EP2162513B1 - Detergent additive-containing mineral oils having improved cold flow properties - Google Patents

Description

The present invention relates to the use of nucleating agents to improve the cold flowability of mineral oil distillates containing detergent additives, as well as the mineral oil distillates additive.

Increasingly stringent environmental legislation requires ever more sophisticated engine technology to comply with established emission limits. However, occupying engine parts such as the combustion residue valves changes the characteristics of the engine and results in increased emissions as well as increased consumption. Therefore, motor fuels are added to detergent additives which remove such deposits or prevent their formation. These are generally oil-soluble amphiphiles which contain a polar head group in addition to an oil-soluble, temperature-stable hydrophobic radical.

On the other hand, in the course of decreasing world oil reserves, increasingly heavier and thus paraffin-rich crude oils are extracted and processed, which consequently also lead to paraffin-rich fuel oils. The paraffins contained in particular in middle distillates can crystallize on lowering the temperature of the oil and partially agglomerate with the inclusion of oil. This crystallization and agglomeration can cause blockages of the filters in engines and firing systems, especially in winter, which prevents safe metering of the fuels and may possibly lead to a complete interruption of the fuel supply. The paraffin problem is also exacerbated by the environmental reasons to reduce the sulfur content increasing hydrodesulfurization of fuel oils, which leads to an increased proportion of cold-critical paraffins in the fuel oil.

To improve the cold flow properties middle distillates are often added chemical additives, so-called cold flow improvers or flow improvers, modify the crystal structure and Agglomerationsneigung the precipitated paraffins, so that the so-additive oils still pump or use at temperatures, often more than 20 ° C. lower than non-additized oils. As the cold flow improver, oil-soluble copolymers of ethylene and unsaturated esters, oil-soluble polar nitrogen compounds and / or comb polymers are usually used. In addition, however, other additions have been proposed.

As engine technology becomes ever more demanding, as well as increasing demands on the environmental performance of fuel oils and their combustion products, detergent additives are being developed with ever increasing effectiveness. In addition, they are often used in very high dosage rates. It is reported that this reduces, for example, in diesel fuels, the specific consumption and the performance of the engines is increased. However, these additives often have negative effects on the cold flowability of middle distillates and in particular on the efficacy of known cold flow improvers. Especially with middle distillates with low boiling point and simultaneously low aromatic content, it is often difficult or even impossible to adjust in the presence of modern detergent additives using conventional flow improvers a satisfactory cold flow behavior. For example, the addition of detergent additives often results in an antagonistic effect on the effectiveness of the added cold flow improvers. In the process, the paraffin dispersion of the middle distillate, set by paraffin dispersants, is impaired, without being able to be reconstituted by increased metering of paraffin dispersant. Often the CFPP measured filterability with cold flow improvers additive oils is significantly reduced in the cold and can be compensated only by greatly increased dosage of the flow improver.

Particularly problematic in this case are, in particular, those detergent additives which are derived from higher polyamines and those which are, for example, conditional have very high molecular weights by multiple alkylation and / or acylation of these polyamines. Also particularly problematic are those detergent additives whose hydrophobic residue is derived from sterically hindered olefins and / or higher molecular weight and / or polyfunctionalized poly (olefins).

1. (A) eine Destillat-Fließverbesserungszubereitung,
2. (B) einen Schmieröl-Fließpunkterniedriger, und
3. (C) eine polare, von (A) und (B) verschiedene, öllösliche, als antiagglomerierendes Mittel für Wachsteilchen in dem Heizöl wirkende Verbindung der allgemeinen Formel RX, in welcher R eine öllöslich machende Kohlenwasserstoffgruppe und X eine polare Gruppe bedeutet,
   enthält.

DE-2921330 teaches an additive preparation for distillate heating oils of three (or more) components, characterized in that they

1. (A) a distillate flow-improving preparation,
2. (B) a lubricating oil pour point depressant, and
3. (C) a polar, oil-soluble, compound other than (A) and (B), which acts as an antiagglomerating agent for wax particles in the heating oil, of the general formula RX in which R represents an oil-solubilizing hydrocarbon group and X represents a polar group,
   contains.

1. (a) eines öllöslichen aschefreien Dispergiermittel umfasst, umfassend ein Amin, das mit einem Hydrocarbylcarboxyacylierungsmittel acyliert ist oder das hydrocarbyliert ist oder das hydrocarboxyliert ist;
2. (b) einen öllöslichen Schmierfähigkeitszusatz, umfassend einen Ester einer Carbonsäure und einen Alkohol, wobei die Säure 2 bis 50 Kohlenstoffatome aufweist und der Alkohol ein oder mehrere Kohlenstoffatome aufweist;
3. (c) einen öllöslichen Nitrat- oder Peroxycetan-Verbesserer; und
4. (d) einen öllöslichen Erdölbrennstoff-Antischaumstoff, umfassend eine Zusammensetzung auf Siliziumbasis oder ein Polyamin mit mindestens einer primären oder sekundären Aminogruppe, die mit einem Carbonsäureacylierungsmittel acyliert ist;

wobei die Verwendung in einer Zusammensetzung vorliegt, die einen Hauptanteil eines Heizöls und einen kleineren Anteil der Komponente (B) umfasst, die einen Kaltfließverbesserer-Zusatzstoff umfasst, der einen copolymeren Ethylenfließverbesserer umfasst, und die Kaltfließeigenschaften der Zusammensetzung verbessern soll. WO-95/03377 teaches the use of a co-additive selected from component (A) containing one or more of

1. (a) an oil-soluble ashless dispersant comprising an amine which is acylated with a hydrocarbyl carboxyacylating agent or which is hydrocarbylated or which is hydrocarboxylated;
2. (b) an oil-soluble lubricity additive comprising an ester of a carboxylic acid and an alcohol, wherein the acid has 2 to 50 carbon atoms and the alcohol has one or more carbon atoms;
3. (c) an oil-soluble nitrate or peroxycetane improver; and
4. (d) an oil-soluble petroleum fuel antifoam comprising a silicon-based composition or a polyamine having at least one primary or secondary amino group acylated with a carboxylic acid acylating agent;

wherein the use is in a composition comprising a major portion of a heating oil and a minor proportion of component (B) comprising a cold flow improver additive comprising a copolymer Contains ethylene flow improvers, and to improve the cold flow properties of the composition.

WO-03/042337 teaches middle distillates with a maximum of 0.05% by weight of sulfur containing fatty acid esters of alkoxylated polyols having at least 3 OH groups (A) and at least one cold flow improver (B), said cold flow improver comprising at least one copolymer of ethylene and one or more ethylenically unsaturated carboxylic acid esters having an ethylene content of 60 to 90 mol%.

It was therefore an object of the present invention to improve the response of cold flow improvers in middle distillates containing detergent additives. Another object of the invention was to provide a prior art improved detergent additive which does not interfere with the response of cold flow improvers.

Surprisingly, it has now been found that certain oil-soluble compounds acting as nucleators for the paraffin crystallization counteract the impairment of the effectiveness of conventional cold flow improvers by nitrogen-containing detergent additives or cancel this impairment.

The invention thus relates to the use of at least one oil-soluble, acting as Nucleator for paraffin crystallization compound B) selected from comb polymers carrying alkyl side chains with a length of at least 20 carbon atoms, to improve the response to the lowering of Pour Point and CFPP Value as well as the improvement of the paraffin dispersion of mineral oil flow improvers C) other than B) in middle distillates containing at least one ashless nitrogen-containing detergent additive A) which is an oil-soluble, amphiphilic compound comprising at least one alkyl or alkenyl radical, which is bonded to a polar group, wherein the alkyl or alkenyl radical 10 to 500 carbon atoms and the polar group comprises 2 or more nitrogen atoms, wherein the ashless nitrogen-containing detergent additive A) comprises a polar moiety derived from polyamines of the formula

(R ⁹ ) ₂ N- [AN (R ⁹ )] _q - (R ⁹ )

wherein each R ⁹ independently of one another represents hydrogen, an alkyl or hydroxyalkyl radical having up to 24 C atoms, a polyoxyalkylene radical - (AO) _r - or polyiminoalkylene radical - [AN (R ⁹ )] _s - (R ⁹ ) but wherein at least one R ^{9 is} hydrogen, q is an integer from 1 to 19, A is an alkylene radical having 1 to 6 C atoms, and r and s are independently integers from 1 to 50, and wherein as cold flow improver C) oil-soluble polar nitrogen compounds are used, which reaction products of compounds of formula NR ⁶ R ⁷ R ⁸ , wherein R ⁶ , R ⁷ and R ^{8 may be the} same or different, and at least one of these groups for C ₈ -C ₃₆ -Alkyl, C ₆ -C ₃₆ -cycloalkyl, C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C ₂₄ -alkyl, C ₁₂ -C ₂₄ -alkenyl or cyclohexyl, and the other groups are either hydrogen, C ₁ -C ₃₆ alkyl, C ₂ -C ₃₆ alkenyl, cyclohexyl, or a group of the formulas - (AO) _x -E or - (CH ₂ ) _{n is} -NYZ, where A is an ethyl or propyl group, x is a number from 1 to 50, E = H, C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₂ -cycloalkyl or C ₆ -C ₃₀ -aryl , and n = 2, 3 or 4, and Y and Z are independently H, C ₁ -C ₃₀ alkyl or - (AO) _x , with compounds containing at least one acyl group.

The combination of A) and B) is also referred to below as "inventive additive".

1. a) mindestens ein aschefreies, stickstoffhaltiges Detergenzadditiv A), welches eine öllösliche, amphiphile Verbindung ist, die mindestens einen Alkyl- oder Alkenylrest umfasst, der an eine polare Gruppe gebunden ist, wobei der Alkyl- oder Alkenylrest 10 bis 500 C-Atome und die polare Gruppe 2 oder mehr Stickstoffatome umfasst, wobei das aschefreie stickstoffhaltige Detergenzadditiv A) einen polaren Anteil umfasst, der von Polyaminen der Formel
   
           (R⁹)₂N-[A-N(R⁹)]_q-(R⁹)
   
   abgeleitet ist, worin jedes R⁹ unabhängig voneinander für Wasserstoff, einen Alkyl- oder Hydroxyalkylrest mit bis zu 24 C-Atomen, einen Polyoxyalkylenrest -(A-O)_r- oder Polyiminoalkylenrest -[A-N(R⁹)]_s-(R⁹) steht, wobei jedoch mindestens ein R⁹ für Wasserstoff steht, q für eine ganze Zahl von 1 bis 19, A für einen Alkylenrest mit 1 bis 6 C-Atomen, und r und s unabhängig voneinander für ganze Zahlen von 1 bis 50 stehen, und
2. b) mindestens eine öllösliche, als Nucleator für die Paraffinkristallisation wirkende Verbindung B), ausgewählt aus Kammpolymeren, die Alkylseitenketten mit einer Länge von mindestens 18 C-Atomen im molaren Mittel tragen, sowie
3. c) mindestens einen von B) verschiedenen Mineralölkaltfließverbesserer C), wobei als Kaltfließverbesserer C) öllösliche polare Stickstoffverbindungen zur Anwendung kommen, welche Umsetzungsprodukte von Verbindungen der Formel NR⁶R⁷R ⁸, worin R⁶, R⁷ und R⁸ gleich oder verschieden sein können, und wenigstens eine dieser Gruppen für C₈-C₃₆-Alkyl, C₆-C₃₆-Cycloalkyl, C₈-C₃₆-Alkenyl, insbesondere C₁₂-C₂₄-Alkyl, C₁₂-C₂₄-Alkenyl oder Cyclohexyl steht, und die übrigen Gruppen entweder Wasserstoff, C₁-C₃₆-Alkyl, C₂-C₃₆-Alkenyl, Cyclohexyl, oder eine Gruppe der Formeln -(A-O)_x-E oder -(CH₂)_n-NYZ bedeuten, worin A für eine Ethyl- oder Propylgruppe steht, x eine Zahl von 1 bis 50, E = H, C₁-C₃₀-Alkyl, C₅-C₁₂-Cycloalkyl oder C₆-C₃₀-Aryl, und n = 2, 3 oder 4 bedeuten, und Y und Z unabhängig voneinander H, C₁-C₃₀-Alkyl oder -(A-O)_x bedeuten, mit Verbindungen, welche mindestens eine Acylgruppe enthalten, sind, und worin 10 bis 10.000 ppm des aschefreien, stickstoffhaltigen Detergenzadditivs A) sowie pro Gewichtsteil dieses Bestandteils A) 0,1 bis 10 Gewichtsteile der öllöslichen als Nucleator für die Paraffinkristallisation wirkenden Verbindung B) enthalten sind.

Another object of the invention are middle distillates having a sulfur content of less than 100 ppm and a 90% distillation point of below 360 ° C, containing

1. a) at least one ashless nitrogen-containing detergent additive A) which is an oil-soluble, amphiphilic compound comprising at least one alkyl or alkenyl radical attached to a polar group, wherein the alkyl or alkenyl radical comprises 10 to 500 carbon atoms and the polar group comprises 2 or more nitrogen atoms, the ashless nitrogen-containing detergent additive A) comprising a polar moiety derived from polyamines of the formula
   
   (R ⁹ ) ₂ N- [AN (R ⁹ )] _q - (R ⁹ )
   
   wherein each R ⁹ independently of one another represents hydrogen, an alkyl or hydroxyalkyl radical having up to 24 C atoms, a polyoxyalkylene radical - (AO) _r - or polyiminoalkylene radical - [AN (R ⁹ )] _s - (R ⁹ ) but wherein at least one R ^{9 is} hydrogen, q is an integer from 1 to 19, A is an alkylene radical having 1 to 6 C atoms, and r and s independently of one another are integers from 1 to 50, and
2. b) at least one oil-soluble compound B) acting as nucleator for the paraffin crystallization, selected from comb polymers which carry alkyl side chains with a length of at least 18 carbon atoms in the molar average, as well as
3. c) at least one of B) Mineralölaltfließverbesserer C), being used as cold flow improver C) oil-soluble polar nitrogen compounds which reaction products of compounds of the formula NR ⁶ R ⁷ R ⁸ , wherein R ⁶ , R ⁷ and R ^{8 are the} same or different can, and at least one of these groups for C ₈ -C ₃₆ alkyl, C ₆ -C ₃₆ cycloalkyl, C ₈ -C ₃₆ alkenyl, in particular C ₁₂ -C ₂₄ alkyl, C ₁₂ -C ₂₄ alkenyl or cyclohexyl and the other groups are either hydrogen, C ₁ -C ₃₆ -alkyl, C ₂ -C ₃₆ -alkenyl, cyclohexyl, or a group of the formulas - (AO) _x -E or - (CH ₂ ) _n -NYZ, where A is an ethyl or propyl group, x is a number from 1 to 50, E = H, C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₂ -cycloalkyl or C ₆ -C ₃₀ -aryl, and n = 2 , 3 or 4, and Y and Z are independently H, C ₁ -C ₃₀ alkyl or - (AO) _x , with compounds containing at least one acyl group, and wherein 10 to 10,000 p pm of the ashless, nitrogen-containing detergent additive A) and per part by weight of this constituent A) 0.1 to 10 parts by weight of the oil soluble as Nucleator for paraffin crystallization acting compound B) are included.

The improvement in the response of cold flow improvers C) according to the invention is understood to improve at least one cold property of middle distillates adjusted or adjustable by cold flow improver C) and adversely affected by the addition of a detergent additive A) by addition of a compound B) acting as a nucleating agent for the paraffin crystallization , Specifically, by adding the nucleating agent B), the cold property set or adjustable without the presence of the detergent additive A) by the cold flow improver C) is achieved. Cold properties are understood here individually or in combination as the pour point, the cold filter plugging point, the low-temperature flow, and the paraffin dispersion of middle distillates.

Particularly affected is the response of flow improvers in middle distillates containing more than 10 ppm of a nitrogen-containing detergent additive A), especially more than 20 ppm and especially more than 40 ppm such as 50 to 2000 ppm of nitrogen-containing detergent additive A).

Preferably, the additives contain, based on one part by weight of the nitrogen-containing detergent additive A) from 0.01 to 10 parts by weight, and in particular from 0.05 to 5 parts by weight, for example from 0.1 to 3 parts by weight of the oil-soluble compound B) acting as nucleator for the paraffin crystallization.

Ashless means that the additives in question essentially consist only of elements which form gaseous reaction products during combustion. Preferably, the additives consist essentially only of the elements carbon, hydrogen, oxygen and nitrogen. In particular, ashless additives are substantially free of metals and metal salts.

Nucleators are understood to be compounds which initiate the crystallization of paraffins on cooling a paraffin-containing oil. They thus shift the beginning of the paraffin crystallization of the oil additized with them, which can be determined, for example, by measuring the cloud point or the Wax Appearance Temperature (WAT), to higher temperatures. These are compounds that are soluble in the oil above the cloud point and begin to crystallize just above the temperature of the paraffin saturation and then serve as seed for the crystallization of the paraffins. Thus, they prevent over-saturation of the oil with paraffins and lead to crystallization near the saturation concentration. This leads to the formation of a multiplicity of equally small paraffin crystals. In the presence of a nucleator, paraffin crystallization thus begins at a higher temperature than in non-additized oil. This can be determined, for example, by measuring the WAT by means of differential scanning calorimetry (DSC) with a slow cooling of the oil at, for example, -2 K / min.

To middle distillates are added 10 to 10,000 ppm and in particular 50 to 3,000 ppm of the nitrogen-containing detergent additives A).

Preferably, the alkyl or alkenyl group imparts oil-solubility to the detergent additives.

Particularly problematic are those detergent additives whose alkyl radical has 15 to 500 carbon atoms and in particular 20 to 350 carbon atoms, for example 50 to 200 carbon atoms. This alkyl radical can be linear or branched, in particular it is branched. In a preferred embodiment, the alkyl radical is derived from oligomers of lower olefins having 3 to 6 C atoms such as propene, butene, pentene or hexene and mixtures thereof. Preferred isomers of these olefins are isobutene, 2-butene, 1-butene, 2-methyl-2-butene, 2,3-dimethyl-2-butene, 1-pentene, 2-pentene and iso-pentene and mixtures thereof. Particular preference is given to propene, isobutene, 2-butene, 2-methyl-2-butene, 2,3-dimethyl-2-butene and mixtures thereof. Particular preference is given to olefin mixtures which are more than 70 mol%, especially more than 80 mol%, for example more than 90 mol% or contain more than 95 mol% of 2-methyl-2-butene, 2,3-dimethyl-2-butene and / or isobutene. Particularly suitable for the preparation of such detergent additives are highly reactive low molecular weight polyolefins having a proportion of terminal double bonds of at least 75%, especially at least 85% and in particular at least 90% such as at least 95%. Particularly preferred low molecular weight polyolefins are poly (isobutylene), poly (2-butene), poly (2-methyl-2-butene), poly (2,3-dimethyl-2-butene), poly (ethylene-co-isobutylene) and atactic poly (propylene). The molecular weight of particularly preferred polyolefins is between 500 and 3000 g / mol. Such oligomers of lower olefins are accessible for example by polymerization by means of Lewis acids such as BF ₃ and AlCl ₃ , by means of Ziegler catalysts and in particular by means of metallocene catalysts.

The polar component of the detergent additives which are particularly problematic for the response of known cold additives is derived from polyamines having 2 to 20 N atoms. Such polyamines correspond to the formula

(R ⁹ ) ₂ N- [AN (R ⁹ )] _q - (R ⁹ )

wherein each R ^{9 is} independently hydrogen, an alkyl or hydroxyalkyl radical of up to 24 carbon atoms, a polyoxyalkylene radical - (AO) _r - or polyiminoalkylene radical - [AN (R ⁹ )] _s - (R ⁹ ) but wherein at least one R ^{9 is} hydrogen, q is an integer from 1 to 19, A is an alkylene radical having 1 to 6 C atoms, r and s independently of one another are from 1 to 50. Usually these are mixtures of polyamines and in particular mixtures of poly (ethylene amines) and / or poly (propyleneamines). Examples which may be mentioned: ethylenediamine, 1,2-propylenediamine, dimethylaminopropylamine, diethylenetriamine (DETA), dipropylenetriamine, triethylenetetramine (TETA), tripropylenetetramine, tetraethylenepentamine (TEPA), tetrapropylenepentamine, pentaethylenehexamine (PEHA) pentapropylenehexamine and heavy polyamines. Heavy polyamines are generally understood as meaning mixtures of polyalkylenepolyamines which, in addition to small amounts of TEPA and PEHA, are mainly oligomers having 7 or more nitrogen atoms, of which two or more in the form of primary amino groups. These polyamines often also contain branched structural elements via tertiary amino groups.

Other suitable amines include those which comprise cyclic structural units derived from piperazine. The piperazine units may preferably carry hydrogen at one or both nitrogen atoms, an alkyl or hydroxyalkyl radical having up to 24 carbon atoms or a polyiminoalkylene radical - [AN (R ⁹ )] _s - (R ⁹ ), where A, R ⁹ and s have the meanings given above.

Other suitable amines include alicyclic diamines such as 1,4-di (aminomethyl) cyclohexane and heterocyclic nitrogen compounds such as imidazolines and N-aminoalkylpiperazines such as N- (2-aminoethyl) piperazine.

Also, detergent additives whose polar portion is derived from hydroxyl-bearing polyamines, heterocycle-substituted polyamines, and aromatic polyamines are problematic. Examples which may be mentioned are: N- (2-hydroxyethyl) ethylenediamine, N, N ¹ -bis- (2-hydroxyethyl) ethylene diamine, N- (3-hydroxybutyl) tetra (methylene) diamine, N-2-aminoethylpiperazine, N-2- and N-3-aminopropylmorpholine, N-3- (dimethylamino) propylpiperazine, 2-heptyl-3- (2-aminopropyl) imidazoline, 1,4-bis (2-aminoethyl) piperazine, 1- (2-hydroxyethyl) piperazine, various isomers of phenylenediamine and naphthalenediamine and mixtures of these amines.

Detergent additives based on heavy polyamines, in which R ^{9 is} hydrogen in the above formula and q has values of at least 3, in particular at least 4, such as 5, 6 or 7, are particularly critical for the cold additization of middle distillates. For mixtures of various polyamines, a proportion of more than 10 wt .-%, in particular more than 20 wt .-% and especially of more than 50 wt .-% of amines having q-values of 4 or higher and especially with q Values of 5 or higher and especially with q values of 6 or higher on the total amount of amines used proved to be particularly critical.

The oil-soluble alkyl moiety and the polar head group of the detergent additives may be linked together either directly via a C-N or through an ester, amide or imide bond. Accordingly, preferred detergent additives are alkylpolyamines, Mannich reaction products, hydrocarbyl-substituted succinic acid amides and imides, and mixtures of these classes of substances.

The detergent additives linked via C-N bonds are preferably alkylpoly (amines) which are obtainable, for example, by reacting polyisobutylenes with polyamines, for example by hydroformylation and subsequent reductive amination with the abovementioned polyamines. In this case, one or more alkyl radicals may be bound to the polyamine. Detergent additives based on higher polyamines having more than 4 N atoms, for example those having 5, 6 or 7 N atoms, are particularly critical for the cold addition.

Detergent additives containing amide or imide bonds are obtainable, for example, by reaction of alkenylsuccinic anhydrides with polyamines. Alkenylsuccinic anhydride and polyamine are preferably reacted in a molar ratio of about 1: 0.5 to about 1: 1. The preparation of the underlying Alkenylbernsteinsäureanhydride is usually carried out by addition of ethylenically unsaturated polyolefins or chlorinated polyolefins to ethylenically unsaturated dicarboxylic acids.

For example, alkenyl succinic anhydrides can be prepared by reaction of chlorinated polyolefins with maleic anhydride. Alternatively, the preparation also succeeds by thermal addition of polyolefins to maleic anhydride in an "ene reaction". In this case, highly reactive olefins with a high content of, for example, more than 75% and especially more than 85 mol%, based on the total number of polyolefin molecules, of isomers having a terminal double bond are particularly suitable. At the terminal arranged double bonds may be both vinylidene double bonds [-CH ₂ -C (= CH ₂ ) -CH ₃ ] as well as vinyl double bonds [-CH = C (CH ₃ ) ₂ ] act.

For the preparation of alkenylsuccinic anhydrides, the molar ratio of the two reactants in the reaction between maleic anhydride and polyolefin can vary within wide limits. Preferably, it may be between 10: 1 and 1: 5, with molar ratios of 6: 1 to 1: 1 being particularly preferred. Maleic anhydride is preferably used in stoichiometric excess, for example 1.1 to 3 moles of maleic anhydride per mole of polyolefin. Excess maleic anhydride can be removed from the reaction by, for example, distillation.

Since the adducts which are primarily formed by the ene reaction, in turn, contain an olefinic double bond, suitable addition of unsaturated dicarboxylic acids to form so-called bis-maleinates is possible with a suitable reaction procedure. The accessible reaction products have, based on the reacted with unsaturated carboxylic acids fractions of the poly (olefins) on average a Maleinierungsgrad of more than 1, preferably about 1.01 to 2.0 and in particular 1.1 to 1.8 dicarboxylic acid per alkyl radical. Reaction with the abovementioned amines results in products with markedly increased effectiveness as detergent additives. On the other hand, as the degree of maleation increases, so does the impairment of the efficacy of cold flow improvers.

The reaction of alkenyl succinic anhydrides with polyamines leads to products which can carry one or more amide and / or imide bonds per polyamine and depending on the Maleinierungsgrad one or two polyamines per alkyl radical. Alkenylsuccinic anhydride per mole of polyamine is preferably used for the reaction of 1.0 to 1.7 and in particular 1.1 to 1.5, so that free primary amino groups remain in the product. In a further preferred embodiment, alkenyl succinic anhydride and polyamine are reacted equimolarly. In the implementation of polyamines with Alkenylsuccinic anhydrides with a high degree of acylation of 1.1 or more anhydride groups per alkyl radical, such as, for example, 1.3 or more anhydride groups per alkyl radical, also give rise to polymers which are particularly problematic for the response of cold additives.

Typical and particularly preferred acylated nitrogen compounds are obtained by reacting poly (isobutylene), poly (2-butenyl), poly (2-methyl-2-butenyl) -, poly (2,3-dimethyl-2-butenyl) - or Poly (propenyl) succinic anhydrides having an average of about 1.2 to 1.5 anhydride groups per alkyl radical whose alkylene radicals carry between 50 and 400 carbon atoms, with a mixture of poly (ethylene amines) having about 3 to 7 nitrogen atoms and about 1 to 6 ethylene units available. Oil-soluble Mannich reaction products based on polyolefin-substituted phenols and polyamines also impair the effectiveness of conventional cold flow improvers. Mannich bases of this kind are prepared by known processes, for example by alkylating phenol and / or salicylic acid with the polyolefins described above, such as, for example, poly (isobutylene), poly (2-butene), poly (2-methyl-2-butene), poly ( 2,3-dimethyl-2-butene) or atactic poly (propylene) and subsequent condensation of the alkylphenol with aldehydes having 1 to 6 carbon atoms such as formaldehyde or its reactive equivalents such as formalin or paraformaldehyde and the above-described polyamines such as TEPA, PEHA or heavy polyamines produced.

The average molecular weight determined by means of vapor pressure osmometry is particularly efficient, but at the same time also for the cold additization of middle distillates of particularly critical detergent additives is above 800 g / mol and in particular above 2,000 g / mol such as above 3,000 g / mol. The average molecular weight of the above-described detergent additives can also be increased via crosslinking reagents and adapted to the intended use.

Suitable crosslinking reagents are, for example, dialdehydes, such as glutaric dialdehyde, bisepoxides derived, for example, from bisphenol A, Dicarboxylic acids and their reactive derivatives such as maleic anhydride and alkenylsuccinic anhydrides and higher polybasic carboxylic acids and their derivatives such as trimellitic acid, trimellitic anhydride and pyromellitic dianhydride.

Preferred comb polymers B) acting as nucleator for the paraffin crystallization are polymers which carry alkyl side chains bonded to the polymer backbone and have a length of at least 20 carbon atoms. Particularly preferred are those polymers which carry side chains having 22 to 60, such as 24 to 45 carbon atoms. The proportion of these alkyl side chains in the total amount of the alkyl side chains of the polymer is at least 10 mol%, preferably at least 25 mol% and in particular at least 50 mol%, for example at least 80 mol%. Preferably, the side chains are linear or have at least correspondingly long linear segments.

The polymer backbone may for example be composed of ethylenically unsaturated mono- and / or polycarboxylic acids such as, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid. In addition, it may contain other monomers such as olefins, vinyl esters and / or vinyl ethers. Particular preference is given to copolymers based on fumaric acid and vinyl acetate and those based on maleic acid and α-olefins.

The polymer backbone carries long-chain alkyl radicals with a molar average of at least 18, preferably at least 20, such as at least 24 C atoms. As in the case of α-olefins, the alkyl radicals can be bonded directly to the backbone via a C-C bond or can be bound to the polymer backbone via an ester, amide, imide or ammonium group. Furthermore, the alkyl radicals can be bonded to the polymer backbone via spacers such as, for example, polyoxyalkylene or polyalkyleneamine groups having in each case 1 to 200 and in particular 2 to 50 oxyalkyl or alkylenamine units.

As nucleator suitable for the paraffin crystallization comb polymers B) are, for example, polymers of the formula (1)

A

R', COOR', OCOR', R"-COOR', OR';

D

H, CH₃, A oder R";

E

H, A;

G

H, R", R"-COOR', einen Arylrest oder einen heterocyclischen Rest;

M

H, COOR", OCOR", OR", COOH;

N

H, R", COOR", OCOR, einen Arylrest;

R'

eine Kohlenwasserstoffkette mit mindestens 20 Kohlenstoffatomen;

R"

eine Kohlenwasserstoffkette mit 1 bis 10 Kohlenstoffatomen;

m

eine Zahl zwischen 0,4 und 1,0; und

n

eine Zahl zwischen 0 und 0,6.

Mean in it

A

R ', COOR', OCOR ', R "-COOR', OR ';

D

H, CH _3, A or R ";

e

H, A;

G

H, R ", R" -COOR ', an aryl radical or a heterocyclic radical;

M

H, COOR ", OCOR", OR ", COOH;

N

H, R ", COOR", OCOR, an aryl radical;

R '

a hydrocarbon chain having at least 20 carbon atoms;

R "

a hydrocarbon chain of 1 to 10 carbon atoms;

m

a number between 0.4 and 1.0; and

n

a number between 0 and 0.6.

Preferred comb polymers are, for example, copolymers of ethylenically unsaturated dicarboxylic acids such as maleic or fumaric acid with other ethylenically unsaturated monomers such as olefins or vinyl esters. Particularly preferred olefins are α-olefins having at least 22 and especially 24 to 60 carbon atoms such as C ₂₀ -α-olefin, C ₂₄ -α-olefin, C ₂₆ -α-olefin and mixtures thereof such as C _20-24 -α-olefin, C _26-28 -α-olefin or C24-28-α-olefin and technical chain cuts in the range C ₃₀₊ . By α-olefins are meant linear alkenes with terminal double bond. A particularly preferred comonomer vinyl ester is vinyl acetate. Usually, the copolymers of unsaturated carboxylic acids are essentially alternating copolymers.

Usually, these copolymers of ethylenically unsaturated carboxylic acids are esterified with alcohols to at least 50%, preferably to 60-100% and in particular to 70-98%, for example to 80-95%. Alcohols having at least 20 and preferably having at least 22 carbon atoms are preferably used for this purpose. However, it is also possible to use shorter-chain alcohols having, for example, 10 to 18 and especially 12 to 16 C atoms for the esterification, provided that the polymer already carries a sufficient amount of long side chains with at least 20 C atoms.

Further preferred comb polymers are homopolymers and copolymers of alkyl acrylates, alkyl methacrylates and alkyl vinyl ethers derived from alcohols having at least 20 and especially 22 to 60 carbon atoms, such as 24 to 40 carbon atoms, as well as homo- and copolymers of alkyl vinyl esters derived from Derive fatty acids with at least 20 and especially 22 to 40 carbon atoms. In a further preferred embodiment, copolymers of dicarboxylic acids, such as maleic or fumaric acid and vinyl acetate, which have been esterified with long-chain fatty alcohols having at least 20 carbon atoms, are used as comb polymers. In the case of copolymers containing at least 10 mol%, preferably at least 25 mol% and in particular at least 50 mol% such as at least 80 mol% of the monomers alkyl chains having at least 20 carbon atoms and preferably 22 to 60 such as 24 to 45 C-atoms.

Further preferred comb polymers are polycondensates containing structural units derived from alkylaromatics. These are in particular alkylphenol-aldehyde resins which are derived from alkylphenols having one or two alkyl radicals in ortho and / or para position to the OH group. Particularly preferred as starting materials are alkylphenols which carry at least two hydrogen atoms capable of condensation with aldehydes on the aromatic and in particular monoalkylated phenols. Particularly preferably, the alkyl radical is in the para position to the phenolic OH group. The alkyl radicals can be used in the alkylphenol-aldehyde resins which can be used in the process according to the invention may be the same or different, they may be saturated or preferably unsaturated

At least 10 mol%, preferably at least 25 mol% and in particular at least 50 mol%, for example at least 80 mol% of the alkyl radicals of the alkylphenol resins suitable according to the invention as nucleator B) have alkyl chains with at least 20 carbon atoms and preferably between 22 and 60 such as 24 to 45 carbon atoms. On a molar average, the alkyl radicals have at least 18, preferably 20 to 60, such as 24 to 45 carbon atoms. In a preferred embodiment, mixtures of alkylphenols having different alkyl radicals are used for the preparation of the alkylphenol resins. Thus, for example, resins based on mixtures of C _20/22/24 -alkylphenols, C _24/26/28 -alkylphenols and of alkylphenols with chain lengths of C ₃₀ and higher have proven particularly suitable.

Suitable alkylphenol resins may also contain or consist of structural units of other phenol analogs such as salicylic acid, hydroxybenzoic acid and derivatives thereof such as esters, amides and salts. That is, the alkyl radicals may be bonded to the phenol directly via a C-C bond or via an ester or ether group.

worin R¹¹ für C₂₀-C₂₀₀-Alkyl oder -Alkenyl, O-R¹⁰ oder O-C(O)-R¹⁰, R¹⁰ für C₂₀-C₂₀₀-Alkyl oder -Alkenyl und n für eine Zahl von 5 bis 200 steht, enthalten. R¹⁰ steht bevorzugt für C₂₂-C₁₀₀-Alkyl oder -Alkenyl und insbesondere für C₂₄-C₅₀-Alkyl oder -Alkenyl. Besonders bevorzugt steht R¹¹ für C₂₂-C₁₀₀-Alkyl oder -Alkenyl und insbesondere für C₂₄-C₅₀-Alkyl oder -Alkenyl. Bevorzugt steht n für eine Zahl von 7 bis 100 und speziell für eine Zahl von 10 bis 50.Preferred polycondensates are accessible by reacting alkylphenols with aldehydes and / or ketones. Suitable aldehydes for the alkylphenol-aldehyde resins are those having 1 to 12 carbon atoms and preferably those having 1 to 4 carbon atoms such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde, glyoxalic acid and their reactive equivalents such as paraformaldehyde and trioxane. Particularly preferred is formaldehyde in the form of paraformaldehyde and especially formalin. The polycondensation can also be carried out in the presence of aldehydes and amines in the form of a Mannich reaction. In a preferred embodiment of the invention, the compounds suitable as nucleator B) are alkylphenol-formaldehyde resins which contain oligomers or polymers having a repeating structural unit of the formula (2)

wherein R ^{11 is} C ₂₀ -C ₂₀₀ -alkyl or -alkenyl, OR ¹⁰ or OC (O) -R ¹⁰ , R ^{10 is} C ₂₀ -C ₂₀₀ -alkyl or -alkenyl and n is a number from 5 to 200, contain. R ¹⁰ preferably represents C ₂₂ -C ₁₀₀ -alkyl or -alkenyl and in particular C ₂₄ -C ₅₀ -alkyl or -alkenyl. R ¹¹ particularly preferably represents C ₂₂ -C ₁₀₀ -alkyl or -alkenyl and in particular C ₂₄ -C ₅₀ -alkyl or -alkenyl. Preferably n is a number from 7 to 100 and especially for a number from 10 to 50.

These alkylphenol-aldehyde resins are accessible by known methods, for. B. by condensation of the corresponding alkylphenols with formaldehyde, ie with 0.5 to 1.5 moles, preferably 0.8 to 1.2 moles of formaldehyde per mole of alkylphenol. The condensation can be carried out solvent-free, but preferably it is carried out in the presence of an inert or only partially water-miscible inert organic solvent such as mineral oils, alcohols, ethers and the like. Particularly preferred are solvents which can form azeotropes with water. As such solvents in particular aromatics such as toluene, xylene diethylbenzene and higher-boiling commercial solvent mixtures such as Shellsol® AB, and solvent naphtha are used. Also, fatty acids and their derivatives such as esters with lower alcohols having 1 to 5 carbon atoms such as ethanol and especially methanol are suitable as solvents. The condensation is preferably carried out between 70 and 200 ° C such as between 90 and 160 ° C. It is usually catalysed by 0.05 to 5 wt .-% bases or preferably by 0.05 to 5 wt .-% acids. As acidic catalysts in addition to carboxylic acids such as acetic acid and oxalic acid in particular strong mineral acids such as hydrochloric acid, phosphoric acid and sulfuric acid and sulfonic acids common catalysts. Particularly suitable catalysts are sulfonic acids which contain at least one sulfonic acid group and at least one saturated or unsaturated, linear, branched and / or cyclic hydrocarbon radical having 1 to 40 C atoms and preferably having 3 to 24 C atoms. Particularly preferred are aromatic sulfonic acids, especially alkylaromatic mono-sulfonic acids having one or more C ₁ -C ₂₈ -alkyl radicals and in particular those having C ₃ -C ₂₂ -alkyl radicals. Suitable examples are methanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, 2-mesitylenesulfonic acid, 4-ethylbenzenesulfonic acid, isopropylbenzenesulfonic acid, 4-butylbenzenesulfonic acid, 4-octylbenzenesulfonic acid; Dodecylbenzenesulfonic acid, didodecylbenzenesulfonic acid, naphthalenesulfonic acid. Mixtures of these sulfonic acids are suitable. Usually, these remain after completion of the reaction as such or in neutralized form in the product. For neutralization, amines and / or aromatic bases are preferably used, since they can remain in the product; Metal ions containing and thus ash-forming salts are usually separated.

The molecular weight of the comb polymers B) preferred as nucleators for paraffin crystallization by gel permeation chromatography against poly (styrene) standards in THF is preferably 1,000-100,000 g / mol, particularly preferably 2,000-50,000 g / mol and especially 2,500-25,000 g / mol for example 3,000-20,000 g / mol. The prerequisite here is that the comb polymers, at least in application-relevant concentrations of 0.001 to 1 wt .-% are oil-soluble.

The quantitative ratio between detergent additive A) and nucleators B) in the additized oil can vary within wide limits. It has proven particularly useful to use from 0.01 to 10 parts by weight, in particular from 0.05 to 5 parts by weight, for example from 0.1 to 3 parts by weight of nucleator per part by weight of detergent additive, in each case based on the active ingredient.

As Mineralölaltfließverbesserer C) the substances hereinafter referred to as oil-soluble polar nitrogen compound (constituent IV) are used.

Preference is given to using ethylene copolymers (constituent III) in mixture with constituent IV. Mixtures of ethylene copolymers (constituent III) with constituents IV and V or constituents IV and VI have proven particularly suitable for the paraffin dispersion.

Preferred cold flow improvers as constituent III are copolymers of ethylene and olefinically unsaturated compounds. Suitable ethylene copolymers are, in particular, those which contain, in addition to ethylene, from 8 to 21 mol%, in particular from 10 to 18 mol%, of olefinically unsaturated comonomer compounds.

The olefinically unsaturated compounds are preferably vinyl esters, acrylic esters, methacrylic esters, alkyl vinyl ethers and / or alkenes, it being possible for the abovementioned compounds to be substituted by hydroxyl groups. One or more comonomers may be included in the polymer.

The vinyl esters are preferably those of the formula 1

CH ₂ = CH-OCOR ¹ (1)

wherein R ^{1 is} C ₁ to C ₃₀ alkyl, preferably C ₄ to C ₁₆ alkyl, especially C ₆ to C ₁₂ alkyl. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups.

In a further preferred embodiment, R ^{1 is} a branched alkyl radical or a neoalkyl radical having 7 to 11 carbon atoms, in particular having 8, 9 or 10 carbon atoms. Particularly preferred vinyl esters are derived from secondary and especially tertiary carboxylic acids whose branching is in the alpha position to the carbonyl group. Suitable vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl hexanoate, vinyl heptanoate, vinyl octanoate, vinyl pivalate, Vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate and versatic acid esters, such as vinyl neononanoate, vinyl neodecanoate, vinyl neoundecanoate.

In a further preferred embodiment, these ethylene copolymers contain vinyl acetate and at least one further vinyl ester of the formula 1 in which R ^{1 is} C ₄ to C ₃₀ -alkyl, preferably C ₄ to C ₁₆ -alkyl, especially C ₆ - to C ₁₂ -alkyl ,

The acrylic esters are preferably those of the formula 2

CH ₂ = CR ₂ -COOR ³ (2)

wherein R ^{2 is} hydrogen or methyl and R ^{3 is} C ₁ - to C ₃₀ -alkyl, preferably C ₄ - to C ₁₆ -alkyl, especially C ₆ - to C ₁₂ -alkyl. Suitable acrylic esters include, for. Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- and iso-butyl (meth) acrylate, hexyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl , Hexadecyl, octadecyl (meth) acrylate and mixtures of these comonomers. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups. An example of such an acrylic ester is hydroxyethyl methacrylate.

The alkyl vinyl ethers are preferably compounds of the formula 3

CH ₂ = CH-OR ⁴ (3)

wherein R ^{4 is} C ₁ - to C ₃₀ -alkyl, preferably C ₄ - to C ₁₆ -alkyl, especially C ₆ - to C ₁₂ -alkyl. Examples which may be mentioned are methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups.

The alkenes are preferably simple unsaturated hydrocarbons having 3 to 30 carbon atoms, especially 4 to 16 carbon atoms and especially 5 to 12 carbon atoms. Suitable alkenes include propene, butene, isobutylene, pentene, hexene, 4-methylpentene, octene, diisobutylene and norbornene and its derivatives such as methylnorbornene and vinylnorbornene. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups.

Particular preference is given to terpolymers which, apart from ethylene, have from 3.5 to 20 mol%, in particular from 8 to 15 mol% of vinyl acetate and from 0.1 to 12 mol%, in particular from 0.2 to 5 mol%, of at least one longer-chain and preferably branched one Vinyl esters such as vinyl 2-ethylhexanoate, vinyl neononanoate or vinyl neodecanoate, wherein the total comonomer content of the terpolymers is preferably between 8 and 21 mol%, in particular between 12 and 18 mol%. Further particularly preferred copolymers contain, in addition to ethylene and 8 to 18 mol% of vinyl esters of C ₂ to C ₁₂ carboxylic acids, from 0.5 to 10 mol% of olefins such as propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene and / or norbornene.

Preferably, these ethylene-co- and terpolymers have melt viscosities at 140 ° C of 20 to 10,000 m · Pas, in particular from 30 to 5,000 m · Pas, especially from 50 to 2,000 m · Pas. The means of ¹ H-NMR spectroscopy, certain degrees of branching are preferably between 1 and 9 CH _3/100 CH ₂ groups, especially between 2 and 6 CH _3/100 CH ₂ groups, which do not stem from the comonomers.

Preference is given to using mixtures of two or more of the abovementioned ethylene copolymers. Particularly preferably, the polymers underlying the mixtures differ in at least one characteristic. For example, they may contain different comonomers, have different comonomer contents, molecular weights and / or degrees of branching.

The mixing ratio between the additives and ethylene copolymers as constituent III can vary within wide limits depending on the application, with the ethylene copolymers III often representing the greater proportion. Such additive and oil mixtures preferably contain 0.1 to 25, preferably 0.5 to 10 parts by weight of ethylene copolymers per part by weight of the additive combination according to the invention.

Other cold flow improvers which are suitable are oil-soluble polar nitrogen compounds (constituent IV). These are preferably reaction products of fatty amines with compounds containing an acyl group. The preferred amines are compounds of the formula NR ⁶ R ⁷ R ⁸ , in which R ⁶ , R ⁷ and R ^{8 may be} identical or different, and at least one of these groups is C ₈ -C ₃₆ -alkyl, C ₆ - C ₃₆ -cycloalkyl, C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C ₂₄ -alkyl, C ₁₂ -C ₂₄ -alkenyl or cyclohexyl, and the other groups are either hydrogen, C ₁ -C ₃₆ -alkyl, C ₂ -C ₃₆ alkenyl, cyclohexyl, or a group of the formulas - (AO) _x -E or - (CH ₂ ) _n -NYZ, where A is an ethyl or propyl group, x is a number from 1 to 50, E = H, C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₂ -cycloalkyl or C ₆ -C ₃₀ -aryl, and n = 2, 3 or 4, and Y and Z independently of one another are H, C ₁ -C ₃₀ Alkyl or - (AO) _x . Also polyamines of the formula - [N- (CH ₂ ) _n ] _m -NR ⁶ R ⁷ , in which m is a number between 1 and 20 and n, R ⁶ and R ^{7 have} the meanings given above, are suitable as fatty amines , The alkyl and alkenyl radicals can be linear or branched and contain up to two double bonds. They are preferably linear and substantially saturated, ie they have iodine numbers of less than 75 gl ₂ / g, preferably less than 60 gl ₂ / g and in particular between 1 and 10 gl ₂ / g. Particularly preferred are secondary fatty amines in which two of the groups R ⁶ , R ⁷ and R ^{8 are} C ₈ -C ₃₆ -alkyl, C ₆ -C ₃₆ -cycloalkyl, C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C ₂₄ alkyl, C ₁₂ -C ₂₄ alkenyl or cyclohexyl. Suitable fatty amines are, for example, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, behenylamine, didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine, dioctadecylamine, dieicosylamine, dibehenylamine and mixtures thereof. Specifically, the amines contain chain cuts based on natural raw materials such as eg coco fatty amine, tallow fatty amine, hydrogenated tallow fatty amine, dicocosfettamine, ditallow fatty amine and di (hydrogenated tallow fatty amine). Particularly preferred amine derivatives are amine salts, imides and / or amides such as, for example, amide ammonium salts of secondary fatty amines, in particular dicocosfettamine, ditallow fatty amine and distearylamine.

By acyl group is meant here a functional group of the following formula: $$>\mathrm{C}=\mathrm{O}$$

Suitable carbonyl compounds for the reaction with amines are both monomeric and polymeric compounds having one or more carboxyl groups. In the case of the monomeric carbonyl compounds, preference is given to those having 2, 3 or 4 carbonyl groups. They can also contain heteroatoms such as oxygen, sulfur and nitrogen. Examples of suitable carboxylic acids are maleic, fumaric, crotonic, itaconic, succinic, C ₁ -C ₄₀ -alkenylsuccinic, adipic, glutaric, sebacic, and malonic acids and benzoic, phthalic, trimellitic and pyromellitic acid, nitrilotriacetic acid , Ethylenediaminetetraacetic acid and their reactive derivatives such as esters, anhydrides and acid halides. Copolymers of ethylenically unsaturated acids, such as, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, have proven particularly suitable as polymeric carbonyl compounds, particular preference is given to copolymers of maleic anhydride. Suitable comonomers are those which impart oil solubility to the copolymer. Oil-soluble means here that the copolymer dissolves without residue in the middle distillate to be additive after reaction with the fatty amine in practice-relevant metering rates. Suitable comonomers are, for example, olefins, alkyl esters of acrylic acid and methacrylic acid, alkyl vinyl esters and alkyl vinyl ethers having 2 to 75, preferably 4 to 40 and in particular 8 to 20 carbon atoms in the alkyl radical. In the case of olefins, the carbon number refers to the alkyl radical attached to the double bond. The molecular weights of the polymeric carbonyl compounds are preferred between 400 and 20,000, more preferably between 500 and 10,000, such as between 1,000 and 5,000.

Oil-soluble polar nitrogen compounds which have been obtained by reaction of aliphatic or aromatic amines, preferably long-chain aliphatic amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides have proven particularly suitable (cf. US 4 211 534 ). Likewise, amides and ammonium salts of aminoalkylene polycarboxylic acids such as nitrilotriacetic acid or ethylenediaminetetraacetic acid with secondary amines are suitable as oil-soluble polar nitrogen compounds (cf. EP 0 398 101 ). Other oil-soluble polar nitrogen compounds are copolymers of maleic anhydride with α, β-unsaturated compounds, which can optionally be reacted with primary monoalkylamines and / or aliphatic alcohols (cf. EP-A-0 154 177 . EP-0 777 712 ), the reaction products of Alkenylspirobislactonen with amines (see. EP-A-0 413 279 B1) and after
EP-A-0 606 055 A2 Reaction products of terpolymers based on α, β-unsaturated dicarboxylic acid anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.
The mixing ratio between the inventive ethylene copolymers III and oil-soluble polar nitrogen compounds as constituent IV may vary depending on the application. Such additive mixtures preferably contain 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on the active compounds, of at least one oil-soluble polar nitrogen compound per part by weight of the additive combination according to the invention.

The mixing ratio between the additives and the further components V and VI is generally in each case between 1:10 and 10: 1, preferably between 1: 5 and 5: 1.

Additives contain 15-80% by weight, preferably 20-70% by weight of detergent additive A), 2-40% by weight, preferably 5-25% by weight of nucleator B) and 15-80% by weight, preferably 20-70% by weight of cold flow improver C).

For easier handling, the additives are preferably used as concentrates which contain from 10 to 95% by weight and preferably from 20 to 80% by weight, for example from 25 to 60% by weight, of solvent. Preferred solvents are higher-boiling aliphatic, aromatic hydrocarbons, alcohols, esters, ethers and mixtures thereof. Such concentrates preferably contain from 0.01 to 10 parts by weight, preferably from 0.05 to 5 parts by weight, for example from 0.1 to 3 parts by weight of the comb polymer B) per part by weight of detergent additive A).

The Nucleatoren B) improve the response of detergent additive-containing middle distillates such as kerosene, jet fuel, diesel and fuel oil for conventional flow improvers with regard to the lowering of pour point and CFPP value and the improvement of paraffin dispersion.

Particularly preferred mineral oil distillates are middle distillates. The middle distillate is in particular those mineral oils which are obtained by distillation of crude oil, boiling in the range of about 150 to 450 ° C and in particular in the range of about 170 to 390 ° C, for example kerosene, jet fuel, diesel and fuel oil. Typically, middle distillates contain about 5 to 50 wt .-%, such as about 10 to 35 wt .-% n-paraffins, of which the longer-chain crystallize on cooling and can affect the flowability of the middle distillate. Particularly advantageous are the compositions of the invention in middle aromatics with low aromatic content of less than 21 wt .-%, such as less than 19 wt .-%. The compositions according to the invention are furthermore particularly advantageous in low boiling end middle distillates, ie in middle distillates which have 90% distillation points below 360 ° C., in particular 350 ° C. and in special cases below 340 ° C. and furthermore in such middle distillates, the boiling ranges have between 20 and 90% distillation volume of less than 120 ° C and in particular of less than 110 ° C. By aromatic compounds is meant the sum of mono-, di- and polycyclic aromatic compounds as determinable by HPLC according to DIN EN 12916 (2001 edition). The middle distillates can also minor amounts such as, for example, up to 40% by volume, preferably 1 to 20% by volume, especially 2 to 15 such as 3 to 10% by volume of the oils of animal and / or vegetable origin described in more detail below, such as, for example, fatty acid methyl esters ,

The compositions according to the invention are also suitable for improving the cold properties of detergent additives containing fuels based on renewable raw materials (biofuels). By biofuels is meant oils obtained from animal and preferably vegetable material or both, and derivatives thereof, which can be used as fuel and especially as diesel or fuel oil. These are, in particular, triglycerides of fatty acids having 10 to 24 carbon atoms and the fatty acid esters of lower alcohols, such as methanol or ethanol, which are obtainable by transesterification.

Examples of suitable biofuels are rapeseed oil, coriander oil, soybean oil, cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, corn oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, beef tallow, bone oil, fish oils and used edible oils. Other examples include oils derived from wheat, jute, sesame, shea nut, arachis oil and linseed oil. The fatty acid alkyl esters, also referred to as biodiesel, can be derived from these oils by methods known in the art. Rapeseed oil, which is a mixture of glycerol esterified fatty acids, is preferred because it is available in large quantities and is readily available by squeezing rapeseed. Furthermore, the also widespread oils of sunflower, palm and soybeans and their mixtures with rapeseed oil are preferred.

Particularly suitable as biofuels are lower alkyl esters of fatty acids. For example, commercially available mixtures of the ethyl, propyl, butyl and especially methyl esters of fatty acids having 14 to 22 carbon atoms, for example of lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroselinic acid, ricinoleic acid, Elaeostearic, linoleic, linolenic, eicosanoic, gadoleic, docosanoic or erucic acid into consideration. Preferred esters have an iodine value of from 50 to 150 and in particular from 90 to 125. Mixtures with particularly advantageous properties are those which contain mainly, ie at least 50% by weight of methyl esters of fatty acids having 16 to 22 carbon atoms and 1, 2 or 3 double bonds contain. The preferred lower alkyl esters of fatty acids are the methyl esters of oleic, linoleic, linolenic and erucic acids.

The additives can be used alone or together with other additives, for. With other pour point depressants or dewaxing aids, with other detergents, with antioxidants, cetane number improvers, dehazers, demulsifiers, dispersants, defoamers, dyes, corrosion inhibitors, lubricity additives, sludge inhibitors, odorants and / or cloud point depressants.

Examples Improvement of the cold flowability of middle distillates

To evaluate the effect of the inventive additives on the cold flow properties of middle distillates, detergent additives (A) with different nucleators (B) and further flow improvers (C) with the characteristics given below were used.

The suppression of the negative effect of the detergent additives A) on known cold flow improvers for mineral oils and mineral oil distillates by nucleators is described on the one hand by means of the CFPP test (Cold Filter Plugging Test according to EN 116).

Furthermore, the paraffin dispersion in middle distillates is determined in the short sediment test as follows:
150 ml of the middle distillates mixed with the additive components indicated in the table were cooled to -13 ° C. in a cold cabinet at -2 ° C./hour in 200 ml graduated cylinders and stored at this temperature for 16 hours. Subsequently, the volume and appearance of both the sedimented paraffin phase and the oil phase above are visually determined and assessed. A small amount of sediment and a cloudy oil phase show a good paraffin dispersion.

In addition, immediately after cold storage, the lower 20% by volume is isolated and the cloud point determined according to IP 3015. Only a small deviation of the cloud point of the lower phase (CP _KS ) from the blank value of the oil shows a good paraffin dispersion. Table 1: Characterization of the test oils: The test oils used were current middle distillates from European refineries. The CFPP value was determined in accordance with EN 116 and the determination of the cloud point in accordance with ISO 3015. The determination of the aromatic hydrocarbon groups was carried out in accordance with DIN EN 12916 (November 2001 edition) Test oil 1 Test oil 2 Test oil 3 distillation IBP [° C] 192 186 165 20% [° C] 250 222 228 90% [° C] 322 324 335 (90-20)% [° C] 72 102 107 FBP [° C] 347 352 359 Cloud point [° C] -8.0 -8.9 -4.4 CFPP [° C] -10 -10 -5 Density @ 15 ° C [g / cm ³ ] 0.835 .8307 .8273 sulfur content [Ppm] <10 <10 15 aromatics [Wt .-%] 19.6 18.8 22.8 of which mono [Wt .-%] 18.0 18.2 20.6 di [Wt .-%] 1.6 0.6 2.1 poly [Wt .-%] <0.1 <0.1 0.1

• (A) Charakterisierung der eingesetzten Detergenzadditive
  Als Detergenzadditive A wurden verschiedene in Tabelle 2 aufgeführte Umsetzungsprodukte aus Alkenylbernsteinsäureanhydriden (ASA) auf Basis hochreaktiver Polyolefine (Anteil der endständigen Doppelbindungen > 90 %; Maleinierungsgrad etwa 1,2 bis 1,3) mit Polyaminen eingesetzt. Alkenylbernsteinsäureanhydrid und Polyamin wurden dazu im molaren Verhältnis von 1,0 bis 1,5 Mol Alkenylbernsteinsäureanhydrid pro Mol Polyamin umgesetzt (siehe Tabelle 2). Zur besseren Dosierbarkeit wurden die Detergenzadditive als 33 %ige Lösungen in höhersiedendem aromatischem Lösemittel verwendet. Die in den Tabellen 2 bis 4 für die Detergenzadditive A) und Nucleatoren B) angegebenen Dosierraten beziehen sich auf die eingesetzten Wirkstoffe.
• (B) Charakterisierung der eingesetzten Nucleatoren
• B1) Alternierendes Copolymer aus Maleinsäureanhydrid und einer Mischung gleicher Teile C₂₂- und C₂₄-α-Olefin, verestert mit 1,5 mol pro mol Anhydridgruppen einer Mischung gleicher Teile Eicosanol und Docosanol, 50 %ig in höhersiedendem aromatischem Lösemittel
• B2) C_20-24-Alkylphenol-Formaldehydharz, 50 %ig in höhersiedendem aromatischem Lösemittel
• (C) Charakterisierung der eingesetzten weiteren Fließverbesserer
• C1) Terpolymer aus Ethylen, 13 mol-% Vinylacetat und 2 mol-% Neodecansäurevinylester mit einer bei 140°C gemessenen Schmelzviskosität V140 von 95 mPas, 65 %ig in Kerosin
• C2) Mischung gleicher Teile von C1) und einem Copolymer aus Ethylen und 13,5 mol-% Vinylacetat mit einer bei 140 °C gemessenen Schmelzviskosität V140 von 125 m·Pas, 56 %ig in Kerosin.
• C3) Mischung aus 2 Teilen Umsetzungsprodukt eines Copolymers aus C14/C16-α-Olefin und Maleinsäureanhydrid mit 2 Equivalenten hydriertem Ditalgfettamin mit einem Teil Nonylphenol-Formaldehydharz, 50 %ig in höhersiedendem aromatischem Lösemittel.
• C4) Umsetzungsprodukt aus Ethylendiamintetraessigsäure mit 4 Equivalenten Ditalgfettamin zum Amid-Ammoniumsalz, hergestellt gemäß EP 0 398 101 , 50 %ig in höhersiedendem aromatischem Lösemittel.
• C5) Mischung gleicher Teile eines Umsetzungsprodukts aus Phthalsäureanhydrid und 2 Equivalenten Di(hydriertem Talgfett)amin mit einem Copolymer aus Fumarsäure-ditetradecylester, 50 %ig in höhersiedendem aromatischem Lösemittel.

The following additives were used:

• (A) Characterization of the detergent additives used
  As detergent additives A, various reaction products of alkenylsuccinic anhydrides (ASA) based on highly reactive polyolefins (proportion of terminal double bonds> 90%, degree of maleation about 1.2 to 1.3) listed in Table 2 with polyamines were used. Alkenyl succinic anhydride and polyamine were reacted thereto in a molar ratio of 1.0 to 1.5 moles alkenyl succinic anhydride per mole of polyamine (see Table 2). For better meterability, the detergent additives were used as 33% solutions in higher boiling aromatic solvent. The dosage rates given in Tables 2 to 4 for the detergent additives A) and nucleators B) relate to the active ingredients used.
• (B) Characterization of the inserted nucleators
• B1) Alternating copolymer of maleic anhydride and a mixture of equal parts C ₂₂ - and C ₂₄ -α-olefin, esterified with 1.5 moles per mole of anhydride groups of a mixture of equal parts eicosanol and docosanol, 50% in higher boiling aromatic solvent
• B2) C _20-24 alkylphenol-formaldehyde resin, 50% in higher boiling aromatic solvent
• (C) Characterization of the further flow improvers used
• C1) Terpolymer of ethylene, 13 mol% vinyl acetate and 2 mol% vinyl neodecanoate with a melt viscosity V140 of 95 mPas, measured at 140 ° C., 65% in kerosene
• C2) mixture of identical parts of C1) and a copolymer of ethylene and 13.5 mol% vinyl acetate with a measured at 140 ° C melt viscosity V140 of 125 m · Pas, 56% in kerosene.
• C3) Mixture of 2 parts of reaction product of a copolymer of C14 / C16-α-olefin and maleic anhydride with 2 equivalents of hydrogenated Ditalgfettamin with one part of nonylphenol-formaldehyde resin, 50% in higher boiling aromatic solvent.
• C4) Reaction product of ethylenediaminetetraacetic acid with 4 equivalents of ditallow fatty amine to the amide ammonium salt prepared according to EP 0 398 101 , 50% in higher boiling aromatic solvent.
• C5) Mixing equal parts of a reaction product of phthalic anhydride and 2 equivalents of di (hydrogenated tallow fat) amine with a copolymer of fumaric acid ditetradecylester, 50% in higher boiling aromatic solvent.

The determination of the CFPP values in test oil 1 was carried out after adding the oil with 200 ppm C2 and 150 ppm C3.

In the examples of Tables 3 and 4, as detergent additive A1, the reaction product of poly (isobutenyl) -succinic anhydride and pentaethylene-hexamine according to Table 2, Example 4 and as detergent additive A2 the reaction product of poly (isobutenyl) succinic anhydride and pentaethylenehexamine according to Table 2, Example 13 used. Table 2: Effect of nucleators on detergent-induced antagonism in test oil 1 example Detergent additive (DA) Dosing rate DA / ppm CFPP in test oil 1 [° C] polyolefin Mw polyolefin polyamine mol of ASA / mol of polyamine without DA with DA with DA + Nucleator (B) 1 PIB 700 TEPA 1.0 150 -29 -25 50 ppm B1 -30 2 PIB 700 TEPA 1.4 150 -29 -26 50 ppm B1 -29 3 PIB 1000 PEHA 1.0 150 -29 -22 75 ppm B2 -28 4 PIB 1000 PEHA 1.5 150 -29 -21 75 ppm B2 -27 5 PIB 1000 PAM 1.0 150 -29 -18 60 ppm B1 -28 6 PIB 1000 PAM 1.3 150 -29 -15 60 ppm B1 -25 7 PIB 1000 PAM 1.3 150 -29 -15 75 ppm B1 -29 8th PIB 1000 PAM 1.3 150 -29 -15 100 ppm B1 -29 9 APP 1150 PEHA 1.5 150 -29 -26 50 ppm B2 -29 10 APP 1150 PAM 1.0 150 -29 -20 70 ppm B2 -30 11 APP 1150 PAM 1.5 150 -29 -20 70 ppm B2 -29 12 P2B 1000 PAM 1.1 150 -29 -11 70 ppm B2 -27 13 P2B 1000 PAM 1.4 150 -29 -14 70 ppm B2 -29 DA = detergent additive; PIB = poly (isobutylene); APP = atactic poly (propylene); P2B = poly (butene) from a mixture of different butene isomers with a proportion of 2-butene of about 80%; TEPA = tetraethylenepentamine; PEHA = pentaethylenehexamine;
PAM = heavy polyamine example additives Test Oil 2 CFPP [° C] A B C 14 (Cf.) - - 75 ppm C2 - -14 15 (Cf.) - - 100 ppm C2 - -19 16 (Cf.) - - 150 ppm C1 - -20 17 (Cf.) - - 75 ppm C1 150 ppm C3 -21 18 (Cf.) - - 100 ppm C1 150 ppm C3 -29 19 (See) - - 150 ppm C1 150 ppm C3 -31 20 (Cf.) 50 ppm A1 - 75 ppm C1 150 ppm C3 -14 21 (Cf.) 50 ppm A1 - 100 ppm C1 150 ppm C3 -19 22 (See) 50 ppm A1 - 150 ppm C1 150 ppm C3 -20 23 (Cf.) 50 ppm A1 - 150 ppm C1 250 ppm C3 -20 24 50 ppm A1 30 ppm B1 75 ppm C1 150 ppm C3 -20 25 50 ppm A1 40 ppm B1 100 ppm C1 150 ppm C3 -30 26 50 ppm A1 40 ppm B1 100 ppm C1 150 ppm C3 -31 27 (Cf.) 50 ppm A2 - 75 ppm C1 150 ppm C4 -15 28 (Cf.) 50 ppm A2 - 100 ppm C1 150 ppm C4 -12 29 (Cf.) 50 ppm A2 - 150 ppm C1 150 ppm C4 -20 30 (Cf.) 50 ppm A2 - 150 ppm C1 250 ppm C4 -21 31 50 ppm A2 30 ppm B1 75 ppm C1 150 ppm C4 -22 32 50 ppm A2 30 ppm B1 100 ppm C1 150 ppm C4 -29 33 50 ppm A2 30 ppm B2 75 ppm C1 150 ppm C4 -21 example Additives [ppm] Test oil 3 (CP -4.4 ° C) A B C D CFPP [° C] Sediment [vol.%] Appearance oil phase CP _KS [° C] 34 (Cf.) - - 400 C2 200 C3 -20 2 cloudy -3.1 35 (Cf.) - - 535 C2 265 C3 -22 2 cloudy -3.2 36 (See) 40 A2 - 400 C2 200 C3 -17 20 cloudy 0.2 37 (Cf.) 40 A2 - 535 C2 265 C3 -18 10 cloudy -1.2 38 40 A2 25 B1 400 C2 200 C3 -21 0 cloudy -2.9 39 40 A2 25 B1 535 C2 265 C3 -22 0 cloudy -3.1 41 40 A2 25 B2 400 C2 200 C3 -19 2 cloudy -2.8 42 40 A2 25 B2 535 C2 265 C3 -22 2 cloudy -3.1 43 (Cf.) - - 400 C3 200 C5 -19 4 cloudy -2.8 44 (Cf.) 50 A1 - 400 C3 200 C5 -15 30 almost clear 0.8 45 50 A1 30 B1 400 C3 200 C5 -19 2 cloudy -2.7

Examples 33, 41, 42 are not according to the invention.

The experiments show that the impairment of the cold flow properties, such as the CFPP value and the paraffin dispersion of middle distillates additized with flow improvers, can only be compensated by adding the nucleators. By higher dosage of the flow improver alone, this result can not be achieved.

Claims (19)

1. Use of at least one oil-soluble compound B) which acts as a nucleator for paraffin crystallization and is selected from comb polymers which bear alkyl side chains having a length of at least 20 carbon atoms for improving the response behavior with respect to lowering pour point 3 and CFPP value and improving paraffin dispersancy of mineral oil cold flow improvers C) different than B) in middle distillates which comprise at least one ashless nitrogen-containing detergent additive A) which is an oil-soluble amphiphilic compound which comprises at least one alkyl or alkenyl radical which is bonded to a polar group, where the alkyl or alkenyl radical comprises 10 to 500 carbon atoms and the polar group 2 or more nitrogen atoms, wherein the ashless nitrogen-containing detergent additive A) comprises a polar component which is derived from polyamines of the formula
   
           (R⁹)₂N-[A-N(R⁹)]_q-(R⁹)
   
   in which each R⁹ is independently hydrogen, an alkyl or hydroxyalkyl radical having up to 24 carbon atoms, a polyoxyalkylene radical -(A-O)_r- or polyiminoalkylene radical -[A-N(R⁹)]_s-(R⁹), but at least one R⁹ is hydrogen, q is an integer from 1 to 19, A is an alkylene radical having 1 to 6 carbon atoms, and r and s are each independently integers from 1 to 50, and wherein the cold flow improvers C) employed are oil-soluble polar nitrogen compounds which are reaction products of compounds of the formula NR⁶R⁷R⁸ in which R⁶, R⁷ and R⁸ may be the same or different, and at least one of these groups is C₈-C₃₆-alkyl, C₆-C₃₆-cycloalkyl, C₈-C₃₆-alkenyl, especially C₁₂-C₂₄-alkyl, C₁₂-C₂₄-alkenyl or cyclohexyl, and the remaining groups are hydrogen, C₁-C₃₆-alkyl, C₂-C₃₆-alkenyl, cyclohexyl or a group of the formula -(A-O)_x-E or -(CH₂)_n-NYZ in which A is an ethyl or propyl group, x is from 1 to 50, E = H, C₁-C₃₀-alkyl, C₅-C₁₂-cycloalkyl or C₆-C₃₀-aryl, and n = 2, 3 or 4, and Y and Z are each independently H, C₁-C₃₀-alkyl or -(A-O)_x, with compounds which contain at least one acyl group.
2. Use according to Claim 1, wherein, based on one part by weight of the nitrogen-containing detergent additive A), 0.01 to 10 parts by weight of the oil-soluble compound B) which acts as a nucleator for paraffin crystallization are used.
3. Use according to Claim 1 and/or 2, wherein the middle distillate contains 10 to 10 000 ppm of an ashless nitrogen-containing detergent additive A).
4. The use as claimed in one or more of Claims 1 to 3, wherein the ashless nitrogen-containing detergent additive A) has an alkyl radical having 15 to 500 carbon atoms.
5. Use according to Claim 4, wherein the alkyl radical is derived from oligomers of lower olefins having 3 to 6 carbon atoms or mixtures thereof.
6. Use according to Claim 5, wherein a mixture of oligomers of lower olefins having 3 to 6 carbon atoms which contains more than 70 mol% of 2-methyl-2-butene, 2,3-dimethyl-2-butene and/or isobutene is employed.
7. Use as claimed in one or more of Claims 1 to 6, wherein the ashless nitrogen-containing detergent additive A) is prepared using high-reactivity low molecular weight polyolefins having a molecular weight of 500 to 3000 g/mol., and having a proportion of terminal double bonds of at least 75 mol%.
8. Use according to Claim 1, wherein R⁹ is hydrogen and q assumes values of at least 3.
9. Use according to one or more of Claims 1 to 8, wherein the ashless nitrogen-containing detergent additive A) comprises an oil-soluble alkyl radical and a polar head group, and the oil-soluble alkyl radical and the polar head group are joined to one another via a C-N bond or via an ester, amide or imide bond.
10. Use according to one or more of Claims 1 to 9, wherein the ashless nitrogen-containing detergent additive A) has a mean molecular weight determined by means of vapor pressure osmometry of more than 800 g/mol.
11. Use according to one or more of Claims 1 to 10, wherein the comb polymers which act as nucleators for paraffin crystallization have a proportion of alkyl side chains having at least 20 carbon atoms in the total amount of the alkyl side chains of the comb polymer of at least 10 mol%.
12. Use according to one or more of Claims 1 to 11, wherein the comb polymers which act as nucleators for paraffin crystallization bear side chains having 22 to 60 carbon atoms.
13. Use according to one or more of Claims 1 to 12, wherein the alkyl side chains of the comb polymers are linear.
14. Use according to one or more of Claims 1 to 13, wherein the comb polymers which act as nucleators for paraffin crystallization contain a backbone composed of ethylenically unsaturated monocarboxylic acids, polycarboxylic acids or a mixture thereof.
15. Use according to one or more of Claims 1 to 14, wherein the alkyl side chains of the comb polymers are bonded to the polymer backbone via an ester, amide, imide or ammonium group.
16. Use according to one or more of Claims 1 to 13 and 15, wherein the comb polymers which act as nucleators for paraffin crystallization are polycondensates which contain structural units derived from alkylaromatics and have alkyl radicals having at least 20 carbon atoms.
17. Use according to Claim 16, wherein the alkyl radicals are bonded to the aromatic via a C-C bond or via an ester or ether group.
18. Use according to one or more of Claims 1 to 17, wherein the ratio between detergent additive A) and comb polymer B) which acts as a nucleator for paraffin crystallization in the additized oil is 0.01 to 10 parts by weight of nucleator per part by weight of detergent additive, based in each case on the active ingredient.
19. Middle distillate having a sulfur content of less than 100 ppm and a 90% distillation point of less than 360°C, comprising

    a) at least one ashless nitrogen-containing detergent additive A) which is an oil-soluble amphiphilic compound which comprises at least one alkyl or alkenyl radical which is bonded to a polar group, where the alkyl or alkenyl radical comprises 10 to 500 carbon atoms and the polar group 2 or more nitrogen atoms, wherein the ashless nitrogen-containing detergent additive A) comprises a polar component which is derived from polyamines of the formula
    
            (R⁹)₂N-[A-N(R⁹)]_q-(R⁹)
    
    in which each R⁹ is independently hydrogen, an alkyl or hydroxyalkyl radical having up to 24 carbon atoms, a polyoxyalkylene radical -(A-O)_r- or polyiminoalkylene radical -[A-N(R⁹)]_s-(R⁹), but at least one R⁹ is hydrogen, q is an integer from 1 to 19, A is an alkylene radical having 1 to 6 carbon atoms, and r and s are each independently integers from 1 to 50, and

    b) at least one oil-soluble compound B) which acts as a nucleator for paraffin crystallization and is selected from comb polymers which bear alkyl side chains having a molar average length of at least 18 carbon atoms,
    and

    c) at least one mineral oil cold flow improver C) different than B), wherein the cold flow improvers C) employed are oil-soluble polar nitrogen compounds which are reaction products of compounds of the formula NR⁶R⁷R⁸ in which R⁶, R⁷ and R⁸ may be the same or different, and at least one of these groups is C₈-C₃₆-alkyl, C₆-C₃₆-cycloalkyl, C₈-C₃₆-alkenyl, especially C₁₂-C₂₄-alkyl, C₁₂-C₂₄-alkenyl or cyclohexyl, and the remaining groups are hydrogen, C₁-C₃₆-alkyl, C₂-C36-alkenyl, cyclohexyl or a group of the formula -(A-O)_x-E or -(CH₂)_n-NYZ in which A is an ethyl or propyl group, x is from 1 to 50, E = H, C₁-C₃₀-alkyl, C₅-C₁₂-cycloalkyl or C₆-C₃₀-aryl, and n = 2, 3 or 4, and Y and Z are each independently H, C₁-C₃₀-alkyl or -(A-O)_x, with compounds which contain at least one acyl group, and in which 10 to 10 000 ppm of the ashless nitrogen-containing detergent additive A) and, for every part by weight of this constituent A), 0.1 to 10 parts by weight of the oil-soluble compound B) that acts as a nucleator for paraffin crystallization.