EP2516605A2

EP2516605A2 - Multifunctional cooling additives for middle distillates, having an improved flow capability

Info

Publication number: EP2516605A2
Application number: EP10800881A
Authority: EP
Inventors: Matthias Krull; Werner Reimann; Stefan Dilsky; Sabine Goetzke
Original assignee: Clariant Finance BVI Ltd
Current assignee: Clariant Finance BVI Ltd
Priority date: 2009-12-24
Filing date: 2010-12-07
Publication date: 2012-10-31
Anticipated expiration: 2030-12-07
Also published as: CN102639682B; RU2540279C2; ES2494591T3; KR20120123261A; CN102639682A; US9150808B2; US20120304532A1; WO2011076337A2; CA2785463C; DE102009060389A1; CA2785463A1; WO2011076337A3; RU2012131475A; JP2013515792A; EP2516605B1; JP5709321B2; KR101650292B1

Abstract

The present invention relates to cooling additives for middle distillates, containing A) at least one polyester of formula (A1) wherein one of the radicals R¹ to R⁴ represents a linear C₁₆-C₄₀ alkyl or alkenyl radical and the remainder of the radicals R¹ to R⁴ represent, independently of one another, hydrogen or an alkyl radical having 1 to 3 C atoms, R⁵ is a C-C bond or an alkylene radical having 1 to 6 C atoms, R¹⁶ is a hydrocarbon group having 2 to 10 carbon atoms, n is an integer from 1 to 100, m is an integer from 3 to 250, p is 0 or 1, and q is 0 or 1, B) at least one copolymer of ethylene and of at least one ethylenically unsaturated ester, the copolymer having a melt viscosity, measured at 140 °C, of at most 5000 mPas, and C) at least one organic solvent.

Description

description

The present invention relates to cold additives for middle distillates having improved low temperature handleability

Use for improving the cold properties of middle distillates, and the corresponding middle distillates. In the course of decreasing world oil reserves, increasingly heavier and thus paraffin-rich crude oils are extracted and processed, which consequently also contribute to

lead paraffin-rich fuel oils. The particular in crude oils and

Paraffins containing middle distillates such as gas oil, diesel and fuel oil may crystallize as the temperature of the oil decreases and agglomerate with the inclusion of oil. Due to this crystallization and agglomeration, blockages of the filters in engines and firing systems can occur, especially in winter, thereby preventing a safe metering of the fuels and under

Circumstances, a complete interruption of fuel or Heizmittelzufuhr can occur. Usually already 0.1 to 0.3 wt .-% of crystallized paraffins in the oil from to block fuel filter. The paraffin problem is further exacerbated by the environmental reasons to reduce the sulfur content to be carried out hydrogenating desulfurization of fuel oils, which leads to an increased proportion of cold-critical paraffins and a reduced proportion of the solubility of paraffins-improving mono- and polycyclic aromatic compounds in the fuel oil.

To improve the cold flow properties of middle distillates are often added chemical additives, so-called cold flow improvers or flow improvers, modify the crystal structure and Agglomerationsneigung the precipitated paraffins, so that the so-additive oils still at

Pump or use temperatures that are often more than 20 ° C lower than non-additivated oils. As cold flow improvers, oil-soluble copolymers of ethylene and unsaturated esters are usually used. Thus, for example, according to DE-A-11 47 799 petroleum distillate fuels having a boiling range between about 120 and 400 ° C oil-soluble copolymers of ethylene and vinyl acetate having a molecular weight between about 1,000 and 3,000 to. Preference is given to copolymers which contain about 60 to 99% by weight of ethylene and about 1 to 40% by weight of vinyl acetate.

For the addition of middle distillates with a high content of

In particular, longer-chain paraffins, these copolymers of ethylene and unsaturated esters are often used together with comb polymers. Comb polymers are understood to mean a special form of the branched macromolecules which, at more or less regular intervals, are longer, more or less the same length, on a linear main chain

Carry alkyl side chains. Often when common use of

Copolymers of ethylene and unsaturated esters with comb polymers reported synergistically enhanced activities as cold additives, presumably due to a paraffin crystallization nucleating function of these comb polymers. These occur in particular when using comb polymers with very long side chains.

US 3,447,916 discloses condensation polymers

Alkenylsuccinic anhydrides, polyols and fatty acids to lower the pour point of hydrocarbon oils. These polymers have a high side chain density due to the almost complete esterification of the hydroxyl groups of the polyol. The font gives no indication of the common use with other additives.

DE-A-19 20 849 discloses condensation polymers

Alkenylsuccinic anhydrides, polyols having at least 4 OH groups and fatty acids to lower the pour point of hydrocarbon oils. Preferably, the stoichiometry of the reactants used for the condensation is selected so that the number of moles of OH groups and carboxyl groups is the same, that is, there is essentially complete esterification. Because of the engagement polyhydric alcohols and the associated further increase in the

Side chain density, these polymers, according to the disclosures of the disclosure a superior to the additives of US-3447916 efficacy. Also, this document gives no indication of the common use with other additives.

DE-A-24 51 047 discloses light, low viscosity distillate fuel oils which contain no residues and are additized with ethylene copolymers and comb polymers having Ci8-C44 side chains. As comb polymers, inter alia ester condensation polymers of alk (en) ylsuccinic anhydride with a Ci6-C4 ₄ -Alk (en) ylrest, a polyol having 2-6 OH groups and a C2o ~ C-44 monocarboxylic acid are used. The three components of the polyester are preferably condensed in equimolar amounts, so that it is an im

Essentially complete esterification of OH as well as COOH groups comes. By way of example (polymer G) is a polycondensate of equimolar amounts of C22-28 alkenyl succinic anhydride, trimethylolpropane and C20-22

Föttc i 1ran

The use of polyols with more than two OH groups leads to the

Polycondensation, however, usually to proportions of branched,

high molecular weight and partially cross-linked structures that impair the solubility of the additives and the filterability of the oils additized with them. By suitable reaction procedure in the preparation of the ester can be counteracted this problem only incomplete. To improve their handleability, additive combinations of copolymers of ethylene and unsaturated esters and comb polymers used to improve the cold properties of middle distillates are commonly used as concentrates in organic solvents. It is particularly important for the use of such additive concentrates in remote locations where there is often no way to heat the additive concentrates, important that they remain flowable at the lowest possible temperature and einmischbar in also cold fuel oils. At the same time, but also the

Concentration of active substance in the concentrates should be as high as possible to increase the volume keep the additive concentrates to be transported and stored as low as possible.

The comb polymers of the prior art prepared by polycondensation show as concentrates in organic solvents as well as in

Blend with copolymers of ethylene and unsaturated esters in

organic solvents often have comparatively high eigenstock points of more than 20 ° C. However, at petrol stations as well as in remote areas such as mountains or in Arctic regions, it is often not possible to store the additive concentrates heated. A dilution of the additives is undesirable for logistical reasons, since then the volumes to be transported and stored strongly increase. In addition, in particular, the comb polymers derived from polyols having 3 or more OH groups often contain relatively high molecular weight fractions which impair the filterability of additized middle distillates.

Consequently, there is a need for highly effective and low ones

Ambient temperatures can be easily handled for cold additives

Middle distillates whose cold flow properties as low as possible

Improve dispensing rates. These additives should also be soluble at low temperatures and easily soluble in the middle distillate to be added. In addition, they should not affect the filterability of the additized middle distillates or at least as little as possible. Surprisingly, it has been found that additive combinations, the solutions or dispersions of copolymers of ethylene and unsaturated esters as well as polyesters produced by polycondensation linear C ₁₆ -C ₄ o-alkyl or Ci ₆ -C ₀ alkenyl radicals carrying dicarboxylic acids or dicarboxylic anhydrides and diols produced in organic polyester Contain solvents, even at low temperatures of below 10 ° C, often below 0 ° C partially below -10 ° C such as at -20 ° C and below in concentrated form flowable and readily soluble in middle distillates. In addition, they have excellent properties as

Cold flow improvers without the filterability of the oils additivated with them affect. Often, the efficacy as a cold flow improver is improved over the prior art comb polymers, which is evidently improved and thus improved on the lowered density of side chains

Interaction with the waxing out of the oil paraffins

is due.

The invention provides cold additives for middle distillates, containing A) at least one polyester of the formula

wherein

one of the radicals R ¹ to R ^{4 is} a linear C ₆ -C 40 -alkyl or alkenyl radical and

the rest of the radicals R ¹ to R ⁴ independently of one another represent hydrogen or an alkyl radical having 1 to 3 C atoms,

R ^{5 is} a CC bond or an alkylene radical having 1 to 6 C atoms, R ^{16 is} a hydrocarbon group having 2 to 10 carbon atoms, n is a number from 1 to 100,

m for a number from 3 to 250,

p for 0 or 1, and

q is 0 or 1,

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester, wherein the copolymer has a measured at 140 ° C melt viscosity of at most 5,000 mPas, and

C) at least one organic solvent.

Another object of the invention is a method for improving the cold flow properties of fuel oils by adding a cold additive to a middle distillate, the at least one polyester of the formula

wherein

one of the radicals R to R ⁴ for a linear Ci6-C4o-alkyl or alkenyl radical and

the rest of the radicals R to R ⁴ independently of one another represent hydrogen or an alkyl radical having 1 to 3 C atoms,

R ^{5 is} a C-C bond or an alkylene radical having 1 to 6 C atoms, R ^{16 is} a hydrocarbon group having 2 to 10 carbon atoms, n is a number from 1 to 00,

m for a number from 3 to 250,

p for 0 or 1, and

q is 0 or 1,

C) at least one organic solvent

contains.

Another object of the invention are fuel oils containing

Itteldestillat and a cold additive, the

A) at least one polyester of the formula

wherein

one of the radicals R ¹ to R ⁴ for a linear Ci6-C4o-alkyl or alkenyl radical and

m for a number from 3 to 250,

p for 0 or 1, and

q is 0 or 1,

C) at least one organic solvent

includes.

Preferred dicarboxylic acids suitable for the preparation of the polyesters A) correspond to the general formula 1

R ¹ R ³ HOOC- C- R ⁵ - C- COOH

I i

wherein

one of the radicals R ¹ to R ⁴ for a linear C ₆ -C ₄ o-alkyl or alkenyl radical and the remaining of the radicals R ¹ to R ⁴ independently of one another represent hydrogen or an alkyl radical having 1 to 3 C atoms, and

R ^{5 is} a CC bond or an alkylene radical having 1 to 6 C atoms. Particularly preferably, one of the radicals R to R ^{4 is} a linear C ₁₆ -C ₄ o-alkyl or alkenyl radical; together also referred to as Ci ₆ -C ₄₀ -Alk (en) ylrest, one for a methyl group and the remaining hydrogen. In a specific embodiment, one of the radicals R ¹ to R ^{4 is} a linear one

Ci6-C ₄₀ alkyl or alkenyl radical and the others are hydrogen. In a particularly preferred embodiment, R ^{5 is} a CC single bond.

In particular, one of the radicals R ¹ to R ^{4 is} a linear C ₆ -C 40 -alkyl or alkenyl radical, the remaining radicals R ¹ to R ^{4 are} hydrogen and R ^{5 is} a

C-C single bond.

The preparation of the dicarboxylic acids or their anhydrides bearing alkyl and / or alkenyl radicals can be carried out by known processes. Thus, for example, they can be prepared by heating ethylenically unsaturated dicarboxylic acids with olefins ("ene reaction") or with chloroalkanes Preferred is the thermal addition of olefins to ethylenically unsaturated dicarboxylic acids, which is usually carried out at temperatures between 100 and 250.degree. The resulting alkenyl radicals bearing dicarboxylic acids and

Dicarboxylic acid anhydrides can be hydrogenated to dicarboxylic acids bearing dicarboxylic acids and dicarboxylic acid anhydrides. Preferred dicarboxylic acids and their anhydrides for the reaction with olefins are maleic acid and particularly preferably maleic anhydride. Also suitable are itaconic acid,

Citraconic acid and its anhydrides and the esters of the aforementioned acids, in particular with lower C-i-Ce alcohols such as methanol, ethanol, propanol and butanol.

For the preparation of the dicarboxylic acids or their anhydrides carrying alkyl radicals, preference is given to using linear olefins having 16 to 40 C atoms and especially having 18 to 36 C atoms, for example having 19 to 32 C atoms. In a particularly preferred embodiment, mixtures of olefins with different chain lengths are used. Preference is given to using mixtures of olefins and, in particular, of α-olefins having 18 to 36 carbon atoms, for example mixtures in the range C20-C22, C20-C24, C24-C28. C26-C28. C30-C36. These olefins may also minor portions of shorter and / or contain longer-chain olefins, but preferably not more than 10 wt .-% and in particular not more than 0.1 to 5 wt .-%. Preferred olefins have a linear or at least substantially linear alkyl chain. Under linear

or largely linear is understood that at least

50 wt .-%, preferably 70 to 99 wt .-%, in particular 75 to 95 wt .-% such as 80 to 90 wt .-% of olefins have a linear portion having 16 to 40 carbon atoms. Suitable olefins are preferably technical alkene mixtures. These preferably contain at least 50 wt .-%, particularly preferably 60 to 99 wt .-% and in particular 70 to 95 wt .-% such as 75 to 90 wt .-% terminal double bonds (α-olefins). In addition, they may contain up to 50% by weight, preferably 1 to 40% by weight and especially 5 to 30% by weight, for example 10 to 25% by weight of olefins having an internal double bond, for example vinylidene double bonds with the structural element

R ¹⁷ - CH = C (CH ₃ ) ₂ , where R ^{17 is} an alkyl radical having 2 to 36 carbon atoms and especially having 14 to 32 carbon atoms, such as having 15 to 28 carbon atoms. Furthermore, minor amounts of technical reasons

Minor components such as paraffins, but preferably not more than 5% by weight. Particularly preferred are olefin mixtures containing at least 75 wt .-% of linear α-olefins having a C chain length in the range of C ₂ o to C ₂ .

Preferred polyesters A) are transmitted by reacting a linear C ₆ -C ₄ o-alkyl or alkenyl alkyl or alkenyl succinic acids and / or anhydrides thereof with diols to produce.

In a first preferred embodiment, n is 1. Preferred such diols have 2 to 10 C atoms, particularly preferably 2 to 6 C atoms and in particular 2 to 4 C atoms. They can be derived from aliphatic or aromatic hydrocarbons. Preferably contain the

Hydrocarbon radicals no further heteroatoms. The hydroxyl groups are located on different C atoms of the hydrocarbon radical. They are preferably located on adjacent C atoms or on the terminal ones

C atoms of an aliphatic hydrocarbon radical or in ortho and para position of an aromatic hydrocarbon radical. aliphatic

Hydrocarbon radicals are preferred. The aliphatic hydrocarbon radicals can be linear, branched or cyclic. Favor are linear. Further preferably, they are saturated. Examples of preferred diols are ethylene glycol, 1,2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1,4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol and mixtures thereof. Particularly preferred is ethylene glycol.

In a second preferred embodiment, n is a number from 2 to 100, more preferably from 3 to 50, and most preferably from 4 to 20, such as from 5 to 15. In this

In an embodiment, the diols are preferably oligomers and polymers of C 2 -C 4 -alkylene oxides and in particular oligomers and

Polymers of ethylene oxide and / or propylene oxide. Preferably, the

Degree of condensation of these oligomers and polymers between 2 and 100, more preferably between 3 and 50, and especially between 4 and 20, for example between 5 and 15. Examples of preferred oligomers and polymers of C 2 -C 4 -alkylene oxides are diethylene glycol, triethylene glycol,

Tetraethylene glycol, poly (ethylene glycol), poly (propylene glycol), poly (ethylene glycol co-propylene glycol) and mixtures thereof.

The reaction of the dicarboxylic acids carrying the alkyl radicals or their anhydrides or their esters with the diol is preferably carried out in a molar ratio of 1: 2 to 2: 1, more preferably in a molar ratio of 1: 1, 5 to 1, 5: 1, in particular molar ratio of 1: 1, 2 to 1.2: 1 and especially in the molar ratio of 1: 1, 1 to 1, 1: 1 such as equimolar. Particularly preferably, the reaction is carried out with a slight excess of diol. In this case, molar excesses of 1 to 10 mol% and especially 1, 5 to 5 mol% based on the amount of dicarboxylic acid used have proven particularly useful. The condensation is preferably carried out by heating of Ci ₆ -C ₄ o-alkyl or

Alkenylsubstituierter dicarboxylic acid or its anhydride or ester with the diol to temperatures above 100 ° C and preferably to temperatures between 120 and 320 ° C such as at temperatures between 150 and 290 ° C. To set the important for the effectiveness of molecular weight of the polyester A) is usually the removal of water of reaction or alcohol

required, which can be done for example by distillation separation. Azeotropic separation by means of suitable organic solvents is also suitable. To accelerate the polycondensation, it has often proven useful to add catalysts to the reaction mixture. Suitable catalysts are known acidic, basic as well as organometallic compounds.

The acid number of the polyesters A) is preferably less than 40 mg KOH / g and particularly preferably less than 30 mg KOH / g, for example less than 20 mg KOH / g. The acid value can be determined, for example, by titration of the polymer with alcoholic tetra-n-butylammonium hydroxide solution in xylene / isopropanol. Further preferably, the hydroxyl number of the polyester A) is below 40 mg KOH / g, more preferably below 30 mg KOH / g and

especially below 20 mg KOH / g. The hydroxyl number can after reacting the free OH groups with! Socyanat by means of ¹ H NMR spectroscopy

quantitative determination of the urethane formed.

In a preferred embodiment, in the reaction mixture to

Adjustment of the molecular weight minor amounts of the dicarboxylic acids carrying the alkyl radicals, their anhydrides or their esters by C to

C3o-monocarboxylic acids, particularly preferably C2- to Cie-monocarboxylic acids, in particular C2- to C16-monocarboxylic acids and especially C3- to

Ci4 monocarboxylic acids such as C4 to Ci2 monocarboxylic acids or their esters replaced with lower alcohols. However, at most 20 mol% and preferably 0.1 to 10 mol% such as 0.5 to 5 mol% of the alk (en) ylreste bearing dicarboxylic acids or their anhydrides or their esters are replaced by a monocarboxylic acid or its esters , Also mixtures of different carboxylic acids are suitable. After the polycondensation, the hydroxyl value of the polymer is preferably less than 10 mg KOH / g, and more preferably less than 5 mg KOH / g, such as less than

2 mg KOH / g. Particularly preferably, the polyesters A) are prepared in the absence of monocarboxylic acids. Furthermore, minor amounts such as up to 10 mol% and in particular 0.01 to 5 mol% of the alkyl radicals carrying dicarboxylic acids whose anhydrides or their esters are also replaced by other dicarboxylic acids such as succinic acid, glutaric acid, maleic acid and / or fumaric acid. In a further preferred embodiment, in the reaction mixture to adjust the molecular weight minor amounts of the diol by Cr to C ₃₀ monohydric alcohols, more preferably C ₂ to C ₂ 4 monoalcohols and especially C3 to C-ie monoalcohols such as C4 bis Replaced Ci2 mono alcohols. Also mixtures of different alcohols are suitable. After the polycondensation, the acid value of the polymer is preferably less than 10 mg KOH / g and in particular less than 5 mg KOH / g, for example less than 2 mg KOH / g. In this case, at most 20 mol% and particularly preferably 0.1 to 10 mol%, for example 0.5 to 5 mol% of the polyol, are replaced by one or more monoalcohols. Particularly preferably, the polyesters A) are prepared in the absence of monoalcohols.

The mean degree of condensation m of the polymers A1 according to the invention is preferably between 4 and 200, more preferably between 5 and 150, and especially between 7 and 100, for example between 10 and 50. The weight average determined by GPC against poly (ethylene glycol) standard

Mw of the polyester A) is preferably between 1,500 and 100,000 g / mol and in particular between 2,500 and 50,000 g / mol as

for example, between 4,000 and 20,000 g / mol. Preferred copolymers of ethylene and olefinically unsaturated esters B) are, in particular, those which contain, in addition to ethylene, from 8 to 21 mol% and in particular from 10 to 19 mol% of olefinically unsaturated esters as comonomers.

The olefinically unsaturated esters are preferably

Vinyl esters, acrylic esters and / or methacrylic esters. One or more esters may be included as comonomers in the polymer.

The vinyl esters are preferably those of the formula 2 CH ₂ = CH - OCOR ¹² (2) where R ^{12 is} Ci to C ₃ oA! Alkyl, preferably Ci to Ci ₆ alkyl, especially Cr to C ₁₂ alkyl. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups.

Particularly preferred vinyl esters are derived from secondary and especially tertiary carboxylic acids whose branching in alpha position to

Carbonyl group is located. Preferably, R ¹² is ₆ -alkyl and especially C ₆ these Vinylestern C for ₄ to Ci - to Ci2 alkyl. In a further preferred

In the embodiment, R ^{12 is} a branched alkyl radical or a neoalkyl radical having 7 to 11 carbon atoms, in particular having 8, 9 or 10 carbon atoms. Suitable vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate,

Vinyl isobutyrate, vinyl hexanoate, vinyl heptanoate, vinyl octanoate,

Vinyl pivalate, vinyl 2-ethylbenzoate, vinyl laurate, vinyl stearate and versatic acid esters such as vinyl neononanoate,

Vinyl neodecanoate, vinyl neoundecanoate. In a further preferred embodiment, these ethylene

Copolymers of vinyl acetate and at least one further vinyl ester of the formula 2 in which R ^{12 is} C ₄ - to C ₃₀ -alkyl, preferably C ₄ to C ₁₆ -alkyl, especially C ₆ - to

Ci ₂ alkyl. The further vinyl esters are particularly preferably branched in the alpha position.

For the acrylic and methacrylic esters, hereinafter referred to as (meth) acrylic esters

summarized, they are preferably those of the formula 3

CH ₂ = CR ¹³ - COOR ¹⁴ (3) where R ^{3 is} hydrogen or methyl and RC to C ₃ o-alkyl, preferably C ₄ - to C ₆ -alkyl, especially C ₆ - to C- | _2- alkyl. Suitable acrylic esters include, for. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- and Iso-butyl (meth) acrylate, hexyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl (meth) acrylate and mixtures of these comonomers. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups. An example of such an acrylic ester is hydroxyethyl methacrylate.

The copolymers B) may contain other olefinically unsaturated compounds as comonomers in addition to olefinically unsaturated esters. Preferred comonomers of this type are alkyl vinyl ethers and alkenes.

The alkyl vinyl ethers are preferably compounds of the formula 4

CH ₂ = CH - OR ¹⁵ (4) wherein R ^{15 is} C ₃ to C ₃ o-alkyl, preferably C ₄ to C-1 ₆ alkyl, especially C6 bis

Ci2-alkyl. Examples which may be mentioned are methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups.

The alkenes are preferably monounsaturated

Hydrocarbons having 3 to 30 carbon atoms, in particular 4 to

16 carbon atoms and especially 5 to 12 carbon atoms. Suitable alkenes include propene, butene, isobutylene, pentene, hexene, 4-methylpentene, octene, diisobutylene and norbornene and its derivatives such as methylnorbornene and vinylnorbornene. In a further embodiment, the mentioned

Alkyl groups substituted with one or more hydroxyl groups.

Particularly preferred are terpolymers which except Ethyleh 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 at least one long-chain and preferably branched Vinyl esters such as vinyl 2-ethylhexanoate,

Vinyl neononanoate or vinyl neodecanoate, the total comonomer content of the terpolymers is preferably between 8.1 and 21 mol%, in particular between 8.2 and 19 mol%, for example between 12 and 18 mol%. Until Ci ₂ carboxylic acids 0.5 to 10 mol% olefins, such as propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene - Further particularly preferred copolymers contain, in addition to ethylene and from 8 to 18 mol% of C ₂ Vinylestern and / or norbornene wherein the total comonomer content is preferably between 8.5 and 21 mol% and in particular between 8.2 and 19 mol%. Preferably, these ethylene-co- and terpolymers have melt viscosities at 140 ° C from 20 to 2,500 mPas, in particular from 30 to 1, 000 mPas, especially from 50 to 500 mPas. The determined by ¹ H NMR spectroscopy

Degrees of branching are preferably between 1 and 9 CH _3/100 Chb groups, in particular 2-6 CH3 / IOO CHFE-groups which are not from the

Comonomers come.

Preference is given to using mixtures of two or more of the abovementioned ethylene copolymers. Particularly preferably, the polymers underlying the mixtures differ in at least one

Characteristic. For example, they may contain different comonomers, have different comonomer contents, molecular weights and / or degrees of branching. Thus, for example, mixtures of ethylene copolymers having different comonomer contents have proved particularly suitable, the comonomer contents of which are at least 2 mol% and

in particular more than 3 mol% differ.

The cold additives of the invention preferably contain 25 to 95 wt .-% and preferably 28 to 80 wt .-%, such as 35 to 70 wt .-% of at least one organic solvent C). Preferred solvents are higher-boiling, low-viscosity organic solvents. Preferably, these solvents contain only minor amounts of heteroatoms and especially they consist only of hydrocarbons. Further preferred is their measured at 20 ° C kinematic viscosity below 10 mm ² / s and in particular below 6 mm ² / s. Particularly preferred solvents are aliphatic and aromatic hydrocarbons and mixtures thereof. Aliphatic hydrocarbons preferred as solvents have 9 to 20 C atoms and in particular 10 to 16 C atoms. They can be linear, branched and / or cyclic. They may also be saturated or unsaturated, preferably they are saturated or at least largely saturated. As solvent preferred aromatic

Hydrocarbons have 7 to 20 carbon atoms and especially 8 to 16 such as 9 to 13 carbon atoms. Preferred aromatic hydrocarbons are mono-, di-, tri- and polycyclic aromatics. These carry in one

preferred embodiment one or more such as two, three, four, five or more substituents. With several substituents they may be the same or different. Preferred substituents are alkyl radicals having 1 to 20 and in particular having 1 to 5 C atoms, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl , n-pentyl, iso-pentyl, tert-pentyl and neo-pentyl. Examples of suitable aromatics are

A! Ky! Benzo! E and alkylnaphthaene. For example, aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, for. B.

Benzine fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercial solvent mixtures such as Solvent Naphtha, Shellsoll ^® AB, Solvesso ^® 150, Solvesso ^® 200, Exxsol ^® , ISOPAR ^® and Shellsol ^® D types particularly suitable. The specified solvent mixtures contain different amounts of aliphatic and / or aromatic hydrocarbons.

Optionally, the solvent C) and polar solubilizers such. As alcohols, organic acids, ethers and / or esters of organic acids. Preferred solubilizers have 4 to 24 carbon atoms, particularly preferably 6 to 18 and in particular 8 to 16 carbon atoms. Examples of suitable solubilizers are butanol, 2-ethylhexanol, decanol, iso-decanol, iso-tridecanol, nonylpenol, benzoic acid, oleic acid, dihexyl ether, dioctyl ether, 2-ethylhexyl acid butyrate, ethyl octanoate, ethylhexanoate, butyl 2-ethylhexylate and 2-ethylhexyl butyrate and higher Ethers and / or higher esters such as di- (2-ethylhexyl) ether, 2-ethylhexyl acid-2-ethylhexyl ester and

2-ethylhexyl. The proportion of polar solubilizers on the solvent C) is preferably from 5 to 80% by weight and in particular from 10 to 65% by weight. In addition to the Mineral oils based solvents are also based on renewable raw materials solvents such. As biodiesel based on vegetable oils and the derived methyl esters, in particular rapeseed, as well as synthetic hydrocarbons, which are obtainable for example from the Fischer-Tropsch process, suitable as solvent C). Mixtures of the solvents mentioned are also suitable.

The cold additives of the invention preferably contain from 1, 5 to 73.5, in particular 15 to 70 and especially 25 to 60 wt .-% of component B).

The cold additives according to the invention preferably contain 0.1 to 50, in particular 0.5 to 30 and especially 1 to 20 wt .-% of the component A).

The cold additives according to the invention are preferably added to middle distillates in amounts of 0.001 to 1.0% by weight, more preferably 0.002 to 0.5% by weight, for example 0.005 to 0.2% by weight.

The cold additives according to the invention can be used together with one or more further cold flow improvers. They are preferably used together with one or more of the cold flow improvers III) to VII):

As a further cold flow improver, oil-soluble polar nitrogen compounds (constituent III) are suitable. These are preferably

Reaction products of fatty amines with compounds containing an acyl group. The preferred amines are compounds of the formula NR ⁶ R ⁷ R ⁸ wherein R ^6, R ⁷ and R ⁸ may be the same or different, and at least one of these groups is C ₈ -C ₃ 6-alkyl, C ₆ C ₃ 6 cycloalkyl, C ₈ -C ₃₆ - alkenyl, in particular C ₂ -C ₂ 4-alkyl, Ci2-C ₂ 4 alkenyl or cyclohexyl, and the remaining groups are either hydrogen, CrC ₃ 6-alkyl, C ₂ -C ₃₆ alkenyl, cyclohexyl, or a group of the formulas - (Α-Ο) χ-Ε or - (CH ₂ ) _k -NYZ, where A is an ethyl or propyl group, x is an integer from 1 to 50, e = H, Ci-C ₃₀ alkyl, C ₅ -C ₁₂ cycloalkyl or C ₆ -C ₃₀ aryl, and k = 2, 3 or 4 and Y and Z independently of one another denote H, CC ₃ o-alkyl or - (A-O) _x . The alkyl and alkenyl radicals can be linear or branched and contain up to two double bonds. They are preferably linear and substantially saturated, ie they have iodine numbers of less than 75 g / g, preferably less than 60 gb / g and in particular between 1 and 10 g / g. Particular preference is given to secondary fatty amines in which two of the groups R ⁶ , R ⁷ and R ^{8 are} C 8 -C 36 -alkyl, C 6 -C 36 -cycloalkyl, C 8 -C 36 -alkenyl, in particular C 12 -C 24 -alkyl, C 12 -C ₂ 4-alkenyl or cyclohexyl and the third are hydrogen. Suitable fatty amines are, for example, octylamine, decylamine, dodecylamine,

Tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, behenylamine, didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine,

Dioctadecylamine, dieicosylamine, dibehenylamine and mixtures thereof.

Specifically, the amines contain chain cuts based on natural raw materials such. Cocosfettamine, tallow fatty amine, hydrogenated tallow fatty amine, dicocosfettamine, ditallow fatty amine and di (hydrogenated tallow fatty amine). Especially preferred

Amine derivatives are amine salts, imides and / or amides such as amide ammonium salts of secondary fatty amines, especially dicocosfettamine, ditallow fatty amine and distearylamine. By acyl group is meant here a functional group of the following formula:

> C = 0

Carbonyl compounds suitable for reaction with amines are both monomeric and polymeric compounds having one or more

Carboxyl groups. In the case of the monomeric carbonyl compounds, preference is given to those having 2, 3 or 4 carbonyl groups. They can also contain heteroatoms such as oxygen, sulfur and nitrogen. Examples of suitable carboxylic acids are maleic, fumaric, crotonic, itaconic, succinic, C 1 -C ₄₀ -alk (en) ylsuccinic, adipic, glutaric, sebacic, and malonic acids

Benzoic, phthalic, trimellitic and pyromellitic acid, nitrilotriacetic acid,

Ethylenediaminetetraacetic acid and its reactive derivatives such as esters, anhydrides and acid halides. As polymeric carbonyl compounds have in particular copolymers of ethylenically unsaturated acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and

Itaconic proved, particularly preferred are copolymers of

Maleic anhydride. Suitable comonomers are those which are the

Confer copolymer oil solubility. Oil-soluble is understood here to mean that the copolymer, after reaction with the fatty amine, becomes practically relevant

Dosing rates residue-free dissolved in the middle distillate to be added. Suitable comonomers are, for example, olefins, alkyl esters of acrylic acid and

Methacrylic acid, alkyl vinyl esters and alkyl vinyl ethers having in each case 2 to 75, preferably 4 to 40 and in particular 8 to 20 carbon atoms in the alkyl radical. In the case of olefins, the carbon number refers to the alkyl radical attached to the double bond. The molecular weights of the polymeric carbonyl compounds are preferably between 400 and 20,000, more preferably between 500 and 0,000, for example between 1,000 and 5,000.

Oil-soluble polar nitrogen compounds which have been obtained by reaction of aliphatic or aromatic amines, preferably long-chain aliphatic amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides have proven particularly suitable (compare US Pat. No. 4,211,534). The same are amides and ammonium salts of

Aminoalkylenpolycarbonsäuren such as nitrilotriacetic acid or

Ethylenediaminetetraacetic acid with secondary amines suitable as oil-soluble polar nitrogen compounds (see EP-A-0 398 101). Other oil-soluble polar nitrogen compounds are copolymers of maleic anhydride with α, β-unsaturated compounds, optionally with primary

Monoalkylamines and / or aliphatic alcohols can be reacted (see, EP-A-0 154 177, EP-A-0 777 712), the reaction products of

Alkenylspirobislactonen with amines (see EP-A-0 413 279 B1) and after

EP-A-0 606055 A2 Reaction products of terpolymers based on

α, β-unsaturated dicarboxylic anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.

The mixing ratio between the cold additives of the present invention and oil-soluble polar nitrogen compounds as component III may vary depending on Use case vary. Such additive mixtures preferably contain from 0.1 to 10 parts by weight, preferably from 0.2 to 10 parts by weight, based on the active compounds

5 parts by weight of at least one oil-soluble polar nitrogen compound

(Component III) per part by weight of the additive combination of A) and B) according to the invention.

Other preferred further cold flow improvers are resins of alkyl radical-bearing phenol derivatives and aldehydes as constituent IV. In one

preferred embodiment of the invention are phenol-formaldehyde resins, the oligo- or polymers having a repetitive structural unit of the formula

wherein R ^{11 is} CC ₂ oo-alkyl or alkenyl, OR ¹⁰ or OC (O) -R ¹⁰ , R ^{0 is}

Ci-C2oo-alkyl or alkenyl and h is a number from 2 to 100 contained. R ¹¹ is preferably -C ₂ o alkyl or alkenyl and especially C4-Ci ₆ alkyl or alkenyl such as, for example, C6-Ci2 alkyl or alkenyl. Particularly preferably, R ^{11 is} C ₁ -C 20 -alkyl or alkenyl and in particular C ₄ -C- ₆ - alkyl or alkenyl such as for C6-C-i2-alkyl or alkenyl. Preferably h is a number from 2 to 50 and especially a number from 3 to 25, for example a number from 5 to 15.

In a particularly preferred embodiment, constituent IV are those resins which are derived from alkylphenols having one or two alkyl radicals in ortho and / or para position to the OH group. Particularly preferred starting materials are alkylphenols which carry at least two hydrogen atoms capable of condensation with aldehydes on the aromatic and in particular monoalkylated phenols. Particularly preferably, the alkyl radical is in the para position to the phenolic OH group. The alkyl radicals

(Among the constituent IV are generally understood hydrocarbon radicals as defined below) may be the same or different in the alkylphenol-aldehyde resins used in the process according to the invention, they may be saturated or unsaturated and have 1 - 200, preferably 1 - 20, especially 4 - 16 such as 6-12 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, tetradecyl, hexadecyl, octadecyl, tripropenyl, tetrapropenyl, poly (propenyl) - and poly (isobutenyl) radicals. In a preferred embodiment, mixtures of alkylphenols are used to prepare the alkylphenol resins

used different alkyl radicals. For example, resins based on butyphenol on the one hand and octyl, nonyl and / or dodecylphenol in a molar ratio of 1:10 to 10: 1, on the other hand, have proven particularly useful.

Resins suitable as constituent IV may also contain or consist of structural units of other phenol analogs, such as salicylic acid, hydroxybenzoic acid, aminophenol and derivatives thereof, such as esters, amides and salts.

Suitable aldehydes for the preparation of the resins are those with 1 to

12 carbon atoms and preferably those having 1 to 4 carbon atoms such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde, glyoxalic acid and their reactive equivalents such as paraformaldehyde and trioxane. Particularly preferred is formaldehyde in the form of paraformaldehyde and especially formalin.

The molecular weight of suitable resins measured by gel permeation chromatography against poly (styrene) standards in THF is preferred

500-25,000 g / mol, more preferably 800-10,000 g / mol and especially

1,000-5,000 g / mol such as 1,500-3,000 g / mol. A prerequisite here is that the resins, at least in application-relevant concentrations of 0.001 to 1 wt .-% are oil-soluble. These resins are accessible by known methods, e.g. B. by condensation of the corresponding alkyl radicals carrying phenol derivatives with formaldehyde. As a further cold flow improver also comb polymers are suitable. Such comb polymers (constituent V) can, for example, be represented by the formula

H H

M N are described. Mean in it

A R \ COOR ', OCOR', R '^ COOR', OR ';

DH, CH _3, A or R ";

E H, A;

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

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

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

R 'is a hydrocarbon chain of 8 to 50 carbon atoms;

R "is a hydrocarbon chain of 1 to 10 carbon atoms;

a is a number between 0.4 and 1, 0; and

b is a number between 0 and 0.6.

These are, in particular, addition polymers which are accessible by free-radical polymerization with CC bonding between the monomers. Suitable comb polymers are, for example, copolymers of ethylenically unsaturated dicarboxylic acids such as maleic or fumaric acid with other ethylenically unsaturated monomers such as olefins or vinyl esters such as vinyl acetate. Particularly suitable olefins are α-olefins having 10 to 36 carbon atoms and especially having 12 to 24 carbon atoms such as 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and mixtures thereof. Also, longer-chain olefins based on oligomerized C2-C6 olefins such as poly (isobutylene) with a high proportion of terminal

Double bonds are suitable as comonomers. Usually, these copolymers are at least 50% esterified with alcohols having 10 to 22 carbon atoms. Suitable alcohols include n-decan-1-ol, n-dodecan-1-ol, n-tetradecan-1-ol, n-hexadecan-1-ol, n-octadecan-1-ol, n-eicosan-1-ol and their mixtures. Particularly preferred are mixtures of n-tetradecane-1-ol and n-hexadecan-1-ol. Also suitable as comb polymers are poly (alkyl acrylates),

Poly (alkyl methacrylates) and poly (alkyl vinyl ethers), which are derived from alcohols having 12 to 20 carbon atoms and poly (vinyl esters), which are derived from fatty acids having 12 to 20 carbon atoms.

Also suitable as further cold flow improvers are homopolymers and copolymers of olefins having 2 to 30 C atoms (constituent VI). These can be derived directly from monoethylenically unsaturated monomers or indirectly by

Hydrogenation of polymers derived from polyunsaturated monomers such as isoprene or butadiene can be prepared. In addition to ethylene, preferred copolymers contain structural units which are derived from α-olefins having 3 to 24 carbon atoms and have molecular weights of up to 120,000 g / mol. Preferred cc-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 small amounts, for. B. up to 10 mol% of other comonomers such. B. non-terminal olefins or non-conjugated olefins. Particularly preferred are ethylene-propylene copolymers. Further preferred are copolymers of various olefins having 5 to 30 carbon atoms such as poly (hexene-co-decene). The olefin homo- and copolymers can be prepared by known methods, e.g. B. 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) _C A and (AB) _d , where c is a number between 1 and 10 and d is a number between 2 and 10.

Also suitable as further cold flow improvers are oil-soluble

Polyoxyalkylene compounds (ingredient VII) such as esters, ethers and ethers / esters of polyols bearing at least one alkyl radical having 12 to 30 carbon atoms. In a preferred embodiment, the oil-soluble ones

Polyoxyalkylenverbindungen at least 2, such as 3, 4 or

5 aliphatic hydrocarbon radicals. Preferably, these radicals have

independently of one another 16 to 26 carbon atoms, such as 17 to

24 C atoms. Preferably, these radicals are the oil-soluble

Polyoxyalkylene compounds linear. Further preferably, they are largely saturated, in particular, these are alkyl radicals. Esters are especially preferred.

Particularly suitable polyols according to the invention are polyethylene glycols,

Polypropylene glycols, polybutylene glycols and their copolymers having a molecular weight of about 100 to about 5,000 g / mol, preferably 200 to

2,000 g / mol. In a particularly preferred embodiment, the oil-soluble polyoxyalkylene compounds are derived from polyols having 3 or more

OH groups, preferably from polyols having from 3 to about 50 OH groups, for example from 4 to 10 OH groups, in particular from neopentyl glycol,

Glycerol, trimethylolethane, trimethylolpropane, sorbitan, pentaerythritol, as well as the resulting from condensation oligomers with 2 to

10 monomer units such. As polyglycerol. Also higher polyols like

For example, sorbitol, sucrose, glucose, fructose and their oligomers such as cyclodextrin are suitable as polyols, provided that their esterified or etherified alkoxylates are oil-soluble at least in application-relevant amounts. Preferred polyoxyalkylene compounds thus have a branched polyoxyalkylene nucleus attached to the multiple oil-solubilizing alkyl radicals are.

The polyols are generally reacted with from 3 to 70 mol of alkylene oxide, preferably from 4 to 50, in particular from 5 to 20, mol of alkylene oxide per hydroxyl group of the polyol. Preferred alkylene oxides are ethylene oxide, propylene oxide and / or butylene oxide. The alkoxylation is carried out by known methods.

The fatty acids which are suitable for the esterification of the alkoxylated polyols preferably have 12 to 30 and in particular 16 to 26 C atoms. suitable

Fatty acids are, for example, lauric, tridecane, myristic, pentadecane,

Palmitic, margarine, stearic, isostearic, arachinic and behenic acid, oleic and erucic acid, palmitoleic, myristoleic, ricinoleic acid and fatty acid mixtures derived from natural fats and oils. Preferred fatty acid mixtures contain more than 50 mol% of fatty acids having at least 20 carbon atoms. Preferably, less than 50 mol% of the fatty acids used for the esterification contain double bonds, in particular less than 10 mol%; they are special

largely saturated. The esterification can also be carried out starting from reactive derivatives of the fatty acids such as esters with lower alcohols (for example methyl or ethyl esters) or anhydrides.

For the purposes of the present invention, the term "iodine number" of the fatty acid or of the fatty alcohol used is understood to be largely saturated by up to 5 g of I per 100 g of fatty acid or fatty alcohol. Polyol and fatty acid are used for the esterification based on the content of hydroxyl groups on the one hand and carboxyl groups on the other hand in a ratio of 1, 5: 1 to 1: 1, 5, preferably in the ratio 1, 1: 1 to 1: 1, 1 and in particular equimolar. The acid number of the esters formed is generally below 15 mg KOH / g, preferably below 10 mg KOH / g, especially below 5 mg KOH / g. The OH number of the esters is preferably below 20 mg KOH / g and especially below

10 mg KOH / g. In a preferred embodiment, after the alkoxylation of the polyol, the terminal hydroxyl groups are converted, for example by oxidation or by reaction with dicarboxylic acids into terminal carboxyl groups. By reaction with fatty alcohols having 8 to 50, in particular 12 to 30, especially 6 to 26 carbon atoms, polyoxyalkylene esters according to the invention are likewise obtained. Preferred fatty alcohols or fatty alcohol mixtures contain more than

50 mol% fatty alcohols with at least 20 C atoms. Preferably, less than 50 mol% of the fatty alcohols used for the esterification contain double bonds, in particular less than 10 mol%; specifically, they are largely saturated. Also, esters of alkoxylated fatty alcohols with fatty acids which contain the abovementioned proportions of poly (alkylene oxides) and whose fatty alcohol and fatty acid have the abovementioned alkyl chain lengths and degrees of saturation are suitable according to the invention.

Furthermore, the above-described alkoxylated polyols can by

Etherification with fatty alcohols having 8 to 50, in particular 12 to 30, especially 16 to 26 C-atoms in accordance with the invention suitable polyoxyalkylene compounds are transferred. The preferred fatty alcohols are linear and

largely saturated. Preferably, the etherification takes place completely or at least largely completely. The etherification is carried out by known methods.

Particularly preferred polyoxyalkylene compounds are derived from polyols having 3, 4 and 5 OH groups, which carry about 5 to 10 mol of structural units derived from ethylene oxide per hydroxyl group of the polyol and as far as possible

are completely esterified with largely saturated Ci7-C24 fatty acids.

Further particularly preferred polyoxyalkylene compounds are with

largely saturated C ₁₇ -C ₂ 4 fatty acids esterified polyethylene glycols having molecular weights of about 350 to 1,000 g / mol. Examples of particularly suitable polyoxyalkylene compounds are stearic and in particular

Behenic acid esterified polyethylene glycols having molecular weights between 350 and 800 g / mol; Neopentyl glycol 14-ethylene oxide distearate (with 14 mol

Ethylene oxide alkoxylated and then esterified with 2 moles of stearic acid neopentyl glycol) and in particular neopentyl glycol-14-ethylene oxide dibehenate; Glycerol 20-ethylene oxide tristearate, glycerol 20-ethylene oxide dibehenate, and especially glycerol 20-ethylene oxide tribehenate; Trimethylolpropane-22-ethylene oxide tribehenate; Sorbitan 25-ethylene oxide tristearate, sorbitan 25-ethylene oxide tetrastearate, sorbitan 25-ethylene oxide tribehenate, and especially sorbitan 25-ethylene oxide tetrabehenate; Pentaerythritol-30-ethylene oxide tribehenate, pentaerythritol-30-ethylene oxide tetrastearate, and especially pentaerythritol-30-ethylene oxide tetrabehenate and pentaerythritol-20-ethylene oxide-10-propylene oxide tetrabehenate. The mixing ratio between the cold additives according to the invention and the other cold flow improvers IV, V, VI and VII is generally between 50: 1 and 1: 1, preferably between 10: 1 and 2: 1 by weight, based on the weights (A + B ): (IV, V, VI and VII). The inventive cold additives improve in particular the

Cold properties of such middle distillates obtained by distillation of crude oil and boiling in the range of about 150 to 410 ° C and in particular in the range of about 170 to 380 ° C or consist mainly of these, such as kerosene, jet fuel, diesel and heating oil. Typically, middle distillates contain about 5 to 50 wt .-%, such as about 10 to 35 wt .-% n-paraffins, of which the longer-chain crystallize on cooling and can affect the flowability of the middle distillate. The cold additives according to the invention are particularly advantageous in middle distillates with a high content of cold-critical constituents with an n-alkyl chain with one

C chain length of 16 and more C atoms. These include, for example, n-paraffins of fossil origin, but also n-paraffins obtained by hydrogenation or co-hydrogenation of animal and / or vegetable fats and esters of saturated fatty acids with lower alcohols such as methanol or ethanol. Especially in middle distillates with a content of more than 4 wt .-% and especially with 6 to 20 wt .-%, such as with 7 to 15 wt .-% of these cold-critical constituents, the cold additives of the invention have proven particularly useful. Particularly advantageous are the inventive

Refrigeration additives continue in such oils, which are only a very small proportion of very long-chain n-paraffins with 28 or more carbon atoms that are considered natural

Nucleators for paraffin crystallization act included. The cold additives according to the invention have proven particularly useful in oils which contain less than 1% by weight and especially less than 0.5% by weight, for example less than 0.3% by weight of long-chain n-paraffins with 28 or more C Contain atoms. Special advantages of the inventive cold additives in particular in such oils containing a high content of cold-critical constituents with an n-alkyl chain having 16 or more carbon atoms and at the same time a very small proportion of very long-chain n-paraffins with 28 or more carbon atoms , The content of n-paraffins and optionally other components critical to refrigeration, such as, for example, fatty acid methyl esters, is usually determined by means of

Gas chromatography determined. The compositions according to the invention are furthermore particularly advantageous in low boiling end middle distillates, ie in middle distillates which have 90% distillation points below 360 ° C., in particular 350 ° C. and in special cases below 340 ° C., and of

Further in such middle distillates, the boiling ranges between 20 and 90% distillation volume of less than 120 ° C and in particular less than 110 ° C. The middle distillates may also contain minor amounts, for example up to 40% by volume, preferably 1 to 20% by volume, especially 2 to 15, for example 3 to 10% by volume of the oils of animal and / or vegetable origin described in more detail below like for example

Contain fatty acid methyl ester. Preferably, the middle distillates contain no residues from the distillation of mineral oils such as residues from atmospheric distillation and / or vacuum distillation.

The cold additives of the invention are also for improving the low-temperature properties of fuels based on renewable raw materials

(Biofuels). By biofuels is meant oils obtained from animal and preferably vegetable material or both, and derivatives thereof, which can be used as fuel and especially as diesel or fuel oil. These are in particular

Triglycerides of fatty acids with 10 to 24 carbon atoms as well as those from them Transesterification of accessible fatty acid esters of lower alcohols such as methanol or ethanol.

Examples of suitable biofuels are rapeseed oil, coriander oil, soybean oil,

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

Particularly suitable as biofuels are lower alkyl esters of fatty acids. For example, commercially available mixtures of the ethyl, propyl, butyl and especially methyl esters of fatty acids having 14 to 22 carbon atoms, for example of lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroselinic acid, ricinoleic acid,

Elaeostearic, linoleic, linolenic, eicosanoic, gadoleic, docosanoic or erucic acid into consideration. Preferred esters have an iodine value of from 50 to 150 and in particular from 90 to 125. Mixtures with particularly advantageous properties are those which are principally, i. H. to contain at least 50 wt .-% of 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.

The cold additives of the invention can be used alone or together with other co-additives, for. B. with others

Pour point depressants or dewaxing aids, with detergents, Antioxidants, cetane improvers, dehazers, demulsifiers, dispersants, defoamers, dyes, corrosion inhibitors, lubricity additives,

Sludge inhibitors, odorants and / or additions to the cloud point.

The advantages of the inventive cold additives and the use of them

Process lie in a relation to corresponding additive combinations of the prior art significantly improved self-flowability in the cold with improved effectiveness. Thus, these cold additives can be used at the same active ingredient content even at lower temperatures than the additives of the prior art without having to be heated. Alternatively, at the same temperature higher concentrated additives can be used, so that the cost of transport and storage is reduced. In addition, the cold additives of the invention surprisingly show a

improved effectiveness in improving the cold flow properties of antibodies. This is all the more unexpected since the side chain density of the comb polymers B) according to the invention is markedly lower than in the comb polymers of the prior art additionally esterified with fatty acids

(DE-A-1 920 849, DE-A-2 451 047). Also, the filterability of the treated with the inventive cold additives fuel oils

Surprisingly significantly less impaired than in the case of additization with additives of the prior art under the same conditions.

Examples Polyester A)

Commercially available mixtures of 1-alkenes having the stated compositions were used as α-olefins. The acid numbers were determined by titration of an aliquot of the reaction mixture with alcohol

Tetra-n-butylammonium hydroxide solution in xylene / isopropanol determined. The hydroxyl numbers were after reaction of the free OH groups of the polymers with Isocyanate determined by H-NMR spectroscopy by quantitative determination of the urethane formed. The values given refer to the solvent-free polymers. The molecular weights were determined by means of lipophilic

Gel permeation chromatography in THF against poly (ethylene glycol) standards and detection by means of RI detector.

A1) copolymer of equimolar amounts of C ₂ O / 24-alkenylsuccinic anhydride (prepared by thermal condensation of maleic anhydride with technical C ₂ o / 24-olefin containing as main constituents 43% C ₂ o-, 35% C ₂₂ - and 17% C ₂₄ - Olefin, with 90% α-olefins and 7.5% linear internal

Olefins were) and ethylene glycol. The reactants were heated as a 50% solution in Shellsol ^® AB (higher boiling aromatic solvent mixture) while stirring at 150 ° C until the acid number remained constant. The resulting water was distilled off. The acid value of the polymer thus prepared was 10.0 mg KOH / g, the hydroxyl value

6 mg KOH / g and the weight-average molecular weight 8,300 g / mol.

A2) In analogy to Example A1) produced copolymer of equimolar

Units C26 / 28-alkenyl succinic anhydride (prepared by thermal condensation of maleic anhydride with technical C26-28-olefin containing, as main components 57% _C26 -, 39% C ₂₈ -, and 2.5%

C ₃ o + olefin, wherein 85% were α-olefins, 4% linear internal olefins, and 9% branched olefins) and ethylene glycol. The acid number of the polymer was 2.7 mg KOH / g, the hydroxyl number was 5 mg KOH / g and the

weight average molecular weight 5,800 g / mol.

In analogy to Example A1) produced copolymer of equimolar proportions C3o ₊ alkenylsuccinic anhydride (prepared by thermal condensation of maleic anhydride with technical C3o ₊ olefin containing as main constituents 9% olefin in the range C ₂₄ -C ₂ 8 and 90% with C chain lengths of at least C ₃ o. wherein 82% were α-olefins, 3% linear internal olefins and 14% branched olefins) and ethylene glycol. The acid number of the polymer was 11.6 mg KOH / g, the hydroxyl number 11 mg KOH / g and the weight-average molecular weight 7,400 g / mol.

A4) In analogy to Example A1) produced copolymer of equimolar

C2o / 24 alkenyl succinic anhydride (prepared by thermal condensation of maleic anhydride with C2o / 24 technical olefin containing as main constituents 43% C ₂ O, 35% C ₂₂ and 17% C ₂₄ olefin, 90% α-olefins and 7.5% linear internal olefins) and

Diethylene glycol. The acid value of the polymer was 9.4 mg KOH / g, the hydroxyl value was 10 mg KOH / g and the weight-average molecular weight was 9,400 g / mol.

A5) In analogy to Example A1) produced copolymer of 1 mol

C ₂ O / ₂ 4-alkenyl succinic anhydride (prepared by thermal

Condensation of maleic anhydride with technical C ₂ o / ₂ 4-olefin containing as main constituents 43% C ₂₀ , 35% C ₂₂ and 17% C ₂₄ olefin, 90% being α-olefins and 7.5% linear internal olefins ), 0.95 moles of ethylene glycol and 0.05 moles of behenyl alcohol. The acid number of the polymer was 5.3 mg KOH / g, the hydroxyl number was 3 mg KOH / g and the

weight average molecular weight 6,900 g / mol.

A6) copolymer of equal molar proportions C ₂ o / ₂ 4-

Alkenylsuccinic anhydride according to Example A1, glycerol and

Behenic acid in analogy to polymer G of DE-A-24 51 047. The acid number of the polymer was 15 mg KOH / g, the hydroxyl number 6 mg KOH / g and the weight average molecular weight 8,300 g / mol (comparative example).

A7) Addition copolymer of equimolar amounts of maleic anhydride and C ₂ o / ₂ 4-olefin, esterified with 2 molar equivalents of behenyl alcohol. The

Acid number of the polymer was 9 mg KOH / g, the hydroxyl number

11 mg KOH / g and the weight-average molecular weight 7,900 g / mol (comparative example) Ethylene copolymers B)

B1) terpolymer of ethylene, 13.5 mol% of vinyl acetate and 1.5 mol%

Neononanoic acid vinyl ester with a measured at 140 ° C.

Melt viscosity of 95 mPas.

B2) Terpolymer of ethylene, 12 mol% of vinyl acetate and 5 mol% of propene with a measured at 140 ° C melt viscosity of 200 mPas.

B3) Copolymer of ethylene and 13 mol% of vinyl acetate with one at 140 ° C.

measured melt viscosity of 125 mPas.

B4) terpolymer of ethylene, 12.5 mol% vinyl acetate and 4 mol%

4-methylpentene-1 with a measured at 140 ° C melt viscosity of

170 mPas.

The determination of the melt viscosity of the ethylene copolymers B) by means of rotary viscometer at a temperature of 140 ° C. From the ethylene copolymer B), all volatiles are removed at 150 ° C./100 mbar before the measurement,

Solvent C)

C1) Solvesso ^® 150: high-boiling aromatic mixture (about 98% aromatics, 0.7% naphthalene, boiling range 175 - 205 ° C, flash point 65 ° C)

C2) White spirit: Mixture of mainly paraffinic and naphthenic

Hydrocarbons in the range C ₁₀ to Cie (aromatics content 16%,

Boiling range 182 - 212 ° C, flash point 63 ° C) To determine the cold properties of the cold additives, their pour points were determined in accordance with DIN ISO 3016. A low pour point indicates a good flowability and thus good handling in the cold. The percentages given for the additives are based on the used

Parts by weight of the additive components. The weight fractions stated for the polymers are based on solvent-free active substances. The

optionally solvent-based components contained in the polymers are indicated as solvent C). Table 1: Determination of pour points

Additive Polyester A Polymer B Solvent C Pour Point

1 6.5% A1 58.5% B1 35% C1 +3

2 6.5% A2 58.5% B1 35% C1 +9

3 6.5% A4 58.5% B1 35% C1 0

4 6.5% A5 58.5% B1 35% C1 -3

5 (Cf.) 6.5% A6 58.5% B1 35% C1 +30

6 (Cf.) 6.5% A7 58.5% B1 35% C1 +30

7 3.5% A1 31, 5% B2 65% C1 -21

8 3.5% A2 31, 5% B2 65% C1 -18

9 3.5% A3 31, 5% B2 65% C1 -15

10 3.5% A4 31, 5% B2 65% C1 -24

11 3.5% A5 31, 5% B2 65% C1 -30

12 (See) 3.5% A6 31, 5% B2 65% C1 -12

13 (See) 3.5% A7 31, 5% B2 65% C1 -9

14 2.0% A1 38.0% B3 60% C2 -3

15 2.0% A2 38.0% B3 60% C2 +3

16 2.0% A3 38.0% B3 60% C2 +9

17 2.0% A4 38.0% B3 60% C2 -3

18 2.0% A5 38.0% B3 60% C2 -6

19 (Compare) 2.0% A6 38.0% B3 60% C2 +12

20 (Compare) 2.0% A7 38.0% B3 60% C2 +12

21 3.5% A1 46.5% B4 50% C1 -21

22 3.5% A2 46.5% B4 50% C1 -15

23 3.5% A4 46.5% B4 50% C1 -18

24 3.5% A5 46.5% B4 50% C1 -21

25 (See) 3.5% A6 46.5% B4 50% C1 3

26 (See) 3.5% A7 46.5% B4 50% C1 0 The effectiveness of the additives was investigated by lowering the CFPP values according to DIN EN 16 in a low-sulfur middle distillate with the characteristics given in Table 2. The determination of the components with n-alkyl radical> C-i6 and n-paraffins - * C28 was carried out by means of

Gas chromatography.

Table 2: Characterization of the test oils

Table 3: CFPP activity in test oil 1

Example additive CFPP [° C]

(according to Tab. 1) 200 ppm 300 ppm

1 (Cf.) without -15 -15

2 (See) B1 (65% in C1) -17-20

3 1 -28 -33

4 2 -26 -32

5 3 -29 -33

6 4 -29 -31

(Cf.) 5 -25 -29

8 (Cf.) 6 -21 -27 Table 4: CFPP activity in test oil 1

To compare the solubility of the cold additives 200 ml of test oil 3 (Table 2) were added in a 250 ml cylinder at the indicated in Table 6 with 1,000 ppm of an additive according to Table 1. The addition of the additives was carried out by means of direct displacement pipette in order to handle the high viscosity in particular of the comparative additives can. After ten times pivoting of the cylinder 180 ° was visually inspected for undissolved additive ingredients. Table 6: Solubility of the additives in test oil 3

Example Additive TAdditive [° C] TÖI [° C] Appearance

27 1 6 -3 homogeneous, clear

28 3 6 -3 homogeneous, clear

29 (Cf.) 5 (Cf.) 6 -3 additive largely unresolved

30 (Cf.) 6 (Comp.) 6 -3 additive largely unresolved

31 7 -12 -20 homogeneous, clear

32 8 -12 -20 homogeneous, clear

33 9 -12 -20 homogeneous, clear

34 (Cf.) 12 (Cf.) -12 -20 contains many flakes

35 (Cf.) 13 (Cf.) -12 -20 contains many flakes

Claims

claims:

1. cold additives for middle distillates, containing

A) at least one polyester of the formula

wherein

one of the radicals R ¹ to R ⁴ for a linear Ci ₆ -C ₄ o-alkyl or alkenyl radical and

m for a number from 3 to 250,

p for 0 or 1, and

q is 0 or 1,

C) at least one organic solvent.

2. cold additives according to claim 1, wherein R ^{1 is} a Ci6- to C ₄ o-alkyl or alkenyl, R ² , R ³ and R ^{4 are} hydrogen and R ^{5 is} a single bond.

3. cold additives according to claim 1 and / or 2, wherein R ^{16 is} an ethylene group.

4. cold additives according to claim 1 and / or 2, wherein R ^{16 is} a C2 to C ₄ alkylene group and n is a number from 2 to 100.

5. cold additives according to one or more of claims 1-4, wherein

Polymer B) is a copolymer of ethylene and 8 to 21 mol% of at least one olefinically unsaturated compound selected from vinyl esters, acrylic esters and / or methacrylic esters.

6. cold additives according to one or more of claims 1-5, wherein

Solvent C) is selected from aliphatic hydrocarbons having 9 to 20 carbon atoms and aromatic hydrocarbons having 7 to

20 carbon atoms.

7. cold additives according to one or more of claims 1-6, wherein the solvent C) additionally contains a solubilizer containing 4 to 24 carbon atoms and is selected from alcohols, organic acids, ethers and esters of organic acids, or mixtures thereof.

8. cold additives according to one or more of claims 1-7, wherein 0.1 to 50 wt .-% A), 1, 5 to 73.5 wt .-% B) and 25 to 95 wt .-% C) are.

9. cold additives according to one or more of claims 1-8, wherein additionally at least one further cold flow improvers is contained, consisting of the group consisting of

III) oil-soluble polar nitrogen compounds,

IV) Resins of alkyl radical-bearing phenol derivatives with aldehydes,

V) comb polymers of the formula

wherein

A R ', COOR \ OCOR', R '-COOR', OR ';

DH, CH _3, A or R "; EH, A;

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

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

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

R 'is a hydrocarbon chain of 8 to 50 carbon atoms;

R "is a hydrocarbon chain of 1 to 10 carbon atoms;

a is a number between 0.4 and 1, 0; and

b is a number between 0 and 0.6,

VI) homo- and copolymers of olefins having 2 to 30 carbon atoms, VII) esters, ethers and esters / ethers of alkoxylated polyols, which

at least one alkyl radical having 12 to 30 carbon atoms, is selected

10. A method for improving the cold flow properties of fuel oils, wherein a middle distillate, a cold additive according to one or more of

Claims 1 to 9 is added.

11. A fuel oil containing a middle distillate and at least one cold additive according to one or more of claims 1-9.

12. A fuel oil according to claim 11, wherein the middle distillate has a content of components with an n-alkyl chain having 16 or more carbon atoms of more than

4 wt .-%.

13. A fuel oil according to claim 11 and / or 12, wherein the middle distillate has a content of long-chain n-paraffins with 28 or more carbon atoms of less than 1 wt .-%.