KR101352753B1 - Additive for oil compositions - Google Patents

Abstract

The present invention relates to an additive composition comprising at least one polyoxyalkylene compound, and at least one ethylene polymer, wherein the at least one ethylene polymer is in addition to units derived from ethylene, units of formula (I), and optionally Contains units of two. The compositions of the present invention are particularly suitable for improving the low temperature properties of fuels having a sharp distillation tail and a low boiling point:

Where

Each R ¹ group independently represents hydrogen or methyl,

Each R ² group independently represents an alkyl group having 5 or more carbon atoms,

Each R ³ group independently represents hydrogen or methyl,

Each R ⁴ group independently represents an alkyl group having 1 to 4 carbon atoms,

In this case, the ratio of the units of formula 1 in the ethylene polymer is 16 to 30 mol%, and the total ratio of the units of formulas 1 and 2 in the ethylene polymer is 19 to 30 mol%.

Description

Additive for oil composition {ADDITIVE FOR OIL COMPOSITIONS}

The present invention relates to additives for oil compositions, mainly additives for fuel oil compositions, and more specifically additives for fuel oil compositions that are susceptible to wax formation at low temperatures.

Fuel oils derived from petroleum or vegetable sources are n-alkanes or methyl n-al, which tend to precipitate as large plate-shaped crystals or spherical waxes in a manner that forms a gel structure that loses the flow ability of the fuel at low temperatures. Contains ingredients such as decanoate. The lowest temperature at which the fuel still flows is known as the pour point.

As the temperature of the fuel reaches and approaches the pour point, difficulties arise in transporting the fuel through lines and pumps. In addition, wax crystals tend to plug fuel lines, screens, and filters at temperatures above the pour point. This problem is widely recognized in the art, and various additives have been proposed for lowering the pour point of fuel oil, most of which are commercially available. Similarly, other additives have been proposed, which are commercially available for reducing the size and changing the shape of the wax crystals formed. Smaller size crystals are preferred because they cause the filter to clog less. Wax from diesel fuel, which is primarily alkanes wax, is crystallized as small plates, with certain additives inhibiting this crystallization to give the wax needle-like properties, and the resulting needle passes through the filter better than the small plates. Or it will readily form a porous crystal layer on the filter. In addition, the additives have the effect of maintaining the wax crystals in suspension in the fuel, reducing sedimentation and preventing clogging.

Effective wax crystal modification (measured by cold filter plugging point (CFPP) and other operability tests as well as by simulation and in-situ implementation) can be achieved by ethylene-vinyl acetate (EVAC) or propionate copolymer-based flow improvers. Can be.

British Patent Nos. 1,086,036, European Patents A 527,322 and A 518,406 are lattice for coatings formed by copolymerizing ethylene with another ester monomer, which may be vinyl esters of tertiary or quaternary aliphatic carboxylic acids and vinyl acetate. Ternary interpolymers suitable for the present invention are described.

British Patent 1,314,855 describes ternary interpolymers of ethylene, vinyl acetate and long chain carboxylic acids which may be saturated carboxylic acids having from 8 to 30 carbon atoms. Such ternary interpolymers are described as useful in lubricating oils as viscosity index improvers.

British Patent No. 1,244,512 describes ternary interpolymers of ethylene, vinyl esters of C ₂ to C ₄ monocarboxylic acids, and small amounts of unsaturated esters (preferably of the formula below) having C ₁₀ to C ₂₂ alkyl groups:

Where

X is hydrogen or methyl group,

Y is OOCR or -COOR,

Wherein R is preferably a C ₁₀ to C ₁₆ straight or branched alkyl group.

International Patent No. 96/07718 discloses oil-soluble ethylene terpolymers containing ethylene units and different vinyl ester units, and their use as additives to improve the low temperature flow properties of fuel oil compositions. have. Examples 1-4 of the polymers are ethylene-vinyl acetate-vinyl 2-ethyl hexanoate terpolymers having not only two unsaturated esters in various proportions but also different number average molecular weight and branching properties.

The polymer of International Patent No. 96/07718 is an effective low temperature flow improver and has the advantage that it can be prepared from commercially available vinyl ester monomers.

EP 0 061 895 describes polyoxyalkylene compounds such as polyoxyalkylene esters and ethers which are useful as flow improvers for distillate fuels. It can be used with EVA polymers.

EP 1 007 606 describes the use of ethylene / vinyl ester copolymers and ternary interpolymers as flow improvers for distillate fuels. It may be combined with a polyoxyalkylene compound as described in EP 0 061 895. The ethylene vinyl ester copolymer of EP 1 007 606 has a maximum vinyl ester content of which 18 mole%, some of which are vinyl acetate.

Although the flow improvers described above are very effective, Applicants have found that their effectiveness decreases when used in certain types of fuels. In particular, Applicants note that ethylene / vinyl ester polymers and polyoxyalkyls having a higher proportion of higher vinyl esters than vinyl acetate when using fuels with sharp distillation tails and low boiling points It has been found that the combination of lene compounds results in improved performance.

Accordingly, according to a first aspect the present invention provides an additive composition comprising at least one polyoxyalkylene compound, and at least one ethylene polymer, wherein the at least one ethylene polymer is in addition to units derived from ethylene, Units, and optionally units of formula (II):

Formula 1

(2)

Where

Each R ¹ group independently represents hydrogen or methyl,

Each R ² group independently represents an alkyl group having 5 or more carbon atoms,

Each R ³ group independently represents hydrogen or methyl,

Each R ⁴ group independently represents an alkyl group having 1 to 4 carbon atoms,

In this case, the ratio of the units of formula 1 in the ethylene polymer is 16 to 30 mol%, and the total ratio of the units of formulas 1 and 2 in the ethylene polymer is 19 to 30 mol%.

Preferably, the proportion of units of formula 1 in the ethylene polymer is 18 to 30 mol%, more preferably 20 to 30 mol%, such as 22 to 28 mol%.

Preferably, the total proportion of units of formulas (1) and (2) in the ethylene polymer is 20 to 30 mole percent, more preferably 22 to 28 mole percent. For the avoidance of doubt, it is evident that the present invention includes embodiments in which the ethylene polymer contains no units of formula (2). The proportion of units of Formula 1 and Formula 2 in the ethylene polymer has proven to be important. Inferior performance has been found when the total proportion of units of Formula 1 and Formula 2 in the ethylene polymer is above or below the preferred range. In addition, too low proportions of units of formula (1) have proven disadvantageous.

Preferably, R ² represents a branched alkyl group having 7 to 15 carbon atoms. Particular preference is given to units derived from monomers such as 2-ethylhexanoate, vinyl neodecanoate and tripropene (eg iso-nonyl).

Advantageously, R ¹ and R ³ are both hydrogen.

The polymer has two or more different repeating monomer units (ie can be derived from two or more different monomers). When units of formula 2 are included, the polymer has three or more different repeating monomer units. Also included are polymers that can be derived from four or more monomers. For example, the polymer may contain two or more different units of Formula 1 or 2 and / or may contain units of Formula 3:

Where

R ⁵ represents a hydrocarbyl group having at least 5 carbon atoms different from that defined by R ⁴ .

As used herein, the term “hydrocarbyl” refers to a group having a carbon atom directly attached to the residue of the molecule, having a hydrocarbon or being primarily hydrocarbonic. Of these, mention may be made of hydrocarbon groups comprising aliphatic (eg alkyl), cycloaliphatic (eg cycloalkyl), aromatic, aliphatic and cycloaliphatic-substituted aromatics, and aromatic-substituted aliphatic and cycloaliphatic groups. Advantageously, aliphatic groups are saturated. The groups may contain non-hydrocarbon substituents, provided their presence does not alter the major hydrocarbon properties of the group. Examples thereof include keto, halo, nitro, cyano, alkoxy and acyl. If the hydrocarbyl group is substituted, a single (mono) substituent is preferred. Examples of substituted hydrocarbyl groups include 2-ketopropyl, ethoxyethyl, and propoxypropyl. The group may additionally or alternatively contain atoms other than carbon in a chain or ring consisting of carbon atoms. For example, suitable heteroatoms include nitrogen, sulfur, and preferably oxygen. Advantageously, the hydrocarbyl group contains up to 30, preferably up to 15, more preferably up to 10, and most preferably up to 8 carbon atoms.

In addition, the polymer may contain units of the formula other than those mentioned above, such as units of the formula 4 or 5:

Where

R ⁶ represents -OH,

Each R ⁷ and R ⁸ independently represents hydrogen or an alkyl group having up to 4 carbon atoms, and the units of formula 5 are advantageously isobutylene, 2-methylbut-2-ene or 2-methylpent- Derived from 2-ene.

Preferably, the number average molecular weight (Mn) of the at least one ethylene polymer is in the range of 3,000 to 8,000, more preferably 4,000 to 8,000, most preferably 4,000 to 7,000. In the context of the present invention, Mn is referred to the value measured by GPC compared to the polystyrene standard.

Preferably, the degree of branching of one or more ethylene polymers is 2 to 5, more preferably 2 to 4, such as 2 to 3.5, methyl groups per 100 methylene units. The degree of branching of the polymer is measured by NMR and is the number of methyl groups per 100 methylene units when corrected for the number of methyl and methylene groups of the R ² group. The branching calculation is for example referenced with reference to FIG. 1 and its specification in European Patent No. 1 007 606. Details of the conditions used for NMR measurements of the degree of branching of ethylene polymers will be known to those skilled in the art. For example, the skilled person knows that NMR spectra of inferior resolution should be avoided and appropriate conditions selected. In general, NMR spectra obtained from high frequency NMR instruments will be preferred. Selecting a suitable NMR solvent will ensure all good signal resolution and will minimize interference between the signal from the solvent and the signal from the polymer. Applicants have found that the spectrum obtained at about 40 ° C. from an NMR instrument running at 400Mhz and above using deuterated chloroform solvent is suitable. If desired, both ¹ H NMR and ¹³ C NMR experiments can be used.

Also provided within the scope of the present invention are compositions comprising a mixture of two or more polymers according to the first aspect of the present invention.

Preferably, the at least one polyoxyalkylene compound comprises polyoxyalkylene esters, polyoxyalkylene ethers, mixed polyoxyalkylene esters / ethers or mixtures thereof.

Particular preference is given to polyoxyalkylene compounds which contain at least one, preferably at least two C ₁₀ to C ₃₀ linear alkyl groups, and polyoxyalkylene glycol groups having a molecular weight of up to 5,000, preferably from 200 to 5,000 The alkylene group in the polyoxyalkylene glycol contains 1 to 4 carbon atoms. This material is the subject of European Patent A 0 061 895. Other such additives are described in US Pat. No. 4,491,455.

Preferred esters, ethers or esters / ethers are compounds of the general formula:

R ³¹ -O- (D) -OR ³²

Where

R ³¹ and R ³² are the same or different and (a) n-alkyl-, (b) n-alkyl-CO-, (c) n-alkyl-O-CO (CH ₂ ) _x -or (d) n -Alkyl-O-CO (CH ₂ ) _x -CO-, where x is for example 1 to 30; the alkyl group is linear and contains 10 to 30 carbon atoms, and D is an alkylene group 1 to Polyalkylene segments of glycols having four carbon atoms such as polyoxymethylene, polyoxyethylene or polyoxytrimethylene moieties that are substantially linear. There may be some branching of lower alkyl side chains (eg side chains in polyoxypropylene glycol), but the glycols are preferably substantially linear. In addition, D may contain nitrogen.

Examples of suitable glycols are substantially linear polyethylene glycol (PEG) and polypropylene glycol (PPG) having a molecular weight of 100 to 5,000, preferably 200 to 2,000. In order to form ester additives by reaction with glycols, esters are preferred, fatty acids containing 10 to 30 carbon atoms are useful, with the use of C ₁₈ -C ₂₄ fatty acids, in particular behenic acid. Esters can also be prepared by esterifying polyethoxylated fatty acids or polyethoxylated alcohols.

Where trace amounts of monoethers and monoesters, which are often formed during the manufacturing process, are also present, polyoxyalkylene diesters, diesters, ethers / esters and mixtures thereof are suitable as additives and diesters Preferred for use in narrow boiling distillates. It is preferred that large amounts of dialkyl compounds are present. In particular, stearic or behenic acid diesters of polyethylene glycol, polypropylene glycol or polyethylene / polypropylene glycol mixtures are preferred.

Other examples of polyoxyalkylene compounds are the materials described in Japanese Patent Laid-Open Nos. 2-51477 and 3-34790, and the esterified alkoxylated amines described in European Patents A 117,108 and A 326,356.

Preferably, the ratio of polyoxyalkylene compound content to ethylene polymer content in the additive composition is 1:99 to 99: 1, more preferably 1:10 to 10: 1, such as 1: 2 or 1: 1. .

In a preferred embodiment, the additive composition further comprises a comb polymer. This further improves the cold flow performance measured by CFPP.

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

In general, comb polymers generally have 10 to 30 carbon atoms and have one or more long-chain hydrocarbyl branches, such as oxyhydrocarbyl branches, pendant from the polymer backbone, wherein the branch is directly or indirectly to the backbone. Combined. Examples of indirect bonds include bonds via inserted atoms or groups, which can include ionic bonds such as in covalent bonds and / or salts.

Advantageously, the comb polymer has at least 25 mol%, preferably at least 40 mol%, more preferably at least 50 mol% of units having side chains containing at least 6 atoms, preferably at least 10 atoms. Homopolymers or copolymers.

As examples of preferred comb polymers, compounds such as the following general formula may be mentioned:

Where

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 , COOH or aryl,

R ¹¹ is C ₁₀ or more hydrocarbyl,

R ¹² is C ₁ or more hydrocarbyl or hydrocarbylene,

m and n represent mole fractions, m being finite, preferably in the range of 1.0 to 0.4, and n being less than 1, preferably in the range of 0 to 0.6. Advantageously, R ¹¹ represents a hydrocarbyl group having 10 to 30 carbon atoms, while R ¹² advantageously represents a hydrocarbyl or hydrocarbylene group having 1 to 30 carbon atoms.

Comb polymers may contain units derived from other monomers, if desired or desired.

The comb polymer may be a copolymer of maleic anhydride or fumaric acid or itaconic acid with another ethylenically unsaturated monomer (e.g., α-olefins including styrene) or unsaturated esters (e.g. vinyl acetate), or fumaric acid or ita Homopolymers of choric acid. It is preferred, but not necessary, to use equimolar amounts of comonomers, and molar ratios in the range of 2 to 1 and 1 to 2 are also suitable. For example, examples of the olefins that can be copolymerized with maleic anhydride include 1-dekene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene.

The acid or anhydride groups of the comb polymer can be esterified by any suitable technique, although it is preferred but not essential that maleic anhydride or fumaric acid be at least 50% esterified. Examples of alcohols that can be used are n-decane-1-ol, n-dodecane-1-ol, n-tedecane-1-ol, n-hexadecane-1-ol and n-octadecane-1-ol It includes. The alcohol may also comprise up to one methyl branch per chain (eg 1-methylpentadecan-1-ol or 2-methyltridecan-1-ol). The alcohol can be a mixture of normal and single methyl branched alcohol. Preference is given to using pure alcohols rather than commercially available alcohol mixtures, but if mixtures are used, R ¹² refers to the average number of carbon atoms in the alkyl group, and if alcohols containing branches in the 1 or 2 position are used, , R ¹² refers to a straight chain backbone segment of the alcohol.

In particular, the comb polymers can be fumarate or itaconate polymers and copolymers such as those described in European Patents A 153176, A 153177, A 225688 and International Patent No. 91/16407.

Particularly preferred fumarate comb polymers are copolymers of alkyl fumarate and vinyl acetate, for example prepared by solution copolymerizing a mixture of equimolar fumarate esters and vinyl acetate, wherein the alkyl group has 10 to 20 carbon atoms, more In particular the alkyl group in the polymer has 12 carbon atoms, or the alkyl group is a mixture of C ₁₂ / C ₁₄ alkyl groups. If a mixture is used, it is advantageously a mixture of normal C ₁₂ and C ₁₄ alcohols of 1: 1 (by weight). In addition, mixtures of mixed C ₁₂ / C ₁₄ esters and C ₁₂ esters may be advantageously used. In the mixture, the ratio of C ₁₂ to C ₁₂ / C ₁₄ is advantageously from 1: 1 to 4: 1 (by weight), preferably from 2: 1 to 7: 2 (by weight), most preferably It is in the range of about 3: 1 (by weight). Particularly preferred comb polymers are those having a number average molecular weight of 1,000 to 100,000, more particularly 1,000 to 30,000 as measured by vapor phase osmotic pressure measurement.

Other suitable comb polymers are polymers and copolymers of α-olefins, and esterified copolymers of styrene and maleic anhydride, and esterified copolymers of styrene and fumaric acid, and mixtures of two or more comb polymers It can be used according to the invention, and as shown above this use can be advantageous. Another example of a comb polymer is a hydrocarbon polymer, such as a copolymer of ethylene and one or more α-olefins, wherein the α-olefins preferably have up to 20 carbon atoms, examples of which are n-deken-1 and n- There is Dodeken-1. Preferably, the number average molecular weight of the copolymer is at least 30,000 as measured by GPC. Hydrocarbon copolymers can be prepared using methods known in the art, such as using catalysts of the Ziegler type.

Preferably, the ratio of comb polymer content to ethylene polymer content in the additive composition ranges from 1:99 to 99: 1, more preferably 1:10 to 10: 1, such as 1: 1.

Preferably, the ratio of comb polymer content to polyoxyalkylene compound content in the additive composition ranges from 1:99 to 99: 1, more preferably 1:10 to 10: 1, such as 1: 1.

According to a second aspect, the present invention provides an additive additive composition comprising the additive composition of the first aspect and a mutually compatible solvent therefor.

According to a third aspect, the present invention provides an oil composition comprising an oil and a trace amount of the composition of the first or second aspect.

According to a fourth aspect, the present invention provides the use of the composition of the first or second aspect for improving the low temperature properties of the oil.

According to a fifth aspect, the present invention provides a method for improving the low temperature properties of an oil comprising adding the composition of the first or second aspect to the oil.

A further advantageous feature of the additive composition of the present invention is their effect on the pour point of the fuel. When polyoxyalkylene compounds are used alone, there is generally little effect on the pour point of the fuel oil. The ethylene polymers defined in connection with the first aspect of the present invention, when used alone, can significantly reduce the pour point of fuel oil, but the combination of the two types has been observed to lead to particularly good pour point reductions. Thus, the composition defined in connection with the first aspect of the present invention is effective to simultaneously reduce the measured CFPP and pour point. The addition of comb polymers increases the CFPP performance described above, while maintaining good pour point reduction benefits.

Preferably, the oil is a fuel oil, such as a petroleum based fuel oil, in particular an intermediate distillate fuel oil. The distillate fuel oil is generally boiled in the range of 110 to 500 ° C, such as 150 to 400 ° C. The fuel oil may comprise a blend of any proportion of distillate or vacuum distillate under atmosphere, cracked gas oil or straight run and thermally and / or catalytically cracked distillate. The most common petroleum distillate fuels are kerosene, jet fuel, diesel fuel, heating oil and heavy fuel oil. The heating oil may be a direct current distillate under atmosphere or may contain a vacuum gas oil or cracked gas oil or traces of both, such as up to 35% by weight. The above-mentioned low temperature flow problem is most frequently caused by the use of diesel fuel and heating oil. The invention can also be used in vegetable fuel oils such as rapeseed oil methyl ester (RME), used alone or in combination with petroleum distillate oil.

Other examples of fuel oils include Fischer-Tropsch fuel. Fischer-Tropsch fuels, also known as FT fuels, include those described as gas-to-liquid (GTL) fuels and coal conversion fuels. To prepare the fuel, syngas (CO + H ₂ ) is first generated and then converted to normal paraffins by the Fischer-Tropsch method. The normal paraffins can then be modified by methods such as catalytic cracking / reforming or isomerization, hydrocracking and hydroisomerization to obtain various hydrocarbons such as isoparaffins, cyclo-paraffins and aromatic compounds. . The resulting FT fuel can be used as above or in combination with other fuel components and fuel types as mentioned in the specification of the present invention.

Preferably, the fuel oil has a sulfur content of at most 0.2% by weight, in particular at most 0.05% by weight. Fuels with very low sulfur concentrations are also suitable, for example, fuels with sulfur of less than 50 ppm, preferably less than 20 ppm, such as 10 ppm or less.

Additives of the present invention are particularly suitable for use in fuels with sharp distillation tails and low species point (FBP). The fuel may be characterized as having an FBP-90% distillation of 30 ° C. or less, such as 25-20 ° C., and an FBP of 370 ° C. or less, such as less than 360 ° C. FBP-90% distillation refers to the difference between FBP and the temperature at which 90% of the volume of the fuel is distilled. Examples of this type of fuel are diesel fuels of Nordic heating oil and Japan's narrow cut ultra low sulfur content.

Alternatively, the oil may be a lubricating oil, which may be animal, vegetable or mineral oil, such as naphtha or spindle oil to petroleum oil fraction, castor oil, fish oil or oxidized mineral oil in the SAE 30, 40 or 50 lubricant grade range. Can be.

The oil may contain additives depending on the intended use. Examples thereof include viscosity index improvers such as ethylene-propylene copolymers, succinic acid based dispersants, metal containing dispersion additives and zinc dialkyldithiophosphate antiwear additives.

The additive composition may also include additional cold flow improvers.

(여기서, R¹³은 8 내지 40개의 원자를 함유하는 하이드로카빌 기를 나타낸다)의 치환기를 지닌 유용성 극성 질소 화합물로, 이때 치환기 또는 하나 이상의 치환기는 이들로부터 유도된 양이온 형태일 수 있다. 일반적으로, 유용성 극성 질소 화합물은 연료에서 왁스 결정 성장 억제제로서 작용할 수 있는 것이다. 예를 들어, 이는 하나 이상의 하기 화합물을 포함한다:Other additives for improving low temperature properties include polar nitrogen compounds. The compound is at least one, preferably at least two formulas

An oil soluble polar nitrogen compound having a substituent of wherein R ¹³ represents a hydrocarbyl group containing 8 to 40 atoms, wherein the substituent or one or more substituents may be in cation form derived from them. Generally, oil soluble polar nitrogen compounds are those that can act as wax crystal growth inhibitors in fuels. For example, it includes one or more of the following compounds:

The amine salts and / or amides formed by reacting at least one hydrocarbyl-substituted amine with a mole ratio of hydrocarbyl acid having 1 to 4 carboxylic acid groups or anhydrides thereof, wherein the amine salts and / or amides Formula -NR ¹³ R ¹⁴ wherein R ¹³ is as defined above and R ¹⁴ represents hydrogen or R ¹³ , provided that R ¹³ and R ¹⁴ may be the same or different and wherein the substituents Amine salts and / or a part of an amide group).

Ester / amides containing from 30 to 300, preferably from 50 to 150, total carbon atoms can be used. Such nitrogen compounds are described in US Pat. No. 4,211,534. Suitable amines are mainly C ₁₂ to C ₄₀ primary, secondary, tertiary or quaternary amines or mixtures thereof, but shorter chain amines may be used, provided that the resulting nitrogen compounds are useful, generally about 30 To 300 total carbon atoms. Preferably, the nitrogen compound contains at least one straight alkyl group of C ₈ to C ₄₀ , preferably C ₁₄ to C ₂₄ .

Suitable amines include primary, secondary, tertiary or quaternary, but are preferably secondary. Only tertiary and quaternary amines form amine salts. Examples of amines include tetradecylamine, cocoamine and hydrogenated tallow amine. Examples of secondary amines include dioctacedyl amine and methylbehenyl amine. Also suitable as amine mixtures are materials such as those derived from natural materials. Preferred amines are secondary hydrogenated tallow amines whose alkyl groups are derived from hydrogenated tallow fat consisting of about 4% C ₁₄ , 31% C ₁₆ , and 59% C ₁₈ .

Examples of suitable carboxylic acids and their anhydrides for preparing nitrogen compounds are ethylenediamine tetraacetic acid, and cyclic skeletal carboxylic acids such as cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane 1,2-dicarboxylic acid and naphthalene dicarboxylic acid, and 1,4-dicarboxylic acid including dialkyl spirobilaclactone. Generally, the acid has 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 and its anhydride are particularly preferred. Particularly preferred compounds are amide-amine salts formed by reacting 1 mole ratio of phthalic anhydride with 2 mole ratio of dihydrogenated tallow amine. Another preferred compound is a diamide formed by dehydrating the amide-amine salt.

Other examples are long-chain alkyl or alkylene substituted dicarboxylic acid derivatives, such as amine salts of monoamides of substituted succinic acids, examples of which are known in the art and described, for example, in US Pat. No. 4,147,520. Suitable amines may be those described above.

For example, another example is the condensate described in European Patent A 327423.

Further additives for improving low temperature properties are compounds containing a cyclic ring system having two or more substituents of the following general formula on the ring system:

-AN R ¹⁵ R ¹⁶

Where

A is a linear or branched chain aliphatic hydrocarbylene group, optionally with one or more heteroatoms interrupted, R ¹⁵ and R ¹⁶ are the same or different, each independently 9 to 40 atoms, with one or more heteroatoms optionally interrupted Hydrocarbyl groups, wherein the substituents are the same or different and the compound is optionally in salt form thereof. Advantageously, A has 1 to 20 carbon atoms and is preferably a methylene or polymethylene group. Such compounds are described in International Patent No. 93/04148.

Hydrocarbon polymers are also suitable. Examples thereof are compounds of the general formula:

Where

T is H or R ²¹ ,

R ²¹ is C ₁ to C ₄₀ hydrocarbyl,

U is H, T or aryl,

v and w represent mole fractions, where v is in the range from 1.0 to 0.0 and w is in the range from 0.0 to 1.0.

Hydrocarbon polymers can be prepared directly from monoethylenically unsaturated monomers or indirectly by hydrogenating polymers from polyunsaturated monomers such as isoprene and butadiene.

Examples of hydrocarbon polymers are disclosed in International Patent No. 91/11488.

Preferred copolymers are ethylene α-olefin copolymers having a number average molecular weight of at least 30,000. Preferably, the α-olefin has up to 28 carbon atoms. Examples of such olefins are propylene, butene, isobutene, n-octene-1, isooctene-1, n-deken-1 and n-dodeken-1. In addition, the copolymer may comprise small amounts (eg, up to 10% by weight) of other copolymerizable monomers such as α-olefins and other olefins, and non-conjugated dienes. Preferred copolymers are ethylene-propylene copolymers.

As indicated above, the number average molecular weight of the ethylene α-olefin copolymer is preferably at least 30,000, advantageously at least 60,000 and preferably at least 80,000 as measured by gel permeation chromatography (GPC) compared to the polystyrene standard. to be. There is no upper limit functionally, but at molecular weights above about 150,000, difficulty in mixing occurs due to the increased viscosity, so preferred molecular weights are 60,000 and 80,000 to 120,000.

Advantageously, the copolymer has an ethylene molar content of 50 to 85%. More advantageously, the ethylene content is in the range of 57 to 80%, and preferably 58 to 73%, more preferably 62 to 71%, and 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 of 60,000 to 120,000. Particularly preferred copolymers are ethylene-propylene copolymers having an ethylene content of 62 to 71% and a molecular weight of 80,000 to 100,000.

The copolymer can be prepared using any method known in the art, such as using a Ziegler type of catalyst. Since the high crystalline polymer is relatively insoluble in fuel oil at low temperatures, the polymer is substantially amorphous.

Other suitable hydrocarbon polymers include low molecular weight ethylene-α-olefin copolymers having a number average molecular weight of preferably 7,500 or less, more preferably 1,000 to 6,000, such as 2,000 to 5,000, as measured by vapor phase osmotic pressure measurement. . Suitable α-olefins are as given above, or styrene, with propylene being preferred. Advantageously, the ethylene content is from 60 to 77 mole percent, but up to 86% by weight ethylene can be advantageously used in the case of ethylene-propylene copolymers.

Most preferably, the hydrocarbon polymer is at least one crystallizable block, which may be prepared by end-to-end polymerization of linear dienes, and the polymerization, branching of 1,2-arrays of linear dienes It may be an oil-soluble hydrogenated block diene polymer comprising one or more non-crystallizable blocks that may be prepared by polymerization of dienes, or a combination of the above polymerizations.

Advantageously, the block copolymer prior to hydrogenation comprises only units derived from butadiene, or units derived from butadiene and one or more comonomers of the formula:

Where

R ²² represents a C ₁ to C ₈ alkyl group and R ²³ represents hydrogen or a C ₁ to C ₈ alkyl group. Advantageously, the total number of carbon atoms in the comonomer is 5 to 8 and the comonomer is advantageously isoprene. Advantageously, the comonomer contains at least 10% by weight of units derived from butadiene.

In general, the crystallizable block or blocks may be hydrogenated products of units primarily resulting from 1,4- or end-to-end polymerization of butadiene, while the non-crystallized block or blocks may be 1,2-polymerization of butadiene. Or a hydrogenation product of units resulting from 1,4-polymerization of alkyl-substituted butadienes.

Additive Concentrate (Second Aspect of the Invention)

Advantageously, the additive additive concentrate according to the invention contains from 3 to 75%, preferably from 10 to 65% of the additive composition in an oil or a solvent that can be miscible with the oil.

Concentrates comprising additives mixed with suitable solvents are convenient as a means of incorporating the additives into bulk oils, such as distillate fuels (which can be carried out by methods known in the art). In addition, the concentrate may contain other additives as required, preferably 3 to 75% by weight, more preferably 3 to 60% by weight, most preferably 10 to 50% by weight, preferably oil Contains additives. Examples of solvents include hydrocarbon solvents such as petroleum fractions such as naphtha, kerosene, diesel and heating oils; Aromatic hydrocarbons such as aromatic fractions, such as those sold under the trade name “SOLVESSO”; Alcohols and / or esters; And paraffinic hydrocarbons such as hexane and pentane and isoparaffin. Of course, the solvent should be chosen to be compatible with the additive and the oil.

Oil Composition (Third Aspect of the Invention)

Advantageously, the oil composition of the present invention comprises the additive composition of the present invention in a proportion of 0.0005 to 1% by weight, advantageously 0.001 to 0.1% by weight, and preferably 0.01 to 0.06% by weight, based on the weight of the oil. It contains.

The invention will now be described using only the following examples.

Example

CFPP performance

Samples of heating oil with a grade point of 355 ° C. and FBP-90% distillation of 14 ° C. were treated using only 200 ppm of polyoxyalkylene compound (polyethylene glycol dibehanate, molecular weight about 600 (PEG600)). This reduces the CFPP of the fuel to -7.5 ° C (base fuel is -2.5 ° C). No further improvement could be achieved using only polyoxyalkylene compounds.

The same oil treated with 400 ppm of ethylene polymer containing only 18.6 mole percent of units of formula 1, wherein the units comprise vinyl 2-ethylhexanoate, gave CFPP of -7.0 ° C. The combination of these ethylene polymers and the polyoxyalkylene compounds described above resulted in worse CFPP performance to -6.0 ° C.

The same oil treated with 400 ppm of ethylene polymer containing only 27.4 mole% of units of Formula 1, wherein the units comprise vinyl 2-ethylhexanoate, gave CFPP of -3.0 ° C. In this case, however, the addition of the polyoxyalkylene compound described above further reduced the CFPP to -10.5 ° C. This example illustrates the effectiveness of the additive composition according to the invention, ie the combination of ethylene polymers with polyoxyalkylene compounds having a higher proportion of vinyl esters than vinyl acetate.

Table 1 below shows additional results:

Compositions A through K comprise 200 ppm of polyethylene glycol dibehanate (molecular weight about 600 (PEG600)), and 400 ppm of ethylene polymer having a ratio of units of Formulas 1 and 2 as described in Table 1. The final column in Table 1 shows the results in compositions A to K with the addition of 200 ppm comb polymer (C ₁₂ / C ₁₄ mixed alkyl fumarate / vinyl acetate copolymer). In the composition of these three components, 200 ppm of each species is used. These results show good CFPP performance, which is further evidenced by the comb polymer.

Inferior performance is observed in the two comparative examples. In an embodiment Compound 1 has a high total amount of units of Formula 1 and Formula 2, and Compound 2 has a lower proportion of units of Formula 1 than required by the present invention. The data show the importance of the relative amounts and total amounts of the units of formulas 1 and 2.

Effect of Additive Composition on Pour Point

Table 2 below lists the results of experiments to measure the pour point of the fuel. The fuel used is the same as that used in the CFPP test described above, and has a pour point of −3 ° C. without any additives:

From the results in Table 2, it is clearly shown that PEG600 alone is not effective for reducing the fluidity of the fuel. Adding only ethylene polymer (used in composition H in Table 1) reduces the pour point to -45 ° C. This is further improved by the combination of PEG600 and ethylene polymer. In addition, the combination of all three components provides good pour point reduction. By comparison, both comb polymers alone (C ₁₂ / C ₁₄ mixed alkyl fumarate / vinyl acetate copolymer) and combinations of PEG600 and comb polymers are less effective.

The present invention adds an additive composition comprising a polyoxyalkylene compound, an ethylene polymer and a comb polymer to the oil to improve the low temperature properties of the oil.

Claims (13)

An additive composition comprising at least one polyoxyalkylene compound, and at least one ethylene polymer, The at least one ethylene polymer comprises, in addition to units derived from ethylene, a unit additive of Formula 1, and optionally a unit of Formula 2: Formula 1

(2)

Where Each R ¹ group independently represents hydrogen or methyl, Each R ² group independently represents an alkyl group having 5 to 15 carbon atoms, Each R ³ group independently represents hydrogen or methyl, Each R ⁴ group independently represents an alkyl group having 1 to 4 carbon atoms, In this case, the ratio of the units of formula 1 in the ethylene polymer is 22 to 30 mol%, and the total ratio of the units of formulas 1 and 2 in the ethylene polymer is 22 to 30 mol%. The method of claim 1, An additive composition in which R ² represents a branched alkyl group having 7 to 15 carbon atoms. The method of claim 1, An additive composition wherein R ⁴ represents ethyl or methyl. The method of claim 1, An additive composition wherein at least one polyoxyalkylene compound comprises a polyoxyalkylene ester, a polyoxyalkylene ether, a mixed polyoxyalkylene ester / ether or a mixture thereof. 5. The method of claim 4, At least one polyoxyalkylene compound contains at least one C ₁₀ to C ₃₀ linear alkyl group and a polyoxyalkylene glycol group having a molecular weight of 200 to 5,000, wherein the alkyl group in the polyoxyalkylene glycol has 1 to 4 carbon atoms Additive composition containing a. The method of claim 1, An additive composition further comprising one or more comb polymers. The method of claim 6, At least one comb polymer comprises a copolymer of at least one alkyl fumarate and vinyl acetate, wherein the alkyl group comprises 10 to 20 carbon atoms. 3 to 75% by weight of the additive composition according to claim 1 and mutually compatible comprising at least one selected from the group consisting of naphtha, kerosene, diesel, heating oil, hexane, pentane and isoparaffin. Additive Concentrate Including Solvent. An oil composition comprising oil and an additive composition according to any one of claims 1 to 7, or an additive concentrate according to claim 8. delete delete A method for inhibiting wax formation of oil at low temperatures, comprising adding the additive composition according to any one of claims 1 to 7 or the additive additive according to claim 8 to the oil. 13. The method of claim 12, Wherein the oil comprises a fuel oil having an FBP-90% distillation of 30 ° C. or less (difference between the temperature at which 90% of the fuel is distilled and the kind point) and an FBP (kind point) of 370 ° C. or less.