WO2018114348A1

WO2018114348A1 - Additives for improving the thermal stability of fuels

Info

Publication number: WO2018114348A1
Application number: PCT/EP2017/081778
Authority: WO
Inventors: Maxim Peretolchin; Ivette Garcia Castro; Aaron FLORES-FIGUEROA; Harald Boehnke
Original assignee: Basf Se
Priority date: 2016-12-19
Filing date: 2017-12-07
Publication date: 2018-06-28
Also published as: EP3555242A1; EP3555242B1

Abstract

The present invention relates to the use of specific polymers as a fuel additive for improving the stability of fuels.

Description

The present invention relates to the use of certain polymers as fuel or lubricant additives for improving the stability of fuels, and to fuels and lubricants additized therewith, especially diesel fuels and especially those containing biofuel oils. WO 15/1 13681 discloses copolymers having at least one free carboxylic acid side group and their use as fuel additives. It is described that in addition stabilizers must be added in fuels, indicating that the copolymers described have no stabilizing property. Background of the invention:

In diesel fuels, a thermal or oxidation stability, measured as text according to DIN EN 15751, of at least 20 hours is required according to DIN EN590. By admixing renewable raw materials, especially fatty acid methyl esters (FAME), this stability is reduced, so that there is a need for additives for fuels to increase the stability.

Decomposition of the fuel occurs at locations where the fuel is exposed to oxygen and / or elevated temperature, often catalyzed by metal surfaces. Such conditions are often within the injection system, where elevated temperatures of up to 100 ° C and higher can be achieved.

In the injection systems of modern diesel engines, deposits from such decompositions cause significant performance problems. The widespread realization is that such deposits in the spray channels can lead to a reduction of the fuel flow and thus to power losses. Deposits on the injector tip, on the other hand, impair the optimum formation of fuel spray and thus cause a deterioration in combustion and, as a result, higher emissions and increased fuel consumption. In contrast to these conventional, "outer" deposition phenomena, "internal" deposits (collectively referred to as internal diesel injector deposits (IDID)) are also present in certain parts of the injectors, in particular the nozzle needle, the control piston, the valve piston, the valve seat , on the drive unit and on the guides of these components, increasingly performance problems. Conventional additives show insufficient activity against these IDIDs.

The term "injection system" is understood to mean that part of the fuel system in motor vehicles from the fuel pump through the injector outlet. In this case, the term "fuel system" is understood to mean the components of motor vehicles that are in contact with the respective fuel, preferably the area from the tank up to and including the injector outlet. It is an embodiment of the present invention that the compounds of the invention against deposits not only act in the injection system, but also in the rest of the fuel system, in particular against deposits in fuel filters and pumps.

The present invention has for its object to provide an additive for use in modern diesel and gasoline fuels, which increase the stability of fuels, especially of biofuels. The task is solved by

the use of copolymers obtainable by

in a first reaction step (I) copolymerization of at least one ethylenically unsaturated mono- or dicarboxylic acid or derivatives thereof, preferably a dicarboxylic acid, at least one α-olefin having from at least 12 up to and including 30 carbon atoms, optionally at least one further, at least 4 carbon atoms, aliphatic or cycloaliphatic olefin other than (B) and optionally one or more other copolymerizable monomers other than the monomers (A), (B) and (C) selected from the group consisting of

(Da) vinyl esters,

(Db) vinyl ethers,

(De) (meth) acrylic esters of alcohols having at least 5 carbon atoms,

(Dd) allyl alcohols or their ethers,

(De) N-vinyl compounds selected from the group consisting of vinyl compound fertilize of at least one nitrogen atom-containing heterocycles, N-vinyl or N-vinyl lactams,

(Df) ethylenically unsaturated aromatics

(Dg) α, β-ethylenically unsaturated nitriles,

(That is) (meth) acrylic acid amides and

(Di) allylamines, followed by, in a second optional reaction step (II), partial or complete hydrolysis and / or saponification of anhydride or carboxylic acid ester functionalities contained in the copolymer obtained from (I), where the second reaction tion step is at least then run if the copolymer obtained from reaction step (I) contains no free carboxylic acid functionalities, to improve the thermal and / or oxidation stability of fuels, preferably diesel fuels, particularly preferably diesel fuels containing biofuel oils.

Such copolymers have been shown to be effective in improving the stability of fuels, especially diesel fuels, especially diesel fuels containing biofuel oils. The stability of such fuels against oxidation or against thermal stress or against both is improved by the use according to the invention.

Summary of the Invention: These copolymers are notable in that they act against oxidation and / or thermal loading of fuels that cause a variety of deposits in the fuel and / or injection system that affect the performance of modern diesel engines. A1) Special embodiments

Specific embodiments of the invention are:

1 . Use of copolymers obtainable by

in a first reaction step (I) copolymerization of

(A) maleic anhydride,

(B) at least one α-olefin having from at least 12 up to and including 30 carbon atoms,

(C) optionally at least one further, at least 4 carbon atoms, aliphatic or cycloaliphatic olefin which is other than (B) and

(D) optionally one or more other copolymerizable monomers other than the monomers (A), (B) and (C) selected from the group consisting of

(Da) vinyl esters,

(Db) vinyl ethers,

(De) (meth) acrylic esters of alcohols having at least 5 carbon atoms,

(Dd) allyl alcohols or their ethers, (De) N-vinyl compounds selected from the group consisting of vinyl compounds of heterocycles containing at least one nitrogen atom, N-vinylamides or N-vinyllactams,

(Df) ethylenically unsaturated aromatics

(Dg) α, β-ethylenically unsaturated nitriles,

(That is) (meth) acrylic acid amides and

(Di) allylamines, followed by partial or complete hydrolysis of anhydride functionalities contained in the copolymer obtained from (I) in a second reaction step (II), to improve the thermal and / or oxidation stability of biofuel oils or preferably diesel fuels containing at least one fatty acid alkyl ester.

Use according to embodiment 1, wherein monomer (A) is selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate and methyl methacrylate and maleic anhydride.

Use according to any one of the embodiments, wherein monomer (B) is an α-olefin having at least 14 to 26 carbon atoms inclusive.

Use according to any one of the embodiments, wherein olefin (C) is more than 30 carbon atoms polymer of propene, 1-butene, 2-butene or iso-butene or olefin mixtures containing such, preferably iso-butene or olefin mixtures containing such average molecular weight M _w in the range of 500 to 5000 g / mol.

Use according to one of the embodiments, wherein mixture of the olefins (B) and (C) averaged over their molar amounts at least 12 carbon atoms.

Use according to any one of the embodiments, wherein the monomer (D) is selected from the group consisting of (Da), (Db), (De), (De) and (Df).

Use according to any one of the embodiments, wherein the molar ratio of (A) / ((B) and (C)) (in total) is from 10: 1 to 1:10.

Use according to any one of the embodiments, wherein the molar ratio of monomer (B) to monomer (C) is from 1: 0.05 to 10. 9. Use according to one of the preceding embodiments, wherein the proportion of one or more of the monomers (D) based on the amount of the monomers (A), (B) and optionally (C) (in total) 5 to 200 mol%.

Use according to one of the preceding embodiments, wherein the fuel is a diesel fuel containing at least one fatty acid alkyl ester selected from the group consisting of sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME"), animal fat methyl ester (" FME "), tallow methyl ester (" TME "), methyl ester of recovered vegetable oils, recycled used cooking oils and frying fats, used vegetable oil (" UVO "), waste vegetable oil (" VWE "), used cooking oil methyl ester (" UCOME ") , Tall oil methyl ester and rapeseed oil methyl ester ("RME").

1 1. Process for increasing the thermal and / or oxidation stability of biofuel oils or preferably diesel fuels, containing biofuel oils, measured in

Form of DIN EN 15751: 2014-06 at least one hour, wherein the fuel at least 10 ppm by weight based on the fuel of at least one copolymer as described in one of the embodiments 1 to 9 is added and the thus obtainable mixture of a thermal and / or exposes to oxidative stress.

Description of the copolymer

The monomer (A) is at least one, preferably one to three, more preferably one or two and most preferably exactly one ethylenically unsaturated, preferably α, β-ethylenically unsaturated mono- or dicarboxylic acid or derivatives thereof, preferably a dicarboxylic acid or their derivatives, more preferably the anhydride of a dicarboxylic acid, most preferably maleic anhydride.

Derivatives are understood here

the relevant anhydrides in monomeric or polymeric form,

Mono- or dialkyl esters, preferably mono- or di-C 1 -C 4 -alkyl esters, particularly preferably mono- or dimethyl esters or the corresponding mono- or diethyl esters, and

mixed esters, preferably mixed esters with different C 1 -C 4 -alkyl components, more preferably mixed methyl ethyl esters.

The derivatives are preferably anhydrides in monomeric form or

Di-C 1 -C 4 -alkyl esters, more preferably anhydrides in monomeric form.

For the purposes of this specification, C 1 -C 4 -alkyl is understood to mean methyl, ethyl, / isopropyl, n-propyl, n-butyl, isobutyl, sec-butyl and fer-butyl, preferably methyl and ethyl, particularly preferably methyl ,

The α, β-ethylenically unsaturated mono- or dicarboxylic acid are those mono- or dicarboxylic acids or derivatives thereof in which the carboxyl group or in the case of dicarboxylic acids at least one carboxyl group, preferably both carboxyl groups are conjugated with the ethylenically unsaturated double bond.

Examples of ethylenically unsaturated mono- or dicarboxylic acid which are not α, β-ethylenically unsaturated are cis-5-norbornene-endo-2,3-dicarboxylic anhydride, exo-3,6-epoxy-1,2,3, 6-tetrahydrophthalic anhydride and cis-4-cyclohexene-1,2-dicarboxylic acid anhydride.

Examples of α, β-ethylenically unsaturated monocarboxylic acids are acrylic acid, methacrylic acid, crotonic acid and ethylacrylic acid, preferably acrylic acid and methacrylic acid, referred to in this document as (meth) acrylic acid, and particularly preferably acrylic acid.

Particularly preferred derivatives of α, β-ethylenically unsaturated monocarboxylic acids are methyl acrylate, ethyl acrylate, n-butyl acrylate and methyl methacrylate.

Examples of dicarboxylic acids are maleic acid, fumaric acid, itaconic acid (2-methylenebutanoic acid), citraconic acid (2-methylmaleic acid), glutaconic acid (pent-2-ene-1, 5-dicarboxylic acid), 2,3-dimethylmaleic acid, 2-methylfumaric acid, 2 , 3-dimethylfumaric acid, methylenemalonic acid and tetrahydrophthalic acid, preferably maleic acid and fumaric acid, and more preferably maleic acid and its derivatives.

In particular, the monomer (A) is maleic anhydride.

The monomer (B) is at least one, preferably one to four, more preferably one to three, most preferably one or two and especially exactly one α-olefin having from at least 12 up to and including 30 carbon atoms. The α-olefins (B) preferably have at least 14, more preferably at least 16, and most preferably at least 18 carbon atoms. Preferably, the alpha-olefins (B) have up to and including 28, more preferably up to and including 26, and most preferably up to and including 24 carbon atoms.

The α-olefins may preferably be linear or branched, preferably linear 1-alkenes. Examples thereof are 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadiene, 1-octadecene, 1-nonodecene, 1-eicosene, 1-doses, 1-tetracoses, 1 -Hexacoses, of which 1-octadecene, 1-eicosene, 1-doses and 1-tetracoses, and mixtures thereof are preferred. Further examples of α-olefin (B) are those olefins which are oligomers or polymers of C ₂ - to C 12 -olefins, preferably C ₃ - to C 10 -olefins, more preferably C ₄ - to C ₆ -olefins. Examples of these are ethene, propene, 1-butene, 2-butene, isobutene, pentene isomers and hexene isomers; preference is given to ethene, propene, 1-butene, 2-butene and isobutene. Named as α-olefins (B) may be mentioned oligomers and polymers of propene, 1-butene, 2-butene, isobutene, and mixtures thereof, especially oligomers and polymers of propene or isobutene or of mixtures of 1-butene and 2-butene. Among the oligomers, the trimers, tetramers, pentamers and hexamers and mixtures thereof are preferred.

In addition to the olefin (B) optionally at least one, preferably one to four, more preferably one to three, most preferably one or two and especially just another, at least 4 carbon atoms, having aliphatic or cycloaliphatic olefin (C), the other than (B) is copolymerized in the copolymer of the invention.

The olefins (C) may be olefins with terminal (o) double bond or those with non-terminal double bond, preferably with a-double bond. Preferably, the olefin (C) is olefins having 4 to less than 12 or more than 30 carbon atoms. When the olefin (C) is an olefin having 12 to 30 carbon atoms, this olefin (C) does not have an α-double bond.

Examples of aliphatic olefins (C) are 1-butene, 2-butene, isobutene, pentene isomers, hexene isomers, heptene isomers, octene isomers, nonene isomers, decene isomers, undecene isomers, and mixtures thereof ,

Examples of cycloaliphatic olefins (C) are cyclopentene, cyclohexene, cyclooctene, cyclodecene, cyclododecene, o or ß-pinene and mixtures thereof, limonene and norbornene.

Further examples of olefins (C) are polymers of propene, 1-butene, 2-butene or isobutene containing more than 30 carbon atoms or olefin mixtures containing such, preferably of isobutene or olefin mixtures containing such, particularly preferably having an average molecular weight M _w in the range of 500 to 5000 g / mol, preferably 650 to 3000, more preferably 800 to 1500 g / mol.

The isobutene in copolymerized form containing oligomers or polymers preferably have a high content of terminal ethylenic double bonds (a-double bonds), for example at least 50 mol%, preferably at least 60 mol%, more preferably at least 70 Mole%, and most preferably at least 80 mole%.

Both isobutene and isobutene-containing C4 hydrocarbon streams, for example C4 raffinates, in particular "raffinate 1", are suitable as isobutene source for the preparation of such isobutene in copolymerized form containing oligomers or polymers.

C4 cuts from isobutane dehydrogenation, C4 cuts from steam crackers and out

FCC (fluid catalysed cracking) crackers, insofar as they are largely of the type contained therein

1, 3-butadiene are free. A C4 hydrocarbon stream from an FCC refinery unit is also known as a "b / b" stream. Further suitable isobutene-containing C4 hydrocarbon streams are, for example, the product stream of a propylene-isobutane co-oxidation or the product Ström from a metathesis unit, which are usually used after conventional purification and / or concentration. Suitable C4 hydrocarbon streams typically contain less than 500 ppm, preferably less than 200 ppm, butadiene. The presence of 1-butene and of cis- and trans-2-butene is largely uncritical. Typically, the isobutene concentration in said C4 hydrocarbon streams is in the range of 40 to 60 weight percent. Thus, raffinate 1 usually consists essentially of 30 to 50 wt .-% of isobutene, 10 to 50 wt .-% 1-butene, 10 to 40 wt .-% cis- and trans-2-butene and 2 to 35 wt .-% butanes; In the polymerization process according to the invention, the unsubstituted butenes in the raffinate 1 are generally practically inert and only the isobutene is polymerized. A preferred embodiment of the monomer source for the polymerization is a C4-hydrocarbon industrial stream having an isobutene content of 1 to

100 wt .-%, in particular from 1 to 99 wt .-%, especially from 1 to 90 wt .-%, particularly preferably from 30 to 60 wt .-%, in particular a raffinate stream 1, a b / b Stream from an FCC refinery unit, a product stream of propylene-isobutane co-oxidation, or a product stream from a metathesis unit.

In particular, when using a raffinate 1 stream as isobutene source, the use of water has proved to be the sole or as a further initiator, especially if at temperatures from -20 ° C to + 30 ° C, in particular from 0 ° C to + 20 ° C, polymerized. At temperatures of -20 ° C to + 30 ° C, in particular from 0 ° C to + 20 ° C, however, it is possible to dispense with the use of an initiator when using a raffinate 1 stream as Isobutenquelle.

Said isobutene-containing monomer mixture may contain small amounts of contaminants such as water, carboxylic acids or mineral acids, without resulting in critical yield or selectivity losses. It is expedient to avoid an accumulation of these impurities by removing such pollutants from the isobutene-containing monomer mixture, for example by adsorption on solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

Although less preferred, monomer mixtures of isobutene or of the isobutene-containing hydrocarbon mixture can also be reacted with olefinically unsaturated monomers which are copolymerizable with isobutene. If monomer mixtures of isobutene are to be copolymerized with suitable comonomers, the monomer mixture preferably contains at least 5% by weight, particularly preferably at least 10% by weight and in particular at least 20% by weight of isobutene, and preferably at most 95% by weight preferably at most 90% by weight and in particular at most

80% by weight of comonomers. In a preferred embodiment, the substance mixture of the olefins (B) and optionally (C) averaged to their substance amounts at least 12 carbon atoms, preferably at least 14, more preferably at least 16 and most preferably at least 17 carbon atoms. For example, a 2: 3 mixture of docoses and tetradecene has an average value for the carbon atoms of 0.4 ^χ 22 + 0.6 x 14 = 17.2.

The upper limit is less relevant and is usually not more than 60 carbon atoms, preferably not more than 55, more preferably not more than 50, most preferably not more than 45 and especially not more than 40 carbon atoms.

The optional monomer (D) is at least one monomer, preferably one to three, more preferably one or two and most preferably exactly one monomer selected from the group consisting of

(Da) vinyl esters,

(Db) vinyl ethers,

(De) (meth) acrylic esters of alcohols containing at least 5 carbon atoms, (Dd) allylic alcohols or their ethers,

(De) N-vinyl compounds selected from the group consisting of vinyl compounds of heterocycles containing at least one nitrogen atom, N-vinylamides or N-vinyllactams,

(Df) ethylenically unsaturated aromatics and

(Dg) α, β-ethylenically unsaturated nitriles

(That is) (meth) acrylic acid amides and

(Di) Allylamines.

Examples of vinyl esters (Da) are vinyl esters of C 2 -C 12 -carboxylic acids, preferably vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pentanoate, vinyl hexanoate, vinyl octanoate, vinyl 2-ethylhexanoate, vinyl decanoate, and also vinyl esters of versatic acids 5 to 10 Vinyl esters of 2,2-dimethylpropionic acid (pivalic acid, versatic acid 5), 2,2-dimethylbutyric acid (neohexanoic acid, versatic acid 6), 2,2-dimethylpentanoic acid (neoheptanoic acid, versatic acid 7), 2,2- Dimethylhexanoic acid (neoctanoic acid, versatic acid 8), 2,2-dimethylheptanoic acid (neononanoic acid, versatic acid 9) or 2,2-dimethyloctanoic acid (neodecanoic acid, versatic acid 10).

Examples of vinyl ethers (Db) are vinyl ethers of Cr to C 12 -alkanols, preferably vinyl ethers of methanol, ethanol, / so-propanol, n-propanol, n-butanol, / so-butanol, sec / c-butanol, ferric butanol, n-hexanol, n-heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol) or 2-ethylhexanol.

Preferred (meth) acrylic esters (De) are (meth) acrylic esters of C5- to C12-alkanols, preferably of n-pentanol, n-hexanol, n-heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol), 2-ethylhexanol or 2-propylheptanol. Particular preference is given to acrylic acid pentyl esters, 2-ethylhexyl acrylate, 2-propylheptyl acrylate.

Examples of monomers (Dd) are allyl alcohols and allyl ethers of C 2 - to C 12 -alkanols, preferably allyl ethers of methanol, ethanol, / so-propanol, n-propanol, n-butanol, / so-butanol, n-butanol, n-hexanol, n-decanol, n-dodecanol (lauryl alcohol) or 2-ethylhexanol.

Examples of vinyl compounds (De) of heterocycles containing at least one nitrogen atom are N-vinylpyridine, N-vinylimidazole and N-vinylmorpholine.

Preferred compounds (De) are N-vinylamides or N-vinyllactams:

Examples of N-vinylamides or N-vinyllactams (De) are N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone and N-vinylcaprolactam.

Examples of ethylenically unsaturated aromatics (Df) are styrene and α-methylstyrene.

Examples of α, β-ethylenically unsaturated nitriles (Dg) are acrylonitrile and methacrylonitrile.

Examples of (meth) acrylic acid amides (Dh) are acrylamide and methacrylamide.

Examples of allylamines (di) are allylamine, dialkylallylamine and trialkyl allylammonium halide.

Preferred monomers (D) are (Da), (Db), (De), (De) and / or (Df), particularly preferably (Da), (Db) and / or (De), very particularly preferably (Da) and / or (De) and in particular (De).

The incorporation ratio of the monomers (A) and (B) and optionally (C) and optionally (D) in the copolymer obtained from the reaction step (I) is usually as follows:

The molar ratio of (A) / ((B) and (C)) (in total) is generally from 10: 1 to 1:10, preferably 8: 1 to 1: 8, particularly preferably 5: 1 to 1 : 5, most preferably 3: 1 to 1: 3, in particular 2: 1 to 1: 2 and especially 1, 5: 1 to 1: 1, 5. For the particular case of maleic anhydride as monomer (A), the molar incorporation ratio of maleic anhydride to monomers ((B) and (C)) (in total) is about 1: 1. To complete the conversion of the α-olefin

(B) it may nevertheless be useful to use maleic anhydride in a slight excess over the α-olefin, for example 1:01-1.5: 1, preferably 1.02-0.1.4.1, more preferably 1.05 - 1, 3: 1, most preferably 1, 07 - 1, 2: 1 and in particular 1, 1 - 1, 15: 1.

The molar ratio of the obligate monomer (B) to the monomer (C), as far as it is present, is generally from 1: 0.05 to 10, preferably from 1: 0.1 to 6, particularly preferably from 1: 0, 2 to 4, most preferably from 1: 0.3 to 2.5 and especially 1: 0.5 to 1.5.

In a preferred embodiment, in addition to monomer (B), it is not an optional monomer

(C) present. The proportion of one or more of the monomers (D), if present, based on the amount of the monomers (A), (B) and optionally (C) (in total) is generally from 5 to

200 mol%, preferably 10 to 150 mol%, particularly preferably 15 to 100 mol%, very particularly preferably 20 to 50 mol% and in particular 0 to 25 mol%.

In a preferred embodiment, no optional monomer (D) is present.

In a particularly preferred embodiment, the copolymer consists of the monomers (A) and (B).

In a second reaction step (II), the anhydride or carboxylic ester functionalities contained in the copolymer obtained from (I) are partially or completely hydrolyzed and / or saponified. In a preferred embodiment, the anhydride functionalities contained in the copolymer after reaction step (II) are substantially completely hydrolyzed.

However, it is also possible, although less preferred, to hydrolyze at least 50% to less than 100%, for example 66% to 95% or 75% to 90% of the anhydride functionalities present in the copolymer after reaction step (II).

For a hydrolysis, based on the anhydride functionalities contained, the amount of water is added which corresponds to the desired degree of hydrolysis and which heats the copolymer obtained from (I) in the presence of the added water. As a rule, a temperature of preferably 20 to 150 ° C. is sufficient for this, preferably 60 to 100 ° C. If necessary, the reaction can be carried out under pressure to prevent the escape of water. Under these reaction conditions, the anhydride functionalities in the copolymer are usually selectively reacted, whereas any carboxylic acid ester functionalities present in the copolymer do not react or at least react only in a subordinate manner.

For saponification, the copolymer is reacted with an amount of a strong base in the presence of water, which corresponds to the desired degree of saponification.

Preferred strong bases are hydroxides, oxides, carbonates or bicarbonates of alkali metals or alkaline earth metals.

The copolymer obtained from (I) is then heated in the presence of the added water and strong base. In general, a temperature of preferably 20 to 130 ° C is sufficient, preferably 50 to 1 10 ° C. If necessary, the reaction can be carried out under pressure.

It is also possible to hydrolyze the carboxylic acid ester functionalities with water in the presence of an acid. Preferred acids are mineral, carbon, sulfone or phosphorous acids. phorhaltige acids having a pKa of not more than 5, more preferably not more than 4 used.

Examples are acetic acid, formic acid, oxalic acid, salicylic acid, substituted succinic acids, aromatic or unsubstituted benzenesulfonic acids, sulfuric acid, nitric acid, hydrochloric acid or phosphoric acid. The use of acidic ion exchanger resins is also conceivable.

The copolymer obtained from (I) is then heated in the presence of the added water and the acid. As a rule, a temperature of preferably 40 to 200 ° C. is sufficient for this, preferably 80 to 150 ° C. If necessary, the reaction can be carried out under pressure.

If the copolymers obtained from step (II) still contain residues of acid anions, it may be preferable to remove these acid anions from the copolymer with the aid of an ion exchanger and to exchange them preferably for hydroxide ions or carboxylate ions, more preferably hydroxide ions. This is particularly the case when the acid anions contained in the copolymer are halides, sulfur-containing or nitrogen-containing. The copolymer obtained from reaction step (II) generally has a weight-average molecular weight Mw of from 0.5 to 20 kDa, preferably from 0.6 to 15, more preferably from 0.7 to 7, very particularly preferably from 1 to 7 and in particular 1, 5 to 54 kDa (determined by gel permeation chromatography with tetrahydrofuran and polystyrene as standard). The number average molecular weight Mn is usually from 0.5 to 10 kDa, preferably from 0.6 to 5, particularly preferably from 0.7 to 4, very particularly preferably from 0.8 to 3 and in particular from 1 to 2 kDa (determined by gel permeation chromatography with tetrahydrofuran and polystyrene as standard). The polydispersity is generally from 1 to 10, preferably from 1, 1 to 8, particularly preferably from 1, 2 to 7, very particularly preferably from 1, 3 to 5 and in particular from 1, 5 to 3.

The content of free acid groups in the copolymer after passing through the reaction step (II) is preferably from 1 to 8 mmol / g copolymer, more preferably from 2 to 7 and most preferably from 3 to 7 mmol / g copolymer.

In a preferred embodiment, the copolymers contain a high proportion of adjacent carboxylic acid groups as determined by an adjuacy measurement. For this purpose, a sample of the copolymer is tempered for 30 minutes at a temperature of 290 ° C between two Teflon films and recorded at a bubble-free FTIR spectrum. From the spectra obtained, the IR spectrum of Teflon is subtracted, determines the layer thickness and determines the content of cyclic anhydride. In a preferred embodiment, the adjacency is at least 10%, preferably at least 15%, particularly preferably at least 20%, very particularly preferably at least 25% and in particular at least 30%. use

The fuel additized with the copolymer according to the invention is a gasoline or, in particular, a middle distillate fuel, above all a diesel fuel, very particularly a diesel fuel, containing at least one biofuel oil.

The fuel may contain other conventional additives. Frequently, the copolymers described are used in the form of fuel additive mixtures, together with customary additives:

In the case of diesel fuels, these are primarily conventional detergent additives, carrier oils, cold flow improvers, lubricity improvers, corrosion inhibitors other than the described copolymers, demulsifiers, dehazers, defoamers, cetane number improvers, combustion improvers, antioxidants or stabilizers, antistatic agents, Me - tallowene, metal deactivators, dyes and / or solvents. In the case of gasoline fuels, these are mainly friction modifiers, corrosion inhibitors other than the copolymers described, demulsifiers, dehazers, antifoams, combustion improvers, antioxidants or stabilizers, antistatic agents, metallocenes, metal deactivators, dyes and / or solvents. Typical examples of suitable co-additives are listed in the following section:

B1) Detergent additives

The customary detergent additives are preferably amphiphilic substances which have at least one hydrophobic hydrocarbon radical with a number average

Have molecular weight (M _n ) of 85 to 20,000 and at least one polar group selected from:

(Da) mono- or polyamino groups with up to 6 nitrogen atoms, where at least one nitrogen atom has basic properties;

(Db) nitro groups, optionally in combination with hydroxyl groups;

(De) hydroxyl groups in combination with mono- or polyamino groups, wherein at least one nitrogen atom has basic properties;

(Dd) carboxyl groups or their alkali metal or alkaline earth metal salts;

(De) sulfonic acid groups or their alkali metal or alkaline earth metal salts; (Df) polyoxy-C 2 - to C 4 -alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, where at least one nitrogen atom has basic properties, or by carbamate groups;

(Dg) carboxylic acid ester groups; succinic anhydride-derived moieties having hydroxy and / or amino and / or amido and / or imido groups; and / or by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated groups.

The hydrophobic hydrocarbon radical in the above detergent additives which provides sufficient solubility in the fuel has a number average molecular weight (M _n ) of from 85 to 20,000, preferably from 13 to 10,000, more preferably from 300 to 5,000, more preferred from 300 to 3,000, more preferably from 500 to 2,500 and in particular from 700 to 2,500, especially from 800 to 1,500. As a typical hydrophobic hydrocarbon radical, in particular in conjunction with the polar in particular polypropenyl, polybutenyl and polyisobutenyl radicals having a number average Molecular weight M _n of preferably in each case 300 to 5,000, particularly preferably 300 to 3,000, more preferably 500 to 2,500, even more preferably 700 to 2,500 and in particular 800 to 1,500.

As examples of the above groups of detergent additives, the following are mentioned:

Mono- or polyamino (Da) -containing additives are preferably polyalkene mono- or polyalkene polyamines based on polypropene or of highly reactive (ie predominantly terminal double bonds) or conventional (ie predominantly intermediate double bonds) polybutene or polyisobutene with M _n = 300 to 5000, especially preferably from 500 to 2500 and in particular from 700 to 2500. Such additives based on highly reactive polyisobutene, which may contain from the polyisobutene, which may contain up to 20% by weight of n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine, are known in particular from EP-A 244 616. If one starts with the preparation of the additives of polybutene or polyisobutene with predominantly intermediate double bonds (usually in the β and γ position), the preparation route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. For amination here amines, such as. As ammonia, monoamines or the above polyamines, are used. Corresponding additives based on polypropene are described in particular in WO-A 94/24231. Other particular monoamino (Da) containing additives are the hydrogenation of the reaction products of polyisobutenes having an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular in WO-A 97/03946.

Further special monoamino (Da) -containing additives are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described in particular in DE-A 196 20 262.

Nitro groups (Db), optionally in combination with hydroxyl groups, containing additives are preferably reaction products of polyisobutenes of average degree of polymerization P = 5 to 100 or 10 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular in WO-A96 / 03367 and in WO-A 96/03479 are described. As a rule, these reaction products are mixtures of pure nitropolyisobutenes (for example α, β-dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (for example α-nitro-β-hydroxypolyisobutene).

Hydroxyl groups in combination with mono- or polyamino (De) containing additives are in particular reaction products of polyisobutene epoxides obtainable from preferably predominantly terminal double bonds having polyisobutene with M _n = 300 to 5000 with ammonia, mono- or polyamines, as described in particular in EP-A 476 485 are described. Carboxyl groups or their alkali metal or alkaline earth metal salts (Dd) containing additives are preferably copolymers of C2 to C4o-olefins with maleic anhydride having a total molecular weight of 500 to 20,000, their carboxyl groups wholly or partly to the alkali metal or alkaline earth metal salts and a remaining Rest of the carboxyl groups are reacted with alcohols or amines. Such additives are known in particular from EP-A 307 815. Such additives are mainly used to prevent valve seat wear and, as described in WO-A 87/01 126, can be advantageously used in combination with conventional fuel detergents such as poly (iso) -butene amines or polyetheramines.

Sulfonic acid groups or their alkali metal or alkaline earth metal salts (De) containing additives are preferably alkali metal or alkaline earth metal salts of a Sulfobern- steinsäurealkylesters, as described in particular in EP-A 639 632. Such additives are primarily for preventing valve seat wear and can be used to advantage in combination with conventional fuel detergents such as poly (iso) buteneamines or polyetheramines.

Polyoxy-C 2 -C 4 -alkylene groups (Df) -containing additives are preferably polyethers or polyetheramines, which are prepared by reaction of C 2 - to C 6 -alkanols, C 6 - to C 3 -alkanediols, mono- or C 1 -C -cycloalkylamines, C to C3o-alkylcyclo-hexanols or C to C30-alkylphenols with 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per Hydroxyl group or amino group and, in the case of polyether amines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. Such products are described in particular in EP-A 310 875, EP-A 356 725, EP-A 700 985 and

US-A 4,877,416. In the case of polyethers, such products also fulfill carrier oil properties. Typical examples thereof are tridecanol or isotridecanol butoxylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates, and the corresponding reaction products with ammonia.

Carboxyl ester groups (Dg) -containing additives are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, especially those having a minimum viscosity of 2 mm ² / s at 100 ° C, as described in particular in DE-A 38 38 918 are described. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or polyols are long-chain representatives having, for example, 6 to 24 C atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of iso-octanol, iso-nonanol, iso-decanol and of isotridecanol. Such products also meet carrier oil properties.

Derivatives derived from succinic anhydride with hydroxyl and / or amino and / or amido and / or imido (Dh) containing additives are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and in particular the corresponding derivatives of polyisobutenyl succinic anhydride, which by reaction of conventional or highly reactive polyisobutene with M _n = preferably 300 to 5000, more preferably 300 to 3000, more preferably 500 to 2500, even more preferably 700 to 2500 and in particular 800 to 1500, with maleic anhydride on a thermal route in an En Reaction or via the chlorinated polyisobutene are available. The groups having hydroxyl and / or amino and / or amido and / or imido groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of diamines or polyamines which, in addition to the amide function, still have free amine groups, succinic acid derivatives with an acid and an amide function, carboximides with monoamines, carboximides with di- or polyamines which, in addition to the imide function, also have free amine groups, or diimides which are formed by reacting di- or polyamines with two succinic acid derivatives. Such fuel additives are well known and described, for example, in documents (1) and (2). Preference is given to the reaction products of alkyl- or alkenyl-substituted succinic acids or derivatives thereof with amines, and particularly preferably to the reaction products of polyisobutenyl-substituted succinic acids or derivatives thereof with amines. Of particular interest here are reaction products with aliphatic polyamines (polyalkyleneimines), in particular ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine, which have an imide structure.

In a preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in WO 2012/004300, there preferably page 5, line 18 to page 33, line 5, particularly preferably of preparation example 1, which is hereby expressly incorporated herein by reference.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in unpublished International Application with the file reference PCT / EP2014 / 061834 and the filing date 6 June 2014, there preferably page 5, line 21 to page 47, line 34, more preferably Preparation Examples 1 to 17. In a further preferred embodiment, the compounds of the invention can be combined with quaternized compounds, as described in WO 1 1/95819 A1, there preferably page 4, line 5 to page 13, line 26, especially preferred preparation example 2.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in WO 1 1/1 10860 A1, there preferably page 4, line 7 to page 16, line 26, particularly preferably the preparation examples 8, 9, 1 1 and 13.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in WO 06/135881 A2, there preferably page 5, line 14 to page 12, line 14, particularly preferably examples 1 to 4.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in WO 10/132259 A1, there preferably page 3, line 29 to page 10, line 21, particularly preferably example 3.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in WO 08/060888 A2, there preferably page 6, line 15 to page 14, line 29, particularly preferably examples 1 to 4.

In a further preferred embodiment, the compounds according to the invention can be combined with quaternized compounds as described in GB 2496514 A, there preferably paragraphs [00012] to [00039], particularly preferably examples 1 to 3. In a further preferred embodiment, the compounds according to the invention can be combined be with quaternized compounds, as described in WO 2013 070503 A1, there preferably paragraphs [0001 1] to [00039], particularly preferably Examples 1 to 5.

By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated moieties containing (di) additives are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetra-ethylenepentamine or dimethyl - aminopropylamine. The polyisobutenyl-substituted phenols can be prepared from conventional or highly reactive polyisobutene with M _n = 300 to 5000 originate. Such "polyisobutene-Mannich bases" are described in particular in EP-A 831 141.

One or more of the detergent additives mentioned may be added to the fuel in such an amount that the metering rate of these detergent additives is preferably 25 to 2500 ppm by weight, in particular 75 to 1500 ppm by weight, especially 150 to 1000 ppm by weight.

B2) Carrier oils Co-used carrier oils can be of mineral or synthetic nature. Suitable mineral carrier oils are fractions obtained in petroleum processing, such as bright stock or base oils having viscosities such as from class SN 500 to 2000, but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. It is also useful as a "hydrocrack oil" known and obtained in the refining of mineral oil fraction (Vakuumdestillatschnitt with a boiling range of about 360 to 500 ° C, available from high pressure catalytically hydrogenated and isomerized and dewaxed natural mineral oil). Also suitable are mixtures of the abovementioned mineral carrier oils.

Examples of suitable synthetic carrier oils are polyolefins (polyalphaolefins or polyternal olefins), (poly) esters, (poly) alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-initiated polyethers, alkylphenol-initiated polyetheramines and carboxylic acid esters of long-chain alkanols.

Examples of suitable polyolefins are olefin polymers having M _n = 400 to 1800, especially based on polybutene or polyisobutene (hydrogenated or non-hydrogenated).

Examples of suitable polyethers or polyetheramines are preferably compounds containing polyoxy-C ₂ - to C ₄ -alkylene groups which are prepared by reacting C ₂ - to C ₆ -alkanols, C ₆ - to C ₃ -oxanediols, mono- or C 1 - to C 20 -alkylamines, C 1 to C 30 -alkylcyclohexanols or C 1 to C 30 -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. Such products are described in particular in EP-A 310 875,

EP-A 356 725, EP-A 700 985 and US-A 4,877,416. For example, P0IV-C2 to C6 alkylene oxide amines or functional derivatives thereof may be used as the polyether amines. Typical examples thereof are tridecanol or isotridecanol butoxylates, isononylphenol butoxylates and also polyisobutenol butoxylates and propoxylates and the corresponding reaction products with ammonia. Examples of carboxylic acid esters of long-chain alkanols are, in particular, esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, as described in particular in DE-A 38 38 918. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or polyols are long-chain representatives having, for example, 6 to 24 carbon atoms. Typical representatives the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, e.g. B. di- (n- or isotridecyl) phthalate.

Further suitable carrier oil systems are described for example in DE-A 38 26 608,

DE-A 41 42 241, DE-A 43 09 074, EP-A 452 328 and EP-A 548 617 described.

Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers having about 5 to 35, preferably about 5 to 30, particularly preferably 10 to 30 and in particular 15 to 30 C3 to C6 alkylene oxide units, for. For example, propylene oxide, n-butylene oxide and isobutylene oxide units or mixtures thereof, per alcohol molecule. Nonlimiting examples of suitable starter alcohols are long-chain alkanols or long-chain alkyl-substituted phenols, where the long-chain alkyl radical is in particular a straight-chain or branched C 6 - to C 18 -alkyl radical. Specific examples include tridecanol and nonylphenol. Particularly preferred alcohol-started polyethers are the reaction products (polyether condensation products) of monohydric C6- to Cis-aliphatic alcohols with C3- to C6-alkylene oxides. Examples of monohydric aliphatic C6-C18-alcohols are hexanol, heptanol, octanol, 2-ethyl-hexanol, nonyl alcohol, decanol, 3-propylheptanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol and their constitution and position isomers. The alcohols can be used both in the form of pure isomers and in the form of technical mixtures. A particularly preferred alcohol is tridecanol. Examples of C3 to C6 alkylene oxides are propylene oxide, such as 1, 2-propylene oxide, butylene oxide, such as 1, 2-butylene oxide, 2,3-butylene oxide, isobutylene oxide or tetrahydrofuran, pentylene oxide and hexylene oxide. Particularly preferred among these are C3 to C4 alkylene oxides, i. Propylene oxide such as 1, 2-propylene oxide and butylene oxide such as 1, 2-butylene oxide, 2,3-butylene oxide and isobutylene oxide. Specifically, butylene oxide is used.

Other suitable synthetic carrier oils are alkoxylated alkylphenols, as described in the

DE-A 10 102 913 are described. Particular carrier oils are synthetic carrier oils, the alcohol-initiated polyethers described above being particularly preferred.

The carrier oil or the mixture of different carrier oils is added to the fuel in an amount of preferably from 1 to 1000 ppm by weight, more preferably from 10 to 500 ppm by weight and in particular from 20 to 100 ppm by weight.

B3) cold flow improver

Suitable cold flow improvers are in principle all organic compounds which are able to improve the flow behavior of middle distillate fuels or diesel fuels in the cold. Conveniently, they must have sufficient oil solubility. In particular, the usually used for middle distillates of fossil origin, ie for conventional mineral diesel fuels, used cold flow improvers ("middle distillate flow improvers", "MDFI") come into consideration. However, organic compounds can also be used When used in conventional diesel fuels, some or most of them have the properties of a Wax Anti-Settling Additive ("WASA"). Also, they can act partly or predominantly as nucleators. However, it is also possible to use mixtures of organic compounds which are active as MDFI and / or which act as WASA and / or as nucleators.

Typically, the cold flow improver is selected from:

(K1) copolymers of a C2 to C4o olefin with at least one further ethylenically unsaturated monomer;

(K2) comb polymers;

(K3) polyoxyalkylenes;

(K4) polar nitrogen compounds;

(K5) sulfocarboxylic acids or sulfonic acids or their derivatives; and

(K6) poly (meth) acrylic acid esters.

Mixtures of different representatives from one of the respective classes (K1) to (K6) as well as mixtures of representatives from different classes (K1) to (K6) can be used. Suitable C 2 - to C 4 -olefin monomers for the copolymers of class (K1) are, for example, those having 2 to 20, in particular 2 to 10 carbon atoms and having 1 to 3, preferably 1 or 2, in particular a carbon-carbon double pelbindung. In the latter case, the carbon-carbon double bond can be arranged both terminally (α-olefins) and internally. However, preference is given to α-olefins, particularly preferably α-olefins having 2 to 6 carbon atoms, for example propene, 1-butene, 1-pentene, 1-hexene and, above all, ethylene.

In the copolymers of class (K1), the at least one further ethylenically unsaturated monomer is preferably selected from carboxylic alkenyl esters, (meth) acrylic esters and further olefins.

If further olefins are polymerized in, these are preferably higher molecular weight than the abovementioned C 2 - to C 4 -olefin base monomers. If, for example, ethylene or propene is used as the olefin base monomer, suitable further olefins are, in particular

C10 to C4o α-olefins. Other olefins are polymerized in most cases only when monomers with carboxylic acid ester functions are used.

Suitable (meth) acrylic acid esters are, for example, esters of (meth) acrylic acid with C 2 to C 20 alkanols, in particular C 1 to C 10 alkanols, especially with methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert Butanol, pentanol, hexanol, heptanol, octanol, 2-ethylhexanol, nonanol and decanol and structural isomers thereof.

Suitable carboxylic acid alkenyl esters are, for example, C 2 - to C 6 -alkenyl esters, for example the vinyl and propenyl esters, of carboxylic acids having 2 to 21 carbon atoms, the hydrocarbons thereof Fabric remainder may be linear or branched. Preferred among these are the vinyl esters. Among the carboxylic acids with a branched hydrocarbon radical, preference is given to those whose branching is in the α-position to the carboxyl group, the α-carbon atom being particularly preferably tertiary, ie the carboxylic acid being a so-called neocarboxylic acid. Preferably, however, the hydrocarbon radical of the carboxylic acid is linear.

Examples of suitable alkenyl carboxylic acid esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, the vinyl esters being preferred. A particularly preferred carboxylic acid alkenyl ester is vinyl acetate; typical resulting copolymers of group (K1) are the most commonly used ethylene-vinyl acetate copolymers ("EVA").

Particularly advantageous ethylene-vinyl acetate copolymers and their preparation are described in WO 99/29748.

Suitable copolymers of class (K1) are also those which contain two or more mutually different carboxylic acid alkenyl esters in copolymerized form, these differing in the alkenyl function and / or in the carboxylic acid group. Likewise suitable are copolymers which, in addition to the carboxylic acid alkenyl ester (s), comprise at least one olefin and / or at least one (meth) acrylic acid ester in copolymerized form.

Also terpolymers of a C2 to C4o-α-olefin, a C to C2o-alkyl ester of an ethylenically unsaturated monocarboxylic acid having 3 to 15 carbon atoms and a C2 to C14-AI kenylester a saturated monocarboxylic acid having 2 to 21 carbon atoms are as Copolymers of class (K1) are suitable. Such terpolymers are described in WO 2005/054314. A typical such terpolymer is composed of ethylene, 2-ethylhexyl acrylate and vinyl acetate. The at least one or the other ethylenically unsaturated monomers are present in the copolymers of class (K1) in an amount of preferably from 1 to 50% by weight, in particular from 10 to 45% by weight and especially from 20 to 40% by weight .-%, based on the total copolymer, copolymerized. The majority by weight of the monomer units in the copolymers of class (K1) thus usually comes from the C2 to C4o-based olefins.

The copolymers of class (K1) preferably have a number average molecular weight M _{n of} from 1000 to 20,000, particularly preferably from 1000 to 10,000 and in particular from 1000 to 8000. Typical comb polymers of component (K2) are, for example, by the copolymerization of maleic anhydride or fumaric acid with another ethylenically unsaturated monomer, for example with an α-olefin or an unsaturated ester such as vinyl acetate, and subsequent esterification of the anhydride or acid function with an alcohol having at least 10 carbon atoms available. Other suitable comb polymers are copolymers of α-olefins and esterified comonomers, for example, esterified copolymers of styrene and maleic anhydride or esterified copolymers of styrene and fumaric acid. Suitable comb polymers may also be polyfumarates or polymaleinates. In addition, homopolymers and copolymers of vinyl ethers are suitable comb polymers. Comb polymers suitable as a component of class (K2) are, for example, those described in WO 2004/035715 and in "Comb-Like Polymers, Structure and Properties", NA Plate and VP Shibaev, J. Poly. Be. Macromolecular Revs. 8, pp. 1 17 to 253 (1974). "Also suitable are compounds of comb polymers.""Polyoxyalkylenes suitable as a component of class (K3) are, for example, polyoxyalkylene ethers, polyoxyalkylene ethers, mixed polyoxyalkylene ester ethers, and mixtures thereof, Preferably, these contain polyoxyalkylene compounds at least one, preferably at least two linear alkyl groups each having from 10 to 30 carbon atoms and a polyoxyalkylene group having a number average molecular weight of up to 5,000. Such polyoxyalkylene compounds are described, for example, in EP-A 061 895 and in US Pat. No. 4,491,455. Particular polyoxyalkylene compounds are based on polyethylene glycols and polypropylene glycols having a number average molecular weight of 100 to 5,000. Polyoxyalkylene mono- and diesters of fatty acids having 10 to 30 carbon atoms, such as stearic acid or behenic acid, are furthermore suitable.

Polar nitrogen compounds suitable as a component of class (K4) may be of both ionic and nonionic nature, and preferably have at least one, especially at least two, tertiary nitrogen substituent of the general formula> NR ⁷ , wherein R ^{7 is} Cs to C 40 Hydrocarbon residue stands. The nitrogen substituents may also be quaternized, ie in cationic form. Examples of such nitrogen compounds are ammonium salts and / or amides obtainable by reacting at least one amine substituted with at least one hydrocarbyl radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. Preferably, the amines contain at least one linear Cs to C4o-alkyl radical. Examples of suitable primary amines for the preparation of said polar nitrogen compounds are octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine and the higher linear homologues; suitable secondary amines are, for example, dioctadecylamine and methylbehenylamine. Also suitable for this purpose are amine mixtures, in particular industrially available amine mixtures such as fatty amines or hydrogenated tallamines, as described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, in the chapter "Amines, aliphatic". Suitable acids for the reaction are, for example, cyclohexane-1, 2-dicarboxylic acid, cyclohexene-1, 2-dicarboxylic acid, cyclopentane-1, 2-dicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and succinic acids substituted by long-chain hydrocarbon radicals.

In particular, the component of class (K4) is an oil-soluble reaction product of poly (C 2 - to C 20 -carboxylic acids) containing at least one tertiary amino group with primary or secondary amines. The poly (C 2 - to C 20 -carboxylic acids) which have at least one tertiary amino group and are based on this reaction product preferably contain at least 3 carboxyl groups, especially 3 to 12, especially 3 to 5 carboxyl groups. The carboxylic acid units in the polycarboxylic acids preferably have 2 to 10 carbon atoms, in particular they are acetic acid units. The carboxylic acid units are suitably linked to the polycarboxylic acids, usually via one or more carbon and / or nitrogen atoms. Preferably, they are attached to tertiary nitrogen atoms, which are connected in the case of several nitrogen atoms via hydrocarbon chains.

The component of the class (K4) is preferably an oil-soluble reaction product based on poly (C 2 - to C 20 -carboxylic acids) having the general formula IIa or IIb and having at least one tertiary amino group

HOOC. _DD OOH

B B

HOOC_ .N_N. OOH

B A B

HOOC ^B "N ' ^B " COOH

^ COOH _{(N b)} in which the variable A is a straight-chain or branched C 2 - to C 6 -alkylene group or the grouping of the formula III

^HOOC'B ^{^} N ^{H2 "CH2"}

i

CH ₂ -CH ₂ - _{(| | |)}

and the variable B denotes a C to Cig alkylene group. The compounds of the general formula IIa and IIb have in particular the properties of a WASA.

Furthermore, the preferred oil-soluble reaction product of component (K4), in particular that of general formula IIa or IIb, is an amide, an amide ammonium salt or an ammonium salt in which no, one or more carboxylic acid groups are converted into amide groups.

Straight-chain or branched C2 to C6-alkylene groups of the variable A are, for example, 1,1-ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1,3-butylene, 1,4-butylene, 2-methyl-1,3-propylene, 1,5-pentylene, 2-methyl-1,4-butylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene (hexamethylene) and in particular 1, 2-ethylene. Preferably, the variable A comprises 2 to 4, in particular 2 or 3 carbon atoms. Cr to Ci9-alkylene groups of the variable B are, for example, 1, 2-ethylene, 1, 3-propylene, 1, 4-butylene, hexamethylene, octamethylene, decamethylene, dodecamethylene, Tetradecamethyl- en, hexadecamethylene, octadecamethylene, Nonadecamethylen and especially methylene. Preferably, the variable B comprises 1 to 10, in particular 1 to 4, carbon atoms. The primary and secondary amines as reaction partners for the polycarboxylic acids to form the component (K4) are usually monoamines, in particular aliphatic monoamines. These primary and secondary amines may be selected from a variety of amines bearing hydrocarbon radicals, optionally linked together.

In most cases, these amines which are the oil-soluble reaction products of component (K4) are secondary amines and have the general formula HN (R ⁸ ) 2, in which the two variables R ⁸ are each independently straight-chain or branched C 10 - to C 30 -alkyl radicals, in particular C to C24 alkyl radicals. These longer-chain alkyl radicals are preferably straight-chain or only slightly branched. As a rule, the abovementioned secondary amines are derived, with regard to their longer-chain alkyl radicals, from naturally occurring fatty acids or from their derivatives. Preferably, the two radicals R ^{8 are the} same. The abovementioned secondary amines can be bound to the polycarboxylic acids by means of amide structures or in the form of the ammonium salts, and only one part can be present as amide structures and another part as ammonium salts. Preferably, only a few or no free acid groups are present. Preferably, the oil-soluble reaction products of component (K4) are completely in the form of the amide structures.

Typical examples of such components (K4) are reaction products of nitrilotriacetic acid, ethylenediaminetetraacetic acid or propylene-1,2-diaminetetraacetic acid with in each case 0.5 to 1.5 mol per carboxyl group, in particular 0.8 to 1.2 mol per carboxyl group, dioleylamine, dipalmitinamine, dicoco fatty amine, distearylamine, dibehenylamine or especially ditallow fatty amine. A particularly preferred component (K4) is the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated ditallow fatty amine.

Further typical examples of component (K4) are the N, N-dialkylammonium salts of 2-N ', N'-dialkylamidobenzoates, for example the reaction product of 1 mol of phthalic anhydride and 2 mol of ditallow fatty amine, the latter hydrogenated or unhydrogenated may be, and the reaction product of 1 mole of a Alkenylspirobislactons with 2 moles of a dialkylamine, for example Ditalgfettamin and / or tallow fatty amine, the latter two may be hydrogenated or not hydrogenated, called. Further typical structural types for the component of the class (K4) are cyclic compounds having tertiary amino groups or condensates of long-chain primary or secondary amines with carboxylic acid-containing polymers, as described in WO 93/181 15.

Sulfocarboxylic acids, sulfonic acids or their derivatives which are suitable as cold flow improvers of the component of class (K5) are, for example, the oil-soluble carboxamides and carboxylic acid esters of ortho-sulfobenzoic acid in which the sulfonic acid function is present as a sulfonate with alkyl-substituted ammonium cations, as described in EP-A 261 957 to be discribed. As a cold flow improver of the component of the class (K6) suitable poly (meth) acrylic acid esters are both homo- and copolymers of acrylic and methacrylic acid esters. Preferred are copolymers of at least two mutually different (meth) acrylic acid esters, which differ with respect to the fused alcohol. Optionally, the copolymer contains a further, different of which olefinically unsaturated monomer copolymerized. The weight-average molecular weight of the polymer is preferably 50,000 to 500,000. A particularly preferred polymer is a copolymer of methacrylic acid and methacrylic acid esters of saturated C14 and Cis alcohols, wherein the acid groups are neutralized with hydrogenated talla- min. Suitable poly (meth) acrylic esters are, for example, in

WO 00/44857 described.

The middle distillate fuel or diesel fuel is the cold flow improver or the mixture of various cold flow improvers in a total amount of preferably 10 to 5000 ppm by weight, more preferably from 20 to 2000 ppm by weight, more preferably from 50 to 1000 ppm by weight and in particular from 100 to 700 ppm by weight, for example from 200 to 500 ppm by weight, added.

B4) Lubricity improvers Suitable lubricity improvers (or friction modifiers) are usually based on fatty acids or fatty acid esters. Typical examples are tall oil fatty acid, as described for example in WO 98/004656, and glycerol monooleate. The reaction products of natural or synthetic oils, for example triglycerides, and alkanolamines described in US Pat. No. 6,743,266 B2 are also suitable as such lubricity improvers.

B5) Other corrosion inhibitors than the described copolymer

Suitable corrosion inhibitors are e.g. Succinic esters, especially with polyols, fatty acid derivatives, e.g. Oleic acid esters, oligomerized fatty acids, substituted ethanolamines and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany), Irgora® L12 (BASF SE) or HiTEC 536 (Ethyl Corporation).

B6) Demulsifiers

Suitable demulsifiers are, for example, the alkali or alkaline earth salts of alkyl-substituted phenol and naphthalenesulfonates and the alkali or alkaline earth salts of fatty acids, as well as neutral compounds such as alcohol alkoxylates, for example alcohol ethoxylates, phenol alkoxylates, for example tert-butylphenol ethoxylate or tert-pentylphenol ethoxylate, fatty acids, Alkylphenols, condensation products of ethylene oxide (EO) and propylene oxide (PO), for example in the form of EO / PO block copolymers, polyethyleneimines or polysiloxanes. B7) Dehazer

Suitable dehazers are e.g. alkoxylated phenol-formaldehyde condensates such as the NALCO 7D07 (Nalco) and TOLAD 2683 (Petrolite) products available under the tradename.

B8) antifoam

Suitable antifoams are e.g. Polyether-modified polysiloxanes such as the TEGOPREN 5851 (Goldschmidt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc) products available under the tradename.

B9) Cetane number improvers Suitable cetane number improvers are e.g. aliphatic nitrates such as 2-ethylhexyl nitrate and cyclohexyl nitrate, and peroxides such as di-tert-butyl peroxide.

B10) Antioxidants Suitable antioxidants are e.g. substituted phenols such as 2,6-di-tert-butylphenol and 6-di-tert-butyl-3-methylphenol and phenylenediamines such as N, N'-di-sec-butyl-p-phenylenediamine.

B1 1) Metal deactivators Suitable metal deactivators are e.g. Salicylic acid derivatives such as N, N'-disalicylidene-1,2-propanediamine.

B12) Solvents Suitable are e.g. nonpolar organic solvents such as aromatic and aliphatic hydrocarbons, for example, toluene, xylenes, white spirit, and products sold under the trade name SHELLSOL (Royal Dutch / Shell Group) and EXXSOL (ExxonMobil), as well as polar organic solvents, for example, alcohols such as 2 Ethylhexanol, decanol and isotridecanol. Such solvents usually enter the diesel fuel together with the abovementioned additives and coadditives which they are intended to dissolve or dilute for better handling.

C) Fuels The additive according to the invention is outstandingly suitable as a fuel additive and can in principle be used in any fuels. It has a number of beneficial effects on the operation of internal combustion engines with fuels. Preferably, the additive is used in middle distillate fuels, especially diesel fuels, especially in diesel fuels containing biofuel oils. The present invention therefore also diesel fuels containing at least one biofuel oil and at least one copolymer, as described above, and optionally at least one further additive.

Another object of the present invention is a method for operating a diesel engine with such a fuel according to the invention, in particular of direct injection diesel engines, especially of diesel engines with common rail injection systems. This effective content (metering rate) of the copolymer in the fuel is generally from 5 to 5000 ppm by weight, preferably from 6 to 1000 ppm by weight, in particular from 8 to

500 ppm by weight, especially at 10 to 200 ppm by weight, in each case based on the total amount of fuel.

The use according to the invention relates in principle to any fuels, preferably diesel and gasoline fuels, especially diesel fuels, especially in diesel fuels containing biofuel oils.

Middle distillate fuels, such as diesel fuels or fuel oils, are preferably petroleum raffinates, which usually have a boiling range of from 100 to 400.degree. These are mostly distillates with a 95% point up to 360 ° C or even beyond. However, these may also be so-called "Ultra Low Sulfur Diesel" or "City Diesel", characterized by a 95% point of, for example, a maximum of 345 ° C and a maximum sulfur content of 0.005 wt .-% or by a 95% point of for example, 285 ° C and a maximum sulfur content of 0.001 wt .-%. In addition to the refining mineral middle distillate fuels or diesel fuels are also those by coal gasification or gas liquefaction ["gas to liquid" (GTL) fuels] or by biomass liquefaction ["biomass to liquid" (BTL ) Fuels] are available. Also suitable are mixtures of the abovementioned middle distillate fuels or diesel fuels with regenerative fuels, such as biodiesel or bioethanol.

The qualities of fuel oils and diesel fuels are specified in greater detail in, for example, DIN 51603 and EN 590 (cf., also, Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A12, page 617 et seq.). The use according to the invention in middle distillate fuels of fossil, vegetable or animal origin, which are essentially hydrocarbon mixtures, also relates to mixtures of such middle distillates with biofuel oils (biodiesel). Such mixtures are encompassed by the term "middle distillate fuel". They are commercially available and usually contain the biofuel oils in minor amounts, typically in amounts of 1 to 50 wt .-%, preferably 2 to 30 wt .-% and in particular from 3 to 10 wt .-%, based on the total amount of middle distillate fossil , of vegetable or animal origin and biofuel oil. Also, fuels are conceivable which contain or even consist of biofuel oils to a greater extent, for example more than 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, very particularly preferably at least 80% by weight and even up to 100% by weight (B100).

Biofuel oils are generally based on fatty acid esters, preferably substantially on alkyl esters of fatty acids derived from vegetable and / or animal oils and / or fats. Alkyl esters are usually lower alkyl esters, preferably C 1 to C ₄ alkyl esters, particularly preferably methyl or ethyl esters and very particularly preferably methyl esters, which are obtained by transesterification of the plant and / or animal oils and / or fats occurring glycerides, especially triglycerides , by means of lower alcohols, for example ethanol or especially methanol ("FAME"), are available. Typical lower alkyl esters based on vegetable and / or animal oils and / or fats which are used as biofuel oil or components thereof are, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME"), animal fat methyl ester ("FME"). ) or methyl ester of tallow methyl ester ("TME"), methyl ester of recovered vegetable oils, recycled used cooking oils and frying fats, so-called used vegetable oil ("UVO") or waste vege- table oil ("WVE") or used cooking oil methyl ester ("UCOME"), tall oil methyl ester and especially rapeseed oil methyl ester ("RME").

The middle distillate fuels or diesel fuels are particularly preferably those with a low sulfur content, ie with a sulfur content of less than 0.05% by weight, preferably less than 0.02% by weight, in particular less as 0.005 wt .-% and especially less than 0.001 wt .-% sulfur.

As gasoline fuels are all commercially available gasoline fuel compositions into consideration. A typical representative here is the market-standard basic fuel of Eurosuper according to EN 228. Furthermore, gasoline compositions of the specification according to WO 00/47698 are also possible fields of use for the present invention.

Another object of the present invention is a method for increasing the thermal and / or oxidation stability, especially the oxidation stability of fuels, preferably diesel fuels, particularly preferably diesel fuels, containing at least one biofuel, measured in the form of DIN EN 15751: 2014-06 by at least one Hour, preferably by at least two hours, particularly preferably by at least three hours, wherein at least 10 ppm by weight, preferably at least 20 ppm by weight, based on the fuel, of at least one of the copolymers described are added to the fuel, and the mixture obtainable in this way exposed to a thermal and / or oxidative stress.

The invention will now be described in detail with reference to the following embodiments. In particular, the test methods mentioned below are part of the general disclosure of the application and are not limited to the specific exemplary embodiments.

The following examples are intended to illustrate the present invention without limiting it. Examples

G PC analysis

Unless otherwise stated, the weight average Mw and number average molecular weight Mn of the polymers were measured by gel permeation chromatography (GPC). GPC separation was achieved via two PLge Mixed B columns (Agilent) in tetrahydrofuran at 35 ° C. The calibration was carried out by means of a narrowly distributed polystyrene standard (PSS, Germany) with molecular weight 162-50400 Da. Hexylbenzene was used as a low molecular weight marker.

Determination of the acid number

Determination of the Reaction Value 50 ml of 0.5 molar ethanolic KOH are heated to 95 ° C. in a 150 ml COD glass provided with an air cooler for three (3) hours. The air cooler is rinsed with 30 ml of ethanol and then the solution is titrated potentiographically with 0.5 molar aqueous hydrochloric acid (HCl).

Determination of the sample

Approximately 1 g of sample is weighed into a 150 ml COD glass and dissolved in 50 ml of 0.5 molar ethanolic KOH. The COD glass is provided with an air cooler and placed in the pre-heated to 95 ° C Rührblockthermostat. After three (3) hours, the COD glass is removed from the heating block, rinsed with 30 ml of ethanol and the solution is titrated potentiographically with 0.5 molar aqueous hydrochloric acid (HCl).

Preparation Examples

General working instructions

The olefin or the mixture of olefins with or without solvent (as bulk polymerization) was initially charged in a reactor with an anchor stirrer. The mixture was heated under nitrogen flow with stirring to the indicated temperature. To this was added the specified radical initiator (optionally diluted in the same solvent) and molten maleic anhydride (1 equivalent based on olefin monomer). The reaction mixture was stirred at the same temperature for the specified reaction time and then cooled. Then, water was added (0.9 equivalents based on maleic anhydride, unless indicated otherwise) and stirred at 95 ° C, 10-14 h or under pressure at 110 ° C for 3 h.

Synthetic Example 1

In a 2 L glass reactor with anchor stirrer, a mixture of C20-C24 olefins (363.2 g, average molecular weight 296 g / mol) and Solvesso 150 (231.5 g, DHC Solvent Chemie GmbH, Speldorf) submitted. The mixture was heated to 160 ° C in a stream of nitrogen and with stirring. To this was added within 5 h a solution of di-tert-butyl peroxide (29.6 g, Akzo Nobel) in Solvesso 150 (260.5 g) and molten maleic anhydride (120.3 g). The reaction mixture was stirred for 1 h at 160 ° C and then cooled to 95 ° C. At this temperature, water (19.9 g) was added within 3 h and then further stirred for 1 1 h.

The GPC (in THF) gave an Mn = 1210 g / mol for the copolymer, Mw = 2330 g / mol, which corresponds to a dispersity of 1.9.

The copolymer had a ratio of carbon atoms per acid group of 13, the acid value determined by the above procedure was 210.8 mg KOH / g.

Synthesis Example 2

In a 6 L metal reactor with anchor stirrer, a mixture of C20-C24 olefins (1743 g, average molecular weight 296 g / mol) and Solvesso 150 (1297 g, DHC Solvent Chemie GmbH, Speldorf) were submitted. The mixture was heated to 150 ° C in a stream of nitrogen and with stirring. To this was added within 5 h a solution of di-tert-butyl peroxide (1 18.4 g, Akzo Nobel) in Solvesso 150 (1041 g) and molten maleic anhydride (577 g). The reaction mixture was stirred for 1 h at 150 ° C and then cooled to 1 10 ° C. At this temperature, water (95 g) was added under pressure and then further stirred for 3 h.

The GPC (in THF) gave an Mn = 1420 g / mol for the copolymer, Mw = 2500 g / mol, which corresponds to a dispersity of 1.8.

Synthesis Example 3

In a 6 L metal reactor with anchor stirrer, a mixture of C20-C24 olefins (1743 g, average molecular weight 296 g / mol) and Solvesso 150 (1297 g, DHC Solvent Chemie GmbH, Speldorf) were submitted. The mixture was heated to 150 ° C in a stream of nitrogen and with stirring. To this was added within 5 h a solution of di-tert-butyl peroxide (23.7 g, Akzo Nobel) in Solvesso 150 (912 g) and molten maleic anhydride (577 g). The reaction mixture was stirred for 1 h at 150 ° C and then cooled to 1 10 ° C. At this temperature, water (95 g) was added under pressure and then further stirred for 3 h. The GPC (in THF) gave an Mn = 1500 g / mol for the copolymer, Mw = 3200 g / mol, which corresponds to a dispersity of 2.1.

applications

A diesel fuel (Aral B7, refinery Gelsenkirchen) in accordance with DIN EN590 was tested with the aid of the test in accordance with DIN EN 15751: 2014-06 in a Rancimat® model, model Metrohm 873 diesel Ranzimat, Metrohm AG, Herisau, Switzerland, on its thermal stability. For this purpose, 7.5 g of the fuel were added to the weight amounts of copolymer from Synthesis Example 1 given in the table and the test was carried out in accordance with DIN EN 15751: 2014-06 by an air flow of 10 liters through the sample heated to 110 ° C. is conducted per hour. The volatiles containing stream is passed into 60 ml of de-mineralized water and the conductivity is determined. A sudden increase in the electrical conductivity indicates the end of the induction time indicated in the table.

The following results were obtained:

Addition of copolymer induction time

[Weight ppm] [hours]

0 (comparison) 21, 55

20 25,91

50 26,44

Claims

claims

1 . Use of copolymers obtainable by

in a first reaction step (I) copolymerization of

(A) maleic anhydride,

(Da) vinyl esters,

(Db) vinyl ethers,

(De) (meth) acrylic esters of alcohols having at least 5 carbon atoms,

(Dd) allyl alcohols or their ethers,

(Df) ethylenically unsaturated aromatics

(Dg) α, β-ethylenically unsaturated nitriles,

(That is) (meth) acrylic acid amides and

Use according to any one of the preceding claims, characterized in that monomer (B) is an α-olefin having at least 14 to 26 carbon atoms inclusive.

3. Use according to one of the preceding claims, characterized in that olefin (C) is a polymer of propene, 1-butene, 2-butene or isobutene having more than 30 carbon atoms or olefin mixtures containing such preferably iso-butene or olefin mixtures containing such having an average molecular weight Mw in the range of 500 to 5000 g / mol.

Use according to one of the preceding claims, characterized in that the substance mixture of the olefins (B) and (C) averaged has at least 12 carbon atoms on their molar amounts.

Use according to any one of the preceding claims, characterized in that monomer (D) is selected from the group consisting of (Da), (Db), (De), (De) and (Df).

Use according to one of the preceding claims, characterized in that the molar ratio of (A) / ((B) and (C)) (in total) is from 10: 1 to 1:10.

Use according to claim 6, characterized in that the molar ratio of monomer (B) to monomer (C) is from 1: 0.05 to 10.

Use according to claim 6 or 7, characterized in that the proportion of one or more of the monomers (D) based on the amount of the monomers (A), (B) and optionally (C) (in total) is 5 to 200 mol% ,

Use according to one of the preceding claims, characterized in that the fatty acid alkyl ester is a C 1 to C ₄ alkyl ester.

Use according to one of the preceding claims, characterized in that the fatty acid alkyl ester is a methyl or ethyl ester.

Use according to one of the preceding claims, characterized in that the fatty acid alkyl ester is selected from the group consisting of sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME"), animal fat methyl ester ("FME"), tallow methyl ester ("TME"). ), Methyl esters of recovered vegetable oils, recycled used cooking oils and frying fats, used vegetable oil ("UVO"), waste vetable oil ("VWE"), used cooking oil methyl ester ("UCOME"), tall oil methyl ester and rapeseed oil methyl ester (" RME ").

Process for increasing the thermal and / or oxidation stability Biofuel oils or preferably diesel fuels containing at least one fatty acid alkyl ester, measured in the form of DIN EN 15751: 2014-06 by at least one hour, characterized in that at least one biofuel oil or preferably a diesel fuel containing at least provides a fatty acid alkyl ester and this biofuel or preferably this diesel fuel containing at least one fatty acid alkyl ester with at least 10 Gew.ppm based on the fuel of at least one copolymer as described in any one of claims 1 to 8 mixed and the like available mixture exposes a thermal and / or oxidative stress.