CA2287660A1 - Polymer mixtures for improving the lubricity of middle distillates - Google Patents

Abstract

The invention relates to an additive for fuel oils, comprising A) from 10 to 90% by weight of at least one copolymer of ethylene and at least one further olefinically unsaturated monomer containing one or more hydroxyl groups, and B) from 90 to 10% by weight of at least one polar nitrogen-containing compound.
The additive according to the invention improves the lubricity of middle distillates.

Description

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4 v Clariant GmbH 1998DE433 Dr.KM/sch Description Polymer mixtures for improving the lubricity of middle distillates The present invention relates to additives comprising hydroxyl-containing copolymers and polar nitrogen compounds which provide middle distillates with better lubricity, and to the corresponding additive-containing middle distillates.
Mineral oils and mineral oil distillates used as fuel oils generally contain 0.5% by weight or more of sulfur, which, on burning, causes the formation of sulfur dioxide. In order to reduce the resultant environmental pollution, the sulfur content of fuel oils is continually being reduced further. The EN 590 standard relating to diesel fuels currently prescribes a maximum sulfur content of 500 ppm in Germany. In Scandinavia, fuel oils containing less than 200 ppm and in exceptional cases less than 50 ppm of sulfur are already in use. These fuel oils are generally produced by hydrotreating the fractions obtained from the crude oil by distillation.
However, the desulfurization also removes other substances which provide the fuel oils with a natural lubricity. These substances include, inter alia, polyaromatic and polar compounds.
However, it has now been found that the friction- and wear-reducing properties of fuel oils worsen with increasing degree of desulfurization. These properties are frequently so poor that the fuel-lubricated materials, such as, for example, the distributor injection pumps of diesel engines, can be expected to exhibit signs of wear after only a short time. The further lowering of the 95% distillation point to below 370°C, in some cases to below 350°C or below 330°C, which has in the meantime been carried out in Scandinavia, further exacerbates this problem.
The prior art therefore describes attempts to solve this problem (so-called lubricity additives).

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EP-A-0 764 198 discloses additives which improve the lubricity of fuel oils and which comprise polar nitrogen compounds based on alkylamines or alkylammonium salts containing alkyl radicals having 8 to 40 carbon atoms.
EP-A-0 743 972 discloses the use of mixtures of lubricity additives (esters of polyhydric alcohols and carboxylic acids having 2 to 50 carbon atoms or dicarboxylic acids) and nitrogen-containing compounds for synergistic improvement of the lubricity of highly desulfurized oils. The nitrogen-containing compounds employed are paraffin inhibitors containing amides or ammonium salts of dicarboxylic acids with fatty amines.
WO 98/16597 discloses the use of C,-C3o-, preferably C9-C24-alkylphenols, their condensation products with aldehydes, and corresponding alkoxylates as lubricity additives for middle distillates.
The object of the present invention was to find multifunctional additives which result in an improvement in lubricity in middle distillates which have been substantially freed from sulfur and aromatic compounds. At the same time, these additives should also improve the inadequate effectiveness in various oil grades of paraffin dispersants, which retard or prevent sedimentation of the paraffin crystals formed in such middle distillates at low temperatures.
Surprisingly, it has been found that polymer mixtures comprising hydroxyl-containing copolymers and simultaneously polar nitrogen compounds are capable of positively affecting both the lubricity and the cold-flow properties of middle distillates and in particular paraffin dispersal. The mixtures have the advantage that the effect can be achieved using lower metering rates than is the case for the components of the mixtures.
The invention relates to an additive for fuel oils, comprising A) from 10 to 90% by weight of at least one copolymer of ethylene and at least . .

one further olefinically unsaturated comonomer containing one or more hydroxyl groups, and B) from 90 to 10% by weight of at least one polar nitrogen-containing compound.
The olefinically unsaturated compounds which make up the hydroxyl-containing comonomers of component A) are preferably vinyl esters, acrylates, methacrylates, alkyl vinyl ethers and/or alkenes carrying hydroxyalkyl, hydroxyalkenyl, hydroxycycloalkyl or hydrvxyaryl radicals. These radicals contain at least one hydroxyl group, which can be in any desired position of the radical, but is preferably at the chain end (w-position) or in the para-position in the case of ring systems. The copolymers which make up component A) may, if desired, also comprise further comonomers in addition to ethylene and olefinically unsaturated compounds containing hydroxyl groups.
The vinyl esters are preferably those of the formula 1 CH2 = CH - OCOR' (1 ) in which R' is C,-C3°-hydroxyalkyl, preferably C,-C,2-hydroxyalkyl, especially C2-Cs-hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals. Suitable vinyl esters include 2-hydroxyethyl vinyl esters, a-hydroxypropyl vinyl esters, 3-hydroxypropyl vinyl esters and 4-hydroxybutyl vinyl esters.
The acrylates are preferably those of the formula (2) CHZ = CRz - CUOR3 (2) in which R2 is hydrogen or methyl, and R3 is C,-C3°-hydroxyalkyl, preferably C,-C,2-hydroxyalkyl, especially CZ-C6-hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals. Suitable acrylates include hydroxyethyl acrylate, diethylene glycol monoacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, hydroxyisopropyl acrylate, 4-hydroxybutyl acrylate, glycerol monoacrylate and the corresponding esters of methacrylic acid.
The alkyl vinyl ethers are preferably compounds of the formula 3 CHZ = CH - OR4 (3) in which R4 is C,-C3°-hydroxyalkyl, preferably C~-C,2-hydroxyalkyl, especially C2-Cs-hydroxyalkyl and the corresponding hydroxyoxalkyl radicals. Suitable alkyl vinyl ethers include 2-hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hexanediol monovinyl ether, 4-(hydroxybutyl)vinyl ether, diethylene glycol monovinyl ether and cyclohexanedimethanol monovinyl ether.
The alkenes are preferably monounsaturated hydroxyhydrocarbons having 3 to 30 carbon atoms, in particular 4 to 16 carbon atoms, especially 5 to 12 carbon atoms. Preferred hydroxy hydrocarbons are also those in which the carbon chain is interrupted by oxygen. Suitable alkenes include dimethylvinylcarbinol (= 2-methyl-3-buten-2-ol), allyloxypropanediol, 2-butene-1,4-diol, 1-buten-3-ol, 3-buten-1-ol, 2-buten-1-ol, 1-penten-3-ol, 1-penten-4-ol, 2-methyl-3-buten-1-ol, 1-hexen-3-ol, 5-hexen-1-of and 7-octene-1,2-diol.
The molar proportion of hydroxyl-functionalized comonomers in the copolymer (A) is preferably from 0.5 to 13%, in particular from 3 to 10%. The OH number of the copolymers is preferably between 1 and 800, in particular between 5 and 200, especially between 10 and 100 mg of KOH/g of polymer.
The melt viscosities of the hydroxyl-functionalized copolymers (A) at 140°C are preferably below 10,000 mPas, in particular between 10 and 1000 mPas, especially between 15 and 500 mPas. Preference is given to copolymers having mean molecular weights (number average) of 500-100,000 units, in particular from 1000 to 50,000 units, especially from 1000 to 10,000 units. The melt viscosities and molecular weights must in all cases be such that the copolymers are oil-soluble.
Besides ethylene, component (A) of the novel additives comprises at least one comonomer containing hydroxyl groups. It may also contain further, for example 5 one, two or three further, olefinically unsaturated comonomers. Examples of such olefinically unsaturated comonomers are vinyl esters, acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, vinyl ethers and olefins. Particularly preferred vinyl esters are vinyl acetate, vinyl hexanoate, vinyl octanoate, vinyl 2-ethylhexanoate, vinyl laurate, vinyl propionate and vinyl esters of neocarboxylic acids having 8, 9, 10, 11 or 12 carbon atoms. Particularly preferred acrylic and methacrylic esters are those with alcohols having 1 to 20 carbon atoms, in particular with methanol, ethanol, propanol, n-butanol, isobutanol and tert-butanol. Particularly preferred olefins are those having 3 to 10 carbon atoms, especially propene, 1-butene, isobutylene, diisobutylene, 4-methyl-1-pentene, heptene, octene, norbornene and hexene. Particular preference is given to terpolymers of ethylene, a hydroxyl-functionalized comonomer and either vinyl acetate or a vinyl ester of a neocarboxylic acid having 8 to 12 carbon atoms. In a preferred embodiment of the invention, the hydroxyl-containing copolymers (A) comprise up to 16 mol%, in particular from 3 to 14 mol%, of these vinyl or (meth)acrylic esters.
The novel additives comprise at least one polar nitrogen compound (B). In preferred embodiments of the invention, these polar nitrogen compounds are those formed by the reaction of a nitrogen compound of the formula NR6R'R°, in which R6, R' and R8 may be identical or different, and at least one of these groups is C8-C36-alkyl, Cs-C3s-cycloalkyl, Ce-C~-alkenyl, in particular C,2-C24-alkyl, C,2-C24-alkenyl or cyclohexyl, and the other groups are hydrogen, C,-C36-alkyl, C2-C36-alkenyl, cyclohexyl, or a group of the formula -(A-O)X E or -(CHZ)~ NYZ, in which A is an ethylene or propylene group, X is a number from 1 to 50, E is H, C,-C3°-alkyl, CS-C,2-cycloalkyl or Cs-C3°-aryl, and n is 2, 3 or 4, and Y and Z, independently of one another, are H, C,-C3°-alkyl or -(A-O)X E, with a compound containing an acyl group.
The term acyl group here is taken to mean a functional group of the following formula:

Preferred carbonyl-containing compounds are carboxylic acids and their anhydrides and esters. Preferred polar nitrogen-containing compounds are listed below.
B1) Products of the reaction of alkenylspirobislactones of the formula 4 R5 Rs O~O~O
in which each RS is C8-CZao-alkenyl, with amines of the formula NRsR'R8.
Suitable reaction products are listed in EP-A-0 413 279. Depending on the reaction conditions, the reaction of compounds of the formula (4) with the amines gives amides or amide-ammonium salts.
B2) Amides or ammonium salts of aminoalkylenepolycarboxylic acids with secondary amines of the formula 5 or 6 Rs Rs \ N-CO-CHz CHz-CO-N/
R~~ ~ ~ ~ R~
Rs N_R~o-N Rg 7 i N-CO-CHz \CHz-CO-N ~
R R~
Rg CHz-CO-N ~ R~
Rs (s) N CHz-CO_N \ R~

CHz-CO-N ~ R
R' in which R'° is a straight-chain or branched alkylene radical having 2 to 6 carbon atoms or the radical of the formula 7 /Rs CHZ-COONS
R~
in which R6 and R' are in particular alkyl radicals having 10 to 30 carbon atoms, preferably 14 to 24 carbon atoms where the amide structures may also be partly or fully in the form of the ammonium salt structure of the formula 8 Rg\
~NH2~0 -(8) R /
The amides or amide-ammonium salts or ammonium salts, for example of nitrotriacetic acid, of ethylenediaminetetraacetic acid or of propylene-1,2-diaminotetraacetic acid, are obtained by reacting acids with from 0.5 to 1.5 mol of amine, preferably from 0.8 to 1.2 mol of amine, per carboxyl group. The reaction temperatures are from about 80 to 200°C, where, in order to prepare the amides, the resultant water of reaction is removed continuously. However, the reaction need not be continued completely to the amide, but instead from 0 to 100 mol% of the amine employed can be in the form of the ammonium salt. Under analogous conditions, the compounds mentioned under B1) can also be prepared.
Suitable amines of the formula 9 Re \NH (9) R~

are in particular dialkylamines in which R6 and R' are a straight-chain alkyl radical having 10 to 30 carbon atoms, preferably 14 to 24 carbon atoms. Specific mention may be made of dioleylamine, dipalmitylamine, dicoconut fatty amine and dibehenylamine, and preferably ditallow fatty amine.
B3) Quaternary ammonium salts of the formula 10 ~NR6R'R8R"Xe (10) in which Rs, R' and R8 are as defined above, and R" is C,-C3o-alkyl, preferably C,-C2z-alkyl, C2-C3o-alkenyl, preferably C2-C22-alkenyl, benzyl or a radical of the formula -(CH2-CH2-O)~-R'2, where R'2 is hydrogen or a fatty acid radical of the formula C(O)-R'3, where R'3 is C6-C4o-alkenyl, n is a number from 1 to 30, and X is halogen, preferably chlorine, or a methylsulfate.
Examples of such quaternary ammonium salts which may be mentioned are the following: dihexadecyldimethylammonium chloride, distearyldimethylammonium -chloride, quaternization products of esters of di- and triethanolamine with long-chain fatty acids (lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid and fatty acid mixtures, such as coconut fatty acid, tallow fatty acid, hydrogenated tallow fatty acid, tallow oil fatty acid), such as N-methyltriethanolammonium distearyl ester chloride, N-methyltriethanolammonium distearyl ester methylsulfate, N,N-dimethyldiethanolammonium distearyl ester chloride, N-methyltriethanolammonium dioleyl ester chloride, N-methyltriethanolammonium trilauryl ester methylsulfate, N-methyltriethanolammonium tristearyl ester methylsulfate and mixtures thereof.
B4) Compounds of the formula 11 R~4 CONRgR~
(11) Rye R~s in which R'4 is CONR6R' or C02 +HZNR6R', R'S and R'6 are H, CONR"Z, C02R" or OCOR", -OR", -R" or -NCOR" and R" is alkyl, alkoxyalkyl or polyalkoxyalkyl and has at least 10 carbon atoms.
Preferred carboxylic acids or acid derivatives are phthalic acid (anhydride), trimellitic acid, pyromellitic acid (dianhydride), isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid (anhydride), malefic acid (anhydride) and alkenylsuccinic acid (anhydride). The formulation (anhydride) means that the anhydrides of said acids are also preferred acid derivatives.
If the compounds (11) are amides or amine salts, they are preferably derived from a secondary amine containing a hydrogen- and carbon-containing group having at least 10 carbon atoms.
R" preferably contains 10 to 30, in particular 10 to 22, for example 14 to 20, carbon atoms and is preferably straight-chain or branched at the 1- or 2-position.
The other hydrogen- and carbon-containing groups may be shorter, for example may contain less than 6 carbon atoms, or, if desired, can have at least 10 carbon atoms.
Suitable alkyl groups include methyl, ethyl, propyl, hexyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl and docosyl, and mixtures thereof, such as coconut fatty alkyl, tallow fatty alkyl and behenyl.
Also suitable are polymers containing at least one amide or ammonium group bonded directly to the polymer skeleton, where the amide or ammonium group carries at least one alkyl group of at least 8 carbon atoms on the nitrogen atom.
Such polymers can be prepared in various ways. One method is to use a polymer containing a plurality of carboxyl or carboxylic anhydride groups and to react this polymer with an amine of the formula NHRsR' in order to obtain the desired polymer.
Suitable polymers here are in general copolymers comprising unsaturated esters, such as C,-C4o-alkyl (meth)acrylates, di-C,-C4o-alkyl fumarates, C,-C4o-alkyl vinyl ethers, C,-C4o-alkyl vinyl esters or C2-C4o-olefins (linear, branched or aromatic) with unsaturated carboxylic acids or reactive derivatives thereof, such as, for example, carboxylic anhydrides (acrylic acid, methacrylic acid, malefic acid, fumaric acid, tetrahydrophthalic acid, citraconic acid, preferably malefic anhydride).

Carboxylic acids are preferably reacted with from 0.1 to 1.5 mol, in particular from 0.5 to 1.2 mol, of amine per acid group, carboxylic anhydrides are preferably reacted with from 0.1 to 2.5 mol, in particular from 0.5 to 2.2 mol, of amine per acid anhydride group, giving, depending on the reaction conditions, amides, ammonium 10 salts, amide-ammonium salts or imides. Thus, copolymers containing unsaturated carboxylic anhydrides give, on reaction with a secondary amine, 50% of amide and 50% of amine salts owing to the reaction with the anhydride group. Heating allows water to be eliminated with formation of the diamide.
Particularly suitable examples of amide group-containing polymers for the novel use are the following:
B5) copolymers (a) of a dialkyl fumarate, maleate, citraconate or itaconate with malefic anhydride, or (b) of vinyl esters, for example vinyl acetate or vinyl stearate with malefic anhydride, or (c) of a dialkyl fumarate, maleate, citraconate or itaconate with malefic anhydride and vinyl acetate.
Particularly suitable examples of these polymers are copolymers of didodecyl fumarate, vinyl acetate and malefic anhydride; ditetradecyl fumarate, vinyl acetate and malefic anhydride; dihexadecyl fumarate, vinyl acetate and malefic anhydride; or the corresponding copolymers in which the fumarate has been replaced by the itaconate.
In the abovementioned examples of suitable palymers, the desired amide is obtained by reacting the polymer containing anhydride groups with a secondary amine of the formula HNR6R' (if desired in addition with an alcohol if an ester-amide is formed). If polymers containing an anhydride group are reacted, the resultant amino groups will be ammonium salts and amides. Such polymers can be used with the proviso that they contain at least two amide groups.
It is essential that the polymer containing at least two amide groups contains at least one alkyl group having at least 10 carbon atoms. This long-chain group, which may be a straight-chain or branched alkyl group, can be bonded to the amide group via the nitrogen atom.
The amines suitable for this purpose can be represented by the formula R6R'NH
and the polyamines by R6NH[R'9NH]XR', where R'9 is a divalent hydrocarbon group, preferably an alkylene or hydrocarbon-substituted alkylene group, and x is an integer, preferably between 1 and 30. One of the two or the two radicals R6 and R' preferably contain at least 10 carbon atoms, for example from 10 to 20 carbon atoms, for example dodecyl, tetradecyl, hexadecyl or octadecyl.
Examples of suitable secondary amines are dioctylamine and those containing alkyl groups having at least 10 carbon atoms, for example didecylamine, didodecylamine, dicoconut amine (i.e. mixed C,2-C,4-amines), dioctadecylamine, hexadecyloctadecylamine, di(hydrogenated tallow)amine (approximately 4% by weight of n-C,4-alkyl, 30% by weight of n-C,°-alkyl, 60% by weight of n-C,8-alkyl, the remainder is unsaturated).
Examples of suitable polyamines are N-octadecylpropanediamine, N,N'-dioctadecylpropanediamine, N-tetradecylbutanediamine and N,N,-dihexadecylhexanediamine. N-(Coconut)propylenediamine (C,2/C,4 alkylpropylenediamine), N-(tallow)propylenediamine (C,s/C,8-alkyl propylenediamine).
The amide-containing polymers usually have an average molecular weight (weight average) of from 1000 to 500,000, for example from 2000 to 100,000.

B6) Copolymers of styrene, its derivatives or aliphatic olefins having 2 to 40 carbon atoms, preferably 6 to 20 carbon atoms, and olefinically unsaturated carboxylic acids or carboxylic anhydrides which have been reacted with amines of the formula NHR6R'. The reaction can be carried out before or after the polymerization.
In detail, the structural units of the copolymers are derived from, for example, malefic acid, fumaric acid, tetrahydrophthalic acid, citraconic acid, preferably malefic anhydride. They can be employed either in the form of their homopolymers or of the copolymers. Suitable comonomers are the following: styrene and alkylstyrenes, straight-chain and branched olefins having 2 to 40 carbon atoms, and mixtures thereof with one another. Examples which may be mentioned are styrene, a-methylstyrene, dimethylstyrene, a-ethylstyrene, diethylstyrene, i-propylstyrene, tert-butylstyrene, ethylene, propylene, n-butylene, di-i-butylene, decene, dodecene, tetradecene, hexadecene and octadecene. Preference is given to styrene and isobutene, particularly preferably styrene.
Examples of polymers which may be mentioned individually are the following:
polymaleic acid, a molar copolymer built up alternatively from styrene/maleic acid, copolymers built up randomly from styrene, malefic acid in a ratio of 10:90, and an alternating copolymer of malefic acid and i-butene. The molar masses of the polymers are generally from 500 g/mol to 20,000 glmol, preferably from 700 to 2000 g/mol.
The reaction of the polymers or copolymers with the amines is carried out at temperatures of from 50 to 200°C for a period of from 0.3 to 30 hours.
The amine is used in amounts of approximately one mole per mole of copolymerized dicarboxylic anhydride, i.e, from about 0.9 to 1.1 mol/mol. The use of larger or smaller amounts is possible, but brings no advantage. If larger amounts than one mole are used, certain amounts of ammonium salts are obtained since the formation of a second amide group requires higher temperatures, longer residence times and removal of water. If smaller amounts than one mole are used, incomplete conversion to the monoamide takes place, and a correspondingly reduced effect is obtained.
Instead of the subsequent reaction of the carboxyl groups in the form of the dicarboxylic anhydride with amines to give the corresponding amides, it may sometimes be advantageous to prepare the monoamides of the monomers and then to copolymerize them directly during the polymerization. However, this is usually much more complex technically since the amines can add onto the double bond of the monomeric mono- and dicarboxylic acid, and copolymerization is then no longer possible.
B7) Copolymers consisting of from 10 to 95 mol% of one or more alkyl acrylates or alkyl methacrylates having C,-C26-alkyl chains and from 5 to 90 mol% of one of more ethylenically unsaturated dicarboxylic acids or anhydrides thereof, where the copolymer has been reacted substantially with one or more primary or secondary amines to give the monoamide or amide/ammonium salt of the dicarboxylic acid.
The copolymers consist of from 10 to 95 mol%, preferably from 40 to 95 mol%, particularly preferably from 60 to 90 mol%, of alkyl (meth)acrylates and from 5 to 90 mol%, preferably from 5 to 60 mol%, particularly preferably from 10 to 40 mol%, of olefinically unsaturated dicarboxylic acid derivatives.
The alkyl groups of the alkyl (meth)acrylates contain from 1 to 26, preferably from 4 to 22, particularly preferably from 8 to 18, carbon atoms. They are preferably straight-chain and unbranched. However, it is also possible for them to contain up to 20% by weight of cyclic and/or branched components.
Examples of particularly preferred alkyl (meth)acrylates are n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tetradecyl (meth)acrylate, n-hexadecyl (meth)acrylate and n-octadecyl (meth)acrylate, and mixtures thereof.

Examples of ethylenically unsaturated dicarboxylic acids are malefic acid, tetrahydrophthalic acid, citraconic acid and itaconic acid and anhydrides thereof, and fumaric acid. Preference is given to malefic anhydride.
Suitable amines are compounds of the formula NHR6R'.
In general, it is advantageous to carry out the copolymerization using the dicarboxylic acids in the form of the anhydrides, if available, for example malefic anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic anhydride, since the anhydrides generally copolymerize better with the (meth)acrylates. The anhydride groups of the copolymers can then be reacted directly with the amines.
The reaction of the polymers with the amines is carried out at temperatures of from 50 to 200°C for a period of from 0.3 to 30 hours. The amine is used in amounts of from approximately 1 to 2 mol per mole of copolymerized dicarboxylic anhydride, i.e.
from about 0.9 to 2.1 mol/mol. The use of larger or smaller amounts is possible, but there is no advantage. If larger amounts than two mole are used, free amine is present. If smaller amounts that one mole are used, incomplete conversion to the monoamide takes place, and a correspondingly reduced action is obtained.
In some cases, it may be advantageous for the amide/ammonium salt structure to be built up from two different amines. Thus, for example, a copolymer of lauryl acrylate and malefic anhydride can first be reacted with a secondary amine, such as hydrogenated ditallow fatty amine, to give the amide, and the free carboxyl group originating from the anhydride can then be neutralized using another amine, for example 2-ethylhexylamine, to give the ammonium salt. The reverse procedure is equally feasible: first reaction with ethylhexylamine to give the monoamide, then with ditallow fatty amine to give the ammonium salt. It is preferred to use at least one amine containing at least one straight-chain, unbranched alkyl group having more than 16 carbon atoms. It is unimportant whether this amine is involved in the build-up of the amide structure or is in the form of the ammonium salt of the dicarboxylic acid.
Instead of subsequently reacting the carboxyl groups or dicarboxylic anhydride with 5 amines to give the corresponding amides or amide/ammonium salts, it may sometimes be advantageous to prepare the monoamides or amide/ammonium salts of the monomers and then to copolymerize thern directly during the polymerization.
Usually, however, this is much more technically complex, since the amines can add onto the double bond of the monomeric dicarboxylic acid, and copolymerization is 10 then no longer possible.
B8) Terpolymers based on a,~i-unsaturated dicarboxylic anhydrides, a,~3-unsaturated compounds and polyoxyalkylene ethers of lower, unsaturated alcohols, which comprise 20-80 mol%, preferably 40-60 mol%, of divalent structural units of 15 the formula 12 and/or 14 and, if desired, 13, where the structural units 13 originate from unreacted anhydride radicals, R22 (R23)b (Rzs)e C C
(12) O C C O
R24 Rzs (R23)b (Rzs)e C C
(13) O C C p R~ (Rz3)b (Rz3)e C C
(14) O C C _-__: p N/
Rg where R22 and R23, independently of one another, are hydrogen or methyl, a and b are zero or one and a + b equals one, R24 and R25 are identical or different and are the -NHR6, N(R6)2 and/or -OR2' groups, and R2' is a cation of the formula H2N(Rs)2~ or H3NR8~, 19-80 mol%, preferably 39-60 mol%, of divalent structural units of the formula Rze CHz C-- (15) Rzs in which RZ° is hydrogen or C,-C4-alkyl and R29 is Cs-C6°-alkyl or C6-C,8-aryl, and 1-30 mol%, preferably 1-20 mol%, of divalent structural units of the formula R3o CHz C (16) R33 - p _ (CHz-CH-O)m - R3z in which R3° is hydrogen or methyl, R3' is hydrogen or C,-C4 alkyl, R33 is C,-C4 alkylene, m is a number from 1 to 100, R32 is C,-C24-alkyl, C5-C2°-cycloalkyl, C6 C,8-aryl or -C(O)-R~°, where R~ is C,-C4°-alkyl, C5-C,°-cycloalkyl or Cs-C,8-aryl.
The abovementioned alkyl, cycloalkyl and aryl radicals may, if desired, be substituted. Suitable substituents of the alkyl and aryl radicals are, for example, (C,-Cs)-alkyl, halogens, such as fluorine, chlorine, bromine and iodine, preferably chlorine, and (C,-C6)-alkoxy.
Alkyl here represents a straight-chain or branched hydrocarbon radical.
Specific mention may be made of the following: n-butyl, tert-butyl, n-hexyl, n-octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, dodecenyl, tetrapropenyl, tetradecenyl, pentapropenyl, hexadecenyl, octadecenyl and eicosanyl, or mixtures, such as coconut-alkyl, tallow fatty alkyl and behenyl.
Cycloalkyl here represents a cyclic aliphatic radical having 5-20 carbon atoms.
Preferred cycloalkyl radicals are cyclopentyl and cyclohexyl.
Aryl here represents a substituted or unsubstituted aromatic ring system having 6 to 18 carbon atoms.
The terpolymers consist of the divalent structural units of the formulae 12 and/or 14 and 15 and 16 and, if desired, 13. They merely still contain the end groups formed in a known manner during the polymerization by initiation, inhibition and chain termination.

In detail, the structural units of the formulae 12 to 14 are derived from a,~i-unsaturated dicarboxylic anhydrides of the formulae 17 and 18 C C (17) O ~ ~ O
O
R~

(18) O ~ ~ O
O
such as malefic anhydride, itaconic anhydride, citraconic anhydride, preferably malefic anhydride.
The structural units of the formula 15 are derived from the a,~3-unsaturated compounds of the formula 19 2 5 R2a Examples which may be mentioned are the following a,~i-unsaturated olefins:
styrene, a-methylstyrene, dimethylstyrene, a-ethylstyrene, diethylstyrene, i-propylstyrene, tert-butylstyrene, diisobutylene and a-olefins, such as decene, dodecene, tetradecene, pentadecene, hexadecene, octadecene, C2o-a-olefin, C24-a-olefin, C3o-a-olefin, tripropenyl, tetrapropenyl, pentapropenyl and mixtures thereof.

Preference is given to a-olefins having 10 to 24 carbon atoms and styrene, particularly preferably a-olefins having 12 to 20 carbon atoms.
The structural units of the formula 16 are derived from polyoxyalkylene ethers of lower, unsaturated alcohols of the formula 20 R3o (20) R33 - p - (CHZ - ~ H - 0)m - R32 R3~
The monomers of the formula 20 are products of the etherification (R32 = -C(O)R~°) or esterification (R3z = -C(O)RD) of polyoxyalkylene ethers (R32 = H).
The polyoxyalkylene ethers (R32 = H) can be prepared by known processes by the adduction of a-olefin oxides, such as ethylene oxide, propylene oxide and/or butylene oxide, onto polymerizable lower, unsaturated alcohols of the formula Rao (21) H2C C R33 -- pH
Polymerizable lower unsaturated alcohols of this type are, for example, allyl alcohol, methallyl alcohol, butenols, such as 3-buten-1-of and 1-buten-3-of or methylbutenols, such as 2-methyl-3-buten-1-ol, 2-methyl-3-buten-2-of and 3-methyl-3-buten-1-ol.
Preference is given to products of the adduction of ethylene oxide and/or propylene oxide onto allyl alcohol.
Subsequent etherification of these polyoxyalkylene ethers to give compounds of the formula 20 in which R32 = C,-C24-alkyl, cycloalkyl or aryl is carried out by processes known per se. Suitable processes are disclosed, for example, in J. March, Advanced Organic Chemistry, 2nd Edition, pp. 357 ff (1977). These products of the etherification of polyoxyalkylene ethers can also be prepared by adducting a-olefin oxides, preferably ethylene oxide, propylene oxide and/or butylene oxide, onto alcohols of the formula 22 R32 - OH (22) in which R32 is C,-Cz4-alkyl, C5-CZO-cycloalkyl or C6-C,8-aryl, by known methods and reacting the product with polymerizable lower unsaturated halides of the formula 23 R~
HZC C Z -_ W
(23) where W is a halogen atom. Preferred halides are the chlorides and bromides.
Suitable preparation processes are given, for example, in J. March, Advanced Organic Chemistry, 2nd Edition, pp. 357 ff (1977).
The esterification of the polyoxyalkylene ethers (R32 = -C(O)-R~') is carried out by reaction with customary esterification agents, such as carboxylic acids, carboxylic acid halides, carboxylic anhydrides or carboxylic esters with C,-C4 alcohols.
Preference is given to the halides and anhydrides of C,-C4o-alkyl-, C5-C,o-cycloalkyl-or Cg-C,e-arylcarboxylic acids. The esterification is generally carried out at temperatures of from 0 to 200°C, preferably from 10 to 100°C.
In the monomers of the formula 20, the index m denotes the degree of alkoxylation, i.e. the number of moles of a-olefin adducted per mole of the formula 20 or 21.
Examples of primary amines which are suitable for the preparation of the terpolymers are the following:
n-hexylamine, n-octylamine, n-tetradecylamine, n-hexadecylamine, n-stearylamine or alternatively N,N-dimethylaminopropylenediamine, cyclohexylamine, dehydroabietylamine and mixtures thereof.
Examples of secondary amines which are suitable for the preparation of the terpolymers are the following: didecylamine, ditetradecylamine, distearylamine, dicoconut fatty amine, ditallow fatty amine and mixtures thereof.
The terpolymers have K values (measured by the Ubbelohde method in 5% strength by weight solution in toluene at 25°C) of from 8 to 100, preferably 8 to 50, corresponding to mean molecular weights (117r w) of between about 500 and 1,000,000. Suitable examples are given in EP 506 055.
B9) Products of the reaction of alkanolamines and/or polyether amines with polymers containing dicarboxylic anhydride groups, which contain 20-80 mol%, preferably 40-60 mol%, of divalent structural units of the formulae 25 and 27 and, if desired, 26 RTT (RT3)b Ts (25) (R ). C C
O C C p R3~ R3a RTT (RT3)b T3 ( (26) (R ), C C
p C C p ~ o ' CA 02287660 1999-10-26 R22 (R23)b 23 ~ 27 (R ), C C ( ) O C C p ' N' R3s where R22 and R23, independently of one another, are hydrogen or methyl, a and b are zero or 1 and a + b equals 1, R3' is -OH, -O-[C,-C3o alkyl], -NRgR' or -OeN~R6R'H2 R38 is R3' or NRgR3a R3a is -(A-O)X E (28) where A is an ethylene or propylene, x is from 1 to 50 and E is H, C,-C3o-alkyl, CS-C,2-cycloalkyl or C6-C3°-aryl, and 80 - 20 mol%, preferably 60-40 mol%, of divalent structural units of the formula 15.
In detail, the structural units of the formulae 25, 26 and 27 are derived from a,[i-unsaturated dicarboxylic anhydrides of the formulae 17 and/or 18.
The structural units of the formula 15 are derived from a,[3-unsaturated olefins of the formula 19. The abovementioned alkyl, cycloalkyl and aryl radicals have the same meanings as under B8).
The radicals R3' and R38 in the formula 25 or R39 in the formula 27 are derived from polyether amines or alkanolamines of the formula H2N-(A-O)X E, amines of the formula NRgR'R° and, if appropriate, from alcohols having 1 to 30 carbon atoms.

In order to derivatize the structural units of the formulae 17 and 18, mixtures of at least 50% by weight of alkylamines of the formula HNRsR'R8 and at most 50% by weight of polyether amines and/or alkanolamines of the formula H2N-(A-O)X E
are preferably used.
The polyether amines employed can be prepared, for example, by reductive amination of polyglycols. Furthermore, polyether amines containing a primary amino group are prepared by the addition reaction of polyglycols onto acrylonitrile followed by catalytic hydrogenation. In addition, polyether amines can be prepared by reacting polyethers with phosgene or thionyl chloride followed by amination to give the polyether amine. The polyether amines employed in accordance with the invention are commercially available (for example) under the name ~Jeffamine (Texaco). Their molecular weight is up to 2000 g/mol, and the ethylene oxide/propylene oxide ratio is from 1:10 to 6:1.
Another way of derivatizing the structural units of the formulae 17 and 18 comprises using an alkanolamine instead of the polyether amines and subsequently subjecting it to alkoxylation.
From 0.01 to 2 mol, preferably from 0.01 to 1 mol, of alkanolamine are employed per mole of anhydride. The reaction temperature is between 50 and 100°C
(amide formation). In the case of primary amines, the reaction is carried out at temperatures above 100°C (imide formation).
The alkoxylation is usually carried out at temperatures between 70 and 170°C with catalysis by bases, such as NaOH or NaOCH3, by introducing gas-form alkylene oxides, such as ethylene oxide (EO) and/or prapylene oxide (PO). From 1 to 500 mol, preferably from 1 to 100 mol, of alkylene oxide are usually added per mole of hydroxyl groups.

Examples of suitable alkanolamines which may be added are the following:
monoethanolamine, diethanolamine, N-methylethanolamine, 3-aminopropanol, isopropanol, diglycolamine, 2-amino-2-methylpropanol and mixtures thereof.
Examples of primary amines which may be mentioned are the following:
n-hexylamine, n-octylamine, n-tetradecylamine, n-hexadecylamine, n-stearylamine or even N,N-dimethylaminopropylenediamine, cyclohexylamine, dehydroabietylamine and mixtures thereof.
Examples of secondary amines which may be mentioned are the following:
didecylamine, ditetradecylamine, distearylamine, dicoconut fatty amine, ditallow fatty amine and mixtures thereof.
Examples of alcohols which may be mentioned are the following:
methanol, ethanol, propanol, isopropanol, n-, sec- and tert-butanol, octanol, tetradecanol, hexadecanol, octadecanol, tallow fatty alcohol, behenyl alcohol and mixtures thereof. Suitable examples are listed in EP-A-688 796.
B10) Copolymers and terpolymers of N-C6-C24 alkylmaleimide with C,-C3°-vinyl esters, vinyl ethers and/or olefins having 1 to 30 carbon atoms, such as, for example, styrene or a-olefins. These are accessible firstly by reacting a polymer containing anhydride groups with amines of the formula H2NRg or by imidation of the dicarboxylic acid followed by copolymerization. The preferred dicarboxylic acid here is malefic acid or malefic anhydride. Preference is given to copolymers comprising from 10 to 90% by weight of CB-C24-a-olefins and from 90 to 10% by weight of N-Ce-C~-alkylmaleimide.
The copolymerization of the comonomers to give copolymers which are components of the additives according to the invention is carried out by known processes (cf. in this respect, for example, Ullmanns Encyclopfidie der Technischen Chemie (Ullmann's Encyclopedia of Industrial Chemistry], 4th Edition, Vol. 19, pages 169 to 178). Suitable processes are polymerization in solution, in suspension or in the gas phase and high-pressure bulk polymerization.
Component A is preferably prepared using high-pressure bulk polymerization, which 5 is carried out at pressures of from 50 to 400 MPa, preferably from 100 to 300 MPa, and at temperatures of from 50 to 350°C, preferably from 100 to 300°C. The reaction of the comonomers is started by initiators which form free radicals (free-radical chain initiators). This class of substances includes, for example, oxygen, hydroperoxides, peroxides and azo compounds, such as cumene hydroperoxide, t-butyl 10 hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis(2-ethylhexyl) peroxydicarbonate, di-tert-butyl peroxide, t-butyl permaleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di(t-butyl) peroxide, 2,2'-azobis(2-methylpropanonitrile) and 2,2'-azobis(2-methylbutyronitrile). The initiators are employed individually or as a mixture of two or more substances in amounts of from 15 0.01 to 20% by weight, preferably from 0.05 to 10% by weight, based on the comonomer mixture.
The desired melt viscosity of the copolymers is set for a given composition of the comonomer mixture by varying the reaction parameters pressure and temperature 20 and if desired by adding moderators. Moderators which have proven successful are hydrogen, saturated and unsaturated hydrocarbons, for example propane, aldehydes, for example propionaldehyde, n-butyraldehyde and isobutyraldehyde, ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and alcohols, for example butanol. Depending on the desired 25 viscosity, the moderators are used in amounts of up to 20% by weight, preferably from 0.05 to 10% by weight, based on the comonomer mixture.
High-pressure bulk polymerization is carried out batchwise or continuously in known high-pressure reactors, for example autoclaves or tubular reactors. Tubular reactors have proven particularly successful. Solvents, such as aliphatic hydrocarbons or hydrocarbon mixtures, benzene or toluene, can be present in the reaction mixture, although the solvent-free procedure has proven particularly successful. In a preferred way of carrying out the polymerization, the mixture of the comonomers, the initiator and, if used, the moderator is fed to a tubular reactor via the reactor inlet and via one or more side branches; the comonamer streams can have different compositions (EP-B-0 271 738).
Suitable copolymers for improving the lubricity of oils according to the invention are likewise those containing structural units derived from ethylene and vinyl alcohol.
Copolymers of this type can be prepared by partially or fully hydrolyzing a copolymer containing structural units derived from ethylene and vinyl esters, for example vinyl acetate. These copolymers are used as a mixture with component B).
The lubricity of oils can furthermore be improved in the manner according to the invention by admixing them as component A with ethylene copolymers containing alkoxylated acid groups. Examples of ethylene copolymers which are suitable for this purpose are those containing acrylic acid, methacrylic acid, itaconic acid, fumaric acid, malefic acid or malefic anhydride. In order to prepare an additive which improves the lubricity of oils, these copolymers containing acid groups are alkoxylated on the acid groups using C,- to C,°-alkylene oxides.
Preferred alkylene oxides are ethylene oxide, propylene oxide and butylene oxide. The alkoxylation is preferably carried out using from 0.5 to 10 mol, in particular from 1 to 5 mol, especially from 1 to 2 mol, of alkylene oxide per mole of acid group. These copolymers are also used as a mixture with component B).
The additives according to the invention are added to mineral oils or mineral oil distillates in the form of solutions or dispersions comprising from 10 to 90%
by weight, preferably from 20 to 80% by weight, of the additives. Components A) and B) can be added together or separately to the oils which are to be treated with additives. Suitable solvents or dispersion media are aliphatic and/or aromatic hydrocarbons or hydrocarbon mixtures, for example gasoline fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercial solvent mixtures, such as solvent naphtha, ~Shellsol AB, ~Solvesso 150, ~Solvesso 200, ~Exxsol-, ~ISOPAR and Shellsol D products, and also alcohols, ethers and/or esters. Mineral oils and mineral oil distillates whose lubricating and/or cold-flow properties have been improved by the additives contain from 0.001 to 2% by weight, preferably from 0.005 to 0.5% by weight, of additives, based on the distillate.
In order to prepare additive packages for specific problem solutions, the additives according to the invention can also be employed together with one or more oil-soluble co-additives which, even alone, improve the cold-flow properties and/or lubricity of crude oils, lubricating oils or fuel oils. Examples of such co-additives are copolymers or terpolymers of ethylene containing vinyl esters, alkylphenol-aldehyde resins and comb polymers.
Thus, mixtures of the additives with copolymers comprising from 10 to 40% by weight of vinyl acetate and from 60 to 90% by weight of ethylene have proven highly successful. In a further embodiment of the invention, the additives according to the invention are employed as a mixture with ethylene-vinyl acetate-vinyl neononanoate terpolymers or ethylene-vinyl acetate-vinyl neodecanoate terpolymers for improving the flow properties of mineral oils or mineral oil distillates. The terpolymers of vinyl neononanoate or vinyl neodecanoate contain, besides ethylene, from 10 to 35%
by weight of vinyl acetate and from 1 to 25% by weight of the respective neo compound. Also suitable are terpolymers comprising ethylene, from 10 to 35% by weight of vinyl acetate and 1-25% by weight of 4-methyl-1-pentene or norbornene.
The mixing ratio of the additives according to the invention with the above-described ethylene-vinyl acetate copolymers or the terpolymers of ethylene, vinyl acetate and the vinyl esters of neononanoic or neodecanoic acid is (in parts by weight) from 20:1 to 1:20, preferably from 10:1 to 1:10.
In order to optimize the properties as flow improvers and/or lubricity additives, the additives according to the invention may furthermore be employed as a mixture with alkylphenol-formaldehyde resins. In a preferred embodiment of the invention, these alkylphenol-formaldehyde resins are those of the formula 29 (29) in which R"' is linear or branched C,-Cso-alkyl ar -alkenyl, R48 is ethoxy and/or propoxy, n is a number from 5 to 100, and p is a number from 0 to 50.
Finally, in a further proven variant of the invention, the additives according to the invention are used together with comb polymers. This is taken to mean polymers in which hydrocarbon radicals having at least 8 carbon atoms, in particular at least 10 carbon atoms, are bonded to a polymer backbone. These are preferably homopolymers whose alkyl side chains contain at least 8 and in particular at least 10 carbon atoms. In the case of copolymers, at least 20%, preferably at least 30%, of the monomers have side chains (cf. Comb-like Polymers - Structure and Properties;
N.A. Platy and V.P. Shibaev, J. Polym. Sci. Macromolecular Revs. 1974, 8, 117 ffj.
Examples of suitable comb polymers are, for example, fumarate-vinyl acetate copolymers (cf. EP 0 153 176 A1 ), copolymers of a Cg- to C24-a-olefin and an N-Cg-to C~-alkylmaleimide (cf. EP 0 320 766), furthermore esterified olefin-malefic anhydride copolymers, polymers and copolymers of a-olefins and esterified copolymers of styrene and malefic anhydride.
Comb polymers can be described, for example, by the formula 30 A H G H
- C I - I ~ m C ~ __ I ~ n (30) D E M
in which A is R', COOR', OCOR', R"-COOR' or OR';

D is H, CH3, A or R";

E isHorA;

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

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

N is H, R", COOR", OCOR, COOH or an aryl radical;

R' is a hydrocarbon chain having 8-50 carbon atoms;

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

m is a number between 0.4 and 1.0; and n is a number between 0 and 0.6.

The mixing ratio (in parts by weight) of the additives according to the invention with paraffin dispersants or comb polymers is in each case from 1:10 to 20:1, preferably from 1:1 to 10:1.
In order to optimize the lubricity, the additives according to the invention can be employed in the form of a mixture with further lubricity additives. Lubricity additives which have proven successful are preferably fatty alcohols, fatty acids and dimeric fatty acids, and esters and partial esters thereof with glycols (as described in DE-A-15 94 417), polyols, such as glycerol (as described in EP-A-0 680 506, EP-A-0 739 970) or hydroxylamines (as described in EP-A-0 802 961).
The additives according to the invention are suitable for improving the lubricating properties of animal, vegetable or mineral oils, alcoholic fuels, such as methanol and ethanol, and mixtures of alcoholic fuels and mineral oils. They are particularly suitable for use in middle distillates. The term middle distillates is taken to mean, in particular, mineral oils boiling in the range from 120 to 450°C, and obtained by distillation of crude oil, for example kerosene, jet fuel, diesel and heating oil. The 5 additives according to the invention are preferably used in middle distillates containing 0.5% by weight or less of sulfur, in particular less than 200 ppm of sulfur and in special cases less than 50 ppm of sulfur. These are generally middle distillates which have been hydrotreated and therefore contain only small proportions of polyaromatic and polar compounds which give them a natural 10 lubricity. The additives according to the invention are furthermore preferably used in middle distillates having 95% distillation points of below 370°C, in particular below 350°C and in special cases below 330°C. At the same time, they prevent or delay sedimentation of precipitated paraffin crystals during storage of the oil at low temperatures and thus prevent or delay the formation of a paraffin-rich layer at the 15 base of storage containers. The effectiveness of the mixtures is better than would be expected from the individual components.
The additives can be used alone or together with other additives, for example with other pour point depressants or dewaxing auxiliaries, with corrosion inhibitors, 20 antioxidants, conductivity improvers, sludge inhibitors, dehazers and additives for lowering the cloud point.
The effectiveness of the additives according to the invention as lubricity improver and paraffin dispersants, is explained in greater detail by means of the examples 25 below.
Examples Characterization of the additives employed 30 The hydroxy-functional comonomers are determined by measuring the OH number by reacting the polymer with excess acetic anhydride and then titrating the acetic acid formed with KOH.
The viscosity is determined in accordance with ISO 3219 (B) using a rotational viscometer (Haake RV 20) with a plate-and-cone measurement system at 140°C.
In order to improve handling, all additives are employed in the form of 50%
solutions in solvent naphtha or kerosene.
Table 1: Characterization of the additives A employed Example Vinyl ester OH monomer V,4 [mPas] OH No.
No.

A1 22% vinyl acetate10% HEMA 97 43 A2 22% vin I acetate6% HEMA 77 38 A3 32% vin I versatate8% HEMA 171 38 A4 28% vinyl acetate5% DMVC 121 24 HEMA - hydroxyethyl methacrylate VA - vinyl acetate DMVC - dimethylvinylcarbinol Table 2: Characterization of the additives B employed Ex. No. Characterization B1 Product of the reaction of a dodecenylspirobislactone with a mixture of primary and secondary tallow fatty amine B2 Product of the reaction of a terpolymer of C,4-C,s-a-olefin, malefic anhydride and allylpolyglycol with 2 equivalents of ditallow fatty amine B3 Copolymer of stearylmaleimide and C,e-a-olefin B4 Nonylphenol-formaldehyde resin B5 Mixture of B2 and B4 in the ratio 2:1 Table 3: Characterization of the flow improvers employed Ex. No. Comonomer(s) V,4o (mPas]

F1 32% of vinyl acetate 140 F2 31 % of vinyl acetate + 8% of vinyl 125 neodecanoate F3 29% of vinyl acetate + 6% of 4-methylpentene220 Table 4: Characterization of the test oils The boiling data are determined in accordance with ASTM D-86, the CFPP value is determined in accordance with EN 116, and the cloud point is determined in accordance with ISO 3015.
Test oil Test oil Test oil Start of boiling198 182 172.7 [C]

20% [C] 246 202 215.9 30% [C] 260 208 231.5 90% [C] 339 286 331.7 95% [C] 355 302 350.0 Cloud point -5.2 -29 -6.6 [C]

CFPP [C] -7 -32 -9 S content [ppm]26 3 388 Density [g/cm3]0.832 0.819 0.836 Wear scar [Nm]564 609 603 Lubricity in middle distillates The lubricity of the additives was measured at 60°C on oils treated with additives using a PCS Instruments high frequency reciprocating rig (HFRR). The HFRR test is described in D. Wei, H. Spikes, Wear, Vol. 111, No. 2, p. 217, 1986. The results are given as coefficient of friction and wear scar. A low coefficient of friction and a low wear scar value indicate a good lubricity.
Table 5: Wear scar in test oil 2 No. Amount of Amount of Wear scar Film Friction A B
added added 1 200 ppm A1 - 559 46% 0.28 2 300 ppm A1 - 435 75% 0.20 3 400 ppm A1 - 350 80% 0.17 4 - 500 ppm B1 560 26% 0.39 5 200 ppm A1 150 ppm B1 2T3 92% 0.12 6 1000 ppm 460 48% 0.21 7 200 ppm A1 150 ppm B2 373 69% 0.18 8 - 300 ppm B4 609 8% 0.34 9 - 1000 ppm 37.8 68% 0.19 10 - 1000 ppm 380 69% 0.18 11 100 ppm A1 250 ppm B2 343 79% 0.19 12 300 ppm A1 50 ppm B5 290 86% 0.14 13 200 ppm A1 150 ppm B4 599 11 0.32 %

14 150 ppm A1 150 ppm B5 380 65% 0.18 15 200 ppm A1 150 ppm B5 288 84% 0.14 16 200 ppm A1 150 ppm B4 340 80% 0.16 17 500 ppm A3 - 310 84% 0.16 18 200 ppm A3 150 ppm B3 242 94% 0.13 19 150 ppm A3 200 ppm B5 285 90% 0.15 20 300 ppm A4 50 ppm B1 295 88% 0.15 Table 6: Wear scar in test oil 1 No. Amount Amount Flow improverWear Film Friction of of scar A added B1 added 20 200 ppm - 560 16% 0.34 21 300 ppm - 535 20% 0.28 22 400 ppm - 238 91 0.12 A1 %

23 - 100 ppm F1 560 15% 0.35 24 - 300 ppm F1 550 17% 0.35 25 200 ppm 100 ppm F 285 87% 0.14 26 300 ppm 100 ppm F1 203 95% 0.13 27 300 ppm - 480 22~ 0.27 28 200 ppm 150 ppm - 381 57~ 0.19 29 200 ppm 100 ppm - 313 52% 0.20 50 ppm 30 300 ppm 100 ppm 100 ppm F 205 94% 0.12 50 ppm 31 200 ppm 100 ppm 100 ppm F1 185 95% 0.12 50 ppm 32 200 ppm 150 ppm 100 ppm f=3 347 49% 0.18 Table 7: Wear scar in test oil 3 No. Amount Amount of Amount Wear scar Film Friction of B2 added of A2 added F2 added 33 200 ppm 200 ppm 391 74 0.177 34 400 ppm - - 299 87 0.148 35 100 ppm 150 ppm 150 ppm 283 88 0.143 36 200 ppm 100 ppm 100 ppm 299 88 0.152 Paraffin dispersal in middle distillates In the following experiments, a Scandinavian winter diesel fuel was used. The middle distillate was admixed at room temperature with 100 ppm of a 50%
dispersion of a commercially available flow improver (ethylene-vinyl acetate 5 copolymer containing 32% by weight of vinyl acetate and having a melt viscosity of 115 mPas measured at 140°C) and the amounts shown in Table 8 of the additives heated to 60°C, the mixture was warmed at 40°C for 15 minutes with occasional shaking and then cooled to room temperature. The CFPP value of the middle distillate treated with additives in this way was determined in accordance with 10 EN 116.
The samples treated with additives were cooled to -13°C at -2°C/hour in 200 ml measuring cylinders in a refrigerator and stored at this temperature for 16 hours. The volume and appearance of both the sediment (paraffin phase) and the supernatant 15 oil phase were then determined and assessed visually. A small amount of sediment and a hazy oil phase show good paraffin dispersal.
In addition, the lower 20% by volume were isolated and the cloud point determined.
An only small difference of the cloud point of the lower phase (CPKS) from the blank 20 value of the oil shows good paraffin dispersal.
Table 8: Dispersal action in test oil 1 Additive CFPP CPKS MCP Appearance 25 No additive (Comp.)-18 + 9.5 Clear, 17% sediment 4.3 150 ppm B2 (Comp.)-14 - 2.7 Hazy, no sediment 2.5 150 ppm B4 (Comp.)-17 + 5.8 Hazy, no sediment p,6 150 ppm B5 (Comp.)-19 - 1.9 Hazy, no sediment 3.3 300 ppm B5 (Comp.)-14 - 5.6 Hazy, 65% sediment 0.4 30 150 ppm B5 200 - 20 - 0.6 Hazy, no sediment ppm A1 4.6 Additive CFPP CPKS OCP Appearance 300 ppm B5 - 20 - 4.7 0.5 Hazy, no sediment 300 ppm A1 300 ppm A1 (Comp.)- 18 + 4.4 9.6 Slightly hazy, 20%

sediment 150 ppm B2 -19 - 4.4 0.8 Hazy, no sediment 150 ppm A1 150 ppm B2 -19 - 4.6 0.6 Hazy, no sediment 150 pm A4 List of trade names used Solvent naphtha aromatic solvent mixtures having a boiling ~Shellsol AB range of from 180 to 210°C
~'Solvesso 150 ~Solvesso 200 aromatic solvent mixture having a boiling range of from 230 to 287°C
~Exxsol Dearomatized solvents in various boiling ranges, for example ~Exxsol D60: 187 to 215°C
~ISOPAR (Exxon) isoparaffinic solvent mixtures in various boiling ranges, for example ~ISOPAR L: 190 to 210°C
~Shellsol D principally aliphatic solvent mixtures in various boiling ranges

Claims (11)

1. An additive for fuel oils, comprising A) from 10 to 90% by weight of at least one copolymer of ethylene and at least one further olefinically unsaturated monomer containing one or more hydroxyl groups, and B) from 90 to 10% by weight of at least one polar nitrogen-containing compound.

2. An additive as claimed in claim 1, wherein the olefinically unsaturated comonomer of component A) conforms to the formula 1 CH2 = CH - OCOR1 (1) in which R1 is C1-C30 hydroxyalkyl, preferably C1-C12-hydroxyalkyl, especially C2-C8-hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals, in particular 2-hydroxyethyl vinyl ester, 2-hydroxypropyl vinyl ester, 3-hydroxypropyl vinyl ester or 4-hydroxybutyl vinyl ester.

3. An additive as claimed in claim 1 or 2, wherein the olefinically unsaturated comonomer from component A) conforms to the formula 2 CH2 = CR2 - COOR3 (2) in which R2 is hydrogen or methyl, and R3 is C1-C30-hydroxyalkyl, preferably C1-C12-hydroxyalkyl, especially C2-C~-hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals, and in particular hydroxyethyl acrylate, hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, hydroxyisopropyl acrylate, 4-hydroxybutyl acrylate and glycerol monoacrylate.

4. An additive as claimed in one or more of claims 1 to 3, wherein the olefinically unsaturated comonomer from component A) conforms to the formula 3 CH2 = CH - OR4 (3) in which R4 is C1-C30-hydroxyalkyl, preferably C1-C12-hydroxyalkyl, especially C2-C6-hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals, and in particular 2-hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hexanediol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether or cyclohexanedimethanol monovinyl ether.

5. An additive as claimed in one or more of claims 1 to 4, wherein the olefinically unsaturated comonomer from component A) is a hydroxyalkene having 3 to 30, in particular 4 to 16, particularly preferably 5 to 12, carbon atoms, especially dimethylvinylcarbinol (= 2-methyl-3-buten-2-ol), allyloxypropanediol, 2-butene-1,4-diol, 1-buten-3-ol, 3-buten-1-ol, 2-buten-1-ol, 1-penten-3-ol, 1-penten-4-ol, 2-methyl-3-buten-1-ol, 1-hexen-3-ol, 5-hexen-1-of and 7-octene-1,2-diol.

6. An additive as claimed in one or more of claims 1 to 5, wherein the molar proportion of the hydroxyl-functionalized comonomers in component A) is from 0.5 to 13%, in particular from 3 to 10%.

7. An additive as claimed in one or more of claims 1 to 6, wherein the OH
number of the copolymers of component A) is between 1 and 800 mg of KOH/g.

8. An additive as claimed in one or more of claims 1 to 7, wherein the melt viscosities of the copolymers of component A) is below 10,000 mPas and preferably from 10 to 1000 mPas.

9. An additive as claimed in one or more of claims 1 to 8, wherein the copolymers of component A) include, besides ethylene and hydroxyl-functionalized comonomers, one, two or three further comonomers from the group consisting of vinyl esters, acrylic acid, acrylates, vinyl ethers and/or alkenes.

10. An additive as claimed in one or more of claims 1 to 9, wherein the polar nitrogen compound is a compound formed by the reaction of an acyl group with a nitrogen compound of the formula NR6R7R8, in which R6, R7 and R8 may be identical or different and at least one of these groups is C8-C38-alkyl, C6-C36-cycloalkyl, C8-C36-alkenyl, in particular C12-C24 alkyl, C12-C24-alkenyl or cyclohexyl, and the other groups are either hydrogen, C1-C36-alkyl, C2-C36-alkenyl, cyclohexyl or a group of the formula -(A-O)x-E or -(CH2)n-NYZ, in which A is an ethylene or propylene group, x is a number from 1 to 50, E = H, C1-C30-alkyl, C5-C12-cycloalkyl or C6-C30-aryl, and n is 2, 3 or 4, and Y and Z, independently of one another, are H, C1-C30-alkyl or -(A-O)x-E.

11. A fuel oil comprising a middle distillate containing a maximum of 0.5% by weight of sulfur and an additive as claimed in one or more of claims 1 to 10.