EP2038380B1 - Mixture from polar oil-soluble nitrogen compounds and acid amides as paraffin dispersant for fuels - Google Patents

Abstract

Provided is a mixture containing: (a) a polar oil-soluble nitrogen compounds which is capable of sufficiently dispersing paraffin crystals precipitated out under cold conditions in a fuel and is a reaction product formed from reacting a poly(C2- to C20-carboxylic acid), which has at least one tertiary amino group, with a primary or secondary amine; (b) an oil-soluble acid amide reaction product formed from reacting a polyamide, which has from 2 to 1000 carbon atoms, with a C8- to C30-fatty acid or fatty acid-like compound, which has a free carboxyl group; and (c) an oil-soluble reaction product formed from reacting an α,β-dicarboxylic acid, which has from 4 to 300 carbon atoms, or a derivatives thereof, with a primary alkylamine, wherein the sum of components (a) to (c) constitute 100 wt. % of the mixture. The mixture is suitable as a paraffin dispersant in fuels, especially those having a biodiesel content.

Description

1. (a) 5 bis 95 Gew.-% mindestens einer von den Komponenten (b) und (c) verschiedenen polaren öllöslichen Stickstoffverbindung, welche in der Lage ist, in Kraftstoffen in der Kälte ausgefallene Paraffinkristalle ausreichend zu dispergieren, und ausgewählt ist unter Umsetzungsprodukten aus mindestens eine tertiäre Aminogruppe aufweisenden Poly(C₂- bis C₂₀-Carbonsäuren) mit primären oder sekundären Aminen,
2. (b) 1 bis 50 Gew.-% mindestens eines öllöslichen Säureamids aus Polyaminen mit 2 bis 1000 Stickstoffatomen und C₈- bis C₃₀-Fettsäuren und
3. (c) 0 bis 50 Gew.-% mindestens eines öllöslichen Umsetzungsproduktes aus α,β-Dicarbonsäuren mit 4 bis 300 Kohlenstoffatomen oder deren Derivaten und primären Alkylaminen,

wobei die Summe aller Komponenten der Mischung (a) bis (c) 100 Gew.-% ergibt.The present invention relates to a mixture containing

1. (a) 5 to 95% by weight of at least one polar oil-soluble nitrogen compound other than components (b) and (c) which is capable of sufficiently dispersing paraffin crystals precipitated in fuels in the cold and selected from reaction products at least one tertiary amino group-containing poly (C ₂ - to C ₂₀ -carboxylic acids) with primary or secondary amines,
2. (B) 1 to 50 wt .-% of at least one oil-soluble acid amide of polyamines having 2 to 1000 nitrogen atoms and C ₈ - to C ₃₀ fatty acids and
3. (c) 0 to 50% by weight of at least one oil-soluble reaction product of α, β-dicarboxylic acids having 4 to 300 carbon atoms or derivatives thereof and primary alkylamines,

wherein the sum of all components of the mixture (a) to (c) gives 100 wt .-%.

Furthermore, the present invention relates to the use of this mixture as an additive to fuels, especially in the function as a paraffin dispersant, such fuels themselves and fuel additive concentrates containing this mixture dissolved in a hydrocarbon solvent. The fuels mentioned have in particular a biodiesel component.

Middle distillate fuels of fossil origin, especially gas oils, diesel oils or light fuel oils derived from petroleum, have different levels of paraffins depending on the source of the crude oil. At low temperatures cloudy point or Cloud Point ("CP") precipitates solid paraffins. Upon further cooling, the platy n-paraffin crystals form a kind of "house of cards structure" and the middle distillate fuel stagnates, although its predominant part is still liquid. The precipitated n-paraffins in the temperature range between cloud point (cloud point) and pour point (pour point), the flowability of middle distillate fuels is significantly affected; The paraffins clog filters and cause uneven or completely interrupted fuel supply to the combustion units. Similar disturbances occur with light fuel oils.

It has long been known that by appropriate additions, the crystal growth of n-paraffins in middle distillate fuels can be modified. Good effective additives prevent middle distillate fuels from already solidifying at temperatures a few degrees Celsius below the temperature at which the first paraffin crystals crystallize out. Instead, fine, well crystallizing, separate paraffin crystals are formed, which pass filters in motor vehicles and heating systems or at least form a permeable for the liquid part of the middle distillates filter cake, so that trouble-free operation is ensured. The effectiveness of the flow improvers is expressed indirectly according to the European standard EN 116 by measuring the Cold Filter Plugging Point ("CFPP").

For example, ethylene-vinyl carboxylate copolymers have long been used as cold flow improvers or Middle Distillate Flow Improvers ("MDFI"). A disadvantage of these additives is that the precipitated paraffin crystals tend due to their relative to the liquid part higher density tend to settle more and more at the bottom of the container during storage. As a result, a homogeneous low-paraffin phase forms in the upper container part and a two-phase paraffin-rich layer at the bottom. Since the deduction of the fuel usually takes place slightly above the container bottom both in the vehicle tanks and in storage or delivery tanks of the mineral oil dealer, there is the risk that the high concentration of solid paraffins leads to blockages of filters and metering devices. This danger is greater the further the storage temperature falls below the excretion temperature of the paraffins, since the amount of paraffin precipitated increases with decreasing temperature. In particular, levels of biodiesel also enhance this undesirable tendency of the middle distillate fuel to paraffin sedimentation.

The additional use of paraffin dispersants or wax anti-settling additives ("WASA") can reduce these problems.

With decreasing world oil reserves and discussions about the environmental impact of fossil and mineral fuel consumption, there is a growing interest in alternative energy sources based on renewable raw materials. These include, in particular, natural oils and fats of plant or animal origin. These are in particular triglycerides of fatty acids having 10 to 24 carbon atoms which are converted to lower alkyl esters such as methyl esters. These esters are also commonly referred to as "FAME" (Fatty Acid Methyl Ester).

Mixtures of these FAME with middle distillates have a worse cold behavior than these middle distillates alone. In particular, the addition of FAME increases the tendency to form paraffin sediments.

In the WO 00/23541 (1) is the use of a mixture of 5 to 95 wt .-% of at least one reaction product of a poly (C ₂ - to C ₂₀ carboxylic acid having at least one tertiary amino group) with secondary amines and 5 to 95 Wt .-% of at least one reaction product of maleic anhydride and a primary alkylamine as an additive for petroleum middle distillates, in particular as paraffin dispersant and lubricity additive described.

From the EP-A 055 355 (2 ), it is known that an oil-soluble acid amide of a polyamine having a fatty acid having at least 8 C atoms or a fatty acid-analogous compound containing free carboxyl groups also effects an improved low-temperature behavior of a petroleum distillate.

In the WO 94/10267 (3) flow improvers and paraffin dispersants, for example comb polymers, for mixtures of fuel oils of vegetable origin and petroleum-based fuel oils are described.

The GB-A 1 410 788 discloses a fuel additive composition consisting of a fatty acid amide of aliphatic polyamines and an alkanolamine ester of a fatty or naphthenic acid in the weight ratio of 1: 8 to 8: 1.

The GB-A 842 991 discloses a fuel additive composition consisting of a fatty acid amide of ethylene diamine with oleic acid and a diethylaminoethyl methacrylate based copolymer.

The object was to provide products which ensure improved fluidity behavior of fuels, in particular those fuels which have a proportion of biofuel (biodiesel) which is based on fatty acid esters, at low temperature, by exhibiting such a dispersing action in that settling of excreted paraffins is delayed or prevented.

The object is achieved by the above-mentioned mixture of components (a) to (c), which is all the more surprising, since the components (a) and (b) alone respectively no or only a small, not sufficient flow improving Effect in a mixture of a conventional middle distillate of fossil origin and a biofuel oil which is based on fatty acid esters have. The component (c) is not necessarily necessary for achieving the intended flowability improvement, but usually significantly enhances this effect.

The polar, oil-soluble nitrogen compounds of component (a) which are capable of sufficiently dispersing paraffin crystals precipitated in fuels in the cold can be both ionic and nonionic and preferably have at least one, especially at least 2, substituents of the general formula > NR ²² , wherein R ^{22 is} a C ₈ - to C ₄₀ hydrocarbon radical. The Nitrogen substituents may also be quaternized, that is 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 hydrocarbon radical with a carboxylic acid having up to 4 carboxyl groups or with a suitable derivative thereof. The amines preferably contain at least one linear C ₈ - to C ₄₀ -alkyl radical. Examples of suitable primary amines are octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine and the higher linear homologues. Suitable secondary amines are, for example, dioctadecylamine and methylbehenylamine. Also suitable 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".

Further examples of suitable polar, oil-soluble nitrogen compounds are ring systems bearing at least two substituents of the formula -A'-NR ²³ R ²⁴ , wherein A 'represents a linear or branched aliphatic hydrocarbon group optionally substituted by one or more moieties selected is interrupted by O, S, NR ³⁵ and CO, and R ²³ and R ^{24 are} a C ₉ to C ₄₀ hydrocarbon radical optionally substituted by one or more moieties selected from O, S, NR ³⁵ and CO, interrupted and / or substituted by one or more substituents selected from OH, SH and NR ³⁵ R ³⁶ , wherein R ^{35 is} C ₁ - to C ₄₀ -alkyl optionally substituted by one or more moieties are selected from CO, NR ³⁵ , O and S, interrupted, and / or by one or more radicals selected from NR ³⁷ R ³⁸ , OR ³⁷ , SR ³⁷ , COR ³⁷ , COLOR ³⁷ , CONR ³⁷ R ³⁸ , aryl or heterocyclyl, s is substituted, wherein R ³⁷ and R ^{38 are} each independently selected from H or C ₁ - to C ₄ alkyl and wherein R ^{36 is} H or R ³⁵ .

The mixture according to the invention contains as component (a) at least one oil-soluble reaction product of at least one tertiary amino group-containing poly (C ₂ - to C ₂₀ -carboxylic acids) with primary or secondary amines.

The component (a) underlying at least one tertiary amino group-containing poly (C ₂ - to C ₂₀ carboxylic acids) 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, for example 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.

in denen die Variable A eine geradkettige oder verzweigte C₂- bis C₆-Alkylengruppe oder die Gruppierung der Formel III

darstellt und die Variable B eine C₁- bis C₁₉-Alkylengruppe bezeichnet.In a preferred embodiment, the mixture according to the invention contains as component (a) at least one oil-soluble reaction product based on poly (C ₂ - to C ₂₀ -carboxylic acids) of general formula I or II containing at least one tertiary amino group

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

and the variable B denotes a C ₁ - to C ₁₉ -alkylene group.

Furthermore, the oil-soluble reaction product of component (a), in particular that of the general formula I or II, is an amide, an amide ammonium salt or an ammonium salt in which none, one or more carboxylic acid groups are converted into amide groups.

Straight-chain or branched C ₂ -C ₆ -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.

C ₁ - to C ₁₉ -alkylene groups of the variable B are, for example, 1,2-ethylene, 1,3-propylene, 1,4-butylene, hexamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, octadecamethylene, nonadecamethylene and in particular 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 (a) are usually monoamines, in particular aliphatic monoamines. These primary and secondary amines can be from a variety be selected from amines carrying - optionally interconnected - hydrocarbon radicals.

In a preferred embodiment, these are the amines secondary amines underlying the oil-soluble reaction products of component (a) and have the general formula HNR ₂ , in which the two variables R independently of one another in each case straight-chain or branched C ₁₀ - to C ₃₀ -alkyl radicals, especially C ₁₄ - to mean C ₂₄ -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 acid or from its derivatives. Preferably, the two radicals R 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. In a preferred embodiment, the oil-soluble reaction products of component (a) are completely in the form of the amide structures.

Typical examples of components (a) 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, Dikokosfettamin, distearylamine, dibehenylamine or especially Ditalgfettamin. A particularly preferred component (a) is the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated ditallow fatty amine.

The polyamines on which the oil-soluble acid amides of component (b) are based can either be structurally clearly defined low molecular weight "oligo" amines or polymers having up to 1000, in particular up to 500, especially up to 100, nitrogen atoms in the macromolecule. The latter are then usually polyalkyleneimines, for example polyethyleneimines, or polyvinylamines.

The polyamines mentioned are reacted with C ₈ - to C ₃₀ -fatty acids, in particular C ₁₆ - to C ₂₀ -fatty acids, to give the oil-soluble acid amides. In principle, instead of the free fatty acids, it is also possible to use reactive fatty acid derivatives, such as the corresponding esters, halides or anhydrides, for the reaction.

The reaction of the polyamines with the fatty acid to the oil-soluble acid amides of component (b) takes place completely or partially. In the latter case, subordinate fractions of the product are usually present in the form of corresponding ammonium salts. The completeness of the conversion to the acid amides can be found in the However, control the rule by the conversion parameters. The preparation of the acid amides of component (b) is described in document (2).

Suitable polyamines for the conversion to the acid amides of component (b) are, for example: ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, pentapropylenhexamine, polyethyleneimines of average degree of polymerization (corresponding to the number of nitrogen atoms) of e.g. , B. 10, 35, 50 or 100 and polyamines, which were obtained by reaction of oligoamines (with chain extension) with acrylonitrile and subsequent hydrogenation, for. N, N'-bis (3-aminopropyl) ethylenediamine.

Suitable fatty acids for the conversion to the acid amides of component (b) are pure fatty acids and technically customary fatty acid mixtures which comprise, for example, stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid and / or linolenic acid. Of particular interest here are naturally occurring fatty acid mixtures, for example tallow fatty acid, coconut oil fatty acid, trans fatty acid, coconut oil fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, peanut oil fatty acid or palm oil fatty acid, which contain oleic acid and palmitic acid as main components.

In a preferred embodiment, the mixture according to the invention contains as component (b) at least one oil-soluble acid amide of aliphatic polyamines having 2 to 6 nitrogen atoms and C ₁₆ - to C ₂₀ -fatty acids, all primary and secondary amino functions of the polyamines being converted into acid amide functions.

A typical example of an oil-soluble acid amide of component (b) is the reaction product of 3 moles of oleic acid with 1 mole of diethylenetriamine.

The oil-soluble reaction products of component (c) underlying α, β-dicarboxylic acids having 4 to 300, especially 4 to 75, especially 4 to 12 carbon atoms, are usually succinic acid, maleic acid, fumaric acid or derivatives thereof, at the bridging ethylene or Ethenylene group may have shorter or longer chain hydrocarbyl substituents which contain or may carry heteroatoms and / or functional groups. For the reaction with the primary alkylamines, these are generally used in the form of the free dicarboxylic acid or its reactive derivatives. Carboxylic acid halides, carboxylic acid esters or, in particular, carboxylic acid anhydrides can be used here as reactive derivatives.

In a preferred embodiment, the mixture according to the invention contains as component (c) at least one oil-soluble reaction product of maleic anhydride and primary alkylamines.

The primary alkylamines underlying the oil-soluble reaction products of component (c) are usually medium-chain or long-chain alkyl monoamines preferably having 8 to 30, in particular 12 to 22 carbon atoms, and linear or branched, saturated or unsaturated alkyl chain, for example octyl, nonyl, iso-nonyl -, decyl, undecyl, tridecyl, iso-tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecylamine and mixtures of such amines. Should be used as such primary alkyl amines naturally occurring fatty amines, especially coconut amine, tallow fatty amine, oleylamine, arachidylamine or behenyl amine and mixtures thereof are suitable. The reaction products of component (c) are usually - depending on the stoichiometry and reaction regime - as half or bisamides of maleic acid before; they may also contain minor amount of corresponding ammonium salts. The preparation of the oil-soluble reaction products of component (c) from maleic anhydride and primary alkylamines is described in document (1).

A typical example of an oil-soluble reaction product of component (c) is the reaction product of 1 mol of maleic anhydride with 1 mol of iso-tridecylamine, which is present predominantly as a half-amide of maleic acid.

The mixture according to the invention can be prepared by simple mixing, optionally in a suitable solvent, of components (a) and (b) or (a) to (c) without heat input.

1. (a) 50 bis 95 Gew.-%, insbesondere 55 bis 85 Gew.-%, vor allem 60 bis 70 Gew.-%;
2. (b) 5 bis 50 Gew.-%, insbesondere 15 bis 45 Gew.-%, vor allem 30 bis 40 Gew.-%.

If component (c) is not used, the mixture according to the invention preferably contains components (a) and (b) in the following ratios, the sum of these two components in each case giving 100% by weight:

1. (A) 50 to 95 wt .-%, in particular 55 to 85 wt .-%, especially 60 to 70 wt .-%;
2. (B) 5 to 50 wt .-%, in particular 15 to 45 wt .-%, especially 30 to 40 wt .-%.

1. (a) 50 bis 85 Gew.-%, insbesondere 55 bis 75 Gew.-%, vor allem 60 bis 70 Gew.-%;
2. (b) 10 bis 40 Gew.-%, insbesondere 15 bis 35 Gew.-%, vor allem 20 bis 30 Gew.-%;
3. (c) 1 bis 25 Gew.-%, insbesondere 5 bis 20 Gew.-%, vor allem 10 bis 20 Gew.-%.

If component (c) is also used, the mixture according to the invention preferably contains components (a) to (c) in the following ratios, the sum of all three components in each case giving 100% by weight:

1. (A) 50 to 85 wt .-%, in particular 55 to 75 wt .-%, especially 60 to 70 wt .-%;
2. (B) 10 to 40 wt .-%, in particular 15 to 35 wt .-%, especially 20 to 30 wt .-%;
3. (C) 1 to 25 wt .-%, in particular 5 to 20 wt .-%, especially 10 to 20 wt .-%.

The mixture according to the invention is suitable as an additive to fuels, especially middle distillate fuels. Middle distillate fuels, which are used in particular as gas oils, petroleum, diesel oils (diesel fuels) or light fuel oils, are often referred to as fuel oils. Such middle distillate fuels generally have boiling temperatures of 150 to 400 ° C.

The mixture according to the invention can be injected directly into the fuels, i. undiluted, but preferably as 10 to 70 wt .-%, in particular as 30 to 65 wt .-%, especially as 45 to 60 wt .-% solution (concentrate) in a suitable solvent, usually a hydrocarbon solvent be added. Such a concentrate, containing 10 to 70 wt .-%, in particular 30 to 65 wt .-%, especially 45 to 60 wt .-%, based on the total amount of the concentrate, the mixture according to the invention, dissolved in a hydrocarbon solvent, is therefore also the subject of the present invention. Common solvents in this context are aliphatic or aromatic hydrocarbons, for example xylenes or mixtures of high-boiling aromatics such as solvent naphtha. Even middle distillate fuels themselves can be used as solvents for such concentrates.

The metering rate of the mixture in the fuels is generally 10 to 10,000 ppm by weight, in particular 50 to 5000 ppm by weight, especially 50 to 1000 ppm by weight, e.g. 150 to 400 ppm by weight, based in each case on the total amount of middle distillate fuel.

1. (A) zu 0,1 bis 75 Gew.-%, vorzugsweise zu 0,5 bis 50 Gew.-%, insbesondere zu 1 bis 25 Gew.-%, vor allem zu 3 bis 12 Gew.-%, aus mindestens einem Biobrennstofföl, welches auf Fettsäureestern basiert, und
2. (B) zu 25 bis 99,9 Gew.-%, vorzugsweise zu 50 bis 99,5 Gew.-%, insbesondere zu 75 bis 99 Gew.-%, vor allem zu 88 bis 97 Gew.-%, aus Mitteldestillaten aus fossilem Ursprung und/oder aus pflanzlichem und/oder tierischem Ursprung, welche im wesentlichen Kohlenwasserstoffmischungen darstellen und frei von Fettsäureestern sind,

bestehen.In a preferred embodiment, the mixture according to the invention is used as an additive to fuels which

1. (A) to 0.1 to 75 wt .-%, preferably to 0.5 to 50 wt .-%, in particular to 1 to 25 wt .-%, especially to 3 to 12 wt .-%, of at least one Biofuel oil based on fatty acid esters, and
2. (B) from 25 to 99.9% by weight, preferably from 50 to 99.5% by weight, in particular from 75 to 99% by weight, in particular from 88 to 97% by weight, of middle distillates of fossil origin and / or of vegetable and / or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters,

consist.

The fuel component (A) is usually referred to as "biodiesel". The middle distillates of the fuel component (A) are preferably substantially alkyl esters of fatty acids derived from vegetable and / or animal oils and / or fats. Alkyl esters are usually lower alkyl esters, in particular C ₁ - to C ₄ alkyl esters, understood by transesterification of occurring in vegetable and / or animal oils and / or fats glycerides, especially triglycerides, by means of lower alcohols, such as ethanol, n-propanol, isoPropanol , n-butanol, iso-butanol, sec-butanol, tert-butanol, or especially methanol ("FAME").

Examples of vegetable oils which are converted into corresponding alkyl esters and thus can serve as a basis for biodiesel are castor oil, olive oil, peanut oil, palm kernel oil, coconut oil, mustard oil, cottonseed oil, and in particular sunflower oil, palm oil, soybean oil and rapeseed oil. Other examples include oils that can be extracted from wheat, jute, sesame and the shea nut; furthermore, arachis oil, jatropha oil and linseed oil are also usable. The recovery of these oils and their conversion to the alkyl esters are known in the art or may be derived therefrom.

It is also possible to convert already used vegetable oils, for example used frying oil, if appropriate after appropriate purification, into alkyl esters and thus serve as the basis for biodiesel.

Vegetable fats are also useful in principle as a source of biodiesel, but play a minor role.

Examples of animal fats and oils that are converted into corresponding alkyl esters and thus can serve as a basis for biodiesel are fish oil, beef tallow, Pig tallow and similar fats and oils derived from the slaughtering or recycling of farmed or wild animals.

As the said vegetable and / or animal oils and / or fats underlying saturated or unsaturated fatty acids, which usually have from 12 to 22 carbon atoms and may carry additional functional group such as hydroxyl groups, occur in the alkyl esters in particular lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid , Linoleic, linolenic, elaidic, erucic and ricinolic acids, especially in the form of mixtures of such fatty acids.

Typical lower alkyl esters based on vegetable and / or animal oils and / or fats which are used as biodiesel or biodiesel components are, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME") and especially rapeseed oil methyl ester ("RME"). ).

However, it is also possible to use the monoglycerides, diglycerides and especially triglycerides themselves, for example castor oil, or mixtures of such glycerides as biodiesel or components for biodiesel.

For the purposes of the present invention, fuel component (B) is to be understood to mean boiling middle distillate fuels in the range from 120 to 450 ° C. Such middle distillate fuels are used in particular as diesel fuel, heating oil or kerosene, with diesel fuel and heating oil being particularly preferred.

Middle distillate fuels are fuels obtained by distillation of crude oil and boiling in the range of 120 to 450 ° C. Preferably, low sulfur middle distillates are used, i. those containing less than 350 ppm of sulfur, in particular less than 200 ppm of sulfur, especially less than 50 ppm of sulfur. In special cases they contain less than 10 ppm sulfur, these middle distillates are also called "sulfur-free". These are generally crude oil distillates, which have been subjected to a hydrogenating refining, and therefore contain only small amounts of polyaromatic and polar compounds. These are preferably middle distillates which have 95% distillation points below 370 ° C., in particular below 350 ° C. and in special cases below 330 ° C.

Low-sulfur and sulfur-free middle distillates can also be obtained from heavier petroleum fractions, which can no longer be distilled under atmospheric pressure. Hydrocarbon cracking, thermal cracking, catalytic cracking, coker processes and / or visbreaking may be mentioned as typical conversion processes for the preparation of middle distillates from heavy petroleum fractions. Depending on the procedure These middle distillates fall to low sulfur or sulfur-free or are subjected to a hydrogenating refining.

The middle distillates preferably have aromatics contents of less than 28% by weight, in particular less than 20% by weight. The content of normal paraffins is between 5% and 50% by weight, preferably between 10 and 35% by weight.

Among the middle distillates referred to as fuel component (B), middle distillates should also be understood here, which can be derived either indirectly from fossil sources such as crude oil or natural gas or else produced from biomass via gasification and subsequent hydrogenation. A typical example of a middle distillate fuel derived indirectly from fossil sources is GTL (gas-to-liquid) diesel fuel produced by Fischer-Tropsch synthesis. From biomass, for example, a middle distillate is produced via the BTL ("bio-to-liquid") process, which can be used either alone or in admixture with other middle distillates as fuel component (B). The middle distillates also include hydrocarbons obtained by hydrogenation of fats and fatty oils. They contain mostly n-paraffins. The said middle distillate fuels have in common that they are essentially hydrocarbon mixtures and are free from fatty acid esters.

The qualities of fuel oils and diesel fuels are specified in greater detail in, for example, DIN 51603 and EN 590 (see also Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A12, pp. 617 et seq., To which reference is expressly made).

The mixture according to the invention is preferably used in the said fuels as a paraffin dispersant ("WASA"). The mixture according to the invention often unfolds its action as paraffin dispersant only particularly well together with the customary flow improvers.

In the context of the present invention, flow improvers are to be understood as meaning all additives which improve the cold properties of middle distillate fuels. In addition to the actual cold flow improvers ("MDFI"), these are also nucleators (see also Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A16, page 719 ff.).

The middle distillate fuels according to the invention contain in addition to the mixture according to the invention in the presence of cold flow improvers these in an amount of usually 1 to 2000 ppm by weight, preferably from 5 to 1000 ppm by weight, especially from 10 to 750 ppm by weight and especially from 50 to 500 ppm by weight, for example from 150 to 400 ppm by weight.

• (d) Copolymere von Ethylen mit wenigstens einem weiteren ethylenisch ungesättigten Monomer;
• (e) Kammpolymere;
• (f) Polyoxyalkylene;
• (g) Sulfocarbonsäuren oder Sulfonsäuren oder deren Derivaten;
• (h) Poly(meth)acrylsäureester

As such cold flow improvers, in particular for the combination with the mixture according to the invention, one or more of the following may be considered, which are typical representatives for use in middle distillate fuels:

• (d) copolymers of ethylene with at least one other ethylenically unsaturated monomer;
• (e) comb polymers;
• (f) polyoxyalkylenes;
• (g) sulfocarboxylic acids or sulfonic acids or their derivatives;
• (h) poly (meth) acrylic ester

In the copolymers of ethylene with at least one other ethylenically unsaturated monomer of group (d), the monomer is preferably selected from alkenylcarboxylic esters, (meth) acrylic esters and olefins.

Suitable olefins are, for example, those having 3 to 10 carbon atoms and having 1 to 3, preferably 1 or 2, in particular having one carbon-carbon double bond. 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 3 to 6 carbon atoms, for example propene, 1-butene, 1-pentene and 1-hexene.

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

Suitable alkenylcarboxylic esters are, for example, the vinyl and propenyl esters of carboxylic acids having 2 to 20 carbon atoms, the hydrocarbon radical of which may be linear or branched. Preferred among these are the vinyl esters. Among the carboxylic acids having a branched hydrocarbon radical, preferred are those whose branch is in the α-position to the carboxyl group, the α-carbon atom being particularly preferably tertiary, ie. H. the carboxylic acid is a so-called neocarboxylic acid. Preferably, however, the hydrocarbon radical of the carboxylic acid is linear.

Examples of suitable alkenylcarboxylic esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, with vinyl esters being preferred. A particularly preferred alkenyl carboxylic acid ester is vinyl acetate; typical copolymers of group (d) resulting therefrom are ethylene-vinyl acetate copolymers ("EVA"), which are widely used in diesel fuels.

Particularly preferably, the ethylenically unsaturated monomer is selected from alkenylcarboxylic esters.

Also suitable are copolymers which contain two or more mutually different alkenylcarboxylic acid esters in copolymerized form, these differing in the alkenyl function and / or in the carboxylic acid group. Also suitable are copolymers which, in addition to the alkenylcarboxylic ester (s), contain at least one olefin and / or at least one (meth) acrylic acid ester in copolymerized form.

The ethylenically unsaturated monomer is in the copolymer of group (d) in an amount of preferably 1 to 50 mol .-%, in particular from 10 to 50 mol .-% and especially from 5 to 20 mol .-%, based on the total copolymer , copolymerized.

The copolymer of group (d) preferably has 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 6000.

worin

• D für R¹⁷, COOR¹⁷, OCOR¹⁷, R¹⁸, OCOR¹⁷ oder OR¹⁷ steht,
• E für H, CH₃, D oder R¹⁸ steht,
• G für H oder D steht,
• J für H, R¹⁸, R¹⁸COOR¹⁷, Aryl oder Heterocyclyl steht,
• K für H, COOR¹⁸, OCOR¹⁸, OR¹⁸ oder COOH steht,
• L für H, R¹⁸ COOR¹⁸, OCOR¹⁸, COOH oder Aryl steht,

wobei

• R¹⁷ für einen Kohlenwasserstoffrest mit wenigstens 10 Kohlenstoffatomen, vorzugsweise mit 10 bis 30 Kohlenstoffatomen, steht,
• R¹⁸ für einen Kohlenwasserstoffrest mit wenigstens einem Kohlenstoffatom, vorzugsweise mit 1 bis 30 Kohlenstoffatomen, steht,
• m für einen Molenbruch im Bereich von 1,0 bis 0,4 steht und
• n für einen Molenbruch im Bereich von 0 bis 0,6 steht.

Comb polymers of group (e) are for example those described in " Comb-like polymers. Structure and Properties ", NA Platé and VP Shibaev, J. Poly. Sci. Macromolecular Revs., 8, pp. 117-253 (1974 Of the described there are, for example comb polymers of the formula IV suitable

wherein

• D is R ¹⁷ , COOR ¹⁷ , OCOR ¹⁷ , R ¹⁸ , OCOR ¹⁷ or OR ¹⁷ ,
• E is H, CH ₃ , D or R ¹⁸ ,
• G is H or D,
• J is H, R ¹⁸ , R ¹⁸ COOR ¹⁷ , aryl or heterocyclyl,
• K is H, COOR ¹⁸ , OCOR ¹⁸ , OR ¹⁸ or COOH,
• L is H, R ¹⁸ COOR ¹⁸ , OCOR ¹⁸ , COOH or aryl,

in which

• R ^{17 is} a hydrocarbon radical having at least 10 carbon atoms, preferably having 10 to 30 carbon atoms,
• R ^{18 is} a hydrocarbon radical having at least one carbon atom, preferably having 1 to 30 carbon atoms,
• m for a mole fraction in the range of 1.0 to 0.4 and
• n represents a mole fraction in the range of 0 to 0.6.

Preferred comb polymers are obtainable, 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. Other preferred 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. Also mixtures of comb polymers are suitable. Comb polymers may also be polyfumarates or polymaleinates. In addition, homopolymers and copolymers of vinyl ethers are suitable comb polymers.

• R¹⁹ und R²⁰ jeweils unabhängig voneinander für R²¹, R^21-CO-, R²¹-O-CO(CH₂)₂- oder R²¹-O-CO(CH₂)_z-CO- stehen, wobei R²¹ für lineares C₁-C₃₀-Alkyl steht,
• y für eine Zahl von 1 bis 4 steht,
• x für eine Zahl von 2 bis 200 steht, und
• z für eine Zahl von 1 bis 4 steht.

Suitable polyoxyalkylenes of group (f) are, for example, polyoxyalkylene esters, ethers, esters / ethers and mixtures thereof. The polyoxyalkylene compounds preferably comprise at least one, particularly preferably at least two, linear alkyl groups each having from 10 to 30 carbon atoms and a polyoxyalkylene group having a molecular weight of up to 5,000. The alkyl group of the polyoxyalkylene radical preferably contains from 1 to 4 carbon atoms. Such polyoxyalkylene compounds are for example in the EP-A 061 895 as well as in the U.S. 4,491,455 which is incorporated herein by reference in its entirety. Preferred polyoxyalkylene esters, ethers and ester / ethers have the general formula V

R ¹⁹ [-O- (CH ₂ ) _y ] _x OR ²⁰ (V)

wherein

• R ¹⁹ and R ^{20 are} each independently R ²¹ , R ^{21 is} CO, R ^{21 is} -O-CO (CH ₂ ) ₂ - or R ^{21 is} -O-CO (CH ₂ ) _z -CO-, wherein R ²¹ is linear C ₁ -C ₃₀ -alkyl,
• y is a number from 1 to 4,
• x is a number from 2 to 200, and
• z is a number from 1 to 4.

Preferred polyoxyalkylene compounds of the formula V in which both R ¹⁹ and R ^{20 are} R ²¹ are polyethylene glycols and polypropylene glycols having a number average molecular weight of 100 to 5,000. Preferred polyoxyalkylenes of the formula V in which one of the radicals R ^{19 is} R ²¹ and the other is R ²¹ -CO-, are polyoxyalkylene esters of fatty acids having 10 to 30 carbon atoms such as stearic acid or behenic acid. Preferred polyoxyalkylene compounds in which both R ¹⁹ and R ^{20 are} R ²¹ -CO- are diesters of fatty acids having 10 to 30 carbon atoms, preferably stearic or behenic acid.

worin

• Y' für SO₃ ^-(NR²⁵ ₃R²⁶)⁺, SO₃ ^-(NHR²⁵ ₂R²⁶)⁺, SO₃-(NH₂R²⁵R²⁶), SO₃-(NH₃R²⁶) oder SO₂NR²⁵R²⁶ steht,
• X' für Y', CONR²⁵R²⁷, CO₂ ^-(NR²⁵ ₃R²⁷)⁺, CO₂ ^-(NHR²⁵ ₂R²⁷)⁺, R²⁸-COOR²⁷, NR²⁷COR²⁷, R²⁸OR²⁷, R²⁸OCOR²⁷, R²⁸R²⁷, N(COR²⁵)R²⁷ oder Z^-(NR²⁵ ₃R²⁷)⁺ steht,

wobei

• R²⁵ für einen Kohlenwasserstoffrest steht,
• R²⁶ und R²⁷ für Alkyl, Alkoxyalkyl oder Polyalkoxyalkyl mit wenigstens 10 Kohlenstoffatomen in der Hauptkette stehen,
• R²⁸ für C₂-C₅-Alkylen steht,
• Z- für ein Anionenäquivalent steht und
• A" und B' für Alkyl, Alkenyl oder zwei substituierte Kohlenwasserstoffreste stehen oder gemeinsam mit den Kohlenstoffatomen, an die sie gebunden sind, ein aromatisches oder cycloaliphatisches Ringsystem bilden.

Suitable sulfocarboxylic acids / sulfonic acids or their derivatives of group (g) are, for example, those of the general formula VI

wherein

• Y 'for SO ₃ ^- (NR ²⁵ ₃ R ²⁶ ) ⁺ , SO ₃ ^- (NHR ²⁵ ₂ R ²⁶ ) ⁺ , SO ₃ - (NH ₂ R ²⁵ R ²⁶ ), SO ₃ - (NH ₃ R ²⁶ ) or SO ₂ NR ²⁵ R ²⁶ stands,
• X 'for Y', CONR ²⁵ R ²⁷ , CO ₂ ^- (NR ²⁵ ₃ R ²⁷ ) ⁺ , CO ₂ ^- (NHR ²⁵ ₂ R ²⁷ ) ⁺ , R ²⁸ -COOR ²⁷ , NR ²⁷ COR ²⁷ , R ²⁸ OR ²⁷ , R ²⁸ OCOR ²⁷ , R ²⁸ R ²⁷ , N (COR ²⁵ ) R ²⁷ or Z ^- (NR ²⁵ ₃ R ²⁷ ) ⁺ ,

in which

• R ^{25 is} a hydrocarbon radical,
• R ²⁶ and R ^{27 are} alkyl, alkoxyalkyl or polyalkoxyalkyl having at least 10 carbon atoms in the main chain,
• R ^{28 is} C ₂ -C ₅ -alkylene,
• Z- represents an anion equivalent and
• A "and B 'are alkyl, alkenyl or two substituted hydrocarbon radicals or together with the carbon atoms to which they are attached form an aromatic or cycloaliphatic ring system.

Such sulfocarboxylic acids or sulfonic acids and their derivatives are in the EP-A-0 261 957 which is incorporated herein by reference in its entirety.

Suitable poly (meth) acrylic esters of group (h) 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 C ₁₄ and C ₁₅ alcohols wherein the acid groups are neutralized with hydrogenated tallamine. Suitable poly (meth) acrylic esters are, for example, in WO 00/44857 which is incorporated herein by reference in its entirety.

With conventional flow improvers - for example, ethylene-vinyl acetate copolymers from the group (d), as described in the WO 99/29748 (4), or comb polymers from the group (e), as described in the WO 2004/035715 (5), the mixture according to the invention is an efficient one in its function as paraffin dispersant and versatile cold stabilization system for middle distillate fuels, especially those with a share of biodiesel.

Likewise, by using the mixture according to the invention a number of other fuel properties can be improved. By way of example, only the additional effect of protecting against corrosion or improving the stability to oxidation should be mentioned here.

When used in low-sulfur fuels containing component (B) predominantly or solely, the use of the mixture according to the invention, in particular in combination with flow improvers, can contribute to an improvement in the lubricating effect. The lubricating effect is determined, for example, in the so-called HFRR test according to ISO 12156.

The mixture according to the invention can be added both middle distillate fuels, which are completely fossil origin, that is, derived from petroleum, as well as fuels containing a proportion of biodiesel in addition to the petroleum-based portion, to improve their properties. In both cases, a significant improvement in the cold flow behavior of the middle distillate fuel, i. a reduction in CP values and / or CFPP values, regardless of the origin or composition of the fuel observed. The precipitated paraffin crystals are effectively kept in suspension, so that there is no clogging of filters and lines by sedimented paraffin. The mixture according to the invention has a good broad action and thus effects that the precipitated paraffin crystals are very well dispersed in the most varied middle distillate fuels.

The present invention also fuels, in particular those with a biodiesel content, which contain the mixture according to the invention.

As a rule, the fuels mentioned or the fuel additive concentrates mentioned contain further additives in customary amounts of flow improver (as described above), further paraffin dispersants, conductivity improvers, corrosion protection additives, lubricity additives, antioxidants, metal deactivators, antifoams, demulsifiers, Detergents, cetane improvers, solvents or diluents, dyes or fragrances, or mixtures thereof. The abovementioned further additives, which have not yet been mentioned above, are familiar to the person skilled in the art and therefore need not be further explained here.

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

Examples Used additive components:

• Component (a): ethylenediaminetetraacetic acid reacted with 4 moles of hydrogenated di-tallow fatty amine prepared in solvent naphtha as described in Example 1 of document (1);
• Component (b): diethylenetriamine reacted with 3 moles of oleic acid prepared as described in Example A 69 of Table 1 of document (2);
• Component (c): maleic anhydride reacted with 1 mol of tridecylamine, prepared in solvent naphtha as described in Example 2 of document (1).

From the above components (a) to (c), the following concentrates K1 (according to the invention), K2 (for comparison) and K3 (for comparison) were prepared: Table 1 K1 K2 (for comparison) K3 (for comparison) Component (a) 63 83 - Component (b) 22 - 100 Component (c) 15 17 -

The mixing ratios given in Table 1 are% by weight; the solvent content of these mixtures was 40 wt .-%, in addition, these mixtures still contained 5% not the cold flow improving effect affecting conventional additives.

DK1:

CP (nach ISO 3015): -5,9°C, CFPP (nach EN 116): -9°C; Dichte d₁₅ (DIN 51577): 837,5 kg/m³; Siedeanfang (DIN 51751): 178°C, Siedeende: 364°C; Paraffingehalt (gemäß GC): 16,6 Gew.-%

DK2:

CP (nach ISO 3015): -5,9°C, CFPP (nach EN 116): -7°C; Siedeanfang (DIN 51751): 180°C, Siedeende: 362°C; Paraffingehalt (gemäß GC): 16,6 Gew.-%

DK3:

CP (nach ISO 3015): -7,0°C, CFPP (nach EN 116): -8°C; Dichte d₁₅ (DIN 51577): 831,6 kg/m³; Siedeanfang (DIN 51751): 170°C, Siedeende: 357°C; Paraffingehalt (gemäß GC): 22,1 Gew.-%

DK4:

CP (nach ISO 3015): -7,0°C, CFPP (nach EN 116): -9°C; Siedeanfang (DIN 51751): 172°C, Siedeende: 355°C; Paraffingehalt (gemäß GC): 22,2 Gew.-%

DK5:

CP (nach ISO 3015): -7,0°C, CFPP (nach EN 116): -9°C; Dichte d₁₅ (DIN 51577): 828,9 kg/m³; Siedeanfang (DIN 51751): 176°C, Siedeende: 356°C; Paraffingehalt (gemäß GC): 22,1 Gew.-%

DK6:

CP (nach ISO 3015): -7,4°C, CFPP (nach EN 116): -7°C; Dichte d₁₅ (DIN 51577): 827,8 kg/m³; Siedeanfang (DIN 51751): 169°C, Siedeende: 349°C; Paraffingehalt (gemäß GC): 21,8 Gew.-%

DK7:

CP (nach ISO 3015): -6,5°C, CFPP (nach EN 116): -8°C; Dichte d₁₅ (DIN 51577): 824,1 kg/m³; Siedeanfang (DIN 51751): 182°C, Siedeende: 350°C; Paraffingehalt (gemäß GC): 23,3 Gew.-%

The mentioned German winter diesel fuels (DK1 to DK7) are characterized by the following parameters:

DK1:

CP (according to ISO 3015): -5.9 ° C, CFPP (according to EN 116): -9 ° C; Density d ₁₅ (DIN 51577): 837.5 kg / m ³ ; Initial boiling point (DIN 51751): 178 ° C, boiling end: 364 ° C; Paraffin content (according to GC): 16.6% by weight

DK2:

CP (according to ISO 3015): -5.9 ° C, CFPP (according to EN 116): -7 ° C; Initial boiling point (DIN 51751): 180 ° C, boiling end: 362 ° C; Paraffin content (according to GC): 16.6% by weight

DK3:

CP (according to ISO 3015): -7.0 ° C, CFPP (according to EN 116): -8 ° C; Density d ₁₅ (DIN 51577): 831.6 kg / m ³ ; Initial boiling point (DIN 51751): 170 ° C, boiling end: 357 ° C; Paraffin content (according to GC): 22.1% by weight

DK 4:

CP (according to ISO 3015): -7.0 ° C, CFPP (according to EN 116): -9 ° C; Initial boiling point (DIN 51751): 172 ° C, boiling end: 355 ° C; Paraffin content (according to GC): 22.2% by weight

DK5:

CP (according to ISO 3015): -7.0 ° C, CFPP (according to EN 116): -9 ° C; Density d ₁₅ (DIN 51577): 828.9 kg / m ³ ; Initial boiling point (DIN 51751): 176 ° C, boiling end: 356 ° C; Paraffin content (according to GC): 22.1% by weight

DK6:

CP (according to ISO 3015): -7,4 ° C, CFPP (according to EN 116): -7 ° C; Density d ₁₅ (DIN 51577): 827.8 kg / m ³ ; Initial boiling point (DIN 51751): 169 ° C, boiling end: 349 ° C; Paraffin content (according to GC): 21.8% by weight

DK7:

CP (according to ISO 3015): -6.5 ° C, CFPP (according to EN 116): -8 ° C; Density d ₁₅ (DIN 51577): 824.1 kg / m ³ ; Initial boiling point (DIN 51751): 182 ° C, boiling end: 350 ° C; Paraffin content (according to GC): 23.3% by weight

As biodiesel additives were used: rapeseed oil methyl ester ("RME"), soybean oil methyl ester ("SME") or palm oil methyl ester ("PME").

• FB1: handelsübliches Ethylen-Vinylacetat-Copolymer mit einem Vinylacetat-Gehalt von 30 Gew.-% gemäß Dokument (4);
• FB2: Mischung gemäß Dokument (5) aus einem handelsüblichen Ethylen-Vinylacetat-Copolymer und einem Hydrocarbylvinylether-Homopolymer mit Kammstruktur;

As cold flow improvers ("MDFI") were also used:

• FB1: commercial ethylene-vinyl acetate copolymer having a vinyl acetate content of 30% by weight according to document (4);
• FB2: Mixture according to document (5) of a commercial ethylene-vinyl acetate copolymer and a hydrocarbyl vinyl ether homopolymer having a comb structure;

FB1 and FB2 were selected for their CFPP performance in the diesel fuels used. It is very likely that other diesel fuels will require other MDFI. Thus, the blends of the invention are not limited to use in conjunction with FB1 and FB2. In the experimental procedure described below, the additives K1 to K3 and FB1 or FB2 were each added separately to the diesel fuels. It is also possible to use the concentrates First mix K1, K2 and K3 with the MDFI FB1 or FB2 and then mix them together in the diesel fuels DK1 to DK7.

Description of the test method:

The fuels DK1 to DK7 were admixed with the amounts of biodiesel additive specified in the table below, the concentrate K1, K2 or K3 and the flow improver FB1 or FB2, mixed with stirring at 40.degree. C. and then cooled to room temperature. Of these additized fuel samples, the CP was determined according to ISO 3015 and the CFPP according to EN 116. Thereafter, the additized fuel samples were cooled in 500 ml glass cylinders in a cold bath from room temperature at a cooling rate of about 14 ° C per hour to -13 ° C and stored for 16 hours at this temperature. From the 20% by volume soil phase separated at -13 ° C., the CP according to ISO 3015 and the CFPP according to EN 116 were again determined from each sample. The lower the deviation of the CP of the 20% by volume soil phase from the original CP of the respective fuel sample, the better the paraffins are dispersed.

The results obtained are shown in Table 2 below: Table 2: Column 1 2 3 4 5 6 7 8th 9 10 11 12 13 Verse no. DK Bio-diesel MDFIs ppm WASA ppm CP * CP # Delta CP CFPP * CFPP # % Sediment 1-1 DK6 5% RME FB2 150 K2 150 -7.4 +1.4 8.8 -19 -9 66 1-2 K1 150 -7.4 -4.4 3.0 -19 -18 99 2-1 DK 4 5% RME FB2 150 K2 150 -7.0 +1.7 8.7 -23 -10 24 2-2 K1 150 -7.0 -4.8 2.2 -28 -26 2 3-1 DK7 5% RME FB2 300 K2 250 -6.5 -0.6 5.9 -26 -14 74 3-2 K1 250 -6.5 -5.4 1.1 -29 -28 96 4-1 DK5 5% RME FB2 300 K2 250 -6.7 -1.0 5.7 -23 -15 32 4-2 K1 250 -6.7 -5.9 0.8 -28 -28 0 5-1 DK3 10% RME FB2 150 K2 150 -7.0 -4.1 2.9 -30 -20 2 5-2 K1 150 -7.0 -4.6 2.4 -29 -26 2 6-1 DK3 5% SME FB2 150 K2 150 -7.0 -4.4 2.6 -21 -20 4 6-2 K1 150 -7.0 -5.1 1.9 -22 -21 2 7-1 DK3 5% PME FB2 400 K2 400 -6.1 -2.9 3.2 -20 -19 26 7-2 K1 400 -6.1 -5.0 1.1 -26 -20 8th 8-1 DK1 Without FB1 200 K2 150 -5.9 -4.8 1.1 -28 -28 6 8-2 K1 150 -5.9 -4.9 1.0 -29 -29 6 8-3 DK2 5% RME FB1 200 K2 150 -6.1 +0.3 6.4 -30 -16 26 8-4 K1 150 -6.1 -3.4 2.7 -29 -27 2 9-1 DK3 without FB2 150 K2 150 -7.0 -5.9 1.1 -28 -27 4 9-2 K3 150 -7.0 3.5 10.5 -17 -6 24 9-3 K1 150 -7.0 -5.6 1.4 -28 -20 2 9-4 DK3 5% RME FB2 150 K2 150 -7.0 +1.7 8.7 -23 -10 24 9-5 K3 150 -7.0 +1.4 8.4 -16 -9 36 9-6 K1 150 -7.0 -4.8 2.2 -28 -26 2

Legend to Table 2:

Column 3 indicates quantity (in wt.%) And type of biodiesel additive used.

Column 5 indicates the metered quantity of the flow improver FB1 or FB2 ("MDFI") stated in the 4th column in ppm by weight.

Column 7 indicates the metered quantity of the paraffin dispersant ("WASA") K1 (according to the invention) or K2 (for comparison) or K3 (for comparison) mentioned in the 6th column in ppm by weight.

CP * (column 8) and CFPP * (column 11) indicate the values of the additized fuel samples before cooling. CP # (column 9) and CFPP # (column 12) indicate the corresponding values of the 20% by volume soil phase each separated after cooling. Column 10 is the absolute value of the difference from CP # to CP *.

Column 13 indicates the vol .-% sediment of paraffin after storage in a cold bath at -13 ° C. If the specified value moves in the lower range (in the case of the examples listed below 40% by volume), the lower the value given here, the better the paraffin dispersing behavior. However, very high values in column 13 (in the case of the examples listed above 60% by volume) are also an indication of good paraffin dispersion behavior. Paraffin sedimentation is usually critical of about 10 to 30% by volume, since then most of the precipitated paraffin crystals are in the 20% by volume soil phase used to characterize the effectiveness of the additives as described.

From Table 2 it can be seen from the delta CP values (column 10) that in the case of the fuel samples with biodiesel content, in all cases with K1 a clear improvement of the dispersing behavior is achieved in comparison to K2 or K3. The tests of series 8 and 9 in Table 2 show the surprising effect of the mixture according to the invention on the paraffin sedimentation of diesel fuel-biodiesel mixtures. In pure diesel fuel (pure fuel DK3) are about equally good with K1 and K2 K3 does not have sufficient performance in newer, low-sulfur diesel fuels (experiment 9-2). By adding 5 wt .-% RME - as in the experiments 8-3 / 4 and 9-4 / 6 - the effect deteriorates drastically with the use of Comparative Examples K2, while the cold properties remain virtually unchanged when using the mixture according to the invention.

However, even with samples 9-1 to 9-3 with middle distillate fuel without biodiesel additive (ie a fuel sample purely based on petroleum), a slight improvement in the dispersion behavior with K1 compared to K2 and K3 can be observed, recognizable by the lower sediment value at approximately the same CP and CFPP values.

Claims (13)

1. A mixture comprising

   (a) from 5 to 95% by weight of at least one polar oil-soluble nitrogen compound other than components (b) and (c) which is capable of sufficiently dispersing paraffin crystals precipitated out under cold conditions in fuels and is selected from reaction products formed from poly(C₂- to C₂₀-carboxylic acids) having at least one tertiary amino group with primary or secondary amines,

   (b) from 1 to 50% by weight of at least one oil-soluble acid amide formed from polyamines having from 2 to 1000 nitrogen atoms and C₈- to C₃₀-fatty acids and

   (c) from 0 to 50% by weight of at least one oil-soluble reaction product formed from α,β-dicarboxylic acids having 4 to 300 carbon atoms or derivatives thereof and primary alkylamines,

   the sum of all components of the mixture (a) to (c) adding up to 100% by weight.
2. The mixture according to claim 1, comprising, as component (a), at least one oil-soluble reaction product based on poly(C₂- to C₂₀-carboxylic acids) which have at least one tertiary amino group and are of the general formula I or II

   

   

   in which the variable A is a straight-chain or branched C₂- to C₆-alkylene group or is the moiety of the formula III

   

   and the variable B is a C₁- to C₁₉-alkylene group.
3. The mixture according to claim 1 or 2, wherein the oil-soluble reaction product of component (a) is an amide, an amide ammonia salt or an ammonia salt, in which no, one or more carboxylic acid groups has/have been converted to amide groups.
4. The mixture according to claims 1 to 3, wherein the parent amines of the oil-soluble reaction products of component (a) are secondary amines and have the general formula HNR₂ in which the two variables R are each independently straight-chain or branched C₁₀- to C₃₀-alkyl radicals.
5. The mixture according to claims 1 to 4, comprising, as component (b), at least one oil-soluble acid amide formed from aliphatic polyamines having from 2 to 6 nitrogen atoms and C₁₆- to C₂₀-fatty acids, all primary and secondary amino functions of the polyamines having been converted to acid amide functions.
6. The use of the mixture according to claims 1 to 5 as an additive to fuels.
7. The use of the mixture according to claim 6 as an additive to fuels which consist

   (A) to an extent of from 0.1 to 75% by weight of at least one biofuel oil which is based on fatty acid esters, and

   (B) to an extent of from 25 to 99.9% by weight of middle distillates of fossil origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters.
8. The use according to claim 7, wherein fuel component (A) essentially comprises alkyl esters of fatty acids which derive from vegetable and/or animal oils and/or fats.
9. The use according to claims 6, 7 or 8 in the function as a paraffin dispersant.
10. A fuel according to claims 6 to 8, comprising a mixture according to claims 1 to 5.
11. The fuel according to claim 10, comprising, as further additives in amounts customary therefor, flow improvers, further paraffin dispersants, conductivity improvers, corrosion protection additives, lubricity additives, antioxidants, metal deactivators, antifoams, demulsifiers, detergents, cetane number improvers, solvents or diluents, dyes or fragrances or mixtures thereof.
12. A fuel additive concentrate comprising from 10 to 70% by weight, based on the total amount of the concentrate, of a mixture according to claims 1 to 5, dissolved in a hydrocarbon solvent.
13. The fuel additive concentrate according to claim 12, comprising, as further additives in amounts customary therefor, flow improvers, further paraffin dispersants, conductivity improvers, corrosion protection additives, lubricity additives, antioxidants, metal deactivators, antifoams, demulsifiers, detergents, cetane number improvers, solvents or diluents, dyes or fragrances or mixtures thereof.