EP1541663B1 - Fuel oils comprising middle distillates and oils of vegetable or animal origin with improved cold properties - Google Patents

Description

The present invention relates to mineral fuel oils containing ingredients of plant or animal origin with improved cold properties and the use of an additive as a cold flow improver for such fuel oils.

As world biodiesel reserves decline and the environmental consequences of fossil and mineral fuel consumption increase, so does the interest in alternative energy sources based on renewable raw materials (biofuels). These include, in particular, natural oils and fats of plant or animal origin. These are typically triglycerides of fatty acids with 10 to 24 C atoms, which have a calorific value comparable to conventional fuels, but at the same time are considered less harmful to the environment. Biofuels, ie fuels derived from animal or plant material, are obtained from renewable sources and thus produce only as much CO ₂ as was previously converted into biomass. It has been reported that combustion produces less carbon dioxide than equivalent amounts of petroleum distillate fuel, eg, diesel fuel, and that very little sulfur dioxide is produced. In addition, they are biodegradable.

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, eg of 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 include glycerides of a variety of acids, the number and variety of which varies with the source of the oil, and may additionally contain phosphoglycerides. Such oils can be obtained by methods known in the art.

Due to the sometimes unsatisfactory physical properties of the triglycerides, the art has shifted to converting the naturally occurring triglycerides into fatty acid esters of lower alcohols such as methanol or ethanol.

As an obstacle in the use of fatty acid esters of lower monohydric alcohols as a diesel fuel substitute alone, their behavior against engine parts, in particular various sealing materials have proven that repeatedly lead to failures of the fuels produced with these fuels from renewable fuels. To circumvent these problems, it is preferred to use these oils based on renewable raw materials as an admixture to conventional middle distillates.

Furthermore, the use of triglycerides as well as fatty acid esters of lower monohydric alcohols as a diesel fuel substitute alone or mixed with diesel fuel, the flow behavior at low temperatures has proved to be an obstacle. The reason for this is in particular their content of esters of saturated fatty acids and the high uniformity (less than 10 main components) of these oils in comparison to mineral oil middle distillates. For example, rapeseed-oil methyl ester (RME) has a Cold Filter Plugging Point (CFPP) of -14 ° C, soybean oil methyl ester a CFPP of -5 ° C and animal fat a CFPP of + 9 ° C. With the additives of the prior art, it has hitherto often not been possible, based on these esters or mineral diesel containing these esters, to require a CFPP value of -20 ° C. for use as winter diesel in Central Europe and for special applications of -22 ° C. and below it safely. This problem is exacerbated by the use of oils containing larger quantities of sunflower and soybean oils, which are also readily available.

EP-B-0 665 873 discloses a fuel oil composition comprising a biofuel, 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 substantially linear alkyl group having from 10 to 30 carbon atoms is bonded to a non-polymeric organic radical to provide at least one linear chain of atoms which includes the carbon atoms of the alkyl groups and one or more non-terminal oxygen atoms, or (e) one or more of the components ( a), (b), (c) and (d).

1. (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,
2. (II) Polyoxyalkylen-ester, -ester/ether oder eine Mischung derselben,
3. (III) Ethylen/ungesättigter Ester-Copolymer,
4. (IV) polarer, organischer, stickstoffhaltiger Paraffinkristallwachstumshemmstoff,
5. (V) Kohlenwasserstoffpolymer,
6. (VI) Schwefelcarboxyverbindungen und
7. (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 portion of oil consisting essentially of alkyl esters of fatty acids derived from vegetable or animal oils or both mixed with a minor proportion of mineral oil flow improver comprising one or more of the following:

1. (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,
2. (II) polyoxyalkylene ester, ester / ether or a mixture thereof,
3. (III) ethylene / unsaturated ester copolymer,
4. (IV) polar, organic, nitrogen-containing wax crystal growth inhibitor,
5. (V) hydrocarbon polymer,
6. (VI) sulfur carboxy compounds and
7. (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 natural products Fatty acids with monohydric C ₁ -C ₆ -alcohols (FAE), characterized in that

• 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 Iodzahlbereich 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 wt .-% of at least one ester in the iodine number 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. Suitable comonomers are unsaturated esters, in particular vinyl acetate, 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-1380635 lehrt ein Additiv, enthaltend
  • 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 $$Q={\displaystyle \sum _i}{w}_{1i}\cdot n_{1i}+{\displaystyle \sum _j}{w}_{2j}\cdot n_{2j}$$
    
  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.

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. EP-1380635 teaches 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 $$Q={\displaystyle \underset{i}{\Sigma }}{w}_{1i}\cdot n_{1i}+{\displaystyle \underset{j}{\Sigma }}{w}_{2j}\cdot n_{2j}$$
    
  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.

WO 94/10267 teaches a fuel oil composition comprising a biofuel, 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 substantially linear alkyl group having from 10 to 30 carbon atoms is bonded to a non-polymeric organic radical to provide at least one linear chain of atoms which includes the carbon atoms of the alkyl groups and one or more non-terminal oxygen atoms, or (e) one or more of the components ( a), (b), (c) and (d).

• A) herkömmlicher Fließverbesserer auf Ethylenbasis und
• B) Copolymere, die
  1. a) zu 10 bis 90 Mol-% aus einem oder mehreren Alkylacrylaten oder Alkylmethacrylaten mit C₁- bis C₃₀-Alkylketten und
  2. b) zu 5 bis 60 Mol-% aus einer oder mehreren ethylenisch ungesättigter Dicarbonsäuren oder deren Anhydride und
  3. c) zu 5 bis 60 Mol-% aus einem oder mehreren Alkylvinylethern mit C₁₈- bis C₂₈-Alkylseitenketten bestehen und

das Gewichtsverhältnis von A zu B zu 60 bis 95 zu 5 beträgt.
EP-A-1526168 lehrt eine Brennstoffölzusammensetzung, enthaltend ein Brennstofföl tierischen oder pflanzlichen Ursprungs und ein Additiv, enthaltend
A) mindestens ein Copolymer aus Ethylen und 8-21 Mol-% mindestens eines Acryl- oder Vinylesters mit einem C₁-C₁₈-Alkylrest und
B) mindestens ein Kammpolymer enthaltend Struktureinheiten mit C₈-C₁₆-Alkylresten, wobei die Struktureinheiten ausgewählt sind aus C₈-C₁₆-Alkyl(meth)acrylaten, C₈-C₁₆-Alkylvinylestern, C₈-C₁₆-Alkylvinylethern, C₈-C₁₆-Alkyl(meth)acrylamiden, C₈-C₁₆-Alkylallylethern und C₈-C₁₆-Diketenen,
wobei die Summe R $$R=m_1\cdot {\displaystyle \sum _i}{w}_{1i}\cdot n_{1i}+m_2\cdot {\displaystyle \sum _j}{w}_{2j}\cdot n_{2j}+\mathrm{.......}+m_g\cdot {\displaystyle \sum _p}{\mathit{w}}_{\mathit{gp}}\cdot n_{\mathit{gp}}$$

der molaren Mittel der C-Kettenlängenverteilungen in den Alkylresten der Monomere B) 11,0 bis 14,0 beträgt,
worin m₁, m₂, ... m_g die Molenbrüche der oben genannten Monomere B) im Polymer sind, wobei die Summe der Molenbrüche m₁ bis m_g = 1 ist, w_1i, w_1j..w_2i, w_2j...w_gp die Gewichtsanteile der einzelnen Kettenlängen i, j, .... p der Alkylreste der verschiedenen Monomeren B) 1 bis g sind, und n_1i, n_1j..n_2i, n_2j...n_gp die Kettenlängen der Alkylreste i, j, .... p der Monomere B) 1 bis g sind. EP-A-485 774 teaches petroleum middle distillates with improved cold flow properties, containing small amounts

• A) conventional ethylene-based flow improvers and
• B) Copolymers which
  1. a) from 10 to 90 mol% of one or more alkyl acrylates or alkyl methacrylates with C ₁ - to C ₃₀ alkyl chains and
  2. b) from 5 to 60 mol% of one or more ethylenically unsaturated dicarboxylic acids or their anhydrides and
  3. c) from 5 to 60 mol% of one or more alkyl vinyl ethers with C ₁₈ - to C ₂₈ alkyl side chains and

the weight ratio of A to B is 60 to 95 to 5.
EP-A-1526168 teaches a fuel oil composition containing a fuel oil of animal or vegetable origin and an additive containing
A) at least one copolymer of ethylene and 8-21 mol% of at least one acrylic or vinyl ester having a C ₁ -C ₁₈ alkyl radical and
B) at least one comb polymer containing structural units with C ₈ -C ₁₆ -alkyl radicals, the structural units being selected from C ₈ -C ₁₆ -alkyl (meth) acrylates, C ₈ -C ₁₆ -alkyl vinyl esters, C ₈ -C ₁₆ -alkyl vinyl ethers, C ₈ -C ₁₆ -alkyl (meth) acrylamides, C ₈ -C ₁₆ -alkyl allyl ethers and C ₈ -C ₁₆ -diketenes,
where the sum R $$R=m_1\cdot {\displaystyle \underset{i}{\Sigma }}{w}_{1i}\cdot n_{1i}+m_2\cdot {\displaystyle \underset{j}{\Sigma }}{w}_{2j}\cdot n_{2j}+\mathrm{.......}+m_G\cdot {\displaystyle \underset{p}{\Sigma }}{\mathit{w}}_{\mathit{gp}}\cdot n_{\mathit{gp}}$$

the molar average C chain length distribution in the alkyl radicals of monomers B) is 11.0 to 14.0,
wherein m ₁ , m ₂ , ... m _g the mole fractions of the abovementioned monomers B) in the polymer are, the sum of the mole fractions m ₁ to m _g = 1, w _1i , w _1j ... w _2i , w _2j ... w _gp the weight fractions of the individual chain lengths i, j,... p of the alkyl radicals of the different monomers B) are 1 to g, and n _1i , n _1j ... n _2i , n _2j ... n _gp the chain lengths of the alkyl radicals i, j,... p of the monomers B) are 1 to g.

EP-B-0 746 598 discloses comb polymers as a cold additive in fuel oils having a cloud point of at most -10 ° C.

With the known additives, it has hitherto often not been possible to reliably adjust middle distillates containing fatty acid esters to a CFPP value of -20 ° C. required for use as winter diesel in Central Europe and for special applications of -22 ° C. and below. A problem with the known additives is also a lack of sedimentation stability of the additized oils. The paraffins and fatty acid esters precipitating below the cloud point sediment under prolonged storage below the cloud point and lead to the bottom of the storage container to form a phase with poorer cold properties.

It was therefore the object to provide fuel oils with improved cold properties available containing middle distillates and fatty acid esters, with their CFPP values at -20 ° C and below. Furthermore, the sedimentation of precipitated paraffins and fatty acid esters should be slowed down or prevented by prolonged storage of the fuel oil in the area of its cloud point or below.

Surprisingly, it has now been found that fuel oils of middle distillates and oils of vegetable and / or animal origin, which comprise an ethylene copolymer and certain comb polymers containing additive, show excellent cold properties.

1. A) mindestens ein Copolymer aus Ethylen und 8-21 Mol-% mindestens eines Acryl- oder Vinylesters mit einem C₁-C₁₈-Alkylrest und
2. B) mindestens ein Kammpolymer enthaltend Struktureinheiten mit C₈-C₁₆-Alkylresten, wobei die Struktureinheiten ausgewählt sind aus C₈-C₁₆-Alkyl(meth)acrylaten, C₈-C₁₆-Alkylvinylestern, C₈-C₁₆-Alkylvinylethern und C₈-C₁₆-Alkyl(meth)acrylamiden, C₈-C₁₆-Alkylallylethern und C₈-C₁₆-Alkyldiketenen

wobei die Summe R $$R=m_1\cdot {\displaystyle \sum _i}{w}_{1i}\cdot n_{1i}+m_2\cdot {\displaystyle \sum _j}{w}_{2j}\cdot n_{2j}+\mathrm{.......}+m_g\cdot {\displaystyle \sum _p}{\mathit{w}}_{\mathit{gp}}\cdot n_{\mathit{gp}}$$

der molaren Mittel der C-Kettenlängenverteilungen in den Alkylresten der Monomere B) 11,0 bis 14,0 beträgt, worin m₁, m₂, ... m_g die Molenbrüche der oben genannten Monomere B) im Polymer sind, wobei die Summe der Molenbrüche m₁ bis m_g = 1 ist, w_1i, w_1j..w_2i, w_2j...w_gp die Gewichtsanteile der einzelnen Kettenlängen i, j, .... p der Alkylreste der verschiedenen Monomeren B) 1 bis g sind, und n_1i, n_1j..n_2i, n_2j...n_gp die Kettenlängen der Alkylreste i, j, .... p der Monomere B) 1 bis g sind. The invention thus relates to a fuel oil composition F) containing
F1) a fuel oil of mineral origin and
F2) more than 2 to 35% by volume of a fuel of vegetable and / or animal origin containing more than 4% by weight of esters of saturated fatty acids and from 0.001 to 5% by weight of a cold additive containing components A and B in weight ratio A: B = 10: 1 to 1:10

1. A) at least one copolymer of ethylene and 8-21 mol% of at least one acrylic or vinyl ester having a C ₁ -C ₁₈ alkyl radical and
2. B) at least one comb polymer comprising structural units having C ₈ -C ₁₆ -alkyl radicals, the structural units being selected from C ₈ -C ₁₆ -alkyl (meth) acrylates, C ₈ -C ₁₆ -alkyl vinyl esters, C ₈ -C ₁₆ -alkyl vinyl ethers and C ₈ -C ₁₆ alkyl (meth) acrylamides, C ₈ -C ₁₆ alkyl allyl ethers and C ₈ -C ₁₆ alkyl diketenes

where the sum R $$R=m_1\cdot {\displaystyle \underset{i}{\Sigma }}{w}_{1i}\cdot n_{1i}+m_2\cdot {\displaystyle \underset{j}{\Sigma }}{w}_{2j}\cdot n_{2j}+\mathrm{.......}+m_G\cdot {\displaystyle \underset{p}{\Sigma }}{\mathit{w}}_{\mathit{gp}}\cdot n_{\mathit{gp}}$$

the molar average C chain length distributions in the alkyl radicals of monomers B) is from 11.0 to 14.0, in which m ₁ , m ₂ , ... m _g the mole fractions of the abovementioned monomers B) in the polymer are, the sum of the mole fractions m ₁ to m _g = 1, w _1i , w _1j ... w _2i , w _2j ... w _gp the weight fractions of the individual chain lengths i, j,... p of the alkyl radicals of the different monomers B) are 1 to g, and n _1i , n _1j ... n _2i , n _2j ... n _gp the chain lengths of the alkyl radicals i, j,... p of the monomers B) are 1 to g.

Another object of the invention is the use of 0.001 to 5 wt .-% of the additive defined above, containing the components A) and B), for improving the cold flow properties of fuel oil compositions F) containing fuel oils mineral (F1) and more than 2 to 35% by volume of animal and / or vegetable (F2) origin containing more than 4% by weight of esters of saturated fatty acids.

Another object of the invention is a process for the preparation of fuel oil compositions F) containing fuel oils mineral (F1) and more than 2 to 35 vol .-%. animal and / or vegetable (F2) origin, containing more than 4% by weight of esters of saturated fatty acids, with improved refrigerating properties, by mixing the mixture of mineral (F1) and more than 2 to 35% by volume animal oils and / or vegetable (F2) origin the additive defined above in an amount of 0.001 to 5 wt .-%, containing the components A) and B), added.

Preferred oils of mineral origin are middle distillates. The mixing ratio between the fuel oils of animal and / or vegetable origin (which are also referred to below as biofuel oils) and middle distillates can be between 1:99 and 99: 1. Particular preference is given to mixtures which contain from 2 to 50% by volume, in particular from 5 to 40% by volume and especially from 10 to 30% by volume, of biofuel oils. These mixtures give the additives of the invention superior cold properties.

In a preferred embodiment of the invention R assumes values between 11.5 and 13.5, in particular 12.0 to 13.0.

Suitable ethylene copolymers A) are those which contain from 8 to 21 mol% of one or more vinyl and / or (meth) acrylic esters and from 79 to 92% by weight of ethylene. Particularly preferred are ethylene copolymers with 10 to 18 mol% and especially 12 to 16 mol% of at least one vinyl ester. Suitable vinyl esters are derived from fatty acids with linear or branched alkyl groups having 1 to 30 carbon atoms. Examples which may be mentioned are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, Vinylheptanoat, vinyl octanoate, vinyl laurate and vinyl stearate and branched fatty acid based esters of vinyl alcohol such as vinyl isobutyrate, vinyl pivalate, vinyl 2-ethylhexanoate, iso-Nonansäurevinylester, Neononansäurevinylester, vinyl neodecanoate and Neoundecansäurevinylester. Also suitable as comonomers are esters of acrylic and methacrylic acid having 1 to 20 C atoms in the alkyl radical, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- and isobutyl (meth) acrylate, hexyl , Octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl (meth) acrylate and mixtures of two, three, four or more of these comonomers.

Particularly preferred terpolymers of 2-ethylhexanoic acid vinyl ester, vinyl neononanoate or vinyl neodecanoate contain, in addition to ethylene, preferably 3.5 to 20 mol%, in particular 8 to 15 mol% vinyl acetate and 0.1 to 12 mol%, in particular 0.2 to 5 mol% of the respective long-chain vinyl ester, wherein the total comonomer content is between 8 and 21 mol%, preferably between 12 and 18 mol%. Further preferred copolymers contain, in addition to ethylene and from 8 to 18 mol% of vinyl esters, from 0.5 to 10 mol% of 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 1 and 9 CH _3/100 CH ₂ groups, especially between 2 and 6 CH _3/100 CH ₂ groups, such as 2.5 to 5 CH _3/100 CH ₂ groups not derived from the comonomers.

The copolymers (A) can be prepared by the usual copolymerization methods such as suspension polymerization, solvent polymerization, gas phase polymerization or high-pressure bulk polymerization. The high-pressure mass polymerization is preferably carried out at pressures of 50 to 400 MPa, preferably 100 to 300 MPa and temperatures of 100 to 300 ° C, preferably 150 to 220 ° C. In a particularly preferred preparation variant, the polymerization takes place in a multi-zone reactor, wherein the temperature difference between the peroxide dosages along the tubular reactor is kept as low as possible, i. <50 ° C, preferably <30 ° C, in particular <15 ° C. The temperature maxima in the individual reaction zones preferably differ by less than 30 ° C., more preferably by less than 20 ° C. and especially by less than 10 ° C.

The reaction of the monomers is initiated by free radical initiators (free radical initiators). 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 permalate, t-butyl perbenzoate, dicumyl peroxide, t-butylcumyl 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 substances in amounts of 0.01 to 20 wt .-%, preferably 0.05 to 10 wt .-%, based on the monomer mixture.

The high-pressure mass polymerization is carried out batchwise or continuously in known high-pressure reactors, for example autoclaves or tubular reactors, tube reactors have proven particularly useful. Solvents such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, benzene or toluene may be present in the reaction mixture. Preferred is the substantially solvent-free operation. In a preferred embodiment of the polymerization, the mixture of the monomers, the initiator and, if used, the moderator, a tubular reactor via the reactor inlet and via one or more side branches supplied. Preferred moderators are, for example, hydrogen, saturated and unsaturated hydrocarbons such as propane or propene, aldehydes such as propionaldehyde, n-butyraldehyde or isobutyraldehyde, ketones such as acetone, methyl ethyl ketone, Methyl isobutyl ketone, cyclohexanone and alcohols such as butanol. The comonomers as well as the moderators can be metered into the reactor both together with ethylene and separately via side streams. 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-0 778 875 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;
• die in EP-A-0 926 168 beschriebenen Terpolymere aus Ethylen und wenigstens einem olefinisch ungesättigten Comonomer, das eine oder mehrere Hydroxylgruppen enthält.

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;
• from DE-A-34 43 475 known ethylene-vinyl acetate-hexene terpolymers;
• in the EP-B-0 203 554 described ethylene-vinyl acetate-diisobutylene terpolymers;
• from EP-B-0 254 284 known mixture of an ethylene-vinyl acetate-diisobutylene terpolymer and an ethylene / vinyl acetate copolymer;
• in the EP-B-0 405 270 disclosed blends of an ethylene-vinyl acetate copolymer and an ethylene-vinyl acetate-N-vinylpyrrolidone terpolymer;
• in the EP-B-0 463 518 described ethylene / vinyl acetate / iso-butyl vinyl ether terpolymers;
• from EP-B-0 493 769 known ethylene / vinyl acetate / vinyl neononanoate or vinyl neodecanoate terpolymers containing, in addition to ethylene, 10-35% by weight of vinyl acetate and 1-25% by weight of the respective neo compound;
• in the EP-0 778 875 described terpolymers 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 carbon atoms or a branched but not tertiary carboxylic acid having 8 to 15 carbon atoms;
• in the DE-A-196 20 118 described terpolymers of ethylene, the vinyl ester of one or more aliphatic C ₂ - to C ₂₀ monocarboxylic acids and 4-methylpentene-1;
• in the DE-A-196 20 119 disclosed terpolymers 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;
• in the EP-A-0 926 168 described terpolymers of ethylene and at least one olefinically unsaturated comonomer containing one or more hydroxyl groups.

Preference is given to using mixtures of identical or different 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 of the various ethylene copolymers 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 derived from alkyl acrylates, alkyl methacrylates, alkyl acrylamides, alkyl methacrylamides, alkyl vinyl esters, alkyl vinyl ethers, alkyl allyl ethers and alkyl diketenes having 8 to 16 carbon atoms in the alkyl radical. These comonomers are referred to below as comonomers B1).

In a preferred embodiment, the copolymers constituting ingredient B are those containing comonomers derived from esters, amides and / or imides of ethylenically unsaturated monocarboxylic acids having from 3 to 8 carbon atoms with alcohols or amines, respectively, wherein Alcohols or amines carry alkyl radicals having 8 to 16 carbon atoms.

Optionally, the copolymers B) may also contain comonomers B2) which comprise i) esters, amides and / or imides of ethylenically unsaturated dicarboxylic acids having 4 to 8 C atoms and alcohols or amines having 8 to 16 C atoms in the alkyl radicals and / or or ii) C ₁₀ to C ₂₀ olefins.

The alkyl radicals of the comonomers B1 and B2 are preferably linear, but may also contain minor amounts of branched isomers of up to 30 mol%, preferably up to 20 mol% and in particular 2 to 5 mol%.

The proportion of the comonomers B1) and optionally B2) in the polymer is preferably more than 50 mol%, in particular more than 70 mol% and especially at least 80 mol%, for example 90 to 95 mol%. The proportion of the monomers B2), if present, is preferably less than 80 mol%, in particular less than 50 mol% and especially less than 20 mol%, for example from 2 to 10 mol% of the total amount of the monomers B1 ) and B2). Particularly preferably, the polymers B) consist only of the monomers B1) and optionally B2), which then add up to 100 mol%.

Preferred monomers of the copolymers B) are esters of acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid with octanol, nonanol, decanol, undecanol, dodecanol, n-tridecanol, isotridecanol, tetradecanol, pentadecanol, hexadecanol and mixtures thereof. Further preferred monomers are amides and optionally imides of these acids with octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine and mixtures thereof.

In a preferred embodiment, the copolymers making up Component B contain comonomers which are esters and / or ethers of ethylenically unsaturated alcohols of 2 to 10 carbon atoms, and carboxylic acids or alcohols bearing alkyl groups of 8 to 16 carbon atoms.

Such preferred monomers of the copolymers B) are, for example, esters of vinyl alcohol with octanoic acid, 2-ethylhexanoic acid, nonanoic acid, neononanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, neoundecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid and mixtures thereof.

Further preferred monomers of the copolymers B) are, for example, ethers of allyl and in particular vinyl alcohol with octanol, nonanol, decanol, undecanol, dodecanol, n-tridecanol, isotridecanol, tetradecanol, pentadecanol, hexadecanol and mixtures thereof.

As comonomers B2 are also olefins having 10-20 carbon atoms, preferably with 12-18 C atoms and in particular with 10-16 C atoms suitable. These are preferably linear α- olefins with terminal double bond. In a further preferred embodiment, it is branched olefins such as in particular oligomers of isobutylene and propylene having 10 to 20 carbon atoms.

By side chain length of olefins is meant here the alkyl radical leaving the polymer backbone, ie the chain length of the monomeric olefin minus the two olefinically bonded C atoms. For olefins having non-terminal double bonds, e.g. Accordingly, olefins with vinylidene grouping must be taken into account for the total chain length of the olefin minus the double bond passing into the polymer backbone.

Other monomers such as alkyl (meth) acrylates, alkyl vinyl esters, alkyl vinyl ethers having 1 to 5 carbon atoms in the alkyl radical and ethylenically unsaturated free carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and functional groups such as -OH, -SH, -N -CN-bearing monomers can also be present in minor amounts of up to 20 mol%, preferably <10 mol%, especially <5 mol% in the copolymers B. In minor amounts of up to 20 mol%, preferably <10 mol%, especially <5 mol%, it is also possible for further comonomers which are copolymerizable with the monomers mentioned to be present, e.g. Allyl polyglycol ethers, vinyl aromatics and higher molecular weight olefins such as poly (isobutylene).

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.

Allyl 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.

All comonomers not covered by the abovementioned definitions of B1) and / or B2) are not taken into account in the calculation of the factor R.

The polymers according to the invention can be prepared by direct polymerization from the monomers mentioned in known polymerization processes such as bulk, solution, emulsion, suspension or precipitation polymerization.

They may also be obtained by derivatization of e.g. Acid- or hydroxyl-bearing base polymer can be prepared with corresponding fatty acids, fatty alcohols or fatty amines having 8 to 16 carbon atoms in the alkyl radical. The esterifications, etherifications, amidations and / or imidations are carried out by known condensation methods. The derivatization may be complete or partial. Partially esterified or amidated acid-based polymers (solvent-free) preferably have acid numbers of 60-140 mg KOH / g and in particular 80-120 mg KOH / g. Copolymers with acid numbers of less than 80, especially less than 60 mg KOH / g are considered to be fully derivatized. Partially esterified or etherified hydroxyl-bearing polymers have OH numbers of 40 to 200 mg KOH / g, preferably 60 to 150 mg KOH / g; Copolymers having hydroxyl numbers less than 60 and especially less than 40 mg KOH / g are considered fully derivatized. Particularly preferred are partially derivatized polymers.

For derivatization with fatty alcohols and / or amines to esters and / or amides suitable acid-bearing polymers are homo- and copolymers of ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid or their reactive equivalents such as lower esters or anhydrides such as Methyl methacrylate and maleic anhydride with each other as well as with other monomers copolymerizable with these acids. Suitable examples are poly (acrylic acid), poly (methacrylic acid), poly (maleic acid), poly (maleic anhydride), poly (acrylic acid-co-maleic acid).

Suitable fatty alcohols and fatty amines are particularly linear, but they can also minor amounts, eg. B. up to 30 wt .-%, preferably up to 20 wt .-% and especially up to 10 wt .-% branched alkyl radicals. The branches are preferably in the 1- or 2-position. Shorter as well as longer-chain fatty alcohols or fatty amines can be used, but their proportion is preferably below 20 mol% and especially below 10 mol%, such as between 1 and 5 mol% based on the total amount of amines used.

Particularly preferred fatty alcohols are octanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol and hexadecanol.

Suitable amines are primary and secondary amines having one or two C ₈ -C ₁₆ alkyl radicals. They can carry one, two or three amino groups which are linked via alkylene radicals having two or three carbon atoms. Preference is given to monoamines. Especially preferred as primary amines are octylamine, 2-ethylhexylamine, decylamine, undecylamine, dodecylamine, n-tridecylamine, iso-tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine and mixtures thereof. Preferred secondary amines are dioctylamine, dinonylamine, didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine, and amines having different alkyl chain lengths such as N-octyl-N-decylamine, N-decyl-N-dodecylamine, N-decyl-N-tetradecylamine, N-decyl N-hexadecylamine, N-dodecyl-N-tetradecylamine, N-dodecyl-N-hexadecylamine, N-tetradecyl-N-hexadecylamine. Secondary amines which, in addition to a C ₈ -C ₁₆ -alkyl radical, bear shorter side chains having 1 to 5 C atoms, for example methyl or ethyl groups, are suitable according to the invention. In the case of secondary amines, the alkyl chain length n is taken into account as the mean value of the alkyl chain lengths of C ₈ to C ₁₆ for the calculation of the Q factor. Shorter and longer alkyl radicals, if present, are not included in the calculation because they do not contribute to the effectiveness of the additives. Therefore, the proportion of shorter and longer alkyl chains is preferably less than 20 mol%, preferably less than 10 mol%, based on the total amount of amine used. Particularly preferred are amides derived from primary monoamines and imides.

Polymers which are particularly suitable for derivatization with fatty acids and / or fatty alcohols to esters and / or ethers are homopolymers and copolymers of monomers carrying hydroxyl groups, such as vinyl alcohol, allyl alcohol or also hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate. Suitable fatty acids have 8 to 16 carbon atoms in the alkyl radical. The alkyl radical is essentially linear, but may also be minor amounts, e.g. up to 30 wt .-%, preferably up to 20 wt .-% and especially up to 10 wt .-% of branched isomers. Particularly suitable are nonanoic, decanoic, undecanoic, dodecanoic, tridecanoic, tetradecanoic, pentadecanoic, hexadecanoic, heptadecanoic and octadecanoic and Nonadecansäure and mixtures thereof.

By using mixtures of different fatty acids, alcohols and / or amines in the esterification, etherification, amidation or imidization, the effectiveness of the additives according to the invention can be further adapted to special fatty acid ester compositions.

The molecular weights of the copolymers B of the invention are between 1,000 and 100,000, in particular between 2,000 and 50,000 and in particular between 2,500 and 25,000 g / mol, measured by gel permeation chromatography (GPC) against poly (styrene). Copolymers of the invention must be oil-soluble in practice-relevant dosing quantities, ie they must dissolve in the oil to be additized at 50 ° C. without residue.

In a preferred embodiment, mixtures of the copolymers B according to the invention are used, with the proviso that the mean value of the R values of the mixture components in turn has values of from 11.0 to 14.0, preferably from 11.5 to 13.5 and in particular values of 12 , 0 to 13.0.

The mixing ratio of the additives A and B according to the invention is (in parts by weight) 10: 1 to 1:10, in particular 5: 1 to 1: 2.

The additives of the invention are added to oils in amounts of 0.001 to 5 wt .-%, preferably 0.005 to 1 wt .-% and especially 0.01 to 0.5 wt .-%. there They may be dissolved as such or dissolved or dispersed in solvents, such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures such as 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 can be used. Preferably, they are dissolved in fuel oil of animal or vegetable origin based on fatty acid alkyl esters. The additives according to the invention preferably contain 1 to 80%, especially 10 to 70%, in particular 25 to 60%, of solvent.

In a preferred embodiment, the fuel oil F2, which is often referred to as "biodiesel", "biofuel" or "biofuel", to fatty acid alkyl esters of fatty acids having 12 to 24 carbon atoms and alcohols having 1 to 4 carbon atoms , Usually, a major part of the fatty acids contains one, two or three double bonds.

Examples of oils F2 derived from animal or vegetable material which can be used in the present invention 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 cooking 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 partially 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 and soybeans and their mixtures with rapeseed oil are preferred.

Particularly suitable as biofuels F2) are lower alkyl esters of fatty acids. Examples of commercially available mixtures of the ethyl, propyl, butyl and especially methyl esters of fatty acids having 14 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 acid or erucic acid, which preferably have an iodine value of 50 to 150, in particular 90 to 125. Mixtures with particularly advantageous properties are those which contain mainly, ie at least 50 wt .-%, methyl esters of fatty acids having 16 to 22 carbon atoms and 1, 2 or 3 double bonds. The preferred lower alkyl esters of fatty acids are the methyl esters of oleic, linoleic, linolenic and erucic acids.

Commercially available mixtures of the type mentioned are obtained, for example, by cleavage and esterification or by transesterification of animal and vegetable fats and oils with lower aliphatic alcohols. The same are also used edible oils as starting materials. For the preparation of lower alkyl esters of fatty acids, it is advantageous to start from 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 whose fatty acid component is derived to greater than 80% by weight of unsaturated fatty acids containing 18 carbon atoms are preferred.

Thus, a biofuel is an oil obtained from plant or animal matter or both, or a derivative thereof, which can be used as a fuel and especially as a diesel or fuel oil. Although many of the above oils can be used as biofuels, vegetable oil derivatives are preferred, with particularly preferred biofuels being alkyl ester derivatives of rapeseed oil, cottonseed oil, soybean oil, sunflower oil, olive oil or palm oil, with methyl rapeseed oil, methyl sunflower oil and soybean oil methyl ester being most preferred. In addition, particularly preferred biofuel or as a component in the biofuel are also old fat esters such as, for example, used fat methyl ester.

As mineral oil component F1, in particular middle distillates are suitable, which are obtained by distillation of crude oil and boiling in the range of 120 to 450 ° C, for example kerosene, jet fuel, diesel and fuel oil. Preferably, such middle distillates are used, the 0.05 wt .-% sulfur and less, more preferably less than 350 ppm sulfur, in particular less than 200 ppm sulfur and in special cases contain less than 50 ppm sulfur, such as less than 10 ppm sulfur. These are generally those middle distillates which have been subjected to a hydrogenating refining, and therefore contain only small amounts of polyaromatic and polar compounds. These are preferably middle distillates which have 95% distillation points below 370.degree. C., in particular 350.degree. C. and in special cases below 330.degree. Synthetic fuels, such as those obtainable by the Fischer-Tropsch process, are also suitable as middle distillates.

The additive may be added to the oil to be added according to methods known in the art. When more than one additive component or co-additive component is to be used, such components may be incorporated into the oil together or separately in any combination and order.

With the additives according to the invention, the CFPP value of mixtures of biodiesel and mineral oils can be improved much more efficiently than with the known additives of the prior art. The additives according to the invention are particularly advantageous in oil mixtures whose mineral oil component F1) has a boiling range between the 20 and 90% distillation point of less than 120 ° C, in particular less than 110 ° C and especially less than 100 ° C. In addition, they are particularly advantageous in oil blends whose mineral oil component F1) has a cloud point of below -4 ° C, especially from -6 ° C to -20 ° C such as from -7 ° C to -9 ° C, as they be used for use especially in winter. In the same way, the pour point of the mixtures according to the invention is reduced by the addition of the additives according to the invention. The additives according to the invention are particularly advantageous in oil mixtures containing more than 2% by volume of biofuel F 2, preferably more than 5% by volume of biofuel F 2 and especially more than 10% by vol. Of biofuel F 2, for example 15 to 35% by vol. % Biofuel F2 included. The additives according to the invention are furthermore particularly advantageous in problematic oils whose biofuel component F2 contains a high proportion of esters of saturated fatty acids of more than 4%, in particular more than 5% and especially from 7 to 25%, for example from 8 to 20% it is the case for example in sunflower and soybean oils. Such biofuels preferably have a cloud point above -5 ° C and especially above -3 ° C.

Oil mixtures F), in which the additives according to the invention show particularly advantageous action, preferably have cloud points above -9 ° C and especially above -6 ° C. With the additives according to the invention, it is therefore also possible to adjust oil blends containing rapeseed oil methyl ester and sunflower oil and / or soya oil fatty acid methyl esters to CFPP values of -22 ° C. and below.

For the preparation of additive packages for special problem solutions, the additives according to the invention can also be used together with one or more oil-soluble co-additives, which in themselves improve the cold flow properties of crude oils, lubricating oils or fuel oils. Examples of such co-additives are polar compounds which differ from the polymers B according to the invention and which effect a paraffin dispersion (paraffin dispersants), alkylphenol condensates, esters and ethers of polyoxyalkylene compounds, olefin copolymers and oil-soluble amphiphiles.

Thus, the additives according to the invention can be used to further reduce the sedimentation in the cold precipitated paraffins and fatty acid esters in admixture with paraffin dispersants. Paraffin dispersants reduce the size of the paraffin and fatty acid ester crystals and cause the paraffin particles to not settle but remain colloidally dispersed with significantly reduced sedimentation effort. Suitable paraffin dispersants are both low molecular weight and polymeric, oil-soluble compounds having ionic or polar groups such as amine salts and / or amides have proven. Particularly preferred paraffin dispersants contain reaction products of fatty amines with alkyl radicals having 18 to 24 C atoms, in particular with secondary fatty amines such as Ditalgfettamin, distearylamine and dibehenylamine with carboxylic acids and derivatives thereof. Paraffin dispersants 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 paraffin dispersants (cf. EP 0 398 101 ). Other paraffin dispersants are copolymers of maleic anhydride and α, β-unsaturated compounds, optionally with primary monoalkylamines and / or aliphatic alcohols can be reacted (see. EP 0 154 177 ) and the reaction products of alkenyl spiro-bis-lactones with amines (cf. EP-0 413 279 B1 ) and after EP-A-0 606 055 A2 Reaction products of terpolymers based on α, β-unsaturated dicarboxylic anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.

Alkylphenol-aldehyde resins are described, for example, in Römpp Chemie Lexikon, 9th edition, Thieme Verlag 1988-92, Volume 4, p. 3351 et seq. described. The alkyl radicals of the o- or p-alkylphenol may be the same or different in the case of the alkylphenol-aldehyde resins which can be used with the additives according to the invention and have 1-50, preferably 1-20, in particular 4-12 carbon atoms; it is preferably n-, iso- and tert-butyl, n- and iso-pentyl, n- and iso-hexyl, n- and iso-octyl, n- and iso-nonyl, n- and iso-decyl , n- and iso-dodecyl and octadecyl. The aliphatic aldehyde in the alkylphenol-aldehyde resin preferably has 1 to 4 carbon atoms. Particularly preferred aldehydes are formaldehyde, acetaldehyde and butyraldehyde, especially formaldehyde. The molecular weight of the alkylphenol-aldehyde resins is 400-10,000, preferably 400-5,000, g / mol. The prerequisite here is that the resins are oil-soluble.

worin R⁵ für C₁-C₅₀-Alkyl oder -Alkenyl und n für eine Zahl von 2 bis 100 steht. Bevorzugt steht R⁵ für C₄-C₂₀-Alkyl oder -Alkenyl und insbesondere für C₆-C₁₆-Alkyl oder -Alkenyl. Bevorzugt steht n für eine Zahl von 4 bis 50 und speziell für eine Zahl von 5 bis 25.In a preferred embodiment of the invention, these alkylphenol-formaldehyde resins are those which are oligomers or polymers having a repeating structural unit of the formula

wherein R ^{5 is} C ₁ -C ₅₀ alkyl or alkenyl and n is a number from 2 to 100. R ⁵ is preferably C ₄ -C ₂₀ -alkyl or -alkenyl and in particular C ₆ -C ₁₆ -alkyl or alkenyl. Preferably, n is a number from 4 to 50 and especially from 5 to 25.

Other suitable flow improvers are polyoxyalkylene compounds such as esters, ethers and ethers / esters, which carry at least one alkyl radical having 12 to 30 carbon atoms. When the alkyl groups are derived from an acid, the remainder is derived from a polyhydric alcohol; If the alkyl radicals come from a fatty alcohol, the remainder of the compound derives from a polyacid.

Suitable polyols are polyethylene glycols, polypropylene glycols, polybutylene glycols and their copolymers having a molecular weight of about 100 to about 5000, preferably 200 to 2000. Also suitable are alkoxylates of polyols, such as glycerol, trimethylolpropane, pentaerythritol, neopentyl glycol, as well as from them Condensation accessible oligomers having 2 to 10 monomer units, such as Polyglycerol. Preferred alkoxylates are those having from 1 to 100, in particular from 5 to 50, mol of ethylene oxide, propylene oxide and / or butylene oxide per mole of polyol. Esters are especially preferred.

Fatty acids containing 12 to 26 carbon atoms are preferred for reaction with the polyols to form the ester additives, preferably using C ₁₈ to C ₂₄ fatty acids, especially stearic and behenic acid. The esters can also be prepared by esterification of polyoxyalkylated alcohols. Preference is given to completely esterified polyoxyalkylated polyols having molecular weights of 150 to 2,000, preferably 200 to 1,500. Particularly suitable are PEG-600 dibehenate and glycerol-ethylene glycol tribehenate.

Suitable olefin polymers as part of the additive according to the invention can be derived directly from monoethylenically unsaturated monomers or prepared indirectly by hydrogenation of polymers derived from polyunsaturated monomers such as isoprene or butadiene. Preferred copolymers contain, in addition to ethylene structural units derived from α-olefins having 3 to 24 carbon atoms and having molecular weights of up to 120,000. Preferred α-olefins are propylene, butene, isobutene, n-hexene, isohexene, n-octene, isooctene, n-decene, isodecene. The comonomer content of olefins is preferably between 15 and 50 mol%, more preferably between 20 and 35 mole% and especially between 30 and 45 mole%. These copolymers may also contain minor amounts, eg, up to 10 mol% of other comonomers such as non-terminal olefins or non-conjugated olefins. Preferred are ethylene-propylene copolymers. The olefin copolymers can be prepared by known methods, for example by Ziegler or metallocene catalysts.

Other suitable olefin copolymers are block copolymers containing blocks of olefinically unsaturated aromatic monomers A and blocks of hydrogenated polyolefins B. Particularly suitable are block copolymers of the structure (AB) _n A and (AB) _m , where n is a number between 1 and 10 and m is a number between 2 and 10.

The mixing ratio (in parts by weight) of the additives according to the invention with paraffin dispersants, comb polymers, alkylphenol condensates, polyoxyalkylene derivatives or olefin copolymers is in each case from 1:10 to 20: 1, preferably from 1: 1 to 10: 1, for example from 1: 1 to 4: 1.

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

Examples Characterization of the test oils:

The CFPP value is determined according to EN 116 and the determination of the cloud point according to ISO 3015. Both properties are determined in ° C. Table 1: Characterization of the biofuel oils used (F2) Oil no. CP CFPP E 1 Rapsölsäuremethylester -2.3 -14 ° C E 2 90% rapeseed oil methyl ester + 10% soybean oil methyl ester -2.0 -8 ° C C ₁₆ C ₁₆ ' C ₁₈ C ₁₈ ' C ₁₈ " C ₁₈ "' C ₂₀ C ₂₀ ' C ₂₂ Σ saturated RME 4.5 0.5 1.7 61.6 18.4 8.7 0.7 1.5 0.4 7.3 SojaME 10.4 0.1 4.1 24.8 51.3 6.9 0.5 0.4 0.4 15.4 RME = rapeseed oil acid methyl ester;
SoyaME = soyaoic acid methyl ester D 1 D 2 Initial boiling point 193 ° C 181 ° C 20% distillation 230 ° C 235 ° C 90% distillation 332 ° C 344 ° C 95% distillation 348 ° C 361 ° C (90-20)% distillation 102 ° C 109 ° C Cloud point -6.0 ° C -8.2 ° C CFPP -8 ° C -12 ° C S content 20 ppm 32 ppm

The following additives were used:

Ethylene copolymers A

The ethylene copolymers used are commercial products having the characteristics given in Table 4. The products were used as 65% settings in kerosene. Table 4: Characterization of the ethylene copolymers (A) 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 i) 14.0 mol% vinyl acetate and 1.6 mol% vinyl neodecanoate and 97 mPas 4.7 ii) 12.9 mol% of vinyl acetate in the ratio i): ii) of 6: 1 145 mPas 5.4

Comb polymers B

Various copolymers and terpolymers with the molar ratios of the monomers given in Table 3 and the factors R calculated therefrom were investigated. The polymers were used as 50% settings in a higher boiling aromatic solvent. The calculated acid numbers refer to these 50% settings. Table 5: Characterization of the comb polymers used (B) example comonomers R Acid number [mg KOH / g] B1 Poly (dodecyl acrylate-co-tetradecyl acrylate) of 70% dodecyl acrylate and 30% tetradecyl acrylate with Mw 10,500 12.6 1.2 B2 Poly (dodecyl methacrylate) with Mw 22,000 12.0 1.7 B3 Poly (2-ethylhexanoate-co-tetradecyl acrylate) from 10% 2-ethylhexyl acrylate and 90% tetradecyl acrylate with Mw 6,400 13.4 10 B4 Poly (dodecyl vinyl ether-co-decyl methacrylate) of equal proportions dodecyl vinyl ether and Decylmethacryat with Mw 5,200 11.0 2.8 B5 Poly (acrylic acid) esterified with a mixture of 75% dodecanol and 25% hexadecanol, Mw 15,000 13.0 43 B6 Poly (acrylic acid) esterified with a mixture of 40% decanol, 30% dodecanol and 30% tetradecanol, Mw 24,000 11.8 51 B7 Poly (acrylic acid-co-maleic acid) esterified with a mixture of 55% decanol and 45% hexadecanol, Mw 19,000 12.7 34 B8 (Cf.) Poly (decyl acrylate) with Mw 19,000 10.0 2.3 B9 (Cf.) Poly (tetradecyl acrylate-co-hexadecyl acrylate) with equal proportions of tetradecyl and hexadecyl acrylate, Mw 24,000 15.0 1.6 B10 (Cf.) Alternating poly (ditetradecylfumarate-altvinylacetate) n / A 0.4 na = not applicable (Comp.) = Comparative Example example comonomers R Acid number [mg KOH / g] B1 Poly (dodecyl acrylate-co-tetradecyl acrylate) of 70% dodecyl acrylate and 30% tetradecyl acrylate with Mw 10,500 12.6 1.2 B2 Poly (dodecyl methacrylate) with Mw 22,000 12.0 1.7 B3 Poly (2-ethylhexanoate-co-tetradecyl acrylate) from 10% 2-ethylhexyl acrylate and 90% tetradecyl acrylate with Mw 6,400 13.4 10 B4 Poly (dodecyl vinyl ether-co-decyl methacrylate) of equal proportions dodecyl vinyl ether and Decylmethacryat with Mw 5,200 11.0 2.8 B5 Poly (acrylic acid) esterified with a mixture of 75% dodecanol and 25% hexadecanol, Mw 15,000 13.0 43 B6 Poly (acrylic acid) esterified with a mixture of 40% decanol, 30% dodecanol and 30% tetradecanol, Mw 24,000 11.8 51 B8 (Cf.) Poly (decyl acrylate) with Mw 19,000 10.0 2.3 B9 (Cf.) Poly (tetradecyl acrylate-co-hexadecyl acrylate) with equal proportions of tetradecyl and hexadecyl acrylate, Mw 24,000 15.0 1.6 B10 (Cf.) Alternating poly (ditetradecylfumarate-altvinylacetate) n / A 0.4 na = not applicable (Comp.) = Comparative Example Ex. flow Comb polymer / CFPP after addition of flow improver improvers co-additive 50 ppm 100 ppm 150 ppm 200ppm 1 A2 150 ppm B4 -13 -18 -19 -20 2 A1 100 ppm B6 -17 -20 -19 -21 3 A2 150 ppm B2 -18 -20 -22 -22 4 A2 150 ppm B1 -19 -21 -21 -23 5 A1 100 ppm B7 -20 -20 -22 -23 6 A1 150 ppm B5 -19 -21 -20 -22 7 A2 150 ppm B3 -16 -18 -19 -21 8th A2 75 ppm B7 -19 -22 -23 -25 75 ppm A4 9 (Cf.) A2 150 ppm B8 -11 -14 -16 -17 10 (Cf.) A2 150 ppm B9 -9 -10 -13 -16 11 (Cf.) A2 150 ppm B10 -10 -11 -15 -20 13 (Cf.) A2 - -11 -16 -17 -19 Ex. flow Comb polymer / CFPP after addition of flow improver improvers co-additive 50 ppm 100 ppm 150 ppm 200ppm 1 A2 150 ppm B4 -13 -18 -19 -20 2 A1 100 ppm B6 -17 -20 -19 -21 3 A2 150 ppm B2 -18 -20 -22 -22 4 A2 150 ppm B1 -19 -21 -21 -23 6 A1 150 ppm B5 -19 -21 -20 -22 7 A2 150 ppm B3 -16 -18 -19 -21 9 (Cf.) A2 150 ppm B8 -11 -14 -16 -17 10 (Cf.) A2 150 ppm B9 -9 -10 -13 -16 11 (Cf.) A2 150 ppm B10 -10 -11 -15 -20 13 (Cf.) A2 - -11 -16 -17 -19 Ex. Ethylene copolymer comb polymer co-additive CFPP 100 ppm 150 ppm 200 ppm 300 ppm 14 80% A3 20% B4 150 ppm C6 -18 -20 -22 -24 15 80% A3 20% B6 150 ppm C6 -20 -21 -24 -25 16 80% A3 20% B2 150 ppm C6 -20 -21 -23 -26 17 80% A3 20% B1 150 ppm C6 -21 -22 -25 -27 19 85% A1 15% B5 150 ppm C6 -20 -22 -24 -27 20 80% A1 20% B3 150 ppm C7 -19 -21 -23 -25 21 (Cf.) 80% A3 20% B8 150 ppm C6 -17 -18 -19 -21 22 (See) 80% A1 20% B9 150 ppm C6 -11 -16 -19 -19 23 (Cf.) 80% A1 20% B10 150 ppm C7 -15 -16 -18 -22 24 (Cf.) 100% A1 - 150 ppm C6 -18 -19 -20 -22

In this series of measurements, a constant amount of co-additive as well as the stated amount of a mixture of ethylene copolymer and comb polymer were added to the oil.

Claims (16)

1. A fuel oil composition F) comprising

   F1) a fuel oil of mineral origin and

   F2) more than 2 to 35% by volume of a fuel oil of vegetable and/or animal origin, containing more than 4% by weight of esters of saturated fatty acids, and, as a cold additive, in an amount of from 0.001 to 5% by weight in the weight ratio A) :B) = 10:1 to 1:10, the constituents

   A) at least one copolymer composed of ethylene and 8-21 mol% of at least one acrylic or vinyl ester having a C₁-C₁₈-alkyl radical and

   B) at least one comb polymer containing structural units having C₈-C₁₆-alkyl radicals, the structural units being selected from C₈-C₁₆-alkyl (meth) acrylates, C₈-C₁₆-alkyl vinyl esters, C₈-C₁₆-alkyl vinyl ethers and C₈-C₁₆-alkyl (meth) - acrylamides, C₈-C₁₆-alkyl allyl ethers and C₈-C₁₆-alkyl diketenes,

   where the sum R $$R=m_1\cdot {\displaystyle \sum _i}{w}_{1i}\cdot n_{1i}+m_2\cdot {\displaystyle \sum _j}{w}_{2j}\cdot n_{2j}+\mathrm{.......}{m}_g\cdot {\displaystyle \sum _p}{\mathit{w}}_{\mathit{gp}}\cdot n_{\mathit{gp}}$$

   

   
   of the molar averages of the carbon chain length distributions in the alkyl radicals of the monomers B) is from 11.0 to 14.0,
   where m₁, m₂, ... m_g are the molar fractions of the abovementioned monomers B) in the polymer, and the sum of the molar fractions m₁ to m_g = 1, w_1i, w_1j .. w_2i, w_2j ... w_gp are the proportions by weight of the individual chain lengths i, j, p of the alkyl radicals of the different monomers B) 1 to g, and n_1i, n_1j .. n_2i, n_2j...n_gp are the chain lengths of the alkyl radicals i, j, .... p of the monomers B) 1 to g.
2. A fuel oil composition as claimed in claim 1, wherein R is from 11.5 to 13.5.
3. A fuel oil composition as claimed in claim 1 and/or 2, wherein constituent A, apart from ethylene, contains from 3.5 to 20 mol% of vinyl acetate and from 0.1 to 12 mol% of vinyl neononanoate, vinyl neodecanoate or vinyl 2-ethylhexanoate, and the total comonomer content is between 8 and 21 mol%.
4. A fuel oil composition as claimed in one or more of claims 1 to 3, wherein constituent A, in addition to ethylene and from 8 to 18 mol% of vinyl esters, also contains from 0.5 to 10 mol% of olefins selected from propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene or norbornene.
5. A fuel oil composition as claimed in one or more of claims 1 to 4, wherein the copolymers which make up constituent A have melt viscosities at 140°C between 20 and 10 000 mPas.
6. A fuel oil composition as claimed in one or more of claims 1 to 5, wherein the copolymers which make up constituent A have degrees of branching determined by means of ¹H NMR spectroscopy between 1 and 9 CH₃/100 CH₂ groups which do not stem from the comonomers.
7. A fuel oil composition as claimed in one or more of claims 1 to 6, wherein the copolymers which make up constituent B contain comonomers which are derived from esters or amides of ethylenically unsaturated monocarboxylic acids having from 3 to 8 carbon atoms with alcohols or amines, the alcohols or amines bearing alkyl radicals having from 8 to 16 carbon atoms.
8. A fuel oil composition as claimed in one or more of claims 1 to 7, wherein copolymers B) contain up to 50 mol% of comonomers B2) which are smaller than i) esters, amides and/or imides of ethylenically unsaturated dicarboxylic acids having from 4 to 8 carbon atoms and alcohols or amines having from 8 to 16 carbon atoms in the alkyl radicals, and/or ii) C₁₀ to C₂₀ olefins.
9. A fuel oil composition as claimed in one or more of claims 1 to 8, wherein the esters and/or amides of constituent B are derived from amines and/or alcohols having linear alkyl radicals.
10. A fuel oil composition as claimed in one or more of claims 1 to 9, wherein copolymers B) are esters of acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid with octanol, nonanol, decanol, undecanol, dodecanol, n-tridecanol, isotridecanol, tetradecanol, pentadecanol, hexadecanol and mixtures thereof, and optionally imides of these acids with octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine and mixtures thereof.
11. A fuel oil composition as claimed in one or more of claims 1 to 10, wherein the copolymers which make up constituent B contain comonomers B2) which are derived from α-olefins having from 10 to 20 carbon atoms.
12. A fuel oil composition as claimed in one of claims 1 to 11, comprising polar nitrogen-containing paraffin dispersants.
13. A fuel oil composition as claimed in one or more of claims 1 to 12 which comprises one or more esters composed of monocarboxylic acid having from 14 to 24 carbon atoms and alcohol having from 1 to 4 carbon atoms.
14. A fuel oil composition as claimed in claim 13, wherein the alcohol having from 1 to 4 carbon atoms is methanol or ethanol.
15. The use of from 0.001 to 5% by weight of an additive as defined in one or more of claims 1 to 12 for improving the cold flow properties of mixtures of mineral fuel oils F1 with more than 2 to 35% by volume of fuel oils of animal or vegetable origin F2, in which more than 4% by weight of esters of saturated fatty acids are contained.
16. A process for producing fuel oil compositions F) comprising fuel oils of mineral (F1) and animal and/or vegetable (F2) origin, containing more than 4% by weight of esters of saturated fatty acids, and in which the fuel oil composition F), in addition to the fuel oil of mineral origin F1), contains more than 2 to 35% by volume of a fuel oil of vegetable and/or animal origin F2), having improved cold flow properties, by adding from 0.001 to 5% by weight of an additive as defined in one or more of claims 1 to 13 to the mixture of fuel oils of mineral F1) and animal and/or vegetable F2) origin.