WO2014067748A1

WO2014067748A1 - Middle distillate formulations containing sulphur-free, dispersant alkylmethacrylate copolymers

Info

Publication number: WO2014067748A1
Application number: PCT/EP2013/070905
Authority: WO
Inventors: Frank-Olaf Mähling; Michael G DUCKWORTH; Justin August Langston; Brian Hess; Barbara VOLTZ; Rhishikesh GOKHALE
Original assignee: Evonik Industries AG
Current assignee: Evonik Industries AG
Priority date: 2012-11-02
Filing date: 2013-10-08
Publication date: 2014-05-08
Anticipated expiration: 2015-05-02
Also published as: AR093317A1

Abstract

The present invention relates to polyalkyl(meth)acrylates (PAMAs) containing dispersant repeating units and their use as an additive component to fuels, especially to middle distillates and blends thereof. The present invention further relates to a composition comprising polyalkyl(meth)acrylates containing dispersant repeating units as dispersing species and the use of said composition as an additive to fuels, especially to middle distillates and blends thereof, and for improving the cold flow properties of fuel oil and fuel oil compositions, especially to middle distillate fuels and blends thereof.

Description

Middle distillate formulations containing sulphur-free, dispersant alkylmethacrylate copolymers

The present invention relates to polyalkyl (meth)acrylates (PAMAs) containing dispersant repeating units and their use as an additive component to fuels, especially to middle distillates and blends thereof. The present invention further relates to a composition comprising polyalkyl (meth)acrylates containing dispersant repeating units as dispersing species and the use of said composition as an additive to fuels, especially to middle distillates and blends thereof, and for improving the cold flow properties of fuel oil and fuel oil compositions, especially to middle distillate fuels and blends thereof.

It is well known to those skilled in the art that middle distillate fuels typified by diesel oil , heating oil, jet fuel, fuel oils, kerosene etc. may be stored for extended periods of time under unfavourable conditions which are conducive to formation of solid deposits.

These deposits, which are formed during storage at room temperature in the presence of air, accumulate on strainers, filters, screens etc. with which the oil comes into contact and ultimately plug the openings with resultant problems in operation.

The formation of insoluble sediments results e.g. in decreased filter flow rates or increased nozzle plugging tendency.

To avoid the formation of ageing products and sediments certain additives are added to the diesel fuels and heating oils in the mineral oil refineries, at fuel terminals or fuel blenders. Typically used multifunctional additive packages comprise antioxidants, detergent additives and optionally cetane improvers as the main constituents as well as cold flow improvers, static dissipator additives, metal deactivators and anti-icing additives.

In the formulation or storage of such additive packages, there are frequent occurrences, especially at temperatures significantly below 40°C, of phase separation with precipitates which cannot be filtered off effectively; attempted filtration can lead to filter conglutination. At least, such additive packages are typically slightly to highly turbid. The presence of common organic solvents in the additive packages cannot prevent such phase separation, precipitates or turbidities. The precipitates, which usually at first remain more or less dispersed in the solution, can subsequently lead to severe sedimentation or to gel formation in the additive package. It was therefore an object of the present invention to stabilize such additive packages which comprise both antioxidants and detergent additives, and also inert organic solvents and if appropriate anti-icing additives and/or cetane improvers, such that the phase separation, the precipitates or turbidities described above do not occur in the course of formulation and storage of the additive packages.

It was surprisingly found that a grafted polyalkyl (meth)acrylate copolymer containing N- dispersant monomers both in the polymer backbone as well as in the grafted side-chain can be used to stabilize additive packages for middle distillates as a compatibilizer.

The polymer can disperse particles, aged components like sludge and gum and/or n-paraffin wax crystals.

The inventive polymers preferably have a nitrogen content of at least 1 % by weight, especially preferred 1 % to 7% by weight.

The use of the inventive polymers allows formulating stable homogeneous fuel additive packages with multiple functions. The main purpose of the additive packages is to stabilize the fuel versus ageing and oxidation. The inventive polymer improves the stabilizer performance as determined in the "Thermal Stability Test" and helps to disperse particles. Fuel additive packages optionally allow improving low temperature properties and/or lubricity, conductivity, cetane number, corrosiveness, combustion and smell. Chemically very different components are not necessarily compatible without the inventive polymers.

A dispersing additive is necessary to produce stable formulations and ensure storage stability without phase separation.

It is commonly known that polymers containing basic nitrogen substituents can be used as oil-soluble surface-active agents (C.B. Biswell et al, "New Polymeric Dispersants for

Hydrocarbon Systems", Industrial and Engineering Chemistry 1955, 47, 8, 1598-1601 ).

Such N-dispersant polymers can be prepared by copolymerizing N-containing monomers.

US Patent No. 6,051 ,039 describes the use of various poly-isobutylene succinimides and conversion products of long chain succinic acids with different amines and their use to improve the storage stability of diesel fuel according to ASTM D2274. The diesel fuel composition is claimed. It is also claimed that rust inhibition and lubricity is improved by this kind of additive.

US patent application publication No. 2009/0307964 A1 describes the use of compatibilizers for multifunctional additive packages. The exemplary packages contain: 1 ) cold flow improver; 2) polyisobutylene succinimide as detergent; 3) solvent naphtha; 4) optionally 2- ethylhexylnitrate as cetane number improver; 5) optionally ethylene glycol monomethylether; and 6) compatibilizer.

The compatibilizer can be obtained from the reaction of maleic acid or phthalic acid with amines. A wide range of non-polymeric molecules are claimed, which typically contain nitrogen and carboxylic groups.

US Patent No. 5,035,719 describes the use of polyalkyi (meth)acrylates containing moieties derived from N-heterocyclic amines to improve the stability of middle distillates according to ASTM D2274. Sulphur containing lauryl mercaptane was used as chain transfer agent. A liquid middle distillate fuel containing a small portion of this kind of polymer is claimed. The use as compatibilizer in additive packages is not discussed.

US Patent Application Publication No. 2009/0270287 A1 describes the use of N-dispersant polyalkyi (meth)acrylates as lubricant booster component, which reduces the emissions of combustion engines by its soot dispersant activity. This was found for diesel engines with exhaust gas recirculation (EGR) systems.

Further disclosed is the operation of a diesel engine with EGR system and a lubricating oil composition containing the booster.

It was therefore an object of the present to provide an additive which has dispersant properties and can be used to stabilize additive packages, especially additive packages which are added to middle distillates.

Surprisingly, it was found that a grafted polyalkyi (meth)acrylate which contains N-dispersant repeating units in the polymer backbone (graft base) as well as in the graft layer (grafted side-chain) and which therefore has a high nitrogen content that provides outstanding properties regarding the stabilization of additive packages and improvement of cold flow properties of middle distillates. Summary of the Invention

In accordance with a first aspect of the invention, there is provided a grafted polyalkyl (meth)acrylate copolymer (A), containing as a polymer backbone monomer units comprising:

(A1 ) 0% to 40% by weight of one or more ethylenically unsaturated ester compounds of formula (I)

wherein

R is H or CH₃,

R¹ represents a linear or branched, saturated or unsaturated alkyl group with 1 to 5 carbon atoms or a cycloalkyl group with 3 to 5 carbon atoms,

R² and R³ independently represent H or a group of the formula -COOR', wherein R' is H or a linear or branched, saturated or unsaturated alkyl group with 1 to 5 carbon atoms or a cycloalkyl group with 3 to 5 carbon atoms,

20% to 93.5% by weight of one or more ethylenically unsaturated ester compounds of formula (II)

wherein

R is H or CHs,

R⁴ represents a linear or branched, saturated or unsaturated alkyl group with 6 to 15 carbon atoms, R⁵ and R⁶ independently represent H or a group of the formula -COOR", wherein R" is H or a linear or branched, saturated or unsaturated alkyl group with 6 to 15 carbon atoms,

(A3) 5% to 60% by weight of one or more ethylenically unsaturated ester compounds of formula (III)

wherein

R is H or CHs,

R⁷ represents a linear or branched, saturated or unsaturated alkyl group with 16 to 30 carbon atoms,

R⁸ and R⁹ independently represent H or a group of the formula -COOR'" wherein R'" is H or a linear or branched, saturated or unsaturated alkyl group with 16 to 30 carbon atoms, and

1 % to 40% by weight of at least one N-dispersant monomer selected from the group consisting of vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidone (NVP),

morpholinoethyl methacrylate, N-vinyl caprolactam, N,N-dimethylaminoethyl methacrylate (DMAEMA), ie f-butyl aminoethyl methacrylate, N,N- dimethylaminopropylmethacrylamide (DMAPMAm), dimethylaminopropylacrylamide and dimethylaminoethylacrylamide, wherein components (A1 ) to (A4) add up to 100% by weight; and

0.5% to 10% by weight of at least one N-dispersant monomer selected from the group consisting of vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidone (NVP),

morpholinoethyl methacrylate, N-vinyl caprolactam, N,N-dimethylaminoethyl methacrylate (DMAEMA), ie f-butyl aminoethyl methacrylate, N,N- dimethylaminopropylmethacrylamide (DMAPMAm), dimethylaminopropylacrylamide and dimethylaminoethylacrylamide which is grafted onto the polymer backbone, wherein components (A1 ) to (A5) add up to 100% by weight. Detailed description of the invention

Within the context of the present invention, the term "alkyi (meth)acrylate" refers to both the alkyi acrylate and the alkyi methacrylate species or a mixture thereof. Alkyi methacrylates are preferred. Non-limiting examples of component (A1 ) include acrylates, methacrylates, fumarates and maleates which derive from saturated alcohols such as methyl (meth)acrylate, ethyl

(meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ie f-butyl (meth)acrylate and pentyl (meth)acrylate; cycloalkyl (meth)acrylates, like cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate and 3-vinylcyclohexyl (meth)acrylate; (meth)acrylates that derive from unsaturated alcohols like 2-propynyl (meth)acrylate, allyl (meth)acrylate and vinyl (meth)acrylate; and the corresponding fumarates and maleates.

Monomer (A1 ) is present in an amount of 0% to 40% by weight, preferably 1 % to 20% by weight, based on the total weight of components (A1 ), (A2), (A3) and (A4).

In a further embodiment of the present invention component (A1 ) comprises monomer units of one or more ethylenically unsaturated ester compounds of formula (I)

wherein R is H or CH₃, preferably CH₃,

R¹ represents a linear or branched, saturated or unsaturated alkyi group with 1 to 5 carbon atoms or a cycloalkyl group with 3 to 5 carbon atoms and

R² and R³ independently represent H. Non-limiting examples of component (A2) include (meth)acrylates, fumarates and maleates that derive from saturated alcohols, such as hexyl (meth)acrylate, 2-ethylhexyl

(meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate and nonyl (meth)acrylate

2- ie f-butylheptyl (meth)acrylate, 3-isopropylheptyl (meth)acrylate, 2-n-propylheptyl

(meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, 5-methylundecyl

(meth)acrylate, dodecyl (meth)acrylate, 2-methyldodecyl (meth)acrylate, tridecyl

(meth)acrylate, 5-methyltridecyl (meth)acrylate, tetradecyl (meth)acrylate and pentadecyl (meth)acrylate; cycloalkyl (meth)acrylates such as bornyl (meth)acrylate, 2,4,5-tri-ie f-butyl-

3- vinylcyclohexyl (meth)acrylate, 2,3,4,5-tetra-ie f-butylcyclohexyl (meth)acrylate; oxiranyl methacrylates such as 10,1 1 -epoxyhexadecyl methacrylate; and the corresponding fumarates and maleates.

Monomer (A2) is present in an amount of 20% to 93.5% by weight, preferably 30% to 60% by weight, based on the total weight of components (A1 ), (A2), (A3) and (A4).

In a further embodiment monomer (A2) is a C_8-i5-alkyl (meth)acrylate, preferably commercial lauryl(meth)acrylate, or a Ci₀-i5-alkyl (meth)acrylate fraction. More preferably the backbone monomer is a C_8-i5-alkyl methacrylate, preferably commercial lauryl methacrylate or a

Cio-15-alkyl methacrylate fraction.

In a further embodiment of the present invention component (A2) comprises monomer units of one or more ethylenically unsaturated ester compounds of formula (II)

wherein

R is H or CH₃, preferably CH₃,

R⁴ represents a linear or branched, saturated or unsaturated alkyl group with 6 to 15 carbon atoms and

R⁵ and R⁶ independently represent H. Non-limiting examples of component (A3) include (meth)acrylates that derive from saturated alcohols, such as hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate, 5-isopropylheptadecyl (meth)acrylate, 4-ie f-butyloctadecyl (meth)acrylate, 5-ethyloctadecyl (meth)acrylate, 3-isopropyloctadecyl (meth)acrylate, octadecyl

(meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, docosyl (meth)acrylate, cetyleicosyl (meth)acrylate, stearyleicosyl (meth)acrylate and eicosyltetratriacontyl

(meth)acrylate; as well as the corresponding fumarates and maleates; and (meth)acrylates that derive from unsaturated alcohols, such as oleyl (meth)acrylate. Monomer (A3) is present in an amount of 5% to 60% by weight, preferably 20% to 50% by weight, based on the total weight of components (A1 ), (A2), (A3) and (A4).

In a further embodiment of the present invention component (A3) comprises monomer units of one or more ethylenically unsaturated ester compounds of formula (III)

wherein

R is H or CH₃, preferably CH₃,

R⁸ and R⁹ independently represent H.

The N-dispersant monomer (A4) may specifically be at least one monomer selected from the group consisting of vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidone (NVP),

morpholinoethyl methacrylate, N-vinyl caprolactam, N,N-dimethylaminoethyl methacrylate (DMAEMA), ie f-butyl aminoethyl methacrylate, N,N-dimethylaminopropylmethacrylamide (DMAPMAm), dimethylaminopropylacrylamide and dimethylaminoethylacrylamide or a mixture thereof. ln a further embodiment the N-dispersant monomer (A4) is selected from the group consisting of N-vinyl pyrrolidone (NVP), Ν,Ν-dimethylaminoethyl methacrylate (DMAEMA) and N,N-dimethylaminopropylmethacrylamide (DMAPMAm); especially preferred is N-vinyl pyrrolidone.

The amount of N-dispersant monomer (A4) is typically from 1 % to 40% by weight, preferably from 2% to 30% by weight, based on the total weight of components (A1 ), (A2), (A3) and (A4).

The N-dispersant monomer (A5), which is grafted onto the polymer backbone, may specifically be at least one monomer selected from the group consisting of vinyl pyridine, N- vinyl imidazole, N-vinyl pyrrolidone (NVP), morpholinoethyl methacrylate, N-vinyl

caprolactam, N,N-dimethylaminoethyl methacrylate (DMAEMA), ie f-butyl aminoethyl methacrylate, Ν,Ν-dimethylaminopropylmethacrylamide (DMAPMAm),

dimethylaminopropylacrylamide and dimethylaminoethylacrylamide.

In a further embodiment the N-dispersant monomer (A5) is selected from the group consisting of N-vinyl pyrrolidone (NVP), N,N-dimethylaminoethyl methacrylate (DMAEMA) and N,N-dimethylaminopropylmethacrylamide (DMAPMAm); especially preferred is N-vinyl pyrrolidone.

The amount of N-dispersant monomer (A5) is typically from 0.5% to 10% by weight, preferably from 1 % to 7% by weight, based on the total weight of components (A1 ), (A2), (A3) and (A4).

A further embodiment of the present invention is directed to the grafted polyalkyl

(meth)acrylate copolymer (A), wherein the overall nitrogen content is at least 1 % by weight, preferably 1 % to 7% by weight, based on the total content of components (A1 ) to (A5). In a preferred embodiment the nitrogen is part of an aminic functionality.

In accordance with the invention, the preferred alkyl groups include the methyl, ethyl, propyl, isopropyl, 1 -butyl, 2-butyl, 2-methylpropyl, tert-butyl, pentyl, 2-methylbutyl, 1 ,1 - dimethylpropyl, hexyl, heptyl, octyl, 1 ,1 ,3,3-tetramethylbutyl, nonyl, 1 -decyl, 2-decyl, undecyl, dodecyl, pentadecyl and the eicosyl group.

The preferred cycloalkyl groups include the cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the cyclooctyl group, which optionally are substituted by branched or non- branched alkyl groups.

The preferred alkenyl groups include the vinyl, allyl, 2-methyl-2-propene, 2-butenyl,

2-pentenyl, 2-decenyl and the 2-eicosenyl group. The polyalkyl (meth)acrylates according to the present invention typically have a number average molecular weight M_n of from 3000 to 150000, preferably 10000 to 100000, as measured by size exclusion chromatography, calibrated versus a polystyrene standard.

The polydispersity M_w/M_n of the polyalkyl(meth)acrylate polymers preferably is in the range of from 1 to 8, especially from 1.5 to 5.0. The weight average molecular weight M_w, the number average molecular weight M_n and the polydispersity M_w/M_n can be determined by GPC using a polystyrene as standard.

The molecular weight and the polydispersity can be determined by known methods. For example, gel permeation chromatography (GPC) can be used. It is equally possible to use an osmometric process, for example vapor phase osmometry, to determine the molecular weights. The processes mentioned are, for example, described in: P.J. Flory, "Principles of Polymer Chemistry" Cornell University Press (1953), Chapter VII, 266-316 and

"Macromolecules, an Introduction to Polymer Science", F.A. Bovey and F.H. Winslow, Editors, Academic Press (1979), 296-312 and W.W. Yau, J.J. Kirkland and D.D. Bly, "Modern Size Exclusion Liquid Chromatography, John Wiley and Sons, New York, 1979. To determine the molecular weights of the polymers presented herein, preference is given to using gel permeation chromatography. Measurement should preferably be made against polymethacrylate or polystyrene standards.

The architecture of the polymer backbone of the polyalkyl(meth)acrylate polymers is not critical for many applications and properties. Accordingly, these polymers may be random copolymers, gradient copolymers, block copolymers, star polymers, hyperbranched polymers and/or graft copolymers. Block copolymers and gradient copolymers can be obtained, for example, by altering the monomer composition discontinuously during the chain growth. According to the present invention, random copolymers are prepared as polymer backbone.

A second aspect of the present invention is directed to the use of the grafted

polyalkyl(meth)acrylate copolymers as defined above as a compatibilizer for additive packages, especially for additive packages for middle-distillates.

A third aspect of the present invention is directed to the use of the grafted

polyalkyl(meth)acrylate copolymers as defined above as a component in additive packages to stabilize middle-distillates.

A fourth aspect of the present invention is directed to the use of the grafted

polyalkyl(meth)acrylate copolymers as defined above for improving the cold flow properties of middle distillates.

A further object of the present invention is directed to a method for improving the cold flow properties of fuel oil compositions, comprising the steps of:

adding at least one grafted polyalkyl (meth)acrylate copolymer as described above to fuels, especially to middle distillate fuels and blends thereof, and

mixing the resulting composition.

The addition is preferably done at temperatures well above the cloud point of the used fuels, preferably at least 10°C above the cloud point.

A fifth aspect of the present invention is directed to the use of the grafted

polyalkyl(meth)acrylate copolymers as defined above for reducing n-Paraffin wax

sedimentation in middle distillates, preferably in diesel fuels and blends thereof.

The polymer according to the present invention is suitable as an additive to fuels, especially middle distillate fuels, renewable fuels and mixtures thereof. Middle distillate fuels are often referred to as fuel oils. They find use in particular in gas oils, petroleum, kerosene, diesel oils or diesel fuels or light and extra light heating oils and have generally boiling ranges from minimum 150°C to maximum 400°C. The heating oils are, for example, low-sulfur or sulfur-rich crude oil raffinates or bituminous or brown coal distillates which typically have a boiling range of from 150 to 400°C. The heating oils may be standard heating oils according to DI N 51603-1 , which has a sulfur content of from 0.005 to 0.2% by weight, or they are low-sulfur heating oils having a sulfur content of from 0 to 0.005% by weight. Examples of heating oil include in particular heating oil for domestic oil-fired boilers or heating oil extra light (H EL). The quality requirements for such heating oils are laid down, for example, in DI N 51603-1 (see also Ullmann's Encyclopedia of Industrial Chemistry, 5^th edition, Volume A12, p. 617 ff., which is hereby explicitly

incorporated by reference). DI N V 51603-6 describes low-sulphur heating oils with max 0,005 w% Sulphur and biofuel fractions of up to 20w%, so called H EL A Bio.

The diesel fuels are, for example, crude oil raffinates which typically have a boiling range from 100 to 400°C. They may also be so-called "Gas Oil", "Diesel Fuel Oil", "No.2 Diesel", "ultra low sulfur diesel" or "city diesel", characterized by a 95% point of, for example, not more than 360°C and a sulfur content of not more than 0.005% by weight, or by a 90% point of, for example, 282°C and a sulfur content of not more than 0.0015 % by weight. Diesel fuel specifications are, for example, ASTM D975 or DI N EN 590.

In addition to the diesel fuels obtainable by refining crude oil, suitable diesel fuels also include those obtainable by coal gasification or gas liquefaction ["gas-to-liquid"

("GTL") fuels] or by biomass liquefaction ["biomass-to-liquid" ("BTL") fuels]. Also suitable are mixtures of the aforementioned diesel fuels with renewable fuels such as biodiesel, vegetable oils, hydrotreated vegetable oils or bio-methyl ie f-butyl ether (MTBE). The diesel fuels are more preferably those having a low sulfur content, i.e. having a sulfur content of less than 0.05% by weight, preferably of less than 0.02% by weight, in particular of less than 0.005% by weight and especially of less than 0.0015 % by weight of sulfur.

Biodiesel (also referred to as biofuel oil) preferably comprises essentially alkyl esters of fatty acids which derive from vegetable and/or animal oils and/or fats. Alkyl esters are understood to mean typically lower alkyl esters, especially Ci_-4- alkyl esters, which are obtainable by transesterifying the glycerides which occur in vegetable and/or animal oils and/or fats, especially triglycerides, by means of lower alcohols, for example ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol or especially methanol ("FAME": fatty acid methyl esters).

The examples of vegetable oils which are converted to corresponding alkyl esters and can thus serve as the basis for biodiesel are castor oil, olive oil, peanut oil, palm kernel oil, coconut oil, mustard oil, cottonseed oil and especially sunflower oil, palm oil, soybean oil, canola oil and rapeseed oil. Further examples include oils which can be obtained from wheat, jute, sesame and the shea tree nut; it is also possible to use arachis oil, jatropha oil and linseed oil.

It is also possible to convert vegetable oils which have already been used, for example used deep fat fryer oil, if appropriate after appropriate cleaning, to alkyl esters and hence for them to serve as the basis for biodiesel. Animal fats are likewise usable in principle as a source for biodiesel.

Examples of animal fats and oils which are converted to corresponding alkyl esters and can thus serve as the basis for biodiesel are fish oil, bovine or beef tallow, porcine tallow and similar fats and oils obtained as wastes in the slaughter or utilization of farm animals or wild animals.

The parent saturated or unsaturated fatty acids of the vegetable and/or animal oils and/or fats mentioned, said fatty acids usually having from 12 to 22 carbon atoms and possibly bearing additional functional groups such as hydroxyl groups. Typical are lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, erucic acid and ricinoleic acid, and especially mixtures of such fatty acids.

Typical lower alkyl esters based on vegetable and/or animal oils and/or fats which find use 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 biofuel or components for biofuel. A sixth aspect of the present invention is directed to a composition, comprising:

(A) 10% to 90% by weight of a grafted polyalkyl (meth)acrylate copolymer as defined above, and (B) 10% to 90% by weight of a hydrocarbon solvent or an oil or a mixture of a

hydrocarbon solvent and an oil, wherein components (A) and (B) add up to 100% by weight. Common hydrocarbon solvents in this context are aliphatic or aromatic hydrocarbons such as xylenes or mixtures of high-boiling aromatics as for example Solvent Naphtha. Middle distillate fuels or biofuels themselves may also be used as the solvent for such concentrates.

The composition may comprise from 10% to 90% by weight, preferably from 30% to 80% by weight, and more preferred from 45% to 75% by weight, based on the total amount of the concentrate, of the inventive polyalkyl(meth(acrylate) as described above.

A seventh aspect of the present invention is directed to the use of the composition as defined above as a compatibilizer for additive packages, especially for additive packages for middle- distillates.

An eighth aspect of the present invention is directed to the use of the composition as defined above as a component in additive packages to stabilize middle-distillates. A ninth aspect of the present invention is directed to the use of the composition as defined above for improving the cold flow properties of middle distillates. A further object of the present invention is directed to a method for improving the cold flow properties of fuel oil compositions, comprising the steps of:

adding a composition comprising

(i) at least one grafted polyalkyl (meth)acrylate copolymer as described above and (ii) a hydrocarbon solvent/an oil

to fuels, especially to middle distillate fuels and blends thereof; and

(finally) reducing the tendency of sedimentation of paraffin waxes and sludgy material in the fuels at low temperatures. A tenth aspect of the present invention is directed to the use of the composition as defined above for reducing n-Paraffin wax sedimentation in middle distillates, preferably in diesel fuels.

In a preferred embodiment, the inventive concentrate is used as an additive to fuels which consists of

(a) 0% to 99% by weight, preferably 1 % to 20% by weight, of at least one biofuel oil which is based on fatty acid esters and (b) 1 % to 100% by weight, preferably 80% to 99% 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, wherein components (a) and (b) add up to 100% by weight.

The fuel component (a) shall be understood to mean middle distillate fuels boiling in the range of from 120°C to 400°C. Such middle distillate fuels are used in particular as diesel fuel, heating oil or kerosene. Preference is given to diesel fuel and heating oil. The fuel composition of the present invention may comprise diesel fuel of mineral origin, i.e. diesel, gas oil or diesel oil. Mineral diesel fuel is widely known per se and is commercially available. This is understood to mean a mixture of different hydrocarbons which is suitable as a fuel for a diesel engine. Diesel can be obtained as a middle distillate, in particular by distillation of crude oil. The main constituents of the diesel fuel preferably include alkanes, cycloalkanes and aromatic hydrocarbons having about 10 to 22 carbon atoms per molecule.

Preferred diesel fuels of mineral origin boil in the range of 120°C to 400°C, more preferably 170°C and 390°C. Preference is given to using those middle distillates which contain 0.2% by weight of sulphur and less, preferably less than 0.05% by weight of sulphur, more preferably less than 350 ppm of sulphur, in particular less than 200 ppm of sulphur and in special cases less than 50 ppm of sulphur, for example less than 15 ppm or less than 10 ppm of sulphur. They are preferably those middle distillates which have been subjected to refining under hydrogenating conditions, and which therefore contain only small proportions of polyaromatic and polar compounds. They are preferably those middle distillates which have 95% distillation points below 370°C, in particular below 360°C and in special cases below 330°C. Synthetic fuels, as obtainable, for example, by the Fischer-Tropsch process or gas to liquid processes (GTL), are also suitable as diesel fuels of mineral origin.

The kinematic viscosity of diesel fuels of mineral origin to be used with preference is in the range of 0.5 to 8 mm²/s, more preferably 1 to 5 mm²/s, and especially preferably 2 to 4.5 mm²/s or 1 .5 to 3 mm²/s, measured at 40°C according to ASTM D 445. The fuel compositions of the present invention may comprise at least 20% by weight, in particular at least 30% by weight, preferably at least 50% by weight, more preferably at least 70% by weight and most preferably at least 80% by weight of diesel fuels of mineral origin.

Furthermore, the present fuel composition may comprise at least one biodiesel fuel component. Biodiesel fuel is a substance, especially an oil, which is obtained from vegetable or animal material or both, or a derivative thereof which can be used in principle as a replacement for mineral diesel fuel.

In a preferred embodiment, the biodiesel fuel, which is frequently also referred to as

"biodiesel" or "biofuel" comprises fatty acid alkyl esters formed from fatty acids having preferably 6 to 30, more preferably 12 to 24 carbon atoms, and monohydric alcohols having 1 to 4 carbon atoms. In many cases, some of the fatty acids may contain one, two or three double bonds. The monohydric alcohols include in particular methanol, ethanol, propanol and butanol, methanol being preferred. Examples of oils which derive from animal or vegetable material and which can be used in accordance with the invention are palm oil, rapeseed oil, coriander oil, soya oil, cottonseed oil, sunflower oil, castor oil, olive oil, groundnut oil, corn oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, oils which are derived from animal tallow, especially beef tallow, bone oil, fish oils and used cooking oils. Further examples include oils which derive from cereal, wheat, jute, sesame, rice husks, jatropha, algae, arachis oil and linseed oil. The fatty acid alkyl esters to be used with preference may be obtained from these oils by processes known in the prior art.

Preference is given in accordance with the invention to highly C16:0/C18:0-glyceride- containing oils, such as palm oils and oils which are derived from animal tallow, and also derivatives thereof, especially the palm oil alkyl esters which are derived from monohydric alcohols. Palm oil (also: palm fat) is obtained from the fruit flesh of the palm fruits. The fruits are sterilized and pressed. Owing to their high carotene content, fruits and oils have an orange-red colour which is removed in the refining. The oil may contain up to 80% C18:0- glyceride.

Particularly suitable biodiesel fuels are lower alkyl esters of fatty acids. Useful examples here are commercial mixtures of the ethyl, propyl, butyl and especially methyl esters of fatty acids having 6 to 30, preferably 12 to 24, more preferably 14 to 22 carbon atoms, for example of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroselic acid, ricinoleic acid, elaeostearic acid, linoleic acid, linolenic acid, eicosanoic acid, gadoleic acid, docosanoic acid or erucic acid.

In a particular aspect of the present invention, a biodiesel fuel is used which comprises preferably at least 10% by weight, more preferably at least 30% by weight and most preferably at least 40% by weight of saturated fatty acid esters which are derived from methanol and/or ethanol. Especially, these esters have at least 16 carbon atoms in the fatty acid part. These include in particular the esters of palmitic acid and stearic acid. The grafted polyalkyi (meth)acrylate copolymer according to the present invention and the composition comprising said grafted polyalkyi (meth)acrylate copolymer may be used in additive packages for middle distillates. Such additive packages comprise one or more additives selected from the group consisting of cold flow improvers, dispersants, conductivity improvers, demulsifiers, defoamers, lubricity additives, antioxidants, cetane number improvers, detergents, dyes, markers, corrosion inhibitors, metal deactivators, metal passivators, anti-icing additives, H₂S-scavengers, biocides, odorants and/or other compatibilizers.

A further aspect of the present invention is directed to a composition, comprising:

(i) a grafted polyalkyi (meth)acrylate copolymer according to the invention; (ii) an antioxidant, selected from the group consisting of phenolic antioxidants, for example butylated hydroxytoluene;

(iii) a metal deactivator, for example N,N-disalicylidene-1 ,2-propandiamine; (iv) a sludge dispersant, selected from the group consisting of polyisobutene with

multiaminic head groups, for example poly-iso-butylen succinimide;

(v) diethyleneglycol monomethylether; and (vi) a solvent, selected from the group consisting of aromatic and aliphatic hydrocarbons.

Process for preparing PAMAs The grafted polymers as described above can be prepared by methods known in the art.

Customary free-radical polymerization is described, inter alia, in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition. In general, a polymerization initiator and a chain transferer are used for this purpose. The usable initiators include the azo initiators widely known in the technical field, such as AIBN and 1 ,1 -azobiscyclohexanecarbonitrile, and also peroxy compounds such as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, fe/f-butyl-per-2- ethylhexanoate, ketone peroxide, ie f-butyl peroctoate, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, fe/f-butyl-peroxybenzoate, fe/f-butyl- peroxyisopropylcarbonate, 2,5-bis(2-ethylhexanoylperoxy)-2,5 dimethylhexane, fe/f-butyl- peroxy-2-ethylhexanoate, fe/f-butyl-peroxy-3,5,5-trimethylhexanoate, dicumyl peroxide, 1 ,1 - bis(fe/f-butylperoxy)cyclohexane, 1 ,1 -bis(fe/f-butylperoxy)-3,3,5-trimethylcyclohexane, cumyl hydroperoxide, ie f-butyl hydroperoxide, bis(4-ie/f-butylcyclohexyl) peroxydicarbonate, mixtures of two or more of the aforementioned compounds with one another, and mixtures of the aforementioned compounds with compounds which have not been mentioned but can likewise form free radicals. Other valid types of initiators are selected from the group consisting of 2,2-di(ie/f- amylperoxy)propane, ie/f-butyl peroxy acetate, dicumyl peroxide, fe/f-butyl peroxyisobutyrate, ie/f-amylperoxy 2-ethylhexanoate, dibenzoyl peroxide and 1 ,1 -di(ie/f- amylperoxy)cyclohexane. Suitable chain transfer agents are in particular sulfur-free compounds which are known per se. These include, for example, without any intention that this should impose a restriction, dimeric alpha-methylstyrene(2,4-diphenyl-4 methyl-1 -pentene), enol ethers of aliphatic and/or cycloaliphatic aldehydes, terpenes, alpha-terpinene, terpinols, 1 ,4-cyclohexadiene, 1 ,4 dihydronaphthalene, 1 ,4,5,8-tetrahydronaphthalene, 2,5-dihydrofuran, 2,5-dimethylfuran and/or 3,6-dihydro-2H-pyran; preference is given to dimeric alpha-methylstyrene.

These chain transfer agents are commercially available. They can also be prepared in the manner known to those skilled in the art. For instance, the preparation of dimeric alpha- methylstyrene is described in the patent DE 966 375. Enol ethers of aliphatic and/or cycloaliphatic aldehydes are disclosed in the patent DE 3 030 373. The preparation of terpenes is explained in EP 80 405. The published specifications JP 78/121 891 and JP 78/121 890 explain the preparation of alpha-terpinene, terpinols, 1 ,4-cyclohexadiene, 1 ,4- dihydronaphthalene, 1 ,4,5,8-tetrahydronaphthalene. The preparation of 2,5-dihydrofuran, 2,5-dimethylfuran and 3,6-dihydro-2H-pyran is explained in the published specification DE 2 502 283.

The polymerization of the polymer backbone can be performed at standard pressure, reduced pressure or elevated pressure. The polymerization temperature should not exceed 200°C. In general, however, it is in the range of -20°C to 200°C, preferably 50° to 150°C and more preferably 80° to 130°C.

The polymerization can be performed with or without solvent. The term "solvent" is to be understood here in a wide sense.

Preference is given to performing the polymerization in a nonpolar solvent. These include hydrocarbon solvents, for example aromatic solvents such as toluene, benzene and xylene, saturated hydrocarbons, for example cyclohexane, heptane, octane, nonane, decane, dodecane, which may also be present in branched form. These solvents may be used individually or else as a mixture. Particularly preferred solvents are mineral oils, natural oils and synthetic oils, and mixtures thereof. Among these, mineral oils are most preferred.

The polymer backbone can be prepared in one or more steps, and it is possible to use different monomer compositions (A1 ) to (A4) which may differ. This allows mixtures of polymer backbones to be generated, which can be used advantageously in accordance with the invention.

To prepare graft polymers from the composition obtained in step 1 , which generally comprises at least one main chain polymer, at least one monomer composition (A5) is grafted.

It is assumed that the grafting forms side chains on the polymer backbone, so that at least a portion of the graft is bonded covalently to the polymer backbone.

The grafting can be effected in one or more steps. In this context, it is possible, inter alia, to change the composition of the monomer composition (A5). For example, different monomers having nitrogen-containing groups can be used. The performance of graft copolymerizations is common knowledge and is detailed, for example, in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition and Rompp Chemie-Lexikon on CD version 2.0, where reference is made to further literature. Having generally described the present invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.

Experimental Part

The following substances were used in the synthesis processes of polymers:

ALFOL® 1214 - homolog distribution

ALFOL® 1620 - homolog distribution

The molecular weights of the described polymers were determined by one of the following methods:

(a) GPC system consisting of a Waters Alliance 2695 system equipped with a Model 2414 Rl detector. Two Waters Styragel 5E columns are used with THF at a flow rate of 1 .0 mL/min and a temperature of 40°C. Calibration is performed with a broad poly(alkyl methacrylate).

(b) GPC system consisting of Agilent 1 100 Series pump equipped with PSS SECcurity inline degaser, Agilent 1 100 series Rl (detection temperature 40°C) and UV detectors (wavelength 239 nm). Five SDV columns and one solvent separation column are used with THF as the eluent at a flow rate of 1 .0 mL/min. Calibration is performed with PMMA standards obtained from PSS (Mainz).

Polymer 1 : grafted polyalkyl (meth)acrylate copolymer with N-dispersant monomers in backbone and grafted side-chain

374.1 g of Mineral Oil #2 was charged to a four-neck glass round bottom flask equipped with glass stirrer, condenser and thermocouple. The oil was heated to 1 15°C. A mixture of 251 .5 g of Ester #1 , 190.5 g of Ester #2, 77.7 g of Ester #3, 32.8 g of N-vinylpyrrolidone, and 5.76 g of LUPEROX 26 was prepared. The entire mixture was added to the round bottom flask via an addition funnel over the course of 120 minutes. The temperature of the reaction mixture was maintained at 1 15°C throughout the course of the addition. Following the complete addition of the mixture, the reaction was held at 1 15°C for an additional 30 minutes. The temperature of the reaction was then raised to 125°C and 23.0 g of N-vinylpyrrolidone was added followed by 2.3 g of LUPEROX 7M50. The reaction mixture was held at 125°C for an additional 120 minutes. Finally, Mineral Oil #2 was added to achieve the desired

concentration of polymer in oil.

M_w: 1 19000 g/mol

M_n: 47500 g/mol

PDI: 2.51

nitrogen content: 1 .2%

Polymer 2: statistical polyalkyl (meth)acrylate copolymer with N-dispersant monomers only in the main chain

374.1 g of Mineral Oil #2 was charged to a four-neck glass round bottom flask equipped with glass stirrer, condenser and thermocouple. The oil was heated to 1 15°C. A mixture of 257.2 g of Ester #1 , 196.2 g of Ester #2, 83.5 g of Ester #3, 38.6 g of N-vinylpyrrolidone, and 5.76 g of LUPEROX 26 was prepared. The entire mixture was added to the round bottom flask via an addition funnel over the course of 120 minutes. The temperature of the reaction mixture was maintained at 1 15°C throughout the course of the addition. Following the complete addition of the mixture, the reaction was held at 1 15°C for an additional 120 minutes. Finally, Mineral Oil #2 was added to achieve the desired concentration of polymer in oil.

nitrogen content: 0.7%

Polymer 3: ethylene vinyl acetate-co-polyalkyl methacrylate polymer (EVA-graft-PAMA) 20 gram of ethylene vinyl acetate (EVA) copolymer was dissolved in 150 g dilution oil (Shell Risella 907) equipped with a glass stirrer, a thermocouple and a condenser and the mixture was stirred overnight at 100°C. Later, the temperature was adjusted to 90°C. 18.8 g of C12- C15 methacrylate (dodecyl pentadecyl methacrylate, DPMA) was charged to the reaction vessel containing ethylene vinyl acetate copolymer. Then 61.2 g DPMA containing 0.58% ie f-butylperoxy-2-ethylhexanoate was fed to the EVA copolymer solution over 3.5 hours. The reaction mixture was stirred at 90°C for another 2 hours. Finally, 0.2% ie f-butylperoxy- 2-ethyl-hexanoate was added to the reaction flask and the reaction was held for another 5 hours. 1 16000 g/mol

M_n: 40000 g/mol

PDI: 2.91

nitrogen content: 0%

Polymer 4: polylalkyl methacrylate containing 2-ethylhexyl methacrylate

(HEMA-co-PAMA)

48.65 g of 100N oil was charged to a four-neck glass round bottom flask equipped with glass stirrer, condenser and thermocouple. The oil was heated to 95°C. A mixture of 506.0 g of a C12-C15 methacrylate, 3.16 g of branched C12-15 methacrylate, 5.75 g of C16-18 methacrylate, 5.75 g of methyl methacrylate, 51 .75 g of 2-ethylhexyl methacrylate, 6.90 g of LUPEROX® 26 and 9.78 g of n-dodecylmercaptan was prepared. The entire mixture was added to the round bottom flask via an addition funnel over the course of 210 minutes. The temperature of the reaction mixture was maintained at 95°C throughout the course of the addition. Following the complete addition of the mixture, the reaction was held at 95°C for an additional 30 minutes followed by the addition of 1 .15 g of LUPEROX® 26. The reaction mixture was held at 95°C for an additional 100 minutes. Finally, Mineral Oil #1 was added to achieve the desired concentration of polymer in oil.

M_w: 21800 g/mol

M_n: 10800 g/mol

PDI: 2.01

nitrogen content: 0%

Polymer 5: statistical polyalkyl methacrylate comprising 2-dimethylaminoethyl

methacrylate (DMAEMA)

143.4 g solvent (Shellsol A150 ND and white oil (95.6 : 4.4)) was charged to a four neck round bottom flask equipped with a glass stirrer, a thermocouple and a condenser. The flask was heated to reaction temperature of 140°C, followed by a continuous feed of 245.0 g of C12-C15 methacrylate (dodecyl pentadecyl methacrylate, DPMA) and 105.0 g of 2- dimethylaminoethyl methacrylate (DMAEMA) containing 13.3 g 2,2-bis(ie f- butylperoxy)butane (50% solution in white oil) for 5 hours. The reaction temperature was reduced to 100°C after 1 .5 hours of the initial feed completion, and after 30 min, 0.2% tert- butylperoxy-2-ethylhexanoate was added and the reaction was held for another 4 hours. M_w: 8030 g/mol

M_n: 4510 g/mol

PDI: 1 .78

nitrogen content: 2.7%

Polymer 6: statistical polyalkyl methacrylate comprising 3-dimethylaminopropyl

methacrylamide (DMAPMAm)

143.4 g solvent (Shellsol A150 ND and white oil (95.6 : 4.4)) was charged to a four neck round bottom flask equipped with a glass stirrer, a thermocouple and a condenser. The flask was heated to reaction temperature of 140°C, followed by a continuous feed of 245.0 g of dodecyl pentadecyl methacrylate (DPMA) and 105.0 g of 3-dimethylaminopropyl methacrylamide (DMAPMAm) containing 13.3 g 2,2-bis(ie/f-butylperoxy)butane (50% solution in white oil) for 5 hours. The reaction temperature was reduced to 100°C after 1 .5 hours of the initial feed completion, and after 30 min, 0.2% ie f-butylperoxy-2-ethylhexanoate was added and the reaction was held for another 4 hours.

M_w: 9100 g/mol

M_n: 5200 g/mol

PDI: 1 .75

nitrogen content: 4.9%

Polymer 7: polyalkyl methacrylate

108.8 g of Shellsol A150 (Solvent Naptha 150) was charged to a four-neck glass round bottom flask equipped with glass stirrer, condenser and thermocouple. The oil was heated to 140°C. A mixture of 287.5 g of a C12-C14 methacrylate, 287.5 g of C16-18 methacrylate, 34.5 g of LUPEROX® 220, and 0.17 g of n-dodecylmercaptan was prepared. The entire mixture was added to the round bottom flask via an addition funnel over the course of 300 minutes. The temperature of the reaction mixture was maintained at 140°C throughout the course of the addition. Following the complete addition of the mixture, the reaction held for an additional 30 minutes. Temperature was then lowered to 100°C and 1 .15 g of

LUPEROX® 26 was added. The reaction mixture was held at 100°C for an additional 120 minutes.

M_w: 7180 g/mol

M_n: 3540 g/mol

PDI: 2.03

nitrogen content: 0 %

Polymer 8:

Mixture of a polylalykl (meth)acrylate and ethylene-vinyl acetate-graft-polylalkyl

(meth)acrylate) with a Ethylene-copolymer wax (Keroflux® by BASF):

70% polylalykl (meth)acrylate and ethylene-vinyl acetate-graft-polylalkyl (meth)acrylate) 15% Ethylene-copolymer wax (Keroflux® by BASF)

15% Solvent Naphtha

Polymer 9a / 9: Polyalkylmethacrylate 9a and polymer mixture 9

126.1 g of Shellsol A150 (Solvent Naptha 150) was charged to a four-neck glass round bottom flask equipped with glass stirrer, condenser and thermocouple. The oil was heated to 140°C. A mixture of 569.3 g of a C12-C14 methacrylate, 5.75 g of methyl methacrylate, 17.25 g of LUPEROX 220®, and 0.17 g of n-dodecylmercaptan was prepared. The entire mixture was added to the round bottom flask via an addition funnel over the course of 300 minutes. The temperature of the reaction mixture was maintained at 140°C throughout the course of the addition. Following the complete addition of the mixture, the reaction held for an additional 30 minutes. Temperature was then lowered to 100°C and 1 .15 g of

850 g of the resulting polymer solution (Polymer 9a) was mixed with 150 g of Polymer 3 to give Polymer 9. Polymer 10: ethylene copolymer wax

Ethylene copolymer wax with a molecular weight distribution of M_w = 6800 g/mol according to GPC with polystyrene standard.

Composition according to NMR:

ethylene / vinyl acetate/ vinyl alkanoate^* = ~ 88/ 9.5/ 2.5 mol.-%

*vinyl alkanoate: main chain length C12-C14

Compatibility

Certain additive compositions were prepared using different polymers as compatibilizer. With the given blends a series of thermal stability investigations according to DIN 51371 were done in domestic heating oil.

The grafted copolymers according to the present invention are used as compatibilizers to ensure sufficient homogenization of multifunctional additive packages which comprise an antioxidant (butylated hydroxytoluene), a metal deactivator (N,N-disalicylidene-1 ,2- propandiamine), a sludge dispersant (poly-iso-butylen succinimide), and an anti-icing agent (diethyleneglycol monomethylether), and also an inert organic solvent (Shellsol A 150 ND) by stabilizing them such that no phase separation or opacity occur in the course of formulation or storage - even in the course of storage over prolonged periods, for example over several weeks - of the additive packages. The examples which follow are intended to illustrate this effect of the compatibilizers according to the present invention.

Additive packages composed of the components as outlined in Tables 1 a-c were prepared by mixing at 60°C. Rating of homogeneity

The degree of homogenization of the additive packages prepared was assessed visually by the following rating scale:

The compositions of the additive packages prepared and the assessment of their degree of homogenization according to the above rating scale is evident from the tables as presented below.

Table 1 a: Visual appearance @ blending temperature of 60°C

BHT: butylated hydroxytoluene

MD: Metal Deactivator: N,N-disalicylidene-1 ,2-propandiamine

PIBSI: poly-iso-butylen succinimide

DiEGME: diethyleneglycol monomethylether (purchased from Merck)

Solvent Naphtha: Shellsol A 150 ND (Shell) Table 1 b: Visual appearance @ room temperature (determined shortly after mixing)

Blend Polymer Polymer BHT MD PIBSI DiEGME Rating # # [wt%]

[wt%] [wt%] [wt%] [wt%]

A 1 10 30 5 30 25 2

B 1 20 30 5 20 25 2

C 1 40 30 5 0 25 2

D 2 10 30 5 30 25 2

E 2 20 30 5 20 25 2

F 2 40 30 5 0 25 3

G 3 10 30 5 30 25 2

H 3 20 30 5 20 25 3

I 3 40 30 5 0 25 3

J 4 10 30 5 30 25 2

K 4 20 30 5 20 25 2

L 4 40 30 5 0 25 2

M 5 10 30 5 30 25 3

N 5 20 30 5 20 25 1

0 5 40 30 5 0 25 1

P 6 10 30 5 30 25 3

Q 6 20 30 5 20 25 2

R 6 40 30 5 0 25 1

S 7 10 30 5 30 25 2

T 7 20 30 5 20 25 2 u 7 40 30 5 0 25 3

V — 0 30 5 40 25 2 Table 1 c: Visual appearance @ room temperature after 5 days

When using Polymer 1 which contains N-dispersant monomers in the backbone as well as in the grafted side-chain and shows an overall nitrogen content of 1 .2% the additive packages can be homogenized even over a longer storage time. Polymer 2, the precursor of Polymer 1 , which is a statistical polymer with N-dispersant monomers in the main chain and an overall nitrogen content of only 0.7% is not active enough. This precursor only contains 5.7% by weight of NVP in the polymer (less than 1 % by weight of nitrogen). Only after the grafting step, when the nitrogen content was increased to more than 1 % by weight, the desired effect was observed.

When using Polymer 2 the additive packages clearly showed phase separation after 5 days of storage.

The addition of Polymer 3 which is an EVA-graft-PAMA and Polymer 4 which contains about 1 % by weight of OH-groups also leads to phase separation of the additive package.

The addition of polymer 5 and polymer 6, respectively, has improved the compatibility. The DMAEMA-containing Polymer 5 contains 2.7% by weight of aminic nitrogen. The DMAPMAm- containing Polymer 6 contains 4.9% by weight of nitrogen, however only 2.5% w% are aminic nitrogen. The amide functionality seems not to be helpful for the compatibilizing activity.

The use of Polymer 7 as a straight PAMA without dispersant functionality does not help to avoid phase separation.

Thermal Stability

The thermal stability tests were run according to DIN 51371.

Determination of the thermal stability according to DIN 51371 of different blends in heating oil containing 5% RME

The used heating oils are low sulfur heating oils extra light (HEL) with a sulfur content < 50 ppm. They are according to DIN 51603. It was shown that blends B and C, containing polymer #1 , perform well to improve the thermal stability of heating oils.

The advantage versus blend V is the homogeneity and phase stability of the package.

Wax sedimentation

The wax sedimentation was run according to the BP short sedimentation test procedure. An ultra low sulfur diesel with a sulfur content of < 15 ppm, containing 5% by weight of soybean oil methyl ester was used.

The blank values for CP, CFPP and PP are given as follows:

CP CFPP PP

[°C] [°C] [°C]

-12.9 -17 -30

Table 3a: CP data: B5 Diesel Fuel, bath temperatu

Table 3b: PP data: B5 Diesel Fuel, bath temperatu

PP before PP after treat rate treat rate

sedimentation sedimentation

Additive 1 Additive 2

[ppm] [ppm]

[°C] [°C]

Polymer 10 500 Polymer 1 0 -39 -39

Polymer 10 750 Polymer 1 0 -42 -45

Polymer 8 250 Polymer 1 0 -45 -42

Polymer 10 500 Polymer 1 50 -42 -42

Polymer 10 750 Polymer 1 50 -45 -45

Polymer 8 250 Polymer 1 50 -57 -54 Table 3c: CFPP data: B5 Diesel Fuel, bath temperatu

Polymer 1 helps to reduce the cloud point (CP) after sedimentation. This can be explained by the wax dispersing activity which prevents n-paraffin wax crystals from settling down during cold storage. The CP after sedimentation is measured in the 20% bottom phase of the fuel sample after 16 hours sedimentation. There is nearly no change versus the original CP before sedimentation after addition of just 50 ppm of Polymer 1 . At the same time, Polymer 1 reduces the pour point (PP) before and after sedimentation. The cold filter plugging point (CFPP) was not affected beyond its repeatability limits.

Test as components in Antioxidant-Stabilizer packages

Table 4a: composition of different blends

Blend # Polymer Polymer Shellsol BHT TBHQ DB Solvent MD treat rate

[%]

[%] [%] [%] [%] [%]

Reference Polymer 9a 42.5 7.5 20 15 15

Polymer 9a 42.5

X-1 + — 20 15 15

Polymer 3 7.5

Polymer 9a 42.5

X-2 + — 20 15 15

Polymer 1 7.5 Blend # Polymer Polymer Shellsol BHT TBHQ DB Solvent MD treat rate

[%]

[%] [%] [%] [%] [%]

Polymer 9a 42.5 0.5

X-3 + — 20 15 15

Polymer 1 7.5

Table 4b: stability of blends

Blends X-2 and X-3 are the most stable ones in contrast to the reference blend and blend X-1 . Blend X-1 contains an EVA-graft-PAMA compatibilizer. Phase separation occurs already after more than 10 days storage at room temperature in blend X-1. Blends X-2 and X-3 are stable over much longer storage periods.

In addition to the stability improvement a slight performance advantage was seen in the Rancimat test. The delta IP (ΔΙΡ) was improved from 8.47 hours to 9.21 hours by changing from Polymer 3 to Polymer 1 in the recipe. Rancimat Test

The common method to evaluate the oxidation stability of oils and fats is the Rancimat test (EN 141 12), measured at 1 10°C. In this test, a purified air stream is fed through the sample to induce the formation of volatile acids formed from the oxidation process. These volatile acids are then carried over into a measurement vessel containing de-ionised water, in which the conductivity of the solution is measured. The end of induction period is measured as the conductivity increases. Typical induction periods for fresh rapeseed oil methyl ester (RME) are 5 to 7 h and 2 to 5 h for soybean oil methyl ester (SME). Aged FAME can have significantly lower Rancimat Induction Periods. A few examples of antioxidants include BHA (butylated hydroxy anisole), BHT (butylated hydroxy toluene), TBHQ (tertiary butylated hydroxy quinone) etc., which are successfully used to improve the oxidation stability of vegetable oils and animal fats.

Rancimat test results in

SME

Blend # oil treat rate IP [hour] ΔΙΡ [hour] remark

EN 141 12

X-1 SME 0 0.95 0.00

2500 9.42 8.47

5000 15.20 14.25

X-2 SME 0 0.95 0.00

2500 10.16 9.21 according to the invention

5000 15.63 14.68 according to the invention

X-3 SME 0 0.95 0.00

2500 16.28 15.33 according to the invention

— — —

Claims

A grafted polyalkyi (meth)acrylate copolymer (A), containing as a polymer backbone monomer units comprising:

(A1 ) 0% to 40% by weight, preferably 1 % to 20% by weight, of one or more

ethylenically unsaturated ester compounds of formula (I)

wherein

R is H or CHs,

(A2) 20% to 93.5% by weight, preferably 30% to 60% by weight, of one or more ethylenically unsaturated ester compounds of formula (II)

wherein

R is H or CHs,

R⁴ represents a linear or branched, saturated or unsaturated alkyl group with 6 to 15 carbon atoms, R⁵ and R⁶ independently represent H or a group of the formula -COOR", wherein R" is H or a linear or branched, saturated or unsaturated alkyl group with 6 to 15 carbon atoms, (A3) 5% to 60% by weight, preferably 20% to 50% by weight, of one or more

ethylenically unsaturated ester compounds of formula (III)

wherein

R is H or CHs,

1 % to 40% by weight, preferably 2% to 30% by weight, of at least one N- dispersant monomer selected from the group consisting of vinyl pyridine, N- vinyl imidazole, N-vinyl pyrrolidone (NVP), morpholinoethyl methacrylate, N- vinyl caprolactam, Ν,Ν-dimethylaminoethyl methacrylate (DMAEMA), ie f-butyl aminoethyl methacrylate, N,N-dimethylaminopropylmethacrylamide

(DMAPMAm), dimethylaminopropylacrylamide and

dimethylaminoethylacrylamide, wherein components (A1 ) to (A4) add up to 100% by weight; and

(A5) 0.5% to 10% by weight, preferably 1 % to 7% by weight, of at least one N- dispersant monomer selected from the group consisting of vinyl pyridine, N- vinyl imidazole, N-vinyl pyrrolidone (NVP), morpholinoethyl methacrylate, N- vinyl caprolactam, N,N-dimethylaminoethyl methacrylate (DMAEMA), ie/f-butyl aminoethyl methacrylate, N,N-dimethylaminopropylmethacrylamide (DMAPMAm), dimethylaminopropylacrylamide and

dimethylaminoethylacrylamide which is grafted onto the polymer backbone, wherein components (A1 ) to (A5) add up to 100% by weight.

2. A copolymer according to claim 1 , wherein in formula (I) of component (A1 ) R² and R³ are each hydrogen.

3. A copolymer according to claim 1 or 2, wherein in formula (II) of component (A2) R⁵ and R⁶ are each hydrogen.

4. A copolymer according to claim 1 , 2 or 3, wherein in formula (III) of component (A3) R⁸ and R⁹ are each hydrogen.

5. A copolymer according to claim 1 , 2, 3 or 4, wherein the N-dispersant monomer of component (A4) is N-vinyl pyrrolidone (NVP).

6. A copolymer according to claim 1 , 2, 3, 4 or 5, wherein the N-dispersant monomer of component (B) which is grafted onto the polymer backbone (A) is N-vinyl pyrrolidone (NVP).

7. A copolymer according to claim 1 , 2, 3, 4, 5 or 6, wherein the nitrogen content of the grafted polyalkyl(meth)acrylate copolymer (A) is at least 1 % by weight, preferably 1 % to 7% by weight, based on the total content of components (A1 ) to (A5).

8. A copolymer according to claim 1 , 2, 3, 4, 5, 6 or 7, characterized in that the polyalkyl(meth)acrylate has a number average molecular weight M_n of from 3000 to 150000.

9. A copolymer according to claim 1 , 2, 3, 4, 5, 6, 7 or 8, characterized in that the polyalkyl(meth)acrylate has a number average molecular weight M_n of from 10000 to 100000.

10. A copolymer according to claim 1 , 2, 3, 4, 5, 6, 7, 8 or 9, characterized in that the polydispersity M_w/M_n of the polyalkyl(meth)acrylate is in the range of from 1 to 8.

1 1 . A copolymer according to claim 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10, characterized in that the polydispersity M_w/M_n of the polyalkyl(meth)acrylate is in the range of from 1 .5 to 5.

12. Use of a grafted polyalkyl(meth)acrylate copolymer according to any one of claims 1 to 1 1 as a compatibilizer for additive packages, especially for additive packages for middle- distillates.

13. Use of a grafted polyalkyl(meth)acrylate copolymer according to any one of claims 1 to 1 1 as a component in additive packages to stabilize middle-distillates.

14. Use of a grafted polyalkyl(meth)acrylate copolymer according to any one of claims 1 to 1 1 for improving the cold flow properties of middle distillates.

15. Use of a grafted polyalkyl(meth)acrylate copolymer according to any one of claims 1 to 1 1for reducing n-Paraffin wax sedimentation in middle distillates, preferably in diesel fuels.

16. The use according to claim 12, 13, 14 or 15, characterized in that the middle distillate is a fuel, comprising: (a) from 0% to 99% by weight, preferably 1 % to 20% by weight, of at least one biofuel oil which is based on fatty acid esters, and

(b) from 1 % to 100% by weight, preferably 80% to 99% 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, wherein components (a) and (b) add up to 100% by weight.

17. The use according to claim 13, characterized in that the additive package comprises one or more additives selected from the group consisting of cold flow improvers, dispersants, conductivity improvers, demulsifiers, defoamers, lubricity additives, antioxidants, cetane number improvers, detergents, dyes, markers, corrosion inhibitors, metal deactivators, metal passivators, anti-icing additives, H₂S-scavengers, biocides, odorants and/or other compatibilizers are present.

18. Composition, comprising:

(A) 10% to 90% by weight of a grafted polyalkyl(meth)acrylate copolymer according to any one of claims 1 to 1 1 , and

(B) 10% to 90% by weight of a hydrocarbon solvent or an oil or a mixture of a

hydrocarbon solvent and an oil, wherein components (A) and (B) add up to 100% by weight.

19. Use of a composition according to claim 18 as a compatibilizer for additive packages for middle-distillates.

20. Use of a composition according to claim 18 as a component in additive packages to stabilize middle-distillates.

21 . Use of a composition according to claim 18 for improving the cold flow properties of middle distillates.

22. Use of a composition according to claim 18 for reducing n-Paraffin wax sedimentation in middle distillates, preferably in diesel fuels.

23. The use according to claim 19, 20, 21 or 22, characterized in that the middle distillate is a fuel, comprising:

(a) from 0% to 99% by weight, preferably 1 % to 20% by weight, of at least one biofuel oil which is based on fatty acid esters, and (b) from 1 % to 100% by weight, preferably 80% to 99% 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, wherein components (a) and (b) add up to 100% by weight.

24. The use according to claim 20, characterized in that the additive package comprises one or more additives selected from the group consisting of cold flow improvers, dispersants, conductivity improvers, demulsifiers, defoamers, lubricity additives, antioxidants, cetane number improvers, detergents, dyes, markers, corrosion inhibitors, metal deactivators, metal passivators, anti-icing additives, H₂S-scavengers, biocides, odorants and/or other compatibilizers are present.