KR0134192B1 - Fuel compositions - Google Patents

Abstract

Cold flow properties are improved by adding in minor proportion by weight to a distillate fuel oil a polymer of a C1 to C17 alkyl vinyl ether. This polymer may be a homopolymer, a mixture of homopolymers, a copolymer of alkyl vinyl ethers of different alkyl chain length, a copolymer of one or more alkyl vinyl ethers with one or more copolymerisable monomers or a mixture of such copolymers. Typical copolymers are copolymers of alkyl vinyl ethers with alkyl acrylates, alkyl methacrylates, olefins, dialkyl fumarates or maleates, eg copolymers of n-butyl vinyl ether with di(n-tetradecyl) fumarate. Other polymers are copolymers of an alkyl vinyl ether with an ethylenically unsaturated carboxylic acid or anhydride, subsequently reacted with an alcohol or an amine or both, eg a copolymer of methyl vinyl ether and maleic anhydride reacted with n-tetradecanol, n-hexadecanol or a mixture of these alcohols.

Description

Fuel composition

The present invention relates to a fuel composition containing a low temperature flow improver.

Mineral oils containing paraffin waxes, such as diesel fuels and distillate fuels used as heating oils, have the property of decreasing fluidity as the oil temperature decreases. This loss of fluidity is due to the crystallization of the wax, where the wax crystallizes into plate-type crystals and eventually forms a sponge mass that sucks the oil, the temperature at which the wax crystals start to form (Cloud Point) and the wax This is due to the temperature (pour point) that impedes the flow.

It has long been known that various additives act as pour point depressants when mixed with waxy mineral oils. The compositions modify the size and shape of the wax crystals and monitor the cohesion between the crystals and the cohesion between the wax and the oil in a manner that allows the oil to remain fluid at lower temperatures to pass through a fluid and coarse filter. .

Various pour point depressants are described in the literature and some of them are commercially available. For example, US Pat. No. 3,048,479 discloses the use of copolymers of ethylene and C ₁ -C ₅ vinyl esters (eg vinyl acetate) as pour point depressants for fuels, especially heating oils, diesel and jet fuels. Hydrocarbon polymeric pour point depressants based on ethylene and higher alpha-olefins (eg propylene) are also known. U.S. Patent No. 3,252,771 relates to the use of aluminum trichloride / alkyl halide catalysts and C ₁₆ to C ₁₈ alpha-olefin polymers as pour point depressants in a wide range of boiling distillate fuels, an easy-to-use type used in the United States in the early 1960s.

GB 1154966 discloses at least one monoolefinic unsaturated having a branched saturated hydrocarbon chain of at least 18 carbon atoms as a pour point depressant for wax-containing fuels having at least 3% by weight of wax having a melting point of at least 350 ° C and a boiling point of at least 350 ° C. The use of certain polymers derived from mono olefinically unsaturated compounds that are at least partially composed of aliphatic compounds is disclosed.

UK patent 14371432 discloses blends of polymers with long side chains which are particularly useful as flow improvers for petroleum fuel oil and crude oil. In Europe in the late 1960s and early 1970s, there was a greater likelihood of improving the filterability of oil at temperatures between the cloud point (CP) and the pour point, as measured by the more stringent cold filter plugging point (CFPP) test (IP 309/80). Emphasis has been given and many patents have been filed since then on additives for improving the performance by the test. Thus, US Pat. No. 3,961,916 teaches the use of a mixture of copolymers to control the size of the wax crystals.

When operating a diesel engine at low temperatures, the wax crystals formed do not pass through the vehicle paper fuel filter but form a permeable cake that can pass liquid fuel on the filter and the wax crystals dissolve as the engine and fuel are subsequently heated ( This may be caused by the bulk fuel heated by the recycled fuel). However, the production of wax blocks the filter, causing the diesel vehicle to start at low temperatures when starting the diesel vehicle in cold weather.

These difficult problems can be substantially overcome by adding certain homopolymers or copolymers of alkyl vinyl ethers to the middle distillate fuel oil according to the invention. Unlike the compositions of UK Patent No. 1,437,132, the wax crystals are smaller and therefore the compositions of the present invention will better match the conditions of CFPP testing and diesel vehicle operability in cold weather.

According to the invention the fuel oil composition comprises a polymer (by weight) of most of the distillate fuel oil (by weight) and of hydrocarbyl vinyl ethers, wherein the hydrocarbyl groups contain 1 to 17 carbon atoms. The present invention also provides the use of polymers of hydrocarbyl vinyl ethers, wherein the hydrocarbyl groups contain 1 to 17 carbon atoms, as cold flow improvers in distillate fuel oils.

Distillate fuel oils can be, for example, diesel fuels, aircraft fuels, kerosene or jet fuels or intermediate distillate fuels such as heating oils or vacuum (processing) gas oils. In general, suitable middle distillate fuels are fuels boiling in the range of 120 ° C. to 500 ° C. (ASTM D1160), preferably fuels boiling in the range of 150 ° C. to 400 ° C., for example relatively high final boiling points of at least 340 ° C. Having fuel. Low temperature flow problems are the most common problems encountered by diesel fuels and heating oils.

Hydrocarbyl vinyl etherpolymers added to distillate fuel oils, usually polymers of alkyl vinyl ethers (hereinafter sometimes referred to as AVE), are homopolymers, mixtures of homopolymers, copolymers of hydrocarbyl vinyl ethers having different hydrocarbyl chain lengths, one Or a copolymer of more than one hydrocarbyl vinyl ether with one or more copolymerizable monomers or a mixture of such copolymers (in all cases the hydrocarbyl group has 1 to 17 carbon atoms). The term polymer of hydrocarbyl vinyl ether thus means a polymer derived from hydrocarbyl vinyl ether as one of the monomers or monomers.

The polymers are derived from hydrocarbyl vinyl ethers. Hydrocarbyl groups having 1 to 17 carbon atoms may be alkyl, alkaryl, aralkyl, aryl, alkenyl, alkynyl and the like. Examples of alkaryl are tolyl and xylyl, 4-decylphenyl in aralkyl is 2-phenyl ethyl, benzyl in aryl is naphthyl and alkenyl is pentenyl, dodecenyl, hexadecenyl, etc. have. However, the preferred hydrocarbyl group is alkyl and will now be described with respect to alkyl vinyl ethers.

Alkyl vinyl ethers are inexpensive alcohol derivatives and are reacted with alcohol and acetaldehyde and then dehydrated,

의 반응 또는 칼륨(또는 나트륨) 알콕사이드가 촉매작용하는 아세틸렌과 알콜과의 반응에 의해 얻을 수 있다.

It can be obtained by the reaction of or with acetylene and alcohol catalyzed by potassium (or sodium) alkoxide.

Alkyl vinyl ethers can be readily polymerized under cationic conditions using acidic catalysts such as, for example, SnCl ₂ , BF ₃ , Al ₂ (SO ₃ ) ₃ H ₂ SO ₄ 7H ₂ 0.

Usually, polymers, ie homopolymers or copolymers, are relatively long chain alkyls as alkyl groups of alkyl vinyl ethers for homopolymers or as part of alkyl groups and / or monomers copolymerizable with alkyl vinyl ethers for copolymers. It is preferred to derive from a monomer having a group (eg at least 12 carbon atoms).

Suitable and preferred polymers of AVE include the following:

1. Homopolymers, alkyl groups of AVE can have any chain length of C ₁ to C ₁₇ but C ₁₂ to C ₁₆ are preferred. The alkyl group is preferably straight chain but may contain a certain proportion (up to 25%) of low content of branching (eg 2- + 3-methyl substituted chain). Examples of suitable AVEs are AVE, wherein the alkyl group is n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-hepta or n-ecosyl.

2. A mixture of homopolymers of AVE, as described above in 1, for example a mixture of n-hexadecyl vinyl ether and n-tetradecyl vinyl ether.

3. Copolymers of AVEs, suitable and preferred alkyl groups in AVE are as described above in connection with homopolymers of AVE1. Very suitable copolymers are copolymers of mixtures of n-alkyl vinyl ethers in the range of 1 to 17 carbon atoms in which the alkyl group often provides an average alkyl chain length of 12 to 13 carbon atoms, for example about 12.5. . A suitable copolymer is therefore a substantially equimolar copolymer of AVEs, wherein the alkyl group is an n-alkyl group having chain lengths of 8, 10, 12, 14 and 16. Another suitable copolymer is a copolymer of short chain alkyl vinyl ethers (eg, C ₃ or C ₄ alkyl vinyl ethers) and mixed C ₁₂ to C ₁₆ n-alkyl vinyl ethers.

4. Copolymers of one or more alkyl vinyl ethers with one or more copolymerizable monomers, usually said copolymerizable monomers are unsaturated in ethylen form. Examples of such monomers include olefins or haloolefins; Dienes (eg, alkoxy butadiene); Acrylate or methacrylate esters; Acrylonitrile, maleic anhydride, maleate or fumarate esters; And allyl or vinyl substituted heterocyclic compounds (eg, allyl or vinyl pyrrole or allyl or vinyl carbazole). Alkyl vinyl ethers can be formulated with free-radical initiators (e.g., AIBN (azo-isobutyronitrile) di-t-butyl peroxide, t-butyl per-octanoate or t-butyl perbenzoate) or coordination-type catalysts. Can be copolymerized with the monomers.

In the case of the copolymer, it is preferred that there are relatively long chain alkyl groups (eg, at least 12 carbon atoms) derived from either AVE and / or copolymerizable monomers.

More specific examples are as follows:

4 (a). Long chain alkyl vinyl ethers copolymerized with short chain monomers, for example C ₁ to C ₁₀ alkyl acrylates, C ₁ to C ₁₀ alkyl methacrylates, C ₁ to C ₆ olefins or di (C ₁ to C ₁₀ alkyl) fumarates Or C ₁₂ to C ₁₆ alkyl vinyl ethers copolymerized with maleate.

Examples of C ₁₂ to C ₁₇ alkyl vinyl ethers are n-dodecyl, tetradecyl and hexadecyl vinyl ethers and examples of C ₁ to C ₁₀ alkyl acrylates and methacrylates are ethyl and n-hexylacrylates and methacryl Examples of C ₁ to C ₁₀ olefins are ethylene, propylene, 1-butene, 1-hexene, and examples of di (C ₁ to C ₁₀ alkyl) fumarate and maleate are di-methyl, large- Ethyl, di-n-butyl and di-n-octyl fumarate and maleate. Specific examples are copolymers of n-tetradecyl vinyl ether copolymerized with ethyl acrylate.

Where n is an integer

4 (b). Copolymerization with long chain monomers (e.g. di (C ₁₂ to C ₁₈ ) alkyl fumarates and maleates, C ₁₂ to C ₁₈ alkyl acrylates and methacrylates and N, N di (C ₁₂ to C ₁₈ ) alkyl acrylamides) Short-chain alkyl vinyl ethers (eg, C ₁ to C ₁₀ alkyl vinyl ethers).

Examples of short chain alkyl vinyl ethers are methyl, propyl, n- and iso-butyl and hexyl vinyl ethers, and examples of long chain dialkyl fumarates, maleates and N, N dialkyl acrylamides are di-dodecyl, terra Decyl and hexadecyl fumarates, maleates and acrylamides, and examples of C ₁₂ to C ₁₈ alkyl acrylates and methacrylates are dodecyl, hexadecyl and octadecyl acrylates and methacrylates.

Specific examples are copolymers of tetradecyl, octadecyl fumarate and ethyl vinyl ether.

Where n is an integer

The equations of the reactants and the polymers produced in the case of 4 (a) and 4 (b) are as follows:

Wherein n and m are integers, R ¹ is an alkyl group, R ² is -H or -COOR ⁴ , R ³ is -COOR ⁵ , CONR ₂ ⁶ or R ⁷ and R ⁴ , R ⁵ , R ⁶ And R ⁷ is an alkyl group)

In the case of reacting AVE with metal acrylate, the reaction is as follows:

Wherein n, R ¹ and R ⁴ are as defined above

In 4 (a) R ¹ is long chain alkyl, R ⁴ , R ⁵ , R ⁶ and R ⁷ are short chain alkyl, and in 4 (b) R ¹ is short chain alkyl, R ⁴ , R ⁵ , R ⁶ and R ⁷ is long chain alkyl.

4 (c). Copolymers of ethylenically unsaturated carboxylic acids or carboxylic anhydrides with short chain lengths of AVE (e.g., C ₁ to C ₁₀ alkyl vinyl ethers) which are subsequently reacted with alcohols or amines or both. Thus, C ₁ to C ₁₀ alkyl vinyl ethers and acrylic acid, methacrylic acid, or can be copolymerized with maleic anhydride and long chain alcohol copolymers (for example, C ₁₂ to C ₁₈ alcohols), and / or long-chain primary or secondary amine ( For example, at least one of the hydrocarbyl groups may be reacted with an amine containing at least 12 carbon atoms.

Suitable examples of short chain AVEs are given in 4 (b) above. Examples of long chain alcohols are aliphatic alcohols, R ⁸ OH, wherein R ⁸ is a C ₁₂ to C ₁₈ substituted or unsubstituted alkyl group. Suitable examples are dodecanol, tetradecanol and octadecanol. Long chain primary or secondary amines may have the general formula R ⁹ R ¹⁰ NH, wherein R ⁹ is hydrogen or an alkyl group and R ¹⁰ is an alkyl group. Examples of hydrocarbyl groups are alkyl, aralkyl or cycloalkyl groups. Alkyl, and alkyl moieties of alkaryl groups may be branched but straight chains are preferred. The alkyl group preferably contains 10 to 18, in particular 12 to 16 carbon atoms, and the alkaryl and aralkyl groups preferably contain 16 to 24 carbon atoms. Particularly preferred alkyl groups are C ₁₂ to C ₁₈ alkyl groups (eg mixtures such as detradecyl, hexadecyl, octadecyl or hexadecyl / tetradecyl).

Specific examples include the following reaction of methyl vinyl ether with maleic anhydride, followed by reaction of the copolymer with tetradecanol or dihexadecyl amine.

In general, the AVE copolymer should have a molecular weight of 1,500 to 50,000, preferably 2,500 to 15,000.

Compared to olefin copolymers where the methylene link is much less flexible than the ether linkages in the AVE polymers used in the fuel oil compositions of the present invention, the AVE polymers are wax crystals similar to, for example, poly-1-octadecene polymers. It has modifier properties but better oil solubility.

The amount of hydrocarbyl vinyl ether polymer added to the fuel oil is preferably in a small amount of 0.0001 to 5.0% by weight, for example 0.001 to 0.5% by weight (active substance) based on the weight of the fuel oil.

The hydrocarbyl vinyl ether polymer is conveniently dissolved in a suitable solvent to form a polymer concentration of 20 to 90 weight percent, such as 30 to 80 weight percent, in the solvent. Suitable solvents include kerosene, aromatic naphtha, mineral lubricants and the like.

Other additives that may be included in fuel oils with alkyl vinyl ether polymers include, for example, other flow improvers.

The flow improver may be one of the following.

(Iii) linear copolymers of ethylene with some comonomers (eg, vinyl esters, acrylates, methacrylates, olefins, styrenes, etc.);

(Ii) comb polymers, ie polymers having C ₈ -C ₃₀ alkyl side chain branches;

(Iii) linear polymers derived from ethylene oxide (eg, polyethylene glycol esters and amino derivatives thereof);

(Iii) monomeric compounds (eg, amine salts and amides of polycarboxylic acids such as citric acid and phthalic acid). Also amide / amine salts of sulfocarboxylic acids such as sulfo-benzoic acid and sulfo-succinic acid can be used.

Unsaturated comonomers capable of inducing the linear copolymer and copolymerizing with ethylene include unsaturated mono and diesters of the general formula:

In which R ² is hydrogen or methyl; R ¹ is —OOCR ⁴ group (wherein R ⁴ is hydrogen C ₁ to C ₂₈ , generally C ₁ to C ₁₇ , and preferably C ₁ to C ₈ straight or branched alkyl group) or hydrocarbyl or -COOR ⁴ group (wherein R ⁴ is as defined above but not hydrogen) and R ³ is hydrogen or —OOCR ⁴ as defined above. The monomers when R ¹ and R ³ are hydrogen and R ² is —OOCR ⁴ are C ₁ to C ₂₉ , generally C ₁ to C ₁₈ monocarboxylic acids, preferably vinyl alcohol esters of C ₂ to C ₅ monocarboxylic acids It includes. Examples of vinyl esters that can be copolymerized with ethylene include vinyl acetate, vinyl propionate and vinyl butyrate or isobutyrate, with vinyl acetate being preferred. It is preferable that the copolymer contains 20 to 40% by weight of vinyl ester, more preferably 25 to 35% by weight. The copolymers may be a mixture of two copolymers as described in US Pat. No. 3,961,916.

Other linear copolymers are derived from comonomers of the general formula: CHR ⁵ = CR ⁶ X, wherein R ⁵ is H or alkyl, R ⁶ is H or methyl, and X is -COOR ⁷ or hydro Carbyls, where R ⁷ is alkyl. The comonomers are acrylate, CH ₂ = COOR ⁷ , methacrylate, CH ₂ = CH ₂ COOR ⁷ , styrene CH ₂ = CH.C ₆ H ₅ and olefin CHR ⁵ = CR ⁶ R ⁸ , wherein R ⁸ is alkyl. Said group R ⁷ is preferably C ₁ to C ₂₈ , generally C ₁ to C ₁₇ and more preferably C ₁ to C ₈ straight or branched chain alkyl groups. In the case of olefins it is preferred that R ⁵ and R ⁶ hydrogen and R ⁸ is a C ₁ to C ₂₀ alkyl group. Thus, suitable olefins are propylene, hexene-1, olten-1, dodecene-1 and tetradecene-1.

In the case of copolymers of this type, it is preferred that the ethylene content is from 50 to 65% by weight, but in the case of ethylene-propylene copolymers it can be used in higher amounts, for example 80% by weight.

The copolymers preferably have a number average molecular weight of 1,000 to 6,000, preferably 1,000 to 3,000, as measured by vapor phase osmotic pressure measurement.

In particular, suitable linear copolymer flow modifiers are copolymers of ethylene and vinyl esters.

Vinyl esters are vinyl esters of motocarboxylic acids, such as those containing from 1 to 20 carbon atoms per molecule. Examples are vinyl acetate, vinyl propionate and vinyl butyrate. But preferred is vinyl acetate.

Usually, the copolymer of ethylene and vinyl ester is comprised in a molar ratio of 3 to 40, preferably 3 to 20, per mole ratio of vinyl ester. The copolymer usually has a number average molecular weight of 1,000 to 50,000, preferably 1,500 to 5,000. The molecular weight can be measured using the freezing point method or vapor phase osmosis characterization method, for example, the Mechrolab Vapor Phase Osmometer Model 310A.

Particularly preferred comb copolymer flow improvers are copolymers (ii) of fumaric acid ester and vinyl ester. The ester of fumaric acid may be mono- or di-ester, with alkyl esters preferred. Each alkyl group of the alkyl ester may contain 6 to 30, preferably 10 to 20 carbon atoms, with mono or di (C ₁₄ to C ₁₈ ) alkyl esters being particularly preferred as single esters or mixed esters. Di-alkyl esters are generally preferred over mono-esters.

Suitable vinyl esters that can be copolymerized with fumarate esters are the vinyl esters mentioned above in connection with ethylene / vinyl ester copolymers. Vinyl acetate is particularly preferred. The fumarate ester is preferably copolymerized with the vinyl ester in a molar ratio of 1.5: 1 to 1: 1.5, for example about 1: 1. The copolymers usually have a number average molecular weight of 1,000 to 100,000, as measured by vapor phase osmotic pressure measurement methods such as a macrobrap vapor pressure osmometer.

The comb polymer (ii) has the following general formula.

Wherein A is H, Me (methyl), CH ₂ CO ₂ R ', wherein R' is C ₁₀ -C ₂₂ alkyl, and B is CO ₂ R 'or R, wherein R = C _10- C ₃₀ alkyl), PhR '(ph = phenyl), D is H or CO ₂ R', E is H, Me or CH ₂ CO ₂ R 'and F is OCOR''' (R '''= C ₁₀ -C ₂₂ alkyl), CO ₂ R ', Ph, R' or PhR ', G is H or CO ₂ R' and n is an integer.

In general, the polymers include dialkyl fumarate / vinyl acetate copolymers (eg, ditetradecyl fumarate / vinyl copolymer); Styrene dialkyl fumarate ester copolymers (eg, styrene / dihexadecyl fumarate copolymer); Poly dialkyl fumarates (eg, poly (di octadecyl fumarate)); Alpha-olepin dialkyl maleate copolymers (eg, copolymers of tetradecene and di hexadecyl maleate); Dialkyl itaconate / vinyl acetate copolymers (eg, dihexadecyl itaconate / vinyl acetate); Poly- (n-alkyl methacrylates) (eg poly (detradecyl methacrylate)); Poly (n-alkyl acrylates) (eg poly (detradecyl acrylate)); Poly-alkenes (eg, poly (1-octadecene)) and the like.

Linear polymers derived from ethylene oxide include poly oxyalkylene esters, ethers, esters / ethers, amides / esters and mixtures thereof, in particular molecular weights of 100 to 5,000 having alkylene groups having from 1 to 4 carbon atoms, Preferably, those containing at least one, preferably at least two, C ₁₀ to C ₃₀ linear saturated alkyl groups of the poly oxyalkylene glycol group of 200 to 5,000 are included. European Patent Publication No. 0,061,985 A2 describes some of these additives. Preferred esters, ethers or esters / ethers can be represented by the formula

R-O- (A) -0-R '

Wherein R and R ¹ are the same or different and

Wherein the alkyl group is linear and saturated and contains 10 to 30 carbon atoms, and A is a polyoxyalkylene fragment of glycol, eg polyoxy, in which the alkylene group has 1 to 4 carbon atoms Methylene, polyoxyethylene or polyoxytrimethylene moieties, which are substantially linear and exhibit some degree of branching (as in the case of polyoxypropylene glycol) with lower alkyl side chains, but the glycol should be substantially linear .

Generally suitable glycols are substantially linear polyethylene glycol (PEG) and polypropylene glycol (PPG) having a molecular weight of about 100 to 5,000, preferably about 200 to 2,000. Preferred are esters and fatty acids containing 10 to 30 carbon atoms are useful for reacting with glycols to form ester additives and preference is given to using C ₁₈ -C ₂₄ fatty acids, in particular behenic acid. Esters can also be prepared by esterifying polyethoxylated fatty acids or polyethoxylated alcohols.

Examples of monomeric compounds (i) as flow improving agents are amine salts, monoamides or diamides or semiamine salts, half amides of polar nitrogen containing compounds such as dicarboxylic acids, tricarboxylic acids or their anhydrides. The polar compounds are generally formed by the reaction of at least 1 mole ratio of hydrocarbyl substituted amines and 1 mole ratio of hydrocarbyl acid with 1 to 4 carboxylic acid groups or their anhydrides; Esters / amides containing a total of 30 to 300, preferably 50 to 150 carbon atoms may also be used. Such nitrogen compounds are described in US Pat. No. 4,211,534. Suitable amines are usually long chain C ₁₂ -C ₄₀ primary, secondary, tertiary or quaternary amines or mixtures thereof, but short chain amines as long as the resulting nitrogen compounds are oil soluble and thus usually contain a total of 30 to 300 carbon atoms. May also be used. The nitrogen compound preferably contains at least one straight chain C ₈ -C ₄₀ , preferably C ₁₄ to C ₂₄ alkyl moiety.

The amine salt or semi amine salt can be derived from primary, secondary, tertiary or quaternary amines, while the amide can only be derived from primary or secondary amines. The amine is preferably an aliphatic amine, preferably a secondary amine, in particular an aliphatic secondary amine of the general formula R ₁ R ₂ NH. R ₁ and R _2, which may be the same or different, preferably contain at least 10 carbon atoms, in particular 12 to 22 carbon atoms. Examples of the amine include dodecyl amine, tetradecyl amine, octadecyl amine, eicosyl amine, cocoamine, hydrogenated resin amine, and the like. Examples of secondary amines are dioctadecyl amine, methyl-vanhenyl amine, and the like. Amine mixtures are also suitable and many amines derived from natural substances are in the form of mixtures. Preferred amines are _secondary hydrogenated resins of the general formula HNR ₁ R ₂ , wherein R ₁ and R ₂ are alkyl groups derived from hydrogenated resin fats consisting of approximately C ₁₄ 4%, C ₁₆ 31%, C ₁₈ 59% Amine.

Examples of suitable carboxylic acids (ming anhydrides thereof) for preparing the nitrogen compound include cyclone-hexane, 1,2-dicarboxylic acid, cyclohexane dicarboxylic acid, cyclopentane 1,2-dicarboxylic acid, naphthalene dicarboxylic acid, citric acid, and the like. . Generally these acids will have about 5 to 13 carbon atoms in the cyclic moiety. Preferred acids are benzene dicarboxylic acids such as phthalic acid, terephthalic acid and iso-phthalic acid. Phthalic acid or its anhydride is particularly preferred.

Examples of suitable sulfocarboxylic acids are ortho sulfo banjoic acid and mono-alkyl sulfo succinic acid.

Other suitable compounds are semiamine salts, halfamides of dicarboxylic acids, where the amine is a secondary amine. Particularly preferred are half amine salts of phthalic acid, half amide and dihydrogenated resin amine-armine 2HT (Armeen 2HT, approximately 4% by weight of nC ₁₄ alkyl, 30% by weight of nC ₁₆ alkyl, 60% by weight of nC ₁₈ alkyl, the remainder being unsaturated )to be.

Another preferred compound is a diamide produced by dehydration of the amide-amine salt.

Example 1

Methyl vinyl ether and maleic anhydride were copolymerized using a free radical catalyst to prepare a copolymer having a number average molecular weight (measured by membrane osmotic pressure measurement) of about 20,000. The anhydride group of the resulting copolymer was then esterified with n-tetradecanol, n-hexadecanol or a mixture of two alcohols. The resulting esterified copolymer was identified as C1, C2 and C3, respectively.

A copolymer (C4) of di (n-tetradecylfumarate and n-butyl vinyl ether) was prepared according to the following reaction conditions:

AINB = catalyst, t 1/2 = 25 min at 90 ° C.

0.6 g of this catalyst was added at an initial addition, followed by 0.1 g every hour for 6 hours. The reaction was detected by IR and GC to determine the free fumarate content.

이 약 2,500인 에틸렌/비닐 에세테이트 공중합체이다)와 함께 하기의 ASTM D86 증류 특성(모두 ℃)을 갖는 3개의 중간 증류 연료율 F1, F2 및 F3에 첨가했다 :Copolymers C1, C2, C3, C4 are known from the prior art copolymer (X), which contains 36% by weight of vinyl acetate units

And about 2,500 ethylene / vinyl acetate copolymers) were added to three intermediate distillate fuel ratios F1, F2 and F3 having the following ASTM D86 distillation properties (all in degrees C.):

The results of the wax appearance temperature measurements are shown in Table 1 as the temperature drop below the WAT of the fuel without the polymer additive to illustrate the efficacy of the polymers as WAT (fogging point) depressants.

Wax Appearance Temperature (WAT) was measured by differential scanning calorimetry using a Du Pont 990 differen-tial scanning calorimeter. In this test 10 ul samples of fuel were cooled to 10 ° C./min from a temperature at least 30 ° C. above the expected cloud point of the fuel. As the wax appearance temperature (WAT) was confirmed by a differential scanning calorimeter, the observed crystallization start point was evaluated without correcting the temperature paper (about 2 ° C).

The drop in wax appearance temperature WAT is expressed as ΔWAT = WAT-WAT by comparing the results of the treated fuel (WAT) with the results of the untreated fuel (WAT). The drop in WAT is expressed as a positive value.

Example 2

Copolymer C4 of Example 1 was added to three further fuel oils F4, F5 and F6 having the following ASTM D86 distillation properties (all in degrees Celsius).

Table 2 shows the results of adding C4 to F4.

Table 3 gives CFPP results of adding 4 parts by weight of prior art copolymer mixture Y and 1 part by weight of mixture Y alone to fuel oil F5 (CFPPO ° C.). Y was a 3: 1 (by weight) mixture of ethylene-vinyl acetate copolymers containing about 36% by weight of vinyl acetate having a number average molecular weight of 2500 and a copolymer containing about 17% by weight of vinyl acetate having a number average molecular weight of 3,000, respectively. .

Cold filter plugging point test (CFPPT)

The cold flow properties of the blend were measured by cold filter plugging point test (CFPPT). This test was carried out by the process described in detail in the Journal of the Institute of Petroleum, Vol 52, No 510, June 1966 pp 173-185. Briefly, 40 ml of the oil sample to be tested was cooled in a bath maintained at about -34 ° C. Tested periodically for the ability of the cooled oil to flow through the fine screen in one minute (when each 1 ° C. hardened at temperatures starting from above the cloud point 10 ° C.). This low temperature property was tested with a device consisting of a pipette with a funnel attached upside down beneath the oil surface to be tested at the bottom. A 350 mesh screen spanning about 0.45 square inches spread across the entrance of the funnel. Periodic tests are initiated by applying a vacuum of 20 cm water to the top of the pipette, whereby the oil is dropped into the pipette until the scale indicates 20 ml oil through the screen. This test is repeated with the temperature lowered by 1 ° C each until the oil fails to fill the pipette within 60 seconds. The results of the test can be illustrated by CFPP (° C.), which is the failure temperature of the fuel treated with the flow improver.

In this case the difference between the failure temperature of the untreated fuel CFPP and the failure temperature of the fuel treated with the additive CFPP is illustrated by ΔCFPP (° C.) (ie, ΔCFPP = CFPPCFPP).

Table 4 shows the results of adding different amounts of copolymer C4, copolymer X of the prior art and cloud point depressant additive Z of the prior art to fuel oil F6. Z is a Cdialkyl fumarate / vinyl acetate copolymer.

The unit is ℃.

Parentheses result from Cdialkyl fumarate / vinyl acetate copolymer, 2.

Table 4 shows that the WAP, CP and WAT drops by C4 alone or in the fuel with X were the same as with Z. In case of the addition of C4 in the X case, the pour point is improved, whereas in the case of Z, the pour point returns. This result is confirmed by the slow cooling test in which the sample is cooled from room temperature to -25 ° C in a cold box. Here Z / X 1000/100 ppm ai provides a gelled sample while C4 / X1000 / 100 ppm ai provides a completely fluid sample.

Claims (9)

Most of the middle distillate fuel oil boiling in the range of 120 to 500 ° C. (by weight) and (I) copolymers of C ₁₂ to C ₁₇ alkyl vinyl ethers and C ₁ to C ₁₀ alkyl vinyl ethers and (II) (a) C ₂ To C ₁₀ olefins or copolymers of C ₁ to C ₁₀ alkyl acrylates, methacrylates, dimaleates or difumarates with C ₁₂ to C ₁₇ alkyl vinyl ethers, (b) C ₁₂ to C ₁₈ alkyl acrylates , A copolymer of methacrylate, N, N-dialkyl acrylamide, dimaleate or difumarate with C ₁ to C ₁₀ alkyl vinyl ethers and (c) after copolymerization with ethylenically unsaturated carboxylic acids or carboxylic anhydrides, or two C ₁₂ to C ₁₈ alkyl group or one or two C ₁₆ to C ₂₄ are first class containing alkyl group or secondary alkyl or aralkyl amine C ₁₂ to C ₁₈ alkyl alcohol or a double one and reacting C ₁ to To C _{1 0} alkyl vinyl small additive comprising a copolymer of an alkyl vinyl ether selected from the copolymerization weight of the ether (by weight) Low temperature flow properties are improved fuel oil composition comprising a. The composition of claim 1 wherein the copolymer is a copolymer of C ₁ to C ₄ alkyl vinyl ethers with di (C ₁₄ to C ₁₆ ) maleate or fumarate. The process according to claim 1 or 2, wherein the additive comprises: (i) a copolymer of ethylene and vinyl ester, (ii) a comb polymer having C ₈ to C ₃₀ alkyl side chains, (iii) C ₁₈ to C _Up to 80% by weight of one or more additional flow improvers selected from polyethylene glycol esters of ₂₄ fatty acids and (iv) amide or amine salts of polycarboxylic acids or sulfocarboxylic acids with one or two C ₁₄ to C ₂₄ alkyl fragments Composition. The composition of claim 2 wherein the additive comprises 10 to 20 weight percent of ethylene vinyl acetate copolymer. The composition of claim 1 wherein said additive is present in an amount to provide 0.001 to 0.5 weight percent alkyl vinyl ether copolymer by weight with fuel oil. (I) a copolymer of C ₁₂ to C ₁₇ alkyl vinyl ether and C ₁ to C ₁₀ alkyl vinyl ether and (II) (a) C ₂ to C ₁₀ olefin in middle distillate fuel oil boiling in the range of 120 to 500 ° C, Copolymers of C ₁ to C ₁₀ alkyl acrylates, methacrylates, dimaliates or difumarates with C ₁₂ to C ₁₇ alkyl vinyl ethers, (b) C ₁₂ to C ₁₈ alkyl acrylates, methacrylates, N A copolymer of N-dialkyl acrylamide, dimariate or difumarate with C ₁ to C ₁₀ alkyl vinyl ethers and (c) one or two C ₁₂ to C copolymerized with an ethylenically unsaturated carboxylic acid or carboxyl anhydride C ₁ to C ₁₀ alkyl vinyl reacting with primary or secondary alkyl or aralkyl amines containing ₁₈ alkyl groups or one or two C ₁₆ to C ₂₄ aralkyl groups and C ₁₂ to C ₁₈ alkylalcohols or one of them ether Use as a cold flow improver additive comprising a copolymer of an alkyl vinyl ether selected from the copolymers. 7. Use according to claim 6, wherein the copolymer is a copolymer of C ₁ to C ₄ alkyl vinyl ethers with di (C ₁₄ to C ₁₆ ) maleate or fumarate. 8. The composition of claim 6, wherein the additive is selected from (i) a copolymer of ethylene cla vinyl ether, (ii) a comb polymer having a C ₈ to C ₃₀ alkyl side chain, and (iii) a C ₁₈ to C ₂₄ fatty acid. Polyethylene glycol ester, and (iv) up to 80% by weight of one or more additional flow improvers selected from amide or amine salts of polycarboxylic acids or sulfocarboxylic acids with one or two C ₁₄ to C ₂₄ alkyl fragments. 8. Use according to claim 7, wherein the additive comprises 10 to 20% by weight of ethylene vinyl acetate copolymer.