EP1541662B1 - 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, waste fat methyl ester a CFPP of +1 ° 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 Fumaratoder 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.

1. 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
2. b) auf eine Temperatur unterhalb des Cold Filter Plugging Point der nichtadditivierten, langkettigen Fettsäureester FAE abkühlt und
3. 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

1. 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
2. b) to a temperature below the cold filter plugging point of the non-additive, long-chain fatty acid ester FAE cools and
3. c) the resulting precipitation (FAN) is separated.

1. 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,
2. 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
3. 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

1. 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,
2. 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
3. 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.

1. 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
2. II) einem anderen Niedertemperaturfließverbesserer für Destillatbrennstofföle umfasst.

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

1. 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
2. II) another low temperature flow improver for distillate fuel oils.

• A) Copolymere aus niederen Olefinen und Vinylestern, enthaltend
• A1) 85 bis 97 mol-% bivalente Struktureinheiten der Formel
  
          -CH₂-CR¹R²-     A1
  
  worin R¹ und R² unabhängig voneinander Wasserstoff oder Methyl bedeuten, und
• A2) mindestens 3 mol-% bivalente Struktureinheiten der Formel
  
  worin R³ gesättigtes, verzweigtes C₆-C₁₆-Alkyl bedeutet, das ein tertiäres Kohlenstoffatom aufweist, dadurch gekennzeichnet, dass R³ mit seinem tertiären Kohlenstoffatom an die Carboxylfunktion gebunden ist,
• B) Copolymere, umfassend
• B1) 40 bis 60 mol-% bivalente Struktureinheiten der Formel
  
  mit X = O oder N - R⁴,
  worin a, b = 0 oder 1 und a + b = 1 sind, und
• B2) 60 bis 40 mol-% bivalente Struktureinheiten der Formel
  
          -H₂C-CHR⁵-     B2
  
  und gegebenenfalls
• B3) 0 bis 20 mol-%, bivalente Struktureinheiten, die sich von Polyolefinen ableiten, wobei die Polyolefine aus Monoolefinen mit 3 bis 5 Kohlenstoffatomen ableitbar sind, und worin
  1. a) R⁴ einen Alkyl- oder Alkenylrest mit 10 bis 40 Kohlenstoffatomen oder einen Alkoxyalkylrest mit 1 bis 100 Alkoxyeinheiten und 1 bis 30 Kohlenstoffatomen im Alkylrest, und
  2. b) R⁵ einen Alkylrest mit 10 bis 50 Kohlenstoffatomen bedeutet, und
  3. c) die Zahl der Kohlenstoffatome der den Struktureinheiten B3) zugrunde liegenden Polyolefinmoleküle zwischen 35 und 350 beträgt, und gegebenenfalls
• C) ein weiteres von A) und B) verschiedenes Copolymer aus Ethylen und einem oder mehreren Vinyl- oder Acrylester, das allein Wirksamkeit als Kaltfließverbesserer für Mitteldestillate aufweist.

EP-A-1146108 teaches: The invention relates to additives for improving the cold flow properties of middle distillates, containing 10 to 95 wt .-% copolymers A), 5 to 90 wt .-% copolymers B) and optionally 0 to 70 wt .-% copolymers C), which correspond to the following formulas

• A) Copolymers of lower olefins and vinyl esters, containing
• A1) 85 to 97 mol% of bivalent structural units of the formula
  
  -CH ₂ -CR ¹ R ² -A1
  
  wherein R ¹ and R ^{2 are} independently hydrogen or methyl, and
• A2) at least 3 mol% of bivalent structural units of the formula
  
  wherein R ^{3 is} saturated, branched C ₆ -C ₁₆ -alkyl having a tertiary carbon atom, characterized in that R ³ is bonded to the carboxyl function with its tertiary carbon atom,
• B) Copolymers comprising
• B1) 40 to 60 mol% of bivalent structural units of the formula
  
  with X = O or N - R ⁴ ,
  wherein a, b = 0 or 1 and a + b = 1, and
• B2) 60 to 40 mol% of bivalent structural units of the formula
  
  -H ₂ C-CHR ⁵ - B2
  
  and optionally
• B3) 0 to 20 mol%, bivalent structural units derived from polyolefins, wherein the polyolefins are derivable from monoolefins having 3 to 5 carbon atoms, and wherein
  1. a) R ^{4 is} an alkyl or alkenyl radical having 10 to 40 carbon atoms or an alkoxyalkyl radical having 1 to 100 alkoxy units and 1 to 30 carbon atoms in the alkyl radical, and
  2. b) R ^{5 is} an alkyl radical having 10 to 50 carbon atoms, and
  3. c) the number of carbon atoms of the polyolefin molecules underlying the structural units B3) is between 35 and 350, and optionally
• C) Another of A) and B) different copolymer of ethylene and one or more vinyl or acrylic esters, which alone has efficacy as a cold flow improver for middle distillates.

US-2003/0163951 teaches multifunctional cold additives containing copolymers of dicarboxylic acid derivatives and olefins, whereupon nitrogen-containing compounds or esters are grafted on.

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 10 to 30 carbon atoms with a non-polymeric organic group 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 components (a), (b), (c) and (d ).

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.

• F1) ein Brennstofföl mineralischen Ursprungs und
• F2) mehr als 2% bis 35 Vol.% eines Brennstofföl pflanzlichen und/oder tierischen Ursprungs, und 0,001 bis 5 Gew.-% eines Kälteadditivs, enthaltend die Bestandteile A und B im Gewichtsverhältnis 20:1 bis 1:20
• 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 aus
  • B1) mindestens einem Olefin als Monomer 1, welches an der olefinischen Doppelbindung wenigstens einen C₈-C₁₈-Alkylrest trägt, und
  • B2) mindestens einer ethylenisch ungesättigten Dicarbonsäure als Monomer 2, welche mindestens einen über eine Amid- und/oder Imidgruppierung gebundenen C₈-C₁₆-Alkylrest trägt, wobei das molare Verhältnis B1):B2) zwischen 1,5:1 und 1:1,5 liegt,
    wobei die Summe Q $$\mathrm{Q}={\displaystyle \sum _{\mathrm{i}}}{\mathrm{w}}_{\mathrm{1}\mathrm{i}}\cdot {\mathrm{n}}_{\mathrm{1}\mathrm{i}}+{\displaystyle \sum _{\mathrm{j}}}{\mathrm{w}}_{\mathrm{2}\mathrm{j}}\cdot {\mathrm{n}}_{\mathrm{2}\mathrm{j}}$$
    

der molaren Mittel der C-Kettenlängenverteilungen in den Alkylresten von Monomer 1 einerseits und den Alkylresten der Amid und/oder Imidgruppen von Monomer 2 andererseits von 21,0 bis 28,0 beträgt, worin

w₁

der molare Anteil der einzelnen Kettenlängen in den Alkylresten von Monomer 1,

w₂

der molare Anteil der einzelnen Kettenlängen in den Alkylresten der Amid- und/oder Imidgruppen von Monomer 2,

n₁

die einzelnen Kettenlängen in den Alkylresten von Monomer 1,

n₂

die einzelnen Kettenlängen in den Alkylresten der Amid und/oder Imidgruppen von Monomer 2,

i

die Laufvariable für die einzelnen Kettenlängen in den Alkylresten von Monomer 1, und

j

die Laufvariable für die einzelnen Kettenlängen in den Alkylresten der Amid und/oder Imidgruppen von Monomer 2 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 oil of vegetable and / or animal origin, and 0.001 to 5% by weight of a cold additive containing components A and B in a weight ratio of 20: 1 to 1:20
• A) at least one 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) at least one comb polymer comprising structural units
  • B1) at least one olefin as monomer 1, which carries at least one C ₈ -C ₁₈ -alkyl radical on the olefinic double bond, and
  • B2) at least one ethylenically unsaturated dicarboxylic acid as monomer 2, which at least one of an amide and / or Carrying imide moiety bonded C ₈ -C ₁₆ -alkyl radical, wherein the molar ratio B1): B2) is between 1.5: 1 and 1: 1.5,
    where the sum Q $$\mathrm{Q}={\displaystyle \underset{\mathrm{i}}{\Sigma }}{\mathrm{w}}_{\mathrm{1}\mathrm{i}}\cdot {\mathrm{n}}_{\mathrm{1}\mathrm{i}}+{\displaystyle \underset{\mathrm{j}}{\Sigma }}{\mathrm{w}}_{\mathrm{2}\mathrm{j}}\cdot {\mathrm{n}}_{\mathrm{2}\mathrm{j}}$$
    

the molar average of the C chain length distributions in the alkyl radicals of monomer 1, on the one hand, and the alkyl radicals of the amide and / or imide groups of monomer 2, on the other hand, is from 21.0 to 28.0, in which

w ₁

the molar fraction of the individual chain lengths in the alkyl radicals of monomer 1,

w ₂

the molar fraction of the individual chain lengths in the alkyl radicals of the amide and / or imide groups of monomer 2,

n ₁

the individual chain lengths in the alkyl radicals of monomer 1,

n ₂

the individual chain lengths in the alkyl radicals of the amide and / or imide groups of monomer 2,

i

the run variable for the individual chain lengths in the alkyl radicals of monomers 1, and

j

are the run variables for the individual chain lengths in the alkyl radicals of the amide and / or imide groups of monomer 2.

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), to improve the cold flow properties of fuel oil compositions F) containing fuel oils mineral (F1) and animal or vegetable ( F2), with a content of more than 2 and 35% by volume of fuel oil or vegetable origin. Another object of the invention is a process for the preparation of fuel oil compositions F) containing fuel oils of mineral (F1) and animal and / or vegetable (F2) origin, with improved cold properties, by mixing the mixture of fuel oils mineral (F1) and animal and / or or vegetable (F2) origin, the additive defined above in an amount of 0.001 to 5 wt .-%, containing the components A) and B), wherein the proportion of fuel oil or vegetable origin is between more than 2 and 35 vol.% lies.

Preferred oils of mineral origin are middle distillates.

Especially preferred are mixtures containing 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 Q assumes values between 22.0 and 27.0, in particular 23.0 to 26.0 and for example 23, 24, 24.5, 25 or 26.

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.

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 from 50 to 400 MPa, preferably from 100 to 300 MPa, and at temperatures of from 100 to 300 ° C., preferably from 150 to 220 ° C. In a particularly preferred preparation variant, the polymerization is carried out in a multizone reactor, wherein the temperature difference between the peroxide doses 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 bulk polymerization is in known high pressure reactors, eg Autoclaves or tubular reactors, discontinuous or continuous, have proven particularly useful tubular reactors. 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 preferably derived from copolymers of ethylenically unsaturated dicarboxylic acids and derivatives thereof, such as lower esters and anhydrides. Preference is given to maleic acid, fumaric acid, itaconic acid and their esters with lower alcohols having 1 to 6 C atoms and their anhydrides, such as, for example, maleic anhydride. Monoolefins having from 10 to 20, in particular from 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 Double bond is preferably terminal such as in dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene and octadecene. The ratio of dicarboxylic acid or dicarboxylic acid derivative to olefin or olefins in the polymer is in the range 1: 1.5 to 1.5: 1, in particular it is equimolar.

In minor amounts of up to 20 mol%, preferably <10 mol%, especially <5 mol%, other comonomers may also be present in copolymer B which are copolymerizable with ethylenically unsaturated dicarboxylic acids and the olefins mentioned, such as, for example, and longer-chain olefins, allyl polyglycol ethers, C ₁ -C ₃₀ -alkyl (meth) acrylates, vinylaromatics or C ₁ -C ₂₀ -alkyl vinyl ethers. Likewise, in minor amounts, poly (isobutylenes) having molecular weights of up to 5,000 g / mol are used, with highly reactive variants having a high content 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.

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.

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 to 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. The polymerization is particularly preferably in less moderating, aliphatic or isoaliphatic solvents. The proportion of solvent in the polymerization mixture is generally between 10 and 90 wt .-%, preferably between 35 and 60 wt .-%. In the solution polymerization, the reaction temperature can be set particularly easily by the boiling point of the solvent or by working under reduced or elevated pressure.

The average molecular weight of the copolymers B according to the invention is generally between 1,200 and 200,000 g / mol, in particular between 2,000 and 100,000 g / mol, measured by gel permeation chromatography (GPC) against polystyrene standards in THF. 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.

The reaction of the monomers is initiated by free radical initiators (free radical initiators). 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 permalate, t-butyl perbenzoate, dicumyl peroxide, t-butylcumyl peroxide, di (t-butyl) peroxide, and azo compounds such as e.g. 2,2'-azobis (2-methylpropanonitrile) or 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 copolymers B can be prepared either by reacting maleic, fumaric and / or itaconic acid or derivatives thereof with the corresponding amine and subsequent copolymerization or by copolymerization of olefin or olefins with at least one unsaturated dicarboxylic acid or its derivative such as itaconund / or maleic anhydride and subsequent reaction with amines. A copolymerization with anhydrides is preferably carried out and the resulting copolymer is converted after production into an amide and / or an imide.

The reaction with amines takes place in both cases, for example by reaction with 0.8 to 2.5 moles of amine per mole of anhydride, preferably with 1.0 to 2.0 moles of amine per mole of anhydride at 50 to 300 ° C. When using about 1 mol of amine per mol of anhydride formed at reaction temperatures of about 50 to 100 ° C preferably hemiamides, which additionally carry a carboxyl group per amide group. At higher reaction temperatures of about 100 to 250 ° C arise from primary amines with elimination of water preferably imides. When using larger amounts of amine, preferably 2 moles of amine per mole of anhydride formed at about 50 to 200 ° C amide ammonium salts and at higher temperatures, for example, 100 - 300 ° C, preferably 120 - 250 ° C diamides. The water of reaction can be distilled off by means of an inert gas stream or discharged in the presence of an organic solvent by means of azeotropic distillation. Preference is given to 20-80, in particular 30-70, especially 35-55 wt .-% of at least one organic solvent used. As half-amides here are considered (50% in solvent) copolymers having acid numbers of 30 - 70 mg KOH / g, preferably from 40 - 60 mg KOH / g. Corresponding copolymers with acid numbers of less than 40, especially less than 30 mg KOH / g are considered diamides or imides. Particularly preferred are hemiamides and imides.

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. In particular, they carry linear alkyl radicals, but they can also minor amounts, eg. B. up to 30 wt .-%, preferably up to 20 wt .-% and especially up to 10 wt .-% (in 1- or 2-position) contain branched amines. Shorter as well as longer-chain amines can be used, but their proportion is preferably less than 20 mol% and especially less than 10 mol%, for example between 1 and 5 mol%, based on the total amount of amines used.

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 average value of the alkyl chain lengths of C ₈ to C _{16 is} taken into account as the alkyl chain length n 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.
Particularly preferred copolymers B are hemiamides and imides of primary monoamines.

By using mixtures of different olefins in the polymerization and mixtures of different amines in the amidation or imidization, the effectiveness can be further adapted to specific fatty acid ester compositions.

In a preferred embodiment, mixtures of the copolymers B according to the invention are used, with the proviso that the mean value of the Q values of the mixture components is in turn values of 21.0 to 28.0, preferably values of 22.0 to 27.0 and especially values of 23.0 to 26.0.

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 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 .-%. 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 are 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 1-80%, especially 10 - 70%, in particular 25 - 60% 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. Here are, for example, commercially available mixtures of ethyl, propyl, butyl and especially methyl esters of fatty acids having 14 to 22 carbon atoms, for example of lauric, myristic, palmitic, palmitolic, stearic, oleic, elaidic, petroselic, ricinoleic, elaeostearic, linoleic, linolenic , 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, 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 which contain 0.05% by weight of sulfur and less, more preferably less than 350 ppm of sulfur, especially less than 200 ppm of sulfur and in special cases less than 50 ppm of sulfur such as less than 10 ppm of 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 F which contain 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 volume of biofuel F 2 such as, for example, 15 to 35% by vol. - contain% biofuel F2. 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%, as is the case, for example, with sunflower and soybean oils. Such biofuels preferably have a cloud point above -5 ° C and especially above -3 ° C. Oil blends F), in which the additives according to the invention have 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 carbon atoms, in particular secondary fatty amines such as ditallow fatty amine, 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, which can optionally be reacted with primary monoalkylamines and / or aliphatic alcohols (cf. 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 acid anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.

Alkylphenol-aldehyde resins are, for example, in Rompp 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 preferable to 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 for example, of glycerol, trimethylolpropane, pentaerythritol, neopentyl glycol, and the oligomers obtainable therefrom by condensation with 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 mol% and especially between 30 and 45 mol%. These copolymers can also be minor amounts, e.g. up to 10 mole% of other comonomers, e.g. contain non-terminal olefins or non-conjugated olefins. Preferred are ethylene-propylene copolymers. The olefin copolymers can be prepared by known methods, e.g. 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 number 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 (F2) used 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% of soybean oil methyl ester -2.0 -8 ° C C-chain distribution used for the preparation of the test oils
Fatty acid methyl ester (main constituents, Fl .-% according to GC): 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 SBME 6.0 0.1 3.8 28.7 58.7 0.1 0.3 0.3 0.7 10.8 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; SBME = sunflower oil methyl ester;
SoyaME = soyaoic acid methyl ester Characterization of the mineral oils used (F1) D1 D2 D3 Initial boiling point 193 ° C 181 ° C 200 ° C 20% distillation 230 ° C 235 ° C 247 ° C 90% distillation 332 ° C 344 ° C 339 ° C 95% distillation 348 ° C 361 ° C 358 ° C (90-20)% distillation 102 ° C 109 ° C 92 ° C Cloud point -6.0 ° C -8.2 ° C -4.7 ° C CFPP -8 ° C -12 ° C -9 ° C S content 20 ppm 32 ppm 9 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
ii) 12.9 mol% of vinyl acetate in the ratio i): ii) of 6: 1 97 mPas
145 mPas 4.7
5.4

Comb polymers B

The polymerization of maleic anhydride (MSA) with α-olefins is carried out in a higher boiling aromatic hydrocarbon mixture at 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. Table 5 shows, by way of example, various copolymers and the molar proportions of the monomers used for their preparation, as well as chain length (R) and molar amount (based on MSA) of the amine used for the derivatization and the factor Q calculated therefrom. The amines used are, unless stated otherwise, monoalkylamines.

The reactions with amines are carried out in the presence of solvent naphtha (40 to 50 wt .-%) at 50 to 100 ° C to the half-amide or amide ammonium salt and at 160 to 200 ° C with azeotropic culling of water of reaction to imide or diamide , The degree of amidation is inversely proportional to the acid number. Table 5: Characterization of the comb polymers used (B) example comonomers Amin Q acid number
[mg KOH / g] R mol B1 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₈ 1 21 52 B2 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₀ 1 23.0 60 B3 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₂ 1 25.0 58 B4 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₄ 1 27.0 56 B5 (V) MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₆ 1 29.0 55 B6 (V) MSA-co-C ₁₀ -α-olefin (1: 1) C ₁₂ 1 20.0 57 B7 MSA-co-C ₁₆ α-olefin (1: 1) C ₁₂ 1 26.0 56 B8 MSA-co-C ₁₄ -α-olefin (1: 1) C ₁₄ 1 26.0 58 B9 MSA-co-C ₁₀ -α-olefin (1: 1) C ₁₆
C ₁₈ 0.5
0.5 25.0 59 B10 MSA-co-C _14/16 -α-olefin-co-Allylmethylpolyglykol (1: 0.45: 0.45: 0.1) C ₁₂ 1 25.0 56 B11 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₂ 2 25.0 0.32 B12 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) C ₁₂ 1 25.0 1.5 B13 MSA-co-C _14/16 -α-olefin (1: 0.5: 0.5) di-C ₁₂ 1 25.0 50 B14 (V) Fumarate vinyl acetate (1: 1) C ₁₄ 2 n / A 0.4 na = not applicable (V) = Comparative Example

Other flow improvers

The further flow improvers used C are commercial products with the characteristics given in Table 6. The products were used as 50% settings in solvent naphtha. Table 6: Characterization of the further flow improvers used C3 Reaction product of a copolymer of C ₁₄ / C ₁₆ olefin and maleic anhydride with 2 equivalents of secondary tallow fatty amine per maleic anhydride unit C4 Reaction product of phthalic anhydride with 2 equivalents of di (hydrogenated tallow fatty amine) to the amide ammonium salt C5 Nonylphenol resin prepared by condensing a mixture of dodecylphenol with formaldehyde, Mw 2000 g / mol C6 Mixture of 2 parts C3 and 1 part C5 C7 Mixture of equal parts C4 and C5

Effectiveness of the additives

The CFPP value (according to EN 116, in ° C) of various biofuels according to the above table after addition of 1200 ppm, 1500 ppm and 2000 ppm additive mixture was determined. 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. Table 7: CFPP testing in a mixture of 75% by volume of test oil D1 and 25% by volume of test oil E1 (CP = -5.2 ° C, CFPP = -9 ° C) Ex. flow improvers Comb polymer / coadditive CFPP after addition of flow improver 50 ppm 100 ppm 150 ppm 200ppm 1 A2 150 ppm B1 -11 -18 -19 -22 2 A2 150 ppm B2 18 -19 -20 -21 3 A2 150 ppm B3 -21 -21 -21 -22 4 A2 150 ppm B4 -11 -15 -18 -20 5 (V) A2 150 ppm B5 -9 -9 -11 -17 6 (V) A2 150 ppm B6 -10 -13 -13 -15 7 A1 150 ppm B9 -19 -20 -22 -23 8th A1 100 ppm B10 -20 -20 -21 -23 9 A1 100 ppm B11 -19 -20 -20 -22 10 A1 100 ppm B12 -21 -22 -22 -23 11 A2 150 ppm B13 -18 -19 -19 -22 12 A2 75 ppm B3
75 ppm A4 -18 -20 -22 -25 13 (V) A2 150 ppm B14 -10 -11 -15 -20 14 (V) A2 - -11 -16 -17 -19 CFPP test in a mixture of 70% by volume of test oil D2 and 30% by volume of test oil E3 (CP = -5.8 ° C., CFPP = -12 ° C.) Ex. Ethylene copolymer comb polymer co-additive CFPP 100 ppm 150 ppm 200 ppm 300 ppm 15 80% A3 20% B1 150 ppm C6 -18 -20 -22 -22 16 80% A3 20% B2 150 ppm C6 -20 -21 -21 -24 17 80% A3 20% B3 150 ppm C6 -20 -22 -23 -27 18 80% A3 20% B4 150 ppm C6 -20 -22 -22 -23 19 75% A1 25% B7 150 ppm C7 -19 -21 -22 -24 20 85% A1 15% B8 150 ppm C7 -19 -22 -24 -25 21 80% A1 20% B11 150 ppm C6 -20 -22 -23 -25 22 80% A1 20% B12 150 ppm C6 -20 -23 -24 -26 23 (V) 80% A3 20% B6 150 ppm C6 -18 -19 -20 -20 24 (V) 80% A3 20% B5 150 ppm C6 -10 -14 -17 -18 25 (V) 80% A1 20% B14 150 ppm C7 -15 -16 -18 -22 26 (V) 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. Table 9: CFPP testing in a mixture of 80% by volume of test oil D3 and 20% by volume of test oil E2 (CP = -3.3 ° C., CFPP = -10 ° C.) Ex. Ethylene copolymer comb polymer CFPP 100 ppm 200 ppm 250 ppm 300 ppm 27 80% A3 20% B1 -16 -19 -24 -26 28 80% A3 20% B2 -20 -23 -25 -27 29 80% A3 20% B3 -21 -22 -24 -28 30 80% A1 20% B12 -21 -23 -25 -29 31 80% A3 20% B4 -19 -21 -23 -25 32 (V) 80% A3 20% B6 -15 -18 -22 -23 33 (V) 80% A3 20% B5 -10 -15 -17 -19 34 (V) 80% A1 20% B14 -15 -17 -19 -21 35 (V) 100% A1 - -11 -20 -22 -22

Claims (18)

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, and 0.001 to 5% by weight of a cold additive, comprising the constituents A and B in the weight ratio A:B = 20:1 to 1:20

   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 composed of

   B1) at least one olefin as monomer 1 which bears at least one C₈-C₁₈ alkyl radical on the olefinic double bond, and

   B2) at least one ethylenically unsaturated dicarboxylic acid as monomer 2 which bears at least one C₈-C₁₆ alkyl radical bonded via an amide and/or imide moiety, where the molar ratio B1):B2) is between 1.5:1 and 1:1.5,

   where the sum Q $$\mathrm{Q}={\displaystyle \sum _{\mathrm{i}}}{\mathrm{w}}_{\mathrm{1}\mathrm{i}}\cdot {\mathrm{n}}_{\mathrm{1}\mathrm{i}}+{\displaystyle \sum _{\mathrm{j}}}{\mathrm{w}}_{\mathrm{2}\mathrm{j}}\cdot {\mathrm{n}}_{\mathrm{2}\mathrm{j}}$$

   

   
   of the molar averages of the carbon chain length distributions in the alkyl radicals of monomer 1 on the one hand and the alkyl radicals of the amide and/or imide groups of monomer 2 on the other is from 21.0 to 28.0, where

   w₁ is the molar proportion of the individual chain lengths in the alkyl radicals of monomer 1,

   w₂ is the molar proportion of the individual chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2,

   n₁ are the individual chain lengths in the alkyl radicals of monomer 1,

   n₂ are the individual chain lengths in the alkyl radical of the amide and/or imide groups of monomer 2,

   i is the serial variable for the individual chain lengths in the alkyl radicals of monomer 1, and

   j is the serial variable for the individual chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2.
2. A fuel oil composition as claimed in claim 1, wherein Q is from 22.0 to 27.0.
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 1 H 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 amides and/or imides of maleic acid, fumaric acid and/or itaconic acid.
8. A fuel oil composition as claimed in one or more of claims 1 to 7, wherein the amides and/or imides of constituent B are derived from primary amines.
9. A fuel oil composition as claimed in one or more of claims 1 to 8, wherein the amides and/or imides of constituent B are derived from amines having linear alkyl radicals.
10. A fuel oil composition as claimed in one or more of claims 1 to 9, wherein the amides and/or imides of constituent B are derived from monoamines.
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 which are derived from α-olefins.
12. A fuel oil composition as claimed in one or more of claims 1 to 11, wherein the mixing ratio A:B is between 10:1 and 1:10.
13. A fuel oil composition as claimed in one or more of claims 1 to 12, comprising polar nitrogen-containing paraffin dispersants.
14. A fuel oil composition as claimed in one or more of claims 1 to 13, wherein the fuel oil of animal or vegetable origin 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.
15. A fuel oil composition as claimed in claim 14, wherein the alcohol is methanol or ethanol.
16. A fuel oil composition as claimed in one or more of claims 1 to 15, wherein the fuel oil of animal or vegetable origin contains more than 4% by weight of esters of saturated fatty acids.
17. The use of 0.001 to 5% by weight of an additive as defined in one or more of claims 1 to 13 for improving the cold flow properties of mixtures of mineral fuel oils and fuel oils of animal or vegetable origin, wherein the proportion of fuel oil of animal or vegetable origin is between more than 2 and 35% by volume.
18. A process for producing fuel oil compositions F comprising fuel oils of mineral (F1) and animal and/or vegetable (F2) origin, having improved cold flow properties, by adding 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, wherein the proportion of fuel oil of animal or vegetable origin is between more than 2 and 35% by volume.