FI120975B - fuel composition - Google Patents

Abstract

Fuel oil compositions containing specific mixtures of esters of unsaturated monocarboxylic acids show improved lubricity properties.

Description

This invention relates to additives for improving the lubricity of fuel oils, such as diesel fuel oil. Diesel fuel oil compositions containing these additives 5 lubricate better and reduce engine wear.

As a result of environmental concerns, the harmful components of emissions have been significantly reduced in the combustion of fuel oils, particularly in engines such as diesel engines. For example, efforts have been made to reduce sulfur dioxide emissions to a minimum. Thus, the aim is to keep the sulfur content of fuel oils as low as possible. For example, while typical diesel fuel oils have previously contained sulfur by weight of 1% or more (expressed as elemental sulfur), it is now considered desirable to reduce the level to preferably 0.05% by weight and preferably to less than 0.01% by weight, especially less than 0.001% by weight. % by weight.

Further refining of fuel oils, which is necessary to achieve these low sulfur levels, often reduces the level of the polar components. Further, refining processes can reduce the amount of polynuclear aromatic compounds present in such fuel oils.

Reducing the level of one or more of the sulfur components, polynuclear aromatic, or polar components may impair the ability of the oil to lubricate the ··· 20 engine injection system, for example engine fuel injection • · · ·. ** ·. the pump is damaged at a relatively early stage in engine life. Vioit- • · ·. ···. This may occur in fuel injection systems, such as rotary high pressure • • dividers, line pumps and injection nozzles. The problem of poor lubrication of diesel fuels is likely to be exacerbated by the future development of engines to further reduce emissions, whereby lubricant requirements are stricter than those of current engines. For example, high-pressure spray nozzles are expected to increase the lubricant performance requirements.

• · • · · * · * | Likewise, poor lubrication may lead to wear problems in other mechanical * ** 30 systems that depend on the natural lubricity of the fuel oil for lubrication.

Lubricant enhancers for fuel oils are described in the art. WO 94/17160 describes an additive comprising an ester of a carboxylic acid and 2 of an alcohol wherein the acid contains from 2 to 50 carbon atoms and the alcohol contains one or more carbon atoms. Glycerol monooleate is specifically mentioned as an example. Although they deal with alloys, no particular ester mixture is mentioned.

US-A 3 273 981 mentions an lubricating additive which is a mixture of A + B, wherein A is a polyhydric acid or a polyhydric acid poester obtained by reacting an acid with a C 1 -C 5 monovalent alcohol; B, in turn, is a partial ester of a polyhydric alcohol and a fatty acid, for example glyceryl monooleate, sorbitan monooleate or pentaerythrito limonooleate. The mixture can be used in jet engine fuels.

However, under certain circumstances, such prior art esters have unexpectedly been found to contribute to the clogging of fuel filters, particularly fine-mesh filters typically found in the fuel lines of diesel vehicles. This filter clogging problem may be due to inadequate fuel flow and engine malfunction, and occurs particularly at low temperatures.

In addition, it has been unexpectedly found that fuels containing the preferred additive (additive A) described in WO 94/17160 deteriorate after cold storage and filtration. Even without severe filter clogging problems, performance degradation can occur. This direct: ·. 20 Deterioration in performance is a significant problem in itself, since fuel stored in field conditions generally · · · * is exposed to temperature cycles and must still be able to provide effective lubrication for mechanical equipment located downstream of the fuel line filters. For example, in a diesel vehicle's fuel system, the di-• * *·· * selenium first flows through a fine-mesh filter before it enters the fuel • · · * · *. ' 25 injection system with injection pump. Impaired lubrication »· ·: After this filtration point, therefore, exposes the injection system to greater heat.

• · • · · • · · *.! Thus, there is a need for better lubricant enhancers with better filtration • · T and that do not lose performance in fuel oils when filtration • ·:. * ·: 30 ° C when stored in cold temperatures.

• ·

Such problems have now surprisingly been solved by additives comprising special mixtures of certain esters.

• · · • · • «« «·

GB-A-1 505 302 describes ester combinations containing, for example, glycerol monoesters and glycerol esters as additives in diesel fuel, and

GB-A-1,505,302 discloses ester combinations containing, for example, glycerol monoesters and glycerol esters as additives in diesel fuel, and said combinations have the advantages of reduced wear on fuel injection equipment, piston rings and cylinder tubes. However, GB-A-1 505 302 is concerned with remedying the functional corrosion and wear damage caused by acidic combustion products, combustion chamber and exhaust system residues. The publication states that these drawbacks are due to incomplete combustion under certain operating conditions. Typical diesel fuels available at the time of publication contained, for example, 0.5 to 1% by weight of 10 sulfur, expressed as elemental sulfur, based on the weight of the fuel.

US-A-3,287,273 describes lubricating additives which are reaction products of a dicarboxylic acid and an oil-insoluble glycol. The acid is generally predominantly a dimer of unsaturated fatty acids such as linoleic or oleic acid, although small amounts of monomeric acid may also be present. In particular, only alkanediols or oxaalkanediols are proposed as glycol reactant.

Accordingly, in a first aspect, the invention relates to a fuel oil composition containing a greater proportion of any middle distillate fuel oil having a sulfur content of 0.2% by weight or less and a lower lubricity enhancer additive comprising: (a) a monounsaturated monocarboxylic acid; an ester; and (b) a polyunsaturated monocarboxylic acid and a polyhydric · · ·. * · ·. an ester of an alcohol containing at least three hydroxy groups, the esters (a) and (b) being different and each of the partial esters having a relative proportion of the components • · · (a) and (b) between 1:10 - 2: 1.

• · ·

In another aspect, the invention relates to the use of an L-T agent as defined in the first aspect for improving the lubricating capacity of a middle distillate fuel oil.

··· • · ♦ ·

According to a third aspect, the invention relates to the operation of the fuel composition 30 of the first aspect in a combustion device for slowing the wear of the fuel supply system of said device.

Another embodiment of the present invention is a method of reducing the wear of a fuel feed system of a combustion apparatus using a middle distillate fuel oil having a sulfur content of 0.2% by weight, containing prepared respectively from a mixture of an unsaturated monocarboxylic acid and a polyhydric alcohol and a polyunsaturated monocarboxylic acid and a polyhydric alcohol containing at least three hydroxy groups.

The mixture of esters (a) and (b) can unexpectedly provide a better lubricity compared to the performance of component (a) or (b) alone. In addition, the mixture of (a) and (b) has a better filterability and retains its good lubricity after cold storage and subsequent filtration.

The invention will now be described in more detail.

Fuel Oil Composition (First Aspect of the Invention) (i) Additive

The term "polyhydric alcohol" is used to describe a compound containing more than one hydroxy group. Advantageously, (a) is an ester of a polyhydric alcohol having at least three hydroxy groups.

Examples of polyhydric alcohols having at least three hydroxy groups include those having 3-10, preferably 3-6, more preferably 3-4, hydroxy groups and having 2 to 90, preferably 2 to 30, more preferably 2 to 12 and: ·. most preferably 3-4 carbon atoms per molecule. Such alcohols may be aliphatic, saturated or unsaturated and straight-chain or branched, or cyclic derivatives thereof. Saturated, aliphatic, straight chain alcohols are considered to be the best.

Preferably both (a) and (b) are trivalent alcohols, in particular glycerol or: * · *: trimethylolpropane. Other suitable polyhydric alcohols include pentaerythritol, sorbitol, mannitol, inositol, glucose and fructose.

Unsaturated monocarboxylic acids from which the esters are derived may have an alkenyl, cycloalkenyl or aromatic hydrocarbyl group attached to the carboxylic acid group. The term "hydrocarbyl" refers to a group containing carbon and hydrogen, which may be straight chain or branched and is attached to a carboxylic acid group by a carbon-carbon bond. The hydrocarbyl chain may be interrupted by one or more heteroatoms such as O, S, N, or P.

• · · • • • • • · ·

Advantageously, (a) and (b) are each esters of alkenyl monocarboxylic acids wherein the alkenyl groups contain 10-36, for example 10-22, more preferably 18-5-26 and especially 18-20 carbon atoms. The alkenyl group may be mono- or poly-unsaturated. It is particularly preferred that (a) is an ester of a monounsaturated alkenyl monocarboxylic acid and (b) is an ester of a polyunsaturated alkenyl monocarboxylic acid. The polyunsaturated acid is preferably di-5 or tri-unsaturated. Such acids may be derived from natural materials such as plant or animal extracts.

Particularly preferred monounsaturated acids are oleic acid and elaidic acid. Particularly preferred polyunsaturated acids are linoleic acid and linolenic acid.

Mixtures having (a) an ester of a monounsaturated acid and (b) an ester of a polyunsaturated acid have been found to have particularly good lubricity and have particularly good filterability and cold storage stability.

Esters are partial esters, m.p. only some of the hydroxy groups of each polyhydric alcohol may be esterified. Particularly good performance is obtained especially when both are monoesters.

Esters may be prepared by methods known in the art, for example by condensation reactions. If desired, alcohols may be reacted with acid derivatives such as anhydrides or acyl chlorides to facilitate the reaction and improve yields.

The esters (a) and (b) can be prepared separately and then mixed together, mixed ··· ·; ***; if it occurs either before adding to the fuel or by adding (a) and (b) separately • · ·. ···. fuel at the same time or at different times. Alternatively, the ester mixture may be prepared directly from a mixture of suitable starting materials. It is reported that the last- • · ·!.! The supported products (i.e., ester mixtures prepared directly from the reaction of the starting materials) have a particularly good filterability and a particularly good lubricating capacity. In particular, commercially available mixtures of suitable acids may be reacted with a selected alcohol, such as glycerol, to form the ester mixture product of this invention. Particularly preferred commercial acid mixtures are those containing oleic acid and linoleic acid. Small amounts of other acids or acid polymerization products may be present in such mixtures, but preferably should be no more than 15% by weight, more preferably up to 10% by weight and most preferably up to 5% by weight based on the total weight of the acid mixture.

Ester mixtures may likewise be prepared by reacting one acid with an al-5 alcohol mixture.

A highly preferred ester mixture is one which is obtained by reacting a mixture of oleic acid and Lino-fatty acid with glycerol, the mixture comprising most of (a) glycerol limonooleate and (b) glycerol monolinolate, preferably in approximately equal parts by weight.

In addition to the esters (a) and (b), the lubricating additive may contain a small amount of other esters formed, for example, by esterification of the acid mixtures described above.

(ii) Fuel Oil

The fuel oil may be any crude oil-based fuel oil, suitably any middle distillate-15 fuel oil, i. fuel oil obtained during the refining of crude oil as a fraction between lighter kerosene and jet fuel and heavy fuel oil. Such distilled fuel oils generally boil above about 100 ° C. The fuel oil may contain normal pressure distillate or vacuum distillate or cracked gas oil or a blend of distillates obtained by any of the direct distillation and thermal and / or catalytic cracking processes. The most common crude oil-based fuel oils are kerosene, jet fuel, and preferably diesel.

The sulfur content of the fuel oil is 0.2% by weight or less, preferably 0.05% by weight, or • · · * · '·', more preferably 0.01% by weight or less and most preferably 0.001% by weight or less based on the weight of fuel oil. The prior art describes methods for reducing the sulfur content of hydrocarbon-based middle distillate fuels: V: solvent extraction, sulfuric acid treatment and hydrodesulfurization.

The preferred fuel oils have a Cetane number of at least 40, preferably greater than 45, and more preferably greater than 50. The cetane number of the fuel oil may be prior to the addition of a min-30 agent to improve the cetane number, or · T M # can increase the cetane number by adding some cetane number improver.

• · • m ·

More preferably, the fuel oil has a Cetane number of at least 52.

7 (iii) Processing Responses

The concentration of the additive in the fuel oil may be, for example, 10 to 5000 ppm based on the weight of the fuel oil, for example 20 to 5000 ppm, such as 50 to 2000 ppm (active ingredient) based on the weight of the fuel oil, preferably 75 to 300 5 ppm. 200 ppm.

The weight ratios of (A) to (b) in fuel oil may be 1:10 to 2: 1. The most preferred ratio is 1: 1.

Use of Additive (Second Aspect of the Invention) and Method (Fourth Aspect of the Invention) Preferred additives for use in the second and fourth aspects of the invention are described above in connection with the first aspect.

The fuel oil of the second and fourth aspects of the invention is preferably described above in connection with the first aspect.

Using the Fuel Composition (Third Aspect of the Invention) When the fuel oil is diesel oil, the fuel oil composition of the first aspect of the invention can be used in diesel engines (compression ignition) as a fuel that, in addition to having good combustion properties, reduces wear in the fuel feed system. and especially in the fuel injection pump. Fuel ··: This increases the life of the machine and reduces the need for expensive mechanical parts 20.

• · · • · • · ♦ ··

The fuel composition of the first aspect of the invention may similarly be used in other fuel oil systems in which the mechanical equipment of the fuel feed system is · · · lubricant dependent on fuel and thus susceptible. . wear and tear.

Concentrates containing the additive mixed with a carrier liquid (eg, as a solution or dispersion) are a convenient way to incorporate the additive. * 1 *. fuel oil and may be accomplished by methods known in the art. The concentrates may also contain other necessary additives, and preferably contain from 3 to 75% by weight, more preferably from 3 to 60% by weight, and most preferably from 10 to 50% by weight, preferably dissolved in oil. Examples of carrier liquids are organic solvents, including hydrocarbon hydrocarbon solvents, for example, oil fractions such as naphtha, jet fuel, diesel and heating oil; aromatic hydrocarbons such as aromatic fractions, for example those sold under the tradename "SOLVESSO"; paraffinic hydrocarbons such as hexane and pentane; and isoparaffins and oxidized solvents such as alcohols. Of course, the carrier fluid should be selected according to its compatibility with the additive and the fuel. The concentrates are added to the crude fuel oil in sufficient amounts to provide the above additive treatment step.

The additives of the invention may be added to the crude fuel oil by other methods such as those known in the art. If kerosene additives are required, they may be added to the fuel oil simultaneously with the additives of the invention or at different times.

Kera Additives

The fuel composition of the first aspect of the invention may further contain other known lubricity enhancing compounds as co-additives, for example mono-15 or polycarboxylic acids such as dicarboxylic acids. These acids are preferably mixtures of polymerized unsaturated fatty acids, which mainly contain dimer and some trimeric acid, as well as minor amounts of monomer and / or higher polymers. Typical examples are dimeric acids of oleic acid, linoleic acid or mixtures thereof. Esters of these acids and monovalent or divalent alcohols may also be used together in a mixture of esters (a) and (b). to get even better additives.

• · • · · · ·

Ethoxylated amine-type lubricating agents may be used.

• · · • · · *

Preferably, the fuel oil according to the first aspect of the invention may also comprise. . 25 one or more fuel oil cold flow enhancers in the form of co-additives, such as: (i) ethylenically unsaturated ester copolymers t · (ii) carbon hydrogen polymers **: * '(iii) sulfur carboxy compounds • · · • 30 (iv) Polar Compounds ·: ··: (v) Aromatic Hydrocarbyl Compounds (vi) Linear Compounds and (vii) Comb Polymers 9 as described below.

(i) Forward ester copolymer

Flow-improving ethylene copolymers, for example, flow-improving ethylene-unsaturated ester copolymers, have a polymethylene ring which is divided by hydrocarbyl side chains which are interrupted by one or more atoms and / or carbonyl groups.

More particularly, the copolymer may comprise an ethylene copolymer having, in addition to ethylene-derived units, units of the formula -CR5R6-CHR7-10 wherein R6 is hydrogen or methyl, R5 is -OOCR8 or -COOR8, wherein R8 is hydrogen or C1-C9 , preferably a C 1 -C 6, more preferably C 1 -C 3 alkyl group having a straight or branched chain and R 7 is hydrogen or a -COOR 8 or -OOCR 8 group.

They may be a copolymer of ethylene and an ethylenically unsaturated ester or derivatives thereof. One example is a copolymer of ethylene and an ester of an unsaturated carboxylic acid, such as ethylene / acrylates (e.g., ethylene / 2-ethylhexyl acrylate), but the ester is preferably an unsaturated alcohol and:. an ester of a saturated carboxylic acid as described in GB-A-1 '263 152. An ethylene / vinyl ester copolymer is preferred: ethylene / vinyl acetate,' III ethylene / vinyl propionate, ethylene / vinylhexanoate, ethylene / 2-ethylhexanoate '20 or an ethylene / vinyl octanoate copolymer is preferred. Copolymers contain • · '··; preferably from 1 to 25, such as less than 25, for example from 1 to 20 mole% vinyl ester, more preferably 3 to 15 mole% vinyl ester. They may also be in the form of mixtures of two copolymers, such as those described in US-A-3,961,916 and EP-A-113,581. The number average molecular weight of the copolymer as measured by vapor phase osmosis is preferably 1,000 to 10,000, more preferably 1,000 to 5,000.

• ·: * · *: If desired, the copolymers may be derived from additional comonomers, for example, they may be terpolymers or tetrapolymers or higher polymers, for example when the additional comonomer is isobutylene or diisobutylene or another ester of · · * ··· ' gives rise to various units of the above formula, and when es-: · *: 30 ter, the above mole% refers to the size ester.

•

The copolymers may also contain small amounts of chain transfer agents and / or molecular weight modifiers (e.g., acetaldehyde or propionaldehyde) that can be used in the polymerization process to make the copolymer.

10

Copolymers can be prepared by direct polymerization of comonomers. Such copolymers can also be prepared by transesterification or hydrolysis and re-esterification of an ethylenically unsaturated ester copolymer to give a different ethylenically unsaturated ester copolymer. For example, ethylene / vinylhex-5 noate and ethylene / vinyl octanoate copolymers can be prepared in this manner, for example, from an ethylene / vinyl acetate copolymer.

Copolymers may have, for example, 15 or less, preferably 10 or less, more preferably 6 or less, most preferably 2 to 5 methyl-terminated side branches / 100 methylene groups, measured by nuclear magnetic resonance, which are 10 non-methyl groups in the comonomer ester chain and non-terminal methyl groups.

The polydispersity of the copolymers may be from 1 to 6, preferably from 2 to 4, with the polydispersity being the ratio of the weight average molecular weight to the number average molecular weight as measured by gel permeation chromatography using polystyrene standards.

(Ii) Hydrocarbon polymers

Linear Hydrocarbon Polymers These have one or more polymethylene rings which are divided into blocks by short-chain hydrocarbyl groups, e.g., containing 5 carbon atoms or less.

• · · "IV. Examples of these are those having the following general formula: * ··· * / O 20 -LCTT-CHT ^ —icHU-CHuj-: Y: 'v' 'w • · • · · • · · * '' Wherein T is H or R1; · · U is H, T or substituted or unsubstituted aryl and · R1 is a hydrocarbyl group containing up to 5 carbon atoms and v and w are molar ratios, where v is 1.0 to 0.0 and w are 0.0 to 1.0 Preferably R1 is a linear or branched alkyl group.

These polymers can be prepared directly from ethylene-unsaturated monomers or indirectly by hydrogenation of a polymer made from monomers such as isoprene and butadiene.

11

Preferred hydrocarbon polymers are copolymers of ethylene and at least one α-olefin. Examples of such olefins are propylene, 1-butene, isobutene and 2,4,4-trimethylpent-2-ene. The copolymer may also contain small amounts, for example up to 10% by weight, of other copolymerizable monomers, for example, olefins other than α-olefin and unconjugated dienes. The preferred copolymer is an ethylene / propylene copolymer. Two or more different ethylene / α-olefin copolymers of this type are not excluded from the scope of the invention.

The ethylene / α-olefin copolymer has a number average molecular weight of less than 150,000 as measured by gel permeation chromatography (GPC) compared to polystyrene standards. For some applications, it is preferably at least 60,000 and preferably at least 80,000. There is no upper limit for operation, but greater than about 150,000 molecular weights cause mixing difficulties due to the increased viscosity, and molecular weight ranges of between 60,000 and 80,000 are most preferred. To 120,000. For other applications, it is less than 30,000, preferably less than 15,000, such as less than 15,10,000 or less than 6,000.

The copolymer preferably has an ethylene mole content of 50 to 85%. More preferably, the ethylene content is 55-80% and preferably 55-75%; more preferably 60-70% and preferably 65-70%.

Examples of ethylene / α-olefin copolymers are ethylene / propylene copolymers having an ethylene molar content of 60-75% and a number average molecular weight of 60,000-120,000, particularly preferred ethylene / propylene copolymers having IV. the ethylene content is 62-71% and the molecular weight is 80,000-100,000.

• · ···

The copolymers can be prepared by any of the methods known in the art, for example using a Ziegler type catalyst. The polymers are preferably substantially amorphous since the highly crystalline polymers are somewhat insoluble. ·. ·. towers for fuel oil at low temperatures.

(Iii) Sulfur Carboxy Compounds Examples are those described in EP-A-0 261 957, which describes compounds of general formula 12 A X-R1 \ / / \ 2 BY-R2 5 wherein -Y-R2 is SO3 (') (+) NR33R2, -SO3 (') (+) HNR32R2, -SO3 (O (+) H 2 NR 3 R 2, -SO 3 (') (+) H 3 NR 2, -SO 2 NR 3 R 2 or -SO 3 R 2 and -X-R 1 is -Y-R 2 or -CONR 3 R 1, -CO 2 (') (+) NR 33 R 1, -CO 2 (' ) (+) HNR 32 R 1, -R 4 -COOR 1, -N 3 -COR 1 -R 4OR 1 -R 1 -COR 1, -R 4, R 1, -N (CO 3 R 3) R 1 or Z (') (+) NR 33 R 1 where Zw is SO3w or - R 2 and R 2 are alkyl, alkoxyalkyl or polyalkoxyalkyl groups containing 10 at least 10 carbon atoms in the backbone; 'J 1 R' is hydrocarbyl and all R groups may be the same or different and R is absent or is C 1 -C 5 alkylene and some

A

\ c

··· .. 15 C

***: the carbon-carbon bond (CC) is either a) ethylenically unsaturated, when A and B may be alkyl, • · · alkenyl or substituted hydrocarbyl groups, or b) part of a cyclic structure which may be «aromatic, multi-core aromatic or cycloaliphatic, and

♦ | J

20, wherein X-R and Y-R between them contain at least three alkyl,. . alkoxyalkyl or polyalkoxyalkyl group.

•: ·: · T: Can be used with multi-component additive system and additive ratios used ..!.: Depending on the fuel being processed.

(Iv) Polar Compounds ♦ * · • · ♦: Such compounds comprise an oil-soluble polar nitrogen compound bearing one or more, preferably two or more hydrocarbyl substituted amino or imino substituents, hydrocarbyl group (s). monovalent groups containing from 8 to 40 carbon atoms, which substituent or one or more of the substituents may be in the form of a cation derived therefrom, the oil-soluble polar nitrogen compound is either ionic or nonionic and can act as wax crystal growth modifier in fuels. The hydrocarbyl group is preferably linear or slightly linear, i. it may have one short hydrocarbyl branch (1-4 carbon atoms). When the substituent is amino, it may carry one or more of said hydrocarbyl groups, which may be the same or different.

The term "hydrocarbyl" refers to a group having a carbon atom directly attached to the rest of the molecule and having the nature of a hydrocarbon or a predominantly hydrocarbon. Examples are hydrocarbon groups including aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic and alicyclic-substituted aromatic and aromatic-substituted aliphatic and alicyclic groups. The aliphatic groups are preferably saturated. These groups may contain non-hydrocarbon substituents, provided that their presence does not alter the predominant hydrocarbon nature of the group. Examples include keto, halo, hydroxy, nitro, cyano, alkoxy and acyl. If the hydrocarbyl group is substituted, one substituent (monosubstituted) is preferred.

Examples of substituted hydrocarbon groups include 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-ketopropyl, ethoxyethyl and propoxypropyl. The groups may also contain, or alternatively contain atoms other than carbon atoms in the chain or • ·: * ·· 20 rings otherwise formed of carbon atoms. Suitable heteroatoms include, for example, nitrogen, sulfur and preferably oxygen.

More particularly, the amino or imino substituent, or each amino or imino substituent, is attached to the group by an intermediate bond group, such as -CO-, CO 2 (), -SO 4 or • · · * ^ * When the linker is anionic, the substituent is part of a cationic group such as an amine salt group.

When a polar nitrogen compound bears one or more amino or imino substituents, the bonding groups of these substituents may be the same or different.

Suitable amino substituents include C 1 -C 4 long chain, preferably C 1 -C 24 alkyl. * * ·. primary, secondary, tertiary or quaternary amino substituents.

The amino substituent is preferably a dialkyl amino substituent which, as mentioned above, may be in the form of one of its amine salts; tertiary and quaternary amines can form only amine salts. Said alkyl groups may be the same or different.

14

Examples of amino substituents include dodecylamino, tetradecylamino, coconut amino and hydrogenated tallow amino. Examples of secondary amino substituents include dioctadecylamino and methylbehenylamino. Mixtures of amino substituents, such as those derived from naturally occurring amino acids, may also be present. A preferred 5 amino substituent is a secondary hydrogenated tallow amino substituent having alkyl groups derived from hydrogenated tallow fat and typically consisting of about 4% by weight C14-31% by weight C16-59 and 59% by weight Cig-n- alkyl groups.

Suitable imino substituents include C12-C40 long chain, preferably C12-C24 alkyl substituents.

Said moiety may be monomeric (cyclic or non-cyclic) or polymeric. When it is non-cyclic, it may be prepared from a cyclic precursor such as an anhydride or a spirobis lactone.

The cyclic ring system may contain homocyclic, heterocyclic, or fused polycyclic entities, or a system where two or more such cyclic entities are joined and wherein the cyclic entities may be the same or different. When two or more such cyclic entities are present, the substituents may be on the same or different entities, preferably on the same entity. The cyclic entity or cyclic entities are preferably aro-: ·. gnomes, preferably a benzene ring or rings. Most preferably, the cyclic ring system is a single benzene ring, wherein it is preferred that the substituents are ory. and meta positions, and this benzene ring may be further substituted if desired.

Y: Ring atoms in the cyclic moiety or moieties are preferably carbon: * · *: atoms, but may for example contain one or more ring-N, -S-25 or -O atoms, wherein: the compound is a heterocyclic compound.

• m: :: Examples of such polycyclic entities are: •. (a) condensed benzene structures such as naphthalene, anthracene, phenanthrene and pyrene; • (b) fused ring structures in which no or all rings are benzene oxides such as azulene, indene, hydrogen indene, fluorene and diphenylene oxides; (c) rings bound "end-on" such as diphenyl; (d) heterocyclic compounds such as quinoline, indole, 2: 3 dihydroindole, benzofuran, coumarin, isocoumarin, benzothiophene, carbazole and thiodiphenylamine; (E) non-aromatic and partially saturated ring systems such as decalin (i.e., de-cahydronaphthalene), α-pinene, cardinine and bomylene; and (f) three-dimensional structures such as norbomene, bicycloheptane (i.e. norbomane), bicyclooctane and bicyclooctene.

Examples of polar nitrogen compounds are described below: (I) An amine salt and / or amide of a mono- or polycarboxylic acid, for example having 1 to 4 carboxylic acid groups. For example, it may be prepared by reacting at least one molar portion of a hydrocarbyl substituted amine with one molar portion of the acid or anhydride thereof.

When the amide is formed, the linker is -CO-, and when the amine salt is formed, the linker is -CO 2 -.

The moiety may be cyclic or non-cyclic. Examples of cyclic moieties include those wherein the acid is cyclohexane-1,2-carboxylic acid, cyclopentane-1,2-dicarboxylic acid and naphthalene dicarboxylic acid. Generally, the cyclic moiety of such acids has from 5 to 13 carbon atoms. Preferably, such acids are benzenedicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid, and benzene tetracarboxylic acids such as pyromelletic acid, with phthalic acid being particularly preferred. US-A-4 211 534 and EP-A-272 889 disclose polar nitrogen compounds containing such moieties.

• · * • ·· ·: ***: 20 Examples of non-cyclic moieties are those in which the acid has a long chain * · ·. · * ·. alkyl- or alkylene-substituted dicarboxylic acid such as succinic acid, as described, for example, in US-A4 147 520.

Other examples of non-cyclic moieties include those wherein the acid is a nitric acid such as diamine tetraacetic acid.

Still further examples are those obtained when an dialkylpyrobisactone is administered. is reacted with an amine.

• ·. · ♦ ·. EP-A-0 261 957 describes polar nitric compounds of the general formula of this disclosure having the general formula.

C

Y, R2 Y-R2 wherein: -Y-R2 is SO3 () (+) NR3R2, - SO3 () (+) HNR23R2, SO3 (m +) H2NR3R2, - SO3 (K +) H3NR2, - SO2NR3R2 or -SO3R2 ; and -X-R 1 is -Y-R 2 or -CONR 3 R 1, -CO 2 (X +) NR 33 R 1, -CO 2 (') (+) HNR 23 R 1, -R 4 -COOR 1, -N 3 COR 1 -R 4OR', 10 -R 4 OCOR 1, -R 4. , R 1, -N (COR 3) R 1 or Z (* x +) NR 33 R 1; -Z (-) is SO 3 () or SO 2 (); R1 and R2 are alkyl, alkoxyalkyl or polyalkoxyalkyl groups containing at least 10 carbon atoms in the backbone; R 3 is hydrocarbyl and all R 3 groups may be the same or different and R 4 is absent or C 1 -C 5 alkylene and

15A

\ • ·· \

*. C

... T I

··· *

:: C

...

: ***: / b • v: the carbon-carbon bond (CC) is either a) ethylenically unsaturated when A and B are alkyl, alkenyl or substituted hydrocarbyl groups, or b) part of the cyclic structure which may be aromatic, multi-core aromatic or cycloaliphatic,

• · _ 1 ___T

. ·: ·. it is common for X-R and Y-R to contain at least three alkyl, alkoxyalkyl or polyalkoxyalkyl groups between them.

• ·

Multi - component additive systems can be used and can be used to add additives. Λ 25 ratios depend on the fuel being processed.

EP-A-0 316 108 describes (a) an amine or diamine salt of a sulfosuccinic acid, (b) an ester or diester of a sulfosuccinic acid, (c) an amide or diamide of a sulfosuccinic acid, or (d) an ester amide of a sulfosuccinic acid.

17 (IV) A chemical compound comprising or containing a cyclic ring system and bearing at least two substituents on the ring system of the general formula (I) -A-NR / R2 (I) shown below, wherein A is an aliphatic hydrocarbyl group which may be cleaved one or more heteroatoms, linear or branched, and R 1 and R 2 are the same or different and independently represent a hydrocarbyl group containing from 9 to 40 carbon atoms optionally interrupted by one or more heteroatoms, the substituents being the same or different in the form of one of its 10 salts.

A preferably contains from 1 to 20 carbon atoms and is preferably a methylene or polymethylene group.

For example, each hydrocarbyl group forming R 1 or R 2 in the invention (Formula 1) may be an alkyl or alkylene group or a mono- or polyalkoxyalkyl group. Each hydrocarbyl group is preferably a straight chain alkyl group. The number of carbon atoms in each hydrocarbyl group is preferably 16 to 40, and more preferably 16 to 24.

It is also preferred that the cyclic system is substituted with only two substituents of general formula (I) and that A is a methylene group.

···· ··· • · 20 Examples of salts of chemical compounds are acetate and hydrochloride.

• · • · • · ·

The compounds may conveniently be prepared by reduction of the corresponding amide, which may be prepared by reacting a secondary amine with a suitable acid chloride.

• · v .: (V) Condensate of a long chain primary or secondary amine and a polymer containing carboxylic acid.

Particular examples are the polymers described in GB-A-2 121 807, FR-A-2 592 387 and DE-A-3 941 561; and also telomeric acid esters and alkanolamines as described in US-A-4,639,256; and a reaction product of a branched amine containing a carboxylic acid ester, an epoxide, and a monocarboxylic acid polyester such as described in US-A-4,631,071.

18

ΕΡ-0 283 292 describes an amide containing polymers and EP-0 343 981 describes a polymer-containing amine salt.

Note that the polar nitrogen compounds may contain functional groups other than ester functional groups.

(V) Hydrocarbylated Aromatic Compounds These materials are condensates comprising aromatic and hydrocarbyl moieties. The aromatic moiety is suitably an aromatic hydrocarbon which may be unsubstituted or substituted, for example, by non-hydrocarbon substituents.

Such an aromatic hydrocarbon preferably contains a maximum amount of these substituent groups and / or three fused rings and is preferably naphthalene. The hydrocarbyl moiety is hydrogen and the carbon containing moiety is attached to the remainder of the molecule by a carbon atom. It may be saturated or unsaturated and linear or branched and may contain one or more heteroatoms, provided they do not substantially affect the hydrocarbyl nature of the moiety. Preferably, the hydrocarbyl moiety is an alkyl moiety of suitably more than 8 carbon atoms.

(vi) Linear Compounds Such compounds include a compound wherein at least one substantially linear alkyl group having from 10 to 30 carbon atoms is attached through an optional linking group which may be branched to a non-polymeric residue such as For example, to an organic residue to form at least one linear chain of carbon atoms containing said alkyl groups and one or more non-terminal oxygen, sulfur and / or nitrogen atoms. The linker may be ··· v: polymeric.

..... "Substantially linear" means that the alkyl group is preferably a straight chain, but that straight chain alkyl groups with a small degree of branching, for example in the form of one methyl group, may also be used.

Preferably, the compound has at least two of said alkyl groups, wherein the linear chain may contain more than one carbon atom of said alkyl group.

When the compound contains at least three of the alkyl groups mentioned, it may have more than one such linear chain which may overlap one another. The linear chain or linear chains may form part of a linker group between any two such alkyl groups in the compound.

19

The oxygen atom or oxygen atoms, if present, are preferably directly in the chain between the carbon atoms and may be, for example, in the form of a linking group, if present, in the form of a mono- or polyoxyalkylene group preferably containing 2-4 carbon atoms propene.

As mentioned, the chain or chains contain carbon, oxygen, sulfur and / or nitrogen atoms.

The compound may be any ester wherein the alkyl groups are attached to the rest of the compound as -O-CO-n-alkyl or -CO-On alkyl groups, in which case the alkyl groups are derived from an acid and the remainder of the compound is derived from and in the latter case the alkyl groups are derived from an alcohol and the rest of the compound is derived from a polycarboxylic acid. The compound may also be an ether wherein the alkyl groups are attached to the rest of the compound as -O-n-alkyl groups. The compound may be both an ester and an ether, or it may contain different ester groups.

Examples are polyoxyalkylene esters, ethers, ester / ethers and mixtures thereof, in particular those containing at least one, preferably two, linear C10-C30 alkyl groups and a polyoxyalkylene glycol group having a molecular weight of up to 5,000, preferably 200-5,000, mentioned in the alkylene group. polyoxyalkylene glycol containing from 1 to 4 carbon atoms as described in EP-A-61 895 and U.S. Pat. No. 4,491,455.

···· ···

Preferred esters, ethers, ether (s) that may be used are compounds in which one or more groups (such as 2, 3 or 4 groups) of the formula: -V: -OR 25 are attached E, where E can be, for example, A (alkyl: T: alkylene) q, wherein A is C or N, or is absent, q is an integer from 1 to 4 and the alkylene group has 1 to 4 carbon atoms, A (alkylene) q for example, N (CH 2 CH 2) 3, y. C (CH 2) 4 or (CH 2) 2 and R 25 may independently be: · (a) n-alkyl ·: ··: (b) n-alkyl-CO · · · *. (c) n-alkyl-OCO- (CH2) n-30 (d) n-alkyl-OCO (CH2) nCO-? being linear and containing from 10 to 30 carbon atoms. For example, they may be represented by the formula R23OBOR24 wherein R23 and R24 are each as R25 above and B is a polyalkylene moiety of glycol having from 1 to 4 carbon atoms in the alkylene group, e.g., a polyoxymethylene, polyoxyethylene or polyoxy trimethylene moiety which is substantially linear; some degree of branching at lower alkyl side chains (such as in polyoxypropylene glycol) can be tolerated, but it is preferred that the glycol be substantially linear.

20

Suitable glycols are generally substantially linear polyethylene glycols (PEG) and polypropylene glycols (PPG) having a molecular weight of about 100-5,000, preferably about 200-2,000. Esters are preferred and fatty acids containing 10-30 carbon atoms are useful. with glycols for the preparation of ester additives, preferably C18-C24 fatty acid, especially behenic acid is preferred. Esters can also be prepared by esterifying polyethoxylated fatty acids or polyethoxylated alcohols.

Polyoxyalkylene diesters, diethers, ether / esters, and mixtures thereof are suitable as additives, with diesters being most preferred when the crude oil-based component is a narrow boiling distillate, which may contain small amounts of monoethers and monoesters (which may be formed). For a high performance, it is important that a greater number of dial-yl components are present. In particular, stearic or behenic acid esters of polyethylene glycol, polypropylene glycol or polyethylene / polypropylene glycol mixtures are preferred.

Examples of other compounds in this general class are those described in Japanese Patent Nos. 2-51477 and 3-34790 and EP-A-117,108 and * '' * 20 in EP-A-326 356, and the esterified ethoxylates described in EP-A-326 356. -A- ··. *: '356,256.

• · · t · • · • ·: ···. (vii) Comb polymers Comb comb polymers are discussed in "Comb-Like Polymers. Structure and Properties", N.A. Plate and V.P. Shibaev, J. Poly. Sci. Macromolecular Revs., 8, s.

25: 117-253 (1974).

Comb polymers generally consist of molecules having long chain branches, such as hydrocarbyl branches which may be cleaved by one or more oxygen atoms and / or carbonyl groups and having from 6 to 30, e.g. for example, 10-30 carbon atoms, branched from the polymeric ring, said branches directly or incompletely: ·. * ·. 30 straight to the penalty. Examples of an indirect bond include attachment through intermediate atoms or groups, whereby the bond may be a covalent and / or electroplated bond, such as in a salt. In general, comb polymers are distinguished by the fact that they have the lowest molar proportion of units containing such long-chain branches.

21

Preferably, the comb polymer is a homopolymer or copolymer having at least 25, and preferably at least 40, more preferably at least 50 mol% units having side chains containing at least 6, such as at least 8 and preferably at least 10 atoms selected from, for example, carbon, nitrogen and 5 oxygen, in a linear chain or in a chain containing a small amount of branching, such as a single methyl branch.

Examples of preferred comb polymers include those containing units of the general formula - ^ CDE - CHG ^ CJK - CHL ^ - 10 m where D is R11, COOR11, OCOR11, R12COORu or OR11; E is H, D or R 12; G is H or D; J is H, R 12, R 12 COORh, or a substituted or unsubstituted aryl or heterocyclic group; K is H, COOR12, OCOR12, OR12 or COOH; L is H, R 12, COOR 12, OCOR 12 or substituted or unsubstituted aryl; wherein: R11 is a hydrocarbyl group having 10 or more carbon atoms, and R12 is a hydrocarbyl group bivalent to 12COOR '' and otherwise monovalent, and m and n are the sum of their molar ratios. with 1 and mn being finite and • · · up to 1 and n being from zero to less than 1, preferably m being from 1.0 to 0.4, n being from 0 to 0, 6. Preferably R11 is a hydrocarbyl group having 10-30 carbon atoms, preferably 10-24, more preferably 10-18. R11 is preferably a linear or branched alkyl group, and R is preferably a hydrocarbyl group having 1 to T 30 carbon atoms when it is monovalent, preferably 6 or more, preferably 10 or more, more preferably no more than 24 and more preferably no more than 18 carbon atoms. When R12 is monovalent, it is a linear or slightly branched alkyl group. *: ** When R12 is divalent, it is preferably a methylene or ethylene group. "Slightly branched" means that it has one methyl branch.

• ·

The comb polymer may contain units derived from other monomers, if desired or required, examples of which are CO, vinyl acetate and 22 ethylene. According to the invention, two or more different comb polymers can be used.

For example, the comb polymers may be copolymers of maleic anhydride or fumaric acid and another ethylenically unsaturated monomer, for example an α-5 olefin or an unsaturated ester, e.g. vinyl acetate, as described in EP-A-214 786. However, comonomers are used in equal molar amounts, although molar proportions of 2: 1 and 1: 2 are suitable. Examples of olefins copolymerizable with maleic anhydride, for example, are 1-decene, 1-dodecene, 1-tetradecene, 10-hexadecene, 1-octadecene and styrene. Other examples of comb polymers include methacrylates and acrylates.

The copolymer may be esterified by any suitable method and although it is desirable but not essential that the fumaric acid anhydride be esterified to at least 50%. Examples of alcohols that may be used are n-decan-15-ol, n-dodecan-1-ol, n-tetradecan-1-ol, n-hexadecan-1-ol and n-octadecan-1-ol.

Alcohols may also contain up to one methyl branch per chain, such as 1-methylpentadecan-1-ol, 2-methyltridecan-1-ol, as described in EP-A-213,879. The alcohol may be a mixture of regular and one methyl branched alcohol. It is preferable to use pure alcohols rather than alcohol blends as they are commercially available; if alloys are used, care should be taken that the number of carbon atoms in the alkyl group is the average number of carbon atoms • »· ·. ···. an alcohol mixture in alkyl groups; if alcohols containing branch 1- • ·. '!! or at the 2-position, the number of carbon atoms in the alkyl group must be the number of carbon atoms in the straight chain portion of the alkyl group of the alcohol.

In particular, the comb polymers may be fumarate or itaconate polymers and copolymers, such as those described in European patent applications; Chem. 153,176; 153,177,156,577; and 225,688; and WO 91/16407.

Particularly preferred fumarate comb polymers are copolymers of alkyl fumarate and vinyl acetic acid having alkyl groups having from 12 to 20 carbon atoms, especially polymers having alkyl groups having 14 carbon atoms and having alkyl groups having 14 carbon atoms. are CWCi6-

• M

a mixture of alkyl groups prepared, for example, by a solution copolymerization of a succinic mixture of fumaric acid and vinyl acetate and reacting the resulting copolymer with an alcohol or a mixture of alcohols, preferably straight chain alcohols. When used, the mixture is preferably a mixture of normal Cm-35 and C16 alcohols in a weight ratio of 1: 1. In addition, mixtures of the 23 C 14 ester with the mixed CW Cl ester can be advantageously used. In such compositions, the weight ratio of C (4 and C14 / C16) is preferably from 1: 1 to 4: 1, preferably from 2: 1 to 7: 2, and most preferably from about 3: 1. The number average molecular weight of particularly preferred fumarate comb polymers is from 1000 to 100,000, preferably 1,000-50,000, as measured by vapor phase osmometry (VPO) 5.

Other suitable comb polymers include polymers and copolymers of α-olefins and esterified copolymers of styrene and maleic anhydride and esterified copolymers of styrene and fumaric acid as described in EP-A-282 342; According to the invention, mixtures of two or more campopolymers may be used and, as mentioned above, the use of such may be advantageous.

Other examples of comb polymers include hydrocarbon polymers such as copolymers of ethylene and at least one α-olefin, preferably an α-olefin having up to 20 carbon atoms, examples of which are n-octene-1, iso-octene-1, n-decene-1 and n- dodecene-1, n-tetradecene-1 and n-hexadecene-1 (for example, as described in WO 93 19106).

The number average molecular weight of such a copolymer, as measured by gel permeation chromatography against polystyrene standards, is, for example, up to 30,000 or up to 40,000. The hydrocarbon copolymers may be prepared by methods known in the art, for example using a Ziegler type catalyst. Such carbon; ** For example, the hydrocarbon polymers may have an isotacticity of 75% or more.

• · · • · · ·

Some of the above-described cold-flow curing agents may produce • · ·: ***; synergistic improvements in lubricity when combined with a mixture of esters (a) and (b).

Other co-additives which may be used are known in the art, for example, detergents, antioxidants, anti-corrosives, anti-humidity agents, demulsifiers, metal deactivators, antifoaming agents, flame retardants such as cetane number enhancers, co-solvents, packability enhancers, odor> t '<; improvers and metal-based additives such as metal burners.

: Evaluating the Benefits of Different Aspects of the Invention *; · * 30 The mixture of esters (a) and (b) is believed to be capable of forming at least a partial layer of lubricating composition on certain metal surfaces. This means that the formed layer is not necessarily complete on the contact surface. The formation of such layers and their degree of contact surface coverage can be demonstrated, for example, by measuring the electrical contact resistance or electrical capacitance.

One assay that can be used to demonstrate wear retardation, reduced friction, or increased electrical contact resistance in accordance with the present invention is the High Frequency Reciprocating Rig (HFRR) described in standard CEC PF 06-T-94 or ISO / TC22 / SC7 / WG6 / N188.

The extent to which an additive composition causes clogging of fuel line filters can be measured by any known filtration test. For example, a method for measuring the filterability of fuel oil blends is described in the Institu-10 te of Petroleum standard "IP 387/190", entitled "Determination of filter blocking tendency for gas oils and distillate diesel fuels". In summary, the sample of the fuel oil mixture to be tested is passed at a constant flow rate through a glass fiber filter; the pressure drop by the oil through the filter is monitored and the volume of fuel oil passing through the filter within a predetermined pressure drop 15 is measured. The tendency of the fuel mixture to clog the filters can be described by decreasing the pressure through the filter with 300 ml of fuel, which is passed through the filter at a rate of 20 ml / min. For further information, please refer to the above standard. This method was applied to evaluate the additive composition of the present invention by performing measurements at various temperatures less than -20 "below that specified in the standard to simulate cold storage conditions in the field.

···· • · ·: The invention is further illustrated by the following examples.

··· • · ·· ·

Example 1 • · · • φ: The following materials and procedures were used.

. *. ·. 25 Fuel Oil • · · s ~ • · ··· * · *: "Class I" diesel oil with the following characteristics: ... Sulfur: 4.5 ppm wt / wt ♦ · * ·; · * Cetane number: 51 , 6

CFPP (auto): -36 ° C

•

Distillation: 50% evaporation at 237.1 ° C

Final boiling point 294.1 ° C Residue (% by volume) 1.2 25

additives

Additives A, B, C and D were added to diesel fuel in the amounts recorded in Table 1 and the filtration rate of each fuel mixture was determined according to the IP 387/90 test at the temperatures shown in Table 1. In each case, after thorough mixing, the fuel blend sample was cooled to the required temperature in the refrigeration unit and stored at that temperature for a predetermined period of time prior to the filtration test.

• • • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · each each · · • 1% * · * · · • · · m * · «• · · · · ·

* ·· · I

# · · • • • • • · · 1 · • · • «· 26 CO CO en en ce S I 22 1 22 t e s 2a f * I 3 ^ 3 - s |

o> 00 Ci, - <3 {N e o 'O

«Γ. ^ - <N ^ - NOO

O (2 00 50

S 3 «5 {N <N

2 o ^ .S .S.

J 5§ a e «e ^ - '* en« e u ----- o

O

7 co ^^ "> -w ^ 5 *« '«5 * 3 2-

Jg £ £ <N £ <N -S

0 ** v-T «N irT« N S

s ~ w ~ w ^ S_____ li «^« «g 2 22 i &

1 3 2 *. I

S. £ en ^ B

rtH β l — I V> _ q o ä 5 ----- J3

e ¢ 2 .O <S O -P -O

H «S £ S. ^ a S a S ä £ O ?! «- £ r.

Ϊ * 2 a * = * e »s • O wm ···· • ·· • * -_ - ______ * · · ··· - * l; cö ^^ __ cö __ ^ · *. CL, .O% O O- Ό rt en tn rt tn: * · * · -g £ ex «M o. ~ sx ... 'Ό - ® -Γ oo rt-::: o w g w \ o w • · · S -2 • * 3 * • · · ce 2

• · * * S S

* · "· S *« o o o o o. 'S. o o o o o o>.

. g · JS CN {N {N <N £ j •: ··: S ^ ^ §

: g s I 'S

• · S a. <* 2

·: · J -s * ______ I

• * # · «* * ·« ^

:. · SS

45 I <CQ O Q g • ·. «S e J 'ö ------« Js ► »- {N m rt- in:« =, z ____ | ___ J_ =' 27

Additive A was prepared by esterification of a commercial mixture of oleic acid and linoleic acid with glycerol to produce a mixed ester product with (a) glycerol monooleate and (b) glycerol monolinoleate as the dominant ingredient in approximately equal weight and triololate and g / lolate. In addition, the acid mixture contained a minor amount of other acids whose esters were not believed to represent more than about 6% by weight of the mixed ester product.

Additive B was prepared by esterification of oleic acid with glycerol to form a product in which glycerol monooleate was the dominant ingredient (additive D of WO 94/17160).

Additive C was prepared by esterification of linoleic acid with glycerol to form a product in which the dominant ingredient was glycerol monolinolate.

Additive D was a mixture of additive B and additive C in a 1: 1 molar ratio.

The test results shown in Table 1 show the pressure drop as a filter at the end of each test, with the larger pressure drop indicating a higher degree of partial blockage of the filter. When the pressure drop was greater than 103.4 kPa (15 psi) during the 15 minute test, the test time at which this pressure was reached (103.4 kPa, i.e. 15 psi) corresponds to a severe filter clog and is considered an "impermeability" of the test for the purposes in question. ).

# · · 20 From the results of Table 1, it can be seen that the filtration of sample 2 (the fuel mixture according to the invention) was surprisingly better than that of sample 3 (the reference fuel * · * · 'mixture containing additive D of WO 94/17160). both at 0 ° C and at -10 ° C.

In addition, although both examples exceeded 103.4 kPa in the test after 1 week at # v · -10 ° C, the performance of sample 2 was better (exceeded just before the end of the 15 minute test, whereas sample 3 exceeded this pressure drop almost immediately).

• * «·· • · ·

In addition, the results obtained at -5 ° C show that Samples 2 and 5 (the fuel mixtures according to the invention) were much more filterable than Samples 3 and 4 (the reference mixtures), which failed the two comparative examples. For sample 2,: ·. * ·. The performance of 50 containing additive A (made by esterification of the mixture of starting acids) was [surprisingly superior to that of sample 5 containing additive D (made by mixing component esters).

28

Example 2

A small aliquot of each sample of Example 1 stored at -5 ° C for 2 weeks was immediately prior to the filtration step described in Example 1, and the HFRR performance of each aliquot at 60 ° C was measured to indicate "pre-filtered" lubrication. Similarly, the HFRR performance of each of the respective sample filtrates produced in Example 1 was measured at 60 ° C to indicate "post-filtration" lubrication. The results are compared in Table 2 below.

Table 2

Sample Additive Additive content HFRR HFRR

(ppm active Wear trace Wear trace ingredient wt / wt) before filtration (pm) after filtration (pm) 1 Without 0 623 610 2 A 200 309 330 3 B 200 249 396 4 C 200 343 411 • · · • »'I' ii · i ^ -i —— m I ^ mmmi — ι— 5 D 200 292 274 • · · «· • ______ 10 • · · • · · · ·

The results in Table 2 show that the lubricity '· * * of Samples 3 and 4 (reference substances) is significantly worse after filtration (i.e., higher wear) compared to Samples 2 and 5 (compositions according to the invention), which retained their lubricating capacity.

There was no change in the untreated fuel (Sample 1), which confirms that the differences in the results of the other samples are due to the presence of additives in these blends.

• · · • · • • • m

Differences in wear diameter after filtration represent a significant technical improvement and demonstrate the superior ointment * * properties of the blends of the esters (a) and (b) compared to the reference additives.

Claims (11)

A fuel oil composition, characterized in that it comprises a predominant proportion of an intermediate distillate fuel oil having a sulfur content of 0.2% by weight or less, and a minor proportion of a lubricating additive (additive) comprising (a) an ester of a monounsaturated monocarboxylic acid and a polyhydric alcohol, and (b) an ester of a polyunsaturated monocarboxylic acid and a polyhydric alcohol having at least three hydroxy groups, wherein the esters (a) and (b) are different and both are partial esters, and the relative proportions of (a) and (b) ) by weight is in the range of 1:10 - 2: 1. Composition according to claim 1, characterized in that the fuel oil has a sulfur content of 0.01% by weight or less. Composition according to claim 1 or 2, characterized in that the fuel oil is a diesel fuel. ·. Composition according to any of the preceding claims, characterized in that (a) • · · * is an ester of a polyhydric alcohol having at least three hydroxy groups. · · · · · · · Composition according to any one of the preceding claims, characterized in that (b) are esters of alkenyl monocarboxylic acids. • · • · · • · ·! Composition according to claim 5, characterized in that both acids have "**" alkenyl groups having 10 to 36 carbon atoms. T: Composition according to any of claims 4 to 6, characterized in that (a) and: ***: (b) both are esters of trivalent alcohols, in particular glycerol. • · · Composition according to claim 7, characterized in that (a) and (b) both are *: · *: monoesters. The composition according to claim 8, characterized in that (a) is a monoester of oleic acid and glycerol, and (b) is a monoester of linoleic acid and glycerol. Use of the additive according to any preceding claim for improving the lubricity of the intermediate distillate fuel oil. Use of the fuel oil composition according to any one of claims 1 to 9 in a combustion device to reduce the wear rate of the fuel supply system of the device. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · • · · • i * • · · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·