WO2011076338A2

WO2011076338A2 - Multifunctional additives having an improved flow capability

Info

Publication number: WO2011076338A2
Application number: PCT/EP2010/007407
Authority: WO
Inventors: Matthias Krull; Werner Reimann; Stefan Dilsky; Sabine Goetzke; Dirk Leinweber
Original assignee: Clariant International Ltd
Priority date: 2009-12-24
Filing date: 2010-12-07
Publication date: 2011-06-30
Also published as: CN102666814A; KR20120123344A; EP2516604A2; RU2012131477A; DE102009060371A1; CA2785465A1; JP2013515793A; US20130000184A1; EP2516604B1; WO2011076338A3

Abstract

The present invention relates to cooling additives for middle distillates, containing A) at least one comb polymer carrying hydroxyl groups, which can be produced by polycondensation of a polyol that contains two primary OH groups and at least one secondary OH group with a dicarboxylic acid or the anhydride or ester thereof, which carries a C₁₆-C₄₀ alkyl radical or a C₁₆-C₄₀ alkenyl radical, characterized in that the OH number of the comb polymer is at least 40 mg KOH/g, B) at least one copolymer of ethylene and of at least one ethylenically unsaturated ester, and C) at least one organic solvent.

Description

description

The present invention relates to cold additives for middle distillates having improved low temperature handleability and their use for improving cold properties and lubricity of middle distillates, as well as 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.

In order to improve the cold flow properties, middle distillates are often added with chemical additives, so-called cold flow improvers or flow improvers, which modify the crystal structure and agglomeration tendency of the precipitated paraffins so that the oils thus added are still intact

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 are the

Hydroxyl groups of the polyol largely completely esterified. 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. By the use of polyhydric alcohols, these polymers according to the information of Disclosure of a superiority to the additives of U.S. 3,447,916. Also, this document gives no indication of the common use with other additives. DE-A-24 51 047 discloses light, low viscous distillate fuel oils which contain no residues and are additized with ethylene copolymers as well as comb polymers having Ci8-C44 side chains. As comb polymers, inter alia polyesters of alk (en) ylnic succinic anhydride with a Ci ₆ -C44 alk (en) yl radical, a polyol having 2-6 OH groups and a C 2o-C44 monocarboxylic acid are used. The three components of the polyester are preferably condensed in equimolar amounts, resulting in substantially complete esterification of both OH and COOH groups. By way of example (polymer G) is a polycondensate of equimolar amounts of C22-28 alkenyl succinic anhydride, trimethylolpropane and C ₂ o -22 fatty acids.

US-A-2008/0295397 discloses additives for lowering the pour point of diesel oils, the polyglycerol esters and optionally further pour point

Contain depressants such as ethylene-vinyl ester copolymers. The hydroxyl groups of the polyglycerol may be completely or partially esterified. Such polyol partial esters have pronounced emulsifying properties and are therefore undesirable in fuels.

To improve their handling properties, additive combinations of copolymers of ethylene and unsaturated esters and comb polymers used for improving the cold properties of middle distillates are usually 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 the active substance in the concentrates should be as high as possible in order to keep the volume of 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.

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. Furthermore, they should improve lubricity, especially in sulfur-reduced or sulfur-free middle distillates.

Surprisingly, it has been found that additive combinations, the solutions of copolymers of ethylene and unsaturated esters and special

Polycondensates of linear C ₁₆ -C ₄ o-alkyl or _Ci-6 alkenyl -C4o-bearing dicarboxylic acids or anhydrides, and polyols having two primary and at least one secondary OH group in organic

Contain solvents, even at low temperatures below 10 ° C, often below 0 ° C partially below -10 ° C such as below -20 ° C in concentrated form flowable and readily soluble in middle distillates. In addition, they have excellent properties as cold flow improvers without affecting the filterability of the oils additized with them. In the synthesis of this

Polycondensates occur despite the omission of the fatty acids additionally used in the prior art for the esterification Surprisingly, not or only to an insignificant extent to the extent to the formation of crosslinked, high molecular weight structures that lead to impaired filterability in the additized oil. Furthermore, these additive combinations are capable of the lubricating properties of low-sulfur oils

improve.

The invention provides cold additives for middle distillates, containing

A) at least one hydroxyl group-carrying comb polymer, by

Polycondensation of a polyol containing two primary OH groups and at least one secondary OH group, with a dicarboxylic acid or its anhydride or esters thereof which bears a Gi6 to C4o-alkyl radical or a C ₁₆ - to C4o-alkenyl radical, can be produced wherein the OH number of the comb polymer is at least 40 mg KOH / g,

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester 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 an additive to a middle distillate, the

A) at least one hydroxyl-carrying comb polymer obtained by polycondensation of a polyol containing two primary OH groups and at least one secondary OH group, with a dicarboxylic acid or its anhydride or its esters which have a Gi6- to C4o-alkyl radical or a Ci ₆ to C4o-alkenyl radical can be produced, wherein the OH number of the polymer is at least 40 mg KOH / g,

C) at least one organic solvent

contains. Another object of the invention is a method for improving the lubricity of fuel oils by a middle distillate with a

Sulfur content of less than 0.05 wt .-% is added to an additive

A) at least one hydroxyl group-carrying comb polymer, by

Polycondensation of a polyol containing two primary OH groups and at least one secondary OH group, with a dicarboxylic acid or its anhydride or esters thereof which carries a Ci6- to C4o-alkyl radical or a Ci6- to C4o-alkenyl radical, can be produced, wherein the OH number of the polymer is at least 40 mg KOH / g,

C) at least one organic solvent

contains. Another object of the invention are fuel oils containing a

Middle distillate and a cold additive, the

A) at least one hydroxyl group-carrying comb polymer, by

Polycondensation of a polyol containing two primary OH groups and at least one secondary OH group, with a dicarboxylic acid or its anhydride or esters thereof, which is a Ci6- to C4o-alkyl radical or a C- ₆ to C4o-alkenyl radical can be produced, wherein the OH number of the polymer is at least 40 mg KOH / g,

C) at least one organic solvent

includes.

The hydroxyl group-carrying comb polymer A is generally obtained by the polycondensation of a C ₁₆ - to C 40 -alkyl radical or alkenyl radical, hereinafter also referred to collectively as C ₁₆ -C 40 -alk (en) yl radical, bearing dicarboxylic acid having the primary hydroxyl groups of the polyol. It is preferred that the secondary OH groups remain substantially unesterified. The preferred Structure of the hydroxyl group-carrying comb polymer A can therefore

For example, according to formula A1 are shown:

wherein

one of the radicals R ¹ to R ⁴ for a linear Ci 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} at least one hydroxyl-bearing

Hydrocarbon group having 3 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,

Preferred dicarboxylic acids carrying C ₆ -C 40 -alkyl- and / or alkenyl radicals which carry the hydroxyl-bearing comb polymers A) correspond to the general formula 1

RR ³

HOOC-C-R ⁵ - C-COOH (1)

wherein

one of the radicals R ¹ to R ⁴ for a linear Ci6-C ₄ o-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 and

R ^{5 is} a CC bond or an alkylene radical having 1 to 6 C atoms. Particularly preferably, one of the radicals R ¹ to R ^{4 is} a linear C 16 -C 40 -alkyl or alkenyl radical, one for a methyl group and the remaining for

Hydrogen. In a specific embodiment, one of the radicals R ¹ to R ⁴ is ₀ alkyl or alkenyl group is a linear Ci6-C4 and the other is 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 other radicals R ⁴ to R ⁴

Hydrogen and R ⁵ for a CC 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 those 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 mixtures of Olefins and in particular of α-olefins having 18 to 36 carbon atoms used such as 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 12 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% by weight of linear α-olefins having a C chain length in the range of C20 to C24. Preferred hydroxyl-carrying comb polymers A) are obtained by reacting a linear C ₆ -C ₄ o-alkyl or alkenyl radical-carrying alkyl or

Alkenylsuccinic acids and / or their anhydrides with polyols which carry two primary and at least one secondary hydroxyl group, can be produced. Preferred polyols are glycerin, poly (glycerol) and mixtures thereof. Under poly (glycerol) are understood in particular by glycerol derivable structures by polycondensation. The degree of condensation according to the invention preferred poly (glycerol) is between 2 and 50, particularly preferably between 3 and 25 and especially between 4 and 20, such as between 5 and 15. The preparation of poly (glycerol) is well known in the art. It can be carried out, for example, via addition of 2,3-epoxy-1-propanol (glycidol) to glycerol. Furthermore, the manufacture of the

Poly (glycerol) by per se known polycondensation of glycerol. The reaction temperature in the polycondensation is generally between 150 and 300 ° C, preferably between 200 and 250 ° C. The polycondensation is usually carried out at atmospheric pressure. Examples of catalyzing acids are HCl, H 2 SO 4, organic sulfonic acids or H 3 PO 4, and bases such as NaOH or KOH. The catalysts are preferably added to the reaction mixture in amounts of from 0.01 to 10% by weight, more preferably from 0.1 to 5% by weight, based on the weight of the reaction mixture. The polycondensation can be carried out solvent-free as well as in the presence of solvent. If the polycondensation takes place in the presence of solvent, its proportion in the reaction mixture is preferably from 0.1 to 70% by weight, for example from 10 to 60% by weight. Preferred solvent! are the solvents used as component C) for the additive mixture. The polycondensation generally takes 3 to 10 hours. The reaction of the dicarboxylic acids carrying the alkyl radicals, their anhydrides or their esters with the polyol 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 and especially in molar ratio of 1:, 2 to 1, 2: 1 such as equimolar. Particularly preferably, the reaction is carried out with an excess of polyol. 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 C ₁₆ -C ₄ o-alkyl- or alkenyl-substituted dicarboxylic acid or its anhydride or ester with the polyol at temperatures above 100 ° C and preferably at temperatures between 120 and 320 ° C such as at temperatures between 150 and 290 ° C. To set the important for the effectiveness of the molecular weight of the comb polymers A) usually the removal of water of reaction or alcohol is required, which is done for example by distillation separation can. 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.

In a preferred embodiment, in the reaction mixture to

Adjustment of the molecular weight minor amounts of the alk (en) ylreste bearing dicarboxylic acids, their anhydrides or their esters by C to

C-ie monocarboxylic acids, preferably C ₂ to C 16 monocarboxylic acids and especially C ₃ to C 1 monocarboxylic acids such as, for example, C ₄ to C 12 monocarboxylic acids. 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 whose anhydrides or their esters replaced by one or more monocarboxylic acids. Furthermore, minor amounts such as up to 10% by mol and especially 0.01 to 5 mol% of the

Alk (en) ylsuccinic acids or their anhydrides also by further dicarboxylic acids such as succinic acid, glutaric acid, maleic acid and / or

Fumaric acid are replaced. Particularly preferably, the hydroxyl-carrying comb polymers A) are prepared in the absence of monocarboxylic acids.

In a further preferred embodiment, in the reaction mixture to adjust the molecular weight minor amounts of the polyol by Ci. to C-30 monoalcohols, preferably C2 to C2 ₄ monoalcohols and especially C3 to C-18 monoalcohols such as C ₄ - to C 12 monoalcohols replaced. 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 preferred by one or more

Monoalcohols replaced. Particularly preferably, the hydroxyl-carrying comb polymers A) are prepared in the absence of monoalcohols. Furthermore, the polyol bearing two primary and at least one secondary hydroxyl group can also be replaced by minor amounts of up to 10 mol%, such as 0.01 to 5 mol%, by one or more diols. Preference is given to diols such as ethylene glycol, propylene glycol and / or neopentyl glycol. Particularly preferably, the hydroxyl-carrying comb polymers A) are prepared in the absence of diols.

The average degree of condensation of the hydroxyl group-carrying comb polymers A) 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 repetitive units of dicarboxylic acid and polyol. The weight-average molecular weight M w of the hydroxyl group-carrying comb polymers A) determined by GPC in THF against polyethylene glycol) is preferably between 1,500 and 100,000 g / mol and in particular between 2,500 and 50,000 g / mol, for example between 4,000 and 20,000 g / mol.

The acid number of the hydroxyl group-carrying comb polymers A) is preferably less than 40 mg KOH / g and more 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 comb polymers A) is between 45 and 500 mg KOH / g, particularly preferably between 50 and 300 mg KOH / g and in particular between 60 and

250 mg KOH / g. The hydroxyl number can be determined by reacting the free OH groups with isocyanate by means of ¹ H NMR spectroscopy by quantitative determination of the urethane formed. Preferred copolymers of ethylene and olefinically unsaturated esters B) are in particular those which, in addition to ethylene, contain 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} C 1 to C ₃₀ -alkyl, preferably C 1 to C ₆ -alkyl, especially C 1 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 for C ₄ to C - to C ₂ 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 suberate, vinyl 2-ethylhexanoate, vinyl diurea, 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 Vinylester of formula 2 wherein R ¹² is C ₄ - to C 3 ₀ alkyl, preferably C ₄ to C ₆ alkyl, especially C 6 to C

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 ³ - COOR ¹⁴ (3) wherein

R ^{13 is} hydrogen or methyl and RC to C ₃₀ alkyl, preferably C ₄ - to C ₆ alkyl, especially C ₆ - to d ₂ alkyl.

Suitable acrylic esters include, for. Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- and iso-butyl (meth) acrylate, hexyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl , Hexadecyl, octadecyl (meth) acrylate and

Mixtures of these comonomers. In a further embodiment, said alkyl groups may be substituted with one or more hydroxyl groups. An example of such an acrylic ester is hydroxyethyl methacrylate. The 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 to C _ß o alkyl, preferably C ₄ - to C ₆ alkyl, especially _C - to

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.

Particular preference is given to terpolymers which, apart from ethylene, have from 3.5 to 20 mol%, in particular from 8 to 15 mol%, of vinyl acetate and from 0.1 to 12 mol%, in particular 0.2 to 5 mol% of at least one longer-chain and preferably branched vinyl ester, for example vinyl 2-ethylhexanoate,

Vinyl neononanoate or vinyl neodecanoate, the total comonomer content of the terpolymers preferably being 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 9.0 and 19 mol%.

These ethylene copolymers and terpolymers preferably have melt viscosities at 140 ° C. of not more than 5,000 mPas, more preferably from 20 to 2,500 mPas, in particular from 30 to 1,000 mPas, especially from 50 to 500 mPas. The degrees of branching determined by means of ¹ H-NMR spectroscopy are preferably between 1 and 9 CH 3 / I OO CH ₂ groups, in particular between 2 and

6 CH3 / I OO CH ₂ groups, which do not come from the comonomers. Preference is given to using mixtures of two or more of the abovementioned ethylene copolymers. Particularly preferably, the polymers underlying the mixtures differ in at least one

Characteristic. For example, they may contain different comonomers, have different comonomer contents, molecular weights and / or degrees of branching. 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. Aromatic 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

Alkylbenzenes and alkylnaphthalenes. For example, aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, for. B.

Petroleum fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercial solvent mixtures, such as solvent naphtha, Shell target ^® AB,

Solvesso ^® 150, Solvesso ^® 200, Exxsol ^®, ISOPAR ^® - and Shellsol ^® D grades 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 C atoms, particularly preferably 6 to 18 and in particular 8 to 16 C atoms. Examples of suitable solubilizers are butanol, 2-ethylhexanol, decanol, iso-decanol, isotridecanol, nonylpenol, benzoic acid, oleic acid, dihexyl ether, dioctyl ether, 2-ethylhexyl acid butyrate, ethyl octanoate,

Hexanoic acid ethyl ester, 2-Ethylhexylsäurebutylester and 2-Ethylhexylbutyrat and higher ethers and / or higher esters such as di (2-ethylhexyl) ether, 2-ethylhexyl acid 2-ethylhexyl ester and 2-ethylhexyl stearate. 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 solvents based on mineral oils are also based on renewable raw materials solvents such. As biodiesel based on vegetable oils and the derived methyl esters, especially rapeseed, as well as synthetic

Hydrocarbons, which are obtainable, for example, from the Fischer-Tropsch process, are 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 ₃ 6- alkenyl, in particular C ₂ -C ₂₄ alkyl, C ₂ -C ₂ H 4 -alkenyl or cyclohexyl, and the remaining groups are either hydrogen, C 1 -C -alkyl, C 2 -C -alkenyl,

Cyclohexyl, or a group of the formulas - (Α-0) χ-Ε or - (CH ₂ ) _k - YZ

where A is an ethyl or propyl group, x is a number from 1 to 50, E = H, CC ₃ o-alkyl, C ₅ -C ₂ -cycloalkyl or C ₆ -C ₃ o-aryl, and k = 2, 3 or 4, and Y and Z independently of one another are H, C 1 -C 30 -alkyl or - (A-O) _x . The alkyl and alkenyl radicals can be linear or branched and contain up to two double bonds. Preferably, they are linear and substantially saturated, that is, they have iodine numbers of less than 75 g / g, preferably less than 60 gl ₂ / g and in particular between 1 and 10 gl ₂ / g. Particularly preferred are secondary fatty amines, in which two of the groups R ^6, R ⁷ and R ⁸ is C ₈ -C ₃ 6-alkyl, C6-C ₃ 6 cycloalkyl, C8-C ₃₆ -alkenyl, in particular C ₂ -C ₂ 4-alkyl, C-i2-C24 alkenyl or cyclohexyl and the third stand for 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 as e.g. Coconut fatty amine, tallow fatty amine, hydrogenated tallow fatty amine, dieocosfettamine, di-tallow 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, in particular of dieocosfettamine, 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) yl succinic acid, adipic, glutaric, sebacic and malonic acids and 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

Give 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 10,000, 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-0 606 055 A2 Reaction products of terpolymers based on α, β-unsaturated dicarboxylic anhydrides, α, β-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols.

The mixing ratio between the inventive cold additives A) and oil-soluble polar nitrogen compounds as constituent 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 ^{1 is} CC ₂ oo-alkyl or alkenyl, OR ¹⁰ or OC (O) -R ¹⁰ , R ^{10 is} C 1 -C 20 -alkyl or alkenyl and h is a number from 2 to 100. R ¹⁰ preferably represents Ci-C ₂ o alkyl or alkenyl and especially C4-Ci ₆ alkyl or alkenyl such as for C ₆ -C ₂ alkyl or alkenyl. With particular preference R ^{11 is} C 1 -C ₂₀ -alkyl or -alkenyl and in particular C ₄ -C ₁₆ -alkyl or -alkenyl, for example C ₆ -C ₁₂ -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 as starting materials are alkylphenols which carry at least two hydrogen atoms capable of condensation with aldehydes on the aromatic and in particular monoalkylated phenols. Particularly preferably, the alkyl radical is in the para position to the phenolic OH group. The alkyl radicals

(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, in particular 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.

Other cold flow improvers also comb polymers are suitable. Such comb polymers (constituent V) can, for example, be represented by the formula

A H G H

C C C C

D E 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 ethylenic

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. Particular preference is given to mixtures of n-tetradecan-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 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 may also be small amounts, e.g. B. up to 10 mol% of other comonomers such. Non-terminal olefins or non-conjugated olefins contain. 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) cA 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 2 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 neopentyl glycol, glycerol, trimethylolethane, trimethylolpropane, sorbitan, pentaerythritol and the oligomers having from 2 to 3 obtainable therefrom by condensation 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 core to which are attached multiple alkyl-solubilizing alkyl radicals.

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, arachic 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 especially 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 16 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, especially 12 to 30, especially 16 to 26 carbon atoms in accordance with the invention suitable polyoxyalkylene compounds are converted. 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 are largely completely esterified with largely saturated C 17 -C 24 -fatty acids.

Further particularly preferred polyoxyalkylene compounds are with

largely saturated Ci7-C2 ₄ fatty acids esterified polyethylene glycols having molecular weights of about 350 to 1,000 g / mol. Examples for special suitable polyoxyalkylene compounds are stearic and especially 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

Refrigeration properties of such middle distillates, which are 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 predominantly consist 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 to be present in oils containing only a very small proportion of very long-chain n-paraffins containing 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 further cold-critical components ^■ such as Fettsäuremethyiestern is usually means

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 further in such middle distillates, the boiling ranges have between 20 and 90% distillation volume of less than 120 ° C and in particular of less than 110 ° C. 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). Biofuels are understood as meaning oils derived from animal and preferably from vegetable material or both, as well as derivatives thereof, which can be used as fuel and especially as diesel or fuel oil. These are in particular

Triglycerides of fatty acids having 10 to 24 carbon atoms and the fatty acid esters of lower alcohols such as methanol or ethanol obtainable by transesterification.

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

Cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, corn oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, beef tallow, bone oil,

Fish oils and used 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 50 and in particular from 90 to 125. Mixtures with particularly advantageous properties are those which are predominantly, 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 acid. 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 improved effectiveness in improving the cold flow properties of middle distillates. 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 1920849, DE 2451047). Also, the filterability of the with the

Inventive cold additives treated fuel oils

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

Examples

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 determined after reaction of the free OH groups of the polymers with isocyanate by means of ¹ 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

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

Polyester A)

A1) Copolymer of equimolar C2o-24-alkenyl succinic anhydride (prepared by thermal condensation of maleic anhydride with technical C ₂ o-24-olefin containing as main constituents 43% C ₂ O, 35% C22 and 17% C24 olefin, 90 % α-olefins and 7.5% linear internal olefins) and glycerol. The reactants were as a 50% solution in Shellsol AB (higher boiling aromatic solvent mixture) under

Stir until 150 ° C until the acidity! remained constant. The resulting water was distilled off. The acid value of the polymer thus prepared was 7.8 mg KOH / g, the hydroxyl number

98 mg KOH / g and the weight-average molecular weight 6,100 g / mol.

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

Proportions of C ₂ O / 24-alkenyl succinic anhydride (prepared by thermal condensation of maleic anhydride with technical C ₂ O / 24-olefin containing as main constituents 43% C ₂₀ -, 35% C ₂₂ - and 17% C ₂ 4-olefin, where 90% α- Olefins and 7.5% linear internal olefins) and

Polyglycerol having a mean condensation degree of 3. The acid value of the polymer was 6.5 mg KOH / g, the hydroxyl value was 195 mg KOH / g and the weight-average molecular weight was 8,700 g / mol. A3) 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 glycerol. The acid number of the polymer was 10.4 mg KOH / g, the hydroxyl number 68 mg KOH / g and the

weight average molecular weight 9,100 g / mol.

A4) copolymer of equal molar proportions C20 / 24-

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).

Addition copolymer of equimolar proportions of maleic anhydride and C2o / 24-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 was included

7,900 g / mo! (Vergleichsbeispie!)

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 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 volatile constituents 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 C10 to C-i6 (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 inventory file. The weight fractions stated for the polymers are based on solvent-free active substances. The

optionally solvent-based components contained in the polymers are solvents! C).

Table 1: Determination of pour points

Additive Polyester Polymer B Solvent C Pour Point

1 3.0% A1 47.0% B1 50% C1 -12 ° C

2 3.0% A2 47.0% B1 50% C1 -9 ° C

3 3.0% A3 47.0% B1 50% C1 -6 ° C

4 (Cf.) 3.0% A4 47.0% B1 50% C1 +6 ° C

5 (See) 3.0% A5 47.0% B1 50% C1 + 9 ° C

6 3.5% A1 31, 5% B2 65% C1 -21 ° C

7 3.5% A2 31, 5% B2 65% C1 -21 ° C

8 3.5% A3 31, 5% B2 65% C1 -15 ° C

9 (Compare) 3.5% A4 31, 5% B2 65% C1 -12 ° C

10 (See) 3.5% A5 31, 5% B2 65% C1 -9 ° C

11 3.0% A1 32.0% B3 65% C2 -6 ° C

12 3.0% A2 32.0% B3 65% C2 -3 ° C 13 3.0% A3 32.0% B3 65% C2 -3 ° C

14 (Cf.) 3.0% A4 32.0% B3 65% C2 +6 ° C

15 (See) 3.0% A5 32.0% B3 65% C2 +6 ° C

16 4.0% A1 56.0% B4 40% C2 -9 ° C

17 4.0% A2 56.0% B4 40% C2 -12 ° C

18 4.0% A3 56.0% B4 40% C2 -3 ° C

19 (Compare) 4.0% A4 56.0% B4 40% C2 +6 ° C

20 (See) 4.0% A5 56.0% B4 40% C2 +6 ° C

The effectiveness of the additives was investigated by lowering the CFPP value according to DIN EN 116 in low-sulfur middle distillates with the characteristics given in Table 2. The determination of the components with n-alkyl radical> C- | ₆ and the n-paraffins C28 was carried out by 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 -12 -12 2 (See) B1 (50% in C1) -14-20

3 1 -22 -29

4 2 -20 -26

5 3 -23 -28

6 (Cf.) 4 (Cf.) -18 -25

7 (Cf.) 5 (Cf.) -17 -25

1 (Cf.) without -12 -12

Table 4: CFPP activity in test oil 1

Example additive CFPP [° C]

(according to Tab. 1) 350 ppm 500 ppm

8 (Cf.) without -15 -15

9 (See) B2 (35% in C1) -16 -18

10 6 -25 -31

11 7 -25 -30

12 8 -23 -30

13 (Cf.) 9 (Cf.) -21 -28

14 (Cf.) 10 (Compare) -19-26

Table 5: CFPP activity in test oil 2

Example additive CFPP [° C]

(according to Tab. 1) 100 ppm 150 ppm

15 (Cf.) without -15 -15

16 (Cf.) B4 (60% in C2) -17 -21

17 16 -24 -31

18 17 -23 -28

19 18 -23 -30

20 (Cf.) 19 (Cf.) -20 -26

21 (Cf.) 20 (Cf.) -20 -24 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 additives were added by means of a direct-displacement pipette in order to be able to handle the high viscosity, in particular of the comparative additives. 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] T _Ö , [° C] Appearance

22 1 6 -3 homogeneous, clear

23 2 6 -3 homogeneous, clear

24 (Cf.) 4 (Comp.) 6 -3 additive largely unresolved

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

26 6 -12 -20 homogeneous, clear

27 7 -12 -20 homogeneous, clear

28 8 -12 -20 homogeneous, clear

29 (Cf.) 9 (Cf.) -12 -20 contains many flakes

30 (Cf.) 10 (Cf.) -12 -20 additive largely unresolved

Claims

claims:

Cold additives for middle distillates, containing

A) at least one hydroxyl group-carrying comb polymer obtained by polycondensation of a polyol containing two primary OH groups and at least one secondary OH group, with a dicarboxylic acid or its anhydride or esters thereof, a C16 to C4o-alkyl radical or a C16 C4o-alkenyl radical is preparable, wherein the OH number of the comb polymer is at least 40 mg KOH / g,

C) at least one organic solvent.

Cold additives according to claim 1, wherein the dicarboxylic acid of formula 1

R ¹ R ³ HOOC- C- R ⁵ - C- COOH (1)

I i

R2 R4 corresponds to where

one of the radicals R ¹ to R ⁴ for a linear Ci 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 carbon atoms and

R ^{5 is} a CC bond or an alkylene radical having 1 to 6 C atoms.

3. cold additives according to claim 2, wherein the dicarboxylic acid

Alkyl succinic acid, alkenyl succinic acid or its anhydride.

4. cold additives according to one or more of claims 1 to 3, wherein the polyol is glycerol.

5. cold additives according to one or more of claims 1 to 4, wherein polymer A) has an OH number between 40 and 500 mg KOH / g.

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

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

Solvent C) is selected from aliphatic hydrocarbons having 9 to

20 carbon atoms and aromatic hydrocarbons with 7 to

20 carbon atoms.

8. cold additives according to one or more of claims 1-7, 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.

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

10. cold additives according to one or more of claims 1-9, wherein additionally at least one further Kaltfließverbesserer 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

A H C C C C

D E M N

wherein AR \ COOR ', OCOR', R '-COOR', OR ';

DH, CH _3l 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) homopolymers 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

11, A method for improving the cold flow properties of fuel oils, in which a middle distillate, a cold additive according to one or more of claims 1 to 10 is added. 12. Brennstöfföl containing a middle distillate and at least one cold additive according to one or more of claims 1-10.

13. A fuel oil according to claim 12, wherein the middle distillate has a content of constituents with an n-alkyl chain having 16 or more carbon atoms of more than 4 wt .-%.

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