KR100249989B1 - Additives for oils - Google Patents

Abstract

One or more additives are used to modify the wax crystal growth properties of oils derived from animal or vegetable material.

Description

Additives for oil

Detailed description of the invention

The present invention relates to the use of wax crystal control additives for oils obtained from animal or vegetable materials or both or derivatives thereof.

Oils obtained from animal or vegetable materials are mainly metabolites comprising triglycerides of monocarboxylic acids containing, for example, 10-25 carbon atoms and having the structure:

Wherein R is an aliphatic radical of 10 to 25 carbon atoms which may be unsaturated or saturated.

In general, such oils contain triglycerides of various acids, varying in number and type, depending on the source of the oil, and may further contain phosphoglycerides. Such oils can be obtained by methods known in the art.

Examples of derivatives of these oils are alkyl esters, such as fatty acid methyl esters of vegetable or animal oils. The esters can be prepared by transesterification.

References herein to oils derived from animal or vegetable materials include references to both the animal material or vegetable material, or both, or all of the oils obtained from derivatives thereof.

Fr-A-2,492,402 discloses fuel compositions containing one or more fatty acid esters of animal and plant origin of the general formula:

R¹-COO-R²

Wherein R 1 is a substantially linear saturated or unsaturated aliphatic radical having 5 to 23 carbon atoms and R 2 is a linear or branched saturated or unsaturated aliphatic radical having 1 to 12 carbon atoms.

Such fuel compositions are disclosed to be particularly suitable for use in diesel engines because they have a cetane-index range that is broadly equivalent to conventional diesel fuels derived from mineral oils.

However, the usefulness of such fatty acid ester compositions as diesel fuel is limited by the low temperature properties of the compositions. DE-A-4,040,317 discloses that at temperatures below −5 ° C. the fuel may be solidified in the feed line due to inadequate filterability, a mixture of short-chain methyl esters of fatty acids and selected polymeric materials, ie carbon number A method for improving low temperature filtration is disclosed, which comprises adding a copolymer of acrylic or / or methacrylic esters or a mixture of polymeric esters derived from alcohols of 1 to 22.

Low temperature properties of petroleum based oils, ie mineral oils and derivatives thereof such as crude oil, lubricating oils and fuel oils such as middle distillate fuel oils, are well documented in the art. Similarly, the use of additives to control the wax crystal structure of these mineral oils and derivatives thereof is known. Such additives and examples of their use are disclosed in US-A-3,048,479, UK-A-1,263,152, US-A-3,961,916, US-A-4,211,534, EP-A-153,176 and EP-A-153,177. These are sometimes referred to as "cold flow additives". Page 112 of the Proceedings of the British Academy of Chemistry Symposium held at the University of Manchester, March 22-23, 1983 (edited by Sir P. Ogden). It is disclosed in what way alkylated moieties are believed to resemble the linear saturated hydrocarbon chains of intermediate n-alkane molecules (paraffin waxes) naturally present in the oil as trace components. Moreover, due to these structural similarities, the additives are believed to interfere in several ways to crystallize the n-alkanes into flaky crystals, such as precipitated from solutions in oil at low temperatures. The additive thus reduces the size and shape of the wax crystals and reduces the cohesion between the crystals and between the wax and the oil in such a way as to allow the oil to remain fluid at low temperatures and pass through the coarse filter. .

In contrast to the mineral oils and derivatives thereof, the low temperature properties of the oils according to the invention, which are oils derived from animal or vegetable substances, are mainly controlled by precipitating higher molecular weight fatty acid esters present as the main component. Such fatty acid esters are often derived from mixtures of saturated and unsaturated fatty acids. By way of example only, the main components of rapeseed oil methyl ester are shown below.

Main components of rapeseed oil methyl ester:

In general, although the unsaturated fatty acid derivatives predominate over their saturated homologues, the exact proportion of the individual components in a particular oil will vary depending on the result of seasonal variation of the constituent fatty acids in the raw material or the result of the particular method of obtaining the material. Can also be.

These predominantly ethylenically unsaturated fatty acid esters form different crystal forms between these two oil groups which are believed to result from the different structural forms of the hydrocarbon chains that precipitate the crystallization modalities, n-alkanes and unsaturated fatty acid esters, respectively, from the mineral oils described above. To provide oil.

Surprisingly, although some additives that are effective as wax crystal control additives for mineral oils and derivatives thereof are also clearly lacking in structural similarity to ethylenically unsaturated hydrocarbon chains, they can be used as wax crystal control additives for oils derived from animal or vegetable materials, Found valid.

In a first aspect of the invention, the invention comprises a mixture of a large amount of oil consisting essentially of an oil derived from animal or vegetable material and a small amount of mineral oil cold flow additive. Provided that the composition does not include copolymers or mixtures of polymeric esters of acrylic acid and / or methacrylic acid esters derived from alcohols having 1 to 22 carbon atoms.

In a preferred embodiment of the first aspect, the present invention comprises a mixture of a large amount of oil consisting essentially of an oil derived from an animal material or a vegetable material and an additive containing a small amount of one or more of the following components, provided that it contains 1 to 22 carbon atoms. A composition that does not include copolymers or mixtures of polymeric esters of acrylic and / or methacrylic esters derived from alcohols of:

(Iii) comb polymers;

(Ii) polyoxyalkylene esters, esters / ethers or mixtures thereof

(Iii) ethylene / unsaturated ester copolymers

(Iii) Polar nitrogen-containing organic wax crystal growth inhibitors

(Iii) hydrocarbon polymers and

(Iii) sulfur carboxy compounds

(Iii) hydrocarbylated aromatic pour point depressants.

In a second aspect, the present invention relates to the use of mineral oil cold flow additives for controlling wax crystal growth properties of oils derived from animal or vegetable materials, provided that the additives are acrylic acid derived from alcohols having 1 to 22 carbon atoms. And / or mixtures of copolymers or polymeric esters of methacrylic acid esters.

In a preferred embodiment of the second aspect, the present invention relates to the use of an additive containing one or more of the following components for controlling the wax crystal growth properties of an oil derived from an animal or vegetable material, provided that the additive contains carbon number Does not include mixtures of copolymers or polymeric esters of acrylic and / or methacrylic esters derived from alcohols of 1 to 22:

(Iii) comb polymer

(Ii) polyoxyalkylene esters, esters / ethers or mixtures thereof

(Iii) ethylene / unsaturated ester copolymers

(Iii) polar nitrogen-containing organic wax crystal growth inhibitors

(Iii) hydrocarbon polymers and

(Iii) sulfur carboxy compounds

(Iii) hydrocarbylated aromatic pour point depressants.

In a third aspect, the present invention relates to a method for modifying the wax crystal growth properties of an oil consisting essentially of an oil derived from an animal or vegetable material, comprising a mixture with an additive as defined in the second aspect.

Features of the present invention will now be discussed in more detail.

oil

Examples of oils derived from animal or vegetable substances include rapeseed oil, coriander oil, soybean oil, cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, corn oil, almond oil, palm sim oil, coconut oil, mustard seed oil, tallow oil. And fish oil. Further examples are oils derived from corn, jute, sesame, sheanut, lumps and flax seeds, which can be derived by methods known in the art. Rapeseed oil, which is a mixture of fatty acids partially esterified with glycerol, is preferred because it is available in large quantities and obtained by a simple method of compressing rapeseed seeds.

As lower alkyl esters of fatty acids, the following commercial mixtures can be considered as examples: fatty acids having 12 to 22 carbon atoms, for example lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, elide Ethyl, propyl, butyl and especially methyl esters of acids, petroleic acid, ricinoleic acid, elaostearic acid, linoleic acid, linolenic acid, eicosane acid, gadoleic acid, docoic acid or erucic acid, which are 50 to 150, in particular Iodine number from 90 to 125. Mixtures with particularly advantageous properties are those which contain mainly methyl esters of fatty acids having 16 to 22 carbon atoms and 1, 2 or 3 double bonds, at least 50% by weight. Preferred fatty acid lower alkyl esters are the methyl esters of oleic acid, linoleic acid, linolenic acid and erucic acid.

Commercial mixtures of the above kind are obtained, for example, by cleavage and esterification of animal and vegetable fats and oils by transesterification with lower aliphatic alcohols. In order to produce lower alkyl esters of fatty acids, it is advantageous to start with fats and oils having a high iodine value, such as sunflower oil, rapeseed oil, coriander oil, castor oil, soybean oil, cottonseed oil, peanut oil or tallow. Preference is given to lower alkyl esters of fatty acids based on new varieties of rapeseed oil, ie fatty acid components of at least 80% by weight derived from unsaturated fatty acids having 18 carbon atoms.

Especially preferred are oils according to the invention which can be used as biofuels. Biofuels, ie fuels derived from animal or vegetable substances, are considered less harmful to the environment upon combustion and are obtained from renewable sources. It is reported that, on combustion, it produces less carbon dioxide and produces less sulfur dioxide than is produced by an equivalent amount of petroleum distillate fuel, for example diesel fuel. Derivatives of some vegetable oils, such as those obtained by saponification and reesterification with monohydric alkyl alcohols, may also be used as substitutes for diesel fuel. Recently, it has been reported that rapeseed esters, for example mixtures of rapeseed oil methyl ester (RME) and petroleum distillate fuels, for example mixtures of 10:90 volume ratios, are likely to be commercially available in the near future.

Thus, biofuels are oils obtained from vegetable or animal materials, or both or derivatives thereof, that can be used as fuel.

Although many of these oils can be used as biofuels, vegetable oils or derivatives thereof are preferred, and particularly preferred biofuels are rapeseed oil, cottonseed oil, soybean oil, sunflower oil, olive oil, palm oil or alkyl ester derivatives thereof, Milk methyl esters are particularly preferred.

The concentration of the additive in the oil is for example 1 to 10,000 ppm by weight of the additive (active ingredient) per fuel weight, for example 10 to 2000 ppm by weight (active ingredient) per fuel weight, preferably 25 to 500 ppm by weight, more preferably It may be in the range of 10 to 5,000 ppm by weight, such as 100 to 200 ppm by weight.

The additive or additives should be soluble in the oil at least 1000 ppm by weight of oil at ambient temperature. However, at least some of the additives may precipitate out of solution near the cloud point of the oil to control the wax crystals formed.

Additives may also be incorporated into the bulk oil by methods known in the art. If more than one additive component or auxiliary additive component is used, these components may be incorporated into the oil together or separately in any blending ratio.

Concentrates comprising additives dispersed in a carrier liquid (such as a solution) are convenient as a means of incorporating the additives. Concentrates of the invention are convenient as a means of incorporating additives into bulk oils, such as distillate fuels, which incorporation can be carried out by methods known in the art. The concentrate may also contain other additives as desired, preferably containing 3 to 75% by weight of additives, more preferably 3 to 60% by weight, most preferably 10 to 50% by weight in a solution in oil. can do. Examples of carrier liquids include organic solvents including hydrocarbon solvents such as petroleum fractions such as naphtha, kerosene, diesel and heating oils; Aromatic fractions such as aromatic hydrocarbons sold under the trade name 'SOLVESSO'; And paraffinic hydrocarbons such as hexane and pentane and isoparaffin. Of course, the carrier liquid should be selected in consideration of the compatibility with the additive and the fuel.

The additives of the present invention may be incorporated into the bulk oil by other methods known in the art. If auxiliary additives are required, they may be incorporated into the bulk oil at the same time as the additives of the invention or at other times.

additive

Preferred additives according to various aspects of the invention are shown below.

(i) comb polymer

Comb polymers are polymers in which hydrocarbyl groups are slack from the polymer backbone, as described in N.A. Plate and V.P. Shibaev, "Comb-Like Polymers.Structure and Properties", J. Poly. Sci. Macromolecular Revs., 8, p117 to 253 (1974).

Advantageously, the comb polymer is at least 25 mole%, preferably at least 40 mole%, more preferably 50 homopolymers having at least 6 carbon atoms, preferably at least 10 side chains, or units having at least 6 carbon atoms, preferably at least 10 side chains. It is a copolymer which has mol% or more.

Examples of preferred comb polymers are those having the following general formula:

In the above formula,

D is R ¹¹ , COOR ¹¹ , OCOR ¹¹ , R ¹² COOR ¹¹ or OR ¹¹ ,

E is H, CH ₃ , D or R ¹² ,

G is H or D,

J is H, R ¹² , R ¹² COOR ¹¹ , or an aryl or heterocyclic group,

K is H, COOR ¹² , OCOR ¹² , OR ¹² or COOH,

L is H, R ¹² , COOR ¹² , OCOR ¹² or aryl,

R ¹¹ is C ₁₀ or more hydrocarbyl,

R ¹² is C ₁ or more hydrocarbyl,

m and n represent molar ratios,

m ranges from 1.0 to 0.4,

n ranges from 0 to 0.6.

R ¹¹ advantageously represents a hydrocarbyl group having 10 to 30 carbon atoms, and R ¹² advantageously represents a hydrocarbyl group having 1 to 30 carbon atoms.

The comb polymer may optionally contain units derived from other monomers. It is within the scope of the present invention to include two or more different comb polymers.

These comb polymers may be copolymers of maleic anhydride or fumaric acid with another ethylenically unsaturated monomer, such as α-olefins or unsaturated esters such as vinyl acetate. It is preferred, but not necessary, to use equimolar amounts of comonomers, and molar ratios ranging from 2 to 1 to 1 to 2 are suitable. Examples of olefins which can be copolymerized with maleic anhydride, for example, are 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene.

The copolymer may be esterified by any suitable technique, although it is preferred but not necessary that at least 50% of maleic anhydride or fumaric acid be esterified. Examples of alcohols that can be used include n-decane-1-ol, n-dodecane-1-ol, n-tedecane-1-ol, n-hexadecane-1ol and n-octadecane-1-ol have. The alcohol may also include up to one methyl branch per chain, as examples being 1-methylpentadecan-1ol, 2-methyltridecan-1-ol. The alcohol may be a mixture of normal and single methyl branched alcohol. Preference is given to using pure alcohols rather than commercially available alcohol mixtures, provided that when a mixture is used R ¹² refers to the average number of carbon atoms in the alkyl group; When an alcohol containing a branch in position 1 or 2 is used, R ¹² refers to the main chain fragment of an alcohol which is straight chain.

These comb polymers are in particular fumarate or itaconate polymers and copolymers, for example as disclosed in EP 153,176, 153,177 and 225, 688, and WO 91/16407.

Particularly preferred fumarate comb polymers are copolymers of vinyl acetate with alkyl fumarates wherein the alkyl groups have from 12 to 20 carbon atoms, more particularly polymers in which the alkyl group has 14 carbon atoms or a mixture of C ₁₄ / C ₁₆ alkyl groups, They are prepared by solution copolymerizing an equimolar mixture of fumaric acid and vinyl acetate and reacting the resulting copolymer with an alcohol or a mixture of alcohols (preferably straight chain alcohols). If a mixture is used, a 1: 1 weight ratio mixture of normal C ₁₄ and C ₁₆ alcohols is advantageous. Furthermore, mixtures of C ₁₄ esters with mixed C ₁₄ / C ₁₆ esters may be advantageously used. In this mixture, the ratio of C ₁₄ to C ₁₄ / C ₁₆ is advantageously in the range of 1: 1 to 4: 1, preferably 2: 1 to 7: 2, most preferably about 3: 1 weight ratio. Particularly preferred fumarate comb polymers may have a number average molecular weight in the range of from 1,000 to 100,000, preferably from 1,000 to 30,000, for example as measured by gas phase osmometry (VPO).

Other suitable comb polymers include polymers and copolymers of α-olefins, esterified copolymers of styrene and maleic anhydride, and esterified copolymers of styrene and fumaric acid; Mixtures of two or more comb polymers may be used according to the invention, and as described above, it may be advantageous to use them.

(ii) polyoxyalkylene compounds

By way of example polyoxyalkylene esters, ethers, esters / ethers, and mixtures thereof, in particular those containing at least one, preferably at least two, linear saturated alkyl groups of C ₁₀ to C ₃₀ , and molecular weight up to 5,000, preferably There are polyoxyalkylene glycol groups containing 200 to 5,000 alkyl groups having 1 to 4 carbon atoms. These materials are the subject of European Patent Publication No. 0,061,895, A2. Other such additives are disclosed in US Pat. No. 4,491,455.

Preferred esters, ethers or esters / ethers which can be used can be represented by the general formula:

R-O (A) -O-R²

In the above formula,

R and R ² are the same or different,

(Where n is 1 to 30, the alkyl group is linear and saturated and has 10 to 30 carbon atoms),

A represents a polyalkylene fragment of glycol wherein the alkylene group has 1 to 4 carbon atoms, for example polyoxymethylene, polyoxyethylene or polyoxytrimethylene moiety (they are substantially linear); There may be some molecules with lower alkyl side chains (eg in polyoxy propylene glycol), provided that the glycols are substantially linear; It may also contain nitrogen.

Examples of suitable glycols are substantially linear polyethylene glycol (PEG) and polypropylene glycol (PEG) having a molecular weight of about 100 to 5,000, preferably about 200 to 2,000. Esters are preferred, fatty acids having from 10 to 30 carbon atoms are useful for preparing ester additives by reacting with glycols, preferably with C ₁₈ -C ₂₄ fatty acids, in particular behenic acid. Such esters may also be prepared by esterifying polyethoxylated fatty acids or polyethoxylated alcohols.

Polyoxyalkylene diesters, diethers, ethers / esters and mixtures thereof are suitable as additives and when a small amount of monoethers and monoesters, which are often formed during the manufacturing process, are also present, narrow boiling ranges of distillation Diesters are preferred for use in water. The presence of large amounts of dialkyl compounds is important for the performance of the additives. In particular, stearic or behenic diesters of polyethylene glycol, polypropylene glycol or polyethylene / polypropylene glycol mixtures are preferred.

Other examples of polyoxyalkylene compounds are disclosed in Japanese Patent Publication Nos. 2-51477 and 3-34790 (all Sanyo patents), and esterified alkoxylated amines are described in EP-A-117, 108 and EP-. A-326,356 (all of Nippon Oil and Fats patent).

(ii) ethylene / unsaturated ester copolymers

Ethylene copolymer flow improvers are ethylenically unsaturated ester copolymer flow improvers having a polymethylene backbone that is split into fragments by oxyhydrocarbon side chains. Unsaturated monomers capable of copolymerizing with ethylene to form copolymers include unsaturated mono and diesters of the general formula:

In the above formula,

R ¹ represents hydrogen or a methyl group:

R ² represents a -OOCR ⁴ or -COOR ⁴ group;

R ³ is hydrogen or —COOR ⁴ ;

R ⁴ represents hydrogen or a straight or branched chain alkyl group of C ₁ to C ₂₈ , preferably C ₁ to C ₁₆ , more preferably C ₁ to C ₈ , provided that R ² represents -COOR ⁴ Does not represent.

Examples of monomers in which R ² and R ³ are hydrogen and R ¹ is —OOCR ⁴ include C ₁ to C ₂₉ , preferably C ₁ to C ₅ monocarboxylic acids, and preferably C ₂ to C ₂₉ , more preferably C ₁ to C ₅ there is a monocarboxylic acid, vinyl alcohol esters of monocarboxylic acids and most preferably C ₂ to C _5. Examples of vinyl esters that can be copolymerized with ethylene include vinyl acetate, vinyl propionate and vinyl butyrate or isobutyrate, with vinyl acetate and vinyl propionate being preferred. Preferably, the copolymers contain 5 to 40 weight percent vinyl ester, more preferably 10 to 35 weight percent vinyl ester. They may also be in the form of a mixture of two copolymers as disclosed in US Pat. No. 3,961,916. Preferably, the number average molecular weight of the copolymer as measured by gas phase osmometry is 1,000 to 10,000, more preferably 1,000 to 5,000. In some cases, the copolymers may be derived from further comonomers. For example, if the additional comonomer is isobutylene or diisobutylene, it can be derived from terpolymers or quaternary polymers or higher polymers.

Such copolymers may also be prepared by transesterification, or hydrolysis and re-esterification of ethylenically unsaturated ester copolymers to obtain different ethylenically unsaturated ester copolymers. For example, ethylene vinyl hexanoate and ethylene vinyl octanoate copolymers may be prepared in the same manner from, for example, ethylene vinyl acetate copolymers.

(iv) polar nitrogen-containing organic compounds

Oil soluble polar nitrogen compounds are either ionic or nonionic and can act as wax crystal growth inhibitors in fuel. The compound comprises, for example, one or more of the following compounds (a) to (c):

(a) amine salts and / or amides formed by reacting at least one mole ratio of hydrocarbyl substituted amines with one mole ratio of hydrocarbyl having from 1 to 4 carboxylic acid groups or anhydrides thereof.

It is possible to use esters / amides having a total of 30 to 300 carbon atoms, preferably 50 to 150 carbon atoms. These nitrogen compounds are disclosed in US Pat. No. 4,211,534. Suitable amines are usually long chain C ₁₂ to C ₄₀ primary, secondary, tertiary or quaternary amines or mixtures thereof, but when the resulting nitrogen compound is oil soluble and thus typically contains about 30 to 300 carbon atoms in total. Short chain amines may also be used. The nitrogen compound preferably contains at least one straight chain alkyl fragment of C ₈ to C ₄₀ , preferably C ₁₄ to C ₂₄ .

Suitable amines include primary, secondary, tertiary or quaternary amines, but secondary amines are preferred. Tertiary and quaternary amines can only form amine salts. Examples of amines are tetradecyl amine, cocoamine and hydrogenated tallow amine. Examples of secondary amines are dioctadecyl amine and methyl-behenyl amine. Amine mixtures derived from natural substances are also suitable. Preferred amines are secondary of the general formula HNR ¹ R ² , wherein R ¹ and R ² are alkyl groups derived from hydrogenated tallow consisting of approximately 4% C ₁₄ , 31% C ₁₆ , 59% C ₁₈ . Hydrogenated tallow amine.

Examples of suitable carboxylic acids and anhydrides thereof for preparing the nitrogen compounds include cyclohexane 1,2 dicarboxylic acid, cyclohexene 1,2 dicarboxylic acid, cyclopentane 1,2 dicarboxylic acid and naphthalene dicarboxylic acid, and dialkyl spirobilaclactone And 1,4-dicarboxylic acid. Generally, these acids have about 5 to 13 carbon atoms in the cyclic moiety. Preferred acids useful in the present invention are benzene dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. Phthalic acid or its anhydride is particularly preferred. Particularly preferred compounds are amide-amine salts formed by reacting one molar ratio of phthalic anhydride with two molar ratios of dihydrogenated tallow amine. Another preferred compound is diamide formed by dehydrating the amide-amine salt.

Other examples include long-chain alkyl or alkylene substituted dicarboxylic acid derivatives, for example amine salts of substituted succinic monoamides as disclosed in US-A-4,147,520 and known in the art. Suitable amines may be those disclosed above.

Other examples are condensates as disclosed in EP-A-327,423.

(b) a compound comprising said ring system having at least two substituents of the general formula (I)

-A-NR ¹ R ² (I)

Wherein A is a straight or branched aliphatic hydrocarbyl group optionally interrupted by one or more heteroatoms, R ¹ and R ² are the same or different, each independently having 9 to 6 carbon atoms optionally interrupted by one or more heteroatoms; A hydrocarbyl group of 40, these substituents being the same or different and optionally in salt form.

Preferably A has 1 to 20 carbon atoms, preferably methylene or polymethylene group.

As used herein, the term "hydrocarbyl" refers to a group having carbon atoms directly bonded to the rest of the molecule and having hydrocarbon properties or predominantly hydrocarbon properties. Examples include hydrocarbon groups including aliphatic (eg alkyl or alkenyl), alicyclic (eg cycloalkyl or cycloalkenyl), aromatic and cycloaliphatic-substituted aromatics, and aromatic-substituted aliphatic and cycloaliphatic groups. have. Aliphatic groups are advantageously saturated. These groups may contain non-hydrocarbon substituents, provided their presence does not alter the prevailing hydrocarbon properties of the group. Examples are keto, halo, hydroxy, nitro, cyano, alcoholic and acyl. If the hydrocarbyl group is substituted, a single (mono) substituent is preferred.

Examples of substituted hydrocarbyl groups are 2-hydroxyethyl, 3-hydroxy propyl, 4-hydroxybutyl, 2-ketopropyl, ethoxyethyl and propoxypropyl. These groups may also contain, on the one hand, atoms other than carbon in a chain or ring consisting of carbon atoms.

Suitable hetero atoms are, for example, nitrogen, sulfur and preferably oxygen.

The annular ring system may comprise a homocyclic, heterocyclic, or fused polycyclic assembly, or a system in which two or more such annular assemblies are bonded to each other and these annular assemblies may be the same or different. . If two or more such annular assemblies are present, the substituents of formula (1) may be present on the same or different assemblies, preferably on the same assembly. Preferably, the or each cyclic assembly is aromatic, more preferably a benzene ring. Most preferably, the cyclic ring system is a single benzene ring where the substituents are preferably at the ortho or meta position, which ring may optionally be further substituted.

The ring atoms in the cyclic assembly or assemblies are preferably carbon atoms, but may for example comprise one or more ring N, S or 0 atoms, in which case the compound is a heterocyclic compound.

Examples of such polycyclic assemblies include the following structures:

(i) condensed benzene structures such as naphthalene, anthracene, phenanthracene and pyrene;

(ii) condensed ring structures in which none of the above rings are benzene, such as azulene, indene, hydroindene, fluorene and diphenylene oxide;

(iii) “end-on” linked rings, such as diphenyl;

(iv) heterocyclic compounds such as quinoline, indole, 2: 3 dihydroindole, benzofuran, coumarin, isocoumarin, benzothiophene, carbazole and thiodiphenylamine;

(v) non-aromatic or partially saturated ring systems such as decalin (ie decahydronaphthalene), α-pinene, cardinene and bonylene; And

(vi) three-dimensional structures such as norbornene, bicycloheptane (ie norbornane), bicyclooctane and bicyclooctene.

Each hydrocarbyl group constituting R ¹ and R ² of the present invention (General Formula (I)) may be, for example, an alkyl or alkylene group or a mono- or poly-alkoxy alkyl group. Preferably, each hydrocarbyl group is a straight chain alkyl group. The number of carbon atoms in each hydrocarbyl group is preferably 16 to 24, more preferably 16 to 24.

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

Examples of salts of these compounds are acetate and hydrochloride. The compounds may also be prepared by reducing the corresponding amide, which may be prepared by reacting the secondary amine with a suitable acid chloride for convenience.

(c) condensates of carboxylic acid-containing polymers with long-chain primary or secondary amines.

Specific examples include the polymers disclosed in GB-A-2,121,807, FR-A-2,592,387 and DE-A-3,941,561; And also esters of telemer acids and alkanolamines disclosed in US-A-4,639,256; Long chain epoxide / amine reaction products capable of optionally further reacting with polycarboxylic acids; And reaction products of amine containing branched carboxylic acid esters, epoxides and mono carboxylic acid polyesters as disclosed in US Pat. No. 4,631,071.

(v) hydrocarbon polymers

Examples are compounds of the general formula:

In the above formula,

T is H or R ¹ ,

U is H, T or aryl,

R ¹ is C ₁ to C ₃₀ hydrocarbyl,

v and w represent the molar ratio,

v ranges from 1.0 to 0.0,

w ranges from 0.0 to 1.0.

These polymers can be prepared directly from ethylenically unsaturated monomers or indirectly by hydrogenating polymers made from monomers such as isoprene and butadiene.

Preferred hydrocarbon polymers are one or more having a number average molecular weight of at least 30,000. -A copolymer of olefin and ethylene. Preferably above -Olefins have up to 20 carbon atoms. Examples of such olefins are propylene, 1-butene, isobutene, n-octene-1, isooctene-1, n-decene-1 and n-dodecene-1. The copolymer may also be present in small amounts, for example up to 10% by weight of other copolymerizable monomers, for example Olefins other than -olefin, and nonconjugated diene may also be included. Preferred copolymers are ethylene-propylene copolymers. It is within the scope of the present invention to include two or more different ethylene-α-olefin copolymers of this type.

The number average molecular weight of the ethylene-α-olefin copolymer is at least 30,000, advantageously at least 60,000, preferably at least 80,000 as compared to the polystyrene standard as measured by gel permeation chromatography (GPC) as indicated above. Functionally there is no upper limit at molecular weights above about 50,000, except for the difficulty of mixing resulting from increased viscosity, with preferred molecular weight ranges of 60,000 and 80,000 to 120,000.

Advantageously, the copolymer has a molar ethylene content of 50 to 85%. More advantageously, the ethylene content is in the range of 57 to 80%, preferably 58 to 73%, more preferably 62 to 71%, most preferably 65 to 70%.

Preferred ethylene-α-olefin copolymers are ethylene-propylene copolymers having an ethylene molar content of 62 to 71% and a number average molecular weight in the range of 60,000 to 120,000, particularly preferred copolymers having a molar ethylene content of 62 to 71% and 80,000 Ethylene-propylene copolymers having a molecular weight ranging from 100,000 to 100,000.

The copolymers may be prepared using any of the methods known in the art, for example using a Ziegler type catalyst. Advantageously, the polymers are substantially amorphous because highly crystalline polymers are relatively insoluble in fuel oil at low temperatures.

The additive composition may also advantageously comprise further ethylene-α-olefin copolymers having a number average molecular weight of 7500 or less, advantageously 1,000 to 6,000, preferably 2,000 to 5,000, as measured by gas phase osmometry. . Suitable α-olefins are those described above, or styrene, with propylene being preferred. Advantageously the ethylene content is from 60 to 77 mole percent, but up to 86 mole percent of ethylene can be advantageously used relative to the ethylene-propylene copolymer.

Examples of hydrocarbon polymers are disclosed in WO-A-9,111,488.

(vi) sulfur carboxy compounds

Examples of such compounds are disclosed in EP-A-0,261,957, which discloses the use of the following general formula compounds:

In the above formula,

-YR ² is -SO ₃ ^{(-) (+)} NR ³ ₃ R ² , -SO ₃ ^{(-) (+)} HNR ³ ₂ R ² ,

-SO ₃ ^{(-) (+)} HH ₂ NR ³ R ² , -SO ₃ ^{(-) (+)} H ₃ NR ² ,

-SO ₂ NR ³ R ² or -SO ₃ R ² ;

XR ¹ is

-YR ² or -CONR ³ R ^1,

-CO ₂ ^{(-) (+)} NR ³ ₃ R ¹ , -CO ₂ ^{(-) (+)} HNR ³ ₂ R ¹ ,

-R ⁴ -COOR ₁ , -NR ³ COR ¹ ,

-R ⁴ OR ¹ , -R ⁴ OCOR ¹ , -R ⁴ R ¹ ,

-N (COR ³ ) R ¹ or Z ^{(−) (+)} NR ³ ₃ R ¹ ;

-Z ^(-) is

SO ₃ ⁽⁻⁾ or —CO ₂ ⁽⁻⁾ ;

R ¹ and R ² are alkyl, alkoxyalkyl or polyalkoxyalkyl containing at least 10 carbon atoms in the main chain;

R ³ is hydrocarbyl and each is the same or different;

R ⁴ is absent or is C ₁ to C ₅ alkylene;

Wherein the carbon-carbon (CC) bond is a part of a cyclic structure which may be a) ethylenically unsaturated when A and B are alkyl, alkenyl or substituted hydrocarbyl groups, or b) aromatic, polynuclear aromatic or cycloaliphatic It is preferred that XR ¹ and YR ² between them contain at least 3 alkyl, alkoxyalkyl or polyalkoxyalkyl groups.

(vii) hydrocarbylated aromatic compounds

These materials are condensates comprising aromatic and hydrocarbyl moieties. Aromatic moieties are typically aromatic hydrocarbons which may be unsubstituted or substituted, for example with non-hydrocarbon substituents.

The aromatic hydrocarbons preferably contain these substituent groups and / or three condensed rings which are most substituted, and are preferably naphthalene. Hydrocarbyl moieties are carbon and hydrogen containing moieties bound to the rest of the molecule by carbon atoms. The moiety may be saturated, unsaturated, straight chain or branched, and may contain one or more heteroatoms, provided they do not substantially affect the hydrocarbyl properties of the moiety. Preferably the hydrocarbyl moiety is for convenience an alkyl moiety having at least 8 carbon atoms, the molecular weight of the condensate may be for example in the range of 2,000 to 200,000, for example 2,000 to 20,000, preferably 2,000 to 8,000.

Examples of these are known in the art as primarily lubricant flow depressants and dewaxing aids, as described above, and can be prepared, for example, by condensing halogenated waxes with aromatic hydrocarbons. More specifically, the condensation reaction may be a Friedel-Crafts condensation reaction in which case the halogenated wax contains 15 to 60 carbon atoms, for example 16 to 50, has a melting point of about 200 to 400 ° C., 5 to Chlorinated to 25% by weight, for example 10 to 18% by weight of chlorine.

Another process for preparing similar condensates may be from olefins and aromatic hydrocarbons.

Multicomponent additive systems may be used and the proportion of additive used will vary depending on the fuel being processed.

EXAMPLE

The invention will now be specifically disclosed by way of the following examples, which are shown by way of example only.

Example 1

additive

The following additives were used:

A: Ethylene / vinyl acetate copolymer having a vinyl acetate content of about 37% by weight and a number average molecular weight of about 2,700.

B: 3: 1 (weight: weight) mixture of additive A with ethylene / vinyl acetate copolymer having a vinyl acetate content of about 13.5% by weight and a number average molecular weight of about 5,000.

C: a mixture containing the same compound as B, provided that the weight: weight ratio is 13: 1.

The number average molecular weight was measured by gas phase osmosis (VPO).

exam

Additives A, B and C are each dissolved in a sample of the same rapeseed methyl ester fuel and subjected to a low temperature filter in the manner described in detail in the Journal of the Institute of Petroleum, Volume 52, Number 510, June 1966, pp 173-285. Blockage point (CFPP) was measured. This CFPP is a measure of filterability.

The results are shown in the table below.

For control, the CFPP of the untreated fuel was -9 ° C. Thus additives A, B and C were each shown to improve the filterability of the fuel as measured by the CFPP test.

Claims (11)

(i) maleic anhydride or copolymer of fumaric acid and another ethylene unsaturated monomer capable of esterification; or Polymers or copolymers of -olefins; Or a comb polymer that is a fumarate or itaconate polymer or copolymer; (Ii) polyoxyalkylene esters, esters / ethers or mixtures thereof; (Iii) ethylene / unsaturated ester copolymers; (Iii) polar nitrogen-containing organic wax crystal growth inhibitors; (Iii) hydrocarbon polymers; (Iii) sulfur carboxy compounds; And (Iii) hydrocarbylated aromatic pour point depressants Mixtures of mineral oil cold flow additives comprising at least one of the above and an oil consisting essentially of alkyl esters of fatty acids derived from vegetable or animal oils or both, wherein the concentration of the additive in the alkyl esters of fatty acids is alkyl esters of fatty acids 1 to 1000 ppm by weight of an additive per weight of, except that it does not include a mixture of copolymers or polymeric esters of esters of acrylic acid, methacrylic acid or mixtures thereof derived from alcohols having 1 to 22 carbon atoms. The composition of claim 1 wherein said polyoxyalkylene ester, ester / ether or mixture thereof is defined by the general formula: RO- (A) -OR ² Wherein R and R ² are the same or different, And Wherein n is 1 to 30, the alkyl group is linear and saturated, and contains 10 to 30 carbon atoms, and A has a polyoxyalkyl having a molecular weight of 100 to 5,000, having an alkylene group of 1 to 4 carbon atoms Ren fragment. The amine salt of claim 1, wherein the polar nitrogen-containing organic wax crystal growth inhibitor is formed by reacting at least 1 molar ratio of hydrocarbyl substituted amine with 1 mole ratio of hydrocarbyl acid having 1 to 4 carboxylic acid groups or anhydrides thereof, Compositions that are amides or mixtures thereof. The composition of claim 1 wherein the alkyl esters of fatty acids are ethyl, propyl, butyl and methyl esters of fatty acids having 12 to 22 carbon atoms. The composition of claim 4 wherein the alkyl ester is a methyl ester of oleic acid, linoleic acid, linolenic acid, and erucic acid. The composition of claim 1 wherein the oil is rapeseed oil methyl ester. The composition of claim 1, wherein the alkyl esters of fatty acids are prepared by transesterification of animal or vegetable oils. The composition of claim 1 wherein said additive comprises an ethylene / vinyl ester copolymer (iii) or a mixture of copolymers thereof. Animal or vegetable oils, comprising mixing with an additive as defined in claim 1 which does not include copolymers or mixtures of polymeric esters of esters of acrylic acid, methacrylic acid or mixtures thereof derived from alcohols having 1 to 22 carbon atoms Or modifying the wax crystal growth properties of an oil consisting essentially of alkyl esters of fatty acids derived from both. 4. The composition of claim 3 wherein the hydrocarbyl acid is benzene dicarboxylic acid or anhydride thereof. The comb polymer (i) is a copolymer of alkyl fumarate and vinyl acetate having an alkyl group of 12 to 20 carbon atoms, or an esterified copolymer of styrene and maleic anhydride, or an ester of styrene and fumaric acid. The composition is a oxidized copolymer.