicals, especially C ₁ - to C ₄ -alkyl radicals. As longer-chain radicals, C ₄ - to C ₂₀ -alkyl radicals, in particular C ₈ - to C ₂₀ -alkyl radicals, especially C ₁₀ - to C ₁₈ -alkyl radicals, are preferred.

Examples of suitable C ₅ - to C ₈ -cycloalkyl radicals are cyclopentyl, cyclohexyl or 2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,6-dimethylcyclohexyl, 3,6-dimethylcyclohexyl, 3,5-dimethylcyclohexyl and 3,4, -Dimethylcyclohexyl. Preference is given to Cylcopentyl- and cyclohexyl, which can still carry up to 2 methyl groups as substituents.

Suitable C ₂ to C ₂₀ alkenyl radicals are, for example, vinyl, 1-propenyl, 2-propenyl (allyl), 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4- Pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl or oleyl. Preference is given to C ₂ to C ₁₀ alkenyl radicals, in particular C ₂ to C ₆ alkenyl radicals, especially C ₂ to C ₄ alkenyl radicals. As longer-chain radicals, C ₄ - to C ₂₀ -alkenyl radicals, in particular C ₈ - to C ₂₀ -alkenyl radicals, especially C ₁₀ - to C ₁₈ -alkenyl radicals, are preferred.

Examples of suitable C ₁ - to C ₂₀ -alkylcarbonyl radicals are acetyl, propionyl, n-butyroyl, isobutyryl, n-valeroyl and stearoyl. Preference is given to C ₁ - to C ₁₀ -alkylcarbonyl radicals, in particular C ₁ - to C ₆ -alkylcarbonyl radicals, especially C ₁ - to C ₄ -alkylcarbonyl radicals. As longer-chain radicals, C ₄ - to C ₂₀ -alkylcarbonyl radicals, in particular C ₈ - to C ₂₀ -alkylcarbonyl radicals, especially C ₁₀ - to C ₁₈ -alkylcarbonyl radicals, are preferred.

Suitable C ₂ -C ₂₀ -alkenylcarbonyl radicals are, for example, acryloyl (vinylcarbonyl), methacryloyl, crotonoyl, allylcarbonyl, but-2-enylcarbonyl, but-3-enylcarbonyl, hex-3-enylcarbonyl or oleoyl. Preference is given to C ₂ - to C ₁₀ -alkenylcarbonyl radicals, in particular C ₂ - to C ₆ -alkenylcarbonyl radicals, in particular C ₂ - to C ₄ -alkenylcarbonyl radicals. As longer-chain radicals, C ₄ - to C ₂₀ -alkenylcarbonyl radicals, in particular C ₈ - to C ₂₀ -alkenylcarbonyl radicals, especially C ₁₀ - to C ₁₈ -alkenylcarbonyl radicals, are preferred.

Suitable C ₆ - to C ₂₀ -aryl radicals are, for example, phenyl, α-naphthyl, β-naphthyl, o-, m- or p-tolyl, o-, m- or p-ethylphenyl or xylylene. Preference is given to C ₆ - to C ₁₂ -aryl radicals, in particular C ₆ - to C ₈ -aryl radicals.

Suitable C ₆ - to C ₂₀ -arylcarbonyl radicals are, for example, benzoyl, α-naphthoyl, β-naphthoyl, o-, m- or p-toluoyl, o-, m- or p-ethylbenzoyl or xylloyene. Preference is given to C ₆ - to C ₁₂ -arylcarbonyl radicals, in particular C ₆ - to C ₈ -arylcarbonyl radicals.

Examples of suitable C ₇ - to C ₂₆ -arylalkyl radicals are benzyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, 6-phenylhexyl, 8-phenyloctyl, methyl-α-naphthyls, methyl-β-naphthyls, o-, m- or p-methylbenzyl, 2- (o-, m- or p-methylphenyl) -ethyl or 2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-dimethylbenzyl. Preference is given to C ₇ - to C ₂₀ -arylalkyl radicals, in particular C ₇ - to C ₁₂ -arylalkyl radicals.

Examples of suitable C ₇ - to C ₂₆ -arylalkylcarbonyl radicals are phenylacetyl, 3-phenylpropionyl, 4-phenylbutyroyl or 5-phenylvaleroyl. C ₇ - to C ₂₀ -arylalkylcarbonyl radicals, in particular C ₇ - to C ₁₂ -arylalkylcarbonyl radicals, are preferred.

R¹ = CH₃ R² = CH₃ R³ = CH₃ (75) R¹ = Ethyl R² = CH₃ R³ = CH₃ (89) R¹ = CH₃ R² = Ethyl R³ = CH₃ (89) R¹ = Ethyl R² = Ethyl R³ = CH₃ (103) R¹ = Ethyl R² = Ethyl R³ = Ethyl (117) R¹ = iso-Propyl R² = CH₃ R³ = CH₃ (103) R¹ = CH₃ R² = iso-Propyl R³ = CH₃ (103) R¹ = iso-Propyl R² = iso-Propyl R³ = CH₃ (131) R¹ = iso-Propyl R² = iso-Propyl R³ = iso-Propyl (159) R¹ = n-Butyl R² = CH₃ R³ = CH₃ (117) R¹ = CH₃ R² = n-Butyl R³ = CH₃ (117) R¹ = n-Butyl R² = n-Butyl R³ = CH₃ (159) R¹ = n-Butyl R² = n-Butyl R³ = n-Butyl (201) R¹ = n-Propyl R² = CH₃ R³ = CH₃ (103) R¹ = tert.-Butyl R² = CH₃ R³ = CH₃ (117) R¹ = n-Pentyl R² = CH₃ R³ = CH₃ (131) R¹ = n-Hexyl R² = CH₃ R³ = CH3 (145) R¹ = n-Heptyl R² = CH₃ R³ = CH₃ (159) R¹ = n-Octyl R² = CH₃ R³ = CH₃ (173) R¹ = 2-Ethylhexyl R² = CH₃ R³ = CH₃ (173) R¹ = n-Decyl R² = CH₃ R³ = CH₃ (201) R¹ = 2-Propylheptyl R² = CH₃ R³ = CH₃ (201) R¹ = n-Undecyl R² = CH₃ R³ = CH₃ R¹ = n-Dodecyl R² = CH₃ R³ = CH₃ R¹ = n-Tridecyl R² = CH₃ R³ = CH₃ R¹ = iso-Tridecyl R² = CH₃ R³ = CH₃ R¹ = n-Tetradecyl R² = CH₃ R³ = CH₃ R¹ = n-Hexadecyl R² = CH₃ R³ = CH₃ R¹ = n-Octadecyl R² = CH₃ R³ = CH₃ (313) R¹ = Oleyl R² = CH₃ R³ = CH₃ (311) R¹ = Cyclohexyl R² = CH₃ R³ = CH₃ (143) R¹ = Acetyl R² = CH₃ R³ = CH₃ (103) R¹ = Benzoyl R² = CH₃ R³ = CH₃ (165) R¹ = Phenyl R² = CH₃ R³ = CH₃ (137) R¹ = Benzyl R² = CH₃ R³ = CH₃ (151) R¹ = CH₃ R² = Ethyl R³ = Ethyl (103) R¹ = CH₃ R² = n-Propyl R³ = n-Propyl (131) R¹ = CH₃ R² = iso-Propyl R³ = iso-Propyl (131) R¹ = CH₃ R² = n-Butyl R³ = n-Butyl (159) R¹ = CH₃ R² = tert.-Butyl R³ = tert.-Butyl (159) R¹ = CH₃ R² = n-Pentyl R³ = n-Pentyl (187) R¹ = CH₃ R² = n-Hexyl R³ = n-Hexyl (215) R¹ = CH₃ R² = n-Heptyl R³ = n-Heptyl R¹ = CH₃ R² = n-Octyl R³ = n-Octyl R¹ = CH₃ R² = 2-Ethylhexyl R³ = 2-Ethylhexyl R¹ = CH₃ R² = n-Decyl R³ = n-Decyl R¹ = CH₃ R² = 2-Propylheptyl R³ = 2-Propylheptyl R¹ = CH₃ R² = n-Undecyl R³ = n-Undecyl R¹ = CH₃ R² = n-Dodecyl R³ = n-Dodecyl R¹ = CH₃ R² = n-Tridecyl R³ = n-Tridecyl R¹ = CH₃ R² = iso-Tridecyl R³ = iso-Tridecyl R¹ = CH₃ R² = n-Tetradecyl R³ = n-Tetradecyl R¹ = CH₃ R² = n-Hexadecyl R³ = n-Hexadecyl R¹ = CH₃ R² = n-Octadecyl R³ = n-Octadecyl (551) R¹ = CH₃ R² = Oleyl R³ = Oleyl (547) R¹ = CH₃ R² = Cyclohexyl R³ = Cyclohexyl (211) R¹ = CH₃ R² = Phenyl R³ = Phenyl (199) R¹ = CH₃ R² = Ethyl R³ = n-Butyl (131) R¹ = n-Butyl R² = iso-Propyl R³ = CH₃ (145) R¹ = Ethyl R² = iso-Propyl R³ = CH₃ (117) R¹ = iso-Propyl R² = n-Butyl R³ = Ethyl (159) R¹ = Acetyl R² = CH₃ R³ = Acetyl (131) R¹ = CH₃ R² = Acetyl R³ = Acetyl (131) R¹ = CH₃ R² = Acetyl R³ = Benzyl (164) R¹ = CH₃ R² = Benzyl R³ = Benzyl R¹ = CH₃ R² = Benzyl R³ = Benzoyl R¹ = CH₃ R² = Benzoyl R³ = Benzoyl R¹ = Oleyl R² = Acetyl R³ = Acetyl R¹ = Oleyl R² = Acetyl R³ = Benzyl R¹ = Oleyl R² = Phenyl R³ = Phenyl R¹ = Oleyl R² = Benzyl R³ = Benzyl R¹ = Oleyl R² = Benzyl R³ = Benzoyl R¹ = Oleyl R² = Benzoyl R³ = Benzoyl (489) Typical examples of oxygen-substituted hydroxylamines of the general formula (Ia) are (in parentheses: molecular weight):

R ¹ = CH ₃ R ² = CH ₃ R ³ = CH ₃ (75) R ¹ = ethyl R ² = CH ₃ R ³ = CH ₃ (89) R ¹ = CH ₃ R ² = ethyl R ³ = CH ₃ (89) R ¹ = ethyl R ² = ethyl R ³ = CH ₃ (103) R ¹ = ethyl R ² = ethyl R ³ = ethyl (117) R ¹ = iso-propyl R ² = CH ₃ R ³ = CH ₃ (103) R ¹ = CH ₃ R ² = iso-propyl R ³ = CH ₃ (103) R ¹ = iso-propyl R ² = iso-propyl R ³ = CH ₃ (131) R ¹ = iso-propyl R ² = iso-propyl R ³ = iso-propyl (159) R ¹ = n-butyl R ² = CH ₃ R ³ = CH ₃ (117) R ¹ = CH ₃ R ² = n-butyl R ³ = CH ₃ (117) R ¹ = n-butyl R ² = n-butyl R ³ = CH ₃ (159) R ¹ = n-butyl R ² = n-butyl R ³ = n-butyl (201) R ¹ = n-propyl R ² = CH ₃ R ³ = CH ₃ (103) R ¹ = tert-butyl R ² = CH ₃ R ³ = CH ₃ (117) R ¹ = n-pentyl R ² = CH ₃ R ³ = CH ₃ (131) R ¹ = n-hexyl R ² = CH ₃ R ³ = CH 3 (145) R ¹ = n-heptyl R ² = CH ₃ R ³ = CH ₃ (159) R ¹ = n-octyl R ² = CH ₃ R ³ = CH ₃ (173) R ¹ = 2-ethylhexyl R ² = CH ₃ R ³ = CH ₃ (173) R ¹ = n-decyl R ² = CH ₃ R ³ = CH ₃ (201) R ¹ = 2-propylheptyl R ² = CH ₃ R ³ = CH ₃ (201) R ¹ = n-undecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = n-dodecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = n-tridecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = iso-tridecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = n-tetradecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = n-hexadecyl R ² = CH ₃ R ³ = CH ₃ R ¹ = n-octadecyl R ² = CH ₃ R ³ = CH ₃ (313) R ¹ = oleyl R ² = CH ₃ R ³ = CH ₃ (311) R ¹ = cyclohexyl R ² = CH ₃ R ³ = CH ₃ (143) R ¹ = acetyl R ² = CH ₃ R ³ = CH ₃ (103) R ¹ = benzoyl R ² = CH ₃ R ³ = CH ₃ (165) R ¹ = phenyl R ² = CH ₃ R ³ = CH ₃ (137) R ¹ = benzyl R ² = CH ₃ R ³ = CH ₃ (151) R ¹ = CH ₃ R ² = ethyl R ³ = ethyl (103) R ¹ = CH ₃ R ² = n-propyl R ³ = n-propyl (131) R ¹ = CH ₃ R ² = iso-propyl R ³ = iso-propyl (131) R ¹ = CH ₃ R ² = n-butyl R ³ = n-butyl (159) R ¹ = CH ₃ R ² = tert-butyl R ³ = tert-butyl (159) R ¹ = CH ₃ R ² = n-pentyl R ³ = n-pentyl (187) R ¹ = CH ₃ R ² = n-hexyl R ³ = n-hexyl (215) R ¹ = CH ₃ R ² = n-heptyl R ³ = n-heptyl R ¹ = CH ₃ R ² = n-octyl R ³ = n-octyl R ¹ = CH ₃ R ² = 2-ethylhexyl R ³ = 2-ethylhexyl R ¹ = CH ₃ R ² = n-decyl R ³ = n-decyl R ¹ = CH ₃ R ² = 2-propylheptyl R ³ = 2-propylheptyl R ¹ = CH ₃ R ² = n-undecyl R ³ = n-undecyl R ¹ = CH ₃ R ² = n-dodecyl R ³ = n-dodecyl R ¹ = CH ₃ R ² = n-tridecyl R ³ = n-tridecyl R ¹ = CH ₃ R ² = iso-tridecyl R ³ = iso-tridecyl R ¹ = CH ₃ R ² = n-tetradecyl R ³ = n-tetradecyl R ¹ = CH ₃ R ² = n-hexadecyl R ³ = n-hexadecyl R ¹ = CH ₃ R ² = n-octadecyl R ³ = n-octadecyl (551) R ¹ = CH ₃ R ² = oleyl R ³ = oleyl (547) R ¹ = CH ₃ R ² = cyclohexyl R ³ = cyclohexyl (211) R ¹ = CH ₃ R ² = phenyl R ³ = phenyl (199) R ¹ = CH ₃ R ² = ethyl R ³ = n-butyl (131) R ¹ = n-butyl R ² = iso-propyl R ³ = CH ₃ (145) R ¹ = ethyl R ² = iso-propyl R ³ = CH ₃ (117) R ¹ = iso-propyl R ² = n-butyl R ³ = ethyl (159) R ¹ = acetyl R ² = CH ₃ R ³ = acetyl (131) R ¹ = CH ₃ R ² = acetyl R ³ = acetyl (131) R ¹ = CH ₃ R ² = acetyl R ³ = benzyl (164) R ¹ = CH ₃ R ² = benzyl R ³ = benzyl R ¹ = CH ₃ R ² = benzyl R ³ = benzoyl R ¹ = CH ₃ R ² = benzoyl R ³ = benzoyl R ¹ = oleyl R ² = acetyl R ³ = acetyl R ¹ = oleyl R ² = acetyl R ³ = benzyl R ¹ = oleyl R ² = phenyl R ³ = phenyl R ¹ = oleyl R ² = benzyl R ³ = benzyl R ¹ = oleyl R ² = benzyl R ³ = benzoyl R ¹ = oleyl R ² = benzoyl R ³ = benzoyl (489)

Typical oxygen-substituted hydroxylamines (Ia) which are outstandingly suitable for the present invention are furthermore C ₁ -C ₂₀ -carboxylic acid N-hydroxysuccinimide esters and C ₁ -C ₂₀ -carboxylic acid N-hydroxyphthalimide esters, especially C ₈ to C ₂₀ -carboxylic acid N-hydroxysuccinimide ester and C ₈ - to C ₂₀ -carboxylic acid N-hydroxyphthalimide ester, especially C ₁₀ - to C ₁₈ -carboxylic acid N-hydroxysuccinimide ester and C ₁₀ - to C ₁₈ -carboxylic acid N-hydroxyphthalimide ester , In these compounds, the two alkylcarbonyl or Arylcarbonylreste R ² and R ³ together with the connecting N-atom each form a five-membered ring; the variable R ¹ is an alkylcarbonyl, alkenylcarbonyl, arylcarbonyl or arylalkylcarbonyl radical. Examples include (in parentheses: molecular weight): Acetic acid N-hydroxysuccinimide ester [R ¹ = CO-CH ₃ ] (157) Propionic acid N-hydroxysuccinimide ester [R ¹ = CO-CH ₂ CH ₃ ] Butyric acid N- [R ¹ = CO-CH ₂ CH ₂ CH ₃ ] Valeria acid N-hydroxysuccinimide [R ¹ = CO-CH ₂ CH ₂ CH ₂ CH ₃ ] Isovaleric acid N- [R ¹ = CO-CH ₂ CH (CH ₃ ) ₂ ] Pivalic acid N- [R ¹ = CO-CH (CH ₃ ) ₃ ] Lauric acid N-hydroxysuccinimide [R ¹ = CO- (CH ₂ ) ₁₀ -CH ₃ ]] Myristic acid N- [R ¹ = CO- (CH ₂ ) ₁₂ -CH ₃ ]] Palmitic acid N- [R ¹ = CO- (CH ₂ ) ₁₄ -CH ₃ )] Stearic acid N- [R ¹ = CO- (CH ₂ ) ₁₆ -CH ₃ )] (395) Acrylic acid-N-hydroxysuccinimide ester [R ¹ = CO-CH = CH ₂ ] Methacrylic acid-N-hydroxysuccinimide ester [R ¹ = CO-C (CH ₃ ) = CH ₂ ] Crotonic acid N- [R ¹ = CO-CH = CH-CH ₃ ] Oleic acid-N-hydroxysuccinimide [R ¹ = CO- (CH ₂ ) ₇ -CH = CH- (CH ₂ ) ₇ -CH ₃ ] Benzoic acid N- [R ¹ = CO-Ph] Phenylacetic acid N- [R ¹ = CO-CH ₂ -Ph] Acetic acid-N-hydroxyphthalimide ester [R ¹ = CO-CH ₃ ] (205) Propionic acid-N-hydroxyphthalimide ester [R ¹ = CO-CH ₂ CH ₃ ] Butyric acid N-hydroxyphthalimide ester [R ¹ = CO-CH ₂ CH ₂ CH ₃ ] Valeria acid N-hydroxyphthalimide ester [R ¹ = CO-CH ₂ CH ₂ CH ₂ CH ₃ ] Isovaleric-N-hydroxyphthalimide ester [R ¹ = CO-CH ₂ CH (CH ₃ ) ₂ ] Pivalic-N-hydroxyphthalimide ester [R ¹ = CO-CH (CH ₃ ) ₃ ] Lauric acid N-hydroxyphthalimide ester [R ¹ = CO- (CH ₂ ) ₁₀ -CH ₃ ]] Myristic acid N-hydroxyphthalimide ester [R ¹ = CO- (CH ₂ ) ₁₂ -CH ₃ ]] Palmitic acid N-hydroxyphthalimide ester [R ¹ = CO- (CH ₂ ) ₁₄ -CH ₃ )] Stearic acid-N-hydroxyphthalimide ester [R ¹ = CO- (CH ₂ ) ₁₆ -CH ₃ )] (443) Acrylic acid-N-hydroxyphthalimide ester [R ¹ = CO-CH = CH ₂ ] Methacrylic acid-N-hydroxyphthalimide ester [R ¹ = CO-C (CH ₃ ) = CH ₂ ] Crotonic acid N-hydroxyphthalimide ester [R ¹ = CO-CH = CH-CH ₃ ] Oleic acid N-hydroxyphthalimide ester [R ¹ = CO- (CH ₂ ) ₇ -CH = CH- (CH ₂ ) ₇ -CH ₃ ] Benzoic acid N-hydroxyphthalimide ester [R ¹ = CO-Ph] Phenylacetic acid N-hydroxyphthalimide ester [R ¹ = CO-CH ₂ -Ph]

R⁴ = CH₃ R⁵ = H R⁶ = H (59) R⁴ = CH₃ R⁵ = CH₃ R⁶ = CH₃ (87) R⁴ = Ethyl R⁵ = CH₃ R⁶ = CH₃ (101) R⁴ = CH₃ R⁵ = Ethyl R⁶ = CH₃ (101) R⁴ = Ethyl R⁵ = Ethyl R⁶ = CH₃ (115) R⁴ = Ethyl R⁵ = Ethyl R⁶ = Ethyl (129) R⁴ = iso-Propyl R⁵ = CH₃ R⁶ = CH₃ (115) R⁴ = CH₃ R⁵ = iso-Propyl R⁶ = CH₃ (115) R⁴ = iso-Propyl R⁵ = iso-Propyl R⁶ = CH₃ (143) R⁴ = iso-Propyl R⁵ = iso-Propyl R⁶ = iso-Propyl (171) R⁴ = n-Butyl R⁵ = CH₃ R⁶ = CH₃ (129) R⁴ = CH₃ R⁵ = n-Butyl R⁶ = CH3 (129) R⁴ = n-Butyl R⁵ = n-Butyl R⁶ = CH₃ (171) R⁴ = n-Butyl R⁵ = n-Butyl R⁶ = n-Butyl (213) R⁴ = n-Propyl R⁵ = CH₃ R⁶ = CH₃ (115) R⁴ = tert.-Butyl R⁵ = CH₃ R⁶ = CH₃ (129) R⁴ = n-Pentyl R⁵ = CH₃ R⁶ = CH₃ (143) R⁴ = n-Hexyl R⁵ = CH₃ R⁶ = CH₃ (157) R⁴ = n-Heptyl R⁵ = CH₃ R⁶ = CH₃ (171) R⁴ = n-Octyl R⁵ = CH₃ R⁶ = CH₃ (185) R⁴ = 2-Ethylhexyl R⁵ = CH₃ R⁶ = CH₃ (185) R⁴ = n-Decyl R⁵ = CH₃ R⁶ = CH₃ (213) R⁴ = 2-Propylheptyl R⁵ = CH₃ R⁶ = CH₃ (213) R⁴ = n-Undecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = n-Dodecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = n-Tridecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = iso-Tridecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = n-Tetradecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = n-Hexadecyl R⁵ = CH₃ R⁶ = CH₃ R⁴ = n-Octadecyl R⁵ = CH₃ R⁶ = CH₃ (325) R⁴ = Oleyl R⁵ = CH₃ R⁶ = CH₃ (323) R⁴ = Cyclohexyl R⁵ = CH₃ R⁶ = CH₃ (155) R⁴ = Acetyl R⁵ = CH₃ R⁶ CH₃ (115) R⁴ = Benzoyl R⁵ = CH₃ R⁶ = CH₃ (177) R⁴ = Phenyl R⁵ = CH₃ R⁶ = CH₃ (149) R⁴ = Benzyl R⁵ = CH₃ R⁶ = CH₃ (163) R⁴ = CH₃ R⁵ = Ethyl R⁶ = Ethyl (115) R⁴ = CH₃ R⁵ = n-Propyl R⁶ = n-Propyl (143) R⁴ = CH₃ R⁵ = iso-Propyl R⁶ = iso-Propyl (143) R⁴ = CH₃ R⁵ = n-Butyl R⁶ = n-Butyl (171) R⁴ = CH₃ R⁵ = tert.-Butyl R⁶ = tert.-Butyl (171) R⁴ = CH₃ R⁵ = n-Pentyl R⁶ = n-Pentyl (199) R⁴ = CH₃ R⁵ = n-Hexyl R⁶ = n-Hexyl (227) R⁴ = CH₃ R⁵ = n-Heptyl R⁶ = n-Heptyl R⁴ = CH₃ R⁵ = n-Octyl R⁶ = n-Octyl R⁴ = CH₃ R⁵ = 2-Ethylhexyl R⁶ = 2-Ethylhexyl R⁴ = CH₃ R⁵ = n-Decyl R⁶ = n-Decyl R⁴ = CH₃ R⁵ = 2-Propylheptyl R⁶ = 2-Propylheptyl R⁴ = CH₃ R⁵ = n-Undecyl R⁶ = n-Undecyl R⁴ = CH₃ R⁵ = n-Dodecyl R⁶ = n-Dodecyl R⁴ = CH₃ R⁵ = n-Tridecyl R⁶ = n-Tridecyl R⁴ = CH₃ R⁵ = iso-Tridecyl R⁶ = iso-Tridecyl R⁴ = CH₃ R⁵ = n-Tetradecyl R⁶ = n-Tetradecyl R⁴ = CH₃ R⁵ = n-Hexadecyl R⁶ = n-Hexadecyl R⁴ = CH₃ R⁵ = n-Octadecyl R⁶ = n-Octadecyl (563) R⁴ = CH₃ R⁵ = Oleyl R⁶ = Oleyl (559) R⁴ = CH₃ R⁵ = Cyclohexyl R⁶ = Cyclohexyl (223) R⁴ = CH₃ R⁵ = Phenyl R⁶ = Phenyl (211) R⁴ = CH₃ R⁵ = Ethyl R⁶ = n-Butyl (143) R⁴ = n-Butyl R⁵ = iso-Propyl R⁶ = CH₃ (157) R⁴ = Ethyl R⁵ = iso-Propyl R⁶ = CH₃ (129) R⁴ = iso-Propyl R⁵ = n-Butyl R⁶ = Ethyl (171) R⁴ = Acetyl R⁵ = CH₃ R⁶ = Acetyl (143) R⁴ = CH₃ R⁵ = Acetyl R⁶ = Acetyl (143) R⁴ = CH₃ R⁵ = Acetyl R⁶ = Benzyl (176) R⁴ = CH₃ R⁵ = Benzyl R⁶ = Benzyl R⁴ = CH₃ R⁵ = Benzyl R⁶ = Benzoyl R⁴ = CH₃ R⁵ = Benzoyl R⁶ = Benzoyl R⁴ = Oleyl R⁵ = Acetyl R⁶ = Acetyl R⁴ = Oleyl R⁵ = Acetyl R⁶ = Benzyl R⁴ = Oleyl R⁵ = Phenyl R⁶ = Phenyl R⁴ = Oleyl R⁵ = Benzyl R⁶ = Benzyl R⁴ = Oleyl R⁵ = Benzyl R⁶ = Benzoyl R⁴ = Oleyl R⁵ = Benzoyl R⁶ = Benzoyl (501) Typical examples of oxime ethers of the general formula (Ib) are (in parentheses: molecular weight):

R ⁴ = CH ₃ R ⁵ = H R ⁶ = H (59) R ⁴ = CH ₃ R ⁵ = CH ₃ R ⁶ = CH ₃ (87) R ⁴ = ethyl R ⁵ = CH ₃ R ⁶ = CH ₃ (101) R ⁴ = CH ₃ R ⁵ = ethyl R ⁶ = CH ₃ (101) R ⁴ = ethyl R ⁵ = ethyl R ⁶ = CH ₃ (115) R ⁴ = ethyl R ⁵ = ethyl R ⁶ = ethyl (129) R ⁴ = iso-propyl R ⁵ = CH ₃ R ⁶ = CH ₃ (115) R ⁴ = CH ₃ R ⁵ = iso-propyl R ⁶ = CH ₃ (115) R ⁴ = iso-propyl R ⁵ = iso-propyl R ⁶ = CH ₃ (143) R ⁴ = iso-propyl R ⁵ = iso-propyl R ⁶ = iso-propyl (171) R ⁴ = n-butyl R ⁵ = CH ₃ R ⁶ = CH ₃ (129) R ⁴ = CH ₃ R ⁵ = n-butyl R ⁶ = CH 3 (129) R ⁴ = n-butyl R ⁵ = n-butyl R ⁶ = CH ₃ (171) R ⁴ = n-butyl R ⁵ = n-butyl R ⁶ = n-butyl (213) R ⁴ = n-propyl R ⁵ = CH ₃ R ⁶ = CH ₃ (115) R ⁴ = tert-butyl R ⁵ = CH ₃ R ⁶ = CH ₃ (129) R ⁴ = n-pentyl R ⁵ = CH ₃ R ⁶ = CH ₃ (143) R ⁴ = n-hexyl R ⁵ = CH ₃ R ⁶ = CH ₃ (157) R ⁴ = n-heptyl R ⁵ = CH ₃ R ⁶ = CH ₃ (171) R ⁴ = n-octyl R ⁵ = CH ₃ R ⁶ = CH ₃ (185) R ⁴ = 2-ethylhexyl R ⁵ = CH ₃ R ⁶ = CH ₃ (185) R ⁴ = n-decyl R ⁵ = CH ₃ R ⁶ = CH ₃ (213) R ⁴ = 2-propylheptyl R ⁵ = CH ₃ R ⁶ = CH ₃ (213) R ⁴ = n-undecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = n-dodecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = n-tridecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = iso-tridecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = n-tetradecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = n-hexadecyl R ⁵ = CH ₃ R ⁶ = CH ₃ R ⁴ = n-octadecyl R ⁵ = CH ₃ R ⁶ = CH ₃ (325) R ⁴ = oleyl R ⁵ = CH ₃ R ⁶ = CH ₃ (323) R ⁴ = cyclohexyl R ⁵ = CH ₃ R ⁶ = CH ₃ (155) R ⁴ = acetyl R ⁵ = CH ₃ R ⁶ CH ₃ (115) R ⁴ = benzoyl R ⁵ = CH ₃ R ⁶ = CH ₃ (177) R ⁴ = phenyl R ⁵ = CH ₃ R ⁶ = CH ₃ (149) R ⁴ = benzyl R ⁵ = CH ₃ R ⁶ = CH ₃ (163) R ⁴ = CH ₃ R ⁵ = ethyl R ⁶ = ethyl (115) R ⁴ = CH ₃ R ⁵ = n-propyl R ⁶ = n-propyl (143) R ⁴ = CH ₃ R ⁵ = iso-propyl R ⁶ = iso-propyl (143) R ⁴ = CH ₃ R ⁵ = n-butyl R ⁶ = n-butyl (171) R ⁴ = CH ₃ R ⁵ = tert-butyl R ⁶ = tert-butyl (171) R ⁴ = CH ₃ R ⁵ = n-pentyl R ⁶ = n-pentyl (199) R ⁴ = CH ₃ R ⁵ = n-hexyl R ⁶ = n-hexyl (227) R ⁴ = CH ₃ R ⁵ = n-heptyl R ⁶ = n-heptyl R ⁴ = CH ₃ R ⁵ = n-octyl R ⁶ = n-octyl R ⁴ = CH ₃ R ⁵ = 2-ethylhexyl R ⁶ = 2-ethylhexyl R ⁴ = CH ₃ R ⁵ = n-decyl R ⁶ = n-decyl R ⁴ = CH ₃ R ⁵ = 2-propylheptyl R ⁶ = 2-propylheptyl R ⁴ = CH ₃ R ⁵ = n-undecyl R ⁶ = n-undecyl R ⁴ = CH ₃ R ⁵ = n-dodecyl R ⁶ = n-dodecyl R ⁴ = CH ₃ R ⁵ = n-tridecyl R ⁶ = n-tridecyl R ⁴ = CH ₃ R ⁵ = iso-tridecyl R ⁶ = iso-tridecyl R ⁴ = CH ₃ R ⁵ = n-tetradecyl R ⁶ = n-tetradecyl R ⁴ = CH ₃ R ⁵ = n-hexadecyl R ⁶ = n-hexadecyl R ⁴ = CH ₃ R ⁵ = n-octadecyl R ⁶ = n-octadecyl (563) R ⁴ = CH ₃ R ⁵ = oleyl R ⁶ = oleyl (559) R ⁴ = CH ₃ R ⁵ = cyclohexyl R ⁶ = cyclohexyl (223) R ⁴ = CH ₃ R ⁵ = phenyl R ⁶ = phenyl (211) R ⁴ = CH ₃ R ⁵ = ethyl R ⁶ = n-butyl (143) R ⁴ = n-butyl R ⁵ = iso-propyl R ⁶ = CH ₃ (157) R ⁴ = ethyl R ⁵ = iso-propyl R ⁶ = CH ₃ (129) R ⁴ = iso-propyl R ⁵ = n-butyl R ⁶ = ethyl (171) R ⁴ = acetyl R ⁵ = CH ₃ R ⁶ = acetyl (143) R ⁴ = CH ₃ R ⁵ = acetyl R ⁶ = acetyl (143) R ⁴ = CH ₃ R ⁵ = acetyl R ⁶ = benzyl (176) R ⁴ = CH ₃ R ⁵ = benzyl R ⁶ = benzyl R ⁴ = CH ₃ R ⁵ = benzyl R ⁶ = benzoyl R ⁴ = CH ₃ R ⁵ = benzoyl R ⁶ = benzoyl R ⁴ = oleyl R ⁵ = acetyl R ⁶ = acetyl R ⁴ = oleyl R ⁵ = acetyl R ⁶ = benzyl R ⁴ = oleyl R ⁵ = phenyl R ⁶ = phenyl R ⁴ = oleyl R ⁵ = benzyl R ⁶ = benzyl R ⁴ = oleyl R ⁵ = benzyl R ⁶ = benzoyl R ⁴ = oleyl R ⁵ = benzoyl R ⁶ = benzoyl (501)

Variables R ¹ to R ⁶ which may additionally carry carboxylic acid ester and / or carboxamide groups are, for example, the following:
-CH ₂ -COO-CH ₃
-CH ₂ -COO-CH ₂ CH ₃
-CH ₂ -COO-CH ₂ (CH ₃ ) ₂
-CH ₂ -COO- (CH ₂ ) ₃ CH ₃
-CH ₂ -COO- (CH ₂ ) ₄ CH ₃
-CH ₂ -COO- (CH ₂ ) ₆ CH ₃
-CH ₂ -COO- (CH ₂ ) ₇ CH ₃
-CH ₂ -COO-CH ₂ -CH (CH ₂ CH ₃ ) - (CH ₂ ) ₃ CH ₃
-CH ₂ -COO- (CH ₂ ) ₉ CH ₃
-CH ₂ -COO-CH ₂ -CH (CH ₂ CH ₂ CH ₃ ) - (CH ₂ ) ₄ CH ₃
-CH ₂ -COO- (CH ₂ ) ₁₁ CH ₃
-CH ₂ -COO- (CH ₂ ) ₁₃ CH ₃
-CH ₂ -COO- (CH ₂ ) ₁₅ CH ₃
-CH ₂ -COO- (CH ₂ ) ₁₇ CH ₃
-CH ₂ -COO- (CH ₂ ) ₈ -CH = CH- (CH ₂ ) ₇ -CH ₃
-CH ₂ -COO-CH ₂ -Ph
-CH ₂ CH ₂ -COO-CH ₃
- (CH ₂ ) ₃ -COO-CH ₃
- (CH ₂ ) ₄ -COO-CH ₃
-CH ₂ -COO-NH ₂
-CH ₂ -COO-NH-CH ₃
-CH ₂ -COO-N (CH ₃ ) ₂
-CH ₂ -COO-N [(CH ₂ ) ₃ CH ₃ ] ₂
-CH ₂ -COO-N [(CH ₂ ) ₅ CH ₃ ] ₂
-CH ₂ -COO-N [(CH ₂ ) ₇ CH ₃ ] ₂
-CH ₂ -COO-N [(CH ₂ ) ₉ CH ₃ ] ₂
-CH ₂ -COO-N [(CH ₂ ) ₁₁ CH ₃ ] ₂
-CH ₂ CH ₂ -COO-NH ₂
- (CH ₂ ) ₃ -COO-NH ₂
- (CH ₂ ) ₄ -COO-NH ₂

R ¹ to R ⁶ with alkyl and alkenyl chains are interrupted by one or more oxygen atoms and / or nitrogen atoms may be interrupted, for example the following:
-CH ₂ -O-CH ₃
-CH ₂ CH ₂ -O-CH ₃
-CH ₂ -O-CH ₂ CH ₃
-CH ₂ -CH (CH ₃ ) -O-CH ₃
-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₃
-CH ₂ CH ₂ CH ₂ -O-CH ₂ CH ₂ CH ₂ -O-CH ₃
-CH ₂ -NH-CH ₃
-CH ₂ CH ₂ -NH-CH ₃
-CH ₂ CH ₂ -NH-CH ₂ CH ₃
-CH ₂ CH ₂ -N (CH ₃₎ -CH ₃
-CH ₂ CH ₂ -NH-CH ₂ CH ₂ -NH-CH ₃

The variables R ¹ to R ⁶ contain no free hydroxyl groups, as their presence has been found to be detrimental to the effect of the organic compounds (I) or (Ia) or (Ib) to reduce the fuel consumption of diesel engines. The non-substituted at the oxygen atom to the organic compounds (Ia) analogous hydroxylamines and also corresponding nitroxides are also not suitable for the present invention.

To reduce fuel consumption, a single substance of said organic compounds (I) or (Ia) or (Ib) or a mixture of a plurality of such organic compounds can be added to the fuel for operating diesel engines.

The metering rate in diesel fuel is usually chosen so that the organic compound (I) or (Ia) or (Ib), if it is used as a single substance, or the mixture of such organic compounds in a concentration of 10 to 10,000 wt . ppm, preferably 50 to 5000 ppm by weight, in particular 100 to 2500 ppm by weight, especially 250 to 1500 ppm by weight, in each case based on the total amount of diesel fuel, as a fuel additive. The addition of further additives, which in themselves also bring about a reduction in fuel consumption or support the said organic compounds, is not necessary.

The diesel fuel may contain other common additives for improving efficacy and reducing wear. Here are primarily detergent additives and carrier oils to call.

• (Da) Mono- oder Polyaminogruppen mit bis zu 6 Stickstoffatomen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
• (Db) Nitrogruppen, gegebenenfalls in Kombination mit Hydroxylgruppen;
• (Dc) Hydroxylgruppen in Kombination mit Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
• (Dd) Carboxylgruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen;
• (De) Sulfonsäuregruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen;
• (Df) Polyoxy-C₂-C₄-alkylengruppierungen, die durch Hydroxylgruppen, Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat, oder durch Carbamatgruppen terminiert sind;
• (Dg) Carbonsäureestergruppen;
• (Dh) aus Bernsteinsäureanhydrid abgeleiteten Gruppierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen; und/oder
• (Di) durch Mannich-Umsetzung von substituierten Phenolen mit Aldehyden und Mono- oder Polyaminen erzeugten Gruppierungen;

Preferably, the detergent additives are amphiphilic substances having at least one hydrophobic hydrocarbon radical having a number average molecular weight (M _n ) of from 85 to 20,000 and at least one polar moiety selected from:

• (Da) mono- or polyamino groups having up to 6 nitrogen atoms, wherein at least one nitrogen atom has basic properties;
• (Db) nitro groups, optionally in combination with hydroxyl groups;
• (Dc) hydroxyl groups in combination with mono- or polyamino groups, wherein at least one nitrogen atom has basic properties;
• (Dd) carboxyl groups or their alkali metal or alkaline earth metal salts;
• (De) sulfonic acid groups or their alkali metal or alkaline earth metal salts;
• (Df) polyoxy-C ₂ -C ₄ -alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, at least one nitrogen atom has basic properties, or by carbamate groups;
• (Dg) carboxylic acid ester groups;
• (Ie) derived from succinic anhydride moieties having hydroxy and / or amino and / or amido and / or imido groups; and or
• (Di) groups generated by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines;

The hydrophobic hydrocarbon radical in the above detergent additives, which provides sufficient solubility in the fuel, has a number average molecular weight (Mn) of 85 to 20,000, preferably 113 to 10,000, more preferably 300 to 5,000, more preferably 300 to 3,000 more preferably from 500 to 2500 and especially from 700 to 2500, especially from 800 to 1500. As a typical hydrophobic hydrocarbon radical, in particular in conjunction with the polar in particular Polypropenyl-, Polybutenyl- and Polyisobutenylreste having a number average molecular weight M _n of preferably 300 to 5000, more preferably 300 to 3000, more preferably 500 to 2500 even more preferably 700 to 2500 and especially 800 to 1500 into consideration.

As examples of the above groups of detergent additives, the following are mentioned:
Mono- or polyamino (Da) -containing additives are preferably polyalkene mono- or polyalkene polyamines based on polypropene or of highly reactive (ie predominantly terminal double bonds) or conventional (ie predominantly intermediate double bonds) polybutene or polyisobutene with M _n = 300 to 5000, especially preferably 500 to 2500 and in particular 700 to 2500. Such additives based on highly reactive polyisobutene, which from the 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 can be prepared, in particular from EP-A 244 616 known. If one proceeds in the preparation of the additives of polybutene or polyisobutene with predominantly intermediate double bonds (usually in the β and γ 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 here amines, such as. As ammonia, monoamines or the above polyamines, are used. Corresponding additives based on polypropene are especially in the WO-A 94/24231 described.

Further preferred monoamine (Da) containing additives are the hydrogenation 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 are described.

Further preferred monoamino (Da) -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 US Pat DE-A 196 20 262 are described.

Nitro groups (Db), optionally in combination with hydroxyl groups, containing additives 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-A96 / 03367 and in the WO-A 96/03479 are described. These reaction products are generally mixtures of pure nitropolyisobutenes (eg, α, β-dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (eg, α-nitro-β-hydroxy polyisobutene).

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

Carboxyl groups or their alkali metal or alkaline earth metal salts (Dd) containing additives 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 are reacted with alcohols or amines. Such additives are in particular from the EP-A 307 815 known. Such additives are primarily for preventing valve seat wear and can, as in the WO-A 87/01126 described, be used with advantage 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 (De) containing additives are preferably alkali metal or alkaline earth metal salts of a Sulfobernsteinsäurealkylesters, as described in particular in EP-A 639 632 is described. 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.

Polyoxy-C ₂ -C ₄ -alkylene (Df) containing additives are preferably polyether or polyetheramines, which 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 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, Monoamines or polyamines are available. Such products are used in particular in the EP-A 310 875 . EP-A 356 725 . EP-A 700 985 and US Pat. No. 4,877,416 described. In the case of polyethers, such products also meet carrier oil properties. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

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

Derived from succinic anhydride Groups containing hydroxyl and / or amino and / or amido and / or imido (Dh) containing additives are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and in particular the corresponding derivatives of polyisobutenyl succinic anhydride, which by reacting conventional or highly reactive Polyisobutene having M _n = preferably 300 to 5000, more preferably 300 to 3000, more preferably 500 to 2500, even more preferably 700 to 2500 and especially 800 to 1500, with maleic anhydride by thermal means in an ene reaction or on the chlorinated polyisobutene available are. The groups having hydroxyl and / or amino and / or amido and / or imido groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of diamines or polyamines which, in addition to the amide function, still have free amine groups, succinic acid derivatives with a Acid and an amide, Carbonsäureimide with monoamines, Carbonsäureimide with di- or polyamines, which still have free amine groups in addition to the imide function, or diimides, which are formed by the reaction of di- or polyamines with two succinic acid derivatives. Such fuel additives are well known and, for example, in the US Pat. No. 4,849,572 described. Preference is given to the reaction products of alkyl- or alkenyl-substituted succinic acids or derivatives thereof with amines and particularly preferably to the reaction products of polyisobutenyl-substituted succinic acids or derivatives thereof with amines. Of particular interest here are reaction products with aliphatic polyamines (polyalkyleneimines) such as, in particular, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine. Of these, particular preference is given to diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated moieties containing (Di) additives 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 may be derived from conventional or highly reactive polyisobutene having M _n = 300 to 5,000. Such "polyisobutene-Mannich bases" are particularly in the EP-A 831 141 described.

Particularly preferred are detergent additives from the group (Dh). These are preferably the reaction products of alkyl- or alkenyl-substituted succinic anhydrides, in particular polyisobutenylsuccinic anhydrides, with amines, especially with the abovementioned polyamines. It goes without saying that these reaction products are obtainable not only when substituted succinic anhydride is used, but also when substituted succinic acid or suitable acid derivatives such as succinic acid halides or esters are used. Particularly preferred detergent additives (Dh) are polyisobutenyl-substituted succinimides, especially the imides with aliphatic polyamines. Particularly preferred polyamines are diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine, with tetraethylenepentamine being particularly preferred. The polyisobutenyl radical has a number average molecular weight M _n of preferably 300 to 5000, z. B. from 300 to 5000, more preferably from 300 to 3000, z. From 500 to 3000, more preferably from 500 to 2500, even more preferably from 700 to 2500, and especially from 800 to 1500, e.g. B. of about 1000.

It goes without saying that the said detergent additives can be used alone or in combination with one another. Preferably, however, the detergent additive (Dh) is used alone or as a mixture of various detergent additives (Dh).

The diesel fuel is the detergent additive or the mixture of various detergent additives in a total amount of preferably 10 to 2000 ppm by weight, more preferably from 20 to 1000 ppm by weight, more preferably from 50 to 500 ppm by weight and especially from 50 to 200 ppm by weight, z. B. from 70 to 150 ppm by weight added.

Carrier oils can be mineral or synthetic in nature. Suitable mineral carrier oils are fractions obtained in petroleum processing, such as bright stock or base oils with viscosities such as from the class SN 500 to 2000 ; but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. It is also useful as a "hydrocrack oil" known and obtained in the refining of mineral oil fraction (Vakuumdestillatschnitt with a boiling range of about 360 to 500 ° C, available from high pressure catalytically hydrogenated and isomerized and dewaxed natural mineral oil). Also suitable are mixtures of the abovementioned mineral carrier oils.

Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins or polyinternalolefins), (poly) esters, poly) alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-initiated polyethers, alkylphenol-initiated polyetheramines and carboxylic acid esters of long-chain alkanols.

Examples of suitable polyolefins are olefin polymers having M _n = 400 to 1800, especially based on polybutene or polyisobutene (hydrogenated or non-hydrogenated).

Examples of suitable polyethers or polyetheramines 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 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. Such products are used in particular in the EP-A 310 875 . EP-A 356 725 . EP-A 700 985 and US-A 4,877,416 described. For example, as polyetheramines, poly-C ₂ -C ₆ alkylene oxide amines or functional derivatives thereof can be used. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

Examples of carboxylic acid esters of long-chain alkanols are, in particular, esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, as are described in particular in US Pat DE-A 38 38 918 are described. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, eg. B. di- (n- or isotridecyl) phthalate.

Other suitable carrier oil systems are for example in the DE-A 38 26 608 . DE-A 41 42 241 . DE-A 43 09 074 . EP-A 452 328 and EP-A 548 617 described.

Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers having about 5 to 35, preferably about 5 to 30, particularly preferably 10 to 30 and in particular 15 to 30 C ₃ -C ₆ -alkylene oxide units, for. For example, propylene oxide, n-butylene oxide and isobutylene oxide units or mixtures thereof, per alcohol molecule. 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. Preferred examples are tridecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyetherification products) of monohydric aliphatic C ₆ -C ₁₈ -alcohols with C ₃ -C ₆ -alkylene oxides. Examples of monohydric aliphatic C ₆ -C ₁₈ -alcohols are hexanol, heptanol, octanol, 2-ethylhexanol, nonyl alcohol, decanol, 3-propylheptanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol and their constitution and position isomers. The alcohols can be used both in the form of pure isomers and in the form of technical mixtures. A particularly preferred alcohol is tridecanol. Examples of C ₃ -C ₆ -alkylene oxides are propylene oxide, such as 1,2-propylene oxide, butylene oxide, such as 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Among these, particularly preferred are C ₃ -C ₄ -alkylene oxides, ie, propylene oxide such as 1,2-propylene oxide and butylene oxide such as 1,2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Specifically, butylene oxide is used.

Other suitable synthetic carrier oils are alkoxylated alkylphenols, as described in the DE-A 10 102 913 are described.

Preferred carrier oils are synthetic carrier oils, the alcohol-initiated polyethers described above being particularly preferred.

The carrier oil or the mixture of different carrier oils is added to the diesel fuel in an amount of preferably from 1 to 1000 ppm by weight, more preferably from 10 to 500 ppm by weight and in particular from 20 to 100 ppm by weight.

In addition, the diesel fuel may contain other conventional additives and co-additives in the amounts customary therefor, in particular cold flow improvers, corrosion inhibitors, demulsifiers, dehazers, defoamers, cetane improvers, combustion improvers, antioxidants or stabilizers, antistatic agents, metallocenes, metal deactivators, dyes, solvents and the like.

Suitable cold flow improvers are in principle all organic compounds which are able to improve the flow behavior of diesel fuels in the cold. Conveniently, they must have sufficient oil solubility. In particular, the usually used for middle distillates of fossil origin, ie for conventional mineral diesel fuels, used cold flow improvers ("middle distillate flow improvers", "MDFI") come into consideration. However, it is also possible to use organic compounds which, when used in conventional diesel fuels, have in part or predominantly the properties of a wax anti-settling additive ("WASA"). Also, they can partly or predominantly as nucleators Act. However, it is also possible to use mixtures of organic compounds which are active as MDFI and / or which act as WASA and / or as nucleators.

• (K1) Copolymeren eines C₂- bis C₄₀-Olefins mit wenigstens einem weiteren ethylenisch ungesättigten Monomer;
• (K2) Kammpolymeren;
• (K3) Polyoxyalkylenen;
• (K4) polaren Stickstoffverbindungen;
• (K5) Sulfocarbonsäuren oder Sulfonsäuren oder deren Derivaten; und
• (K6) Poly(meth)acrylsäureestern.

Typically, the cold flow improver is selected from:

• (K1) copolymers of a C ₂ to C ₄₀ olefin with at least one further ethylenically unsaturated monomer;
• (K2) comb polymers;
• (K3) polyoxyalkylenes;
• (K4) polar nitrogen compounds;
• (K5) sulfocarboxylic acids or sulfonic acids or their derivatives; and
• (K6) poly (meth) acrylic acid esters.

Mixtures of different representatives from one of the respective classes (K1) to (K6) as well as mixtures of representatives from different classes (K1) to (K6) can be used.

Suitable C ₂ to C ₄₀ olefin monomers for the copolymers of class (K1) are, for example, those having 2 to 20, in particular 2 to 10 carbon atoms and having 1 to 3, preferably 1 or 2, in particular having one carbon-carbon double bond. In the latter case, the carbon-carbon double bond can be arranged both terminally (α-olefins) and internally. However, preferred are α-olefins, more preferably α-olefins having 2 to 6 carbon atoms, for example propene, 1-butene, 1-pentene, 1-hexene and especially ethylene.

In the copolymers of class (K1), the at least one further ethylenically unsaturated monomer is preferably selected from carboxylic alkenyl esters, (meth) acrylic esters and further olefins.

If further olefins are polymerized in, these are preferably higher molecular weight than the abovementioned C ₂ to C ₄₀ olefin base monomers. If, for example, as the olefin-base monomer is ethylene or propene, are suitable as other olefins, in particular C ₁₀ - to C ₄₀ -α-olefins. Other olefins are polymerized in most cases only when monomers with carboxylic acid ester functions are used.

Suitable (meth) acrylic esters are, for example, esters of (meth) acrylic acid with C ₁ - to C ₂₀ -alkanols, in particular C ₁ - to C ₁₀ -alkanols, especially with methanol, ethanol, propanol, isopropanol, n-butanol, sec. Butanol, isobutanol, tert-butanol, pentanol, hexanol, heptanol, octanol, 2-ethylhexanol, nonanol and decanol and structural isomers thereof.

Suitable carboxylic alkenyl esters are, for example, C ₂ -C ₁₄ -alkenyl esters, eg. As the vinyl and propenyl esters of carboxylic acids having 2 to 21 carbon atoms, the hydrocarbon radical may be linear or branched. Preferred among these are the vinyl esters. Among the carboxylic acids with a branched hydrocarbon radical, preference is given to those whose branching is in the α-position to the carboxyl group, the α-carbon atom being particularly preferably tertiary, ie the carboxylic acid being a so-called neocarboxylic acid. Preferably, however, the hydrocarbon radical of the carboxylic acid is linear.

Examples of suitable carboxylic alkenyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, the vinyl esters being preferred. A particularly preferred carboxylic acid alkenyl ester is vinyl acetate; typical resulting copolymers of group (K1) are the most commonly used ethylene-vinyl acetate copolymers ("EVA"). Particularly advantageous ethylene-vinyl acetate copolymers and their preparation are in the WO 99/29748 described.

Also suitable as copolymers of class (K1) are those which contain two or more different carboxylic acid alkenyl esters in copolymerized form, these differing in the alkenyl function and / or in the carboxylic acid group. Also suitable are copolymers which, in addition to the carboxylic acid alkenyl ester (s), contain at least one olefin and / or at least one (meth) acrylic acid ester in copolymerized form.

Also, terpolymers of a C ₂ - to C ₄₀ -α-olefin, a C ₁ - to C ₂₀ alkyl ester of an ethylenically unsaturated monocarboxylic acid having 3 to 15 carbon atoms and a C ₂ - to C ₁₄ alkenyl ester of a saturated monocarboxylic acid having 2 to 21 Carbon atoms are suitable as copolymers of class (K1). Such terpolymers are in the WO 2005/054314 described. A typical such terpolymer is composed of ethylene, 2-ethylhexyl acrylate and vinyl acetate.

The at least one or the other ethylenically unsaturated monomers are present in the copolymers of class (K1) in an amount of preferably from 1 to 50% by weight, in particular from 10 to 45% by weight and especially from 20 to 40% by weight. %, based on the total copolymer, copolymerized. The majority by weight of the monomer units in the copolymers of class (K1) is thus usually derived from the C ₂ to C _{40 based} olefins.

The copolymers of class (K1) preferably have a number average molecular weight M _{n of} from 1000 to 20,000, particularly preferably from 1000 to 10,000 and in particular from 1000 to 8000.

Typical comb polymers of component (K2) are, for example, by the copolymerization of maleic anhydride or fumaric acid with another ethylenically unsaturated monomer, for example with an α-olefin or an unsaturated ester such as vinyl acetate, and subsequent esterification of the anhydride or acid function with an alcohol having at least 10 carbon atoms available. Further suitable comb polymers are copolymers of α-olefins and esterified comonomers, for example esterified copolymers of styrene and maleic anhydride or esterified copolymers of styrene and fumaric acid. Suitable comb polymers may also be polyfumarates or polymaleinates. In addition, homopolymers and copolymers of vinyl ethers are suitable comb polymers. As a component of class (K2) suitable comb polymers are, for example, those which are described in the WO 2004/035715 and in "Comb-Like Polymers. Structure and Properties ", NA Platé and VP Shibaev, J. Poly. Sci. Macromolecular Revs. 8, pages 117 to 253 (1974) " are described. Also mixtures of comb polymers are suitable.

As the component of the class (K3), suitable polyoxyalkylenes are, for example, polyoxyalkylene esters, polyoxyalkylene ethers, mixed polyoxyalkylene ester ethers, and mixtures thereof. Preferably, these polyoxyalkylene contain at least one, preferably at least two linear alkyl groups each having 10 to 30 carbon atoms and a polyoxyalkylene group having a number average molecular weight of up to 5000. Such polyoxyalkylene compounds are for example in the EP-A 061 895 as well as in the U.S. 4,491,455 described. Preferred polyoxyalkylene compounds are based on polyethylene glycols and polypropylene glycols having a number average molecular weight of 100 to 5000. Further, polyoxyalkylene mono- and diesters of fatty acids having 10 to 30 carbon atoms such as stearic acid or behenic acid are suitable.

Polar nitrogen compounds suitable as a component of class (K4) may be of both ionic and nonionic nature, and preferably have at least one, especially at least two, tertiary nitrogen substituent of the general formula> NR ⁷ wherein R ^{7 is} C ₈ - to C ₄₀ hydrocarbon radical stands. The nitrogen substituents may also be quaternized, that is in cationic form. Examples of such nitrogen compounds are ammonium salts and / or amides obtainable by reacting at least one amine substituted with at least one hydrocarbyl radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. The amines preferably contain at least one linear C ₈ - to C ₄₀ -alkyl radical. Examples of suitable primary amines for the preparation of said polar nitrogen compounds are octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine and the higher linear homologues, and suitable secondary amines are, for example, dioctadecylamine and methylbehenylamine. Also suitable for this purpose are amine mixtures, in particular industrially available amine mixtures such as fatty amines or hydrogenated tallamines, as described, for example, in US Pat Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, in the chapter "Amines, aliphatic" to be discribed. Suitable acids for the reaction are, for example, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and succinic acids substituted by long-chain hydrocarbon radicals.

In particular, the component of class (K4) is an oil-soluble reaction product of at least one tertiary amino group-containing poly (C ₂ - to C ₂₀ -carboxylic acids) with primary or secondary amines. The poly (C ₂ - to C ₂₀ -carboxylic acids) which have at least one tertiary amino group and are based on this reaction product preferably contain at least 3 carboxyl groups, in particular 3 to 12, especially 3 to 5 carboxyl groups. The carboxylic acid units in the polycarboxylic acids preferably have 2 to 10 carbon atoms, in particular they are acetic acid units. The carboxylic acid units are suitably linked to the polycarboxylic acids, usually via one or more carbon and / or or nitrogen atoms. Preferably, they are attached to tertiary nitrogen atoms, which are connected in the case of several nitrogen atoms via hydrocarbon chains.

in denen die Variable A eine geradkettige oder verzweigte C₂- bis C₆-Alkylengruppe oder die Gruppierung der Formel III

darstellt und die Variable B eine C₁- bis C₁₉-Alkylengruppe bezeichnet. Die Verbindungen der allgemeinen Formel IIa und IIb weisen insbesondere die Eigenschaften eines WASA auf.Preferably, the component of class (K4) is an oil-soluble reaction product based on at least one tertiary amino group-containing poly (C ₂ - to C ₂₀ -carboxylic acids) of the general formula IIa or IIb

in which the variable A is a straight-chain or branched C ₂ - to C ₆ -alkylene group or the grouping of the formula III

and the variable B denotes a C ₁ - to C ₁₉ -alkylene group. The compounds of the general formula IIa and IIb have in particular the properties of a WASA.

Furthermore, the preferred oil-soluble reaction product of component (K4), in particular that of general formula IIa or IIb, is an amide, an amide ammonium salt or an ammonium salt in which no, one or more carboxylic acid groups are converted into amide groups.

Straight-chain or branched C ₂ -C ₆ -alkylene groups of the variable A are, for example, 1,1-ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1,3-butylene, 1,4- Butylene, 2-methyl-1,3-propylene, 1,5-pentylene, 2-methyl-1,4-butylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene (hexamethylene), and especially 1,2-ethylene. Preferably, the variable A comprises 2 to 4, in particular 2 or 3 carbon atoms.

C ₁ - to C ₁₉ -alkylene groups of the variables B are, for example, 1,2-ethylene, 1,3-propylene, 1,4-butylene, hexamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, octadecamethylene, nonadecamethylene and in particular methylene , Preferably, the variable B comprises 1 to 10, in particular 1 to 4, carbon atoms.

The primary and secondary amines as reaction partners for the polycarboxylic acids to form the component (K4) are usually monoamines, in particular aliphatic monoamines. These primary and secondary amines may be selected from a variety of amines bearing hydrocarbon radicals, optionally linked together.

In most cases, these amines are secondary amines on which the oil-soluble reaction products of component (K4) are based and have the general formula HN (R ⁸ ) ₂ , in which the two variables R ⁸ are each independently straight-chain or branched C ₁₀ - to C ₃₀ -alkyl radicals, in particular C ₁₄ - to C ₂₄ -alkyl radicals. These longer-chain alkyl radicals are preferably straight-chain or only slightly branched. As a rule, the abovementioned secondary amines are derived with regard to their longer-chain alkyl radicals from naturally occurring fatty acid or from its derivatives. Preferably, the two radicals R ^{8 are the} same.

The abovementioned secondary amines can be bound to the polycarboxylic acids by means of amide structures or in the form of the ammonium salts, and only one part can be present as amide structures and another part as ammonium salts. Preferably, only a few or no free acid groups are present. Preferably, the oil-soluble reaction products of component (K4) are completely in the form of the amide structures.

Typical examples of such components (K4) are reaction products of nitrilotriacetic acid, ethylenediaminetetraacetic acid or propylene-1,2-diaminetetraacetic acid with in each case 0.5 to 1.5 mol per carboxyl group, in particular 0.8 to 1.2 mol per carboxyl group, dioleylamine , Dipalmitinamin, Dikokosfettamin, distearylamine, dibehenylamine or especially Ditalgfettamin. A particularly preferred component (K4) is the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated ditallow fatty amine.

Other typical examples of the component (K4) include the N, N-dialkylammonium salts of 2-N ', N'-dialkylamidobenzoates, for example the reaction product of 1 mole of phthalic anhydride and 2 moles of ditallow fatty amine, the latter being hydrogenated or unhydrogenated, and the reaction product of 1 mole of a Alkenylspirobislactons with 2 moles of a dialkylamine, for example Ditalgfettamin and / or tallow fatty amine, the latter two may be hydrogenated or not hydrogenated, called.

Further typical structural types for the component of class (K4) are cyclic compounds with tertiary amino groups or condensates of long-chain primary or secondary amines with carboxylic acid-containing polymers, as described in US Pat WO 93/18115 are described.

Sulfocarboxylic acids, sulfonic acids or their derivatives which are suitable as cold flow improvers of the component of class (K5) are, for example, the oil-soluble carboxamides and carboxylic acid esters of ortho-sulfobenzoic acid in which the sulfonic acid function is present as sulfonate with alkyl-substituted ammonium cations, as described in US Pat EP-A 261 957 to be discribed.

As cold flow improvers of the component of the class (K6) suitable poly (meth) acrylic acid esters are both homo- and copolymers of acrylic and methacrylic acid esters. Preferred are copolymers of at least two mutually different (meth) acrylic acid esters, which differ with respect to the fused alcohol. Optionally, the copolymer contains a further, different of which olefinically unsaturated monomer copolymerized. The weight-average molecular weight of the polymer is preferably 50,000 to 500,000. A particularly preferred polymer is a copolymer of methacrylic acid and methacrylic acid esters of saturated C ₁₄ and C ₁₅ alcohols wherein the acid groups are neutralized with hydrogenated tallamine. Suitable poly (meth) acrylic esters are, for example, in WO 00/44857 described.

The diesel fuel is the cold flow improver or the mixture of various cold flow improvers in a total amount of preferably 10 to 5000 ppm by weight, more preferably from 20 to 2000 ppm by weight, more preferably from 50 to 1000 ppm by weight and especially from 100 to 700 ppm by weight, z. B. from 200 to 500 ppm by weight added.

Suitable corrosion inhibitors are z. As succinic acid esters, especially with polyols, fatty acid derivatives, eg. Oleate esters, oligomerized fatty acids, substituted ethanolamines, and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany) or HiTEC 536 (Ethyl Corporation).

Suitable demulsifiers are z. As the alkali or alkaline earth metal salts of alkyl-substituted phenol and naphthalenesulfonates and the alkali or alkaline earth metal salts of fatty acids, also neutral compounds such as alcohol alkoxylates, eg. For example, alcohol ethoxylates, phenol alkoxylates, e.g. As tert-butylphenol ethoxylate or tert-Pentylphenolethoxylat, fatty acids, alkylphenols, condensation of ethylene oxide (EO) and propylene oxide (PO), z. B. in the form of EO / PO block copolymers, polyethyleneimines or polysiloxanes.

Suitable dehazers are z. Example, alkoxylated phenol-formaldehyde condensates, such as the available under the trade name NALCO 7D07 products (Nalco) and TOLAD 2683 (Petrolite).

Suitable antifoams are for. Polyether-modified polysiloxanes, such as the TEGOPREN 5851 (Goldschmidt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc) products available under the tradename.

Suitable Cetanzahlverbesserer are z. As aliphatic nitrates such as 2-ethylhexyl nitrate and cyclohexyl nitrate and peroxides such as di-tert-butyl peroxide.

Suitable antioxidants are, for. As substituted phenols, such as 2,6-di-tert-butylphenol and 6-di-tert-butyl-3-methylphenol and phenylenediamines such as N, N'-di-sec-butyl-p-phenylenediamine.

Suitable metal deactivators are, for. B. salicylic acid derivatives such as N, N'-disalicylidene-1,2-propanediamine.

Suitable solvents are, for. For example, non-polar organic solvents such as aromatic and aliphatic hydrocarbons, for example toluene, xylenes, "white spirit" and products sold under the trade name SHELLSOL (Royal Dutch / Shell Group) and EXXSOL (ExxonMobil), as well as polar organic solvents, for example alcohols such as 2-ethylhexanol, decanol and isotridecanol. Such solvents usually enter the diesel fuel together with the abovementioned additives and co-additives, which they are intended to dissolve or dilute for better handling.

The diesel fuels are, for example, petroleum raffinates, which usually have a boiling range of 100 to 400 ° C. These are mostly distillates with a 95% point up to 360 ° C or even beyond. However, these may also be so-called "Ultra Low Sulfur Diesel" or "City Diesel", characterized by a 95% point of, for example, a maximum of 345 ° C and a maximum sulfur content of 0.005 wt .-% or by a 95% point of for example, 285 ° C and a maximum sulfur content of 0.001 wt .-%. In addition to refining mineral diesel fuels, those available from coal gasification or gas-to-liquid (GTL) fuels or biomass to liquid (BTL) fuels are also suitable. Also suitable are mixtures of the abovementioned diesel fuels with regenerative fuels, such as biodiesel or bioethanol.

The diesel fuels are particularly preferably those with a low sulfur content, ie with a sulfur content of less than 0.05% by weight, preferably less than 0.02% by weight, in particular less than 0.005% by weight. % and especially less than 0.001% by weight of sulfur.

The inventive use of the organic compounds (I) or (Ia) or (Ib) is achieved that the fuel consumption of diesel engines permanently, d. H. both at the factory and even after a longer running time of the engine, for example, after 100,000 km, is lower than in corresponding engines, which are operated with the otherwise same diesel fuel, but the organic compounds (I) or (Ia) or (Ib ) does not contain. The fuel economy using the present invention is usually in the range of 1% to 3%.

In addition to reducing fuel consumption, the organic compounds (I) or (Ia) or (Ib) to the same extent as known from the prior art systems reduce the emissions of particles and noxious gases such as carbon monoxide and nitrous gases in the exhaust gases of diesel engines ,

The following. Examples are intended to illustrate the present invention without limiting it.

Examples

Preparation Examples

Example 1: acetone-n-butyl ether (R ⁴ = n-butyl, R ⁵ = R ⁶ = CH ₃₎

In a reaction flask, 80.0 g of water, 160.0 g of sodium hydroxide solution (50 wt .-%), 6.0 g of tetrabutylammonium bromide (50 wt .-% in water) and 146.3 g of chlorobutane presented at room temperature and 96 , 5 g of acetone oxime were added. The reaction mixture was heated to 100 ° C reflux temperature. The organic phase was separated and dried with magnesium sulfate. After distilling off solvent residues, a pale yellow liquid was obtained, which was purified by vacuum distillation. 63 g of acetone oxime-n-butyl ether were obtained.

Example 2: Tricosanone oxime methyl ether (R ⁴ = CH ₃ , R ⁵ = R ⁶ = n-undecyl)

200.4 g of an aqueous methoxyamine hydrochloride solution (30% strength by weight) and 720 ml of methanol were introduced at 40 ° C. to 45 ° C. and mixed with 169.0 g of sodium hydroxide solution (25% strength by weight) to a Value adjusted from 3.8 to 3.9. 126.7 g of 12-tricosanone was added portionwise. Subsequently, the temperature was raised to 60 ° C and it was stirred at 60 ° C for 8 h. To the reaction mixture, 200 ml of water was added and the phases were separated. The aqueous phase was extracted three times with petroleum ether and the combined organic phases were dried over sodium sulfate and freed from the solvent by distillation. 135 g of tricosanone oxime methyl ether were obtained.

Example 3 Diisobutyl ketone oxime methyl ether (R ⁴ = CH ₃ , R ⁵ = R ⁶ = isopropyl)

556.7 g of an aqueous methoxyamine hydrochloride solution (30% strength by weight) and 800 ml of methanol were initially charged. With 308.0 g of sodium hydroxide solution (25 wt .-%), a pH of about 4.0 was set. At about 45 ° C were added dropwise within 10 minutes 114.2 g of di-iso-propyl ketone. The mixture was stirred for 2 h at 60 ° C. After addition of 250 ml of tert-butyl methyl ether, the phases were separated and the organic phase was dried over magnesium sulfate. The solvents were removed in vacuo to give 71.8 g of the desired product di-iso-propyl ketone oxime methyl ether.

Example 4: acetone oxime (2-ethylhexyl) ether (R ⁴ = CH ₃ , R ⁵ = R ⁶ = 2-ethylhexyl)

52 g of sodium hydroxide powder were suspended in 270 ml of N-methylpyrrolidone and 73 g of acetone oxime were added at room temperature. This reaction mixture was heated to 40 ° C and within 30 minutes 193 g of 1-chloro-2-ethylhexane were added dropwise (temperature rise to 105 ° C). The suspension was stirred at 80 ° C. for 7 h. To the cooled reaction mixture was slowly added with stirring 400 ml of water, followed by 300 ml of tert-butyl methyl ether. The organic phase was separated and the aqueous phase shaken out again with 100 ml of tert-butyl methyl ether. The combined organic phases were dried with magnesium sulfate and the solvents removed in vacuo. The crude product obtained was purified by distillation under high vacuum (0.6 mbar / 65 ° C). There were obtained 108 g of light yellow oil.

Example 5: Oleic acid N-hydroxysuccinimide ester

82.5 g of N-hydroxysuccinimide and 197.5 g of oleic acid were dissolved in 500 ml of n-heptane. At 9 ° C 147.5 g of dicyclohexylcarbodiimide (melted) were added dropwise within 25 minutes. The temperature rose to 12 ° C. The reaction mixture was warmed to room temperature and stirred for 24 h. The formed white precipitate was removed by filtration. The filtrate was treated with dilute NaCl solution and extracted. The organic phase was dried with magnesium sulfate and then freed from the solvent by distillation. After removal of the n-heptane residues in a high vacuum, crystallizing yellow oil was obtained (231.9 g).

applications

Example 6 (engine test bench)

In a direct-injection diesel engine with a common-rail injection system (Alfa Romeo 159JTDM, 4-cylinder), fuel consumption was determined at various speeds and loads on an engine test bench (Specific Fuel Consumption, "BSFC" brake specific fuel consumption). The fuel was an unadditized diesel fuel ("Artic Diesel") according to EN 590 used, were added to each of which 1000 ppm of the following organic compounds (I) or (Ia) or (Ib) as an additive. This unadditized diesel fuel also served as a reference in determining fuel economy. By repeating the reference points regularly, it was ensured that only the fuel influence was evaluated and no changes were made to the test carrier.

Table 1 below shows the results of the tests on the engine test bench: Table 1 additive Savings in% of consumption compared to unadditized fuel Acetone oxime n-butyl ether (Example 1) 3.5 Tricosanone oxime methyl ether (Example 2) 3.5 Acetonoxime (2-ethylhexyl) ether (Example 4) 1.5 Oleic acid N-hydroxysuccinimide ester (Example 5) 1.0

Example 7 (chassis dynamometer)

The fuel consumption was also determined by a standardized test procedure on the chassis dynamometer (according to "New European Driving Cycle", modification by start with warm engine). It became the average fuel economy over the same diesel fuel containing no organic compound (I) or (Ia) or (Ib). The fuel was an unadditized diesel fuel ("Artic Diesel") according to EN 590 used, were added to each of which 1000 ppm of the following organic compounds (I) or (Ia) or (Ib) as an additive. This unadditized diesel fuel also served as a reference in determining fuel economy.

Table 2 below shows the results of the tests on the chassis dynamometer: Table 2 additive consumption consumption consumption city Oberland combined [Liter / 100 km] [Liter / 100 km] [Liter / 100 km] (each saving in%) Run 1: without 6.91 4.40 5.33 Acetone-n-butyl ether 6.86 4.38 5.30 (Example 1) (0.7) (0.5) (0.6) Run 2: without 6.91 4.48 5.38 Tricosanon-oxime methyl ether 6.80 4.42 5.30 (Example 2) (1.6) (1,3) (1.5)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• FR 2305491 A [0003]
• US 5433756 [0004]
• EP 630958 A [0005]
• WO 2002/068334 [0007]
• WO 2002/068570 [0007]
• WO 2003/020852 [0007]
• US 4233035 [0008]
• US 4,069,226 [0009]
• US 3799984 [0010]
• US 3965177 [0010]
• JP 2006-104301 A1 [0011]
• EP 244616A [0046]
• WO 94/24231 A [0046]
• WO 97/03946 A [0047]
• DE 19620262 A [0048]
• WO 96/03367 [0049]
• WO 96/03479 A [0049]
• EP 476485A [0050]
• EP 307815A [0051]
• WO 87/01126 A [0051]
• EP 639632A [0052]
• EP 310875A [0053, 0063]
• EP 356725A [0053, 0063]
• EP 700985 A [0053, 0063]
• US 4877416A [0053, 0063]
• DE 3838918 A [0054, 0064]
• US 4849572A [0055]
• EP 831141A [0056]
• DE 3826608 A [0065]
• DE 4142241 A [0065]
• DE 4309074 A [0065]
• EP 452328A [0065]
• EP 548617A [0065]
• DE 10102913 A [0067]
• WO 99/29748 [0079]
• WO 2005/054314 [0081]
• WO 2004/035715 [0084]
• EP 061895A [0085]
• US 4491455 [0085]
• WO 93/18115 [0097]
• EP 261957A [0098]
• WO 00/44857 [0099]

Cited non-patent literature

• SN 500 to 2000 [0060]
• "Comb-Like Polymers. Structure and Properties ", NA Platé and VP Shibaev, J. Poly. Sci. Macromolecular Revs. 8, pages 117 to 253 (1974) " [0084]
• Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, in the chapter "Amines, aliphatic" [0086]
• EN 590 [0119]
• EN 590 [0121]

Claims (7)

Use of at least one organic compound (I) having a molecular weight of 59 to 1500 and at least one NOC structural element in which the two free valencies on the N atom and the three free valencies on the C atom are each saturated by carbon atoms and / or hydrogen atoms, and wherein the structural element NOC is not part of a ring system, as a fuel additive for reducing the fuel consumption of diesel engines. Use of at least one organic compound (I) according to claim 1, which is represented by the general formula (Ia) or (Ib)

in which the variables R ¹ and R ^{4 are} each C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl, C ₁ - to C ₂₀ -alkylcarbonyl , C ₂ to C ₂₀ alkenylcarbonyl, C ₆ to C ₂₀ aryl, C ₆ to C ₂₀ arylcarbonyl, C ₇ to C ₂₆ arylalkyl or C ₇ to C ₂₆ arylalkylcarbonyl radicals in which the variables R ¹ and R ^{4 may} each additionally carry carboxylic acid ester and / or carboxamide groups and / or present alkyl and alkenyl chains in these variables may be interrupted by one or more oxygen and / or nitrogen atoms in which the variables R ² and R ^{3 are} independently C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl, C ₁ - to C ₂₀ -alkylcarbonyl, C ₂ - to C ₂₀ -Alkenylcarbonyl, C ₆ - to C ₂₀ -aryl, C ₆ - to C ₂₀ -arylcarbonyl, C ₇ - to C ₂₆ -arylalkyl or C ₇ - to C ₂₆ -arylalkylcarbonyl radicals, where the variables R ² and R ³ each additionally C Arbonsäureester- and / or Carbonsäureamidgruppen present, present alkyl and alkenyl chains may be interrupted in these variables by one or more oxygen and / or nitrogen atoms and / or the variables R ² and R ³ together with the N-atom connecting them a five or ⁶ -membered ring, and in which the variables R ⁵ and R ⁶ independently of one another are hydrogen, C ₁ - to C ₂₀ -alkyl, C ₅ - to C ₈ -cycloalkyl, C ₂ - to C ₂₀ -alkenyl , C ₁ - to C ₂₀ -alkylcarbonyl, C ₂ - to C ₂₀ -alkenylcarbonyl, C ₆ - to C ₂₀ -aryl, C ₆ - to C ₂₀ -arylcarbonyl, C ₇ - to C ₂₆ -arylalkyl- or C ₇ - denote C ₂₆ -arylalkylcarbonyl radicals, where the variables R ⁵ and R ^{6 may} each additionally carry carboxylic acid ester and / or carboxamide groups, present alkyl and alkenyl chains in these variables are interrupted by one or more oxygen and / or nitrogen atoms can be and / or the variables R ⁵ and R ⁶ together with the connecting C-atom can form a five- or six-membered ring. Use of at least one organic compound (Ia) or (Ib) according to claim 2, wherein at least one of the variables R ¹ to R ³ or R ⁴ to R ^{6 is} a radical having at least 4 carbon atoms. Use of at least one organic compound (Ia) or (Ib) according to claim 2 or 3, wherein the two variables R ² and R ³ or R ⁵ and R ^{6 are the} same. Use of at least one organic compound (I) or (Ia) or (Ib) according to claims 1 to 4 as a fuel additive in a concentration of 10 to 10,000 ppm by weight, based on the total amount of diesel fuel. Use of at least one organic compound (I) or (Ia) or (Ib) according to claims 1 to 5 as a fuel additive for reducing the fuel consumption of direct-injection diesel engines. Use of at least one organic compound (I) or (Ia) or (Ib) according to claim 6 as a fuel additive for reducing the fuel consumption of diesel engines with common-rail injection systems.