EP1380635A2 - Cold flow improver for fuel oils of vegetable or animal origin. - Google Patents

Abstract

Additives containing (A) a copolymer of ethylene and an acrylate or vinyl ester and (B) a comb polymer derived from 8-16C alkyl ester(s) of unsaturated dicarboxylic acids and 10-20C olefin(s), in which the sum of the average molar C-chain distributions in the alkyl side chains of the olefins and in the fatty alcohols of the ester groups is 23-27. Additives (I) containing (A) a copolymer of ethylene and 8-21 mol% acrylate or vinyl ester with a 1-18C alkyl group and (B) a comb polymer derived from 8-16C alkyl ester(s) of unsaturated dicarboxylic acid(s) and 10-20C olefin(s), in which the sum Q of the average molar C-chain distributions in (a) the alkyl side chains of the olefin and in (b) the fatty alcohols in the ester groups = 23-27, Q being given by the expression Q = approximately Siw1i.n1i + approximately Sjw2j.n2j, where w1 and w2 are the molar proportions of individual chain lengths in (a) and (b) respectively, n1 and n2 are the side chain lengths in (a) without the original olefinic carbons and in (b) respectively, and the variables i and j are the individual side-chain lengths in (a) and (b). An Independent claim is also included for a fuel oil composition containing a fuel oil of animal or vegetable origin and an additive (I).

Description

The present invention relates to an additive, its use as Cold flow improver for vegetable or animal fuel oils and accordingly additized fuel oils.

In the course of decreasing world oil reserves and the discussion about the environment debilitating consequences of fossil and mineral consumption Fuels is increasing interest in alternative, renewable resources based energy sources. These include, in particular, native oils and fats of plant or animal origin. These are usually triglycerides of Fatty acids with 10 to 24 C atoms, which are one of the conventional fuels have comparable calorific value, but at the same time as biodegradable and environmentally friendly.

entsprechen, in der R ein aliphatischer Rest mit 10 bis 25 Kohlenstoffatomen ist, der gesättigt oder ungesättigt sein kann.Oils obtained from animal or vegetable material are mainly metabolites comprising triglycerides of monocarboxylic acids, e.g. As acids having 10 to 25 carbon atoms, and the formula

in which R is an aliphatic radical of 10 to 25 carbon atoms, which may be saturated or unsaturated.

In general, such oils contain glycerides of a number of acids whose Number and variety varies with the source of the oil, and they may additionally Contain phosphoglycerides. Such oils can be used in the prior art known methods are obtained.

Due to the partially unsatisfactory physical properties of the Triglycerides, the technique has gone over to the naturally occurring Triglycerides in fatty acid esters of lower alcohols such as methanol or ethanol convict.

As an obstacle to the use of fatty acid esters of lower monohydric alcohols as a diesel fuel substitute alone or mixed with diesel fuel has the Flow behavior at low temperatures proved. The reason for this is the high Uniformity of these oils compared to mineral oil middle distillates. Thus, e.g. Rapeseed acid methyl ester (RME) has a CFPP of -14 ° C. With the additives of Prior art, it is not yet possible, one for use as Winter diesel in Central Europe demanded CFPP value of -20 ° C as well as for special Safe application of -22 ° C and below. This is aggravated Problem with the use of oils, the larger amounts of the likewise easily accessible Oils of sunflower and soy included.

EP-B-0 665 873 discloses a fuel oil composition comprising a A biofuel comprising a petroleum-based fuel oil and an additive which comprises (a) an oil-soluble ethylene copolymer or (b) a comb polymer or (c) a polar Nitrogen compound or (d) a compound in which at least one in the Substantially linear alkyl group having 10 to 30 carbon atoms with one not polymeric organic radical is connected to at least one linear chain of To provide atoms containing the carbon atoms of the alkyl groups and one or more includes non-terminal oxygen atoms, or (e) one or more of Components (a), (b), (c) and (d).

(I) Kammpolymer, das Copolymer von Maleinsäureanhydrid oder Fumarsäure und einem anderen ethylenisch ungesättigten Monomer, wobei das Copolymer verestert sein kann, oder Polymer oder Copolymer von α-Olefin, oder Fumarat- oder Itaconatpolymer oder -copolymer ist,

(II) Polyoxyalkylen-ester, -ester/ether oder eine Mischung derselben,

(III) Ethylen/ungesättigter Ester-Copolymer,

(IV) polarer, organischer, stickstoffhaltiger Paraffinkristallwachstumshemmstoff,

(V) Kohlenwasserstoffpolymer,

(VI) Schwefelcarboxyverbindungen und

(VII) mit Kohlenwasserstoffresten versehenes aromatisches Stockpunktsenkungsmittel

umfasst, mit der Maßgabe, dass die Zusammensetzung keine Mischungen von polymeren Estern oder Copolymeren von Estern von Acryl- und/oder Methacrylsäure umfasst, die von Alkoholen mit 1 bis 22 Kohlenstoffatomen abgeleitet sind.EP-B-0 629 231 discloses a composition comprising a major proportion of oil consisting essentially of alkyl esters of fatty acids derived from vegetable or animal oils, or both, mixed with a small proportion of mineral oil flow improver comprising one or more of following:

(I) comb polymer, the copolymer of maleic anhydride or fumaric acid and another ethylenically unsaturated monomer, which copolymer may be esterified, or polymer or copolymer of α-olefin, or fumarate or itaconate polymer or copolymer,

(II) polyoxyalkylene ester, ester / ether or a mixture thereof,

(III) ethylene / unsaturated ester copolymer,

(IV) polar, organic, nitrogen-containing wax crystal growth inhibitor,

(V) hydrocarbon polymer,

(VI) sulfur carboxy compounds and

(VII) hydrocarbon residue-containing aromatic pour point depressant

with the proviso that the composition does not comprise mixtures of polymeric esters or copolymers of esters of acrylic and / or methacrylic acid derived from alcohols having from 1 to 22 carbon atoms.

a) an sich bekannte, zur Verbesserung des Tieftemperaturverhaltens von Mineralölen verwendete Additive PPD ("Pour Point Depressant") in Mengen von 0,0001 bis 10 Gew.-% bezogen auf die langkettigen Fettsäureester FAE zusetzt und

b) auf eine Temperatur unterhalb des Cold Filter Plugging Point der nichtadditivierten, langkettigen Fettsäureester FAE abkühlt und

c) die entstehenden Niederschläge (FAN) abtrennt.

EP-B-0 543 356 discloses a process for the preparation of compositions having improved low-temperature behavior for use as fuels or lubricants, starting from the esters of long-chain fatty acids obtained from natural sources with monohydric C ₁ -C ₆ -alcohols (FAE), characterized that he

a) known per se used to improve the low-temperature behavior of mineral oils additives PPD ("pour point depressant") in amounts of 0.0001 to 10 wt .-% based on the long-chain fatty acid esters FAE added and

b) to a temperature below the cold filter plugging point of the non-additive, long-chain fatty acid ester FAE cools and

c) the resulting precipitation (FAN) is separated.

a) 58 bis 95 Gew.-% mindestens eines Esters im lodzahlbereich 50 bis 150, der sich von Fettsäuren mit 12 bis 22 Kohlenstoffatomen und niederen aliphatischen Alkoholen mit 1 bis 4 Kohlenstoffatomen ableitet,

b) 4 bis 40 Gew.-% mindestens eines Esters von Fettsäuren mit 6 bis 14 Kohlenstoffatomen und niederen aliphatischen Alkoholen mit 1 bis 4 Kohlenstoffatomen und

c) 0,1 bis 2 Gew.-% mindestens eines polymeren Esters.

DE-A-40 40 317 discloses mixtures of fatty acid lower alkyl esters having improved low temperature stability

a) 58 to 95% by weight of at least one ester in the iodine value range 50 to 150, which is derived from fatty acids having 12 to 22 carbon atoms and lower aliphatic alcohols having 1 to 4 carbon atoms,

b) 4 to 40 wt .-% of at least one ester of fatty acids having 6 to 14 carbon atoms and lower aliphatic alcohols having 1 to 4 carbon atoms and

c) 0.1 to 2 wt .-% of at least one polymeric ester.

EP-B-0 153 176 discloses the use of polymers based on unsaturated C ₄ -C ₈ dicarboxylic acid di-alkyl esters having average alkyl chain lengths of 12 to 14 as cold flow improvers for certain petroleum distillate fuel oils. Particularly suitable comonomers are vinyl esters, but also α-olefins.

I) einem Copolymer mit mindestens 25 Gew.-% eines n-Alkylesters einer monoethylenisch ungesättigten C₄-C₈-Mono- oder Dicarbonsäure, wobei die durchschnittliche Zahl der Kohlenstoffatome in den n-Alkylresten 12- 14 ist und einem anderen ungesättigten Ester oder einem Olefin enthält, mit

II) einem anderen Niedertemperaturfließverbesserer für Destillatbrennstofföle umfasst.

EP-B-0 153 177 discloses an additive concentrate which is a combination of

I) a copolymer having at least 25% by weight of an n-alkyl ester of a monoethylenically unsaturated C ₄ -C ₈ mono- or dicarboxylic acid, wherein the average number of carbon atoms in the n-alkyl radicals is 12-14 and another unsaturated ester or an olefin, with

II) another low temperature flow improver for distillate fuel oils.

With the well-known additives it is often not possible, one for the Use as winter diesel in Central Europe demanded CFPP value of -20 ° C as well as for special applications of -22 ° C and below. In addition, a problem with the known additives is a lack of Chilling resistance of the additized oils, ie the set CFPP value The oil gradually rises when the oil is changing for a long time Temperatures are stored in the area of the cloud point or below.

It was therefore the task of additives for improving the cold flow behavior of fatty acid esters of monohydric alcohols, for example of rapeseed, Sunflower and / or soybean oil are derived, wherein CFPP values of -20 ° C and below are set and the CFPP value set even with longer storage of the oil in the area of its cloud point or below that remains constant.

Surprisingly, it has now been found that an ethylene copolymer, Comb polymers and optionally polyalkyl (meth) acrylates containing additive an excellent flow improver for such fatty acid esters.

A) ein Copolymer aus Ethylen und 8 - 21 Mol-% mindestens eines Acryl- oder Vinylesters mit einem C₁-C₁₈-Alkylrest und

B) ein Kammpolymer aus mindestens einem C₈-C₁₆-Alkylester einer ethylenisch ungesättigten Dicarbonsäure und mindestens einem C₁₀-C₂₀-Olefin, wobei die Summe Q

der molaren Mittel der C-Kettenverteilungen in den Alkylseitenketten der Olefine einerseits und den Fettalkoholen in den Estergruppen andererseits von 23 bis 27 beträgt, wobei w₁ und w₂ die molaren Anteile der einzelnen Kettenlängen in den Alkylseitenketten der Olefine einerseits und den Fettalkoholen in den Estergruppen andererseits sind und n₁ und n₂ für die Seitenkettenlängen, bei Olefinen ohne die ursprünglich olefinisch gebundenen C-Atome, der Alkylseitenketten der Olefine einerseits und der Fettalkohole in den Estergruppen andererseits stehen, und die Laufvariablen i und j für die einzelnen Seitenkettenlängen in den Alkylseitenketten der Olefine einerseits und der Fettalkohole in den Estergruppen andererseits stehen.

The invention relates to an additive containing

A) a copolymer of ethylene and 8 to 21 mol% of at least one acrylic or vinyl ester having a C ₁ -C ₁₈ -alkyl radical and

B) a comb polymer of at least one C ₈ -C ₁₆ alkyl ester of an ethylenically unsaturated dicarboxylic acid and at least one C ₁₀ -C ₂₀ olefin, wherein the sum Q

the molar average of the C chain distributions in the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups on the other hand from 23 to 27, wherein w ₁ and w _2, the molar ratios of the individual chain lengths in the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups On the other hand, and n ₁ and n _{2 are} the side chain lengths, olefins without the originally olefinically bonded C atoms, the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups on the other hand, and the run variables i and j for the individual side chain lengths in the alkyl side chains the olefins on the one hand and the fatty alcohols in the ester groups on the other hand.

Another object of the invention is a fuel oil composition, containing a fuel oil of animal or vegetable origin and the above defined additive.

Another object of the invention is the use of the above defined Additive to improve the cold flow properties of animal fuel oil or of vegetable origin.

Another object of the invention is a method for improving the Cold flow properties of fuel oils of animal or vegetable origin, by giving fuel oils of animal or vegetable origin the above Adds defined additive.

In a preferred embodiment of the invention Q has values from 24 to 26.

In determining the contribution of the esters to Q, the chain length distribution is used alcohols. The degree of esterification will not considered. The molar ratio of olefins and ethylenically unsaturated Dicarboxylic acid ester is not included in the calculation of Q, since in the Copolymerization of these monomers Copolymers with approximately equal molar Monomer shares arise.

Suitable ethylene copolymers A) are those which contain 8 to 21 mol% vinyl and / or (Meth) acrylic ester and 79 to 92 wt .-% ethylene. Particularly preferred Ethylene copolymers with 10 to 18 mol% and especially 12 to 16 mol% at least a vinyl ester. Suitable vinyl esters are derived from fatty acids with linear or branched alkyl groups having 1 to 30 carbon atoms. As examples may be mentioned Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl heptanoate and Vinyl octanoate and branched fatty acid based esters of vinyl alcohol such as vinyl isobutyrate, vinyl pivalate, vinyl 2-ethylhexanoate, Vinyl neononanoate, vinyl neodecanoate and Neoundecansäurevinylester. Also suitable as comonomers are esters of Acrylic and methacrylic acid having 1 to 20 carbon atoms in the alkyl radical as 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 two, three, four or also several of these comonomers.

Particularly preferred terpolymers of 2-Ethylhexansäurevinylesters, the Neononanoic or vinyl neodecanoate contain except Ethylene preferably 3.5 to 20 mol%, in particular 8 to 15 mol% of vinyl acetate and 0.1 to 12 mol%, in particular 0.2 to 5 mol% of the respective long-chain Vinylester, wherein the total comonomer content between 8 and 21 mol%, preferably between 12 and 18 mol%. Further preferred copolymers contain, in addition to ethylene and 8 to 18 mol% vinyl esters, 0.5 to 10 mol% Olefins such as propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene and / or norbornene.

The copolymers A preferably have molecular weights which correspond to melt viscosities at 140 ° C. of from 20 to 10,000 mPas, in particular from 30 to 5,000 mPas and especially from 50 to 1,000 mPas. The determined by ¹ H NMR spectroscopy degrees of branching are preferably between 2 and 9 CH _3/100 CH ₂ groups, in particular between 2.5 and 6 CH _3/100 CH ₂ groups, which do not stem from the comonomers.

The copolymers (A) are prepared by the usual copolymerization methods such as for example suspension polymerization, solvent polymerization, Gas phase polymerization or high-pressure mass polymerization produced. Preference is given to high pressure bulk polymerization at pressures of 50 to 400 MPa, preferably 100 to 300 MPa and temperatures of 100 to 300 ° C, preferably 150 to 220 ° C performed. In a particularly preferred production variant the polymerization takes place in a multizone reactor, wherein the Temperature difference between the Peroxiddosierungen along the tube reactor is kept as low as possible, i. <50 ° C, preferably <30 ° C, in particular <15 ° C. Preferably, the temperature maxima differ in the individual Reaction zones thereby by less than 30 ° C, more preferably by less than 20 ° C and especially less than 10 ° C.

The reaction of the monomers is by free-radical initiators (Radical chain starter) initiated. This class of substance includes e.g. Oxygen, Hydroperoxides, peroxides and azo compounds such as cumene hydroperoxide, t-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis (2-ethylhexyl) peroxide carbonate, t-butyl perpivalate, t-butyl per-maleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di- (t-butyl) peroxide, 2,2'-azobis (2-methylpropanonitrile), 2,2'-azobis (2-methylbutyronitrile). The initiators are used individually or as a mixture of two or more Substapzen in amounts of 0.01 to 20 wt .-%, preferably 0.05 to 10 wt .-%, based on the monomer mixture used.

High pressure bulk polymerization is used in known high pressure reactors, e.g. Autoclaves or tube reactors, discontinuous or continuous, Tube reactors have proven particularly useful. Solvents such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, benzene or toluene, may be included in the reaction mixture. Preferably, in the essential solvent-free operation. In a preferred embodiment the polymerization is the mixture of the monomers, the initiator and, if used, the moderator, a tubular reactor via the reactor inlet and above supplied to one or more side branches. The comonomers can both metered together with ethylene as well as separately via side streams in the reactor become. In this case, the monomer streams can be composed differently (EP-A-0 271 738 and EP-A-0 922 716).

Ethylen-Vinylacetat-Copolymere mit 10- 40 Gew.-% Vinylacetat und 60 - 90 Gew.-% Ethylen;

,die aus DE-A-34 43 475 bekannten Ethylen-Vinylacetat-Hexen-Terpolymere;

die in EP-B-0 203 554 beschriebenen Ethylen-Vinylacetat-Diisobutylen-Terpolymere;

die aus EP-B-0 254 284 bekannte Mischung aus einem Ethylen-Vinylacetat-Diisobutylen-Terpolymerisat und einem Ethylen/Vinylacetat-Copolymer;

die in EP-B-0 405 270 offenbarten Mischungen aus einem Ethylen-Vinylacetat-Copolymer und einem Ethylen-Vinylacetat-N-Vinylpyrrolidon-Terpolymerisat;

die in EP-B-0 463 518 beschriebenen Ethylen/Vinylacetat/iso-Butylvinylether-Terpolymere;

die aus EP-B-0 493 769 bekannten Ethylen/Vinylacetat/Neononansäurevinylester bzw. Neodecansäurevinylester-Terpolymere, die außer Ethylen 10 - 35 Gew.-% Vinylacetat und 1 - 25 Gew.-% der jeweiligen Neoverbindung enthalten;

die in EP 0778875 beschriebenen Terpolymere aus Ethylen, einem ersten Vinylester mit bis zu 4 C-Atomen und einem zweiten Vinylester, der sich von einer verzweigten Carbonsäure mit bis zu 7 C-Atomen oder einer verzweigten aber nicht tertiären Carbonsäure mit 8 bis 15 C-Atomen ableitet;

die in DE-A-196 20 118 beschriebenen Terpolymere aus Ethylen, dem Vinylester einer oder mehrerer aliphatischer C₂- bis C₂₀-Monocarbonsäuren und 4-Methylpenten-1;

die in DE-A-196 20 119 offenbarten Terpolymere aus Ethylen, dem Vinylester einer oder mehrerer aliphatischer C₂- bis C₂₀-Monocarbonsäuren und Bicyclo[2.2.1]hept-2-en.

Suitable copolymers or terpolymers include, for example:

Ethylene-vinyl acetate copolymers with 10-40% by weight of vinyl acetate and 60-90% by weight of ethylene;

, the ethylene-vinyl acetate-hexene terpolymers known from DE-A-34 43 475;

the ethylene-vinyl acetate-diisobutylene terpolymers described in EP-B-0 203 554;

the mixture known from EP-B-0 254 284 comprising an ethylene-vinyl acetate-diisobutylene terpolymer and an ethylene / vinyl acetate copolymer;

the blends disclosed in EP-B-0 405 270 of an ethylene-vinyl acetate copolymer and an ethylene-vinyl acetate-N-vinylpyrrolidone terpolymer;

the ethylene / vinyl acetate / iso-butyl vinyl ether terpolymers described in EP-B-0 463 518;

the ethylene / vinyl acetate / vinyl neononanoate or vinyl neodecanoate terpolymers known from EP-B-0 493 769, which contain, in addition to ethylene, 10-35% by weight of vinyl acetate and 1-25% by weight of the respective neo compound;

the terpolymers described in EP 0778875 of ethylene, a first vinyl ester having up to 4 C atoms and a second vinyl ester, which is derived from a branched carboxylic acid having up to 7 C atoms or a branched but not tertiary carboxylic acid having 8 to 15 C Deriving atoms;

the terpolymers of ethylene, the vinyl ester of one or more aliphatic C ₂ to C ₂₀ monocarboxylic acids and 4-methylpentene-1 described in DE-A-196 20 118;

the terpolymers disclosed in DE-A-196 20 119 of ethylene, the vinyl ester of one or more aliphatic C ₂ to C ₂₀ monocarboxylic acids and bicyclo [2.2.1] hept-2-ene.

Preference is given to mixtures of identical or different ethylene copolymers used. The mixing ratio is preferably between 20: 1 and 1:20, preferably 10: 1 to 1:10, in particular 5: 1 to 1: 5.

The copolymers B are preferably derived from dicarboxylic acids and their derivatives, such as esters and anhydrides. Preference is given to maleic acid, fumaric acid, itaconic acid and especially maleic anhydride. Monoolefins having 10 to 20, in particular 12 to 18, carbon atoms are particularly suitable as comonomers. These are preferably linear and the double bond is preferably terminal such as in dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene and octadecene. The ratio of maleic anhydride to olefin or olefins in the polymer is preferably in the range 1: 1.5 to 1.5: 1, especially equimolar. In minor amounts of up to 20 mol%, preferably <10 mol%, especially <5 mol%, it is also possible to contain further comonomers which are copolymerizable with maleic anhydride and the olefins mentioned, for example shorter-chain and longer-chain olefins, allyl polyglycol ethers , C ₁ -C ₃₀ -alkyl (meth) acrylates, vinylaromatics or C ₁ -C ₂₀ -alkyl vinyl ethers. In the same way, minor amounts of poly (isobutylene) having molecular weights of up to 5,000 g / mol are used, with highly reactive variants having a high proportion of terminal vinylidene groups being preferred. These other comonomers are not taken into account in the calculation of the factor Q which is decisive for the effectiveness.

worin

R¹

Wasserstoff oder Methyl,

R²

Wasserstoff oder C₁-C₄-Alkyl,

m

eine Zahl von 1 bis 100,

R³

C₁-C₂₄-Alkyl, C₅-C₂₀-Cycloalkyl, C₆-C₁₈-Aryl oder -C(O)-R⁴,

R⁴

C₁-C₄₀-Alkyl, C₅-C₁₀-Cycloalkyl oder C₆-C₁₈-Aryl, bedeuten.

Alkyl polyglycol ethers correspond to the general formula

wherein

R ¹

Hydrogen or methyl,

R ²

Hydrogen or C ₁ -C ₄ -alkyl,

m

a number from 1 to 100,

R ³

C ₁ -C ₂₄ -alkyl, C ₅ -C ₂₀ -cycloalkyl, C ₆ -C ₁₈ -aryl or -C (O) -R ⁴ ,

R ⁴

C ₁ -C ₄₀ alkyl, C ₅ -C ₁₀ cycloalkyl or C ₆ -C ₁₈ aryl.

The preparation of the copolymers B) according to the invention is preferably carried out at Temperatures between 50 and 220 ° C, in particular 100 to 190 ° C, especially 130 up to 170 ° C. The preferred manufacturing process is the solvent-free Bulk polymerization, but it is also possible, the polymerization in the presence aprotic solvents such as benzene, toluene, xylene or higher-boiling aromatic, aliphatic or isoaliphatic solvents or Solvent mixtures such as kerosene or solvent naphtha perform. Especially the polymerization is preferably in moderately moderating, aliphatic or isoaliphatic solvents. The solvent content in the polymerization mixture is generally between 10 and 90% by weight, preferably between 35 and 60% by weight. In the solution polymerization, the reaction temperature by the boiling point of the solvent or by working under reduced or elevated pressure be set particularly easy.

The reaction of the monomers is by free-radical initiators (Radical chain starter) initiated. This class of substance includes e.g. Oxygen, Hydroperoxides and peroxides such as e.g. Cumene hydroperoxide, t-butyl hydroperoxide, Dilauroyl peroxide, dibenzoyl peroxide, bis (2-ethylhexyl) peroxide carbonate, t-butyl perpivalate, t-butyl per-maleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di- (t-butyl) peroxide, and azo compounds such as e.g. 2,2'-azobis (2methylpropanonitril) or 2,2'-azobis (2-methylbutyronitrile). The initiators be used individually or as a mixture of two or more substances in quantities of 0.01 to 20 wt .-%, preferably 0.05 to 10 wt .-%, based on the Monomer mixture used.

The copolymers can be prepared either by esterification of maleic, fumaric and / or Itaconic acid with the corresponding alcohols and subsequent Copolymerization or by copolymerization of olefin or olefins with itacon and / or Maleic anhydride and subsequent esterification are produced. Preferably, a copolymerization is carried out with anhydrides and the resulting copolymer esterified after preparation.

This esterification takes place in both cases, for example, by conversion with 0.8 to 2.5 moles of alcohol per mole of anhydride, preferably with 1.0 to 2.0 moles of alcohol per mole Anhydride at 50 to 300 ° C. When using about 1 mole of alcohol per mole of anhydride arise half ester. Here are esterification temperatures of about 70 to 120 ° C. prefers. When using larger amounts of alcohol, preferably 2 moles of alcohol per mole Anhydride formed at 100-300 ° C, preferably 120-250 ° C diester. The Reaction water can be distilled off by means of an inert gas or in Presence of an organic solvent by azeotropic distillation be discharged. Preference is given to 20-80, especially 30-70, especially 35-55 wt .-% of at least one organic solvent used. As a half-ester here copolymers with acid numbers of 30 - 70 mg KOH / g, preferably from 40 - 60 mg KOH / g considered. Copolymers with acid numbers less than 40, especially less than 30 mg KOH / g are considered as diesters. Particularly preferred Halbester.

The resulting acid in the incomplete esterification can in the additive preferably present as such or as a salt. Preferred cations are Ammonium ions of primary, secondary and tertiary amines. The alkyl radicals of the amines preferably have 1 to 20 carbon atoms and can contain heteroatoms such as nitrogen, Contain oxygen or sulfur. Further suitable cations are alkali metal ions such as. Sodium and potassium, alkaline earth ions such as e.g. Calcium and magnesium as well Transition metal ions such as chromium, manganese, cerium and iron.

Suitable alcohols are particularly linear, but they may also be minor amounts, e.g. B. up to 30 wt .-%, preferably up to 20 wt .-% and especially up to 10 wt .-% (in the 1- or 2-position) branched alcohols. Particularly preferred are octanol, decanol, undecanol, dodecanol, tridecanol, Tetradecanol, pentadecanol and hexadecanol. By using mixtures different olefins in the polymerization and mixtures of various Alcohols during esterification can further reduce the effectiveness to special ones Fatty acid ester compositions are adjusted.

In a preferred embodiment, in addition to components A and B, the additives may also contain polymers and copolymers based on C ₁₀ -C ₂₄ -alkyl acrylates or methacrylates (component C). These poly (alkyl acrylates) and methacrylates have molecular weights of 800 to 1,000,000 g / mol, and are preferably derived from caprylic, capric, undecyl, lauryl, myristyl, cetyl, palmitoleyl, stearyl alcohol or the like Mixtures such as coconut, palm, tallow or behenyl from.

In a preferred embodiment, mixtures of the invention Copolymers B are used, provided that the mean of the Q values of the Mixture components in turn have values from 23 to 27 and preferably values of 24 to 26 accepts.

The mixing ratio of the additives A and B according to the invention is (in Parts by weight) 20: 1 to 1:20, preferably 10: 1 to 1:10, in particular 5: 1 to 1: 2. The proportion of component C in the formulations of A, B and C can be up to 40 wt .-% amount; it is preferably less than 20% by weight, in particular between 1 and 10% by weight.

The additives according to the invention are oils in amounts of from 0.001 to 5% by weight, preferably 0.005 to 1 wt .-% and especially added 0.01 to 0.5 wt .-%. there they may be dissolved as such or dissolved in solvents, e.g. aliphatic and / or aromatic hydrocarbons or Hydrocarbon mixtures such. Toluene, xylene, ethylbenzene, decane, Pentadecane, gasoline fractions, kerosene, naphtha, diesel, fuel oil, isoparaffins or commercial solvent mixtures such as Solvent Naphtha, ®Shellsol AB, ® Solvesso 150, ®Solvesso 200, ®Exxsol, ®Isopar and ®Shellsol D types. Preferably, they are based on fuel oil of animal or vegetable origin dissolved by fatty acid alkyl esters. Preferably, the inventive Additives 1 - 80%, especially 10 - 70%, in particular 25 - 60% solvents.

In a preferred embodiment, the fuel oil is the often referred to as "biodiesel" or "biofuel" to Fatty acid alkyl esters of fatty acids having 14 to 24 carbon atoms and alcohols having 1 to 4 C atoms. Usually a major part of the fatty acids contains one, two or three Double bonds. It is particularly preferred to e.g. around Rapsölsäuremethylester and especially mixtures, rapeseed, sunflower and / or Sojaölfettsäuremethylester included. The additives of the invention can with equal success in mixtures of fatty acid methyl esters and Mineral oil diesel are used. Such mixtures preferably contain up to 25 wt .-%, in particular up to 10 wt .-%, especially up to 5 wt .-% of Fuel oil of animal or vegetable origin.

Examples of oils derived from animal or vegetable material, and in where the additive according to the invention can be used 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 and fish oils. Further examples include oils derived from wheat, Derive jute, sesame, shea nut, arachis oil and linseed oil. Also called biodiesel designated fatty acid alkyl esters can be prepared from these oils in the state of Technique known methods are derived. Rapeseed oil, which is a mixture of with Glycerol is partially esterified fatty acids, is preferred because it is in large quantities is available and is readily available by squeezing rapeseed. Furthermore, the also widespread oils of sunflower and soy and their mixtures with rapeseed oil preferred.

As lower alkyl esters of fatty acids, the following may be considered for example, as commercial mixtures: the ethyl, propyl, butyl and in particular methyl esters of fatty acids having 12 to 22 carbon atoms, for example, lauric acid, myristic acid, palmitic acid, palmitoleic acid, Stearic acid, oleic acid, elaidic acid, petroselinic acid, ricinoleic acid, Elaeostearic acid, linoleic acid, linolenic acid, eicosanoic acid, gadoleic acid, Docosanoic or erucic acid, preferably having an iodine value of 50 to 150, especially 90 to 125 have. Mixtures with particularly advantageous Properties are those that are mainly, i. H. at least 50% by weight, Methyl esters of fatty acids having 16 to 22 carbon atoms and 1, 2 or 3 Double bonds included. The preferred lower alkyl esters of fatty acids are the methyl esters of oleic acid, linoleic acid, linolenic acid and erucic acid.

Commercial mixtures of the type mentioned are, for example, by Cleavage and esterification of animal and vegetable fats and oils their transesterification with lower aliphatic alcohols. For the production of lower alkyl esters of fatty acids, it is advantageous to use fats and oils with high iodine value, such as sunflower oil, rapeseed oil, Coriander oil, castor oil (castor oil), soybean oil, cottonseed oil, peanut oil or Beef tallow. Lower alkyl esters of fatty acids based on a new type of rapeseed oil, their fatty acid component to more than 80 wt .-% of unsaturated fatty acids derived with 18 carbon atoms are preferred.

Particular preference is given to oils according to the invention which are used as biofuels can be. Biofuels, i. of animal or vegetable material Inferred fuels, when burned, are considered less harmful to the car Environment and are obtained from a renewable source. It is It has been reported that combustion produces less carbon dioxide than equivalent Amount of petroleum distillate fuel, e.g. Diesel fuel, is formed and that very little sulfur dioxide is formed. Certain derivatives of vegetable oil, e.g. those obtained by saponification and reesterification with a monovalent Alkyl alcohol can be used as a substitute for diesel fuel become. Similarly, used cooking oils are also suitable as fuels. It It has recently been reported that mixtures of rapeseed esters, for example Rapeseed oil methyl ester (RME), with petroleum distillate fuels in proportions of for example, 10:90 (by volume) in the near future in the trade will be available. Also for such mixtures are the inventive Additives suitable.

Thus, a biofuel is an oil derived from vegetable or animal material or either or a derivative thereof used as a fuel can be.

Although many of the above oils can be used as biofuels Vegetable oil derivatives are preferred, with particularly preferred biofuels Alkyl ester derivatives of rapeseed oil, cottonseed oil, soybean oil, sunflower oil, olive oil or palm oil, with rapeseed oil methyl ester genz being particularly preferred.

The additive may be added to the oil to be treated according to art known in the art Procedures are introduced. If more than one additive component or Coadditive component should be used, such components be introduced together or separately in any combination in the oil.

With the additives of the invention, the CFPP value of biodiesel can be on Set values below -20 ° C and sometimes to values below -25 ° C, as they do be required for marketing for use especially in winter. This also applies to problematic oils that are high in oils Sunflowers and soy included. In addition, the so-additive oils have good cold-cycle stability, ie the CFPP value remains even during storage constant under winter conditions.

For the production of additive packages for special problem solutions, the additives according to the invention also together with one or more oil-soluble Co-additives are used, which already by themselves the cold flow properties of crude oils, lubricating oils or fuel oils. Examples of such co-additives are polar compounds that cause paraffin dispersion (Paraffin dispersants) and oil-soluble amphiphiles:

The additives according to the invention can be mixed with paraffin dispersants be used. Paraffin dispersants reduce the size of the paraffin crystals and cause the paraffin particles do not settle, but colloid with significantly reduced tendency to sediment, remain dispersed. When Paraffin dispersants have oil-soluble polar compounds with ionic or polar groups, e.g. As amine salts and / or amides proven by reaction aliphatic or aromatic amines, preferably long-chain aliphatic Amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides are obtained (see US 4 211 534). Other Paraffin dispersants are copolymers of maleic anhydride and α, β-unsaturated Compounds optionally with primary monoalkylamines and / or aliphatic alcohols (cf., EP 0 154 177), which Reaction products of alkenyl spiro-bis-lactones with amines (compare EP 0 413 279 B1) and according to EP 0 606 055 A2 reaction products of terpolymers based α, β-unsaturated dicarboxylic anhydrides, α, β-unsaturated compounds and Polyoxyalkylene ethers of lower unsaturated alcohols.

The mixing ratio (in parts by weight) of the additives according to the invention Paraffin dispersants are 1:10 to 20: 1, preferably 1: 1 to 10: 1.

The additives according to the invention can, except in the described Fuel oils of animal or vegetable origin in mixtures such oils with middle distillates. The mixing ratio between the biofuel oils and middle distillates can be between 1:99 and 99: 1 lie. Particularly preferred are mixing ratios of Biofuel: middle distillate = 1:99 to 10:90.

As middle distillate one calls in particular those mineral oils, which by Crude oil distillation and boiling in the range of 120 to 450 ° C, For example, kerosene, jet fuel, diesel and heating oil. Preferably, such Middle distillates used, the 0.05 wt .-% sulfur and less, especially preferably less than 350 ppm sulfur, in particular less than 200 ppm Sulfur and in special cases less than 50 ppm of sulfur. It These are generally those middle distillates that a hydrogenating Refining, and therefore only small proportions contain polyaromatic and polar compounds. Preferably it is such middle distillates, the 95% distillation points below 370 ° C, especially 350 ° C and in special cases below 330 ° C. Also synthetic Fuels, such as those obtainable by the Fischer-Tropsch process are suitable as middle distillates.

The additives can be used alone or together with other additives be, e.g. with other pour point depressants or dewaxing aids, with Corrosion inhibitors, antioxidants, sludge inhibitors, dehazem and additives for lowering the cloud point.

Examples Characterization of the test oils:

The CFPP value is determined in accordance with EN 116 and the determination of the cloud point in accordance with ISO 3015. Characterization of the used test oils Oil no. CP CFPP E 1 Rapsölsäuremethylester -2.3 -14 ° C E 2 80% rapeseed oil methyl ester + 20% sunflower oil methyl ester -1.6 -10 ° C E 3 90% rapeseed oil methyl ester + 10% soybean oil methyl ester -2.0 -8 ° C

The following additives were used:

Ethylene copolymers A

The ethylene copolymers used are commercial products having the characteristics given in Table 2. The products were used as 65% and 50% (A3) settings in kerosene, respectively. Characterization of the ethylene copolymers used example Comonomer (s) V140 CH _3/100 CH ₂ A1 13.6 mole% vinyl acetate 130 mPas 3.7 A2 13.7 mole percent vinyl acetate and 1.4 mole percent vinyl neodecanoate 105 mPas 5.3 A3 (V) 11.2 mol% vinyl acetate 220 mPas 6.2 A4 (V) Mixture of EVA copolymer with 16 mol% vinyl acetate and EVA with 5 mol% vinyl acetate in the ratio 13: 1 95 mPas / 350 mPas 3.2 / 5.7

Comb polymers B

The polymerization of maleic anhydride with α-olefins was carried out (in analogy to EP 0606055) in a higher boiling aromatic hydrocarbon mixture 160 ° C in the presence of a mixture of equal parts tert-butyl peroxybenzoate and tert-butyl peroxy-2-ethylhexanoate as a radical chain initiator. In Table 3 are the molar ratios of the monomers, the chain length of the esterification fatty alcohol used and the factor Q calculated therefrom.

The esterifications are carried out in the presence of solvent naphtha (40-50 wt .-%) at 90 - 100 ° C for half ester and at 160 - 180 ° C with azeotropic culling of water of reaction to the diester. The degree of esterification is inversely proportional to the acid number. Characterization of the comb polymers used example comonomers alcohol Q Acid number [mg KOH / g] B1 MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) C10 23.0 47.0 B2 MSA-co-C14 / 16-α-ovine (1: 0.5: 0.5) C10 23.0 8.5 B3 MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) C12 25.0 48.2 B4 MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) C12 25.0 28.8 B5 MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) C14 27.0 51.0 B6 MSA-co-C12 / 14 α-olefin (1: 0.5: 0.5) C14 25.0 44.8 B7 MSA-co-C12 / 14 α-olefin (1: 0.5: 0.5) C12 23.0 51.1 B8 MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) 85% C12
15% C16 25.6 49.9 B9 MSA-co-C16 α-olefin (1: 1) C12 26.0 12.3 B10 MSA-co-C14 α-olefin (1: 0.5: 0.5) C14 26.0 46.3 B11 MSA-co-C14 α-olefin (1: 0.5: 0.5) C12 24.0 49.3 B12 MSA-co-C16 α-olefin (1: 0.5: 0.5) C10 24.0 47.9 B13 MSA-co-C18 / 18 α-olefin (1: 0.5: 0.5) C10 25.0 53.0 B14 MSA-co-C10 α-olefin (1: 0.5: 0.5) 50% C ₁₆
50% C ₁₈ 25.0 48.0 B15 MSA-co-C14 / 16-α-olefin-co-allylmethyl polyglycol (1: 0.45: 0.45: 0.1) C12 25.0 45.8 B16 (V) MSA-co-C16 α-olefin (1: 1) C12 26.0 49.1 B17 MSA-co-C10 α-olefin (1: 1) C12 20.0 48.8 B18 (V) MSA-co-C14 / 16 α-olefin (1: 0.5: 0.5) C16 29.0 16.5 B19 (V) Fumarate-vinyl acetate C14 n / A 0.4 B20 (V) Fumarate-vinyl acetate 50% C14
50% C16 n / A o, 7 na = not applicable

Poly (alkyl (meth) acrylates) C

As poly (alkyl (meth) acrylate), the compounds listed in the table were used as 50% settings in higher-boiling solvent. The K values are determined according to Ubbelohde at 25 ° C. in 5% strength toluene solution. Characterization of the poly (acrylates) used C1 Poly (octadecyl acrylate), K value 32 C2 Poly (dodecyl acrylate), K value 35.6 C3 Poly (phenyl acrylate), K value 22.4

Effectiveness of the terpolymers

The CFPP value (according to EN 116, in ° C) of various biofuels according to the above table was determined after addition of 1200 ppm, 1500 ppm and 2000 ppm of additive mixture. Percentages refer to parts by weight in the respective mixtures. The results presented in Tables 5 to 7 show that comb polymers with the factor Q according to the invention achieve excellent CFPP reductions even at low dosing rates and offer additional potential at higher dosing rates. CFPP testing in test oil E1 Ex. comb polymer Ethylene copolymer polyacrylate CFPP in test oil 1 1200 ppm 1500 ppm 2000 ppm 1 20% B1 80% A2 - -18 -19 -20 2 20% B2 80% A2 - -20 -21 -21 3 20% B3 80% A2 - -20 -23 -24 4 20% B4 80% A2 - -21 -23 -21 5 20% B5 80% A2 - -19 -21 -25 8th 20% B8 80% A2 - -20 -22 -24 9 20% B9 80% A2 - -20 -22 -22 10 20% B10 80% A2 - -21 -23 -24 11 20% B11 80% A2 - -21 -23 -23 * 12 20% B12 80% A2 - -20 -22 -29 13 20% B13 80% A2 - -20 -23 -26 14 20% B14 80% A2 - -21 -22 -25 15 19% B8 76% A2 5% C1 -20 -22 -25 16 19% B8 76% A2 5% C2 -21 -23 -21 17 19% B8 76% A2 5% C3 -20 -24 -26 18 34% B8 66% A2 - -20 -22 -24 19 50% B8 50% A2 - -19 -22 -23 20 20% B8 80% A1 - -20 -23 -24 21 20% B8 80% A3 - -19 -20 -21 22 B15 80% A2 - -20 -22 -24 23 B16 80% A2 - -20 -21 -24 24 10% B11
10% B16 80% A2 - -21 -24 -25 25 20% B9 80% A4 - -20 -23 -25 26 20% B13 80% A4 - -20 -22 -24 27 (V) - A2 - -14 -16 -10 28 (V) - A4 - -13 -15 -18 29 (V) B17 80% A2 - -18 -18 -19 30 (V) 20% B18 80% A2 - -17 -18 -18 31 (V) 20% B19 80% A2 - -18 -17 -17 32 (V) 20% B20 80% A2 - -18 -20 -13 33 (V) - - C1 -9 -11 -12 34 (V) - - C3 -18 -17 CFPP testing in test oil E2 Ex. comb polymer Ethylene copolymer polyacrylate CFPP in test oil 2 1200 ppm 1500 ppm 2000 ppm 35 20% B3 80% A2 - -20 -21 -24 36 20% B4 80% A2 - -19 -21 -23 37 20% B6 80% A2 - -20 -22 -23 38 20% B7 80% A2 - -19 -22 -21 39 20% B8 80% A2 - -19 -21 -23 40 20% B9 80% A2 -18 -19 -20 41 20% B12 80% A2 - -19 -22 -24 42 20% B13 80% A2 - -18 -22 -28 43 20% B14 80% A2 - -19 -23 -26 44 20% B15 80% A2 - -19 -22 -25 45 20% B16 80% A2 - -18 -23 -26 46 10% B11
10% B16 80% A2 - -20 -22 -25 47 19% B8 76% A2 5% C1 -19 -23 -25 48 19% B8 76% A2 5% C3 -20 -22 -24 49 (V) 20% B17 80% A2 - -15 -17 -18 50 (V) 20% B18 80% A2 - -11 -13 -14 51 (V) 20% B19 80% A2 - -16 -17 -19 52 (V) 20% B20 80% A2 - -15 -15 -16 CFPP testing in test oil E3 Ex. comb polymer Ethylene copolymer polyacrylate CFPP in test oil E3 1200 ppm 2000 ppm 53 20% B3 80% A2 - -19 -24 54 20% B5 80% A2 - -15 -14 55 20% B8 80% A2 - -19 -24 56 20% B10 80% A2 - -21 -24 57 20% B11 80% A2 - -18 -24 58 20% B14 80% A2 - -18 -24 59 10% B11
10% B16 80% A2 - -19 -24 60 19% B8 76% A2 5% C1 -20 -23 61 19% B8 76% A2 5% C3 -18 -26 62 (V) 20% B17 80% A2 - -15 -17 63 (V) 20% B18 80% A2 - -15 -14 64 (V) 20% B19 80% A2 - -14 -17 65 (V) 20% B20 80% A2 - -14 -17 66 (V) - - C1 -14 -14

Chilling resistance of fatty acid methyl esters

The CFPP value is used to determine the resistance to cold corrosion of an oil according to DIN EN 116 before and after a standardized cold change treatment compared.

500 ml of biodiesel (test oil E1) are treated with the appropriate cold additive, placed in a cylinder and stored in a programmable cold chamber for one week. During this time, a program is run through which repeatedly cools to -13 ° C and then warms up again to -3 ° C. 6 cycles are consecutively run through (Table 8). Cooling program for determining the resistance to cold chill: section begin The End duration description A → B + 5 ° C -3 ° C 8 h Pre-cooling to cycle start temperature B → C -3 ° C -3 ° C 2 h stationary temperature, start of cycle C → D -3 ° C -13 ° C 14 h Temperature reduction, incipient crystal formation D → E -13 ° C - 13 ° C 2 h Stationary temperature, crystal growth E → F -13 ° C -3 ° C 6 h Temperature increase, melting of the crystals F → B Another 6 cycles B → F are carried out.

Subsequently, the additivierte oil sample is reheated to room temperature without shaking. From each of the upper, middle and lower sections of the cylinder a sample of 50 ml is drawn for CFPP measurements.
A difference between the mean values of the CFPP values after storage to the CFPP value before storage and between the individual phases of less than 3 K shows a good resistance to cold flashes.

Claims (13)

Additive containing A) a copolymer of ethylene and 8 to 21 mol% of at least one acrylic or vinyl ester having a C ₁ -C ₁₈ -alkyl radical and B) a comb polymer of at least one C ₈ -C ₁₆ alkyl ester of an ethylenically unsaturated dicarboxylic acid and at least one C ₁₀ -C ₂₀ olefin, wherein the sum Q

the molar average of the C chain distributions in the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups on the other hand from 23 to 27, wherein w ₁ and w _2, the molar ratios of the individual chain lengths in the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups On the other hand, and n ₁ and n _{2 are} the side chain lengths, olefins without the originally olefinically bonded C atoms, the alkyl side chains of the olefins on the one hand and the fatty alcohols in the ester groups on the other hand, and the run variables i and j for the individual side chain lengths in the alkyl side chains the olefins on the one hand and the fatty alcohols in the ester groups on the other hand. An additive according to claim 1, wherein Q is from 24 to 26. An additive according to claim 1 and / or 2, wherein in component A except ethylene ad 100 mol% 3.5 to 20 mol% vinyl acetate and 0.1 to 12 mol% Vinyl neononanoate or vinyl neodecanoate are contained, wherein the total comonomer content is between 8 and 21 mol%. An additive according to one or more of claims 1 to 3, wherein in ingredient A in addition to ethylene ad 100 mol% and 8 to 18 mol% vinyl esters still 0.5 to 10 mol% of olefins selected from propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene or norbornene are included. An additive according to one or more of claims 1 to 4, wherein the Copolymers that make up Component A have molecular weights between 3,000 and 15,000 g / mol (GPC vs. poly (styrene)). Additive according to one or more of claims 1 to 5, wherein the copolymers comprise component A, have degrees of branching 2-9 CH _3/100 CH ₂ groups, which do not stem from the comonomers. An additive according to one or more of claims 1 to 6, wherein the Copolymers constituting component B contain comonomers derived from Esters and anhydrides derived from maleic acid, fumaric acid or itaconic acid are. An additive according to one or more of claims 1 to 7, wherein the Copolymers constituting component B contain comonomers derived from α-olefins are derived. An additive according to one or more of claims 1 to 8, wherein in addition to constituents A and B as constituent C, a polymer or copolymer comprising (C ₁₀ -C ₂₄ alkyl) acrylate units or methacrylate units having a molecular weight of 800 to 1,000. 000 g / mol in an amount of up to 40 wt .-% based on the total weight of A, B and C is contained. An additive according to any one of claims 1 to 9, containing polar nitrogen-containing Paraffin. A fuel oil composition containing an animal or a fuel oil of vegetable origin and an additive according to one or more of the claims 1 to 10. Use of an additive according to one or more of claims 1 to 10 for improving the cold flow properties of fuel oil animal or of plant origin. Use of an additive according to one or more of claims 1 to 10 for improving the cold flow properties of fuel oils, the mixtures from biofuels and middle distillates.